A multicriteria evolutionary algorithm for mechanical design optimization with expert rules

This paper addresses the problem of optimizing mechanical components during the first stage of the design process. While a previous study focused on parameterized designs with fixed configurations—which led to the development of the PAMUC (Preferences Applied to Multiobjectivity and Constraints) method, to tackle constraints and preferences in evolutionary algorithms (EAs)—, the models to be considered in this work are enriched by the presence of topological variables. In this context, in order to create optimal but also realistic designs, i.e. fulfilling not only technical requirements but also technological constraints (more naturally expressed in terms of rules), a novel approach is proposed: PAMUC II. It consists in integrating an inference engine within the EA to repair the individuals violating the user‐defined rules. PAMUC II is tested on mechanical benchmarks, and provides very satisfactory results in comparison with a weighted sum method with penalization to deal with the constraints. Copyright © 2004 John Wiley & Sons, Ltd.     

Review on the Trend for Development of World＇s Petroleum Refining Industry

This article introduces the situation related with the increasingly deteriorating crude quality, the demand for cleaner transportation fuels and clean production processes that the world＇s petroleum refining industry is faced with. This article also suggests that the trend for future development of global refining industry is focused on the economy of scale for the refineries and the oil processing units, the refining structure readjustment, integration of the oil refining and chemical production and formation of oil refining bases. The oil refining industry will uninterruptedly rectify its industry allocation and processing unit configuration and strive for the reduction of production cost through technical progress and management innovations to reduce the production cost, boost the profitability and sharpen the market competitive edge.     

我国高精铝板带产品的生产现状及发展趋势

本文论述了我国高精铝板带产品的生产现状、市场需求及存在问题，对将来的发展趋势进行了预测和分析。     

化学的发展趋势

分子间的作用、学科间的交叉综合以及复杂体系的化学，是２１世纪化学研究的重要方向。     

蜜蜂进化型遗传算法在水库优化调度中的应用

提出了一种基于蜜蜂进化型遗传算法的水库优化调度问题的求解方法,并通过实例对蜜蜂进化型遗传算法和标准遗传算法的性能做了比较.结果表明,在进化代数相同的条件下,由于蜜蜂进化型遗传算法在配种选择算子上使用种群的最优个体作为蜂王,提高了种群收敛速度;再者,在代进化过程中引入一个随机种群,保持了群体的多样性,提高了算法的勘测能力.     

Dairy cows trapped between performance demands and adaptability

The tremendous increase in the lactation performance of dairy cows during the last 60 years has had dramatic consequences on fertility and vitality (fitness) of the animals. Unprecedented average lactation performance levels have resulted in an equally unprecedented reduction in longevity. Economic pressure to further reduce the age at first calving is still high, although the negative correlation between precocious maturity and longevity is well documented in the relevant literature. Ever more aggressive selection and feeding measures are being taken to shorten the rearing time of heifers in order to reduce the cost of replacement heifers. An additional decrease in the stayability of cows has to be expected when the age at first calving is lowered even further. For reasons of profitability, dairy cows should complete an average of at least four lactations. Cows from the most important dairy breeds in the United States and Bavaria, Germany, already dropped below that crucial threshold many years ago. The same phenomenon has been observed in dairy cows in Austria over the past few years. Holstein cows that were culled in Austria in 2007 had an average of only 3.3 parities. To improve this situation, dairy cattle breeding programs should put a much higher emphasis on selection for traits of longevity and lifetime performance and, in return, markedly reduce the emphasis on selection for lactation performance in general and early‐lactation performance test results in particular. Over millions of years of evolutionary adaptation, cattle have acquired the ability to utilize fibrous low‐quality plant substrate. Only a strongly forage‐based feeding regimen is, in the long run, in accordance with their digestive and metabolic configuration. The massive use of concentrates (mostly grain) in cattle rations increases the risk of digestive and metabolic disorders in cattle and consequently leads to impaired animal welfare. Finally, the careful management of scarce resources demands that a closer look be taken at the food balance in dairy rations, i.e., an awareness of how much food that is edible for humans is being fed to livestock. Copyright © 2009 Society of Chemical Industry     

从角抵到百戏——秦汉时期中国戏剧的艺术走向

百戏与角抵戏乃一物之异名,为包容甚广戏剧的总称。其发于秦,大盛于汉,而其远源又可上溯到商周的社祭和社乐,其余绪至今仍葆存于国家盛典与民间赛会之中。     

中国精细化工市场现状及加入WTO后的变化趋势

中国精细化工企业总数一万余家，年总产值达1200亿元左右，约占化学工业总产值的40％。本文介绍了中国精细化工的市场现状及加入WTO后的变化趋势。     

向多极化发展的飞航导弹

简单回顾了飞航导弹的发展历程；从飞航导弹的基本特性出发，指出了以往一些文献中所给的飞航导弹定义的某些局限性；讨论了飞航导弹概念创新的重要意义；阐述了飞航导弹朝多极化发展的几个可能方向。     

南水北调中线工程某引水渠坡稳定的可靠性分析

讨论了复杂边坡可靠性分析方法，建立了边坡可靠性分析的模型；以南水北调中线工程某引水渠为例，着重研究了渠坡稳定的失效概率计算方法，将土的容重、内摩擦角、粘聚力作为随机变量，建立渠坡稳定可靠度分析模式，并将可靠度计算的Monte-Carlo法和全局寻优的遗传算法相结合，用FOR-TRAN90编制了计算程序，确定了渠坡的最危险滑动面及其对应的失效概率和可靠指标．