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pelicanhpc pelicanhpc operating system based debian live provides rapid means setting high performance computer cluster pelicanhpc formerly known parallelknoppix
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Operating systems
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redo backup recovery redo backup recovery free backup disaster recovery software runs bootable linux cd image presently ubuntu 12.04 lts features gui front end partclone command line utility capable bare-metal backup recovery disk partitions use external hard drives network shares addition backup software disk includes additional supporting programs
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Computer security
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component-oriented database component-oriented database codb way data administration programming dbms using paradigm component-orientation paradigm component-orientation co development object-orientation oo programming data modeling leading toward extreme possibilities reuse model type classes aggregate cells called components execute role similar function structured programming way processing information contemporary relational database model component-orientation mixes set features predecessor models understanding simpler thinking visual component application deployed executable bytecode otherwise turned linked icon inside another application icon one clicks implements certain tasks concepts extended non-visual components database activities component visual aggragate classes sense oo linked ones adapters oo model conception data code programming code mixed cohesive body difficulties conceiving codb co programming separate one although enigma important conceptual epistemological area practical data processing n't importance question usage mapping models large scale used software like mappings called ordbms crdb component-relational database separation data code still well defined programming activity co often taken place large-scale used oo languages like c++ java mapping adaptation designing paradigm supored uml data modeling data administration database administration mapping adaptation alike ordbms paradigm adapted paradigm component-based models known component-relational database crdb main advantage component-oriented thinking seen early chapters optimization reusability work going far away uses oo models co paradigm allows use ready use applications modules new bigger projects necessary regard technical features achieved traditional oo models although idea component came naturally oo thinking basis support notions oo like encapsulation inheritance polymorphism necessarily leads idea reusing applications modules new works co thinking also assures components fully tested real application thus model paroxism reuse well feature understanability end users corollary app- comp way realizing works even using software present oo paradigm many specific consequences world data-oriented activities analogous way whole models composed classes treated part component new comprehensive model
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Databases
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hybrid-core computing hybrid-core computing technique extending commodity instruction set architecture e.g x86 application-specific instructions accelerate application performance form heterogeneous computing wherein asymmetric computational units coexist commodity processor hybrid-core processing differs general heterogeneous computing computational units share common logical address space executable composed single instruction stream—in essence contemporary coprocessor instruction set hybrid-core computing system contains instructions dispatched either host instruction set application-specific hardware typically hybrid-core computing best deployed predominance computational cycles spent identifiable kernels often seen high-performance computing applications acceleration especially pronounced kernel ’ logic maps poorly sequence commodity processor instructions and/or maps well application-specific hardware hybrid-core computing used accelerate applications beyond currently physically possible off-the-shelf processors lower power cooling costs data center reducing computational footprint i.e. circumvent obstacles power/density challenges faced today commodity processors
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Computer architecture
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optenet optenet global security company provides customers multi-tenant secure web gateway e-mail infrastructure solution primarily carriers managed security service providers mssps large enterprises optenet private company spin-off university navarra engineering faculty san sebastian research centre san sebastian spain provides customers multi-tenant secure web gateway e-mail infrastructure solution primarily carriers managed security service providers mssps large enterprises want create service offerings clients product optenet websecure recently awarded five stars sc magazine ’ web content management group test defining 'solid web security solution optenet named cool vendor gartner innovative multi-tenant technology 2011 gartner report cool vendors communications service provider infrastructure 2011 authored akshay sharma deborah kish
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Computer security
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semaphore flag signaling system computer networking semaphore flag signaling system sfss humorous proposal carry internet protocol ip traffic semaphores semaphore flag signaling system initially described rfc 4824 april fools rfc issued internet engineering task force edited j. hofmueller et al released april fool day 2007 one several april 1 rfcs reference implementation ip sfs done authors rfc within project talking fish email transmitted using smtp semaphore flag signals
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Internet protocols
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optiv cybersecurity company optiv security inc. optiv privately owned information security company based denver colorado november 5 2014 security firms accuvant fishnet security announced would join forces create new company merger would create roughly 1.5 billion information security giant solutions covering nearly every aspect cyberdefense merger completed february 2 2015 company announced previously announced transaction closed new company owned primarily blackstone group private equity firm acquired majority stake accuvant march 2014 april 21 2015 accuvant fishnet security announced plans launch new combined corporate name brand begin conducting business optiv security summer 2015 black hat usa 2015 conference two companies announced completed merger subsequently conducting business optiv security company also launched new brand conference february 1 2017 optiv announced acquired global investment firm kkr mid-2018 optiv moved headquarters newly constructed 40-story 1144 fifteenth tower downtown denver considered primary tenant building
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Computer security
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ubasic ubasic freeware public domain software without source code basic interpreter written yuji kida rikkyo university japan specialized mathematical computing ubasic ready-to-run language need set another advanced language common problem multi-digit math languages runs dos dos box dos shell microsoft windows etc specialized number theory primality testing factoring large integers 2600 digits implementation basic makes easy read programs without extensive study basic language structure syntax close ordinary algebra help files articles lessons beginners ubasic built-in on-line editor several aids debugging show cross references calling lines lines containing variable lists variables/arrays renumber lines change variable names append additional programs trace single step time milliseconds help determine fastest way highly repetitive sections redefine function keys either provide easy one-keypress function prevent standard function accidentally used n't shell dos execute dos command convert single-byte character set double-byte character set much use host computer would likely need aware operating system documents may added modified ubhelp.hlp primality testing aprt-cle 884 digits best run ubasic version 8.8f later 500 digits said take 5 hours pp-200 150 digits takes 16 minutes 486-100 2¼ minutes k6 233 250 digits takes 13½ minutes k6 233 recent machines 10 times faster aprt-cle often algorithm choice testing primality integers within range factoring programs ecmx quite fast find factors number digits low-20s fairly easily mid-20s somewhat less easily upper-20s lower chance success found 30-digit factor finding factors elliptic curve method always chancy larger factors greater number curves tested greater chances success number needed average one sometimes get lucky unlucky increases rapidly size factors always best use fastest machine available ecmx uses accepted standards limits stop working one curve switch next preliminary primality testing finding small factors powers interpreted allows modifying programs restarting using goto middle run even multi-day without losing accumulated data stopping recommended unless program saving data safely somewhere users forgot write way save data quitting perhaps expect find trying prove anything might lose valuable data need something else time freeze current program file later melt long lower memory configuration ubasic line numbers use indentation control structure subroutines user functions passed parameters local variables parameters passed value name user functions subroutines may passed parameters limited labels various options conditional functions users indent much needed much structure wanted spaghetti code mistake consider ubasic modern might inferred reader articles confuse indentation structure n't favor line numbers line numbers allows easy jumping intermediate point routine sometimes save duplicating lines ubasic version 8 high-precision real complex arithmetic 2600 digits prior versions adds exact rational arithmetic arithmetic single-variable polynomials complex rational modulo p coefficients well string handling limited list handling abilities also context-sensitive on-line documentation read ubhelp.doc information file uses ascii printed paper document 2005 help file many errors ten-year project rewrite/correct nearly ready publication probably late summer 2005 new help file new extension '.hlp eventually package name u3d748f* list updates available many changes remain unreported version 8.8 different precision 8.74 still commands documentation new command version 8.8c polyconv converts polynomials modulus=0 modulus=prime formatting specifications warning never test anything important might running suspended somewhere else lockups may expected particularly keyscan see freeze roll melt similar warning ubasic several types arrays logical operators bit operators 4 standard loop structures combined operators call machine language routines increased speed ecmx must know assembly language even understand instructions able write tsr debug enough ubasic used process almost kind data example .wav files process text files convert tabs spaces spaces tabs programs generate tabs actually choke early 2005 internet search turned versions 8.74 32 8.74 16 8.71 4000 16 9.0ze 9.0zc 9.0e 8.8f 32 8.8f 16 8.8f c 8.7e 32 8.7e 16 8.30 32 8.30 16 7.25 32 7.25 16 8.8a 32 8,8a 16 8.8a c 8.8c 32 8.8c 16 8.8c c 8.8e 32 8.8e 16 8.8e c 12 versions 52 known numbers many directly identified 16 32 refer number bits multiplication engine 4000 refers special versions go 4000 digits users may need one generate first 792 bernoulli numbers double index 1584 latest version get 540/1080 c cga machines versions italics recommended users would need 8.8f already using version later 8.74 especially using version later 8.7e strongly advised switch latest version 8.8f programs fancy display example written 8.74 may work 8.8f without considerable rewriting latest versions strip carriage returns/line feeds ascii files programs ubh even one 8.8f need added lines strip program written one version used another version without checking certain programs nfs run experimental version 9.** ppmpx36e version multi-polynomial quadratic sieve needs 8.8f windows versions ubasic came defective ubconst7.dat file check one supplied 8.8f identical switch obtaining latest version ubasic see external links sections many internet math pages language/packages sites following short simple program partition count function although n't many fancier structures real program invented article modern fast athlon calculate partition counts p 0 p 1000 ½ second contrast ½ century first time save result file uncomment line 40 remove leading apostrophe working continued fractions number terms limited available accuracy size term approximate formula 2 decimal fraction digit accuracy term times base ten logarithm term way work safely twice parallel initial input one dithered final several digits least 1 word two calculations give identical terms stop previous term ubasic calculate partition function p 1330521 8.74 p 1361911 4000 digit versions get many essential features consists following
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Programming language topics
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swsusp swsusp software suspend kernel feature/program part power management framework linux kernel default suspend framework kernel 3.8 swsusp helps drive system low power state called suspend actively used providing ability return state suspend called resume restore 3.8 swsusp provides following options suspend details swsusp refer kernel documentation documentation/power/swsusp.txt enable swsusp following selected kernel configuration /dev/resume_partition needs replaced actual swap partition used suspending otherwise resume=/dev/resume_partition given parameter system bootup actual suspend done may check suspend options available cat /sys/power/state depending kernel config show something similar standby mem disk options available disk viewed cat /sys/power/disk depending kernel config show something similar platform shutdown reboot swsusp lacks compression graphical progress indication provided uswsusp
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Operating systems
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desktop cleanup wizard desktop cleanup wizard component included microsoft windows xp operating system aims reduce clutter user desktop environment moving unused shortcuts separate directory called unused desktop shortcuts run shows list shortcuts user select shortcuts move unused desktop shortcuts directory desktop cleanup wizard works scheduled task runs day wizard run 60 days wizard displayed user desktop cleanup wizard also accessible desktop context menu arrange icons sub-menu desktop cleanup wizard scheduled task enabled disabled desktop items configuration screen available desktop tab display properties dialog box windows xp successor windows vista include desktop cleanup wizard windows 7 function integrated system maintenance wizard troubleshooting control panel
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Operating systems
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spoofing attack context information security especially network security spoofing attack situation person program successfully masquerades another falsifying data gain illegitimate advantage many protocols tcp/ip suite provide mechanisms authenticating source destination message thus vulnerable spoofing attacks extra precautions taken applications verify identity sending receiving host ip spoofing arp spoofing particular may used leverage man-in-the-middle attacks hosts computer network spoofing attacks take advantage tcp/ip suite protocols may mitigated use firewalls capable deep packet inspection taking measures verify identity sender recipient message websites especially pornographic paysites allow access materials certain approved login- pages enforced checking referrer header http request referrer header however changed known referrer spoofing ref-tar spoofing allowing users gain unauthorized access materials spoofing also refer copyright holders placing distorted unlistenable versions works file-sharing networks public telephone networks often provide caller id information includes caller number sometimes caller ’ name call however technologies especially voice ip voip networks allow callers forge caller id information present false names numbers gateways networks allow spoofing public networks forward false information since spoofed calls originate countries laws receiver country may apply caller limits laws effectiveness use spoofed caller id information scam sender information shown e-mails codice_1 field spoofed easily technique commonly used spammers hide origin e-mails leads problems misdirected bounces i.e e-mail spam backscatter e-mail address spoofing done quite way writing forged return address using snail mail long letter fits protocol i.e stamp postal code smtp protocol send message done using mail server telnet geolocation spoofing occurs user applies technologies make appear located somewhere actually located common geolocation spoofing use virtual private network vpn dns proxy order user appear located different country state territory actually located according study globalwebindex 49 global vpn users utilize vpns primarily access territorially restricted entertainment content type geolocation spoofing also referred geo-piracy since user illicitly accessing copyrighted materials via geolocation spoofing technology another example geolocation spoofing occurred online poker player california used geolocation spoofing techniques play online poker new jersey contravention california new jersey state law forensic geolocation evidence proved geolocation spoofing player forfeited 90,000 winnings gps spoofing attack attempts deceive gps receiver broadcasting incorrect gps signals structured resemble set normal gps signals rebroadcasting genuine signals captured elsewhere different time spoofed signals may modified way cause receiver estimate position somewhere actually located different time determined attacker one common form gps spoofing attack commonly termed carry-off attack begins broadcasting signals synchronized genuine signals observed target receiver power counterfeit signals gradually increased drawn away genuine signals suggested capture lockheed rq-170 drone aircraft northeastern iran december 2011 result attack gps spoofing attacks predicted discussed gps community previously known example malicious spoofing attack yet confirmed proof-of-concept attack successfully performed june 2013 luxury yacht white rose drachs misdirected spoofed gps signals group aerospace engineering students cockrell school engineering university texas austin students aboard yacht allowing spoofing equipment gradually overpower signal strengths actual gps constellation satellites altering course yacht june 2017 approximately twenty ships black sea complained gps anomalies showing vessels transpositioned miles actual location professor todd humphreys believed likely spoofing attack gps anomalies around putin palace moscow kremlin led researchers believe russian authorities use gps spoofing wherever vladimir putin located affecting maritime traffic since advent software defined radio gps simulator applications made available general public made gps spoofing much accessible meaning performed limited expense modicum technical knowledge different ways prevent gps spoofing department homeland security collaboration national cybersecurity communications integration center nccic national coordinating center communications ncc released paper lists methods prevent type spoofing important recommended use installation operation strategies development opportunities described herein significantly enhance ability gnss receivers associated equipment defend range interference jamming spoofing attacks
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Computer security
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180 video game 180 darts video game released zx spectrum commodore 64 amstrad cpc atari 8-bit family msx player competes 501 darts darts players waiting championship tournament normal darts rules applying subtracting score 501 zero whilst finishing double beginning quarter finals player must win best three match advance tournament win another match semi final stage advance final face world champion jammy jim final match however player needs win one leg win tournament players also compete another human player play round clock throwing darts around dartboard 20 1 within time limit total eight computer-controlled opponents game start match computer randomly selects opponent though jammy jim played final opponents del boy desmond sure shot sidney devious dave limp wrist larry beer belly bill mega mick tactical tel jammy jim time release ratings game favourable spectrum version got 72 rating crash magazine labelled best darts game ever commodore 64 version received 70 rating zzap magazine amstrad version got rating 67 amstrad action game reviewed sinclair user rated game 5 5 stating darts ought boring tedious 180 made funny exciting impressive closet hit game reviewed sinclair rated game 9 10 stating presentation 180 veer toward macho crafty cockney bristow school darts rather gentleman john lowe otherwise little quibble winner across board game reviewed ace stating definitive computer darts game must play arrows micro one get
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Computer architecture
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rogue security software rogue security software form malicious software internet fraud misleads users believing virus computer pay money fake malware removal tool actually introduces malware computer form scareware manipulates users fear form ransomware rogue security software serious security threat desktop computing since 2008 two earliest examples gain infamy addestroyer virtualbouncer often bundled back 2004 rogue security software mainly relies social engineering fraud defeat security built modern operating system browser software install onto victims computers website may example display fictitious warning dialog stating someone machine infected computer virus encourage manipulation install purchase scareware belief purchasing genuine antivirus software trojan horse component users misled installing trojan may disguised rogue security software however propagate onto users computers drive-by downloads exploit security vulnerabilities web browsers pdf viewers email clients install without manual interaction recently malware distributors utilizing seo poisoning techniques pushing infected urls top search engine results recent news events people looking articles events search engine may encounter results upon clicked instead redirected series sites arriving landing page says machine infected pushes download trial rogue program 2010 study google found 11,000 domains hosting fake anti-virus software accounting 50 malware delivered via internet advertising cold-calling also become vector distribution type malware callers often claiming microsoft support another legitimate organization black hat search engine optimization seo technique used trick search engines displaying malicious urls search results malicious webpages filled popular keywords order achieve higher ranking search results end user searches web one infected webpages returned usually popular keywords services google trends used generate webpages via php scripts placed compromised website php scripts monitor search engine crawlers feed specially crafted webpages listed search results user searches keyword images clicks malicious link redirected rogue security software payload websites usually employ third-party services advertising webpages one advertising services compromised may end inadvertently infecting websites using service advertising rogue security software spam messages include malicious attachments links binaries drive-by download sites another common mechanism distributing rogue security software spam emails often sent content associated typical day-to-day activities parcel deliveries taxation documents designed entice users click links run attachments users succumb kinds social engineering tricks quickly infected either directly via attachment indirectly via malicious website known drive-by download usually drive-by download attacks malware installed victim machine without interaction awareness occurs simply visiting website desktop pop-ups pop-under longer regular feature operating systems computer attacked popups appears even user active computer definite red flag installed rogue security software may attempt entice user purchasing service additional software developers rogue security software may also entice people purchasing product claiming give portion sales charitable cause rogue green antivirus example claims donate 2 environmental care program sale made rogue security software overlaps function scareware also sanction ftc increasing effectiveness anti-malware tools since 2006 made difficult spyware adware distribution networks—already complex begin with—to operate profitably malware vendors turned instead simpler profitable business model rogue security software targeted directly users desktop computers rogue security software often distributed highly lucrative affiliate networks affiliates supplied trojan kits software paid fee every successful installation commission resulting purchases affiliates become responsible setting infection vectors distribution infrastructure software investigation security researchers antivirus xp 2008 rogue security software found affiliate network members grossing commissions upwards usd150,000 10 days tens thousands successful installations law enforcement legislation countries slow react appearance rogue security software even though simply uses new technical means carry mainly old well-established kinds crimes contrast several private initiatives providing discussion forums lists dangerous products founded soon appearance first rogue security software reputable vendors kaspersky also began provide lists rogue security software 2005 anti-spyware coalition founded coalition anti-spyware software companies academics consumer groups many private initiatives first less informal discussions general internet forums started even entirely carried individual people perhaps famous extensive one spyware warrior list rogue/suspect antispyware products websites eric howes however updated since may 2007 website recommends checking following websites new rogue anti-spyware programs however really new simply re-branded clones knockoffs rogue applications around years december 2008 us district court maryland—at request ftc—issued restraining order innovative marketing inc kiev-based firm producing marketing rogue security software products winfixer winantivirus drivecleaner errorsafe xp antivirus company us-based web host bytehosting internet hosting services llc assets frozen barred using domain names associated products advertisement false representation law enforcement also exerted pressure banks shut merchant gateways involved processing rogue security software purchases cases high volume credit card chargebacks generated purchases also prompted processors take action rogue security software vendors
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Computer security
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netdynamics application server netdynamics application server early java-based integrated software platform product developed netdynamics silicon valley start-up company founded 1995 zack rinat ofer ben-shachar unlike early application server competitors netdynamics chose java development language platform java became dominant development language web-based applications netdynamics experienced significant revenue growth 1997 1998 however product soon encountered problems due relative immaturity java rush release new product versions rapidly changing marketplace believing new jdbc api immature netdynamics created proprietary database development api based product rogue wave software netdynamics inc. acquired sun microsystems july 1998 application server software together netscape application server basis sun iplanet application server offering netdynamics initially competed bluestone application server based c programming language kiva application server mid-1998 new competitor weblogic inc. released java application server compliant jdbc another emerging standard javabeans weblogic application server eventually marketplace explosive growth application server business caught attention larger information technology companies 1998 early application server start-up companies acquired hewlett-packard purchased bluestone sun microsystems acquired netdynamics netscape communications corporation bought kiva weblogic acquired bea systems weblogic continues survive product oracle corporation acquired bea 2008 product renamed oracle weblogic
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Web technology
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conversion funnel conversion funnel phrase used e-commerce describe journey consumer takes internet advertising search system navigating e-commerce website finally converting sale metaphor funnel used describe way users guided goal fewer navigation options step using metaphor advertising efforts aimed upper funnel middle funnel lower funnel potential customers typically large number customers search product/service register page view referring page linked e-commerce site banner ad ad network conventional link small proportion seeing advertisement link actually click link metric used describe ratio click-through rate ctr represents top level funnel typical banner advertising click-through rates 0.02 late 2010 decreased past three years click-through rates highly sensitive small changes link text link size link position many others effects interact cumulatively process understanding creative material brings highest click-through rate known ad optimization link clicked visitor referring page enters e-commerce site small proportion visitors typically proceed product pages creating constriction metaphorical funnel step visitor takes reduces number visitors typically 30 –80 per page adding product shopping cart registering filling contact details payment reduce numbers step-by-step cumulatively along funnel steps fewer visitors get becoming paying customers reason sites similar pricing products hugely different conversion rates visitors customers therefore greatly differing profits
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Web technology
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cyber threat intelligence integration center cyber threat intelligence integration center ctiic new united states federal government agency fusion center existing agencies private sector real-time use cyber attacks ctiic created due blocked efforts congress stymied liability privacy concerns citizens ctiic formally announced lisa monaco february 10 2015 wilson center agency within office director national intelligence tonya ugoretz br january 7 2016 march 13 2019 erin joe march 13 2019 present
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Computer security
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postcode plants database postcode plants database uk resource identifying locally native plants species based postcode hosted natural history museum london used determine plant conservation schemes also information relationships plants associated animals
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Databases
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archive bit archive bit file attribute used cp/m microsoft operating systems os/2 amigaos used indicate whether file backed archived windows os/2 file created modified archive bit set i.e turned file backed archive bit cleared i.e turned thus meaning archive bit file archived cp/m meaning inverted creating modifying file clears archive bit bit set file backed incremental backup task may use archive bit distinguish files already backed select new modified files backup backup software may provide option full backup clearing archive bits – back files regardless archive bit status clear archive bit files processed backup allows creation initial full backup supplemented incremental backups future operating system never clears archive bit unless explicitly told user even user explicitly tells operating system copy file purpose archiving archive bit still cleared specific command clearing setting bit must executed ms-dos well nearly versions windows archive bit status viewed changed attrib command-line utility viewing properties file windows shell windows explorer archive bit status also viewed changed getfileattributes getfileattributesex setfileattributes windows apis archive bit set cleared attributes property vbscript jscript file clear archive bit moved one place file system another archive bit reverts set typically computer system never backed manner clears archive bits files computer archive bits set applications make use archive bits without user request archive bit file attribute part file contents file remain unchanged status archive bit changes relying archive bit backing files unreliable multiple backup programs setting clearing archive bit volume another possibility use timestamp last change file directory typically technique used unix-like operating systems
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Computer file systems
