Don'tMakeMeThink第3版英文版文字版全彩色觉得好请留评论DontmakemeThinkRevisitedACommonSenseapproachtoWebUsabilityCopyrighto2014SteveKrugNewriderswww.newniders.comToreporterrorspleasesendanotetoerrata@peachpit.comNewridersisanimprintofpeachpitadivisionofpearsoneducationEditor:ElisabethbayleProjecteditor:NancyDavisProductioneditor:lisabraziealCopyEditorBarbaraFlanaganInteriorDesignandComposition:RomneyLangeIllustrationsbymarkMatchaandMimiHeftFarnhamfontsprovidedbyTheFontbureauInc.(www.fontbureau.comNoticeofRightsAllrightsreservedNopartofthisbookmaybereproducedortransmittedinanyformbyanymeans,electronic,mechanical,photocopying,recording,orotherwise,withoutthepriorwrittenpermissionofthepublisher.Forinformationongettingpermissionforreprintsandexcerpts,contactpermissions@peachpit.comNoticeofliabilityTheinformationinthisbookisdistributedonan"asisbasiswithoutwarranty.whilileeveryprecautionhasbeentakeninthepreparationofthebook,neithertheauthornorPeachpitshallhaveanyliabilitytoanypersonorentitywithrespecttoanylossordamagecausedorallegedtobecauseddirectlyorindirectlybytheinstructionscontainedinthisbookorbythecomputersoftwareandhardwareproductsdescribedinittrademarksItsnotrocketsurgeryisatrademarkofStevekrugManyofthedesignationsusedbymanufacturersandsellerstodistinguishtheirproductsareclaimedastrademarks.Wherethosedesignationsappearinthisbook,andpeachpitwasawareofatrademarkclaim,thedesignationsappearasrequestedbytheownerofthetrademark.allotherproductnamesandservicesidentifiedthroughoutthisbookareusedineditorialfashiononlyandforthebenefitofsuchcompanieswithnointentionofinfringementofthetrademark.Nosuchuse,ortheuseofanytradename,isintendedtoconveyendorsementorotheraffiliationwiththisbookISBN-13:978-0-32196551-6ISBN-10:0-321-96551-5987654321PrintedandboundintheunitedstatesofamericaFirsteditionTomyfather,whoalwayswantedmetowriteabook,Mymother,whoalwaysmademefeellikeIcouldMelanie,whomarriedme-thegreateststrokeofgoodfortuneofmylifeandmyson,Harry,whowillsurelywritebooksmuchbetterthanthisonewheneverhewantstoSecondeditionTomybigbrother,Phil,whowasamenschhiswholelifeThirdeditionToallthepeoplefromallpartsoftheworld--whohavebeensoniceaboutthisbookforfourteenyears.Yourkindwords--inperson,inemail,andinyourblogs-havebeenoneofthegreatjoysofmylifeEspeciallythewomanwhosaiditmadeherlaughsohardthatmilkcameoutheofhernoseContentsPREFACEAboutthiseditionINTRODUCTIONReadmefirstThroatclearinganddisclaimersGUIDINGPRINCIPLESCHAPTER1Dontmakemethink!Krug'sFirstLawofusabilityCHAPTER2HowwereallyusethewebScanning,satisficing,andmuddlingthroughCHAPTER3.BillboardDesign101Designingforscanning,notreadingCHAPTER4.AnimaL,Vegetable,orMineral?WhyuserslikemindlesschoicesCHAPTER5OmitneedlesswordsTheartofnotwritingfortheWebTHINGSYOUNEEDTOGETRIGHTCHAPTER6.StreetsignsandBreadcrumbsDesigningnavigationCHAPTERZTheBigBangTheoryofWebDesignTheimportanceofgettingpeopleoffontherightfootMAKINGSUREYOUGOTTHEMRIGHTCHAPTER8Thefarmerandthecowmanshouldbefriends>Whymostargumentsaboutusabilityareawasteoftime,andhowtoavoidthemChAPTER9.USabilitytestingon10centsadayKeepingtestingsimple--soyoudoenoughofitLARGERCONCERNSANDOUTSIDEINFLUENCESCHAPTER10MObile:It'snotjustacityinAlabamaanymoreWelcometothe21stCentury.YoumayexperienceaslightsenseofvertigoCHAPTER11UsabilityascommoncourtesyWhyyourWebsiteshouldbeamenschCHAPTER12.AccessibilityandyouJustwhenyouthinkyouredone,acatfloatsbywithbutteredtoaststrappedtoitsbackCHAPTER13GuidefortheperplexedMakingusabilityhappenwhereyouliveAcknowledgmentsIndexPreface:aboutthiseditionPeoplecomeandgosoquicklyhere!DOROTHYGALEJUDYGARLAND)INTHEWIZARDOFOZ(1939)Iwrotethefirsteditionofdon'tmakemethinkbackin2000By2002,Ibegantogetafewemailsayearfromreadersasking(verypolitely)ifI'dthoughtaboutupdatingit.Notcomplaining,justtryingtobehelpful."alotoftheexamplesareoutofdate"wastheusualcommentMystandardresponsewastopointoutthatsinceiwroteitrightaroundthetimetheinternetbubbleburstmanyofthesitesiusedasexampleshadalreadydisappearedbythetimeitwaspublishedButIdidn'tthinkthatmadetheexamplesanylessclear.Finally,in2006Ihadastrongpersonalincentivetoupdateit.ButasIrereadittoseewhatIshouldchange,Ijustkeptthinking"Thisisallstilltrue>Ireallycouldn'tfindmuchofanythingthatithoughtshouldbechangedHalfoftheroyaltiesforthebookweregoingtoacompanythatnolongerexisted,anddoinganeweditionmeantanewcontractandtwicetheroyalties-formeIfitwasanewedition,though,somethinghadtobedifferent.SoIaddedthreechaptersthatididn'thavetimetofinishbackin2000,hitthesnoozebutton,andhappilypulledthecoversbackovermyheadforanothersevenyearsSteveKrugACommonSenseApproachtoWebUsabilityFOREWORDBYROGERBLACK2000SteveKrugTHINKACommonSenseApproachtoWebUsabilitySECONDEDITION2006WRitingisreallyhardforme,andI'malwayshappytohaveareasonnottodoit.GivemeagoodoldrootcanaloverwritinganydaySowhynowfinallyanewedition?Tworeasons#1。
Let’sfaceit:It'soldThere'snodoubtaboutitatthispoint:Itfeelsdated.Afterall,it'sthirteenyearsold,whichislikeahundredyearsinInternettime.(See?Nobodyevensaysthingslike"inInternettimeanymoreMostofthewebpagesiusedforexamples,likeSenatorOrrinHatch'scampaignsiteforthe2000electionlookreallyold-fashionednowSitesthesedaystendtolookalotmoresophisticated,asyoumightexpectPRENIDEN'TWWw.\TOCiTheRepublicans:ANewHampshireForumTheDec2DebateThefirstakeahddyeGoPdebyetesThursdayheatsupthepoltcalstylewarsaSenatorHatchfightstokeepsubstancenCampaign2000.EVLLSTORYTheExperiencedCandidateLw警mHatchCampaign2000BeneoiceThatMatters!ClickheretoCONTRIBUTECAMPAIGNNEWSlIVESCONTIRIHIUTORLINTsCOILINKS)LUNTEEILThieRar4每MCICK2cpM(.DisHachPre的d时Ceme,ntP0.00多』LC,UT0403nTERNETANDNTwoRxsaunaSwww.orrinhatch.com1999

英文原版，数字版，非影印版，无水印，有目录，第三版。
HowcanyoubringoutMySQL’sfullpower?WithHighPerformanceMySQL,you’lllearnadvancedtechniquesforeverythingfromdesigningschemas,indexes,andqueriestotuningyourMySQLserver,operatingsystem,andhardwaretotheirfullestpotential.Thisguidealsoteachesyousafeandpracticalwaystoscaleapplicationsthroughreplication,loadbalancing,highavailability,andfailover.UpdatedtoreflectrecentadvancesinMySQLandInnoDBperformance,features,andtools,thisthirdeditionnotonlyoffersspecificexamplesofhowMySQLworks,italsoteachesyouwhythissystemworksasitdoes,withillustrativestoriesandcasestudiesthatdemonstrateMySQL’sprinciplesinaction.Withthisbook,you’lllearnhowtothinkinMySQL.LearntheeffectsofnewfeaturesinMySQL5.5,includingstoredprocedures,partitioneddatabases,triggers,andviewsImplementimprovementsinreplication,highavailability,andclusteringAchievehighperformancewhenrunningMySQLinthecloudOptimizeadvancedqueryingfeatures,suchasfull-textsearchesTakeadvantageofmodernmulti-coreCPUsandsolid-statedisksExplorebackupandrecoverystrategies—includingnewtoolsforhotonlinebackups

