微型低速短波数据终端的研制

短波信道是一种变参信道,存在严重的衰落和干扰。本文讨论了信道对数据信号传输的影响,并详细叙述了用于中短距离数据通信的微型短波数据终端的设计思想,最后还提供了该终端的硬件系统框图及信道实验结果。     

固体吸附制冷系统发生器温度场数值模拟

以内燃机排气－固体吸附制冷系统为背景，建立了固体吸附制冷系统发生器瞬态温度场数值计算模型，并讨论模型中涉及的部分物性参数。通过实验验证，该模型能较好地模拟发生器内瞬态温度场。     

用酉几何构作笛卡尔认证码

利用有限域上的酉几何构作了一个笛卡尔认证码，并计算了它们的参数。此外，假定根据均匀概率分布选择编码规则，计算了模仿攻击与替换攻击成功的概率的最大值Ｐ１与Ｐｓ。     

复杂系统集成控制及其仿真研究

本文对于复杂系统提出一种集成控制策略,即解耦/模糊控制。并以机器人关节运动控制为例,进行仿真研究,仿真结果是令人满意的。全文包括五个部分:1.前言;2.复杂系统的解耦模型;3.复合规则库与模糊控制;4.仿真研究;5.结论。     

电离层薄层倾斜带来的电离层附加时延偏差分析

在考虑电离层薄层倾斜的基础上,数值模拟、分析了电离层倾斜带来的电离层附加时延相对不考虑电离层倾斜的偏差,从而说明了在电离层倾斜地区消除电离层倾斜的必要性     

Mechanism and Defense on Malicious Code

With the explosive growth of network applications, the threat of the malicious code against network security becomes increasingly serious. In this paper we explore the mechanism of the malicious code by giving an attack model of the maliciouscode, and discuss the critical techniques of implementation and prevention against the malicious code. The remaining problems and emerging trends in this area are also addressed in the paper.     

A Survey of the Use of the Discrete-event Simulation in Manufacturing Industry

In this work, a survey of companies has been produc ed from a questionnaire and in-depth inter-views. The aimof the paper is to give a current view of the use of DES (Discrete- Event Simulation) in the indust ry. The companies have been selected in a wide range in e.g. size, capital turno ver and employees. The survey was restricted to Sweden, although the results may be applicable to other countries with similar industrial structure. Some of the companies investigated are also multinational with branc...     

Study on End Milling Generation Surface Model and Simulation in View of Main Axle s Tolerance

In accordance with the relative movement between end-milling cutter and workpiece surface, a theoretical generation model for milled surface was established with the movement error of principal axle considered. Then the milled surfaces under various cutting condition were simulated, the results of which showed that end milled surfaces were of “vaulted profile“, heights of surface irregularty at various points to be different with maximum value in the middle and smaller at both sides, the difference were ...     

用于分布式识别的语音参数的提取和性能分析

主要研究用于分布式语音识别(DSR)的语音参数的提取方法以及参数性能分析。以前所用到的语音参数大部分是LPC倒谱参数,但其抗噪声性能较差。文中主要讨论了MEL倒谱参数,并在移动通信环境下,比较了两者的性能。     

两种跟踪低阶模型的模型参考自适应控制方案设计与仿真

采用滤波器降阶和系统分解，并将部分因式看成未建模动态，进而转化成扰动的方法，分别设计了两种高阶系统跟踪低阶参考模型的模型参考自适应控制(MRAC)方案。使用低阶参考模型简化了系统结构。仿真验证了方案的有效性。