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operation cyber condition zebra operation cyber condition zebra network operations campaign conducted united states navy deny network intrusion establish adequate computer network defense posture provide defense-in-depth warfighting capability operation specifies perimeter security legacy networks deny intrusions data infiltration firewalls maintained risk assessment formal adjudication legacy application waiver requests legacy networks shut quickly possible enterprise networks nmci established name analogue term material condition zebra standard configuration equipment systems set warship provide greatest degree subdivision tightness ship set immediately automatically general quarters sounded
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Computer security
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endchan endchan internet imageboard different conversation threads users post names anonymously opened 2015 became popular similar website 8chan taken offline august 2019 endchan describes anonymous image-board promotes ideas identity according guardian august 2019 three terrorists posted far-right manifestos imageboard 8chan within six months website taken offline host server alternatives popular 8chan include older imageboard 4chan well variety others seen much popularity time endchan new website lack reputation attracted former 8chan users websites posting advertisements attract users 8chan one message endchan describes situation driven exile le monde saying website many 8chan users taken refuge endchan twitter reported large influx 8ch refugees ... hit us drastically chang ed pace site operates sic causing add extra global moderator user name philip manshaus name perpetrator shooting attack mosque bærum norway posted messages endchan shortly attack board initially misidentified 4chan 8chan media nature websites rather individual existence criticized enabling promoting terrorism manshaus messages referred three shootings six months preceding caused shut-down 8chan praising attackers suggesting would attack endchan twitter account announced attack manshaus thread politics board said denounce violence quickly taken moderators also explained manifesto posted manshaus thread deleted shooting prompted website enter radar internet extremism researchers
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Web technology
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city id city id cequint first-generation caller mobile identification service city id displays city state country associated caller telephone number partnership mobile network operators city id service available many devices alltel u.s. cellular verizon wireless city state information determined referencing area code exchange npa-nxx calling party telephone number using database stored locally mobile phone database updated new area codes exchanges introduced city id application integrated firmware mobile phones providing city state country information phone application native display incoming call screen call logs outgoing call screen city state information provided city id service based area code exchange phone registered land-line phones information reliable method determining phone originating calling office switch exchange mobile phones information potentially less useful mobile phones often operate outside originally registered area code exchange area city id integrated many android devices partnership several mobile network operators service offers 15-day free trial subscription fee required continue service software pre-installed integrated firmware users remove disable unless root privileges e.g rooted phone application manager settings application used force stop application according cequint way disable city id select “ ” end free trial ends 15 days receive initial free trial notification select “ remind later ” press back end key similar action trial expired message appear incoming call 10 times please sure select “ ” upon first expiration message disable city id city id pre-installed many brew successor os brewmp devices partnership several mobile network operators brew brewmp phones usually obvious branding like android blackberry phones cheaper feature phones north america often brew-based mobile phones media center allow removal pre-installed city id application
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Computer security
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linear cryptanalysis cryptography linear cryptanalysis general form cryptanalysis based finding affine approximations action cipher attacks developed block ciphers stream ciphers linear cryptanalysis one two widely used attacks block ciphers differential cryptanalysis discovery attributed mitsuru matsui first applied technique feal cipher matsui yamagishi 1992 subsequently matsui published attack data encryption standard des eventually leading first experimental cryptanalysis cipher reported open community matsui 1993 1994 attack des generally practical requiring 2 known plaintexts variety refinements attack suggested including using multiple linear approximations incorporating non-linear expressions leading generalized partitioning cryptanalysis evidence security linear cryptanalysis usually expected new cipher designs two parts linear cryptanalysis first construct linear equations relating plaintext ciphertext key bits high bias whose probabilities holding space possible values variables close possible 0 1 second use linear equations conjunction known plaintext-ciphertext pairs derive key bits purposes linear cryptanalysis linear equation expresses equality two expressions consist binary variables combined exclusive-or xor operation example following equation hypothetical cipher states xor sum first third plaintext bits block cipher block first ciphertext bit equal second bit key formula_1 ideal cipher linear equation relating plaintext ciphertext key bits would hold probability 1/2 since equations dealt linear cryptanalysis vary probability accurately referred linear approximations procedure constructing approximations different cipher basic type block cipher substitution-permutation network analysis concentrated primarily s-boxes nonlinear part cipher i.e operation s-box encoded linear equation small enough s-boxes possible enumerate every possible linear equation relating s-box input output bits calculate biases choose best ones linear approximations s-boxes must combined cipher actions permutation key mixing arrive linear approximations entire cipher piling-up lemma useful tool combination step also techniques iteratively improving linear approximations matsui 1994 obtained linear approximation form formula_2 apply straightforward algorithm matsui algorithm 2 using known plaintext-ciphertext pairs guess values key bits involved approximation set values key bits right-hand side referred partial key count many times approximation holds true known plaintext-ciphertext pairs call count partial key whose greatest absolute difference half number plaintext-ciphertext pairs designated likely set values key bits assumed correct partial key cause approximation hold high bias magnitude bias significant opposed magnitude probability procedure repeated linear approximations obtaining guesses values key bits number unknown key bits low enough attacked brute force
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Computer security
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system time computer science computer programming system time represents computer system notion passage time sense time also includes passing days calendar system time measured system clock typically implemented simple count number ticks transpired since arbitrary starting date called epoch example unix posix-compliant systems encode system time unix time number seconds elapsed since start unix epoch 1 january 1970 00:00:00 ut exceptions leap seconds systems implement 32-bit 64-bit versions windows api windows 9x windows nt provide system time systemtime represented year/month/day/hour/minute/second/milliseconds value filetime represented count number 100-nanosecond ticks since 1 january 1601 00:00:00 ut reckoned proleptic gregorian calendar system time converted calendar time form suitable human comprehension example unix system time seconds since beginning epoch translates calendar time 9 september 2001 01:46:40 ut library subroutines handle conversions may also deal adjustments timezones daylight saving time dst leap seconds user locale settings library routines also generally provided convert calendar times system times closely related system time process time count total cpu time consumed executing process may split user system cpu time representing time spent executing user code system kernel code respectively process times tally cpu instructions clock cycles generally direct correlation wall time file systems keep track times files created modified and/or accessed storing timestamps file control block inode file directory first-generation personal computers keep track dates times included systems ran cp/m operating system well early models apple ii bbc micro commodore pet among others add-on peripheral boards included real-time clock chips on-board battery back-up available ibm pc xt ibm first widely available pc came equipped date/time hardware built motherboard prior widespread availability computer networks personal computer systems track system time respect local time make allowances different time zones current technology modern computers keep track local civil time many household personal devices vcrs dvrs cable tv receivers pdas pagers cell phones fax machines telephone answering machines cameras camcorders central air conditioners microwave ovens microcontrollers operating within embedded systems raspberry pi arduino similar systems always internal hardware keep track time many controller systems operate without knowledge external time require information typically initialize base time upon rebooting obtaining current time external source time server external clock prompting user manually enter current time system clock typically implemented programmable interval timer periodically interrupts cpu starts executing timer interrupt service routine routine typically adds one tick system clock simple counter handles periodic housekeeping tasks preemption etc returning task cpu executing interruption following tables illustrate methods retrieving system time various operating systems programming languages applications values marked system-dependent may differ across implementations dates given gregorian proleptic gregorian calendar dates note resolution implementation measurement time imply precision measurements example system might return current time value measured microseconds actually capable discerning individual clock ticks frequency 100 hz 10 ms
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Operating systems
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commentary edward snowden disclosure commentary edward snowden disclosure part reactions global surveillance disclosures made edward snowden june 8 2013 director national intelligence dni james r. clapper denounced reckless disclosures intelligence community measures used keep americans safe condemned leaks done huge grave damage u.s. intelligence capabilities later month u.s. president barack obama dismissive snowden saying 'm going scrambling jets get 29-year-old hacker early august obama said snowden patriot americans would better remained unaware nsa surveillance activities snowden revealed obama also said called thorough review surveillance operations mr. snowden made leaks ... preference think american people preference would lawful orderly examination laws thoughtful fact-based debate would lead us better place august 4 chairman joint chiefs staff martin dempsey said weekly abc interview show week snowden caused us considerable damage intelligence architecture adversaries changing way communicate september dni clapper acknowledged snowden may done public service started needed debate balance privacy security loath give credit happened egregious think clear conversations generated debate actually probably needed happen said unfortunate n't happen time ago good side january 29 2014 dni clapper gave public testimony session senate intelligence committee asked snowden accomplices return purloined nsa documents clapper asked whether word accomplices referred journalists clapper spokesperson shawn turner responded director clapper referring anyone assisting edward snowden threaten national security unauthorized disclosure stolen documents related lawful foreign intelligence collection programs late june 2013 former us president jimmy carter said obviously violated laws america responsible think invasion human rights american privacy gone far ... think secrecy surrounding invasion privacy excessive think bringing public notice probably long term beneficial earlier month former vice president dick cheney suggested snowden might spy working chinese government former u.s. intelligence officials speculated chinese russian intelligence agents might gleaned additional classified material snowden view shared former russian agents snowden however told journalist glenn greenwald july never gave information either government never took anything laptops stewart baker former nsa general counsel early 1990s said july 18 2013 hearing afraid hyped distorted press reports orchestrated edward snowden allies may cause us – nations – construct new restraints intelligence gathering restraints leave us vulnerable another security disaster former cia nsa chief general michael hayden late june 2013 welcomed public debate balance privacy security leaks provoked convinced american people know exactly balance privacy security know comfortable feel september 2013 hayden stressed indisputable legality nsa called snowden troubled young man albeit morally arrogant tremendous degree also said prospects russia suspect end like rest defectors went old soviet union isolated bored lonely depressed -- ended alcoholics speaking university connecticut april 23 2014 former u.s. secretary state hillary clinton insinuated found snowden motives suspicious emerged absconded material puzzled protections whistle-blowers concerned wanted part american debate could said struck as—i honest you—as sort odd would flee china hong kong controlled china would go russia—two countries difficult cyberrelationships put mildly clinton added think turning lot material—intentionally unintentionally—drained gave kinds information big countries networks terrorist groups like hard time thinking somebody champion privacy liberty taken refuge russia putin authority reactions snowden disclosures among members congress initially largely negative speaker house john boehner senators dianne feinstein bill nelson called snowden traitor several senators representatives joined calling snowden arrest prosecution representative thomas massie one members congress question constitutional validity government surveillance programs suggest snowden granted immunity prosecution senators ted cruz rand paul offered tentative support snowden saying reserving judgment snowden information surveillance programs snowden motives known senator paul said think history looks going contrast behavior james clapper national intelligence director edward snowden mr. clapper lied congress defiance law name security mr. snowden told truth name privacy paul later called snowden civil disobedient like martin luther king jr. faced life imprisonment representative john lewis made comparisons snowden gandhi saying leaker appealing higher law senator bill nelson edward snowden amounts act treason similar comments also made rep. peter t. king rep. john boehner sen. dianne feinstein july 25 us senate committee appropriations unanimously adopted amendment senator lindsey graham fiscal year 2014 department state foreign operations related programs appropriations bill would seek sanctions country offers asylum snowden response information release snowden rep. justin amash r-mich. rep. john conyers d-mich. proposed amendment national defense authorization act curtail nsa gathering storage personal records house rejected narrow margin 205–217 amash subsequently told fox news snowden whistle-blower told us need know sunday abc interview show week rep. dutch ruppersberger d-maryland united states house select committee intelligence asked raddatz efforts thwarted trying get information members congress replied ... ince incident occurred snowden 've three different hearings members democratic caucus republican caucus general alexander come deputy chris inglis ask questions people relates information continue 're trying get american public know going ... better educate caucus democratic caucus 're trying declassify much u.s senator john mccain r-az said august 11 edition fox news sunday snowden become hero young americans reminded jason bourne character mccain attributed generation change lack confidence federal government right kind generational change said young americans trust government gordon humphrey conservative republican senator new hampshire 1979–1991 expressed support snowden glenn greenwald revealed humphrey former member senate foreign relations committee contact snowden via email humphrey told snowden provided leaked information would put harms way intelligence agent believe done right thing exposing regard massive violation united states constitution humphrey cited snowden courageous whistle-blower tom mcclintock r-calif came favor amnesty snowden saying think would best american government granted amnesty get back america answer questions without threat prosecution ... good laws sharing secrets broke laws hand broke good reason laws used direct contravention 4th amendment rights americans arizona senator john mccain criticized politicians voted favor patriot act outraged nsa spying phone calls saying passed patriot act passed specific provisions act allowed program take place enacted operation members congress know voting think responsibility lot government glenn greenwald one journalists received documents praised snowden done service revealing surveillance american public john cassidy new yorker called snowden hero said revealing colossal scale us government eavesdropping americans people around world snowden performed great public service outweighs breach trust may committed cnn columnist douglas rushkoff also called snowden leak act heroism amy davidson writing new yorker thankful overdue conversation privacy limits domestic surveillance american political commentators public figures noam chomsky chris hedges michael moore cornel west glenn beck ref name= michael moore/glenn beck /ref matt drudge alex jones andrew napolitano oliver stone michael savage stephen walt praised snowden exposing secret government surveillance commentators critical snowden methods motivations jeffrey toobin example denounced snowden grandiose narcissist deserves prison writing new yorker toobin argued programs exposed illegal therefore snowden whistleblower toobin questioned whether government function employees contractors take upon sabotage programs ’ like editors bloomberg news argued government ought prosecute snowden media focus snowden took attention away issues u.s. government surveillance interpretations patriot act foreign intelligence surveillance act fisa court actions really matters greenwald accused media u.s. focusing edward snowden instead wrongdoing director national intelligence james r. clapper u.s. officials op-ed author alex berenson argued federal government flown representative hong kong ask snowden give testimony front u.s. congress offer fair criminal trial view preventing unintended disclosures classified information countries cybersecurity scholar peter singer divided material disclosed snowden three categories smart useful espionage enemies united states legally questionable activities involved us citizens backdoors fudging policy/law un-strategic stupid actions targeting american allies huge blowback us standing us business postulated differing ways people viewed snowden could explain polarizing singer also spoke double legacy nsa revelations released snowden one hollowed american ability operate effectively ensuring future internet way would hope would huge long-term consequences second hammer-blow american technology companies cloud computing industry example recent estimate 'll lose 36 billion worth business surveys conducted news outlets professional polling organizations found american public opinion divided snowden disclosures polled canada europe supportive snowden respondents u.s june 2013 emnid survey 50 percent germans polled considered snowden hero 35 percent would hide homes october 2013 67 percent canadians polled considered snowden hero 60 percent uk respondents april 2014 uk yougov poll 46 percent british people thought newspapers reporting materials given snowden good society 22 percent thought bad society 31 percent n't know january 1 2014 editorial board new york times praised snowden whistleblower wrote favor granting clemency arguing snowden may broken law done country great service bringing abuses nsa light someone reveals government officials routinely deliberately broken law wrote person face life prison hands government times cast doubt claim made snowden critics damaged national security concluded request president obama discontinue vilification snowden give incentive return home article garnered unusual amount blowback editorial responses multiple media outlets guardian called pardon editorial coincidentally published day saying snowden allowed return home dignity january 4 2014 article peter baker new york times laid polarization opinions throughout u.s. impetus toward clemency gained public reaction snowden revelations yet despite growing backlash government surveillance baker noted calls leniency made little headway white house justice department national security establishment september 2016 editorial board washington post characterized issue whether snowden deserved presidential pardon complicated question president answer editors post credited snowden necessary reforms brought revelations en masse collection telephone data nsa stressed snowden separate leak information agency prism program basically defensible intelligence operations reasons face trial saying snowden hurt credibility avatar freedom accepting asylum russia editors post dismissed calls human-rights organizations clemency snowden noble purposes policy changes resulting leaks urged president pardon snowden despite post responsible publishing leaked material according guardian editorial stunned many american journalists glenn greenwald one journalists snowden initially leaked classified documents characterized post editorial act journalistic treachery cowardice noting post accepted pulitzer prize publishing snowden leaks concerning prism operations mentioned editorial amnesty international met edward snowden moscow mid july 2013 organization said disclosed patently public interest whistleblower actions justified exposed unlawful sweeping surveillance programmes unquestionably interfere individual ’ right privacy states attempt stop person revealing unlawful behaviour flouting international law freedom expression fundamental right widney brown senior director amnesty feared snowden would great risk human rights violations forcibly transferred united states urged country return snowden us michael bochenek director law policy amnesty international deplored us pressure governments block snowden asylum attempts saying unassailable right enshrined international law human rights watch said snowden able raise issue nsa mass surveillance without facing espionage charges would left united states first place human rights watch writes country snowden seeks asylum consider claim fairly protect rights international law recognizes revealing official secrets sometimes justified public interest navi pillay united nations high commissioner human rights said snowden case shown need protect persons disclosing information matters implications human rights well importance ensuring respect right privacy transparency international international association lawyers nuclear arms vereinigung deutscher wissenschaftler awarded snowden german whistleblowerpreis 2013 humanist union awarded fritz bauer prize 2013 daniel ellsberg whistleblower leaker top-secret pentagon papers 1971 stated interview cnn thought snowden done incalculable service country leaks might prevent united states becoming surveillance state said snowden acted sort courage patriotism soldier battle op-ed following morning ellsberg added american history important leak edward snowden release nsa material ... including pentagon papers ray mcgovern retired cia officer turned political activist agreed ellsberg added time today 'm feeling much hopeful democracy feeling time yesterday william binney whistleblower disclosed details nsa mass surveillance activities said snowden performed really great public service begin exposing programs making government sense publicly accountable 're snowden cited conversation reliable source allegations us hacking china binney felt transitioning whistle-blower traitor thomas drake former senior executive nsa whistleblower said feels extraordinary kinship snowden magnificent act civil disobedience exposing inner workings surveillance state public interest truly wikileaks founder julian assange hailed snowden hero exposed one serious events decade – creeping formulation mass surveillance state charges snowden revealed assange released statement asking people step forward stand snowden following president obama assurances changes planned nsa surveillance program assange said written statement obama validated edward snowden role whistle-blower shamai leibowitz leaked details fbi operation said legal threats smear campaign snowden grave mistake government really wanted keep secrets coming would well let man conscience go live life country october 2013 four us whistleblowers activists visited moscow present snowden award truth-telling titled sam adams award integrity intelligence thomas drake one presenters told reporters event us unchained constitution banning real law using secret law secret interpretations law explained snowden escape us ensure chance freedom claiming us made snowden stateless revoking passport russia leading temporary asylum country drake praised russia saying actually recognized international law granted political asylum
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Computer security
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kathryn s. mckinley kathryn s. mckinley american computer scientist noted research compilers runtime systems computer architecture also known leadership broadening participation computing mckinely co-chair cra-w 2011 2014 mckinley received b.a computer science engineering rice university 1985 went earn m.s computer science rice university 1990 ph.d computer science rice university 1992 joined department computer science university massachusetts amherst assistant professor 1993 promoted associate professor 1999 2001 moved university texas austin associate professor 2005 promoted professor 2010 endowed professor computer science 2011 moved microsoft research principal researcher currently senior research scientist google mckinley married scotty strahan three boys cooper dylan wyatt strahan colleagues introduced first general purpose model optimization framework based dependences cache line reuse improving cache locality dense matrix algorithms using loop permutation loop reversal fusion distribution mckinley advisor ken kennedy showed use model introduce parallelism locality eliminate false sharing work selected 2014 ics 25th anniversary volume mckinley phd student emery d. berger colleagues introduced hoard c/c++ memory allocator widely used applications apple os x hoard limits contention caused multiple threads allocate free memory time avoids false sharing due memory allocation time hoard enforces provable bounds total amount fragmentation mckinley leader dacapo research group spanned nine institutions funded nsf itr 2000-2006 project produced number innovative virtual machine technologies open source tools open source benchmarks new methodologies evaluating managed runtimes benchmarking methodologies efforts led stephen m. blackburn dacapo java benchmark suite evaluation methodologies widely used academia industry evaluate java analysis optimization testing technologies blackburn cheng mckinley first perform apples-to-apples comparison garbage collection algorithms showed free-list allocators give substantial amounts locality even though require less memory compared copying algorithms allocate contemporaneous objects contiguously work sigmetrics 2014 test time award based insight blackburn mckinley designed new class garbage collectors named mark-region immix mark-region collector manages memory hierarchically using fixed sized blocks consisting lines contiguous object allocation may cross lines noblocks immix collection mixes line marking object copying single pass design delivers substantial performance benefits due smaller heap footprints improvements locality phd student michael bond received acm sigplan outstanding doctoral dissertation award 2008 february 14 2013 mckinley testified house committee science space technology subcommittee research spoke academic industry government computing research ecosystem driving innovation economic advances almost fields 2008 named acm fellow notable awards include
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Computer architecture
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comparison javascript engines following tables compare standards support notable javascript/ecmascript engines used web browsers see list ecmascript engines full list
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Programming language topics
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unobtrusive javascript unobtrusive javascript general approach use javascript web pages though term formally defined basic principles generally understood include javascript historically reputation clumsy language unsuitable serious application development largely due inconsistent implementations language document object model dom various browsers widespread use buggy copy-and-paste code runtime errors common difficult debug programmers ever tried fix long script behaved less way supposed scripts often failed completely browsers web developers promoting graceful degradation since 1994 recent emergence standards-compliant browsers javascript frameworks high-quality debugging tools made organized scalable javascript code possible emergence ajax interfaces made desirable whereas javascript reserved relatively simple non-critical tasks form validation decorative novelties used write large complex codebases often part site core functionality run time errors unpredictable behavior longer minor annoyances fatal flaws advocates unobtrusive javascript see part larger web standards movement much demand cross-browser compatibility driven increasing emphasis standardized markup style increasing demand rich internet applications driving movement toward better practices use javascript concept unobtrusiveness relation javascript programming coined 2002 stuart langridge article unobtrusive dhtml power unordered lists article langridge argues way keep javascript code including event handlers outside html stuart langridge since expanded upon thought book article format authors tried refine define essential elements unobtrusive paradigm david flanagan seminal javascript definitive guide says specific formula three main goals web standards project describes four benefits unobtrusive dom scripting javascript manifesto paris web conference 2007 christian heilmann identified seven rules unobtrusive javascript traditionally javascript often placed inline together html document markup example following typical way register javascript event handler html purpose html markup describe document structure programmatic behavior combining two negatively impact site maintainability like combining content presentation javascript behavior created referenced html harder use maintain example setting handlers several events single element setting event handler several elements using event delegation unobtrusive solution register necessary event handlers programmatically rather inline rather adding codice_2 attribute explicitly relevant element simply identified example codice_3 codice_4 means markup script runs page first loaded browser look relevant element set accordingly unobtrusive javascript add little possible global object global namespace environment runs scripts may override variable function created global namespace lead unexpected failures difficult debug javascript built-in explicit namespace mechanism desired effects easy produce using language facilities flanagan suggests use developer domain name dotted segments reversed single global name publish likely unique style developed java language variables functions objects kinds defined within namespace objects usually recommended use closures within namespace isolate become private variables functions well export public interface module functionality code could followed directly following module public methods could invoked either way follows way module-writer code contained private unique namespace interfere intrude upon code time writing event listener detects loading html page adds relevant listeners events page well behaviors required solve problem separating javascript functionality html markup use client-side javascript libraries jquery mootools prototype simplify process help ensure individual browser browser version implementation details hidden catered keeping javascript default namespace helps ensure unobtrusive possible sense criterion unobtrusive javascript often cited ensure added behavior degrades gracefully browsers unexpected configurations user may disabled javascript altogether requirement basic tenet web accessibility ensure javascript-enhanced websites usable people abilities disabilities users whatever computing platform get equal access site information functionality sometimes extra work involved achieving web accessibility optional extra many countries example uk equality act 2010 refer explicitly website accessibility makes illegal discriminate people disabilities applies anyone providing service public private voluntary sectors lot effort may put designing implementing slick client-side user interface unobtrusive javascript remain unobtrusive user without client-side scripting find access published information meet goal often necessary implement equivalent albeit clunkier server-side functionality available without use javascript take example webpage thumbnail images need javascript behaviours full-size images appear front page mouse rolled clicked first server-side markup ensure relevant full-size image served users without javascript click thumbnail case basic html markup may look like following thumbnail work without javascript unobtrusive javascript case page-load could find codice_5 elements class codice_6 remove page dom could find images class codice_7 attach codice_8 codice_9 event handler specified in-line provide slick behaviour example invoked event handler may send ajax request server full-size image add codice_10 page dom invoking existing css appears front existing content may become partially greyed codice_10 need close button perhaps visual 'spinner show data loading etc finally ajax data arrives handler hides spinner inserts full-size image new codice_10 display way client-side functionality depends javascript function function succeeds begins removing basic manual behavior goes add client-side scripted behavior script fails whatever reason manual behavior remains place remains functional though essence unobtrusive javascript concept added separate behavior layer advocates paradigm generally subscribe number related principles
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Programming language topics
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bitnami bitnami library installers software packages web applications development stacks well virtual appliances bitnami sponsored bitrock company founded 2003 seville spain daniel lopez ridruejo erica brescia bitnami stacks used installing software linux windows mac os x solaris vmware acquired bitnami may 15th 2019 bitnami stacks available web applications wordpress drupal joomla redmine abantecart prestashop magento mediawiki many others addition application stacks include software required run application example wordpress stack include wordpress well mysql database manage data apache web server serve pages openssl library basic cryptographic functions phpmyadmin administer mysql bitnami installers released apache license 2.0 using automated cloud computing management bitnami offers users automated application deployments open source server apps oracle cloud amazon ec2 azure google cloud platform servers since july 2009 bitnami also offers ready-to-run virtual machines contain minimal configured linux operating system bitnami offers open source applications modules xampp package developed apache friends distinct difference installation bitnami installers native installs e.g rpms debs linux installed way prevent interference existing software libraries multiple applications installed web server considerations resolving conflicts specific ports must made february 13 2009 bitnami announced release enano cms web stack unique according bitnami enano cms project stack module first externally developed february 2010 bitnami announced release bitnami cloud hosting service allows deploying bitnami stacks amazon ec2 cloud automatic monitoring backups may 15 2019 vmware announced intent acquire bitnami
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Operating systems
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bank switching bank switching technique used computer design increase amount usable memory beyond amount directly addressable processor used configure system differently different times example rom required start system diskette could switched longer needed video game systems bank switching allowed larger games developed play existing consoles bank switching originated minicomputer systems many modern microcontrollers microprocessors use bank switching manage random-access memory non-volatile memory input-output devices system management registers small embedded systems technique common 8-bit microcomputer systems bank-switching may also used work around limitations address bus width hardware constraint prevents straightforward addition address lines control-oriented microprocessors use bank-switching technique access internal i/o control registers limits number register address bits must used every instruction unlike memory management paging data exchanged mass storage device like disk storage data remains quiescent storage memory area currently accessible processor although may accessible video display dma controller subsystems computer bank switching considered way extending address bus processor external register example processor 16-bit external address bus address 2 65536 memory locations external latch added system could used control two sets memory devices 65536 addresses could accessed processor could change set current use setting clearing latch bit latch set cleared processor several ways particular memory address may decoded used control latch processors separately-decoded i/o addresses output address may decoded several bank-switching control bits could gathered register approximately doubling available memory spaces additional bit register external bank-selecting latch register directly connected program counter processor automatically change state program counter overflows detected external latch since program counter internal register processor extra memory seamlessly available programs internal registers processor remain original length processor directly span bank-switched memory example incrementing internal register instead processor must explicitly bank-switching operation access large memory objects limitations generally bank-switching system one block program memory common banks matter bank currently active part address space one set memory locations used area would used hold code manages transitions banks also process interrupts often single database spans several banks need arises move records banks sorting one bank accessible time would necessary move byte twice first common memory area perform bank switch destination bank actually move byte destination bank computer architecture dma engine second cpu bank access restrictions differ whichever subsystem transfer data directly banks used unlike virtual memory scheme bank-switching must explicitly managed running program operating system processor hardware automatically detect data currently mapped active bank required application program must keep track memory bank holds required piece data call bank-switching routine make bank active however bank-switching access data much faster example retrieving data disk storage processors 16-bit addressing 8080 z80 6502 6809 etc commonly used early video game consoles home computers directly address 64 kb systems memory divide address space number blocks could dynamically mapped parts larger address space bank switching used achieve larger address space organizing memory separate banks 64kb blocks various sizes switched via bank select registers similar mechanisms cromemco first microcomputer manufacturer use bank switching supporting 8 banks 64kb systems using bank switching caution required order corrupt handling subroutine calls interrupts machine stack contents memory temporarily switched cpu inaccessible processor could used hardware video display dma i/o devices etc cp/m-80 3.0 released 1983 z80-based trs-80s model 4 model ii supported bank switching allow use 64k memory 8080 z80 processor could address bank switching allowed extra memory functions added computer design without expense incompatibility switching processor wider address bus example c64 used bank switching allow full 64kb ram still provide rom memory-mapped i/o well atari 130xe could allow two processors 6502 antic access separate ram banks allowing programmers make large playfields graphic objects without using memory visible cpu microcontrollers microprocessors significant input/output hardware integrated on-chip may use bank switching example access multiple configuration registers on-chip read/write memory example pic microcontroller allows short instruction words save space routine program execution cost extra instructions required access relatively infrequently used registers used system configuration start-up 1985 companies lotus intel introduced expanded memory specification ems 3.0 use ibm pc compatible computers running ms-dos microsoft joined versions 3.2 1986 4.0 1987 specification became known lotus-intel-microsoft ems lim ems form bank switching technique allows 640 kb ram defined original ibm pc architecture letting appear piecewise 64 kb window located upper memory area 64 kb divided four 16 kb pages independently switched computer games made use though ems obsolete feature nowadays emulated later microsoft windows operating systems provide backwards compatibility programs later extended memory specification xms also obsolete standard principle simulating bank switching memory 1 mb called extended memory directly addressable real mode x86 processors ms-dos runs xms allows extended memory copied anywhere conventional memory boundaries banks fixed every way works like bank switching ems perspective program uses later versions ms-dos starting circa version 5.0 included emm386 driver simulates ems memory using xms allowing programs use extended memory even written ems microsoft windows emulates xms also programs require bank switching also used video game consoles atari 2600 instance could address 4 kb rom later 2600 game cartridges contained bank switching hardware order permit use rom thus allow sophisticated games via program code equally important larger amounts game data graphics different game stages nintendo entertainment system contained modified 6502 cartridges sometimes contained megabit rom addressed via bank switching called multi-memory controller game boy cartridges used chip called mbc memory bank controller offered rom bank switching also cartridge sram bank switching even access peripherals infrared links rumble motors bank switching still used later game systems several sega mega drive cartridges 4mb size required use technique 4mb maximum address size gp2x handheld gamepark holdings uses bank switching order control start address memory offset second processor types computer video displays related technique double buffering may used improve video performance case processor updating contents one set physical memory locations video generation hardware accessing displaying contents second set processor completed update signal video display hardware swap active banks transition visible screen free artifacts distortion case processor may access memory video display hardware bank-switched parts video memory two banks video memory contain slightly different images rapidly cycling page-flipping create animation visual effects processor might otherwise slow carry directly bank switching later supplanted segmentation many 16-bit systems turn gave way paging memory management units embedded systems however bank switching still often used simplicity low cost often better adaptation contexts general purpose computing