DifferentialEquationsandLinearAlgebra(4th)英文无水印原版pdf第4版pdf所有页面使用FoxitReader、PDF-XChangeViewer、SumatraPDF和Firefox测试都可以打开本资源转载自网络，如有侵权，请联系上传者或csdn删除查看此书详细信息请在美国亚马逊官网搜索此书EditorialDirector,Mathematics:ChristinehoagEditor-in-Chief:DeirdreLynchAcquisitionsEditor:WilliamHoffmaProjectTeamLead:ChristinaleProjectmanager:LaurenMorseEditorialAssistant:JenniferSnyderProgramTeamLead:KarenwernholmProgramManagerDaniellesimbajonCoverandillustrationDesign:StudioMontageProgramDesignLead:BethPaquinProductMarketingManagerClaireKozarProductMarketingCoordiator:BrookesmithFieldMarketingManager:EvanStCyrSeniorAuthorSupport/TechnologySpecialist:JoevetereSeniorProcurementSpecialist:CarolMelvilleInteriorDesign,ProductionManagement,AnswerArt,andCompositioneNergizerAptara,LtdCoverImage:LighttrailsonmodernbuildingbackgroundinShanghai,China-hxdyl/123RFCopyrightO2017,2011,2005PearsonEducation,Inc.oritsaffiliates.AllRightsReserved.PrintedintheUnitedStatesofAmerica.Thispublicationisprotectedbycopyright,andpermissionshouldbeobtainedfromthepublisherpriortoanyprohibitedreproduction,storageinaretrievalsystem,ortransmissioninanyformorbyanymeans,electronic,mechanical,photocopyingrecording,orotherwise.Forinformationregardingpermissions,requestformsandtheappropriatecontactswithinthePearsonEducationGlobalRights&Permissionsdepartmentpleasevisitwww.pearsoned.com/permissions/PEARSONandALWAYSLEARNINGareexclusivetrademarksintheU.s.and/orothercountriesownedbyPearsonEducation,Inc.oritsaffiliatesUnlessotherwiseindicatedherein,anythird-partytrademarksthatmayappearinthisworkarethepropertyoftheirrespectiveowandanyreferencestothird-partytrademarks,logosorothertradedressarefordemonstrativeordescriptivepurposesonly.SuchofsuchmarksoranyrelationshipbetweentheownerandPearsonEducation,Inc.oritsaffiliates,authors,licenseesordistributortreferencesarenotintendedtoimplyanysponsorship,endorsement,authorization,orpromotionofPearsonsproductsbytheownersLibraryofCongressCataloging-in-PublicationDataGoode.StephenwDifferentialequationsandlinearalgebra/StephenW.GoodeandScottA.AnninCaliforniastateUniversity,Fullerton.-4theditionpagescmIncludesindexISBN978-0-321-96467-0—ISBN0-32196467-51.Differentialequations.2.Algebras,Linear.I.Annin,Scott.II.TitleQA371.G6442015515’.35-dc23201400601512345678910V031-1918171615PEARSONISBN10:0-321-96467-5www.pearsonhighered.comISBN13:978-0-321-96467-0ContentsPrefacevii1First-OrderDifferentialEquations1.1DifferentialEquationsEverywhere11.2BasicIdeasandTerminology131.3TheGeometryofFirst-OrderDifferentialEquations231.4SeparableDifferentialEquations341.5SomeSimplePopulationModels451.6First-OrderLinearDifferentialEquations531.7ModelingProblemsUsingFirst-OrderLinearDifferentialEquations61.8Changeofvariables711.9ExactDifferentialEquations821.10Numericalsolutiontofirst-OrderDifferentialEquations931.11SomeHigher-OrderDifferentialEquations1011.12ChapterReview1062MatricesandSystemsofLinearEquations1142.1Matrices:Definitionsandnotation1152.2MatrixAlgebra1222.3TerminologyforSystemsofLinearEquations13824R。
