简介:Therandomstepmaneuverwithuniformlydistributedstartingtimeshasthedisadvantagethatitcannotfocusthestartingtimeonthemoreefficiencytime.Itdecreasesthepenetrationprobability.Toresolvethisproblem,arandomsteppenetrationalgorithmwithnormaldistributionstartingtimeisproposed.Usingtheshapingfiltersandadjointsystemmethod,themissdistancewithdifferentstartingtimescanbeacquired.Accordingtothepenetrationstandard,thetimewindowensuringsuccessfulpenetrationcanbecalculatedanditisusedasthe3σboundofthenormallydistributedrandommaneuver.Simulationresultsindicatethatthenormallydistributedrandommaneuverhashigherpenetrationprobabilitythantheuniformlydistributedrandommaneuver.
简介:WediscussavariantofrestartedGMRESmethodthatallowschangesoftherestartingvectorateachcycleofiterations.Themeritofthevariantisthatpreviouslygeneratedinformationcanbeutilizedtoselectanewstartingvector,suchthattheoccurrenceofstagnationbemitigatedortheconvergencebeaccelerated.ThemoreappealingutilizationofthenewmethodisinconjunctionwithaharmonicRitzvectorasthestartingvector,whichisdiscussedindetail.Numericalexperimentsarecarriedouttodemonstratethattheproposedprocedurecaneffectivelymitigatetheoccurrenceofstagnationduetothepresenceofsmalleigenvaluesinmodulus.
简介:底价拍卖是在传统的拍卖理论的热研究问题之一。这里,我们在联机拍卖学习开始的价格,在传统的拍卖的公共底价的对应物。由认为象eBay一样的三个特征联机,投标人(到泊松过程的题目)的auctions:stochastic入口,与开始的价格成正比的插入费用,和时间打折,我们为最大化分析了开始的价格的极值点的性质卖主期望了收入,并且发现了那,在某些条件下面,最佳的开始价格应该在最低许可的水平,它与从经典拍卖理论的结果相反并且事实上发现它的optimality。我们也开发了多级式的拍卖的一个一般扩大模型并且在它的性质上执行了分析。最后,为进一步的研究的一些方向也被提出。
简介:ThispaperisconcernedwiththeanalysisofafeedbackM[X]/G/1retrialqueuewithstartingfailuresandgeneralretrialtimes.Inabatch,eachindividualcustomerissubjecttoacontroladmissionpolicyuponarrival.Iftheserverisidle,oneofthecustomersadmittedtothesystemmaystartitsserviceandtherestjoinstheretrialgroup,whereasalltheadmittedcustomersgototheretrialgroupwhentheserverisunavailableuponarrival.Anarrivingcustomer(primaryorretrial)mustturn-ontheserver,whichtakesnegligibletime.Iftheserverisstartedsuccessfully(withacertainprobability),thecustomergetsserviceimmediately.Otherwise,therepairfortheservercommencesimmediatelyandthecustomermustleavefortheorbitandmakearetrialatalatertime.ItisassumedthatthecustomerswhofindtheserverunavailablearequeuedintheorbitinaccordancewithanFCFSdisciplineandonlythecustomerattheheadofthequeueisallowedforaccesstotheserver.TheMarkovchainunderlyingtheconsideredqueueingsystemisstudiedandthenecessaryandsufficientconditionforthesystemtobestableispresented.Explicitformulaeforthestationarydistributionandsomeperformancemeasuresofthesysteminsteady-stateareobtained.Finally,somenumericalexamplesarepresentedtoillustratetheinfluenceoftheparametersonseveralperformancecharacteristics.
简介:<正>Lastyear,1998,wasanextraordinaryyear.Inthefaceoffinancialtur-moilinternationallyandrecord--breakingfloodsdomestically,wehavestoodseveretests.Themacroeconomiccontrolpolicyadoptedbythecen-tralauthoritiestoexpandinvestmentinordertoprovideincentivestodo-mesticdemandyieldedpositiveresultsandtheeconomicgrowthratereached7.8percent.Howevertheinvestmentexpansionwasonlythebe-
简介:GABAtransporter1(GAT1)takesimportantrolesinmultiplephysiologicalprocessesthroughtheuptakeandreleaseofGABA,buttheregulationofGAT1geneexpressionindifferenttissuesisrarelyknown.Toaddressthequestion,first,5'RapidamplificationofcDNAend(RACE)wasusedtodetermineGAT1transcriptionalstartingsitesinneonatalmousecerebralcortexandintestine,adultmousebrainandadultrattestis.Theproductsof5'RACEwereconfirmedbyDNAsequencing.WefoundthatthetranscriptofGAT1inneonatalmousecerebralcortexandadultmousebrainstartsatthesamesite(insideofexon1),whileinmouseintestine,GAT1startstranscriptioninintron1,andinrattestis,thetranscriptofGAT1hasanadditionaluntranslationexontothe5'direction.
简介:Asthefirstacrobaticartistictroupewiththeperformanceonice,HeilongjiangAcrobaticsandDancingonIceTroupehasbeenonafastdevelopingwayinvirtueofherperseveranceonacrobaticsandhasstartedtoshineuniquelyintheperformancemarketsinceherfounding.
