计算机科学导论-课件1

Unit1IntroductionUnit121-1WhatIsComputerScience?1-2VonNeumannModel1-3ComputerComponents1-4HistoryandDevelopmentTrends1-5FrontiersofComputerTechnology1-6MajorFieldsofComputerScience1-7ReferencesandRecommendedReadings1-8Keyterms1-9Summary1-10PracticeSetOUTLINE21-1WhatIsComputerScience?3Understand

thedefinitionofcomputerscience.Understand

thedevelopmentandthefrontiers

ofcomputertechnology. Afterreadingthischapter,youaresupposedto

beableto:OBJECTIVESMaster

thevonNeumannarchitecture.Understandthreeimportantcomponentsofacomputer:computerhardware,computersoftware,anddata.Understand

thehistoryofcomputers.Understandthemajorfieldsofcomputerscience.3Understandthedefinitionof41-1WhatIsComputerScience?Computerscienceisadisciplinethatinvolvesthetheoreticalfoundationsofcomputationandtheirapplicationsincomputersystems.Itisdifficulttolistacompleterangeofcomputerresearchareasduetotheirrapidpaceofinnovation.Thisdisciplinecontainsmanysub-fields,suchas:databasesystemsartificialintelligencecomputerarchitecturecomputernetworkingandcommunicationparallelcomputation……programmingmethodologyandlanguagesalgorithmanddatastructurecomputationalcomplexitytheorycomputergraphicsoperatingsystemssoftwareengineering41-1WhatIsComputerScience?51-1WhatIsComputerScience?Computerscienceisarelativelyyoungdisciplinethatbeginsinthe1940s.Itspanstheoryandpractice.Itcanbeseenasascienceofproblemsolving.Ithasstrongassociationswithotherdisciplines.Manyproblemsinengineering,science,medicine,agriculture,business,andotherfieldscanbesolvedeffectivelywithcomputers.Thecross-disciplinaryknowledgeisnecessaryinordertofindasolution.51-1WhatIsComputerScience?6 ThevonNeumannmodel【冯•诺依曼模型】isadesignarchitectureforanelectronicdigitalcomputer.Itconsistsofanarithmeticlogicunit【算术逻辑单元】,acontrolunit【控制器】,amemory【内存】,anexternalstorage【外部存储器】,andinput【输入】andoutput【输出】mechanisms(Figure1.1).1-2VonNeumannModel6 ThevonNeumannmodel【冯•诺依曼模7 ComputersbasedontheTuringmachine【图灵机】

storedata【数据】intheirmemory.Around1944–1945,JohnvonNeumannproposedthatprograms【程序】shouldalsobestoredinthememory.

BothdataandprogramsinthevonNeumannmodelhavethesamelogicalformat.Theyarestoredasbinary【二进制】patternsinmemory—asequenceof0sand1s.AprograminthevonNeumannmodelcontainsafinitenumberofinstructions【指令】thatareexecutedsequentially【按顺序执行】.1-2VonNeumannModel7 ComputersbasedontheTurin8

Thebus【总线】isshared【共享】betweentheprogrammemoryanddatamemory,leadingtothevonNeumannbottleneck【瓶颈】.Ithasoftenbeenconsideredanissueduetothelimitedthroughput【吞吐量】betweenthecentralprocessingunit(CPU)【中央处理单元（器）】andmemory,becauseofthesinglebusthatcanonlyaccessoneofthetwoclassesofmemoryatatime.

WhentheCPUisrequiredtoexecuteminimalprocessingonlargeamountsofdata,itisforcedtowaitforneededdatatobetransferredtoorfrommemory,whichseriouslylimitstheprocessingspeed.1-2VonNeumannModel8Thebus【总线】isshared【共享9Acomputingsystemconsistsofhardware【硬件】,software【软件】,anddata【数据】.Computerhardwareisthecollectionofphysicalpartsofacomputer,suchasamonitor【显示器】,agraphiccard【显卡】,aharddiskdrive(HDD)【硬盘驱动器】,asoundcard【声卡】,memory,amotherboard【主板】,amouse【鼠标】,akeyboard【键盘】,andsoon.Computersoftwareisacollectionofcomputerprograms,say,operationsystems,procedures,anddocumentation.Dataarethedistinctinformationwithwhichacomputersystemdeals.1-3ComputerComponents9Acomputingsystemconsistso10Computerhardwarereferstothecomponentsthatyoucan

