In previous work we described how the process algebra based language PSF can be used in software engineering, using the ToolBus, a coordination architecture also based on process algebra, as implementation model. We also described this software development process more formally by presenting the tools we use in this process in a CASE setting, leading to the PSF-ToolBus software engineering envi...

WebLab 6.0, our latest release, is constructed around the newly developed iLab Shared Architecture – a three-tier framework designed at MIT to expedite the development and simplify the management of online laboratories [1]. The iLab Shared Architecture introduces a piece of middleware (termed the “Service Broker”) between the Client application and the Lab Server. This Service Broker uses Web S...

Traditional Voice over Internet Protocol (VoIP) technique is based on client/server architecture. In this paper, we proposed a VoIP architecture for Ad-hoc network that provides users to communicate with each other directly through embedded pseudo SIP server. This architecture will establish a distributed VoIP system. The performance analysis of signal transmission delay will show the advantage...

Many requirements to product data technology for concurrent engineering can be most efficiently satisfied through the application of advanced client/server architectures enhanced with appropriate knowledge-based methods. This paper outlines the basic design considerations for a knowledge-based product data client/server system and suggests a development approach on the example of a prototype se...

This paper presents the idea of \tuple bit-vectors" for distributed query processing. Using tuple bit-vectors, a new two-way semijoin operator called 2SJ++ that enhances the semijoin with an essentially \free" backward reduction capability is proposed. We explore in detail the beneets and costs of 2SJ++ compared with other semijoin variants, and its eeect on distributed query processing perform...

CSCW applications require availability, portability, familiarity, scalability, bandwidth and performance. This paper describes the use of Web-multicasting to address these issues. Web-multicasting is a concept that use a standard Web-browser to communicate between multiusers. The web-browser will use multicasting methods, so that no Web server is necessary needed. A prototype Web-multicast Chat...

A distributed architecture for the support of programs written in the persistent programming language Napier is described. The architecture consists of a central server containing the stable persistent store and a collection of clients, each executing Napier processes. Since each client has a cache of objects, some of which may be shared with other clients, a protocol is required to ensure that...

In this paper we present a traffic control scheme for server to client communication in distributed haptic virtual environments (VE). We adopt a client-server architecture where the server manages the state consistency of the distributed VE, while haptic feedback is computed locally at each client. The update rate of network traffic from the server to the client is dynamically adapted by exploi...

Advances in multimedia computing technologies offer new approaches to support on-line accesses to information from a variety of sources such as video clips, audio, images, and books. A client-server distributed multimedia system would be a practical approach to support such functionalities. In this paper, we present the design and implementation of a client-server distributed multimedia databas...