城市多网点配送车辆调度模型与算法研究

通过对城市多网点车辆调度特点的深入分析和研究,建立了追求总体效益最优的多网点车辆调度多目标决策模型,并设计了求解该模型有效的启发式算法。     

基于RBF神经网络集成的供应商评价方法

供应链管理代表了当前经济环境下的趋势与需求,其中的伙伴企业选择是其主要研究的问题之一.本文提出了一种基于径向基函数神经网络集成的供应商识别方法.该方法首先通过系统聚类,在每一类中单独训练具有一定差异度的单个径向基函数神经网络,并加以集成,构成以系统聚类与RBF神经网络相结合的模型,以解决供应链的企业伙伴选择问题.最后以企业为背景,运用这种模型解决实际问题,并给出了结果.     

最短路径算法在物流中心选址中的应用

分析了目前物流中心选址最常用的线性规划法和重心法的不足，阐述了利用图论中最短路径算法进行选址的新思路，使选址方法更符合实际，更合理。     

A note on multinomial maximum likelihood estimation under ordered restrictions and the EM algorithm

A frequently occurring problem is to find the maximum likelihood estimation (MLE) of p subject to p∈C (C⊂ P the probability vectors in R ^k ). The problem has been discussed by many authors and they mainly focused when p is restricted by linear constraints or log-linear constraints. In this paper, we construct the relationship between the the maximum likelihood estimation of p restricted by p∈C and EM algorithm and demonstrate that the maximum likelihood estimator can be computed through the EM algorithm (Dempster et al. in J R Stat Soc Ser B 39:1–38, 1997). Several examples are analyzed by the proposed method.     

A genetic algorithm for the partial binary constraint satisfaction problem: an application to a frequency assignment problem

We describe a genetic algorithm for the partial constraint satisfaction problem. The typical elements of a genetic algorithm, selection, mutation and cross-over, are filled in with combinatorial ideas. For instance, cross-over of two solutions is performed by taking the one or two domain elements in the solutions of each of the variables as the complete domain of the variable. Then a branch-and-bound method is used for solving this small instance. When tested on a class of frequency assignment problems this genetic algorithm produced the best known solutions for all test problems. This feeds the idea that combinatorial ideas may well be useful in genetic algorithms.     

基于改进遗传算法的TSP问题优化研究

旅行商问题（TSP问题）已经被证明属于NP完全问题。遗传算法是一种模拟自然界中生物的进化机制的优化策略．是一种基于群体、隐并行搜索策略，是求解TSP问题效率相当高的一种算法。因此．本文提出使用改进的遗传算法．即用个体数量控制选择策略以保证群体的多样性，用顺序交叉算子和部分路径翻转变异算子来提高算法的收敛速度．较好地解决了群体的多样性和收敛速度的矛盾。算法的分析和测试表明．该改进算法的是有效的。     

Grants structure when the type of public project is endogenous

This paper gives an insight into changes in intergovernmental grants structure, focusing on the type of public project. Presenting a simple model which incorporates the endogenous determination of project type and grants structure, the results show that as the relative cost encountered by central government in collecting public funds increases, the central government tends to choose types of projects which local governments prefer and adopt block grant systems. The resulting equilibrium is compared with an optimal solution based on an utilitarian welfare function. Received: December 22, 2000 / Accepted: September 20, 2001     

运输商选择与配送中心选址联合优化研究——基于供应链系统观念

系统观念是供应链管理的一个重要思想,它要求将供应链做为一个各环节相互联系的有机整体,而不是孤立的阶段.本文基于供应链管理的系统观念,将传统上孤立研究的运输商选择问题与配送中心选址问题结合起来,考虑供应链核心企业管理多个运输商的成本（文中称为C成本）,建立运输商--配送中心联合优化模型[TDJOM],以实现供应链中这两个问题领域的联合优化,实现整体最优,同时设计了一种启发式算法,将非线性规划转为线性规划求解,避免了现有的各种非线性规划求解算法往往只能求得近似最优解的缺陷.本文用算例证明了模型和算法的有效性.     

物流工程投资中的净现值方法

运用AoA网络方法提出物流工程投资与规划的最大净现值模型，然后将其变换为线性规划问题，通过对偶原理将问题的计算化为可行树的搜索问题，最后给出了求解最大化净现值的算法设计，从而为现代物流工程投资与规划提供了有效的解决方法。     

基于灰色理论和模糊数学综合集成算法的第三方物流企业绩效评价体系研究

随着第三方物流在我国的不断发展，客观上要求建立有效实际的第三方物流企业绩效评价体系和方法，以便科学、客观地反映第三方物流企业的运营情况。为了解决这个问题，本文就介绍了一种切实可行的综合集成算法，它是由灰色理论和模糊数学综合集成而成的。