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1、Lecture2Theinformationlayer:DataandNumberRepresentationsOutlineDataRepresentationDataandInformationDataTypesDigitalDataRepresentationHowToRepresentDifferentTypesofDataNumberRepresentationNumberSystemsConversionBetweenNumberSystemsIntegerRepresentationFloating-point
2、RepresentationOperationsonBitsArithmeticOperationsLogicalOperationsObjectivesDifferentiatebetweendataandinformation.Explainhowtext,images,audioandvideoarerepresentedincomputers.Explaindecimalnotation,binarynotation,hexadecimalnotation,andoctalnotation.Applyconversi
3、onsfromonenumbersystemtoanother.ObjectivesExplainhowintegersarestoredincomputers(sign-and-magnitude,one’scomplement,two’scomplement).ExplainhowtheExcesssystemworks.Explainhowtorepresentafloating-pointnumberincomputers.Applybitoperationssuchasarithmeticoperations,lo
4、gicaloperations,andshiftoperations.Part1DataRepresentationWhat’sdata?Datareferstothesymbolsthatacomputerusestorepresentfacts(suchaspeople,eventsandthings)andideas.What’sinformation?Thewords,numbers,andgraphicsusedasthebasisforhumanactionsanddecisions.Thedifferenceb
5、etweendataandinformation:Databecomesinformationwhenitispresentedinaformatthatpeoplecanunderstandanduse.OverviewDataInformationGraphicsTableDataenteredintoacomputeriscalledinput.Theprocessedinformationarecalledoutput.Thecycleofinput,process,output,andstorageiscalled
6、theinformationprocessingcycle.Overview(con.)DatainformationThecomputerindustryusestheterm “multimedia”todefineinformationthatcontainsnumbers,text,images,audio,andvideo.Thereareseveraltypesofdata.Overview(con.)DataTextNumberImageAudioVideoNote:Question:Howdoyouhandl
7、eallthesedatatypes(text,number,image,audioandvideo)?1234…890….TextSolutionThemostefficientsolutionistouseauniformrepresentationofdata.Alldatatypesfromoutsideacomputeraretransformedintothisuniformrepresentationwhenstoredinacomputerandthentransformedbackwhenleavingth
8、ecomputer.Thisuniversalformatiscalledabitpattern.DigitalDataRepresentationDigitaldeviceworkswithdiscrete,distinctdataordigits,suchas1and0.Analogd
