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简介：Despiteitsname,e-commerceisnotfullyautomated.Typically,onlinetransactionsrequireasignificantlevelofhumanintervention.Customersundertakethesearchforproducts,services,potentialvendorsandbusinesspartners.Theyevaluatealternatives,decidewhatgoodstobuyandwhen,fromwhichvendor,andhowmuchtheyarewillingtopayfor.Theyengageinpotentialnegotiations,carryoutthetransactionsandsoon.Asthosemarketsbecomemature,newproductsandservices,aswellasnewpractices,arebeginningtoappear.Thereisalreadyampleevidencethatagent-basedtechnologywillbecrucialforthesedevelopments,reflectingthatbothbuyersandsellersbeingvigorouslyseektechniquestoimprovetheirperformance.ThisworksurveysseveraloftheseagentsthathelpelectroniccommercesystemsbydescribingtheirrolesinthecontextofaConsumerBuyingBehavior(CBB)model.TheCBBmodelpresentedaugmentstraditionalmarketingmodelswithconceptsfromSoftwareAgentsresearchtoaccommodateelectronicmarkets.

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简介：Wepresentthesolidmodeleditdistance(SMED),apowerfulandflexibleparadigmforexploitingshapesimilaritiesamongstCADmodels.ItisdesignedtomeasurethemagnitudeofdistortionsbetweentwoCADmodelsinboundaryrepresentation(B-rep).Wegivetheformaldefinitionbyanalogywithgrapheditdistance,oneofthemostpopulargraphmatchingmethods.Toavoidtheexpensivecomputationalcostpotentiallycausedbyexactcomputation,anapproximateprocedurebasedonthealignmentoflocalstructuresetsisprovidedinaddition.Inordertoverifytheflexibility,wemakeintensiveinvestigationsonthreetypicalapplicationsinmanufacturingindustry,anddescribehowourmethodcanbeadaptedtomeetthevariousrequirements.Furthermore,amultilevelmethodisproposedtomakefurtherimprovementsofthepresentedalgorithmonbotheffectivenessandefficiency,inwhichthemodelsarehierarchicallysegmentedintotheconfigurationsoffeatures.ExperimentresultsshowthatSMEDservesasareasonablemeasurementofshapesimilarityforCADmodels,andtheproposedapproachprovidesremarkableperformanceonareal-worldCADmodeldatabase.

简介：一个阳光灿烂的午后．当我们正在为本期的“千姬变”栏目中模特的甄选工作忙得焦头烂额的时候．摄影师Petter给我们来了一个电话：“我认识一个小姑娘学化妆的．看了你们杂志特感兴趣，要不要看看她的资料？”我们抱着多一个不多．少一个不少的心态查看了Petter发来的女孩资料。十分让人意外的是．这位学化妆的小姑娘竟然跟我们以前印象中的女性化妆师大不相同——印象中的女性化妆师虽说容颜装束都很时尚．但是大多身材并不出众，

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简介：Parameterizationisoneofthekeyproblemsintheconstructionofacurvetointerpolateasetoforderedpoints.Weproposeanewlocalparameterizationmethodbasedonthecurvaturemodelinthispaper.Thenewmethoddeterminestheknotsbyminimizingthemaximumcurvatureofquadraticcurve.Whentheknotsbythenewmethodareusedtoconstructinterpolationcurve,theconstructedcurvehavegoodprecision.Wealsogivesomecomparisonsofthenewmethodwithexistingmethods,andourmethodcanperformbetterininterpolationerror,andtheinterpolatedcurveismorefairing.

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简介：Amingatwaterconservancyprojectvisualization,ahidden-removalmethodofdamperspectivedrawingsisrealizedbybuildingahidden-removalmathematicalmodelforoverlappingpointslocationtosetupthehiddenrelationshipamongpointandplane,planeandplaneinspace.Onthisbasis,asanexampleofpanelrockfilldam,adamhidden-removalperspectivedrawingisgeneratedindifferentdirectionsanddifferentvisualanglesthroughadaptingVC++andOpenGLvisualizingtechnology.Theresultsshowthatthedataconstructionofthemodelissimplewhichcanovercomethedisadvantagesofconsiderableandcomplicatedcalculation.Thismethodalsoprovidesthenewmeanstodrawhidden-removalperspectivedrawingsforthoselandformsandgroundobjects.

简介：InCAGDandCG,energymodelisoftenusedtocontrolthecurvesandsurfacesshape.Incurve/surfacemodeling,wecangetfaircurve/surfacebyminimizingtheenergyofcurve/surface.However,ourresearchindicatesthatinsomecaseswecan'tgetfaircurves/surfaceusingthecurrentenergymodel.Soanimprovedenergymodelispresentedinthispaper.Examplesarealsoincludedtoshowthatfaircurvescanbeobtainedusingtheimprovedenergymodel.

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简介：Thetraditionalstrategyof3Dmodelreconstructionmainlyconcentratesonorthographicprojectionsorengineeringdrawings.Buttherearesomeshortcomings.Suchas,onlyfewkindsofsolidscanbereconstructed,thehighcomplexityoftimeandlessinformationaboutthe3Dmodel.Theresearchisextendedandprocesscardistreatedaspartofthe3Dreconstruction.Asetofprocessdataisasupersetof2Dengineeringdrawingsset.Thesetcomprisesprocessdrawingsandprocesssteps,andshowsasequencingandasymptoticcoursethatapartismadefromroughcastblanktofinalproduct.Accordingtothesecharacteristics,theobjecttobereconstructedistranslatedfromthecomplicatedengineeringdrawingsintoaseriesofmuchsimplerprocessdrawings.Withtheplentifulprocessinformationaddedforreconstruction,thedisturbancessuchasirrelevantgraph,symbolandlabel,etc.canbeavoided.Andmore,theformchangeofbothneighborprocessdrawingsissolittlethattheengineeringdrawingsinterpretationhasnodifficulty;inaddition,theabnormalsolutionandmulti-solutioncanbeavoidedduringreconstruction,andtheproblemsofbeingapplicabletomoreobjectsissolvedultimately.Therefore,theutilitymethodfor3Dreconstructionmodelwillbepossible.Ontheotherhand,thefeatureinformationinprocesscardsisprovidedforreconstructionmodel.Focusingonprocesscards,thefeasibilityandrequirementsofWorkingProcedureModelreconstructionisanalyzed,andthemethodtoapplyandimplementtheNaturalLanguageUnderstandingintothe3Dreconstructionisstudied.Themethodofasymptoticapproximationproductwasproposed,bywhicha3Dprocessmodelcanbeconstructedautomaticallyandintelligently.Theprocessmodelnotonlyincludestheinformationaboutpartscharacters,butalsocandelivertheinformationofdesign,processandengineeringtothedownstreamapplications.