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aptana aptana inc. company makes web application development tools use variety programming languages javascript ruby php python aptana main products include aptana studio aptana cloud aptana jaxer aptana studio open-source integrated development environment ide building web applications based eclipse supports javascript html dom css code-completion outlining javascript debugging error warning notifications integrated documentation additional plugins allow aptana studio support ruby rails php python perl adobe air apple iphone nokia wrt web runtime aptana studio available standalone windows mac os x linux plugin eclipse aptana studio 3 provides following support php application development 2.0 version aptana provide php plugin transferred development efforts pdt project aptana version 1.5 provided support developing php applications via add-on php plugin included aptana studio supports ruby rails development using radrails open source plugin ruby rails framework includes aptana studio provides support python form pydev plugin provides following advantages aptana announced previously commercial pydev extensions open sourced aptana ide provides considerable support adobe air nokia web runtime provides support developing rich mobile apps nokia s60 series phones includes 30 models tens millions units use around world nokia wrt plug-in aptana studio provides features enable creation editing testing deployment wrt widgets within aptana studio wrt widgets small task-focused web applications installed run way s60 applications wrt widgets allow websites web services optimised use s60 devices easy develop use wrt widgets ideal driving traffic website s60 devices aptana studio comes following javascript libraries added updated desired code assist similar completing code statements presenting pop-up either applies built-in functions/methods already coded — latter use requires documenting functions/methods scriptdoc documentation dialect similar used javadoc code assist feature includes information browser support javascript methods/properties html elements css properties support uploading downloading synchronization using ftp sftp pro community editions support integrated javascript debugging firefox internet explorer supported pro edition aptana studio available open source community edition previously available features paid-for pro edition merged community edition features pro part standard community edition studio thus aptana ceased exist multiple edition ide aptana uses dual licensing model model users may choose use aptana ide free software/open source gnu general public license commonly known gpl aptana public license known apl gpl license aptana ide available free charge long redistribution aptana ide adheres terms gpl license users may download software free modify integrate distribute aptana also offers simplified apl license organizations n't need redistribute aptana studio derivatives outside company aptana currently led paul colton founder ceo uri sarid cto/vp engineering kevin hakman director evangelism staff headcount surpassed 25 september 1 2008 aptana active participant openajax alliance hakman serving director ide working group aptana acquired appcelerator inc. january 7 2011 employees aptana absorbed mountain view campus appcelerator work scheduled continue release aptana 3.0 appcelerator webcast made users aware intention integrate mobile application framework aptana studio planned beta within q1 2011 emphasis visual workflow indicated products continued support continue existing aptana products appcelerator put jaxer github aptana jaxer made obsolete node.js open-source ajax web server building rich web pages applications using unified ajax model wherein client-side server-side code written javascript jaxer server-side engine based mozilla gecko browser engine used firefox mozilla engine allows jaxer provide server-side dom page may manipulated server-side processing using techniques familiar client-side programmers jaxer server-side javascript apis enable database access file system access network communications user sessions functions typical web application servers jaxer also provides access java objects via open source dwr project jaxer github aptana jaxer provides page-processing environment based mozilla engine provides gecko-based dom spidermonkey javascript engine allow pages rendered manipulated server sent browser jaxer also provides ajax model performing asynchronous requests server client server apis allow requests made simply calling server-side javascript functions client behind scenes jaxer provides logic required manage request retrieve response server useful web scraping jaxer standalone web server works another server apache jetty tomcat jaxer provides server-side dom api processing pages served web server delivering results browser jaxer may integrated aptana studio via optional plugin open source gpl available windows mac os x linux/solaris november 2009 aptana significantly scaled back development support jaxer aptana representative noted n't sufficient adoption make money earning proposition aptana cloud connect aptana web hosting application management service cloud connect provides infrastructure required host applications developed using technologies supported aptana studio primarily based apache support general web/ajax php ruby rails jaxer cloud connect also supports java-based web applications may deployed managed using cloud service applications hosted cloud connect may developed offline deployed managed directly using cloud management features included aptana studio cloud connect service also provides team management hosted source control using subversion remote editing/preview application synchronization local staging production environments
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Distributed computing architecture
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hypersparc hypersparc code-named pinnacle microprocessor implements sparc version 8 instruction set architecture isa developed ross technology cypress semiconductor hypersparc introduced 1993 competed sun microsystems supersparc raju vegesna microarchitect hypersparc sun microsystem primary competitor mid-1990s fujitsu acquired ross cypress hypersparc considered important new owner sparc64 developed hal computer systems also fujitsu subsidiary view shared analysts hypersparc two-way superscalar microprocessor four execution units integer unit floating-point unit load/store unit branch unit hypersparc on-die 8 kb instruction cache two instructions fetched per cycle decoded decoder could decode new instructions previously decoded instructions issued execution units integer register file contained 136 registers providing eight register windows feature defined sparc isa two read ports integer unit four-stage pipeline two stages added pipeline would equal non-floating-point pipelines integer multiply divide instructions added v8 version sparc architecture 18- 37-cycle latency respectively stalled pipeline completed microprocessor supported multiprocessing mbus systems hypersparc consists 1.2 million transistors fabricated cypress 0.65 µm two-layer metal complementary metal–oxide–semiconductor cmos process later iterations hypersparc transistors due new features ported newer processes fabricated fujitsu except last iteration fabricated nec hypersparc multi-chip design packaged ceramic multi-chip module mcm pin grid array pga hypersparc used cypress sparcset chipset introduced late july 1992 developed santa clara california start-up nimbus technologies inc. cypress fabricated design sparcset also compatible sparc microprocessors
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Computer architecture
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microsoft windows library files microsoft windows operating system supports form shared libraries known dynamic-link libraries code libraries used multiple processes one copy loaded memory article provides overview core libraries included every modern windows installation top windows applications built hal.dll kernel-mode library file used user-mode program ntdll.dll used programs dependency win32 libraries used programs windows hardware abstraction layer hal implemented hal.dll hal implements number functions implemented different ways different hardware platforms context refers mostly chipset components operating system call functions way platforms without regard actual implementation example responding interrupt quite different machine advanced programmable interrupt controller apic one without hal provides single function purpose works kinds interrupts various chipsets components need concerned differences hal loaded kernel address space runs kernel mode routines hal called directly applications user mode apis correspond directly hal routines instead hal provides services primarily windows executive kernel kernel mode device drivers although drivers hardware contained files commonly file type .sys core drivers compiled hal.dll kernel mode device drivers devices buses pci pci express directly call routines hal access i/o ports registers devices drivers use hal routines different platforms may require different implementations operations hal implements operations appropriately platform driver executable file used platforms using cpu architecture driver source file portable across architectures x86 systems several different hal files installation media windows installation procedure determines ones appropriate current platform copies hard drive renaming hal.dll necessary among criteria selection presence acpi-compatible bios presence apic whether multiple processors present enabled multiple cores multi-core cpu even logical processors implemented hyperthreading cpu count processors purpose x86-64 itanium platforms one possible hal.dll cpu architecture ntdll.dll exports windows native api native api interface used user-mode components operating system must run without support win32 api subsystems api implemented ntdll.dll upper edge ntoskrnl.exe variants majority exported symbols within libraries prefixed nt example ntdisplaystring native apis also used implement many kernel apis base apis exported kernel32.dll large majority windows applications call ntdll.dll directly applications linked directly library said use native subsystem primary reason existence perform tasks must run early system startup sequence win32 subsystem available obvious important example creation win32 subsystem process csrss.exe csrss.exe process exists win32 processes may created therefore process creates smss.exe session manager must use native subsystem csrss.exe application despite .exe file extension native applications executed user program win32 subsystems example autochk.exe binary runs chkdsk system initialization blue screen prominent examples services implement various subsystems csrss.exe unlike win32 applications native applications instantiate within kernel runtime code ntoskrnl.exe must different entry point ntprocessstartup rather w win maincrtstartup found win32 application obtain command-line arguments via pointer in-memory structure manage memory using rtl heap api win32 heap apis wrappers around—no real difference return execution call ntterminateprocess opposed exitprocess common library linked native applications nt.lib contains startup code native applications similar c runtime provides startup code win32 apps though api undocumented native applications built using windows driver development kit many antivirus software utility software vendors incorporate native applications within products usually perform boot-time task carried userspace libraries section implement various subsets win32 api kernel32.dll exposes applications win32 base apis memory management input/output i/o operations process thread creation synchronization functions many implemented within kernel32.dll calling corresponding functions native api exposed ntdll.dll gdi32.dll exports graphics device interface gdi functions perform primitive drawing functions output video displays printers used example xp version paint applications call gdi functions directly perform low-level drawing line rectangle ellipse text output font management similar functions initially gdi supported 16 256 color ega/vga display cards monochrome printers functionality expanded years includes support things like truetype fonts alpha channels multiple monitors user32.dll implements windows user component creates manipulates standard elements windows user interface desktop windows menus thus enables programs implement graphical user interface gui matches windows look feel programs call functions windows user perform operations creating managing windows receiving window messages mostly user input mouse keyboard events also notifications operating system displaying text window displaying message boxes many functions user32.dll call upon gdi functions exported gdi32.dll actual rendering various elements user interface types programs also call gdi functions directly perform lower-level drawing operations within window previously created via user32 functions comctl32.dll implements wide variety standard windows controls file open save save dialogs progress bars list views calls functions user32.dll gdi32.dll create manage windows ui elements place various graphic elements within collect user input comdlg32.dll common dialog box library implements wide variety windows dialog boxes intended perform microsoft deems 'common application tasks starting release windows vista microsoft considers open save dialog boxes provided library deprecated replaced 'common item dialog api ws2_32.dll implements winsock api provides tcp/ip networking functions provides partial broken compatibility network apis wsock.dll wsock32.dll older versions win3.11 win95 compatibility advapi32.dll provides security calls functions manipulating windows registry netapi32.dll provides functions querying managing network interfaces ole32.dll provides component object model well object linking embedding shscrap.dll part object linking embedding ole mechanism implements support shell scrap files automatically created drag selected content ole-capable application explorer window desktop also use object packager create dragged another ole-capable application functionality removed windows vista therefore later versions improve security rid operating system generally unused functionality scrap .shs files used viruses contain wide variety files including executable code file extension shown even hide file extensions known file types disabled functionality restored copying registry entries dll windows xp system winmm.dll provides access original winmm audio api imm32 responsible invoking interacting input method editor msvcrt.dll c standard library visual c++ msvc compiler version 4.2 6.0 provides programs compiled versions msvc standard c library functions include string manipulation memory allocation c-style input/output calls others msvcp*.dll corresponding c++ library shipped windows versions since windows 95 osr2 use windows components earlier versions shipped crtdll.dll library instead older versions windows programs linked msvcrt.dll expected install compatible copy system32 folder contributed dll hell many installers failed check library version installed version replacing versions msvc 4.0 7.0 13.0 used differently named dlls version msvcr20.dll msvcr70.dll msvcr71.dll msvcp110.dll etc. applications required install appropriate version microsoft offers visual c++ redistributable packages purpose though windows typically comes one version already installed version 14.0 c/c++ runtime moved new dll ucrtbase.dll however c/c++ programs using ucrtbase.dll forced link another new dll vcruntime whose name continues change version msvc e.g vcruntime140.dll source code runtime libraries included visual c++ reference debugging e.g codice_1 runtime library used programs written visual c++ compilers e.g mingw compilers runtime libraries programs written c visual basic.net c++/cli .net languages require .net framework many libraries one mscorlib.dll multilanguage standard common object runtime library formerly microsoft common object runtime library so-called assemblies e.g system.windows.forms.dll
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Operating systems
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windows installer windows installer previously known microsoft installer codename darwin software component application programming interface api microsoft windows used installation maintenance removal software installation information optionally files packaged installation packages loosely relational databases structured com structured storages commonly known msi files default filename extensions windows installer contains significant changes predecessor setup api new features include gui framework automatic generation uninstallation sequence windows installer positioned alternative stand-alone executable installer frameworks older versions installshield nsis introduction windows store microsoft encouraged third parties use windows installer basis installation frameworks synchronize correctly installers keep internal database installed products consistent important features rollback versioning depend consistent internal database reliable operation furthermore windows installer facilitates principle least privilege performing software installations proxy unprivileged users package describes installation one full products universally identified guid product made components grouped features windows installer handle dependencies products single installed working program set programs product product identified unique guid productcode property providing authoritative identity throughout world guid combination version number productversion property allows release management product files registry keys package includes package logic metadata relates package executes running example changing exe file product may require productcode productversion changed release management however merely changing adding launch condition product remaining exactly previous version would still require packagecode change release management msi file feature hierarchical group components feature may contain number components sub-features smaller packages consist single feature complex installers may display custom setup dialog box user select features install remove package author defines product features word processor example might place program core file one feature program help files optional spelling checker stationery modules additional features component basic unit product component treated windows installer unit installer install part component components contain program files folders com components registry keys shortcuts user directly interact components components identified globally guids thus component shared among several features package multiple packages ideally use merge modules key path specific file registry key odbc data source package author specifies critical given component file common type key path term key file commonly used component contain one key path component explicit key path component destination folder taken key path msi-based program launched windows installer checks existence key paths mismatch current system state value specified msi package e.g. key file missing related feature re-installed process known self-healing self-repair two components use key path user interface phase typically queries target system displays installation wizard enables user change various options affect installation however user interface sequence make changes system following reasons user clicks install button typical msi installation wizard installation proceeds execute phase software components actually installed execute phase makes system changes display user interface elements execute phase happens two steps installation operations transactional words operation windows installer performs generates equivalent undo operation would revert change made system case script action fails deferred execution operation cancelled user actions performed point rolled back restoring system original state standard windows installer actions automatically write information rollback script package authors create custom actions change target system also create corresponding rollback actions well uninstall actions uninstallation-rollback actions design feature applied correctly mechanism also roll back failed uninstall application good working state windows installer advertise product rather actually install product appear installed user actually installed run first time triggering entry point means start menu shortcut opening document product configured handle invoking advertised com class package advertised administrator using group policy deployment mechanism running msiexec executable /jm per-machine advertisement /ju per-user advertisement switch msi packages authored installshield may prevent use native msi features user must administrator privileges complete advertised installation similar advertising installs feature soon user tries use administrative installation creates uncompressed source image product typically used installing running application network location administrative installation typical installation create shortcuts register com servers create add remove programs entry often administrative installation enables user install product way features run uncompressed installation source administrative installations also useful creating windows installer patch requires uncompressed images earlier current versions product order compute binary file differences administrative installation performed running msiexec executable /a switch developer installer package may write code serve purpose delivered dll exe vbscript javascript executed installation sequences including user clicks button user interface installexecutesequence custom actions typically validate product license keys initialize complex services developers normally provide inverse custom actions use uninstall msiexec provides way break loading specified custom action dll invoking action windows installer package may contain another package installed time ideally provided .msm file component may also separate executable program unpacked installer package installexecutesequence run immediately file optionally deleted end installexecutesequence ideal using older installers .msm file component called microsoft merge module utilized single integrate common components contains images tables relevant information regarding common components ready-made merge modules supplied visual studio downloaded alternative sources windows installer 4.0 shipped windows vista incorporates capabilities take advantage user account control feature application install without elevated privileges msi package marked thus allowing install without prompting user administrator credentials windows installer also works conjunction restart manager installing updating application system component full user interface mode user displayed list affected applications shut restarted files updated installer actions running silent mode perform application restarts automatically system services tray applications also restarted manner creating installer package new application trivial necessary specify files must installed registry keys non-standard operations done using custom actions typically developed dlls number commercial freeware products assist creating msi packages including visual studio vs 2010 installshield wix varying degrees user interface behavior may configured use less common situations unattended installation prepared installer package compiled reading instructions files developer local machine creating .msi file user interface dialog boxes presented start installation changed configured setup engineer developing new installer limited language buttons text fields labels arranged sequence dialogue boxes installer package capable running without ui called unattended installation microsoft provides set internal consistency evaluators ice used detect potential problems msi database ice rules combined cub files stripped-down msi files containing custom actions test target msi database contents validation warnings errors ice validation performed platform sdk tools orca msival2 validation tools ship various authoring environments example ice rules addressing ice validation warnings errors important step release process october 2018 microsoft released msix packaging tool successor msi
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Operating systems
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compaq presario 1700 compaq presario 1700 notebook pc first manufactured compaq 1999 notable intel processors 8 mb 8 mib mobility rage m1 graphics chip relatively large screen coupled thin light casing allowed balance power portability especially given quoted 3 hour battery life made notebook especially popular business users inclusion ati rage m1 graphics chip allowed 1700 compete closely high-end notebooks higher price ranges heightened attraction business market system could comfortably run high-demand applications relative ease lightweight portable form
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Computer architecture
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veeva systems veeva systems inc. cloud-computing company focused pharmaceutical life sciences industry applications headquartered pleasanton california founded 2007 peter gassner matt wallach works software service global life science industry company went public 2013 march 28 2018 market capitalization usd 10 billion 2015 veeva acquired zinc ahead content management software company
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Distributed computing architecture
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luis villa luis villa american attorney programmer worked deputy general counsel senior director community engagement wikimedia foundation previously attorney mozilla worked revision mozilla public license mpl continued work next job greenberg traurig part team defending google oracle claims concerning android prior graduating columbia law school 2009 employee ximian acquired novell 2003 spent year senior geek residence harvard berkman center internet society working stopbadware.org elected four times board gnome foundation editor-in-chief columbia science technology law review blogs regularly director open source initiative april 2012 march 2015
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Operating systems
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windows display driver model windows display driver model wddm graphic driver architecture video card drivers running microsoft windows versions beginning windows vista replacement previous windows 2000 windows xp display driver model xddm/xpdm aimed enabling better performance graphics new graphics functionality stability display drivers windows vista windows 7 choose either adhere wddm xddm removal xddm windows 8 however wddm became option wddm provides functionality required render desktop applications using desktop window manager compositing window manager running top direct3d also supports new dxgi interfaces required basic device management creation wddm specification requires least direct3d 9-capable video card display driver must implement device driver interfaces direct3d 9ex runtime order run legacy direct3d applications may optionally implement runtime interfaces direct3d 10 higher wddm drivers enable new areas functionality uniformly provided earlier display driver models include context graphics virtualization means individual processes user mode see memory adjacent processes even means insertion forged commands command stream wddm drivers allow video memory virtualized video data paged video memory system ram case video memory available turns insufficient store video data textures currently unused data moved system ram disk swapped data needed fetched back virtualization could supported previous driver models xp driver model extent responsibility driver instead handled runtime level runtime handles scheduling concurrent graphics contexts list commands put queue execution gpu preempted runtime critical task arrives begun execution differs native threads cpu one task interrupted therefore take longer necessary make computer appear less responsive hybrid scheduling algorithm native light threads cooperation threads would achieve seamless parallelism important note scheduling new concept previously responsibility individual driver developers wddm attempts unify experience across different vendors controlling execution gpu tasks direct3d graphics surface memory area contains information textured meshes used rendering 2d 3d scene wddm allows direct3d surfaces shared across processes thus application incorporate mesh created another application scene rendering sharing textures processes wddm difficult would required copying data video memory system memory back video memory new device wddm driver hangs encounters fault graphics stack restart driver graphics hardware fault intercepted necessary driver reset drivers windows xp free deal hardware faults saw fit either reporting user attempting recover silently wddm driver hardware faults cause driver reset user notified popup unifies behavior across vendors previous drivers fully implemented kernel mode whereas wddm implemented partly user mode user mode area fails unrecoverable error cause application quit unexpectedly instead producing blue screen error would previous driver models wddm also allows graphics hardware reset users update drivers without requiring reboot new driver model requires graphics hardware shader model 2.0 support least since fixed function pipeline translated 2.0 shaders however according microsoft 2009 1–2 percent hardware running windows vista used xddm rest already wddm capable also requires hardware features consequently sm 2.0-supporting hardware intel gma 900 fails wddm certification one limitations wddm driver model version 1.0 support multiple drivers multi-adapter multi-monitor setup multi-monitor system one graphics adapter powering monitors adaptors must use wddm driver one driver used windows disable one wddm 1.1 limitation wddm 1.0/1.1 allow modes previously handled driver spanning mode stretching desktop across two monitors although dual view still available one chief scenarios windows display driver model enables desktop window manager since desktop application windows managed dwm direct3d applications number open windows directly affects amount video memory required limit number open windows video memory available may prove insufficient necessitating virtualization window contents dwm composes final desktop generated different processes cross-process surface sharing necessary also directx applications running alongside dwm dwm-managed desktop must able access gpu shared manner necessitating scheduling though true microsoft implementation composited desktop windows vista hand composited desktop need theoretically require new display driver model work expected successful implementations composited desktops done windows vista platforms quartz compiz windowfx approach microsoft attempted try make sure wddm unified experience across different gpus multiple vendors standardizing features performance software features missing driver models could made immaterial extensions less restrictive simply different driver model place windows vista introduced wddm 1.0 new display driver architecture designed better performing reliable support new technologies including hdcp hybrid sleep combines hibernation sleep mode functionality enhanced stability event power failure also requires wddm windows 7 supports major additions wddm known wddm 1.1 details new version unveiled winhec 2008 new features include hardware acceleration gdi direct2d/directwrite operations helps reduce memory footprint windows 7 dwm compositing engine longer needs keep system memory copy surfaces used gdi/gdi+ windows vista dxgi 1.1 direct3d 11 direct2d directwrite made available windows vista platform update however gdi/gdi+ vista continues rely software rendering desktop window manager continues use direct3d 9ex wddm 1.1 drivers backward compatible wddm 1.0 specification 1.0 1.1 drivers used windows vista without platform update windows 8 includes wddm 1.2 dxgi 1.2 new features first previewed build 2011 conference include performance improvements well support stereoscopic 3d rendering video playback major features include preemptive multitasking gpu finer granularity dma buffer primitive triangle pixel instruction-level reduced memory footprint improved resource sharing faster timeout detection recovery 16-bit color surface formats 565 5551 4444 mandatory windows 8 direct3d 11 video supports yuv 4:4:4/4:2:2/4:2:0/4:1:1 video formats 8 10 16-bit precision well 4 8-bit palettized formats wddm 1.2 supports display-only render-only wddm drivers microsoft basic display driver warp-based microsoft basic render driver replaced kernel-mode vga driver wddm 1.0/1.1 allows rudimentary task scheduling using batch queue granularity improvements multitasking well fast context switching support virtual memory initially expected versions tentatively named wddm 2.0 wddm 2.1 announced winhec 2006 windows 8.1 includes wddm 1.3 dxgi 1.3 new additions include ability trim dxgi adapter memory usage multi-plane overlays overlapping swap chains swap chain scaling select backbuffer subregion swap chain lower-latency swap chain presentation driver feature additions include wireless displays miracast yuv format ranges cross-adapter resources gpu engine enumeration capabilities graphics kernel performance improvements windows 10 includes wddm 2.0 designed dramatically reduce workload kernel-mode driver gpus support virtual memory addressing allow multithreading parallelism user-mode driver result lower cpu utilization windows 10 also includes dxgi 1.4 direct3d 12 api announced build 2014 requires wddm 2.0 new api away automatic resource-management pipeline-management tasks allow developers take full low-level control adapter memory rendering states display driver model windows 8.1 windows phone converged unified model windows 10 new memory model implemented gives gpu per-process virtual address space direct addressing video memory still supported wddmv2 graphics hardware requires considered legacy case ihvs expected develop new hardware supports virtual addressing significant changes made ddi enable new memory model windows 10 anniversary update version 1607 includes wddm 2.1 supports shader model 6.0 mandatory feature levels 12_0 12_1 dxgi 1.5 supports hdr10 10-bit high dynamic range wide gamut format defined itu-t rec 2100/rec.2020 variable refresh rates windows 10 creators update version 1703 includes wddm 2.2 tailored virtual augmented mixed reality stereoscopic rendering windows mixed reality platform dxgi 1.6 windows 10 fall creators update version 1709 includes wddm 2.3 following list new features windows display driver development windows 10 version 1709 windows 10 april 2018 update version 1803 includes wddm 2.4 following updates display driver development windows 10 version 1803 since introduction windows 10 april 2018 update due changes wddm became possible use dual graphics laptops example allows run programs games powerful video card display image via built-in graphics directly internal pci-e external bus without connect monitor powerful video card also act solution problem vga video output video card present motherboard windows 10 october 2018 update version 1809 includes wddm 2.5 updates display driver development windows 10 version 1809 include following windows 10 may 2019 update version 1903 includes wddm 2.6 super-wet ink feature revolves around front-buffer rendering ihv drivers support creation “ displayable ” textures formats modes supported hardware allocating texture app requested along “ shadow ” texture format/layout displayed copying two present-time “ shadow ” may necessarily texture normal way think may compression data additionally may required exist may optimization instead runtime evolve understand aspects displayable surfaces whether shadow must exist display particular vidpnsource/plane whether optimal shadow exist transfer contents application surface shadow surface runtime explicit operation opposed implicit within present request setting mode dynamically flipping original shadow surfaces scanout may begin shortly vblank scans vertically top bottom image completes shortly next vblank always case depending timing pixel clock layout data texture especially actually compression available new ddis added separate understand transformations occur prior scanout order possible enable front-buffer rendering variable rate shading coarse pixel shading mechanism enable allocation rendering performance/power varying rates across rendered images previous model order use msaa multi-sample anti-aliasing reduce geometric aliasing amount reduce geometric aliasing needs known up-front target allocated amount reduce geometric aliasing ’ changed target allocated wddm 2.6 new model extends msaa opposite coarse pixel direction adding new concept coarse shading shading performed frequency coarser pixel group pixels shaded single unit result broadcast samples group coarse shading api allows apps specify number pixels belong shaded group coarse pixel size varied render target allocated different portions screen different draw passes different course shading rates multiple-tier implementation available two user-queryable caps tiers 1 2 coarse shading available single-sampled msaa resources msaa resources shading performed per-coarse-pixel per-sample usual however tiers 1 2 msaa resources coarse sampling used shade frequency per-pixel per-sample tier 1 shading rate specified per-draw-basis nothing granular shading rate applies uniformly drawn independently lies within render target tier 2 shading rate specified per-draw-basis tier 1 also specified combination per-draw-basis semantic per-provoking-vertex screenspace image shading rates three sources combined using set combiners screen space image tile size 16x16 smaller shading rate requested app guaranteed delivered exactly precision temporal reconstruction filters sv_shadingrate ps input supported per-provoking vertex rate also referred per-primitive rate valid one viewport used sv_viewportindex written per-provoking vertex rate also referred per-primitive rate used one viewport supportspervertexshadingratewithmultipleviewports cap marked true additionally case used sv_viewportindex written collect diagnostic info allows os collect private data drivers graphics adapters consist rendering display functions new feature requirement wddm 2.6 new ddi allow os collect information time driver loaded currently os uses dxgkddicollectdebuginfo function implemented miniport query driver private data tdr timeout detection recovery related cases new ddi used collect data variety reasons os call ddi diagnostic needed providing type information requested driver collect private information important investigate issue submit os dxgkddicollectdebuginfo eventually deprecated replaced dxgkddicollectdiagnosticinfo background processing allows user mode drivers express desired threading behavior runtime control/monitor user mode drivers would spin background threads assign threads low priority possible rely nt scheduler ensure threads ’ disrupt critical-path threads generally success apis allow apps adjust amount background processing appropriate workloads perform work driver hot update reduces server downtime much possible os component needs updated driver hot patch used apply security patch kernel mode driver case driver asked save adapter memory adapter stopped driver unloaded new driver loaded adapter started
