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《秦曉飛系列-深度學(xué)習(xí)-3.2機(jī)器學(xué)習(xí)策略2(遷移學(xué)習(xí))ppt課件.ppt》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在教育資源-天天文庫(kù)。
1、機(jī)器學(xué)習(xí)策略(2)MachineLearningStrategy(2)主講教師：秦曉飛上海理工大學(xué)光電學(xué)院2.1CarryingoutErrorAnalysis2.1CarryingoutErrorAnalysisLookatdevexamplestoevaluateideasSupposeyourcatclassifierachieved90%accuracy(10%error),whichisnotverygood.Youlookatthemisrecognizedcatsandfindsomeofthemaredogs.Shouldyoutr
2、ytomakeyourcatclassifierdobetterondogs?Erroranalysis:Get~100mislabeleddevsetexamples.Countuphowmanyaredogs.5%5/100Ceilingimprovement5%Error10%→9.5%50%50/100Ceilingimprovement50%Error10%→5%2.1CarryingoutErrorAnalysisEvaluatemultipleideasinparallelIdeasforcatdetection:Fixpicture
3、sofdogsbeingrecognizedascats.Fixgreatcats(lions,panthers,etc..)beingmisrecognized.Improveperformanceonblurryimages.ImagesDogsGreatcatsBlurComments123100%oftotal√√√√√√PitballRainyday,zoo8%43%61%12%Instagramfilter2.2CleaningupIncorrectlyLabeledData2.2CleaningupIncorrectlyLabeled
4、DataIncorrectlylabeledexamplesDLalgorithmsarequiterobusttorandomerrorsinthetrainingset.xy1011011DLalgorithmscannothandlesystematicerrors,suchasrecognizingallwhitedogsascats.Incorrectlylabeleddataindev/testsetmayhurtDLalgorithms’performance.Youneedtodoerroranalysistodecidewheth
5、ertocorrectthem.2.2CleaningupIncorrectlyLabeledDataErroranalysisImagesDogsGreatcatsBlurComments9899100%oftotal√√√LabelermissedcatinbackgroundDrawingofacat;Notarealcat.8%43%61%6%Incorrectlylabeled30%Overalldevseterror…………………...10%Errorsduetoincorrectlabels……….0.6%Errorsduetooth
6、ercauses…..……….9.4%2%0.6%1.4%GoalofdevsetistohelpyouselectbetweentwoclassifiersA&B.2.1%1.9%2.2CleaningupIncorrectlyLabeledDataGuidelinesofcorrectingincorrectdev/testsetexamplesApplysameprocesstoyourdevandtestsetstomakesuretheycontinuetocomefromthesamedistribution.Considerexami
7、ningexamplesyouralgorithmgotrightaswellasonesitgotwrong.(Howeverthisismoredifficultthanonlydoingitonwrong,becauserightexamplesismuchmorethanwrongexamples.)Trainanddev/testdatamaynowcomefromslightlydifferentdistributions.2.3BuildYourFirstSystem Quickly,thenIterate2.3BuildYourFi
8、rstSystemQuickly,thenIterateWhenbuildingabrandnewMLsystem,the
