MRO parts service in the machine tool industry

This article examines the post purchase Parts servicing of Machine Tools. Survey results outline the policies and criteria that influence the degree to which replacement parts will be provided for old machines. The survey indicates that the policies of some American manufacturers leave service gaps that can be exploited by foreign as well as domestic competitors.     

Characteristics of growth and limitations in electronics

Since its origin about 75 years ago, electronics has grown faster than any other major engineering discipline. Analysis of the essential characteristics of electronics leads to the conclusion that the normal growth-limiting mechanisms are not operative in this area. The commitment of electronics to information handling is stipulated and it is concluded that electronic information processing is a new milestone in a field that is vital for human survival and that is as old as mankind. Though growth in electronics is open-ended, as in other engineering branches, developments within the field are subject to recognizable constraints. These constraints are identified and classified. Most of them turn out to be relative and sliding with the progress of time. The consequences of changing patterns of constraints are illustrated on past developments and their possible impact on future trends is brought forward.     

免疫遗传算法的分析与研究

遗传算法GA在理论上己经形成了一套较为完善的算法体系,然而在实际使用中,还有许多问题有待于进一步改进.例如,对于多峰函数的优化问题,它往往会收敛于局部极值.这使得遗传算法的收敛精度大大下降,本文阐述的免疫遗传算法是基于人工免疫理论,在遗传算法的基本框架之上结合免疫算子而形成的一种新型优化算法,可有效的提升算法收敛精度,应用于各类参数优化系统.     

Mindfulness-based training interventions for employees: A qualitative review of the literature

We provide a comprehensive qualitative review of 67 published studies that have examined mindfulness-based training interventions conducted with employees. The findings indicate that the most common research designs were the pre-test/post-test only design (35.8%) and the randomized waitlist control group design (26.9%). About two-thirds of the studies included a control group (61.2%), with approximately three-quarters (75.6%) of these studies using random assignment. Of the 63 studies that used a conventional experimental design, the majority (65.1%) included only one follow-up assessment, most often immediately after training. Results indicated a great degree of heterogeneity in terms of program content, although many studies used some adaptation of Kabat-Zinn's (1990) Mindfulness-Based Stress Reduction (41.8%), an approach with a strong evidentiary base with clinical populations. All training programs incorporated practice, most (85.1%) used multiple methods of delivering the training material, and training varied considerably in total duration, session length, and the number of training sessions. Our review also found that the intended purpose of mindfulness-based training for employees was most commonly the reduction of stress/strain (80.6%), although a wide range of other targeted outcomes were documented. Based on our findings, we offer suggestions for future research aimed at advancing our understanding of mindfulness-based training interventions with employees.     

一种基于实数编码遗传算法的常模盲均衡

盲均衡可以看作代价函数优化问题。为了改进经典常模算法的性能,研究了利用实数编码遗传算法的常模盲均衡,把均衡器系数向量作为遗传算法的决策变量,采用轮盘赌选择和精英保留策略相结合的混合选择算子、算术交叉算子和非均匀变异方式,经过一系列的遗传操作,搜索到适应度值最高的个体,即均衡器的最优系数。计算机仿真结果证明了算法具有收敛速率快、能够搜索到全局最优解等特点。     

基于混合遗传算法的码书设计方法

将遗传算法与LBG算法相结合,得到了一种矢量量化码书设计算法.利用遗传算法的全局优化能力得到最优的矢量量化码书;同时,克服了传统遗传算法收敛速度慢的缺点.实验结果表明,文中提出的算法性能上优于LBG算法,且收敛速度较快.     

MIMO系统中线性弥散空时码的优化设计

MIMO系统的大部分空时编码方法在设计时单一强调对传输分集性能或传输复用性能的提高,为了联合提高分集性能和复用性能,在LDC编码基础上提出了线性正交弥散空时码(OLDC),LDC编码的优化中利用遗传算法来构造OLDC的空时正交调制基矩阵.优化的编码方法设计简单,便于调制解调.仿真结果表明,OLDC码比传统的LDC编码在误码性能、分集性能、复用性能等方面均有大幅度提高.     

车辆优化调度的遗传算法求解

根据货运车辆调度问题的定义,研究单个发货点对多个收货点的车辆调度问题。以车辆的载重量利用最高,且车辆周转时间最短为目标建立模型,并把原问题分解为两段用遗传算法求解：先求出第一个目标的优化结果,在此结果上再按第二个目标优化,得到问题的满意解。通过实例计算说明该算法的实际应用和效果。     

基于遗传算法的集装箱多式联运联盟合作伙伴的选择

集装箱多式联运是一个复杂的大系统,其多式联盟的组成首先要选择正确的合作伙伴。建立基于遗传算法的集装箱多式联运联盟合作伙伴选择的模型,从联盟的运营成本、运营时间和运营风险的最小化进行择优,同时给出应用算例进行验证,并利用MATLAB7.0求解,得到能以最佳性能完成运输任务的联盟伙伴组合。     

基于遗传算法改进的BP神经网络在我国主要城市人居环境质量评价中的应用

文章试图在已有研究的基础上,综合考虑城市人居环境的内涵,在国内首次将遗传算法全局寻优和BP神经网络局部寻优相结合的改进神经网络模型应用在人居环境评价中,并对中国35个主要城市人居环境质量进行定量判定,揭示城市人居环境现状及各城市在国内人居环境中的相对水平。结果表明该模型取得了令人满意的结果,是一种有效的评价方法。