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Operating systems
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dnf software dnf dandified yum next-generation version yellowdog updater modified yum package manager .rpm-based distributions dnf introduced fedora 18 default package manager fedora since version 22 perceived deficiencies yum dnf intended address include poor performance high memory usage slowness iterative dependency resolution dnf uses libsolv external dependency resolver dnf performs package management tasks top rpm supporting libraries dnf originally written python efforts way port c move functionality python code new libdnf library libdnf already used packagekit linux distribution-agnostic package system abstraction library even though library dnf features dnf default package manager fedora since version 22 released may 2015 libdnf library used package backend packagekit dnf also available alternate package manager mageia linux since version 6 may become default sometime future
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Operating systems
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kyma sound design language kyma visual programming language sound design used musicians researchers sound designers kyma user programs multiprocessor dsp graphically connecting modules screen macintosh windows computer kyma characteristics object-oriented functional programming languages basic unit kyma sound object note traditional music notation sound defined sound atom ii unary transform sound iii n-ary transform s.. s..s sounds sound atom source audio like microphone input noise generator unary transform modifies argument example lowpassfilter might take running average input n-ary transform combines two sounds mixer example defined sum inputs first version kyma computed digital audio samples macintosh 512k written smalltalk programming language 1986 carla scaletti champaign illinois may 1987 scaletti partitioned kyma graphics sound generation engines ported sound generation code digital signal processor called platypus designed lippold haken kurt j. hebel cerl sound group 1987 scaletti presented paper kyma demonstrated live digital sound generation platypus international computer music conference identified electronic synthesis pioneer bob moog technology watch conference report keyboard magazine one new language acknowledges distinction sound synthesis composition kyma music composition language macintosh views elements piece music structure single sound structure entire composition objects composed university illinois urbana-champaign eliminated funding plato laboratory 1989 scaletti hebel formed symbolic sound corporation order continue developing kyma digital audio signal processing hardware
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Programming language topics
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palamedes video game palamedes puzzle game requiring player match dice holding dice top screen using b button player change number his/her dice throw dice using button matches dice top screen wipes target dice screen player play solitaire mode computer another player tournament mode ai opponents six sides numbers dice making attempt match numbers screen eliminating challenge ports game published nes msx fm towns game boy hot-b japan-only sequel palamedes 2 star twinkles released 1991 nes hot-b featured basic gameplay elements original play field scrolling opposite direction release famitsu magazine scored game boy version game 22 40
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Computer architecture
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vidix vidix video interface *nix portable programming interface unix-like operating systems allows video card drivers running user space directly access framebuffer direct graphics access extension x window system nick kurshev author vidix writes motivation creating interface resolve issue reported vladimir dergachev rfc alternative kernel multimedia api dergachev noted existing multimedia interfaces hard-coded device suggested driver developers would flexibility layer abstraction vidix born alternative linux kernel-based drivers mplayer project long time vidix lived within mplayer project later lived within mplayerxp project fork mplayer kurshev time linux many unix-like operating systems lacked quality drivers video subsystems almost technical documentation video hardware non-disclosure agreements time many programmers code drivers blindly developers became interested using vidix players asked kurshev separate mplayer project vidix became alternative set device drivers based idea direct hardware access similar microsoft directx drivers mapped accelerated video memory avoid colour-space conversion software scaling side players x window system includes direct rendering infrastructure provides similar functionality broad hardware support kurshev continued develop vidix 2007 version 1.0.0 software released
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Operating systems
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delay insensitive circuit delay-insensitive circuit type asynchronous circuit performs digital logic operation often within computing processor chip instead using clock signals global control signals sequencing computation delay-insensitive circuit determined data flow data flows one circuit element another using handshakes sequences voltage transitions indicate readiness receive data readiness offer data typically inputs circuit module indicate readiness receive acknowledged connected output sending data encoded way receiver detect validity directly data safely received receiver explicitly acknowledge allowing sender remove data thus completing handshake allowing another datum transmitted delay-insensitive circuit therefore need provide clock signal determine starting time computation instead arrival data input sub-circuit triggers computation start consequently next computation initiated immediately result first computation completed main advantage circuits ability optimize processing activities take arbitrary periods time depending data requested function example process variable time completion would mathematical division recovery data data might cache delay-insensitive di class robust asynchronous circuit delay models makes assumptions delay wires gates model transitions gates wires must acknowledged transitioning condition stops unseen transitions occurring di circuits transition input gate must seen output gate subsequent transition input allowed happen forces input states sequences become illegal example gates must never go state inputs one entry exit state seen output gate although model robust practical circuits possible due lack expressible conditionals di circuits instead quasi-delay-insensitive model smallest compromise model yet capable generating useful computing circuits reason circuits often incorrectly referred delay-insensitive quasi delay-insensitive
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Computer architecture
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symantec symantec corporation commonly known symantec american software company headquartered mountain view california united states company provides cybersecurity software services symantec fortune 500 company member p 500 stock-market index company also development centers pune chennai bengaluru india october 9 2014 symantec declared would split two independent publicly traded companies end 2015 one company would focus security information management january 29 2016 symantec sold information-management subsidiary named veritas technologies symantec acquired 2004 carlyle group name symantec portmanteau words syntax semantics technology august 9 2019 broadcom announced would acquiring enterprise security software division symantec 10.7 billion dollars usd attempted purchase whole company founded 1982 gary hendrix national science foundation grant symantec originally focused artificial intelligence-related projects including database program hendrix hired several stanford university natural language processing researchers company first employees among barry greenstein professional poker player developer word processor component within q hendrix also hired jerry kaplan entrepreneur author consultant build in-ram database q 1984 became clear advanced natural language database system symantec developed could ported dec minicomputers pc left symantec without product expertise natural language database query systems technology result later 1984 symantec acquired another smaller software startup company c e software founded denis coleman gordon eubanks headed eubanks c e software developed combined file management word processing program called q question answer merged company retained name symantec eubanks became chairman vern raburn former president original symantec remained president combined company new symantec combined file management word processing functionality c e planned added advanced natural language query system designed gary hendrix engineered dan gordon set new standards ease database query report generation natural language system named intelligent assistant turner chose name q symantec flagship product large part name lent use short easily merchandised logo brett walter designed user interface q brett walter director product management q released november 1985 1986 vern raburn gordon eubanks swapped roles eubanks became ceo president symantec raburn became chairman subsequent change raburn little involvement symantec years time eubanks added chairmanship roles slow start sales q fall 1985 spring 1986 turner signed new advertising agency called elliott/dickens embarked aggressive new advertising campaign came six pack program symantec employees regardless role went road training selling dealer sales staff nationwide united states turner named six pack employees work six days week see six dealerships per day train six sales representatives per store stay friends free motel 6 simultaneously promotion run jointly sofsell symantec exclusive wholesale distributor united states first year q market promotion successful encouraging dealers try q time symantec advised jim lally john doerr — board members symantec stage — kleiner perkins caufield byers symantec would cut expenses grow revenues enough achieve cash flow break-even kpcb would back company raising venture capital accomplish management team worked salary reduction schedule chairman ceo would take zero pay vice presidents would take 50 pay cut employees pay cut 15 two employees laid eubanks also negotiated sizable rent reduction office space company leased days original symantec expense reductions combined strong international sales q enabled company attain break-even significantly increased traction q re-launch grew symantec revenues substantially along early success q international markets uniquely german version shipped three weeks united states version first software world supported german natural language following turner placed emphasis establishing international sales distribution multiple language versions q initial shipment 1985 rod turner negotiated publishing agreement david whitney symantec second product turner named noteit annotation utility lotus 1-2-3 evident turner noteit would confuse dealer channel launched symantec name symantec built interest stage q yet shipped low price utility would initially attractive dealer channel demand built turner felt product marketed unique brand name turner gordon e. eubanks jr. chairman symantec corporation agreed form new division symantec eubanks delegated choice name turner turner chose name turner hall publishing new division symantec devoted publishing third-party software hardware objective division diversify revenues accelerate growth symantec turner chose name turner hall publishing using last name dottie hall director marketing communications order convey sense stable long established company turner hall publishing first offering note-it notation utility add-in lotus 1-2-3 developed david whitney licensed symantec second product turner hall card 256k ram half slot memory card initially made inexpensively increase available memory symantec flagship product q turner hall division also marketed card standalone product turner hall third product also 1-2-3 add-in sqz lotus 1-2-3 spreadsheet compression utility developed chris graham synex systems summer 1986 eubanks turner recruited tom byers digital research expand turner hall publishing product family lead turner hall effort winter 1986–87 turner hall publishing division achieved success noteit turner hall card sqz popularity products contributing relatively small portion revenues symantec conveyed impression symantec already diversified company indeed many industry participants impression symantec acquired turner hall publishing 1987 byers recruited ted schlein turner hall product group assist building product family marketing revenues q symantec early launch international marketplace combined turner hall publishing generated market presence scale enabled symantec make first merger/acquisition february 1987 breakthrough software maker timeline project management software dos first time symantec acquired business revenues inventory customers eubanks chose change nothing breakthrough software six months actual merger logistics started summer 1987 turner appointed eubanks general manager timeline business unit turner made responsible successful integration company symantec ongoing growth business p l heavy emphasis placed making minimum disruption eubanks turner soon acquisition timeline/breakthrough software eubanks reorganized symantec structuring company around product-centric groups development quality assurance technical support product marketing functions general manager profit loss responsibility sales finance operations centralized functions shared structure lent well symantec growth mergers acquisitions eubanks made turner general manager new timeline product group simultaneously q product group made tom byers general manager turner hall product group turner continued build lead company international business marketing whole company timeline product group turner drove strong marketing promotion sales programs order accelerate momentum 1989 merger successful—product group morale high timeline development continued apace increased sales marketing efforts applied built timeline clear market lead pc project management software dos q timeline product groups healthily profitable profit stream merger success set stage subsequent merger acquisition activity company indeed funded losses product groups subsequently acquired 1989 eubanks hired john laing vp worldwide sales turner transferred international division laing eubanks also recruited bob dykes executive vice president operations finance anticipation upcoming ipo july 1989 symantec ipo may 1990 symantec announced intent merge acquire peter norton computing developer various utilities dos turner appointed product group manager norton business made responsible merger p l responsibility ted schlein made product group manager q business peter norton group merger logistical effort began immediately companies sought approval merger august 1990 symantec concluded purchase—by time combination companies already complete symantec consumer antivirus data management utilities still marketed norton name time merger symantec built upon turner hall publishing presence utility market introducing symantec antivirus macintosh sam symantec utilities macintosh sum two products already market leaders mac success made norton merger strategic symantec already begun development dos-based antivirus program one year merger norton management team decided enter antivirus market part felt antivirus market entailed great deal ongoing work stay ahead new viruses team felt microsoft would unlikely find effort attractive would lengthen viability market symantec turner decided use norton name obvious reasons became norton antivirus turner norton team launched 1991 time merger norton revenues approximately 20 25 combined entity 1993 led turner norton product group revenues grown approximately 82 symantec total one time symantec also known development tools particularly think pascal think c symantec c++ enterprise developer visual cafe packages popular macintosh ibm pc compatible platforms product lines resulted acquisitions made company late 1980s early 1990s businesses living videotext acquisition consistently unprofitable symantec losses diverted expenditures away q windows timeline windows development efforts critical period 1988 1992 symantec exited business late-1990s competitors metrowerks microsoft borland gained significant market share 1996 symantec corporation alleged misleading financial statements violation gaap 1999 april 2009 symantec led ceo john w. thompson former vp ibm time thompson african-american leading major us technology company succeeded april 2009 company long-time symantec executive enrique salem salem symantec completed acquisition verisign certificate authority business dramatically increasing share market salem abruptly fired 2012 disappointing earnings performance replaced steve bennett former ceo intuit ge executive january 2013 bennett announced major corporate reorganization goal reducing costs improving symantec product line said sales marketing high costs provide quality outcomes concluded system broken robert enderle cio.com reviewed reorganization noted bennett following general electric model product-focused instead customer-focused concluded eliminating middle management removes large number highly paid employees tactically improve symantec bottom line reduce skills needed ensure high-quality products long term march 2014 symantec fired steve bennett ceo position named michael brown interim president chief executive including interim ceo symantec 3 ceos less two years september 25 2014 symantec announced appointment michael brown president chief executive officer brown served company interim president chief executive officer since march 20 2014 mr. brown served member company board directors since july 2005 following acquisition veritas software corporation mr. brown served veritas board directors since 2003 july 2016 symantec introduced solution help carmarkers protect connected vehicles zero-day attacks symantec anomaly detection automotive iot solution manufacturers uses machine learning provide in-vehicle security analytics greg clark assumed position ceo august 2016 november 2016 symantec announced intent acquire identity theft protection company lifelock 2.3 billion august 2017 symantec announced agreed sell business unit verifies identity websites thoma bravo acquisition thoma bravo plans merge symantec business unit web certification company digicert january 4 2018 symantec bt formerly british telecom announced partnership provides new endpoint security protection may 2018 symantec initiated internal audit address concerns raised former employee causing delay annual earnings report august 2018 symantec announced hedge fund starboard value put forward five nominees stand election symantec board directors symantec 2018 annual meeting stockholders followed schedule 13d filing starboard showing accumulated 5.8 stake symantec september 2018 symantec announced three nominees starboard joining symantec board two immediate effect including starboard managing member peter feld one following 2018 annual meeting stockholders may 9 2019 symantec announced ceo greg clark businessman stepping immediate effect board member rick hill previously put forward starboard appointed interim president ceo vincent pilette also joined symantec new cfo august 9 2019 broadcom announced would acquiring enterprise software division symantec 10.7 billion dollars usd attempted purchase whole company norton family products remain symantec portfolio october 9 2014 symantec declared company would separate two independent publicly traded companies end 2015 symantec continue focus security new company established focusing information management symantec confirmed january 28 2015 information management business would called veritas technologies corporation marking return veritas name august 2015 symantec agreed sell veritas private equity group led carlyle group 8 billion sale completed february 2016 turned veritas privately owned company 2015 symantec norton product line includes norton security norton small business norton family norton mobile security norton online backup norton360 norton utilities norton computer tune 2012 pctools iantivirus rebranded norton product name iantivirus released mac app store also 2012 norton partner portal relaunched support sales consumers throughout emea technologies 1993 symantec acquired act contact software international symantec sold act saleslogix 1999 time world popular crm application windows macintosh december 16 2004 veritas software symantec announced plans merger veritas valued 13.5 billion largest software industry merger date symantec shareholders voted approve merger june 24 2005 deal closed successfully july 2 2005 july 5 2005 first day business u.s. offices new combined software company result merger symantec includes storage- availability-related products portfolio namely veritas file system vxfs veritas volume manager vxvm veritas volume replicator vvr veritas cluster server vcs netbackup nbu backup exec enterprise vault ev january 29 2016 symantec sold veritas technologies carlyle group august 16 2005 symantec acquired sygate security software firm based fremont california 200 staff november 30 2005 sygate personal firewall products discontinued january 29 2007 symantec announced plans acquire altiris april 6 2007 acquisition completed altiris specializes service-oriented management software allows organizations manage assets also provides software web services security systems management products established 1998 altiris headquartered lindon utah november 5 2007 symantec announced acquisition vontu leader data loss prevention dlp solutions 350 million january 17 2008 symantec announced spinning application performance management apm business i3 product line vector capital precise software solutions took development product management marketing sales apm business launching independent company september 17 2008 august 18 2008 symantec announced signing agreement acquire pc tools agreement pc tools would maintain separate operations financial terms acquisition disclosed may 2013 symantec announced discontinuing pc tools line internet security software december 2013 symantec announced discontinuing retiring entire pc tools brand offering non expiring license pc tools performance toolkit pc tools registry mechanic pc tools file recover pc tools privacy guardian users active subscription december 4 2013 april 18 2008 symantec completed acquisition appstream inc. “ appstream ” nonpublic palo alto california-based provider endpoint virtualization software appstream acquired complement symantec endpoint management virtualization portfolio strategy october 9 2008 symantec announced intent acquire gloucester-based messagelabs spun star internet 2007 boost software-as-a-service saas business symantec purchased online messaging web security provider 695 million cash acquisition closed november 17 2008 april 29 2010 symantec announced intent acquire pgp corporation guardianedge acquisitions closed june 4 2010 provided access established encryption key management technologies symantec customers may 19 2010 symantec signed definitive agreement acquire verisign authentication business unit included secure sockets layer ssl certificate public key infrastructure pki verisign trust verisign identity protection vip authentication services acquisition closed august 9 2010 august 2012 symantec completed rebranding verisign ssl certificate service renaming verisign trust seal norton secured seal acquired october 10 2010 rulespace web categorisation product first developed 1996 categorisation automated using symantec refers automated categorization system acs used base content filtering many uk isp may 19 2011 symantec announced acquisition clearwell systems approximately 390 million january 17 2012 symantec announced acquisition cloud email-archiving company liveoffice acquisition price 115 million last year symantec joined cloud storage backup sector enterprise vault.cloud cloud storage enterprise vault solutions addition cloud messaging solution symantec instant messaging security cloud ims.cloud symantec stated acquisition would add information governance products allowing customers store information on-premises symantec data centers march 2 2012 symantec completed acquisition odyssey software odyssey software main product athena device management software extended microsoft system center solutions adding ability manage support control mobile embedded devices smartphones ruggedized handhelds symantec completed acquisition nukona provider mobile application management mam april 2 2012 acquisition agreement symantec nukona announced march 20 2012 may 2014 symantec acquired nitrodesk provider touchdown market-leading third-party eas mobile application june 13 2016 announced symantec acquired blue coat 4.65 billion august 9 2004 company announced discovered error calculation deferred revenue represented accumulated adjustment 20 million arrival year 2010 triggered bug symantec endpoint symantec reported malware intrusion protection updates date greater december 31 2009 11:59pm considered 'out date company created distributed workaround issue march 2010 reported symantec antivirus symantec client security prone vulnerability might allow attacker bypass on-demand virus scanning permit malicious files escape detection january 2011 multiple vulnerabilities symantec products could exploited denial-of-service attack thereby compromise system reported products involved symantec antivirus corporate edition server symantec system center november 12 2012 vulnerability bulletin united states computer emergency readiness team us-cert reported following vulnerability older versions symantec antivirus system decomposer engine symantec endpoint protection sep 11.0 symantec endpoint protection small business edition 12.0 symantec antivirus corporate edition savce 10.x symantec scan engine sse 5.2.8 properly perform bounds checks contents cab archives allows remote attackers cause denial service application crash possibly execute arbitrary code via crafted file problem relates older versions systems patch available us-cert rated seriousness vulnerability 9.7 10-point scale decomposer engine component scanning system opens containers compressed files scanner evaluate files within january 2012 james gross filed lawsuit symantec distributing fake scareware scanners purportedly alerted users issues computers gross claimed scan errors problems corrected prompted scanner purchase symantec app remove rest gross claimed bought app speed computer remove detected viruses hired digital forensics expert back claim symantec denied allegations said would contest case symantec settled 11 million fund 9 1 million eligible customers representing overpaid amount app case dismissed court january 17 2012 symantec disclosed network hacked hacker known yama tough obtained source code symantec software hacking indian government server yama tough released parts code threatened release according chris paden symantec spokesman source code taken enterprise products five six years old september 25 2012 affiliate hacker group anonymous published source code norton utilities symantec confirmed part code stolen earlier leak included code 2006 versions norton utilities pcanywhere norton antivirus february 2012 reported verisign network data hacked repeatedly 2010 breaches disclosed publicly noted sec filing october 2011 verisign provide information whether breach included certificate authority business acquired symantec late 2010 oliver lavery director security research ncircle asked rhetorically trust site using verisign ssl certificates without clarity logical answer february 17 2012 details exploit pcanywhere posted exploit would allow attackers crash pcanywhere computers running windows symantec released hotfix issue twelve days later according mandiant symantec security products used new york times detected one 45 pieces malware installed chinese hackers newspaper network three-month period late 2012 symantec responded advanced attacks like ones new york times described following article http //nyti.ms/tztr5z underscore important companies countries consumers make sure using full capability security solutions advanced capabilities e ndpoint offerings including unique reputation-based technology behavior-based blocking specifically target sophisticated attacks turning signature-based anti-virus components e ndpoint solutions alone enough world changing daily attacks threats encourage customers aggressive deploying solutions offer combined approach security anti-virus software alone enough february 2015 symantec found guilty two counts patent infringement suit intellectual ventures inc ordered pay 17 million compensation damages september 2016 decision reversed appeal federal circuit september 18 2015 google notified symantec latter issued 23 test certificates five organizations including google opera without domain owners knowledge symantec performed another audit announced additional 164 test certificates mis-issued 76 domains 2,458 test certificates mis-issued domains never registered google requested symantec update public incident report proven analysis explaining details failures company asked report certificates issued certificate transparency log henceforth symantec since reported implementing certificate transparency ssl certificates google insisted symantec execute security audit third party maintain tamper-proof security audit logs march 24 2017 google stated lost confidence symantec latest incident improper certificate issuance google says millions existing symantec certificates become untrusted google chrome next 12 months according google symantec partners issued least 30,000 certificates questionable validity several years symantec disputes number google said symantec failed comply industry standards could provide audits showing necessary documentation google ryan sleevi said symantec partnered cas crosscert korea electronic certificate authority certisign certificatadora digital certsuperior s. de r. l. de c.v. certisur s.a. follow proper verification procedures leading misissuance certificates following discussions google required symantec migrate symantec-branded certificate issuance operations non-symantec-operated “ managed partner infrastructure ” deal announced whereby digicert acquired symantec website security business september 2017 google announced starting chrome 66 chrome remove trust symantec-issued certificates issued prior june 1 2016 google stated december 1 2017 symantec transition issuance operation publicly-trusted certificates digicert infrastructure certificates issued old symantec infrastructure date trusted chrome google predicted toward end october 2018 release chrome 70 browser would omit trust symantec old infrastructure certificates issued affecting certificates chaining symantec roots mozilla firefox planned distrust symantec-issued certificates firefox 63 released october 23 2018 delivered change firefox 64 released december 11 2018 apple also plan distrust symantec root certificates
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Computer security
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socket 4 socket 4 presented 1993 first cpu socket designed early p5 pentium microprocessors socket 4 5-volt socket pentium socket 4 intel switched 3.3-volt-powered socket 5 socket 4 support special pentium overdrive allows running 120 mhz 60 mhz pentium 133 mhz 66 mhz pentium socket 4 replaced socket 5 1996
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Computer architecture
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linux dm multipath dm-multipathing dm-mpio provides input-output i/o fail-over load-balancing using multipath i/o within linux block devices utilizing device-mapper multipathd daemon provides host-side logic use multiple paths redundant network provide continuous availability higher-bandwidth connectivity host server block-level device dm-mpio handles rerouting block i/o alternate path event path failure dm-mpio also balance i/o load across available paths typically utilized fibre channel fc iscsi san environments dm-mpio based device mapper provides basic framework maps one block device onto another utilizing linux dm-mpio datacenter operating systems multipath solutions key components path management must considered dm-mpio started patch set created joe thornber later maintained alasdair g kergon red hat included mainline linux kernel version 2.6.12 released june 17 2005 dm-mpio linux consists kernel components user-space components configuration file /etc/multipath.conf makes many dm-mpio features user-configurable multipath command kernel daemon multipathd use information found file file consulted configuration multipath devices changes must made prior running multipath command changes file afterwards require multipath executed multipath.conf five sections
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Operating systems
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numbuster numbuster phone community users access via mobile phone client web application developed numbuster ltd allows users find contact details phone number exchange information numbers users block calls messages client available android windows phone numbuster developed numbuster ltd privately held company founded evgeny gnutikov ilya osipov others project launched moscow business school graduates android web site february 2014 september 2014 100 000 users russia cis first launched july–august 2014 numbuster accelerated biggest startup accelerator france numa paris service global telephone directory social call-blocking functionality allows users find name unknown caller whether ’ person business also rate comment thus adding value service helping users community get information apart users block phone number in-app im sms chat available september 2014 numbuster available 13 languages english russian arabic german french chinese italian portuguese spanish polish ukrainian japanese korean upon release numbuster gathered positive feedback russian bloggers media including publication leading news web-site
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Computer security
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cognitive dimensions notations cognitive dimensions cognitive dimensions notations design principles notations user interfaces programming languages described researchers thomas r.g green marian petre dimensions used evaluate usability existing information artifact heuristics guide design new one cognitive dimensions designed provide lightweight approach analyse quality design rather in-depth detailed description provide common vocabulary discussing many factors notation ui programming language design also cognitive dimensions help exploring space possible designs design maneuvers changes intended improve design along one dimension thomas green originally defined 14 cognitive dimensions addition new dimensions sometimes proposed hci research field different levels adoption refinement candidate dimensions include creative ambiguity notation encourage interpreting several meanings element indexing elements guide finding specific part synopsis gestalt view whole annotated structure unevenness creation paths easier others bias expressed ideas developed artifact authors identify four main user activities interactive artifacts incrementation creation transcription modification exploratory design activity best served different trade-off usability dimension example high viscosity resistance change harmful modification exploration activities less severe one-off tasks performed transcription incrementation design maneuver change made designer notation design alter position within particular dimension dimensions created pairwise independent design altered one dimension keeping second one constant usually results trade-off dimensions modification increasing usability notation one dimension keeping second one constant typically reduce usability third dimension reflects assumption framework perfect interface trade-offs fundamental part usability design example design maneuver reducing viscosity notation adding abstraction mechanisms done incorporating style sheets abstraction represent common styling attributes items document notation item document defined individual style design maneuver made editor changes style sheet modify items eliminating repetition viscosity present need change style individual item
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Programming language topics
