一种变量是梯形模糊数的两层多随从线性规划模型及其算法

针对具有递阶特征的多层管理系统,本文建立了一种变量为梯形模糊数的两层多随处线性规划模型.利用模糊结构元理论,通过模糊数的结构元加权序,将梯形模糊数的排序转化为单调有界函数的排序,从而证明了该模型的最优解等价于两层多随处线性规划模型的最优解;进而提出了求解该模型的有效算法.最后,通过两个数值算例验证了该方法的可行性.     

模糊关系方程的解的模糊遗传导优算法

在一般遗传算法ＧＡ的基础上，基于模糊集理论中的模糊关系方程的解的寻优问题提出了模糊遗传算法ＦＧＡ，它能有效地找出模糊关系方程的解的寻优问题的近似最优解。美学 给出了一个重要的定理：模糊模式定理。     

模糊关系方程的解的模糊遗传寻优算法

在一般遗传算法ＧＡ的基础上，基于模糊集理论中的模糊关系方程的解的寻优问题提出了模糊遗传算法ＦＧＡ，它能有效地找出模糊关系方程的解的寻优问题的近似最优解。还给出了一个重要的定理：模糊模式定理。     

一类变量为梯形模糊数的线性规划

针对变量为梯形模糊数的模糊线性规划问题,利用结构元方法定义了一种模糊数的排序准则,讨论了如何将变量是梯形模糊数的线性规划去模糊化,即将含有变量为梯形模糊数的模糊线性规划转化为经典模糊线性规划.同时,证明了该模型的最优解等价于经典的线性规划的最优解,再利用单纯形法求出最优解.并设计了求解该类模型的算法.通过算例验证了该方法的可行性和算法的有效性,从而为变量模糊的广义模糊线性规划问题的研究提供了新的方法.     

模糊环境下企业最优外币持有量模型研究

提出模糊环境下企业最优外币持有量模型.引入采用LR型模糊数符号距离的求解的方法.提出LR型模糊数形式运算的计算方法,并指出在所论问题中LR型模糊数对形式运算的封闭性,提出最优解求解的步骤并编制计算机程序以用于实际计算.举出示例,得出最优持有量为22.5万元的结论.     

模糊环境下考虑供应中断的再制造闭环供应链研究

为研究需求和回收品质量模糊不确定环境下供应中断对再制造闭环供应链的影响,建立了系统总成本模型。运用模糊机会约束规划方法解决模型中不确定性问题,并采用遗传算法和粒子群算法来寻找算例的最优解。结果表明：在不同需求量和回收品质量的水平下企业成本有不同的变化;随着供应中断概率的增加,平均总成本也随之增加。因此,再制造企业在面临需求量和回收品质量模糊不确定的环境时,应尽量避免供应中断,制定符合企业发展的运作计划。     

多目标全系数模糊线性规划

在模糊线性规划理论的基础上,对同时含有等式约束和不等式约束的多目标全系数模糊线性规划的最优解进行研究。首先定义了目标协调度的概念,然后以目标协调度最大化为最优性条件,提出多目标全系数模糊线性规划的模糊最优解的定义,最后给出一种可行的求解方法。     

一种运用遗传算法确定船舶航向控制模糊规则的方法

为了克服船舶航向控制模糊规则确定过程中的盲目性，引入一种与之相适应的遗传算法，以使结果成为某种意义下的最优解，从而从根本上解决这一重要问题．文中运用Matlab的C语言MEX—文件技术，将遗传算法源代码与Matlab直接结合起来，利用后者的强大建模能力，建立起完整的仿真模型．仿真结果表明，船舶的航向控制能力得到明显改善．     

预应力开孔梁模糊优化设计

本文在前期工作的基础上,建立预应力开孔梁优化模型,采用模糊理论对优化模型的约束边界进行合理的模糊化处理,并讨论研究在不同约束条件下预应力开孔梁的局部最优解。最后,通过综合评判,得到价格性能比最优的满意解。     

基于模糊层次分析法的模块创建方法

面向大规模定制模块创建面临一个由相互关联的各个部分构成的复杂系统,解决的关键在于如何在一系列非劣解中确定最优解.本文利用基于三角模糊数的模糊层次分析法对减速器模块方案评判进行论述,结果表明该方法可以解决面向大规模定制的产品模块评价问题.     

