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flex machine flex computer system developed michael foster ian currie royal signals radar establishment rsre malvern england late 1970s 1980s used tagged storage scheme implement capability architecture designed safe efficient implementation strongly typed procedures hardware custom microprogrammable operating system modular compiler editor garbage collector filing system written algol 68rs least two incarnations flex implemented using hardware writable microcode first supplied logica rsre design second used icl perq microcode alone responsible storage allocation deallocation garbage collection immediately precluded whole class errors arising misuse deliberate accidental pointers notable feature flex tagged write-once filestore allowed arbitrary code data structures written retrieved transparently without recourse external encodings data could thus passed safely program program similar way remote capabilities allowed data procedures machines accessed network connection without application program involved external encodings data parameters result values whole scheme allowed abstract data types safely implemented data items procedures permitted access could bound together resulting capability passed freely around capability would grant access procedures could used way obtain access data another notable feature flex notion shaky pointers recently often called weak references points blocks memory could freed next garbage collection used example cached disc blocks list spare procedure work-spaces comflex packet switching network capable transmitting data magnetic-disc speed developed alongside flex made feasible use remote file-stores remote capabilities remote procedure calls
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Computer architecture
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super cobra super cobra horizontally scrolling shooter developed konami originally released coin-operated arcade game 1981 published konami japan march 1981 manufactured distributed stern north america june 22 1981 sequel 1981 scramble arcade game game commercial success selling 12,337 arcade cabinets united states four months october 2 1981 becoming stern third best-selling arcade classic berzerk scramble scramble sold 15,136 cabinets u.s. five months earlier year adding 27,473 u.s. cabinet sales super cobra widely ported parker brothers adventure vision standalone versions entex player controls helicopter tight caverns slightest misstep result loss life however unlike scramble game continued player left adding credits machine may usually offer option others n't player loses points upon continuing joystick accelerates decelerates moves moves helicopter uses laser bomb destroy defenders tanks ufos infiltrating 10 super cobra defense systems ship limited fuel supply depleted time fuel acquired destroying fuel tanks game game divided ten sections plus finale different style terrain different obstacles players navigate ten levels base must safely make level remove booty levels described follows intermission section game simply scrolls new terrain player destroys booty final level must start back beginning level booty safely carried away player starts back beginning first level cycle repeats second time levels tanks fire much aggressively fuel consumed much faster third subsequent times levels fuel consumed still faster faster rate fuel consumption second subsequent cycles may make difficult complete cycles without losing least one chopper due running fuel although compensated somewhat awarding extra chopper time cycle completed booty carried away game ported atari 2600 atari 5200 colecovision intellivision odyssey² atari 8-bit family parker brothers released also sord m5 msx entex adventure vision entex also made standalone tabletop version game arcade express november 1982 gave adventure vision port score 9 10 concluded takes real skill master represents state-of-the-art scrolling shoot-outs atari 2600 version awarded certificate merit category best action videogame 5th annual arkie awards 1983 compared vanguard said provides brand relentless multi-scenario action super cobra appeared alongside scramble retro compilation konami arcade classics released sony playstation 1999 made available microsoft defunct game room service march 24 2010
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Computer architecture
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andrew project andrew project distributed computing environment developed carnegie mellon university cmu beginning 1982 ambitious project time resulted unprecedentedly vast accessible university computing infrastructure information technology center partnership carnegie mellon ibm began work andrew project 1982 initial phase project involved software hardware including wiring campus data developing workstations distributed students faculty cmu elsewhere proposed 3m computer workstations included million pixel display megabyte memory running million instructions per second unfortunately cost order us 10,000 made computers beyond reach students budgets initial hardware deployment 1985 established number university-owned clusters public workstations various academic buildings dormitories campus fully wired ready eventual availability inexpensive personal computers early development within information technology center originally called vice vast integrated computing environment virtue virtue reached unix emacs focused centralized tools file server workstation tools including window manager editor email file system client code initially system prototyped sun microsystems machines ibm rt pc series computers running special ibm academic operating system people involved project included james h. morris nathaniel borenstein james gosling david s. h. rosenthal project extended several times 1985 order complete software renamed andrew andrew carnegie andrew mellon founders institutions eventually became carnegie mellon university mostly rewritten result experience early deployments andrew four major software components afs moved information technology center transarc 1988 ams fully decommissioned replaced cyrus imap server 2002 ibm funding ended andrew continued open source project named andrew user interface system auis set tools allows users create distribute documents containing variety formatted embedded objects open-source project run department computer science cmu andrew consortium governs maintains development distribution andrew user interface system andrew user interface system encompasses three primary components andrew user environment aue contains main editor help system user interface tools rendering multimedia embedded objects andrew toolkit atk contains formattable embeddable objects allows method developers design objects atk allows multi-level object embedding objects embedded one another example raster image object embedded spreadsheet object andrew message system ams provides mail bulletin board access allows user send receive organize mail well post read message boards version 6.3 following components auis wireless andrew first campus-wide wireless internet network built 1993 predating wi-fi branding wireless andrew 2-megabit-per-second wireless local area network connected access points wired andrew network high-speed ethernet backbone linking buildings across cmu campus wireless andrew consists 100 access points covering six buildings campus university tested current setup 40 mobile units allowing general use researchers students february 1997
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Distributed computing architecture
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desqview desqview dv text mode multitasking operating environment developed quarterdeck office systems enjoyed modest popularity late 1980s early 1990s running top dos allowed users run multiple programs concurrently multiple windows quarterdeck predecessor desqview task switching product called desq shipped late april may 1984 allowed users switch running programs quarterdeck revamped package bringing multitasking adding topview compatibility desqview released july 1985 four months microsoft released first version windows widely thought first program bring multitasking windowing capabilities dos fact predecessor ibm topview shipped march 1985 desqview inherited pop-up menu desqview well-behaved dos programs could run concurrently resizable overlapping windows something first version ms windows could simple hideable menu allowed cutting pasting programs desqview provided support simple editable macros well quarterdeck also developed set optional utilities desqview including notepad dialer later versions allowed graphics mode programs loaded well run full screen mode desqview gui graphical user interface operating system rather non-graphical windowed shell ran real mode top dos although could run intel 8086- intel 80286-based pc could also use expanded memory add-ons work around 640 kb ram limit conventional memory early pcs desqview really came intel 80386 machines better utilizing memory dos limit however either case ran real mode rather protected mode meaning misbehaving program could still crash system make maximum use extended memory intel 80386 processors transforming expanded memory upper memory blocks umbs accessible desqview real-mode programs quarterdeck developed sophisticated memory manager owing foresight marketing manager quarterdeck marketed separate product qemm-386 quarterdeck expanded memory manager 386 became popular desqview sold steadily many years generating us 150 million sales 1987 1994 release intel pentium processor 386 qemm dropped combination package desqview qemm-386 called desqview 386 dv386 introduction 80386 memory management features enhanced allow system shifted protected mode also allowing addresses configured virtual 8086 mode extended memory could mapped addressing frames accessible real-mode programs dos allowed 386 implement lim lotus intel microsoft ems expanded memory specification memory manager easily controlled user dos program qemm.com desqview able use qemm features far beyond lim ems api mapping conventional address space 640 kb multiple extended memory blocks could execute transparently context main copy dos device networking drivers loaded desqview resulting space largest single program could run desqview qemm could run many instances programs ems would allow 8 mb system could generally dozen full-sized dos programs running concurrently 16 mb system could run twenty desqview noteworthy supported common dos-compatible programs achieved degree performance stability remarkable given constraints host operating system also clever interface generally unobtrusive quickly available easy learn normal pcs include keyboard three shift modifier keys control alt normal shift keys keys normally held combination keys desqview default monitored alt key isolated presses combination pressing alt key would bring desqview menu allowing access program features start new tasks switch among mark text screen paste text input current task resize move text windows configure new menu items etc addition shift+alt combination would cause desqview learn set keys macro allowed desqview run programs without interfering keybindings might using desqview critically acclaimed many fans never met mass appeal despite quarterdeck sustained efforts win people one area however desqview lasting success many multiuser bulletin board systems based thanks modest hardware requirements robust multitasking superlative handling multiple communication ports free inexpensive bbs software time ran single-node single-tasking dos program normally one copy bbs software could run limiting host pc running one node desqview allowed multiple copies single-task programs run computer allowing anyone even unimpressive hardware run large powerful multiuser bbs home desqview provide graphical user interface gui quarterdeck provide suites programming libraries utilities support development software use features never became widely popular desqview ability run software modification cost run-time licenses combined costs development suites made unreasonable combination commercial shrink-wrapped software publishers vendors microsoft released ms windows version 3.0 memory management multitasking features desqview far faster smaller stable expensive n't include support graphical features ms windows decline qemm started bundling memory manager digital research dr dos 5.0 released 1990 catch microsoft included emm386 ms-dos 5.0 previously memory management functionality available windows qemm could still used instead notably windows 3.1x provided incremental benefits sales qemm declined august 1994 three quarters losses company laid 25 employees ceo president founder terry myers resigned users moved desqview platforms notably windows 3.x os/2 third party utility authors wrote utility programs emulated desqview api functions allow suitably equipped dos programs co-operate os notable tame windows os/2speed os/2 quarterdeck eventually also released product named desqview/x dvx x window system server running dos desqview thus provided gui x software mostly unix could ported desqview/x three window managers launched x/motif open look twm default package contained twm others costly optional extras ability interact tcp/ip networks mosaic ported dvx dvx could serve dos programs 16-bit windows environment across network x programs made useful wished run dos windows programs unix workstations functionality available ncd wincenter internetworking company novell developed product called netware access server nas incorporating features desqview 386 pcanywhere desqview multitasking support used create environment 16 pc macintosh clients could login remotely access netware services run dos applications desqview development continued parallel desqview/x ceasing development desqview/x another version desqview released qemm still developed discontinuation desqview version compatible windows 98 released mid-1990s quarterdeck tried recast internet company releasing version mosaic web browser eventually company acquired symantec byte 1984 stated desq application compatibility highest five window managers tested magazine 1989 listed version 3.0 among distinction winners byte awards stating unlike os/2 desqview lets run programs 've already paid … many users find desqview need
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Operating systems
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optical character recognition optical character recognition optical character reader ocr mechanical electronic conversion images typed handwritten printed text machine-encoded text whether scanned document photo document scene-photo example text signs billboards landscape photo subtitle text superimposed image example television broadcast widely used form information entry printed paper data records – whether passport documents invoices bank statements computerized receipts business cards mail printouts static-data suitable documentation – common method digitizing printed texts electronically edited searched stored compactly displayed on-line used machine processes cognitive computing machine translation extracted text-to-speech key data text mining ocr field research pattern recognition artificial intelligence computer vision early versions needed trained images character worked one font time advanced systems capable producing high degree recognition accuracy fonts common support variety digital image file format inputs systems capable reproducing formatted output closely approximates original page including images columns non-textual components early optical character recognition may traced technologies involving telegraphy creating reading devices blind 1914 emanuel goldberg developed machine read characters converted standard telegraph code concurrently edmund fournier d'albe developed optophone handheld scanner moved across printed page produced tones corresponded specific letters characters late 1920s 1930s emanuel goldberg developed called statistical machine searching microfilm archives using optical code recognition system 1931 granted usa patent number 1,838,389 invention patent acquired ibm advent smart-phones smartglasses ocr used internet connected mobile device applications extract text captured using device camera devices ocr functionality built operating system typically use ocr api extract text image file captured provided device ocr api returns extracted text along information location detected text original image back device app processing text-to-speech display 1974 ray kurzweil started company kurzweil computer products inc. continued development omni-font ocr could recognize text printed virtually font kurzweil often credited inventing omni-font ocr use companies including compuscan late 1960s 1970s kurzweil decided best application technology would create reading machine blind would allow blind people computer read text loud device required invention two enabling technologiesthe ccd flatbed scanner text-to-speech synthesizer january 13 1976 successful finished product unveiled widely reported news conference headed kurzweil leaders national federation blind 1978 kurzweil computer products began selling commercial version optical character recognition computer program lexisnexis one first customers bought program upload legal paper news documents onto nascent online databases two years later kurzweil sold company xerox interest commercializing paper-to-computer text conversion xerox eventually spun scansoft merged nuance communications research group headed a. g. ramakrishnan medical intelligence language engineering lab indian institute science developed printtobraille tool open source gui front end used ocr convert scanned images printed books braille books 2000s ocr made available online service webocr cloud computing environment mobile applications like real-time translation foreign-language signs smartphone various commercial open source ocr systems available common writing systems including latin cyrillic arabic hebrew indic bengali bangla devanagari tamil chinese japanese korean characters ocr engines developed many kinds domain-specific ocr applications receipt ocr invoice ocr check ocr legal billing document ocr used ocr generally offline process analyses static document handwriting movement analysis used input handwriting recognition instead merely using shapes glyphs words technique able capture motions order segments drawn direction pattern putting pen lifting additional information make end-to-end process accurate technology also known on-line character recognition dynamic character recognition real-time character recognition intelligent character recognition ocr software often pre-processes images improve chances successful recognition techniques include segmentation fixed-pitch fonts accomplished relatively simply aligning image uniform grid based vertical grid lines least often intersect black areas proportional fonts sophisticated techniques needed whitespace letters sometimes greater words vertical lines intersect one character two basic types core ocr algorithm may produce ranked list candidate characters matrix matching involves comparing image stored glyph pixel-by-pixel basis also known pattern matching pattern recognition image correlation relies input glyph correctly isolated rest image stored glyph similar font scale technique works best typewritten text work well new fonts encountered technique early physical photocell-based ocr implemented rather directly feature extraction decomposes glyphs features like lines closed loops line direction line intersections extraction features reduces dimensionality representation makes recognition process computationally efficient features compared abstract vector-like representation character might reduce one glyph prototypes general techniques feature detection computer vision applicable type ocr commonly seen intelligent handwriting recognition indeed modern ocr software nearest neighbour classifiers k-nearest neighbors algorithm used compare image features stored glyph features choose nearest match software cuneiform tesseract use two-pass approach character recognition second pass known adaptive recognition uses letter shapes recognized high confidence first pass recognize better remaining letters second pass advantageous unusual fonts low-quality scans font distorted e.g blurred faded ocr result stored standardized alto format dedicated xml schema maintained united states library congress list optical character recognition software see comparison optical character recognition software ocr accuracy increased output constrained lexicona list words allowed occur document might example words english language technical lexicon specific field technique problematic document contains words lexicon like proper nouns tesseract uses dictionary influence character segmentation step improved accuracy output stream may plain text stream file characters sophisticated ocr systems preserve original layout page produce example annotated pdf includes original image page searchable textual representation near-neighbor analysis make use co-occurrence frequencies correct errors noting certain words often seen together example washington d.c. generally far common english washington doc knowledge grammar language scanned also help determine word likely verb noun example allowing greater accuracy levenshtein distance algorithm also used ocr post-processing optimize results ocr api recent years major ocr technology providers began tweak ocr systems deal efficiently specific types input beyond application-specific lexicon better performance may taking account business rules standard expression rich information contained color images strategy called application-oriented ocr customized ocr applied ocr license plates invoices screenshots id cards driver licenses automobile manufacturing new york times adapted ocr technology proprietary tool entitle document helper enables interactive news team accelerate processing documents need reviewed note enables process amounts many 5,400 pages per hour preparation reporters review contents several techniques solving problem character recognition means improved ocr algorithms special fonts like ocr-a ocr-b micr fonts precisely specified sizing spacing distinctive character shapes allow higher accuracy rate transcription bank check processing ironically however several prominent ocr engines designed capture text popular fonts arial times new roman incapable capturing text fonts specialized much different popularly used fonts google tesseract trained recognize new fonts recognize ocr-a ocr-b micr fonts comb fields pre-printed boxes encourage humans write legiblyone glyph per box often printed dropout color easily removed ocr system palm os used special set glyphs known graffiti similar printed english characters simplified modified easier recognition platform computationally limited hardware users would need learn write special glyphs zone-based ocr restricts image specific part document often referred template ocr crowdsourcing humans perform character recognition quickly process images like computer-driven ocr higher accuracy recognizing images obtained computers practical systems include amazon mechanical turk recaptcha national library finland developed online interface users correct ocred texts standardized alto format crowd sourcing also used perform character recognition directly invite software developers develop image processing algorithms example use rank-order tournaments commissioned u.s. department energy doe information science research institute isri mission foster improvement automated technologies understanding machine printed documents conducted authoritative annual test ocr accuracy 1992 1996 recognition latin-script typewritten text still 100 accurate even clear imaging available one study based recognition 19th- early 20th-century newspaper pages concluded character-by-character ocr accuracy commercial ocr software varied 81 99 total accuracy achieved human review data dictionary authentication areas—including recognition hand printing cursive handwriting printed text scripts especially east asian language characters many strokes single character —are still subject active research mnist database commonly used testing systems ability recognise handwritten digits accuracy rates measured several ways measured greatly affect reported accuracy rate example word context basically lexicon words used correct software finding non-existent words character error rate 1 99 accuracy may result error rate 5 95 accuracy worse measurement based whether whole word recognized incorrect letters example difficulties inherent digitizing old text inability ocr differentiate long f characters web-based ocr systems recognizing hand-printed text fly become well known commercial products recent years see tablet pc history accuracy rates 80 90 neat clean hand-printed characters achieved pen computing software accuracy rate still translates dozens errors per page making technology useful limited applications recognition cursive text active area research recognition rates even lower hand-printed text higher rates recognition general cursive script likely possible without use contextual grammatical information example recognizing entire words dictionary easier trying parse individual characters script reading amount line cheque always written-out number example using smaller dictionary increase recognition rates greatly shapes individual cursive characters simply contain enough information accurately greater 98 recognize handwritten cursive script programs allow users set confidence rates means software achieve desired level accuracy user notified manual review characters support ocr added unicode standard june 1993 release version 1.1 characters mapped fonts specific micr ocr-a ocr-b
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Computational linguistics
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winzip winzip trialware file archiver compressor windows macos ios android developed winzip computing formerly nico mak computing create archives zip file format unpack archive file formats winzip 1.0 released april 1991 graphical user interface gui front-end pkzip earlier january 1991 nico mak computing released gui front-end os/2 presentation manager called pmzip used os/2 versions pkware inc. pkzip pkunzip programs originally released compuserve availability winzip expanded across major online services including genie prodigy online services 1993 winzip announced launch official support customers windows utility forum serving 100,000 members providing updates related information freely downloadable winzip soon found included best-selling windows computing titles part companion disks including all-time best-selling windows 3.0 book windows secrets brian livingston 1994 winzip become official required compression tool used system operators compuserve forum file libraries starting version 5.0 1993 creators winzip incorporated compression code info-zip project thus eliminating need pkzip executable present version 6.0 version 9.0 registered users could download newest versions software enter original registration information install top existing registered version thereby obtain free upgrade upgrade scheme discontinued version 10.0 winzip available standard professional versions however shell windows later versions microsoft windows ability open create .zip files titled compressed folders reduces need extra compression software may 2 2006 corel corporation best known wordperfect coreldraw product lines announced completed acquisition winzip computing vector capital winzip 1.0 mac os x released november 2010 version compatible mac os x 10.6 snow leopard intel-based v10.5 leopard macs winzip mac edition 2 includes support os x 10.8 mountain lion zip file archive format zip originally invented ms-dos 1989 phil katz seeing need archive application graphical user interface nico mak employed mansfield software group inc developed winzip application microsoft windows winzip 1.0 initial version windows winzip 2.0 added support arc files support self-extracting zip files zip2exe optional interface virus scan software dialog box specify paths filenames external programs winzip 3.0 added full support lzh files including self-extracting lzh files configurable support virus scanners simplified options add extract files subdirectory tree winzip 3.1 added support windows 3.1 drag drop interface enhanced extract dialog box common dialog directory drive list test action zip lzh files added file types zip lzh arc new open dialog boxes winzip 3.2 added built-in zip extraction pkunzip needed zip extract operations winzip always uses pkzip.exe modify zip files winzip 4.0 added support pkzip 2.0 including built-in zip extraction support arj file format new toolbar descriptive pictorial buttons added 3-d look dialog boxes winzip 5.0 added pkzip-compatible built-in zipping pkzip needed basic archive management note two advanced features disk-spanning encryption still require pkzip added support windows-based virus scanners added built-in actions/test operation zip files built-in unzipping used running dos virus scanners added support international characters archive names files archives winzip 5.5 added ability install try uninstall software packed zip files winzip 5.6 added compression support popular internet file formats tar gzip unix winzip 6.0 added many windows 95-specific features including tight integration windows 95 shell explorer-style dialog boxes enhancements included improved interface file viewers express setup option better support virus scanners winzip 6.0a features improved windows 95 drag drop support winzip 7.0 introduced microsoft cab cabinet format internet explorer 4.0-style one click open interface zip comments registry-based configuration arj 2.60 long file name support explorer-style fonts winzip self-extractor personal edition creates zip files span multiple removable disks winzip 8.0 wizard interface extended allow users create update zip files wizard ability extract install mime encoded files automatic installation desktop themes screensavers addition explorer context menu opening files within archives inclusion subfolders adding updating archives explorer-style toolbar buttons displaying tooltip zip file selected windows explorer winzip context menus displays small icons correspond toolbar buttons windows 98 windows 2000 ability install desktop themes screensavers contained zip files new 'zip e-mail context menu commands automatic display zip comments context menu help winzip dialogs viewing multiple files one action windows extensions 32-bit explorer shell extensions winzip self-extractor personal edition longer supports creation 16-bit self-extracted archive winzip 8.1 last major release officially support windows 95 included ability extract multiple zip archives explorer configurable explorer context menus creation split zip archives new 'quick pick system tray icon resizable dialog boxes windows 98 higher extraction files split spanned zip archives wizard interface windows xp theme support opening skin files microsoft media player 7 .wmz yahoo player .yfs winamp .wsz displaying file comments 64,000 characters support filenames containing multi-byte character set mbcs characters increasing number entries created 'checkout feature programs menu 500 winzip 9.0 added support aes encryption zip archives bzip2-compressed zip archives extraction also removed previous limitations 65,535 files per zip file maximum file size 4 gigabytes version released 2004 winzip 10 added support creating extracting ppmd-compressed zip archives last major release officially support windows 98/me winzip pro added release added automation task scheduling features version released 2005 winzip 11 added support creating extracting wavpack-compressed zip archives installer still installed windows 98/me operating systems longer officially supported winzip pro added passive ftp support ftp transfers e-mail notification option job wizard custom jobs selection full-size image viewer opening archive version released 2006 winzip 11.1 certified windows vista vista theme support 64-bit windows support winzip 11.2 could create lha archives without external utility unicode file name support zip archives also added support external archivers arc arj removed winzip 12.0 2008 added support creating zip archives lossless jpeg lzma compression methods .iso .img 7-zip archive extractions added encryption policies integrated image thumbnail viewer jpeg compression compresses metadata lzma compression image compressed binary arithmetic coding winzip 12.1 2009 introduces new default .zipx file extension creating zip archives using methods newer deflate64 added automatic resizing images sent using zip e-mail functions winzip 13 skipped winzip 14 2009 added windows 7 support library grouping taskbar icon jump lists explorer preview multi-touch two finger gestures winzip 14 backup edition added supports automatic backup feature aes new instructions used supported speed aes encryption winzip 14.5 april 2010 added microsoft office 2010-style ribbon interface support windows 7 libraries jump lists multi-touch gestures interface functionality improvements winzip 15 november 2010 december 1 2010 implemented new performance architecture high-speed zipping interface improvements refined menu designs intuitive icons new desktop zip/unzip gadget drag-and-drop functionality new extensive email/webmail support backup function pro version due bug first release version creating backup jobs *.wjf job file selection needs reset/set working properly winzip 15.5 april 2011 new compression algorithms designed multi-processor systems zip files twice fast new winzip desktop gadget option called 'folder choose allows create select target folder zipping/unzipping files case-by-case basis dynamic context-sensitive icons automatically change reflect winzip tasks available specific situation streamlined processes remove unnecessary dialogs cut extra steps ability show/hide address bar ability instantly jump instances winzip currently open ability customize look feel winzip interface interchangeable themes improved destination folder management open/alter zipped file contents directly email attachment winzip prompt save work new location computer rather email temp folder streamlined 'unzip try processes remove extra steps making temporary viewing even quicker easier extended enterprise support provides control addition/alteration e-mail services winzip 16.0 released october 25 2011 implemented new 64-bit zip engine added 64-bit version winzip added ability zip write files blu-ray discs added integration zipsend zipshare services improved capabilities file conversion supported formats zip enhanced preview tools browsing editing contents compressed file types added system scanner diagnostic tool scans possible performance issues zipsend zipsend pro send message 50mb 2gb zipped data per message zipshare post files 20 mb data directly facebook free 100mb total data per account winzip 16.5 supports opencl acceleration file compression engine amd fusion processors amd radeon users streamlined interface winzip 17.0 released october 16 2012 introduced online sharing storage social media sites image resizing converting files pdf watermark addition context-sensitive toolbars winzip 17.5 released may 9 2013 new features include sharing features permission controls updated modernized user interface watermark timestamping four times faster .zip archive extraction maximum 23gb free cloud storage via box dropbox google drive skydrive cloudme new winzip 18.0 released october 31 2013 new features include support xz lzma2 compression additional features winzip express cloud backup winzip 18.5 released may 12 2014 includes support zipshare send zip files instant messaging facebook google talk/google+ hangouts yahoo messenger jabber cloud sharing includes mediafire integration winzip 19 released october 28 2014 includes unified local network cloud file management modern ui touch support adds enterprise edition corporate government use added fips 140-2 encryption enterprise edition also open extract vhd files winzip 19.5 released may 7 2015 adds smartshare share via clipboard cloud links view thumbnails auto-hide scroll bars slide-in action pane enterprise adds vmware file support vhd files ntfs compression winzip 20.0 released october 20 2015 new features include extract vhd vmdk virtual disks expanded sharing youtube instant message support scan share snap share improved file management winzip 21.0 released october 25 2016 new features include 16 accounts per cloud service domain access enhanced mp3 compression preview pane image information combined address book dis-aggregation individual zip file creation send inline conversion winzip 1.0 mac os x november 16 2010 initial release compatible intel macs run v10.5 'leopard winzip mac edition 2 released june 26 2012 new features include os x 10.8 mountain lion support finder integration in-place editing ios version first released february 17 2012 free english app designed ios 4.2 iphone ipad ipod touch available apple app store version 1.1.1 may 4 2012 includes following winzip android first released june 19 2012 free english app designed android operating system versions 2.1 eclair 2.2 froyo 2.3 gingerbread 3.x honeycomb 4.x ice cream sandwich higher initially available google play new version 1.1.0 winzip e-mail companion version 2.0 supports microsoft outlook 2002 2003 2007 windows mail 6.0 outlook express 6.0 optionally supports microsoft word microsoft powerpoint microsoft excel versions 2007 2003 2002 unlisted support outlook 2010 works 32-bit versions outlook 2010 winzip system utilities released february 14 2011 includes winzip driver updater 1.0 winzip registry optimizer 2.0
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Computer file systems
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socket fm1 socket fm1 cpu socket desktop computers used llano processors llano-derived athlon ii processors released july 2011 direct successors socket fm2 september 2012 socket fm2+ january 2014 socket am1 january 2014 targeting low-power socs available chipsets consult fusion controller hubs fch apu using socket fm1 amd platform please consult list amd accelerated processing units concrete product denominations
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Computer architecture
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novell bordermanager bordermanager multi purpose network security application developed novell inc. bordermanager designed proxy server firewall vpn access point novell announced migration superlumin 4.0 proxy cache novell preferred firewall proxy solution netware customers upgrading novell open enterprise server linux bordermanager designed run top netware kernel takes advantage fast file services netware kernel delivers aside easily copied firewall vpn access point services novell designed proxy services retrieve web data server server connection rather client server connection prior proxy servers market done retrieval method along netware fast file io proprietary code made bordermanager proxy engine one fastest existence 2003 novell announced successor product netware open enterprise server oes first released march 2005 oes completes separation services traditionally associated netware i.e file print makes possible customer choose netware linux kernel services run time novell announced end development netware kernel numerous public private statements 64-bit future netware linux path 64-bit computing oes follow migration path novell began porting applications linux company began looking alternate ways deliver services firewall vpn access point services equivalent functionality readily available free/open-source community also basic proxy services well i.e squid desire deliver functional equivalent could done full software code port much cache engine sold part volera excelerator novell holds great desire use create open-source software basic services novell entered agreement astaro relabel astaro security gateway license novell security manager product removed novell price list 15 february 2007 late summer 2006 novell announced would bordermanager 3.9 release novell brainshare conference 2010 novell announced superlumin 4.0 proxy cache path forward bordermanager customers also announced extended bordermanager general support two years march 7 2012 give customers adequate time make move november 2011 novell support lifecycle page states border manager 3.9 general support extended september 30 2013 make easy customers plan execute upgrade novell open enterprise server upgrade path border manager remains superlumin nemesis third-party filtering solutions available novell bordermanager following companies
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Computer security
