个人便携式网络硬件防水墙设计

文中介绍了防水墙技术和数据包过滤技术,针对个人计算机网络安全的问题,设计了一种便携式的防水墙系统。本系统运用了防水墙技术和网络数据包过滤技术,采用MEGA128单片机控制DM9000网络控制器的方法,对本地计算机发出的数据进行过滤,达到了防止信息被窃取的目的。     

基于文本理解的自动文摘系统研究与实现

本系统模拟人的理解、知识获取认知过程，利用全信息词典有效地组织语言学知识。背景知识和领域知识，利用部分分析器算法，实现语法语义语用分析一体化，从文本中提取重要信息，将任一篇文章转换为计算机内的一个信息提取框架实体．根据填充情况，由文摘生成器产生合适的文摘．目前已实现计算机病毒领域文章的自动文摘，验证了文摘模型的可行性和有效性．文摘系统模型与领域无关．     

The missing link-computer-supported telephony

From an engineering viewpoint, the physical realisation of a computer-supported telephony application involves connecting a computer with a telephone system by a signalling or data link which supports a protocol to carry command and status information between the two systems. In principle, any computer can support the computer supported telephony (CST) protocol, and the telephone system may be a PABX, an automatic call distributor, a key system or any other telephone switch. Existing or new systems can be linked by CST. The author discusses applications of CST the main one being telemarketing. The technology to support CST is not very advanced. At the heart of a modern telephone system is a computer. What CST does is link that embedded computer to a less specialised one. This technology is discussed by the author. The role of CST within the wide telecommunications and IT environment is also discussed     

Fast Hartley transforms for spectral analysis of ultrasound Dopplersignals

Spectral analysis of Doppler ultrasound is known to yield valuable information to assess the state of circulation in the peripheral blood vessels. In the past, the raw Doppler data have been directly input into a dedicated spectrum analyzer or transformed on a microcomputer using the fast Fourier transform (FFT) technique. In the present study, the first Hartley technique is used to transform on a microcomputer to the digitized Doppler data obtained from a normal common carotid artery is presented and the resulting spectra are compared to those obtained by using the Cooley-Tukey FFT algorithm. The Hartley transform has the advantages of being a purely real-numbered transform; therefore, for real Doppler data, it is not only more conceptually straightforward, but also requires less computer memory, is simpler to calculate, and is better suited to large-scale integration implementation. The raw Doppler data were input into a digital oscilloscope from the analog Doppler unit, digitized in real time with 12-b resolution, and displayed on the computer monitor. These data were then stored in a file, on floppy or hard disk, using software provided with the digitizing oscilloscope, and then transformed to the spectral domain using either transform technique. In this application, the transforms were performed using a compiled BASIC language     

一种非相参雷达回波信号模拟器的设计

分析雷达回波特性,从非相参信号模拟开始,提出一种雷达回波模拟器的实现方法。该方法可以利用已知或计算机产生的目标信息运算获得回波信号数据,通过FPGA或DSP芯片控制DDS产生中频回波信号。这种方法具有极大的灵活性和通用性,只要改变计算机回波信号计算模型或参数,即可实现不同回波信号的模拟。     

基于云计算的密码恢复系统模型

随着互联网的普及和信息技术的发展,密码恢复作为密码学分析的一个重要方向,在计算机数据和电子取证等领域有着重要的应用。当前的密码恢复系统实现多采用C/S架构,无法满足目前计算机取证的时间要求。运用云计算（Cloud Computing）设计了一类新的方法来实现快速的密码恢复系统,基于Map-Reduce编程模型和分布式文件系统存储搭建了密码恢复私有云,为构建高性能和高扩展性的密码恢复系统提供了一种新的思路和解决方案。     

A prototype expert system in OPS5 for data error detection

A prototype expert system has been developed in the OPS5 language to perform error checking on data which spacecraft builders/users supply to the NASA Goddard Space Flight Center for processing on the Communications Link Analysis and Simulation System (CLASS) computer. This prototype expert system, called Trajectory Preprocessing System (TRAPS), contains 49 rules and at present runs on an IBM PC in the OPS5+ software package from Artelligence, Inc. In its operational phase, TRAPS will run in the Oak Ridge Production Language (ORPL) on the CLASS computer (a Perkin-Elmer 3244 supermini). ORPL, an implementation of OPS5 by the Oak Ridge National Laboratory in MULTIFORTH on a Hewlett-Packard 9836 desktop computer, is now being ported to SS-FORTH on the CLASS computer. This paper discusses the expert system problem domain, development approach, tools, results and future plans stemming from the TRAPS project.     

The NBS Network Measurement System

The NBS Network Measurement System reipresents the implementation of an approach to the measurement of interactive computer networks, teleprocessing systems, and network series which focuses on the service delivered to users rather than on the internal operating efficiency of the system. The information obtained aids users in the quantitative evaluation of such systems and services. The Network Measurement System consists of a data acquisition System and a separate set of data analysis programs. This paper describes the approach to network measurement taken by this system, the models of user-system dialogue employed, and technical summary of, the implementation of the data acquisition system and the data analysis programs.     

