Fabrication process of open surfaces by robotic fibre placement

Composite materials are being used extensively in many industrial sectors. They offer excellent material properties compared to other structural materials available. However, the traditional fabrication process using manual hand lay-up is time consuming and labour intensive. Therefore, robotic fibre placement has been introduced to overcome these drawbacks. This approach may greatly reduce cycle time and manufacturing costs. This paper describes the overall strategy for the establishment of a flexible robotic fibre placement technique. The fabrication process planning of this new technique is presented. Three different types of fibre placement for open surfaces are discussed. These include simulation-based fibre path generation, fibre steering, and sensory-based contour following methodologies. The system architecture for the process control is also presented.     

8～18GHz双刀双掷开关研究

采用混合集成电路的方法,用ＰＩＮ管芯制作了８～１８ＧＨｚ双刀双掷开关。开关采用管芯全并联结构。反射式ＤＰＤＴ开关插损≤２．０ｄＢ,隔离度＞５９ｄＢ,开态驻波比≤１．６５,承受功率为连续波５Ｗ。吸收式ＤＰＤＴ开关插损≤２．９ｄＢ,隔离度＞５８ｄＢ,开态与全关断态驻波比≤２．１,承受功率连续波２Ｗ。电路由ＴＴＬ信号控制。     

Wavelength Conversion Placement in WDM Mesh Optical Networks*

Wavelength conversion helps improve the performance of wavelength division multiplexed (WDM) optical networks that employ wavelength routing. In this paper, we address the problem of optimally placing a limited number of wavelength converters in mesh topologies. Two objective functions, namely, minimizing the average blocking probability and minimizing the maximum blocking probability over all routes, are considered. In the first part of the paper, we extend an earlier analytical model to compute the blocking probability on an arbitrary route in a mesh topology, given the traffic and locations of converters. We then propose heuristic algorithms to place wavelength converters, and evaluate the performance of the proposed heuristics using the analytical model. Results suggest that simple heuristics are sufficient to give near-optimal performance.     

异步电动机取消线圈间接头连续嵌线工艺

介绍显极接法的异步电动机取消线圈间接头连续嵌线工艺,是1998年第1期《防爆电机》刊载的多极异步电动机线圈间不接头一条龙嵌线工艺的续篇。     

智能型溶解氧分析仪的研制

介绍了溶解氧分析仪的硬件结构和软件设计。该仪器由极谱型复膜氧电极传感器和ＡＴ８９Ｃ５２单片微机系统两大部分组成，软件采用模块式编制，结构紧凑，操作简便。仪器的测量范围为：溶解氧：０～１９．９９ｍｇ／Ｌ（温度为－１０℃～４０℃）；测量精度：溶解氧±０．３ｍｇ／Ｌ（温度±１℃     

三回路驾驶仪的极点配置方法设计

将三回路驾驶仪等效为全状态反馈的状态空间模型,证实了冗余参数预先设定的可行性。考虑舵机状态反馈的约束,利用优化程序搜索符合舵机反馈约束的附加极点并进行极点配置,可把系统主导极点完全配置到期望的极点位置。设计结果表明了文中所提出方法的正确有效性。     

Algorithm design for a class of base station location problems in sensor networks

