共查询到19条相似文献,搜索用时 171 毫秒
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为确定影响维修保障信息分析结果不确定性的关键输入参数,提出一种基于熵的不确定性敏感性分析方法.首先分析了模型输出结果的不确定性的表现形式、度量方法、产生机制;其次基于条件熵思想给出分析不确定性的敏感性参数以及敏感性分析方法;然后,简单介绍了盲数理论在计算不确定性数据中的应用;最后,结合平均维修时间模型进行了案例研究,说明了基于熵的不确定性敏感性分析方法的可用性,并证明了不确定性敏感性分析与求导不能等同的结论. 相似文献
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库存不确定性问题是供应链不确定性研究的重点之一.利用粒子群优化算法快速搜寻最优解的优点对库存不确定性问题进行仿真分析,得出了库存不确定性环境下的最优解,这说明了粒子群优化算法能够辅助供应链管理者在不确定性环境下对供应链进行优化设计和决策分析. 相似文献
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针对精益、敏捷、精敏供应链范式选择决策涉及到多种定性指标和定量指标这一特点,提出一种基于模糊集理论、熵和TOPSIS的混合型多属性决策模型。为了避免主观赋权法无法反映客观条件变化,或客观赋权法无法反映专家经验的双重弊端,在对定量指标赋权时,采用主观赋权的三角模糊数法和客观赋权的熵权法对定量指标进行组合赋权。对于定性指标仅依靠三角模糊数法确定其权重。然后,运用fuzzy TOPSIS法选择出最佳的供应链范式。最后通过实例对模型进行验证以及对评价指标权重进行敏感性分析,证实了该模型能为企业选择适用自身运作的供应链范式提供高效方法。 相似文献
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《数学的实践与认识》2017,(21)
工程招投标已成为建筑市场最主要的竞争模式,投标决策是建筑企业必须面对和要解决的首要难题.在分析投标风险因素的基础上,针对投标风险影响因素众多且复杂,不确定性等特点,提出基于粗糙集理论和相对熵的投标优选模型.首先,分别运用层次分析法和改进的粗糙集条件信息熵确定指标主、客观权重,然后采用博弈集结模型对指标主客观权重进行组合赋权.其次,针对TOPSIS决策模型的不足,运用相对熵理论构建投标优选模型对投标项目进行投标决策.最后,结合工程实例并运用相对熵投标决策模型对投标项目进行优选,验证模型的合理性和可操作性. 相似文献
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竞争供应链的结构和链内协调策略分析 总被引:3,自引:0,他引:3
供应链的结构及供应链竞争环境下的链内协调问题是供应链管理的核心问题。本文利用超网络方法分析供应链运作过程,建立了两条竞争供应链的超网络结构;已知产品总需求的随机分布函数,运用顾客选择理论得到每条供应链的产品需求情况;利用博弈理论和Newsvendor模型,得到了供应链竞争环境下可协调链内成员的收益共享合同。最后的算例表明:供应链协调可以提高供应链的运作效率,但协调供应链间的竞争将更激烈,可能出现囚徒困境现象。 相似文献
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郭进利 《数学的实践与认识》2012,42(13):105-116
针对信息量是消息发生前的不确定性给出一个直观测量信息量公式.为了克服Shannon熵的局限性和分析信息度量本质,借鉴距离空间理论中度量公理定义的思路,通过非负性、对称性、次可加和极大性给出信息熵的公理化新定义.将Shannon熵、直观信息熵和β-熵等不同形式的信息度量统一在同一公理化结构下.应用直观信息熵公式仅采用四则运算进行决策树分析,避免了利用Shannon熵公式的对数运算. 相似文献
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《European Journal of Operational Research》1998,109(2):299-309
This paper describes fuzzy modelling and simulation of a supply chain (SC) in an uncertain environment, as the first step in developing a decision support system. An SC is viewed as a series of facilities that performs the procurement of raw material, its transformation to intermediate and end-products, and distribution and selling of the end-products to customers. All the facilities in the SC are coupled and interrelated in a way that decisions made at one facility affect the performance of others. SC fuzzy models and a simulator cover operational SC control. The objective is to determine the stock levels and order quantities for each inventory in an SC during a finite time horizon to obtain an acceptable delivery performance at a reasonable total cost for the whole SC. Two sources of uncertainty inherent in the external environment in which the SC operates were identified and modelled: customer demand and external supply of raw material. They were interpreted and represented by fuzzy sets. In addition to the fuzzy SC models, a special SC simulator was developed. The SC simulator provides a dynamic view of the SC and assesses the impact of decisions recommended by the SC fuzzy models on SC performance. 相似文献
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假定生产商委托零售商回收废旧产品以进行再制造活动,研究两条分别由单生产商和单零售商组成的闭环供应链的竞争和链内协调。对应两条闭环供应链均为分散式供应链、均为集中式供应链、一条为分散式供应链另一条为集中式供应链,运用博弈论和均衡分析方法分别建立了三种情况下刻画闭环供应链竞争的带均衡约束的均衡模型、纳什均衡模型和带均衡约束的优化模型,进行了模型求解。基于合同理论,提出供应链竞争下协调链内零售商的零售价和回收价格决策的批发价加回收补贴合同。最后的算例验证了模型的合理性和协调合同的有效性。研究表明:产品零售价、需求量与产品替代效应正相关,废旧产品供给量、供应链利润与回收价格敏感性正相关;供应链协调是供应链竞争下的占优策略,有利于提高供应链的运作效率,但两条协调供应链之间的竞争将更激烈,存在囚徒困境现象。 相似文献
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本文研究供需同时不确定条件下考虑双边努力的供应链契约设计问题,在一个供应商和一个零售商组成的二级供应链系统中,供应商的努力影响产量的不确定性,零售商的努力影响市场需求的不确定性。首先,利用Stackerberg主从博弈模型计算了分散决策时零售商、供应商的最优期望利润,并将计算结果与集中决策时供应链整体的最优期望利润进行对比。由于双重边际效应的存在,分散决策时供应链的最优期望利润小于集中决策时供应链的最优期望利润。基于此,本文设计了回购和成本分担组合契约来协调该供应链,计算了回购价格和成本分担系数的表达式,得到了回购和成本分担契约下供应商和零售商的最优期望利润。结果表明,在特定条件下,该组合契约不仅可以协调供应链,还可以实现供应链利润的任意分配。最后,通过数值计算,分析了供需双方的决策变量和期望利润随契约参数的变化情况。 相似文献
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In the past few years the literature on supply chain management has widely emphasized that cooperation among supply chain (SC) firms is a key source of competitive advantage. This paper explores the topic in a particular context, i.e. the industrial district (ID), which constitutes a specific production model where complex SC networks can be identified. SC cooperation may take on several forms in IDs and may produce several benefits (e.g. upgrading quality and reducing costs) so this paper also analyzes the benefits of a specific form of SC cooperation in different competitive scenarios and for diverse ID organizational structures. An agent-based model of SC cooperation in IDs has been developed and a simulation analysis carried out. 相似文献