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Operating systems
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socket 6 socket 6 486-generation cpu socket slightly modified version common socket 3 used motherboards intel designed new standard near end 80486 market life motherboards produced used especially socket 3 standard already sufficient
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Computer architecture
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ipad 2017 ipad officially fifth-generation ipad 9.7-inch tablet computer designed developed marketed apple inc. announcement march 21 2017 conflicting naming conventions spawned number different names including seventh-generation ipad ipad 2017 retains screen size ipad air line tablets powerful ipad air 2 even overall dimensions weight similar original ipad air unlike ipad air 2 generation ipad fully laminated display lacks anti-reflective coating unlike ipad pro smart connector features dual-speaker system ipad received mixed reviews significantly praised performance reviewers asserting model noticeably faster older ipad models also received positive reviews price battery life criticized however lacking laminated anti-reflective screen lack support apple pencil attachable keyboards smart connector introductory price united states lowest ever ipad media noting lower price might effort encourage wider adoption tablet education sector well businesses needing inexpensive tablets undemanding uses march 27 2018 apple announced successor 2018 ipad also marked discontinuation ipad ipad announced apple march 21 2017 press release confusion around naming referred ipad marketing called fifth-generation ipad official statements specifications sheets title previously taken 2013 ipad air sources refer seventh-generation ipad including ipad air ipad air 2 fifth- sixth-generation ipads respectively also referred ipad 2017 matt kapko cio wrote apple introductory pricing 329 united states ipad 70 price reduction versus ipad air 2 appeared designed fend encroachment google chromebook laptops education sector foster wider adoption customer-facing terminals kapko also wrote device designed appeal businesses require inexpensive tablets undemanding use including kiosks checkout terminals hospitality screens time original release ipad shipped ios 10 version apple mobile operating system new units sold come new ios 11 operating system instead included touch id fingerprint sensor allows user unlock device well approve purchases app store itunes store ibooks store touch id apple pay let user purchase items websites within apps ipad 9.7-inch 25cm screen compared ipad air 2 processor updated apple a8x a9 embedded apple m9 motion co-processor ipad 2 gigabytes ram 7.5mm thick thickness ipad air compared 6.1mm ipad air 2 unlike ipad models available ipad display fully laminated anti-reflective coating however ipad brighter screen ipad air 2 25 brighter according apple available 32 128 gigabyte storage options contrasting ipad pro lineup ipad features two speakers opposed four smart connector support flash back offered silver gold space grey colors despite use apple a9 processor accompanying m9 motion co-processor introduced iphone 6s 2015 ipad feature support always-on hey siri voice input feature advertised made possible low-power processing then-new chips use hey siri limited ipad connected power product teardown ifixit showed design ipad nearly identical ipad air except differences addition touch id lack physical mute switch microphone holes smaller single row speaker holes dieter bohn verge wrote thin fast tablet praised screen good despite fancy true tone display ipad pro things made screen ipad air 2 nice lamination anti-reflectivity criticized lack support attachable keyboards apple pencil praising a9 processor significantly faster older ipads though noting n't necessarily significantly faster ipad air 2 fast ipad pro also disliked ipad features two speakers opposed four ipad pro summarizing overall review fundamentally trying tell ipad trust ipads decent tablets basic level quality speed functionality get one need one n't stress 're missing n't sascha segan pc magazine wrote apple ipad affordable ever noted little reason existing ipad owners upgrade new ipad price stabs stake heart many competing android tablets although criticizing non-laminated display little washed predecessor claimed could n't see measurable difference nominal degradation quality n't really matter everyday use segan also praised performance compared prior ipad models also praised improved wi-fi performance writing quite impressive double wi-fi speeds new ipad air 2 jeff benjamin 9to5mac wrote sure lacks gorgeous laminated anti-reflective display ipad air 2 sure ’ svelte either thickness weight ’ denying 2017 ipad a9 dual core processor tow good value described tablet solid buy upgraders new users igor bonifacic mobilesyrup also praised performance well number ipad apps available criticized camera outdated keyboard/pencil incompatibility summarization reading 2017 ipad exciting tablet ’ supposed exciting ... apple ’ latest tablet iterative update designed appeal specific subset consumers bonifacic also called tablet perfect first-time tablet buyers chris velazco engadget praised battery life describing one best ipads 've tested also criticized lack anti-reflection display calling another cost-saving measure wish apple reconsidered
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Operating systems
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xak ii rising redmoon xak ii rising redmoon fantasy role-playing video game developed published japanese software developer microcabin direct sequel xak game released japan due msx scene arose europe predominately netherlands region msx versions xak received fan translations enhanced remake later released nec pc-engine together first game series xak ii telenet japan development team riot xak ii direct sequel first game series features high fantasy setting xak gods division world xak world men oceanity world faeries xexis world demons referenced xak depicted game introduction adventure main hero xak series latok kart exploring vast region situated around single central village banuwa xak protagonist latok kart fought defeated demon zemu badu one badu minions escaped black-robed man known necromancer three years later necromancer able contact one allies demon world xexis fearsome demon called zamu gospel following prophecy foretold ancient extremely powerful sorcerer name amadok necromancer three demons referred demonlords attempting complete dark ritual revive zamu gospel world xak player controls latok nineteen years age rumour whereabouts latok father dork surfaced around village banuwa latok faerie companion pixie travel village investigate soon run gospel minions latok playable character game faerie pixie accompanies throughout game comments latok actions controllable player however notable non-player characters latok pixie meet include xak ii follows structure predecessor game proceeds player finding way labyrinthine maps defeating opposing monsters way map puzzles solved keys npcs objects found gain entrance room boss dwells defeating boss player proceed towards next map structure repeats various sub-quests involving npcs present obligatory combat real-time player character walks around game maps well monster characters character attack defense rating player latok swing sword pressing action key monster character near enough sustain damage monsters damage latok touching hitting projectiles combat system requires manual dexterity especially boss fights—bosses generally several times larger latok msx2 xak ii displayed screen 256x212 display resolution game uses scrolling display map scrolls away player character reaches distance screen side 1/3 total display due larger amount memory available 256x212 display compared 512x212 one game scrolling markedly smoother xak game music supports internal psg sound system well optional msx-music style heard microcabin productions msx psg channels used main melody sound effects msx-music channels used supporting instruments prominence psg less marked first game
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Computer architecture
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allegro software allegro software library video game development functionality library includes support basic 2d graphics image manipulation text output audio output midi music input timers well additional routines fixed-point floating-point matrix arithmetic unicode strings file system access file manipulation data files 3d graphics library written c programming language designed used c c++ objective-c bindings available python lua scheme go languages allegro comes extensive documentation many examples allegro supports windows macos unix-like systems android ios abstracting application programming interfaces apis one portable interface previous versions 4.4 supported windows macos dos beos various unix-like systems without x window system also independent port allegro amigaos 4 morphos released terms zlib license allegro free open source software initially standing atari low-level game routines allegro originally created atari st early 1990s however hargreaves abandoned atari version realized platform dying reimplemented work borland c++ djgpp compilers 1995 support borland c++ dropped version 2.0 djgpp supported compiler djgpp dos compiler games used allegro therefore used dos around 1998 allegro branched several versions port windows winallegro created also time unix port allegro xwinallegro created various ports brought together allegro 3.9 wip versions allegro 4.0 first stable version allegro support multiple platforms current development focused allegro 5 branch complete redesign api much library internal operation effort made make api consistent multi-thread safe default library hardware accelerated using opengl directx rendering backends appropriate many addons existed separate projects allegro 4 interface seamlessly allegro proper bundled default installation allegro 5 event driven allegro provides following graphic functions community allegro users contributed several library extensions handle things like scrolling tile maps import export various file formats e.g png gif jpeg images mpeg video ogg mp3 s3m xm music ttf fonts allegro 4.x used conjunction opengl using library allegrogl extends allegro functionality opengl therefore hardware allegro 5 natively supports opengl
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Operating systems
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database testing database testing usually consists layered process including user interface ui layer business layer data access layer database ui layer deals interface design database business layer includes databases supporting business strategies databases collection interconnected files server storing information may deal type data i.e databases may heterogeneous result many kinds implementation integration errors may occur large database systems negatively affect system performance reliability consistency security thus important test order obtain database system satisfies acid properties atomicity consistency isolation durability database management system one critical layers data access layer deals databases directly communication process database testing mainly takes place layer involves testing strategies quality control quality assurance product databases testing different layers frequently used maintain consistency database systems commonly seen following examples figure indicates areas testing involved different database testing methods black-box testing white-box testing black-box testing involves testing interfaces integration database includes help techniques functionality database tested thoroughly pros cons black box testing include test case generation black box testing fairly simple generation completely independent software development done early stage development consequence programmer better knowledge design database application uses less time debugging cost development black box test cases lower development white box test cases major drawback black box testing unknown much program tested also certain errors detected white-box testing mainly deals internal structure database specification details hidden user main advantage white box testing database testing coding error detected internal bugs database eliminated limitation white box testing sql statements covered generating test cases database testing semantics sql statement need reflected test cases purpose technique called white box database application technique whodate used shown figure sql statements independently converted gpl statements followed traditional white box testing generate test cases include sql semantics set fixture describes initial state database entering testing setting fixtures database behavior tested defined test cases depending outcome test cases either modified kept tear stage either results terminating testing continuing test cases successful database testing following workflow executed single test commonly executed
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Databases
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directory utility directory utility utility included macos previously mac os x operating system configure connections directory services os x 10.6 10.9 directory utility /system/library/coreservices/ accessed gui via accounts system preferences panel clicking 'join next network account server clicking 'open directory utility os x 10.10 directory utility moved /system/library/coreservices/applications prior mac os x 10.5 tool named directory access
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Operating systems
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socket 8 socket 8 cpu socket used exclusively intel pentium pro pentium ii overdrive computer processors intel discontinued socket 8 favor slot 1 introduction pentium ii slot 2 release pentium ii xeon 1999 socket 8 unique rectangular socket 387 pins supports fsb speeds ranging 60 66 mhz voltage 3.1 3.3v support pentium pro pentium ii overdrive cpus socket 8 also unique pin arrangement pattern one part socket pins pga grid part uses spga grid
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Computer architecture
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list applications using lua lua programming language lightweight multi-paradigm language designed primarily embedded systems clients list applications use lua purpose extensibility video game development lua widely used scripting language game programmers perhaps due perceived easiness embed fast execution short learning curve 2003 poll conducted gamedev.net showed lua popular scripting language game programming 12 january 2012 lua announced winner front line award 2011 magazine game developer category programming tools among websites popular website using lua pornhub according wappalyzer applications using lua include
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Programming language topics
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data hub data hub collection data multiple sources organized distribution sharing often subsetting sharing generally data distribution form hub spoke architecture data hub differs data warehouse generally unintegrated often different grains differs operational data store data hub need limited operational data data hub differs data lake homogenizing data possibly serving data multiple desired formats rather simply storing one place adding value data de-duplication quality security standardized set query services data lake tends store data one place availability allow/require consumer process add value data data hubs ideally go-to place data within enterprise many point-to-point connections callers data suppliers need made data hub organization negotiate deliverables schedules various data enclave teams rather organizational free-for-all different teams try get new services features many teams includes integration project management systems account management systems..
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Databases
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movidius movidius company based san mateo california designs specialised low-power processor chips computer vision company acquired intel september 2016 movidius co-founded dublin 2005 sean mitchell david moloney 2006 2016 raised nearly 90 million capital funding may 2013 company appointed remi el-ouazzane ceo january 2016 company announced partnership google movidius active google project tango project movidius announced planned acquisition intel september 2016 company myriad 2 chip always-on manycore vision processing unit function power-constrained devices fathom usb stick containing myriad 2 processor allowing vision accelerator added devices using arm processors including pcs drones robots iot devices video surveillance tasks identifying people objects run 80 150 gflops little 1w power intel myriad x vpu vision processing unit third generation advanced vpu movidius intel company intel myriad x vpu first class feature neural compute engine—a dedicated hardware accelerator deep neural network deep-learning inferences neural compute engine conjunction 16 shave cores ultra-high throughput intelligent memory fabric makes myriad x strong option on-device deep neural networks computer vision applications intel myriad x vpu received additional upgrades imaging vision engines including additional programmable shave cores upgraded expanded vision accelerators new native 4k image processor pipeline support 8 hd sensors connecting directly vpu myriad 2 myriad x vpu programmable via myriad development kit mdk includes necessary development tools frameworks apis implement custom vision imaging deep neural network workloads chip intel movidius neural compute stick ncs tiny fanless deep-learning device used learn ai programming edge ncs powered low-power high-performance intel movidius vision processing unit found millions smart security cameras gesture-controlled drones industrial machine vision equipment supported frameworks tensorflow caffe 14 november 2018 company announced latest version ncs marketed neural compute stick 2 ai devcon event beijing google clips camera uses myriad 2 vpu
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Computer architecture
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netscape application server netscape application server integrated software platform developing running transaction-oriented business applications web developed originally kiva software netscape acquired 1997 netscape sun microsystems formed sun-netscape alliance 1999 netscape application server chosen basis iplanet application server offering netdynamics application server acquired sun 1998
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Web technology
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elements crm ios elements crm ios mac customer relationship management mac crm solution built ntractive apple business using apple devices offered cloud computing subscription-based service elements crm ios universal mobile app iphone ipad elements crm ios add-on elements crm desktop app ipad crm version elements crm ios looks works feels like desktop app iphone crm app limited version important functions desktop app architecture overall development elements crm product line begun 2003 company founder justin bartak first product elements sbm launched october 2007 july 2009 product name changed elements crm ntractive privately held software development company based grand forks north dakota markets business software small medium-sized companies established 2006 company sole product elements crm customer relationship management application aimed small businesses use mac os x computers ipads iphones elements crm cloud based app employs unique site-specific browser merge os x desktop web application functionality product first introduced public keynote address apple 2007 world wide developer conference official launch elements sbm product ’ original name 1.0 took place macworld/iworld 2009 product renamed elements crm 2.0 release awarded honor apple staff pick july 2009 mac customer relationship management mac crm approach managing company ’ interaction current future customers apple inc desktop computers ios devices mac crm solutions web-based applications use web browser interaction instead mac crm combination cloud based app built apple programming language objective-c swift programming language mac crms involve using apple devices technology organize automate synchronize sales marketing customer service technical support
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Distributed computing architecture
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digital packet video link digital packet video link dpvl video standard released vesa 2004 unlike previous technologies order save bandwidth portions screen modified sent means link dpvl also introduces metadata video attributes support dpvl standard aimed mobile wireless hardware
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Computer architecture
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gobuntu gobuntu short-lived official derivative ubuntu operating system conceived provide distribution consisting entirely free software ubuntu incorporates free software installer option gobuntu project rendered redundant early 2008 result canonical made decision officially end gobuntu project version 8.04 march 2009 announced gobuntu 8.04.1 final release gobuntu project merged back mainline ubuntu need separate distribution mark shuttleworth first mentioned idea creating ubuntu derivative named gnubuntu consisting entirely free software 24 november 2005 due richard stallman disapproval name project later renamed ubuntu-libre stallman previously endorsed distribution based ubuntu called gnewsense criticized ubuntu using proprietary non-free software successive distributions notably ubuntu 7.04 introducing ubuntu 7.10 mark shuttleworth said would gobuntu officially announced mark shuttleworth 10 july 2007 daily builds gobuntu 7.10 began publicly released initial version gobuntu 7.10 released 18 october 2007 text-only installer next release long-term release codenamed hardy heron also made available alternate installation image release 7.10 initially met criticism free software advocates included mozilla firefox firefox considered 100 free software includes mozilla foundation copyrighted icons mozilla licence icons states ... may reproduced without permission debate developer list problem quickly addressed canonical applications non-free logos replaced follow-up gobuntu release hardy heron firefox replaced epiphany free logos drivers firmware binary blobs removed gobuntu would run fewer computers ubuntu canonical stated time release 7.10 13 june 2008 ubuntu community manager jono bacon announced gobuntu project would end release gobuntu 8.04 shuttleworth explained project ended release version 8.04.1 gobuntu versions intended released twice year coinciding ubuntu releases gobuntu uses version numbers code names ubuntu using year month release version number first gobuntu release example 7.10 indicating october 2007 gobuntu releases also given code names using adjective animal first letter e.g gutsy gibbon respective ubuntu code names commonly gobuntu releases referred developers users adjective portion code name example gutsy gibbon often called gutsy
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Operating systems
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cooperative storage cloud cooperative storage cloud decentralized model networked online storage data stored multiple computers nodes hosted participants cooperating cloud cooperative scheme viable total storage contributed aggregate must least equal amount storage needed end users however nodes may contribute less storage may contribute may reward models compensate nodes contributing unlike traditional storage cloud cooperative directly employ dedicated servers actual storage data thereby eliminating need significant dedicated hardware investment node cooperative runs specialized software communicates centralized control orchestration server thereby allowing node consume contribute storage space cloud centralized control orchestration server requires several orders magnitude less resources storage computing power bandwidth operate relative overall capacity cooperative files hosted cloud fragmented encrypted leaving local machine distributed randomly using load balancing geo-distribution algorithm nodes cooperative users add additional layer security reduce storage space compressing encrypting files copied cloud order maintain data integrity high availability across relatively unreliable set computers wide area network like internet source node add level redundancy data block allows system recreate entire block even nodes temporarily unavailable due loss network connectivity machine powered hardware failure storage bandwidth efficient forms redundancy use erasure coding techniques like reed-solomon simple less cpu intensive expensive form redundancy duplicate copies due bandwidth hardware constraints nodes may able contribute much space consume cloud hand nodes large storage space limited bandwidth constraints may contribute consume thereby cooperative stay balance university california oceanstore project mit chord non-commercial example june 1 2016 minebox gmbh announced forthcoming minebox networked attached storage device nas utilize sia network persist backups users minebox also able rent free disk space via sia partly centralized system operated symform inc. startup company based seattle symform generated kept keys used encrypt decrypt since also decided server host parts file users trust symform share party misuse information symform discontinued service july 31 2016
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Distributed computing architecture
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cloud computing cloud computing on-demand availability computer system resources especially data storage computing power without direct active management user term generally used describe data centers available many users internet large clouds predominant today often functions distributed multiple locations central servers connection user relatively close may designated edge server clouds may limited single organization enterprise clouds available many organizations public cloud cloud computing relies sharing resources achieve coherence economies scale advocates public hybrid clouds note cloud computing allows companies avoid minimize up-front infrastructure costs proponents also claim cloud computing allows enterprises get applications running faster improved manageability less maintenance enables teams rapidly adjust resources meet fluctuating unpredictable demand cloud providers typically use pay-as-you-go model lead unexpected operating expenses administrators familiarized cloud-pricing models availability high-capacity networks low-cost computers storage devices well widespread adoption hardware virtualization service-oriented architecture autonomic utility computing led growth cloud computing 2019 linux used type operating systems used including microsoft offerings thus described dominant cloud computing popularized amazon.com releasing elastic compute cloud product 2006 references phrase cloud computing appeared early 1996 first known mention compaq internal document cloud symbol used represent networks computing equipment original arpanet early 1977 csnet 1981—both predecessors internet word cloud used metaphor internet standardized cloud-like shape used denote network telephony schematics simplification implication specifics end points network connected relevant purposes understanding diagram term cloud used refer platforms distributed computing early 1993 apple spin-off general magic used describing paired telescript personalink technologies wired april 1994 feature bill andy excellent adventure ii andy hertzfeld commented telescript general magic distributed programming language 1960s initial concepts time-sharing became popularized via rje remote job entry terminology mostly associated large vendors ibm dec. full-time-sharing solutions available early 1970s platforms multics ge hardware cambridge ctss earliest unix ports dec hardware yet data center model users submitted jobs operators run ibm mainframes overwhelmingly predominant 1990s telecommunications companies previously offered primarily dedicated point-to-point data circuits began offering virtual private network vpn services comparable quality service lower cost switching traffic saw fit balance server use could use overall network bandwidth effectively began use cloud symbol denote demarcation point provider responsible users responsible cloud computing extended boundary cover servers well network infrastructure computers became diffused scientists technologists explored ways make large-scale computing power available users time-sharing experimented algorithms optimize infrastructure platform applications prioritize cpus increase efficiency end users use cloud metaphor virtualized services dates least general magic 1994 used describe universe places mobile agents telescript environment could go described andy hertzfeld use cloud metaphor credited general magic communications employee david hoffman based long-standing use networking telecom addition use general magic also used promoting associated personalink services cloud computing existence since 2000 august 2006 amazon created subsidiary amazon web services introduced elastic compute cloud ec2 april 2008 google released google app engine beta early 2008 nasa opennebula enhanced reservoir european commission-funded project became first open-source software deploying private hybrid clouds federation clouds mid-2008 gartner saw opportunity cloud computing shape relationship among consumers services use services sell observed organizations switching company-owned hardware software assets per-use service-based models projected shift computing ... result dramatic growth products areas significant reductions areas 2008 u.s. national science foundation began cluster exploratory program fund academic research using google-ibm cluster technology analyze massive amounts data february 2010 microsoft released microsoft azure announced october 2008 july 2010 rackspace hosting nasa jointly launched open-source cloud-software initiative known openstack openstack project intended help organizations offering cloud-computing services running standard hardware early code came nasa nebula platform well rackspace cloud files platform open source offering along open-source solutions cloudstack ganeti opennebula attracted attention several key communities several studies aim comparing open sources offerings based set criteria march 1 2011 ibm announced ibm smartcloud framework support smarter planet among various components smarter computing foundation cloud computing critical part june 7 2012 oracle announced oracle cloud cloud offering poised first provide users access integrated set solutions including applications saas platform paas infrastructure iaas layers may 2012 google compute engine released preview rolled general availability december 2013 2019 revealed linux used microsoft azure dominant elsewhere goal cloud computing allow users take benefit technologies without need deep knowledge expertise one cloud aims cut costs helps users focus core business instead impeded obstacles main enabling technology cloud computing virtualization virtualization software separates physical computing device one virtual devices easily used managed perform computing tasks operating system–level virtualization essentially creating scalable system multiple independent computing devices idle computing resources allocated used efficiently virtualization provides agility required speed operations reduces cost increasing infrastructure utilization autonomic computing automates process user provision resources on-demand minimizing user involvement automation speeds process reduces labor costs reduces possibility human errors cloud computing uses concepts utility computing provide metrics services used cloud computing attempts address qos quality service reliability problems grid computing models cloud computing shares characteristics cloud computing exhibits following key characteristics national institute standards technology definition cloud computing identifies five essential characteristics though service-oriented architecture advocates everything service acronyms eaas xaas simply aas cloud-computing providers offer services according different models three standard models per nist infrastructure service iaas platform service paas software service saas models offer increasing abstraction thus often portrayed layers stack infrastructure- platform- software-as-a-service need related example one provide saas implemented physical machines bare metal without using underlying paas iaas layers conversely one run program iaas access directly without wrapping saas infrastructure service iaas refers online services provide high-level apis used dereference various low-level details underlying network infrastructure like physical computing resources location data partitioning scaling security backup etc hypervisor runs virtual machines guests pools hypervisors within cloud operational system support large numbers virtual machines ability scale services according customers varying requirements linux containers run isolated partitions single linux kernel running directly physical hardware linux cgroups namespaces underlying linux kernel technologies used isolate secure manage containers containerisation offers higher performance virtualization hypervisor overhead also container capacity auto-scales dynamically computing load eliminates problem over-provisioning enables usage-based billing iaas clouds often offer additional resources virtual-machine disk-image library raw block storage file object storage firewalls load balancers ip addresses virtual local area networks vlans software bundles nist definition cloud computing describes iaas consumer able deploy run arbitrary software include operating systems applications consumer manage control underlying cloud infrastructure control operating systems storage deployed applications possibly limited control select networking components e.g. host firewalls iaas-cloud providers supply resources on-demand large pools equipment installed data centers wide-area connectivity customers use either internet carrier clouds dedicated virtual private networks deploy applications cloud users install operating-system images application software cloud infrastructure model cloud user patches maintains operating systems application software cloud providers typically bill iaas services utility computing basis cost reflects amount resources allocated consumed nist definition cloud computing defines platform service paas vendors offer development environment application developers provider typically develops toolkit standards development channels distribution payment paas models cloud providers deliver computing platform typically including operating system programming-language execution environment database web server application developers develop run software cloud platform instead directly buying managing underlying hardware software layers paas underlying computer storage resources scale