基于CORBA的分布式通信管理系统关键技术的探讨

随着网络技术的发展和计算机应用的深入,分布式系统已经成为各个行业主流的软件系统。分布式系统具有诸多优点,但是在开发时面临诸多的挑战。本课题则主要研究中间件CORBA技术在该项目关键模块中的应用,包括:CORBA框架的设计与实现,可靠性保障层设计与实现,以及如何对分布式通信系统中的资源进行管理。     

基于ACE/TAO的分布式网络测量管理平台的研究与实现

将基于公共对象请求代理体系结构(CORBA)的应用与面向消息、松散耦合的Web 服务技术结合起来,提出并实现了一种基于ACE/TAO的分布式网络测量管理平台来完成对测量探针的管理、测量任务的控制、测量结果的处理及呈现等功能.基于该平台实现的网络测量系统可以灵活地部署于现有网络中,开展对各种网络性能及应用性能的测量.在试验网上的实际测试结果验证了该平台的有效性和运行可靠性.     

基于CORBA/JDBC的异构数据库互操作的研究

本文提出了基于CORBA/JDBC的系统体系框架结构,解决了异构平台间的通信问题,使不同的数据库间实现了信息的共享和交流,可以跨越平台、跨越语言地实现集成工程数据库,具有良好的可扩展性与可移植的能力.     

基于CORBA的银行缴费系统的设计与实现

首先介绍中间件的基本思想,并讨论其实现技术之一CORBA,然后对构建银行中间业务系统的实现原理进行了讨论,介绍该系统的主要功能模块,最后利用C++Builder实现一个基于CORBA的银行中间业务--手机缴费系统.     

CORBA在电子商务系统中的安全性应用研究

电子商务在因特网开放的网络环境下,基于浏览器／服务器应用方式,买卖双方不谋面地进行各种商贸活动,是一种新型的商业运营模式。由于电子商务是建立在开放的Internet平台上的,而在开放的网络上传输的任何信息都可能被他人载取,存在大量的安全隐患。本文引入了对象请求代理体系结构（CORBA）,井将CORBA作为电子商务系统的底层结构,从而提高电子商务的安全性。     

基于Web的生产现场总线控制网动态监控的一种实现方法

基于WEB技术实现对生产现场的远程动态监控是研究远程监控的关键技术之一.本文首先设计了基于WEB的生产现场总线控制网远程动态监控的体系结构,基于CORBA技术研究并实现了对分布的生产现场总线控制网系统中异构主节点工作站的集成控制;采用实时数据库技术,实现生产控制层和企业管理层的信息集成;使用了XML技术对监控信息进行了应用封装,从而快速有效地实现各异构主节点工作站之间通信及实时监控数据的传递.     

计算机与可编程仪器的串行通信探析

串行通信技术作为一个古老的通信技术广泛的应用在目前所有的计算机系统之中,在主流的操作系统都已经具备串行通信的底层支持,而虚拟化软件的发展也使得利用串行通信控制可编程芯片越来越容易。     

虚拟制造组织中服务定位机制研究

提出一种基于公共对象请求代理结构(Common Object Request Broker Architecture,CORBA)的多自主体系统(Multi-agent System,MAS)体系结构作为虚拟制造组织(Virtual Manufacturing Organization,VMO)的组织框架和信息基础设施,以跨越成员企业之间在位置、网络、协议、平台、语言以及数据结构和类型等方面的异构性,实现在语义和应用层上的互操作。在此基础上提出一种基于中间Agent的服务定位机制(Setvice Location Mechanism,SLM),以支持虚拟制造组织的构建以及成员企业间的通信、互操作和资源／服务共享,并在开发的VMO概念原型系统上进行了实现和验证。     

单片机与PC机的串行通信

本文阐述了ME300b单片机开发系统与PC机COM串口间的通信方法。该方法通过汇编语言指令对单片机、PC机底层硬件的访问,分别以查询方式和中断方式实现了异步串行通信。     

几个最小2容错广播网络

广播是研究通信刚络的某个成员的消息如何尽快地传递给所有其它成员的消息传递问题。有两种常见的通信模式,一类是shouting模式,即在一个单位时间内,一个顶点能够和它的所有邻点通信：另一类是whispering模式,即在一个单位时间以内,一个顶点最多只能和它的一个邻点通信。通信刚络通常用图来描述。最初贮存消息的嘲络成员称为源点。一个极小κ容错广播网络是指n个顶点的通信网络,它的每个成员都能在κ条边失效的情形下在最小的时间Tκ(n)内实现广播。Ts(n)定义为一个这样的最小整数,使得存在一个n阶刚络,以该刚络的任何顶点为源点都能在不超过Tκ(n)个单位时间内执行κ容错广播。Bκ(n)是n阶极小κ容错广播刚络必需的通信线路的最小数目。本义提出了呼叫图的新概念,构造它可以直观地判断κ容错广播方案的正确性,并且可以作为求解Bκ(n)的一种有效的辅助手段,本文给出了一些B2(n)值(n≤10)。     

OADM设备分布式网络管理接口的设计和实现

介绍了基于OADM网元管理系统的CORBA分布式网络管理接口的设计,并给出推模式下传递结构化事件的具体实现过程.在遵循TMF814接口集的网络管理系统中,该网元管理系统及其网络管理接口能够实现设备的本地管理和分布式网络管理,有助于多种设备共存的光通信网络实现统一管理.     

