令网疯狂令我醉的ML

HTML大家一定不会陌生,我做了一个主页,其中就有不少.htm文件,不过我的主页确实不够美观,干巴巴的一些文字、图像。     

Ada语言与Occam语言的比较

一、引言过去十年在计算语言领域的重要进展之一是出现了具有并行计算能力的Ada语言和Occam语言。Ada语言是具有类似Pascal语言的控制结构,并且能重植入过程和函数的大型语言,其初始设计目标是满足美国国防部所规定的要求,即首先考虑支持适于军事装备的嵌入式编程系统。就本质而言,Ada语言是在串行语言的结构上,扩充增加了并发执行的能力。 Occam语言是和Transputer同时设计实     

GCLISP对其他高级语言的调用方法

目前的GCLISP版本,对用其他高级语言编写的程序交互能力差,这对需要进行复杂计算或想直接调用其他高级语言编写的“标准程序”的用户造成了一定的困难。本文介绍了作者在使用GCLISP调用其他高级语言的一点体会,提出了用高级批处理的方法来解决这种联接调用。这对使用GCLISP的用户可能会有一定的启发。     

Source-to-Source Conversion Based on Formal Definition

This paper proposes the idea of source-to-source conversion between two heterogeneous high-level programming languages.The conversion is based on formal definition and oriented to multi-pairs of languages.The issues in conversion from PASCAL to C are also discussed.     

怎样选择一门语言

许多高校将取得计算机等级考试相应的证书作为学生毕业的必要条件之一，因此不少新生刚入学就末雨绸缪，准备考级，但在其中对程序语言的选择却充满了困惑，甚至感到无所适从。这里我就语言的选择发表一些自己的看法。选择语言要坚持以下几个方面的原则：（一）空间性原则空间性原则指的是要确定你选择的语言在你所计划的整个计算机系统学习中的地位。也就是说，在选择一门语言时，要了解其在计算机学习过程中所处的地位，在你以后的计算机系统学习过程，是否可以使用到这门语言，从而相对减少学习量。例如C语言，在以后学习数据结构这门专…     

C#是一种新的语言？或者仅仅只是J……

C＃与Java两者在相似性外,又是非常不同的,它们有许多细微的语义和设计区别,适台不同的技术和市场环境     

从VB到VBA

多年来,Microsoft公司一直对新闻界及开发人员暗示,它的长远策略包括一种通用的应用程序编程语言。这种语言将用于微软的所有应用程序中,它起源于应用得相当广泛的计算机语言—VB。这种语言将向高级用户及开发人员提供一种应用程序间通用的应用程序语言(也就是宏语言),因而可以减少学习时间和支持费用;而且这种语言也会为开发人员提供一种开发方法,用于开发集成多个应用程序的系统,即多个应用程序协调工作,以解决商业上的问题。 这个期待已久的语言就是Visual Basic for Application(简称VBA)。包括这种语言的第一个微软产品就是Excel 5.0。VBA为高级用户及开发人员提供了使用这种最通用的Windows编程语言—Visual Basic的能力,并可以将它应用到Excel的问题中。它也使得用户可以更容易控制其它Microsoft的应用程序。 虽然VBA起源于VB,但它成为一个对应用程序几乎没     

C和Ada语言比较及C到Ada转换技术

本文比较Ｃ和Ａｄａ语言的异同，探讨用Ａｄａ语言实现Ｃ语言特殊语法功能的技术。     

A new approach to performance modelling of Client/Server distributed data base architectures

The recent technological advances in the field of computer and communication lead to distributed data base (DDB) architectures based on the Client/Server paradigm. Available DDB performance prediction methodologies are not sufficiently adequate being too expensive both in the model definition and in the model analysis because of the structural complexity and the large system dimension.

This paper concentrates on a new approach to performance modeling of DDB systems called “independent modelling approach”. This approach separates the DDB software model from the DDB machinery model, and models from solution techniques. This way the aspects related to data contention can be analysed as a pure software characteristic and separated from resource contention, considered as a machinery characteristic. Furthermore, it is possible to analytically model some system aspects (e.g., the software only, or part of it, without involving the machinery model), and apply combined analytical/simulation methods for the remaining system aspects. This results in higher flexibility at lower computational cost in the performance analysis of complex DDB architectures.

A case study is developed and experimental results are discussed to show the effectiveness of the approach.     