A framework for linking distributed simulations using softwareagents

The paper presents the basic ideas behind the use of software agent technology for distributed simulation and data assimilation. A software agent is an autonomous computer program that operates on behalf of someone or something. A mobile agent has the ability to migrate during execution from machine to machine in a heterogeneous network, while a stationary agent executes only on the system on which it began execution. To understand the role of agents in distributed simulation, note that simulations often operate on static datasets and data sources. Many simulations would produce more accurate results if they could access dynamically changing data from other sources, such as sensors or even other simulations. From the perspective of one simulation, other simulations are data resources, producing information possibly relevant to the past, present, or future of the system being modeled. Software agents allow dynamic linking between distributed simulations and efficient monitoring of and access to remote data resources. Specifically, they conserve bandwidth, provide custom operations without precompiling or preloading, and adapt to support disconnected operations. The paper describes the development of a software agent based framework for dynamically linking distributed simulations and other remote data resources. The framework called ABELS (Agent-Based Environment for Linking Simulations) allows independently designed simulations to communicate seamlessly with no a priori knowledge of the details of other simulations and data sources. We discuss our architecture and current implementation developed using the D'Agents mobile agent system     

一种新的基于被扰动的Lorenz系统的混沌加密算法

提出一种基于被抚动的Lorenz系统的加密算法.首先通过Legendre多项式对Lorenz系统中的系统参数b进行扰动,然后再利用Lorenz产生的随机序列对原文信息进行一系列的操作变换,使得加密的信息更加安全.通过扰动有效的补偿了计算机有限精度导致的混沌系统退化行为,经对本算法的模拟实验及详细性能分析,结果表明该加密...     

基于Karhunen-Loeve变换和最低位替代的图像隐写术

为了提高信息通信安全性能,防止信息被窃取,提出了一种新颖的图像隐写术.采用Karhunen-Loeve变换压缩数据,构造其最低位替代加密数据,并在载体图像内对信息进行编码,其压缩过程用于去除冗余性,同时还设计了编码到一个级别的像素矩阵,由最低位替换的方式进一步实施.实验结果表明,该算法效率高,并能对原始数据进行有效的解密;且与其他机制相比,所提出的技术具有更高的容量和平均信噪比.     

Identity-based information security management system for personalcomputer networks

A network information security management system which authenticates and/or encrypts messages is proposed. Both authentication and key distribution are executed in a simple scheme. Once the system is set up, the transactions are done independently by the users involved, yet the amount of information that users must keep is small. The experimental implementation of the system on a personal computer network, using IC cards (smart cards) and digital signal processors, is described. The signal processors shorten calculation time and make the concept practical     

计算机网络安全问题及防范措施

科学技术的发展,促进了各行各业的进步,计算机网络已逐步渗透到各个领域,计算机网络技术在为人们提供便捷的同时,也造成了信息安全风险,如病毒入侵与黑客攻击,容易导致计算机数据被破坏。文中分析了加强计算机网络信息安全的重要性,并阐述了计算机网络安全问题的类型,从系统漏洞、计算机病毒及黑客入侵等方面进行了论述,最后总结了增强计算机网络安全的防范措施,希望可以提升用户信息的安全性和稳定性。     

论计算机技术在医院中的重要作用

随着科学技术水平的不断进步,计算机技术在各个领域被广泛运用。医院信息系统的构建及运维都离不开计算机技术,通过计算机系统对医院相关信息以及流程等能进行更好的整合与重组。本文以计算机技术在医院中的运用为主要的阐述对象,介绍了现阶段计算机技术在我国医院发展过程中的具体运用现状,同时也具体分析了计算机技术在医院各个方面的重要作用,同时,文章也探究了计算机技术在医院的运用过程中存在的相应问题,并针对这些问题提出相应的可行性建议。     

Automated chemistry laboratory: Application of a novel time-shared computer system

A promising strategy for providing a hospital information system is the gradual development and subsequent integration of well-defined information processing modules. A computer system which is suitable and economical to serve one or more of these modules has been developed. Its unique feature is that it uses an interpretive language for all the application programs both in the developmental and service modes of operation. The interpretive language, which has been designed specifically for data management applications, facilitates the creation and debugging of programs; in addition, it allows the time-sharing of a relatively small computer with a negligible overhead for switching control from one program to the next. The multiterminal, real-time remote-access computer system has been in service operation at the Clinical Chemistry Laboratory of the Massachusetts General Hospital since the early Fall of 1968. Presently, the system accepts typed-in requisition information, creates patient files, and generates schedules for centrifuging blood samples and for the performing of all tests; the system also accepts test results and provides reports on individual patients. In the near future all test results will be manually entered into the machine, which will then generate cumulative test reports each day. The on-line connection of automated laboratory equipment (AutoAnalyzers) will soon follow. Analysis of the system performance shows that the use of an interpretive language is suitable for this application, and it also indicates that the system has sufficient capacity for serving additional information processing needs.     

