求旅行商(TSP)问题的几种改进遗传算法的比较分析

随着现代科技的发展,待研究问题的规模与难度越来越大,单一的算法已经不能很好地解决问题。本文在阅读了大量关于混合遗传算法论文的基础上,总结了三种能够比较有效地求解旅行商(TSP)问题的改进型遗传算法,并阐述了它们的基本思想以及操作步骤。最后指出了它们的优缺点和今后的研究方向。     

基于模拟工况的电动汽车动力电池化成监测系统

针对常规电池化成方法的初期容量不合格、化成过度、效率低等不足,提出了基于模拟工况的电池化成新方法.系统采用模块化设计和网络控制技术,以单片机控制器为核心构成控制管理模块,在模拟实际工况的基础上,完成对电池化成过程的控制和管理;用AC/DC、DC/AC变换器实现能量的转换,完成对电池的充放电.运行结果表明,能够提高电池生产的效率和电池化成质量,延长电动汽车电池使用寿命和充电行驶里程.     

一种位场数据补充的插值法数学模型

指出位场函数具有变化梯度大等特点，与多项式函数的特性相差甚远，用拉格朗日插值法公式计算的插值精度低、可靠性差。当待插点离已知点较远时，几乎没有参考的价值。根据位场函数的特点，依据指数函数拟合位场函数导出指数函数拟合法插值公式。用这种插值公式内插补充和外推（包含向上和向下延拓计算）在理论模型上和在实际矿区上试算都证明了指数函数拟合法插值公式在位场数据补充上是一种精度比较高的插值数学模型。     

A New Capacitated Vehicle Routing Problem with Split Service for Minimizing Fleet Cost by Simulated Annealing

We address a capacitated vehicle routing problem (CVRP) in which the demand of a node can be split on several vehicles celled split services by assuming heterogeneous fixed fleet. The objective is to minimize the fleet cost and total distance traveled. The fleet cost is dependent on the number of vehicles used and the total unused capacity. In most practical cases, especially in urban transportation, several vehicles transiting on a demand point occurs. Thus, the split services can aid to minimize the number of used vehicles by maximizing the capacity utilization. This paper presents a mix-integer linear model of a CVRP with split services and heterogeneous fleet. This model is then solved by using a simulated annealing (SA) method. Our analysis suggests that the proposed model enables users to establish routes to serve all given customers using the minimum number of vehicles and maximum capacity. Our proposed method can also find very good solutions in a reasonable amount of time. To illustrate these solutions further, a number of test problems in small and large sizes are solved and computational results are reported in the paper.     

计算机检索模拟系统的研制

机检教学实习长春困扰着从事文献检索课教学的教师们,尤其是对那些条件稍差一些的高等院校,本文介绍了一种自行研制的计算机检索模拟系统,包括它的设计思想,系统结构及其检索功能和特点。     

Caprine cardiac sarcoplasmic reticulum: Effect of simulated ischemia on membrane structure and Ca<Superscript>2+</Superscript>-ATPase activity

The sarcoplasmic reticulum was isolated and characterized in the pure form from normal caprine (Capra hircus) hearts. Under ischemic condition, fatty acids like palmitic acid, palmitoyl carnitine and oleic acid accumulatein vivo. These are known to have a detrimental effect on membrane components. The effects of simulated ischemia on the Ca²⁺-ATPase were studied using these fatty acidsin vitro at concentrations at which they occurin vivo in the ischemic heart. All three fatty acids inhibited Ca²⁺-ATPase activity. At lower concentrations, palmitoyl carnitine was the most potent, followed by oleic acid while palmitic acid displayed the least potency. Electron microscopy studies with fatty acids showed morphological disruptions in SR vesicles. The decline in Ca²⁺-ATPase activity could be attributed to the change in membrane morphology.     

A comparison of the physiological response to simulated altitude exposure and r-HuEpo administration

Concerns have been raised about the morality of using simulated altitude facilities in an attempt to improve athletic performance. One assumption that has been influential in this debate is the belief that altitude houses simply mimic the physiological effects of illegal recombinant human erythropoietin (r-HuEpo) doping. To test the validity of this assumption, the haematological and physiological responses of 23 well-trained athletes exposed to a simulated altitude of 2650-3000 m for 11-23 nights were contrasted with those of healthy volunteers receiving a low dose (150 IU·kg^-1 per week) of r-HuEpo for 25 days. Serial blood samples were analysed for serum erythropoietin and percent reticulocytes; maximal oxygen uptake ([Vdot]O_2max) was assessed before and after r-HuEpo administration or simulated altitude exposure. The group mean increase in serum erythropoietin (422% for r-HuEpo vs 59% for simulated altitude), percent reticulocytes (89% vs 30%) and [Vdot]O_2max (6.6% vs -2.0%) indicated that simulated altitude did not induce the changes obtained with r-HuEpo administration. Based on the disparity of these responses, we conclude that simulated altitude facilities should not be considered unethical based solely on the tenet that they provide an alternative means of obtaining the benefits sought by illegal r-HuEpo doping.     

多种群自适应模拟退火遗传算法求解TSP问题

TSP问题是一个具有广泛应用背景和重要理论价值的组合优化NP难题。遗传算法是求解NP完全问题的一种方法。针对传统遗传算法求解TSP问题的不足,提出了一种多种群自适应模拟退火遗传算法,并给出了多种群分级、混合变异算子的设计。最后,对CHN31、ATT48和EIL51的TSP问题进行求解．仿真结果表明该改进遗传算法具有更好的收敛性,可以得到更好的最优解。     

用模拟退火算法解决生产调度问题

介绍了Metropolis准则，给出了模拟退火算法解决生产调度问题的基本方法和步骤，并对算法的有效性进行了验证．     

Hybrid discrete particle swarm optimization algorithm for capacitated vehicle routing problem

INTRODUCTION The vehicle routing problem (VRP), which was first introduced by Dantzig and Ramser (1959), is a well-known combinatorial optimization problem in the field of service operations management and logis- tics. The capacitated vehicle routing problem (CVRP) is an NP-hard problem for simultaneously determining the routes for several vehicles from a central depot to a set of customers, and then return to the depot without exceeding the capacity constraints of each vehicle. In pr…