计算机导论课件（北航）chapter 1

Chapter1

ComputersandDigitalBasicsChapterContentsSectionA:AllThingsDigitalSectionB:DigitalDevicesSectionC:DigitalDataRepresentationSectionD:DigitalProcessingSectionE:PasswordSecurityChapter1:ComputersandDigitalBasics2SectionA:AllThingsDigitalChapter1:ComputersandDigitalBasics3TheDigitalRevolutionThedigitalrevolutionisanongoingprocessofsocial,political,andeconomicchangebroughtaboutbydigitaltechnology,suchascomputersandtheInternetThetechnologydrivingthedigitalrevolutionisbasedondigitalelectronicsandtheideathatelectricalsignalscanrepresentdata,suchasnumbers,words,pictures,andmusicChapter1:ComputersandDigitalBasics4TheDigitalRevolutionDigitizationistheprocessofconvertingtext,numbers,sound,photos,andvideointodatathatcanbeprocessedbydigitaldevicesThedigitalrevolutionhasevolvedthroughfourphases,beginningwithbig,expensive,standalonecomputers,andprogressingtotoday’sdigitalworldinwhichsmall,inexpensivedigitaldevicesareeverywhereChapter1:ComputersandDigitalBasics5TheDigitalRevolutionChapter1:ComputersandDigitalBasics6DataProcessingSomehistoriansmarkthe1980sasthebeginningofthedigitalrevolution,butengineersbuiltthefirstdigitalcomputersduringWorldWarIIforbreakingcodesandcalculatingmissiletrajectoriesComputerswereoperatedbytrainedtechniciansBackthen,processingcomponentsforcomputerswerehousedincloset-sizedcabinetsthatdidnotusuallyincludeakeyboardordisplaydeviceChapter1:ComputersandDigitalBasics7DataProcessingDataprocessingisbasedonaninput-processing-outputcycleDatagoesintoacomputer,itisprocessed,andthenitisoutputChapter1:ComputersandDigitalBasics8PersonalComputingThemodelforthesecondphaseofthedigitalrevolution,personalcomputingischaracterizedbysmall,standalonecomputerspoweredbylocalsoftwareLocalsoftwarereferstoanysoftwarethatisinstalledonacomputer’sharddriveChapter1:ComputersandDigitalBasics9PersonalComputingChapter1:ComputersandDigitalBasics10NetworkComputingThethirdphaseofthedigitalrevolutionmaterializedascomputersbecamenetworkedandwhentheInternetwasopenedtopublicuseAcomputernetworkisagroupofcomputerslinkedtogethertosharedataandresourcesTheInternetisaglobalcomputernetworkoriginallydevelopedasamilitaryproject,andwasthenhandedovertotheNationalScienceFoundationforresearchandacademicuseChapter1:ComputersandDigitalBasics11NetworkComputingTheWeb(shortforWorldWideWeb)isacollectionoflinkeddocuments,graphics,andsoundsthatcanbeaccessedovertheInternetDuringtheperiodfrom1995–2010,computingwascharacterizedbytheWeb,e-mail,multiplayergames,musicdownloads,andenormoussoftwareapplications,suchasMicrosoftOffice,Norton’sInternetSecuritySuite,andCorelDigitalStudioChapter1:ComputersandDigitalBasics12CloudComputingLocalapplicationsarebeingeclipsedbycloudcomputing,whichcharacterizesthefourthphaseofthedigitalrevolutionCloudcomputingprovidesaccesstoinformation,applications,communications,andstorageovertheInternetTheexpansionofcloudcomputingisdueinparttoconvergence,aprocessbywhichseveraltechnologieswithdistinctfunctionalitiesevolvetoformasingleproductChapter1:ComputersandDigitalBasics13CloudComputingChapter1:ComputersandDigitalBasics14CloudComputingConvergenceisimportanttothedigitalrevolutionbecauseitcreatedsophisticatedmobiledeviceswhoseownersdemandaccesstothesameservicesavailablefromfull-sizecomputersontheirdesksSocialmediaarecloud-basedapplicationsdesignedforsocialinteractionandconsumer-generatedcontentChapter1:ComputersandDigitalBasics15CloudComputingChapter1:ComputersandDigitalBasics16DigitalSocietyDigitaltechnologiesandcommunicationsnetworksmakeiteasytocrossculturalandgeographicboundariesAnonymousInternetsites,suchasFreenet,andanonymizertoolsthatcloakaperson’sidentity,evenmakeitpossibletoexercisefreedomofspeechinsituationswherereprisalsmightrepressitCitizensoffreesocietieshaveanexpectationofprivacyIntellectualpropertyreferstotheownershipofcertaintypesofinformation,ideas,orrepresentationsChapter1:ComputersandDigitalBasics17DigitalSocietyDigitaltechnologyisanimportantfactoringlobalandnationaleconomies,inadditiontoaffectingtheeconomicstatusofindividualsGlobalizationcanbedefinedastheworldwideeconomicinterdependenceofcountriesthatoccursascross-bordercommerceincreasesandasmoneyflowsmorefreelyamongcountriesSomeindividualsareaffectedbythedigitaldivide,atermthatreferstothegapbetweenpeoplewhohaveaccesstotechnologyandthosewhodonotDigitaltechnologypermeatestheverycoreofmodernlifeChapter1:ComputersandDigitalBasics18TopInnovationsinRecentYears(23ofthe30areinthefieldofIT)InformationTechnologyInformationTechnology(IT)describesanytechnologythathelpstoproduce,manipulate,store,communicate,and/ordisseminateinformationAcomputerisaprogrammable,multiusemachinethatacceptsdata–rawfactsandfigures–andprocesses,ormanipulatesitintoinformationwecanuse.Communicationstechnology,alsocalledtelecommunicationstechnology,consistsofelectromagneticdevicesandsystemsforcommunicatingoverlongdistances.InformationTechnology(IT)=ComputerTechnology+CommunicationsTechnologyThreeDirectionsofComputerDevelopmentsMiniaturizationSpeedAffordabilityThreeDirectionsofCommunicationsDevelopmentConnectivityInteractivityMultimediaComputers&CommunicationsCombineConvergencePortabilityPersonalizationCollaborationCloudcomputing:TheglobalcomputerQuestionComputersandthedigitalrevolutionhavechangedourlivesinmanyfundamentalways.Ifyouwereonthefrontlinesofthedigitalrevolutionwhencomputerswerefirstdevelopedtobreakcodesandcalculatemissiletrajectories,youweremostlikelylivinginwhattimeperiod?A.WorldWarIB.TheRoaringTwentiesC.WorldWarIID.The1960sChapter1:ComputersandDigitalBasics24AnswerCChapter1:ComputersandDigitalBasics25QuestionAccordingtoFigure1-2,AOLandCompuServewerepopularwhen:A.dataprocessingwasthemaindigitaltechnologyB.mostpeoplehaddial-upInternetaccessandused

desktopcomputersC.smartphonesandtabletswereintroducedD.peoplestoppedusingcloudcomputingChapter1:ComputersandDigitalBasics26AnswerBChapter1:ComputersandDig