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personal inc personal also referred personal.com personal inc. consumer personal data service identity management system individuals aggregate manage reuse data merged digi.me august 2017 business europe business model empowering people data combined company called digi.me one product lines collaborative data management information security solution workplace called teamdata spun new company result merger personal founded 2009 washington dc management team built map network location data mapping platform acquired nokia/navteq 2006 personal first online consumer-facing company named ambassador privacy design technical business legal commitments providing users control data store personal service called “ life management platform ” economist “ personal encrypted cloud service ” time user-centric approach data company associated infomediary model originated 1999 john hagel iii mark singer well vendor relationship management vrm model developed doc searls personal raised 30m funding develop platform products leading investors steve case ’ revolution ventures grotech ventures allen company ted leonsis neil ashe jonathan miller bill miller legg mason esther dyson edventures eric c. anderson company received recognition user agreement called owner data agreement acted like reverse license agreement data shared registered parties emphasized data ownership resides user doc searls wrote owner data agreement “ precedent modeled new legal position vendors intermediaries. ” personal early embrace “ small data ” defines “ big data benefit individuals. ” term “ small data ” may originally coined jeremie miller sing.ly mentioned talk web 2.0 summit november 2011 cited intention economy 2011 personal part first group companies join personal data ecosystem consortium startup circle small data meetup group also formed new york city bringing together technology legal business experts exchange ideas user-centric user-driven models internet products services personal included case studies ctrl-shift forrester regarding personal data stores personal identity management 2011 personal received innovator spotlight award privacy identity innovation conference pii2011 participated technology showcase pii2012 2012 techhive named personal one top five apps web services sxsw personal 2013 campus technology innovators award lone star college july 2013 personal included list executive travel magazine favorite travel apps 2013 may/june issue 2013 personal also included part nyu govlab open data 500 named j. walter thompson one 100 things watch 2014 2015 national law journal named company chief policy officer general counsel joshua p. galper one 50 cybersecurity privacy trailblazers personal platform privacy- security-by-design platform individuals manage reuse data information fill app 1-click form-filling solution web mobile logins checkouts forms data vault app served main cloud-based repository user data personal helped individuals take control benefit information knowing information data vault remained legally could used without permission personal spent two years building personal platform launching data vault product beta november 2011 following privacy design principles personal enabled users see share sensitive data files stored data vault information encrypted could decrypted user password users could choose know passwords vault personal store user passwords – therefore could reset without deleting user sensitive data files stored vault personal apps services linked user private data vault data vault featured automatic synchronization data files added device logged personal also featured “ secure share ” function created live private network allowing registered users share access data files exchange encrypted keys without risk transmitting data files non-secure direct means also allowed users immediately update data across network revoke access choose fast company called data vault “ tool simplify lives. ” personal launched android app november 30 2011 ios data vault app released may 7 2012 personal officially launched application programming interface apis october 2 2012 mashery business apis conference review cnet highlighted challenges getting people trust new service sensitive data spending time required entering enough data make useful data vault launched november 2011 mashable posed question “ never fill form ” world economic forum february 2013 report highlighted possibility saving 10 billion hours globally “ improv ing delivery public private sector services ” automated form-filling tools specifically citing personal fill app january 2013 personal launched fill beta web bookmarklet automatic form-filling june 11 2014 personal released fill web extension announced publishing index 140,000 1-click online forms www.fillit.com company also announced mobile version product launch later year according story tech cocktail launch personal “ web extension mobile app able support 1,200 different types reusable data even enabling unlock confidential information complete longer forms including patient registrations job applications event registrations school admissions insurance bank applications government forms. ” november 2014 mobile version fill launched could autofill mobile forms using apis personal form portal ultimately indexed 500,000 forms three components together allowed data captured reused across forms 1 form graph mapped individual form fields personal ontology 2 semantic layer determined data required form e.g one field vs. three fields u.s. telephone number 3 correlations graph helped individuals match specific data form without looking data value e.g knowing phone number mobile phone number address billing address person uses middle name first name forms initial public offering facebook may 2012 media interest question monetary value personal data whether tools services might emerge help consumers monetize data personal frequently cited company could potentially offer service articles pieces focusing subject appeared new york times adweek mit technology review cnn national public radio company co-founder ceo shane green quoted saying “ average american consumer would soon able realize 1,000 per year ” granting limited anonymous access data marketers figure never supported green company may 2016 personal shifted product focus teamdata focuses problem securing collaboratively managing data workplace onboardly included new collaborative teamdata solution list top 10 apps keep team track part top 50 list time best content marketing tools teamdata separate business
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Computer security
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xotcl xotcl object-oriented extension tool command language created gustaf neumann uwe zdun derivative mit otcl xotcl based dynamic object system metaclasses influenced clos class method definitions completely dynamic xotcl provides language support design patterns via filters decorator mixins
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Programming language topics
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signature signature sign handwritten often stylized depiction someone name nickname even simple x mark person writes documents proof identity intent writer signature signatory signer similar handwritten signature signature work describes work readily identifying creator signature may confused autograph chiefly artistic signature lead confusion people autograph signature people public eye keep signatures private whilst fully publishing autograph traditional function signature permanently affix document person ’ uniquely personal undeniable self-identification physical evidence person personal witness certification content specified part document example role signature many consumer contracts solely provide evidence identity contracting party also provide evidence deliberation informed consent many countries signatures may witnessed recorded presence notary public carry additional legal force legal documents illiterate signatory make mark often x occasionally personalized symbol long document countersigned literate witness countries illiterate people place thumbprint legal documents lieu written signature united states signatures encompass marks actions sorts indicative identity intent legal rule unless statute specifically prescribes particular method making signature may made number ways include mechanical rubber stamp facsimile signature may made purported signatory alternatively someone else duly authorized signatory acting signer presence signatory direction may make signature many individuals much fanciful signatures normal cursive writing including elaborate ascenders descenders exotic flourishes much one would find calligraphic writing example final k john hancock famous signature us declaration independence loops back underline name kind flourish also known paraph paraphe term meaning flourish initial signature french paraph used graphology analyses several cultures whose languages use writing systems alphabets share western notion signatures per se signing one name results written product different result writing one name standard way languages write sign involves written characters also see calligraphy special signature machines called autopens capable automatically reproducing individual signature typically used people required sign lot printed matter celebrities heads state ceos recently members congress united states begun signature made truetype font file allows staff members congressman office easily reproduce correspondence legislation official documents east asian languages chinese japanese korean people traditionally use stamp-like objects known name-seals name carved tensho script seal script lieu handwritten signature government agencies require professional persons official reviewers sign originals copies originals authenticate personally viewed content united states prevalent architectural construction plans intent prevent mistakes fraud practice known effective e-mail newsgroup usage another type signature exists independent one language users set one lines custom text known signature block automatically appended messages text usually includes name contact information sometimes quotations ascii art shortened form signature block including one name often distinguishing prefix used simply indicate end post response web sites also allow graphics used note however type signature related electronic signatures digital signatures technical nature directly understandable humans wikipedia online wiki-based encyclopedia edited volunteers contributors sign comments talk pages username username holder right digitally affix signature signature painting work art always important item assessment art fake signatures sometimes added enhance value painting added fake painting support authenticity notorious case signature johannes vermeer fake supper emmaus made art-forger han van meegeren however fact painters signatures often vary time particularly modern contemporary periods might complicate issue signatures painters take artistic form may less value determining forgeries term signature also used mean characteristics give object piece information identity—for example shape coca-cola bottle rock music heavy metal music electric guitarists develop unique tone sound using particular settings guitar amp effects units modifications guitar pickups called signature sound wrestling wwe wrestlers known distinctive signature finishing moves golf courses signature hole aesthetically pleasing photogenic hole makes particular course unique analogy word signature may used refer characteristic expression process thing example climate phenomenon known enso el niño characteristic modes different ocean basins often referred signature icie collier signatory indicates party agreement especially international treaty convention e.g brazil signatory convention biological diversity british law appearance signatures names may protected copyright law united states copyright law titles names c ... mere variations typographic ornamentation lettering coloring eligible copyright however appearance signatures names may protected copyright law uniform commercial code §1-201 37 united states generally defines signed using symbol executed adopted present intention adopt accept writing uniform commercial code §3-401 b negotiable instruments states signature may made manually means device machine ii use name including trade assumed name word mark symbol executed adopted person present intention authenticate writing
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Computer security
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american national corpus american national corpus anc text corpus american english containing 22 million words written spoken data produced since 1990 currently anc includes range genres including emerging genres email tweets web data included earlier corpora british national corpus annotated part speech lemma shallow parse named entities anc available linguistic data consortium fifteen million word subset corpus called open american national corpus oanc freely available restrictions use anc website corpus annotations provided according specifications iso/tc 37 sc4 linguistic annotation framework using freely provided transduction tool anc2go corpus user-chosen annotations provided multiple formats including conll iob format xml format conformant xml corpus encoding standard xces usable british national corpus xaira search engine uima-compliant format formats suitable input wide variety concordance software plugins import annotations general architecture text engineering gate also available anc differs corpora english richly annotated including different part speech annotations penn tags claws5 claws7 tags shallow parse annotations annotations several types named entities additional annotations added parts corpus become available often contributions projects unlike on-line searchable corpora due copyright restrictions allow access individual sentences entire anc available enable research involving example development statistical language models full-text linguistic annotation anc annotations automatically produced unvalidated 500,000 word subset called manually annotated sub-corpus masc annotated approximately 20 different kinds linguistic annotations hand-validated manually produced include penn treebank syntactic annotation wordnet sense annotation framenet semantic frame annotations among others like oanc masc freely available use downloaded anc site linguistic data consortium also distributed part-of-speech tagged form natural language toolkit anc sub-corpora differ similar corpora primarily range linguistic annotations provided inclusion modern genres appear resources like british national corpus also initial target use corpora development statistical language models full data annotations available thus differing corpus contemporary american english coca available selectively web browser continued growth oanc masc relies contributions data annotations computational linguistics corpus linguistics communities proceedings 48th annual meeting association computational linguistics uppsala sweden
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Computational linguistics
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hoc programming language hoc acronym high order calculator interpreted programming language used 1984 book unix programming environment demonstrate build interpreters using yacc hoc developed brian kernighan rob pike glorified interactive calculator basic functionality evaluate floating-point numerical expressions e.g. 1+2*sin 0.7 variables added conditionals loops user-defined functions simple io using syntax resembling c. improved hoc interpreter included eighth edition research unix 1985 generally adopted commercial unix systems linux distributions instead earlier calculator languages dc bc become widespread systems hoc survived continued evolve part plan 9 operating system several improved versions hoc released free software bell labs individuals see list hoc used primary scripting language neuron simulator following simple example interactive calculator session hoc text represents hoc output simple example functions flow control
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Programming language topics
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gnash software gnash media player playing swf files gnash available standalone player desktop computers embedded devices well plugin several browsers part gnu project free open-source alternative adobe flash player developed gameswf project gnash first announced late 2005 software developer john gilmore project maintainer rob savoye main developer web site gnash located free software foundation gnu savannah project support server gnash supports swf v7 features swf v8 v9 however swf v10 supported writing free software flash player priority gnu project time prior launch gnash gnu project asked people assist gplflash project majority previous gplflash developers moved gnash project existing gplflash codebase refocused towards supporting embedded systems primary distribution terms gnash gnu gpl however since gnash started using codebase gameswf project public domain code developed gnash project might useful gameswf placed public domain adobe provides outdated version 11.2 official player linux ia-32 amd64 developer preview release binary-only form gnash however compiled executed many architectures including x86 arm mips powerpc also supports bsd-based operating systems early port risc os never macromedia/adobe flash support beyond flash 3 exist well early port beos flash support terminated version 4 development port amigaos 4.1 also recently begun port haiku operating system also exists gnash requires one agg cairo opengl rendering contrast gnu projects typically written c gnash written c++ programming language gameswf heritage gnash play swf files version 7 80 actionscript 2.0 goal gnash developers compatible possible proprietary player including behavior bad actionscript code however gnash offers special features available adobe player possibility extend actionscript classes via shared libraries sample extensions include mysql support file system access security reasons extension mechanism must compiled-in explicitly enabled via configuration files gnash supports playback flv videos allows playing flv files youtube myspace showmedo similar websites older files sound – newer files without playing sound flv support requires ffmpeg gstreamer installed system free-software programs mplayer vlc media player players windows based ffdshow directshow codecs play back flv format file specially downloaded piped version 0.8.8 released 22 august 2010 rob savoye announced gnash work youtube videos version 0.8.8 gpu support pushed ahead proprietary adobe flash player linux flash 10.2 came hardware acceleration built gnash still suffers high cpu usage flashblock plugin installed user turning flash support case-by-case needed basis youtube video controls full screen mode functioning although version 0.8.8 bug cause youtube display invalid parameters many popular flash games work gnash 0.8.8 cygnal gnash project flash media server-compatible audio video server handles negotiating copyright metadata exchange well streaming content need handle many thousands simultaneous network connection support running large gnu/linux clusters support handling multiple streams differing content well multicast stream single data source due patent issues surrounding mp3 fact flv on2 closed formats one main goals project support free codes free protocols primary way things optional support mp3 flv on2 vp6 vp7 playing existing flash content flv vp6 vp7 codecs included ffmpeg users use ffmpeg plugin gstreamer 0.10 use proprietary codecs gnash successfully run microsoft windows darwin os x irix solaris beos os/2 haiku gnash also run following 64-bit systems powerpc itanium ultrasparc amd64 gnash ported windows plugin works best firefox 1.0.4 newer work mozilla-based browser however newer browsers plugin may become unstable inoperative newer gnash binaries windows include plugin currently newer working gnash plugin windows project financially supported commercial company lulu.com july 2010 march 2012 lead developer reported donations barely enough pay hosting project web one problem project difficulty finding developers current developers never installed adobe flash player fear anyone ever installed adobe flash player time accepted agreement modify reverse engineer flash player therefore gnash project 6 active developers november 2010 generic clauses however may national anticompetition laws used normal software license agreements may 2 2012 court justice european union ruled case c-406/10 sas institute inc v world programming ltd functionality computer program covered copyright european union contractual provisions null void forbid observing studying testing computer program order reproduce behavior second program holds long source code object code copied
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Programming language topics
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comparison web server software web server software allows computers act web servers first web servers supported static files html images commonly allow embedding server side applications web application frameworks include simple http servers example django framework provides codice_1 php built-in server generally intended use initial development production server require robust http front-end one servers listed
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Web technology
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omega2 computer omega2 personal single-board computer created toronto-based startup company called onion released kickstarter advertised world smallest linux server system combines tiny form factor power-efficiency arduino power flexibilities raspberry pi identified fcc identifier 2ajvp-omega2 runs linux kernel based lightweight operating system embedded system called openwrt soc planned shipped end november 2016 omega2 next generation old product onion makes omega original omega based qualcomm atheros ar9331 mips architecture soc runs full linux operating system designed embedded system sold 19.99 company discontinued development omega replaced successor omega2 using another soc chip mediatek mt7688 also metal cover chip also drastically cut price 5 later increased 7.5 beginning 2017 onion already attracted crowdfunding 850,000 omega2 greatly exceeded initial goal 440,000 omega2 comes two versions basic omega2 omega2 plus omega2 cpu based mips architecture running 580 mhz clock speed equipped 64 mb ram 16 mb flash memory omega2 plus similar omega2 except 128 mb ram 32 mb memory microsd slot sold 9 usd system comes small pcb footprint dual-in-line 16x2mm pins board runs 3.3 volts power average power consumption 0.6w devices intended headless computers graphical interfaces embedded systems
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Computer architecture
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clmul instruction set carry-less multiplication clmul extension x86 instruction set used microprocessors intel amd proposed intel march 2008 made available intel westmere processors announced early 2010 mathematically instruction implements multiplication polynomials finite field gf 2 bitstring formula_1 represents polynomial formula_2 clmul instruction also allows efficient implementation closely related multiplication larger finite fields gf 2 traditional instruction set one use instructions improve speed applications block cipher encryption galois/counter mode depends finite field gf 2 multiplication another application fast calculation crc values including used implement lz77 sliding window deflate algorithm zlib pngcrush instruction computes 128-bit carry-less product two 64-bit values destination 128-bit xmm register source may another xmm register memory immediate operand specifies halves 128-bit operands multiplied mnemonics specifying specific values immediate operand also defined presence clmul instruction set checked testing one
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Computer architecture
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automated logic corporation automated logic corporation located kennesaw georgia united states manufactures building automation systems several technological innovations include webctrl® building automation system environmental index™ tool thermographic color floor plans time-lapse™ graphics fault detection diagnostics fdd eikon uniquely powerful universal programming tool i/o hardware including controllers routers webctrl bacnet native browser-based building automation system users fully access buildings schedules setpoints trends alarms control functions virtually computer anywhere world users also control buildings webctrl wireless devices tablets cell phones webctrl supports multiple languages simultaneously includes powerful spreadsheet-based reporting tool native bacnet system webctrl interfaces lonworks modbus many protocols provide integrated solution building control needs webctrl certified bacnet testing laboratory bacnet advanced workstation software automated logic systems installed commercial office buildings industrial plants critical mission facilities healthcare facilities educational facilities government complexes hospitality/entertainment venues retail locations worldwide products sold international network dealers design engineer install support automated logic products automated logic corporation acquired carrier corporation parent united technologies corporation 2004 founding member bacnet manufacturers association automated logic one first offer products using industry ’ standard protocol – bacnet
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Web technology
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skillhive skillhive enterprise social software collaborative software designed assessing finding sharing developing expertise within organizations professional associations skillhive used various purposes competence-based management development knowledge management talent management organizational learning innovation skillhive targeted medium large sized businesses organizations operating dynamic environment continuous learning knowledge sharing experts vital skillhive built concept called swarm work swarm work defined way working aims imitate swarm intelligence form collective intelligence enable decentralized groups self-organize effectively work together towards common goal without need central coordination skillhive provided software service saas cloud on-demand service software servers data maintained service provider customer gets right receive use service since need download install software saas services like skillhive seen easy deploy skilllhive web browser based works operating systems supported up-to-date web browsers service developed using html5 javascript css php technologies enables scale different mobile devices like tablets smartphones skillhive provides advanced programming interface api enables integrate information systems human resource systems intranets skillhive linkedin integration enables transfer profile information including photos cv information service skillhive developed intunex ltd finnish technology company founded janne ruohisto 2008 intunex received innovation product development fund tekes 2010 intunex launched first commercial version skillhive called xtune 2011 skillhive received awards including association finnish elearning centre interactive learning award eeemeli – best collaboration application 2012 hr tech europe finalist 2012
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Distributed computing architecture
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inmage inmage computer software company based us india markets product line called scout uses continuous data protection cdp backup replication scout consists two product lines host-offload line uses software agent protected servers fabric line uses agent fibre channel switch fabric software protects volume block level tracking write changes allows local remote protection policies first version product released 2002 scout features capacity optimized cdp repository continuous approach allows near zero backup windows point time restores second level rpos within datacenter across datacenters target volume kept updated either synchronously asynchronously based product line retention logs allow point time recovery user specified retention window scout also features application failover support disaster recovery 6.2 release scout supported microsoft windows linux solaris aix hp ux also supports vmware xenserver hyper-v solaris zones server virtualization platforms server application failover supported microsoft windows application failover supports microsoft exchange blackberry enterprise server microsoft sql server file servers microsoft sharepoint oracle mysql among others 6.2 release series supports clustered non clustered operation scout integrates traditional tape backup software enable longer term retention tape scout integrates microsoft vss apis sql exchange hyper-v consistent snapshots also integrates oracle db2 mysql postgresql consistency apis inmage founded 2001 dr. murali rajagopal kumar malvalli sv systems microsoft corporation acquired inmage 2014
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Computer security
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random-access channel random-access channel rach shared channel used wireless terminals access mobile network tdma/fdma cdma based network call set-up bursty data transmission whenever mobile wants make mo mobile originating call schedules rach rach transport-layer channel corresponding physical-layer channel prach since rach shared probability two mobiles transmit time transmissions collide medium air granted access network happens limit number mobiles transmitting one rach time slot defined gsm standard collision happens mobile waits random period time transmits rach rach uses gsm 51 frame multiframe structure uplink transmit information mostly ts1 used high capacity gsm cell areas ts2 ts4 ts6 also used rach leaving ts0 mainly used broadcast frequency random-access channel like mobile phone networks also used openairmesh network cluster heads mesh routers key feature random-access channel messages scheduled compared example dedicated channel umts assigned exclusively one user time certainty single device makes connection attempt one time collisions result
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Internet protocols
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conditional compilation computer programming conditional compilation compilation implementing methods allow compiler produce differences executable program produced controlled parameters provided compilation technique commonly used differences needed run software different platforms different versions required libraries hardware many programming languages support conditional compilation typically compiler directives define undefine certain variables directives test variables modify compilation accordingly example using actual language compiler may set define macintosh undefine pc code may contain c languages similar syntax done using ifdef directive similar procedure using name conditional comment used microsoft internet explorer version 5 9 interpret html code also similar proprietary mechanism adding conditional comments within jscript known conditional compilation
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Programming language topics
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backscatter email backscatter also known outscatter misdirected bounces blowback collateral spam incorrectly automated bounce messages sent mail servers typically side effect incoming spam recipients messages see form unsolicited bulk email spam solicited recipients substantially similar delivered bulk quantities systems generate email backscatter may listed various email blacklists may violation internet service providers terms service backscatter occurs worms spam messages often forge sender addresses instead simply rejecting spam message misconfigured mail server sends bounce message forged address normally happens mail server configured relay message after-queue processing step example antivirus scan spam check fails time antivirus scan spam check done client already disconnected cases normally possible reject smtp transaction since client would time waiting antivirus scan spam check finish best thing case silently drop message rather risk creating backscatter measures reduce problem include avoiding need bounce message rejections initial smtp connection stage cases sending bounce messages addresses reliably judged forged cases sender verified thus ignoring message i.e. dropping authors spam viruses wish make messages appear originate legitimate source fool recipients opening message often use web-crawling software scan usenet postings message boards web pages legitimate email addresses due design smtp mail recipient mail servers receiving forged messages simple standard way determine authenticity sender accept email connection phases checking refuse e.g. software determines message likely spam use potentially forged sender address attempt good-faith effort report problem apparent sender mail servers handle undeliverable messages four fundamentally different ways backscatter occurs bounce method used sender information incoming email unrelated third party every step control worms spam messages helps reduce backscatter common approaches section also reduce problem initial smtp connection mailservers range checks often reject email 5xx error code sending server still connected rejecting message connection-stage way usually cause sending mta generate local bounce message non-delivery notification ndn local authenticated user reasons rejection include mail transfer agents mtas forward mail avoid generating backscatter using transparent smtp proxy mail servers sending email bounce messages use range measures judge whether return address forged preventing backscatter desirable also possible reduce impact filtering many spam filtering systems include option attempt detect reject backscatter email spam addition systems using schemes bounce address tag validation tag outgoing email way allows reliably detect incoming bogus bounce messages
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Computer security
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enterprise objects framework enterprise objects framework commonly simply eof introduced next 1994 pioneering object-relational mapping product nextstep openstep development platforms eof abstracts process interacting relational database mapping database rows java objective-c objects largely relieves developers writing low-level sql code eof enjoyed niche success mid-1990s among financial institutions attracted rapid application development advantages next object-oriented platform since apple inc merger next 1996 eof evolved fully integrated part webobjects application server also originally next many core concepts eof re-emerged part core data abstracts underlying data formats allow based non-sql stores early 1990s next computer recognized connecting databases essential businesses yet also potentially complex every data source different data-access language api driving costs learn use vendor product next engineers wanted apply advantages object-oriented programming getting objects talk relational databases two technologies different solution create abstraction layer insulating developers writing low-level procedural code sql specific data source first attempt came 1992 release database kit dbkit wrapped object-oriented framework around database unfortunately nextstep time powerful enough dbkit serious design flaws next second attempt came 1994 enterprise objects framework eof version 1 complete rewrite far modular openstep compatible eof 1.0 first product released next using foundation kit introduced autoreleased objects developer community development team time four people jack greenfield rich williamson linus upson dan willhite eof 2.0 released late 1995 refined architecture introducing editing context point development team consisted dan willhite craig federighi eric noyau charly kleissner eof achieved modest level popularity financial programming community mid-1990s would come emergence world wide web concept web applications clear eof could help companies plug legacy databases web without rewriting data addition frameworks state management load balancing dynamic html generation next able launch first object-oriented web application server webobjects 1996 eof core 2000 apple inc. merged next officially dropped eof standalone product meaning developers would unable use create desktop applications forthcoming mac os x would however continue integral part major new release webobjects webobjects 5 released 2001 significant fact frameworks ported native objective-c programming language java language critics change argue power eof side effect objective-c roots eof lost beauty simplicity third-party tools eogenerator help fill deficiencies introduced java mainly due loss categories objective-c code base re-introduced modifications desktop application developers core data part apple cocoa api release mac os x tiger april 2005 enterprise objects provides tools frameworks object-relational mapping technology specializes providing mechanisms retrieve data various data sources relational databases via jdbc jndi directories mechanisms commit data back data sources mechanisms designed layered abstract approach allows developers think data retrieval commitment higher level specific data source data source vendor central mapping model file eomodel build visual tool — either eomodeler eomodeler plug-in xcode mapping works follows build data models based existing data sources build data models scratch use create data structures tables columns joins data source result database records transposed java objects advantage using data models applications isolated idiosyncrasies data sources access separation application business logic database logic allows developers change database application accesses without needing change application eof provides level database transparency seen tools allows model used access different vendor databases even allows relationships across different vendor databases without changing source code power comes exposing underlying data sources managed graphs persistent objects simple terms means organizes application model layer set defined in-memory data objects tracks changes objects reverse changes demand user performs undo command time save changes application data archives objects underlying data sources designing enterprise objects developers leverage object-oriented feature known inheritance customer object employee object example might inherit certain characteristics generic person object name address phone number kind thinking inherent object-oriented design relational databases explicit support inheritance however using enterprise objects build data models reflect object hierarchies design database tables support inheritance also designing enterprise objects map multiple tables particular views database table enterprise object analogous often known object-oriented programming business object — class models physical conceptual object business domain e.g customer order item etc. makes eo different objects instance data maps data store typically enterprise object contains key-value pairs represent row relational database key basically column name value row database said eo properties persist beyond life particular running application precisely enterprise object instance class implements com.webobjects.eocontrol.eoenterpriseobject interface enterprise object corresponding model called eomodel defines mapping class object model database schema however enterprise object n't explicitly know model level abstraction means database vendors switched without affecting developer code gives enterprise objects high degree reusability despite common origins two technologies diverged technology retaining subset features original objective-c code base adding new features eof supports custom sql shared editing contexts nested editing contexts pre-fetching batch faulting relationships features original objective-c implementation supported core data core data also provide equivalent eomodelgroup—the nsmanagedobjectmodel class provides methods merging models existing models retrieving merged models bundles core data supports fetched properties multiple configurations within managed object model local stores store aggregation data given entity may spread across multiple stores customization localization property names validation warnings use predicates property validation features original objective-c implementation supported java implementation
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Operating systems
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ognl object-graph navigation language ognl open-source expression language el java using simpler expressions full range supported java language allows getting setting properties defined setproperty getproperty methods found javabeans execution methods java classes also allows simpler array manipulation aimed used java ee applications taglibs expression language ognl created luke blanshard drew davidson ognl technology ognl development continued opensymphony closed 2011 ognl developed part apache commons ognl began way map associations front-end components back-end objects using property names associations gathered features drew davidson created key-value coding language kvcl luke blanshard reimplemented kvcl using antlr started using name ognl technology reimplemented using java compiler compiler javacc ognl uses java reflection introspection address object graph runtime application allows program change behavior based state object graph instead relying compile time settings also allows changes object graph due ability create change executable code ognl capable introducing critical security flaws framework uses multiple apache struts 2 versions vulnerable ognl security flaws october 2017 recommended version struts 2 2.5.13 users urged upgrade latest version older revisions documented security vulnerabilities — example struts 2 versions 2.3.5 2.3.31 2.5 2.5.10 allow remote attackers execute arbitrary code
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Programming language topics
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pum.bad.proxy pum.bad.proxy form malware known registry hack unauthorized alteration windows registry file specifically redirects lan settings within internet explorer popular web browser commonly installed default web browser microsoft windows first spotted users malwarebytes anti-malware security software 22 january 2011 reported malwarebytes software 200 times first day alone name assigned malwarebytes anti-malware specific name unique virus hack pum defines potentially unwanted modification bad.proxy defines modification ability search alert user potentially unwanted modifications added malware bytes november 2010 likely first day users began reporting pum.bad.proxy first day hack existed rather first time malware bytes could alert user vulnerability also fact proxy server often active malware bytes alerts user presence may indicate remnant virus hack malicious software previously removed quarantined hack alters proxy server address settings redirect web access requests back computer internal lan address 127.0.0.1 effectively cutting computer access internet origin method propagation currently unknown altered registry setting affects users internet explorer including recent version internet explorer 9 browsers firefox depend upon specific windows registry item proxy address port settings affected registry value hkey_current_user\software\microsoft\windows\currentversion\internet settings\proxyserver value set 127.0.0.1 computer internal address network card various port numbers reported
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Computer security