automatically match application demand cloud user allocate resources manually integration data management providers also use specialized applications paas delivery models data examples include ipaas integration platform service dpaas data platform service ipaas enables customers develop execute govern integration flows ipaas integration model customers drive development deployment integrations without installing managing hardware middleware dpaas delivers integration—and data-management—products fully managed service dpaas model paas provider customer manages development execution programs building data applications customer dpaas users access data data-visualization tools platform service paas consumers manage control underlying cloud infrastructure including network servers operating systems storage control deployed applications possibly configuration settings application-hosting environment nist definition cloud computing defines software service software service saas model users gain access application software databases cloud providers manage infrastructure platforms run applications saas sometimes referred on-demand software usually priced pay-per-use basis using subscription fee saas model cloud providers install operate application software cloud cloud users access software cloud clients cloud users manage cloud infrastructure platform application runs eliminates need install run application cloud user computers simplifies maintenance support cloud applications differ applications scalability—which achieved cloning tasks onto multiple virtual machines run-time meet changing work demand load balancers distribute work set virtual machines process transparent cloud user sees single access-point accommodate large number cloud users cloud applications multitenant meaning machine may serve one cloud-user organization pricing model saas applications typically monthly yearly flat fee per user prices become scalable adjustable users added removed point proponents claim saas gives business potential reduce operational costs outsourcing hardware software maintenance support cloud provider enables business reallocate operations costs away hardware/software spending personnel expenses towards meeting goals addition applications hosted centrally updates released without need users install new software one drawback saas comes storing users data cloud provider server result could unauthorized access data mobile backend service model also known backend service baas web app mobile app developers provided way link applications cloud storage cloud computing services application programming interfaces apis exposed applications custom software development kits sdks services include user management push notifications integration social networking services relatively recent model cloud computing baas startups dating 2011 later trends indicate services gaining significant mainstream traction enterprise consumers serverless computing cloud computing code execution model cloud provider fully manages starting stopping virtual machines necessary serve requests requests billed abstract measure resources required satisfy request rather per virtual machine per hour despite name actually involve running code without servers serverless computing named business person owns system purchase rent provision servers virtual machines back-end code run function service faas service-hosted remote procedure call leverages serverless computing enable deployment individual functions cloud run response events faas included broader term serverless computing terms may also used interchangeably private cloud cloud infrastructure operated solely single organization whether managed internally third party hosted either internally externally undertaking private cloud project requires significant engagement virtualize business environment requires organization reevaluate decisions existing resources improve business every step project raises security issues must addressed prevent serious vulnerabilities self-run data centers generally capital intensive significant physical footprint requiring allocations space hardware environmental controls assets refreshed periodically resulting additional capital expenditures attracted criticism users still buy build manage thus benefit less hands-on management essentially lacking economic model makes cloud computing intriguing concept cloud called public cloud services rendered network open public use public cloud services may free technically may little difference public private cloud architecture however security consideration may substantially different services applications storage resources made available service provider public audience communication effected non-trusted network generally public cloud service providers like amazon web services aws ibm oracle microsoft google operate infrastructure data center access generally via internet aws oracle microsoft google also offer direct connect services called aws direct connect oracle fastconnect azure expressroute cloud interconnect respectively connections require customers purchase lease private connection peering point offered cloud provider hybrid cloud composition public cloud private environment private cloud on-premise resources remain distinct entities bound together offering benefits multiple deployment models hybrid cloud also mean ability connect collocation managed and/or dedicated services cloud resources gartner defines hybrid cloud service cloud computing service composed combination private public community cloud services different service providers hybrid cloud service crosses isolation provider boundaries ca n't simply put one category private public community cloud service allows one extend either capacity capability cloud service aggregation integration customization another cloud service varied use cases hybrid cloud composition exist example organization may store sensitive client data house private cloud application interconnect application business intelligence application provided public cloud software service example hybrid cloud extends capabilities enterprise deliver specific business service addition externally available public cloud services hybrid cloud adoption depends number factors data security compliance requirements level control needed data applications organization uses another example hybrid cloud one organizations use public cloud computing resources meet temporary capacity needs met private cloud capability enables hybrid clouds employ cloud bursting scaling across clouds cloud bursting application deployment model application runs private cloud data center bursts public cloud demand computing capacity increases primary advantage cloud bursting hybrid cloud model organization pays extra compute resources needed cloud bursting enables data centers create in-house infrastructure supports average workloads use cloud resources public private clouds spikes processing demands specialized model hybrid cloud built atop heterogeneous hardware called cross-platform hybrid cloud cross-platform hybrid cloud usually powered different cpu architectures example x86-64 arm underneath users transparently deploy scale applications without knowledge cloud hardware diversity kind cloud emerges rise arm-based system-on-chip server-class computing community cloud shares infrastructure several organizations specific community common concerns security compliance jurisdiction etc whether managed internally third-party either hosted internally externally costs spread fewer users public cloud private cloud cost savings potential cloud computing realized cloud computing platform assembled distributed set machines different locations connected single network hub service possible distinguish two types distributed clouds public-resource computing volunteer cloud multicloud use multiple cloud computing services single heterogeneous architecture reduce reliance single vendors increase flexibility choice mitigate disasters etc differs hybrid cloud refers multiple cloud services rather multiple deployment modes public private legacy issues transferring large amounts data cloud well data security data cloud initially hampered adoption cloud big data much data originates cloud advent bare-metal servers cloud become solution use cases including business analytics geospatial analysis hpc cloud refers use cloud computing services infrastructure execute high-performance computing hpc applications applications consume considerable amount computing power memory traditionally executed clusters computers 2016 handful companies including r-hpc amazon web services univa silicon graphics international sabalcore gomput penguin computing offered high performance computing cloud penguin demand pod cloud one first non-virtualized remote hpc services offered pay-as-you-go basis penguin computing launched hpc cloud 2016 alternative amazon ec2 elastic compute cloud uses virtualized computing nodes cloud architecture systems architecture software systems involved delivery cloud computing typically involves multiple cloud components communicating loose coupling mechanism messaging queue elastic provision implies intelligence use tight loose coupling applied mechanisms others cloud engineering application engineering disciplines cloud computing brings systematic approach high-level concerns commercialization standardization governance conceiving developing operating maintaining cloud computing systems multidisciplinary method encompassing contributions diverse areas systems software web performance information technology engineering security platform risk quality engineering cloud computing poses privacy concerns service provider access data cloud time could accidentally deliberately alter delete information many cloud providers share information third parties necessary purposes law order without warrant permitted privacy policies users must agree start using cloud services solutions privacy include policy legislation well end users choices data stored users encrypt data processed stored within cloud prevent unauthorized access identity management systems also provide practical solutions privacy concerns cloud computing systems distinguish authorized unauthorized users determine amount data accessible entity systems work creating describing identities recording activities getting rid unused identities according cloud security alliance top three threats cloud insecure interfaces api data loss leakage hardware failure —which accounted 29 25 10 cloud security outages respectively together form shared technology vulnerabilities cloud provider platform shared different users may possibility information belonging different customers resides data server additionally eugene schultz chief technology officer emagined security said hackers spending substantial time effort looking ways penetrate cloud real achilles heels cloud infrastructure making big holes bad guys get data hundreds thousands companies stored large cloud servers hackers theoretically gain control huge stores information single attack—a process called hyperjacking examples include dropbox security breach icloud 2014 leak dropbox breached october 2014 7 million users passwords stolen hackers effort get monetary value bitcoins btc passwords able read private data well data indexed search engines making information public problem legal ownership data user stores data cloud cloud provider profit many terms service agreements silent question ownership physical control computer equipment private cloud secure equipment site someone else control public cloud delivers great incentive public cloud computing service providers prioritize building maintaining strong management secure services small businesses n't expertise security could find secure use public cloud risk end users understand issues involved signing cloud service persons sometimes n't read many pages terms service agreement click accept without reading important cloud computing becoming popular required services work example intelligent personal assistant apple siri google fundamentally private cloud seen secure higher levels control owner however public cloud seen flexible requires less time money investment user according bruce schneier downside limited customization options cloud computing cheaper economics scale and—like outsourced task—you tend get get restaurant limited menu cheaper personal chef cook anything want fewer options much cheaper price feature bug also suggests cloud provider might meet legal needs businesses need weigh benefits cloud computing risks cloud computing control back end infrastructure limited cloud vendor cloud providers often decide management policies moderates cloud users able deployment cloud users also limited control management applications data services includes data caps placed cloud users cloud vendor allocating certain amount bandwidth customer often shared among cloud users privacy confidentiality big concerns activities instance sworn translators working stipulations nda might face problems regarding sensitive data encrypted cloud computing beneficial many enterprises lowers costs allows focus competence instead matters infrastructure nevertheless cloud computing proven limitations disadvantages especially smaller business operations particularly regarding security downtime technical outages inevitable occur sometimes cloud service providers csps become overwhelmed process serving clients may result temporary business suspension since technology systems rely internet individual able access applications server data cloud outage cloud computing still subject research driving factor evolution cloud computing chief technology officers seeking minimize risk internal outages mitigate complexity housing network computing hardware in-house major cloud technology companies invest billions dollars per year cloud research development example 2011 microsoft committed 90 percent 9.6 billion r budget cloud research investment bank centaur partners late 2015 forecasted saas revenue would grow 13.5 billion 2011 32.8 billion 2016 issue carrying investigations cloud storage devices physically accessed generated number changes way digital evidence located collected new process models developed formalize collection scenarios existing digital forensics tools employed access cloud storage networked drives although slow process generating large amount internet traffic alternative approach deploy tool processes cloud organizations using office 365 'e5 subscription option use microsoft built-in ediscovery resources although provide functionality typically required forensic process
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Distributed computing architecture
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grid security infrastructure grid security infrastructure gsi formerly called globus security infrastructure specification secret tamper-proof delegatable communication software grid computing environment secure authenticatable communication enabled using asymmetric encryption authentication performed using digital signature technology see digital signatures explanation works secure authentication allows resources lock data access authentication introduces problem often service retrieve data resource independent user order must supplied appropriate privileges gsi allows creation delegated privileges new key created marked delegated signed user possible service act behalf user fetch data resource communications may secured using combination methods
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Distributed computing architecture
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pattern directed invocation programming language computer science pattern-directed invocation programming languages programming languages procedures invoked indirectly specifying pattern set procedures opposed specifying one directly name pointer url etc. conventional programming languages initiated planner featured high level plans invoked patterns assertions goals include logic programming languages prolog special case ether pattern-directed invocation language introduced scientific community metaphor pattern-directed invocation commonly used practical alternative first-order theorem proving automated theorem proving primary method implementing blackboard system automated reasoning general database facts la prolog augmented set procedures called demons demon automatically invoked whenever term matching demon pattern added database pattern-directed invocation related rule-based programming
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Programming language topics
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sap anywhere sap anywhere front office software package sap se sap small medium sized enterprises smbs 10 500 employees early 2018 sap decided sunset product focus smb market established sap business one sap business bydesign erp solutions sap anywhere includes several front office applications intended help retail wholesale businesses market sell products services multiple sales channels including in-store direct sales online system facilitates effective customer relationship management allowing business owners review direct marketing inventory direct customer experiences using single system mobile devices according research firm international data corporation idc many small businesses struggle date processes fail optimise online business tools e-commerce increasing factor maintaining relationships customers sap anywhere intended allow small businesses take advantage digital revolution increase customer reach e-commerce business-to-business b2b business-to-consumer b2c channels president global channels general business sap rodolpho cardenuto said 2016 “ 79 million small midsize companies worldwide lifeblood economy sap anywhere primarily used smbs 20 clients falling outside smb category sap anywhere launched sap china telecom 20 october 2015 mainland china sap german multinational software corporation headquartered walldorf baden-württemberg germany founded 1972 sap focuses creating enterprise software 2014 sap created new division focus smb small-medium business customers smb solutions group smb software preceding sap anywhere includes china telecom established 2000 largest fixed-line service provider people ’ republic china third largest mobile telecommunication provider china developing sap anywhere sap utilised telecommunications infrastructure china telecom developed product customised chinese market smbs represent two thirds businesses china initial plans release focused building strong customer base china expanding markets due competitive pressure sap released sap anywhere english-speaking market earlier planned uk availability announced march 2016 us availability announced may 2016 canadian pilot currently planned 2016 sap anywhere cloud based saas software service delivered sap public cloud amazon cloud us market sap anywhere accessed mobile devices desktops includes applications sap anywhere uses sap hana enables data captured mined real time allowing accurate inventory sales order management across multiple channels sap anywhere integrates constant contact mailchimp payment gateways like paypal stripe sap anywhere uses secure transactions secure sockets layer ssl protection well sap anywhere integrated delivery company ups sap anywhere allows businesses utilise google productivity collaboration tools interact customers google apps integration internal back office enterprise resource planning applications like hr finance also available
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Distributed computing architecture
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cross-site scripting cross-site scripting xss type computer security vulnerability typically found web applications xss enables attackers inject client-side scripts web pages viewed users cross-site scripting vulnerability may used attackers bypass access controls same-origin policy cross-site scripting carried websites accounted roughly 84 security vulnerabilities documented symantec 2007 2017 xss still considered major threat vector xss effects vary range petty nuisance significant security risk depending sensitivity data handled vulnerable site nature security mitigation implemented site owner network security web depends variety mechanisms including underlying concept trust known same-origin policy essentially states content one site nowiki https //mybank.example1.com /nowiki granted permission access resources like cookies etc web browser content url 1 uri scheme 2 host name 3 port number share permissions content urls three attributes different granted permissions separately cross-site scripting attacks use known vulnerabilities web-based applications servers plug-in systems rely exploiting one attackers fold malicious content content delivered compromised site resulting combined content arrives client-side web browser delivered trusted source thus operates permissions granted system finding ways injecting malicious scripts web pages attacker gain elevated access-privileges sensitive page content session cookies variety information maintained browser behalf user cross-site scripting attacks case code injection microsoft security-engineers introduced term cross-site scripting january 2000 expression cross-site scripting originally referred act loading attacked third-party web application unrelated attack-site manner executes fragment javascript prepared attacker security context targeted domain taking advantage reflected non-persistent xss vulnerability definition gradually expanded encompass modes code injection including persistent non-javascript vectors including activex java vbscript flash even html scripts causing confusion newcomers field information security xss vulnerabilities reported exploited since 1990s prominent sites affected past include social-networking sites twitter facebook myspace youtube orkut cross-site scripting flaws since surpassed buffer overflows become common publicly reported security vulnerability researchers 2007 estimating many 68 websites likely open xss attacks single standardized classification cross-site scripting flaws experts distinguish least two primary flavors xss flaws non-persistent persistent sources divide two groups traditional caused server-side code flaws dom-based client-side code non-persistent reflected cross-site scripting vulnerability far basic type web vulnerability holes show data provided web client commonly http query parameters e.g html form submission used immediately server-side scripts parse display page results user without properly sanitizing content html documents flat serial structure mixes control statements formatting actual content non-validated user-supplied data included resulting page without proper html encoding may lead markup injection classic example potential vector site search engine one searches string search string typically redisplayed verbatim result page indicate searched response properly escape reject html control characters cross-site scripting flaw ensue reflected attack typically delivered via email neutral web site bait innocent-looking url pointing trusted site containing xss vector trusted site vulnerable vector clicking link cause victim browser execute injected script persistent stored xss vulnerability devastating variant cross-site scripting flaw occurs data provided attacker saved server permanently displayed normal pages returned users course regular browsing without proper html escaping classic example online message boards users allowed post html formatted messages users read example suppose dating website members scan profiles members see look interesting privacy reasons site hides everybody real name email kept secret server time member real name email browser member signed ca n't see anyone else suppose mallory attacker joins site wants figure real names people sees site writes script designed run users browsers visit profile script sends quick message server collects information question describe ideal first date mallory gives short answer appear normal text end answer script steal names emails script enclosed inside script element wo n't shown screen suppose bob member dating site reaches mallory profile answer first date question script run automatically browser steals copy bob real name email directly machine persistent xss vulnerabilities significant types attacker malicious script rendered automatically without need individually target victims lure third-party website particularly case social networking sites code would designed self-propagate across accounts creating type client-side worm methods injection vary great deal cases attacker may even need directly interact web functionality exploit hole data received web application via email system logs im etc controlled attacker could become injection vector historically xss vulnerabilities first found applications performed data processing server side user input including xss vector would sent server sent back user web page need improved user experience resulted popularity applications majority presentation logic maybe written javascript working client-side pulled data on-demand server using ajax javascript code also processing user input rendering web page content new sub-class reflected xss attacks started appear called dom-based cross-site scripting dom-based xss attack malicious data touch web server rather reflected javascript code fully client side example dom-based xss vulnerability bug found 2011 number jquery plugins prevention strategies dom-based xss attacks include similar measures traditional xss prevention strategies implemented javascript code contained web pages i.e input validation escaping javascript frameworks built-in countermeasures types attack — example angular.js self-xss form xss vulnerability relies social engineering order trick victim executing malicious javascript code browser although technically true xss vulnerability due fact relies socially engineering user executing code rather flaw affected website allowing attacker still poses risks regular xss vulnerability properly executed mutated xss happens attacker injects something seemingly safe rewritten modified browser parsing markup makes extremely hard detect sanitize within websites application logic example rebalancing unclosed quotation marks even adding quotation marks unquoted parameters parameters css font-family attackers intending exploit cross-site scripting vulnerabilities must approach class vulnerability differently class specific attack vector described names technical terms taken alice-and-bob cast characters commonly used computer security browser exploitation framework could used attack web site user local environment several things could done mitigate attack bob website software stripped script tag done something make sure n't work security bug fact n't contextual output encoding/escaping could used primary defense mechanism stop xss attacks several escaping schemes used depending untrusted string needs placed within html document including html entity encoding javascript escaping css escaping url percent encoding web applications need accept rich data use escaping largely eliminate risk xss attacks fairly straightforward manner although widely recommended performing html entity encoding five xml significant characters always sufficient prevent many forms xss attacks encoding often difficult security encoding libraries usually easier use web template systems understand structure html produces automatically pick appropriate encoder many operators particular web applications e.g forums webmail allow users utilize limited subset html markup accepting html input users say b /b large output encoding lt b gt lt /b gt large suffice since user input needs rendered html browser shows large instead b /b large stopping xss attack accepting html input users much complex situation untrusted html input must run html sanitization engine ensure contain xss code also noted many validations rely parsing blacklisting specific risk html tags following script link iframe several issues approach example sometimes seemingly harmless tags left utilized correctly still result xss see example img src= javascript alert 1 another popular method strip user input however also bypassed payload concealed obfuscation see link extreme example besides content filtering imperfect methods cross-site scripting mitigation also commonly used one example use additional security controls handling cookie-based user authentication many web applications rely session cookies authentication individual http requests client-side scripts generally access cookies simple xss exploits steal cookies mitigate particular threat though xss problem general many web applications tie session cookies ip address user originally logged permit ip use cookie effective situations attacker cookie obviously breaks situations attacker behind nated ip address web proxy victim victim changing mobile ip another mitigation present internet explorer since version 6 firefox since version 2.0.0.5 safari since version 4 opera since version 9.5 google chrome httponly flag allows web server set cookie unavailable client-side scripts beneficial feature neither fully prevent cookie theft prevent attacks within browser web 2.0 ajax developers require use javascript web applications written allow operation without need client-side scripts allows users choose disable scripting browsers using application way even potentially malicious client-side scripts could inserted unescaped page users would susceptible xss attacks browsers browser plugins configured disable client-side scripts per-domain basis approach limited value scripting allowed default since blocks bad sites user knows bad late functionality blocks scripting external inclusions default allows user enable per-domain basis effective possible long time internet explorer since version 4 setting called security zones opera since version 9 using site specific preferences solution firefox gecko-based browsers open source noscript add-on addition ability enable scripts per-domain basis provides xss protection even scripts enabled significant problem blocking scripts websites default substantial reduction functionality responsiveness client-side scripting much faster server-side scripting need connect remote server page frame need reloaded another problem script blocking many users understand know properly secure browsers yet another drawback many sites work without client-side scripting forcing users disable protection site opening systems vulnerabilities firefox noscript extension enables users allow scripts selectively given page disallowing others page example scripts example.com could allowed scripts advertisingagency.com attempting run page could disallowed content-security-policy csp allows html documents opt-into disabling scripts leaving others enabled browser checks script policy deciding whether run long policy allows trustworthy scripts disallows dynamic code loading browser run programs untrusted authors regardless html document structure shifts security burden policy authors studies cast doubt efficacy host whitelist based policies.in total find 94.68 policies attempt limit script execution ineffective 99.34 hosts csp use policies offer benefit xss.modern csp policies allow using nonces mark scripts html document safe run instead keeping policy entirely separate page content long trusted nonces appear trustworthy scripts browser run programs untrusted authors large application providers report successfully deployed nonce-based policies popularity client-side frameworks changed attackers craft xss.script gadgets legitimate javascript fragments within application ’ legitimate code base … demonstrate gadgets omnipresent almost modern javascript frameworks present empirical study showing prevalence script gadgets productive code result assume mitigation techniques web applications written today bypassed.trusted types changes web apis check values trademarked trusted long programs trademark trustworthy values attacker controls javascript string value cause xss trusted types designed auditable blue teams another defense approach use automated tools remove xss malicious code web pages tools use static analysis and/or pattern matching methods identify malicious codes potentially secure using methods like escaping cookie set samesite=strict parameter stripped cross-origin requests set samesite=lax stripped non- safe cross-origin requests requests get options trace read-only semantics feature implemented google chrome since version 63 firefox since version 60 universal cross-site scripting uxss universal xss attack vulnerabilities browser browser plugins exploited rather vulnerabilities websites case xss attacks attacks commonly used anonymous along ddos compromise control network several classes vulnerabilities attack techniques related xss cross-zone scripting exploits zone concepts certain browsers usually executes code greater privilege http header injection used create cross-site scripting conditions due escaping problems http protocol level addition enabling attacks http response splitting cross-site request forgery csrf/xsrf almost opposite xss rather exploiting user trust site attacker malicious page exploits site trust client software submitting requests site believes represent conscious intentional actions authenticated users xss vulnerabilities even applications running domain allow attackers bypass csrf prevention efforts covert redirection takes advantage third-party clients susceptible xss open redirect attacks normal phishing attempts easy spot malicious page url usually couple letters real site difference covert redirection attacker could use real website instead corrupting site malicious login pop-up dialogue box lastly sql injection exploits vulnerability database layer application user input incorrectly filtered sql statements executed application specific xsss affect given version web browser tend unique consequently possible use xss fingerprint browser vendor version user
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Computer security
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oracle fusion applications oracle fusion applications ofa enterprise resource planning software applications oracle corporation applications distributed across various product families including financial management human capital management customer relationship management supply chain management procurement governance project portfolio oracle fusion applications announced shortly oracle 18 billion usd acquisition spree peoplesoft jd edwards siebel systems 2005 oracle fusion applications envisioned pitched enterprise resource planning suite—a combination features functionalities taken oracle e-business suite jd edwards peoplesoft siebel product lines suite built top oracle fusion middleware technology stack layers implement oracle fusion architecture leverages capabilities service-oriented architecture oracle fusion applications launched september 2010 released one year later openworld 2011
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Distributed computing architecture
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rethinkdb rethinkdb free open-source distributed document-oriented database originally created company name database stores json documents dynamic schemas designed facilitate pushing real-time updates query results applications initially seed funded combinator june 2009 company announced october 2016 unable build sustainable business products would future entirely open-sourced without commercial support cncf cloud native computing foundation purchased rights rethinkdb source code contributed linux foundation rethinkdb founded 2009 open-sourced version 1.2 2012 2015 rethinkdb released version 2.0 announcing production-ready october 5 2016 company announced shutting transitioning members engineering team stripe would longer offer production support february 6 2017 cloud native computing foundation purchased rights source code relicensed apache license 2.0 rethinkdb uses reql query language internal embedded domain-specific language officially available ruby python java javascript including node.js support table joins groupings aggregations functions also unofficial community-supported drivers languages including c clojure erlang go haskell lua php according db-engines ranking february 2016 46th popular database distinguishing feature rethinkdb first class support real-time change feeds change query returns cursor allows blocking non-blocking requests keep track potentially infinite stream real-time changes due seeming stagnation rethinkdb forked members community may 17 2018 new project called rebirthdb also hosted github project later merged back original repository