physicallytouch.Therearemanypartsofcomputerhardwarethatcanbeinstalledinside,orconnectedtotheoutside,ofacomputer.Theexternalhardwareincludesaflat-panel【平板显示器】,aprinter【打印机】,aprojector【投影仪】,ascanner【扫描仪】,aspeaker【扬声器】,akeyboard,amouse,aflashmemory【闪存】,andsoon.TheinternalhardwareincludesCPU,amulti-coreprocessor【多核处理器】,amotherboard,anetworkcard【网卡】,amodem【调制解调器】,asoundcard,avideocard【显卡】,adrive(e.g.Blue-Ray【蓝光】,CD-ROM【只读光盘驱动器】,DVD【数字通用光盘】,floppydrive【软盘驱动器】,harddiskdrive(HDD)【硬盘驱动器】),asolid-statedisk(SSD)【固态硬盘】,andsoon.Computerhardware10Computerhardwarerefersto11Computersoftwareisa

collectionofprogramsthatacomputerexecutes【执行】.Theprogramconsistsofasequenceofinstructions.Eachinstructionoperatesononeormoredataitems.Theseinstructionsmightbeasetofinternalsystemcommands【系统命令】,orresponsestotheexternalinputorrequest.Softwaretellsvarioushardwarecomponentswhattodoandhowtointeractwitheachother.Therearetwomaintypesofsoftwaresets:systemsoftware【系统软件】andapplicationsoftware【应用软件】.Systemsoftwareisusedtorunhardware,whileapplicationsoftwareisusedtocarryoutothertasks.Themainsystemsoftwareincludesoperatingsystems【操作系统】anddrivers【驱动程序】.Themainapplicationsoftwareincludesgames,mediaplayers,wordprocessors,anti-virusprograms【杀毒软件】,andsoon.Softwareisusuallywritteninhigh-levelprogramminglanguages【高级编程语言】,whicharetranslatedintothemachinelanguage【机器语言】byacompiler【编译器】oraninterpreter【解释器】.Softwaremayalsobewritteninalow-levelassemblylanguage【汇编语言】insomededicatedscenarios.Computersoftware11Computersoftwareisacolle12Datacouldbeanysequenceofsymbolshavinggivenmeaningbyspecificactionsofinterpretation【解释】.Indailylife,weusuallyusedigitsthatcantakeoneoftenstates(0to9).However,datastoredinacomputergenerallyuseonlytwostates(0and1).Someformsofdata(text,image,audio,andvideo)cannotbestoredinacomputerdirectly,andneedstobeconvertedintothebinary【二进制】form(0sand1s).Datacanbeorganizedinmanytypesofdatastructures【数据结构】,suchas