w-EchelonMatricesandElementaryR。
wOperations1462.5Gaussianelimination1562.6TheInverseofasquarematrix1682.7ElementaryMatricesandtheLUFactorization1792.8TheInvertiblematrixtheoremi1882.9ChapterReview1903Determinants1963.1TheDefinitionofthedeterminant1963.2PropertiesofDeterminants2093.3CofactorExpansions2223.4SummaryofDeterminants2353.5ChapterReview242iyContents4VectorSpaces2464.1Vectorsinrn2484.2DefinitionofaVectorSpace2524.3Subspaces2634.4SpanningSets2744.5LinearDependenceandLinearIndependence2844.6Basesanddimension2984.7Changeofbasis3114.8RowSpaceandColumnSpace3194.9TheRank-NullityTheorem3254.10InvertibleMatrixTheoremll3314.11ChapterReview3325InnerProductSpaces3395.1DefinitionofanInnerproductspace3405.2OrthogonalSetsofvectorsandorthogonalProjections3525.3Thegram-Schmidtprocess3625.4LeastSquaresApproximation3665.5ChapterReview3766LinearTransformations3796.1Definitionofalineartransformation3806.2Transformationsofr23916.3TheKernelandrangeofalineartransformation3976.4AdditionalPropertiesofLinearTransformations4076.5Thematrixofalineartransformation4196.6Chaiterreview4287EigenvaluesandEigenvectors4337.1TheEigenvalue/EigenvectorProblem4347.2GeneralResultsforEigenvaluesandEigenvectors4467.3Diagonalization4547.4AnIntroductiontotheMatrixExponentialFunction4627.5OrthogonalDiagonalizationandQuadraticforms4667.6Jordancanonicalforms4757.7Chapterreview4888LinearDifferentialEquationsofOrdern4938.1GeneralTheoryforLinearDifferentialEquations4958.2ConstantCoefficientHomogeneousLinearDifferentialEquations5058.3ThemethodofundeterminedcoefficientsAnnihilators5158.4Complex-ValuedTrialSolutions5268.5OscillationsofaMechanicalSystem529Contentsv8.6RLCCircuits5428.7TheVariationofparametersmethod5478.8ADifferentialEquationwithNonconstantCoefficients5578.9Reductionoforder5688.10ChapterReview5739SystemsofDifferentialEquations5809.1First-OrderLinearSystems5829.2VectorFormulation5889.3GeneralResultsforfirst-OrderLinearDifferentialystems5939.4VectorDifferentialEquations:NondefectiveCoefficientMatrix5999.5VectorDifferentialEquations:DefectiveCoefficientMatrix6089.6Variation-of-ParametersforLinearSystems6209.7SomeApplicationsofLinearSystemsofDifferentialEquations6259.8MatrixExponentialFunctionandSystemsofDifferentialEquations6359.9ThePhasePlaneforLinearAutonomousSystems6439.10NonlinearSystems6559.11ChapterReview66310TheLaplaceTransformandSomeElementaryApplications67010.1DefinitionoftheLaplaceTransform67010.2TheExistenceofthelaplacetransformandtheInversetransform67610.3PeriodicFunctionsandtheLaplacetransform68210.4ThetransformofderivativesandsolutionofInitial-Valueproblems68510.5TheFirstShiftingTheorem69010.6TheUnitStepFunction69510.7TheSecondShiftingTheorem69910.8ImpulsiveDrivingTerms:TheDiracDeltaFunction70610.9TheConvolutionIntegral71110.10ChapterReview71711SeriesSolutionstoLinearDifferentiaEquations72211.1AReviewofpowerseries72311.2SeriesSolutionsaboutanOrdinaryPoint73111.3TheLegendreEquation74111.4SeriesSolutionsaboutaRegularSingularPoint75011.5Frobeniustheory75911.6Bessel'sEquationofOrderp77311.7Chapterreview785ViContentsAReviewofComplexNumbers791BReviewofPartialFractions797CReviewofIntegrationTechniques804DLinearlyIndependentSolutionstox2y+xp(x)y+g(x)y=0811Answerstoodd-NumberedExercises814Index849S.W.GoodededicatesthisbooktomeganandtobiS.A.annindedicatesthisbooktoarthurandJuliannthebestparentsanyonecouldaskforPretraceLikethefirstthreeeditionsofDifferentialEquationsandLinearalgebra,thisfourtheditionisintendedforasophomorelevelcoursethatcoversmaterialinbothdifferentialequationsandlinearalgebra.Inwritingthistextwehaveendeavoredtodevelopthestudentsappreciationforthepowerofthegeneralvectorspaceframeworkinformulatingandsolvinglinearproblems.Thematerialisaccessibletoscienceandengineeringstu-dentswhohavecompletedthreesemestersofcalculusandwhobringthematurityofthatsuccesswiththemtothiscourseThistextiswrittenaswewouldnaturallyteachblendinganabundanceofexamplesandillustrations,butnotattheexpenseofadeliberateandrigoroustreatment.MostresultsareprovenindetailHowever,manyofthesecanbeskippedinfavorofamoreproblem-solvingorientedapproachdependingonthereader'sobjectives.Somereadersmayliketoincorporatesomeformoftechnology(computeralgebrasystem(CAS)orgraphingcalculator)andthereareseveralinstancesinthetextwherethepoweroftechnologyisillustratedusingtheCasMaple.Furthermore,manyexercisesetshaveproblemsthatrequiresomeformoftechnologyfortheirsolutionTheseproblemsaredesignatedwithaoIndevelopingthefourtheditionwehaveoncemorekeptmaximumflexibilityofthematerialinmind.Insodoing,thetextcaneffectivelyaccommodatethedifferentemphasesthatcanbeplacedinacombineddifferentialequationsandlinearalgebracourse,thevaryingbackgroundsofstudentswhoenrollinthistypeofcourse,andthefactthatdifferentinstitutionshavedifferentcreditvaluesforsuchacourse.Thewholetextcanbecoveredinafivecredit-hourcourse.Forcourseswithalowercredit-hourvalue,someselectivitywillhavetobeexercised.Forexample,much(orall)ofChapterImaybeomittedsincemoststudentswillhaveseenmanyofthesedifferentialequationstopicsinanearliercalculuscourse,andtheremainderofthetextdoesnotdependonthetechniquesintroducedinthischapter.Alternatively,whileoneofthemajorgoalsofthetextistointerweavethematerialondifferentialequationswiththetoolsfromlinearalgebrainasymbioticrelationshipasmuchaspossible,thecorematerialonlinearalgebraisgiveninChapters2-7sothatitispossibletousethisbookforacoursethatfocusessolelyonthelinearalgebrapresentedinthesesixchapters.ThematerialondifferentialequationsiscontainedprimarilyinChapters1and8-1l,andreaderswhohavealreadytakenafirstcourseinlinearalgebracanchoosetoproceeddirectlytothesechaptersThereareothermeansofeliminatingsectionstoreducetheamountofmaterialtobecoveredinacourse.Section2.7containsmaterialthatisnotrequiredelsewhereinthetext,Chapter3canbecondensedtoasinglesection(Section3.4)forreadersneedingonlyacursoryoverviewofdeterminants,andSections4.7,5.4,andthelatersectionsofChapters6and7couldallbereservedforasecondcourseinlinearalgebra.InChapter8Sections8.4,8.8,and8.9canbeomitted,and,dependingonthegoalsofthecourse,Sections8.5and8.6couldeitherbede-emphasizedoromittedcompletelySimilarremarksapplytoSections9.7-9.10.AtCaliforniaStateUniversity,Fullertonwehaveafourcredit-hourcourseforsophomoresthatisbasedaroundthematerialinChapters1-9viiiPrefaceMajorChangesintheFourthEditionSeveralsectionsofthetexthavebeenmodifiedtoimprovetheclarityofthepresentationandtoprovidenewexamplesthatreflectinsightfulillustrationswehaveusedinourowncoursesatCaliforniaStateUniversity,Fullerton.OthersignificantchangeswithinthetextarelistedbeleOW1.ThechapteronvectorspacesinthepreviouseditionhasbeensplitintotwochaptersChapters4and5)inthepresentedition,inordertofocusseparateattentiononvectorspacesandinnerproductspaces.Theshorterlengthofthesetwochaptersisalsointendedtomakeeachofthemlessdaunting2.Thechapteroninnerproductspaces(Chapter5)includesanewsectionprovidinganapplicationoflinearalgebratothesubjectofleastsquaresapproximation3.Thechapteronlineartransformationsinthepreviouseditionhasbeensplitintotwochapters(Chapters6and7)inthepresentedition.Chapter6isfocusedonlineartransformations,whileChapter7placesdirectemphasisonthetheoryofeigenvaluesandeigenvectors.Oncemore,readersshouldfindtheshorterchapterscoveringthesetopicsmoreapproachableandfocused4.Mostexercisesetshavebeenenlargedorrearranged.Over3,000problemsarenowcontainedwithinthetext,andmorethan600concept-orientedtrue/falseitemsarealsoincludedinthetext5.Everychapterofthebookincludesoneormoreoptionalprojectsthatallowformorein-depthstudyandapplicationofthetopicsfoundinthetext6.ThebackofthebooknowincludestheanswertoeveryTrue-FalsereviewitemcontainedinthetextAcknowledgmentsWewouldliketoacknowledgethethoughtfulinputfromthefollowingreviewersofthefourthedition:JameyBassofCityCollegeofSanFrancisco,TamarFriedmannofUniversityofrochester,andlinghaiZhangofLehighUniversityAlloftheircommentswereconsideredcarefullyinthepreparationofthetextS.A.Annin:Ioncemorethankmyparents,ArthurandJuliannAnnin,fortheirloveandencouragementinallofmyprofessionalendeavors.Ialsogratefullyacknowledgethemanystudentswhohavetakenthiscoursewithmeovertheyearsand,insodoinghaveenhancedmyloveforthesetopicsanddeeplyenrichedmycareerasaprofessorFirst-OrderDifferentiaEquations1.1DifferentialEquationsEverywhereadifferentialequationisanyequationthatinvolvesoneormorederivativesofanunknownfunction.Forexample(1.1.1dxds(S-1)(1.1.2)aredifferentialequations.Inthedifferentialequation(1.1.1)theunknownfunctionordependentvariableisy,andxistheindependentvariable;inthedifferentialequation(1.1.2)thedependentandindependentvariablesareSandt,respectively.Differentialequationssuchas(1.1.1)and(1.1.)inwhichtheunknownfunctiondependsonlyonasingleindependentvariablearecalledordinarydifferentialequations.Bycontrast,thedifferentialequationLaplace'sequation)0involvespartialderivativesoftheunknownfunctionu(x,y)oftwoindependentvariablesxandy.SuchdifferentialequationsarecalledpartialdifferentialequationsOnewayinwhichdifferentialequationscanbecharacterizedisbytheorderofthehighestderivativethatoccursinthedifferentialequationThisnumberiscalledtheorderofthedifferentialequation.Thus,(l1.1)hasordertwo,whereas(1.1.2)isafirst-orderdifferentialequation1