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Distributed computing architecture
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per brinch hansen per brinch hansen november 13 1938 – july 31 2007 danish-american computer scientist known work operating systems concurrent programming parallel distributed computing per brinch hansen born frederiksberg enclave surrounded copenhagen denmark father worked civil engineer becoming leading expert soil mechanics later accepting professorship technical university denmark mother elsebeth brinch hansen née ring daughter danish composer oluf ring worked hairdresser marrying brinch hansen attended st. jørgens gymnasium studied electrical engineering technical university denmark sought area pursue still pioneering phase belief subject taught probably already late make fundamental contributions seven-week student internship ibm hursley laboratory england decided dedicate career computers initially focused computer construction reading book ibm project stretch described computer organization programmer point view refocused interest toward becoming computer architect completing master degree electronic engineering 1963 brinch hansen landed job regnecentralen research institution working compiler group led peter naur jørn jensen first significant project writing parser cobol compiler siemens 3003 computer subsequently wrote file system used execution compiled cobol programs later observing 1966 brinch hansen moved henning isaksson hardware group regnecentralen company shareholders together peter kraft defined architecture instruction set regnecentralen third computer rc 4000 using algol 60 hardware definition language produce formal specification inexperienced multiprogramming used copy cooperating sequential processes edsger dijkstra sent understand process synchronization using semaphores implemented specialized rc 4000 real-time monitor use managing fertilizer plant peter kraft then-teenaged charles simonyi wrote p-code interpreter data logging task programs compiled p-code summer 1967 brinch hansen left regnecentralen hardware group become head rc 4000 software development led team including jørn jensen peter kraft søren lauesen defining general-purpose rc 4000 multiprogramming system goal avoid developing custom real-time control operating system every rc 4000 installation support batch processing time-sharing well resulting system complete operating system small kernel providing mechanisms upon operating systems different purposes could built spring 1969 well-documented reliable version rc 4000 multiprogramming system running late 1970 brinch hansen moved pittsburgh accepting invitation alan perlis visit department computer science carnegie mellon university research associate wrote first systematic textbook operating system principles time 1971 summer school marktoberdorf symposium belfast brinch hansen tony hoare dijkstra began discuss ideas evolved monitor concept spring 1972 reading class concept invented ole-johan dahl kristen nygaard simula 67 brinch hansen completed text chapter resource protection proposed first monitor notation using shared classes 1973 operating system principles published becoming first comprehensive textbook operating systems july 1972 brinch hansen joined faculty caltech associate professor computer science began work defining programming language concurrent processes monitors april 1974 distributed technical report concurrent pascal concurrent pascal compiler pdp 11/45 written brinch hansen doctoral student al hartmann released january 1975 subsequently brinch hansen began writing model operating systems concurrent pascal evaluate language may 1975 completed solo single-user operating system development concurrent pascal programs next rewrote original rc 4000 real-time scheduler concurrent pascal taking three days write three hours machine time systematically test caltech computer science department shifted focus toward computer engineering away programming brinch hansen decided leave rather seek tenure 1976 brinch hansen chose usc next post family could remain altadena home joining faculty tenured full professor first chair newly created computer science department led efforts identify attract top-notch faculty build first rate department 1980 usc computer science department ranked national research council one top ten us usc brinch hansen wrote second book architecture concurrent programs based work developing operating systems concurrent pascal published 1977 first book concurrent programming 1978 brinch hansen became first computer scientist awarded doctor technices degree highest academic distinction within engineering technological science denmark work documented architecture concurrent programs later 1978 brinch hansen published distributed processes language concept proposing use remote procedure calls synchronize processes running across microcomputer network also 1978 l. j. sevins steve goings mostek visited brinch hansen usc outlined low-cost multiprocessor architecture mostek began project implement multiprocessor brinch hansen working consultant brinch hansen developed new concurrent programming language edison project rc 4000 project edison also used formal specification language hardware mostek got initial 4-node multiprocessor working brinch hansen wrote portable edison compiler pdp 11/55 shortly united technologies acquired mostek cancelled project 1982 brinch hansen moved edison system ibm pc published third book programming personal computer 1982 brinch hansen named first henry salvatori professor computer science usc 1984 feeling homesick denmark fourteen years abroad brinch hansen left usc joined faculty university copenhagen professor datalogy 1985 elected fellow ieee later 1985 fourth book brinch hansen pascal compilers used compiler course published designing multicomputer operating system danish company gn elmi brinch hansen concluded needed new language time leveraging message passing paradigm hoare csp resulting language joyce removed major limitation csp introducing parallel recursion brinch hansen developed portable implementation ibm pc finding neither family felt home denmark brinch hansen decided return us discovered immigration status required quickly brinch hansen contacted john reynolds syracuse university 1987 joined faculty distinguished professor working student rangachari anand joyce moved encore multimax 320 multiprocessor su northeast parallel architectures center recognizing scaling limitations multiprocessors however brinch hansen sought suitable multicomputer work acquiring meiko computing surface 1989 began experimenting scientific applications developing parallel programs householder reduction n-body simulation learning exercises surprised find programs nearly identical control structures concluding fit all-pairs paradigm focused exploring reusable parallel algorithm structures termed programming paradigms generic programs later popularly known design patterns 1995 brinch hansen fifth book studies computational science parallel programming paradigms published programs rewritten superpascal fully implemented publication language created parallel algorithms later years brinch hansen published retrospective important papers search simplicity 1996 text course programming non-majors programming everyone java 1999 retrospective evolution operating systems classic operating systems batch processing distributed systems 2001 retrospective evolution concurrent programming origin concurrent programming semaphores remote procedure calls 2002 self-published 2004 memoir programmer story life computer pioneer website 2002 brinch hansen awarded ieee computer pioneer award pioneering development operating systems concurrent programming exemplified work rc 4000 multiprogramming system monitors concurrent pascal july 31 2007 brinch hansen died shortly diagnosed terminal cancer brinch hansen met wife milena née hrastar class trip yugoslavia 1962 married 1965 two children daughter mette son thomas career spanning five decades brinch hansen made seminal contributions areas operating systems concurrent computing parallel distributed computing influential shaping development fields advancing ad hoc techniques systematic engineering disciplines impact work amplified relentless search simplicity insistence clarity writing rewriting papers many times publishing becoming one best explainers business commitment testing concepts working systems – brinch hansen implemented distributed working systems new concepts developed noting rc 4000 multiprogramming system introduced now-standard concept operating system kernel separation policy mechanism operating system design modern microkernel architectures trace roots extensible nucleus architecture rc 4000 improving microkernel performance major theme operating system research three decades rc 4000 brinch hansen text operating system principles first comprehensive textbook operating systems eventually published six languages english japanese german czech polish serbo-croatian remained print decades years rc 4000 system described become outdated 1990 nearly two decades initial publication p.j plauger reviewed saying 2005 acm members voted operating system principles top 25 classic book survey choose out-of-print classic books add acm digital library operating system principles ranked 15th survey appearing 8.8 ballots available acm digital library using concurrent pascal brinch hansen demonstrated feasible fully implement operating systems high level languages reduced development effort one two orders magnitude furthermore entire operating systems could published understood entirety brinch hansen precisely architecture concurrent programs leading roy maddux harlan mills declare part two book indeed remarkable entire operating system visible every line program open scrutiny hidden mystery studying extensive examples reader feels could tackle similar jobs could change system never seen operating system shown detail manner amenable modification brinch hansen hoare developed monitor concept brinch hansen published first monitor notation adopting class concept simula 67 invented queueing mechanism hoare refined rules process resumption brinch hansen created first implementation monitors concurrent pascal dozen additional monitor-based languages created 1990 simone modula csp/k ccnpascal ply pascal plus mesa sb-mod concurrent euclid pascalc concurrent c emerald real-time euclid pascal-fc turing plus predula concurrent pascal first concurrent programming language first language developed specifically concurrent programming importantly first language demonstrate possible incorporate secure high-level facilities concurrency system could guarantee processes access disjoint sets variables interfere time dependent ways hoare described outstanding example best academic research area source portable code concurrent pascal solo operating system distributed least 75 companies 100 universities 21 countries resulting widespread adoption porting adaptation industry academia greg andrews observed concurrent pascal monitors greatly influenced subsequent concurrent language proposals brinch hansen architecture concurrent programs first book concurrent programming eventually published three languages english japanese german dozen years publication p. j. plauger observed sure improvements made past dozen years better synchronization algorithms fancier necessarily better languages concurrency control wo n't find better overview concurrent programming book least n't found one 2005 acm members voted architecture concurrent programs top 25 classic book ranking 18th survey appearing 8 ballots available acm digital library remote procedure calls used modern operating systems trace roots back rc 4000 multiprogramming system used request-response communication protocol process synchronization 1978 paper distributed processes brinch hansen proposed language distributed computing based external requests consisting procedure calls processes later became known operating system context remote procedure call later brinch hansen developed two languages extending hoare csp message-passing paradigm parallel recursion showed efficiently implement
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Programming language topics
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pme aggregation function pme aggregation function paf computer networking mechanism defined clause 61 ieee 802.3 standard allows one physical medium entities pmes combined together form single logical ethernet link paf located physical coding sublayer pcs media access control mac -phy rate matching function transmission convergence tc sublayer interfaces pmes across λ-interface mac-phy rate matching function using abstract interface paf optional function defined 2007 two ieee 802.3 interfaces 2base-tl 10pass-ts ethernet first mile efm copper physical layers pme aggregation function following characteristics paf transmit function works fragmenting incoming ethernet frames number fragments limited size range 64 512 bytes sequential fragmentation header prepended fragment indicating fragment start-of-packet end-of-packet middle packet frame check sequence fcs appended fragment transmitted next available active pme aggregated group following diagram illustrates paf fragmentation paf receive function reassembles original frames received fragments buffered per-mac fragment buffer algorithm uses fragmentation header make sure reassembled frames order pme aggregation function first defined ieee 802.3ah 2004 original loop aggregation proposal submitted klaus fosmark defunct first mile systems 2001 later referenced itu-t g.998.2 ethernet-based multi-pair bonding ansi equivalent nipp-nai t1.427.02 paf algorithm fragmentation header similar mlppp works layer 3 ip paf asymmetric protocol i.e information required reassembly contained fragmentation header sent fragment allowing great flexibility transmitter receiver implementations requires overhead consuming 5 bandwidth estimation 2base-tl protocol including 64b/65b encapsulation paf optimized ethernet traffic inverse multiplexing atm ima another aggregation protocol unlike paf uses fixed size cells sending across multiple links round-robin fashion ima optimized atm extreme cases short ethernet frames may add much 40 overhead due aal5 encapsulation itu-t g.998.3 multi-pair bonding using time-division inverse multiplexing specification a.k.a g.bond/tdim defines symmetric aggregation protocol sides point-to-point link exchange information aggregation need separate header g.bond/tdim optimized time-division multiplexing packet traffic less 3 overhead estimation ethernet traffic including generic framing procedure gfp encapsulation
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Internet protocols
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intel 82288 intel 82288 bus controller designed intel 80286 chip supplied 20-pin dip package replaces 8288 used earlier processors
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Computer architecture
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cannon lake microarchitecture cannon lake formerly skymont intel codename 10-nanometer die shrink kaby lake microarchitecture die shrink cannon lake new process intel process-architecture-optimization execution plan next step semiconductor fabrication cannon lake cpus first mainstream cpus include avx-512 instruction set prior cannon lake launch intel launched another 14 nm process refinement codename coffee lake successor cannon lake microarchitecture ice lake represents architecture phase intel process-architecture-optimization model cannon lake initially expected released 2015/2016 release pushed back 2018 intel demonstrated laptop unknown cannon lake cpu ces 2017 announced cannon lake based products would available 2018 earliest ces 2018 intel announced started shipping mobile cannon lake cpus end 2017 would ramp production 2018 april 26 2018 report first-quarter 2018 financial results intel stated currently shipping low-volume 10 nm product expects 10 nm volume production shift 2019 july 2018 intel announced volume production cannon lake would delayed yet late q2 2019 first laptop featuring cannon lake cpu namely intel core i3-8121u dual core cpu hyperthreading turbo boost without integrated gpu released may 2018 limited quantities august 16 2018 intel announced two new models nucs would use 10nm cannon lake-u i3-8121u cpu models later became readily available retail late november 2018
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Computer architecture
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yield multithreading computer science yield action occurs computer program multithreading forcing processor relinquish control current running thread sending end running queue scheduling priority different programming languages implement yielding various ways coroutines fine-grained concurrency primitive may required yield explicitly may enable specifying another function take control coroutines explicitly yield allow cooperative multitasking
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Operating systems
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focal point data risk focal point data risk llc commonly known focal point risk management consulting firm based tampa fl focal point formed january 2017 result merger sunera aptec llc anrc llc company provides range cybersecurity risk management cybersecurity workforce development enterprise technology implementation services 2017 focal point named former cisco executive brian marlier chief executive officer focal point publishes annual cyber balance sheet report covering board-level cyber issues focal point originally founded sunera april 2005 former kpmg partners executives sunera focused original service offerings controls testing vulnerability assessments internal audit sarbanes-oxley compliance 2014 sunera acquired cyber risk management company formed norwest equity partners halyard capital partners sunera cyber risk management acquired anrc cyber security training provider 2014 aptec llc identity access management solutions integrator 2015 february 6 2015 florida governor rick scott announced expansion company ’ tampa headquarters expansion brought 41 new jobs 2015 2018
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Computer security
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tuxonice tuxonice formerly known suspend2 implementation suspend-to-disk hibernate feature available patches 2.6 linux kernel 2.5 kernel era pavel machek forked original out-of-tree version swsusp approximately beta 10 got merged vanilla kernel development continued swsusp/suspend2/tuxonice line tuxonice includes support smp highmem preemption major advantages swsusp tuxonice originally called 'suspend2 beta releases time pavel forked code base 1.0 release 2.0 release name 'suspend2 developed contraction 'software suspend 2.x efforts made time merge tuxonice vanilla kernel opposed pavel primarily seems pavel believes much suspend-to-disk process run userspace see uswsusp nigel cunningham thinks code belongs kernel nigel stated desire frustration getting tuxonice specific features merged back mainline currently actively pursuing
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Computer architecture
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andy bill law andy bill law statement regarding relationship hardware software upgrades law originates humorous one-liner told 1990s computing conferences andy giveth bill taketh away phrase riff upon business strategies former intel ceo andy grove former ceo microsoft bill gates intel microsoft entered lucrative partnership 1980s 1990s standard chipsets microsoft windows intel brand despite profit intel gained deal grove felt gates n't making full use powerful capabilities intel chips fact refusing upgrade software achieve optimum hardware performance grove frustration dominance microsoft software intel hardware became public spawned humorous catchphrase later andy bill law new software always push ahead hardware get credit performance computer
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Computer architecture
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international thylacine specimen database international thylacine specimen database itsd culmination four-year research project catalogue digitally photograph known surviving specimen material thylacine thylacinus cynocephalus tasmanian tiger held within museum university private collections itsd first published electronic resource series three cd-roms april 2005 updated july 2006 completely revised may 2009 released single dvd totalling 3.68 gb data images itsd designed free access academic tool promote facilitate undergraduate postgraduate research species accessed offices curators heads department universities museums hold thylacine material alternatively libraries several major zoological societies itsd lists available catalogue data individual specimen e.g holding institution catalogue identification number sex date acquisition specimen type source locality collector field number old additional catalogue numbers purchase exchange information finally additional remarks pertaining specimen support data component significantly enhance educational worth high-resolution digital images specimens included itsd specimen image bank forms largest single photographic resource kind anywhere world primary justification including digital images specimen material within itsd comprises skins skeletons skulls taxidermy mounts wet specimens wet specimens whole animals organs body parts preserved either alcohol formalin specimens thylacine spread extensively around globe search locate specimens outset international search involving total 106 museum university private collections 23 countries master copy itsd held zoological society london mirror copies held within university tasmania hobart australian national wildlife collection canberra queen victoria museum art gallery launceston master mirror copies kept constantly revised updated new information comes light zoological society chosen hold master copy itsd historic association thylacine bulk early scientific papers species published within proceedings society zoo regent park exhibited thylacines zoo outside australia year royal zoological society new south wales hosts whitley awards awards tribute gilbert whitley eminent australian ichthyologist presented outstanding publications contain significant amount new information relating fauna australasian region september 2005 international thylacine specimen database awarded whitley award best zoological database first time history awards whitley citation presented database
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Databases
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applocker applocker application whitelisting technology introduced microsoft windows 7 operating system allows restricting programs users execute based program path publisher hash enterprise configured via group policy windows applocker allows administrators control executable files denied allowed execute applocker administrators able create rules based file names publishers file location allow certain files execute unlike earlier software restriction policies originally available windows xp windows server 2003 applocker rules apply individuals groups policies used group users different enforcement levels example users added 'audit policy allow administrators see rule violations moving user higher enforcement level several generic techniques bypassing applocker
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Operating systems
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espresso microprocessor espresso codename 32-bit central processing unit cpu used nintendo wii u video game console designed ibm produced using 45 nm silicon-on-insulator process espresso chip resides together gpu amd mcm manufactured renesas revealed e3 2011 june 2011 released november 2012 ibm nintendo revealed espresso processor powerpc-based microprocessor three cores single chip reduce power consumption increase speed cpu graphics processor placed single substrate multi-chip module mcm reduce complexity increase communication speed chips reduce power consumption reduce cost space required two chips assembled complete mcm renesas japan espresso manufactured ibm 300 mm plant east fishkill new york using 45 nm soi-technology embedded dram edram caches unverified nintendo hackers teardowns unofficial informants since revealed information espresso name size speed microarchitecture seems quite similar predecessors broadway gekko i.e powerpc 750 based enhanced larger faster caches multiprocessor support rumors wii u cpu derived ibm high-end power7 server processor proved false presumably order cut costs espresso shares technology power7 edram general instruction set similarities superficial similarities following specifications officially confirmed either nintendo ibm obtained reverse engineering hacker hector martin goes alias marcan
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Computer architecture
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ioactive ioactive independent computer security company active several areas known reporting high severity security vulnerabilities variety products ioactive offices seattle london dubai madrid
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Computer security
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p3p platform privacy preferences project p3p obsolete protocol allowing websites declare intended use information collect web browser users designed give users control personal information browsing p3p developed world wide web consortium w3c officially recommended april 16 2002 development ceased shortly thereafter implementations p3p microsoft internet explorer edge major browsers support p3p microsoft ended support windows 10 onwards microsoft internet explorer edge windows 10 longer support p3p president truste stated p3p implemented widely due difficulty lack value world wide web became genuine medium sell products services electronic commerce websites tried collect information people purchased merchandise companies used controversial practices tracker cookies ascertain users demographic information buying habits using information provide specifically targeted advertisements users saw invasion privacy would sometimes turn http cookies use proxy servers keep personal information secure p3p designed give users precise control kind information allow release according w3c main goal p3p “ increase user trust confidence web technical empowerment. ” p3p machine-readable language helps express website ’ data management practices p3p manages information privacy policies website uses p3p set set policies allows state intended uses personal information may gathered site visitors user decides use p3p set set policies state personal information allow seen sites visit user visits site p3p compare personal information user willing release information server wants get – two match p3p inform user ask he/she willing proceed site risk giving personal information example user may store browser preferences information browsing habits collected policy website states cookie used purpose browser automatically rejects cookie main content privacy policy following privacy policy retrieved xml file included compact form http header location xml policy file applies given document p3p allows specify codice_1 caching dummy /w3c/p3p.xml file could use feature microsoft internet explorer edge mainstream web browsers supported p3p browsers implemented due perceived lack value provides ie provides ability display p3p privacy policies compare p3p policy browser settings decide whether allow cookies particular site however p3p functionality internet explorer extends cookie blocking alert user entire web site violates active privacy preferences microsoft considers feature deprecated browsers totally removed p3p support windows 10 mozilla supported p3p features years p3p related source code removed 2007 privacy finder service also created carnegie mellon usable privacy security laboratory publicly available p3p-enabled search engine user enter search term along stated privacy preferences presented list search results ordered based whether sites comply preferences works crawling web maintaining p3p cache every site ever appears search query cache updated every 24 hours every policy guaranteed relatively date service also allows users quickly determine site comply preferences well allowing view dynamically generated natural language privacy policy based p3p data advantageous simply reading original natural language privacy policy web site many privacy policies written legalese extremely convoluted additionally case user visit web site read privacy policy p3p allows browsers understand privacy policies simplified organized manner rather searching throughout entire website setting privacy settings certain level user enables p3p automatically block cookies user might want computer additionally w3c explains p3p allow browsers transfer user data services ultimately promoting online sharing community additionally p3p toolbox developed internet education foundation recommends anyone concerned increasing users ’ trust privacy consider implementing p3p p3p toolbox site explains companies taken individuals data order promote new products services furthermore recent years companies taken individuals information created profiles market without individual consent moreover data misused consumers pay price become worrisome issues junk mail identity theft forms discrimination therefore implementing p3p protocol good beneficial internet browsers moreover since increase browsers users risk running privacy problems internet education foundation points “ p3p developed help steer force technology step toward automatic communication data management practices individual privacy preferences. ” electronic privacy information center epic critical p3p believes p3p makes difficult users protect privacy 2002 assessed p3p referred technology “ pretty poor policy ” according epic p3p software complex difficult average person understand many internet users unfamiliar use default p3p software computers install additional p3p software another concern websites obligated use p3p neither internet users moreover epic website claims p3ps protocol would become burdensome browser beneficial efficient intended key problem occurs use p3p lack enforcement thus promises made users p3p go unfulfilled though using p3p company/website makes promise privacy use gathered data site ’ users real legal ramifications company decides use information functions currently actual laws passed united states data protection though ideally companies honest use customers personal information binding reason company must actually adhere rules says comply though using p3p technically qualifies contract lack federal regulation downplays need companies abide agreement use p3p puts place unenforceable promises also prolongs adoption federal laws would actually inhibit access ability use private information government step attempt protect internet users federal laws information accessed specific regulations user information used companies ’ maintain leeway use information please despite may actually tell users 2002 epic employee chris hoofnagle argued p3p displacing chances government regulation privacy critics p3p also argue non-compliant sites excluded according study done cylab privacy interest group carnegie mellon university 15 top 5,000 websites incorporate p3p therefore many sites ’ include code practice high privacy standards accessible users use p3p online privacy guide epic also talks development implementation p3p cause monopoly private information since tends major companies implement p3p websites major companies tending gather information seeing privacy policies compare privacy preferences users epic website says incredible complexity p3p combined way popular browsers likely implement protocol would seem preclude privacy-protective technology epic continues state rather p3p may actually strengthen monopoly position personal information u.s. data marketers enjoy failure immediate adoption related idea notice choice approach ’ comply fair information practices according chairman ftc privacy laws key today ’ society order protect consumer providing much personal information others ’ benefit believe limit collection use consumer ’ personal data online currently sites required united states laws comply privacy policies publish therefore p3p causes controversy consumers concerned release personal information able rely p3p ’ protocol protect privacy michael kaply ibm reported saying following mozilla foundation considering removal p3p support browser-line 2004 ah memories ibm wrote original p3p implementation netscape proceeded write companies wasted immense amounts time everyone thought crappy proposal begin remove live leer pr manager opera software explained 2001 deliberate lack p3p support browser moment n't sure whether p3p best solution p3p among specifications considering support future issues well p3p protect privacy reason decided wait resolved p3p user agents option available internet users want ensure privacy several main alternatives p3p include using web browsers privacy mode anonymous e-mailers anonymous proxy servers main alternative p3p may technologies instead stronger laws regulate kind information internet users collected retained websites example europe data protection directive provides individuals certain set principles personal information collected person rights protecting personal data act allows individuals control type information collected various principles included within act rule individual right retrieve data collected time certain conditions moreover individual personal information kept longer necessary personal information released others unless individual gives consent currently united states federal law protecting privacy personal information shared online however sectoral laws federal state level offer protection certain types information collected individuals example fair credit reporting act fcra 1970 makes legal consumer reporting agencies disclose personal information three specified circumstances credit employment insurance evaluation government grant license “ legitimate business need ” involves consumer list sectoral privacy laws united states viewed consumer privacy guide website many groups working future p3p make easier people use groups transparent accountable datamining initiative tami group mit ’ computer science artificial intelligence laboratory goal tami create technical legal policy foundations transparency accountability large-scale aggregation tami hopes help people manage privacy risks world technology constantly changing policy aware web paw scalable mechanism exchange rules proofs unlimited access control web “ creates system policy aware infrastructure using systematic web rules language theorem prover ”
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Web technology
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commotion wireless commotion wireless open-source wireless mesh network electronic communication project developed open technology institute development included 2 million grant united states department state 2011 use mobile ad hoc network manet concomitant arab spring preliminarily deployed detroit late 2012 launched generally march 2013 project called internet suitcase commotion 1.0 first non-beta release launched december 30 2013 commotion relies several open source projects olsr openwrt openbts serval project ubiquiti tp-link mikrotik
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Distributed computing architecture