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socket 3 socket 3 series cpu sockets various x86 microprocessors sometimes found alongside secondary socket designed math coprocessor chip case 487 socket 3 resulted intel creation lower voltage microprocessors upgrade socket 2 rearranged pin layout socket 3 237-pin low insertion force lif zero insertion force zif 19×19 pin grid array pga socket suitable 3.3 v 5 v 25–50 mhz intel 486 sx 486 dx 486 dx2 486 dx4 486 overdrive pentium overdrive processors well amd am486 am5x86 cyrix cx5x86 processors
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Computer architecture
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microsoft management console microsoft management console mmc component windows 2000 successors provides system administrators advanced users interface configuring monitoring system management console host component object model components called snap-ins microsoft administration tools implemented mmc snap-ins third parties also implement snap-ins using mmc application programming interfaces published microsoft developer network web site snap-ins registered codice_1 codice_2 registry keys snap-in combined mmc called management saved console file .msc extension launched using syntax codice_3 prolific mmc component computer management appears administrative tools folder control panel system security category view computer management actually consists collection mmc snap-ins including device manager disk defragmenter internet information services installed disk management event viewer local users groups except home editions windows shared folders tools computer management also pointed another windows machine altogether allowing monitoring configuration computers local network user access mmc snap-ins common use include
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Operating systems
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greynet within context corporate organizational networks greynet grayware elusive networked computer application downloaded installed end user systems without express permission network administrators often without awareness cognition deeply embedded organization ’ network fabric applications may marginal use user inevitably consume system network resources addition greynet applications often open door end use systems become compromised additional applications security risks malware computer workstations become connected internet variety programs proliferated offer ability extend communications gather deliver information serve needs marketing concerns among first emerge instant messaging clients icq aol instant messenger msn messenger developments technology added video capability webcam units worked together take advantage available bandwidth single small network corporate environments growth greynets takes advantage software hardware developments informal networks appearing provide variety streaming media content supplied modified end users emerging category podcasting users generate content widespread download portable mp3 players problem greynet programs fourfold first greynet programs create network security risks causing broad vectors malware dissemination second create privacy issues network opening large holes information leakage third greynet programs create compliance issues computer network creating invisible parallel communications network fourth create issues local machines consumption local system resources possible operating system program stability concerns things increase network administration time costs added corporate work environment loss meaningful production time due non-work related distractions greynet applications individual network environment policies may vary non-existent full lockdown end user system privileges see risks liabilities section instant messaging detailed overview threats risks solutions problems prevalent greynet programs public im dealing security aspects greynets led emergence specific administrative software packages monitor control traffic well enhancement security suites adware clients among first prevalent specific administrative software packages products secure networks threats borne im p2p networks products first introduced 2002 protect 10 15 u.s. corporations
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Computer security
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platial platial collaborative user generated cartographic website founded 2004 di-ann eisnor jake olsen jason wilson platial inc. headquartered portland oregon platial used hundreds thousands people globally share associate relevant content geographic places interest platial claims 25 web map widgets used 10,000 sites october 18 2007 platial acquired frappr another social mapping website increasing total user-generated locations 100 million february 27 2010 platial announced service would closing within days geographic information science literature concept 'platial refers place-based studies parallel use 'spatial space-based coordinate-system oriented studies
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Web technology
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discriminator distributed computing discriminator typed tag field present omg idl discriminated union type value definitions determines union member selected current union instance unlike conventional programming languages offering support unions discriminator idl identical selected field name example idl union type definition effective value register type may contain ax selected field discriminator value may either b stored memory separately therefore idl logically separates information currently selected field name union effective value information current discriminator value example discriminator value may anything following b c well characters belonging idl codice_1 type since codice_2 branch specified example register type allows use remaining characters well microsoft interface definition language also supports tagged unions allowing choose discriminator via attribute enclosing structure function
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Programming language topics
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cylinder 1024 cylinder 1024 first cylinder hard disk inaccessible original ibm pc compatible hardware specification interrupt 13h uses cylinder-head-sector addressing boot time bios many old pcs could access first 1024 cylinders numbered 0 1023 chs addressing defines 10 bits cylinder count 2^10=1024 problem operating systems x86 platform bios must able load bootloader entire kernel image memory must therefore located first 1024 cylinders disk older versions microsoft windows resolved necessitating operating system installed first partition partly bug users linux operating system traditionally created /boot partition reside within first 1024 cylinders disk containing little kernel bootloader
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Computer architecture
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palm viix palm viix personal digital assistant made palm inc device featured antenna used wireless data communication connectivity provided mobitex network defunct palm.net service web clipping applications used network process data cost service 14.95 per month allowed limited number web pages viewed palm viix succeeded original palm vii replaced palm i705
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Computer architecture
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hp 2100 hp 2100 series 16-bit minicomputers produced hewlett-packard hp mid-1960s early 1990s tens thousands machines series sold twenty-five year lifetime making hp fourth largest minicomputer vendor 1970s design started data systems inc dsi originally known dsi-1000 hp purchased company 1964 merged dymec division original model 2116a built using integrated circuits magnetic-core memory released 1966 next four years several new versions released including sub-models c different types memory expansion 2115 2114 cost-reduced versions 2116 models replaced hp 2100 series 1971 21mx series 1974 magnetic-core memory replaced semiconductor memory models also packaged hp 2000 combining 2100-series machine optional components order run basic programming language multi-user time sharing fashion hp time-shared basic popular 1970s many early basic programs written platform notably seminal star trek popular early home computer era people computer company published programs hp 2000 format introduction hp 3000 1974 provided high-end competition 2100 series entire line renamed hp 1000 1977 positioned real-time computers greatly redesigned version introduced 1979 1000 l-series using cmos large scale integration chips introducing desk-side tower case model first version break backward compatibility previous 2100-series expansion cards final upgrade a-series new processors capable 1 mips performance final a990 released 1990 hp formed dynac 1956 act development shop projects main company would normally undertake original logo simply hp logo turned upside forming something approximating dy learning westinghouse owned trademark name 1958 changed dymec company brought in-house 1959 become dymec division november 1967 renamed palo alto division dymec originally made variety products hp family time became primarily integrator building test equipment similar systems used hp 1964 kay magleby paul stoft began experimenting use pdp-5 pdp-8 computers act controllers complex test systems however felt machines would require changes truly suit needs time digital equipment corporation dec still small company takeover target however david packard found ken olsen difficult deal plans went nowhere looking another design could purchase packard led five-person data systems inc. dsi detroit dsi owned union carbide packard asked union carbide came computer company hp labs manager barney oliver replied n't demand answer question bill hewlett initially refused consider development minicomputer packard reframed instrument controller deal approved dsi purchased 1964 initially set dymec four original five employees dsi number employees coming hp instrumentation divisions computer group later moved offices cupertino california building purchased varian associates becoming cupertino division led magleby new division completed design 2116a demonstrated 7–10 november 1966 joint computer conference san francisco one earliest 16-bit minis hit market notable unusual new instrumentation computer highly expandable design real-time support system featured oversized cabinet held 16 expansion cards could expanded 48 cards external expansion cage system launched 20 different instrumentation cards including counters nuclear scalers electronic thermometers digital voltmeters ac/ohms converters data amplifiers input scanners additional set added input/output devices like tape drives printers punched cards paper tape peripherals real-time service provided card slot assigned fixed interrupt vector called appropriate device driver machine entered market quickly became clear selling much rapidly business data processing market originally targeted instrumentation market led introduction 2115a 1967 removed much expansion capabilities make lower-cost offering commercial users simplified version shipped 2114a 1968 eight slots leaving room power supply incorporated main chassis 2115 2114 also lacked extensive dma control 2116 removed mathematical operations ran slightly slower speeds original models using core memory hardwired cpu november 1968 company released 2000a timeshare system later known hp 2000/access based 2116b 2116a expanded 8k core memory running hp time-shared basic used separate 2114 terminal server t-s basic allowed multiple user accounts created 16 users logged newer models 2000 b f used newer versions underlying cpu introduced models used low-end versions cpu terminal server 2000f instance used 2100s main cpu primary storage controller 2100a acted terminal server b c f models dual-processor last version 2000f 2100s 2100a cpu used 2100a connected 32 serial terminals via serial multiplexer interfaces spite relatively high costs — 2000f cost 105,000 1974 — first minicomputer offer time-shared basic made popular early-to-mid 1970s hp 2000 series introduced 1969 sold june 1978 supported 1985 versions many seminal basic games written ported platform notable among mike mayfield star trek 1971 popularity made dialect basic lingua franca many basic listings normally provided format people computer company published programs hp 2000 format 32 users largest configuration hp-2000 part university timesharing life used coursework much somewhat later case decsystem-20 1970s lineup constantly improved new models remained compatible software expansion original 2116 early 1970 fred allard formerly ampex memory core division asked design new magnetic-core memory system systems rather continue purchasing ampex using newer 18 mil cores 22 mil using single sense/inhibit line able fit 8 kw memory onto single expansion card used starting 2116c models 1971 updated 2100a replaced entire existing 211x lineup overall system similar earlier models continued based core memory physically resembled 2114 power supply built-in limited internal expansion however cpu rebuilt microcode could user-programmed added hardware multiply divide added simple memory protection system caused high-priority interrupt triggered two-channel dma controller provided higher throughput optional floating-point unit also available front panel buttons illuminated small incandescent lamps burned use use switched-mode power supply allowed chassis significantly smaller earlier models 1972 hp shipped 4,500 minis making one largest companies market year merged mountain view division made magnetic tape drives cupertino division create data systems division dsd time hp 3000 project serious trouble february 1973 packard sent paul ely take division sales 2100 series remained strong 6000th shipped august 1973 8000th february 1974 10,000th february 1975 declared obsolete 1978 1972 division decided move 4kbit sram memory chips place core twice fast contemporary low-cost core much smaller allowing 32kword machines built 2114-like form factor time made decision 4kbit srams actually available experimental machines using core 2100 series used initially replaced 1kbit sram first appeared 4k parts would available time rest machine upgraded company canvassed various manufacturers found aggressively developing 4k parts particular intel mostek motorola texas instruments suggesting parts would available quantity late 1974 using memories expansion chassis like earlier systems meant room much memory megaword range however cpu use 15-bit addresses limited size 32kwords address desire larger systems hp developed dynamic mapping system dms dms expanded address format 15 20 bits allowing maximum 1,048,576 words dramatic expansion original system changes led 1974 introduction first 21mx series machines stood 21-m processor 21-x memory memory control systems separated cpu order provide flexibility case chosen 4k parts changed production proved useful practice machines shipped memories using either motorola texas instruments parts could mixed single machine higher density system based 16-pin mostek parts could supported replacing normal 21-x/2 controller 21-x/1 entire 2100 series replaced 1974 first 21mx series machines using highest-density parts new machines could support 1.2 mb largest models cpu upgraded 1976 new models became 21mx e-series original models retroactively became 21mx m-series main difference e e used clever timing improve speed twice m. wider variety machine styles released part 21mx series including smaller systems four slots larger ones 9 14 slots 21mx series featured memory management unit semiconductor memory expandable 1,048,576 words one megaword bit displays front panel buttons used small red light-emitting diodes leds instead burnout-prone incandescent bulbs used earlier versions 21mx ran hp rte real time operating system os started refrigerator-sized 19-inch rackmount systems lights switches front panels last models would use 1-chip processor fit desk using console terminal rather front panel new l series models hp-ib interface ability hp systems time blinking led lights removed front panel despite customer demands real-time ability hp r efforts using installable real-time card rte-a os good real-time operations rte 21mx important reason computer hard kill many companies use real-time operations take measurements control processes — turn pump heater valve speed slow motor etc end 1977 entire line renamed hp 1000 becoming hp 1000 m-series hp 1000 e-series next year hp 1000 f-series introduced e-series added floating point unit 1978 success line propelled hp become fourth largest manufacturer minicomputer space trailing dec ibm data general 1980 hp 1000 l-series introduced used new processor based hp large scale integration silicon sapphire process additionally expansion cards also equipped processors allowed access main memory conduct input/output without bothering cpu although made expansion cards incompatible earlier models first time also greatly improved overall performance models lacked memory management unit l-series turn replaced 1982 hp 1000 a-series included new lightning cpu design reached 1 mips even faster magic cpu 3 mips wide variety different models produced including desk-side towers variety different size rack-mount systems low-end a400 model introduced 1986 final high-end a990 released 1990 addressable 32 mb ram 2000 2100 desginations reused hp 2100 designed era ram form magnetic core memory falling dollars pennies per bit implementing processor registers using transistors small-scale integration remained expensive favored designs registers storage ram turn influenced instruction set architecture isa use memory-memory memory-accumulator design basic concept first widely introduced seminal 12-bit pdp-8 spawned many similar designs like 2100 2100 addresses 15-bits long allowing total 32k 16-bit words memory 64kb modern terms smallest addressable unit memory 16-bit word instructions fetch single 8-bit byte address broken two parts 5 significant bits refer one 32 pages 10 least significant bits displacement pointing single word within 1,024-word page dms system 21mx series upper 5 bits instead used select one 32 registers holds 12 bits least significant 10 bits register placed front original 10-bit displacement produce 20-bit address two significant bits used implement memory protection processing handled two b registers 16 bits wide registers also accessible memory locations 0 1 respectively means one load value accumulator using normal register-save operation instance codice_1 load value register memory location 1 thereby copying value b addition b registers cpu also includes register holds current memory address register holds value address p register used program counter automatically incremented every instruction also used base address memory accesses see calculated placed m. also two one-bit registers overflow extend additionally 16-bit witch /d isplay register used input output front panel certain areas memory reserved special purposes like locations 0 1 used accumulators additional words lowest 64-locations memory used direct memory access dma vectored interrupts see later models highest 64 words available memory reserved boot loader original instruction set contained 68 70 instructions 68 instructions standard instruction set 16 bits long execute one memory cycle 16 clock cycles although indirect addressing codice_2 use 36 cycles conditional branching done conditional skip-over-one instruction one instruction normally jump instruction stack subroutines instead first memory location routine reserved return address written location codice_3 instruction means internal support re-entrant code support added via user implemented stack three basic styles instructions isa memory references register references input/output certain models extended isa add-on hardware adding instance floating point instructions additional integer math memory instructions would fall three basic categories memory instructions use four bits instruction two special flags total six bits 16-bit word leaves room 10-bit address instruction stored least significant bits lsbs 0 9 bit 15 set indicates indirect addressing instead direct direct mode address instruction address operand indirect mode address pointer another memory location contained address operand one could set bit 15 location well allowing indirection required depth ending one locations 0 bit 15 addition direct/indirect mode bit 10 instruction controls z/c flag set 0 means address upper five bits zero lower 10 value instruction allows fast access z ero page first 1,024 words memory set 1 address constructed combining 10 bits instruction top 5 bits p register c urrent page memory allowing memory accessed 32 pages 1024 words thus 2,048 words addressed given time 1,024 within page zero another 1,024 within page instruction performing reference register instructions require address thus free bits work used pack four eight instructions single memory word used properly significantly speed operations total 39 register operations included broken shift-and-rotate instructions alter-and-skip instructions indicated bit 10 bit 11 indicates whether applied register b two general classes register instructions shift-and-rotate group alter-and-skip first used basic bitwise manipulation values register four instructions per word although two instructions middle always codice_4 clear e skip a/b zero second group eight instructions perform increments registers conditional branch normally used implement loops input/output instructions normally communicate accumulators instruction format starts bits 1000 significant bits followed single bit indicating register use a=0 b=1 followed 1 h/c flag bit three bits instruction remaining six bits i/o device id channel allowing 64 devices device numbers used system i/o initiated clearing flag bit codice_5 setting c bit using codice_6 hardware notices pattern begins operation operation complete device sets flag bit program loads resulting data card using codice_7 instruction sends card codice_8 actual data transfer normally accomplished using interrupt system memory locations 4 63 decimal hold addresses routines jump interrupt fired providing 60 interrupt levels location 4 7 hard-wired power failures parity check errors later models memory protection errors locations 8 user-accessible interrupt vectors mapped i/o channel arranged priority order i/o device 13 produced interrupt cpu jumps location memory location 13 masked higher-priority interrupt 1 12 another key feature 2100 series separate direct memory access controller uses cycle stealing access memory cpu using times performing internal calculations instance using feature lengthy i/o processes completed cpu works problems system set sending instruction dma controller using i/o commands dma controller channel 6 initially sent instruction containing number i/o device wants use dma whether input write memory device output read memory device starting location memory data number words setup code often installed one interrupt vectors automating process dms separate tables cpu dma system dma load data separate parts extended memory hp supplied three-pass assembler machine using column-delimited format first area left line code label start column 1 present next comes instruction mnemonic parameters rest line used comment assembler allows basic mathematical expressions written directly instead using mnemonics also includes number pseudo-instructions like codice_9 set base address program addition assembler associated linker machines initially shipped fortran 66 compiler operating system i/o drivers time additional languages added including basic algol fortran iv fortran 77 hp ported implementations agl platform added commands basic produce graphics graphics terminals plotters similar expansion fortran called graphics/1000 2100s normally used real time executive operating system rte short several versions rte released different versions machine rte-ii 2114-2116 rte-iii 2100s rte-iv 21mx series rte-a series operating system shell even late 1970s primitive single-level file system file manager fmgr example command run fortran compiler would follows meaning run f77 program using special characters distinguish source file object executable files hp 1000 also one minicomputers restricted file names five characters rather six common time made porting even writing programs challenge later rte-a hp 1000 provided conventional directory structure 16.4 file names made ru command optional tods test oriented disk system developed technician hp board repair center improve turn-around time center used load diagnostics central repository opposed loading individual paper tapes tods also used hp 2116 thru 21mx-f series test systems missiles phoenix 9206b harpoon 9500d-354 tomahawk many others early test sets 9500a evolving 9500d followed ats automated test system specific hp test systems 9500d-a46 minuteman launch component test set ats-e35 peacekeeper/minuteman launch component test set hp 8580/8542 microwave ana/asa automatic network analyzer automated spectrum analyzer ran tods tdrss microwave transponder test set used tods large system also mtos magnetic tape operating system similar tods hp 9810 9820 9830 desktop computers use slow serialized ttl version 2116 cpu although ultimately use operating system application software instead relying user-friendly rom-based interpreters basic work powered integrated keyboards displays rather disks standard terminals 1975 hp introduced bpc one world first 16-bit microprocessors using hp nmos-ii process bpc usually packaged ceramic hybrid module emc ioc chips added extended math i/o instructions hybrid developed heart new 9825 desktop computer later 9845 workstation added mmu chip forerunners personal computers technical workstations major differences original 2116 architecture bpc microprocessor completely redesigned i/o structure removal multiple levels indirect addressing provision stack register subroutine call return elimination multiple indirection made additional bit available memory word containing indirect address allowing maximum memory capacity increased 32k 16-bit words 64k bpc also added input allowing current page relative location current instruction rather power-of-two aligned page bpc used wide range hp computers peripherals test equipment discontinued late 1980s poland manufactured hp 2114b clone since 1973 polish clones called prototype 1973 pilot production 17 machines 1975-1977 production series 150 machines 1978-1987 czechoslovakia produced hp 1000 compatible clones designated 4300 4500 4700 4900 1000 units delivered vendors aritma prague development zpa čakovice zpa trutnov 1973 1990 computers served power plants including nuclear ones industry military universities etc. high reliability real-time features operating systems dos/adt several versions unix oldest hybrid adt7000 1974 composed digital adt4000 analog adt3000 parts digital part interesting customers adt4316 1976 16k words ferrite core memory adt4500 1978 4m words semiconductor ram adt 4900 designed single-board computer mass production start czechoslovak people army used adt based momi 1 momi 2 mobile minicomputers built container carried tatra 148 truck
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Computer architecture
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spysubtract spysubtract name anti-spyware application microsoft windows developed intermute maintained trend micro new name trend micro anti-spyware came effect version 3.0 previous versions trend micro branding trend micro anti-spyware later discontinued november 30 2007 replaced trend micro antivirus plus antispyware 2008 program shareware available download 30-day trial previously spysubtract often pre-installed new desktop notebook computers
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Computer security
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yottaa yottaa web mobile optimization services company based waltham massachusetts main product platform helps website conversions well performance security featured publications include xconomy techcrunch boston globe wall street journal yottaa founded 2009 boston coach wei tsinghua university mit alumnus robert buffone studied applied mathematics suny brockport prior yottaa wei founded served chairman nexaweb apart office boston yottaa opened office beijing described anti-lean startup due rather big global team inception coach wei served ceo 2009 late 2014 continues executive chairman robert buffone serve company cto respectively vick viren vaishnavi acts ceo since late 2014 series round 2010 yottaa raised 4 million venture funding general catalyst partners stata venture partners cambridge west ventures build acceleration platform 2012 yottaa named raymie stata former cto yahoo board directors series b round 2012 company raised additional 9 million expand platform technology include monitoring security features following round yottaa masstlc award innovative technology year cloud beating likes acquia basho technologies 16 million raised 2013 round led intel capital also attracting funding previous investors expand sales marketing operations attract enterprise customers equity issuance december 2014 yottaa received 10.45 million early 2015 yottaa moved offices boston waltham massachusetts yottaa developed web mobile optimization platform providing cloud services improve website speed visibility device company initial target group mid-sized enterprises smes yottaa aiming sell platform software service yottaa platform combines adaptive content delivery network dynamic site acceleration web analytics internet security yottaa deals problem website speed software optimization problem instead dealing problem bits movement different places require code changes yottaa platform named context intelligence identifies user location browser device interaction web content sort application content delivery thus modifying web content match end user browsing context context intelligence comprises several components adaptivecdn delivery component appsequencing neutralizing ad-blocking software ensuring websites speed reduced instanton accelerating component contextsafe provides security platform impactanalytics offers web analytics
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Distributed computing architecture
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univa univa privately held software company develops workload management products manage applications services containers univa software-defined computing infrastructure workload orchestration solutions enable companies scale computer resources across on-premises cloud computing hybrid systems company based chicago offices canada germany univa develops sells supports univa grid engine software univa version grid engine workload distributed resource management technology univa announced january 2011 hired personnel formerly working oracle sun microsystems grid engine development october 2 2014 univa roll new version grid engine new functionality improved scalability performance resource control small large clusters october 22 2013 univa announced acquired intellectual property copyrights trademarks pertaining grid engine technology oracle would support oracle grid engine customers univa announced navops may 2016 new business unit products enable enterprises easily migrate cloud hybrid cloud navops launch migrates hpc workload cloud univa offers consulting services installation tuning configuration products univa founded 2004 name univa corporation carl kesselman ian foster steve tuecke time primarily known providing open source products technical support based around globus toolkit september 17 2007 company announced would merge austin texas-based united devices operate new name univa ud company operated univa ud formally dropping ud returning common use univa corporation leadership current ceo gary tyreman univa announced january 17 2011 hired principal founding engineers grid engine team oct 22 2013 univa announced acquired intellectual property well copyrights trademarks pertaining grid engine technology oracle take supporting oracle grid engine customers june 2014 technical partnership racing point f1 team formerly sahara force india univa announced may 2016 univa announced new business unit navops product line based grid engine cluster workload scheduling technology originally sun microsystems later acquired univa oracle navops line differs univa grid engine enables enterprises easily migrate cloud hybrid could increase efficiencies run containers scale march 2018 univa open sources navops launch née unicloud project tortuga apache 2.0 license
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Distributed computing architecture
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virtual link aggregation control protocol virtual lacp vlacp avaya extension link aggregation control protocol provide layer 2 handshaking protocol detect end-to-end failure two physical ethernet interfaces allows switch detect unidirectional bi-directional link failures irrespective intermediary devices enables link recovery less one second vlacp far-end failures detected allows link aggregation trunk fail properly end-to-end connectivity guaranteed certain links internet aggregation group remote link failure detected change propagated partner port
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Internet protocols
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egl api egl interface khronos rendering apis opengl opengl es openvg underlying native platform windowing system egl handles graphics context management surface/buffer binding rendering synchronization enables high-performance accelerated mixed-mode 2d 3d rendering using khronos apis egl managed non-profit technology consortium khronos group acronym egl initialism starting egl version 1.2 refers khronos native platform graphics interface prior version 1.2 name egl specification opengl es native platform graphics interface x.org development documentation glossary defines egl embedded-system graphics library
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Internet protocols
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angry birds video game angry birds later remarketed angry birds classic 2009 casual puzzle video game developed rovio entertainment inspired primarily sketch stylized wingless birds game first released ios maemo devices december 2009 since time 12 million copies game purchased ios app store prompted developer design versions touchscreen-based smartphones notably android symbian windows phone blackberry 10 devices series since expanded include titles dedicated video game consoles pcs sequel angry birds 2 released july 2015 ios android gameplay revolves around players using slingshot launch birds pigs stationed around various structures goal destroying pigs playing field players advance game new types birds become available special abilities activated player rovio mobile supported angry birds numerous free updates add additional game content company also released stand-alone holiday promotional versions game angry birds game eventually praised critics success leveraging combination addictive gameplay comical style low price viable franchise long-term potential profit game popularity led release angry birds games personal computers gaming consoles created market merchandise featuring angry birds characters 2016 feature-length animated film several seasons television cartoons angry birds series combined tally 2 billion downloads across platforms january 2014 including special editions release original game called one mainstream games 2010 one great runaway hits 2010 largest mobile app success world seen 2011 angry birds player controls flock multi-colored birds attempting retrieve eggs stolen group hungry green pigs stage gameplay enemy pigs sheltered structures made various materials wood glass stone resembling children toy building blocks objective game eliminate pigs level using slingshot players launch limited set birds goal either striking enemy pigs directly damaging surrounding structures causing blocks collapse squash pigs player must set angle force bird travel pulling back slingshot using intuitive touch-controls mobile versions launch process quick casual visible trajectory data player simply selects point x-y field behind launch post virtual slingshot released various stages game additional objects tnt crates rocks incorporated structures power-ups may used enhance birds attack hard-to-reach pigs also levels players unlock bonus levels collecting golden eggs several different types birds used game distinguished color shape earliest levels basic red bird red available player advances game additional types birds become available birds effective particular materials special abilities may activated player bird airborne example yellow bird chuck speeds blue bird fragments three birds blues black bird bomb explodes white bird matilda drop egg-shaped projectile pink bird stella trap objects bubbles green bird hal boomerangs back giant red bird named terence similar original red bird damage structures smaller counterparts orange bird bubbles expands inflates pigs also vary hardiness relative size small pigs weaker easily vanquished direct hits debris damaged structures larger pigs able withstand damage succumbing defeat addition pigs wear hats armor making even resistant damage level starts quantity types firing order birds predetermined pigs eliminated last bird launched level completed next level unlocked birds run pigs defeated level incomplete must repeated points scored pig defeated well damage destruction structures hefty bonus points awarded unused birds upon completing level players receive one two three stars depending score received players encouraged repeat previously beaten levels full three stars n't awarded order fully master earn full three star rating early 2009 rovio staff began reviewing proposals potential games one proposal came senior game designer jaakko iisalo form simulated screenshot featuring angry-looking birds visible legs wings picture gave clue type game played staff liked characters team elected design game around early 2009 physics games crush castle popular flash-based web games rovio team inspired games development angry birds staff realized birds needed enemy time swine flu epidemic news staff made birds enemies pigs angry birds studio 52nd produced game initial release game sell many copies angry birds featured app uk app store february 2010 quickly reached no.1 reached 1 spot paid apps chart us app store middle 2010 stayed 275 days initial cost develop angry birds estimated exceed €100,000 including costs subsequent updates ios version rovio partnered distributor chillingo publish game app store chillingo claimed participated final game polishing adding visible trajectory lines pinch zoom pigs grunts birds somersaults landing since rovio self-published almost later ports game exception psp version produced license abstraction games rovio began writing new versions game devices new issues came light team began working version android systems observed large number configurations device types versions android software number combinations software version processor speed even user interfaces significantly larger ios version ultimately team settled minimum set requirements even though left nearly 30 types android phones unable run game including newly released phones released october 15 2010 one month initial release android rovio mobile began designing lite version game devices early 2010 rovio began developing version angry birds facebook project became one company largest development taking year company understood challenges transplanting game concept social platforms mobile/gaming systems march 2011 interview rovio peter vesterbacka said ’ take experience works one environment one ecosystem force-feed onto another like zynga ’ take farmville throw mobile see sticks titles successful mobile ones ’ built ground platform facebook version incorporate social-gaming concepts in-game purchases entered beta-testing april 2011 game became officially available facebook february 2012 improvements game include ability synchronize player progress across multiple devices example player completes level android phone log copy game android tablet see statistics level progress initial ios version game included single episode entitled poached eggs contained three themed chapters 21 levels time time rovio released free upgrades include additional content new levels new in-game objects even new birds updates released incorporated game full version offered download platform application store first update released february 11 2010 added new episode called mighty hoax containing two new chapters 21 levels updates released april 6 2010 added golden eggs feature placed hidden golden eggs throughout game would unlock bonus content found new episode called danger initially contained single chapter 15 levels two later updates added two chapters danger 15 levels big setup episode released july 18 2010 added new chapter 15 levels additional golden egg levels big setup later given two chapters 15 levels fifth episode called ham 'em high launched december 23 2010 celebration game first year ios app store ham 'em high contained 15 american old west-themed levels single chapter updates february 4 2011 march 18 2011 added one new 15-level chapter ham 'em high also introduced mighty eagle new bird may used per hour clear uncompleted levels mighty eagle also used previously completed levels without once-per-hour limit play mini-game called total destruction player attempts destroy much scenery possible standard birds mighty eagle achieving 100 destruction earns player mighty eagle feather level mighty eagle offered one-time in-game purchase initially available ios app store customers itunes accounts pre-linked credit cards late 2011 rovio also added mighty eagle chrome app version game rovio begun testing android update called bad piggy bank elisa wireless service finland t-mobile allows users charge in-app purchases mighty eagle mobile phone bills service went live android release version 2.2.0 august 2012 using google play transaction system allows mobile billing credit cards allowing android phones wifi-only tablets unlock features version also added powerups facebook version added option pay remove ads allowing android players enjoy game ad-free ios players sixth episode