以太城域网技术及其性能优化

千兆以太网发展起来以后,由于它具有简单、灵活、成本低廉、可扩展性强、与IP技术有天然的适应性等特点,广泛应用于城域网领域。本文首先讨论了以太城域网核心技术、IP组播技术及其在多媒体中的应用,然后介绍了优化网络性能的方法,以满足服务质量(QoS)要求,这些方法允许应用程序向路由器通知它们的载入和延迟要求,让路由器同它们以及策略服务器一起共享QoS信息。     

设计沪上行——创意产业园在上海兴起

“创意产业”作为一个新颖却又陌生的概念已经进入了许多世界大都市的战略发展计划．伦敦、纽约、柏林、米兰、东京、香港开始形成以城市为单元的网络．共同探索着创意产业的发展之路。最近上海成立了十八个创意产业园，将上海城市中心的十八个旧工业厂房区改造成了创意工业的聚集区．各种各样的设计公司开始纷纷进驻．一时让“创意产业园”成为以经济发展迅速著称的上海这个城市最时髦的经济词汇，甚至上海各区开始争相开办新的园区。然而如果经济只是赶时髦或是简单重复．也必然是泡沫和危机。于是我们这一期“上海设计”专辑将探寻这一时髦的经济现象中产品设计业的快乐与哀愁。     

A boundary element-free method (BEFM) for three-dimensional elasticity problems

This study combines the boundary integral equation (BIE) method and improved moving least-squares (IMLS) approximation to present a direct meshless boundary integral equation method, the boundary element-free method (BEFM) for three-dimensional elasticity. Based on the improved moving least-squares approximation and the boundary integral equation for three-dimensional elasticity, the formulae of the boundary element-free method are given, and the numerical procedure is also shown. Unlike other meshless boundary integral equation methods, the BEFM is a direct numerical method in which the basic unknown quantity is the real solution of the nodal variables, and the boundary conditions can be applied directly and easily, thus giving it a greater computational precision. Three selected numerical examples are presented to demonstrate the method.Aknowledgement The work in this project was fully supported by a grant from the Research Grants Council (RGC) of the Hong Kong Special Administrative Region, China (Project No. CityU 1011/02E).The work that is described in this paper was supported by Project No. CityU 1011/02E, which was awarded by the Research Grants Council of the Hong Kong Special Administrative Region, China. The authors are grateful for the financial support.     

Direct solution of ill‐posed boundary value problems by radial basis function collocation method

Numerical solution of ill‐posed boundary value problems normally requires iterative procedures. In a typical solution, the ill‐posed problem is first converted to a well‐posed one by assuming the missing boundary values. The new problem is solved by a conventional numerical technique and the solution is checked against the unused data. The problem is solved iteratively using optimization schemes until convergence is achieved. The present paper offers a different procedure. Using the radial basis function collocation method, we demonstrate that the solution of certain ill‐posed problems can be accomplished without iteration. This method not only is efficient and accurate, but also circumvents the stability problem that can exist in the iterative method. Copyright © 2005 John Wiley & Sons, Ltd.     

Boundary element‐free method (BEFM) for two‐dimensional elastodynamic analysis using Laplace transform

In this paper, we present a direct meshless method of boundary integral equation (BIE), known as the boundary element‐free method (BEFM), for two‐dimensional (2D) elastodynamic problems that combines the BIE method for 2D elastodynamics in the Laplace‐transformed domain and the improved moving least‐squares (IMLS) approximation. The formulae for the BEFM for 2D elastodynamic problems are given, and the numerical procedures are also shown. The BEFM is a direct numerical method, in which the basic unknown quantities are the real solutions of the nodal variables, and the boundary conditions can be implemented directly and easily that leads to a greater computational precision. For the purpose of demonstration, some selected numerical examples are solved using the BEFM. Copyright © 2005 John Wiley & Sons, Ltd.     

虚拟制造环境下VE型分配泵的研发

介绍了虚拟制造技术及其分类，探讨了以设计为中心的虚拟制造技术在汽车零部件研发中的实践．利用该技术，以柴油发动机VE型分配泵为研究对象，重点分析了传动部件易断裂问题，研究内容涉及产品全生命周期的各个阶段，包括虚拟样机设计、虚拟样机运动学动力学仿真、虚拟装配、有限元分析和零件虚拟加工仿真等，并对研究结果进行了实验验证．结合企业实际，给出了解决方案．     

相关瑞利衰落信道的最大比合并

现有的文献对于相关瑞利信道最大比合并的研究不是假设条件比较特殊，就是分析的方法过于繁琐；针对这种情况，本文证明了相关瑞利信道的最大比合并性能等价于独立瑞利支路的最大比合并的性能，同时也证明了相关瑞利支路的输出信噪比的概率密度函数等于各个不相关瑞利支路的信噪比概率密度函数的加权和，最后在上述结论的基础上，针对BPSK调制方式，用数值计算的方法说明了上述结论的正确性及简单有效性。     

软交换网络的测试过程与方法

本文主要对软交换网络的测试方法和测试过程进行了详细的阐述，并指出了目前存在的一些问题。     

苏北盆地白驹凹陷深层油气成藏研究

通过有机相分析、二次生烃机理研究、油气成藏静态要素和动态要素分析，对苏北盆地白驹凹陷深层油气成藏进行研究。认为：白驹凹陷深层烃源岩有机相包括B、B1和D亚相，下寒武统幕府山组(∈1mu)、下志留统高家边组(S1g)烃源岩为B亚相，生油气潜力大；无论一次生烃还是二次生烃，烃源岩总的产烃能力是一定的，二次生烃与一次生烃有一定连续性；白驹凹陷深层烃源岩二次生烃史极为复杂，大致经历了加里东期、海西-印支期、燕山期、燕山晚期-喜山期；根据成藏基本要素的不同，白驹凹陷深层油气成藏模式可分为下部油气成藏模式(下古生界)和上部油气成藏模式(上古生界)。     

一种智能仪器仪表的通用人机接口方案

讨论了智能仪器仪表人机接口的交互式方案，将LCD显示屏划分为运行模式、预置参数、运行参数、提示信息等4个显示区，采用优先权编码器作为键盘编码器，按键读数直接送至MCU，实现了占用单片机I／O口线少、占用单片机机时少、简化相应程序等最优设计。