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xputer xputer design reconfigurable computer proposed computer scientist reiner hartenstein hartenstein uses various terms describe various innovations design including config-ware flow-ware morph-ware anti-machine xputer represents move away traditional von neumann computer architecture coarse-grained soft arithmetic logic unit alu architecture parallelism achieved configurable elements known reconfigurable datapath arrays rdpa organized two-dimensional array alu similar kressarray xputer architecture data-stream-based counterpart instruction-based von neumann computer architecture xputer architecture one first coarse-grained reconfigurable architectures consists reconfigurable datapath array rdpa organized two-dimensional array alus rdpu bus-width alu 32-bit first version xputer alus also known rdpus used computing single mathematical operation addition subtraction multiplication also used purely routing alus mesh-connected via three types connections data-flow along connections managed address generation unit programs xputer written c language compiled usage xputer using codex compiler written author codex compiler maps suitable portions c program onto xputer rdpa fabric remainder program executed host system personal computer reconfigurable datapath array rdpa semiconductor device containing reconfigurable data path units programmable interconnects first proposed rainer kress 1993 university kaiserslautern instead fpgas field-programmable gate arrays single bit configurable logic blocks clbs rdpas multiple bits wide instance 32 bit path width reconfigurable datapath units rdpus rdpu configured perform individual function rdpus interconnects programmed manufacturing process customer/designer hence term reconfigurable rdpa perform whatever complex computation needed rdpus multiple bits wide instance 32 bits talk coarse-grained reconfigurability contrast fpgas single-bit wide configurable logic blocks called fine-gained reconfigurable rdpas structurally programmed config-ware source code compiled pipe-networks mapped onto rdpa rdpas instruction-stream-driven instruction fetch run time rdpus program counter
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Computer architecture
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wdc 65c02 western design center wdc 65c02 microprocessor enhanced cmos version popular nmos-based 8-bit mos technology 6502 65c02 fixed several problems original 6502 added small number new commands however main feature greatly lowered power usage order 10 times less 6502 running speed made useful portable computer roles microcontroller systems industrial settings used home computers well embedded applications including medical-grade implanted devices development began 1981 known 65802 first sample versions released early 1983 wdc licenced design synertek ncr gte rockwell semiconductor rockwell primary interest embedded market asked several new commands added aid role later copied back baseline version point wdc added two new commands create w65c02 sanyo later licenced design well seiko epson produced modified version huc6280 early versions used 40-pin dip packaging available 1 2 4 mhz versions later versions produced plcc qfp increasing speed well latest version wdc w65c02s-14 runs speeds 14 mhz 65c02 low cost general-purpose 8-bit microprocessor 8-bit registers data bus 16-bit program counter address bus register set small single 8-bit accumulator two 8-bit index registers x 8-bit status register p 16-bit program counter pc addition single accumulator first 256 bytes ram zero page 0000 00ff allow faster access dedicated addressing mode requires single byte address instead two stack lies next 256 bytes page one 0100 01ff moved extended stack grows downwards stack pointer starting 01ff decrementing stack grows variable-length instruction set varying one three bytes per instruction basic architecture 65c02 identical original 6502 considered low-power implementation design 1 mhz popular speed original 6502 65c02 requires 20 mw original uses 450 mw reduction twenty times manually optimized core low power use intended make 65c02 well suited low power system-on-chip soc designs verilog hardware description model available designing w65c02s core application-specific integrated circuit asic field-programmable gate array fpga common semiconductor industry wdc offers development system includes developer board in-circuit emulator ice software development system w65c02s–14 production version available pdip plcc qfp packages maximum officially supported ϕ2 primary clock speed 14 mhz indicated –14 part number suffix designation indicates part fully static core feature allows ϕ2 slowed fully stopped either high low state loss data typical microprocessors implemented cmos dynamic cores lose internal register contents thus crash continuously clocked rate minimum maximum specified values w65c02s may operated convenient supply voltage v 1.8 5 volts ±5 data sheet ac characteristics table lists operational characteristics 5 v 14 mhz 3.3 v 3 v 8 mhz 2.5 v 4 mhz 1.8 v 2 mhz information may artifact earlier data sheet graph indicates typical devices capable operation higher speeds suggested ac characteristics table reliable operation 20 mhz readily attainable v 5 volts assuming supporting hardware allow w65c02s may also operated non-integral clock rates 13.5 mhz digital sdtv luma sampling rate 14.31818 mhz ntsc colour carrier frequency × 4 14.75 mhz pal square pixels 14.7456 baud rate crystal etc. long v sufficient support frequency designer bill mensch pointed f affected off-chip factors capacitive load microprocessor pins minimizing load using short signal tracks fewest devices helps raise f. plcc qfp packages less pin-to-pin capacitance pdip package economical use printed circuit board space wdc reported fpga realizations w65c02s successfully operated 200 mhz although 65c02 mostly thought low-power 6502 also fixes several bugs found original adds new opcodes help increase code density estimated average 6502 assembly program made 10 15 smaller 65c02 see similar improvement performance avoided memory accesses original 6502 56 instructions combined different addressing modes produced total 151 opcodes possible 256 8-bit patterns remaining 105 unused opcodes undefined set codes low-order 4-bits 3 7 b f left entirely unused 2 single opcode 6502 famous way leftover codes actually performed actions due way 6502 instruction decoder worked simply setting certain bits opcode would cause parts instruction processing take place opcodes would immediately crash processor performed useful functions even given unofficial assembler mnemonics users 65c02 added number new opcodes used number previously undocumented instruction slots instance ff used new codice_5 instruction see remained truly unused set perform codice_6s programs took advantage codes work 65c02 codes always documented non-operational used original 6502 several bugs initially launched among notorious codice_7 rotate right broken due problem chip mos addressed documenting instruction bug fixed early production run generally issue vast majority machines using processor contrast another bug remained design lifetime involved commonly-used jump command codice_8 using indirect addressing mode address jmp looked another memory location instance codice_9 would fetch value bytes 1234 1235 use 16 bits actual memory location jump however initial address ended ff boundary memory page jmp took significant byte 16-bit address 00 original page rather 00 new page instance codice_10 would get first byte 12ff second incorrectly 1200 rather 1300 fixed 65c02 another bug original 6502 concerned behaviour ecimal flag status register left undefined reset interrupt meant programmers forced set flag known value one finds codice_11 instruction clear decimal following initial codice_12 almost interrupt handlers 65c02 automatically set reset flag correctly pushing status register onto stack related problem occurred operating decimal mode n egative v erflow z ero flags updated properly ways address code cost additional instructions 65c02 addresses problem sets flags correctly cost single clock cycle 6502 included variation indirect addressing mode based x index registers instruction used mode processor took initial zero page address added x register returned value resulting location unfortunately way load data zero page one wanted access single byte known location page code first codice_13 codice_14 65c02 added new mode codice_15 removing need ldy 6502 also included mode known preindexing offset address value x register fetched data address pointed 16-bit data instance x register holds value 4 codice_16 would add value x absolute addresses 12 pick two bytes 16 17 value two bytes 1234 fetches 8-bit value memory location 1234 basic idea allow set series unrelated locations memory access changing x register useful could used zero page data intermediate address 65c02 extended new postindexed version officially known indexed absolute indirect available register mode fetched address zero page added value retrieving 16-bits zero page instance codice_17 would first look address 12/ 13 retrieve instance 1230 add loading accumulator value 1234 new mode extremely useful implementing jump tables set subroutines previously locations would zero page list could placed anywhere main memory starting location list placed zero page program codice_18 call routine number 10 sort access pattern extremely common notably widely used basic programming language found many 6502 systems sort access possible original preindexing version cost entire table zero page limited resource new mode particularly useful routines rom addition new addressing modes base model 65c02 also added set new instructions initial design 65c02 modified rockwell interested 6502 basis embedded processors roles common device drivers communicate cpu encoding status bits single byte fashion similar cpu status register makes various bit manipulation instructions common embedded applications normally one tests bits codice_44ing desired pattern memory location holding data branching based status register z ero flag instance address 1234 status register device bit 3 held ready status one could implement continue ready codice_45 hex 08 third bit bit set equal branch routine 2345 sort test common original 6502 included special-purpose codice_46 instruction automating bit change accumulator unlike anding tested bits 6 7 time placing results n egative v erflow flags long device drivers used bits 6 7 commonly tested flags using bit could reduce number tests needed 65c02 improved bit command adding new addressing modes including ability test constant accumulator instead pattern initially stored memory however rockwell changes went far beyond changes bit adding host commands directly setting testing bit combining test clear branch single opcode new instructions available start rockwell r65c00 family part original 65c02 specification found versions made wdc licensees later copied back baseline design available later wdc versions denoted leading w w65c02 new instructions include addition new commands wdc also added codice_4 codice_3 instructions supporting low-power modes stp stop processor halted processing hardware reset issued could used put system sleep rapidly wake reset however required external system maintain memory widely used wait similar effect entering low-power mode time woke reception interrupt embedded uses meant device driver poll changes instead simply issued wai jumped interrupt processing started added advantage always entering low-power mode instructions completed handler always started one cycle instead wait currently processing instructions complete first 65sc02 variant wdc 65c02 without bit instructions
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Computer architecture
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token bus network token bus network implementing token ring protocol virtual ring coaxial cable token passed around network nodes node possessing token may transmit node n't anything send token passed next node virtual ring node must know address neighbour ring special protocol needed notify nodes connections disconnections ring due difficulties handling device failures adding new stations network token ring gained reputation unreliable difficult upgrade bus networks ethernet flexible reliable physical architecture ethernet access protocol could absolutely guarantee maximum time station would wait access network thought unsuitable manufacturing automation applications token bus protocol created combine benefits physical bus network deterministic access protocol token ring network token bus standardized ieee standard 802.4 mainly used industrial applications token bus used general motors manufacturing automation protocol map standardization effort application concepts used token ring networks main difference endpoints bus meet form physical ring order guarantee packet delay transmission token bus protocol modified token bus proposed manufacturing automation systems flexible manufacturing system fms means carrying internet protocol ieee 802 networks including token bus networks developed ieee 802.4 working group disbanded standard withdrawn ieee
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Internet protocols
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open transport open transport name given apple inc. implementation unix-originated system v streams networking stack based code licensed mentat portable streams product open transport built provide classic mac os modern tcp/ip implementation replacing mactcp apple also added implementation appletalk stack support legacy networks prior release open transport classic mac os used variety stand-alone inits provide networking functionality one widely used throughout os appletalk system among protocol stacks supported mactcp becoming increasingly important internet boom started gain momentum mactcp emulated berkeley sockets system widely used among unix-like operating systems mactcp previous generation appletalk library slow powerpc-based macintoshes written previous generation 680x0-based macintoshes therefore ran emulation powerpc-based machines mactcp also lacking features however major upgrade clearly needed apple keep hand internet market late 1980s several major efforts re-combine many unix derivatives single system underway significant among t-led system v. system v included entirely new networking stack streams replacing existing berkeley sockets system streams number advantages sockets including ability support multiple networking stacks time ability plug modules middle existing stacks provide simple mechanisms filtering similar duties offering single application programming interface user programs time appeared streams would become de facto standard change market led apple move support streams well also presented two practical advantages company streams multiprotocol support would allow support tcp/ip appletalk single interface portable cross-platform version streams available purchase commercially one included high-quality tcp implementation using streams also appeared offer way one microsoft whose tcp/ip networking system winsock based apparently soon-to-be-obsolete sockets open transport introduced may 1995 power mac 9500 included system 7.5.2 release new pci based power macs became available older hardware later mactcp supported pci-based macs older systems could switch mactcp open transport using control panel called network software selector unlike mactcp open transport allowed users save switch configuration sets developer opinion open transport divided felt offered enormous speed improvements mactcp developers also liked flexible way allowed protocols stacked apply filters duties however system also large complex flexibility open transport architecture one could plug desired protocol felt thoroughly overcomplicated additionally unix code still used sockets streams mactcp offered real advantages terms porting software mac vaunted flexibility open transport architecture undermined ultimately made obsolete rapid rise tcp/ip networking mid-90s true wider unix market system v undermined rapid rise free unix-like systems notably linux systems grew popularity vast majority programmers ignored closed streams favour bsd-licensed sockets open transport abandoned move os x derived bsd networking stack based entirely sockets open transport received deprecation status starting mac os x 10.4 sdks open transport support removed entirely os x starting version 10.9 mavericks
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Operating systems
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national information assurance partnership national information assurance partnership niap united states government initiative meet security testing needs information technology consumers producers operated national security agency nsa originally joint effort nsa national institute standards technology nist long-term goal niap help increase level trust consumers information systems networks use cost-effective security testing evaluation validation programs meeting goal niap seeks principal objective niap validation body ensure provision competent security evaluation validation services government industry validation body ultimate responsibility operation ccevs accordance policies procedures appropriate interpret amend policies procedures nsa responsible providing sufficient resources validation body may carry responsibilities validation body led director deputy director selected nsa management director validation body reports niap director administrative budgetary matters nsa certificate-issuing authorities ccevs related operational matters general director deputy director serve two-year term service term service may extended discretion nsa management also significant number technical administrative support personnel required provide full range validation services sponsors evaluations common criteria testing laboratories cctl personnel include validators technical experts various technology cells senior members technical staff security community oversight board validation body ensures appropriate mechanisms place protect interests parties within ccevs participating process security evaluation dispute brought forth participating party i.e. sponsor evaluation product protection profile developer cctl concerning operation ccevs associated activities shall referred validation body resolution disputes involving validation body nsa management attempt resolve dispute procedures agreed upon two organizations
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Computer security
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db networks db networks privately held information security company founded united states company provides enterprise database security equipment software service company ’ headquarters san diego california regional offices located palo alto california seattle washington db networks founded united states 2009 provide database security including database infrastructure assessment compromised credential identification sql injection defense predominantly financial services industry federal government company initially financed angel investors 2012 company raised 4.5m venture capital khosla ventures 2014 company closed 17 million round funding led khosla ventures grotech ventures company first product adf-4200 launched february 2013 also february 2013 company announced partnership alamo city engineering services aces offer products us military civilian federal agencies october 2013 company announced ids-6300 later renamed dbn-6300 originally sql injection defense database infrastructure security product 2013 db networks invited join cync cybersecurity technology program direction northrop grumman university maryland baltimore county research park corporation cync program identifies innovative technologies combat cybersecurity threats 2014 amp tech solutions announced channel partner offer db network products nasa solutions enterprise-wide procurement sewp iv contract united states federal agencies 2015 db networks awarded two united states patents database security technologies db networks began licensing database security software technologies original equipment manufacturers oems february 2016 coinciding launch layer 7 database sensor partnerships announced fireeye cyphort security on-demand db networks database security technology based machine learning behavioral analysis opposed traditional information security approach requiring human generated blacklists whitelists machine learning behavioral analysis platform learns applications proper sql transaction behavior compromised credentials rogue sql statements sql injection attack deviate established model raise alarm database attack machine learning behavioral analysis technologies ability prevent advanced zero-day database attacks without prior threat intelligence need establish maintain signature files known attack strings db networks dbn-6300 announced october 2013 originally referred ids-6300 dbn-6300 2u purpose-built database security appliance uses machine learning behavioral analysis identify database attacks real-time virtual appliance version dbn-6300 launched february 2014 referred dbn-6300v layer 7 database sensor launched february 2016 layer 7 database sensor enables information security product manufactures integrate db networks database security technology products march 2016 insider threat protection capabilities added dbn-6300 layer 7 database sensor products 2016 2015 2014 2013
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Computer security
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x video extension x video extension often abbreviated xvideo xv video output mechanism x window system protocol designed david carver specification version 2 protocol written july 1991 mainly used today resize video content video controller hardware order enlarge given video watch full screen mode without xvideo x would scaling main cpu requires considerable amount processing power could slow degrade video stream video controllers specifically designed kind computation much cheaply similarly x video extension video controller perform color space conversions change contrast brightness hue displayed video stream order work three things come together modern video controllers provide functions required xvideo feature known hardware scaling yuv acceleration sometimes 2d hardware acceleration xfree86 x display server implemented xvideo since version 4.0.2 check whether given x display server supports xvideo one use utility xdpyinfo check whether video controller provides required functions whether x device driver implements xvideo one use xvinfo program video playback programs run x window system mplayer mythtv xine typically option enable xvideo output advisable switch option system gpu video-hardware device drivers supports xvideo modern rendering systems opengl vdpau unavailable – speedup noticeable even fast cpu protocol features reading writing video streams video adapters practice today functions xvputimage xvshmputimage used client program repeatedly prepares images passes graphics hardware scaled converted displayed video scaled prepared display video card must displayed possible ways display accelerated video stage since full acceleration means video controller responsible scaling converting drawing video technique used depends entirely video drawn onto x video finally drawn depends largely x window manager use properly installed drivers gpu hardware supported intel ati nvidia chip sets window managers called compositing window managers allow windows separately processed rendered composited involves windows rendered separate output buffers memory first later combined form complete graphical interface video memory individual windows transformed separately accelerated video may added stage using texture filter window composited drawn xvideo also used accelerate video playback drawing windows using opengl framebuffer object pbuffer metacity x window manager uses compositing way compositing also make use 3d pipelines accelerations glx_ext_texture_from_pixmap among things process allows many video outputs share screen without interfering compositing window managers compiz also use compositing however system limited opengl acceleration function specifically lack opengl framebuffer object pbuffer use opengl environment like xgl makes xv hardware accelerations impossible event window manager n't directly support compositing difficult isolate video stream rendered time accelerated output already turned single image way usually employ post processed hardware overlay using chroma keying windows already drawn pieces information available size position video window canvas third piece information required indicate parts video window canvas obscured windows therefore video player draws canvas using solid color 'll say green color becomes makeshift third dimension windows drawn windows covering video player block green color video stream added output graphics card simply scan co-ordinates canvas encounters green knows found visible portion video window draws portions video process also available option render hardware accelerated video microsoft windows xp earlier since window management features deeply embedded operating system accelerating would impossible window manager n't support compositing post processed hardware overlays using chroma keying described previous paragraph make impossible produce proper screenshots xvideo applications also make impossible view kind playback secondary display one overlay allowed hardware level
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Internet protocols
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proof age standards scheme pass proof age standards scheme government-backed scheme uk gives young people valid accepted form proof age identification scheme supported home office chartered trading standards institute ctsi national police chiefs ’ council npcc acts umbrella system issue identification cards various proof age card schemes operate pass umbrella issue cards bear pass hologram proof authenticity validity set 2001 develop recognisable way endorsing proof age card schemes due united kingdom issuing government identification card individuals ‘ drive difficulty providing proof age purchasing age-restricted products cigarettes alcohol june 2014 18+ card designs standardised apart young scot card scotland real variation appearance logo issuing organisation corner citing feedback police retailers effort increase acceptance venues especially night-time economy november 2016 pass reorganised become community interest company ownership british retail consortium ended january 2018 national police chiefs ’ council npcc logo replaced association chief police officers acpo logo lower left corner standardised 18+ card design two types card suppliers national regional regional cards often requirements residency area issued national cards obtained anyone provide required information currently three councils offer regional cards bracknell forest council e+ card milton keynes council 1 card london borough southwark pal national suppliers citizencard id card oneid4u validateuk young scot card available eligible individuals resident scotland proof age standards scheme goal become preferred standard proving age britons 5 million cards issued since 2001 200,000 2017 2018 several trade bodies currently support pass association convenience stores british beer pub association british institute innkeeping uk hospitality wine spirits trade association addition home office chartered trading standards institute national police chiefs council security industry authority also support organisation responsibility sellers supply alcohol tobacco age restricted products people legal age checking proof age card protects inadvertently selling under-age people look older places requiring proof age accept cards despite pass hologram retailers licensees right refuse sell product deny entry individual even possess pass endorsed card 2011 500,000 holders pass endorsed card refused entry pubs clubs result 2014 police security industry authority licences doorstaff agreed permit logos displayed pass cards displaying standardised design 2017 passport office urged passport-holders leave passports home use pass card nights 2019 pass agreed develop standards presentation digital proof age purpose enabling home office amend mandatory licensing conditions approved forms digital physical proof age could accepted licensees purpose demonstrating due diligence
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Computer security
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prince software prince formerly prince xml proprietary software program converts xml html documents pdf files applying cascading style sheets css technology electronic publishing dynamic data-driven pdf generation enables replacing xsl-fo frameworks css3 ones developed yeslogic small company based melbourne australia marketed professional xml+css3 pdf solution received positive reviews considered unique product 2000s april 2003 prince 1.0 released basic support xhtml cascading style sheets css scalable vector graphics svg arbitrary xml first version command-line program supported microsoft windows linux graphical user interface windows yet subsequent releases css support steadily extended comparable web browsers opera mozilla firefox also expanded support additional platforms—the latest offering include packages apple mac freebsd solaris platforms december 2005 prince 5.1 passed acid2 test web standards project third user agent pass test safari konqueror prince developed using mercury functional logic programming language main driving force behind prince standard css3-paged integrates paged media including pdf layout specification w3c technologies html4 html5 xhtml free xml working javascript sources
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Programming language topics
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ithc ithc health check security assessment required part accreditation process many government computer systems uk ithc generally performed external service provider although ncsc personnel may perform ithcs especially sensitive systems touch applications infrastructure involves element penetration testing check scheme ithc providers run ncsc
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Computer security
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list intel cpu microarchitectures following partial list intel cpu microarchitectures list incomplete additional details found intel tick-tock model process-architecture-optimization model
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Computer architecture
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java virtual machine java virtual machine jvm virtual machine enables computer run java programs well programs written languages also compiled java bytecode jvm detailed specification formally describes required jvm implementation specification ensures interoperability java programs across different implementations program authors using java development kit jdk need worry idiosyncrasies underlying hardware platform jvm reference implementation developed openjdk project open source code includes jit compiler called hotspot commercially supported java releases available oracle corporation based openjdk runtime eclipse openj9 another open source jvm openjdk java virtual machine abstract virtual computer defined specification garbage-collection algorithm used internal optimization java virtual machine instructions translation machine code specified main reason omission unnecessarily constrain implementers java application run inside concrete implementation abstract specification java virtual machine starting java platform standard edition j2se 5.0 changes jvm specification developed java community process jsr 924. changes specification support changes proposed class file format jsr 202 done maintenance release jsr 924 specification jvm published blue book preface states one oracle jvms named hotspot inherited bea systems jrockit clean-room java implementations include kaffe openj9 skelmir cee-j oracle owns java trademark may allow use certify implementation suites fully compatible oracle specification one organizational units jvm byte code class class loader implementation must able recognize load anything conforms java class file format implementation free recognize binary forms besides class files must recognize class files class loader performs three basic activities strict order general two types class loader bootstrap class loader user defined class loader every java virtual machine implementation must bootstrap class loader capable loading trusted classes java virtual machine specification n't specify class loader locate classes jvm operates primitive values integers floating-point numbers references jvm fundamentally 32-bit machine codice_1 codice_2 types 64-bits supported natively consume two units storage frame local variables operand stack since unit 32 bits codice_3 codice_4 codice_5 codice_6 types sign-extended except codice_6 zero-extended operated 32-bit integers codice_8 types smaller types type-specific instructions loading storing type conversion codice_3 operated 8-bit codice_4 values 0 representing codice_11 1 representing codice_12 although codice_3 treated type since java virtual machine specification second edition clarified issue compiled executed code little difference codice_3 codice_4 except name mangling method signatures type boolean arrays codice_3s method signatures mangled codice_17 codice_4s mangled codice_19 boolean arrays carry type codice_20 use 8 bits per element jvm built-in capability pack booleans bit array except type perform behave codice_4 arrays uses codice_3 type effectively unknown jvm instructions operate booleans also used operate codice_4s jvm garbage-collected heap storing objects arrays code constants class data stored method area method area logically part heap implementations may treat method area separately heap example might garbage collect jvm thread also call stack called java virtual machine stack clarity stores frames new frame created time method called frame destroyed method exits frame provides operand stack array local variables operand stack used operands computations receiving return value called method local variables serve purpose registers also used pass method arguments thus jvm stack machine register machine jvm instructions following groups tasks aim binary compatibility particular host operating system needs implementation jvm runtime jvms interpret bytecode semantically way actual implementation may different complex emulating bytecode compatibly efficiently implementing java core api must mapped host operating system instructions operate set common rather native data types specific instruction set architecture jvm language language functionality expressed terms valid class file hosted java virtual machine class file contains java virtual machine instructions java byte code symbol table well ancillary information class file format hardware- operating system-independent binary format used represent compiled classes interfaces several jvm languages old languages ported jvm completely new languages jruby jython perhaps well-known ports existing languages i.e ruby python respectively new languages created scratch compile java bytecode clojure apache groovy scala kotlin may popular ones notable feature jvm languages compatible example scala libraries used java programs vice versa java 7 jvm implements jsr 292 supporting dynamically typed languages java platform new feature supports dynamically typed languages jvm feature developed within da vinci machine project whose mission extend jvm supports languages java basic philosophy java inherently safe standpoint user program crash host machine otherwise interfere inappropriately operations host machine possible protect certain methods data structures belonging trusted code access corruption untrusted code executing within jvm furthermore common programmer errors often led data corruption unpredictable behavior accessing end array using uninitialized pointer allowed occur several features java combine provide safety including class model garbage-collected heap verifier jvm verifies bytecode executed verification consists primarily three types checks first two checks take place primarily verification step occurs class loaded made eligible use third primarily performed dynamically data items methods class first accessed another class verifier permits bytecode sequences valid programs e.g jump branch instruction target instruction within method furthermore verifier ensures given instruction operates fixed stack location allowing jit compiler transform stack accesses fixed register accesses jvm stack architecture imply speed penalty emulation register-based architectures using jit compiler face code-verified jvm architecture makes difference jit compiler whether gets named imaginary registers imaginary stack positions must allocated target architecture registers fact code verification makes jvm different classic stack architecture efficient emulation jit compiler complicated typically carried slower interpreter original specification bytecode verifier used natural language incomplete incorrect respects number attempts made specify jvm formal system security current jvm implementations thoroughly analyzed potential security exploits prevented also possible optimize jvm skipping unnecessary safety checks application run proven safe virtual machine architecture allows fine-grained control actions code within machine permitted take assumes code semantically correct successfully passed formal bytecode verifier process materialized tool possibly off-board virtual machine designed allow safe execution untrusted code remote sources model used java applets secure code downloads bytecode-verified downloaded code runs restricted sandbox designed protect user misbehaving malicious code addition bytecode verification process publishers purchase certificate digitally sign applets safe giving permission ask user break sandbox access local file system clipboard execute external pieces software network formal proof bytecode verifiers done javacard industry formal development embedded verifier java card byte code hardware architecture different java bytecode interpreter needed computer java bytecode interpreter run java bytecode program program run computer interpreter java bytecode executed interpreter execution always slower execution program compiled native machine language problem mitigated just-in-time jit compilers executing java bytecode jit compiler may translate java bytecode native machine language executing program translated parts program executed much quickly could interpreted technique gets applied parts program frequently executed way jit compiler significantly speed overall execution time necessary connection java programming language java bytecode program written java compiled directly machine language real computer programs written languages java compiled java bytecode java bytecode intended platform-independent secure jvm implementations include interpreter consist just-in-time compiler start java platform lifetime jvm marketed web technology creating rich internet applications web browsers operating systems bundling web browsers ship java plug-in permit side-loading non-flash plug-in java browser plugin deprecated jdk 9 npapi java browser plug-in designed allow jvm execute so-called java applets embedded html pages browsers plug-in installed applet allowed draw rectangular region page assigned plug-in includes jvm java applets restricted java programming language language targeting jvm may run plug-in restricted set apis allow applets access user microphone 3d acceleration although applets able modify page outside rectangular region adobe flash player main competing technology works way respect may 2016 javapoly allows users import unmodified java libraries invoke directly javascript javapoly allows websites use unmodified java libraries even user java installed computer continuing improvements javascript execution speed combined increased use mobile devices whose web browsers implement support plugins efforts target users compilation javascript possible either compile source code jvm bytecode javascript compiling jvm bytecode universal across jvm languages allows building upon language existing compiler bytecode main jvm bytecode javascript compilers teavm compiler contained dragome web sdk bck2brwsr j2js-compiler leading compilers jvm languages javascript include java-to-javascript compiler contained google web toolkit clojurescript clojure grooscript apache groovy scala.js scala others java runtime environment jre released oracle freely available software distribution containing stand-alone jvm hotspot java standard library java class library configuration tool and—until discontinuation jdk 9—a browser plug-in common java environment installed personal computers laptop desktop form factor mobile phones including feature phones early smartphones ship jvm likely include jvm meant run applications targeting micro edition java platform meanwhile modern smartphones tablet computers handheld pcs run java apps likely support android operating system includes open source virtual machine incompatible jvm specification instead google android development tools take java programs input output dalvik bytecode native input format virtual machine android devices jvm specification gives lot leeway implementors regarding implementation details since java 1.3 jre oracle contains jvm called hotspot designed high-performance jvm speed-up code execution hotspot relies just-in-time compilation speed-up object allocation garbage collection hotspot uses generational heap java virtual machine heap area memory used jvm dynamic memory allocation hotspot heap divided generations permanent generation permgen used class definitions associated metadata prior java 8 permanent generation part heap permanent generation removed java 8 originally permanent generation objects classes stored together area class unloading occurs much rarely objects collected moving class structures specific area allowed significant performance improvements oracle jre installed large number computers end users out-of-date version jre therefore vulnerable many known attacks led widely shared belief java inherently insecure since java 1.7 oracle jre windows includes automatic update functionality discontinuation java browser plug-in web page might potentially run java applet provided easily accessible attack surface malicious web sites 2013 kaspersky labs reported java plug-in method choice computer criminals java exploits included many exploit packs hackers deploy onto hacked web sites java applet removed java 11 launched september 25th 2018
