局网的协议分析方程及其解

在集合理论的基础上引进了几种概念,用于表达由三个映射构成的局网协议的抽象环境.与传统的概率模型不同,这里提出的方程分析法能直接描述协议中各观察对象之间的时间关系,每个观察对象被表示成该对象的可见时刻集,由这些时刻集构成的数学方程式简捷地表达了协议的机理及细节,方程的解为协议性能和仿真提供了详尽的分析基础.CSMA/CD在文中作为一个示例被形式化为一组易读的数学方程式及精确的仿真模型.     

面向读者信息需求的浏览空间

提出面向读者信息需求的浏览空间 .该浏览空间是由基于读者的信息需求所生成的web页面构造的 ,并且web的信息显示方式和页面之间的链接都是以读者的逻辑思维为依据 .最后 ,给出实现面向读者信息需求的浏览空间的一个应用实例     

Automatic Discovery of Information Resources on the World Wide Web

A basis for automatic discovery of information resources on the World Wide Web is characterized by three underlying equations. With these equations, the information universe on the Web is divided into three associated spaces. This model differs from the hypertext employed by the Web, in that the former supports the notion of automatic resource discovery. A private library, which is able to gather automatically from the Web the information useful to the library owner, is envisaged to illustrate that the basic equations and their derivations can be applied to Web automation, including crawling and classifying.     

一种使用JavaMail的邮件直接发送方法及其实现

随着国际互联网的蓬勃发展，电子邮件已经成为人们交流、联系和接收信息的一种重要方式，每天数以万计的电子邮件穿梭在国际互联网上。本文提出一种电子邮件的直接发送方法，其优点是减少了邮件传输的环节，避免了邮件发送服务嚣对电子邮件的限制，从而不仅加快了邮件传输的速度，而且特别适用于大批邮件群发系统。     

局网仿真数学模型及其面向对象实现方法

从局网的基本关系式出发,为局网仿真系统建立了一种数学模型.与传统的性能模型不同,该数学模型把各种局网的差异隐蔽在5个映射之中,没有排斥实际系统中的任何细节.这些映射的功能可以由模拟局网的协议、传输介质和站点的对应对象来分别完成,形成面向对象仿真系统的基本结构.对象内部不同的结构和细化可以实现不同局网的差异和细节,而仿真系统的基本结构保持不变.令牌总线和混合CSMA令牌协议被作为范例演示了该数学模型的普遍适用性.     

A FULLY-HYBRID MAC PROTOCOL IN LANS

In announced hybrid protocols,there are two mechanisms usually employed.One operates in aCSMA family manner and the other follows a token passing family way.However,only one ofthem works efficiently when traffic is light or heavy.This results in an inefficient redundance and aburden to the protocol implementation.In this paper,we present a new hybrid concept and its idealmodel in which risky transmissions alternate with safe transmissions in response to the dynamicchange in traffic.Being similar to virtual time CSMA in the abstract,a single control mechanism isproposed to approach this ideal model.The mechanism is rather compact,and its implementationcan be designed to be simple,efficient,reliable,robust,and fully distributed without any centralizedelement at any instant.Simulation results show that the proposed mechanism performs well overthe entire range of the traffic load from light to heavy.