arrays【数组】,lists【列表】,graphs【图】,andobjects【对象】.Modernhighperformancedatapersistence【数据持久性】technologiesrelyonmassivelyparalleldistributeddataprocessing【并行分布式数据处理】,suchasApacheHadoop.Insuchsystems,thedataaredistributedacrossmultiplecomputersandcanbeprocessedondifferentcomputersatthesametime.Data12Datacouldbeanysequenceo13Computersciencehasundergonearapiddevelopmentsinceitsbirth.Asthefieldofcomputersciencehasemerged,newdirectionsofresearchandapplicationshavecreatedandcombinedwithclassicaldiscoveriesinacontinuouscycleofgrowthandrevitalization.Lifewithoutacomputerisunimaginable.Thehistoryofcomputerisanattractivestory.Computerswerenotalwaysthebrilliantfastmachinesempoweringustoobtainlotsofknowledge.Actually,thefirstcomputerwasverydifferentfromtherecentcomputers.Generallyspeaking,thehistoryofcomputerscanbedividedintothreeperiods.1-4HistoryandDevelopmentTrends13Computersciencehasundergo14(1)MechanicalmachinesIntheearly17thcentury,aFrenchmathematiciancalledBlaisePascalinventedPascaline,whichisamechanicalcalculator【机械计算器】performingaddition【加法】andsubtraction【减法】.Inthelate17thcentury,GottfriedLeibnitz,aGermanmathematician,inventedLeibnitz’Wheel.Intheearly19thcentury,Joseph-MarieJacquardinventedJacquardloom,whichadoptedtheideaofstorageandprogrammingatthefirsttime.Inthe1820s,CharlesBabbageinventedAnalyticalEngine.In1890,HermanHollerithinventedaprogrammablemachinethatcouldreadandsortdataonpunchedcardsautomatically.Computerhistory14(1)MechanicalmachinesComp15(2)ElectroniccomputersBetween1930and1950,severalscientistscontributedintheevolutionofcomputertechnologywhocouldbeconsideredthetrueearlypioneersofcomputerscience.JohnVincentAtanasoffandhisassistantCliffordBerryinventedtheABC(AtanasoffBerryComputer)tosolveasystemoflinearequations.Itencodedinformationelectrically.Inthe1930s,ahugecomputercalledMarkI,wasbuiltunderthedirectionofHowardAikenatHarvardUniversity.InEngland,AlanTuringinventedacomputercalledColossustobreaktheGermanEnigmacode.In1946,JohnMauchlyandJ.PresperEckertinventedENIAC(ElectronicNumericalIntegratorandCalculator),thefirsttotallyelectroniccomputer【电子计算机】.In1950,EDVAC,thefirstcomputertoimplementthestoredprogramconceptbasedonvonNeumann’sideaswasbuiltattheUniversityofPennsylvania.Computerhistory15(2)ElectroniccomputersCom16(3)Computersafter1950Between1950and1959,computerswerebulkyandutilizedvacuumtubes【电子管】aselectronicswitches.Between1959and1965,transistors【晶体管】replacedvacuumtubes.Thenthesizeandthecostofthetransistorizedcomputersweredramaticallyreduced.From1965to1975,theappearanceoftheintegratedcircuit(IC)【集成电路】furtherreducedthesizeandcostofcomputers.Between1975and1985,microcomputersappeared.TheAltair8800,thefirstdesktopcalculator【台式计算机】,wasinventedin1975.Computerhistory16(3)Computersafter1950Com17(3)Computersafter1950Between1985and1995,someadvancedcomputertechnologyappeared,suchasClusters【集群】,VectorProcessors【向量处理器】,workstations【工作站】,minicomputers【小型计算机】,laptops【笔记本电脑】andpalmtopcomputers【掌上电脑】,andsoon.After1995,high-performancecomputers(HPC)【高性能计算机】obtainedagreatadvancement,suchassupercomputers【超级计算机】,many-cores【多核】

personalcomputers【个人电脑】,general-purposegraphicsprocessingunit(GPGPU)【通用计算图形处理单元（器）】,andsoon.Computerhistory17(3)Computersafter1950Com18Inthefuture,computertechnologywillbecharacterizedbyhighperformance,miniaturization,network,popularization,intelligence,andhumanization.(1)Lightweightmicrocomputer

Thelightweightmicrocomputer【轻量级微型计算机】withsmallsize,lowprice,powerfulfunction,andhighreliabilitywillbepopular.(2)HighperformancecomputerDevelopmentofpowerfulsupercomputerswithhighspeed,highperformance,andcapabilityofprocessinglargeandcomplexproblemsisalsothedefinitetrend.Developmenttrends18Inthefuture,computertech19(1)LightweightmicrocomputerAPocketPC【掌上电脑】isahandhelddevice【手持设备】thatcanbeusedtoprocesse-mail,playgames,exchangemessages,browsetheWeb,andsoon.Alaptopcomputer【笔记本电脑】hasmostofthesamecomponentsintoasingleunitasadesktopcomputer,suchasakeyboard,apointingdevice,adisplay,andspeakers.Laptopcomputershavebecomeincreasinglypopularbecausetheyarebecomingsmaller,lighter,cheaper,andmorepowerful,andtheirscreensarebecomingsmallerandofbetterquality.Developmenttrends19(1)Lightweightmicrocomput20(1)LightweightmicrocomputerAsmartphone【智能手机】isbasedonamobileoperatingsystemsuchasAndroid【安卓】oriOS.Theearlysmartphonesaddedthefunctionsofapersonaldigitalassistant(PDA)【个人数字助理】,aportablemediaplayer,alow-endcompactdigitalcamera,andapocketvideocamera.Manymodernsmartphonesalsocontainhigh-resolutiontouchscreens【触摸屏】,webbrowsers,globalpositioningsystem(GPS)【全球定位系统】