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Programming language topics
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decstation decstation brand computers used dec refers three distinct lines computer systems—the first released 1978 word processing system latter widely known two released 1989 comprised range computer workstations based mips architecture range pc compatibles mips-based workstations ran ultrix dec-proprietary version unix early releases osf/1 first line computer systems given decstation name word processing systems based pdp-8 systems built vt52 terminal also known vt78 second completely unrelated line decstations began decstation 3100 released 11 january 1989 decstation 3100 first commercially available risc-based machine built dec line decstations fruit advanced development skunkworks project carried dec palo alto hamilton ave facility known pmax project focus produce computer systems family economics performance compete likes sun microsystems risc-based unix platforms day brainchild james billmaier mario pagliaro armando stettner joseph dinucci systems family also employ truly risc-based architecture compared heavier cisc vax still development prism architectures time dec mostly known cisc systems including successful pdp vax lines several architectures considered intel motorola others group quickly selected mips line microprocessors early mips microprocessors supported big- little-endian modes configured hardware reset little-endian mode chosen match byte ordering vax-based systems growing number intel-based pcs computers contrast vax later dec alpha architectures decstation 3100 family specifically designed built run unix system ultrix version vms operating system ever released decstations one issues debated project inception whether dec could sustain grow compete architecture invent manage core advocates later left company mips-based line computers shut favor alpha-based computers dec invented owned architecture descended prism development work first generation commercially marketed dec alpha systems dec 3000 axp series similar respects contemporaneous mips-based decstations sold alongside alpha systems decstation line gradually phased used turbochannel expansion bus video network cards well sold turbochannel option modules mice monitors keyboards later decstations planned based ecl-based r6000 canceled 14 august 1990 bipolar integrated technology failed deliver sufficient volumes microprocessor difficult fabricate yields r6000 reduced dec required little-endian mode used beginning continue available mips-based decstations used first target system development platform mach microkernel well early development windows nt operating system shortly prior release dec alpha systems port osf/1 decstation completed commercially released recently various free operating systems netbsd linux/mips ported mips-based decstations extending useful life providing modern operating system gxemul project emulates several decstation models original mips-based decstation 3100 followed cost reduced 2100 decstation 3100 claimed world fastest unix workstation time introduced three times fast vaxstation 3100 introduced time server configurations decstation models distributed without framebuffer graphics accelerator turbochannel q-bus based called decsystem confused pdp-10 machines name early models decstation heavily integrated systems little expansion capability even possess expansion buses decstation 5000 systems introduced later improved lack expansion capabilities providing turbochannel interconnect decstation 5000 systems also arc advanced risc computing compatible last decstation models focused increased component integration using custom asics reduce number discrete components begun decstation 5000 model 240 replaced discrete components lsi asics ended last model decstation 5000 model 260 used single vlsi asic much control logic packaged decstation 5000 systems sometimes suffixed two three letters letters refer graphics option system decstation 3100 2100 uses r2000 processor r2010 floating point coprocessor four r2020 write buffers r2000 uses external 64 kb direct-mapped instruction cache 64 kb direct-mapped write-through data cache cache line size four bytes four r2020 implement four-stage write buffer improve performance permitting r2000 write write-through data cache without stalling r2000 microprocessor could configured run either big-endian little-endian mode decstation family decision made run little-endian maintain compatibility vax family growing population intel-based pc decstation 3100 2100 memory system contains dram-based system memory vram-based framebuffers amount system memory supported 4 24 mb organized six physical memory banks systems 12 simm slots use 2 mb simms simm containing 1,048,576 word × 18-bit drams simms installed pairs increments 4 mb memory system byte-parity protected monochrome framebuffer implemented 256 kb vfb01 simm color framebuffer 1 mb vbf02 simm one framebuffer simms present framebuffer used simm slots rated 25 removal insertion cycles five recommended limit graphics capability provided two frame buffer modules monochrome color frame buffer monochrome frame buffer supports 1-bit color resolution 1024 × 864 pixels color frame buffer supports 8-bit color resolution monochrome frame buffer frame buffers use brooktree bt478 ramdac three 256-entry 8-bit color maps hardware cursor generated dc503 pcc programmable cursor chip provide 16 × 16 pixel 2-bit color cursor color frame buffer 8-bit write mask used select pixel updated none framebuffers use memory provided frame buffer module color frame buffer vram organized 2048 × 1024 pixels monochrome frame buffer 1024 × 1024 leftmost pixels displayed color frame buffer topmost pixels monochrome frame buffer unused areas vram may used store graphical structures fonts frame buffers parity-protected unlike rest system memory db15 male connector used video connector uses rs343a/rs170 compatible signals decstations onboard 10 mbit/s ethernet provided amd 7990 lance local area network controller ethernet amd 7992 sia serial interface adapter implements interface bnc thinwire ethernet connector 32 768 word × 16-bit 64 kb network buffer constructed srams provided improve performance 32 word 8-bit ethernet station address rom esar provides mac address mounted dip socket removable 5 mb/s single-ended scsi interface provided dc7061 sii gate array 64 k 16-bit 128 kb scsi buffer used improve performance decstations provide internal storage scsi interface connected external port honda68 male connector connected drive expansion boxes systems four asynchronous serial lines provided dc7085 gate array four serial lines third line required modem control signals support modem 4-pin mmj connector provided keyboard line 7-pin din connector mouse line two 6-pin mmj connectors printer modem lines real time clock motorola mc146818 also 50 bytes ram storing console configuration information 256 kb rom storing boot-strap self-test software provided two 128 kb roms dip sockets enclosure used decstation 3100 2100 identical enclosure used vaxstation 3100 systems use mechanically identical system module enclosure accommodate two 3.5-inch drives mounted trays system module system module located left enclosure power supply takes fourth space inside enclosure located left personal decstation 5000 series entry-level workstations code named maxine personal decstation uses low-profile desktop case contained power supply left two mounts two fixed drives one fixed drive one diskette drive front system logic contained two printed circuit boards base system module contained majority logic cpu module contained processor three models cpu module contains cpu subsystem first model contains chipset consisting 20 25 33 mhz r3000a cpu r3010 fpu accompanied 64 kb instruction cache 64 kb data cache caches direct-mapped 4-byte cache line data cache write components cpu module operate clock frequency r300a cpuctl asic also present purpose provide interfacing buffering faster cpu module slower 12.5 mhz system module cpuctl asic also implements 12.5 mhz turbochannel serves system interconnect second model revised version first module 20 25 mhz r3000a r3010 used plastic packaging whereas previous model used ceramic packaging third model contains r4000 microprocessor internal instruction data caches complemented 1 mb secondary cache systems 8 mb onboard memory four simm slots used expand amount memory 32 mb total 40 mb memory simm slots accept 2 8 mb simms pairs simms system must size memory bus 40 bits wide 32 bits used data four bits used byte-parity memory control asic controls memory communicates cpu subsystem via turbochannel bus expansion provided two turbochannel slots 64 mb physical address space personal decstation features integrated 8-bit color frame buffer capable resolution 1024 × 768 refresh rate 72 hz frame buffer consists 1 mb vram organized 262,144 32-bit words 32-bit word containing four 8-bit pixels frame buffer uses inmos ims g332 ramdac 256-entry 24-bit color look table selects 256 colors display palette 16,777,216 frame buffer treated part memory subsystem i/o subsystem provides system 8-bit single-ended scsi bus 10 mbit/s ethernet serial line serial desktop bus analog audio scsi provided ncr 53c94 asc advanced scsi controller ethernet provided amd am7990 lance local area network controller ethernet amd am7992 sia serial interface adapter implements aui interface single serial port capable 50 19,200 baud full modem control capability provided zilog z85c30 scc serial communications controller analog audio isdn support provided amd 79c30a dsc digital subscriber controller devices connected ioctl asic via two 8-bit buses one 16-bit bus asic interfaces subsystem turbochannel interconnect decstation 5000 model 100 series code named 3min mid-range workstations early models used chipset consisting r3000a cpu r3010 cpu 3- 5-inch daughter card plugs connector system module model 150 replaces r3000a r3010 single r4000 integrated fpu model 120 125 two external caches 64 kb instruction cache 64 kb data cache model 133 128 kb instruction cache systems support 16 128 mb memory 16 simm slots accept 2 8 mb simms one type simm may used 2 8 mb simms mixed system 2 mb simm identical simm used decstation 2100 3100 allowing upgrades older systems model 100 series reuse old memory three turbochannel option slots provided model 100 series introduces i/o controller asic later known ioctl asic interfaces two 8-bit i/o buses 12.5 mhz turbochannel decstation 200 series high-end workstations server configurations decstation 500 model 200 240 260 known decsystem 5000 model 200 240 260 respectively systems contain cpu module system module power supply located left side enclosure internal storage capability drives intended installed external single- multiple-drive enclosures enclosures connected system via scsi connector located rear system alternatively storage provided file server accessed network member model 200 series unique cpu subsystem model 200 cpu subsystem located kn02 system module contains chipset composed r3000 cpu r3010 fpu r3220 mb six-stage write/memory buffer also part subsystem processor external 64 kb instruction cache 64 kb write-through data cache contrast model 240 cpu subsystem located daughter card cpu module use processor chipset featuring single 40 mhz r3400 instead r3400 integrates r3000a cpu r3010 fpu single die package processor external 64 kb instruction cache 64 kb data cache connected r3400 40 mhz bus also serves datapath mb asic model 260 cpu subsystem also located cpu module daughter card features 120 mhz 60 mhz external r4000 internal instruction data caches external secondary cache model 260 cpu subsystem unique model 200 series contains boot rom firmware unlike members boot rom located system module difference due r4000 requiring different firmware could replaced upgrading model 240 model 260 model 200 series 15 simm slots located system module hold 8 480 mb memory proprietary 128-pin memory array modules simms capacities 8 mb 39 1 mbit dram chips 32 mb 39 4 mbit dram chips used simms installed system must size 8 mb simms used system may contain 8 120 mb memory 32 mb simms used system may contain 32 480 mb memory memory subsystem operates 25 mhz 32 bits wide match native word length r3000 memory subsystem protected ecc scheme seven bits check every 32-bit transaction simms two-way interleaved using low-order method even odd memory addresses treated separate banks memory interleaving memory subsystem doubles bandwidth non-interleaved memory subsystem using drams allowing model 200 series achieve effective maximum bandwidth 100 mb/s optional 1 mb nvram module provides disk cache improve performance installed one simm slots slot 14 simm slot closest front edge system module module uses battery prevent data lost case power failure module useful optional software installed model 200 uses discrete components implement memory subsystem logic model 240 discrete components replaced three asics mb asic mt asic ms asic mb memory buffer asic serves interface 40 mhz cpu module domain 25 mhz system module domain connected mt asic serves memory controller mt asic provides memory control refresh handles memory dma transactions ecc checking ms memory strobe asic provides 15 sets memory control lines routes memory control signals mt asic destination simm ms asic replaces 16 discrete components used model 200 also generates 25 mhz system clock signal replacing three discrete components used model 200 model 200 series uses turbochannel interconnect expansion models three turbochannel option slots model 200 provides 4 mb physical address space turbochannel option model 240 260 provides 8 mb turbochannel model 240 260 clocked 25 mhz model 240 260 mt asic implements turbochannel serves controller model 200 i/o subsystem significantly different model 240 260 i/o subsystem model 200 ethernet scsi capabilities provided two integrated turbochannel option modules pmad-aa ethernet pmaz-aa scsi pmad-aa uses amd 7990 lance local area network controller ethernet provides 10base-t ethernet interface implemented amd 7992 sia serial interface adapter bnc thinwire connector 8-bit single-ended scsi bus provided ncr 53c94 asc advanced scsi controller integrated option modules 128 kb sram serving buffer improve performance four serial lines also provided keyboard mouse communications port printer lines implemented two dc7085s dallas semiconductor ds1287 real time clock 50 bytes nvram also featured 256 kb system boot-strap diagnostic rom socket contrast model 240 260 i/o subsystem based around i/o controller asic serves bridge turbochannel two i/o buses implements i/o devices two zilog z85c30 sccs serial communications controller ncr 53c94 asc amd 7990 lance dallas semiconductor ds1287 real time clock system rom connected i/o buses i/o controller asic introduced model 240 first featured model 100 series asic used model 240 differs clocked twice high 25 mhz instead 12.5 mhz model 240 i/o subsystem would later used dec 3000 axp modified form decstation systems turbochannel slots could use turbochannel-based framebuffers 2d graphics accelerators 3d graphics accelerators options pxg variants capable either 8-bit 24-bit color resolution 1280 × 1024 refresh rate either 66 72 hz pxg also 8-bit 24-bit z-buffer double buffered color depth depth z-buffer extended installing additional vsimms z-buffer modules module pxg turbo variants capable 24-bit color resolution 1280 × 1024 refresh rate either 66 72 hz differ featuring 24-bit buffer storing off-screen pixmaps addition 24-bit z-buffer double buffer 3d graphics accelerators implemented digital proprietary pixelstamp architecture derived two research projects pixel planes university north carolina 8 8 display carnegie-mellon university pixelstamp architecture geometry pipeline consists dma engine geometry engine pixelstamp dma engine interfaces pipeline system via turbochannel receiving packets cpu sending geometry engine geometry engine consists amount sram intel i860 packets dma engine stored sram processed i860 writes results fifo pixelstamp consists stic stamp interface chip asic one two stamp asics stic fetches results fifo passes stamp asic performs scan conversion graphical functions data processed stamp asics final result consists rgb data written framebuffer built vsimms simm vrams located graphics accelerator option module displayed graphics accelerators grouped two distinct categories double-width options triple-width options pxg pxg+ double-width turbochannel option modules pxg turbo pxg turbo+ triple-width turbochannel option modules models suffixed higher performance models base model 44 mhz i860 instead 40 mhz i860 stic stamp asics operate clock frequencies 33 higher models suffixed turbo differ featuring 256 kb sram two stamp asics instead 128 kb sram one stamp asic models known lo 3d graphics accelerator lo 3d plus graphics accelerator upgraded mid 3d graphics accelerator mid 3d plus graphics accelerator installing vsimms z-buffer modules depending model decstation systems capable performing video conferencing high-quality audio output video input achieved use turbochannel option modules external peripherals video input achieved using decvideo also known pip picture-in-picture live-video-in option daughterboard plugs tx framebuffer provide ntsc pal secam input option used conjunction video camera microphone required software decstation used video conferencing audio capabilities provided decaudio turbochannel option module contained two amd 79c30a dsc digital subscriber controller devices motorola 56001 dsp two amd 79c30a dscs used voice-quality audio input output motorola 56001 used high-quality audio dsp initially used due firmware incomplete although capability provided later update confusingly simultaneous launch decstation workstation line digital also announced range decstation-branded pc compatibles intel x86 processors ran ms-dos identified three-digit model numbers decstation 2xx 3xx 4xx series using intel 80286 80386 80486 processors respectively computers built digital tandy corporation united states olivetti europe time introduction digital offered trade-in program owners earlier x86 pc incompatible computer rainbow 100 systems based 80286 systems based 80386 systems based 80486
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Computer architecture
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aanval aanval commercial siem product designed specifically use snort suricata syslog data aanval active development since 2003 remains one longest running snort capable siem products industry aanval dutch attack aanval created loyal moses 2003 publicly made available march 2004 released private commercial license c1-ra1008 throughout lifecycle software also referred openaanval comaanval addition current registered trademark name aanval aanval original success providing ajax style security event monitoring reporting web-browser since aanval creation become intrusion detection correlation threat management console specific focus normalizing snort suricata syslog data 2010 aanval first intrusion detection vendor provide integrated ios app allowed users view security events remotely iphone ipad ipod touch several information security related books published include details references aanval including linux server security second edition o'reilly media security log management o'reilly media snort ids ips toolkit o'reilly media 2010 unix linux system administration handbook fourth edition o'reilly media
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Computer security
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wireless application protocol wireless application protocol wap technical standard accessing information mobile wireless network wap browser web browser mobile devices mobile phones uses protocol introduced much hype 1999 wap achieved popularity early 2000s 2010s largely superseded modern standards modern handset internet browsers fully support html need use wap markup web page compatibility therefore longer able render display pages written wml wap markup language introduction wap mobile service providers limited opportunities offer interactive data services needed interactivity support internet web applications email stock prices news sports headlines japanese i-mode system offered another major competing wireless data protocol wap standard described protocol suite stack allowing interoperability wap equipment software different network technologies gsm is-95 also known cdma bottom-most protocol suite wireless datagram protocol wdp functions adaptation layer makes every data network look bit like udp upper layers providing unreliable transport data two 16-bit port numbers origin destination upper layers view wdp one protocol several technical realizations top data bearers sms ussd etc native ip bearers gprs umts packet-radio service ppp top circuit-switched data connection wdp fact exactly udp wtls optional layer provides public-key cryptography-based security mechanism similar tls wtp provides transaction support reliable request/response adapted wireless world wtp supports effectively tcp problem packet loss occurs commonly 2g wireless technologies radio conditions misinterpreted tcp network congestion finally one think wsp initially compressed version http protocol suite allows terminal transmit requests http https equivalent wap gateway gateway translates requests plain http wireless application environment wae space defines application-specific markup languages wap version 1.x primary language wae wireless markup language wml wap 2.0 primary markup language xhtml mobile profile wap push incorporated specification allow wap content pushed mobile handset minimal user intervention wap push basically specially encoded message includes link wap address wap push specified top wireless datagram protocol wdp delivered wdp-supported bearer gprs sms gsm networks wide range modified processors gprs activation network generally supported wap push messages delivered top sms bearer receiving wap push wap 1.2 later -enabled handset automatically give user option access wap content also known wap push si service indication variant known wap push sl service loading directly opens browser display wap content without user interaction since behaviour raises security concerns handsets handle wap push sl messages way si providing user interaction network entity processes wap pushes delivers ip sms bearer known push proxy gateway ppg re-engineered 2.0 version released 2002 uses cut-down version xhtml end-to-end http dropping gateway custom protocol suite used communicate wap gateway used conjunction wap 2.0 however scenario used standard proxy server wap gateway role would shift one translation adding additional information request would configured operator could include telephone numbers location billing information handset information mobile devices process xhtml mobile profile xhtml mp markup language defined wap 2.0 subset xhtml superset xhtml basic version cascading style sheets css called wap css supported xhtml mp multimedia messaging service mms combination wap sms allowing sending picture messages wap forum founded 1998 ericsson motorola nokia unwired planet aimed primarily bring together various wireless technologies standardised protocol 2002 wap forum consolidated along many forums industry open mobile alliance oma first company launch wap site dutch mobile phone operator telfort bv october 1999 site developed side project christopher bee euan mcleod launched debut nokia 7110 marketers hyped wap time introduction leading users expect wap performance fixed non-mobile internet access bt cellnet one uk telecoms ran advertising campaign depicting cartoon wap user surfing neuromancer -like information space terms speed ease use appearance interoperability reality fell far short expectations first handsets became available 1999 led wide usage sardonic phrases worthless application protocol wait pay waplash 2003 2004 wap made stronger resurgence introduction wireless services vodafone live t-mobile t-zones easily accessible services operator revenues generated transfer gprs umts data different business model used traditional web sites isps according mobile data association wap traffic uk doubled 2003 2004 year 2013 wap use largely disappeared major companies websites since retired use wap mainstream technology web mobile number years modern handset internet browsers support full html css javascript need use kind wap markup webpage compatibility list handsets supporting html extensive includes android handsets versions iphone handset blackberry devices devices running windows phone many nokia handsets wap saw major success japan largest operator ntt docomo use wap favor in-house system i-mode rival operators kddi au softbank mobile previously vodafone japan successfully deployed wap technology particular j-phone sha-mail picture mail java jscl services well au chakuuta/chakumovie ringtone song/ringtone movie services based wap like europe wap i-mode usage declined 2010s html-capable smartphones became popular japan adoption wap us suffered many cell phone providers required separate activation additional fees data support also telecommunications companies sought limit data access approved data providers operating license signal carrier recognition problem u.s. federal communications commission fcc issued order 31 july 2007 mandated licensees 22-megahertz wide upper 700 mhz c block spectrum would implement wireless platform allows customers device manufacturers third-party application developers others use device application choice operating particular licensed network band commentators criticized several aspects wireless markup language wml wap technical criticisms include criticisms address wireless carriers particular implementations wap original wap model provided simple platform access web-like wml services e-mail using mobile phones europe se asian regions 2009 continued considerable user base later versions wap primarily targeting united states market designed different requirement enable full web xhtml access using mobile devices higher specification cost higher degree software complexity considerable discussion addressed question whether wap protocol design appropriate suggested bandwidth-sparing simple interface gopher would better match mobile phones personal digital assistants pdas initial design wap specifically aimed protocol independence across range different protocols sms ip ppp circuit switched bearer ip gprs etc. led protocol considerably complex approach directly ip might caused controversial especially many ip side design wap ip wap transmission layer protocol wtp uses retransmission mechanisms udp attempt solve problem inadequacy tcp high-packet-loss networks
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Internet protocols
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people finder interchange format people finder interchange format pfif widely used open data standard information missing displaced people pfif designed enable information sharing among governments relief organizations survivor registries help people find contact family friends disaster pfif extended xml consists person records contain identifying information person note records contain comments updates status location person note attached one person pfif defines set fields records xml-based format store transfer pfif xml records embedded atom feeds rss feeds pfif allows different repositories missing person data exchange aggregate records every record unique identifier indicates domain name original repository record created unique record identifier preserved record copied one repository another example repository receives copy given person publish note attached person even note person copied repositories remain traceable respective original sources within three days 2001 september 11 attacks people using 25 different online forums survivor registries report check family friends one first largest survivor registry safe.millennium.berkeley.edu created graduate students ka-ping yee miriam walker hosted millennium computer cluster uc berkeley reduce confusion caused proliferation different websites berkeley survivor registry began collecting data several major sites one searchable database information formatted differently site site site required manual effort custom programming download incorporate data hurricane katrina displaced hundreds thousands people 2005 online survivor registries appeared many different websites large volunteer effort called katrina peoplefinder project worked gather manually re-enter information one searchable database provided salesforce.com organizer project david geilhufe put call technical help create data standard would enable survivor registries aggregate share information via automated means working katrina volunteers kieran lal jonathan plax civicrm team yee drafted first specification people finder interchange format released september 4 2005 pfif 1.0 pfif 1.1 small corrections released september 5 salesforce.com database added support pfif yahoo google also launched searchable databases katrina survivors exchanged information using pfif next major use pfif occurred 2010 haiti earthquake google launched google person finder used data model based pfif exchanged data cnn new york times national library medicine survivor registries using pfif however pfif 1.1 made us-specific assumptions applicable haiti released january 26 2010 pfif 1.2 added fields person home country international postal code fields sex age date birth status links duplicate records person pfif 1.3 released march 2011 addressed privacy personal information adding field specify expiry date person record setting requirements data deletion pfif 1.3 also moved away us-specific assumption first last name adding one field person full name pfif 1.4 released may 2012 renamed name fields given_name last_name added field alternate names added field linking personal profiles websites added support multiple photos per person following websites software projects implement pfif
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Internet protocols
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uhuru mobile uhuru mobile secure android-based operating system operating system principal program allowing smartphones tablets pcs run central tool connects coordinates components kernel computers programs software device drivers letting users managing devices uhuru mobile solution composed application encryption market modified android-based os virtual private network sms encryption solution purpose uhuru mobile prevent physical attacks name uhuru comes swahili language means freedom independence uhuru mobile result research development project initiated 2012 promote digital sovereignty android-based operating system uhuru mobile focuses security privacy end-users individuals businesses mobile devices operating system currently developed software editor company called teclib ’ ensure os protection security using applications dedicated market installed replacing google play store uhuru mobile ’ applications market provides apps approved certified team security experts companies also customize uhuru marketplace providing in-house applications uhuru mobile provided deception system sending fake gps location coordinates applications decoy geolocation tool allows users fool applications using geolocation administrators define redirecting coordinates example demo version nsa headquarters coordinates sent deception system mobile device management tool administration mobile devices provided without additional setup administrators access web-console order manage uhuru mobile fleet linked applications remote apps installation/suppression set user accounts
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Operating systems
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crocbite crocbite online database crocodile attacks reported humans non-profit online research tool helps scientifically analyze crocodile behavior via complex models users encouraged feed information crowdsourcing manner uploaded information needs verifiable database provides key insights crocodile attack patterns draws inferences save human lives online database established dr adam britton researcher charles darwin university student brandon sideleau erin britton compilation government records individual reports registered contributors historical data dr simon pooley junior research fellow imperial college london joined hands studies collaboration culminated dr pooley met dr britton iucn crocodile specialist group louisiana 2014 brandon instrumental designing database work infrastructure program received funds economic social research council united kingdom tune unspecified resourced plus amount big gecko crocodilian research crocodillian.com charles darwin university research already yielded pertinent observations provide inside crocodile attacks observed attacks humans occur bites saltwater crocodile popular understanding nile crocodiles taking top spot broad category nile crocodile attacks segmented west african crocodile crocodylus niloticus nile crocodile species get clear understanding respective attack zones objective information used communities conservation managers help inform educate people keep safe information vital australia africa attacks likely parts world database kind comprehensive collection information made available online
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Databases
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tidb tidb open-source newsql database supports hybrid transactional analytical processing htap workloads mysql compatible provide horizontal scalability strong consistency high availability developed supported primarily pingcap inc. licensed apache 2.0 tidb drew initial design inspiration google ’ spanner f1 papers tidb recognized infoworld 2018 bossie award one best open source software data storage analytics pingcap inc. software company founded april 2015 began developing tidb founding company primary developer maintainer driver tidb associated open-source communities pingcap venture-backed company announced 50 million usd series c round financing september 2018 tidb expand sql processing storage capacity adding new nodes makes infrastructure capacity scaling easier flexible compare traditional relational database scale vertically tidb acts like mysql 5.7 server applications user continue use existing mysql client libraries tidb ’ sql processing layer built scratch mysql fork compatibility 100 known behavior differences mysql tidb tidb internally shards table small range-based chunks referred regions region defaults approximately 100mib size tidb uses two-phase commit internally ensure regions maintained transactionally consistent way tidb designed work cloud make deployment provisioning operations maintenance flexible storage layer tidb called tikv became cloud native computing foundation member project august 2018 sandbox level project architecture tidb platform also allows sql processing storage scaled independently tidb support online transaction processing oltp online analytical processing olap workloads means user may traditionally transacted mysql extracted transformed loaded etl data column store analytical processing step longer required tidb uses raft consensus algorithm ensure data highly available safely replicated throughout storage raft groups event failure raft group automatically elect new leader failed member self-heal tidb cluster without required manual intervention failure self-healing operations transparent applications tidb deployed kubernetes-enabled cloud environment using tidb operator operator method packaging deploying managing kubernetes application designed running stateful workloads first introduced coreos 2016.tidb operator originally developed pingcap open-sourced august 2018 tidb operator used deploy tidb laptop google cloud platform ’ google kubernetes engine amazon web services ’ elastic container service kubernetes tidb deployed using ansible using tidb-ansible playbook docker used deploy tidb containerized environment multiple nodes multiple machines docker compose used deploy tidb single command testing purposes tidb series open-source tools built around help data replication migration existing mysql mariadb users syncer tool supports full data migration incremental data replication mysql mariadb instances tidb cluster data migration dm second-generation iteration syncer suited replicating data already sharded mysql mariadb tables tidb common use case syncer/dm connect mysql mariadb tables tidb treating tidb almost slave directly run analytical workloads tidb cluster near real-time lightning tool supports high speed full-import large mysql dump new tidb cluster providing faster import experience executing sql statement tool used populate initially empty tidb cluster lots data quickly order speed testing production migration import speed improvement achieved parsing sql statements key-value pairs directly generate sorted string table sst files rocksdb tidb-binlog tool used collect logical changes made tidb cluster used provide incremental backup replication either two tidb clusters tidb cluster another downstream platform similar functionality mysql master-slave replication main difference since tidb distributed database binlog generated tidb instance needs merged sorted according time transaction commit consumed downstream
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Databases
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expressive power computer science computer science expressive power also called expressiveness expressivity language breadth ideas represented communicated language expressive language greater variety quantity ideas used represent example web ontology language expression language profile owl2 el lacks ideas negation expressed owl2 rl rule language owl2 el may therefore said less expressive power owl2 rl restrictions allow efficient polynomial time reasoning owl2 el owl2 rl owl2 el trades expressive power efficient reasoning processing knowledge representation language term expressive power may used range meaning may mean measure ideas expressible language first sense dominates areas mathematics logic deal formal description languages meaning formal language theory mathematical logic process algebra informal discussions term often refers second sense often case discussing programming languages efforts made formalize informal uses term notion expressive power always relative particular kind thing language question describe term normally used comparing languages describe kind things least comparable kinds things design languages formalisms involves trade-off expressive power analyzability formalism express harder becomes understand instances formalism say decision problems become harder answer completely undecidable formal language theory mostly studies formalisms describe sets strings context-free grammars regular expressions instance formalism e.g grammar regular expression describes particular set strings context expressive power formalism set sets strings instances describe comparing expressive power matter comparing sets important yardstick describing relative expressive power formalisms area chomsky hierarchy says instance regular expressions nondeterministic finite automatons regular grammars equal expressive power context-free grammars greater means sets sets strings described first three formalisms equal proper subset set sets strings described context-free grammars area cost expressive power central topic study known instance deciding whether two arbitrary regular expressions describe set strings hard arbitrary context-free grammars completely impossible however still efficiently decided whether given string set expressive formalisms problem harder even undecidable turing complete formalism arbitrary formal grammars problem every nontrivial property regarding set strings describe undecidable fact known rice theorem results conciseness well instance nondeterministic state machines regular grammars concise regular expressions sense latter translated former without blowup size i.e 1 reverse possible similar considerations apply formalisms describe sets strings sets trees e.g xml schema languages graphs structures database theory concerned among things database queries e.g formulas given contents database extract certain information predominant relational database paradigm contents database described finite set finite mathematical relations boolean queries always yield true false formulated first-order logic turns first-order logic lacking expressive power express certain types boolean queries e.g queries involving transitive closure however adding expressive power must done care must still remain possible evaluate queries reasonable efficiency case e.g. second-order logic consequently literature sprang many query languages language constructs compared expressive power efficiency e.g various versions datalog similar considerations apply query languages types data e.g xml query languages xquery