mine dine released june 16 2011 15 new mining-themed levels new golden egg august 24 2011 update expanded mine dine two 15-level chapters seventh update birdday party released december 11 2011 commemorate second anniversary first release ios version itunes app store included 15 new birthday cake-theme levels well updated graphics addition elements spin-off games scoring graphic seen angry birds rio introduction orange bird first appeared angry birds seasons update later released android microsoft windows eighth update released initially ios march 20 2012 lead-up release angry birds space new update included animated tutorial enhanced gameplay new ui graphics first 15 levels surf turf angry birds facebook -exclusive episode see another 15 levels added later ios version receiving power-ups first seen facebook version october 9 2012 final chapter surf turf released along new episode called bad piggies released advertise new rovio game bad piggies another update released december 11 2012 3rd anniversary game release 15 new levels birdday party 15 new levels bad piggies second set 15 levels birdday party introduced pink bird game 15 levels later released bad piggies episode march 7 2013 day final 15 levels released angry birds became free app week apple app store march 14 2013. became instant hit top free app charts app store march 18 2013 app returned normal price 0.99 june 17 2013 rovio teased facebook page red main protagonist game would receive ability new episode june 26 2013 rovio released youtube video uncovering three new facts episode would called red mighty feathers update would come july angry birds app icon would receive new design july 3 2013 update released fifteen levels all-new game play instead knocking pigs castles player goal keep pigs stealing egg leaving playing field pigs arrive waves complicated vehicles available bird red whose new ability target nearest pig score three stars awarded completing three objectives one try first objective finish level without getting egg stolen second pop pigs level third use fewer equal certain number birds clear level people skeptical new gameplay rovio later announced would add levels episode based original level style september 16 2013 rovio added 15 levels episode using original style levels include manual targeting red bird november 26 2013 rovio added 30-level episode called short fuse transforms bomb explosions highly-destructive electrical pulses adds powerup transforms bird bomb bird 3 different potions change pigs december 11 2013 rovio added 15 levels episode birdday party cake 4 celebrate fourth birthday march 4 2014 15 levels added short fuse power-up icons updated july 22 2014 15-level episode called flock favorites inspired fans favorite episodes poached eggs danger mine dine bad piggies red mighty feathers short fuse surf turf added november 23 2014 partnership red apple inc. update app released exclusive ios update added special red -themed golden egg level red power red mighty feathers episode stand-alone power-up purchased used indefinitely 1 use per level 100 money went global fund end aids purchase available december 7 2014 december 11 2014 honor angry birds 5th birthday episode 30 user-inspired levels added june 23 2015 flock favorites added 15 levels inspired previous episodes december 11 2015 honor angry birds 6th birthday new 15 levels added birdday party december 11 2016 honor angry birds seventh birthday 15 levels added birdday party may 16 2017 dual virtual currency system added game currency earned throughout gameplay accrued in-app purchases used purchase power-ups in-game items since initial release nokia n900 multimedia internet device apple iphone ipod touch mobile digital devices rovio released versions angry birds additional devices ipad-exclusive version angry birds hd released ipad mobile digital device april 2010 august 2010 angry birds made available palm pre phone running palm webos operating system app catalog online store symbian^3 phones received version game october 2010 initially includes poached eggs mighty hoax episodes angry birds works kindle fire kindle fire hd may 2010 rovio announced plans version devices using google android operating system beta version released android market google play september 2010 full android version game first released instead getjar october 2010 though subsequently released android market within days rovio officials noted getjar global reach android market getjar availability smartphone platforms including symbian would make cross-platform promotion game easier unlike previous versions angry birds android free ad-supported application paid applications n't available android nations update called bad piggy bank enabled players buy in-game ads october 2010 microsoft suggested one websites windows phone version angry birds development rovio complained microsoft asked permission make statement noting time committed design windows phone version although rovio asked microsoft revise site remove references game windows phone version ultimately released june 2011 near end 2010 rovio stated developing new ports game time devices outside mobile phone market january 2011 three ports launched first sony announced release angry birds playstation portable handheld system form playstation mini game includes nearly 200 levels original game version also playable playstation 3 next rovio announced release windows version game january 4 2011 available sale exclusively intel appup center included 195 levels launch plans exclusive features available smartphone versions one day windows version released mac app store launched one first offerings version angry birds ports angry birds also proposed wii nintendo ds systems former becoming realized angry birds trilogy see 3d-enhanced version game proposed release lg optimus 3d october 2011 popularity angry birds helped spread game devices initially designed gaming machines barnes noble announced future update nook color e-reader let android-based device run applications including port angry birds june 2011 rovio announced plans partner roku include version angry birds new model internet-connected set-top box roku 2 xs may 2011 in-browser html5 version angry birds released beta form game uses webgl canvas distributed chrome web store use google chrome web browser runs webgl- canvas-enabled browser features exclusive content played chrome exclusive levels so-called chrome bombs version includes offline playability features 60 fps gameplay selection graphics settings accommodate variety hardware capabilities october 2011 nokia world 2011 announced angry birds would come preloaded nokia asha series series 40 touch handsets aimed emerging markets india china south africa december 2011 rovio released angry birds hd angry birds seasons hd angry birds rio hd blackberry playbook tablet research motion january 2012 angry birds released devices using bada os february 2012 angry birds made official debut facebook known angry birds friends since may 23 2012 version launched two chapters original game along exclusive surf turf chapter facebook version adds number new power-up items maximum two use per level example power potion power-up formerly known super seeds make launched bird larger thus powerful king sling power-up makes slingshot stronger able launch birds higher faster power-ups purchased in-game given friends also play game surf turf would later included original mobile versions game starting ios facebook version features weekly tournaments among friends top 3 winners earning free in-game bird coins used purchase power-ups unique green day themed episode facebook version game however removed december 2012 2012 electronic entertainment expo los angeles california rovio distribution partner activision announced plans bring angry birds two spin-off games angry birds seasons angry birds rio playstation 3 xbox 360 nintendo 3ds systems bundled together angry birds trilogy games built specifically respective consoles taking advantage unique features support playstation move kinect high-definition displays glasses-free 3d visuals trilogy also ported wii wii u almost year later motion controlled version game also released samsung smart tv app reviews angry birds mostly acclaimed critics chris holt macworld called game addictive clever challenging puzzler pocket gamer keith andrew said angry birds nugget puzzling purity dished relish aplenty jonathan liu wired news wrote going maximum number stars certainly adds lot replay value fairly extensive game reviews first versions game use touch-screen playstation 3/psp version windows version also positive disagreement different interfaces greenwald pc magazine review playstation network version said control scheme platforms good 're nearly satisfying touch-screen controls found smartphone versions playstation 3 version appeared blocky unpleasant like smartphone screen blown hdtv size conversely greg miller ign preferred analog control setup psp version saying offered tiny variances control n't feel like get fat finger screen giving game positive review miller concluded denying angry birds fun could use polish – sharper visuals better price smoother action damien mcferrin british website electric pig reviewed pc version saying mouse-driven control method showcases many distinct advantages finger-focused counterpart angry birds also described critically impossible understand playing rules criteria game critic chris schiller eurogamer.net contemptuous attitude towards players keeping frustrated enough switch play something else instead angry birds became top-selling paid application apple uk app store february 2010 reached top spot us app store weeks later remained october 2010 since release free limited version angry birds downloaded 11 million times apple ios full-featured paid version downloaded nearly 7 million times september 2010 android version game downloaded 1 million times within first 24 hours release even though site crashed one point due load 2 million downloads first weekend rovio receives approximately us 1 million per month revenue advertising appears free android version according rovio players logged 5 million hours game time day across platforms series 200 million monthly active users may 2012 november 2010 digital trends stated 36 million downloads angry birds one mainstream games right msnbc video game news blog written n game app comes close following christian science monitor remarked angry birds one great runaway hits 2010 december 2010 honor one-year anniversary release angry birds rovio mobile announced game downloaded 50 million times 12 million ios devices 10 million android january 2014 angry birds series reached 2 billion downloads including angry birds angry birds seasons angry birds rio angry birds space angry birds star wars ii angry birds go christmas day 2011 alone 6.5 million copies various angry birds games downloaded across supported platforms history apple app store angry birds holds record days top paid apps chart spent total 275 days no.1 position angry birds rio no.1 total 23 days ranking ninth list apple itunes rewind list popular itunes store media 2011 angry birds top-selling paid iphone/ipod app app store free version fourth-most downloaded game two special-edition versions angry birds seasons angry birds rio also ranked top 10 paid iphone/ipod apps ipad-exclusive angry birds hd versions top-selling top-downloaded ipad apps year mattel also made board games based app called angry birds knock wood angry birds thin ice angry birds mega smash february 2010 angry birds nominee best casual game award 6th annual international mobile gaming awards barcelona spain september 2010 ign named angry birds fourth best iphone game time april 2011 angry birds best game app app year uk appy awards 2011 webby awards angry birds awarded best game handheld devices
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Operating systems
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tim-600 tim-600 important pc computer system series tim microcomputers mihajlo pupin institute-belgrade developed 1987-1988 see ref.lit 1 2 6 based intel microprocessor types 80386 80387 word-length 32 bits basic cycle time 20 mhz operating system unix v.3 ref.lit. 3 6 computer system tim-600 exposed munich international computer exhibition september 1988 fig.1 tim designers tim-600 architecture based three system buses 32 16 8-bits respectively cpu performs 5,000.000 simple operations per second primary memory ram 8 x 2 mb capacity max eight tim terminals equipment units max connected rs-232c centronics types interface used line printers also possibilities connections two hard disks well magnetic cassettes diskettes tim-600 uses programming languages c++ fortran cobol basic pascal data base management performed informix oracle software ref.lit 4 5 6 computer system tim-600 used business data processing many offices serbia example public health scientific organizations process automation industrial production road traffic control banks military government services etc
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Computer architecture
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list computer security certifications credentialing process establishing qualifications licensed professionals organizational members organizations assessing background legitimacy computer security information security fields number tracks professional take demonstrate qualifications four sources categorizing many credentials licenses certifications quality acceptance vary worldwide security credentials well-known high quality examples like master degree field accredited school cissp microsoft certification controversial list many dozens lesser known credentials organizations addition certification obtained taking courses and/or passing exams case cissp others noted demonstrating experience and/or recommended given reference existing credential holder award certificates also given winning government university industry sponsored competitions including team competitions contests scope note article certification credentialing individuals include certification organizations classified computer systems authorizing accrediting approval bodies authorities meeting prescribed set safeguards
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Computer security
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b32 business basic b32 business basic competitor data general business basic written murray haszard 1986 ran data general eclipse mv line computers initially ported unix 1989 dos 1991 b32 software company developed supported b32 business basic original site auckland new zealand supplemented sales support centre blue ash ohio b32 interpreter highly compatible data general business basic dgbb also enhanced extended language many ways like dgbb b32 could access data general infos ii database could use dgbb lock server improved version b32 twice fast number crunching string manipulation disk i/o many internal restrictions dgbb removed b32 allowed 32,767 line numbers 65,535 later versions compared dgbb 9,999 b32 allowed memory programs simultaneous locks files open language enhancements included high-speed internal sort routine do-while blocks ability step backwards indexed file debugging facilities also significantly improved dgbb b32 allowed programs run full cursor positioning attribute support non-data general terminals even programs data general control sequences hard-coded b32 carried arithmetic quad precision i.e 64-bit emulated triple precision double precision versions dgbb runtime avoided subtle incompatibilities two versions dgbb unix dos b32 emulated commonly used system calls data general aos/vs rdos operating systems including implementing symbolic links sco xenix dos 1991 features war b32 one competitors transoft universal business basic saw major improvements b32 language b32 added bluebird business basic emulation mode made line numbers optional added subroutine calls name parameter passing transoft greater financial resources b32 effective marketing purchased b32 1992 dos unix versions b32 discarded universal business basic ran operating systems eclipse mv version b32 continued sold mv line lasted b32 software staff blue ash moved transoft atlanta georgia office new zealand staff went found binary research
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Programming language topics
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windows rss platform windows rss platform included internet explorer 7 later windows vista later platform exposes feed handling management windows applications rss support internet explorer built windows rss platform windows rss platform consists three components start
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Operating systems
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android jelly bean android jelly bean tenth version android codename given three major point releases android mobile operating system developed google spanning versions 4.1 4.3.1 operating systems run android 4.3/4.4 asus nexus 7 2013 first three 4.1 unveiled google i/o developer conference june 2012 focusing performance improvements designed give operating system smoother responsive feel improvements notification system allowing expandable notifications action buttons internal changes two releases made jelly bean name october 2012 july 2013 respectively including 4.2—which included optimizations multi-user support tablets lock screen widgets quick settings screen savers 4.3—contained improvements updates underlying android platform jelly bean versions longer supported google statistics issued google indicate 3.2 android devices accessing google play run jelly bean android 4.1 jelly bean first unveiled google i/o developer conference june 27 2012 focus delightful improvements platform user interface along improvements google search experience platform knowledge graph integration new digital assistant google unveiling asus-produced nexus 7 tablet unveiling nexus q media player jelly bean work made optimizing operating system visual performance responsiveness series changes referred project butter graphical output triple buffered vsync used across drawing operations cpu brought full power touch input detected—preventing lag associated inputs made processor low-power state changes allow operating system run full 60 frames per second capable hardware following 4.1 two android releases made jelly bean codename releases focused primarily performance improvements changes android platform contained relatively user-facing changes alongside android 4.1 google also began decouple apis services android new system-level component known google play services serviced google play store allows addition certain forms functionality without distribute upgrade operating system addressing infamous fragmentation problems experienced android ecosystem attendees google i/o conference given nexus 7 tablets pre-loaded android 4.1 galaxy nexus smartphones could upgraded 4.1 google announced intent release 4.1 updates existing nexus devices motorola xoom tablet mid-july android 4.1 upgrade released general public gsm galaxy nexus models july 10 2012 late 2012 following official release jelly bean number third-party android oems began prepare distribute updates 4.1 existing smartphones tablets including devices acer htc lg motorola samsung sony toshiba august 2012 nightly builds aftermarket firmware cyanogenmod based 4.1 branded cyanogenmod 10 began released selected devices including nexus devices nexus galaxy nexus samsung galaxy galaxy ii galaxy tab 2 7.0 motorola xoom asus transformer october 29 2012 google unveiled android 4.2 dubbed sweeter tasting jelly bean alongside accompanying launch devices nexus 4 nexus 10 firmware updates nexus 7 galaxy nexus released november 2012 android 4.3 subsequently released july 24 2013 via firmware updates galaxy nexus 2012 nexus 7 nexus 4 nexus 10 visually jelly bean interface reflects refinement holo appearance introduced android 4.0 default home screen jelly bean received new features ability shortcuts widgets home screen page re-arrange fit item moved resized notification system also improved addition expandable actionable notifications individual notifications display additional content action buttons call back message missed call accessible dragging open notification two finger gesture notifications also disabled individually per-app android 4.2 added additional features user interface lock screen swiped left display widget pages swiped right go camera pane quick settings toggles feature often seen oem android skins also added notification area—accessible either swiping two fingers phones swiping top-right edge screen tablets pressing button top-right corner notifications pane previous browser application officially deprecated 4.2 favor google chrome android 4.2 also adds gesture typing keyboard redesigned clock app new screen saver system known daydreams tablets android 4.2 also supports multiple users promote consistency device classes android tablets use expanded version interface layout home screen used phones default centered navigation keys status bar across top changes took effect small tablets nexus 7 4.1 larger tablets 4.2 small tablets android optimized primarily use portrait vertical orientation giving apps expanded versions layouts used phones used landscape horizontal orientation apps adjust widescreen-oriented layouts seen larger tablets large tablets navigation buttons previously placed bottom-left bar along bottom screen clock notification area bottom-right developers 4.1 also added new accessibility apis expanded language support bi-directional text support user-supplied keymaps support managing external input devices video game controllers support multichannel usb gapless audio new media routing api low-level access hardware software audio video codecs dns-based service discovery pre-associated service discovery wi-fi android beam also used initiate bluetooth file transfers near-field communication android 4.2 added rewritten bluetooth stack changing previous bluez stack gpl originated qualcomm rewritten broadcom open source stack called bluedroid new stack initially considered immature promised several forward-looking benefits including improved support multiple displays support miracast native right-to-left support updated developer tools accessibility improvements zooming gestures number internal security improvements always-on vpn support app verification new nfc stack added time android 4.3 consisted low-level changes including bluetooth low energy avrcp support selinux opengl es 3.0 new digital rights management drm apis ability apps read notifications vp8 encoder improvements android 4.3 also included hidden privacy feature known app ops allowed users individually deny permissions apps however feature later removed android 4.4.2 google spokesperson stated feature experimental could prevent certain apps functioning correctly used certain ways concept revisited basis redesigned notifications system android 6.0
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Operating systems
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penryn microarchitecture intel tick-tock cycle 2007/2008 tick shrink core microarchitecture 45 nanometers cpuid model 23 core 2 processors used code names penryn socket p wolfdale lga 775 yorkfield mcm lga 775 also sold celeron pentium xeon processors xeon brand wolfdale-dp harpertown code names used lga 771 based mcms two four active wolfdale cores architectural improvements 65 nanometer core 2 cpus include new divider reduced latency new shuffle engine sse4.1 instructions enabled new single-cycle shuffle engine maximum l2 cache size per chip increased 4 6 mb l2 associativity increased 16-way 24-way cut-down versions 3 mb l2 also exist commonly called penryn-3m wolfdale-3m well yorkfield-6m respectively single-core version penryn listed penryn-l separate model like merom-l version penryn-3m model one active core processors core microarchitecture categorized number cores cache size socket combination unique code name product code used across number brands instance code name allendale product code 80557 two cores 2 mb l2 cache uses desktop socket 775 marketed celeron pentium core 2 xeon different sets features enabled mobile desktop processors come two variants differ size l2 cache specific amount l2 cache product also reduced disabling parts production time wolfdale-dp quad-core processors except dunnington qc multi-chip modules combining two dies 65 nm processors product code shared processors different dies specific information one used derived stepping model 23 cpuid 01067xh intel started marketing stepping full 6 mib reduced 3 mib l2 cache time giving identical cpuid values steppings new sse4.1 instructions stepping c1/m1 bug fix version c0/m0 specifically quad core processors used stepping e0/r0 adds two new instructions xsave/xrstor replaces earlier steppings mobile processors stepping c0/m0 used intel mobile 965 express santa rosa refresh platform whereas stepping e0/r0 supports later intel mobile 4 express montevina platform model 29 stepping a1 cpuid 106d1h adds l3 cache well six instead usual two cores leads unusually large die size 503 mm² february 2008 found way high-end xeon 7400 series dunnington
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Computer architecture
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windows advanced rasterization platform windows advanced rasterization platform warp software rasterizer component directx graphics runtime windows 7 later available windows vista windows server 2008 platform update windows vista warp used compatible hardware available kernel mode applications headless environment remote rendering direct2d/directwrite remote desktop connection clients warp full-featured direct3d 10.1 renderer device performance par current low-end graphics cards intel gma 3000 running multi-core cpus achieve level rendering performance warp employs advanced techniques just-in-time compilation x86 machine code support advanced vector extensions sse2 sse4.1 warp supports direct3d 11 runtime compatible feature levels 10_1 10_0 9_3 9_2 9_1 direct3d 11.1 runtime warp additionally supports feature levels 11_0 11_1 windows 8 warp provides functionality microsoft basic render driver replaces kernel-mode vga driver windows 8.1 warp updated support feature level 11_1 tiled resources windows 10 warp updated support direct3d 12 feature level 12_1 direct3d 12 warp also replaces reference rasterizer
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Operating systems
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deutsche börse cloud exchange ag deutsche börse cloud exchange ag dbce joint venture established may 2013 deutsche börse ag zimory gmbh operates international marketplace buying selling cloud resources users marketplace either cover additional storage computing requirements offer iaas capacities begin february 2016 dbce publicly announced discontinuing operations march 2016 website www.cloud.exchange following message deutsche börse cloud exchange discontinues operations dear visitor shareholders deutsche börse cloud exchange decided cease operations marketplace evaluating business model approach company ended registration new users marketplace january 18 existing contracts fulfilled expire accordance individual agreements public marketplace scheduled retired march 2016 thank interest cooperation support please contact us directly case questions dbce team vendor-agnostic iaas marketplace dbce functions neutral intermediary cloud providers cloud users marketplace providers offer infrastructure resources cpu storage ram service side buyers opportunity search buy subsequently use appropriate iaas offers providers access marketplace reserved companies open private individuals marketplace dbce platform worldwide iaas resources compared purchased used paid standardized basis makes individual offers providers directly comparable creating transparency buyer 2013 dbce established joint venture deutsche börse ag zimory gmbh beginning 2014 marked beta launch cloud marketplace various providers already linked services marketplace official launch marketplace may 20 2015 start five providers various european countries offered iaas resources via dbce contrast marketplaces cloud services dbce seeks make available vendor-agnostic cloud resources procured via marketplace means system behind trading platform offers central interface api standard cloud technologies enables provision purchased resources independent technologies used customers therefore enables companies liberate proprietary systems order guarantee quality security services dbce cooperation tüv rheinland developed special testing procedure providers prerequisite access marketplace existing suppliers marketplace annual review various parameters conducted including performance services offered well modifications storage location servers marketplace based consistent standardization concept addition standardized seek buy procedure agreements buyers dbce standardized well intended accelerate normally drawn-out contract negotiations providers users cloud sector dbce acts controlling entity thus ensures certain security compliance procedures always upheld services traded via marketplace also standardized order enable comparison individual provider offers storage available blocks 100 gigabytes memory gibibytes compute resources dbce introduced performance unit pu dbce differentiates cloud providers different cpu offers normally difficult compare dbce specifies pu defined standard cpu offers marketplace means matter provider buyer procuring cpu resources via marketplace pu always delivers comparable performance independent underlying hardware dbce 49 employees comprising experts cloud computing industry financial sector members management board deutsche börse cloud exchange ag randolf roth maximilian ahrens
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Distributed computing architecture
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cakephp cakephp open-source web framework follows model–view–controller mvc approach written php modeled concepts ruby rails distributed mit license cakephp uses well-known software engineering concepts software design patterns convention configuration model–view–controller active record association data mapping front controller cakephp started april 2005 polish programmer michal tatarynowicz wrote minimal version rapid application development framework php dubbing cake published framework mit license opened online community developers december 2005 l. masters g. j. woodworth founded cake software foundation promote development related cakephp version 1.0 released may 2006 one project inspirations ruby rails using many concepts community since grown spawned several sub-projects october 2009 project manager woodworth developer n. abele resigned project focus projects including lithium web framework previously part cakephp project remaining development team continued focus original roadmap previously defined cake software foundation operates annual conference focusing cakephp called cakefest initially held bi-annual event 2008
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Web technology
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index coincidence cryptography coincidence counting technique invented william f. friedman putting two texts side-by-side counting number times identical letters appear position texts count either ratio total normalized dividing expected count random source model known index coincidence ic short index coincidence provides measure likely draw two matching letters randomly selecting two letters given text chance drawing given letter text number times letter appears length text chance drawing letter without replacement appearances 1 text length 1 product two values gives chance drawing letter twice row one find product letter appears text sum products get chance drawing two kind probability normalized multiplying coefficient typically 26 english express index coincidence ic given letter-frequency distribution summation n length text n n frequencies integers c letters alphabet c 26 monocase english sum n necessarily n products count number combinations n elements taken two time actually counts pair twice extra factors 2 occur numerator denominator formula thus cancel n occurrences -th letter matches remaining occurrences letter total letter pairs entire text 1/ c probability match pair assuming uniform random distribution characters null model see thus formula gives ratio total number coincidences observed total number coincidences one would expect null model expected average value ic computed relative letter frequencies source language letters alphabet equally probable expected index would 1.0 actual monographic ic telegraphic english text around 1.73 reflecting unevenness natural-language letter distributions sometimes values reported without normalizing denominator example english values may called κ kappa-plaintext rather ic κ kappa-random used denote denominator expected coincidence rate uniform distribution alphabet english index coincidence useful analysis natural-language plaintext analysis ciphertext cryptanalysis even ciphertext available testing plaintext letter identities disguised coincidences ciphertext caused coincidences underlying plaintext technique used cryptanalyze vigenère cipher example repeating-key polyalphabetic cipher arranged matrix coincidence rate within column usually highest width matrix multiple key length fact used determine key length first step cracking system coincidence counting help determine two texts written language using alphabet technique used examine purported bible code causal coincidence count texts distinctly higher accidental coincidence count texts different languages texts using different alphabets gibberish texts see imagine alphabet two letters b suppose language letter used 75 time letter b used 25 time two texts language laid side side following pairs expected overall probability coincidence 62.5 56.25 aa 6.25 bb consider case messages encrypted using simple monoalphabetic substitution cipher replaces b vice versa overall probability coincidence situation 62.5 6.25 aa 56.25 bb exactly unencrypted plaintext case effect new alphabet produced substitution uniform renaming original character identities affect whether match suppose one message say second encrypted using substitution cipher b → b following pairs expected probability coincidence 37.5 18.75 aa 18.75 bb noticeably lower probability same-language same-alphabet texts used evidently coincidences likely frequent letters text principle applies real languages like english certain letters like e occur much frequently letters—a fact used frequency analysis substitution ciphers coincidences involving letter e example relatively likely two english texts compared coincidence count higher english text foreign-language text used easily imagined effect subtle example similar languages higher coincidence count dissimilar languages also n't hard generate random text frequency distribution similar real text artificially raising coincidence count nevertheless technique used effectively identify two texts likely contain meaningful information language using alphabet discover periods repeating keys uncover many kinds nonrandom phenomena within among ciphertexts expected values various languages description introduction use index coincidence related general concept correlation various forms index coincidence devised delta i.c given formula effect measures autocorrelation single distribution whereas kappa i.c used matching two text strings although applications constant factors formula_4 formula_5 ignored general situations considerable value truly indexing i.c value expected null hypothesis usually match uniform random symbol distribution every situation expected value correlation 1.0 thus form i.c expressed ratio number coincidences actually observed number coincidences expected according null model using particular test setup foregoing easy see formula kappa i.c formula_5 common aligned length two texts b bracketed term defined 1 formula_8-th letter text matches formula_8-th letter text b otherwise 0 related concept bulge distribution measures discrepancy observed i.c null value 1.0 number cipher alphabets used polyalphabetic cipher may estimated dividing expected bulge delta i.c single alphabet observed bulge message although many cases repeating key used better techniques available practical illustration use i.c. suppose intercepted following ciphertext message suspecting english plaintext encrypted using vigenère cipher normal a–z components short repeating keyword consider ciphertext stacked number columns example seven key size happens assumed number columns letters within single column enciphered using key letter effect simple caesar cipher applied random selection english plaintext characters corresponding set ciphertext letters roughness frequency distribution similar english although letter identities permuted shifted constant amount corresponding key letter therefore compute aggregate delta i.c columns delta bar around 1.73 hand incorrectly guessed key size number columns aggregate delta i.c around 1.00 compute delta i.c assumed key sizes one ten see key size likely five actual size five would expect width ten also report high i.c. since columns also corresponds simple caesar encipherment confirm stack ciphertext five columns try determine likely key letter column considered separately performing trial caesar decryption entire column 26 possibilities a–z key letter choosing key letter produces highest correlation decrypted column letter frequencies relative letter frequencies normal english text correlation n't need worry normalizing readily computed formula_11 observed column letter frequencies formula_12 relative letter frequencies english try best-fit key letters reported codice_1 recognize actual word using vigenère decryption produces plaintext one obtains word divisions restored obvious positions codice_2 evidently null characters used pad final group transmission entire procedure could easily packaged automated algorithm breaking ciphers due normal statistical fluctuation algorithm occasionally make wrong choices especially analyzing short ciphertext messages
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Computer security
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varnish software varnish http accelerator designed content-heavy dynamic web sites well apis contrast web accelerators squid began life client-side cache apache nginx primarily origin servers varnish designed http accelerator varnish focused exclusively http unlike proxy servers often support ftp smtp network protocols varnish used websites including wikipedia online newspaper sites new york times guardian gulf news hindu corriere della sera social media content sites facebook twitter reddit spotify vimeo tumblr 2012 5 top 10,000 sites web used software project initiated online branch norwegian tabloid newspaper verdens gang architect lead developer danish independent consultant poul-henning kamp well-known freebsd core developer management infrastructure additional development originally provided norwegian linux consulting company linpro support management development varnish later spun separate company varnish software varnish free open source software available two-clause bsd license commercial support available varnish software amongst others version 1.0 varnish released 2006 varnish 2.0 2008 varnish 3.0 2011 varnish 4.0 2014 varnish 5.0 2016 varnish 6.0 march 2018 varnish stores data virtual memory leaves task deciding stored memory gets paged disk operating system helps avoid situation operating system starts caching data moved disk application varnish heavily threaded client connection handled separate worker thread configured limit number active worker threads reached incoming connections placed overflow queue queue reaches configured limit incoming connections rejected principal configuration mechanism varnish configuration language vcl domain-specific language dsl used write hooks called critical points handling request policy decisions left vcl code making varnish configurable adaptable http accelerators vcl script loaded translated c compiled shared object system compiler loaded directly accelerator thus reconfigured without restart number run-time parameters control things maximum minimum number worker threads various timeouts etc command-line management interface allows parameters modified new vcl scripts compiled loaded activated without restarting accelerator order reduce number system calls fast path minimum log data stored shared memory task monitoring filtering formatting writing log data disk delegated separate application varnish designed reduce contention threads minimum authors claim performance good system pthreads implementation additionally slow malloc implementation like ones microsoft windows msvcrt may add unnecessary contention thereby limit performance hence general recommendation running varnish linux unix based environments varnish cache speed information delivery factor several hundred ensure proper operation performance varnish exposes metrics monitored following areas varnish cache ships monitoring logging tools one used varnishstat gives detailed snapshot varnish ’ current performance provides access in-memory statistics cache hits misses resource consumption threads created running varnishstat command line returns continuously updating list available varnish metrics -1 flag added varnishstat exit printing list one time varnishstat used standalone tool spot-check health cache order graph metrics time correlate statistics across infrastructure set alerts problems may arise monitoring services integrate varnish collect varnishstat metrics varnishlog tool used debug tune varnish configuration provides detailed information individual request varnish supports load balancing using round robin random director per-backend weighting basic health-checking backends also available varnish cache also features
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Web technology