Deeplearningdoesn'thavetobeintimidating.Untilrecently,thismachine-learningmethodrequiredyearsofstudy,butwithframeworkssuchasKerasandTensorflow,softwareengineerswithoutabackgroundinmachinelearningcanquicklyenterthefield.Withtherecipesinthiscookbook,you'lllearnhowtosolvedeep-learningproblemsforclassifyingandgeneratingtext,images,andmusic.Eachchapterconsistsofseveralrecipesneededtocompleteasingleproject,suchastrainingamusicrecommendingsystem.AuthorDouweOsingaalsoprovidesachapterwithhalfadozentechniquestohelpyouifyou'restuck.ExamplesarewritteninPythonwithcodeavailableonGitHubasasetofPythonnotebooks.You'lllearnhowto:CreateapplicationsthatwillserverealusersUsewordembeddingstocalculatetextsimilarityBuildamovierecommendersystembasedonWikipedialinksLearnhowAIsseetheworldbyvisualizingtheirinternalstateBuildamodeltosuggestemojisforpiecesoftextReusepretrainednetworkstobuildaninverseimagesearchserviceComparehowGANs,autoencodersandLSTMsgenerateiconsDetectmusicstylesandindexsongcollections

由中国建筑科学研究院出版的美国开发的DOE-2，建筑节能软件使用手册

在Linux系统的/etc目录下有这样一个文件passwd，该文件里包含系统中所有用户信息的记录，记录里包含每个用户的如下信息：用户名、密码、用户ID、组ID、用户全名、用户主目录和用户登录所用的shell。
请设计一个脚本（shell）程序能实现增加、删除、查找和显示特定用户信息的功能。
你们可以通过创建一些UNIX/LINUXshell脚本文件来满足以上需求。
　　可以用任意一个文本编辑器打开passwd文件，该文件里包含用冒号分隔开的字段组成的记录，如下所示：　　root:x:0:0:root:/root:/bin/bash　　zxj:x:500:500:zxj303:/home/zxj:/bin/bash　　.　　.　　.　　在主Shell脚本文件里（必须以menu命名）要有一个多操作选项的菜单以便用户从中选择。
在不同任务的中，这些操作能自动实现以下功能：在屏幕上显示当前所有用户的记录在屏幕上显示当前所有用户（经过格式化和排序的）的记录只在屏幕上显示用户名和用户ID只在屏幕上显示（经过格式化和排序的）用户名和用户ID查询并显示特定用户的记录往passwd文件里增加新的用户记录从passwd文件里删除某个用户记录　　你可以使用UNIX/LINUX中一些比较简单的命令或命令组合来执行1、2、3、4、5的任务。
对于任务6和7，你需要编写单独的Shell脚本文件（必须分别命名为add和delete）并且在你的主脚本menu文件中调用这些脚本文件。
　　可能你还需要查询一些Unix/Linux命令，比如awk,、sort、tr、cut、paste、sed、grep；
你也可能还需要查询其他的Unix/Linux命令。
　　建议你在主目录下建立一个以xxxxxx（xxxxxx为学号）命名的目录，并且在本次作业中使用它作为工作目录。
主脚本文件中的菜单　　在menu脚本文件里将创建如下菜单，菜单里包含供用户选择的一些操作。
用户信息主菜单打印当前所有记录打印当前所有记录（格式化后的）打印用户名和用户ID打印（格式化了的）用户名和用户ID查询特定记录增加新记录删除记录Q——退出你的选择是：（等待用户输入）　　当用户做了选择且所选的操作完成之后，应再次显示主菜单以供用户做下一步选择。
你必须用while循环和case条件语句配合来完成此操作。
另外在显示主菜单前必须先清除用户屏幕。
在以下所有步骤中，当显示主菜单前都需要先清屏。
　　在menu脚本文件的前面部分你首先要定义三个变量，这三个变量分别存放passwd、add、delete文件的文件名，并且能在所有涉及到passwd、add、delete文件的语句中使用他们。
比如，可以定义成：　　　　　　　　　　record_file=passwd　　在所有访问passwd文件的语句中，只要使用$record_file即可。
这样做的一个优点就是，如果以后你需要重新命名记录或者需要在不同的记录文件中使用你的脚本的话，你只需要修改以上一个语句而不须在所有有关的记录文件里逐一修改语句。
如下定义另外两个变量：　　add_file=add　　delete_file=delete　　定义以上变量之后，你必须核对menu脚本文件，看看所需的文件（passwd、add、delete）是否准确存放在当前目录下。
如果其中任何一个不存在，你的脚本menu文件就必须显示以下信息，然后退出：　　RequiredfiletheMissingFiledoesnotexist.（所需文件不存在）　　比如，如果passwd文件不存在，就显示“Requiredfilepasswddoesnotexist.（所需文件记录不存在）”然后退出。
　　在以上等待用户做出选择的菜单中，如果用户偶尔输入了一个代码而不是1、2、3、4、5、6、7或Q，就有信息提示“无效的代码，请按回车键继续``````”（务必保证光标停留在此信息行末尾而不是在下一行的开始处）。
等用户按了回车键之后，再次显示主菜单供用户做其他选择。
可以允许用户使用Q或q退出。
　　在以上等待用户做出选择的菜单中，如果用户简单地按了回车键（而不是输代码）的话，就会出现信息“Selectionnotentered.PressEntertocontinue…"（务必保证光标停留在此信息行末尾而不是在下一行的开始处）。
等用户按了回车键之后，再次显示主菜单供用户做其他选择。
　　当用户选择了第一项——打印当前所有用户记录　　以下是当用户在主菜单中选择第一个选项后，menu脚本文件

清晰彩色Whenmostpeoplehear“MachineLearning,”theypicturearobot:adependablebutleroradeadlyTerminatordependingonwhoyouask.ButMachineLearningisnotjustafuturisticfantasy,it’salreadyhere.Infact,ithasbeenaroundfordecadesinsomespecializedapplications,suchasOpticalCharacterRecognition(OCR).ButthefirstMLapplicationthatreallybecamemainstream,improvingthelivesofhundredsofmillionsofpeople,tookovertheworldbackinthe1990s:itwasthespamfilter.Notexactlyaself-awareSkynet,butitdoestechnicallyqualifyasMachineLearning(ithasactuallylearnedsowellthatyouseldomneedtoflaganemailasspamanymore).ItwasfollowedbyhundredsofMLapplicationsthatnowquietlypowerhundredsofproductsandfeaturesthatyouuseregularly,frombetterrecommendationstovoicesearch.