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Programming language topics
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spice spice simulation program integrated circuit emphasis general-purpose open-source analog electronic circuit simulator program used integrated circuit board-level design check integrity circuit designs predict circuit behavior unlike board-level designs composed discrete parts practical breadboard integrated circuits manufacture high costs photolithographic masks manufacturing prerequisites make essential design circuit close perfect possible integrated circuit first built simulating circuit spice industry-standard way verify circuit operation transistor level committing manufacturing integrated circuit board-level circuit designs often breadboarded testing even breadboard circuit properties may accurate compared final printed wiring board parasitic resistances capacitances parasitic components often estimated accurately using spice simulation also designers may want information circuit available single mock-up instance circuit performance affected component manufacturing tolerances cases common use spice perform monte carlo simulations effect component variations performance task impractical using calculations hand circuit appreciable complexity circuit simulation programs spice derivatives prominent take text netlist describing circuit elements transistors resistors capacitors etc connections translate description equations solved general equations produced nonlinear differential algebraic equations solved using implicit integration methods newton method sparse matrix techniques spice developed electronics research laboratory university california berkeley laurence nagel direction research advisor prof. donald pederson spice1 largely derivative cancer program nagel worked prof. ronald rohrer cancer acronym computer analysis nonlinear circuits excluding radiation hint berkeley liberalism 1960s times many circuit simulators developed united states department defense contracts required capability evaluate radiation hardness circuit nagel original advisor prof. rohrer left berkeley prof. pederson became advisor pederson insisted cancer proprietary program rewritten enough restrictions could removed program could put public domain spice1 first presented conference 1973 spice1 coded fortran used nodal analysis construct circuit equations nodal analysis limitations representing inductors floating voltage sources various forms controlled sources spice1 relatively circuit elements available used fixed-timestep transient analysis real popularity spice started spice2 1975 spice2 also coded fortran much-improved program circuit elements variable timestep transient analysis using either trapezoidal second order adams-moulton method gear integration method also known bdf equation formulation via modified nodal analysis avoiding limitations nodal analysis innovative fortran-based memory allocation system developed another graduate student ellis cohen last fortran version spice 2g.6 1983 spice3 developed thomas quarles a. richard newton advisor 1989 written c uses netlist syntax added x window system plotting early public domain software program source code available spice widely distributed used ubiquity became spice circuit remains synonymous circuit simulation spice source code beginning distributed uc berkeley nominal charge cover cost magnetic tape license originally included distribution restrictions countries considered friendly us source code currently covered bsd license birth spice named ieee milestone 2011 entry mentions spice evolved become worldwide standard integrated circuit simulator nagel awarded 2019 ieee donald o. pederson award solid-state circuits development spice newer versions berkeley spice released version 3f.5 1993 since open-source academic continuations spice include xspice developed georgia tech added mixed analog/digital code models behavioral simulation cider previously codecs developed uc berkeley oregon state univ. added semiconductor device simulation spice opus developed maintained university ljubljana based spice 3f.4 xspice ngspice based spice 3f.5 xspice cider berkeley spice inspired served basis many circuit simulation programs academia industry commercial products first commercial version spice ispice interactive version timeshare service national css prominent commercial versions spice include hspice originally commercialized ashawna kim hailey meta software owned synopsys pspice owned cadence design systems integrated circuit industry adopted spice quickly commercial versions became well developed many ic design houses proprietary versions spice today ic manufacturers typically larger companies groups continuing develop spice-based circuit simulation programs among adice analog devices ltspice linear technology available public freeware mica freescale semiconductor tina texas instruments similarly linear technology texas instruments makes available freeware windows version tina software called tina-ti also includes version spice comes preloaded models company integrated circuits analog devices offers similar free tool called adisimpe based simetrix/simplis implementation spice companies maintain internal circuit simulators directly based upon spice among powerspice ibm titan infineon technologies lynx intel corporation pstar nxp semiconductor spice became popular contained analyses models needed design integrated circuits time robust enough fast enough practical use precursors spice often single purpose bias program example simulation bipolar transistor circuit operating points slic program small-signal analyses spice combined operating point solutions transient analysis various small-signal analyses circuit elements device models needed successfully simulate many circuits spice2 included analyses since spice generally used model nonlinear circuits small signal analyses necessarily preceded quiescent point calculation circuit linearized spice2 also contained code small-signal analyses sensitivity analysis pole-zero analysis small-signal distortion analysis analysis various temperatures done automatically updating semiconductor model parameters temperature allowing circuit simulated temperature extremes circuit simulators since added many analyses beyond spice2 address changing industry requirements parametric sweeps added analyze circuit performance changing manufacturing tolerances operating conditions loop gain stability calculations added analog circuits harmonic balance time-domain steady state analyses added rf switched-capacitor circuit design however public-domain circuit simulator containing modern analyses features needed become successor popularity spice yet emerged important use appropriate analyses carefully chosen parameters example application linear analysis nonlinear circuits justified separately also application transient analysis default simulation parameters lead qualitatively wrong conclusions circuit dynamics spice2 included many semiconductor device compact models three levels mosfet model combined ebers–moll gummel–poon bipolar model jfet model model junction diode addition many elements resistors capacitors inductors including coupling independent voltage current sources ideal transmission lines active components voltage current controlled sources spice3 added sophisticated mosfet models required due advances semiconductor technology particular bsim family models added also developed uc berkeley commercial industrial spice simulators added many device models technology advanced earlier models became inadequate attempt standardization models set model parameters may used different simulators industry working group formed compact model council choose maintain promote use standard models standard models today include bsim3 bsim4 bsimsoi psp hicum mextram traditional photonic device simulators apply direct methods solve maxwell equations complete structure whereas photonic circuit simulators based segmentation building blocks bbs represented logic level phothonic device coupled bbs guided modes optical waveguides circuit-level modeling photonic integrated circuit pic contain electrical wires optical signals respectively described voltage/current complex-valued envelope forward- backward-propagating modes building block netlist photonic electronic circuits including net port connections expressed spice format schematic editors like ones used electronic design automation reproduce complete photonic signal information without losing eventual optical phenomena needed real-time waveform electric magnetic field every mode polarization waveguide spice works 10 time steps timescale datacommunications ≈10–100 10 common make amount information tractable modulation increases complexity encode amplitude phase way similar simulation rf circuits however photonic integrated circuit simulators need test multiple communication channels match different carrier frequencies equivalently amplitudes single channel type sophisticated signal unsupported spice program features structure described 2019 spice ca n't used simulate photonics electronics together photonic circuit simulator thus n't yet considered test simulator photonic integrated circuits spice2 took text netlist input produced line-printer listings output fit computing environment 1975 listings either columns numbers corresponding calculated outputs typically voltages currents line-printer character plots spice3 retained netlist circuit description allowed analyses controlled command-line interface similar c shell spice3 also added basic x plotting unix engineering workstations became common vendors various free software projects added schematic capture front-ends spice allowing schematic diagram circuit drawn netlist automatically generated also graphical user interfaces added selecting simulations done manipulating voltage current output vectors addition capable graphing utilities added see waveforms graphs parametric dependencies several free versions extended programs available introductory limited packages without restrictions since transient analysis dependent time uses different analysis algorithms control options different convergence-related issues different initialization parameters dc analysis however since transient analysis first performs dc operating point analysis unless uic option specified .tran statement dc analysis algorithms control options initialization convergence issues apply transient analysis circuits oscillators circuits feedback stable operating point solutions circuits either feedback loop must broken dc operating point calculated initial conditions must provided simulation input dc operating point analysis bypassed uic parameter included .tran statement uic included .tran statement transient analysis started using node voltages specified .ic statement node set 5 v .ic statement value node first time point time 0 5 v. use .op statement store estimate dc operating point transient analysis codice_1 .tran statement uic parameter example bypasses initial dc operating point analysis .op statement calculates transient operating point 20 ns transient analysis although transient analysis might provide convergent dc solution transient analysis still fail converge transient analysis error message internal timestep small indicates circuit failed converge convergence failure might due stated initial conditions close enough actual dc operating point values
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Programming language topics
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chack n pop arcade rom-set also contains unused graphics mechanical wind-up zen-chan later appeared bubble bobble home ports released sg-1000 msx famicom nec pc-6001 nec pc-8801 arcade emulation included taito legends power-up psp taito legends 2 xbox playstation 2 pc chack n small yellow creature later recolored green extendable legs must traverse series single-screen mazes capable walking floors ceilings walls climb steps traverse high walls extending legs tall enough pass onto next step capable throwing hand grenades left right short period explode cloud smoke separate fire buttons control rolling left right chack n killed caught explosion cloud screen played time limit marked mighta pushing boulder along top screen mighta reappears bubble bobble recurring enemy chack n aim reach top screen time limit expires delayed process series solid walls order get past walls must free hearts cages using hand grenades obstruction comes form monstas creatures appear bubble bobble hatching eggs hand grenades also used destroy creatures eggs producing however player get bonus points completing level destroying enemies later levels include moving platforms reminiscent bubble bobble water bottles blown flood level water water destroy anything way inhibit movement enemies allows chack n swim otherwise unreachable platforms levels completed chack n able marry girlfriend miss chack n sega sg-1000 version extended introduction ending sequences small additional training stage first chack n content chack n pop appeared bubble bobble fairyland story parasol stars puzzle bobble bubble symphony bubble memories pop n pop arkanoid ds huge silver robotic chack n also mid-boss stage 5 taito arcade shooter megablast
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Computer architecture
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coffee lake coffee lake intel codename second 14 nm process node refinement following broadwell skylake kaby lake integrated graphics coffee lake chips allow support dp 1.2 hdmi 2.0 hdcp 2.2 connectivity coffee lake natively supports ddr4-2666 mhz memory dual channel mode used xeon core i5 i7 i9 cpus ddr4-2400 mhz memory dual channel mode used celeron pentium core i3 cpus lpddr3-2133 mhz memory used mobile cpus desktop coffee lake cpus introduces major changes intel core cpus nomenclature i5 i7 cpus feature six cores along hyper-threading case latter core i3 cpus four cores dropping hyper-threading first time received change well 9th generation release october 2018 changed nomenclature core i7 moving 8 cores dropping hyper-threading first time new mainstream desktop core i9 processors released featuring 8 cores hyper-threading chips released october 5 2017 coffee lake used conjunction 300-series chipset officially work 100- 200-series chipset motherboards although desktop coffee lake processors use physical lga 1151 socket skylake kaby lake pinout electrically incompatible older processors motherboards april 2 2018 intel released additional desktop core i3 i5 i7 pentium gold celeron cpus first six-core core i7 i9 mobile cpus hyper-threaded four-core core i5 mobile cpus first coffee lake ultra-power cpus intel iris plus graphics october 8 2018 intel launched 9th generation coffee lake refresh cpus eight cores avoid running thermal problems high clockspeeds intel soldered integrated heat spreader ihs cpu die instead using thermal paste core i7 i9 however core i5 still use thermal paste cpu die ihs development led intel israel processor design team haifa israel optimization kaby lake intel first launched 8th generation intel core family processors august 2017 release new 8th gen intel core i9 processor 2018 intel said would highest-performance laptop processor intel ever built coffee lake cpus built using second refinement intel 14 nm process 14 nm++ features increased transistor gate pitch lower current density higher leakage transistors allows higher peak power higher frequency expense die area idle power coffee lake marks shift number cores intel mainstream desktop processors first update previous ten-year history intel core cpus 8th generation mainstream desktop i7 cpus feature six cores 12 threads i5 cpus feature six single-threaded cores i3 cpus feature four single-threaded cores 9th generation intel core i9 branding made debut mainstream desktop describing cpus 8 cores 16 threads 9th generation i7s feature 8 single-threaded cores marking first time desktop core i7s featured intel hyper-threading technology 9th generation i5 cpus feature six single-threaded cores like 8th generation predecessors ninth generation core series includes hardware fixes meltdown v3 l1 terminal fault 300 series chipsets using physically identical lga 1151 socket 100 200 series chipsets officially compatible coffee lake cpus meaning older motherboards officially support coffee lake processors 300 series motherboards officially support skylake kaby lake processors enthusiast z370 rebranded z270 launched alongside first coffee lake cpus october 2017 officially supported chipset mainstream cpus full lineup cpus revealed april 2018 accompanied lower-end h310 b360 h370 q370 chipsets home business users z390 chipset launched alongside release 9th generation cpus supporting 8th 9th generation mainstream desktop parts b365 chipset added later 9th generation xeons need motherboards chipset c246 coffee lake features largely cpu core performance per mhz skylake/kaby lake features specific coffee lake include august 8 2017 intel announced new eighth generation processors would revealed following august 21 intel previous changes product generations coincided new microarchitectures unclear generally expected eighth core generation products would based new coffee lake microarchitecture however officially announced august 21 2017 intel stated eighth generation would based multiple microarchitectures including kaby lake coffee lake cannon lake additional core resources mid-range eighth-generation coffee lake desktop chips offer significant gains performance versus previous seventh-generation intel cpus multi-threaded workloads however architecture delivers noipc difference skylake kaby lake processors mark first time intel released mainstream consumer cpus support 128gb ram nowiki /nowiki various reviews show core i7-8700k cpu may consume 110w load first 9th generation coffee lake cpus released fourth quarter 2018 include hardware mitigations certain meltdown/spectre vulnerabilities main differences 8th generation besides increased frequency even though f suffix cpus lack integrated gpu intel set price cpus featureful counterparts nowiki /nowiki various reviews show core i9-9900k cpu may consume 140w load
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Computer architecture
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http post flood http post flood simply post flood denial service attack uses post requests part hypertext transfer protocol http one kind http flood attack late 2013 post floods increasingly launched mobile devices
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Computer security
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generalized algebraic data type functional programming generalized algebraic data type gadt also first-class phantom type guarded recursive datatype equality-qualified type generalization parametric algebraic data types gadt product constructors called data constructors haskell provide explicit instantiation adt type instantiation return value allows defining functions advanced type behaviour data constructor haskell 2010 return value type instantiation implied instantiation adt parameters constructor application -- parametric adt gadt data list nil cons list integers cons 12 cons 107 nil -- type integers list int strings cons boat cons dock nil -- type strings list string -- gadt data expr eval expr eval e case e expr1 eequal eint 2 eint 3 -- type expr1 expr bool ret eval expr1 -- ret false currently implemented ghc compiler non-standard extension used among others pugs darcs ocaml supports gadt natively since version 4.00 ghc implementation provides support existentially quantified type parameters local constraints early version generalized algebraic data types described based pattern matching alf generalized algebraic data types introduced independently prior extensions ml haskell algebraic data types essentially equivalent similar inductive families data types inductive datatypes found coq calculus inductive constructions dependently typed languages modulo dependent types except latter additional positivity restriction enforced gadts type inference absence programmer supplied type annotations undecidable functions defined gadts admit principal types general type reconstruction requires several design trade-offs area active research applications gadts include generic programming modelling programming languages higher-order abstract syntax maintaining invariants data structures expressing constraints embedded domain-specific languages modelling objects important application gadts embed higher-order abstract syntax type safe fashion embedding simply typed lambda calculus arbitrary collection base types tuples fixed point combinator type safe evaluation function factorial function written would run problems using regular algebraic data types dropping type parameter would made lifted base types existentially quantified making impossible write evaluator type parameter would still restricted single base type furthermore ill-formed expressions codice_1 would possible construct type incorrect using gadt well-formed analogue codice_2 type codice_3 codice_4 inferred type codice_5 data constructor
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Programming language topics
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bredolab botnet bredolab botnet also known alias oficla russian botnet mostly involved viral e-mail spam botnet eventually dismantled november 2010 seizure command control servers estimated consist millions zombie computers though earliest reports surrounding bredolab botnet originate may 2009 first malware samples bredolab trojan horse found botnet rise prominence august 2009 major surge size botnet bredonet main form propagation sending malicious e-mails included malware attachments would infect computer opened effectively turning computer another zombie controlled botnet peak botnet capable sending 3.6 billion infected emails every day main form propagation use drive-by downloads method exploits security vulnerabilities software method allowed botnet bypass software protection order facilitate downloads without user aware main income botnet generated leasing parts botnet third parties could subsequently use infected systems purposes security researchers estimate owner botnet made 139,000 month botnet related activities due rental business strategy payload bredolab diverse ranged scareware malware e-mail spam 25 october 2010 team dutch law enforcement agents seized control 143 servers contained three command control servers one database server several management servers bredolab botnet datacenter leaseweb effectively removing botnet herder ability control botnet centrally attempt regain control botnet botnet herder utilized 220,000 computers still control unleash ddos attack leaseweb servers though attempts ultimately vain taking control botnet law enforcement team utilized botnet send message owners infected computers stating computer part botnet subsequently armenian law enforcement officers arrested armenian citizen georgy avanesov basis suspected mastermind behind botnet suspect denied involvement botnet sentenced four years prison may 2012 seizure command control servers severely disrupted botnet ability operate botnet still partially intact command control servers persisting russia kazakhstan security firm fireeye believes secondary group botnet herders taken remaining part botnet purposes possibly previous client reverse engineered parts original botnet creator code even group noted botnet size capacity severely reduced law enforcement intervention
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Computer security
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ultrasurf ultrasurf freeware internet censorship circumvention product created ultrareach internet corporation software bypasses internet censorship firewalls using http proxy server employs encryption protocols privacy software developed chinese dissidents means allowing internet users bypass great firewall china currently boasts many 11 million users worldwide tool described one important free-speech tools internet wired best performing circumvention tool harvard university 2007 study 2011 study freedom house ranked fourth critics open-source community george turner says expressed concern software closed-source nature alleged security obscurity design ultrareach says security considerations mean prefer third party expert review open source review 2001 ultrareach founded chinese dissidents silicon valley shortly ultrasurf created allow internet users china evade government censorship monitoring 2011 ultrasurf reported eleven million users worldwide arab spring ultrareach recorded 700 percent spike traffic tunisia similar traffic spikes occur frequently times unrest regions tibet burma saffron revolution wired magazine 2010 called ultrasurf one important free-speech tools internet enabling citizens access share information oppressed countries times humanitarian human rights crises ultrasurf funded part contracts u.s. government broadcasting board governors administers voice america radio free asia 2012 ultrareach difficulty serving growing user base due insufficient funding ultrasurf free download requires installation ultrasurf install files user computer leaves registry edits exits words leaves trace use fully remove software computer user needs delete exe file named u.exe available windows platform runs internet explorer default optional plug-in firefox chrome ultrareach website notes anti-virus software companies misclassify ultrasurf malware trojan ultrasurf encrypts communications circumvents internet censorship security companies agreed whitelist ultrasurf according applebaum ultrasurf client uses anti-debugging techniques also employs executable compression client acts local proxy communicates ultrareach network appears obfuscated form tls/ssl software works creating encrypted http tunnel user computer central pool proxy servers enabling users bypass firewalls censorship ultrareach hosts servers software makes use sophisticated proprietary anti-blocking technology overcome filtering censorship online according wired magazine ultrasurf changes ip addresses proxy servers 10,000 times hour server-side 2011 analysis found ultrareach network employed squid ziproxy software well isc bind servers bootstrapping wider network open recursive dns servers latter ultrareach control ultrasurf designed primarily anti-censorship tool also offers privacy protections form industry standard encryption added layer obfuscation built ultrareach uses internal content filter blocks sites deemed pornographic otherwise offensive according wired magazine partly network lacks bandwidth accommodate much data-heavy traffic also falun gong frowns erotica additionally falun gong criticism website facts.org.cn alleged operated chinese government also unreachable ultrasurf 2007 study harvard university berkman center internet society found ultrasurf best performing tested circumvention tools in-country tests recommended widespread use particular report found ultrasurf effectively bypassed various forms censorship blocking include ip block dns block keyword filtering also fastest tool in-country tests noted easy use install simple user interface report noted however ultrareach designed primarily circumvention product rather anonymity tool suggested users concerned anonymity disable browser support active content using ultrasurf 2011 report u.s.-based human rights group freedom house ranked ultrasurf fourth overall among censorship circumvention privacy tools measured combination performance usability support security particular tool recommended users interested downloading viewing information required relatively high degree privacy favored fast connection speed technologists expressed reservations ultrareach model however particular developers criticized proponents open-source software allowing peer review tool design except discretion creators moreover ultrareach operates servers developers access user logs architecture means users required trust ultrareach reveal user data ultrareach maintains keeps logs short period time uses purpose analyzing traffic signs interference monitor overall performance efficacy company says disclose user logs third parties according jacob appelbaum tor project essentially amounts example privacy policy april 2012 report appelbaum criticized ultrasurf use internal content filtering including blocking pornographic websites willingness comply subpoenas u.s. law enforcement officials appelbaum report also noted ultrasurf pages employed google analytics potential leak user data systems date latest security patches make use forward security mechanisms furthermore applebaum claims ultrasurf client uses open free software including putty zlib use putty zlib disclosed use lack disclosure violation licenses response posted day ultrareach wrote already resolved issues asserted appelbaum report misrepresented misunderstood aspects software ultrareach also argued differences software approaches internet censorship represented tor ultrasurf base philosophical simply different approaches censorship circumvention top-secret nsa presentation revealed part 2013 global surveillance disclosures dismisses response ultrasurf talk show due restrictions imposed organizations mcafee virusscan flagging ultrasurf versions potentially unwanted program avoiding execution machines ultrasurf virus ultrasurf virus used inappropriately students minors circumvent firewalls measures put place prevent exposure inappropriate and/or indecent content pornography fact runs undetected operating system makes virtually impossible disable block
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Internet protocols
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metacharacter metacharacter character special meaning computer program shell interpreter regular expression regex engine posix extended regular expressions 14 metacharacters must escaped preceded backslash order drop special meaning treated literally inside expression opening closing square brackets backslash caret dollar sign period/full stop/dot vertical bar/pipe symbol question mark asterisk plus sign opening closing curly brackets/braces opening closing parentheses example match arithmetic expression 1+1 *3=6 regex correct regex 1\+1\ \*3=6 otherwise parentheses plus sign asterisk special meanings characters may special meaning environments term escape metacharacter means make metacharacter ineffective strip special meaning causing literal meaning example pcre dot stands single character regular expression a.c match abc a3c even c however escaped lose meaning metacharacter interpreted literally causing regular expression a\.c match string a.c usual way escape character regex elsewhere prefixing backslash environments may employ different methods like ms-dos/windows command prompt caret used instead
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Programming language topics
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software upgrade protocol software upgrade protocol sup system set programs developed carnegie mellon university 1980s andrew file system provides collections files maintained identical versions across number machines originally developed mach operating system implementations provided debian ubuntu linux distributions
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Internet protocols
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named data networking named data networking ndn related content-centric networking ccn content-based networking data-oriented networking information-centric networking icn proposed future internet architecture inspired years empirical research network usage growing awareness unsolved problems contemporary internet architectures like ip ndn roots earlier project content-centric networking ccn van jacobson first publicly presented 2006 ndn project investigating jacobson proposed evolution today host-centric network architecture ip data-centric network architecture ndn belief conceptually simple shift far-reaching implications people design develop deploy use networks applications premise internet primarily used information distribution network good match ip future internet thin waist based named data rather numerically addressed hosts underlying principle communication network allow user focus data needs named content rather reference specific physical location data retrieved named hosts motivation derived fact vast majority current internet usage high 90 level traffic consists data disseminated source number users named-data networking comes potential wide range benefits content caching reduce congestion improve delivery speed simpler configuration network devices building security network data level today internet hourglass architecture centers universal network layer ip implements minimal functionality necessary global inter-connectivity contemporary internet architecture revolves around host-based conversation model created 1970s allow geographically distributed users use big immobile computers thin waist enabled internet explosive growth allowing lower upper layer technologies innovate independently however ip designed create communication network packets named communication endpoints sustained growth e-commerce digital media social networking smartphone applications led dominant use internet distribution network distribution networks general communication networks solving distribution problems via point-to-point communication protocol complex error-prone named data networking ndn project proposed evolution ip architecture generalizes role thin waist packets name objects communication endpoints specifically ndn changes semantics network service delivering packet given destination address fetching data identified given name name ndn packet name anything – endpoint data chunk movie book command turn lights etc hope conceptually simple change allows ndn networks apply almost internet well-tested engineering properties broader range problems beyond end-to-end communications examples ndn applying lessons learned 30 years networking engineering self-regulation network traffic via flow balance interest data request data packets security primitives via signatures named data integrated protocol start philosophy behind ndn pioneered ted nelson 1979 later brent baccala 2002 1999 triad project stanford proposed avoiding dns lookups using name object route towards close replica 2006 data-oriented network architecture dona project uc berkeley icsi proposed content-centric network architecture improved triad incorporating security authenticity persistence first-class primitives architecture van jacobson gave google talk new way look networking 2006 evolution network argued ndn next step 2009 parc announced content-centric architecture within ccnx project led jacobson time research fellow parc september 21 2009 parc published specifications interoperability released initial open source implementation gpl content-centric networking research project project ccnx site ndn one instance general network research direction called information-centric networking icn different architecture designs emerged internet research task force irtf established icn research working group 2012 ndn includes sixteen nsf-funded principal investigators twelve campuses growing interest academic industrial research communities 30 institutions form global testbed exists large body research actively growing code base contributed ndn ndn forwarder currently supported ubuntu 16.04 18.04 fedora 20+ centos 6+ gentoo linux raspberry pi openwrt freebsd 10+ several platforms common client libraries actively supported c++ java javascript python .net framework c squirrel programming languages ndn simulator emulator also available actively developed several client applications developed areas real-time conferencing ndn friendly file systems chat file sharing iot communication ndn driven receivers i.e. data consumers exchange two types packets interest data types packets carry name identifies piece data transmitted one data packet packet types complete specification see ndn packet format specification carry interest data packet forwarding functions ndn router maintains three data structures forwarding policy interest packet arrives ndn router first checks content store matching data exists router returns data packet interface interest came otherwise router looks name pit matching entry exists simply records incoming interface interest pit entry absence matching pit entry router forward interest toward data producer based information fib well router adaptive forwarding strategy router receives interests name multiple downstream nodes forwards first one upstream toward data producer data packet arrives ndn router finds matching pit entry forwards data down-stream interfaces listed pit entry removes pit entry caches data content store data packets always take reverse path interests absence packet losses one interest packet results one data packet link providing flow balance fetch large content objects comprise multiple packets interests provide similar role controlling traffic flow tcp acks today internet fine-grained feedback loop controlled consumer data neither interest data packets carry host interface addresses routers forward interest packets toward data producers based names carried packets forward data packets consumers based pit state information set interests hop interest/data packet exchange symmetry induces hop-by-hop control loop confused symmetric routing routing eliminates need notion source destination nodes data delivery unlike ip end-to-end packet delivery model ndn names opaque network allows application choose naming scheme fits needs naming thus evolve independently network ndn design assumes hierarchically structured names e.g. video produced ucla may name /ucla/videos/demo.mpg ‘ ’ delineates name components text representations similar urls hierarchical structure many potential benefits retrieve dynamically generated data consumers must able deterministically construct name desired piece data without previously seen name data either current research exploring applications choose names facilitate application development network delivery aim work develop refine existing principles guidelines naming converting rules naming conventions implemented system libraries simplify future application development data may retrieved globally must globally unique names names used local communications may require local routing local broadcast find matching data individual data names meaningful various scopes contexts ranging “ light switch room ” “ country names world ” namespace management part ndn architecture address space management part ip architecture however naming important part ndn application designs enabling application developers sometimes users design namespaces data exchange several benefits ndn routes forwards packets based names eliminates three problems caused addresses ip architecture ndn use conventional routing algorithms link state distance vector instead announcing ip prefixes ndn router announces name prefixes cover data router willing serve conventional routing protocols ospf bgp adapted route name prefixes treating names sequence opaque components component-wise longest prefix match name interest packet fib table enables wide array inputs aggregated real time distributed across multiple interface environments simultaneously without compromising content encryption pit state router supports forwarding across ndn data plane recording pending interest incoming interface removing interest matching data received timeout occurs per hop per packet state differs ip stateless data plane based information fib performance measurements adaptive forwarding strategy module router makes informed decisions router decides interest satisfied e.g. upstream link forwarding entry fib extreme congestion occurs router send nack downstream neighbor transmitted interest negative acknowledgment nack may trigger receiving router forward interest interfaces explore alternate paths pit state enables routers identify discard looping packets allowing freely use multiple paths toward data producer packets loop ndn means need time-to-live measures implemented ip related protocols address issues contrast tcp/ip leaves responsibility security lack thereof endpoints ndn secures data requiring data producers cryptographically sign every data packet publisher signature ensures integrity enables determination data provenance allowing consumer trust data decoupled obtained ndn also supports fine-grained trust allowing consumers reason whether public key owner acceptable publisher specific piece data specific context second primary research thrust designing developing usable mechanisms manage user trust research 2 different types trust models ndn data-centric security natural applications content access control infrastructure security applications encrypt data distribute keys named packets using named infrastructure distribute keys effectively limiting data security perimeter context single application verify data packet signature application fetch appropriate key identified packet key locator field like content trust management i.e. determine authenticity given key particular packet given application primary research challenge consistent experimental approach ndn trust management research driven application development use solving specific problems first identifying common patterns example security needs nlsr required development simple hierarchical trust model keys lower closer root levels used sign keys higher levels keys published names reflect trust relationship trust model namespace matches hierarchy trust delegation i.e. /root/site/operator/ router/process publishing keys particular name hierarchy authorizes sign specific data packets limits scope paradigm easily extended applications real world trust tends follow hierarchical pattern building management systems bms since ndn leaves trust model control application flexible expressive trust relations may also expressed one example chronochat motivated experimentation web-of-trust model security model current chatroom participant introduce newcomer others signing newcomer key future applications implement cross-certifying model sdsi 13 3 provides redundancy verification allowing data key names independent easily accommodates variety real-world trust relationships furthermore ndn treats network routing control messages like ndn data requiring signatures provides solid foundation securing routing protocols attack e.g. spoofing tampering ndn use multipath forwarding together adaptive forwarding strategy module mitigates prefix hijacking routers detect anomalies caused hijacks retrieve data alternate paths since ndn packets reference content rather devices trickier maliciously target particular device although mitigation mechanisms needed ndn-specific attacks e.g. interest flooding dos. furthermore pending interest table keeps state regarding past requests make informed forward decisions handle interest numerous security advantages
