基于改进遗传算法的电力系统无功优化

在简单遗传算法的基础上，针对无功优化的动态、多目标、多约柬以及非线性特点，提出了基于简单遗传算法的改进算法．改进遗传算法中采用了个体适应度函数的线性变换、归一化的选择方法，以及定向变异策略的应用．以Ward＆Hale6节点标准测试系统为例对该算法进行了有效性验证．仿真结果表明，该方法对电力系统的无功优化效果良好．     

Forecasting lead times with economic data

Procurement lead time estimates are critical factors in production planning; however, they are generally based on a buyer's experience. The Westinghouse Corporation developed a linear model which successfully predicted procurement lead times for hot and cold rolled steel. This paper discusses nine models which use utilization and inventory data to predict lead time planning factors for aluminum, magnesium, steel and titanium products. The Lockheed-Georgia Company, which produces aerospace products, provided data for this research. The functional form of the models is significant and suggests that a nonlinear transformation of utilization based upon simple queueing models is a significant predictor of lead time duration.     

An industrial application for total productivity optimization

Abstract. This paper presents four strategies for total productivity optimization of a real-life manufacturing company. These strategies are developed to attain overall growth, cost reduction, upgrading of technical efficiency and management effectiveness. Such strategies have been modelled mathematically by using a nonlinear mathematical programming approach. The model base and the data base used in implementing the strategies can serve as decision support to management for optimizing total productivity.     

The maximum loading and the optimum number of vehicles in a double-loop of an interbay material handling system

In this paper, the loading analysis of an automated double-loop interbay material handling system (AMHS) in a wafer fabrication was analysed, considering the effects of the vehicle numbers in the inner and outer loops. Discrete-event simulation models were developed in e-M Plant to study this AMHS system with a zone control scheme to avoid any vehicle collision. The layout of an interbay system is a combination configuration in which the hallway contains double loops and the vehicles have double capacity. The combination of the shortest distance with nearest vehicle (SD–NV) and the first-encounter-first-served (FEFS) dispatching rule was used in this study. The maximum loading of this interbay system can be determined by the simulation approach. We also found that the number of vehicles in the inner and outer loops can significantly affect the interbay performance. Furthermore, the optimum combination of the vehicle numbers in the inner and outer loops can be obtained by response surface methodology.     

引入整合风险的4PL模式下供应链资源整合优化

在对4PL模式下供应链资源整合运作特征及整合中主导因素及其关系进行简要描述的基础上,围绕对整合决策具有重要影响作用的整合风险进行了分析;提出了引入整合风险的资源整合决策模式,建立了4PL模式下供应链资源整合决策的拓展多目标优化数学模型,搭建了改进的蚁群寻优算法实现该整合决策优化过程的求解。最后通过算例验证了优化过程及算法的有效性与可行性。整合决策优化模型及算法突出体现了4PL的运作优势,突出了从战略高度及系统性角度对供应链整合风险的把握,同时实现了资源整合优化多目标之间的权衡。     

以专业建设为核心，不断提升办学水平

通过回顾总结成都理工大学改革开放以来学科专业建设与发展情况,分析了学校四大学科专业群和特色专业的优势,指出了专业建设中存在的主要问题,就学校下一阶段进一步优化学科专业结构、加强专业的建设提出了建议。     

一种分级超结构换热器网络综合优化方法及其应用

对分级超结构换热器网络模型的温度计算提出了一种通用的精确解方法,同时得到了显式解析解,并以这一解析解为基础,设计了以遗传算法和模拟退火算法为主,结合最速下降法的混合遗传算法,此外还在算法中引进精英策略和结构变异策略.应用实例的计算结果显示了这一混合遗传算法对于换热器网络的参数和结构都具有良好的搜索能力.     

模糊条件下企业联盟和集团最优组建成本

将企业联盟和企业集团的组建过程分解为四个阶段,建立了其组建成本的数学模型;给出了企业联盟和企业集团在确定性情况下组建成本的模型,并将其扩展为适合于实际情况的组建成本模糊模型,即对该组建成本模型中与时间因素相关的各参数模糊化,再用模糊优化和非线性规划技术对该问题求解,得到不同组建阶段的最优时间分配,其方法对企业选择相应的发展战略有参考意义。     

T-optimum designs for discrimination between two multiresponse dynamic models

Summary.  The paper is concerned with a problem of finding an optimum experimental design for discriminating between two rival multiresponse models. The criterion of optimality that we use is based on the sum of squares of deviations between the models and picks up the design points for which the divergence is maximum. An important part of our criterion is an additional vector of experimental conditions, which may affect the design. We give the necessary conditions for the design and the additional parameters of the experiment to be optimum, we present the algorithm for the numerical optimization procedure and we show the relevance of these methods to dynamic systems, especially to chemical kinetic models.     

电力企业备件仓库选址模型分析

本文以某省电力集团公司所属市级供电公司的备件供应体系为研究背景,深入分析备件管理中的各项成本构成,挖掘出资金占压成本和跌价计提成本等隐性成本,提高了成本统计的准确性和完备性;然后从成本最小的角度出发,建立符合企业业务流程、地理特征和电力企业特定服务要求的备件仓库选址模型,并根据具体应用环境的特点进行合理的剪裁,最后对模型的计算复杂度等进行了初步的分析.