岩土边坡稳定性的遗传算法分析

非线性优化方法主要缺陷在于当边坡土层为非均质复杂条件时,无法保证搜索到安全系数的全局最小解,而只能搜索到局部极小解。基于遗传算法,建立了搜索岩土边坡稳定性分析最小安全系数和滑移面中心坐标与半径的数值方法。问题的可行解在变量搜索区间内搜索,包括滑弧的圆心坐标和半径。数值模拟结果表明,遗传算法搜索到的边坡稳定最小安全系数与理论解是一致的。     

中铁快运北京分公司配送网络优化研究

随着社会经济的发展,货物运输呈现几大趋势,其中包括货物运输的物流化。而物流作业(装卸搬运、储存、运输、包装、流通、加工、信息处理等)的很大部分都是在物流节点上完成的,所以,配送中心的选址是否合理直接影响配送中心各项经济活动的成本,同时也关系到企业的长久发展。针对中铁快运公司的具体实例,提出可行的网络优化设计方案,为中铁快运的决策提供支持。     

物流实时配送系统优化模型的构建与求解分析研究

为了解决物流实时配送系统过程的具体实施问题,以满足人们不断增长的物流需求,本文主要研究物流实时配送系统问题中,最优的配送中心个数,配送中心的选址,配送运输车辆行程路线安排,探讨寻求解决问题的有效方法,从而构建适当的运筹学数学模型,并对模型的求解进行深入透彻的分析研究,以实现整个集成物流系统的最小成本,从而实现最优化目标。为物流配送企业解决此类问题提供了思路和方法,并在部分企业进行了实证运用。     

基于两阶段法的多车型卷烟配送路径优化研究

在烟草商业企业中,物流是其重要的环节,是连接客户与烟草企业间的纽带,其卷烟配送线路设计的合理与否直接影响到卷烟的配送效率和配送成本,就如何合理的规划线路成为卷烟配送的关键问题。文章以Q烟草公司为例,运用先分组后路线的两阶段法对问题进行求解,先利用K-means聚类算法对区域进行划分,再考虑工作量均衡的条件下引入遗传算法对区域进一步调整,最后利用混合遗传算法对各配送区域进行线路优化,通过实例从线路数、车辆数、空载率、配送里程及总成本等指标上可以看出两阶段法的配送效果更优。     

Linkage Disequilibrium Mapping of Disease Susceptibility Genes in Human Populations

The paper reviews recent work on statistical methods for using linkage disequilibrium to locate disease susceptibility genes, given a set of marker genes at known positions in the genome. The paper starts by considering a simple deterministic model for linkage disequilibrium and discusses recent attempts to elaborate it to include the effects of stochastic influences, of drift, by the use of either Writht-Fisher models or by approaches based on the coalescence of the genealogy of the sample of disease chromosomes. Most of this first part of the paper concerns a series of diallelic markers and, in this case, the models so far proposed are hierarchical probability models for multivariate binary data. Likelihoods are intractable and most approaches to linkage disequilibrium mapping amount to marginal models for pairwise associations between individual markers and the disease susceptibility locus. Approaches to evalutation of a full likelihood require Monte Carlo methods in order to integrate over the large number of unknowns. The fact that the initial state of the stochastic process which has led to present-day allele frequencies is unknown is noted and its implications for the hierarchical probability model is discussed. Difficulties and opportunities arising as a result of more polymorphic markers and extended marker haplotypes are indicated. Connections between the hierarchical modelling approach and methods based upon identity by descent and haplotype sharing by seemingly unrelated case are explored. Finally problems resulting from unknown modes of inheritance, incomplete penetrance, and phenocopies are briefly reviewed.     

基于两层架构协调的应急物资分配与车辆调度集成优化方法

针对突发事件下的应急物资调运问题,考虑了多个地区同时受灾以及多个出救点需要对其进行救灾并且各出救点的运力有限的情况,以最小化总的车辆运输费用,最大化救灾效率、各受灾点的救灾满意度,以及各受灾点得到救助的公平性为目标,建立了该问题的多目标混合整数非线性规划模型,并提出了一个基于两层架构协调的迭代式遗传算法进行求解。基于仿真数据的实验结果证明了所提出的模型和算法的有效性。     

The Geographic Extent of the Market for Soybeans and Soybean Products

This study looks at the question of whether soybeans, soybean meal, and soybean oil produced in the United States and exported were part of a single, world geographic market during the decade of the 1980s. An answer to this question is sought using an approach to defining a geographic market based on the notion of instantaneous causality. The empirical results suggest that there was but a single identifiable world market for these commodities over the period of study.     

基于遗传算法的模糊控制器参数优化

针对非线性量化因子模糊控制器的参数对系统性能影响和参数间的相互制约,提出了一种基于遗传算法的参数整定与优化方法,并进行了仿真研究。仿真结果表明通过该方法寻优的系统具有更好的响应速度和控制精度；当对象结构或参数发生变化时,非线性量化因子模糊控制器可以重新整定参数,以保持良好的控制效果,具有很强的鲁棒性。     

基于RAGA的PPE模型在物流管理综合评价中的应用

目前,在物流管理研究中,不确定分析方法占有重要位置,但这些传统的评价方法需要人为确定各个评价指标的权重系数,存在较大的主观性和人为干扰因素。论文应用一种新兴的评价方法——投影寻踪模型,对物流发展进行综合评价,克服了人为因素的干扰,取得了满意的评价结果,为物流发展综合评价提供了一条新的思路,为今后的物流管理提供科学依据。