舰船无线激光通信

简要介绍了舰船间无线激光通信的发展和技术特点，关键技术包括：发射器温度控制、自动捕获瞄准、自适应光学系统、自适应收发和分段编码技术等。最后讨论了舰船间通信的不同网络拓扑方案。     

Simultaneous optimal design of structural topology, actuator locations and control parameters for a plate structure

 Simultaneous optimization with respect to the structural topology, actuator locations and control parameters of an actively controlled plate structure is investigated in this paper. The system consists of a clamped-free plate, a H ₂ controller and four surface-bonded piezoelectric actuators utilized for suppressing the bending and torsional vibrations induced by external disturbances. The plate is represented by a rectangular design domain which is discretized by a regular finite element mesh and for each element the parameter indicating the presence or absence of material is used as a topology design variable. Due to the unavailability of large-scale 0–1 optimization algorithms, the binary variables of the original topology design problem are relaxed so that they can take all values between 0 and 1. The popular techniques in the topology optimization area including penalization, filtering and perimeter restriction are also used to suppress numerical problems such as intermediate thickness, checkerboards, and mesh dependence. Moreover, since it is not efficient to treat the structural and control design variables equally within the same framework, a nested solving approach is adopted in which the controller syntheses are considered as sub processes included in the main optimization process dealing with the structural topology and actuator locations. The structural and actuator variables are solved in the main optimization by the method of moving asymptotes, while the control parameters are designed in the sub optimization processes by solving the Ricatti equations. Numerical examples show that the approach used in this paper can produce systems with clear structural topology and high control performance. Received 16 November 2001 / Accepted 26 February 2002     

Topology optimization of resonating structures using SIMP method

The present paper is concerned with the layout optimization of resonating actuators using topology optimization techniques. The goal of the optimization is a maximization of the magnitude of steady‐state vibrations for a given excitation frequency. The problem formulation includes an external viscous damper at the output port which models a working load on the structure. Copyright © 2002 John Wiley & Sons, Ltd.     

基于Transputer的分布并行处理机的通信与任务分解

本文基于Ｍｕｌｔｉ－Ｔｒａｎｓｐｕｔｅｒ并行处理系统的结构特点，分析了Ｔｒａｎｓｐｕｔｅｒ网的通信通信及任务通信开销对作业运行效率的制约关系。结果表明：并行程序设计的作业分解方式、选取合理的任务粒度和Ｔｒａｎｓｐｕｔｅｒ网络拓扑是其影响通信开销和作业运行效率的主要原因。     

空间效应离心结构模型试验相似材料的研究

 根据相似理论对离心相似模型材料的特点进行了分析，对离心相似模型材料的准备、力学性能的测试方法及应用进行了归纳和分析。通过分析，探明了离心结构模型材料的选择方法和范围。     

Stone表现定理与广义空间理论

Ｓｔｏｎｅ表现定理揭示了格论与拓朴空间理论之间的深刻联系，该定理表明可以从纯代数的角度出发而得到若干不同类型的拓的眩空间，并可用格论的方法与技巧和拓扑空间的物性进行研究，从而得出关于拓扑学中带有普遍意义的结论。广义空间理论就是沿此方面而诞生的新学科。拓扑分子格理论则是与此相关的又一新学科。     

软件表达形式种类“有限”的讨论

中国计算机软件保护条例规定“由于可供选用的表达形式种类有限”是使软件从侵权指控解脱的根据之一。因此，什么情况下才导致这个“有限”和承认这个“有限”，是软件保护研究的重要课题。本文是针对制约因素和“有限”的关系所设计的试验结果的总结，在一定程度上为判定软件的“实质相似性”和表达形式种类是否“有限”提供了量化分析。     

A novel document similarity measure based on earth mover’s distance

In this paper we propose a novel measure based on the earth mover’s distance (EMD) to evaluate document similarity by allowing many-to-many matching between subtopics. First, each document is decomposed into a set of subtopics, and then the EMD is employed to evaluate the similarity between two sets of subtopics for two documents by solving the transportation problem. The proposed measure is an improvement of the previous OM-based measure, which allows only one-to-one matching between subtopics. Experiments have been performed on the TDT3 dataset to evaluate existing similarity measures and the results show that the EMD-based measure outperforms the optimal matching (OM) based measure and all other measures. In addition to the TextTiling algorithm, the sentence clustering algorithm is adopted for document decomposition, and the experimental results show that the proposed EMD-based measure does not rely on the document decomposition algorithm and thus it is more robust than the OM-based measure.     

适用于48 V供电系统的VRM拓扑分析

介绍了适用于48V供电系统的电压调整模块(VRM)的6种拓扑，分析了这些拓扑的优缺点。     

Genetic algorithms for symbolic clustering

This paper introduces a novel methodology for clustering of symbolic objects by making use of Genetic Algorithms (GAs). GAs are a family of computational models inspired by evolution. These algorithms encode potential solutions to specific problems on simple chromosome-like data structures and apply recombination operators to these structures so as to preserve critical information. A new type of representation for chromosome structure is presented here along with a new method for mutation. The efficacy of the proposed method is examined by application to numeric data of known number of classes and also to assertion type of symbolic objects drawn from the domain of fat oil, microcomputers, microprocessors and botany. The validity of the clusters obtained is examined.