控制理论——模型论还是控制论

控制理论发展历史中的最近30年称为现代控制理论时期.学者们从不同角度描述过这一时期各个阶段的特征,也展望过未来发展趋势.我们从另一角度概括这一时期的特征为控制理论发展史中的“模型论”时期.建立控制系统的模型、分析系统的模型、依靠模型寻求控制律,是这一时期主流的思考方式.无论是线性系统还是非线性系统,无论是状态空间法还是频域法,系统的数学模型是研究问题的出发点(分析与设计)或归宿(建模与辨识).数学模型作为研究对象,以科学发展史上少见的速度和广度提出揭开控制系统本     

全面成绩管理的初探

利用数量化方法,数字特征法,W ilcoxon顺序和检验法以及试卷分析的各种方法(试题难度,区分度,信度,效度等),定量地解决了影响学生成绩的主要因素,并引入全面管理方法,明显地改善了学生成绩,学生综合能力明显加强.     

Liquid Nuclear Magnetic Resonance Implementation of Quantum Computation in Subspace

Based on the logical labelling method, we prepare an effective pure state in a subsystem of a three spin system via liquid nuclear magnetic resonance technique. Then with this subspace effective pure state we implement the Deutsch-Jozsa algorithm. The tomography for the subspace effective pure state and the corresponding spectrum of the output for the Deutsch-Jozsa algorithm agree with theoretical predictions, which shows that we have successfully implemented the Deutsch-Jozsa algorithm in a subsystem of a nuclear spin system and demonstrated a subspace quantum computation.     

基于EPP协议的便携机数据采集系统

设计了基于EPP协议的便携机数据采集系统 ,给出了技术解决方案。方案具有软硬件设计简捷、无需插卡等优点 ,可使外设工作于PC并行口的多种模式下。解决了线阵CCD图像采集系统与笔记本电脑之间的数据通讯 ,达到了便携数据采集的目的。     

宁波港船舶交通管理系统(VTS)

通过对宁波港的交通环境，现有VTS系统及港口发展的趋势研究，提出了改善宁波港通航环境，建立和完善VTS系统的有效措施。     

复制受限的环境演算中模态逻辑的内涵性

环境演算(MA)的模态逻辑AL进行了研究．在考虑了复制操作和限制操作的情况下，提出了逻辑等价的协归纳操作描述，并利用协归纳关系与进程结构同余关系进行比较，证明了若对MA加上约束条件得到子集MAIF^syn，此时逻辑等价(=L)与结构同余关系是等价的，即AL在MAIF^syn中是内涵的．同时发现由于复制操作的存在，AL的内涵性受到了影响，使得AL的区分能力被削弱，但通过对复制公式的构造验证了AL的表达能力．     

2-（υ，5，1）设计的非可解区传递自同构群

研究了2-(υ，κ，1)设计的区传递自同构群．特别讨论了2-(υ，5，1)设计的非可解区传递自同构群．得到定理：设G是一个2-(υ，5，1)设计Q的区传递．点本原但非旗传递的自同构群．若G是非可解群．则G的基柱Soc(G)不是典型群PSUn(q)，这里q为奇数，n≥3。     

多元χ演算运行时错误的不可判定性

针对多元χ演算运行时刻通信安全的判定性问题进行了研究．通过从Lazyλ项到χ项的编码，将判定一个Lazyλ项是否有范式的问题归约为进程是否有通信错误的问题．证明了在多元χ演算中，通讯错误也是不可判定的．结论说明不存在算法直接来检测进程的通信安全性，而只有通过其他间接的手段(如构造类型系统)才能部分达到预防运行时错误的目的．     

A projection method for solving incompressible viscous flows on domains with moving boundaries

In this paper, a projection method is presented for solving the flow problems in domains with moving boundaries. In order to track the movement of the domain boundaries, arbitrary‐Lagrangian–Eulerian (ALE) co‐ordinates are used. The unsteady incompressible Navier–Stokes equations on the ALE co‐ordinates are solved by using a projection method developed in this paper. This projection method is based on the Bell's Godunov‐projection method. However, substantial changes are made so that this algorithm is capable of solving the ALE form of incompressible Navier–Stokes equations. Multi‐block structured grids are used to discretize the flow domains. The grid velocity is not explicitly computed; instead the volume change is used to account for the effect of grid movement. A new method is also proposed to compute the freestream capturing metrics so that the geometric conservation law (GCL) can be satisfied exactly in this algorithm. This projection method is also parallelized so that the state of the art high performance computers can be used to match the computation cost associated with the moving grid calculations. Several test cases are solved to verify the performance of this moving‐grid projection method. Copyright © 2004 John Wiley Sons, Ltd.     

Possible triggering of solar activity to big earthquakes (Ms ≥ 8) in faults with near west-east strike in China

A big earthquake (Ms = 8.1) occurred at western Kunlun Mts gap on November 14, 2001. It is the biggest earthquake in China in the past 50 years and the only one with a magnitude bigger than 8 in China after Dangxiong Earthquake (M = 8) in Tibet in 1951. The big earthquake has drawn wide attention of scientists in seismological, geophysical, geological and astro-geodynamic circles. Scientists are interested in the occurrence regularity of the very big earthquakes and try to find out the fac…