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大学期末英语

大学期末英语

Overthelastdecade,businessesandgovernmentshavebeengivingincreasingattentiontothedescription,automation,andmanagementofbusinessprocessesusingITtechnologies.Thisinterestgrowsoutoftheneedtostreamlinebusinessoperations,consolidateorganizations,andsavecosts,reflectingthefactthattheprocessisthebasicunitofbusinessvaluewithinanorganization.TheBusinessProcessExecutionLanguageforWebServices(BPEL4WS,BPELforshort)providesanXMLnotationandsemanticsforspecifyingbusinessprocessbehaviorbasedonWebServices.ABPELprocessisdefinedintermsofitsinteractionswithpartnerprocesses.Apartnerprocessmayprovideservicestotheprocess,requireservicesfromtheprocess,orparticipateinatwo-wayinteractionwiththeprocess.Mission-criticalbusinesssolutionsneedcomprehensivetestingtoensureitperformscorrectlyandreliablyinoperation.Acommonstrategyistosubjectthesolutiontoseveralphasesoftestingsuchasunit,integrationandsystemtesting,amongwhichunittestingisusedtoverifythefunctionsofasinglemodule(class,component,process,etc).Oftenthelaterabugisdiscovered,themoreexpensiveitistofix.Thereforeitisnosurprisingthatrecentlysoftwareengineeringpracticehasbeenlayingmoreemphasisonunittesting.However,incurrentindustrialpractice,businessprocesstestingfocusesonsystemanduseracceptancetesting,whereasunittestinghasnotgainedmuchattention.Businessprocessunittestingtreatsanindividualprocessastheunitundertest,andtestsitsinternallogicthoroughly.

Thequalityofsoftwareisahottopicattractingattentionsfrombothresearchersandpractitioners.Softwaretestingisanimportanttechniquetoguaranteethequalityofsoftware.Itaimstoreducethesoftwarefaultsasmuchaspossible.Mymainworkistostudytheproblemofhowtoapplytheconstraintsatisfactiontechniquestosoftwaretestingautomatically.Thestudycanbedividedintothefollowingthreeparts.Thefirstpartofisrelatedtowhite-boxtesting.White-boxtestingisanaccuratecode-basedsoftwaretestingmethod.Wecanemploysymbolicexecutiontechniquestoprocesstheprogrampaths,soastotestsomefeaturesofprograms.However,thecomplexityofsymbolicexecutiontechniquemakesitimpossibletotestallthepathsoftheprogramundertest.Furthermore,someoftheprogrampathsmaybeinfeasible.Thereforeweneedsometestcriteriaandpathselectionstrategiestoguidethegenerationofthetestpaths.Thisworkincludesthefollowingtwoaspects.1)Anefficientmethodispresentedtogenerateasetoffeasiblebasispaths.Thismethodcangeneratefeasiblebasispathsforreal-worldCunitprogramsautomaticallyinacceptabletime.Thebasispathsetgeneratedbythismethodhastheminimumsumofweightedlength.2)BPELisabusinessdescriptionlanguagethatcouldexpresscomplexconcurrentbehaviors.InthefutureIwillpresentanovelmethodofBPELtestcasegeneration,whichisbasedonconcurrentpathanalysis.Toavoidthecombinationexplosionofthepathnumber,sometechniquesandtestcriteriaareusedtorestrictthecombination.Thismethodismodularizedsothatmanytesttechniques,suchasvarioustestcriteriaandcomplexconstraintsolvers,canbeapplied.Thesecondpartofworkisaboutblack-boxtesting.Black-boxTestingisusedtotestthefunctionsandinterfacesofprograms.WecanuseconstraintstodescribethetestcriteriaandthespecificationsofSoftwareunderTest.Thereforethetestgenerationforblack-boxtestingcanbetranslatedintothefinitedomainconstraintsatisfactionproblem.Thispartalsoincludestwoaspects.1)ASAT-basedapproachandabacktrackingsearchalgorithmarepresentedtosolvetheproblem.AnovelpruningstrategycalledSCEHisproposedtoincreasetheefficiencyofthemethods.Severalexistingsearchheuristicsandsymmetrybreakingtechniquesarealsousedinthebacktrackingsearchalgorithm.Theexperimentsshowthatourmethodoutperformsothermethodsinmanysmallsizecases.2)proposesaSAT-basedmethodtogeneratethetestcasesautomaticallyforMUMCUTtestingofBooleanspecifications.TospeeduptheprocessingforthecompleteSATtools,wemakeuseofsomesymmetrybreakingtechniques.ThelastpartofworkstudiestheproblemoffindingBooleanrelationsamongasetoflinearnumericalconstraints.Inprogramanalysisandverification,therearesomeconstraintsthathavetobeprocessedrepeatedly.Apossiblewaytospeeduptheprocessingistofindsomerelationsamongtheseconstraintsfirst.Therelationscanberepresentedbyrules.Itisbelievedthatwecannotgeneratealltherulesinpolynomialtime.Asearchbasedalgorithmwithsomeheuristicstospeedupthesearchprocessisproposed.Experimentalresultswithvariousexamplesshowthatourmethodcangenerateenoughrulesinacceptabletime.

WS-BPELapplicationsareatypeofservice-orientedworkflowapplication.Intheseapplications,abusinessprocessisspecifiedasaBPELprogram,andindividualloosely-coupledworkflowstepsarelinkedupviatheexchangeofXML-basedmessages.FailingtoextractarightpieceofdatafromanXMLmessage,forinstance,willposeanintegrationerrorinsuchanapplication.Ontheotherhand,XMLisfundamentaltomanyservice-orientedworkflowapplications,andXPathisthemeanstoqueryonXMLdocuments.TheextensiveusageofXPathposesademandtostudyhowtotesttheseapplicationseffectively.BPELunittestingiscomplexaswemusthandleanetworkofdependenciesamongindividualprocesses.Thistestframeworkonlyprovidesageneraldiscussiononmethods,issuesandtechniquesinBPELprocessunittesting.AlthoughspecializedforBPEL,thebasicideasmaybeapplicabletootherbusinessprocessdefinitionlanguagesafterpossiblegeneralization.Infuture,IplantoworkonautomatictestgenerationfromBPELsourcecode,whichshouldbealignedwiththeproposedtestframework.DrivenbyincreasinglycomplexWebServiceprocess,BPEL-basedtestingreductionfacesdemandsfromtestcaselargeness.ThereisaneedfortechniquestailoredtotestcasegenerationefficientlyinBPEL-basedtesting.Thefurtherstudiesalsoincludetheresearchontherelationshipofinputparameterwithnon-uniformrangeandtheefficientassignmentofinputparameterintorelationset.