共查询到19条相似文献,搜索用时 100 毫秒
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一类跳扩散需求存贮系统(s,S)库存控制策略研究 总被引:1,自引:0,他引:1
考虑的是连续检查库存,需求为一个常时间函数和-个复合Poison跳扩散随机过程的和的存贮系统最优库存控制问题.基于期望折扣成本最小建立了无穷时间区间具有固定订购成本的最优库存模型,确定可采用(s,S)策略进行库存控制,给出了最优(s,S)策略的充要条件--HJB方程Ⅰ、Ⅱ.我们采用"猜测"的方法确定了最优(s,S)策略对应的值函数形式,建立了确定库存参数的最优化模型. 相似文献
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《数学的实践与认识》2017,(23)
研究了带有服务员多重休假、损失销售和(s,S)补货策略的库存系统,其中顾客到达为泊松过程、休假时间及系统前置补货时间都服从指数分布.利用拟生灭过程方法对系统进行稳态分析,给出了带有休假的库存系统的稳态分布、平均库存和平均损失率,并将带有休假库存系统的性能指标与经典无休假库存系统的性能指标做了比较.最后通过数值算例说明服务员休假对库存系统的影响. 相似文献
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研究了基于(s,S)策略有不耐烦顾客的生产服务库存系统.建立了水平相依的拟生灭过程,通过截尾近似的方法求出系统稳态概率向量,并给出系统一些性能指标.最后,设计遗传算法并通过数值算例求解最优生产策略. 相似文献
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VMI条件下具有复合二项随机需求的销售商库存策略研究 总被引:1,自引:0,他引:1
考虑一个典型的单一产品的二级供应链系统:单供应商对单销售商,假定系统中销售商的需求分布为复合二项分布,未满足的需求机会损失;补货间隔时间为一随机变量.本文采用概率方法对销售商的需求分布、期望缺货、期望库存周期及库存的稳定性分布进行研究的基础上,构建了使单位时间内销售商的期望库存成本费用最小的库存模型,由此模型便可确定VMI模式下供应商对销售商的库存补货参数s和S,并且给出了在补货响应时间为泊松分布的情况下模型的求解算法,还给出了及时补货响应情况下的5个算例.为补货策略的实施提供了一种简单易于控制的思路和方法. 相似文献
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企业为了货源的稳定而与供应商签订一定期限内的订购框架协议,但如何实施订购策略以保障协议量的完成,保证满足需求的同时最小化企业的库存成本成为企业必须考虑的一个问题.传统的企业库存管理方法如(r,Q)、(s,S)等订购策略在一定程度上只考虑了如何满足需求,避免缺货,而没有考虑供应商的供货能力,在协议期内的总订购量只考虑了需求的影响,因而不能保证框架协议的完成.本文在(s,S)策略的基础上,考虑了框架协议的约束,提出了一种既能够保障框架协议的完成,又能够最大限度满足需求,同时降低企业库存成本的方法一“双表作业法”,并验证了方法的有效性. 相似文献
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研究具有不耐烦顾客和多重工作休假的M/M/1/N排队库存系统模型,分别考虑了系统中库存为零时服务员休假和系统中顾客数为零时服务员休假两种休假方式,基于(s,S)库存策略,运用矩阵迭代方法得到了系统稳态概率分布,并给出系统相关性能指标,进而建立系统平均库存费用函数.通过数值算例对比分析了两种休假方式下的系统主要参数变化对系统重要性能指标的影响,并在最优费用的层面对两个模型的优劣进行了对比分析. 相似文献
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在供应有限的情况下,研究常规补货和快速补货下商品动态定价问题.首先,建立了动态规划模型,理论证明了最优库存策略是基于(s,S)策略下改进的基本库存策略.其次,提出了一种启发式策略求复杂系统的最优策略,启发式算法能够求出最优价格和最优库存水平.最后,数值算例研究表明,库存管理中采用快速补货提高了零售商的利润;初始库存水平越高零售商的利润越高. 相似文献
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《随机分析与应用》2013,31(3):827-842
Abstract This paper analyzes an (s, S) Inventory system where arrivals of customers form a Poisson process. When inventory level reaches zero due to demands, further demands are sent to a pool which has capacity M(<∞). Service to the pooled customers will be provided after replenishment against the order placed on reaching that level s. Further they are served only if the inventory level is at least s + 1. The lead-time is exponentially distributed. The joint probability distribution of the number of customers in the pool and the Inventory level is obtained in both the transient and steady state cases. Some measures of the system performance in the steady state are derived and some numerical illustrations are provided. 相似文献
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Abstract In this article we consider a continuous review perishable inventory system in which the demands arrive according to a Markovian arrival process (MAP). The items in the inventory have shelf life times that are assumed to follow an exponential distribution. The inventory is replenished according to an (s, S) policy and the replenishing times are assumed to follow a phase type distribution. The demands that occur during stock out periods either enter a pool which has capacity N (<∞) or leave the system. Any demand that arrives when the pool is full and the inventory level is zero, is also assumed to be lost. The demands in the pool are selected one by one, if the replenished stock is above s, with interval time between any two successive selections is distributed as exponential with parameter depending on the number of customers in the pool. The joint probability distribution of the number of customers in the pool and the inventory level is obtained in the steady state case. The measures of system performance in the steady state are derived and the total expected cost rate is also calculated. The results are illustrated numerically. 相似文献
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本文研究了滞后时间为正的、连续盘点的 (s,S)易腐库存模型 .利用矩阵表示方法求出了平稳分布的递推表达式 ,证明了循环周期的分布服从 PH分布 ,并求得了费用函数 f (s,S.K) . 相似文献
