移动通信中的密钥托管方案

本文以文献[5]中移动通信网的安全密钥分配协议为基础，提出了一种适用于数字移动通信网的密钥托管方案，该方案可以任意指定托管方数量，能够保证移动用户问的安全通信，实现网络中心与通信双方的相互认证，并提供给法律执行机构实时监听无线通信的能力．     

陆地移动通信网的有关标准及说明

<正> 近年来,由于移动通信在一些部门取得了明显的经济效益和社会效益,所以目前不论是专用移动通信网还是公用移动通信网都有大力发展之趋势。为了加强管理和统筹安排,制定我国移动通信网的标准是毋庸置疑的。根据国外移动通信的发展和我国移动通信设备生产水平,有关部门起草制定了陆地移动通信网的有关标准。为了便于理解执行,本文就标准的主要部份做     

移动通信网无线网络优化工作研究

近年来社会发展进步很快,移动通信事业也获得了长足发展,但是面临的市场环境也更加严峻.需要不断优化移动通信网无线网络,才能让客户的实际需求得到满足,实现市场占有率与经济效益的提升.本文将简述移动通信网无线网络的现状,并介绍了具体的优化措施,旨在提升移动通信网的服务质量.     

网络入侵告警在移动通信网网管系统中的实现设计研究

随着通信技术的不断发展,我国对移动通信网网管系统的要求有了进一步的提升,而网络入侵告警在网管系统中的实际应用,不仅提高了移动通信网网管系统的安全性与可靠性,还在很大程度上降低了系统建设及后期运行时的成本。因此,本文将针对网络入侵告警系统,对其在移动通信网网管系统中的实现设计进行深入的分析和探究。     

移动定位技术综述

移动终端的位置是移动互联网中的关键信息。本文从移动定位技术的基本概念、分类方法、移动通信网中的定位技术等方面对其进行了阐述。     

基于PDA的应用服务

文章介绍了基于PDA的移动应用服务，如：手机网络定位或GPS定位，周边信息查询以及数据统计分析等。它的实现方法是用移动终端PDA发送信息服务请求，通过移动通信网，GSM、GPRS、CDMA等发送到后台应用服务器，经过后台应用服务器的计算处理后返回给移动终端，以获取客户感兴趣的信息服务。     

基于电力现场校验系统的移动终端设计

传统的电力移动终端面对现今多种通信网络,存在多通信网自适切换应能力不足的情况。为此,设计基于电力现场的校验系统的移动终端设计。在原有移动终端的基础上,选择TU-30作为GPS模块的核心模块,实现对电力现场的定位,设计移动网络和WiFi网络融合的通信模块,并修改原有的供电电路,防止供电电压过低,利用电力现场校验系统处理现场校验数据,通过XMPP协议和Openfire服务器实现移动终端的通信功能,至此基于电力现场校验系统的移动终端设计完成。测试结果表明:与传统的电力移动终端相比,设计的基于电力现场校验系统的移动终端多通信网自适应切换时间缩短了3倍左右,大大提高了多通信网自适应切换能力。     

GSM网络中短消息系统的安全风险分析

在介绍移动通信网中短消息系统架构的基础上，详细分析了短消息系统中存在的安全风险及可能的安全攻击，并提出了相应的解决方案建议。     

某军用移动电站可靠性评估软件包的开发

为了对某军用移动电站的可靠性进行定量的分析和评估,针对该电站的特点以及作战和训练中的可靠性模型,提出了基于布尔行列式展开求取最小路集的故障模式后果分析法的配电系统可靠性评估方法,用VC＋＋编写了可靠性评估软件包。论文介绍了该软件包的设计开发思路、工作流程、功能特点、主要界面和使用方法,并用传统的可靠性评估试验系统（IEEE DRTS）对开发的软件包进行了验证。通过对某军用移动电站可靠性的计算和分析,表明该软件包是有效和实用的。     

浅析基于3G技术的移动学习

3G(第三代移动通信系统)是以卫星移动通信网与地面移动通信网结合形成的全球无缝覆盖的立体通信网络。移动学习(M-learning)是网络化学习(E-learning)发展的一个新阶段,是现代教育技术的一个新方向。本文结合移动学习的特征,在保证移动学习有效性的前提下介绍如何在3G网络中应用移动学习,希望以此推动移动学习的广泛开展。     

协同式钻具组合辅助设计系统的研究

分析了网络环境下石油钻具组合设计的特点,针对目前钻具组合设计集成软件系统在处理复杂动态的、跨地区部门的钻具组合设计人员群体协作工作时,缺乏足够的协同性和临场感,运用计算机支持协同工作的最新技术,面向石油钻井中钻具组合设计过程,研究开发基于CSCW的协同式钻具组合辅助设计软件系统,建立由计算机网络支持的多智能体钻具组合协作设计软件应用平台环境,利用网络通信和移动计算技术来实现动态钻具组合设计信息的多方传输和并行设计.     

Considerations in the outline specification of an effective computer-aided draughting system

Selecting and developing the most effective computer aided draughting system is dependent upon adequate effort being put into its original outline specification. Identifying an company's needs in such terms is not always an easy task and in particular the effects of the proposed system on related systems must be carefully considered.A case study provides a useful example of factors and criteria used in the progressive specification of an industrial computer aided draughting system.     