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frequency analysis cryptanalysis frequency analysis also known counting letters study frequency letters groups letters ciphertext method used aid breaking classical ciphers frequency analysis based fact given stretch written language certain letters combinations letters occur varying frequencies moreover characteristic distribution letters roughly almost samples language instance given section english language samp e /samp samp /samp samp /samp samp /samp common samp z /samp samp q /samp samp x /samp rare likewise samp th /samp samp er /samp samp /samp samp /samp common pairs letters termed bigrams digraphs samp ss /samp samp ee /samp samp tt /samp samp ff /samp common repeats nonsense phrase etaoin shrdlu represents 12 frequent letters typical english language text ciphers properties natural language plaintext preserved ciphertext patterns potential exploited ciphertext-only attack simple substitution cipher letter plaintext replaced another particular letter plaintext always transformed letter ciphertext instance occurrences letter samp e /samp turn letter samp x /samp ciphertext message containing numerous instances letter samp x /samp would suggest cryptanalyst samp x /samp represents samp e /samp basic use frequency analysis first count frequency ciphertext letters associate guessed plaintext letters samp x /samp ciphertext anything else suggests samp x /samp corresponds samp e /samp plaintext certain samp /samp samp /samp also common english samp x /samp might either also unlikely plaintext samp z /samp samp q /samp less common thus cryptanalyst may need try several combinations mappings ciphertext plaintext letters complex use statistics conceived considering counts pairs letters bigrams triplets trigrams done provide information cryptanalyst instance samp q /samp samp u /samp nearly always occur together order english even though samp q /samp rare suppose eve intercepted cryptogram known encrypted using simple substitution cipher follows example uppercase letters used denote ciphertext lowercase letters used denote plaintext guesses samp x /samp samp /samp used express guess ciphertext letter samp x /samp represents plaintext letter samp /samp eve could use frequency analysis help solve message along following lines counts letters cryptogram show samp /samp common single letter samp xl /samp common bigram samp xli /samp common trigram samp e /samp common letter english language samp th /samp common bigram samp /samp common trigram strongly suggests samp x /samp samp /samp samp l /samp samp h /samp samp /samp samp e /samp second common letter cryptogram samp e /samp since first second frequent letters english language samp e /samp samp /samp accounted eve guesses samp e /samp samp /samp third frequent letter tentatively making assumptions following partial decrypted message obtained using initial guesses eve spot patterns confirm choices samp /samp moreover patterns suggest guesses samp rtate /samp might samp state /samp would mean samp r /samp samp /samp similarly samp atthattmze /samp could guessed samp atthattime /samp yielding samp /samp samp /samp samp z /samp samp /samp furthermore samp heve /samp might samp /samp giving samp v /samp samp r /samp filling guesses eve gets turn guesses suggest still others example samp remara /samp could samp remark /samp implying samp /samp samp k /samp relatively straightforward deduce rest letters eventually yielding plaintext point would good idea eve insert spaces punctuation example gold-bug eve guesses correct would always case however variation statistics individual plaintexts mean initial guesses incorrect may necessary backtrack incorrect guesses analyze available statistics much depth somewhat simplified justifications given example also possible plaintext exhibit expected distribution letter frequencies shorter messages likely show variation also possible construct artificially skewed texts example entire novels written omit letter samp e /samp altogether — form literature known lipogram first known recorded explanation frequency analysis indeed kind cryptanalysis given 9th century al-kindi arab polymath manuscript deciphering cryptographic messages suggested close textual study qur'an first brought light arabic characteristic letter frequency use spread similar systems widely used european states time renaissance 1474 cicco simonetta written manual deciphering encryptions latin italian text arabic letter frequency detailed study letter word frequency analysis entire book qur'an provided intellaren articles several schemes invented cryptographers defeat weakness simple substitution encryptions included disadvantage attempts defeat frequency counting attacks increases complication enciphering deciphering leading mistakes famously british foreign secretary said rejected playfair cipher even school boys could cope successfully wheatstone playfair shown attachés could never learn rotor machines first half 20th century example enigma machine essentially immune straightforward frequency analysis however kinds analysis attacks successfully decoded messages machines frequency analysis requires basic understanding statistics plaintext language problem solving skills performed hand tolerance extensive letter bookkeeping world war ii wwii british americans recruited codebreakers placing crossword puzzles major newspapers running contests could solve fastest several ciphers used axis powers breakable using frequency analysis example consular ciphers used japanese mechanical methods letter counting statistical analysis generally ibm card type machinery first used world war ii possibly us army sis today hard work letter counting analysis replaced computer software carry analysis seconds modern computing power classical ciphers unlikely provide real protection confidential data frequency analysis described fiction edgar allan poe gold-bug sir arthur conan doyle sherlock holmes tale adventure dancing men examples stories describe use frequency analysis attack simple substitution ciphers cipher poe story encrusted several deception measures literary device anything significant cryptographically
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Computer security
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farcry cms farcry cms popular open-source content management system cfml built farcry core addition standard cms features menu management system administration page layout customization farcry features also include farcry framework actively maintained daemon internet consultants
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Programming language topics
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ibm 8100 dpcx dpcx distributed processing control executive operating system ibm 8100 small computer system ibm hoped would help installed base ibm 3790 customers migrate 8100 dppx operating system mainly deployed support word processing system distributed office support facility dosf derived earlier ibm 3730 word processing system like dppx written pl/s-like pl/ds language applications including much dosf however written interpreted language compiled using system/370 assembler macro facility 8100/dpcx/dosf system first type distributed system connect ibm distributed office support system disoss running data host later versions disoss relied sna distribution system snads eventually became peer-to-peer communication documents complied document interchange architecture dia document content architecture dca types distributed system gained disoss support – scanmaster displaywriter 5520 office system
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Operating systems
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workgroup computer networking workgroup microsoft term peer-to-peer local area network computers running microsoft operating systems workgroup may share files printers internet connection workgroup contrasts domain computers rely centralized authentication
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Operating systems
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carrier grade linux carrier grade linux cgl set specifications detail standards availability scalability manageability service response characteristics must met order linux kernel-based operating system considered carrier grade i.e ready use within telecommunications industry term particularly applicable telecom converges technically data networks commercial off-the-shelf commoditized components blade servers carrier-grade term public network telecommunications products require 5 nines 6 nines 99.999 99.9999 percent availability translates downtime per year 30 seconds 6 nines 5 minutes 5 nines term 5 nines usually associated carrier-class servers 6 nines usually associated carrier-class switches primary motivation behind cgl effort present open architecture alternative closed proprietary software proprietary hardware systems currently used telecommunication systems proprietary systems monolithic hardware software applications integrated tightly operate well unit however hard maintain scale telecommunications companies utilize services vendor even relatively minor enhancements system cgl seeks progressively reduce eliminate dependence proprietary systems provide path easy deployment scalability utilizing cheap cots systems assemble telecommunications system cgl effort started open source development lab cgl working group specification combined linux foundation latest specification release cgl 5.0 several cgl-registered linux distributions exist including montavista wind river systems red flag linux osdl cglwg defines three main types applications carrier-grade linux support — gateways signaling servers management
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Operating systems
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trace scheduling trace scheduling optimization technique developed josh fisher used compilers computer programs compiler often rearranging generated machine instructions faster execution improve program performance increases ilp instruction level parallelism along important execution path statically predicting frequent execution path trace scheduling one many known techniques trace sequence instructions including branches including loops executed input data trace scheduling uses basic block scheduling method schedule instructions entire trace beginning trace highest frequency adds compensation code entry exit trace compensate effects order execution may result large increases code sizes poor erratic performance program behavior varies significantly input trace scheduling originally developed long instruction word vliw machines form global code motion works converting loop long straight-line code sequence using loop unrolling static branch prediction process separates unlikely code adds handlers exits trace goal common case executed sequential set instructions without branches
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Programming language topics
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unreferenced variable unreferenced variable source code computer program variable defined never used may result harmless waste memory many compilers detect variables allocate storage i.e. optimize away storage generally also issuing warning coding guideline documents consider unreferenced variable symptom potential coding fault hand unreferenced variables used temporary placeholders indicate expected future developments code c example j unreferenced variable
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Programming language topics
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corporate emergency access system corporate emergency access system ceas credentialing program united states company critical employees event disaster serious emergency employees show ceas id cards first responders admitted business location ceas helps businesses mitigate damage loss resulting allowing rapid access restricted areas ceas helps businesses mitigate damage loss allowing critical employees rapid access restricted areas allows rapidly recover essential operations retrieve assets securities valuables vital records computer hardware critical equipment core systems also conduct damage assessments ceas developed new york state 1990s business network emergency resources not-for-profit organization pioneered emergency-identification-card-based capability ceas access system adopted boston cambridge massachusetts chester county philadelphia pennsylvania erie nassau suffolk counties new york new york city baltimore stamford connecticut order businesses enroll ceas local municipalities must adopt ceas program receive id cards local authorities implement ceas following emergency immediate threats life stabilized participating businesses select pre-determined number employees receive ceas access id cards based total employee population
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Computer security
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xigmanas xigmanas network-attached storage nas server software dedicated management web interface written php free software terms simplified bsd license xigmanas continuation original freenas code developed 2005 late 2011 released name nas4free 22 march 2012 name changed xigmanas july 2018 sourceforge elected “ 'community choice project month ” twice august 2015 march 2017 respectively xigmanas embedded open-source nas software distribution based latest release freebsd developed original freenas 7 code updated work current latest freebsd releases however xigmanas preserves freenas ’ original m0n0wall/php architecture introduces experimental support arm architecture xigmanas supports sharing across windows apple unix-like systems includes zfs v5000 software raid 0,1,5 disk encryption s.m.a.r.t email reports etc. following protocols smb samba active directory domain controller ad ftp nfs tftp afp rsync unison file synchronizer iscsi initiator target hast carp bridge upnp bittorrent configurable web interface xigmanas installable almost boot media including livecd optionally small usb flash drive config storage necessary x86-64 x86-32 computer platforms version 10.3 version 11.0 xigmanas longer supports x86-32 version 10.3 still getting updates xigmanas installed compact flash usb flash drive ssd hard drive bootable devices supports advanced formatted drives using 4 kb sectors booted livecd liveusb software distribution currently distributed iso image .iso ~370 mb usb flash drive image .img ~320 mb format source form special small footprint embedded image also available .img ~150 mb preferred method embedded installation onto usb stick compact flash card cf hard disk hdd/ssd xigmanas designed xigmanas os load system memory eliminating system writes drive flash devices energy efficient updating process done webgui browser downloading installing new firmware image original freenas project derives m0n0wall freenas 0.7 branch end-of-life 'd late 2011 freenas name legally acquired ixsystems inc starting version 8.x new ixsystems developers rewrote freenas legacy freenas 0.7 longer available download legacy freenas 0.7 code unable developed longer name name change necessary founder freenas olivier cochard-labbé donated original freenas source code nas4free project support former developers namely daisuke aoyama michael zoon carries original freenas code base freenas 8.x.y software fork original freenas new rewritten code-base continuing old branded name 2018 project applied xigmanas trademark order protect brand prior release v11.2
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Operating systems
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second-generation programming language second-generation programming language 2gl generational way categorize assembly languages term coined provide distinction higher level machine independent third-generation programming languages 3gl cobol earlier first-generation programming languages machine code second-generation programming languages following properties second-generation languages sometimes used parts kernels device drivers sometimes used video games graphics programs intensive programs modern programs second generation assembly languages rarely used second generation languages may advantages mainly speed programming low level assembly language downsides downsides requirements programmers lead decline assembly vast majority programs written third-generation programming language fourth-generation programming language assembly main advantage speed degraded fact well written c code often fast even faster hand written assembly second generation languages perhaps significant place computing history long time second generation assembly languages good option development many machines nes commodore 64 second generation languages represented massive step away tradition programmers conforming needs machine first step towards machine accommodating programmer phenomenon would repeated subsequent programming language generations
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Programming language topics
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shanghai video game shanghai computerized version mahjong solitaire published activision 1986 amiga atari st atari 8-bit family commodore 64 ibm pc macintosh apple iigs master system shanghai originally programmed brodie lockard winning game tiles reveal three-dimensional blinking eye dragon behind game screen macintosh master system versions show animated dragon spitting fire shanghai sold 500,000 copies 1991 computer gaming world december 1986 published varying opinions gregg williams stated could n't believe activision wasted resources putting charles ardai called probably best game year info gave amiga version four-plus stars five stating program ought illegal impossible play 'just one game describing gameplay swift deceptively simple magazine warned plan spending lot time one gave commodore 64 version three-plus stars five describing shanghai fanatically addictive criticizing user interface graphics magazine concluded 'll find hard quit compute reviewed game favorably reporting shanghai mania proportions beginning fear health 1988 dragon gave game 5 5 stars 1996 computer gaming world declared shanghai 146th-best computer game ever released dragon magazine also gave atari lynx version 5 stars may 1992 issue robert jung ign gave game score 10 10 review cvg magazine reviewed game march 1991 issue giving score 84 100 sequel shanghai ii dragon eye published 1990 ms-dos ports released macintosh fm towns msx pc-98 sharp x68000 windows sega genesis super nes genesis version re-released wii virtual console pal regions november 27 2009 north america january 11 2010 later delisted end 2013
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Computer architecture
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dioneos dioneos pronounced /djoneos/ multitasking preemptive real-time operating system system designed texas instruments msp430x microcontrollers target microcontroller platform limited resources i.e system clock frequency tens mhz memories amount tens hundreds kb system adapted conditions providing compact efficient image efficiency term means minimization additional cpu load caused system usage according definition system effective consumes less cpu time execution internal parts e.g threads management dioneos system intended autonomic devices user interface limited functions core functionality provided system environment building multitasking firmware means standard well known concepts e.g semaphores timers etc. target domain application system graphic user interface texas instruments company manufactures wide range microcontrollers use msp430 core depending version chip contains different amount flash memory ram e.g msp430f2201 1kb/128b correspondingly msp430f5438 256kb/16kb size memory exceeds 64 kb limit 16 bits addressing insufficient due constraint chips larger memory equipped extended core msp430x version processor wider registers 20 bits new instructions processing compilation programmer selects type memory model 'near 'far used flash ram memories choice determines accessible memory range hence flash 64 kb limit programmed 'far model must used dioneos supports 'far model code modules large firmware uses extended flash developed run system control system uses 'near memory model data segments firmware started dioneos system consists threads executed pseudo-parallel way thread unique priority used ordering threads important least one thread priority value defines precedence running others dioneos system thread one following states one core processor one thread running state thread highest priority threads waiting state change thread state caused system handles 16 threads including idle one lowest priority idle thread always ready run never switched 'waiting state permitted call functions would block inside thread idle thread used determine total system load dioneos system provides stated 'threads management chapter firmware consists pseudo-parallel threads thread context contains core registers processor last execution address private stack switch threads system saves context stopped thread recovers context one run state saving makes possible breaking thread execution continuation even thread executed note preemption followed context switch may happen moment even system function called thread although may happen unexpected location executed code thread work distorted due system context saving thread point view switch done background context switch critical operation system time execution determines effective system context switch dioneos system optimized short time important parts written assembler switch done 12–17 μs f=25 mhz dioneos system context switch initiated interrupt service routine property useful moving event handling thread commonly implemented two-layer architecture context switch measured signaling point isr thread recovery takes 10us f=25 mhz dioneos system dioneos multiple configuration options affects features inserted compiled image system lot source code switches gathered configuration file altered developer firmware means possible control additional testing parts enabled system built version provides detection unusual conditions run-time information helps debugging process errors found eliminated extra features disabled full performance system example fragment configuration file
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Operating systems
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service choreography service choreography form service composition interaction protocol several partner services defined global perspective idea underlying notion service choreography summarised follows dancers dance following global scenario without single point control run-time participant service choreography executes part according behavior participants choreography role specifies expected messaging behavior participants play terms sequencing timing messages consume produce choreography describes sequence conditions data exchanged two participants order meet useful purpose service choreography better understood comparison another paradigm service composition service orchestration one hand service choreographies logic message-based interactions among participants specified global perspective service orchestration hand logic specified local point view one single participant called orchestrator service orchestration language bpel example specification service orchestration e.g bpel process file workflow deployed service infrastructure example bpel execution engine like apache ode deployment service orchestration specification transforms workflow composite service sense service choreography orchestrations two flips coin one hand roles service choreography extracted service orchestrations process called projection projection possible realize skeletons i.e incomplete service orchestrations used baselines realize web services participate service choreography hand already existing service orchestrations may composed service choreographies service choreographies executed enacted service choreography enacted participants execute roles unlike service orchestration service choreographies run engine service infrastructure “ happen roles executed logic service choreography specified global point view thus realized one single service like service orchestration key question much research choreography seeks answer suppose global choreography constructed describes possible interactions participants collaboration conditions choreography need obey guaranteed collaboration succeeds succeeds means emergent behaviour results collaboration enacted participant acting independently according skeleton exactly follows choreography skeletons originally projected case choreography said realizable general determining realizability choreography non-trivial question particularly collaboration uses asynchronous messaging possible different participants send messages simultaneously ambit specifications concerning web services following specifications focused defining languages model service choreographies moreover omg specification bpmn version 2.0 includes diagrams model service choreographies academic proposals service choreography languages include moreover number service choreography formalisms proposed based web service choreography ws-choreography specification w3c defining xml-based business process modeling language describes collaboration protocols cooperating web service participants services act peers interactions may long-lived stateful orchestration another term similar still different meaning main effort get choreography w3c web services choreography working group closed 10 july 2009 leaving ws-cdl candidate recommendation many presentations w3c workshop web services 11–12 april 2001 pointed need common interface composition language help address choreography web services architecture requirements working draft created web services architecture working group also lists idea web service choreography capabilities critical success factor support several different top-level goals nascent web services architecture problem choreography great interest industry time efforts wscl web service conversation language wsci web service choreography interface submitted w3c published technical notes moreover complementary efforts launched june 2002 intalio sun bea sap released joint specification named web services choreography interface wsci specification also submitted w3c note august 2002 w3c since formed new working group called web services choreography working group within web services activity wsci specification one primary inputs web services choreography working group published candidate recommendation ws-cdl version 1.0 november 9th 2005 xlang wsfl wsci longer supported standard organization companies bpel replaced xlang wsfl wsci superseded ws-cdl upcoming business process modeling notation version 2.0 introduce diagrams specifying service choreographies academic field put forward service choreography languages example let dance bpel4chor map service choreographies specify message-based interactions among participants global perspective way programming languages grouped programming paradigms service choreography languages grouped styles several active research projects topic service choreography
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Web technology
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storm botnet storm botnet storm worm botnet also known dorf botnet ecard malware remotely controlled network zombie computers botnet linked storm worm trojan horse spread e-mail spam height september 2007 storm botnet running anywhere 1 million 50 million computer systems accounted 8 malware microsoft windows computers first identified around january 2007 distributed email subjects 230 dead storm batters europe giving well-known name botnet began decline late 2007 mid-2008 reduced infecting 85,000 computers far less infected year earlier december 2012 original creators storm still n't found storm botnet displayed defensive behaviors indicated controllers actively protecting botnet attempts tracking disabling specifically attacking online operations security vendors researchers attempted investigate security expert joe stewart revealed late 2007 operators botnet began decentralize operations possible plans sell portions storm botnet operators reportedly powerful enough force entire countries internet estimated capable executing instructions per second world top supercomputers united states federal bureau investigation considered botnet major risk increased bank fraud identity theft cybercrimes first detected internet january 2007 storm botnet worm so-called storm-related subject lines infectious e-mail employed initially 230 dead storm batters europe later provocative subjects included chinese missile shot usa aircraft u.s. secretary state condoleezza rice kicked german chancellor angela merkel suspected information security professionals well-known fugitive spammers including leo kuvayev may involved operation control storm botnet according technology journalist daniel tynan writing robert x. cringely pseudonym great portion fault existence storm botnet lay microsoft adobe systems sources state storm worm primary method victim acquisition enticing users via frequently changing social engineering confidence trickery schemes according patrick runald storm botnet strong american focus likely agents working support within united states experts however believe storm botnet controllers russian pointing specifically russian business network citing storm software mentions hatred moscow-based security firm kaspersky lab includes russian word buldozhka means bulldog botnet zombie network comprises computers running microsoft windows operating system infected computer becomes known bot bot performs automated tasks—anything gathering data user attacking web sites forwarding infected e-mail—without owner knowledge permission estimates indicate 5,000 6,000 computers dedicated propagating spread worm use e-mails infected attachments 1.2 billion virus messages sent botnet september 2007 including record 57 million august 22 2007 alone lawrence baldwin computer forensics specialist quoted saying cumulatively storm sending billions messages day could double digits billions easily one methods used entice victims infection-hosting web sites offers free music artists beyoncé knowles kelly clarkson rihanna eagles foo fighters r. kelly velvet revolver signature-based detection main defense computer systems virus malware infections hampered large number storm variants back-end servers control spread botnet storm worm automatically re-encode distributed infection software twice hour new transmissions making difficult anti-virus vendors stop virus infection spread additionally location remote servers control botnet hidden behind constantly changing dns technique called ‘ fast flux ’ making difficult find stop virus hosting sites mail servers short name location machines frequently changed rotated often minute minute basis storm botnet operators control system via peer-to-peer techniques making external monitoring disabling system difficult central command-and-control point storm botnet shut botnet also makes use encrypted traffic efforts infect computers usually revolve around convincing people download e-mail attachments contain virus subtle manipulation one instance botnet controllers took advantage national football league opening weekend sending mail offering football tracking programs nothing infect user computer according matt sergeant chief anti-spam technologist messagelabs terms power botnet utterly blows supercomputers away add 500 top supercomputers blows away 2 million machines frightening criminals access much computing power much estimated 10 -20 total capacity power storm botnet currently used computer security expert joe stewart detailed process compromised machines join botnet attempts join botnet made launching series exe files said machine stages usually named sequence game0.exe game5.exe similar continue launching executables turn typically perform following stage compromised system connect botnet fast flux dns makes tracking process exceptionally difficult code run windir \system32\wincom32.sys windows system via kernel rootkit connections back botnet sent modified version edonkey/overnet communications protocol storm botnet variants employ variety attack vectors variety defensive steps exist well storm botnet observed defending attacking computer systems scanned storm virus-infected computer systems online botnet defend ddos counter-attacks maintain internal integrity certain points time storm worm used spread botnet attempted release hundreds thousands versions onto internet concentrated attempt overwhelm defenses anti-virus malware security firms according joshua corman ibm security researcher first time remember ever seeing researchers actually afraid investigating exploit researchers still unsure botnet defenses counterattacks form automation manually executed system operators try attach debugger query sites reporting knows punishes instantaneously secureworks chunk ddos-ed distributed-denial-of-service attacked researcher network every time hear investigator trying investigate 're automatically punished knows investigated punishes fights back corman said spameater.com well sites 419eater.com artists 419 deal 419 spam e-mail fraud experienced ddos attacks temporarily rendering completely inoperable ddos attacks consist making massed parallel network calls target ip addresses overloading servers capacities preventing responding requests anti-spam anti-fraud groups spamhaus project also attacked webmaster artists 419 said website server succumbed attack increased 100mbit similar attacks perpetrated dozen anti-fraud site hosts jeff chan spam researcher stated terms mitigating storm challenging best impossible worst since bad guys control many hundreds megabits traffic evidence may control hundreds gigabits traffic enough force countries internet storm botnet systems also take steps defend locally victims computer systems botnet compromised systems creates computer process windows machine notifies storm systems whenever new program processes begin previously storm worms locally would tell programs—such anti-virus anti-malware software simply run however according ibm security research versions storm also simply fool local computer system run hostile program successfully fact anything programs including av exes dlls sys files also software p2p applications bearshare edonkey appear run successfully even though n't actually anything far less suspicious process gets terminated suddenly outside said richard cohen sophos compromised users related security systems assume security software running successfully fact september 17 2007 republican party website united states compromised used propagate storm worm botnet october 2007 botnet took advantage flaws youtube captcha application mail systems send targeted spam e-mails xbox owners scam involving winning special version video game halo 3 attack methods include using appealing animated images laughing cats get people click trojan software download tricking users yahoo geocities service download software claimed needed use geocities geocities attack particular called full-fledged attack vector paul ferguson trend micro implicated members russian business network well-known spam malware service christmas eve 2007 storm botnet began sending holiday-themed messages revolving around male interest women titles find christmas tail twelve girls christmas mrs. claus tonight photos attractive women described attempt draw unprotected systems botnet boost size holidays security updates protection vendors may take longer distributed day e-mails christmas strippers distributed storm botnet operators immediately began sending new infected e-mails claimed wish recipients happy new year 2008 january 2008 botnet detected first time involved phishing attacks major financial institutions targeting barclays halifax around october 15 2007 uncovered portions storm botnet variants could sale done using unique security keys encryption botnet internet traffic information unique keys allow segment sub-section storm botnet communicate section matching security key however may also allow people detect track block storm botnet traffic future security keys unique lengths signatures computer security vendor sophos agreed assessment partitioning storm botnet indicated likely resale services graham cluley sophos said storm use encrypted traffic interesting feature raised eyebrows lab likely use cybercriminals lease portions network misuse would n't surprise network used spamming distributed denial-of-service attacks malicious activities security experts reported storm broken malware market form ready-to-use botnet-making spam kit world could see sharp rise number storm related infections compromised computer systems encryption seems affect systems compromised storm second week october 2007 onwards meaning computer systems compromised time frame remain difficult track block within days discovery segmenting storm botnet spam e-mail new subsection uncovered major security vendors evening october 17 security vendors began seeing new spam embedded mp3 sound files attempted trick victims investing penny stock part illegal pump-and-dump stock scam believed first-ever spam e-mail scam made use audio fool victims unlike nearly storm-related e-mails however new audio stock scam messages include sort virus storm malware payload simply part stock scam january 2008 botnet detected first time involved phishing attacks customers major financial institutions targeting banking establishments europe including barclays halifax royal bank scotland unique security keys used indicated f-secure segments botnet leased september 25 2007 estimated microsoft update windows malicious software removal tool msrt may helped reduce size botnet 20 new patch claimed microsoft removed storm approximately 274,372 infected systems 2.6 million scanned windows systems however according senior security staff microsoft 180,000+ additional machines cleaned msrt since first day likely home user machines notably incorporated daily operation 'storm botnet indicating msrt cleaning may symbolic best late october 2007 reports indicated storm botnet losing size internet footprint significantly reduced size brandon enright university california san diego security analyst estimated botnet late october fallen size approximately 160,000 compromised systems enright previous estimated high july 2007 1,500,000 systems enright noted however botnet composition constantly changing still actively defending attacks observation 're researcher hit pages hosting malware much… automated process automatically launches denial service attack said added research caused storm botnet attack knocked part uc san diego network offline computer security company mcafee reported saying storm worm would basis future attacks craig schmugar noted security expert discovered mydoom worm called storm botnet trend-setter led usage similar tactics criminals one derivative botnet dubbed celebrity spam gang due use similar technical tools storm botnet controllers unlike sophisticated social engineering storm operators use entice victims however celebrity spammers make use offers nude images celebrities angelina jolie britney spears cisco systems security experts stated report believe storm botnet would remain critical threat 2008 said estimated size remained millions early 2008 storm botnet also found business competition black hat economy form nugache another similar botnet first identified 2006 reports indicated price war may underway operators botnets sale spam e-mail delivery following christmas new year holidays bridging 2007-2008 researchers german honeynet project reported storm botnet may increased size 20 holidays messagelabs intelligence report dated march 2008 estimates 20 spam internet originates storm storm botnet sending spam two years decline late 2008 one factor — account making less interesting creators maintain botnet — may stormfucker tool made possible take control parts botnet april 28 2010 mcafee made announcement so-called rumors stormbot 2 verified mark schloesser tillmann werner felix leder german researchers lot work analyzing original storm found around two-thirds new functions copy paste last storm code base thing missing p2p infrastructure perhaps tool used p2p bring original storm honeynet blog dubbed stormbot 2
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Computer security
