简介:(GB)组买出现了并且在过去的十年演变为各种各样的形式。我们调查GB的一种不同形式,也就是消费者驱动的组买,一些消费者由此形成购买组一起访问店并且为折扣谈判。我们把这些消费者叫作不同于个别地访问店并且付出常规代价的常规消费者的GB消费者。由一个购买组,访问了一家店不得不做一个立即的决定在它的全部服务他们的需求。由它访问的第一家店拒绝了,购买组继续访问另外的店。在提供GB需求以后,店使用留下的股票为常规消费者服务。我们证明GB能是到采用合适的政策作为一台仪器利用它联系消费者的店的享受。店能在大多数情形以比常规价格低的价格提供组需求,但是设法仍然挣稳定的利润。常规消费者的存在在平衡形成上有微妙的效果,由加强在与微弱地做分类价格的消费者与组尺寸增加的GB谈判的店力量。而且,竞争的店能操作在购买组之间的相互作用并且当GB消费者说明市场底的小部分时,一起比一家独占者店挣更高全部的利润,竞争是强烈的。
简介:Inthispaper,theoptimalmaintenancepolicyisinvestigatedforasystemwithstochasticleadtimeandtwotypesoffailures.Thesystemhastwotypesoffailures,onetypeisrepairable,whentherepairablefailureoccurs,thesystemwillberepairedbyrepairman,andthesystemafterrepairisnot“asgoodasnew".Theothertypeoffailureisunrepairable,andwhentheunrepairablefailureoccursthesystemmustbereplacedbyanewandidenticalone.Thesparesystemforreplacementisavailableonlybyorder,andtheleadtimefordeliveringthesparesystemisstochastic.Thesuccessivesurvivaltimesofthesystemformastochasticallydecreasinggeometricprocess,theconsecutiverepairtimesafterfailuresofthesystemformarenewalprocess.Byusingtherenewalprocesstheoryandgeometricprocesstheory,theexplicitexpressionofthelong-runaveragecostperunittimeunderorderingpolicy(N-1)isderived,andthecorrespondingoptimalcanbefoundanalytically.Finally,thenumericalanalysesaregiven.
简介:WeconsideranM/M/2queueingsystemwithtwo-heterogeneousserversandmultiplevacations.CustomersarriveaccordingtoaPoissonprocess.However,customersbecomeimpatientwhenthesystemisonvacation.Weobtainexplicitexpressionsforthetimedependentprobabilities,meanandvarianceofthesystemsizeattimetbyemployingprobabilitygeneratingfunctions,continuedfractionsandpropertiesofthemodifiedBesselfunctions.Finally,twospecialcasesareprovided.
简介:Inthispaper,westudyacentralizedsupplychainforatwo-stagewithsellingpricediscount.Thissupplychainconsistsofasupplierandaretailer.Basedonthefeaturethattheproduct’ssellingseasonisshortandthesupplychainfacesgreatdemanduncertainty.Weconsideratwo-stagescenariowhere,atthebeginningofstage1,thesupplierreservesproductioncapacitybasedonhistoricdatainadvance,stage2comestousaftersomeleadtime,boththesupplierandtheretailerupdatethedemandinformation,theretailerthenplacesanordernotexceedingthereservedcapacitybasedontheselling-pricingdiscountdependentdemand.Wemakeoptimaldecisionsonthereservedcapacityinstage1,sellingpricediscountandorderquantityinstage2.Inthissupplychain,thepatterninstage2isfiguredoutfirst,andthenstage1isclearedaswell.Thenwepresentanumericalexampletogivesomeinsights.Finallywegetsomeconclusions.
简介:这份报纸考虑通过离线、联机的隧道为一小部分房间的分发由一个宾馆和一个联机旅行代理人(OTA)组成的宾馆供应链。在商人合作假设下面,为无常建模并且要求克服分散的决定的劣势,二合作机制,也就是,一个二阶段的订合同和一种选择收缩,被介绍在宾馆供应链增加利润。这份报纸在不同合同模型下面调查宾馆和OTA的最佳的决定。而且,作者在不同模型下面在宾馆和OTA的利润上分析需求无常和需求可变性和宾馆能力的相互作用的效果。结果证明二阶段的订合同和选择合同能增加全部供应链和宾馆的利润;然而,仅仅当宾馆能力是相对小的,需求可变性大时,OTA的利润能通过二阶段的订合同和选择合同被增加;否则,二合作机制不能增加OTA利润。
简介:在这份报纸,有合并Crowley燕子的二分布式的细胞内部的延期的一个HIV动力学模型功能的反应感染率被调查。作者在我们的系统考虑多重阶段疾病传播和隐而不见地的感染的房间(还没生产的病毒)。作者考虑nonnegativity,解决方案的固定,和系统的全球asymptotic稳定性。由构造合适的Lyapunovfunctionals并且使用Lyapunov-LaSalle不变性原则,作者证明全球稳定性感染(地方性)为时间延期的平衡和diseasefree平衡。作者证明了如果基本繁殖数字R0是不到统一,那么,没有疾病的平衡是全球性asymptotically稳定,并且如果R0比统一大,那么,感染的平衡是全球性asymptotically稳定。结果获得了模型的全球动态行为被基本繁殖数字R0完全决定并且时间延期不影响模型的全球asymptotic性质的表演。
简介:Inthispaper,wefocusonthereal-timeinteractionsamongmultipleutilitycompaniesandmultipleusersandformulatereal-timepricing(RTP)asatwo-stageoptimizationproblem.Atthefirststage,basedoncostfunction,weproposeacontinuoussupplyfunctionbiddingmechanismtomodeltheutilitycompanies’profitmaximizationproblem,bywhichtheanalyticexpressionofelectricitypriceisfurtherderived.Atthesecondstage,consideringthatindividuallyoptimalsolutionmaynotbesociallyoptimal,weemployconvexoptimizationwithlinearconstraintstomodelthepriceanticipatingusers’dailypayoffmaximum.Substitutetheanalyticexpressionofelectricitypriceobtainedatthefirststageintotheoptimizationproblematthesecondstage.Usingcustomizedproximalpointalgorithm(C-PPA),theoptimizationproblematthesecondstageissolvedandelectricitypriceisobtainedaccordingly.WealsoprovetheexistenceanduniquenessoftheNashequilibriuminthementionedtwostageoptimizationandtheconvergenceofC-PPA.Inaddition,inordertomakethealgorithmmorepractical,astatisticalapproachisusedtoobtainthefunctionofpriceonlythroughonlineinformationexchange,insteadofsolvingitdirectly.TheproposedapproachoffersRTP,powerproductionandloadschedulingformultipleutilitycompaniesandmultipleusersinsmartgrid.Statisticalapproachhelpstoprotectthecompany’sprivacyandavoidtheinterferenceofrandomfactors,andC-PPAhasanadvantageoverLagrangianalgorithmbecausetheformerneednotobtaintheobjectionfunctionofthedualoptimizationproblembysolvinganoptimizationproblemwithparameters.Simulationresultsshowthattheproposedframeworkcansignificantlyreducepeaktimeloadingandefficientlybalancesystemenergydistribution.