Base station placement has significant impact on sensor network performance. Despite its significance, results on this problem remain limited, particularly theoretical results that can provide performance guarantee. This paper proposes a set of procedure to design (1− ε) approximation algorithms for base station placement problems under any desired small error bound ε > 0. It offers a general framework to transform infinite search space to a finite-element search space with performance guarantee. We apply this procedure to solve two practical problems. In the first problem where the objective is to maximize network lifetime, an approximation algorithm designed through this procedure offers 1/ε² complexity reduction when compared to a state-of-the-art algorithm. This represents the best known result to this problem. In the second problem, we apply the design procedure to address base station placement problem when the optimization objective is to maximize network capacity. Our (1− ε) approximation algorithm is the first theoretical result on this problem. Yi Shi received his B.S. degree from University of Science and Technology of China, Hefei, China, in 1998, a M.S. degree from Institute of Software, Chinese Academy of Science, Beijing, China, in 2001, and a second M.S. degree from Virginia Tech, Blacksburg, VA, in 2003, all in computer science. He is currently working toward his Ph.D. degree in electrical and computer engineering at Virginia Tech. While in undergraduate, he was a recipient of Meritorious Award in International Mathematical Contest in Modeling and 1997 and 1998, respectively. His current research focuses on algorithms and optimizations for wireless sensor networks, wireless ad hoc networks, UWB-based networks, and SDR-based networks. His work has appeared in journals and highly selective international conferences (ACM Mobicom, ACM Mobihoc, and IEEE Infocom). Y. Thomas Hou received the B.E. degree from the City College of New York in 1991, the M.S. degree from Columbia University in 1993, and the Ph.D. degree from Polytechnic University, Brooklyn, New York, in 1998, all in Electrical Engineering. Since Fall 2002, he has been an Assistant Professor at Virginia Tech, the Bradley Department of Electrical and Computer Engineering, Blacksburg, VA. His current research interests are radio resource (spectrum) management and networking for software-defined radio wireless networks, optimization and algorithm design for wireless ad hoc and sensor networks, and video communications over dynamic ad hoc networks. From 1997 to 2002, Dr. Hou was a Researcher at Fujitsu Laboratories of America, Sunnyvale, CA, where he worked on scalable architectures, protocols, and implementations for differentiated services Internet, service overlay networking, video streaming, and network bandwidth allocation policies and distributed flow control algorithms. Prof. Hou is a recipient of an Office of Naval Research (ONR) Young Investigator Award (2003) and a National Science Foundation (NSF) CAREER Award (2004). He is a Co-Chair of Technical Program Committee of the Second International Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM 2007), Orlando, FL, August 1–3, 2007. He also was the Chair of the First IEEE Workshop on Networking Technologies for Software Defined Radio Networks, September 25, 2006, Reston, VA. Prof. Hou holds two U.S. patents and has three more pending. Alon Efrat earned his Bachelor in Applied Mathematics from the Technion (Israel’s Institute of Technology) in 1991, his Master in Computer Science from the Technion in 1993, and his Ph.D in Computer Science from Tel-Aviv University in 1998. During 1998–2000 he was a Post Doctorate Research Associate at the Computer Science Department of Stanford University, and at IBM Almaden Research Center. Since 2000, he is an assistant professor at the Computer Science Department of the University of Arizona. His main research areas are Computational Geometry, and its applications to sensor networks and medical imaging.     

基于代理的协同计算模型研究与实现

针对大规模多数据源实时协同计算结构模型的可扩展进行研究.分析目前协同计算体系结构的缺点,提出一个三层的协同计算结构模型.然后给出该模型中最重要的覆盖层的构建方法,即以自治域为单位征集或部署代理节点,并在每个自治域选出一个或多个代理作为核心代理,核心代理节点采用点对点的Pastry协议互联构成自治域间的覆盖网.实验结果表明,该模型具有良好的可扩展性.     

基于坐标转换法研究三振子圆极化天线

文中通过直角坐标转换的方法，分析了一种三振子天线．通过推导出的解析解，对圆极化天线进行了Matlab仿真，发现该天线在两个坐标平面上都为圆极化场，可以在这两个平面法线方向同时进行极化分集接收，改善通信质量。     

深亚微米SOI工艺SoC设计中天线效应的消除

深亚微米SOI片上系统芯片(SoC)因其工艺特性,按照常规的布局布线(PNR)流程,出现了约一万个天线效应违规。介绍了一种在布局布线阶段不插入反偏二极管就可以消除大量天线效应违规的优化迭代流程。通过对天线效应的产生以及天线比率公式的分析,从线长和栅面积角度考虑天线效应的修复,结合自动布局布线设计工具SoC Encounter对这些因素的控制,可以在布局布线阶段消除天线效应的违规,并能与版图验证的结果保持一致。在一款通用抗辐照SoC芯片的设计中,应用该优化流程在布局布线阶段消除了设计中的天线效应违规,有效节约了芯片整体设计时间。