Fuzzy goal programming for material requirements planning under uncertainty and integrity conditions

In this paper, we formulate the material requirements planning) problem of a first-tier supplier in an automobile supply chain through a fuzzy multi-objective decision model, which considers three conflictive objectives to optimise: minimisation of normal, overtime and subcontracted production costs of finished goods plus the inventory costs of finished goods, raw materials and components; minimisation of idle time; minimisation of backorder quantities. Lack of knowledge or epistemic uncertainty is considered in the demand, available and required capacity data. Integrity conditions for the main decision variables of the problem are also considered. For the solution methodology, we use a fuzzy goal programming approach where the importance of the relations among the goals is considered fuzzy instead of using a crisp definition of goal weights. For illustration purposes, an example based on modifications of real-world industrial problems is used.     

基于模糊需求的三级供应链库存协调策略

以一个制造商、一个分销商和一个零售商组成的三级供应链系统为研究对象,将市场需求预测视为一个三角模糊数,利用模糊数学工具和运筹学计算得到了无协调机制情况下供应链成员企业面对模糊需求时最优决策的具体表达式。然后,在此基础之上,通过构建一个关于分销商的目标规划问题建立了基于转移支付的三级供应链库存协调模型。为了验证模型的有效性和可行性,设计了一个应用算例。算例分析表明:在模糊需求环境下,利用转移支付协调机制,制造商和零售商的收益不变,但分销商和供应链的总收益增加了。     

一类劳动力受限的模糊集约生产计划

通过对模糊需求量和模糊等式的描述，建立了模糊环境下具有劳动力水平约束的集约生产计划模型，利用区间数规划方法将其进一步转化为清晰型的一般参数规划问题来求解。决策者可以根据自已的主观判断和客观情况，对约束条件水平做出不同的估计，从而得到在相应情况下的满意解，使决策过程更具柔性。     

集成模糊Kano模型和余弦相似度的顾客需求满意度测评

目的 在企业发展过程中,对顾客需求的满意度测评有助于企业发现问题与不足,以便更好地满足顾客需求。为使顾客需求满意度的评价结果更加科学有效,提出一种集成模糊Kano模型和余弦相似度的顾客需求满意度测评方法。方法 通过前期问卷调研和深度访谈获得顾客需求要素作为满意度测评的对象,利用模糊Kano模型分析顾客对需求要素的满意程度值及其属性分类,采用余弦相似度计算各个需求要素的满意程度值与其最优值之间的相似度值,得到顾客需求满意度的权重值,通过顾客需求的属性调整系数对顾客需求满意度权重值进行调整,得到最终的顾客需求满意度测评值。结论 将模糊Kano模型与余弦相似度相结合对顾客需求的满意度进行测评研究,以某公司电动汽车充电设备的顾客需求满意度测评为例,并与现有的满意度计算方法进行对比分析,验证了所提方法的可行性和有效性。     

Integrated inventory models with fuzzy annual demand and fuzzy production rate in a supply chain

The successful implementation of Just-in-time (JIT) production in today's supply chain environment requires a new spirit of cooperation between the buyer and the vendor. An integrated inventory model with such a consideration is based on the total cost optimization under a common stock policy and business formula. However, the supposition of known annual demand in most related literature may not be realistic. This paper proposes the inclusion of fuzzy annual demand and/or the production rate, and then employs the signed distance, a ranking method for fuzzy numbers, to find the estimate of the common total cost in the fuzzy sense, and subsequently derives the corresponding optimal buyer's quantity and the integer number of lots in which the items are delivered from the vendor to the purchaser. Numerical examples are provided to illustrate the results of proposed models.     

A simulated annealing algorithm to the multi-period fixed charge distribution problem associated with backorder and inventory

This paper addresses a multi-period fixed charge distribution problem associated with backorder and inventory. The objective is to determine the size of the shipments, backorder and inventory at each period, so that the total cost incurred during the entire period towards transportation, backorder and inventory is minimised. A pure integer non-linear programming problem is formulated. A simulated annealing based heuristic is proposed to solve and is illustrated. The proposed methodology is evaluated by comparing its solutions with the lower bound and equivalent variable cost solutions. The comparisons reveal that the simulated annealing generates better solutions than the equivalent variable cost solutions and is capable of providing solutions closer to the lower bound solutions of the problems.     

