简介:RandomMatrixTheory(RMT)isavaluabletoolfordescribingtheasymptoticbehaviorofmultiplesystems,especiallyforlargematrices.Inthispaper,usingasymptoticrandommatrixtheory,anewcooperativeMultiple-InputMultiple-Output(MIMO)schemeforspectrumsensingisproposed,whichshowshowasymptoticfreepropertyofrandommatricesandthepropertyofWishartdistributioncanbeusedtoassistspectrumsensingforCognitiveRadios(CRs).SimulationsoverRayleighfadingandAWGNchannelsdemonstratetheproposedschemehasbetterdetectionperformancecomparedwiththeenergydetectiontechniqueseveninthecaseofasmallsampleofobservations.
简介:Inrecentyears,theredtideeruptedfrequently,andcausedagreateconomicloss.Atpresent,mostliteraturesemphasizetheacademicresearchonthegrowthmechanismofredtidealga.Inordertofindoutthecharactersofredtideindetailandimprovetheprecisionofforecast,thispapergivessomenewapproachestodealingwiththeredtide.Bytheextremevalues,wedealwiththeredtidefrequencyanalysisandgettheestimationofT-timesredtidelevelU(T),whichistheleveloncetheconsistenceofredtidealgaexceedsontheaverageinaperiodofTtimes.
简介:Thesimilaritytheorywassystematicallyintroduced,bycombiningthetheoryandtheanalytichierarchyprocess(AHP),andtakingthedynamicchangesoftwo-stagegreenlandpatchesinShenzhenasanexample,thepatchessimilarityofeachdistrictandeachgreenlandtypewereestimated.Thelocation,shapeandareasofgreenlandunitwereusedasthesimilarityelements.Thenthesimilaritycoefficientscanbedefined.Theoverlappingnumberofgreenlandpatchesindicatedthelocationvariationofgreenland.Theratioofminimumandmaximumshapeindexofgreenlandindicatedtheshapevariationofgreenland.Withthesamemethod,theareasvariationcoefficientwasalsoobtained.Theresultsshowsthatbasedonsimilaritytheoryandmethodtheestimationofgreenlandvariationisfeasible,whichcanprovideeffectivemethodsandaccordanceforthefurtherassessmentofgreenlanddevelopmentinShenzhenSpecialEconomicZone.
简介:Featureselection(FS)isaprocesstoselectfeatureswhicharemoreinformative.Itisoneoftheimportantstepsinknowledgediscovery.Theproblemisthatnotallfeaturesareimportant.Someofthefeaturesmayberedundant,andothersmaybeirrelevantandnoisy.TheconventionalsupervisedFSmethodsevaluatevariousfeaturesubsetsusinganevaluationfunctionormetrictoselectonlythosefeatureswhicharerelatedtothedecisionclassesofthedataunderconsideration.However,formanydataminingapplications,decisionclasslabelsareoftenunknownorincomplete,thusindicatingthesignificanceofunsupervisedfeatureselection.However,inunsupervisedlearning,decisionclasslabelsarenotprovided.Inthispaper,weproposeanewunsupervisedquickreduct(QR)algorithmusingroughsettheory.ThequalityofthereduceddataismeasuredbytheclassificationperformanceanditisevaluatedusingWEKAclassifiertool.Themethodiscomparedwithexistingsupervisedmethodsandtheresultdemonstratestheefficiencyoftheproposedalgorithm.
简介:ThispaperexaminestheeffectofgovernmentpoliciesonthefinancingdecisionsoffirmsinChina.Arealoptionsmodelisdevelopedtounderstandhowfiscalandmonetarypoliciesaffectcorporateleverage.Themodelpredictionswillbetestedwithacomprehensivepaneldatasetspanningfrom2002to2011.Thisworkdocumentsrobustevidencethatshowthepositiveassociationofbothtaxandrisk-freeratewithfirmleverage:increaseintaxrateandriskfreeratebyonestandarddeviationresultsintheincreaseincorporateleveragesby0.61to1.06percentand2.54to3.68percent,respectively.Inaddition,theproductionsofthefirmsarenotaffectedbythetaxrateintheshortrun,andthefirmsareoperatingintheiroptimalmarketleverage.Theimpliedtaxrateandriskfreeratearesolvedbyassumingthatthefirmsachievetheiroptimalleverages.Theimpliedtaxratedeclineswiththesize,whereastheoppositegoesforimpliedrisk-freerate.
简介:ThispaperpresentsdesigntheoryandmethodoftheintellectualizedCAI.whichincludestheorganizationandexpressionoftheteachingcontentandtheteachingrequirementdeterminationinteachingprocess,anddevelopsahighlyintellectualizedCA1software.LA-CAI,touseforlinerarithmeticteachingprogram.
简介:Fromthecomparisonofcorrelationtensorinthetheoryofquantumnetwork,theAlexanderrelationmatrixinthetheoryofknotcrystalsandtheidenticalinversionrelationsundertheactionofPaulimatrices,weshowthatthereisaonetoonecorrespondencebetweenfourBellbasesandfourorientedlinksofthelinkage41inknottheory.
简介:Withthedevelopmentofscienceandtechnology,largequantitiesofneologismsarecreated.Neologismsaretheresultofpeople’sconceptualizationofnewthingsbasedontheirlifeexperiences.Cognitivelinguisticsviewsthatcategorizationoforganismsandconcreteobjectsarebasedontheprototypecategory.Thispapertakes167EnglishNeologismsfromWordspyin2015asthedataforanalysisandfindsthattheseEnglishNeologismsarecharacterizedbyfamilyresemblances,degreeofmembershipincategoryandboundaryfuzzinessfromtheviewofprototypecategorytheory.ThisstudyalsohassomeimplicationsfortheresearchofEnglishlanguageteachingandlearning.
简介:Byusingthelogarithmicstrain,thefinitedeformationplastictheory,correspondingtotheinfinitesimalplastictheory,isestablishedsuccessively.Theplasticconsistentalgorithmwithfirstorderaccuracyforthefiniteelementmethod(FEM)isdeveloped.Numericalexamplesarepresentedtoillustratethevalidityofthetheoryandeffectivenessofthealgorithm.
简介:ThispaperstudiesthepowercontrolprobleminfemtocellsystembasedonNashnon-cooperativegametheory.Itdesignsanutilityfunctiontakingfemstations'transmitpowerasvariableandrelatesittotherequirementsofmacrousers'andfemusers'signaltointerferenceplusnoiseratio(SINR).Theutilityalsotakestheimpactoffemstations'locationintoaccountandimprovesthefairnessofnon-cooperativegame.Onthisbasis,thispaperproposesadistributedpowercontrolalgorithmandprovestheexistenceanduniquenessofParetooptimalpoint.Thesimulationresultsshowthatthealgorithmimprovestheconvergencespeedandsystemperformancethroughimprovingusers'SINR.