共查询到20条相似文献,搜索用时 31 毫秒
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浅析办公自动化网络安全 总被引:2,自引:0,他引:2
随着计算机网络技术的普及,利用联网实现办公自动化,并将办公自动化应用到机关事业单位等安全性要求较高的机构已成为一种迫切的需要.所谓办公自动化是指运用电脑及相关外设,有效地管理和传输各种信息,达到提高工作效率的目的。办公自动化网络是一个中小型的局部网络.办公自动化网络系统是自动化无纸办公系统的重要组成部分。在实现联网办公时,由于覆盖面大,使用人员混杂,管理水平各异,往往不能保证公文在网络上安全传输和管理。还有一些人专门在网络上从事信息破坏活动,给国家、企业造成巨大的损失.因此,加强网络安全,防止信息被泄露、修改和非法窃取成为当前网络办公自动化普及与应用迫切需要解决的问题。本文总结了办公自动化网络常见的安全问题及其后果,探讨了解决这些安全问题的方法,提供了基于网络内部的安全策略。 相似文献
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Thomas Rolander 《Microprocessors and Microsystems》1981,5(2):69-71
The purpose of the CP/NET software system is to support network technology by allowing independent microcomputers access to common, and often expensive, facilities such as peripherals, programs and databases. It is designed for adaptation to a wide range of network hardware, operating with CP/M and MP/M to support the many CP/M-compatible products available. This article considers aspects of this operating system and some of the network configurations possible. 相似文献
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Nadia Magnenat-Thalmann Alain Choquette Daniel Thalmann 《Microprocessors and Microsystems》1983,7(3):107-110
A powerful graphical PASCAL extension has transferred from a large computer to a microcomputer. The graphical extension, called M1RA-2D, allows the user to program computer graphics applications in a modern, structured and efficient language. The problems encountered were mainly due to the limits of a microcomputer-based system and to the size of the project. Problems involved memory space, documentation, low-power peripherals, PASCAL restrictions and hardware robustness and quality. Finally, M1RA-2D is compared with two other graphics software packages implemented on microcomputers: Applegraphics and an implementation of a 2D, level 2 Core System. 相似文献
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为了防止不法分子在USB设备与电脑连接时植入非法程序,从而窃取电脑中的敏感信息或控制电脑向外设发出非法指令,本文针对USB-key的接入安全问题,提出了建立黑、白名单的方案。传统的USB-key安全防范措施都是基于加密认证,未考虑税控机接入的USB设备安全性。因此,本文提出对接入的USB设备进行分类,并对不同类别的USB设备执行相应的处理方案。通过设计开发针对税控系统的硬件检测设备和软件控制程序,从物理层面对接入税控机的USB设备进行安全检测。文中给出了USB设备过滤器的硬件设计图和软件控制程序的流程图,并对几种有代表性的设备进行了测试。测试结果表明,该设备能够对USB设备合法性进行有效的检测,并对违规的USB设备做出相应的处理,提高了税控系统USB-key接入USB设备的安全性。 相似文献
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This special issue of Computer presents five papers covering as many major areas of microcomputer applications: high-level languages development for microcomputer applications, special-purpose microcomputers, computer peripherals and instrumentation, microcomputer networks, and distributed process control. 相似文献
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The key to software reliability is to design, develop, and manage software with a formalized methodology which can be used by computer scientists and applications engineers to describe and communicate interfaces between systems. These interfaces include: software to software; software to other systems; software to management; as well as discipline to discipline within the complete software development process. The formal methodology of Higher Order Software (HOS), specifically aimed toward large-scale multiprogrammed/multiprocessor systems, is dedicated to systems reliability. With six axioms as the basis, a given system and all of its interfaces is defined as if it were one complete and consistent computable system. Some of the derived theorems provide for: reconfiguration of real-time multiprogrammed processes, communication between functions, and prevention of data and timing conflicts. 相似文献
