Application of the optimal Latin hypercube design and radial basis function network to collaborative optimization

Improving the efficiency of ship optimization is crucial for modern ship design. Compared with traditional methods, multidisciplinary design optimization (MDO) is a more promising approach. For this reason, Collaborative Optimization (CO) is discussed and analyzed in this paper. As one of the most frequently applied MDO methods, CO promotes autonomy of disciplines while providing a coordinating mechanism guaranteeing progress toward an optimum and maintaining interdisciplinary compatibility. However, there are some difficulties in applying the conventional CO method, such as difficulties in choosing an initial point and tremendous computational requirements. For the purpose of overcoming these problems, optimal Latin hypercube design and Radial basis function network were applied to CO. Optimal Latin hypercube design is a modified Latin Hypercube design. Radial basis function network approximates the optimization model, and is updated during the optimization process to improve accuracy. It is shown by examples that the computing efficiency and robustness of this CO method are higher than with the conventional CO method.     

马在美洲的传播初探

自哥伦布第二次航行后,新旧大陆之间开始了前所未有的大交流时代,为了满足殖民者作战和饮食的需要,欧洲的家畜、家禽等被陆续传到美洲,并繁衍生息,美洲土著居民的生产和生活也因此发生重大改变。其中马的传播意义尤为重要,而中国学界对此还很缺乏研究。大量西语原文文献记载了马是如何传到美洲、何人传入、传播路线及其在美洲的发展过程等。     

The Brazilian National Plan for Coastal Management (PNGC)

The article is divided into three clearly defined sections. The first outlines the Brazilian National Coastal Zone Management Plan. The second offers a critical assessment of its introduction. To conclude, some general considerations are made. In this way, the author aims to achieve two objectives: to disseminate the aforementioned plan and offer a critical opinion of it.     

探险者的新面孔Ford Explorer America Concept

福特这个具有悠久历史的品牌之前没有给国人留下深刻的印象，我们记住福特这个名字还是在近两年：蒙迪欧在竞争最为激烈的中级车市场一直有着不错的表现，新蒙迪欧致胜的推出更加说明福特占据中级车市场并不断扩张的坚定决心。福特福克斯凭借动感的外形和出色的操控性一举赢得了中国年轻消费者的青睐，销量在同级别车型中遥遥领先，连续数月创造了上万辆的销售佳绩。     

Developing management guidelines for oil and gas activities: The louisiana experience

Abstract

Preliminary management guidelines have been derived for oil and gas activities in coastal Louisiana. Derivation of these guidelines was done in terms of the natural function of the coastal ecosystem; this means that all economic activities should be designed to complement natural function as much as possible. The guidelines range in scope from very specific, almost performance standards, to very general admonitions. For example, we have suggested that spoil banks, produced as a result of dredging, should not be higher than the height of the daily tide or roughly 15 cm in coastal Louisiana, and at the other extreme, we have suggested that all dredging should be done with great care during wildlife migrations, spawning, and nesting times.     

基于LHS-MC法的土石坝坝坡失稳风险分析

利用拉丁超立方抽样–蒙特卡罗((Latin hypercube sampling-Monte Carlo,LHS-MC)方法评估了土石坝坝坡失稳风险。MC是目前坝坡失稳风险分析中一种相对精确的方法,使用广泛。但是该法计算量大,收敛速度慢,尤其是对小失效概率问题。建议采用LHS代替MC的随机抽样。在极限平衡法的基础上,应用LHS抽样结合MC模拟,考虑坝坡土体参数的不确定性和水位的随机性进行坝坡失稳风险分析。以坝坡失稳风险问题为例说明了LHS-MC的有效性。结果表明:LHS-MC可有效地提高运算效率,运算次数较传统的MC法减少25%左右。具体的计算减少量取决于应用LHS的细节及坝坡滑移面的形状。     

美国的建造师执业资格认证制度

美国是工程项目管理理论、实践和相关制度建设的发源地,注册建造师制度也已建立了近40年。文中简要总结和介绍了美国建造师认证制度中的认证机构、认证办法、考试和认证后的继续教育等内容,对我国建造师认证制度的建设和完善有一定的参考借鉴价值。     

北美铁路经历的车轴故障

对北美铁路重载货车的车轴故障、车轴疲劳试验和车轴应力进行了研究,并介绍了几种解决车轴故障的措施.     

美国ASCE7-10规范在高桩码头抗震设计中的应用浅析

本文对美国ASCE7-10规范中的抗震设计进行了详细介绍,分析了抗震设计中的关键参数;以印尼某高桩码头为例,建立了高桩码头三维有限元模型,并计算了该结构在地震工况下桩基受到的等效地震侧向力的作用,对比分析了该结构在横向以及纵向两个方向的差异,得到了一些有益结论,为涉外工程提供了有益参考。