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A fuzzy linear programming based approach for tactical supply chain planning in an uncertainty environment 总被引:1,自引:0,他引:1
David Peidro Josefa Mula Mariano Jiménez Ma del Mar Botella 《European Journal of Operational Research》2010
This paper models supply chain (SC) uncertainties by fuzzy sets and develops a fuzzy linear programming model for tactical supply chain planning in a multi-echelon, multi-product, multi-level, multi-period supply chain network. In this approach, the demand, process and supply uncertainties are jointly considered. The aim is to centralize multi-node decisions simultaneously to achieve the best use of the available resources along the time horizon so that customer demands are met at a minimum cost. This proposal is tested by using data from a real automobile SC. The fuzzy model provides the decision maker (DM) with alternative decision plans with different degrees of satisfaction. 相似文献
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《European Journal of Operational Research》2006,171(1):123-134
A better management of time uncertainty in major equipment procurement in engineering construction projects can significantly contribute to project performance. A survey study shows that time buffer is a popularly used approach to protect project schedule from activity duration variation and uncertainty. The problem is that there are repetitive time allowances inserted in the procurement supply chain process and these time buffers are used ineffectively, thus leading to considerable time wastage. Relevant lessons from supply chain management and critical chain project management are combined and applied to create an enhanced critical supply chain management model for major equipment procurement to achieve better management of time uncertainty. This model does not perceive uncertainty purely as a threat, but also as an opportunity to reduce procurement cycle times. 相似文献
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Integrating effective flexibility measures into a strategic supply chain planning model 总被引:1,自引:0,他引:1
Kanchan Das 《European Journal of Operational Research》2011,211(1):170-183
This paper develops models for capacity, product mix, distribution and input supply flexibility and integrates them in a strategic level, mixed integer supply chain (SC) planning model as a way of addressing demand and supply uncertainty, as well as improving market responsiveness. Capacity flexibility is modeled via the SC’s production capacity planning to address budgeted demand and ensure the fulfillment of prospective demand increases when considering various market scenarios. This model selects an optimal number of products from fast moving and extended product range options—based on the product mix flexibility. The model confirms a quick response to a changing marketplace by considering elements like transportation and supply lead time along with the probabilities of stock out options when addressing input supply and distribution flexibility. This paper proposes a solution procedure to solve the model for real world problems, and investigates the sensitivity of the model outputs with respect to changes in flexibility measures. 相似文献
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This paper models supply chain (SC) uncertainties by fuzzy sets and develops a possibilistic SC configuration model for new products with unreliable or unavailable SC statistical data. The supply chain is modeled as a network of stages. Each stage may have one or more options characterized by the cost and lead-time required to fulfill required functions and may hold safety stock to prevent an inventory shortage. The objective is to determine the option and inventory policy for each stage to minimize the total SC cost and maximize the possibility of fulfilling the target service level. A fuzzy SC model is developed to evaluate the performance of the entire SC and a genetic algorithm approach is applied to determine near-optimal solutions. The results obtained show that the proposed approach allows decision makers to perform trade-off analysis among customer service levels, product cost, and inventory investment depending on their risk attitude. It also provides an alternative tool to evaluate and improve SC configuration decisions in an uncertain SC environment. 相似文献
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收益共享契约是实现供应链系统绩效改善或完美协调的一种机制.考虑了零售商与供应商分别具有风险厌恶决策偏好情况下,在随机市场需求下建立了由单供应商和单零售商组成的二级供应链的收益共享契约模型,并对模型进行了分析,揭示了供应商和零售商的风险厌恶决策偏好对收益共享契约参数的影响.研究结果表明:当销售商(供应商)的风险厌恶控制在... 相似文献