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lamebook lamebook blog re-posts 'everything lame funny social networking site facebook users send screenshots unusual amusing facebook posts re-posted site every weekday jonathan standefer matthew genitempo graphic designers austin texas launched web site april 2009 facebook parody site two acquaintances baylor university yet became friends graduated 2005 started lamebook little meeting months got popular able quit jobs offices full time said genitempo graduated 2007 degree graphic design brought lot different design opportunities us last names faces blurred pixellated upon upload avoid invasion privacy content removed request lamebook also discourages users trying contact people seen posts sites lamebook would existence without concept oversharing overshare word year 2008 webster new world® college dictionary defined much information either intentionally accidentally revealed editors webster new world explain new word old phenomenon made much easier emergence modern technology ease combined wide reach many social networking sites allow users made oversharing quite common occurrence today according huffington post online oversharers 32 say experienced poster ’ remorse regretted posting certain information lamebook cocreator jonathan standefer quoted saying people overshare internet favorite ones used mushy ones fights funniest like fighting drunk one friends everyone else room views lamebook forum people vent inappropriate cringe-worthy things inevitably seen facebook glamour magazine described facebook personal confession booth air dirty laundry sitting behind computer screen people often forget everyone else room facebook anything posted outside private message seen many people one communicated leads kinds content people submit lamebook couple fights inappropriate pictures embarrassing statuses etc march 2010 facebook contacted lamebook alleging website infringed diluted facebook trademark requested lamebook cease desist using lamebook mark change name look website 4 november 2010 lamebook filed legal action facebook seeking declaration website infringe rights facebook protection parody first amendment response 11 november facebook sued lamebook trademark infringement claiming site parody provide critique comment facebook 22 november 2010 facebook confirmed deleted lamebook fan page blocked 'like function lamebook powered facebook blocked facebook users able type word lamebook facebook facebook cto bret taylor later conceded mistake part process dealing routine trademark violation issue regarding links posted facebook blocked mentions phrase “ lamebook ” facebook committed promoting free expression facebook apologize mistake case working fix process led happening conor civins one lamebook lawyers said lamebook parody website supposed social commentary protected free speech lamebook website litigation process banner asking viewers support efforts facebook read really love running lamebook aside laughs represents opportunity work incredibly fun project buddies makes lot people happy still allows us make rent end month … problem facebook ’ get joke ’ decided pick little guys small business owners seem match multi-billion dollar behemoth one website ’ going without fight dispute came end facebook efforts relocate litigation process austin texas palo alto california denied texas federal judge joint statement released 25 august 2011 companies proclaimed pleased arrive agreement protects facebook brand trademark allows lamebook continued operation parties satisfied users likely confused thus forth lamebook permitted continue name yet must add disclaimer website reads unofficial parody affiliated associated endorsed approved facebook lamebook also allowed seek trademark protection name lamebook best worst facebook expected released chronicle books 2012
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Web technology
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star force released north america video ware arcades mega force vertically scrolling shooter released 1984 tehkan game player pilots starship called final star shooting various enemies destroying enemy structures points unlike later vertical scrolling shooters like toaplan twin cobra final star two levels weapon power secondary weapons like missiles and/or bombs stage game named letter greek alphabet certain versions game additional level called infinity represented infinity symbol occurs omega game repeats indefinitely nes version defeating omega target player see black screen tecmo logo announcing future release sequel super star force infinity target becomes available game repeats level boss without increasing difficulty star force ported published 1985 hudson soft msx home computer family computer famicom japan north american version nintendo entertainment system nes published 1987 tecmo although nes version hudson port released famicom japan tecmo made alterations graphics music control increased difficulty game also despite u.s. arcade version titled mega force tecmo decided release nes version original name star force star force also ported sg-1000 sega x68000 dempa shinbunsha mobile phones tecmo 1995 along two nes shooters famicom version star force remade hudson soft minimal upgrades super famicom part japan-only release caravan shooting collection version also included hudson compilation nes shooters 2006 hudson best collection vol 5 original arcade version later added compilation titled tecmo classic arcade released xbox 2009 arcade version made available download wii virtual console 500 wii points one four initial offerings virtual console arcade category wii shop channel three gaplus mappy tower druaga namco
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Computer architecture
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broadwell microarchitecture broadwell intel codename 14 nanometer die shrink haswell microarchitecture tick intel tick–tock principle next step semiconductor fabrication like previous tick-tock iterations broadwell completely replace full range cpus previous microarchitecture haswell low-end desktop cpus based broadwell processors based broadwell microarchitecture marketed 5th-generation core i3 i5 i7 processors moniker however used marketing broadwell-based celeron pentium xeon chips microarchitecture also introduced core processor branding broadwell h c variants used conjunction intel 9 series chipsets z97 h97 hm97 addition retaining backward compatibility intel 8 series chipsets broadwell launched three major variants broadwell introduces instruction set architecture extensions broadwell intel quick sync video hardware video decoder adds vp8 hardware decoding encoding support adds vp9 hevc 10-bit decoding support integrated gpu hevc decode achieved combination fixed function video decoder shaders also two independent bit stream decoder bsd rings process video commands gt3 gpus allows one bsd ring process decoding bsd ring process encoding time broadwell integrated gpu supports windows direct3d 11.2 opengl 4.4 opengl 4.5 linux opencl 2.0 however marketed direct3d-12-ready broadwell-e introduced intel turbo boost max technology 3.0 september 10 2013 intel showcased broadwell 14 nm processor demonstration idf intel ceo brian krzanich claimed chip would allow systems provide 30 percent improvement power use haswell chips released mid-2013 krzanich also claimed chips would ship end 2013 however shipment delayed due low yields intel 14 nm process october 21 2013 leaked intel roadmap indicated late 2014 early 2015 release k-series broadwell lga 1150 platform parallel previously announced haswell refresh would coincide release intel 9-series chipset would required broadwell processors due change power specifications lga 1150 socket reuters quoted intel ceo promising broadwell-based pcs would shelves holiday season probably back-to-school shopping mobile cpus expected q4 2014 high-performance quad-core cpus 2015 mobile cpus would benefit reduced energy consumption die shrink intel told cnet specialized broadwell-based products would q4 2014 broader availability including mobile cpus would happen 2015. broadwell cpus available intel hardware partners sample quantities intel expected release 17 broadwell u series family microprocessors ces 2015 also according leak posted vr-zone broadwell-e chips would available 2016 intel unveiled formally 14 nm manufacturing process indicated mobile variants process would known core products additionally core products announced shipping end 2014 desktop variants shipping shortly broadwell intel focused mainly laptops miniature desktops all-in-one systems left traditional desktop users new socketed cpu options beyond fourth-generation haswell first arrived 2013 even though company finally introduced two broadwell desktop chips summer 2015 launched high-end sixth-generation skylake cpus shortly thereafter september 2015 kirk skaugen senior vice president general manager intel client computing group admitted skipping desktops broadwell poor decision end-of-life windows xp 2014 lack new desktop chips intel given desktop pc users good reasons upgrade 2015 intel launched first three broadwell-based processors belong low-tdp core family core 5y10 core 5y10a core 5y70 first laptop broadwell intel core 5y70 cpu lenovo yoga 3 pro launched four broadwell based cpus launched belonging core family increasing number launched broadwell cpus seven 17 additional broadwell laptop cpus launched celeron pentium core i3 i5 i7 series intel officially launched 14 nm broadwell-ep xeon e5 v4 cpus intel officially launched 14 nm broadwell-e core i7 69xx/68xx processor family
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Computer architecture
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operating system service management computing mechanisms techniques managing services often differ operating system examples operating system service management init
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Operating systems
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comparison streaming media systems comparison streaming media systems complete list streaming media systems also available following tables compare general technical information number streaming media systems audio video please see individual systems linked articles information information digital container formats supported information internet protocols supported broadcasting streaming media content
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Distributed computing architecture
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macintosh quadra 630 macintosh quadra 630 also sold macintosh lc 630 macintosh performa 630 personal computer designed manufactured sold apple computer inc. july 1994 october 1995 introduced replacement quadra 610 least-expensive computer macintosh lineup prices starting 1,199 usd apple transition powerpc cpus already begun introduction power macintosh months prior 630 built around older motorola 68040 68lc040 chips two reasons cited one older chips less expensive two powerpc-native education software almost non-existent time also existing powerpc software yet translated non-english languages 630 last new macintosh quadra introduced though earlier quadra 950 remained available longer discontinued direct replacement 630 form factor retained power macintosh 6200 introduced months earlier entry price 2,300 cost nearly twice much power macintosh 4400 apple inexpensive power macintosh 1,725 still cost several hundred dollars 630 form factor quadra 630 introduced new case design macintosh family front headphone jack volume up/down buttons included first macintosh infrared receiver intended use remote included tv tuner card included performa 637cd 638cd models case motherboard accessible opening cover bottom rear case sliding drawer motherboard mounted similar lc 575 memory 630 models 4 mb memory soldered logic board depending logic board system either one two simm slots cases first simm slot requires 80nm non-parity chips refresh rate 2k better 4 8 16 32 mb simms work second slot supports single-sided simm cards 16 mb size maximum memory therefore 52 mb two-slot systems 36 mb one-slot systems hard drive controller one big differences compared previous macintosh models choice internal hard drive interface conforming standards ibm pc compatible platform cheaper slower ide drives used instead scsi first time external scsi port still available cd-rom used scsi internally 630 used older controller much slower ones used higher-end macs time video one external monitor supported db-15 connector non-upgradeable 1 mb dram soldered motherboard provides resolution 640x480 16-bit color 832x624 8-bit color separate video card required 24-bit color higher resolutions choice use dram instead vram saves money due commonality results lower performance increased chance flickering testing macworld described video performance quadra 630 mediocre cd-rom models equipped cd-rom use apple cd 300i plus 2x-speed scsi drive capable reading 656mb 748mb data cds well audio cds caddy tray quadra 610 replaced tray-based loading mechanism remote control models equipped tv/video system included sony rmc-a1 remote control consequently remote would control macintosh compatible sony television time performance macworld magazine ran benchmarks time quadra release reported performance similar quadra 950 slightly slower 800 quadra 630 different names depending target market macintosh quadra 630 professional business use macintosh lc 630 k-12 educational market macintosh performa 630 consumer higher-education markets performa 630 sold several slightly different model numbers depending included hardware software features models included 14 shadow mask crt called apple performa plus display introduced july 1 1994 introduced july 18 1994 introduced november 3 1994 introduced april 3 1995 introduced may 1 1995 introduced july 17 1995
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Computer architecture
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hardware-based full disk encryption hardware-based full disk encryption fde available many hard disk drive hdd vendors including istorage limited seagate technology hitachi western digital samsung toshiba also solid-state drive vendors ocz sandisk samsung micron integral memory symmetric encryption key maintained independently cpu thus removing computer memory potential attack vector relation hard disk drives term self-encrypting drive sed common usage hardware-fde two major components hardware encryptor data store currently three varieties hardware-fde common use hdd fde made hdd vendors using opal enterprise standards developed trusted computing group key management takes place within hard disk controller encryption keys 128 256 bit advanced encryption standard aes keys authentication power drive must still take place within cpu via either software pre-boot authentication environment i.e. software-based full disk encryption component hybrid full disk encryption bios password hitachi micron seagate samsung toshiba disk drive manufacturers offering tcg opal sata drives older technologies include proprietary seagate drivetrust older less secure pata security command standard shipped drive makers including western digital enterprise sas versions tcg standard called tcg enterprise drives within standard hard drive form factor case encryptor bc smaller form factor commercially available hard disk drive enclosed example viasat formerly stonewood electronics flagstone eclypt drives encryptor bridge chipset bc placed computer standard hard disk drive encrypting every sector written intel announced release danbury chipset since abandoned approach hardware-based encryption built drive within drive enclosure notably transparent user drive except bootup authentication operates like drive degradation performance complication performance overhead unlike disk encryption software since encryption invisible operating system host computers processor two main use cases data rest protection cryptographic disk erasure data rest protection laptop simply powered disk self-protects data data safe even os encrypted secure mode aes locked reading writing drive requires authentication code strong 32 bytes 2^256 unlock crypto-shredding practice 'deleting data deleting overwriting encryption keys cryptographic disk erasure crypto erase command given proper authentication credentials drive self-generates new media encryption key goes 'new drive state without old key old data becomes irretrievable therefore efficient means providing disk sanitization lengthy costly process example unencrypted unclassified computer hard drive requires sanitizing conform department defense standards must overwritten 3+ times one terabyte enterprise sata3 disk would take many hours complete process although use faster solid-state drives ssd technologies improves situation take enterprise far slow problem worsen disk sizes increase every year encrypted drives complete secure data erasure action takes milliseconds simple key change drive safely repurposed quickly sanitization activity protected seds drive key management system built firmware order prevent accidental data erasure confirmation passwords secure authentications related original key required way retrieve data erased way keys self generated randomly record anywhere protecting data accidental loss theft achieved consistent comprehensive data backup policy recent hardware models circumvents booting devices allowing access using dual master boot record mbr system whereby mbr operating system data files encrypted along special mbr required boot operating system data requests intercepted sed firmware allow decryption take place unless system booted special sed operating system load mbr encrypted part drive works separate partition hidden view contains proprietary operating system encryption management system means boot methods allow access drive typical self-encrypting drives unlocked remain unlocked long power provided researchers universität erlangen-nürnberg demonstrated number attacks based moving drive another computer without cutting power additionally may possible reboot computer attacker-controlled operating system without cutting power drive computer self-encrypting drive put sleep mode drive powered encryption password retained memory drive quickly resumed without requesting password attacker take advantage gain easier physical access drive instance inserting extension cables firmware drive may compromised data sent may risk even data encrypted physical medium drive fact firmware controlled malicious third-party means decrypted third-party data encrypted operating system sent scrambled form drive would matter firmware malicious
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Computer file systems
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weblogic company weblogic company 1995 1998 credited creating first j2ee application server weblogic application server paul ambrose bob pasker laurie pitman carl resnikoff founded weblogic inc. september 1995 founders worked together pursue eventually became application server 1998 weblogic appointed ali kutay president ceo weblogic funded regis mckenna frank j. caufield bea systems acquired weblogic inc. 1998 oracle corporation acquired bea systems 2008
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Web technology
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degradation telecommunications telecommunication degradation loss quality electronic signal may categorized either graceful catastrophic following meanings several forms causes degradation electric signals time domain physical domain including runt pulse voltage spike jitter wander swim drift glitch ringing crosstalk antenna effect antenna effect ic manufacturing phase noise degradation usually refers reduction quality analog digital signal signal transmitted received undergoes changes undesirable changes called degradation degradation usually caused
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Computer security
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domain fronting domain fronting technique circumvents internet censorship obfuscating domain https connection working application layer domain fronting allows user connect service may otherwise blocked dns ip deep packet inspection one configuration large hosting service amazon s3 google app engine uses shared sni certificate containing common target https domains domain name actual blocked endpoint communicated establishment encrypted https connection http host header making invisible censors done blocked innocuous sites hosted large provider google app engine configurations allow content delivery network common https certificate infrastructure act reflector target server behind techniques work using different domain names different layers communication domain name innocuous site used initialize connection domain name exposed censor clear-text part dns request tls server name indication given domain name censors typically unable differentiate circumvention traffic legitimate traffic forced either allow traffic domain name including circumvention traffic block domain name entirely may result expensive collateral damage google disabled domain fronting april 2018 saying never supported feature google amazon also decided disable domain fronting cloudfront april 2018 claiming already handled breach aws terms service effort google amazon part due pressure russian government telegram domain fronting activity using cloud providers services
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Computer security
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openmoko openmoko project create family open source mobile phones including hardware specification operating system openmoko linux actual smartphone development implementation like neo 1973 neo freerunner whole project sponsored openmoko inc first sub-project openmoko linux linux-based operating system designed mobile phones built using free software second sub-project developing hardware devices openmoko linux runs first device released neo 1973 ref name= openmoko.org/wiki/neo1973 /ref 2007 followed neo freerunner 25 june 2008 2 april 2009 openmoko suspended development third device codenamed gta03 focus freerunner 2010 development gta03 continued golden delicious computers new codename gta04 includes major hardware revision first unit shipped 10 october 2011 unlike mobile phone platforms phones designed provide end users ability modify operating system software stack openmoko-supported phones also available project openmoko announced 7 november 2006 founders first international computer fic initial core team openmoko project included werner almesberger michael lauer sean moss-pultz harald welte name openmoko acronym open mobile kommunikations codename phone product series gta abbreviation gsm-ti-agps indicates main components phone originally openmoko inc. developed operating system phones called openmoko linux om uses linux kernel together graphical user environment built using x.org server openembedded build framework opkg package system used create maintain software packages initial version named om 2007 used gtk+ toolkit matchbox window manager om 2008 released august 2008 added support qt toolkit enlightenment 17 despite continuous improvements versions reach stable state result openmoko started developing om 2009 goal providing stable environment based middleware freesmartphone.org project financed openmoko however version finished either april 2009 openmoko cancelled development software task taken several efforts community several groups created modified versions original software ported systems work phones among others openmoko phones support android debian gentoo qt extended improved qtmoko shr openmoko hardware aspires term open-source hardware although various areas availability cell phone components legal requirements prevent full conformance term many vendors openmoko inc. notoriously failed meet publicly announced hardware release dates postponed releases many times first supported phone neo 1973 gta01 version bv4 distributed exclusively openmoko.com july 2007 february 2008 second revision hardware based gta01 design dash express automotive navigation system dash express faster cpu samsung 2440 wi-fi ability third hardware platform neo freerunner codenamed gta02 improved version neo 1973 neo 1973 codenamed gta01 phone developers release device named first year cellular telephone communication inventor cellular phone martin cooper made first call 1973 phone released inconsistently-named neo 1973 neo1973 neo 1973 sold july 9 2007 february 2008 priced us 300 basic model us 450 kit including tools hardware work initial releases neo 1973 hampered supplier shortages forced shipping date slip hardware development difficulties exacerbated small size core team furthermore platforms ported neo 1973 including qt extended debian android phone supports 900 mhz 1800 mhz 1900 mhz gsm frequency bands many linux unix programs used desktop server platforms including utilities games successfully run phone addition linux netbsd freebsd l4 kernels adapted users run platform development hardware platform emulated software high level compatibility using version qemu included openmoko software suite shortly shipping successor neo freerunner openmoko project released cad files schematics development resources neo 1973 freerunner creative commons license cc by-sa 3.0 schematics available download openmoko creative commons attribution sharealike license neo freerunner codenamed gta02 successor neo 1973 changes include faster processor clocked 400 mhz 802.11b/g wi-fi two accelerometers 3d graphics acceleration released mass market 25 june 2008 intended users high demand customizability neo freerunner started shipping june 24 2008 priced individually us 250 us 200 purchased multiples five debug board available us 99 neo freerunner includes features present development release phone neo 1973 changes include 802.11 b/g wi-fi smedia 3362 graphics accelerator two 3d accelerometers samsung 2442 soc 256 mb flash memory 2008.08 software revision gsm phone module working reliably freerunner hardware yet fully functional software interfaces software development split qtopia x11 gtk+ fso debian also derivates openmoko main distribution shr fdom fat dirty openmoko vanilla qtopia distribution recommended openmoko users wishing use early development stage software fdom want test latest features fixes without worrying stability also possible run inferno openmoko neo freerunner android patched run openmoko neo freerunner least two different developers openwrt compiled neo freerunner neo freerunner makes appearance william gibson 2010 novel zero history phone initially used character milgrim 2 january 2008 dash express gps device hardware developed openmoko inc. announced running openmoko linux device initially codenamed hxd8 seems use little none openmoko user-interface simply using patches kernel developed openmoko inc running application dash navigation provide navigation user interface lack reference material happened gta03 codename 3d7k openmoko built 3 working prototypes capacitive touchscreens fully transparent curved case latest product openmoko inc. wikireader device read wikipedia articles offline german engineering firm golden delicious computers began producing gta04 800 mhz cortex-a8 arm 1 ghz processor 800 mhz c64x+ dsp digital signal processor core 3d graphics accelerator specifications 512mb ram combined 512mb nand flash 32gb expandable microsdhc would similar performance iphone 4 iphone 4s golden delicious gta04 board designed exchange gta02 board neo freerunner housing gta01 board neo 1973 housing release openmoko beagle hybrid platform using beagle board basis developing prototyping next generation openmoko phone following month golden delicious stated long-term goal bringing phone market new gta04 board fit neo freerunner case connected existing display components first batch gta04a3 ea early adopter started shipping 10 october 2011 version gta04a4 first batch started shipping 31 january 2012 design next revision gta04a5 contained minor relevant upgrades design parts replacement end-of-life components production crowd funded also possible order ready made phone called openphoenux gta04 complete hardware
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Computer architecture
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swedish film database swedish film database internet database swedish films published swedish film institute contains information swedish films 1897 onwards foreign films cinema premiere sweden also provides lot biographies actors directors producers etc participated swedish films years created support bank sweden tercentenary foundation database comprises 62,000 films 17,000 swedish films 265,000 people
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Databases
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superframe telecommunications superframe sf t1 framing standard 1970s replaced original t1/d1 framing scheme 1960s framing bit simply alternated 0 1 superframe sometimes called d4 framing avoid confusion single-frequency signaling first supported d2 channel bank first widely deployed d4 channel bank order determine channel located stream data received set 24 channels aligned frame frame 192 bits long 8 24 terminated 193rd bit framing bit used find end frame order framing bit located receiving equipment predictable pattern sent bit equipment search bit correct pattern align framing based bit pattern sent 12 bits long every group 12 frames called superframe pattern used 193rd bit 100011 011100 channel sends two bits call supervision data superframe using robbed-bit signaling frames 6 12 superframe specifically 6th 12th bit superframe pattern least significant data bit channel bit 8 t1 data sent big-endian uses 1-origin numbering replaced channel-associated signalling bit bits b respectively superframe remained service many places turn century replaced improved extended superframe esf 1980s applications additional features desired
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Internet protocols
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wintel wintel partnership microsoft windows intel producing personal computers using intel x86-compatible processors running microsoft windows word wintel blend windows intel early 1980s chaos incompatibility rife early microcomputer market given way smaller number de facto industry standards including s-100 bus cp/m apple ii microsoft basic read-only memory rom inch floppy drive single firm controlled industry fierce competition ensured innovation hardware software rule rather exception microsoft windows intel processors gained ascendance ongoing alliance gave market dominance intel claimed partnership enabled two companies give customers benefit seemingly unending spiral falling prices rising performance addition claim history innovation shared vision flexible computing agile business 1981 ibm entered microcomputer market ibm pc created small subdivision firm unusual ibm product largely sourced outside component suppliers intended run third-party operating systems software ibm published technical specifications schematics pc allowed third-party companies produce compatible hardware so-called open architecture ibm pc became one successful computers time key feature ibm pc ibm enormous public respect behind accident history ibm pc happened intel cpu instead technically superior motorola 68000 tipped ibm in-house design shipped ibm pc dos licensed version microsoft ms-dos rather cp/m-86 operating system accidents enormous significance later years ibm pc ibm product ibm badge personal computers became respectable became easier business justify buying microcomputer even year two easiest justify buying ibm personal computer since pc architecture well documented ibm manuals pc dos designed similar earlier cp/m operating system pc soon thousands different third-party add-in cards software packages available made pc preferred option many since pc supported hardware software needed industry competitors took one several approaches changing market apple amiga atari acorn persevered independent quite different systems systems apple macintosh one remaining market macintoshes since december 2006 fact wintel-compatible hardware level least others digital world second-largest computer company hewlett-packard apricot concentrated making similar technically superior models early market leaders tandy-radio shack texas instruments stayed outdated architectures proprietary operating systems time belatedly realizing way market trends going switching successful long-term business strategy build machine duplicated ibm pc closely possible sell slightly lower price higher performance given conservative engineering early ibm personal computers higher average prices terribly difficult task first bar great technical challenge crafting bios duplicated function ibm bios exactly infringe copyrights two early leaders last strategy start-up companies columbia data products compaq first achieve reputations close compatibility ibm machines meant could run software written ibm machine without recompilation long ibm best-selling personal computer world least two next-best sellers practical purposes identical software industry effect profound first meant rational write ibm pc clones high priority port versions less common systems leisure second even importantly software writer pre-ibm days careful use plain subset possible techniques practicable able run hardware ran cp/m major part market using exact hardware similar clone practical take advantage every hardware-specific feature offered ibm independent bios companies like award chips technologies phoenix began market clean room bios 100 compatible ibm time competent computer manufacturer could achieve ibm compatibility matter routine around 1984 market fast growing relatively stable yet sign win half wintel though microsoft achieving enormous revenues dos sales ibm ever-growing list manufacturers agreed buy ms-dos license every machine made even shipped competing products intel every pc made either intel processor one made second source supplier license intel intel microsoft enormous revenues compaq many makers made far machines ibm power decide shape personal computer rested firmly ibm hands 1987 ibm introduced ps/2 computer line although open architecture pc successors great success biggest single manufacturer market buying faster cheaper ibm-compatible machines made firms ps/2s remained software compatible hardware quite different introduced technically superior micro channel architecture bus higher speed communication within system failed maintain open bus later called isa bus meant none millions existing add-in cards would function words new ibm machines ibm-compatible ibm planned ps/2 way technical legal reasons would difficult clone instead ibm offered sell ps/2 licence anyone could afford royalty would require royalty every ps/2-compatible machine sold also payment every ibm-compatible machine particular maker ever made past many pc manufacturers signed ps/2 licensees apricot lost badly persevering better pc ibm strategy time one many others many others decided hold committing major manufacturers known gang nine decided group together decide bus type would open manufacturers fast faster ibm microchannel yet still retain backward compatibility isa crucial turning point industry whole longer content let ibm make major decisions technical direction event new eisa bus commercial failure beyond high end time cost implementing eisa reduced extent would implemented desktop pcs much cheaper vesa local bus removed need desktop pcs though remained common servers due example possibility data corruption hard disk drives attached vlb controllers intel pci bus around corner although eisa systems sold achieved purpose ibm longer controlled computer industry ibm would belatedly amend ps/2 series ps/valuepoint line tracked features emerging ad hoc platform around time end 1980s beginning 1990s microsoft windows operating environment started become popular microsoft competitor digital research started recover share dos press dos market dr-dos ibm planned replace dos vastly superior os/2 originally ibm/microsoft joint venture unlike ps/2 hardware highly backward compatible microsoft preferred push industry direction product windows ibm suffering greatest ever public humiliation wake ps/2 disaster massive financial losses marked lack company unity direction microsoft combination soft marketing voice big financial stick effective windows became de facto standard competing computer manufacturers large small common factors provide joint technical leadership operating software microsoft cpus intel following years firms wintel partnership would attempt extend monopolies intel made successful major push motherboard chipset markets—becoming largest motherboard manufacturer world one stage almost chipset manufacturer—but badly fumbled attempt move graphics chip market 1991 faced sharp competition core cpu territory amd cyrix via transmeta microsoft fared better 1990 microsoft two competitors core market digital research ibm intel none 1996 intel two competitors core market cpus microsoft none microsoft pursued policy insisting per-processor royalties thus making competing operating systems unattractive computer manufacturers provoking regulatory scrutiny european commission us authorities leading undertaking microsoft cease practices however integration dos windows 95 masterstroke operating system vendors frozen microsoft could require computer manufacturers comply demands pain higher prices required ibm stop actively marketing os/2 else pay twice much windows 95 competitor compaq withholding designed windows 95 endorsement regarded essential hardware marketing tool microsoft also able require free publicity given hardware makers example windows key advertising symbols nearly modern keyboards strict license restrictions may may displayed system boot windows desktop also microsoft able take networking market formerly domain artisoft lantastic novell*s netware windows nt business application market formerly led lotus wordperfect microsoft office although microsoft far dominant player wintel partnership intel continuing influence underestimated intel microsoft closest partners operated uneasy distance one another since first major dispute intel heavy investment 32-bit optimized pentium pro microsoft delivery unexpectedly high proportion 16-bit code windows 95 firms talk one another competitors time time notably microsoft close relationship amd development windows xp professional x64 edition utilizing amd-designed 64-bit extensions x86 architecture intel decision sell processors apple inc wintel platform still dominant desktop laptop computer architecture opinions microsoft windows natural software bloat eaten much hardware progress intel processors gave wintel platform via moore law rise smartphones netbooks media outlets speculated predicting possible end wintel dominance cheap devices employing technologies intel investing linux microsoft ported windows arm architecture windows 8 strictest sense wintel refers computers run windows intel processor however wintel commonly used refer system running modern microsoft operating system modern x86 compatible cpu manufactured either intel amd pc applications run x86 intel processor usually run x86 amd processor mid-october 2017 microsoft announced windows 10 qualcomm snapdragon final stage testing would considered wintel systems running microsoft operating system using intel processor based itanium arm architecture despite fact processor manufactured intel also considered wintel system
