An adaptive non‐conforming finite‐element method for Reissner–Mindlin plates

Adaptive algorithms are important tools for efficient finite‐element mesh design. In this paper, an error controlled adaptive mesh‐refining algorithm is proposed for a non‐conforming low‐order finite‐element method for the Reissner–Mindlin plate model. The algorithm is controlled by a reliable and efficient residual‐based a posteriori error estimate, which is robust with respect to the plate's thickness. Numerical evidence for this and the efficiency of the new algorithm is provided in the sense that non‐optimal convergence rates are optimally improved in our numerical experiments. Copyright © 2003 John Wiley & Sons, Ltd.     

主轴回转精度测试中的多圈数据采集及处理

本文就主轴回转精度测试中的多圈数据采集和处理方法作了探讨。根据提出的方法和改进后的测试系统编制了实用程序,进行了实测,获得了测试结果。     

分压式电阻测量的闭环负反馈方法

提出一种反馈分压式电阻测量方法，给出了两种改进方案，分析了它们的测量误差，指出了减小误差的途径和方法。     

一种椭圆弧长的作图求解法及其误差分析

本文给出了一种椭圆弧长的作图求解方法,即由作图求得椭圆弧长的近似值。通过对100个椭圆弧长的求解结果表明,由此方法求得的椭圆弧长的误差甚小,从而在相当高的精度范围内,提供了一种工程中适用并且简单易行的求解椭圆弧长的方法。     

分布系统中多米诺效应的分析与消除

分布系统中发生故障后,错误信息在进程间的传播,以及由此引起的系统恢复过程中的多米诺效应是分布系统容错恢复技术所面临的最重要与最困难的问题.目前各种研究工作偏重于具体的系统动态恢复技术.本文的研究重点在于首次揭示多米诺效应本身固有的数量特征及其与分布系统技术参数间的联系,给出多米诺效应动态消除技术,引入系统额外开销的下限,并针对动态技术的缺点,探讨多米诺效应的静态消除技术,为解决困难开辟新途径.     

浅谈天馈线电压驻波比对微波电路的影响

天馈线电压驻波比是微波电路运行的重要指标，通过典型事例来阐述天馈线电压驻波比的劣化对微波电路的影响，并根据多年实践经验提出天馈线维护需注意的事项。     

光测遥测数据联合计算速度的方法

提出了利用遥测的过载、俯仰角信息和光测的坐标联合计算弹道关机段速度的方法，从遥测结果的系统误差、随机误差和数值积分的截断误差三万面对剩余误差的影响进行了精度分析，并给出了速度精度的算法。     

Multi-User MIMO Mobile CDMA Uplink System Employing Turbo Coding and Joint Detection Through a Multipath Rayleigh Fading Channel

In this paper, a generalized multiple-input multiple-output (MIMO) antenna system that can be fitted to the uplink of a wireless communication system is considered for the general case of multi-user. At the transmitter, the information bits are Turbo coded, then interleaved and passed through a serial-to-parallel converter. The channel is assumed bad urban suffering from multipath Rayleigh fading resulting in inter-symbol and multiple access interferences (ISI and MAI). At the front-end of the receiver, a number of receiving antennas are used followed by a joint multi-user estimator based on the Minimum Mean Square Error Block Linear Equalizer (MMSE-BLE).Computer simulations demonstrate a significant performance improvement in both single user and multi-user cases.This paper depends in parts on that presented at the 11th European Wireless Conference, Cyprus, Nicosia, pp. 187–192, April 2005. Yasmine A. Fahmy was born in Guiza, Egypt, on June 4, 1976. She received the B.Sc., M.Sc. and Ph.D. degrees in Communication and Electronics engineering from Cairo University, Egypt on 1999, 2001 and 2005 respectively. She is presently an assistant professor at Cairo University, Egypt. Her current field of interest is wireless communication and channel estimation. Hebat-Allah M. Mourad received her B.Sc., M. Sc. and Ph.D. degrees in electrical communication engineering from Cairo University, Egypt, in 1983, 1987 and 1994 respectively. Since 1983, she has been with the Department of Electronics and Communications, Faculty of Engineering, Cairo University, and is currently associate professor there. Her research interests include optical fiber communications, mobile and satellite communications. Emad K. Al-Hussaini received his B.Sc degree in Electrical Communication Engineering from Ain-Shams University, Cairo, Egypt, in 1964 and his M.Sc and Ph.D. degrees from Cairo University, Giza, Egypt, in 1974 and 1977, respectively. From 1964 to 1970, he was with the General Egyptian Aeroorganization. Since 1970, he has been with the Department of Electronics and Communications, Faculty of Engineering, Cairo University, and is currently professor there. He was a research fellow at Imperial College, London, UK, and at the Moore School of Electrical Engineering, University of Pennsylvania, Philadelphia, PA, USA, in the academic years 1976/1977 and 1981/1982, respectively. In 1990, he received the Egyptian national encouragement award for outstanding engineering research. He has written several papers for technical international journals and conferences. His research interests include signal processing, fading channel communication, modulation, and cellular mobile radio systems. Dr Al-Hussaini is a senior member of IEEE. He is listed in Marquis Whos Who in the World and in the IBC (International Biographical Center, Cambridge) for outstanding people of the 20th century.     

金属材料性能试验数据的统计处理

详细阐述了试验数据的表示方法以及数据统计的方法，分析了测量数据的不确定性产生的原因及其确定和测量误差产生的原因及其传递。     

水工监测传感器指标使用误区的探讨

本文旨在讨论目前岩土工程中使用的传感器技术指标及其含义，希望通过探讨以弄清楚这些指标的含义及指标对评价传感器的意义。由于传感器是用于测量工程物理量的，因此，引人目前在国际上通用的测量与误差的概念，以国家现有的测量术语的定义为准来描述传感器的指标。