简介:这篇论文在波动的环境下面探讨定价和库存补充策略的同时的决心。明确地,我们分析单个条款,周期的评论模型。需求由二部分组成:确定的部件,被价格影响,和随机的部件(不安)。随机的部件的分发由外长的Markov链的当前的国家被决定。在任何给定的时期被控告的价格能动态地被指定。一份补充订单可以被放在一些时期或所有的开始,并且无存货是充分backlogged。订是更低的semicontinuous,并且库存/积压事物的费用或剩余)与多项式生长是连续的费用。有限地平线、无限地平线的问题被处理。最佳的政策的存在被建立。而且,optimality(s,S,p)当订的费用由组成时,类型政策被证明修理,比例的费用部件和剩余花费了(这些费用都是州依赖者的)是凸的。关键词随机的库存管理-Markov链-定价-有限地平线-无限的地平线2000苏布杰克特先生分类90B05-90B06由国家天赋支持了中国的科学基础(号码70621061,号码70890082,号码70671100)并且北京交通的科学基础大学(2007RC014)。
简介:Inthisarticle,wemainlydiscusstheasymptoticbehaviorformulti-dimensionalcontinuous-timerandomwalkinrandomenvironmentwithholdingtimes.Byconstructingarenewalstructureandusingthepoint'environmentviewedfromtheparticle',underGeneralKalikow'sCondition,weshowthelawoflargenumbers(LLN)andcentrallimittheorem(CLT)fortheescapespeedofrandomwalk.
简介:Westudyamodelforthelong-termbehaviorofasingle-speciespopulationwithsomedegreeofpollutiontoleranceinapollutedenvironment.Themodelconsistsofthreeordinarydifferentialequations:oneforthepopulationdensity,onefortheamountoftoxicantinsidethelivingorganisms,andonefortheamountoftoxicantintheenvironment.Wederivesufficientconditionsforthepersistenceandtheextinctionofthepopulationdependingontheexogenousinputrateofthetoxicantintotheenvironmentandthelevelofpollutiontoleranceoftheorganisms.Numericalsimulationsarecarriedouttoillustrateourmainresults.
简介:Inthispaper,westudyatwo-speciesperiodicBeddington-DeAngelispredator-preymodelwithdelayinatwo-patchenvironment,inwhichthepreyspeciescandispersebetweentwopatches,butthepredatorspeciescannotdisperse.Onthebasisofthecomparisontheoremofdifferentialequations,weestablishsufficientconditionsforthepermanenceandextinctionofthesystem.
简介:Therearethreepartsinthisarticle.InSection1,weestablishthemodelofbranchingchainwithdriftinspace-timerandomenvironment(BCDSTRE),i.e.,thecouplingofbranchingchainandrandomwalk.InSection2,weprovethatanyBCDSTREmustbeaMarkovchainintimerandomenvironmentwhenweconsiderthedistributionoftheparticlesinspaceasarandomelement.InSection3,wecalculatethefirst-ordermomentsandthesecond-ordermomentsofBCDSTRE.