IstartedthisbookwiththeintentionofbringinganewsideofSugarCRMtolight.SinceIbeganworkingatSugarCRM,Isawtheflexibilityandextensibilitythattheapplicationcouldprovide.Ilookedbackonmypreviouspositiondevelopinginternalbusinessapplications,andsawthatmanyofthefeaturesIaddedanddesignissuesIwouldwrestlewithwereproblemsthatSugarCRMhadalreadysolved.TheengineeringteamatSugarCRMhadbuilttheapplicationtosolvethisproblem,yetfewdevelopersoutsideofSugarCRMreallyknewhowpowerfultheunderlyingplatformwas.Iknewtherewereotherdevelopersinthissameboat,andthatifIcouldreachthemitwouldmaketheirjobsmucheasier.WhataCRMapplicationdoesordoesn’tdoisn’tauthoritativelydefined;instead,itsgoalistofillinthegapwhereacompanyneedstosolveproblemsintheirrelationshipswiththeircustomers.Sometimesthismeanskeepingtrackofmeetingsandphonecalls.Othertimes,thismeanstrackingtheprogressofanongoingproject.Itcouldalsomeanmanagingsupportcasesandproductdefects.Yetsometimesanapplicationmaynotcompletelycoverthis.Justaseverybusinessororganizationisunique,somustbewhatCRMwillmeantothem.UpuntilSugarCRM,thisapplicationspacewasfullofplayerswhothoughttheyhadtheCRMproblemsolved,andbuiltlargeproprietaryapplicationsthatwereexpensivetoimplementandsupportandnotoriouslydifficulttocustomizetomeettheirneeds.SugarCRMcameinandchangedthatscene,makingCRMsomethingthatisinexpensivetoimplement,easiertocustomize,andmoreapproachableforend-userstoworkwith.It’sdesignedtobeaCRMthatyouruserswon’thate,whichisthephilosophythatthefoundersofSugarCRMsetastheirparamountgoalwhenbuildingit.

Demo测试跨线更新UI第一种：Thread达到跨线程更新UI虽然使用Dispatcher.Invoke和模拟winform里面的DoEvent但是运行中关闭还是会有异常，而且耗资源高；
第二种：DispatcherTimer失败:UI还是会卡顿；
第三种：Timer建议使用、资源占用少，关闭启动自如。

ETL4LODETL4LOD-步骤进行Pentaho数据集成（水壶）可轻松链接数据。
数据属性映射：在数据属性映射中，您可以选择一个枫糖厂，一个通缉犯，一个通缉犯，乌干达RDF组件（sujeito，predicadoeobjeto）和一个通缉犯，以及不动产。
对象属性映射：对象属性映射的步骤与数据属性映射的步骤类似，不同之处在于对象之间的关联性和可用性。
Sparql端点：在Sparql终结点上，请使用SPARQL终结点进行外部发布，并从SPARQL终结点和URL上分配特定的URL。
Sparql更新输出：在步骤SparqlUpdate输出中，请在capregarcartripgartriplasRDFemumbancodetriplas中输出（示例：Virtuoso）。
NTripleGenerator：步骤NTriple生成器可以简

在日常工作中，钉钉打卡成了我生活中不可或缺的一部分。然而，有时候这个看似简单的任务却给我带来了不少烦恼。 每天早晚，我总是得牢记打开钉钉应用，点击"工作台"，再找到"考勤打卡"进行签到。有时候因为工作忙碌，会忘记打卡，导致考勤异常，影响当月的工作评价。而且，由于我使用的是苹果手机，有时候系统更新后，钉钉的某些功能会出现异常，使得打卡变得更加麻烦。 另外，我的家人使用的是安卓手机，他们也经常抱怨钉钉打卡的繁琐。尤其是对于那些不太熟悉手机操作的长辈来说，每次打卡都是一次挑战。他们总是担心自己会操作失误，导致打卡失败。 为了解决这些烦恼，我开始思考是否可以通过编写一个全自动化脚本来实现钉钉打卡。经过一段时间的摸索和学习，我终于成功编写出了一个适用于苹果和安卓系统的钉钉打卡脚本。