Default logic as a query language

Research in nonmonotonic reasoning has focused largely on the idea of representing knowledge about the world via rules that are generally true but can be defeated. Even if relational databases are nowadays the main tool for storing very large sets of data, the approach of using nonmonotonic AI formalisms as relational database query languages has been investigated to a much smaller extent. In this work, we propose a novel application of Reiter's default logic by introducing a default query language (DQL) for finite relational databases, which is based on default rules. The main result of this paper is that DQL is as expressive as SO_∃∀ the existential-universal fragment of second-order logic. This result is not only of theoretical importance: We exhibit queries-which are useful in practice-that can be expressed with DQL and cannot with other query languages based on nonmonotonic logics such as DATALOG with negation under the stable model semantics. In particular, we show that DQL is well-suited for diagnostic reasoning     

一个语义Web构架及其实现

语义Web是国际互联网组织W3C制定的关于未来Web的一个长远蓝图,近两年发展异常迅猛,并显示出诱人的应用前景。该文在概述语义Web基本技术的基础上,设计了一个面向企业门户网站的语义Web体系结构;提出了页面代理的概念及其作用与功能结构;设计了语义Web查询语言CDQL,该语言在跨信息源查询、约束表示等方面扩充了DQL查询语言。     

基于Web的分布式数据库的开发

运用分布式系统的软件技术,构造一个基于Web的分布式数据库系统,在该系统中可进行远程数据采集、查询和管理。对DHMS进行了无关性设计及DDB Server的设计,连接了开放数据库,结合了W eb计算和客户/服务器计算的优势,具有灵活性、高效率、统一界面等优点,使客户端成为真正的零维护。     

High-Performance Telemedicine Information Management

The rapid advances in high performance global communication have accelerated cooperative image-based medical services to a new frontier. Traditional image-based medical services such as radiology and diagnostic consultation can now fully utilize multimedia technologies to provide novel services, including remote cooperative medical triage, distributed virtual simulation of operations, as well as cross-country collaborative medical research and training. Fast (efficient) and easy (flexible) retrieval of relevant images remains a critical requirement for the provision of remote medical services. This paper describes the database system requirements and presents a system architecture of a distributed multimedia database system, MISSION-DBS, which has been designed to fulfill the goals of Project MISSION (medical imaging support via satellite integrated optical network)—an experimental high performance gigabit satellite communication network linking remote supercomputing power, medical image databases, and 3D visualization capabilities, in addition to medical expertise anywhere and anytime around the globe. The MISSION-DBS design employs a synergistic fusion of techniques in distributed databases (DDB) and artificial intelligence (AI) for storing, migrating, accessing, and exploring images. The efficient storage and retrieval of voluminous image information is achieved by integrating DDB modeling and AI techniques for image processing while the flexible retrieval mechanisms are accomplished by combining attribute-based and content-based retrievals.     

分布数据库系统内核TX的设计与实现

本文介绍由清华大学计算机科学与技术系数据库组于１９８７—１９９０年开发的一个开放系统──分布数据库系统内核ＴＸ的设计思想和实现技术，从其部分实现开始，ＴＸ就在他们的分布数据库、知识库、超文本数据库等研究中发挥着重要作用。本文着重于ＴＸ的体系结构、数据组织、查询处理、数据字典及并发控制。     

A transformation system for deductive database modules with perfect model semantics

We present a transformation system for deductive database (DDB) modules. We show that it preserves several data-dependency properties of a DDB and is correct for the “perfect model” semantics of DDBs. Perfect models are not directly amenable to logical reasoning since logically equivalent DDBs may have different perfect models. We develop an approach which involves using a condition on data dependencies in DDBs (stratification compatibility) to pass from a logical equivalence to equivalence under perfect model semantics. This is readily applicable to the transformation system.     

用XML建造专家系统知识库

专家系统是一种基于知识的智能系统，主要包括知识库、数据库、推理机制、解释机制、人机接口和知识获取等功能模块。它的主要特征是，系统中有一个巨大的知识库，存贮某个领域的专门知识，有很多种技术管理知识库。随着网络技术的发展，XML已经成为重要的网络计算语言。文中就如何用XML建造专家系统的知识库以及其相关操作做了深入的探讨。     

用XML建造专家系统知识库

专家系统是一种基于知识的智能系统,主要包括知识库、数据库、推理机制、解释机制、人机接口和知识获取等功能模块。它的主要特征是,系统中有一个巨大的知识库,存贮某个领域的专门知识,有很多种技术管理知识库。随着网络技术的发展,XML已经成为重要的网络计算语言。文中就如何用XML建造专家系统的知识库以及其相关操作做了深入的探讨。     

基于Petri 网知识库维护方法的实现

知识库的维护是知识系统的关键部分，直接关系到系统能否正常运行，本文介绍了基于Petri网知识库维护方法的实现。