A membership function approach to lot size re-order point inventory problems in fuzzy environments

Inventory models play an important role in logistics and supply chain management for reducing cost and increasing customer satisfaction. This paper develops an approach to derive the fuzzy objective value and decision variables of the fuzzy lot size re-order point inventory problem with parameters being fuzzy numbers and the shortages are backordered with extra cost incurred. Different from the existing studies, the idea is based on Zadeh's extension principle. A pair of mixed integer nonlinear programs (MINLP) parameterised by the possibility level α is formulated to calculate the lower and upper bounds of the minimal total cost per unit time at α, through which the membership function of the minimal total cost per unit time is constructed. At the same time the membership functions of the optimal order quantity and the optimal re-order point are also provided. A numerical example studied by previous studies is solved successfully to demonstrate the validity of the proposed method. Compared with previous studies, the obtained results which precisely and completely conserve the fuzziness of the input information are more informative for finding the best inventory policy since they are expressed by membership functions rather than by crisp ones. Moreover, to provide representative crisp solutions for designing inventory systems, the Yager's ranking index method is adopted to defuzzify the obtained membership functions. The successful extension of inventory models to fuzzy environments permits inventory models to have wider applications in practice.     

应用作业成本法的模糊EPQ模型

应用作业成本法,研究了库容有限且缺陷产品可修复的经济生产批量问题。考虑企业自身库容有限及缺陷产品可修复,在系统中存在多个模糊参数的情况下,建立了一个基于作业成本法的模糊期望值模型,通过求解该模型确定出最佳生产批量和最大缺货量。最后的数值例子说明了所建模型是有效可行的。     

Multimodal Fuzzy Downstream Petroleum Supply Chain: A Novel Pentagonal Fuzzy Optimization

The petroleum industry has a complex, inflexible and challenging supply chain (SC) that impacts both the national economy as well as people’s daily lives with a range of services, including transportation, heating, electricity, lubricants, as well as chemicals and petrochemicals. In the petroleum industry, supply chain management presents several challenges, especially in the logistics sector, that are not found in other industries. In addition, logistical challenges contribute significantly to the cost of oil. Uncertainty regarding customer demand and supply significantly affects SC networks. Hence, SC flexibility can be maintained by addressing uncertainty. On the other hand, in the real world, decision-making challenges are often ambiguous or vague. In some cases, measurements are incorrect owing to measurement errors, instrument faults, etc., which lead to a pentagonal fuzzy number (PFN) which is the extension of a fuzzy number. Therefore, it is necessary to develop quantitative models to optimize logistics operations and supply chain networks. This study proposed a linear programming model under an uncertain environment. The model minimizes the cost along the refineries, depots, multimode transport and demand nodes. Further developed pentagonal fuzzy optimization, an alternative approach is developed to solve the downstream supply chain using the mixed-integer linear programming (MILP) model to obtain a feasible solution to the fuzzy transportation cost problem. In this model, the coefficient of the transportation costs and parameters is assumed to be a pentagonal fuzzy number. Furthermore, defuzzification is performed using an accuracy function. To validate the model and technique and feasibility solution, an illustrative example of the oil and gas SC is considered, providing improved results compared with existing techniques and demonstrating its ability to benefit petroleum companies is the objective of this study.     

Fuzzy multi-objective optimisation for master planning in a ceramic supply chain

In this paper, we consider the master planning problem for a centralised replenishment, production and distribution ceramic tile supply chain. A fuzzy multi-objective linear programming (FMOLP) approach is presented which considers the maximisation of the fuzzy gross margin, the minimisation of the fuzzy idle time and the minimisation of the fuzzy backorder quantities. By using an interactive solution methodology to convert this FMOLP model into an auxiliary crisp single-objective linear model, a preferred compromise solution is obtained. For illustration purposes, an example based on modifications of real-world industrial problems is used.