全过程动画自动生成中的中文文本处理

研究全过程动画自动生成系统中的自然语言处理模块,设计一种面向手机中文短信的信息抽取系统。根据中文语言处理的特殊性,抽取短信中可动画化的信息,并进行否定判断和否定内容识别。实验结果表明,该系统的召回率和准确率较高,可满足动画自动生成系统对信息抽取强度的要求。     

CATC — A Computer Aided Tolerance Control system

Computer utilization in manufacturing systems is increasing at a rapid rate. Developments thus far have been disjointed. Much work needs to be done in the area of integrating computer aided design and computer aided manufacturing (CAD/CAM). Tolerance control is an important component in the integration of CAD and CAM. Selection of design tolerances affects the build-ability of a product. The selection of manufacturing processes and sequence of processes affects process tolerance stacking. Unexamined process tolerance stacking leads to scrap and rework. A computer aided tolerance control (CATC) system is presented in this paper. This system is based on the tolerance chart technique. The CATC system is interactive and uses computer graphics for information display. The system can be used for computer aided process planning (CAPP) and for CAD/CAM integration.     

乙烯氧氯化反应过程微机辅助监测优化的实现

工业氯乙烯生产装置是一类大规模存在的化工工业装置，本文针对其中乙烯氧氯化法反应过程特点设计的微机辅助监测优化系统，对该过程的运行特征进行在线监测，并进行数据处理和工艺分析，为该过程的优化提供了依据，此外，对这一类的化工工业装置微机辅助监测优化系统设计进行探讨，为如何在工业装置优化领域利用计算机这一先进工具提供了一个范例，并就此提出了具有普遍意义的功能模型和运行逻辑，以供类似的系统开发借鉴。     

Form tolerance-based measurement points determination with CMM

In an intelligent manufacturing environment, computer aided inspection (CAI) provides a critical role in closing the computer aided design (CAD) to computer aided manufacturing (CAM) loop. A coordinate measuring machine (CMM) is often used as a measurement tool in a mechanical part manufacturing environment. Feature-based measurement (FBM) with CMM plays an important role in the concurrent engineering environment (Fig. 1) (Yau and Menq, 1993). It measures a part and feedbacks the results to the concurrent control center to modify related process attributes. Feature-based computer aided inspection (CAI) systems define various measurement attributes for different features (Jacobohn et al., 1990). Part of the system determines the number of measurement points for a feature. In this research, a computer aided feature-based statistical concept is used to calculate sufficient measurement points for a feature. Circular and cylindrical parts are used to demonstrate the proposed methodology for determining the number of measurement points. The results show that the measurement error is significantly lower with the proposed method in determining the number of measurement points as compared to the method commonly used with a CMM. The proposed methodology is also computerized for on-line applications.     

Computer‐aided macroergonomics for improved performance and safety

The U.S. presidential election of 2000 was characterized by alleged ergonomic problems associated with the design of voting ballots. However, this visible event actually exemplified the fact that many apparent ergonomic issues are, in fact, macroergonomic issues. That is, in such cases, there are larger systemic factors at work that interact with and contribute to human–machine interface issues. Further complicating system effectiveness is the notion that modern work systems are distributed and therefore require computer aiding to establish a communication pipeline through which decisions can flow and performance can be enhanced. A conceptual and theoretical framework is presented for understanding such computer‐aided work systems and a taxonomy and research examples for three types of computer‐aided work systems are also offered. It is concluded that the single operator–single machine paradigm is not obsolete and the focus remains ultimately on the ergonomic level, but relevant macroergonomic, sociotechnical system factors require consideration prior to optimizing this level for overall ergonomic success. © 2002 Wiley Periodicals, Inc.     

基于软件无线电的通信信号测试平台设计与实现

软件无线电所具有的灵活性、开放性等特点,使其在军民无线通信领域获得了广泛应用。以微电子技术和计算机技术为基础,利用计算机、MATLAB、FPGA和ADI公司的AD9364射频捷变收发器,设计了一种适合测试WCDMA、TD_SCDMA、GSM、LTE等通信系统的信号测试平台,该测试平台能生成任意数字化正弦波,实时检测通信信号的相关信息以及调整射频链路参数。实验结果表明,该设计符合软件无线电的设计思想,具有较强的通用性、可移植性和软硬件均可重构能力。     

A cognitively based methodology for evaluating human performance in the computer-aided design task domain

This article describes a methodology for evaluating human performance in the computer aided design (CAD) task environment. The methodology is based primarily on cognitive theoretic frameworks that are consistent with processes presumed to underlie human design activities. The motivation for its development stems from rapid software and hardware advances in CAD systems and our relative lack of understanding of how these enhancements affect human design performance for (1) fundamentally different types of tasks and (2) different levels of complexity for a particular task. This methodology is currently being applied to computer aided architectural design, an area where artificial intelligence (AI), enhanced geometric modelling and other system features are being debated in terms of their usefulness in aiding the human's design activities.     

基于插值法的地形重建在平流层通信传播损耗预测中的应用

提出了基于插值法的地形重建算法,并应用于平流通信系统电流传播损耗的预测,给出了地形重建算法的计算机实现方法,并对随机产生的地形数据进行了模拟,得出了平流层通信传播损耗与地形数据特征之间的关系。通过地形库数据的行插值、列插值和对角线插值方法解决了平流层通信系统传播损耗预测的地形重建问题,保证了传播损耗预测算法的有效性。本文的工作对于当没有平流层通信实没怕情况下进行平流层通信系统性仿真具有重要意义。