Tools for transparent synchronous collaborative environments

Synchronous collaborative environments can provide an identical visual and operable working area among geographically separated participants. There are two basic approaches for providing a shared workspace. They are collaborative-aware approach and collaborative-unaware approach. Since the second approach allows single-user applications to be reused, most users choose to use it. Our work is based on the collaborative-unaware environment. This paper describes the design and implementation of some transparent synchronous collaborative tools. They are: (1) the latecomer support for Java applications, Java applets and JMF players (2) the client synchronization to minimize data transmission latency and (3) the lightweight multi-session support to let different collaboration groups work at the same time. These tools optimize existing transparent synchronous collaboration systems and make them more realistic, more complete and more generic.

基于80C552单片机的多芯片同步复位电路

首先分析了单片机应用系统的一般复位电路,然后讨论了多芯片系统对复位功能的要求,并针对80C552的特殊复位结构,详细介绍了一种软件、硬件相结合的同步复位电路。     

快速分组交换环网SFPring及其特性

本文介绍了一种新型同步时隙快速分组交换环网（ＳＦＰｒｉｎｇ）及其特性。此网通过对时隙环增加环路帧同步器的方法，使得环路的时隙一致，简化环路接口，虽使时隙环在低负荷下延时特性略有下降，但由于能采用分组目的站回收方案，可使其重负荷条件下效率提高一倍，因而其十分适于综合业务局域数字网。     

IBM微机专业图形显示器与VGA显示卡兼容的实现

论述了用 74F86芯片实现IBM微机专业图形显示器与VGA系列显示适配器兼容的方法。     

Synchronous set relations in rewriting logic

This paper presents a mathematical foundation and a rewriting logic infrastructure for the execution and property verification of synchronous set relations. The mathematical foundation is given in the language of abstract set relations. The infrastructure, which is written in the Maude system, enables the synchronous execution of a set relation provided by the user. By using the infrastructure, algorithm verification techniques such as reachability analysis and model checking, already available in Maude for traditional asynchronous rewriting, are automatically available to synchronous set rewriting. In this way, set-based synchronous languages and systems such as those built from agents, components, or objects can be naturally specified and simulated, and are also amenable to formal verification in the Maude system. The use of the infrastructure and some of its Maude-based verification capabilities are illustrated with an executable operational semantics of the Plan Execution Interchange Language (PLEXIL), a synchronous language developed by NASA to support autonomous spacecraft operations.     

Design and optimization of buck and double buck converters by means of geometric programming

This paper describes a new method for determining the optimal components values and switching frequencies of buck DC–DC converters. First, we revisit some concepts of the optimization technique named geometric programming. Then, we observe that the problem of converter designing can be modeled by means of an objective function and certain constraints which can be written in a specific form known as the posynomial form. The constraints involve expressions that depend on magnitudes such as efficiency, bandwidth, and current and voltage ripples.     

基于Domino数据同步的全局化OA系统的实现策略

介绍在广域,网范内,采用Ｌｏｔｕｓ公司的Ｄｏｍｉｎｏ作为ＯＡ系统的平台并利用其复制功能实现了多个数据库副本同步的策略,以提高信息传输效率,降低网络通讯负担。     

基于VxWorks的T比特路由器2.5GPOS接口板的设计与实现

因特网流量的快速增长,对骨干网的传输提出了更高的要求,为此我们研制了总吞吐率高达1.28T比特高性能IPv4/v6路由器。本路由器提供2.5GPOS,10GPOS,100M以太网,1000M以太网,10GLAN以太网,10GWAN以太网等接口,可方便组网。本文简要介绍了此路由器的总体结构,并深入研究了2.5GPOS接口板的设计与实现。     

支持并发控制的多智能体系统构造方法

基于桌面共享或远程登录实现的协同过程,容易出现并发冲突问题,这是同步协同设计走向实用化面临的瓶颈问题。本文提出了面向控制权限的多智能体系统构造方法,通过控制客户端与服务器之间的行为解析和发送,从而消解并发冲突。本文详细阐明了支持并发控制的多智能体系统的构造原理与实现方法。     

A Note on Kobayashi's and Yonezawa's “Asynchronous Communication Model Based on Linear Logic”

We explain why the Kobayashi–Yonezawa translation of CCS into linear logic does not work properly. Then we introduce our own translation and prove its correctness. Received September 1997 / Accepted in revised form June 1998