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Internet protocols
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vipre vipre security also known vipre brand j2 global develops cybersecurity products focused endpoint email security along advanced threat intelligence solutions vipre based clearwater florida operations washington d.c. vancouver b.c. spain uk philippines company originally founded 1994 sunbelt software acquired 2010 gfi software becoming vipre distributed products threattrack security 2017 concentrates vipre suite company uses name vipre portfolio encompasses endpoint security heritage original sunbelt software anti-virus products email security heritage fusemail electric mail products previously acquired j2 2017 vipre earned recognition av-comparatives one six top-rated products av-test virus bulletin february 2018 acquired j2 global recently featured pc world magazine article
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Computer security
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android version history version history android mobile operating system began public release android beta november 5 2007 first commercial version android 1.0 released september 23 2008 android continually developed google open handset alliance seen number updates base operating system since initial release versions android 1.0 1.1 released specific code names although android 1.1 unofficially known petit four android code names confectionery-themed alphabetical order since 2009 android 1.5 cupcake recent version android android 9 pie released august 2018 development android started 2003 android inc. purchased google 2005 beta released november 5 2007 software development kit sdk released november 12 2007 november 5 date popularly celebrated android birthday public beta versions sdk released following order following tables show release dates key features android operating system updates date listed chronologically official application programming interface api levels main hardware platform android arm architecture armv7 armv8-a architectures formerly also armv5 x86 mips architectures also officially supported later versions android mips support since deprecated support removed ndk r17 unofficial android-x86 project used provide support x86 mips architectures ahead official support 2012 android devices intel processors began appear including phones tablets gaining support 64-bit platforms android first made run 64-bit x86 arm64 since android 5.0 lollipop 64-bit variants platforms supported addition 32-bit variants requirements minimum amount ram devices running android 7.1 depend screen size density type cpu ranging 816mb–1.8gb 64-bit 512mb–1.3gb 32-bit meaning practice 1gb common type display minimum android watch 416mb recommendation android 4.4 least 512 mb ram low ram devices 340 mb required minimum amount include memory dedicated various hardware components baseband processor android 4.4 requires 32-bit armv7 mips x86 architecture processor latter two unofficial ports together opengl es 2.0 compatible graphics processing unit gpu android supports opengl es 1.1 2.0 3.0 3.2 since android 7.0 vulkan version 1.1 available devices applications may explicitly require certain version opengl es suitable gpu hardware required run applications android used require autofocus camera relaxed fixed-focus camera
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Operating systems
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red condor red condor inc. privately held company offers anti-spam appliances hosted service block e-mail spam spyware viruses company also offers message archiving service provides back-up inbound outbound email messages 2007 red condor introduced vx technology integrates local appliance hosted service technology redirects email appliance hosted service event network failure november 2008 company named dr. thomas steding former ceo pgp corporation president ceo january 2009 red condor received technology year award infoworld magazine april 2010 red condor purchased st. bernard software
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Computer security
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patr-ii patr-ii linguistic formalism used computational linguistics developed stuart m. shieber uses context-free grammar rules feature constraints rules
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Computational linguistics
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dasboot dasboot software utility produced subrosasoft.com inc allows user create bootable mac os x usb device mac os x 10.5 earlier freeware product live usb device used diagnostic repair recovery mac os x systems macworld uk editor choice 5 star award creating dasboot device requires steps addition dasboot application user needs bootable cd dvd firewire usb flash drive intel-powered apple computers support booting via usb usb firewire hard drives may also used dasboot works versions mac os x prior 10.6 bootable mac os x cd/dvds included programs drive genius diskwarrior filesalvage copycatx software utilities bootable dvd used mac os x installer disc used lacks libraries required create bootable device default following applications installed dasboot devices also present user applications folder following applications automatically included users add additional applications dasboot device dragging dropping desired application applications area dasboot application users also select deselect included applications simply clicking icon within applications section user selected device 'd like make bootable selected bootable disk copy required libraries information chosen programs include dasboot device clicking single button starts process building required information copying device boot system dasboot device user starts mac 'option sometimes called 'alt key held display startup screen allows select bootable device would like start system select dasboot device system start normal dasboot interface appear system boots allow user select installed application would like run release version 2.0 added support mac os x 10.6 snow leopard along support newer intel macs performance enhancements bug fixes
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Operating systems
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preprocessor computer science preprocessor program processes input data produce output used input another program output said preprocessed form input data often used subsequent programs like compilers amount kind processing done depends nature preprocessor preprocessors capable performing relatively simple textual substitutions macro expansions others power full-fledged programming languages common example computer programming processing performed source code next step compilation computer languages e.g. c pl/i phase translation known preprocessing also include macro processing file inclusion language extensions lexical preprocessors lowest-level preprocessors require lexical analysis operate source text prior parsing performing simple substitution tokenized character sequences tokenized character sequences according user-defined rules typically perform macro substitution textual inclusion files conditional compilation inclusion common example c preprocessor takes lines beginning directives knows nothing underlying language use criticized many features built directly languages example macros replaced aggressive inlining templates includes compile-time imports requires preservation type information object code making feature impossible retrofit language conditional compilation effectively accomplished codice_1 dead code elimination languages however key point remember preprocessor directives start new line lexical preprocessors include general-purpose m4 commonly used cross-platform build systems autoconf gema open source macro processor operates patterns context syntactic preprocessors introduced lisp family languages role transform syntax trees according number user-defined rules programming languages rules written language program compile-time reflection case lisp ocaml languages rely fully external language define transformations xslt preprocessor xml statically typed counterpart cduce syntactic preprocessors typically used customize syntax language extend language adding new primitives embed domain-specific programming language dsl inside general purpose language good example syntax customization existence two different syntaxes objective caml programming language programs may written indifferently using normal syntax revised syntax may pretty-printed either syntax demand similarly number programs written ocaml customize syntax language addition new operators best examples language extension macros found lisp family languages languages simple dynamically typed functional cores standard distributions scheme common lisp permit imperative object-oriented programming well static typing almost features implemented syntactic preprocessing although bears noting macro expansion phase compilation handled compiler lisp still considered form preprocessing since takes place phases compilation one unusual features lisp family languages possibility using macros create internal dsl typically large lisp-based project module may written variety minilanguages one perhaps using sql-based dialect lisp another written dialect specialized guis pretty-printing etc common lisp standard library contains example level syntactic abstraction form loop macro implements algol-like minilanguage describe complex iteration still enabling use standard lisp operators metaocaml preprocessor/language provides similar features external dsls preprocessor takes description semantics language i.e interpreter combining compile-time interpretation code generation turns definition compiler ocaml programming language—and language either bytecode native code preprocessors specific particular data processing task e.g. compiling c language preprocessor may promoted general purpose meaning aimed specific usage programming language intended used wide variety text processing tasks m4 probably well known example general purpose preprocessor although c preprocessor sometimes used non-c specific role examples
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Programming language topics
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sethi–ullman algorithm computer science sethi–ullman algorithm algorithm named ravi sethi jeffrey d. ullman inventors translating abstract syntax trees machine code uses registers possible generating code arithmetic expressions compiler decide best way translate expression terms number instructions used well number registers needed evaluate certain subtree especially case free registers scarce order evaluation important length generated code different orderings may lead larger smaller numbers intermediate values spilled memory restored sethi–ullman algorithm also known sethi–ullman numbering fulfills property producing code needs fewest instructions possible well fewest storage references assumption commutativity associativity apply operators used distributive laws i.e formula_1 hold please note algorithm succeeds well neither commutativity associativity hold expressions used therefore arithmetic transformations applied algorithm also take advantage common subexpressions apply directly expressions represented general directed acyclic graphs rather trees simple sethi–ullman algorithm works follows load/store architecture arithmetic expression formula_2 abstract syntax tree looks like continue algorithm need examine arithmetic expression formula_3 i.e look right subtree assignment '= start traversing tree preorder assigning number registers needed evaluate subtree note last summand expression formula_3 constant tree seen need 2 registers compute left subtree '* 1 register compute right subtree nodes c g need registers following reasons tree leaf number registers evaluate either 1 0 depending whether left right subtree since operation add r1 handle right component directly without storing register therefore shall start emit code left subtree first might run situation 2 registers left compute whole expression computed right subtree first needs 1 register would need register hold result right subtree computing left subtree would still need 2 registers therefore needing 3 registers concurrently computing left subtree first needs 2 registers result stored 1 since right subtree needs 1 register compute evaluation expression 2 registers left advanced version sethi–ullman algorithm arithmetic expressions first transformed exploiting algebraic properties operators used
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Programming language topics
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sgi iris sgi iris series line terminals workstations silicon graphics built 1980s early systems use motorola 68000 family processors originally later models feature early-generation mips processors
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Computer architecture
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pefs pefs private encrypted file system kernel level stacked cryptographic file system freebsd open source software available bsd license pefs official website pefs.io sources available github
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Computer file systems
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wamp.net wamp.net combination typical wamp/wnmp stacks supports apache nginx current packages include apache nginx php mariadb mysql postgresql mongodb memcache redis downloaded cached installed/uninstalled via instance manager run standalone windows services multiple simultaneous instances supported meaning one could run mariadb mysql simultaneously apache nginx either different ports port across different interfaces sites/vhosts stored database tied specific web server instance allows moved different web server types versions click button creating new site/vhost automatically creates vhost file http https either apache nginx well update windows hosts file ssl certificates automatically generated background using internal ca root certificate automatically added trusted root store give warnings errors browsing site site/vhost use version php without need switching typically case stack implementations
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Web technology
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lga 1567 lga 1567 socket ls cpu socket used high-end server segment 1567 protruding pins make contact pads processor supports intel nehalem codenamed beckton xeon 7500 xeon 6500 series processors first released march 2010 6500 series scalable 2 sockets 7500 series scalable 4/8 sockets supporting motherboard later xeon e7 series using westmere-ex architecture reused socket
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Computer architecture
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anti-malware testing standards organization anti-malware testing standards organization amtso international non-profit organization set 2008 address perceived need improvement quality relevance objectivity anti-malware testing methodologies according amtso web site organization charter lists following objectives 2012 amtso administered elected unpaid board directors strategic input advisory board six committees handle specific operations membership fees pr subsequently major infrastructural change took place introducing executive team ceo cto cfo vps marketing strategy addition already existing board grew discussions security vendors security product testing organizations membership amtso also open academics reviewers publications include individual members however high cost full membership generally discourages individual members small organizations joining early 2011 organization offered much cheaper subscription rate n't however offer full voting rights amtso currently offers two-tier membership model entity members get full benefits membership individual members get benefits apart right vote members wider security community even testers raised issue organization membership includes preponderance security vendors organization created potentially useful resources testers including page flags relevant papers resources outside amtso repository guidelines documents benefit aspiring testers wide range topics another popular freely available resource security features check attempts download faux malicious file desktop android device simple test ensure basic anti-malware standards implemented test device also organizes workshops three times year discussion generation guidelines documents major by-product sessions
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Computer security
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verbnet verbnet project maps propbank verb types corresponding levin classes lexical resource incorporates semantic syntactic information contents verbnet part semlink project development university colorado
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Computational linguistics
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binary application markup language binary application markup language file format microsoft generated compiling xaml files xaml file compiled binary application markup language file .baml extension may inserted resource .net framework assembly run-time framework engine extracts .baml file assembly resources parses creates corresponding wpf visual tree workflow format content loadable faster runtime xaml enriched tokens lexical analysis completed
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Operating systems
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t-systems t-systems german global services consulting company headquartered frankfurt founded 2000 subsidiary deutsche telekom 2012 t-systems largest german one largest european services companies serving customers westlb old mutual daimler volkswagen royal dutch shell sanlam murray roberts bp tui ag de agostini philips man se airbus e.on british american tobacco company operates 20 countries 2015 employed 45,990 people 2003 approximately 50,000 people worldwide among around 27,000 germany 23,000 outside beginning december 2007 reinhard clemens ceo president eds hp enterprise services germany since 2003 since january 2018 adel al-saleh ceo t-systems june 2018 t-systems announced cut 10,000 jobs 3 years including 6,000 germany hope returning company profitability t-systems founded 2000 deutsche telekom acquired 50.1 stake debis systemhaus one largest services companies germany time deutsche telekom existing service businesses merged incorporated control one single company newly founded t-systems 2001 t-system headquarters moved bonn frankfurt 2002 remaining 49.9 share debis systemhaus acquired fully incorporated t-systems however company underwent leadership crisis first years creation due different agendas former debis management leadership former telekom subsidiaries since t-systems made number acquisitions notably purchase subsidiary volkswagen group december 2005 2007 2018 t-systems ceo t-systems also supported creation silicon saxony major cluster germany 2008 t-systems global services provider cognizant entered global alliance t-systems india operations taken cognizant following alliance late march 2008 t-systems also working german government market leader germany 2009 t-systems came another wing india t-systems ict india pvt ltd. support global partners t-systems ict india head office pune set another 'point production bangalore april 2016 expanding provide ict services also global customers t-systems international since september 2016 laszlo posset managing director t-systems ict india vivek krishnatray managed company indian operations t-systems different international subsidiaries
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Distributed computing architecture
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nagle algorithm nagle algorithm means improving efficiency tcp/ip networks reducing number packets need sent network defined john nagle working ford aerospace published 1984 request comments rfc title congestion control ip/tcp internetworks see rfc 896 rfc describes called small-packet problem application repeatedly emits data small chunks frequently 1 byte size since tcp packets 40-byte header 20 bytes tcp 20 bytes ipv4 results 41-byte packet 1 byte useful information huge overhead situation often occurs telnet sessions keypresses generate single byte data transmitted immediately worse slow links many packets transit time potentially leading congestion collapse nagle algorithm works combining number small outgoing messages sending specifically long sent packet sender received acknowledgment sender keep buffering output full packet worth output thus allowing output sent rfc defines algorithm inhibit sending new tcp segments new outgoing data arrives user previously transmitted data connection remains unacknowledged mss maximum segment size largest segment sent connection window size currently acceptable window unacknowledged data written pseudocode algorithm interacts badly tcp delayed acknowledgments delayed ack feature introduced tcp roughly time early 1980s different group algorithms enabled applications two successive writes tcp connection followed read fulfilled data second write reached destination experience constant delay 500 milliseconds ack delay reason tcp implementations usually provide applications interface disable nagle algorithm typically called codice_1 option solution recommended nagle avoid algorithm sending premature packets buffering application writes flushing buffer user-level solution avoid write-write-read sequences sockets write-read-write-read fine write-write-write fine write-write-read killer buffer little writes tcp send using standard unix i/o package flushing write read usually works nagle considers delayed acks bad idea since application layer usually respond within time window protocol level recommends disabling delayed ack example codice_2 linux instead algorithm quick acks incur much overhead many small packets algorithm applies data size data single write spans 2 n packets last packet withheld waiting ack previous packet request-response application protocols request data larger packet artificially impose hundred milliseconds latency requester responder even requester properly buffered request data nagle algorithm disabled requester case response data larger packet responder also disable nagle algorithm requester promptly receive whole response general since nagle algorithm defense careless applications benefit carefully written application takes proper care buffering algorithm either effect negative effect application applications expect real-time responses low latency react poorly nagle algorithm applications networked multiplayer video games movement mouse remotely controlled operating system expect actions sent immediately algorithm purposefully delays transmission increasing bandwidth efficiency expense latency reason applications low-bandwidth time-sensitive transmissions typically use codice_1 bypass nagle delay another option use udp instead modern operating systems implement nagle algorithms aix linux enabled default disabled per-socket basis using codice_1 option
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Internet protocols
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xsl formatting objects xsl-fo xsl formatting objects markup language xml document formatting often used generate pdf files xsl-fo part xsl extensible stylesheet language set w3c technologies designed transformation formatting xml data parts xsl xslt xpath version 1.1 xsl-fo published 2006 xsl-fo considered feature complete w3c last update working draft january 2012 working group closed november 2013 unlike combination html css xsl-fo unified presentational language semantic markup term used html unlike css modifies default presentation external xml html document stores document data within general idea behind xsl-fo use user writes document fo xml language xhtml docbook tei possible examples user obtains xslt transform either writing one finding one document type question xslt transform converts xml xsl-fo xsl-fo document generated passed application called fo processor fo processors convert xsl-fo document something readable printable common output xsl-fo pdf file postscript fo processors output formats like rtf files even window user gui displaying sequence pages contents xslt language originally conceived purpose widespread use general xml transformations transformation step taken much granted xsl-fo uncommon people call xslt turns xml xsl-fo actual xsl-fo document even tutorials xsl-fo tend written xslt commands around fo processing instructions xslt transformation step exceptionally powerful allows automatic generation table contents linked references index various possibilities xsl-fo document like pdf postscript document definitively describe layout text various pages instead describes pages look like various contents go fo processor determines position text within boundaries described fo document xsl-fo specification even allows different fo processors varying responses regard resultant generated pages example fo processors hyphenate words minimize space breaking line others choose different processors may even use different hyphenation algorithms ranging simple complex hyphenation algorithms take account whether previous next line also hyphenated change borderline cases quite substantially layout various pages cases xsl-fo specification explicitly allows fo processors degree choice regard layout differentiation fo processors creating inconsistent results processors often concern general purpose behind xsl-fo generate paged printed media xsl-fo documents usually used intermediaries mostly generate either pdf files printed document final form distributed opposed html generated distributed final form directly user distributing final pdf rather formatting language input whether html/css xsl-fo means one hand recipients n't affected unpredictability resulting differences among formatting language interpreters hand means document easily adapt different recipient needs different page size preferred font size tailoring on-screen versus on-paper versus audio presentation xsl-fo language designed paged media concept pages integral part xsl-fo structure fo works best could called content-driven design standard method layout books articles legal documents forth involves single flowing span fairly contiguous text various repeating information built margins page opposed layout-driven design used newspapers magazines content documents fit required space trimmed away fit xsl-fo easily handle tight restrictions magazine layout indeed many cases lacks ability express forms said layout despite basic nature language design capable great deal expressiveness tables lists side floats variety features available features comparable css layout features though features expected built xslt xsl-fo documents xml documents conform dtd schema instead conform syntax defined xsl-fo specification xsl-fo documents contain two required sections first section details list named page layouts second section list document data markup uses various page layouts determine content fills various pages page layouts define properties page define directions flow text match conventions language question define size page well margins page importantly define sequences pages allow effects odd even pages look different example one define page layout sequence gives extra space inner margins printing purposes allows space given margin book bound document data portion broken sequence flows flow attached page layout flows contain list blocks turn contain list text data inline markup elements combination two content may also added margins document page numbers chapter headings like blocks inline elements function much way css though rules padding margins differ fo css direction relative page orientation progression blocks inlines fully specified thus allowing fo documents function languages read different english language fo specification unlike css 2.1 uses direction-neutral terms like start end rather left right describing directions xsl-fo basic content markup derived css cascading rules many attributes xsl-fo propagate child elements unless explicitly overridden xsl-fo capable great deal textual layout functionality addition information specified xsl-fo language allows specification following page defined multiple columns case blocks flow one column next default individual blocks set span columns creating textual break page columns break flow columns break text allowed flow section section nature xsl-fo page specification multiple pages may actually different numbers widths columns text flow 3 column page 5 column page 1 column page quite easily fo features work within restrictions multi-column page span multiple columns specifying two attributes i.e.. span padding-after xsl-fo list essentially two sets blocks stacked side side entry consists block left start inline direction block sequence right end inline direction block left conceptually would number bullet list however could easily string text one might see glossary entry block right works expected blocks block containers multiple blocks single list entry numbering xsl-fo lists numbered expected done xslt whatever process generated xsl-fo document number lists explicitly numbered xsl-fo user specify widow orphan blocks flow allow attributes cascade child blocks additionally blocks specified kept together single page example image block description image set never separated fo processor best adhere commands even requires creating great deal empty space page user create footnotes appear bottom page footnote written fo document regular flow text point referenced reference represented inline definition though required body one blocks placed fo processor bottom page fo processor guarantees wherever reference footnote cited reference begin page even means creating extra empty space page fo table functions much like html/css table user specifies rows data individual cell user also specify styling information column background color additionally user specify first row table header row separate styling information fo processor told exactly much space give column told auto-fit text table fo extensive controls orienting blocks text one middle page designate block text oriented different orientation oriented blocks used languages different orientation rest document simply one needs orient text layout purposes blocks contain virtually kind content tables lists even blocks reoriented text version 1.1 xsl-fo adds number new features version 1.0 xsl-fo 1.0 fairly restrictive text allowed go areas page version 1.1 loosens restrictions significantly allowing flowing text mapped multiple explicit regions page allows newspaper-like typesetting many output formats xsl-fo processors specifically pdf bookmarking features allow format specify string text separate window selected user selected document window scrolls immediately specific region document xsl-fo v1.1 provides ability create named bookmarks xsl-fo thus allowing processor pass output format supports xsl-fo 1.1 features support generation index might found back book done referencing properly marked-up elements fo document last page generated without providing explicit in-document reference specific anchor fo document definition last page restricted within specific set pages cover entire document allows user specify something like page 2 15 page 15 page number last page definition table markers allow user create dynamic content within table headers footers running totals bottom page table table continued indicators xsl-fo 1.1 adds keywords inside outside side floats makes possible achieve page layouts marginalia positioned outside inside edges pages inside refers side page towards book binding outside refers side page away book binding xsl-fo 1.1 refines functionality sizing graphics fit ability shrink fit grow fit well ability define specific scaling steps addition resulting scaling factor referenced display example say figure caption image shown 50 actual size trying decide whether xsl-fo work given document following typographic layout requirements usually indicate xsl-fo work although may satisfied proprietary extensions xml html standards css standard since css2 paged media module starts supply basic features printed media css paged media module level 3 w3c completing formulation integrated standard document formatting generate pdfs since 2013 css3-paged w3c proposal xsl-fo replacement software products like prince antenna house formatter demonstrated comparable quality xsl-fo using css pdf production design notes version 2.0 xsl formatting objects first published 2009 last updated 2012
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Programming language topics
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joint interoperability tactical command control systems joint interoperability tactical command control systems jintaccs united states military program development maintenance tactical information exchange configuration items cis operational procedures originated ensure command control c2 c3 weapons systems us military services nato forces would interoperable made standard message text formats mtf man-readable machine-processable information core set common warfighting symbols data link standards called tactical data links tdls
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Computer architecture
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keykit keykit graphical environment programming language midi synthesis algorithmic composition originally developed tim thompson released tim thompson software engineer originator various software titles including keykit stevie predecessor widely distributed popular text editor vim keykit originally named keynote developed thompson spare time worked though related actual job keynote originally released toolchest 1995 released keykit license making freely available non-commercial use keykit noteworthy versatility expressiveness complex algorithmic arrangements produced much detail sophistication required software works multiple platforms operating systems dependent peripherals sound cards specific vendor unique advantages similar music workstation products similar functionality algorithmic composition computer generated music features
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Programming language topics
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ibm websphere application server community edition websphere application server community edition wasce free-of-charge certified java ee 6 application server building managing java applications ibm supported distribution apache geronimo uses tomcat servlet container axis 2 web services difference apache geronimo wasce comes db2 informix database drivers better xml parser libraries xml4j xlxp contains latest patches unreleased upstream versions 30 wasce developers committers apache geronimo project ibm announced september 20 2013 wasce withdrawn marketing support withdrawn september 30 2016
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Web technology