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用可变拓扑互连结构来实现多机间的互连,是计算机多机通讯研究的一个重要方向。本文给出了一个采用现场可编程技术实现的多单片系统的体系结构的设计和实现。它将四片MCS-51系列单片机通过全互连的拓扑结构连接起来,以PC386/486为主机,构成一个主从分布式控制的多机系统。该系统还在Xilinx XACT的C
CAD工具上进行了模拟验证,并得到FPGA(现场可编程门阵列)实现。 相似文献
CAD工具上进行了模拟验证,并得到FPGA(现场可编程门阵列)实现。 相似文献
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Pranay Chaudhuri 《Microprocessors and Microsystems》1985,9(3):114-117
Microcomputers are increasingly being used in various process control systems. A recent trend is to use them in multiprogrammed realtime environments rather than as dedicated controllers. The paper describes the design of a scheduler for realtime process control using microcomputers. For simplicity, a static-priority-based round-robin scheduling policy is used whereby the working time slice can be varied for the different processes. The memory size for the process scheduler is estimated at approximately 1 kbyte using the Intel 8085 instruction set. 相似文献
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针对中小工厂拉丝工艺较低的自动化程度,介绍了一种用AT89S52,PIC16F628A单片机控制的和用Visual Basic设计的实时监控界面的玻璃拉丝测控系统。叙述了该系统的软硬件组成,着重介绍了上位机,以及下位机与它之间的通信。经现场运用表明,系统运行情况良好,满足了所要求的功能和精度,且使用维护方便。 相似文献
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针对RS-485总线的矿用摄像机控制系统存在的问题,设计了基于控制器局域网(CAN)远程控制技术的新型系统。系统以嵌入式处理器LPC2129为控制器,并利用其CAN接口外挂收发器CTM8250构建了CAN网络,并在CAN V2.0B规范的基础上开发了控制协议,能够在远程上位机上对摄像机的调焦、缩放以及工作台的上下、左右移动进行可靠控制。为方便与上位机的连接,设计了RS-232-CAN转接器,另外在转接器中进行控制器地址映射,通过软件实现了地址在上位机设定的功能,避免了人员必须到现场通过拨码设定地址的繁琐。 相似文献
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AmigoBot移动机器人上位控制系统的设计 总被引:1,自引:1,他引:0
针对AmigoBot移动机器人存在不支持本地可编程控制、只能作为网络终端的问题,提出了一种基于OMAP3530和Android嵌入式平台的AmigoBot移动机器人上位控制系统的设计方案;给出了该系统的硬件及软件结构,详细介绍了在OMAP3530上移植Android系统的过程:首先对Android系统进行裁剪,使其内核功能模块既能满足上位控制系统的要求,又不冗余;在裁剪后的Android系统的基础上,对AmigoBot移动机器人的Aria控制软件、无线通信等应用软件进行设计。实验结果表明,该系统解决了AmigoBot本地控制问题,提高了AmigoBot的扩展能力。 相似文献
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小型水电站综合自动化系统的设计与实现 总被引:1,自引:0,他引:1
随着单机2000kW以下的小型水电站的迅速发展,建立以计算机监控为基础的综合自动化系统已经成为其自身生存和发展的需要。文章从系统的结构、功能、一体化现地控制层、电站控制层、系统保护和预警装置、通讯网络、系统软件配置等多方面进行了具体的阐述,最终实现了小型水电站的综合自动化系统的设计。 相似文献
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贺亮 《计算机光盘软件与应用》2011,(15)
随着计算机应用科学技术的发展,各行各业基本上普及应用了计算机局域网,各个单位的局域网服务器安装了内部管理软件和办公自动化软件,局域网通过局域网服务器与internet连接,从而实现了整个系统的资源共享。它具有传输速率高、覆盖范围小、误码率低、易于实现和扩充、成本低等特点,特别适合于企事业单位的信息管理、工业控制、办公自动化及网上教学,并得到了迅速的推广和应用。本文在此基础上对网络安全维护做出一番探讨。 相似文献
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基于单片机的温室自动控制系统设计 总被引:14,自引:0,他引:14
温度、湿度和CO2浓度等是影响作物生长的重要环境因子,为有效进行作物生长的环境控制,针对日光温室的特点,以模糊控制理论为基础,计算机控制技术为平台,设计了一个基于模糊控制技术的计算机温室控制系统;介绍了以PC机为上位计算机,MCS一51单片机为核心的智能仪表为下位机的智能温室分布式测控系统的工作原理及主要功能;详细阐述了该系统的软、硬件实现方法;该套控制系统符合我国现阶段的国情且能很好地满足生产要求,成本低,运行可靠,便于推广应用. 相似文献
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Powerful, inexpensive processors, low-cost storage, and high-resolution color displays make single-user, networked, multiprogrammed computer workstations suitable replacements for the time-shared mainframe environment of the scientific and engineering professional. Distributed processing via networks of workstations connected to larger server machines, which are in turn connected to national and international networks, allows a completely new form of computer-aided organization for institutions. The flexibility and speed of such machines mean that a new revolution in information processing and human activity support is inevitable. The professional workstation project has as its immediate goal a networked, distributed system of single-user workstations. Each will use the Unix operating system and provide powerful object-oriented graphics tools that will enhance the productivity of scientific and engineering professionals. 相似文献