navigation【导航】units,andsoon.AniPadisakindoftabletcomputers【平板电脑】builtonApple'siOSoperatingsystem.Ithasmanyfunctionssuchasvideoplayer,camera,musicplayer,webbrowser,email,game,GPSnavigation,socialservice,etc.Developmenttrends20(1)Lightweightmicrocomput21(2)HighperformancecomputerAparallelcomputer【并行计算机】hasasetofprocessorsthatworksimultaneously【同时运行】.Parallelcomputersusemultiplecomputationalresourcestosolvelargeproblemsthatcanoftenbedividedintosmallerones.Fromsmartphones,tolargesupercomputersandwebsites,tomulti-coreCPUsandGPUs,theparallelprocessingisubiquitousinmoderncomputing.Asupercomputer【超级计算机】hashigh-levelprocessingcapacitythatmakesitpossibletocalculateproblemsatultra-highspeed.Supercomputerscanbeusedforhighlycomputationallyintensivetaskssuchasquantumcomputing【量子计算】,weatherforecasting,climateresearch,oilandgasexploration,etc.Developmenttrends21(2)Highperformancecomput22(2)HighperformancecomputerAgraphicsprocessingunit(GPU)【图形处理单元（器）】isaspecializedelectroniccircuitusedtorapidlyhandlememorytoacceleratetheprocessingofimages.GPUcomputingutilizesaGPUtogetherwithaCPUtoacceleratebusiness,scientificandengineeringapplications.GPU+CPUisapowerfulunionbecauseGPUsconsistofthousandsofsmall,efficientcoresdesignedforparallelcomputing,andCPUsconsistofafewcoresoptimizedforserialcomputing【串行计算】.Thecomputeunifieddevicearchitecture(CUDA)【统一计算设备架构】isaparallelcomputingplatformandanapplicationprogramminginterface(API)【应用程序编程接口】modelinventedbyNVIDIA.TheCUDA-enabledGPUcanbeusedforgeneralpurposecomputing.TheCUDAparallelcomputingplatformprovidesafewsimpleCandC++extensionstoexpressdataandtaskparallelism.Developmenttrends22(2)Highperformancecomput23

Thefrontiersofcomputertechnologyincludesupercomputers,cloudcomputing【云计算】,bigdata【大数据】,InternetofThings【物联网】,mobilecomputing【移动计算】,quantumcomputers【量子计算机】,biocomputers【生物计算机】,virtualization【虚拟化技术】,visualization【可视化技术】，service-orientedarchitecture(SOA)【面向服务的体系结构】,modernartificialintelligence【现代人工智能技术】etc.1-5FrontiersofComputerTechnology23Thefrontiersofcompute24(1)SupercomputerAsupercomputerisacomputerthatperformscalculationatthecurrentlyhighestoperationalrate.Itistypicallyusedforscientificandengineeringapplicationsthatdealwithverylargedatabasesordolargeamountsofcomputation(orboth).Figure1.2showsthatsupercomputinghasincreasinglybecomethecornerstoneofmodernsociety.1-5FrontiersofComputerTechnologyScientificResearchBusinessFinanceNationalandSocialSecuritySocialandPublicServicesInnovationinIndustrySupercomputer24(1)Supercomputer1-5Fronti25(1)SupercomputerSupercomputersplayanimportantroleinthefieldofcomputationalscience.Thestagesofsupercomputerapplicationincludesimulation【仿真】andmodeling【建模】,weatherforecasting,meteorology【气象学】,geologicalexploration【地质勘探】,cryptography【密码学】(encryption【加密】anddecryption【解密】),virtualreality【虚拟现实】,visualization【大规模场景的可视化】,artificialintelligence【人工智能】,nuclearweapons