Markov Chain Based Roaming Schemes for Honeypots

The paper proposes a reactive roaming scheme for honeypots. The main aim of a honeypot is to capture the activities of the attacker. If the attacker detects honeypot on a system, its value drops. So, the concept of roaming honeypots is being proposed, to prevent the attacker from detecting the honeypot, which in turn increases the efficiency of honeypot and allows collecting rich data about activities of active attackers. The honeypot is shifted to another system which is most probable to be attacked within the network. The concept of Markov chain analysis is being used to detect the most probable system to be attacked based on the current status of the network. Further, using IP shuffling and services on/off concepts, honeypots roam on the network to the most probable system to be attacked using the threat score. Snort is used to capture data about the number of attacks on each of the nodes of the network and the data collected is then used as an input for Markov chain analysis to identify the most probable system where honeypot can be roamed/moved. The roaming scheme has been implemented for both high interaction honeypots and low interaction honeypots. The high interaction implementation helps in capturing in depth information on a shorter range of IP addresses, whereas the low interaction implementation is efficient in capturing information on a large range of IP addresses. The main advantage of this approach is that it predicts the frequency of attacks on the nodes of a particular network and takes a reactive step by starting the honeypot services on that particular node/system on the network.     

企业安全环保计算机信息管理系统的应用

企业安全环保管理信息系统的实际内涵就是实现对安全环保管理工作的有效把握,对管理的水平以及效率进行提升,这是有别于以往的安全环保工作,相对于以往借助人为的管理到现在,已经将安全环保工作从人为管理变为计算机协助的管理工作.相对于传统的管理方法,这种管理方法更加便捷有效,可以更好地实现环保工作系统的完善,减少人为管理当中所出现的问题,除此之外,也可以更加快捷地收集信息,并且对信息进行处理,本文对安全环保计算机信息管理系统的实际应用进行探讨,介绍计算机管理系统在安全环保管理当中的实际应用,以及技术的实现和所得到的实施效果.     

Using expert systems to implement a semantic data model of a large mass store system

The successful development of large volume data storage systems will depend not only on the ability of the designers to store data, but on the ability to manage such data once it is in the system. Our hypothesis is that mass storage data management can only be implemented successfully based on highly “intelligent” meta data management services. Such services would allow database administrators and users to manipulate, update, and access data and related information and knowledge in a logical manner, and yet would be powerful enough to support the performance needs of a large mass store system. Historically, there have been attempts at building data management services for very large volume data systems; however, when the amount of data being managed got large the meta database itself failed as a consequence of its own size and complexity.

However, if the standard were expanded to include the semantics and pragmatics of the data domain using a Semantic Data Model (SDM), the result would be an overall information system design that is organized and accessible in the context of the data's user and purpose. The implementation of an SDM requires the application of Artificial Intelligence (AI) and related computer science technologies such as object oriented representation, property inheritance, and rule-based decision making. Presently, there does not exist unique software for developing SDMs that addresses the complex representation of data meta data and related information and knowledge.

This paper presents the results of a demonstration prototype SDM implemented using the expert system development tool NEXPERT OBJECT. In the prototype, a simple instance of a SDM was created to support a hypothetical application for the Earth Observing System, Data Information System (EOS-DIS). The massive amounts of data that EOSDIS will manage requires the definition and design of a powerful information management system to support even the most basic needs of the project. The application domain is characterized by a semantic-like network that represents the data content and the relationships between the data based on user views and on more generalized domain architectural views of the information world. The data in the domain are represented by objects that define classes, types, and instances of the data. In addition, data properties are selectively inherited between parent and daughter relationships in the domain. Based on the SDM, a simple information system design is developed from the low-level data storage media, through record management and meta data management, to the user interface.     

基于HL7的医疗数据集成及系统设计

HL7是数字化医院系统电子数据交换的一个标准,覆盖整个医院信息系统。分析了HL7标准及其数据交换的基本原理,并通过基于SOA构架的服务总线技术,建立基于HL7标准的数字化医院信息系统构架。该系统通过HL7数据网关的数据转换实现与医院内部LIS、PACS等多个系统的无缝集成。讨论了该系统的通信协议及数据整合方案,设计了完整的基于HL7的数据通信协议及数据集成模块实现框架。     

分布式智能地理信息系统(DKGTS)

本文介绍了分布式地理信息系统(DKGIS)的设计和实现。其中提出了以对象为中心的关系-框架数据模型,新型的物理数据结构。系统采用先进的分布策略,很好地实现了数据的分布查询和更新;DKGIS具有以知识和模型为基础的辅助决策功能和友好的自适应人机接口.测试表明,该系统功能齐全,智能水平高,分布能力强,使用方便.