基于改进小生境GA的有时间窗物流配送路径优化问题研究

有时间窗的物流配送车辆路径优化问题是一个NP难题,较难得到满意解.本文在基于隔离机制的小生境遗传算法的基础上,引入迁徙操作和模拟退火方法,用来解决有时间窗的车辆路径优化问题.这种方法不仅能够保证群体的多样性,而且具有良好的全局收敛性.实例也证明了该方法的有效性和实用性.     

人身危险性研究的历史脉络

本文通过对法学领域中人身危险性研究的方法和路径进行分析,结合哲学等人文社科领域研究的进展,介绍人身危险性研究的方法和路径始终围绕先天危险性和后天危险性的展开的状况,同时分析后天危险性研究路线得到普遍支持的原因,提出先天危险性研究的路线应当被重视,以新技术为依托的新犯罪学的研究空间广阔。     

基于遗传算法和BP神经网络的信用风险测量模型

随着新巴赛尔协议的推出,信用风险测量问题越来越受到重视。在西方发达国家,商业银行的信用风险管理测量技术已比较成熟,继传统的比例分析、主观分析之后,统计方法得到广泛的应用,如判别分析和logit回归分析等。自从20世纪80年代末期以来,人工智能技术如神经网络、专家系统等也被应用于商业银行信用风险测量中。目前,该领域应用最多的就是BP神经网络,但其固有的一些缺点,如易陷入局部极小点,会影响预测效果。但可以利用改进的遗传算法对BP神经网络进行优化,实验证明效果非常好。     

多平台下的参数化产品族多目标智能优化

针对大规模定制下基于多平台的参数化产品族优化方法中,需要事先指定平台变量的不足,本文提出了一种多平台产品族双层多目标并行协同优化算法,用于求解多平台下参数化产品族多目标优化问题.仿真实验结果表明,所提方法能够允许在平台变量未知的情况下,通过在运行过程中自动改变平台共性,并搜索共性与产品差异性之间的最佳平衡点,经过一次优化过程即可选择平台变量和差异性变量的最佳配置,以及平台变量和差异性变量取值的最佳设置;与文献中其他方法相比,本文方法所得产品族优化设计方案整体性能更佳.     

Genetic risk of domestication in artificial fish stocking and its possible reduction

Genetic hazards associated with the stocking of fish juveniles produced in hatcheries were studied with simple mathematical models. Domestication is the process of acquiring a genetic characteristics that are advantageous in a hatchery environment but that are disadvantageous in a natural environment due to the selection pressure in the hatchery differing from that in the natural environment. Conditions for the propagation of mutants enhancing domestication were obtained for a variety of stocking strategies specified by parameters related to hatchery productivity and kind of brood stock used. By using this, the possibility of reducing the risk of domestication was studied. As a means of reducing the risk, selective use of wild-born individuals for brood stock was considered. The effectiveness of this was analyzed for both the cases where all brood stock is collected from the wild, and the male brood stock is collected from the wild and the female brood stock is born and reared in a hatchery. We also estimate how much hatchery release can be increased without increasing the risk by employing these means. It is concluded that the use of only male brood stock from the wild is not very effective in reducing the risk of domestication. Further, it is concluded that selective use of the wild-born individuals of both sexes for brood stock is highly desirable if the contribution of released individuals to the natural reproduction is high. In other words, substantial increase of hatchery release may be possible while keeping risk at a level comparable to that under moderate hatchery release, if it is accompanied by the selective use of wild-born individuals for brood stock.     

基于CFD的离心泵结构参数优化

为获得离心泵的最佳结构参数，根据给定的离心泵设计参数确定离心泵的结构形式和性能评价指标，计算离心泵各结构参数，利用CFD对离心泵进行流场数值模拟分析，设计了叶轮结构L16（45）正交实验表，选择叶轮进口安装角βb1、出口安装角βb2、包角φ、进口直径D1、出口直径D2为正交实验的5个因素，完成了正交实验并对实验结果进行极差分析，得到各结构参数对各优化方向评价指标影响排序及其影响情况，构造出效率最大、汽蚀余量最小条件下的目标函数及统一目标函数，并运用遗传算法对离心泵效率和汽蚀进行多目标优化，得到离心泵的最佳结构组合参数.     

Double-objective economic statistical design of the VP T2 control chart: Wald's identity approach

Research has shown that applying the T² control chart by using a variable parameters (VP) scheme yields rapid detection of out-of-control states. In this paper, the problem of economic statistical design of the VP T²control chart is considered as a double-objective minimization problem with the statistical objective being the adjusted average time to signal and the economic objective being expected cost per hour. We then find the Pareto-optimal designs in which the two objectives are met simultaneously by using a multi-objective genetic algorithm. Through an illustrative example, we show that relatively large benefits can be achieved by applying the VP scheme when compared with usual schemes, and in addition, the multi-objective approach provides the user with designs that are flexible and adaptive.     

From the molecules the history of life

Nucleic acids, the molecules responsible for the storage and transmission of genetic information, can disclose the beguiling history of the evolution of life on the Earth. In this paper, the molecular mechanisms underlying the evolutionary processes are illustrated together with the methods for the recollection of their history. The impact of molecular data on the evolutionary studies is stressed together with the importance of suitable mathematical models for the treatment of sequence data.

Possible future scenarios are conceived for the evolutionary process in relation to environmental phenomena, on account of the new technologies and the development of genetic engineering.     

Camping,climbing trees and marching to Parliament: spatial dimensions of environmental protest in New Zealand

Environmental movements are key actors in challenging social and political constructions of the physical environment. A wide variety of protest campaigns have been undertaken in New Zealand, from local issues of pollution and road building through to national opposition to native forest logging and genetic engineering (GE). The aim of this paper is to examine the scales at which environmental protest in New Zealand have taken place and the impact upon the actions and durability of environmental campaigns. Through an analysis of a catalogue of protest events over the period 1997–2013, this paper describes patterns of actions, before examining the campaigns against GE field trials and mineral extraction in more detail. The findings point to the importance of cross-scale operations in enabling campaigns to capitalise on and respond to changes in the external environment including governance structures, resources and countermovement actors.     

内嵌基因表达式编程及其在函数发现中的应用

为了提高表达效率,提出了新的基因解码方案,形成了内嵌基因表达式编程算法EGEP;提出了极大表达树、嵌套表达树和拼接表达树等概念;分析了基因的表达空间和算法的复杂度。实验表明,该算法提高了函数发现的成功率;在小规模种群的函数中其能力明显优于GEP。在单基因情况下,目标为一元函数和二元函数时,EGEP平均成功辈数分别为GEP算法的25.5%和16.3%;各种规模下,在EGEP算法中二元函数的成功率平均比GEP提高43%以上。