计算机导论98291

计算机导论98291

IntroductiontoComputerScience(计算机科学概论)教师：王立斌Email：lbwang@gmail.com\nWHOareU？YouarenamedasCSer！Pleaseletmeknowsthaboutyou.2\nWhoamI？Iamyourguide……And1990:SCNUBA1994:SCNUMA1997:SCNUTA2000:SJTUPH.D2006:SCNUAssociateProf.MajorNetworkSecurityandCrptography3\nThegeneralgoalsofthisCOURSEHowacomputingsystemworkTounderstandtheevolutionofcomputingsystemTobuildablueprintofyourstudyWhatarethecoresubjectsofCS?4\nMoreambitiousgoals……ThinklikeacomputerscientistTrainthecapabilityofABSTRACTION（抽象能力）BuildupaALGORITHMICmind（算法思维）5\nAtleast……Iwilltellyouguyssomefunnystores,ofcourse,aboutCSorCSers…6\nTextbookComputerScienceIlluminated(ThirdEdition)byNellDaleandJohnLewisRequired！！READINGismandatory.7\nGrading40%ClassAssignmentsIncludeaCourseReportBehaviors60%FinalExam8\nCourseStrategyThepresentationwillnotcoverallthetopicsofthebook.DiscussionandQuestionswillbepermittedintheclassroom.READING,READINGandREADING…9\nChapter1\n25ChapterGoalsDescribethelayersofacomputersystemDescribetheconceptofabstractionanditsrelationshiptocomputingDescribethehistoryofcomputerhardwareandsoftwareDescribethechangingroleofthecomputeruserDistinguishbetweensystemsprogrammersandapplicationsprogrammersDistinguishbetweencomputingasatoolandcomputingasadiscipline11\n2Computingsystemsaredynamic!Whatisthedifferencebetweenhardwareandsoftware?ComputingSystems12\n3HardwareThephysicalelementsofacomputingsystem(printer,circuitboards,wires,keyboard…)SoftwareTheprogramsthatprovidetheinstructionsforacomputertoexecuteComputingSystems13\n4CommunicationApplicationOperatingSystemProgrammingHardwareInformationLayersofaComputingSystem14\n5AbstractionAmentalmodelthatremovescomplexdetailsThisisakeyconcept.Abstractionwillreappearthroughoutthetext–besuretounderstandit!Abstraction15\nAlgorithmicmethodAlgorithm（算法）Asetofinstructionsforsolvingaproblemorsub-probleminafiniteamountoftimeusingafiniteamountofdataWhatcanbesolved？Whatcanbeefficientlysolved?Howtodesignthealgorithm?16\nNOTE!Algorithmisthefoundationofcomputerscience.Algorithmsmake“computerscience”beascience!17\n6AbacusAnearlydevicetorecordnumericvaluesBlaisePascalMechanicaldevicetoadd,subtract,divide&multiplyJosephJacquardJacquard’sLoom,thepunchedcardCharlesBabbageAnalyticalEngineEarlyHistoryofComputing18\n7AdaLovelaceFirstProgrammer,theloopAlanTuringTuringMachine,ArtificialIntelligenceTestingHarvardMarkI,ENIAC,UNIVACIEarlycomputerslaunchnewerainmathematics,physics,engineeringandeconomicsEarlyHistoryofComputing19\n8VacuumTubes(真空管)Large,notveryreliable,generatedalotofheatMagneticDrum（磁鼓）Memorydevicethatrotatedunderaread/writeheadCardReadersMagneticTapeDrives（读卡器磁带机）SequentialauxiliarystoragedevicesFirstGenerationHardware(1951-1959)20\n9Transistor（晶体管）Replacedvacuumtube,fast,small,durable,cheapMagneticCores（磁芯）Replacedmagneticdrums,informationavailableinstantlyMagneticDisks（磁盘）Replacedmagnetictape,datacanbeaccesseddirectlySecondGenerationHardware(1959-1965)21\n10IntegratedCircuits（集成电路）Replacedcircuitboards,smaller,cheaper,faster,morereliable.TransistorsNowusedformemoryconstructionTerminalAninput/outputdevicewithakeyboardandscreenThirdGenerationHardware(1965-1971)22\n11Large-scaleIntegration（大规模集成电路）GreatadvancesinchiptechnologyPCs,theCommercialMarket,WorkstationsPersonalComputersweredevelopedasnewcompanieslikeAppleandAtaricameintobeing.Workstationsemerged.FourthGenerationHardware(1971-?)23\n12ParallelComputingComputersrelyoninterconnectedcentralprocessingunitsthatincreaseprocessingspeed.NetworkingWiththeEthernetsmallcomputerscouldbeconnectedandshareresources.AfileserverconnectedPCsinthelate1980s.ARPANETandLANsInternetParallelComputingandNetworking24\n13MachineLanguageComputerprogramswerewritteninbinary(1sand0s)AssemblyLanguages（汇编语言）andtranslatorsProgramswerewritteninartificialprogramminglanguagesandwerethentranslatedintomachinelanguageProgrammerChangesProgrammersdivideintoapplicationprogrammersandsystemsprogrammersFirstGenerationSoftware(1951-1959)25\n14HighLevelLanguagesUseEnglish-likestatementsandmakeprogrammingeasier.Fortran,COBOL,Lispareexamples.High-LevelLanguagesAssemblyLanguageMachineLanguageSecondGenerationSoftware(1959-1965)26\n15ThirdGenerationSoftware(1965-1971)SystemsSoftwareutilityprograms,languagetranslators,andtheoperatingsystem,whichdecideswhichprogramstorunandwhen.SeparationbetweenUsersandHardwareComputerprogrammersbegantowriteprogramstobeusedbypeoplewhodidnotknowhowtoprogram27\n16ApplicationPackageSystemsSoftwareHigh-LevelLanguagesAssemblyLanguageMachineLanguageThirdGenerationSoftware(1965-1971)28\n17StructuredProgrammingPascal,C,C++NewApplicationSoftwareforUsersSpreadsheets,wordprocessors,databasemanagementsystemsFourthGenerationSoftware(1971-1989)29\n18MicrosoftTheWindowsoperatingsystem,andotherMicrosoftapplicationprogramsdominatethemarketObject-OrientedDesignBasedonahierarchyofdataobjects(i.e.Java)WorldWideWebAllowseasyglobalcommunicationthroughtheInternetNewUsersToday’suserneedsnocomputerknowledgeFifthGenerationSoftware(1990-present)30\n20Programmer/UserApplicationsProgrammer(usestools)UserwithNoComputerBackgroundSystemsProgrammer(buildstools)Domain-SpecificProgramsComputingasaTool31\n21ComputingasaDisciplineWhatcanbe(efficiently)automated?FourNecessarySkillsAlgorithmicThinkingRepresentationProgrammingDesign32\nIsComputerScienceamathematical,scientific,orengineeringdiscipline?22Whatdoyouthink?ComputingasaDiscipline33\n23SystemsAreasofComputerScienceAlgorithmsandDataStructuresProgrammingLanguagesArchitectureOperatingSystemsSoftwareMethodologyandEngineeringHuman-ComputerCommunication34\n24ApplicationAreasofComputerScienceNumericalandSymbolicComputationDatabasesandInformationRetrievalArtificialIntelligenceandRoboticsGraphicsOrganizationalInformaticsBioinformatics35\nAssignment(作业)Whatisyourlongtermexpectationofbeingaundergraduatestudentwhosemajoriscomputerscienceorrelateddomain.(ShortessayinEnglish.)ExerciseP.27-P.3136\nRichardHamming’sQuotesThepurposeofcomputingis insight,notnumbers.37