基于LINGO的优化问题动态规划法求解

介绍了LINGO优化软件的使用,指出LINGO在求解动态规划问题时可以不需要目标函数。基于LINGO分别对最短路问题和生产批量计划问题使用动态规划法进行了求解,给出了相应的LINGO求解代码,增强了学生对动态规划法的理解同时提高了使用优化软件编程解决问题的能力。     

LINGO及其在化工过程优化中的应用

LINGO处理优化问题编程简单、收敛速度快、稳定性好、可靠性高.本文介绍了LINGO软件的编程特点和使用方法,选取了3个测试函数对LINGO优化性能进行测试,并应用模型语言结合化工中一些优化实例进行了应用探讨.测试结果表明LINGO具有良好的优化性能,值得在化工科研中推广和应用.     

一类带时间约束的多工件排序优化

研究了多个工件在多台机床上顺序加工,满足不同工件时间约束下总体加工时间最短的排序问题。建立了该问题的0-1整数优化模型,编写了基于LINGO软件的求解方程,算例表明了该模型的有效性。     

Influence of nitrogen on hot ductility of steels and its relationship to problem of transverse cracking

Abstract

The present review examines the influence of nitrogen on the hot ductility of steels, with particular relevance to the problem of transverse cracking during continuous casting. Nitrogen itself is not detrimental to hot ductility, but when it is present with aluminium or microalloying additions, ductility can be adversely affected through the formation of nitrides or carbonitrides. The addition of aluminium to low nitrogen C–Mn steels (0·005%N)impairs ductility during casting at an acid soluble level as low as 0·02%Al. This arises because segregation of aluminium to the grain boundaries occurs on solidification, and the temperature cycling that takes place when the strand is cooled encourages AlN precipitation. However, for low nitrogen, high strength low alloy (HSLA) steels with carbon levels in the peritectic range 0·08–0·17%C, transverse cracking is not generally encountered until the aluminium level is >0·04%. Higher nitrogen levels are likely to cause problems even at very low aluminium levels, as precipitation of AlN is controlled by the product of the aluminium and nitrogen contents. The microalloying additions vanadium and niobium are detrimental to ductility but, of the two elements, niobium is more damaging, as it gives finer precipitation. Increasing the nitrogen level has a more pronounced influence on ductility in vanadium containing steels, since vanadium forms a nitride while niobium forms Nb (CN), which is mainly carbon based. Nevertheless, the product of vanadium and nitrogen contents has to approach 1·2 × 10^-3, for example 0·1%V and 0·012%N, before ductility deteriorates to that normally given by a niobium containing steel with 0·03%Nb and 0·005%N. When small titanium additions are made to low nitrogen C–Mn–Al steels (0·005%N), the best ductility is likely to be given by a high Ti/N ratio of 4–5 : 1; the excess titanium in solution encourages growth of the TiN particles. For high nitrogen steels (0·01%N), a low titanium level (0·01%)is recommended to limit the volume fraction of TiN particles. A low soluble aluminium level is also needed to prevent the excess nitrogen from combining to form AlN. For C–Mn–Nb–Al steels, similar recommendations can be made with regard to adding titanium. However, the presence of niobium and aluminium appears to have little influence on ductility, since these elements coarsen the titanium containing precipitates.     

基于LINGO线性规划的数控设备生产排程方法研究

本文结合生产实际建立线性规划模型,应用LINGO进行编程求解。车间接收生产任务后分配到各个工作中心,然后将每个工作中心的任务分配到各个加工中心,安排各加工中心的加工顺序,实现工作中心与加工中心的双优化,较好的实现企业车间的生产排程。     

海运集装箱空箱调运优化模型及算法研究

为了提高船公司集装箱运输效率,降低运输成本,应用线性规划的方法,以租箱成本和集装箱空箱调运费用之和最低为目标,建立了海运集装箱空箱调运问题的优化模型。利用LINGO软件能够求得线性规划问题最优解的特点,编写了求解该问题的LINGO程序代码,通过实例验证,该模型和算法可以快速有效求得最优解。     

基于全局优化设计的桁架结构优化设计研究

桁架结构优化设计中普遍存在约束的作用.现有优化设计一般采用满应力法和遗传优化等优化方法,编程复杂.本文介绍了优化设计软件LINGO10.0的功能、特点、使用方法和使用注意事项等,建立了桁架结构优化设计的数学模型.采用LINGO软件的全局优化方法求解.实例计算表明,采用LINGO的全局优化方法能获得全局优化解,且方法简单,值得推广应用.     

LINGO在环境经济负荷调度中的应用

介绍了LINGO软件优化方法以及它在环境经济负荷调度问题上的应用.结合一个含有3个电力生产单元的燃煤电力系统模型验证了该方法的可行性和有效性.LINGO为环境经济负荷调度问题提供了一个新的方法,具有很好的应用前景.     

应用线性规划方法优化再制干酪配方的研究

对涂抹型再制干酪建立配方优化的线性规划模型,着重研究了各个原料添加量的约束方程以及终产品的水分和脂肪质量分数约束方程的建立。利用LINGO软件进行线性规划计算,得到最低成本为35.26元(每1 000 g),配方为水分250.00 g,脱脂乳粉50.00 g,乳清粉106.20 g,奶油50.00 g,淀粉123.04 g,凝块420.76 g。     

生态工业园区的MINLP模型

生态工业园区的设计和管理需要建立在定量分析的基础上，目前仍然是一个薄弱环节. 本文提出了一个引入逻辑表达式的生态工业园区模型，可以通过对一个混合整数非线性规划(MINLP)问题进行求解来获得有价值的参考信息. 模型可以分为成员模型和连接模型两部分，成员模型作为积木，通过连接模型搭建成不同拓扑结构的生态工业园区方案. 开发的生态工业园区模型具有良好的扩展性、可修改性、可重用性，可以作为生态工业园区决策系统的核心模型. 以山东枣庄市南工业区为对象进行了案例分析. 模型用非线性优化软件LINGO求解.