Manufacturer’s CORBA Interface Testing Toolkit: Overview

The Manufacturer’s CORBA Interface Testing Toolkit (MCITT) is a software package that supports testing of CORBA components and interfaces. It simplifies the testing of complex distributed systems by producing “dummy components” from Interface Testing Language and Component Interaction Specifications and by automating some error-prone programming tasks. It also provides special commands to support conformance, performance, and stress testing.     

PPT: A parallel programming tool for distributed memory multiprocessors

Abstract

Traditionally, to program a distributed memory multiprocessor, a programmer is responsible for partitioning an application program into modules or tasks, scheduling tasks on processors, inserting communication primitives, and generating parallel codes for each processor manually. As both the number of processors and the complexity of problems to be solved increases, programming distributed memory multiprocessors becomes difficult and error‐prone. In a distributed memory multiprocessor, the program partitioning and scheduling play an important role in the performance of a parallel program. However, how to find the best program partitioning and scheduling so that the best performance of a parallel program on a distributed memory multiprocessor can be achieved, is not an easy task. In this paper, we present a parallel programming tool, PPT, to aid programmers to find the best program partitioning and scheduling and automatically generate the parallel code for the single program multiple data (SPMD) model on a distributed memory multiprocessor. An example of designing a parallel FFT program by using PPT on an NCUBE‐2 is also presented.     

A framework for CAD-based geometric reasoning for robot assembly language†

For automatic robot programming, world modelling of the robot's environment is one of the most important phases of the task planning. World modelling requires that the robot know the environment in which it operates, including the spatial configuration of all objects in the task environment. In robotic assembly planning at the task level, representation of these objects requires symbolic feature and shape identification of the objects to be assembled by the robot. In this paper, we present a framework for reasoning about objects based on their shapes and features and the representation of such objects for robotic assembly planning when the modelling is done on a CAD system. We show the importance of AI languages in the communication of constructive solid geometry (CSG) based information from modellers. Finally, we present the schematic for a formalism, based on Prolog, for expressing object properties and assembly situations.     

A framework for interaction of distributed autonomous systems and human supervisors

Semi-autonomous systems are rapidly gaining importance in a large number of situations relevant to the general public. By their nature, their need for external control is low but still necessary. In this paper, we present a framework for interaction of distributed autonomous systems and human supervisors. This framework exploits progress made in several related areas and shows that they can be effectively combined into one single framework. To this end, it combines an environment for computational steering with virtual reality techniques for visualization and WAP-based communication for ubiquitous intervention. Given the current state for the technology, the current version must be regarded as a proof of principle.     

CONCORD: A Control Framework for Distributed Real-Time Systems

Novel network technology combined with advances in hardware development have permitted the enabling of distributed real-time systems and have shortened the time-to-market period. Distributed frameworks, also known as middleware, are often used to integrate enterprise systems, shorten the development time, and reduce complexity. However, to deploy standard middleware in robotics and control applications, we have to deal with the challenge of producing predictable outputs. Most real-time applications in these areas are developed in ad hoc manner, and as such, it is hard to migrate them to new platforms. To overcome this issue while minimizing development effort and increasing reusability for distributed real-time systems, we propose a control framework for distributed real-time systems based on standard middleware specifications. The control framework is composed of asynchronously running task modules, which can be located on either the local or the remote machines. The task modules are connected by an event channel, which uses the publish/subscribe communication method. We also have developed an adaptive event channel in order to meet real-time system requirements and to produce predictable outputs. Detailed development of the control framework along with the adaptive event channel are assessed through a set of experimental results.     

User‐friendly image sharing using polynomials with different primes

Recently, Thien and Lin proposed a user‐friendly (k, n)‐threshold scheme which employs Lagrange interpolation to produce shadow images representing a shrunken version of the original image. In this paper, we introduce a new framework which uses more (k ? 1)‐degree polynomials with different primes to enhance the functionality of the user‐friendly (k, n)‐threshold framework and obtain more effective performance for large k. Since the proposed framework significantly reduces reconstruction errors compared to the previously published user‐friendly schemes, it is suitable for modern visual communication applications where features such as distributed trust, secure transmission and storage, fault tolerance, and high‐quality image reconstruction are required. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 40–47, 2007     

Assertion checking environment (ACE) for formal verification of C programs

In this paper we describe an Assertion Checking Environment (ACE) for compositional verification of programs, which are written in an industrially sponsored safe subset of C programming language called MISRA C [Guidelines for the Use of the C Language in Vehicle Based Software, 1998]. The theory is based on Hoare logic [Commun. ACM 12 (1969) 576] and the C programs are verified using static assertion checking technique. First the functional specifications of the program, captured in the form of pre- and post-conditions for each C function, are derived from the specifications. These pre- and post-conditions are then introduced as assertions (also called annotations or formal comments) in the program code. The assertions are then proved formally using ACE and theorem proving tool called Stanford Temporal Prover [The Stanford Temporal Prover User's Manual, 1998]. ACE has been developed by us and consists mainly of a translator c2spl, a GUI and some utility programs. The technique and tools developed are targeted towards verification of real-time embedded software.