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graph database computing graph database gdb database uses graph structures semantic queries nodes edges properties represent store data key concept system graph edge relationship graph relates data items store collection nodes edges edges representing relationships nodes relationships allow data store linked together directly many cases retrieved one operation graph databases hold relationships data priority querying relationships within graph database fast perpetually stored within database relationships intuitively visualized using graph databases making useful heavily inter-connected data graph databases part nosql databases created address limitations existing relational databases graph model explicitly lays dependencies nodes data relational model nosql database models link data implicit connections graph databases design allow simple fast retrieval complex hierarchical structures difficult model relational systems graph databases similar 1970s network model databases represent general graphs network-model databases operate lower level abstraction lack easy traversal chain edges underlying storage mechanism graph databases vary depend relational engine “ store ” graph data table although table logical element therefore approach imposes another level abstraction graph database graph database management system physical devices data actually stored others use key-value store document-oriented database storage making inherently nosql structures graph databases based non-relational storage engines also add concept tags properties essentially relationships pointer another document allows data elements categorized easy retrieval en masse retrieving data graph database requires query language sql designed manipulation data relational system therefore “ elegantly ” handle traversing graph single graph query language universally adopted way sql relational databases wide variety systems often tightly tied one product standardization efforts occurred leading multi-vendor query languages like gremlin sparql cypher addition query language interfaces graph databases accessed application programming interfaces apis graph databases differ graph compute engines graph databases technologies translations relational oltp databases hand graph compute engines utilized olap bulk analysis graph databases attracted considerable attention 2000s due successes major technology corporations using proprietary graph databases introduction open-source graph databases graph databases portray data viewed conceptually accomplished transferring data nodes relationships edges graph within graph databases based graph theory set objects either node edge labeled-property graph model represented set nodes relationships properties labels nodes data relationships named store properties represented key/value pairs nodes labelled grouped edges representing relationships two qualities always start node end node directed making graph directed graph relationships also properties useful providing additional metadata semantics relationships nodes direct storage relationships allows constant-time traversal popular form graph model 2018 model popular graph database october 2018 neo4j rdf graph model addition information represented separate node example imagine scenario user add name property person represented distinct node graph labeled-property graph model would done addition name property node person however rdf user add separate node called 'hasname connecting original person node specifically rdf graph model composed nodes arcs rdf graph notation statement represented node subject node object arc predicate node may left blank literal and/or identified uriref arc may also identified uriref literal node may two types plain untyped typed plain literal lexical form optionally language tag typed literal made string uriref identifies particular datatype blank node may used accurately illustrate state data data uri used open graph protocol used facebook allow web page functionality object facebook semantic web multiple types graphs categorized gartner suggests five broad categories graphs execution queries within graph database localized portion graph search irrelevant data making advantageous real-time big data analytical queries consequently graph database performance proportional size data needed traversed staying relatively constant despite growth data stored graph databases powerful tool graph-like queries example computing shortest path two nodes graph graph-like queries performed graph database natural way example graph diameter computations community detection graphs flexible meaning allows user insert new data existing graph without loss application functionality need designer database plan extensive details databases future use-cases underlying storage mechanism graph databases vary depend relational engine “ store ” graph data table although table logical element therefore approach imposes another level abstraction graph database graph database management system physical devices data actually stored others use key-value store document-oriented database storage making inherently nosql structures one nosql database utilizes method arangodb arangodb native multi-model database supports graphs one data models stores graphs holding edges nodes separate collections documents node would represented document store edges link two different nodes hold special attributes inside document _from _to attributes data lookup performance dependent access speed one particular node another index-free adjacency enforces nodes direct physical ram addresses physically point adjacent nodes results fast retrieval native graph system index-free adjacency move type data structures find links nodes directly-related nodes graph stored cache one nodes retrieved making data look-up even faster first time user fetches node however advantage comes cost index-free adjacency sacrifices efficiency queries use graph traversals native graph databases use index-free adjacency process crud operations stored data since edgar f. codd 1980 paper relational model relational databases de facto industry standard large-scale data storage systems however relational model requirement strict schema data normalization imposed limitations relationships queried increasing amount data needing processed became additional problem posed relational model traditionally databases designed relational model relational model data normalized support acid transactions data normalization process removes duplicate data within database goal data normalization preserve data consistency relational model enforces acid transactions separating data many tables relational models enforce heavy data normalization order guarantee consistency one relational model design motivation achieve fast row-by-row access problems arise need form complex relationships stored data although relationships analyzed relational model complex queries performing many join operations many different attributes several tables required working relational models foreign key constraints also considered retrieving relationships causing additional overhead compared relational databases graph databases often faster associative data sets map directly structure object-oriented applications scale naturally large data sets typically need costly join operations costly means executed databases non-optimal designs logical physical levels depend less rigid schema marketed suitable manage ad hoc changing data evolving schemas conversely relational database management systems typically faster performing operation large numbers data elements permitting manipulation data natural structure despite graph databases advantages recent popularity relational databases recommended graph model sole reason replace already placed well-designed relational database benefit utilizing graph database becomes relevant evidence performance improvement orders magnitude lower latency relational model gathers data together using information data example one might look users whose phone number contains area code 311 would done searching selected datastores tables looking selected phone number fields string 311 time consuming process large tables relational databases offer concept database index allows data like stored smaller subtable containing selected data unique key primary key record part phone numbers indexed search would occur smaller index table gathering keys matching records looking main data table records keys generally tables physically stored look-ups keys fast relational databases inherently contain idea fixed relationships records instead related data linked storing one record unique key another record data example table containing email addresses users might hold data item called codice_1 contains primary key user record associated order link users email addresses system first looks selected user records primary keys looks keys codice_1 column email table likely index extracts email data links user email records make composite records containing selected data operation termed join computationally costly depending complexity query number joins indexing various keys system may search multiple tables indexes gather lots information sort match together contrast graph databases directly store relationships records instead email address found looking user key codice_1 column user record contains pointer directly refers email address record selected user pointer followed directly email records need search email table find matching records eliminate costly join operations example one searches email addresses users area code 311 engine would first perform conventional search find users 311 retrieve email addresses following links found records relational database would first find users 311 extract list pk perform another search records email table pk link matching records together types common operations graph database theory least significantly faster true value graph approach becomes evident one performs searches one level deep example consider search users subscribers table linking users users 311 area code case relational database first search users area code 311 search subscribers table users finally search users table retrieve matching users contrast graph database would search users 311 follow back-links subscriber relationship find subscriber users avoids several searches look-ups memory usage involved holding temporary data multiple records needed construct output technically sort look-up completed log n 1 time time proportional logarithm size data contrast relational version would multiple log n look-ups plus time needed join data records relative advantage graph retrieval grows complexity query example one might want know movie submarines actor movie actor played lead gone wind first requires system find actors gone wind find movies find actors movies lead gone wind find movies finally filtering list descriptions containing submarine relational database require several separate searches movies actors tables another search submarine movies finding actors movies comparing large collected results contrast graph database would simply walk gone wind clark gable gather links movies gather links movies actors follow links actors back list movies resulting list movies searched submarine done via one search properties add another layer abstraction structure also improves many common queries properties essentially labels applied record cases edges well example one might label clark gable actor would allow system quickly find records actors opposed director camera operator labels edges allowed one could also label relationship gone wind clark gable lead performing search people lead actor movie gone wind database would produce vivien leigh olivia de havilland clark gable equivalent sql query would rely added data table linking people movies adding complexity query syntax sorts labels may improve search performance certain circumstances generally useful providing added semantic data end users relational databases well suited flat data layouts relationships data one two levels deep example accounting database might need look line items invoices given customer three-join query graph databases aimed datasets contain many links especially well suited social networking systems friends relationship essentially unbounded properties make graph databases naturally suited types searches increasingly common online systems big data environments reason graph databases becoming popular large online systems like facebook google twitter similar systems deep links records illustrate imagine relational model two different tables people friend people table contains two columns person_id person_name similarly friend tables two columns well person_id friend_id person_id foreign key people table case searching jack friends would result following sql query select p2.person_name people p1 join friend p1.person_id == friend.person_id join people p2 p2.person_id == friend.friend_id p1.person_name 'jack query may translated -- match ee person friend-with friend ee.name jack return ee friend prefix foaf http //xmlns.com/foaf/0.1/ select name foaf person prefix foaf http //xmlns.com/foaf/0.1/ select name foaf name jack select people.name examples simple illustration basic relationship query condense idea relational models query complexity increases total amount data comparison graph database query easily able sort relationship graph present results also results indicate simple condensed declarative queries graph databases necessarily provide good performance comparison relational databases graph databases offer intuitive representation data relational databases offer better results set operations needed pre-history graph databases mid-1960s navigational databases ibm ims supported tree-like structures hierarchical model strict tree structure could circumvented virtual records graph structures could represented network model databases late 1960s codasyl defined cobol 1959 defined network database language 1969 labeled graphs could represented graph databases mid-1980s logical data model several improvements graph databases appeared early 1990s accelerating late 1990s endeavors index web pages mid-late 2000s commercial atomicity consistency isolation durability acid graph databases neo4j oracle spatial graph became available 2010s commercial acid graph databases could scaled horizontally became available sap hana brought in-memory columnar technologies graph databases also 2010s multi-model databases supported graph models models relational database document-oriented database became available orientdb arangodb marklogic starting 7.0 version time graph databases various types become especially popular social network analysis advent social media companies following list graph databases
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Databases
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highq software highq privately owned software service saas company providing cloud-based secure file sharing team collaboration social networking software enterprise customers customers legal banking corporate sectors well government life sciences highq founded london 2001 university friends ajay patel veenay shah company offices uk london australia sydney netherlands amsterdam germany frankfurt usa new york r operation india ahmedabad january 2016 highq raised first ever investment round 50m morgan stanley goldman sachs one peak partners help accelerate company expansion us market one top 10 biggest funding rounds europe first quarter 2016 july 2019 thomson reuters announced acquisition highq press release highq included one watch 2013 sunday times tech track 100 league table ranked 74th 2014 tech track 100 league table ranked 32nd among uk ’ top 100 smes sunday times heathrow sme export track 100 2016 highq ranked deloitte technology fast 500 emea 2011 2013 ranked deloitte technology fast 50 uk 2013 highq major clients include barclays linklaters lex mundi clifford chance osborne clarke clyde co allen overy highq clients include 21 top 25 uk law firms including uk magic circle law firms 45 top 100 uk law firms highq offers file sharing extranet collaboration project management virtual data room enterprise social networking knowledge sharing publishing solutions three products cover different aspects use cases highq collaborate highq publisher highq dataroom primary product highq collaborate provides secure document exchange enterprise social collaboration client extranets knowledge portals organisations summer 2013 highq released new mobile-optimised version collaborate saw redesign existing modules added features including responsive design microblogging private messaging centralised notifications enhanced people profiles highq publisher integrated digital marketing publishing platform supports various publishing formats channels including publications videos events microsites email campaigns highq dataroom virtual data room product aimed primarily law firms banks corporations help users exchange transactional information clients partners outside company
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Distributed computing architecture
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ibm system 9000 system 9000 s9000 family microcomputers ibm consisting system 9001 9002 9003 first member family system 9001 laboratory computer introduced may 1982 ibm instruments computer system model 9000 renamed system 9001 1984 system 9000 family name system 9002 multi-user general-purpose business computer introduced last member family system 9003 industrial computer introduced 1985 members system 9000 family find much commercial success entire family discontinued 2 december 1986 system 9000 based around motorola 68000 microprocessor motorola versabus system bus members ibm csos real-time operating system os stored read-only memory system 9002 could also run multi-user microsoft xenix os suitable business use supported four users three versions system 9000 9001 benchtop lab model 9002 desktop model without laboratory-specific features 9003 manufacturing process control version modified suitable factory environments system 9002 9003 based system 9001 based around 8mhz motorola 68000 motorola versabus system bus system 9000 one used versabus input/output ports included three rs-232c serial ports ieee-488 instrument port bidirectional 8-bit parallel port laboratory data acquisition analog-to-digital converters could attached i/o ports available user input could via user-definable 10-key touch panel integrated crt display 57-key user-definable keypad 83-key model f keyboard touch panel keypad designed controlling experiments system 9000 members ibm real-time operating system called csos computer system operating system 128kb read-only memory rom multi-tasking operating system could extended loading components disk ibm also offered microsoft xenix system 9002 required least 640kb main memory versabus card containing memory management unit machines shipped 128kb main memory standard 5mb could added system using memory boards plugged versabus board could contain 1mb installed 256kb increments system 9000 developed ibm instruments inc. ibm subsidiary established 1980 focused selling scientific technical instruments well computer equipment designed control log process instruments originally introduced ibm instruments computer system model 9000 may 1982 long name led referred computer system 9000 cs-9000 cs/9000 cs9000 originally cs9000 available scientific instrument users offered customers wanted use purposes cs9000 unsuccessful niche cheaper ibm personal computer adequate many instrumentation tasks ibm larger general-purpose computers used demanding tasks ibm repositioned cs9000 february 21 1984 family computers renaming system 9000 consisted system 9001 9002 9001 renamed cs9000 retained focus instrumentation market 9002 general-purpose business computer ran ibm csos microsoft xenix operating systems supported one four users 9002 unsuccessful business market due lack business application software support software developers ibm ibm finally introduced new model system 9003 april 1985 computer-aided manufacturing computer also unsuccessful result manufacturing system 9000 family stopped january 1986 remained limited availability discontinued 2 december 1986 reasons cited failure system 9000 poor performance high price led ibm pc used price concern 32-bit microcomputers used performance mattered ibm closed instrument division january 1987 reassigning approximately 150 employees worked positions noting obscurity 1982 release byte january 1983 called system 9000 ibm 'secret computer stated quiet way one exciting new arrivals today microcomputer scene magazine speculated changes would natural candidate business general-purpose computer later review member brandeis university chemistry department criticized several aspects hardware software praised sophisticated basic ibm customer service reviewer concluded cs-9000 fast powerful laboratory computer affordable 1983 ads dealers referred ibm 9000 multi-user micro although name ibm computer system 9000 also advertised ibm also informally referred ibm 9000
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Computer architecture
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view sql database view result set stored query data database users query would persistent database collection object pre-established query command kept database dictionary unlike ordinary base tables relational database view form part physical schema result set virtual table computed collated dynamically data database access view requested changes applied data relevant underlying table reflected data shown subsequent invocations view nosql databases views way query data views provide advantages tables function programming provide abstraction database view another parallel functions database users manipulate nested views thus one view aggregate data views without use views normalization databases second normal form would become much difficult views make easier create lossless join decomposition rows base table lack defined ordering rows available view appear default sorting view relational table relational model defines table set rows since sets ordered — definition — neither rows view therefore order clause view definition meaningless sql standard allow order clause subquery create view command refused create table statement however sorted data obtained view way table — part query statement view nevertheless dbms oracle database abide sql standard restriction database practitioners define views read-only updatable database system determine reverse mapping view schema schema underlying base tables view updatable insert update delete operations performed updatable views read-only views support operations dbms map changes underlying base tables view update done key preservation systems support definition instead triggers views technique allows definition logic execution place insert update delete operation views thus database systems implement data modifications based read-only views however instead trigger change read-only updatable property view various database management systems extended views read-only subsets data particularly materialized views pre-executed non-virtual views commonly used data warehousing give static snapshot data may include data remote sources accuracy materialized view depends frequency trigger mechanisms behind updates materialized views introduced oracle database ibm db2 provides so-called materialized query tables mqts purpose microsoft sql server introduced 2000 version indexed views store separate index table entire data postgresql implemented materialized views 9.3 release view equivalent source query queries run views query modified example exists view named accounts_view content follows application could run simple query rdbms takes simple query replaces equivalent view sends following query optimizer optimizer removes unnecessary fields complexity example necessary read address since parent invocation make use sends query sql engine processing
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Databases
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resource access control facility racf usually pronounced rack-eff short resource access control facility ibm software product security system provides access control auditing functionality z/os z/vm operating systems racf introduced 1976 main features racf establishes security policies rather permission records set permissions file patterns — set permissions even files yet exist permissions used file object created later time racf continuously evolved support modern security features digital certificates/public key infrastructure services ldap interfaces case sensitive ids/passwords latter reluctant concession promote interoperability systems unix linux underlying zseries z systems hardware works closely racf example digital certificates protected within tamper-proof cryptographic processors major mainframe subsystems especially db2 version 8 use racf provide multi-level security mls primary competitors acf2 topsecret produced ca technologies
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Operating systems
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alexander repenning dr. alexander repenning director scalable game design project computer science professor founder agentsheets inc. member center lifelong learning design university colorado boulder repenning inventor drag drop blocks programming research interests include computer science education end-user programmable agents human-computer interaction artificial intelligence repenning teaches educational game design usa asia europe worked research development asea brown boveri research xerox parc apple computer hewlett packard repenning creator agentsheets agentcubes cyberlearning tools used game design computational science applications director scalable game design project using agentsheets leads effort reinvent computer science education public schools game design starting middle school level 10,000 students funding national science foundation itest ce21 programs google scalable game design project conducting largest us study computer science education middle school level including inner city schools remote rural areas native american communities results indicate students across genders ethnicities highly motivated learn computer science game design also learn essential computational thinking skills acquire skills game design later leverage stem simulation creation repenning theoretical contributions include pedagogical framework called zones proximal flow combining vygotsky ’ zone proximal development csikszentmihalyi ’ state flow agentsheets work received numerous awards including gold medal mayor paris “ innovative application education world wide web ” www5 invitation association computing machinery showcase agentsheets one “ best best innovators ” acm1 conference repenning telluride tech festival honoree contributions computer science education previous honorees include vint cerf recognized one fathers internet alan kay recognized one pioneers object-oriented programming repenning served advisor national academy sciences european commission japanese ministry education organization economic co-operation development oecd white house office science technology policy ostp national science foundation reviewer research funding organizations usa canada europe asia chaired conferences end-user programming kids invited give talks guest lectures workshops keynote addresses nationally including stanford mit media lab university colorado numerous international conferences beyond academic recognition repenning work also featured tv news radio newspapers popular press including wired magazine switzerland repenning selected one 100 digital shapers
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Programming language topics
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perf linux perf sometimes called perf_events perf tools originally performance counters linux pcl performance analyzing tool linux available linux kernel version 2.6.31 userspace controlling utility named codice_1 accessed command line provides number subcommands capable statistical profiling entire system kernel userland code supports hardware performance counters tracepoints software performance counters e.g hrtimer dynamic probes example kprobes uprobes 2012 two ibm engineers recognized perf along oprofile one two commonly used performance counter profiling tools linux interface perf utility kernel consists one syscall done via file descriptor mmapped memory region unlike lttng older versions oprofile service daemons needed functionality integrated kernel perf utility dumps raw data mmapped buffer disk buffer becomes filled according r. vitillo lbnl profiling performed perf involves low overhead architectures provide support hardware counters include x86 powerpc64 ultrasparc iii iv arm v5 v6 v7 cortex-a8 -a9 alpha ev56 superh usage last branch records branch tracing implementation available intel cpus since pentium 4 available patch since version 3.14 linux kernel mainline released march 31 2014 perf also supports running average power limit rapl power consumption measurements available feature certain intel cpus perf natively supported many popular linux distributions including red hat enterprise linux since version 6 released 2010 debian since squeeze version released 2011 perf used several subcommands documentation perf detailed 2014 example document events explain aliases often external tools used get names codes events perf tools also profile based true wall-clock time perf subsystem linux kernels 2.6.37 3.8.8 rhel6 kernel 2.6.32 contained security vulnerability cve-2013-2094 exploited gain root privileges local user problem due incorrect type used 32-bit int instead 64-bit event_id verification code path
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Operating systems
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atmel arm-based processors atmel arm-based processors microcontrollers microprocessors integrated circuits microchip technology previously atmel based various 32-bit arm processor cores in-house designed peripherals tool support arm licenses core design series 32-bit processors arm manufacture complete silicon products intellectual property ip arm processors risc reduced instruction set computing similar microchip ’ avr 8-bit products later adoption risc architecture whereas avr architecture used harvard architecture exclusively arm cores harvard cortex-m3 others von neumann architecture arm7tdmi semiconductor companies microchip take arm cores use consistent set instructions register naming add peripheral circuits adcs analog digital converters clock management serial communications usart spi i2c lin usb ethernet lcd camera touch controllers microchip made efforts adapt advanced peripherals power management used little power operate independently without cpu core powered sleepwalking also provided dma external interfaces memories increasing data throughput minimal processor intervention microchip sells mcus microcontroller units internal flash memory mpus microprocessor units use external memory addition chips microchip offers demo boards website distribution channels digi-key farnell ineltek arrow avnet future electronics mouser microchip arm-based products meant specific applications sam4cp used smart-grid energy meters microcontrollers internal program memory well conventional internal registers ram microchip arm mcus range sam d10 series 14 pins 144-pin sam s70 sam e70 products sam4s sam4n sam3s sam3n sam7s 64-pin families pin-compatible ic footprints except usb device though voltage level compatible sam family microchip consists four different sub series sam d10 sam d11 sam d20 sam d21 devices based arm cortex-m0+ processor offer different pin memory feature combinations devices pin- code-compatible share peripherals like event system sercom module arduino zero board uses atsamd21g18 chip 2009 atmel announced atsam3u line flash-based microcontrollers based arm cortex-m3 processor higher end evolution sam7 microcontroller products top clock speed range 100 mhz come variety flash sizes summer 2009 parts still sampling development board recently made available december 2009 atsam3s line announced features several enhancements lower power operation bill materials cost reduction market watchers observe cortex-m3 products competition atmel avr32 uc3a products microcontrollers largely identical peripherals hardware technology flash-based similar clock speeds dense 16/32 bit risc instruction sets atsam4 based arm cortex-m4 core sam4e includes fpu floating-point unit sam4c includes dual-core arm cortex-m4 one core fpu based arm cortex-m7 core wide variety at91 flash-based microcontrollers based arm7tdmi cores chips top clock speed range 60 mhz come variety flash sizes peripheral sets at91sam9xe flash-based microcontrollers based arm926ej-s cores top clock speed range 200 400 mhz come variety flash sizes somewhat resemble flash-equipped at91sam9260 chips microchip introduced at91sam9 processors using arm926ej-s core armv5tej architecture first broad market follow highly successful at91rm9200 processor processors improved predecessor using less power incorporating newer powerful arm core providing variety chips different peripheral sets clocked 200 mhz run twice speed processors include series based arm cortex-a5 core integrated development environments amount documentation arm chips daunting especially newcomers documentation microcontrollers past decades would easily inclusive single document chips evolved documentation grown total documentation especially hard grasp arm chips since consists documents ic manufacturer example microchip documents cpu core vendor arm holdings typical top-down documentation tree manufacturer website manufacturer marketing slides manufacturer datasheet exact physical chip manufacturer detailed reference manual describes common peripherals aspects physical chip family arm core generic user guide arm core technical reference manual arm architecture reference manual describes instruction set microchip additional documents evaluation board user manuals application notes getting started guides software library documents errata see external links section links official microchip arm documents
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Computer architecture
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iefbr14 iefbr14 ibm mainframe utility program runs ibm mainframe environments derived os/360 including z/os placeholder returns exit status zero similar true command unix-like systems os/360 derived mainframe systems programs never specify files usually called datasets directly instead reference indirectly job control language jcl statements invoke programs data definition codice_1 statements include disposition codice_2 parameter indicates file managed — whether new file created old one re-used whether file deleted upon completion retained etc iefbr14 created codice_1 statements create delete files easily without program run due certain peculiarity job management system always requires initiator actually execute program even program effectively null statement program used jcl actually need use files cause creation deletion — codice_4 specification work thus simple do-nothing program needed fill role iefbr14 thus used create delete data set using jcl secondary reason run iefbr14 unmount devices usually tapes disks left mounted previous job perhaps error job jcl job ended error either event system operators would often need demount devices started task – codice_5 – often provided purpose simply entering command system console would run started task consisted one step however due design job management dealloc must actually exist system procedure library sys1.proclib lest start command fail also started tasks must single jobstep started task control stc module within job management component operating system accepts single-step jobs fails multi-step jobs without exception least z/os branching execute another program would cause calling program evaluated syntax errors point ief derives convention mainframe computers programs supplied ibm grouped together function creator group shared three-letter prefix os/360 first letter almost always programs produced job management group including iefbr14 used prefix ief common prefixes included ieb dataset utility programs ieh system utility programs iew program linkage loading major components still iea operating system supervisor iec input/output supervisor explained br 14 essential function program simply return operating system portion program name often mnemonic — example iebupdte dataset utility ieb applied updates updte source code files iehinitt system utility ieh initialized init magnetic tape labels explained usage name br14 comes ibm assembler-language instruction branch address register 14 convention used return subroutine early users os/360 familiar ibm assembler language would recognized example jcl would //iefbr14 job acct 'delete dataset msgclass=j class=a //step0001 exec pgm=iefbr14 //deldd dd dsn=xxxxx.yyyyy.zzzzz // disp= mod delete delete unit=dasd create partitioned data set //tzzz84r job notify= sysuid msgclass=x //step01 exec pgm=iefbr14 //dd1 dd dsn=tkol084.demo disp= new catlg delete // dcb= recfm=fb lrecl=80 blksize=80 dsorg=po // space= trk 1,1,1 rlse // unit=sysda iefbr14 consisted initially single instruction branch register 14 mnemonic used ibm assembler br hence name ief br 14 br 14 identically equivalent bcr 15,14 branch always mask 15 always address contained general purpose register 14 br pseudo instruction bcr 15 system assembler accepts many cases pseudo-instructions logical equivalents canonical system/360 instructions canonical instance br 14 bcr 15,14 linkage convention os/360 descendants requires program invoked register 14 containing address return control complete register 15 containing address called program loaded memory completion program loads return code register 15 branches address contained register 14 initially iefbr14 coded characteristics mind iefbr14 initially used dummy control section one simply returned caller executable module original version program alter register 15 original application placeholder certain load modules generated sysgen system generation executable program per se since iefbr14 always invoked functional equivalent canonical balr 14,15 instruction return code register 15 always non-zero later second instruction added clear return code would exit determinant status namely zero initially programmers using properties job control language anyway indeterminate return code problem however subsequently programmers indeed using properties determinate status became mandatory modification iefbr14 way impact original use placeholder machine code modified program equivalent machine code eliminating br clarity makes perfect sense os/360 initiator initially attaches job-step task using attach macro-instruction svc 42 unwinding effect attach macro type 2 svc instruction must complementary instruction namely exit macro necessarily type 1 svc instruction svc 3 trombetta michael finkelstein sue carolyn 1985 os jcl utilities addison wesley page 152
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Operating systems