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aliasing computing computing aliasing describes situation data location memory accessed different symbolic names program thus modifying data one name implicitly modifies values associated aliased names may expected programmer result aliasing makes particularly difficult understand analyze optimize programs aliasing analysers intend make compute useful information understanding aliasing programs example implementations c programming language perform array bounds checking one exploit implementation programming language compiler computer architecture assembly language conventions achieve aliasing effects writing outside array type buffer overflow invokes undefined behaviour according c language specification however many implementations c show aliasing effects described array created stack variable laid memory directly beside array one could index outside array directly change variable changing relevant array element example int array size 2 example sake calling arr next another int variable call arr 2 i.e 3rd element would aliased adjacent memory int main possible implementations c array block contiguous memory array elements merely referenced offsets address beginning block multiplied size single element since c bounds checking indexing addressing outside array possible note aforementioned aliasing behaviour undefined behaviour implementations may leave space arrays variables stack instance align variables memory locations multiple architecture native word size c standard generally specify data laid memory iso/iec 9899:1999 section 6.2.6.1 erroneous compiler omit aliasing effects accesses fall outside bounds array another variety aliasing occur language refer one location memory one name example pointers see c example xor swap algorithm function assumes two pointers passed distinct fact equal aliases function fails common problem functions accept pointer arguments tolerance lack thereof aliasing must carefully documented particularly functions perform complex manipulations memory areas passed controlled aliasing behaviour may desirable cases aliasing behaviour specified unlike enabled memory layout c common practice fortran perl programming language specifies constructs aliasing behaviour foreach loops allows certain data structures modified directly less code example array 1 2 3 foreach element array print 2 3 4 result one wanted bypass aliasing effects one could copy contents index variable another change copy optimizers often make conservative assumptions variables presence pointers example knowing value variable codice_1 5 normally allows certain optimizations constant propagation however compiler use information assignment another variable example c codice_2 could codice_3 alias codice_1 could case assignment like codice_5 effect assignment codice_3 value x would changed well propagating information codice_1 5 statements following codice_2 would potentially wrong codice_3 indeed alias codice_1 however information pointers constant propagation process could make query like codice_1 alias codice_3 answer codice_13 propagated safely another optimization impacted aliasing code reordering compiler decides codice_1 aliased codice_3 code uses changes value codice_1 moved assignment codice_2 would improve scheduling enable loop optimizations carried enable optimizations predictable manner iso standard c programming language including newer c99 edition see section 6.5 paragraph 7 specifies illegal exceptions access memory location using pointers different types compiler may therefore assume pointers alias rule known strict aliasing rule sometimes allows impressive increases performance known break otherwise valid code several software projects intentionally violate portion c99 standard example python 2.x implement reference counting required changes basic object structs python 3 enable optimization linux kernel strict aliasing causes problems optimization inlined code cases compiled gcc option codice_18 invoked prevent unwanted optimizations could yield unexpected code term aliasing also used describe situation due either hardware design choice hardware failure one available address bits used memory selection process may design decision address bits available necessary support installed memory device failure one address bits may shorted together may forced ground logic 0 supply voltage logic 1 example assume memory design 8 locations requiring 3 address lines bits since 2 8 address bits named a2 a0 decoded select unique memory locations follows standard binary counter fashion table 8 unique combinations address bits selects different memory location however one address bit say a2 shorted ground table would modified follows case a2 always zero first four memory locations duplicated appear second four memory locations 4 7 become inaccessible change occurred different address bit decoding results would different general effect would loss single address bit cuts available memory space half resulting duplication aliasing remaining space
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Programming language topics
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health apple health health informatics mobile app announced apple inc. worldwide developers conference wwdc 2014 app included ios 8 later healthkit accompanying developer application programming interface api included ios sdk software development kit mac used software developers design applications extensibility interact health application ios release ios 8 september 2014 apple removed healthkit-compatible apps app store fix bug causing cellular touch id issues re-released healthkit release ios 8.0.2 september 26 2014 initially health criticized lack compatible third-party applications launch glucose tracking proper health data explanations sluggish app performance eventually apple fixed issues software update february 2017 several manufacturers apple sold hardware healthkit enabled july 2016 ios 10 users united states able sign organ eye tissue donor apple health app
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Operating systems
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remote application programming interface remote application programming interface rapi remote procedure call rpc mechanism pocket pc server pc application client words rapi allows pc applications call functions executed pocket pc rapi registry file system database configuration pocket pc device available pc application
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Operating systems
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kynapse kynapse artificial intelligence middleware product developed kynogon bought autodesk 2008 called autodesk kynapse 2011 re-engineered rebranded autodesk navigation kynapse used development 80 game titles including mafia ii crackdown alone dark 5 fable ii sonic hedgehog 2006 unreal engine kynapse also used companies eads bae systems électricité de france develop military industrial simulation
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Distributed computing architecture
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soapjr soapjr protocol specification exchanging structured information implementation web services computer networks hybrid soap json-rpc abbreviated jr case soapjr designed create clean fast ajax-style apis analogous introduction band signalling telephony world traditional soap longer simple object access protocol initially designed bloated overly verbose making bandwidth-hungry slow also based xml making expensive parse manipulate especially mobile embedded clients however core envelope/head/body design pattern useful ajax style apis soapjr uses similar envelope/head/body model using lightweight easier manipulate json contrast soap json-rpc overly simplistic basically tunnels http get-style key/value pairs within query string using json however within json-rpc head/body separation leaving metadata pollute main data space soapjr combines best two concepts designed create modern ajax apis easily used mobile devices embedded systems desktop browsers see soapjr specs detailed description soapjr open source project software released gpl content creative commons following soapjr entities defined json-schemas latest versions also downloaded single file soapjr.org also aims contribute creation common set dmds data model definitions may align json-schema proposal service mapping description proposal applications within specific domains easily share data primary extension soapjr may provide use consistent standardised error codes resources may inform development common data models utilised within microformats rdf basic request view jcard details single user based username message would passed request within json parameter e.g simple soapjr response head.result represents success body contains single jcard record list list search context would contain array 0 jcard records
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Web technology
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hindu genealogy registers haridwar genealogy registers families maintained brahmin pandits priests ‘ pandas ’ double professional genealogists haridwar subject study many years several cases voluminous records vahis bahi also used settling legal cases regarding inheritance property disputes records held sacrosanct pilgrims pandas many places records trace family history twenty prior generations stretching across many centuries haridwar traditionally site death rites also shraaddha amongst hindus soon also became customary family pandits priest record visit family along gotra family tree marriages members present etc. grouped according family home town centuries registers became important genealogical source many families part splintered families tracing family tree family history well especially partition india 1947 later amongst indian diaspora custom similar panjis panji prabandh extensive genealogical records maintained among maithil brahmins bihar custom well known today indians settled abroad ancient custom detailed family genealogies hindu families past several generations kept professional hindu brahmin pandits popularly known pandas hindu holy city haridwar hand written registers passed generations pandit ancestors classified according original districts villages ones ancestors special designated pandit families charge designated district registers even cases ancestral districts villages left behind pakistan partition india hindus migrate india several cases present day descendants sikhs muslims christians uncommon one find details even one past seven generations genealogy registers kept pandas haridwar centuries hindu ancestors visited holy town haridwar purpose may mostly pilgrimage purposes or/and cremation dead immersion ashes bones kin cremation waters holy river ganges required hindu religious custom ancient custom go pandit charge ones family register update family genealogical family tree details marriages births deaths ones extended joint family present day india people visiting haridwar dumbfounded pundits blue solicit come update ancestral genealogical family tree news travels like wildfire among pandits ones family designated pandit quickly notified ones visit nowadays hindu joint family system broken people preferring nuclear families record keeping pandits prefer visitors haridwar come prepared getting touch ones extended family bringing relevant details regarding ones ancestral district village names grand parents great grand parents marriages births deaths occurred extended family even much details possible families married visiting family member required personally sign family genealogical register furnished ones family panda updating future family visitors generations see authenticate updated entries friends family members accompanying visit may also requested sign witnesses starting around 1977 hindu genealogy records microfilmed later housed genealogical society utah gsu usa since 1981 places records records hindu families kurukshetra pehowa chintpurni jawalapur haridwar jawalamukhi genealogical society utah currently restricts online access hindu genealogy records members church jesus christ latter-day saints lds church others notable places shraadhs performed pitrs noted sites became customary family pandits priest record visit family along gotra family tree marriages members present etc. grouped according family home town centuries registers became important genealogical source many families part splintered families tracing family tree family history thanesar kurukshetra traditionally site death rites also shraaddha amongst hindus genealogy records also kept pitrudhak teerth pehowa banks sarasvati river kurukshetra district haryana site hindu pilgrimage pandava performed death rites mahabharata war genealogy records pilgrims also kept jawalamukhi shakti peetha town nagar parishad kangra district indian state himachal pradesh site hindu pilgrimage genealogy records also kept chintpurni village una district himachal pradesh one shakti peethas major hindu pilgrimage site genealogy records also kept ghats varanasi ganges river major site hindu pilgrimage death rites performed especially manikarnika ghat genealogy records also kept ghats ganges prayagraj long place pilgrimage hindus spawned set priests maintain genealogy records often dating back centuries trimbakeshwar shiva temple ancient hindu temple town trimbak trimbakeshwar tehsil nashik district maharashtra india 28 km city nashik 40 km nashik road dedicated god shiva one twelve jyotirlingas genealogy records also kept purohits pandas tarakeswar shiva temple maintain genealogy records pilgrims
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Databases
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map higher-order function many programming languages map name higher-order function applies given function element functor e.g list returning list results order often called apply-to-all considered functional form concept map limited lists works sequential containers tree-like containers even abstract containers futures promises suppose list integers codice_1 would like calculate square integer first define function codice_2 single number shown haskell square x x x afterwards may call » map square 1 2 3 4 5 yields codice_3 demonstrating codice_4 gone entire list applied function codice_2 element see view step mapping process list integers codice_6 want map new list codice_7 according function formula_1 codice_4 provided part haskell base prelude i.e standard library implemented map b b map map f x xs f x map f xs haskell polymorphic function codice_9 generalized polytypic function codice_10 applies type belonging codice_11 type class type constructor lists codice_12 defined instance codice_11 type class using codice_4 function previous example instance functor examples codice_11 instances include trees -- simple binary tree data tree leaf fork tree tree instance functor tree mapping tree yields » fmap square fork fork leaf 1 leaf 2 fork leaf 3 leaf 4 fork fork leaf 1 leaf 4 fork leaf 9 leaf 16 every instance codice_11 type class codice_17 contractually obliged obey functor laws fmap id ≡ id -- identity law fmap f g ≡ fmap f fmap g -- composition law codice_18 denotes function composition haskell among uses allows defining element-wise operations various kinds collections moreover two functors natural transformation function polymorphic type formula_2 respects function defined parametric polymorphism type definition specification always satisfied mathematical basis maps allow number optimizations composition law ensures lead result formula_5 however second form efficient compute first form codice_4 requires rebuilding entire list scratch therefore compilers attempt transform first form second type optimization known map fusion functional analog loop fusion map functions often defined terms fold codice_22 means one map-fold fusion codice_23 equivalent codice_24 implementation map singly linked lists tail-recursive may build lot frames stack called large list many languages alternately provide reverse map function equivalent reversing mapped list tail-recursive implementation utilizes fold-left function reversemap f foldl \ys x f x ys since reversing singly linked list also tail-recursive reverse reverse-map composed perform normal map tail-recursive way map function originated functional programming languages language lisp introduced map function called codice_25 1959 slightly different versions already appearing 1958 original definition codice_25 mapping function successive rest lists function codice_25 still available newer lisps like common lisp though functions like codice_28 generic codice_4 would preferred squaring elements list using codice_25 would written s-expression notation like using function codice_28 example would written like today mapping functions supported may defined many procedural object-oriented multi-paradigm languages well c++ standard template library called codice_32 c 3.0 linq library provided extension method called codice_33 map also frequently used operation high level languages coldfusion markup language cfml perl python ruby operation called codice_4 four languages codice_35 alias codice_4 also provided ruby smalltalk common lisp provides family map-like functions one corresponding behavior described called codice_28 codice_38 indicating access using car operation also languages syntactic constructs providing functionality map function map sometimes generalized accept dyadic 2-argument functions apply user-supplied function corresponding elements two lists languages use special names map2 zipwith languages using explicit variadic functions may versions map variable arity support variable-arity functions map 2 lists encounters issue handling lists different lengths various languages differ raise exception stop length shortest list ignore extra items lists continue length longest list lists already ended pass placeholder value function indicating value languages support first-class functions codice_4 may partially applied lift function works one value element-wise equivalent works entire container example codice_40 haskell function squares element list
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Programming language topics
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fido alliance fido fast identity online alliance open industry association launched february 2013 whose mission develop promote authentication standards help reduce world ’ over-reliance passwords fido addresses lack interoperability among strong authentication devices reduces problems users face creating remembering multiple usernames passwords fido supports full range authentication technologies including biometrics fingerprint iris scanners voice facial recognition well existing solutions communications standards trusted platform modules tpm usb security tokens embedded secure elements ese smart cards near field communication nfc usb security token device may used authenticate using simple password e.g four-digit pin pressing button specifications emphasize device-centric model authentication wire happens using public-key cryptography user device registers user server registering public key authenticate user device signs challenge server using private key holds keys device unlocked local user gesture biometric pressing button fido provides two types user experiences depending protocol used protocols define common interface client whatever local authentication method user exercises nok nok labs paypal lenovo among fido founders end september 2016 fido members totaled 260 including board made aetna alibaba group amazon american express arm bank america bc card broadcom crucialtec daon egis technology feitian gemalto google hypr infineon intel ing lenovo mastercard microsoft nok nok labs ntt docomo nxp semiconductors oberthur technologies paypal qualcomm rsa samsung electronics synaptics usaa visa vmware onespan yubico full list members available official website following open specifications may obtained fido web site u2f 1.0 proposed standard october 9 2014 starting point short-lived specification known fido 2.0 proposed standard september 4 2015 latter formally submitted world wide web consortium w3c november 12 2015 subsequently first working draft w3c web authentication webauthn standard published may 31 2016 webauthn standard revised numerous times since becoming w3c recommendation march 4 2019 meanwhile u2f 1.2 proposed standard july 11 2017 became starting point client authenticator protocol 2.0 proposed standard published september 27 2017 fido ctap 2.0 complements w3c webauthn scope fido2 project
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Computer security
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quicklaw lexisnexis quicklaw canadian electronic legal research database provides court decisions levels news reports provincial federal statutes journals legal commentary also offers case citator case digests 2002 quicklaw purchased lexisnexis subsidiary lexisnexis canada lexisnexis quicklaw used lawyers law firms canada access case law legislation exclusive current awareness services expert commentary addition research lexisnexis quicklaw service also includes citation tools help lawyers law firms validate authority cases find summaries judicial considerations along treatment pinpoint references lexisnexis quicklaw composed several products providing legal practitioners access need perform research designed practices focus particular legal segments lexisnexis quicklaw essentials provides content needed research areas westlaw/ecarswell offers similar fee-based services canlii.org non-profit organization managed federation law societies canada canlii goal make canadian law accessible free internet website provides access court judgments tribunal decisions statutes regulations canadian jurisdictions canlii part collaboration legal information institute around world include austlii bailii lii etc
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Databases
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f* programming language f* pronounced f star functional programming language inspired ml aimed program verification type system includes dependent types monadic effects refinement types allows expressing precise specifications programs including functional correctness security properties f* type-checker aims prove programs meet specifications using combination smt solving manual proofs programs written f* translated ocaml f c execution previous versions f* could also translated javascript latest version f* written entirely common subset f* f bootstraps ocaml f open source apache 2.0 license active development github
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Programming language topics
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bridging programming computer science bridging describes systems map runtime behaviour different programming languages share common resources often used allow foreign languages operate host platform native object libraries translating data state across two sides bridge bridging contrasts embedding systems allow limited interaction black box mechanism state sharing limited non-existent apple inc. made heavy use bridging several occasions notably early versions mac os x bridged older classic systems using carbon system well java microsoft common language runtime introduced .net framework designed multi-language start avoided need extensive bridging solutions platforms recently added new bridging systems javascript apple objc-to-js microsoft html bridge programming languages include concept subroutine function mechanism allows commonly used code encapsulated re-used throughout program instance program makes heavy use mathematics might need perform square root calculation various numbers throughout program code might isolated codice_1 function passed number perform square root calculation returns result many cases code question already exists either implemented hardware part underlying operating system program runs within cases codice_2 function simplified calling built-in code functions often fall easily identifiable groups similar capabilities mathematics functions instance handling text files functions often gathered together collections known libraries supplied system commonly past programming language language method calling functions libraries written one language may work another semantics calling functions c different pascal generally c programs call pascal libraries vice versa commonly used solution problem pick one set call semantics default system platform programming languages conform standard computer languages platforms generally added functionality expressed call/return model function garbage collection instance runs throughout lifetime application run sort functionality effectively outside program present expressed directly program functions like generally implemented ever-growing runtime systems libraries compiled programs necessarily visible within code introduction shared library systems changed model conventional program construction considerably past library code copied directly programs linker effectively became part program dynamic linking library code normally exists one place vendor-provided file system applications share aryl systems presented many problems often performance terms shared libraries largely isolated particular languages platforms opposed operating system whole many problems addressed 1990s early 2000s major platforms switched shared libraries primary interface entire system although systems addressed problem providing common code libraries new applications systems generally added runtimes well meant language library entire system often tightly linked together instance openstep entire operating system effect objective-c program programs running wished use extensive object suite provided openstep would able call libraries using obj-c semantics also interact obj-c runtime provide basic control application contrast microsoft .net framework designed start able support multiple languages initially c c++ new version visual basic ms isolated object libraries runtime common language infrastructure cli instead programs compiling directly source code underlying runtime format case languages cli model languages first compiled common intermediate language cil calls common language runtime clr theory programming language use cli system use .net objects although platforms like osx .net offer ability programming languages adapted platform runtime system also case programming languages often target runtime mind objective-c essentially requires obj-c runtime c clr one wants use c code within obj-c vice versa one find version written use runtime often n't exist common version problem concerns use languages platform independent like java runtimes libraries although possible build java compiler calls underlying system like j system would also able interact java code unless re-compiled access code java libraries may difficult impossible rise web browser sort virtual operating system made problem acute modern programming paradigm html5 includes javascript js language document object model major library browser runtime environment although would possible build version js runs clr would largely defeat purpose language designed largely operating browsers unless compiler interact browser directly little purpose using cases many like need arises system allows two runtimes interoperate known bridging runtimes apple made considerable use bridging technologies since earliest efforts led mac os x next first purchased apple plan build new version openstep then-known rhapsody emulator known blue box would run classic mac os programs led considerable push-back developer community rhapsody cancelled place os x would implement many older mac os calls top core functionality openstep providing path existing applications gracefully migrated forward apple took useful code openstep platform re-implemented core functionality pure-c library known core foundation cf short openstep libraries calling cf underlying code became cocoa api new mac-like c libraries became carbon api c obj-c sides system needed share data data obj-c side normally stored objects opposed base types conversions cf could expensive apple willing pay performance penalty implemented scheme known toll-free bridging help reduce eliminate problem time java becoming major player programming world apple also provided java bridging solution developed webobjects platform classical bridging solution direct conversions java openstep/cf types completed code required carbon program using cfstrings using code cocoa application using nsstring two could bridged toll-free java bridge cfstrings instead cast java string objects required work made porting essentially invisible developers made widespread use similar technologies provide support languages including peering system used allow obj-c code call .net code mono need porting solutions waned carbon java bridge deprecated eventually removed later releases system java support migrated using java native interface jni standard java world allowed java interact c-based code osx jni allowed obj-c code used difficulty around 2012 apple extensive work webkit led introduction new bridging technology allows javascript program code call obj-c/cocoa runtime vice versa allows browser automation using obj-c alternately automation cocoa applications using javascript originally part safari web browser 2013 code promoted part new osx 10.9 although examples bridging used past microsoft cli system intended support languages top .net system rather running native runtimes bridging led number new languages implemented cli system often including either hash mark iron name see list cli languages comprehensive set examples concept seen example ms embrace extend extinguish behaviour produced java-like languages c j instance work java code used libraries nevertheless classic windows ecosystem included considerable code would needed used within .net world role ms introduced well supported bridging system system included numerous utilities language features ease use windows visual basic code within .net system vice versa microsoft also introduced javascript bridging technology silverlight html bridge bridge exposes js types .net code .net types js code manages memory access safety similar bridging technologies often javascript one side common various platforms one example js bridge android os written example term also sometimes used describe object-relational mapping systems bridge divide sql database world modern object programming languages
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Programming language topics
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time stamp counter time stamp counter tsc 64-bit register present x86 processors since pentium counts number cycles since reset instruction codice_1 returns tsc edx eax x86-64 mode codice_1 also clears higher 32 bits rax rdx opcode codice_3 pentium competitors cyrix 6x86 always tsc may consider codice_1 illegal instruction cyrix included time stamp counter mii time stamp counter excellent high-resolution low-overhead way program get cpu timing information advent multi-core/hyper-threaded cpus systems multiple cpus hibernating operating systems tsc relied upon provide accurate results — unless great care taken correct possible flaws rate tick whether cores processors identical values time-keeping registers promise timestamp counters multiple cpus single motherboard synchronized therefore program get reliable results limiting run one specific cpu even cpu speed may change power-saving measures taken os bios system may hibernated later resumed resetting tsc latter cases stay relevant program must re-calibrate counter periodically relying tsc also reduces portability processors may similar feature recent intel processors include constant rate tsc identified kern.timecounter.invariant_tsc sysctl freebsd codice_5 flag linux codice_6 processors tsc ticks processor nominal frequency regardless actual cpu clock frequency due turbo power saving states hence tsc ticks counting passage time number cpu clock cycles elapsed windows platforms microsoft strongly discourages using tsc high-resolution timing exactly reasons providing instead windows apis codice_7 codice_8 posix systems program get similar function reading value codice_9 clock using codice_10 function starting pentium pro intel processors practiced out-of-order execution instructions necessarily performed order appear program cause processor execute codice_1 later simple program expects producing misleading cycle count programmer solve problem inserting serializing instruction cpuid force every preceding instruction complete allowing program continue using codice_12 instruction serializing variant codice_1 instruction intel processor families increment time-stamp counter differently specific processor configuration determines behavior constant tsc behavior ensures duration clock tick uniform makes possible use tsc wall clock timer even processor core changes frequency architectural behavior later intel processors amd processors k8 core always incremented time-stamp counter every clock cycle thus power management features able change number increments per second values could get sync different cores processors system windows amd provides utility periodically synchronize counters multiple core cpus since family 10h barcelona/phenom amd chips feature constant tsc driven either hypertransport speed highest p state cpuid bit codice_14 advertises operating system may provide methods use n't use codice_1 instruction time keeping administrator control example versions linux kernel seccomp sandboxing mode disables codice_1 also disabled using codice_17 argument codice_18 system call time stamp counter used time instructions accurately exploited meltdown spectre security vulnerabilities however available counters timers used case arm processors vulnerable type attack processors also registers count cpu clock cycles different names instance avr32 called performance clock counter pccnt register sparc v9 provides codice_19 register armv7 armv8 architectures provide generic counter counts constant frequency powerpc provides 64-bit codice_20 register
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Computer architecture
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checkinstall checkinstall computer program unix-like operating systems eases installation uninstallation software compiled source making use package management systems software compilation automatically generate slackware- rpm- debian-compatible package later cleanly uninstalled appropriate package manager checkinstall monitors installation phase normal software build process notes files added system builds package contains files using additional information gathered user finally files installed original run removed package installed using system package tools package properly registered local installed packages database primary benefits provided checkinstall versus simply running codice_1 ability remove package system using system packaging tools ability install resulting package multiple machines checkinstall sometimes cited mechanism creating packages open source projects lieu creating numerous platform-specific build packages checkinstall usually used running configure script codice_2 follows entering information author package description get folder generated package saved
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Operating systems
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symantec endpoint protection symantec endpoint protection developed symantec security software suite consists anti-malware intrusion prevention firewall features server desktop computers largest market-share product endpoint security first release symantec endpoint protection published september 2007 called version 11.0 endpoint protection result merger several security software products including symantec antivirus corporate edition 10.0 client security network access control sygate enterprise edition endpoint protection also included new features example block data transfers unauthorized device types usb flash drives bluetooth devices time symantec antivirus corporate edition widely criticized become bloated unwieldy endpoint protection 11.0 intended address criticisms disk footprint symantec corporate edition 10.0 almost 100 mb whereas endpoint protection projected 21 mb 2009 symantec introduced managed service whereby symantec staff deploy manage symantec endpoint protection installations remotely small business edition faster installation process released 2010 february 2011 symantec announced version 12.0 endpoint protection version 12 incorporated cloud-based database malicious files called symantec insight insight intended combat malware generates mutations files avoid detection signature-based anti-malware software late 2012 symantec released version 12.1.2 supports vmware vshield cloud version endpoint protection released september 2016 followed version 14 november version 14 incorporates machine learning technology find patterns digital data may indicative presence cyber-security threat also incorporates memory exploit mitigation performance improvements symantec endpoint protection security software suite includes intrusion prevention firewall anti-malware features according sc magazine endpoint protection also features typical data loss prevention software typically installed server running windows linux macos 2018 version 14 currently-supported release endpoint protection scans computers security threats used prevent unapproved programs running apply firewall policies block allow network traffic attempts identify block malicious traffic corporate network coming web browser uses aggregate information users identify malicious software 2016 symantec claims use data 175 million devices installed endpoint security 175 countries endpoint protection administrative console allows department modify security policies department programs files exclude antivirus scans manage mobile devices directly treats peripherals connected computer protects computer malicious software mobile device early 2012 source code symantec endpoint protection stolen published online hacker group called lords dharmaraja claimed credit alleging source code stolen indian military intelligence indian government requires vendors submit source code computer program sold government ensure used espionage july 2012 update endpoint protection caused compatibility issues triggering blue screen death windows xp machines running certain third-party file system drivers 2014 offensive security discovered exploit symantec endpoint protection penetration test financial services organization exploit application device control driver allowed logged-in user get system access patched august according gartner symantec endpoint protection 14 one comprehensive endpoint security products available regularly scores well independent tests however common criticism customers fatigued near constant changes product company direction sc magazine said enpoint protection 14 comprehensive tool type superb installation documentation review said endpoint protection no-brainer setup administration wart support fees bit steep forrester said version 12.1 complete endpoint security software product market different security functions software well-integrated report speculated lack integration would addressed version 14 network world ranked symantec endpoint protection sixth endpoint security products based data nss labs testing
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Computer security
