Abstract
In a distributed memory MIMD parallel machine, the efficient communication between processes/processors, through messages, is an important task to be handled by the programmer. Because the number of inter-processor connections is limited, the communication between any two processors is made by passing the messages through several other processors and then, a problem of messages routing appears. For dedicated systems, special architectures can be defined simplifying the problem but, if an environment constituting a basis for general applications development is desired, the problem is more serious due to the deadlock possibility. A general router, able to avoid the problem, becomes then a very important tool for software development in parallel architectures. We have been defining a development platform, based on a network of Transputers and written in OCCAM, for image synthesis applications. This paper reports our efforts in writing different versions of routers, based on two different strategies, and justifies the choice of an efficient one to integrate in the platform.

Abstract
Cooperative environments to support Software Development (CSD) have as main goal to enable several users connected over network to work together in order to develop software. They have to solve problems such as: coherence maintenance of the software project through the distributed system by managing possible conflicts between local versions of each group member and promote the necessary mechanisms for the inter-group awareness and integrity. We introduce in this paper a distributed solution to support CSD by describing our own prototype: a Computer-Supported Cooperative Work (CSCW) architecture for software development. It enables a group of developers (2 to 4), possibly located at remote places and connected over network, to develop software together. A cooperative multimedia editing environment is available during the development cycle, enclosing mechanisms of computer-conferencing (text, audio and video communications).

Abstract

Abstract
Cooperative environments to support Software Development (CSD) have as main goal to enable several users connected over network to work together in order to develop software. They have to solve problems such as: coherence maintenance of the software project through the distributed system by managing possible conflicts between local versions of each group member and promote the necessary mechanisms for the inter-group awareness and integrity We introduce in this paper a distributed solution to support CSD by describing our own prototype: a Computer-Supported Cooperative Work (CSCW) architecture for software development. It enables a group of developers (2 to 4), possibly located at remote places and connected over network, to develop software together. A cooperative multimedia editing environment is available during the development cycle, enclosing mechanisms of computer-conferencing (text, audio and video communications).

Abstract

Abstract
This paper1 contains a proposal for a knowledge representation formalism based on a taxonomy of theories. It aims at clarifying the notions of inheritance and dependency among properties and classes, which are mixed together in the “inheritance networks” formalism, while also providing more expressiveness. A model-theoretic semantics in terms of sets of individuals is presented, which is parametric on the characterization of specificity. The case most thoroughly presented is rule inheritance which builds on the assumption that only facts have the force to impose overriding. A double denotation for classes, corresponding to two nested sets, is the key for interpreting defaults and exceptions. The problem of ambiguity propagation in the resulting system is addressed in the context of a discussion of the relationship between it and inheritance nets. © Springer-Verlag Berlin Heidelberg 1993.