development

【核武器开发】,precisemissile

guide【精确制导】,long-rangeattack【远程打击】,quantumsimulation【量子模拟】,noveldrugsynthesisanddiscovery【新型药物的合成和发现】,novelmaterialsynthesis【新材料的合成】,spaceexplorations【太空探索】,datamining【数据挖掘】,businessintelligence,etc.Supercomputerscanbeappliedtocalculatethestructuresandpropertiesofchemicalcompounds【化合物】,biologicalmacromolecules【生物大分子】,polymers【聚合物】,andcrystals【晶体】.Highperformancesupercomputersarewidelyemployedinphysicalsimulations,suchassimulationofairplanesinwindtunnels【风洞】,simulationofthedetonation【爆炸】ofnuclearweapons,andresearchintonuclearfusion【核聚变】.1-5FrontiersofComputerTechnology25(1)Supercomputer1-5Fronti26(1)SupercomputerAccordingtothe47theditionoftheTOP500listoftheworld’smostpowerfulsupercomputersannouncedinJune2016,ChinamaintainedhisNo.1position,butwithanewsystembuiltentirelyusingChinadesignedandmadeprocessors.ThenewsystemiscalledSunwayTaihuLight【神威•太湖之光】.ItisthenewNo.1systemwith93petaflop/s(quadrillionsofcalculationspersecond【每秒1千万亿次运算】)ontheLINPACKbenchmark.DevelopedbytheNationalResearchCenterofParallelComputerEngineering&Technology(NRCPC)andinstalledattheNationalSupercomputingCenterinWuxi,SunwayTaihuLightdisplaces

Tianhe-2(Milkyway-2)【天河二号】,anIntel-basedChinesesupercomputerthathasretainedtheNo.1positionwith33.86petaflop/sonthepastsixTOP500lists.Table1.1showsthetop10sitesforJune2016.1-5FrontiersofComputerTechnology26(1)Supercomputer1-5FrontiTable1.1TOP10SitesforJune201627Table1.1TOP10SitesforJu28SunwayTaihuLight,with10,649,600computingcorescomprising40,960nodes,istwiceasfastandthreetimesasefficientasTianhe-2,whichpostedaLINPACKperformanceof33.86petaflop/s.Table1.2showsthetechniquedataofSunwayTaihuLight.Supercomputer28SunwayTaihuLight,with10,629(1)SupercomputerSunwayTaihuLightischaracterizedby4supers,namely,superhighspeed,superhighcapacity,superlargesize,andsuperheavyenergyconsumption(Figure1.3).1-5FrontiersofComputerTechnologysuperheavyenergyconsumption

superlargesizesuperhighcapacitysuperhighspeedSunwayTaihuLight29(1)Supercomputer1-5Fronti30ExponentialgrowthofsupercomputingpowerwasrecordedbytheTOP500list.Figure1.4showstheachievedperformancedevelopmentofsupercomputers.EFlop=1018

.SupercomputerPFlop=1015(Onequadrillion,每秒千万亿次),TFlop=1012(trillion,每秒万亿次)P=PetaT=Tera30Exponentialgrowthofs31

Figure1.5showstheprojectedperformancedevelopmentofsupercomputers.EFlop=1018.SupercomputerPFlop=1015(Onequadrillion,每秒千万亿次),TFlop=1012(trillion,每秒万亿次)P=PetaT=Tera31Figure1.5showsthepr32(1)SupercomputerHowever,ithasbeenfoundbyJapaneseandGermanscientiststhatatotalperformanceof83,000processorsthatrunfor40minutes,isnomorethanjustonepercentofonesecond‘sworthofhumanbrainactivity.So,

thehumanbeingwillnotstoptodevelopfasterandfastersupercomputer.