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atari basic atari basic interpreter basic programming language shipped atari 8-bit family 6502-based home computers unlike basics home computer era atari basic derivative microsoft basic differs significant ways includes keywords atari-specific features lacks support string arrays example language originally 8 kb rom cartridge first machines 8-bit series 400 800 1200xl starting 600xl 800xl basic built-in machines disabled holding codice_1 key booting xegs disables basic powered without keyboard attached complete annotated source code design specifications atari basic published atari basic source book 1983 machines would become atari 8-bit family originally developed second-generation video game consoles intended replace atari 2600 ray kassar new president atari decided challenge apple computer building home computer instead meant designs among changes needed support basic programming language standard language home computers 1978 atari purchased source code mos 6502 version microsoft 8k basic original 8k basic referred memory footprint compiled intel 8080 instruction set lower code density 6502 expanded code 9 kb slightly larger natural 8 kb size atari rom cartridges atari felt also needed expand language add better support specific hardware features computers similar apple done applesoft basic increased size 9 kb around 11 kb paring code 11 8 kb fit rom turned significant problem adding problem fact 6502 code supplied microsoft undocumented six months later almost ready shippable version interpreter however atari facing january 1979 deadline consumer electronics show ces machines would demonstrated decided ask help get version basic ready time show september 1978 shepardson microsystems bid completing basic shepardson written number programs apple ii family used 6502 processor middle finishing new basic cromemco s-100 bus machines cromemco 32k structured basic shepardson examined existing work decided difficult continue cutting size instead recommended developing completely new version originally 10k size make fit 8k rom common routines would moved operating system roms atari accepted proposal specifications finalized october 1978 paul laughton kathleen o'brien began work new language contract specified delivery date 6 april 1979 also included file manager system later known dos 1.0 atari plans take early 8k version microsoft basic 1979 ces switch new atari basic production development proceeded quickly helped bonus clause contract 8k cartridge available release machines atari took version ces instead ms version atari microsoft basic later became available separate product version shepardson gave atari ces demo supposed final version time delivered demo final delivery weeks later shepardson found several bugs code developed fixes however unknown shepardson atari already sent ces version manufacturing version later known revision among several problems version contains major bug subroutine copies memory deleting lines code exactly 256 bytes long causes lockup sometimes known two-line lockup trigger next line code command entered notorious one problems could fixed pressing key revision b attempted fix major bugs revision released 1983 built-in rom 600xl 800xl models fixing memory copying bug programmer noticed pattern code section inserting lines applied fix fix instead introduced original bug code inserting new lines much common deleting old ones change dramatically increased number crashes another major problem revision b bug added 16 bytes memory program every time codice_2d codice_3ed eventually causing machine run memory even smallest programs mapping atari described awesome bugs advised revision b owners n't fool around get new rom available cartridge atari book provided type-in program patch revision b revision c without cartridge revision c finally eliminated memory leaks revision b version built-in later versions 800xls xe computers xegs revision c also available cartridge production run version determined typing codice_4 ready prompt result codice_5 revision codice_6 revision b codice_7 revision c. atari basic uses line editor like home computer basics unlike basics atari basic scans just-entered program line reports errors immediately error found editor re-displays line highlighting text near error inverse video errors displayed numeric codes descriptions printed manual program lines entered starting line number insert new line amend existing one lines without line number executed immediately programmer types codice_8 program executes lowest line number atari basic allows commands executed modes instance codice_9 command used inside program list statement used display either entire basic program section program lines specifying starting ending line separated comma used output program listing printer program lines logical lines three screen lines physical lines 40 characters 120 characters total cursor moved freely lines unlike basics cursor moved left right editor os handles tracking whether physical line flowed next logical line moving cursor could move within logical lines automatically pressing sends tokenizer logical line cursor sits example pictured codice_10 author needs fix error move cursor codice_11 type editor overwrite mode hit common editing technique say renumbering lines atari basic built-in renumbering command one quickly learn overwrite numbers set lines hit repeatedly put back program atari basic uses token structure handle lexical processing better performance reduced memory size contrast ms-derived basics perform tokenization line-by-line basis program runs atari basic occurs user hits immediate syntax checking described program editing section side effect converting line tokenized form stored shepardson referred early-tokenizing concept pre-compiling interpreter tokenizer converts lines using small buffer memory program stored parse tree token output buffer addressed pointer lomem – 80 81 256 bytes tokenized statement larger buffer generates error 14 – line long output tokenizer moved permanent storage various locations memory set pointers addresses indicates locations variables stored variable name table pointed vntp – 82 83 values stored variable value table pointed vvtp – 86 87 indirecting variable names way reference variable needs two bytes address entry appropriate table strings area pointed starp – 8c 8d runtime stack pointed runstk – 8e 8f used store line numbers looping statements codice_12 subroutines codice_13 finally end basic memory usage indicated address stored memtop – 90 91 pointer atari basic uses unique way recognize abbreviated reserved words keyword abbreviated using period point writing codice_14 expanded codice_9 codice_16 expand abbreviation tokenizer searches list reserved words find first matches portion supplied commonly used commands occur first list reserved words codice_17 beginning typed codice_18 program later codice_9ed always write full words three exceptions codice_20 synonym codice_21 codice_22 synonym codice_23 codice_24 synonym empty string mean thing separate tokens remain program listing keywords communicating peripherals see input/output section codice_25 codice_26 codice_27 actually part tokenized keyword separate symbol example codice_20 codice_29 thing presented differently atari basic includes 12 functions mathematical trigonometric calculations tan function included may derived via exp function deg rad used set whether trigonometric functions use radians degrees radians default rnd function generates number 0 1 parameter function used number derived via pokey random number register address d20a atari basic differs considerably microsoft-style basics way handles strings microsoft basic mostly copied string-handling system dec basic-plus strings first-class types variable bounds allows string variables well arrays strings represented internally computer word pointing storage heap contrast atari basic copied string-handling system hewlett-packard basic basic data type single character strings arrays characters side-effect design true string arrays string variable must dimensioned used example program 20 character string reserved characters excess string length truncated maximum possible length string atari basic 32,768 characters ms basic included function accessing bits strings instance codice_30 would return leftmost 10 characters codice_31 atari basic string represented array access using array indexing functions equivalent statement atari basic would codice_32 note arrays 1-indexed 0-indexed modern variations slicing syntax two-dimensional arrays basics way define work arrays strings atari basic initialize array variables string array may contain whatever random data present memory allocated following trick allows fast string initialization also useful clearing large areas memory unwanted garbage numeric arrays cleared slow ... next loop string concatenation atari basic works following example target string must large enough hold combined string error result input statement used prompt array variables latter must filled indirectly via statement like 20 input b 1 =a array variables atari basic also may contain two subscripts strings included data statements enclosed quote marks atari basic result also possible data items contain comma read statement also used array variables arrays base index 0 statement dim 10 actually creates 11-element array elements 0-10 atari os includes subsystem peripheral device input/output i/o known cio central input/output programs written independently device might use conform common interface rare home computers time new device drivers could written fairly easily would automatically available atari basic program using atari os existing drivers could supplanted augmented new ones replacement example could displace one rom provide 80-column display piggyback generate checksum whenever line returned used verify type-in program listing atari basic supports cio access reserved words routines os graphics fill draw available specific basic keywords line drawing supported command providing area fill fill feature used general cio entry point called using basic command basic statement prepares device i/o access means ensure channel 1 free call driver prepare device set cassette tape spools onto tension advance heads keeping cassette tape player paused means read codes write read-and-write third number auxiliary information set 0 needed name device filename filename ignored cassette driver physical devices numbers mainly disks printers serial devices might plotter daisy-wheel printer may one disk drive present 1 assumed lprint statement used output strings printer atari basic include equivalent microsoft basic get inkey commands detect keypress simulated either pokeing keyboard driver directly opening file e.g open 1,4,0 k get 1 although latter wait keypress unlike get inkey typing codice_33 basic exit atari dos command menu unsaved programs lost command display disk directory within basic must done exiting dos dos occupies roughly 5k memory thus cassette-based atari machine 48k greater around 37,000 bytes free basic program memory 32,000 bytes dos present basic use extra ram xl xe machines atari basic built-in support sound via statement graphics joysticks paddles n't supplied command fill arbitrary shape pixels limited operating system function exists called command also commands drawing lines graphics primitives combination plot drawto statements used draw lines dedicated command clearing screen atari basic usually done prints clear screen control code analogous commodore basic atari basic include tab function simulated either pokeing cursor column position 55 tab position c9 default value 10 changed values take effect print statement executed also spc function atari basic advanced aspects hardware player/missile graphics sprites redefined character sets setting color palette/luminance tables scrolling custom graphics modes supported basic require machine language routines peek/poke statements graphics modes accessed basic atari 400/800 os roms support way access machine language setting antic registers display list manually os roms xl/xe added support modes bitmap modes basic normally set text window occupying last three rows bottom screen user may display prompts enter data program 16 added mode number invoked via graphics statement entire screen bitmap mode e.g graphics 8+16 bitmap mode full screen invoked atari basic automatically switch back text mode program execution terminated unlike many basics leave user bitmap mode unreadable screen switched via typing blind command resetting computer bitmap coordinates calculated range 1 maximum row/column minus one thus mode 6 160x192 maximum coordinates pixel 159 191 user goes allowed coordinates mode basic exit error unlike ms-derived basics atari basic allows numeric variables expressions used supply line numbers codice_22 codice_35 commands used clarify code instance subroutine clears screen could written codice_36 much easier understand typical codice_37 particular subroutine executed frequently placing line number variable also improve execution speed faster basic look constant variable instead processing time statement executed basics era allow codice_9 command send source code printer device atari basic also includes codice_39 command reads source code device merges back program user typed allows programs saved sections reading using codice_39 merge replace existing code carefully using blocks line numbers overlap programmers build libraries subroutines merge new programs needed atari basic call machine code subroutines machine code generally stored strings anywhere memory code needs position independent 256-byte page 6 area starting address 1536 600 used basic operating system code loaded page 6 reading codice_41 statements machine code invoked codice_42 function first parameter address machine code routine following values parameters example machine language code stored string named codice_43 called parameters parameters pushed onto hardware stack 16-bit integers order specified codice_42 function low byte high byte order last value pushed stack byte indicating number arguments machine language code must remove values returning via codice_45 instruction value returned basic program placing addresses 212 213 d4 d5 16-bit integer running original hardware atari basic slower home computer basics often large amount two widely used benchmarks era byte magazine sieve eratosthenes creative computing benchmark test written david h. ahl atari much slower apple ii even sinclair zx81 finishing near end list terms performance despite atari cpu running 1.79 mhz twice speed 6502-based computers language slowness stemmed two problems first numeric values basic stored floating-point binary coded decimal bcd format includes numbers integers like line numbers array indexes every time number encountered interpreter convert bcd format internal binary representation using routines operating system floating point math routines atari slow notably bcd binary conversion function affected programs byte benchmark constant conversion array indexes greatly slows program ahl benchmark single exponent operation loops poorly optimized multiplication function responsible much machine poor showing second problem due atari basic implemented loops branches perform branch codice_22 codice_35 interpreter searches entire program matching line number needs atari already slowed need convert numbers binary however serious problem case codice_48 ... codice_49 loop interpreters would push pointer location codice_48 stack reached codice_49 could easily return codice_48 atari basic location memory placed stack line number meant every time codice_49 encountered system search entire program find line loops atari basic program cause large loss performance relative basics several basics atari addressed issues resulting large performance gains basic xl reduced time byte benchmark 194 58 seconds three times fast accomplished caching location codice_54 loops basics cache also used codice_22 codice_35 improvements turbo-basic xl included similar caching well re-written high-performance floating-point library ahl benchmark atari basic required 405 seconds exactly code turbo basic took 41.6 seconds
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Programming language topics
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modem script modem script settings file software programs use communicate modem also known ccl files connection control language files like modem init string modem scripts files provide modem configuration settings modem scripts go beyond init strings providing internal scripting language script authors use tune modem response main use terminal emulators dialers
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Programming language topics
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greenpois0n greenpois0n name shared series ios jailbreaking tools developed chronic dev team sometimes called greenpois0n team use exploits remove software restrictions iphones ipads ipod touches apple tvs greenpois0n initial release october 2010 jailbroke ios 4.1 second version february 2011 jailbroke ios 4.2.1 well ios 4.2.6 cdma iphones second generation tool greenpois0n absinthe developed iphone dev team members jailbroke ios 5.0.1 january 2012 providing first jailbreak iphone 4s second version jailbroke ios 5.1.1 may 2012 providing first jailbreak third generation ipad jailbreaking enables root access ios operating system allowing installation applications customizations unavailable official app store ios jailbreaking voids device warranty apple releases ios updates make jailbreaking difficult october 12 2010 chronic dev team released greenpois0n desktop-based tool jailbreaking ios 4.1 iphone 4 iphone 3gs ipod touch third fourth generation ipad 1 development apple released second generation apple tv greenpois0n developers reported could jailbreak apple tv well developers announced plans release october 10 news spread another jailbreak developer george hotz preparing release jailbreaking tool called limera1n would perform similar function different exploit greenpois0n developers delayed order integrate limera1n exploit supported devices using limera1n also meant original greenpois0n exploit shatter could saved use later jailbreaks shatter limera1n boot rom exploits means patched ios updates boot rom code embedded ios devices manufacturing february 2011 chronic dev team released new version greenpois0n jailbreak ios 4.2.1 jailbreak ios 4.2.6 cdma verizon iphone 4 desktop-based tools os x microsoft windows linux provides untethered jailbreak means jailbroken device rebooted without computer assistance supports ipad iphone ipod touch apple tv chronic dev team announced support newly released cdma iphone 4 devices stores developers chronic dev team iphone dev team released greenpois0n absinthe sometimes simply known absinthe january 2012 desktop-based tool os x microsoft windows linux jailbreak iphone 4s first time ipad 2 second time ios 5.0.1 devices also ios 5.0 iphone 4s absinthe provides untethered jailbreak means jailbroken device rebooted without computer assistance incorporated untether exploit called corona pod2g released december older ios devices next web said jailbreak took long time released venturebeat said absinthe n't easy use earlier jailbreaking tool jailbreakme according iphone dev team approximately one million devices newly jailbroken three days absinthe release developers called joint effort jailbreak dream team apple credited document listing security patches subsequent version ios may 2012 developers chronic dev team iphone dev team released absinthe 2.0 os x windows linux jailbreak ios 5.1.1 untethered iphone ipad ipod touch models support ios 5.1.1 including jailbreaking third generation ipad first time announced hack box security conference amsterdam end presentation earlier absinthe jailbreak initially support recently released model ipad 2 according chronic dev team approximately one million devices jailbroken weekend friday release pc world noted devices jailbroken tools absinthe 2.0 security concern companies bring device policies
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Computer security
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windows nt 6 startup process startup process windows nt 6 windows vista windows server 2008 successors differs startup process part previous versions windows article unless otherwise specified said windows vista also applies later nt operating systems windows vista boot sector uefi loads windows boot manager file named bootmgr either system boot partition accesses boot configuration data store uses information load operating system bcd invokes boot loader turn proceeds initiate windows kernel initialization point proceeds similarly previous windows nt versions windows vista introduces complete overhaul windows operating system loader architecture earliest known reference revised architecture included within powerpoint slides distributed microsoft windows hardware engineering conference 2004 operating system codenamed longhorn documentation mentions windows operating system loader would undergoing significant restructuring order support efi major overhaul legacy code new boot architecture completely replaces ntldr architecture used previous versions windows nt steps follows nt kernel loaded including kernel initialization user-space initialization kept earlier nt systems refactoring winlogon resulted gina completely replaced credential providers graphical components windows vista later boot configuration data bcd firmware-independent database boot-time configuration data used microsoft new windows boot manager replaces boot.ini used ntldr boot configuration data stored data file format windows registry hives eventually mounted registry key hkey_local_machine\bcd00000 restricted permissions uefi boot file located codice_1 efi system partition traditional bios boot file codice_2 active partition boot configuration data may altered using command-line tool bcdedit.exe using registry editor regedit.exe using windows management instrumentation third-party tools easybcd bootice visual bcd editor boot configuration data contain menu entries presented windows boot manager boot.ini contained menu entries presented ntldr menu entries include boot configuration data allows third-party integration anyone implement tools like diagnostics recovery options windows boot manager invokes winload.exe—the operating system boot loader—to load operating system kernel executive ntoskrnl.exe core device drivers respect winload.exe functionally equivalent operating system loader function ntldr prior versions windows nt uefi systems file called codice_3 file always located codice_4 computer recently hibernated codice_5 instead invoke codice_6 difference alternate boot mode splash screen displaying resuming windows uefi systems file called codice_7 always located codice_4 advent new boot manager windows vista many components changed one advanced boot options menu provides options advanced boot modes i.e safe mode due implementation hybrid boot windows 8 access advanced boot options menu disabled default however access still possible bcd modification possible boot modes abo menu accessible rapidly pressing holding codice_11 key windows boots
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Operating systems
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multivalue multivalue type nosql multidimensional database typically considered synonymous pick database originally developed pick operating system multivalue databases include commercial products rocket software zumasys revelation ladybridge intersystems northgate information solutions ongroup companies databases differ relational database features support encourage use attributes take list values rather attributes single-valued often categorized mumps within category post-relational databases although data model actually pre-dates relational model unlike sql-dbms tools multivalue databases accessed without sql nelson designed multivalue data model early mid-1960s dick pick developer trw worked first implementation model us army 1965 pick considered software public domain written military first dispute regarding multivalue databases addressed courts ken simms wrote databasic sometimes known s-basic mid-70 based dartmouth basic enhanced features data management simms played lot star trek developing language order language function satisfaction three implementations multivalue pick version r77 microdata reality 3.x prime information 1.0 similar spite attempts standardize particularly international spectrum spectrum manufacturers association designed logo use standards across multivalue implementations subsequently flavors diverged although cross-over streams multivalue database development could classified one stemming pick r83 one microdata reality one prime information differences implementations provisions supporting several flavors languages attempt document similarities differences found post-relational database reference prdb marketing groups others industry years classified multivalue databases pre-relational post-relational relational embedded detractors often classifying legacy could classified nosql data model aligns well json xml permits access without use sql one reasonable hypothesis data model lasting 50 years new database implementations model even 21st century provides inexpensive database solutions historically industry benchmarks tied sql transactions difficult hypothesis test although considerable anecdotes failed attempts get functionality multivalue application relational database framework spite history 40 years implementations starting trw many multivalue industry remained current various multivalue implementations employ object-oriented versions data/basic support ajax frameworks one needs use sql databases fit nosql umbrella fact multivalue developers first acquire nosql domain names likely prior database products classifying offerings nosql well multivalue seasoned data model several vendors competing multivalue space continuously enhanced years multivalue database system data stored using two separate files file store raw data dictionary store format displaying raw data example assume file table called person file attribute called emailaddress emailaddress field store variable number email address values single record list joe example.com jdb example.net joe_bacde example.org stored accessed via single query accessing associated record achieving one-to-many relationship within traditional relational database system would include creating additional table store variable number email addresses associated single person record however modern relational database systems support multi-value data model example postgresql column array base type like java programming language typical data/basic compiler compiles p-code runs p-machine jbase notable exception many different implementations compilers multivalue databases like php programming language data/basic language typecasting programmer known english access aql uniquery retrieve cmql many names years corresponding different multivalue implementations multivalue query language differs sql several respects query issued single dictionary within schema could understood virtual file portal database view data statement would list e-mail addresses person whose last name starts van single entry would output person multiple lines showing multiple e-mail addresses without repeating data person
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Databases
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usb image usb image — bootable image operating system os software boot loader located usb flash drive another usb device memory storage instead conventional cd dvd discs operating system loads usb device either load much like live cd runs os software storage installs os usb image runs usb device whole time usb image easier carry stored safely conventional cd dvd drawbacks older devices may support usb booting usb storage devices lifespan might shortened ubuntu included utility installing operating system image file usb flash drive since version 9.10 windows support also added step step set usb device bootable drive
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Operating systems
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timothee besset timothée besset french software programmer also known ttimo best known supporting linux well macintosh ports id software products involved game ports various id properties past ten years starting quake iii arena since development doom 3 also charge multiplayer network code various aspects game coding id role heavily involved development online game quakelive occasionally called zerowing never gone name derived community oriented system zerowing.idsoftware.com linux port pages prominent system actually named christian antkow based zero wing meme besset grew france started programming early 1990s school majored computer science well pursuing courses chemistry mechanics fluid mechanics school also first introduced linux originally system administration networking eventually adopting main system first serious game development project working qeradiant free game editor tool id software games work editor got know robert duffy point working contractor id got hired full-time duffy managed secure timothee contract work new cross-platform gtkradiant editor project 2000 eventually led timothee hired become id official linux port maintainer took back support rights linux release quake iii arena floundering loki software first actual porting project came release return castle wolfenstein 2001 linux client released march 16 2002 followed year later release linux builds sharing release date windows release next porting work came release doom 3 releasing first linux builds october 4 2004 around time also assumed responsibility becoming charge network coding id october 20 2005 released linux binaries quake 4 followed releasing source code gtkradiant gnu general public license february 17 2006 next porting project porting linux binaries released october 19 2007 also worked quake live project game entering invitation-based closed beta 2008 open beta february 24 2009 linux macintosh support coming august 18 2009 response fears linux gaming community id would abandon linux future titles september 13 2009 well publicized statement reaffirmed id support linux stating blog fundamentally nothing changed policy regarding linux games ... 'll damned n't find time get linux builds done january 2012 besset resigned id software ending hope future linux builds though doom 3 bfg edition came linux via source port year later john carmack revealed zenimax media n't policy 'unofficial binaries prevented id software pursuing sort third-party builds past linux ports experimental releases suggested use wine instead july 2 2012 announced joined frozen sand currently developing urban terror hd september 2016 ported rocket league steamos/linux help ryan c. gordon
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Operating systems
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sf city id card sf city id card municipal identification card program operated san francisco california residents city-county regardless immigration status cards also specify person gender assist transgender individuals often difficulty identification documents stated purpose photo id card streamline access city programs connect residents local businesses program modeled similar program operating new connecticut since 2007 according sf city id card website users card use cards accepted licenses drive purchase alcohol tobacco recognized federal state law possession cards considered mandatory city government applicants must submit proof identity city residency parents may obtain card minor separate cards children 13 anyone 14 years age older fee ranging 5 15 charged card expiration card occurs every 2 years cardholder turns 14 years age loses residency city limits supervisor tom ammiano said card public safety measure make residents living social margins likely seek help police well giving access banking services city bound law keep names private information confidential “ maximum extent permitted applicable laws ” according city attorney office early months 2007 immigration customs enforcement ice conducted dozens raids us conducted arrest deportation hundreds immigrants one states affected california latin american alliance immigrant rights aliadi bay area based grassroots organization founded miguel robles conformed local leaders like ramon cardona attorney daniel luna miguel perez julio garcia among others organized press conference san francisco city hall request order materialize sanctuary status city county san francisco city officials must issue resident identification card improve interaction community members regardless migratory status police officers well allow san francisco residents access city services open bank accounts aliadi started conversations supervisors chris daly gerardo sandoval tom ammiano supervisor chris daly showed interest political reasons could n't sponsor gerardo sandoval interested chief staff lupita peimbert suggested aliadi ask supervisor tom ammiano showed interest finally supported concept aliadi gathered 40 grassroots organizations non profits saw city id card tool improve life clients members concept adopted san francisco aliadi organized february 16 2008 women building first 3 conferences called cities integrating communities 1st event attended 100 organizers spark launch campaigns support city identification cards richmond santa clara county oakland los angeles detroit chicago minneapolis among others aliadi invited present experiences ordinance authorizing county clerk issue id card passed board supervisors november 20 2007 immigration group washington-based immigration reform law institute filed legal challenge law claiming program conflicts federal law judge dismissed challenge october 14 2008 first cards issued january 15 2009 san francisco thus became one small growing number municipalities issuing municipal identification cards undocumented immigrants access form document
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Computer security
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logical address computing logical address address item memory cell storage element network host appears reside perspective executing application program logical address may different physical address due operation address translator mapping function mapping functions may case computer memory architecture memory management unit mmu cpu memory bus physical address computer memory banks may mapped different logical addresses various purposes system supporting virtual memory may actually physical memory mapped logical address access attempted access triggers special functions operating system reprogram mmu map address physical memory perhaps writing old contents memory disk reading back disk memory contain new logical address case logical address may referred virtual address
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Operating systems
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http response splitting http response splitting form web application vulnerability resulting failure application environment properly sanitize input values used perform cross-site scripting attacks cross-user defacement web cache poisoning similar exploits attack consists making server print carriage return cr ascii 0x0d line feed lf ascii 0x0a sequence followed content supplied attacker header section response typically including input fields sent application per http standard rfc 2616 headers separated one crlf response headers separated body two therefore failure remove crs lfs allows attacker set arbitrary headers take control body break response two separate responses—hence name generic solution url-encode strings inclusion http headers location set-cookie typical examples sanitization include casting integers aggressive regular expression replacement although response splitting specific php php interpreter contains protection attack since version 4.4.2 5.1.2
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Computer security
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browser hijacking browser hijacking form unwanted software modifies web browser settings without user permission inject unwanted advertising user browser browser hijacker may replace existing home page error page search engine generally used force hits particular website increasing advertising revenue browser hijackers also contain spyware example install software keylogger gather information banking e-mail authentication details browser hijackers also damage registry windows systems often permanently browser hijacking easily reversed instances may difficult reverse various software packages exist prevent modification many browser hijacking programs included software bundles user choose included offers installer another program often included uninstall instructions documentation presented way designed confusing average user order trick installing unwanted extra software several methods browser hijackers use gain entry operating system email attachments files downloaded suspicious websites torrents common tactics browser hijackers use rogue security software also hijack start page generally displaying message warning computer infected spyware lead antispyware vendor page start page return normal settings user buys software programs winfixer known hijack user start page redirect another website domain name system queried user types name website e.g wikipedia.org dns returns ip address website exists user mistypes name website dns return non-existent domain nxdomain response 2006 earthlink started redirecting mistyped domain names search page done interpreting error code nxdomain server level announcement led much negative feedback earthlink offered services without feature unwanted programs often include sign installed uninstall opt-out instructions hijacking programs constantly change settings browsers meaning user choices browser overwritten antivirus software identifies browser hijacking software malicious software remove spyware scanning programs browser restore function set user browser settings back normal alert browser page changed malicious browser hijacking programs steal browser cookies person computer order manipulate online accounts logged one company maliciously used google cookies install android apps onto user phone without knowledge consent microsoft windows 10 web browsers longer set user default without intervention changing default web browser must performed manually user settings default apps page ostensibly prevent browser hijacking number hijackers change browser homepage display adverts and/or set default search engine include astromenda www.astromenda.com ask toolbar ask.com esurf esurf.biz binkiland binkiland.com delta claro dregol jamenize mindspark groovorio sweet page search protect conduit along search.conduit.com variants tuvaro spigot en.4yendex.com yahoo etc ask toolbar widely bundled installer oracle java se criticized malware users remember manually deselect toolbar installation java installation especially severe denmark government sponsored digital signature system nemid reality single sign system public servers banks government offices 2015 relied java client side thus computers running microsoft windows denmark vulnerable unwanted ask toolbar installed babylon toolbar browser hijacker change browser homepage set default search engine isearch.babylon.com also form adware displays advertisements sponsored links spurious paid search results program collect search terms search queries babylon translation software prompts add babylon toolbar installation toolbar also comes bundled add-on software downloads 2011 cnet site download.com started bundling babylon toolbar open-source packages nmap gordon lyon developer nmap upset way toolbar tricked onto users using software vice-president download.com sean murphy released apology bundling software mistake part apologize user developer communities unrest caused similar variants babylon toolbar search homepage exist including bueno search delta search claro search search gol variants state owned babylon terms service toolbars created montiera conduit pup hijacker steals personal confidential information user transfers third party toolbar identified potentially unwanted programs pups malwarebytes typically bundled free downloads toolbars modify browser default search engine homepage new tab page several browser settings similar variants conduit search trovi.com trovigo.com better-search.net seekforsearch.com searchitdown.com need4search.com clearsearches.com search-armor.com searchthatup.com premiumsearchweb.com along variants created customized way toolbar creation service conduit ltd used offer program called conduit search protect better known search protect conduit cause severe system errors upon uninstallation claims protect browser settings actually blocks attempts manipulate browser settings page words makes sure malicious settings remain unchanged search protect option change search homepage recommended search home page trovi however users reported changing back trovi period time uninstall program search protect cause windows unbootable uninstall file removes files also boot files root c drive leaves backgroundcontainer.dll file start-up registry conduit associated malware spyware adware victims hijacker reported unwanted pop-ups embedded in-text advertisements sites without ads perion network ltd. acquired conduit clientconnect business early january 2014 later partnered lenovo create lenovo browser guard uses components search protect victims unwanted redirections conduit.com also reported attacked phishing attempts received unwanted email spam junk mail messages telephone calls telemarketers victims claim callers claimed apple microsoft isp told personal information used phone calls calls concerned browsing habits recent browsing history personal information used phishing attempts may associated spyware one first browser hijackers redirected user existing home page rogue coolwebsearch search engine results sponsored links antivirus antispyware programs unable properly remove particular hijacker man named merijn bellekom developed special tool called cwshredder specifically remove kind hijacker coolwebsearch popular browser hijacker owned 'fun web products coupon server adware program bundled multiple freeware applications downloaded internet users program may appear pcs without user knowledge coupon server may appear useful intrusive display ads without users permissions coupon server also considered malicious domain browser hijacker hijack internet browser forcibly lead user homepage disguised legitimate search engine fool visitors using website also direct browser suspicious domain alter browser settings ad-triggering software called gosave reported cause user experience issues intrusive characteristics victim appropriately informed installation ads inserted webpages adds plugin extension whichever web browsers default currently compatible internet explorer firefox chrome name add-on necessarily gosave – varies gs booster gs sustainer something else browser hijacker istartsurf.com may replace preferred search tools infection travels bundled third party applications installation may silent due affected users aware hijacker infected internet explorer google chrome mozilla firefox browsers mixi.dj offers media player also free toolbar conduit-based search engine toolbar add-on prompted add installation toolbar new hijacker alters browser homepage also adds computer registry creates strings memory changes internet explorer icon magnifying glass mystart.incredibar search mystart search incredibar mystart toolbar mystart search incredibar incredibar games-en dangerous internet browser hijacker virus spyware often comes embedded many download applications installers hypercam known install firefox internet explorer safari google chrome symptoms range symptoms simple processor drainage complete system crashes severe victim re-install entire operating system mystart uses browser helper objects case search tools infects users installing mystart search toolbar browser firefox vulnerable redirects internet users mystart ’ websites mystart.incredibar.com particular internet users report redirected every search webpage visit removing incredibar extremely daunting task since countless different variations infected systems expect