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Abstract This article analyzes a two-commodity continuous review inventory system with renewal demands. The ordering policy is a combination of policies namely ordering individual commodities and ordering jointly both commodities. The steady state probability distribution for the joint inventory levels is computed. Various system performance measures in the steady state are derived. The results are illustrated numerically. 相似文献
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本文研究了Hanski et al(1991)提出的生态学模型dx/dt=r0x(1-x/k)-cxy/d+x-gx2/(h2+x2);dy/dt=s0y(1-qy/x)。对捕食者既有HollingⅡ型功能性反应,又有HollingⅢ型功能性反应,对食饵来说既有广食者又有专食者,本文将分析Hanski et al(1991)提出的模型的平衡点、极限环和全局渐近稳定性等动力学行为。 相似文献
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A. Bensoussan M. Çakanyildirim S. P. Sethi 《Journal of Optimization Theory and Applications》2006,130(2):153-172
Information delays exist when the most recent inventory information available to the inventory manager (IM) is dated; namely, the IM observes only the inventory level of an earlier period. We introduce information delays into the standard multiperiod stochastic inventory problem with backorders. We consider two types of information delays: (i) a constant delay and (ii) a random delay. We define an appropriate reference inventory position, which is a sufficient statistics for finding the optimal order quantity. We show that the optimal ordering policy is of base-stock type with respect to the reference inventory position and is of (s, S) type if there is also a fixed cost of ordering.All authors were supported in part by NSF Grant DMS-0509278. 相似文献
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A. Bensoussan M. Çakanyıldırım J. A. Minjárez-Sosa A. Royal S. P. Sethi 《Journal of Optimization Theory and Applications》2008,136(3):321-340
This paper considers the case of partially observed demand in the context of a multi-period inventory problem with lost sales.
Demand in a period is observed if it is less than the inventory level in that period and the leftover inventory is carried
over to the next period. Otherwise, only the event that it is larger than or equal to the inventory level is observed. These
observations are used to update the demand distributions over time. The state of the resulting dynamic program consists of
the current inventory level and the current demand distribution, which is infinite dimensional. The state evolution equation
for the demand distribution becomes linear with the use of unnormalized probabilities. We study two demand cases. First, the
demands evolve according to a Markov chain. Second, the demand distribution has an unknown parameter which is updated in the
Bayesian manner. In both cases, we prove the existence of an optimal feedback ordering policy.
Permanent address of J. Adolfo Minjárez-Sosa: Departamento de Matemáticas, Universidad de Sonora, Hermosillo, Sonora, México.
This project was partially supported by NSF Grant 0509278, ARPATP Grant 009741-0019-2006, and CONACYT (Mexico) Grant 46633-F. 相似文献
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This paper is concerned with long-run average cost minimization of a stochastic inventory problem with Markovian demand, fixed ordering cost, and convex surplus cost. The states of the Markov chain represent different possible states of the environment. Using a vanishing discount approach, a dynamic programming equation and the corresponding verification theorem are established. Finally, the existence of an optimal state-dependent (s, S) policy is proved. 相似文献
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This paper considers the standard deterministic inventory system for two products with a capacity constraint and describes how to find the optimal policy amongst all policies which have fixed order quantities. This involves the idea of staggered initial orders and periodic policies, and includes the classical Lagrange multiplier technique and the equal order intervals method as special cases. It is shown that the usual Lagrange multiplier technique will never produce the optimal policy (in the class described above) except in the trivial case, when the capacity constraint is satisfied by the optimal unconstrained policy. 相似文献