1-5FrontiersofComputerTechnology32(1)Supercomputer1-5Fronti33(2)CloudcomputingCloudcomputingisamodelforenablingubiquitous,convenient,on-demand【按需所选】networkaccesstoasharedpoolofconfigurablecomputingresources(e.g.,networks,servers,storage,applications,andservices),accordingtotheNIST(NationalInstituteofStandardsandTechnology)definition.Cloudcomputinghasbecomeoneofthemostpowerfulandeconomicalparadigmsintermsoftechnology,architecture,andITservicesforperformingcomplexcomputationsinlarge-scalescientificandbusinessapplications.Agreatnumberoforganizationshavebeenshiftingtocloudcomputingenvironment.Thebenefitsofcloudcomputingincludevirtualizedresources【虚拟化的资源】,elasticity【自由伸缩性】,scalability【可扩展性】,flexibility【灵活性】ofservices,on-demanddeliveryofresources,efficiency,parallelprocessing,costsaving,andalotmore.1-5FrontiersofComputerTechnology33(2)Cloudcomputing1-5Fron34(2)CloudcomputingCloudcomputingisaformofutilitycomputing【效用计算】whereITresourcesaredeliveredonaPay-As-You-Use【使用才支付】basis,justaselectricityischargedbasedonusage.Usingcloudcomputing,largeorganizationscanprocesstheirlarge-scalejobsmorequickly,sinceusinghundredserversperhouroutweighsthebenefitsthanusingoneserverforhundredhours.Incloudcomputing,userscanubiquitouslyrunapplications,andstore/accesstheirdataonanoff-site,location-transparent【位置透明】,centrallymanaged,sharedplatform.Theresourcesprovidedbycloudareusuallyrunonvirtualmachines【虚拟机】paralleledwiththephysicalinfrastructure.Therearemanytypesofpubliccloudcomputing,suchasInfrastructureasaservice(IaaS)【基础设施即服务】,Platformasaservice(PaaS)【平台即服务】,Softwareasaservice(SaaS)【软件即服务】,Dataasaservice(DaaS)【数据即服务】,andsoon.1-5FrontiersofComputerTechnology34(2)Cloudcomputing1-5Fron35(2)CloudcomputingAsupercomputerconsistsofthebestprocessors,rapidmemory,speciallydesignedcomponents,andelaboratecoolingmechanisms,soitisnoteasytoscaleasupercomputer.Onthecontrary,thedistributedcloudcomputingismuchmoreaffordableandscalable.Theprocessingpowerofcloudcomputinggrowsasadditionalservers(withtheirprocessors)areaddedtothenetwork.Ontheotherhand,supercomputershavetheadvantageofsendingdatathroughfastconnections,whilecloudcomputingarchitecturesendsdatathroughslowernetworks.1-5FrontiersofComputerTechnology35(2)Cloudcomputing1-5Fron36(3)BigDataData,structuredorunstructured,producedbyorganizations,InternetofThings(IoT)【物联网】andsocialmediaisgrowingtremendously.Thisfastandsuddengrowthofbigdatarequiresfastdevelopmentofbigdatatechnologiesthroughvirtualizationplatforms.Bigdatareferstothelargeincreaseinthevolumesofdatathatneededadvancedtechnologiesandtechniquestocapture,store,process,distribute,manageandanalyzetheinformation.Thetermsvolume,variety,andvelocitywereinitiallypresentedbyGartnertodescribechallengesofbigdata.GantzandReinselproposedthattheelementsofbigdataarecharacterizedby4Vs,namely,volume【容量大】,variety【种类多】,velocity【要求处理速度快】,andvalue【密度低，但价值高】.1-5FrontiersofComputerTechnology36(3)BigData1-5Frontierso37(3)BigDataVolumereferstothecontinuouslyexpandingmagnitudeofalltypesofdataproducedfromvarioussources,suchasIoT,socialmedia,multimedia,andalotmore.VarietyreferstothevariousstructuresofdatagatheredthroughIoT,socialnetworks,smartdevices,orsensors.Velocityreferstotherateofdatagenerationandspeedofdatatransferandanalysis.Valueisverycrucialcharacteristicofbigdata.Itistheprocessofrapidlydetermininghiddenpatternsorvaluableinformationfromvarioustypesofbigdata.ITorganizationswanttotakeadvantageofcloudcomputingarchitecturetosupportbigdataprojects.Cloudcomputingprovidesenterprisescost-effective,flexibleaccesstobigdata’shugevolumesofinformation.Meanwhilebigdataonthecloudgeneratesplentifulon-demandcomputingresources.Bothcloudcomputingandbigdatatechnologieswillcontinuetoevolveandcongregateinthefuture.1-5FrontiersofComputerTechnology37(3)BigData1-5Frontierso38(4)InternetofThingsTheInternetofThings,orIoT,isanetworkofitems,eachembeddedwithsensors【传感器】,whichareconnectedtotheInternet.IoTisdefinedastheworldwidedynamicglobalautonomousnetworkofinterconnectedphysicalorvirtualthings,devicesorobjectsbasedonstandardnetworkprotocols【网络协议】.IoTreferstoanemergingparadigmconsistingofacontinuumofuniquelyaddressablethingscommunicatingwithoneanothertoformaworldwidedynamicnetwork.Nowadays,manysmartdevices【智能设备】areconnectedtotheInternet;smartbuildingshavemultiplesensorstoprotectthemfromdisastersoraccidentsandtosaveenergy;andsmartdevicessupportvariousfieldsincludinghealthcareservices,business,education,andindustry.Hugevolumesofdataandinformationaregeneratedbythesedevices,whichareconnecteddirectlyorindirectlyviaInternet.1-5FrontiersofComputerTechnology38(4)InternetofThings1-5F39(4)InternetofThingsCloudbasedplatformsandapplicationshelptoconnectobjectsinIoTatanyplaceandatanytime.Therefore,thefrontendtoaccessIoTisthecloud.Cloudprovidestheneededinfrastructure【基础设施】,computationpowers,storageandapplicationstointeractwithsmartdevicesinreal-time.ThehugeamountsofdataproducedfromtheconnectionsofdevicesinIoTcanonlybecaptured,processed,storedandtransformedintovaluableinformationthroughclouds.Cloudsprovidephysicalandvirtualsystems,applicationsandtoolstoefficientlyandintelligentlyprocessandanalyzebigdataandIoT.1-5FrontiersofComputerTechnology39(4)InternetofThings1-5F40(5)MobilecomputingMobilecomputingisatechnologythatallowstransmissionofdata,viaacomputeroranyotherwirelessdevicewithouthavingtobeconnectedtoafixedphysicallink.Mobilecomputinginvolvesmobilecommunication【移动通信】,mobilehardware,andmobilesoftware.Mobilecommunicationissuesincludead-hoc【点对点】andinfrastructurenetworks【基础设施网络】,communicationproperties,protocols【协议】,dataformatsandconcretetechnologies,etc.Hardwareincludesmobiledevicesorcomponents.Mobilesoftwarehandlesthecharacteristicsandrequirementsofmobileapplications.Oneofthemostimportantcharacteristicsofmobilecomputingisportability.Mobilecomputingcanuseacomputingdeviceevenwhenbeingmobileorchanginglocation.1-5FrontiersofComputerTechnology40(5)Mobilecomputing1-5Fro41(6)QuantumcomputerAquantumcomputer【量子计算机】makesdirectuseofquantummechanicalphenomena,suchassuperposition【叠加】andentanglement【纠缠】,toperformcalculations.Quantumcomputersaredifferentfromdigitalcomputersbasedontransistors.Quantumcomputationmakesuseofquantumpropertiestorepresentdataandperformoperationsondata,whiledigitalcomputersrequiredatatobeencodedintobinarydigits.Quantumcomputationusesquantumbits【量子比特（位）】,whichcanbeinsuperpositionsofstates.Quantumcomputershavetheabilitytobeinmultiplestatessimultaneously.Large-scalequantumcomputersmaytheoreticallybeabletosolvecertainproblemsasymptoticallyfasterthananyconventionalcomputerbyusingthebestalgorithms,suchasintegerfactorization【整数分解】usingShor'salgorithm.1-5FrontiersofComputerTechnology41(6)Quantumcomputer1-5Fro42(7)BiocomputerBiocomputers【生物计算机】usebiologicallyderivedmaterials,suchasDNAandproteins【蛋白质】,toperformcomputationalfunctions.Currently,biocomputershavevariousfunctionalcapabilities,suchasoperationsofbinarylogicandmathematicalcalculations.Threetypicaltypesofbiocomputersincludebiochemicalcomputers,biomechanicalcomputers,andbioelectroniccomputers.Inthefuture,biocomputerscanobtainalong-termdevelopmentbytheexpandingnewscienceofnanobiotechnology【纳米生物技术】.

1-5FrontiersofComputerTechnology42(7)Biocomputer1-5