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Computer architecture
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gnutella gnutella large peer-to-peer network first decentralized peer-to-peer network kind leading later networks adopting model celebrated decade existence march 14 2010 user base millions peer-to-peer file sharing june 2005 gnutella population 1.81 million computers increasing three million nodes january 2006 late 2007 popular file-sharing network internet estimated market share 40 first client also called gnutella network got name developed justin frankel tom pepper nullsoft early 2000 soon company acquisition aol march 14 program made available download nullsoft servers event prematurely announced slashdot thousands downloaded program day source code released later gnu general public license gpl however original developers never got chance accomplish purpose next day aol stopped availability program legal concerns restrained nullsoft work project stop gnutella days protocol reverse engineered compatible free open source clones began appear parallel development different clients different groups remains modus operandi gnutella development today among first independent gnutella pioneers gene kan spencer kimball launched first portal aimed assemble open-source community work gnutella also developed gnubile one first open-source gnu-gpl programs implement gnutella protocol gnutella network fully distributed alternative semi-centralized systems fasttrack kazaa original napster initial popularity network spurred napster threatened legal demise early 2001 growing surge popularity revealed limits initial protocol scalability early 2001 variations protocol first implemented proprietary closed source clients allowed improvement scalability instead treating every user client server users treated ultrapeers routing search requests responses users connected allowed network grow popularity late 2001 gnutella client limewire basic became free open source february 2002 morpheus commercial file sharing group abandoned fasttrack-based peer-to-peer software released new client based free open source gnutella client gnucleus word gnutella today refers one project piece software open protocol used various clients name portmanteau gnu nutella brand name italian hazelnut flavored spread supposedly frankel pepper ate lot nutella working original project intended license finished program gnu general public license gnutella associated gnu project gnu peer-to-peer network gnunet october 26 2010 popular gnutella client limewire ordered shut judge kimba wood united states district court southern district new york signed consent decree recording industry plaintiffs limewire agreed event likely cause notable drop size network negotiating injunction limewire staff inserted remote-disabling code software injunction came force users installed affected versions newer 5.5.10 cut p2p network since limewire free software nothing prevented creation forks omitted disabling code long limewire trademarks used shutdown affect example frostwire fork limewire created 2004 carries neither remote-disabling code adware november 9 2010 limewire resurrected secret team developers named limewire pirate edition based limewire 5.6 beta version server dependencies removed pro features enabled free envision gnutella originally worked imagine large circle users called nodes gnutella client software initial startup client software must bootstrap find least one node various methods used including pre-existing address list possibly working nodes shipped software using updated web caches known nodes called gnutella web caches udp host caches rarely even irc connected client requests list working addresses client tries connect nodes shipped well nodes receives clients reaches certain quota connects many nodes locally caching addresses yet tried discards addresses tried invalid user wants search client sends request actively connected node version 0.4 protocol number actively connected nodes client quite small around 5 node forwarded request actively connected nodes turn forwarded request packet reached predetermined number hops sender maximum 7 since version 0.6 2002 gnutella composite network made leaf nodes ultra nodes also called ultrapeers leaf nodes connected small number ultrapeers typically 3 ultrapeer connected 32 ultrapeers higher outdegree maximum number hops query travel lowered 4 leaves ultrapeers use query routing protocol exchange query routing table qrt table 64 ki-slots 2 mi-slots consisting hashed keywords leaf node sends qrt ultrapeers connected ultrapeers merge qrt leaves downsized 128 ki-slots plus qrt share files exchange neighbors query routing done hashing words query seeing whether match qrt ultrapeers check forwarding query leaf node also forwarding query peer ultra node provided last hop query travel search request turns result node result contacts searcher classic gnutella protocol response messages sent back along route query came query contain identifying information node scheme later revised search results delivered user datagram protocol udp directly node initiated search usually ultrapeer node thus current protocol queries carry ip address port number either node lowers amount traffic routed gnutella network making significantly scalable user decides download file negotiate file transfer node requested file firewalled querying node connect directly however node firewalled stopping source node receiving incoming connections client wanting download file sends so-called push request server remote client initiate connection instead push file first push requests routed along original chain used send query rather unreliable routes would often break routed packets always subject flow control therefore so-called push proxies introduced usually ultrapeers leaf node announced search results client connects one push proxies using http request proxy sends push request leaf behalf client normally also possible send push request udp push proxy efficient using tcp push proxies two advantages first ultrapeer-leaf connections stable routes makes push requests much reliable second reduces amount traffic routed gnutella network finally user disconnects client software saves list nodes actively connected collected pong packets use next time attempts connect becomes independent kind bootstrap services practice method searching gnutella network often unreliable node regular computer user constantly connecting disconnecting network never completely stable also bandwidth cost searching gnutella grew exponentially number connected users often saturating connections rendering slower nodes useless therefore search requests would often dropped queries reached small part network observation identified gnutella network unscalable distributed system inspired development distributed hash tables much scalable support exact-match rather keyword search address problems bottlenecks gnutella developers implemented tiered system ultrapeers leaves instead nodes considered equal nodes entering network kept 'edge network leaf responsible routing nodes capable routing messages promoted ultrapeers would accept leaf connections route searches network maintenance messages allowed searches propagate network allowed numerous alterations topology improved efficiency scalability greatly additionally gnutella adopted number techniques reduce traffic overhead make searches efficient notable query routing protocol qrp dynamic querying dq qrp search reaches clients likely files rare files searches grow vastly efficient dq search stops soon program acquired enough search results vastly reduces amount traffic caused popular searches gnutella users vast amount information improvements gnutella user-friendly style one benefits gnutella decentralized make difficult shut network make network users ones decide content available unlike napster entire network relied central server gnutella shut shutting one node impossible company control contents network also due many free open source gnutella clients share network gnutella operate purely query flooding-based protocol outdated gnutella version 0.4 network protocol employs five different packet types namely mainly concerned searching gnutella network file transfers handled using http development gnutella protocol currently led gnutella developers forum gdf many protocol extensions developed software vendors free gnutella developers gdf extensions include intelligent query routing sha-1 checksums query hit transmission via udp querying via udp dynamic queries via tcp file transfers via udp xml metadata source exchange also termed download mesh parallel downloading slices swarming efforts finalize protocol extensions gnutella 0.6 specification gnutella protocol development website gnutella 0.4 standard although still latest protocol specification since extensions exist proposals far outdated fact hard impossible connect today 0.4 handshakes according developers gdf version 0.6 new developers pursue using work-in-progress specifications gnutella protocol remains development spite attempts make clean break complexity inherited old gnutella 0.4 design clean new message architecture still one successful file-sharing protocols date following tables compare general technical information number applications supporting gnutella network tables attempt give complete list gnutella clients tables limited clients participate current gnutella network gnutella2 protocol often referred g2 despite name successor protocol gnutella related original gnutella project rather completely different protocol forked original project piggybacked gnutella name sore point many gnutella developers gnutella2 name conveys upgrade superiority led flame war criticism included use gnutella network bootstrap g2 peers poor documentation g2 protocol additionally frequent search retries shareaza client one initial g2 clients could unnecessarily burden gnutella network protocols undergone significant changes since fork 2002 g2 advantages disadvantages compared gnutella advantage often cited gnutella2 hybrid search efficient original gnutella query flooding later replaced efficient search methods starting query routing 2002 proposed 2001 limewire developers advantage gnutella users number millions whereas g2 network approximately order magnitude smaller difficult compare protocols current form individual client choice probably much effect end user either network
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Internet protocols
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henry poole technologist henry poole technologist social entrepreneur ceo civicactions board member free software foundation co-founded one first digital agencies vivid studios 1993 year served technical editor book demystifying multimedia 1994 led project study social interactions use technology well community 1995 firm managed online launch microsoft windows 95 largest online technology product introduction time 2000 poole joined ceo french gnu/linux publisher mandrakesoft 2001 poole founded first opensaas enterprise affero inc. 2002 published affero general public license version 1 poole joined board free software foundation december 2002 2003 poole managed digital team kucinich us president 2004 founded government digital services firm civicactions may 2006 poole free software foundation launched anti-drm campaign defective design software freedom activist poole organized fundraisers dmitry sklyarov free software foundation signatory 9/11 truth statement
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Operating systems
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dynamic language runtime dynamic language runtime dlr microsoft runs top common language runtime clr provides computer language services dynamic languages services include dlr used implement dynamic languages .net framework including ironpython ironruby projects dynamic language implementations share common underlying system easier interact one another example possible use libraries dynamic language dynamic language addition hosting api allows interoperability statically typed cli languages like c visual basic .net microsoft dynamic language runtime project announced microsoft mix 2007 microsoft shipped .net dlr 0.9 beta november 2008 final 0.9 december 2008 version 1.0 shipped april 2010 july 2010 microsoft changed license dlr microsoft public license apache license v2.0 release .net 4 also april 2010 dlr incorporated .net framework open source dlr project hosted github additional features language implementers activity project since july 2010 release could linked including microsoft developer worked ironruby saw lack commitment microsoft dynamic languages .net framework dlr services currently used development version ironruby .net implementation ruby language ironpython 2007 microsoft planned use dlr upcoming visual basic 2010 vb 10.0 managed jscript ecmascript 3.0 however august 2009 microsoft plans implement managed jscript ecmascript 3.0 dlr like c visual basic access objects dynamic languages built dlr ironpython ironruby powershell 3.0 released windows 8 updated use dlr ironscheme upcoming scheme implementation planning build upon dlr idea abandoned dlr branch used project became sync trunk also according project coordinator current version dlr time could support majority scheme requirements dynamic language runtime built idea possible implement language specificities top generic language-agnostic abstract syntax tree whose nodes correspond specific functionality common many dynamic languages architecture backed idea number elementary language constructs would implemented generic stack inherently limited dlr dynamically generates code corresponding functionality expressed nodes compiler dynamic language implemented top dlr generate dlr abstract trees hand dlr libraries dlr provides dynamically-updated codice_1 objects cache task binding methods objects since type object—as well members contains—in dynamic languages change program lifetime method invocation must check method list see invocation valid one codice_1 objects represent cache state object methods update object reflected codice_1 objects well dlr routes method invocations via codice_1 objects performs fast lookup binding method actual implementation contrast efforts like parrot virtual machine dependencies da vinci machine built java jvm adding new bytecodes jvm instruction set dlr built top existing common language runtime .net framework virtual machine
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Operating systems
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de-identification de-identification process used prevent someone personal identity revealed example data produced human subject research might de-identified preserve privacy research participants applied metadata general data identification process also known data anonymization common strategies include deleting masking personal identifiers personal name suppressing generalizing quasi-identifiers date birth reverse process using de-identified data identify individuals known data re-identification successful re-identifications cast doubt de-identification effectiveness systematic review fourteen distinct re-identification attacks found high re-identification rate … dominated small-scale studies data de-identified according existing standards de-identification adopted one main approaches data privacy protection commonly used fields communications multimedia biometrics big data cloud computing data mining internet social networks audio–video surveillance survey conducted census collect information group people encourage participation protect privacy survey respondents researchers attempt design survey way people participate survey result published possible match participant individual response data published result online shopping website wants know users preferences shopping habits decides retrieve customers data database analysis personal data information including personal identifiers collected directly customers created accounts website needs pre-handle data de-identification techniques analyzing data records avoid violating customers privacy anonymization refers irreversibly severing data set identity data contributor study prevent future re-identification even study organizers condition de-identification also severing data set identity data contributor may include preserving identifying information re-linked trusted party certain situations debate technology community whether data re-linked even trusted party ever considered de-identified common strategies de-identification masking personal identifiers generalizing quasi-identifiers pseudonymization main technique used mask personal identifiers data records k-anonymization usually adopted generalizing quasi-identifiers pseudonymization performed replacing real names temporary id deletes masks personal identifiers make individuals unidentified method makes possible track individual record time even though record updated however prevent individual identified specific combinations attributes data record indirectly identify individual k-anonymization defines attributes indirectly points individual identity quasi-identifiers qis deal data making least k individuals combination qi values qi values handled following specific standards example k-anonymization replaces original data records new range values keep values unchanged new combination qi values prevents individual identified also avoid destroying data records research de-identification driven mostly protecting health information libraries adopted methods used healthcare industry preserve readers privacy big data de-identification widely adopted individuals organizations.with development social media e-commerce big data de-identification sometimes required often used data privacy users personal data collected companies third-party organizations analyze personal usage smart cities de-identification may required protect privacy residents workers visitors without strict regulation de-identification may difficult sensors collect information without consent whenever person participates genetics research donation biological specimen often results creation large amount personalized data data uniquely difficult de-identify anonymization genetic data particularly difficult huge amount genotypic information biospecimens ties specimens often medical history advent modern bioinformatics tools data mining demonstrations data individuals aggregate collections genotypic data sets tied identities specimen donors researchers suggested reasonable ever promise participants genetics research retain anonymity instead participants taught limits using coded identifiers de-identification process may 2014 united states president council advisors science technology found de-identification somewhat useful added safeguard useful basis policy robust near‐term future re‐identification methods hipaa privacy rule provides mechanisms using disclosing health data responsibly without need patient consent mechanisms center two hipaa de-identification standards – safe harbor expert determination method safe harbor relies removal specific patient identifiers e.g name phone number email address etc expert determination method requires knowledge experience generally accepted statistical scientific principles methods render information individually identifiable safe harbor method uses list approach de-identification two requirements expert determination takes risk-based approach de-identification applies current standards best practices research determine likelihood person could identified protected health information method requires person appropriate knowledge experience generally accepted statistical scientific principles methods render information individually identifiable requires key law research electronic health record data hipaa privacy rule law allows use electronic health record deceased subjects research hipaa privacy rule section 164.512 1 iii
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Computer security
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oracle application server oracle application server 10g g stands grid short oracle consists integrated standards-based software platform forms part oracle corporation fusion middleware technology stack heart oracle application server consists oracle http server based apache http server oc4j oracleas containers java ee deploys java ee-based applications version oc4j offers full compatibility java ee 1.4 specifications oracle application server became first platform designed grid computing well full life-cycle support service-oriented architecture soa release oracle application server 10g r3 feature metadata repository tier relying instead metadata repositories provided previous releases following oracle acquisition bea systems “ key features integrated weblogic server seamless migration ” oracle corporation marketed first application server using name oracle web server ows subsequent repackaging resulted oracle application server oas later product superseding oas became internet application server oracle corporation subdivides products varying editions — apparently facilitate marketing license-tracking available oracle editions include oracle corporation refers implementation java ee specification oracle containers j2ee abbreviates concept oc4j oc4j originally based ironflare orion application server developed solely oracle control since oracle corporation acquired source code oc4j includes following servers oracle application server utilize oracle infrastructure database — oracle database instance supporting oracle metadata repository and/or oracle identity management opmn oracle process management notification server monitors components oracle application server opmnctl command starts stops monitors oracle components
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Web technology
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loglogic loglogic technology company specializes security management compliance reporting operations products loglogic developed first appliance-based log management platform loglogic log management platform collects correlates user activity event data loglogic products used many world largest enterprises rapidly identify alert compliance violations policy breaches cyber attacks insider threats loglogic founded 2002 jason destefano thomas grabowski peter jordan minneapolis mn company established help system administrators automate management log data diagnose system problems 2009 loglogic released database security compliance management products acquired security information event management siem company 2012 company acquired tibco loglogic makes computer appliance system administrators compliance managers cios cisos use collect logs events network devices servers databases operating systems applications appliances also translate various log formats search logs generate alerts create graphs logging trends loglogic products help several industry compliance mandates standards payment card industry data security standard pci dss health insurance portability accountability act hipaa sarbanes-oxley sox focus ventures sequoia capital telesoft partners worldview technology partners invesco private capital sap ventures cm-cic private equity crédit agricole private equity elaia partners
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Computer security
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sun ray sun ray oracle stateless thin client solution aimed corporate environments originally introduced sun microsystems september 1999 discontinued oracle 2014 featured smart card reader several models featured integrated flat panel display idea stateless desktop significant shift eventual successor sun earlier line diskless java-only desktops javastation concept began sun microsystems laboratories 1997 project codenamed networkterminal newt client designed small low cost low power silent based sun microelectronics microsparc iiep processors initially considered included intel strongarm philips semiconductors trimedia national semiconductors geode microsparc iiep selected high level integration good performance low cost general availability newt included 8 mb edo dram 4 mb flash graphics controller used ati rage 128 low power 2d rendering performance low cost also included ati video encoder tv-out removed sun ray 1 philips semiconductor saa7114 video decoder/scaler crystal semiconductor audio codec sun microelectronics ethernet controller pci usb host interface 4 port hub i²c smart card interface motherboard daughtercard housed off-the-shelf commercial small form-factor pc case internal +12/+5vdc auto ranging power supply newt designed much feature parity modern business pc every way possible client n't use commercial operating system instead used real-time exec originally developed sun labs part ethernet-based security camera project codenamed netcam less 60 newt ever built survived however one collection computer history museum mountain view california july 2013 reports circulated oracle ending development sun ray related products scott mcnealy long-time ceo sun tweeted official announcement made august 1 2013 last order february 2014 support hardware maintenance available 2017 contrast thick client sun ray networked display device applications running server elsewhere state user session independent display enables another feature sun ray portable sessions user go one sun ray another continue work without closing programs smart card user insert card presented session reauthentication requirement depends mode operation without smart card procedure almost identical except user must specify username well password get session either case session yet exist new one created first time user connects sun ray clients connected via ethernet network sun ray server sun ray software srs available solaris linux operating systems sun developed separate network display protocol appliance link protocol alp sun ray system vmware announced support protocol vmware view 2008 sun ray software two basic modes operation—generic session kiosk mode generic session user see solaris gnu/linux login screen operating system running srs kiosk mode log screen varies depending session type use kiosk mode used number different desktop applications oracle integrated rdp client vmware view client sun ray software used kiosk mode start full screen windows session mode window manager unix desktop started windows environment os supports rdp 2007 sun uk company thruput integrated sun ray 2fs 28 2048 × 2048 30 2560 × 1600 56 3840 × 2160 displays 2008 trialled external graphics accelerator enables sun ray used high resolution display sun ray 3 models last production—last order date february 28 2014 last ship date august 31 2014 sun oem partners produced wi-fi notebook versions sun ray sun ray 1 clients used 100mhz microsparc iiep processor initially followed custom soc version codenamed copernicus us 6993,617 b2 based microsparc iiep core added 4mb on-chip dram usb smart card interface addition memory controller pci interface already microsparc iiep sun ray 2 3 clients use mips architecture-based rmi alchemy au1550 processor pure software implementation available sun ray software 5 srs5 commercial environments sun rays commonly deployed thin client access microsoft windows desktop using srss built-in rdp client uttsc desktop terminal server session virtual machine vdi setup flexible works well many environments intermediate sun ray server layer transparent windows desktop time however transparency also become issue software location dependent location dependent information needs added possible extend functionality sun ray software additional custom scripts sun ray wiki offers follow printing setup example e.g user always gets nearest printer default printer going room-to-room location-to-location also inside windows session relatively easy administrator extend add functionality required
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Computer architecture
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oracle cloud oracle cloud cloud computing service offered oracle corporation providing servers storage network applications services global network oracle corporation managed data centers company allows services provisioned demand internet oracle cloud provides infrastructure service iaas platform service paas software service saas data service daas services used build deploy integrate extend applications cloud platform supports numerous open standards sql html5 rest etc open-source solutions kubernetes hadoop kafka etc variety programming languages databases tools frameworks including oracle-specific open source third-party software systems oracle branded infrastructure service oracle cloud infrastructure oci oracle cloud infrastructure offerings include following services oracle announced generation 2 cloud oracle openworld 2018 oracle branded platform service oracle cloud platform ocp oracle cloud platform offerings include following services july 28 2016 oracle bought netsuite first cloud company 9.3 billion may 16 2018 oracle announced acquired datascience.com privately held cloud workspace platform data science projects workloads oracle provides saas applications also known oracle cloud applications applications offered across variety products industrial sectors various deployment options adhere compliance standards list mentions oracle cloud applications provided oracle corporation platform known oracle data cloud platform aggregates analyzes consumer data powered oracle id graph across channels devices create cross-channel consumer understanding oracle cloud deployed public cloud private cloud hybrid cloud deployment models oracle cloud offered global network oracle corporation managed data centers oracle corporation deploys cloud regions inside region least three fault-independent availability domains availability domains contains independent data center power thermal network isolation oracle cloud generally available north america emea apac japan announced south america us gov regions coming soon oracle developers forum responsible engaging developer community provides information documentation discussion authored oracle community members large oracle offers certifications infrastructure service iaas platform service paas several specializations software service
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Distributed computing architecture
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processor supplementary capability processor supplementary capability feature added existing central processing unit cpu design initial introduction design marketplace supplementary capability increases usefulness processor design allowing compete favorably competitors giving consumers reason upgrade retaining backwards compatibility original design cpu supplementary instruction capability rule apply 8 16 bit cpus many cpus used mostly microcontrollers modern 32 64 bit cpus processor supplementary capability extend floating point units fpus memory management units mmus considered fundamental core functionalities extensions core functionalities mmu fpu may considered cpu extensions however supplementary instructions feature always assumed mean fixed sets instructions obligatory across cpus cpu family supplementary instructions simply found processors within family programmer wishes use supplementary feature cpu faced couple choices supplemental instruction programming options needed instructions fall back presumably slower otherwise less desirable alternative technique initiated else program may set run reduced functionality using lowest common denominator strategy avoiding use processor supplementary capabilities programs kept portable across machines architecture popular processor architectures x86 68000 mips seen many new capabilities introduced several generations design capabilities seen widespread adoption programmers spurring consumer upgrades making previous generations processors obsolete processor supplementary instructions instructions implemented certain processors within family present processors within particular family following instructions considered processor supplementary instructions ia-32 architecture instructions added later production processors part original ia-32 instruction set programs containing instructions may operate correctly machines ia-32 family fpu floating point unit maths co-processing capability available x86 processors since 80486dx series fpu mmu instruction sets x86 family considered supplementary instructions since introduction due importance core cpu functionality
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Computer architecture