简介:Inresponsetothechallengeinherentinclassicalhigh-dimensionalmodelsofrandomgroundmotions,afamilyofsimulationmethodsfornonstationaryseismicgroundmotionswasdevelopedpreviouslythroughemployingawave-grouppropagationformulationwithphasespectrummodelbuiltuponthefrequencycomponents’starting-timeofphaseevolution.Thepresentpaperaimsatextendingtheformulationtothesimulationofnon-stationaryrandomseismicgroundmotions.ThegroundmotionrecordsassociatedwithN–ScomponentofNorthridgeEarthquakeatthetype-IIsiteareinvestigated.Thefrequencycomponents’starting-timeofphaseevolutionofisidentifiedfromthegroundmotionrecords,andisprovedtoadmittheGammadistributionthroughdatafitting.Numericalresultsindicatethatthesimulatedrandomgroundmotionfeatureszeromean,non-stationary,andnon-Gaussianbehaviors,andthephasespectrummodelwithonlyafewstarting-timesofphaseevolutioncouldcomeupwithasoundcontributiontothesimulation.更多还原
简介:Themarinemedium-speeddieselenginesarestartedbytwomethods;oneistheelectricmotors,andtheotherairstartingmotors.Eventhoughairstartingmotorisdependentoftheenginetypesandsizes,ithasbeenwidelyusedinthisareaduetoitssimplicity,convenienceandreliability.Thepurposeofthispaperistogivethedesigningparametersinordertomakeaproper'AirStartingMotor'usingCFD.Theaerodynamicapproachesweregiventounderstandtheinternalflowcharacteristicsoftheairstartingmotor.Inaddition,wehavecarriedouttheinvestigationofeffectsoftipclearance.Inthecalculationsthetipclearanceofairstartingmotorhasbeenvariedbetween0,2.8,4.3and5.7%ofbladespan.Theresultsofcomputationarethetipclearanceincreasedto2.8%,thetorquedecreased24%,andtherewasnomorelargechangeswhentheclearancesincreasedto4.3%and5.7%.
简介:Background:The2mostcitedsportsinjurypreventionresearchframeworksincorporateinterventiondevelopment,yetlittleguidanceisavailableinthesportsscienceliteratureonhowtoundertakethiscomplexprocess.Thispaperpresentsageneralizableprocessfordevelopingimplementablesportsinjurypreventioninterventions,includingacasestudyapplyingtheprocesstodevelopalowerlimbinjurypreventionexercisetrainingprogram(FootyFirst)forcommunityAustralianfootball.Methods:Theinterventiondevelopmentprocessisunderpinnedby2complementarypremises:(1)thatevidence-basedpracticeintegratesthebestavailablescientificevidencewithpractitionerexpertiseandenduservaluesand(2)thatresearchevidencealoneisinsufficienttodevelopimplementableinterventions.Results:Thegeneralizable6-stepinterventiondevelopmentprocessinvolves(1)compilingresearchevidence,clinicalexperience,andknowledgeoftheimplementationcontext;(2)consultingwithexperts;(3)engagingwithendusers;(4)testingtheintervention;(5)usingtheory;and(6)obtainingfeedbackfromearlyimplementers.Followingeachstep,interventioncontentandpresentationshouldberevisedtoensurethatthefinalinterventionincludesevidence-informedcontentthatislikelytobeadopted,properlyimplemented,andsustainedovertimebythetargetedinterventiondeliverers.ForFootyFirst,thisprocessinvolvedestablishingamultidisciplinaryinterventiondevelopmentgroup,conducting2targetedliteraturereviews,undertakinganonlineexpertconsensusprocess,conductingfocusgroupswithprogramendusers,testingtheprogrammultipletimesindifferentcontexts,andobtainingfeedbackfromearlyimplementersoftheprogram.Conclusion:Thissystematicyetpragmaticanditerativeinterventiondevelopmentprocessispotentiallyapplicabletoanyinjurypreventiontopicacrossallsportssettingsandlevels.Itwillguideresearcherswishingtoundertakeinterventiondevelopment.
简介:摘要:Starting out,作为外研版新教材中单元的首个组成部分,涵盖了广泛的主题,包括但不限于watching the video、问题回答、表格填写或者录音听取、图片观看等,内容十分丰富。Starting out部分实施了新课程标准的导入要求,以激发学生的背景知识和语言技能。在高中英语的授课过程中,教师应当充分利用Starting out板块,以提升高中英语单元导入效率,从而增强学生的整体学习效果。因此本文对利用Starting out版块提升高中英语单元导入效率进行了具体分析,以期为相关人士提供一些参考。
简介:Hexagonplate-likeAl8B4C7powdersweresuccessfullysynthesizedusingamixtureofdiborontrioxide,activatedcarbonandaluminumoraluminabyacarbothermalreductionprocess.TheeffectofAlsourceandstartingmaterialsadditionsonsynthesisofAl8B4C7wasinvestigated.ThephasecompositionandmicrostructureofAl8B4C7powderwerecharacterizedbymeansofXRD,SEMandEDS.ThemainphasecompositionsoftheproductssynthesizedfromAl,B2O3andactivatedcarbonareAl8B4C7andAl2OC.Al2O3canreplaceAltosynthesizeAl8B4C7.Al8B4C7grainssynthesizedfromAl2O3,B2O3andactivatedcarbonarehexagonplate-likeandhaveathicknessof10μmandasizeofabout100μm.