find undesirable windows registry changes browser configuration changes files random strings installed user local settings folders depending user operating system version even computer location vary one pc next one version incredibar appears removable add-on plug-in extension within web browsers however simply removing incredibar via inbuilt browser add-on removal process enough since program already combined registry file installs re-installs upon system browser reboot virus spyware removal applications webroot spysweeper eset nod32 adwcleaner junkware removal tool known remove mystart.incredibar using applications revert user default search engine onewebsearch referred onewebsearch virus onewebsearch.com redirection virus malware categorized browser hijacker onewebsearch utilizes browser hijackers black-hat techniques infect computer system attach add-ons extensions toolbars popular internet browsers without permission turn causes internet browsers like chrome firefox internet explorer redirect onewebsearch.com search- home- start.onewebsearch.com related web pages third party domain names rockettab browser hijacker runs program browser plugin embeds search results rockettab search providers rockettab sets proxy runs http https traffic known create problems security applications uninstalling application removes proxy targeted ads search results rockettab provides sear4m.xyz categorized browser hijacker alters computer performance adware uses sear4m.xyz cause user click sear4m.xyz ads sear4m.xyz installed changes default dns settings browsers like mozilla firefox google chrome internet explorer often redirect various fake websites often laiden viruses searchassist browser hijacker piggybacks downloads untrusted websites change new tab homepage searchassist.net opens searchassist browser start-up stubborn uninstalled repeatedly change browser tabs homepage settings works firefox safari chrome internet explorer though compatible windows linux detected adwcleaner spyhunter malwarebytes also known slow computer performance cause blue screen death bsod screen causes computer restart viruses came searchassist searchassist unlike vosteran spyware links review sites cnet may recommend searchassist many users rate poorly searchassist claims legitimate search engine great personal results tempting victims hijack making one hardest hijacks recognize image search assist much like genuine google doodle search-daily.com hijacker may downloaded zlob trojan redirects user searches pornography sites also known slow computer performance searchult.com browser hijacker replaces users home page new tab page default search engine program advertised browser add-on supposed help customize tabs protect browsers affected programs searchult.com associated malware distribution website displays banner ad search box often adverts flash games searchgol.com also found search-gol search engine may show infected computer instead user default search engine cause getting onto homepage unknown known downloading malware onto computer replaces default homepage without user permission numerous antivirus websites blogs report searchgol virus potentially unwanted program pup sneaks inside system bundle programs initiates changes system without user permission removing searchgol easy victim must perform browser restore removing programs related downloaded browser hijacker searchnu.com domain domain search-results.com belong iac search media inc company known name ask jeeves inc lot popular domains web famous ask.com something searched searchnu search engine search results redirect ask.com related websites user still access google either entering address bar searching searchnu still homepage searchnu 3 clones searchnu.com/406 /409 /421 however removing searchnu easy following instructions shorte.st browser hijacker alters users ’ web browser settings without permission adware function injecting unwanted advertising users ’ browser detail shorte.st enter device modifies internet settings start tracking users internet activities cookies browser histories shares information third parties users ip address web page visits time users spend browser hijackers break devices several ways manual removal shorte.st work cases device may malfunction removal done correctly however removing shorte.st easy automatic following instructions snap.do smartbar developed resoft potential malware categorized browser hijacker spyware causes internet browsers redirect snap.do search engine snap.do manually downloaded resoft website though many users entrapped unethical terms affects windows removed add/remove program menu snap.do also download many malicious toolbars add-ons plug-ins like dvdvideosofttb general crawler save valet general crawler installed snap.do known use backdoor process re-installs re-enables every time affected user removes browser snap.do disable option change homepage default search engine resoft track following information using resoft products user consents personal data transferred processed within outside united states america using resoft website user agrees preceding uses information way resoft previous installer sourceforge included adware pup installers one particular one changes browser settings firefox chrome internet explorer show website istartsurf.com homepage changing registry settings installing software resets settings user tries change june 1 2015 sourceforge claimed stopped coupling third party offers unmaintained sourceforge projects taplika browser hijacker contains trojan viruses steals personal information user sends third party encrypt personal files folders well emails photographs video documents etc infects system user may lose data affected system could cause possible hardware damage tv wizard injekt internet toolbar/plugin internet explorer runs bho chrome firefox run extension plugs user default web browser modify number settings taking control browser search home pages new tab functionality well dns 'not found redirections additionally tv wizard change security settings browser might also lower overall security user pc done order allow program run uninterrupted user attempt uninstall tv wizard using standard methods add/remove programs parts program uninstalled items modified search home pages may still point unwanted web page privacy policy program states program track report behaviors user plugin installed including limited urls web pages user visits well search terms search results user queries vosteran browser hijacker changes browser home page default search provider vosteran.com infection essentially bundled third-party applications vosteran carries pup virus identity vosteran protected privacyprotect.org australia vosteran registered whiteknight suptab pup hijacker installation adds search toolbars redirects home page another link displays unwanted ads program bundled installation random freeware shareware programs may remain unseen security programs like legitimate software found installing cheat engine different version vlc player www.oldapps.com downloading applications certain freeware sites softonic.com download.com trovi uses bing legitimate search engine provide results user address bar changes bing.com searching n't fooled still searching trovi trovi used use website show search results logo top left hand corner page later switched bing attempt fool users little easier trovi deadly used taking ads search results depending browser using still considered browser hijacker also hijacks homepage new tab page settings change back original settings depending browser using might see ads page infects makes browser redirect google search engines trovi.com trovi created using conduit toolbar creation service known infect similar ways conduit toolbar
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Computer security
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remote job entry remote job entry procedure sending requests data processing tasks 'jobs mainframe computers remote workstations extension process receiving output tasks remote workstation rje workstation called remote usually located distance host computer workstation connects host modem local area network lan today known client–server model rje early form request–response architecture terms remote batch remote job system remote job processing also used rje facilities remote job entry rje also name os/360 component provided rje services rje workstation operator may complete console control job flow workstation mainframe depending local configuration policy conversational remote job entry crje component os/360 os/vs1 provides job submission job retrieval editing user interactive terminal netrjs protocol developed campus computing network ucla deliver batch jobs ibm 360 model 91 protocol originally assigned arpanet initial connection protocol sockets 71 73 75 later reassigned internet ports 71-74
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Internet protocols
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usage analysis usage analysis technique understanding usage statistics something example web statistics website
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Web technology
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smarterphone smarterphone norwegian company making software mobile phones founded 1993 kvaleberg renamed december 2010 june 2007 venture capital investor ferd invested €2 million company january 2010 €3.6 million invested nokia completed acquisition smarterphone november 2011 head office oslo norway company also offices taiwan south korea japan united states smarterphone develops mobile software handsets mobile phone oems odms chipset vendors customers company also provides professional services areas 2008 kvaleberg company joined limo foundation 2009 mobile world congress presented madrid handset cooperation compal communications company main product smarterphone os platform-independent full mobile phone operating system applications suite feature phone segment smarterphone os called mimiria first unveiled mobile world congress show february 2008 used handsets kyocera c4700 vibo t588 madrid limo device smarterphone architecture clean-room strict model-view-controller design enables variations implemented little effort user interface smarterphone os programmed scripting language variant scheme object-oriented extensions smarterphone os includes user interface mmi software stack implementing full user interface middleware 2g 3g feature phones also integrates range third-party modules java jvm oracle corporation mobile browser obigo mms sms stack mobile messaging factory predictive text input nuance cootek handwriting recognition sinovoice nokia asha platform inherits capabilities smarterphone
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Operating systems
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ibm thinkpad 240 ibm thinkpad 240 ultra-portable laptop computer designed produced ibm june 1999 2001 one thinkpad 200 series models made available america smallest lightest thinkpad model produced date 240 series discontinued well 570 series replaced thinkpad x series 2000 first 240 series models included 300 mhz mobile celeron processor 64 mb built-in ram one slot memory expansion maximum 320 mb laptop also one first feature mini pci card slot built-in optical drive diskette drive included due size limitations external drive access via usb 1.0 port and/or ibm external floppy drive connector unit shipped either standard 6 gb hard disk drive 12 gb upgrade option 240 series models feature 10.4 tft display first models featured neomagic magicgraph128xd graphics chips 2 mb video memory 240 capable displaying svga 800x600 tft display xga output available external monitor 240s also audio controllers vga ports connect external display devices
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Computer architecture
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shadow paging computer science shadow paging technique providing atomicity durability two acid properties database systems page context refers unit physical storage probably hard disk typically order 1 64 kib shadow paging copy-on-write technique avoiding in-place updates pages instead page modified shadow page allocated since shadow page references pages disk modified liberally without concern consistency constraints etc page ready become durable pages referred original updated refer new replacement page instead page activated ready atomic referring pages must also updated via shadow paging procedure may recurse many times becoming quite costly one solution employed wafl file system write anywhere file layout lazy making pages durable i.e write-behind caching increases performance significantly avoiding many writes hotspots high referential hierarchy e.g file system superblock cost high commit latency write-ahead logging popular solution uses in-place updates shadow paging similar old master–new master batch processing technique used mainframe database systems systems output batch run possibly day work written two separate disks form storage medium one kept backup used starting point next day work shadow paging also similar purely functional data structures in-place updates avoided
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Computer file systems
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emergency power system emergency power system independent source electrical power supports important electrical systems loss normal power supply standby power system may include standby generator batteries apparatus emergency power systems installed protect life property consequences loss primary electric power supply type continual power system find uses wide variety settings homes hospitals scientific laboratories data centers telecommunication equipment ships emergency power systems rely generators deep-cycle batteries flywheel energy storage fuel cells emergency power systems used early world war ii naval ships combat ship may lose function boilers power steam turbines ship generator case one diesel engines used drive back-up generators early transfer switches relied manual operation two switches would placed horizontally line position facing rod placed order operate switch one source must turned rod moved side source turned mains power lost due downed lines malfunctions sub-station inclement weather planned blackouts extreme cases grid-wide failure modern buildings emergency power systems still based generators usually generators diesel engine driven although smaller buildings may use gasoline engine driven generator larger ones gas turbine however lately use made deep cycle batteries technologies flywheel energy storage fuel cells latter systems produce polluting gases thereby allowing placement done within building also second advantage require separate shed built fuel storage regular generators automatic transfer switch used connect emergency power one side connected normal power feed emergency power feed side connected load designated emergency electricity comes normal side transfer switch uses solenoid throw triple pole single throw switch switches feed normal emergency power loss normal power also triggers battery operated starter system start generator similar using car battery start engine transfer switch switched generator starts building emergency power comes back going normal power lost unlike emergency lights emergency lighting type light fixture pattern building normal lights provides path lights allow safe exit lights service areas mechanical rooms electric rooms exit signs fire alarm systems back batteries electric motor pumps fire sprinklers almost always emergency power equipment emergency power may include smoke isolation dampers smoke evacuation fans elevators handicap doors outlets service areas hospitals use emergency power outlets power life support systems monitoring equipment buildings may even use emergency power part normal operations theater using power show equipment show must go use emergency power systems aviation either aircraft ground commercial military aircraft critical maintain power essential systems emergency done via ram air turbines battery emergency power supplies enables pilots maintain radio contact continue navigate using mfd gps vor receiver directional gyro hour localizer glideslope instrument landing aids microwave transmitters high power consumers mission-critical reliably operated battery supply even short periods hence absolute reliability required category 3 operations force airport usual run system diesel generator automatic switchover mains supply generator fail avoids interruption transmission generator brought operating speed opposed typical view emergency power systems backup generators seen secondary mains electrical supply computers communication networks modern electronic devices need power also steady flow continue operate source voltage drops significantly drops completely devices fail even power loss fraction second even generator back-up provide protection start-up time involved achieve comprehensive loss protection extra equipment surge protectors inverters sometimes complete uninterruptible power supply ups used ups systems local one device one power outlet may extend building-wide local ups small box fits desk telecom rack powers small number devices building-wide ups may take several different forms depending application directly feeds system outlets designated ups feed power large number devices since telephone exchanges use dc building battery room generally wired directly consuming equipment floats continuously output rectifiers normally supply dc rectified utility power utility power fails battery carries load without needing switch simple though somewhat expensive system exchanges never lost power moment since 1920s recent years large units utility power station usually designed unit system basis required devices including boiler turbine generator unit power step unit auxiliary transformer solidly connected one unit less common set-up consists two units grouped together one common station auxiliary turbine generator unit attached unit auxiliary transformer connected circuit automatically starting unit auxiliaries supplied power another unit auxiliary transformer station auxiliary transformer period switching first unit transformer next unit designed automatic instantaneous operation times emergency power system needs kick imperative power unit auxiliaries fail station shutdown occurrence known black-out regular units temporarily fail instead shutdowns grid expected remain operational problems occur usually due reverse power relays frequency-operated relays grid lines due severe grid disturbances circumstances emergency station supply must kick avoid damage equipment prevent hazardous situations release hydrogen gas generators local environment emergency power systems called emergency diesel generators edgs required feature nuclear power plants typically installed sets three edg installation designed safety-grade requirements safety systems plant next upcoming generation nuclear power plants includes designs multiple independent banks edgs abwrs 208 vac emergency supply system central battery system automatic controls located power station building used avoid long electric supply wires central battery system consists lead-acid battery cell units make 12 24 vdc system well stand-by cells battery charging unit also needed voltage sensing unit capable receiving 208 vac automatic system able signal activate emergency supply circuit case failure 208 vac station supply
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Computer security
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exerion exerion ported msx family computer sg-1000 two sequels released exerion features parallax effects inertia simulation player shoots formations bizarre alien amoeba egg-throwing birds pterosaur-like creatures well ufos flying surface planet player two types guns slow double shot unlimited fast single shot limited family computer version game included compilation jaleco collection vol 1 playstation 2003 well game boy advance game jajamaru jr. denshoki jaleco memorial along five jaleco family computer games original arcade version later released playstation 4 part arcade archives label october 23 2014 japan july 7 2015 north america two sequels game released exerion ii zorni released msx 1984 alongside port original arcade game second exerizer released arcades 1987 released north america nichibutsu title sky fox player ship fighter ex playable character jaleco game tengoku series
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Computer architecture
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pda optional packages j2me platform pda optional packages j2me platform jsr 75 specification standardizes access java embedded devices mobile phones pdas data resides natively mobile devices jsr 75 part java framework sits top cldc set lower level programming interfaces 2 main components devices claim implement jsr 75 implement components
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Programming language topics
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dark data dark data data acquired various computer network operations used manner derive insights decision making ability organisation collect data exceed throughput analyse data cases organisation may even aware data collected ibm estimate roughly 90 percent data generated sensors analog-to-digital conversions never get used industrial context dark data include information gathered sensors telematics organizations retain dark data multitude reasons estimated companies analyzing 1 data often stored regulatory compliance record keeping organizations believe dark data could useful future acquired better analytic business intelligence technology process information storage inexpensive storing data easy however storing securing data usually entails greater expenses even risk potential return profit lot dark data unstructured means information formats may difficult categorise read computer thus analysed often reason business analyse dark data amount resources would take difficulty data analysed according computer weekly 60 organisations believe business intelligence reporting capability inadequate 65 say somewhat disorganised content management approaches useful data may become dark data becomes irrelevant processed fast enough called perishable insights live flowing data example geolocation customer known business business make offer based location however data processed immediately may irrelevant future according ibm 60 percent data loses value immediately analysing data immediately letting go 'dark lead significant losses organisation terms identifying fraud example fast enough addressing issue late according new york times 90 energy used data centres wasted data stored energy costs could saved furthermore costs associated underutilisation information thus missed opportunities according datamation storage environments emea organizations consist 54 percent dark data 32 percent redundant obsolete trivial data 14 percent business-critical data 2020 add 891 billion storage management costs otherwise avoided continuous storage dark data put organisation risk especially data sensitive case breach result serious repercussions financial legal seriously hurt organisation reputation example breach private records customers could result stealing sensitive information could result identity theft another example could breach company sensitive information example relating research development risks mitigated assessing auditing whether data useful organisation employing strong encryption security finally determined discarded discarded way becomes unretrievable generally considered advanced computing systems analysis data built higher value dark data noted data analytics foundation modern industrial revolution course includes data currently considered dark data since enough resources process data collected used future bring maximum productivity ability organisations meet consumers demand technology advancements helping leverage dark data affordably thanks young innovative companies datumize veritas lucidworks furthermore many organisations realise value dark data right example healthcare education organisations deal large amounts data could create significant potential service students patients manner consumer financial services pursue target population
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Databases
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eruby eruby embedded ruby templating system embeds ruby text document often used embed ruby code html document similar asp jsp php server-side scripting languages templating system eruby combines ruby code plain text provide flow control variable substitution thus making easy maintain view module rails responsible display response output browser simplest form view piece html code static content applications static content may enough many rails applications require dynamic content created controller action method displayed view made possible using embedded ruby generate templates contain dynamic content embedded ruby allows ruby code embedded view document code gets replaced proper value resulted execution code run time ability embed code view document risk bridging clear separation present mvc frame thus responsibility developer make sure clear separation responsibility among model view controller modules his/her application eruby allows ruby code embedded within pair codice_1 codice_2 delimiters embedded code blocks evaluated in-place replaced result evaluation apart creating web pages eruby also used create xml documents rss feeds forms structured text files eruby dynamically generates static files based templates functionalities eruby found erb library different types tag markers used erb templates indicates tag encloses expression tag starts opening tag delimiter followed equal symbol ends end tag delimiter rendering template piece code gets substituted result code evaluated result string gets converted string rendered example resulting text looks like value x 500 code enclosed tags called scriptlet code tag gets executed result gets replaced place scriptlet tags must matching tag denote end functional block example example text list item gets printed four times scriptlet produces text makes enclosed statement run multiple times output code contents comment tags n't get rendered output tags start open tag delimiter followed hash symbol end end tag delimiter example comment tag shown comment ruby ruby code ignored generates nothing things common eruby simply common ruby string substitution codice_3 similar languages perl php newlines eruby suppressed adding hyphen beginning end tag delimiter example 2.times end output code value name gets printed twice line several implementations eruby namely erb implementation eruby written purely ruby programming language included ruby standard library template generated running piece code written using erb object simple example shown require 'erb' x 400 simple_template value x x renderer erb.new simple_template puts output renderer.result binding result looks follows value x 400 could achieved using code make use erb object x 400 string value x x puts string code snippets generate output happens interchange lines 2 line 3 first code snippet line 1 line 2 second code snippet first snippet changes code shown require 'erb' simple_template value x x x 400 renderer erb.new simple_template puts output renderer.result binding still generates output i.e. value x 400 second code snippet changes code string value x x x 400 puts string code get executed 1st line know value x gets executed thus main reason using erb object write templates ahead time binding variables methods may exist given time template gets processed result called erb object order get access instance methods instance variable object erb makes use binding object access variables methods object given private binding object exists ruby class easy get access methods variables within method class access variables different class class expose binding object via public method example shown class erbexample end example erbexample.new variable1 renderer erb.new template puts output renderer.result example.get_binding see example exposing binding object class erbexample furthermore used binding object access variables methods class within one methods new method erb object takes two parameters second parameter specifies safety level giving number second parameter max value 4 one make template run different thread value number determines safety level maximum isolation level unless binding object marked trusted erb use third parameter specify optional modifiers used control adding newlines output example make sure erb output newlines tag ends create erb object shown renderer erb.new template 3 provide third parameter ignore second parameter use 0 input second parameter erb many methods exposed used render template full list apis exposed erb object refer erb documentation given reference section already explained previous sections erb used generate templates often used generate web pages text files usually needs erb push output desired file achieve use redirection ability provided command-line redirect output file rather making print standard output example output gets redirected my_view.html.erb file linking third party libraries achievable making use -r option providing name library remember functionality one remember ruby key word require functionality -r option example uses ipaddr library mentioned safety levels previous section one specify safety level command line argument using -s option erubis implementation eruby implemented ruby also java according home page runs faster eruby erb several useful options including alternate tags allowing valid xml ember pure ruby implementation eruby linux allows debugging eruby templates improves composability provides powerful shorthand eruby directives table compares tags available implementations
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Web technology
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heinz rutishauser heinz rutishauser 30 january 1918 – 10 november 1970 swiss mathematician pioneer modern numerical mathematics computer science heinz rutishauser father died 13 years old mother died three years later together younger brother sister went live uncle home 1936 rutishauser studied mathematics eth zürich graduated 1942 1942 1945 assistant walter saxer eth 1945 1948 mathematics teacher glarisegg trogen 1948 received phd eth well-received thesis complex analysis 1948 1949 rutishauser united states universities harvard princeton order study state art computing 1949 1955 research associate institute applied mathematics eth zürich recently founded eduard stiefel worked together ambros speiser development first swiss computer ermeth developed programming language superplan 1949–1951 name reference rechenplan i.e computation plan konrad zuse terminology designating single plankalkül-program contributed particular field compiler pioneering work eventually involved defining programming languages algol 58 algol 60 among contributions introduced number basic syntactic features programming notably keyword codice_1 loop first german für superplan next via english translation algol 58 1951 rutishauser became lecturer german privatdozent 1955 appointed extraordinary professor 1962 associate professor applied mathematics eth 1968 became head group computer science later became computer science institute ultimately 1981 division computer science eth zürich least since 1950s rutishauser suffered heart problems 1964 suffered heart attack recovered died 10 november 1970 office acute heart failure untimely death wife margaret took care publication posthumous works
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Programming language topics
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andrew d. gordon andrew d. gordon british computer scientist employed microsoft research research interests include programming language design formal methods concurrency cryptography access control gordon earned ph.d. university cambridge 1992 1997 gordon research fellow university cambridge computer laboratory joined microsoft research laboratory cambridge england principal researcher programming principles tools group also holds professorship university edinburgh gordon one designers concurrent haskell functional programming language explicit primitives concurrency co-designer martin abadi spi calculus extension π-calculus formalized reasoning cryptographic systems luca cardelli invented ambient calculus reasoning mobile code moritz y. becker cédric fournet gordon also designed secpal microsoft specification language access control policies gordon ph.d. thesis functional programming input/output 1993 distinguished dissertation award british computer society 2000 paper ambient calculus subject luca cardelli anytime anywhere modal logics mobile ambients 2010 sigplan influential popl paper award
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Programming language topics
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instruction-level parallelism instruction-level parallelism ilp measure many instructions computer program executed simultaneously two approaches instruction level parallelism hardware level works upon dynamic parallelism whereas software level works static parallelism dynamic parallelism means processor decides run time instructions execute parallel whereas static parallelism means compiler decides instructions execute parallel pentium processor works dynamic sequence parallel execution itanium processor works static level parallelism consider following program operation 3 depends results operations 1 2 calculated completed however operations 1 2 depend operation calculated simultaneously assume operation completed one unit time three instructions completed total two units time giving ilp 3/2 goal compiler processor designers identify take advantage much ilp possible ordinary programs typically written sequential execution model instructions execute one order specified programmer ilp allows compiler processor overlap execution multiple instructions even change order instructions executed much ilp exists programs application specific certain fields graphics scientific computing amount large however workloads cryptography may exhibit much less parallelism micro-architectural techniques used exploit ilp include known ilp exploited compiler hardware support compiler also provides inherent implicit ilp programs hardware compilation optimization optimization techniques extracting available ilp programs would include scheduling register allocation/renaming memory access optimization dataflow architectures another class architectures ilp explicitly specified recent example see trips architecture recent years ilp techniques used provide performance improvements spite growing disparity processor operating frequencies memory access times early ilp designs ibm system/360 model 91 used ilp techniques overcome limitations imposed relatively small register file presently cache miss penalty main memory costs several hundreds cpu cycles principle possible use ilp tolerate even memory latencies associated resource power dissipation costs disproportionate moreover complexity often latency underlying hardware structures results reduced operating frequency reducing benefits hence aforementioned techniques prove inadequate keep cpu stalling off-chip data instead industry heading towards exploiting higher levels parallelism exploited techniques multiprocessing multithreading
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Computer architecture
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ampere microarchitecture ampere codename graphics processing unit gpu microarchitecture developed nvidia successor turing architecture scheduled release 2020 named french mathematician physicist andré-marie ampère june 2019 samsung electronics announced awarded contract produce ampere 7nm euv finfet process replacing tsmc nvidia partner
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Computer architecture
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hiya company hiya seattle-based company provides caller profile information help consumers identify incoming calls block unwanted ones hiya originally developed caller-id app whitepages largest database contact information americans april 2016 hiya spun whitepages april 2016 hiya app 25 million downloads whitepages founder alex algard stepped parent company focus leading hiya april 2016 employs 40 february 2016 hiya time part whitepages reached deal samsung integrate caller profile spam protection services galaxy s7 galaxy s7 edge phones 16 countries.the company extended partnership samsung separate deal august 2016 include service galaxy note 7 expand partnership total 28 countries august 2016 hiya launched hiya cloud network level caller id call-blocking offering offering limited version app iphones hiya announced september 2016 full version app would available ios 10 soon hiya began providing spam protection services phones call protect product 2017 hiya entered similar partnership zte provide call spam protection services axon 7 users october 2017 hiya announced received first outside funding series 18 million led balderton capital participation nautilus venture partners lumia capital hiya said would use funds expand globally following investment balderton ’ lars fjeldsoe-nielsen early executive uber dropbox joined hiya ’ board hiya database 1.5 billion phone numbers draws identify source incoming calls helps users make decision whether want pick call unknown number service automatically block calls numbers deemed associated fraud notifies user blocked call cases app let call go notify user number suspected spam users report numbers associated unwanted calls app well block future calls certain phone numbers
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Computer security
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monitoring service monitoring service maas one many cloud computing delivery models anything service xaas framework facilitates deployment monitoring functionalities various services applications within cloud common application maas online state monitoring continuously tracks certain states applications networks systems instances element may deployable within cloud
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Distributed computing architecture
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.net core .net core free open-source managed computer software framework windows linux macos operating systems open source cross platform successor .net framework project primarily developed microsoft released mit license 1.0 announced november 12 2014 released june 27 2016 along microsoft visual studio 2015 update 3 enables .net core development 1.0.4 .net core 1.1.1 released along .net core tools 1.0 visual studio 2017 march 7 2017 .net core 2.0 released august 14 2017 along visual studio 2017 15.3 asp.net core 2.0 entity framework core 2.0 2.1 released may 30 2018 .net core 2.2 released december 4 2018 .net core 3 announced may 7 2019 microsoft build currently preview builds available official release planned september 2019 .net core 3 framework get support development desktop application software artificial intelligence/machine learning iot apps next release .net core 3.0 .net 5 .net framework deprecated .net 5 .net going forwardhence removal core branding skipping version 4 avoid confusion .net framework 4.x .net core fully supports c f partially supports visual basic .net currently vb.net compiles runs .net core separate visual basic runtime implemented microsoft announced .net core 3 would include visual basic runtime c++/cli yet supported although support planned windows supports four cross-platform scenarios asp.net core web apps command-line apps libraries universal windows platform apps prior .net core 3.0 implement windows forms windows presentation foundation wpf render standard gui desktop software windows however .net core 3 supports desktop technologies winforms wpf universal windows platform uwp supports use nuget packages unlike .net framework serviced using windows update relies package manager receive updates similar .net framework implements common language infrastructure cli via common language runtime clr framework class library fcl two main components coreclr corefx respectively cli implementation virtual execution system ves coreclr complete runtime virtual machine managed execution programs includes just-in-time compiler called ryujit also contains corert runtime optimized integrated aot compiled native binaries cli implementation foundational standard libraries corefx shares subset apis however also comes apis part variant library used uwp command-line interface offers execution entry point operating systems provides developer services like compilation package management
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Operating systems
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