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wireless security wireless security prevention unauthorized access damage computers data using wireless networks include wi-fi networks common type wi-fi security includes wired equivalent privacy wep wi-fi protected access wpa wep notoriously weak security standard password uses often cracked minutes basic laptop computer widely available software tools wep old ieee 802.11 standard 1997 superseded 2003 wpa wi-fi protected access wpa quick alternative improve security wep current standard wpa2 hardware support wpa2 without firmware upgrade replacement wpa2 uses encryption device encrypts network 256-bit key longer key length improves security wep enterprises often enforce security using certificate-based system authenticate connecting device following standard 802.1x many laptop computers wireless cards pre-installed ability enter network mobile great benefits however wireless networking prone security issues hackers found wireless networks relatively easy break even use wireless technology hack wired networks result important enterprises define effective wireless security policies guard unauthorized access important resources wireless intrusion prevention systems wips wireless intrusion detection systems wids commonly used enforce wireless security policies risks users wireless technology increased service become popular relatively dangers wireless technology first introduced hackers yet time latch new technology wireless networks commonly found work place however many security risks associated current wireless protocols encryption methods carelessness ignorance exists user corporate level hacking methods become much sophisticated innovative wireless access hacking also become much easier accessible easy-to-use windows- linux-based tools made available web charge organizations wireless access points installed feel need address wireless security concerns in-stat mdr meta group estimated 95 corporate laptop computers planned purchased 2005 equipped wireless cards issues arise supposedly non-wireless organization wireless laptop plugged corporate network hacker could sit parking lot gather information laptops and/or devices even break wireless card–equipped laptop gain access wired network anyone within geographical network range open unencrypted wireless network sniff capture record traffic gain unauthorized access internal network resources well internet use information resources perform disruptive illegal acts security breaches become important concerns enterprise home networks router security activated owner deactivates convenience creates free hotspot since 21st-century laptop pcs wireless networking built see intel centrino technology n't need third-party adapter pcmcia card usb dongle built-in wireless networking might enabled default without owner realizing thus broadcasting laptop accessibility computer nearby modern operating systems linux macos microsoft windows make fairly easy set pc wireless lan base station using internet connection sharing thus allowing pcs home access internet base pc however lack knowledge among users security issues inherent setting systems often may allow others nearby access connection piggybacking usually achieved without wireless network operator knowledge may even without knowledge intruding user computer automatically selects nearby unsecured wireless network use access point wireless security aspect computer security however organizations may particularly vulnerable security breaches caused rogue access points employee trusted entity brings wireless router plugs unsecured switchport entire network exposed anyone within range signals similarly employee adds wireless interface networked computer using open usb port may create breach network security would allow access confidential materials however effective countermeasures like disabling open switchports switch configuration vlan configuration limit network access available protect network information contains countermeasures must applied uniformly network devices due availability low cost use wireless communication technologies increases domains beyond originally intended usage areas e.g m2m communication industrial applications industrial applications often specific security requirements hence important understand characteristics applications evaluate vulnerabilities bearing highest risk context evaluation vulnerabilities resulting vulnerability catalogs industrial context considering wlan nfc zigbee available wireless networks common organizations individuals many laptop computers wireless cards pre-installed ability enter network mobile great benefits however wireless networking prone security issues hackers found wireless networks relatively easy break even use wireless technology hack wired networks result important enterprises define effective wireless security policies guard unauthorized access important resources wireless intrusion prevention systems wips wireless intrusion detection systems wids commonly used enforce wireless security policies relatively dangers wireless technology first introduced effort maintain communication high effort intrude always higher variety risks users wireless technology increased service become popular technology commonly available today great number security risks associated current wireless protocols encryption methods carelessness ignorance exists user corporate level hacking methods become much sophisticated innovative wireless modes unauthorised access links functions data variable respective entities make use program code exist full scope model threat extent prevention relies known modes methods attack relevant methods suppression applied methods however new mode operation create new options threatening hence prevention requires steady drive improvement described modes attack snapshot typical methods scenarios apply violation security perimeter corporate network come number different methods intents one methods referred “ accidental association ” user turns computer latches wireless access point neighboring company overlapping network user may even know occurred however security breach proprietary company information exposed could exist link one company especially true laptop also hooked wired network accidental association case wireless vulnerability called mis-association mis-association accidental deliberate example done bypass corporate firewall result deliberate attempts wireless clients lure connecting attacker aps “ malicious associations ” wireless devices actively made attackers connect company network laptop instead company access point ap types laptops known “ soft aps ” created cyber criminal runs software makes his/her wireless network card look like legitimate access point thief gained access he/she steal passwords launch attacks wired network plant trojans since wireless networks operate layer 2 level layer 3 protections network authentication virtual private networks vpns offer barrier wireless 802.1x authentications help protection still vulnerable hacking idea behind type attack may break vpn security measures likely criminal trying take client layer 2 level ad hoc networks pose security threat ad hoc networks defined peer peer networks wireless computers access point types networks usually little protection encryption methods used provide security security hole provided ad hoc networking ad hoc network bridge provides networks usually corporate environment unfortunate default settings versions microsoft windows feature turned unless explicitly disabled thus user may even know unsecured ad hoc network operation computer also using wired wireless infrastructure network time providing bridge secured organizational network unsecured ad hoc connection bridging two forms direct bridge requires user actually configure bridge two connections thus unlikely initiated unless explicitly desired indirect bridge shared resources user computer indirect bridge may expose private data shared user computer lan connections shared folders private network attached storage making distinction authenticated private connections unauthenticated ad-hoc networks presents threats already familiar open/public unsecured wifi access points firewall rules may circumvented case poorly configured operating systems local settings non-traditional networks personal network bluetooth devices safe hacking regarded security risk even barcode readers handheld pdas wireless printers copiers secured non-traditional networks easily overlooked personnel narrowly focused laptops access points identity theft mac spoofing occurs hacker able listen network traffic identify mac address computer network privileges wireless systems allow kind mac filtering allow authorized computers specific mac ids gain access utilize network however programs exist network “ sniffing ” capabilities combine programs software allow computer pretend mac address hacker desires hacker easily get around hurdle mac filtering effective small residential soho networks since provides protection wireless device air 802.11 device air freely transmits unencrypted mac address 802.11 headers requires special equipment software detect anyone 802.11 receiver laptop wireless adapter freeware wireless packet analyzer obtain mac address transmitting 802.11 within range organizational environment wireless devices air throughout active working shift mac filtering provides false sense security since prevents casual unintended connections organizational infrastructure nothing prevent directed attack man-in-the-middle attacker entices computers log computer set soft ap access point done hacker connects real access point another wireless card offering steady flow traffic transparent hacking computer real network hacker sniff traffic one type man-in-the-middle attack relies security faults challenge handshake protocols execute “ de-authentication attack ” attack forces ap-connected computers drop connections reconnect hacker soft ap disconnects user modem connect using password one extract recording event man-in-the-middle attacks enhanced software lanjack airjack automate multiple steps process meaning required skill done script kiddies hotspots particularly vulnerable attack since little security networks denial-of-service attack dos occurs attacker continually bombards targeted ap access point network bogus requests premature successful connection messages failure messages and/or commands cause legitimate users able get network may even cause network crash attacks rely abuse protocols extensible authentication protocol eap dos attack little expose organizational data malicious attacker since interruption network prevents flow data actually indirectly protects data preventing transmitted usual reason performing dos attack observe recovery wireless network initial handshake codes re-transmitted devices providing opportunity malicious attacker record codes use various cracking tools analyze security weaknesses exploit gain unauthorized access system works best weakly encrypted systems wep number tools available launch dictionary style attack possibly accepted security keys based model security key captured network recovery network injection attack hacker make use access points exposed non-filtered network traffic specifically broadcasting network traffic “ spanning tree ” 802.1d ospf rip hsrp hacker injects bogus networking re-configuration commands affect routers switches intelligent hubs whole network brought manner require rebooting even reprogramming intelligent networking devices caffe latte attack another way defeat wep necessary attacker area network using exploit using process targets windows wireless stack possible obtain wep key remote client sending flood encrypted arp requests assailant takes advantage shared key authentication message modification flaws 802.11 wep attacker uses arp responses obtain wep key less 6 minutes three principal ways secure wireless network ready designed system prevent fraudulent usage wireless communication protect data functions wirelessly communicating computers entities however system qualifying taken measures whole according common understanding shall seen state art system qualifying international consensus specified iso/iec 15408 wireless intrusion prevention system wips concept robust way counteract wireless security risks however wips exist ready designed solution implement software package wips typically implemented overlay existing wireless lan infrastructure although may deployed standalone enforce no-wireless policies within organization wips considered important wireless security july 2009 payment card industry security standards council published wireless guidelines pci dss recommending use wips automate wireless scanning protection large organizations range wireless security measures varying effectiveness practicality simple ineffective method attempt secure wireless network hide ssid service set identifier provides little protection anything casual intrusion efforts one simplest techniques allow access known pre-approved mac addresses wireless access points contain type mac id filtering however attacker simply sniff mac address authorized client spoof address typical wireless access points provide ip addresses clients via dhcp requiring clients set addresses makes difficult casual unsophisticated intruder log onto network provides little protection sophisticated attacker ieee 802.1x ieee standard authentication mechanisms devices wishing attach wireless lan wired equivalent privacy wep encryption standard original encryption standard wireless since 2004 ratification wpa2 ieee declared deprecated often supported seldom never default modern equipment concerns raised security early 2001 dramatically demonstrated 2005 fbi yet 2007 t.j. maxx admitted massive security breach due part reliance wep payment card industry took 2008 prohibit use even allowed existing use continue june 2010 wi-fi protected access wpa wpa2 security protocols later created address problems wep weak password dictionary word short character string used wpa wpa2 cracked using long enough random password e.g 14 random letters passphrase e.g 5 randomly chosen words makes pre-shared key wpa virtually uncrackable second generation wpa security protocol wpa2 based final ieee 802.11i amendment 802.11 standard eligible fips 140-2 compliance encryption schemes client network knows keys read traffic wi-fi protected access wpa software/firmware improvement wep regular wlan-equipment worked wep able simply upgraded new equipment needs bought wpa trimmed-down version 802.11i security standard developed ieee 802.11 replace wep tkip encryption algorithm developed wpa provide improvements wep could fielded firmware upgrades existing 802.11 devices wpa profile also provides optional support aes-ccmp algorithm preferred algorithm 802.11i wpa2 wpa enterprise provides radius based authentication using 802.1x wpa personal uses pre-shared shared key psk establish security using 8 63 character passphrase psk may also entered 64 character hexadecimal string weak psk passphrases broken using off-line dictionary attacks capturing messages four-way exchange client reconnects deauthenticated wireless suites aircrack-ng crack weak passphrase less minute wep/wpa crackers airsnort auditor security collection still wpa personal secure used ‘ good ’ passphrases full 64-character hexadecimal key information however erik tews man created fragmentation attack wep going reveal way breaking wpa tkip implementation tokyo pacsec security conference november 2008 cracking encryption packet 12–15 minutes still announcement 'crack somewhat overblown media august 2009 best attack wpa beck-tews attack partially successful works short data packets decipher wpa key requires specific wpa implementations order work addition wpav1 tkip wids eap may added alongside also vpn-networks non-continuous secure network connections may set 802.11-standard vpn implementations include pptp l2tp ipsec ssh however extra layer security may also cracked tools anger deceit ettercap pptp ike-scan ikeprobe ipsectrace ikecrack ipsec-connections stands temporal key integrity protocol acronym pronounced tee-kip part ieee 802.11i standard tkip implements per-packet key mixing re-keying system also provides message integrity check avoid problems wep wpa-improvement ieee 802.1x standard already improved authentication authorization access wireless wired lans addition extra measures extensible authentication protocol eap initiated even greater amount security eap uses central authentication server unfortunately 2002 maryland professor discovered shortcomings next years shortcomings addressed use tls enhancements new version eap called extended eap available several versions include eap-md5 peapv0 peapv1 eap-mschapv2 leap eap-fast eap-tls eap-ttls mschapv2 eap-sim eap-versions include leap peap eap leap stands lightweight extensible authentication protocol protocol based 802.1x helps minimize original security flaws using wep sophisticated key management system eap-version safer eap-md5 also uses mac address authentication leap secure thc-leapcracker used break cisco ’ version leap used computers connected access point form dictionary attack anwrap asleap finally crackers capable breaking leap peap stands protected extensible authentication protocol protocol allows secure transport data passwords encryption keys without need certificate server developed cisco microsoft rsa security eaps types extensible authentication protocol implementations based eap framework framework established supports existing eap types well future authentication methods eap-tls offers good protection mutual authentication client network authenticated using certificates per-session wep keys eap-fast also offers good protection eap-ttls another alternative made certicom funk software convenient one need distribute certificates users yet offers slightly less protection eap-tls solutions include newer system authentication ieee 802.1x promises enhance security wired wireless networks wireless access points incorporate technologies like often also routers built thus becoming wireless gateways one argue layer 2 layer 3 encryption methods good enough protecting valuable data like passwords personal emails technologies add encryption parts communication path still allowing people spy traffic gained access wired network somehow solution may encryption authorization application layer using technologies like ssl ssh gnupg pgp similar disadvantage end-to-end method may fail cover traffic encryption router level vpn single switch encrypts traffic even udp dns lookups end-to-end encryption hand service secured must encryption turned often every connection must also turned separately sending emails every recipient must support encryption method must exchange keys correctly web web sites offer https even browser sends ip addresses clear text prized resource often access internet office lan owner seeking restrict access face nontrivial enforcement task user authenticate router newest rigorous security implement wlan today 802.11i rsn-standard full-fledged 802.11i standard uses wpav2 however require newest hardware unlike wpav1 thus potentially requiring purchase new equipment new hardware required may either aes-wrap early version 802.11i newer better aes-ccmp-equipment one make sure one needs wrap ccmp-equipment 2 hardware standards compatible wpa2 wifi alliance branded version final 802.11i standard primary enhancement wpa inclusion aes-ccmp algorithm mandatory feature wpa wpa2 support eap authentication methods using radius servers preshared key psk number wpa wpa2 networks increasing number wep networks decreasing security vulnerabilities wep wpa2 found least one security vulnerability nicknamed hole196 vulnerability uses wpa2 group temporal key gtk shared key among users bssid launch attacks users bssid named page 196 ieee 802.11i specification vulnerability discussed order exploit performed gtk must known attacker unlike 802.1x 802.11i already additional security-services tkip wpav1 wpav2 may work cooperation eap wids stands wlan authentication privacy infrastructure wireless security standard defined chinese government strong form security combined server software hardware software card token use internal identity code combined user entered pin create powerful algorithm frequently generate new encryption code server time synced card token secure way conduct wireless transmissions companies area make usb tokens software tokens smart cards even make hardware versions double employee picture badge currently safest security measures smart cards usb tokens however expensive next safest methods wpa2 wpa radius server one three provide good base foundation security third item list educate employees contractors security risks personal preventive measures also task keep company workers knowledge base up-to-date new dangers cautious employees educated much lower chance anyone accidentally cause breach security locking laptop bring wide open home access point extend mobile range employees need made aware company laptop security extends outside site walls well includes places coffee houses workers vulnerable last item list deals 24/7 active defense measures ensure company network secure compliant take form regularly looking access point server firewall logs try detect unusual activity instance large files went access point early hours morning serious investigation incident would called number software hardware devices used supplement usual logs usual safety measures practical cases apply specialized wall paint window film room building significantly attenuate wireless signals keeps signals propagating outside facility significantly improve wireless security difficult hackers receive signals beyond controlled area enterprise within parking lots dos attacks easy detect however lot difficult stop even detection three common ways stop dos attack black holing one possible way stopping dos attack situation drop ip packets attacker good long-term strategy attackers change source address quickly may negative effects done automatically attacker could knowingly spoof attack packets ip address corporate partner automated defenses could block legitimate traffic partner cause additional problems validating handshake involves creating false opens setting aside resources sender acknowledges firewalls address syn floods pre-validating tcp handshake done creating false opens whenever syn segment arrives firewall sends back syn/ack segment without passing syn segment target server firewall gets back ack would happen legitimate connection would firewall send original syn segment server originally intended firewall n't set aside resources connection syn segment arrives handling large number false syn segments small burden rate limiting used reduce certain type traffic amount reasonably dealt broadcasting internal network could still used limited rate example subtle dos attacks good attack aimed single server keeps transmission lines least partially open communication rate limiting frustrates attacker legitimate users helps fully solve problem dos traffic clogs access line going internet nothing border firewall help situation dos attacks problems community stopped help isp organizations whose computers taken bots used attack firms increasing number mobile devices 802.1x interfaces security mobile devices becomes concern open standards kismet targeted towards securing laptops access points solutions extend towards covering mobile devices also host based solutions mobile handsets pda 802.1x interface security within mobile devices fall three categories wireless ips solutions offer wireless security mobile devices mobile patient monitoring devices becoming integral part healthcare industry devices eventually become method choice accessing implementing health checks patients located remote areas types patient monitoring systems security reliability critical influence condition patients could leave medical professionals dark condition patient compromised order implement 802.11i one must first make sure router/access point well client devices indeed equipped support network encryption done server radius ads nds ldap needs integrated server computer local network access point router integrated authentication server remote server ap's/routers integrated authentication servers often expensive specifically option commercial usage like hot spots hosted 802.1x servers via internet require monthly fee running private server free yet disadvantage one must set server needs continuously set server server client software must installed server software required enterprise authentication server radius ads nds ldap required software picked various suppliers microsoft cisco funk software meetinghouse data open-source projects software includes client software comes built-in windows xp may integrated os using following software remote authentication dial user service radius aaa authentication authorization accounting protocol used remote network access radius originally proprietary later published isoc documents rfc 2138 rfc 2139 idea inside server act gatekeeper verifying identities username password already pre-determined user radius server also configured enforce user policies restrictions well record accounting information connection time purposes billing today almost full wireless network coverage many urban areas infrastructure wireless community network consider future internet already place one could roam around always connected internet nodes open public due security concerns nodes encrypted users n't know disable encryption many people consider proper etiquette leave access points open public allowing free access internet others think default encryption provides substantial protection small inconvenience dangers open access fear may substantial even home dsl router density access points even problem limited number channels available partly overlap channel handle multiple networks places many private wireless networks example apartment complexes limited number wi-fi radio channels might cause slowness problems according advocates open access points n't involve significant risks open wireless networks public hand countries including germany persons providing open access point may made partially liable illegal activity conducted via access point also many contracts isps specify connection may shared persons
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Computer security
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compatibility card compatibility card expansion card computers allows hardware emulation another device popular macintosh systems allowed emulate windows pcs via nubus pci apple computer made many cards including compatibility card apple iie later orange micro made end 1990s greater application availability made cards obsolete besides pc compatibility cards others existed 3do blaster pcs
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Computer architecture
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mutt email client mutt text-based email client unix-like systems originally written michael elkins 1995 released gnu general public license version 2 later version mutt slogan mail clients suck one sucks less mutt supports mail storing formats notably mbox maildir protocols pop3 imap etc. also includes mime support notably full pgp/gpg s/mime integration mutt originally designed mail user agent mua relied locally accessible mailbox sendmail infrastructure according mutt homepage though written scratch mutt initial interface based largely elm mail client new mutt message scoring threading capabilities support fetching sending email via various protocols pop3 imap smtp added later however mutt still relies external tools composing filtering messages mutt hundreds configuration directives commands allows changing key bindings making keyboard macros complex actions well colors layout interface variants concept known hooks many settings changed based criteria current mailbox outgoing message recipients also many patches extensions available add functionality nntp support sidebar similar often found graphical mail clients mutt fully controlled keyboard support mail conversation threading meaning one easily move around long discussions mailing lists new messages composed external text editor default unlike pine embeds editor known pico mutt capable efficiently searching mail stores calling mail indexing tools notmuch many people recommend mutt used way alternatively users search mail stores mutt calling grep via bash script mutt often used security professionals security-conscious users smaller attack surface compared clients ship web browser rendering engine javascript interpreter relation transport layer security mutt configured trust certificates first use use older less secure versions transport layer security protocol
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Internet protocols
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flex operating system flex single-tasking operating system developed technical systems consultants tsc west lafayette indiana motorola 6800 1976 original version 8 floppy disks smaller version 5.25 floppies called mini-flex also later ported motorola 6809 version called flex9 versions text-based intended use display devices ranging printing terminals like teletype model 33 asr smart terminals graphic displays supported tsc software hardware manufacturers supported elementary graphics pointing devices disk-based operating system using 256-byte sectors soft-sectored floppies disk structure used linkage bytes sector indicate next sector file free list directory structure much simplified result tsc others provided several programming languages including basic two flavors standard extended tokenizing version extended basic called pre-compiled basic forth c fortran pascal tsc also wrote version flex smoke signal dos california hardware manufacturer smoke signal broadcasting version used forward back linkage bytes sector increased disk reliability expense compatibility speed later tsc introduced multitasking multi-user unix-like uniflex operating system required dma disk controllers 8 disk sold small numbers several tsc computer languages ported uniflex early 1980s flex offered compusense ltd operating system 6809-based dragon 64 home computer following list commands supported different versions flex operating system
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Operating systems
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thomas e. kurtz thomas eugene kurtz born february 22 1928 retired dartmouth professor mathematics computer scientist along colleague john g. kemeny set motion revolutionary concept making computers freely available college students library books implementing concept time-sharing dartmouth college mission allow non-expert users interact computer co-developed basic programming language beginners all-purpose symbolic instruction code dartmouth time sharing system 1963 1964 native oak park illinois united states kurtz graduated knox college 1950 awarded ph.d. degree princeton university 1956 advisor john tukey joined mathematics department dartmouth college year taught statistics numerical analysis 1983 kurtz kemeny co-founded company called true basic inc. market true basic updated version language kurtz also served council chairman trustee educom well trustee chairman nercomp pierce panel president scientific advisory committee kurtz also served steering committees conduit project ccuc conferences instructional computing 1974 american federation information processing societies gave award kurtz kemeny national computer conference work basic time-sharing 1991 computer society honored kurtz ieee computer pioneer award 1994 inducted fellow association computing machinery 1951 kurtz first experience computing came summer session institute numerical analysis university california los angeles interests included numerical analysis statistics computer science ever since graduated 1950 obtained bachelor degree majoring mathematics 1956 age 28 went acquire phd princeton university thesis problem multiple comparisons mathematical statistics kurtz composed first computer program 1951 working computers ucla institute numerical analysis performed feat finishing grad school one year tuition princeton university 1963 1964 kurtz kemeny developed first version dartmouth time-sharing system time-sharing system university use basic language 1966 1975 kurtz served director kiewit computation center dartmouth 1975 1978 director office academic computing 1980 1988 kurtz director computer information systems program dartmouth ground-breaking multidisciplinary graduate program develop leaders industry subsequently kurtz returned teaching full-time professor mathematics emphasis statistics computer science part dartmouth time-sharing system kemeny kurtz created basic programming language first basic program ran may 1 1964 4 a.m. neither kemeny kurtz thought start something grand merely hoped would help students learn something computers using pair made certain invention immediately dispersed public made real money dartmouth college copyrighted basic however made basic available free anyone wanting use name language originated kurtz ’ wish simple acronym meant something well kurtz states “ wanted word simple simple-minded basic one. ” basic along books published earned lot positive feedback example “ second edition basic programming gives thorough description basic useful beginner also experienced programmer. ” “ overall evaluation basic programming ideal individual wishes program minimum effort equal value group classroom instruction. ” theme basic average computer user stressed kurtz open letter reiterates upon past statements basic invented give students simple programming language easy learn current languages time dedicated professionals went say basic people want dedicate lives programming repetition idea kurtz accentuates even success language wrote would remain implemented masses specialists basic standards created 1980s ecma ansi versions released 1986 1987 respectively basic popularity skyrocketed 1975 pair youngsters harvard dormitory bill gates paul allen created version basic viable one earliest personal computers gates allen ’ version became prominent iterations basic road basic long one kemeny kurtz forged darsimco – dartmouth simplified code – dartmouth ’ inaugural attempt making computing language 1956 however darsimco soon became obsolete language fortran manifested 1962 kemeny dartmouth undergraduate sidney marshall created language dope dartmouth oversimplified programming experiment direct predecessor basic dope little used kurtz preferred trying implement successful languages fortran algol kurtz experience dartmouth algol 30 lgp-30 convinced devising subsets languages quite practical led adopt kemeny ’ notion creating new language entirely although basic widely regarded success many computing professionals thought poor choice larger complicated programs larger programs became confusing messy used “ go ” statement jump one line program another criticism original language unstructured made difficult split programs separate parts improve readability basic structured also hindered ability debug modify parts code limited use larger companies hence largely remained language used smaller programs 1983 response proliferation street basics group graduating dartmouth students persuaded kemeny kurtz offer dartmouth version language commercial product first offering company true basic inc. based dartmouth basic 7 featured modern programming constructs “ if..then..else do..loop exit ” company described product “ simple elegant powerful true basic. “ upon kemeny advice true basic limited single os computer system “ today versions true basic available dos mac os windows unix linux systems ” kurtz retired dartmouth college 1993 continued develop maintain true basic
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Programming language topics
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reverso language tools reverso website specializing online translation aids language services include online dictionaries translation context spell checking conjugation tools softissimo inc. active since 1998 aim providing online translation linguistic tools corporate mass markets 2013 released reverso context bilingual dictionary tool based big data machine learning algorithms 2016 reverso acquired fleex service learning english via subtitled movies based content netflix fleex expanded also include video content youtube ted talks custom video files 2018 released new mobile app combines translations learning activities reverso suite online linguistic services 40 million users comprises various types language web apps tools translation language learning tools support many languages including english french hebrew spanish italian russian since founding reverso provided machine translation tools automated translation texts various languages including neural machine translation reverso context online mobile application combining big data large multilingual corpora allow users search translations context texts sourced mainly films books governmental documents allowing users see idiomatic usages translations well synonyms voice output reverso context app also provides language-learning features flashcards based words example sentences reverso context mobile app 4.7 ranking google play app store reverso also released browser extensions chrome firefox incorporate features reverso context web browsing reverso website also provides collaborative bilingual dictionaries various pairs languages use crowd sourcing allow users submit new entries provide feedback also tools conjugation verbs various language spell checking tools written multilingual grammar guides language learners reverso online localize service translates documents websites preserving layout february 2018 revealed translations reverso translation web site returned antisemitic results much nicer returning dachau much nicer auschwitz results prompted international league racism anti-semitism threaten reverso legal actions reverso answered twitter controversial content would removed one month time
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Computational linguistics
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security-focused operating system list operating systems specifically focused security general-purpose operating systems may secure practice without specifically security-focused similar concepts include security-evaluated operating systems achieved certification auditing organization trusted operating systems provide sufficient support multilevel security evidence correctness meet particular set requirements operating systems engineered around object-capabilities security paradigm instead system deciding access request granted bundling authority designation makes impossible request anything legitimate starting windows server 2008 windows server added installation option called server core traditional graphical user interface installed administration windows server 2008 rely windows command prompt roles components installed individually option reduces windows server footprint result reduced demand system resources reduced number components could potentially exploited via potential security vulnerabilities later windows server 2016 microsoft introduced nano server installation option even reduced footprint headless support locally connected keyboard monitor nano server windows server 1709 constantly updated sibling windows server 2016 installed container
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Operating systems
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ibm http server ibm http server ihs web server based apache software foundation http server runs aix hp-ux linux solaris jade windows nt ibm z/os available download use free charge without ibm support http server also included ibm websphere application server distribution packages default web console administration port 8008 ibm administration port 2001 license agreement ibm http server ibm international license agreement non-warranted programs ilan
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Web technology
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snappii snappii sometimes stylized snappii cloud-based codeless platform rapid mobile app development largely businesses enterprises 2015 company helped produce 26,000 mobile apps 29 different industries 17 languages snappii-produced apps include starbucks location finder public safety app college campuses mobile pdf form uploader snappii used ios android devices snappii founded 2010 alex bakman also serves ceo snappii platform launched 2011 primarily tool iphone app creation company ipad android app creation systems still beta november 2011 2012 snappii added compatibility support android devices also 2012 customers created 6,000th app using snappii platform 2015 snappii released series new features ranging audio video support enhanced charting capabilities also announced new offer called 5 weeks- 5k-guaranteed app guarantees customers custom native app within five weeks 5,000 august 2015 company raised 250,000 investor funding 2015 snappii platform produced around 26,000 applications 17 languages companies 29 different industries snappii offers cloud-based codeless platform developing business enterprise mobile applications ios android devices users including non-programmers create apps using wysiwyg formatting rather source code snappii also create custom native apps clients whether client opts create app enlists help snappii programmers must pay monthly hosting fee snappii helped develop apps companies 29 different industries including health care construction public safety retail oil gas others features snappii platform include audio video support charting capabilities ability upload pdf forms via pdf form manager app
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Distributed computing architecture
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lga 1366 lga 1366 also known socket b intel cpu socket socket supersedes intel lga 775 socket high-end performance desktop segments also replaces server-oriented lga 771 socket j entry level superseded lga 2011 lga stands land grid array socket 1,366 protruding pins touch contact points underside processor cpu accesses three channels ddr3 memory via processor internal memory controller socket 1366 socket b uses qpi connect cpu reduced-function northbridge serves mainly pci-express controller slower dmi used connect intel recent northbridge southbridge components comparison intel socket 1156 socket h moves qpi link pci-express controller onto processor using dmi interface single-component chipset called pch serves traditional southbridge functions difference pin number mostly reflection number memory channels served november 2008 intel released core i7 first processor requiring socket lga 1366 socket processors discontinued sometime 2012 superseded lga 2011 socket 14 november 2011 supporting sandy bridge e-series processors accompanying lga 1156 discontinued time replaced lga 1155 socket b processors following mechanical maximum load limits exceeded heatsink assembly shipping conditions standard use load limits crack processor die make unusable processors using socket lower static load limit previous models using lga 775 available reference heat sinks include circular design heatpipe design chipsets support lga 1366 intel x58 desktop 3400 3420 3450 5500 5520 7500 server
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Computer architecture
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cloudpassage cloudpassage company provides automation platform delivered via software service improves security private public hybrid cloud computing environments cloudpassage headquartered san francisco cloudpassage founded carson sweet talli somekh vitaliy geraymovych 2010 company used cloud computing big data analytics implement security monitoring control platform called halo cloudpassage spent year stealth developing halo technology coming stealth mode closed beta january 2011 june 2012 company launched commercial product included configuration security monitoring network microsegmentation two-factor authentication privileged access management 2013 cloudpassage expanded halo support large enterprises advanced security compliance requirements product called halo enterprise first round venture funding company raised 6.5 million april 2012 cloudpassage raised 14 million financing round led tenaya capital february 2014 cloudpassage announced raised 25.5 million funding led shasta ventures total company invested 30 million technology raised approximately 88 million capital cloudpassage platform provides cloud workload security compliance systems hosted public private cloud infrastructure environments including hybrid cloud multi-cloud workload hosting models flagship product company offers called halo halo secures virtual servers public private hybrid cloud infrastructures provides file integrity monitoring fim also administering firewall automation vulnerability monitoring network access control security event alerting assessment halo platform also provides security applications privileged access management software vulnerability scanning multifactor authentication log-based ids december 2013 cloudpassage set six servers microsoft windows linux operating systems combinations popular programs invited hackers attempt hack servers top prize 5,000 winning hacker novice completed task four hours cloudpassage programmed servers use basic default security settings show vulnerable cloud computing programs security threats may 2011 gigaom named cloudpassage list top 50 cloud innovators month eweek recognized cloudpassage one 16 hot startup companies flying radar sc magazine named cloudpassage industry innovator virtualization cloud security category 2012 also 2012 wall street journal named cloudpassage runner information security category technology innovation awards cloudpassage large-scale security program halo best security solution 2014 siia codie awards
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Computer security
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monopoly 1985 video game monopoly 1985 multi-platform video game based board game monopoly released amiga amstrad cpc bbc micro commodore 64 ms-dos msx tatung einstein thomson mo thomson zx spectrum published leisure genius title one many inspired property game contains similar gameplay board game based various physical tasks replaced automation digital representations computer shopper praised game graphics animation deemed excellent value spectrum thought game excellent conversion board game sinclair user wrote game boring one issue amiga power deemed sound conversion albeit expensive source material another publication said competent arguably quite pointless
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Computer architecture
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mundial de fútbol mundial de fútbol football sports game released amstrad cpc zx spectrum msx ms-dos platforms created 1990 opera soft due internal problems company released celebration 1990 fifa world cup simulation show upper view goals upper lower parts screen players reached tough scroll
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Computer architecture
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