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linux-vserver linux-vserver virtual private server implementation created adding operating system-level virtualization capabilities linux kernel developed distributed open-source software project started jacques gélinas maintained herbert pötzl related linux virtual server project implements network load balancing linux-vserver jail mechanism used securely partition resources computer system file system cpu time network addresses memory way processes mount denial-of-service attack anything outside partition partition called security context virtualized system within virtual private server chroot-like utility descending security contexts provided booting virtual private server simply matter kickstarting init new security context likewise shutting simply entails killing processes security context contexts robust enough boot many linux distributions unmodified including debian fedora virtual private servers commonly used web hosting services useful segregating customer accounts pooling resources containing potential security breaches save space installations virtual server file system created tree copy-on-write hard links template file system hard link marked special filesystem attribute modified securely transparently replaced real copy file linux-vserver provides two branches stable 2.2.x devel 2.3.x 2.6-series kernels single stable branch 2.4-series separate stable branch integrating grsecurity patch set also available
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Operating systems
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security attribute modulation protocol security attribute modulation protocol samp protocol used encode role based user based access control attributes transmission network typically embedded tcp/ip udp/ip packet application layer payload trailing afterwards sun microsystems makes brief mention samp trusted solaris 8 administration manuals case trusted solaris 8 trusted network daemon parses samp headers manages system security conjunction security provisions system
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Computer security
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bluekeep bluekeep security vulnerability discovered microsoft remote desktop protocol implementation allows possibility remote code execution first reported may 2019 present unpatched windows nt-based versions microsoft windows windows 2000 windows server 2008 r2 windows 7 microsoft issued security patch including out-of-band update several versions windows reached end-of-life windows xp 14 may 2019 13 august 2019 related bluekeep security vulnerabilities collectively named dejablue reported affect newer windows versions including windows 7 recent versions windows 10 operating system well older windows versions bluekeep security vulnerability first noted uk national cyber security centre 14 may 2019 reported microsoft vulnerability named bluekeep computer security expert kevin beaumont twitter bluekeep officially tracked wormable remote code execution vulnerability u.s. national security agency issued advisory vulnerability 4 june 2019 microsoft stated vulnerability could potentially used self-propagating worms microsoft based security researcher estimation nearly 1 million devices vulnerable saying theoretical attack could similar scale eternalblue-based attacks notpetya wannacry day nsa advisory researchers cert coordination center disclosed separate rdp-related security issue windows 10 may 2019 update windows server 2019 citing new behaviour rdp network level authentication nla login credentials cached client system user re-gain access rdp connection automatically network connection interrupted microsoft dismissed vulnerability intended behaviour disabled via group policy 1 june 2019 active malware vulnerability seems publicly known however undisclosed proof concept poc codes exploiting vulnerability may available 1 july 2019 sophos british security company reported working example poc order emphasize urgent need patch vulnerability 22 july 2019 details exploit purportedly revealed conference speaker chinese security firm 25 july 2019 computer experts reported commercial version exploit may available 31 july 2019 computer experts reported significant increase malicious rdp activity warn based histories exploits similar vulnerabilities active exploit bluekeep vulnerability wild may imminent 13 august 2019 related bluekeep security vulnerabilities collectively named dejablue reported affect newer windows versions including windows 7 recent versions operating system windows 10 well older windows versions rdp protocol uses virtual channels configured pre-authentication data path client server providing extensions rdp 5.1 defines 32 static virtual channels dynamic virtual channels contained within one static channels server binds virtual channel ms_t120 channel legitimate reason client connect static channel 31 heap corruption occurs allows arbitrary code execution system level windows xp windows vista windows 7 windows server 2003 windows server 2008 windows server 2008 r2 named microsoft vulnerable attack versions newer 7 windows 8 windows 10 affected cybersecurity infrastructure security agency stated also successfully achieved code execution via vulnerability windows 2000 microsoft released patches vulnerability 14 may 2019 windows xp windows vista windows 7 windows server 2003 windows server 2008 windows server 2008 r2 included versions windows end-of-life vista xp server 2003 longer eligible security updates patch forces aforementioned ms_t120 channel always bound 31 even requested otherwise rdp server nsa recommended additional measures disabling remote desktop services associated port used requiring network level authentication nla rdp according computer security company sophos two-factor authentication may make rdp issue less vulnerable however best protection take rdp internet switch rdp needed needed make rdp accessible via vpn
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Computer security
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rock processor rock rock multithreading multicore sparc microprocessor development sun microsystems canceled 2010 separate project sparc t-series coolthreads/niagara family processors rock aimed higher per-thread performance higher floating-point performance greater smp scalability niagara family rock processor targeted traditional high-end data-facing workloads back-end database servers well floating-point intensive high-performance computing workloads whereas niagara family targets network-facing workloads web servers rock processor implements 64-bit sparc v9 instruction set vis 3.0 simd multimedia instruction set extension rock processor 16 cores core capable running two threads simultaneously yielding 32 threads per chip servers built rock use fb-dimms increase reliability speed density memory systems rock processor uses 65 nm manufacturing process design frequency 2.3 ghz maximum power consumption rock processor chip approximately 250 w. 16 cores rock arranged four core clusters cores cluster share 32 kb instruction cache two 32 kb data caches two floating point units sun designed chip way server workloads usually high re-utilization data instruction across processes threads low number floating-point operations general thus sharing hardware resources among four cores cluster leads significant savings area power low impact performance 2005 sun publicly disclosed feature rock processor called hardware scout hardware scout uses otherwise idle chip execution resources perform prefetching cache misses march 2006 marc tremblay vice president chief architect sun scalable systems group gave presentation xerox palo alto research center parc thread-level parallelism hardware scouting thread-level speculation multithreading technologies expected included rock processor august 2007 sun confirmed rock would first production processor support transactional memory provide functionality two new instructions introduced chkpt commit one new status register cps instruction chkpt fail_pc used begin transaction commit commit transaction transaction abort condition detected jump fail_pc issued cps used determine reason support best-effort based addition data conflicts transactions aborted reasons include tlb misses interrupts certain commonly used function call sequences difficult instructions e.g. division nevertheless many arguably fine-grained code blocks requiring synchronization could benefited transactional memory support rock processor february 2008 marc tremblay announced unique feature called out-of-order retirement isscc benefits include replacing traditional instruction window much smaller deferred queue april 2008 sun engineers presented transactional memory interface transact 2008 adaptive transactional memory test platform simulator announced made available general public shortly rock processor intended used sun proposed supernova server line details server specifications released opensolaris architecture review case fwarc/2008/761 physical resource inventory pri specification arc 2008/761 indicates supernova platforms would support ieee 1275 openfirmware platform virtualization logical domains ldoms independent system controller sc fault management architecture fma domain services fma feature originally referenced fwarc/2006/141 closed extended fwarc/2008/455 successfully diagnose pci fabric errors occur root domains arc 2008/761 indicated planned support pci express pcie hot-pluggable slots well bridge older pci extended pci-x bronze servers would support pcie slots 0-5 silver servers would support i/o boards 0-1 pcie slots 0-7 board platinum servers would support i/o boards 0-3 pcie slots 0-7 board silver-ii servers would support pcie slots 00-19 platinum-ii servers would support boards 0-7 slots 0-3 board february 2005 ceo sun microsystems scott mcnealy stated taping rock would schedule later year however tape-out ultimately delayed january 2007 april 2007 sun ceo jonathan i. schwartz blogged image bga-packaged rock chip labeled ultrasparc rk disclosed could address 256 terabytes virtual memory single system running solaris next month sun announced created rock chip could boot operating system solaris successfully august year sun released details use transactional memory rock architecture however result entirely new design given uniqueness complexity release rock delayed 2008 2009 2008 mark moir presented rock transactional memory exploit sun labs open house 2008 discussing transactional memory well scouting threads mitigated computing problems solved innovative use massive thread counts slower processors september opensolaris project began integrate code supporting rock-based supernova program january 2009 sun ceo jonathan schwartz announced rock still track 2009 release 10 march 2009 dave dice yossi lev mark moir dan nussbaum presented early experience commercial hardware transactional memory implementation fourteenth international conference architectural support programming languages operating systems asplos '09 published experience hardware transactional memory htm feature two pre-production revisions new commercial multicore processor 2009 april 20 2009 sun oracle corporation announced entered definitive agreement oracle would acquire sun june 12 posting sun blog announced technical nda-only presentation rock july 14 2009 hamburg opensolaris users group meeting 15 june 2009 new york times reported two people briefed sun ’ plans said rock project canceled sun comment two days later ee times reported sun submit paper rock nowiki hot chips 21 /nowiki leading speculation company may canceled chip 24 june 2009 presentation speculative threading parallelization featured novel pipeline architecture implemented sun rock processor 36th international symposium computer architecture 6 august 2009 support rock removed opensolaris project 13 august 2009 presentation nztm nonblocking zero-indirection transactional memory written fuad tabba mark moir james goodman andrew hay cong wang presented 21st acm symposium parallelism algorithms architectures calgary canada nzstm algorithm performance evaluated sun ’ forthcoming rock processor 11 september 2009 register reported rock processor left sparc processor roadmap shown sun customers partners 15 september 2009 paper tm_db generic debugging library transactional programs written yossi lev maurice herlihy presented eighteenth international conference parallel architectures compilation techniques pact raleigh north carolina 26 october 2009 dave dice yossi lev mark moir dan nussbaum expanded formerly published paper early experience commercial hardware transactional memory implementation presented fourteenth international conference architectural support programming languages operating systems asplos '09 january 27 2010 oracle announced completed acquisition sun 5 april 2010 dave dice yossi lev virendra marathe mark moir marek olszewski dan nussbaum released paper simplifying concurrent algorithms exploiting hardware transactional memory presented 22nd acm symposium parallelism algorithms architectures spaa 2010 5 april 2010 dave dice nir shavit released paper tlrw return read-write lock presented spaa 2010 12 may 2010 reuters reported oracle ceo larry ellison shut rock project oracle acquired sun quoting saying processor two incredible virtues incredibly slow consumed vast amounts energy hot put 12 inches cooling fans top cool processor madness continue project
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Computer architecture
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tacacs terminal access controller access-control system tacacs usually pronounced like tack-axe refers family related protocols handling remote authentication related services networked access control centralized server original tacacs protocol dates back 1984 used communicating authentication server common older unix networks spawned related protocols tacacs originally developed 1984 bbn technologies administering milnet ran unclassified network traffic darpa time would later evolve u.s. department defense niprnet originally designed means automate authentication – allowing someone already logged one host network connect another network without needing re-authenticate – first formally described bbn brian anderson december 1984 ietf rfc 927 cisco systems began supporting tacacs networking products late 1980s eventually adding several extensions protocol 1990 cisco extensions top tacacs became proprietary protocol called extended tacacs xtacacs although tacacs xtacacs open standards craig finseth university minnesota cisco assistance published description protocols 1993 ietf rfc 1492 informational purposes tacacs defined rfc 1492 uses either tcp udp port 49 default tacacs allows client accept username password send query tacacs authentication server sometimes called tacacs daemon simply tacacsd tacacsd uses tcp usually runs port 49 would determine whether accept deny authentication request send response back tip routing node accepting dial-up line connections user would normally want log would allow access based upon response way process making decision opened algorithms data used make decision complete control whomever running tacacs daemon xtacacs stands extended tacacs provides additional functionality tacacs protocol also separates authentication authorization accounting aaa functions separate processes even allowing handled separate servers technologies tacacs+ radius generally replaced tacacs xtacacs recently built updated networks tacacs+ entirely new protocol compatible predecessors tacacs xtacacs tacacs+ uses tcp radius operates udp since tcp connection oriented protocol tacacs+ implement transmission control radius however detect correct transmission errors like packet loss timeout etc since rides udp connectionless radius encrypts users password travels radius client radius server information username authorization accounting transmitted clear text therefore vulnerable different types attacks tacacs+ encrypts information mentioned therefore vulnerabilities present radius protocol tacacs+ cisco designed extension tacacs encrypts full content packet moreover provides granular control command command authorization
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Computer security
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astap astap advanced statistical analysis program general purpose analog electronic circuit simulator developed primarily in-house use ibm 1973 powerful program used simulation integrated circuit designs analysis statistical variations manufacturing process combination built-in monte carlo method capabilities allowed prediction performance electronic circuits wide range material parameters temperatures astap designed run ibm mainframe computers unlike spice used modified nodal analysis mna form system circuit equations astap instead used sparse tableau formulation sta construct solve sparse matrix sparse tableau formulation produced large sparse matrices required special techniques solve efficiently even time advantage sta statistical analysis originally outlined subsequent analysis circuit randomly varied parameters required changing entries matrix
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Programming language topics
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ibm pc convertible ibm pc convertible first laptop computer released ibm released april 3 1986 convertible also first ibm computer use 3½-inch floppy disk format went become industry standard like modern laptops featured power management ability run batteries follow-up ibm portable model number 5140 replaced 1991 ibm ps/2 l40 sx japan ibm personal system/55note predecessor thinkpad ibm engineers 1983 reportedly developed tandy model 100-like laptop codenamed sweetpea estridge rejected pc compatible 1984 larger lcd screen another prototype p-14 reportedly failed chiclet rule especially poor reception data general-one display pc convertible used cmos version intel 8088 cpu running 4.77 mhz 256 kb ram expandable 640 kb dual 720 kb 3.5 floppy drives monochrome cga-compatible lcd screen price 2,000 weighed 13 pounds 5.8 kg featured built-in carrying handle pc convertible expansion capabilities proprietary isa bus-based port rear machine extension modules including small printer video output module could snapped place machine could also take internal modem room internal hard disk concept design body made german industrial designer richard sapper pressing power button computer turn put machine suspend mode would hold place long battery power avoided long boot-up process cmos 80c88 cpu static core held state indefinitely stopping system clock oscillator resume processing clock signal restarted long kept powered cmos 80c88 processor used little power clock signal stopped system ram convertible sram rather dram lower power consumption less circuitry fit cramped laptop case convertible 256k ram included 128k eventually also 256k memory cards available space 4 memory cards system least one 256k card order able upgrade system full 640k base memory screen half size lid text characters graphics compressed vertically appearing half normal height display capable 80x25 text graphics modes 640x200 320x200 pixels pressing lever two floppy drives display detached entire screen unit feature allowed convenient use full-size desktop monitor one desk early forerunner docking station concept well apple powerbook duo machine sold poorly number reasons convertible heavy much faster portable replaced despite newer cmos processor use static ram traditional pc expansion ports serial ports parallel port without add-on hard-to-read oddly-shaped lcd screen first screens lacked backlight also competed faster portables based intel 80286 offered optional hard drives companies compaq laptops companies toshiba zenith lighter offered similar specifications sometimes half price keyboard also widely criticized
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Computer architecture
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patched malware win32/patched computer trojan targeting microsoft windows operating system first detected october 2008 files detected trojan.win32.patched usually windows components patched malicious application purpose patching varies example certain malware patches system components order disable security windows safe file check feature malware add parts code system component patch certain functions original file point appended code trojan operates modification legitimate systems files infected system additionally malware add parts code system component patch certain functions original file point appended code frequently patched components obvious symptoms indicate presence malware affected machine additionally common symptoms associated threat alert notifications installed antivirus software may symptom advised delete rename quarantine patched windows components may affect system stability even though windows locks main files active might still possible affect anti-virus software detected certain file trojan.win32.patched attempt create copy patched file try restore contents add renaming command windows registry order replace patched file cleaned one next windows startup restoration one recent system restore points may advisable many cases patched system component replaced clean one restoring system restore point advised backup personal data avoid losing windows rolls back previously saved state windows installation discs contain repair option replace patched file another course action includes attaching hard drive patched file slave similar windows-based system boot replace patched file file taken clean system
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Computer security
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zero insertion force zero insertion force zif type ic socket electrical connector requires little force insertion zif socket ic inserted lever slider side socket moved pushing sprung contacts apart ic inserted little force generally weight ic sufficient external downward force required lever moved back allowing contacts close grip pins ic zif sockets much expensive standard ic sockets also tend take larger board area due space taken lever mechanism therefore used good reason normal integrated circuit ic socket requires ic pushed sprung contacts grip friction ic hundreds pins total insertion force large hundreds newtons leading danger damage device circuit board also even relatively small pin counts pin extraction fairly awkward carries significant risk bending pins particularly person performing extraction n't much practice board crowded low insertion force lif sockets reduce issues insertion extraction lower insertion force conventional socket likely produce less reliable connections large zif sockets commonly found mounted pc motherboards used mid 1990s forward cpu sockets designed support particular range cpus allowing computer retailers consumers assemble motherboard/cpu combinations based individual budget requirements rest electronics industry largely abandoned sockets kind instead moved use surface mount components soldered directly board smaller zif sockets commonly used chip-testing programming equipment e.g. programming testing eeproms microcontrollers etc standard dip packages come number widths measured pin centers 0.3 7.62 mm 0.6 15.24 mm common allow design programmers similar devices support range devices universal test sockets produced wide slots pins drop allowing devices differing widths inserted zif sockets used ball grid array chips particularly development sockets tend unreliable failing grab solder balls another type bga socket also free insertion force zif socket traditional sense better job using spring pins push underneath balls zif wire-to-board connectors used attaching wires printed circuit boards inside electronic equipment example would cable lcd screen motherboard laptops wires often formed ribbon cable pre-stripped bare ends placed inside connector two sliding parts connector pushed together causing grip wires important advantage system require mating half fitted wire ends therefore saving space cost inside miniaturised equipment see flexible flat cable zif tape connections used connecting parallel ata serial ata disk drives mostly drives 1.8-inch form factor pata hard drives zif-style connectors used primarily design ultra-portable notebooks since phased sata relatively small-form-factor connector default mini-sata msata used even smaller form factors required internally nearly hard drives use zif tape connect circuit board platter motor zif tape connections also heavily used design ipod range portable media players hard drive also connections main circuit board three types zif connectors known exist 1.8 inch pata drives zif-24 zif-40 zif-50 24 40 50 pins respectively
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Computer architecture
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webroot antivirus spy sweeper webroot antivirus spy sweeper previously known webroot antivirus antispyware antimalware utility developed webroot software product added antivirus detection engine company ’ previous standalone antispyware product spy sweeper product originally launched october 30 2006 name spy sweeper antivirus product re-launched year later october 24 2007 webroot antivirus antispyware firewall enhanced rebranded version product included new two-way firewall built various changes including windows vista compatibility recent version product webroot antivirus spy sweeper 7.0 launched july 27 2010 versions product antivirus antispyware malware detection within various changes user interfaces system shields additional features added compatibilities new microsoft windows operating systems changed version 5.2 received editor ’ choice award integration effectiveness combining antispyware antivirus utilities one product shield names changed version including spy communication shield renamed internet communication shield spy installation shield changed installation shield product update included quick sweep option allowed users rapidly scan computer use many system resources full sweep option would various smart shields protect pc changes activex controls common browser threats update also included daily definition flex defs flexible definitions updates version 5.3 added windows vista compatibility product version 5.5 added several changes real-time protection shields within product execution shield file system shield replaced old spy installation shield still work together block malicious programs executing reading changing files “ system services shield ” added prevent unauthorized changes numerous system services microsoft windows email attachments shield also added allows scanning email attachments malware behavioral based detection also added release allowing zero-day threats dealt hit system version 5.8 added compatibility 64-bit vista “ gamer mode ” allows play online games uninterrupted notifications background shields run background product included 1gb online storage space time release firewall component found earlier versions product removed release significant user interface changes made 7.0 version software well optimized scanning feature new ui commented reviewers simplistic easier use previous versions tray icons added notify user state program currently three icons used include br “ fix ” feature added 7.0 versions allows users opt webroot software resolve situation without user interaction version added automatic periodic scans computer eliminated option quick sweeps full sweeps seen previous versions default 7.0 version eliminated option run virus-scanning access web portal accessible computer web access includes account information software license status keycode well access certain tasks upgrading software installing computers 7.0 version product require reboot installation previous versions webroot antivirus spysweeper received virus bulletin certifications four times including april 2010 windows ex december 2009 windows 7 august 2008 windows xp february 2003 windows server xp webroot antivirus spysweeper icsa labs certified desktop/server anti-virus detection anti-virus cleaning windows 7 32 64 bit numerous certifications dating 2008 received west coast labs product including anti-spyware desktop anti-trojan anti-virus desktop anti-virus disinfection desktop firewall
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Computer security
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windows system assessment tool windows system assessment tool winsat module microsoft windows vista windows 7 windows 8 windows 10 available control panel performance information tools except windows 8.1 windows 10 measures various performance characteristics capabilities hardware running reports windows experience index wei score wei includes five subscores processor memory 2d graphics 3d graphics disk basescore equal lowest subscores average subscores winsat reports wei scores scale 1.0 5.9 windows vista 7.9 windows 7 9.9 windows 8 windows 10 wei enables users match computer hardware performance performance requirements software example aero graphical user interface automatically enabled unless system wei score 3 higher wei also used show part system would expected provide greatest increase performance upgraded example computer lowest subscore memory would benefit ram upgrade adding faster hard drive component detailed raw performance information like actual disk bandwidth obtained invoking codice_1 command line also allows specific tests re-run obtaining wei score command line done invoking codice_2 also updates value stored codice_3 xml files stored easily hacked report fake performance values wei also available applications api configure function hardware performance taking advantage capabilities without becoming unacceptably slow windows experience index score displayed windows 8.1 onwards graphical user interface winsat removed versions windows although command line winsat tool still exists operates correctly along final score launching command shell games according article pc pro microsoft removed winsat gui order promote idea kinds hardware run windows 8 equally well 2003 game developers conference dean lester microsoft general manager windows graphics gaming stated interview gamespot microsoft intended focus improvements pc gaming experience part new gaming initiative next version windows windows vista codenamed longhorn lester stated part initiative operating system would include games folder would centralize settings pertinent gamers among features display driver streamlining parental controls games ability start windows game directly optical media installation—in manner similar games designed video game console microsoft would also require new method displaying system requirements retail packaging windows games rating system would categorize games based numerical system 2004 lester expanded microsoft intentions stating company would work hardware manufacturers create pcs windows vista used level system designate performance capabilities system hardware xbox 360 peripherals would fully compatible operating system windows experience index feature windows vista relies measurements taken winsat provide accurate assessment system capabilities—these capabilities presented form rating higher rating indicates better performance preliminary design elements created microsoft robert stein 2004 suggest winsat intended rate user hardware out-of-box experience design decision would retained operating system release manufacturing windows hardware engineering conference 2005 microsoft formally unveiled existence winsat presented technology games one would allow windows vista make decisions whether enable desktop composition based machine hardware capabilities winsat would remain key focus throughout development operating system release manufacturing winsat windows vista windows 7 performs following tests running tests show progress bar working background animation aero glass deactivated windows vista windows 7 testing tool properly assess graphics card cpu windows 8 winsat runs maintenance scheduler every week default schedule 1am sundays maintenance scheduler collates various os tasks schedule computer randomly interrupted individual tasks scheduler wakes computer sleep runs scheduled tasks puts computer back sleep weekly task winsat runs long enough detect hardware changes tests run winsat simply ends existing scores must valid winsat perform tests laptop battery-operated
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Operating systems
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managed voip service computing managed voip services mvs simply put voip services outsourced company providing service managed voip service provider managed voip services provide enterprises necessary skills expertise assure voice quality meets expectations managed voip services equipment software included along network operations centers technical resources usage-based pricing replaced fixed flat-rate billing based number users number network elements managed criteria relevant given business making ongoing costs predictable manageable
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Computer security
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ralph echemendia ralph rafael echemendia cyber security specialist known ethical hacker specialises protecting intellectual property entertainment industry educating security echemendia born cuba raised miami attended miami senior high first computer commodore 64 began hacking age 14 echemendia began working entertainment created secure online ticketing system marley family also investigated early online leak eminem album 2011 echemendia lead technical investigator breach security led leaking worked identify person responsible leaking behind scenes pictures videos film almost year movie ’ release 2015 echemendia worked stone snowden providing technical supervision supported actors explaining background technical terms script echemendia screenwriter kieran fitzgerald also worked edward snowden replicate actual nsa log-in screen 2016 echemendia became hacking consultant directors producers nerve
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Computer security
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avie tevanian dr. avadis avie tevanian american computer scientist carnegie mellon university principal designer engineer mach operating system leveraged work next inc. foundation nextstep operating system senior vice president software engineering apple 1997 2003 chief software technology officer 2003 2006 redesigned nextstep become macos became ios longtime friend steve jobs tevanian westbrook maine armenian descent tevanian cloned 1980s arcade game missile command giving name version xerox alto mac missiles macintosh platform b.a mathematics university rochester m.s ph.d. degrees computer science carnegie mellon university principal designer engineer mach operating system vice president software engineering next inc. responsible managing next software engineering department designed nextstep operating system based upon previous academic work mach senior vice president software engineering apple 1997 2003 chief software technology officer 2003 2006 redesigned nextstep become macos became ios united states v. microsoft 2001 witness united states department justice testifying microsoft tevanian left apple march 31 2006 joined board dolby labs theranos inc resigned board theranos late 2007 acrimonious ending faced legal threats forced sign waiver waive right buy company cofounder shares may 2006 joined board tellme networks later sold microsoft january 12 2010 became managing director elevation partners july 2015 cofounded nextequity partners currently serving managing director
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Operating systems
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socket 7 socket 7 physical electrical specification x86-style cpu socket personal computer motherboard released june 1995 socket supersedes earlier socket 5 accepts p5 pentium microprocessors manufactured intel well compatibles made cyrix/ibm amd idt others socket 7 socket supported wide range cpus different manufacturers wide range speeds differences socket 5 socket 7 socket 7 extra pin designed provide dual split rail voltage opposed socket 5 single voltage however motherboard manufacturers supported dual voltage boards initially socket 7 backwards compatible socket 5 cpu placed socket 7 motherboard processors used socket 7 amd k5 k6 cyrix 6x86 6x86mx idt winchip intel p5 pentium 2.5–3.5 v 75–200 mhz pentium mmx 166–233 mhz rise technology mp6 amd geode lx geode gx used socket 7 2015 socket 7 typically uses 321-pin arranged 19 19 pins spga zif socket rare 296-pin arranged 37 37 pins spga lif socket size 1.95 x 1.95 4.95 cm x 4.95 cm extension socket 7 super socket 7 developed amd k6-2 k6-iii processors operate higher clock rate use agp socket 7 socket 8 replaced slot 1 slot 2 1999
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Computer architecture
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