Abstract
Vehicle number plate recognition systems are expected to have numerous applications in traffic surveying and monitoring, e,g. finding stolen cars and controlling access to car parks. In this paper algorithmic improvements to a previous version of a number plate reading system are described. The work builds on the experience gained by the Computer Vision Group at the University of Bristol. This paper addresses the problem of locating the number plate area in the image and proposes a new line based method for number plate location, which is suitable for realtime number plate recognition.

Abstract
Ray-Tracing is a well known algorithm that simulates the reflection and refraction of light rays in the objects surfaces, beginning with rays sent from the view point. Each ray has to be tested against objects in the 3D scene and this is very time consuming. This paper describes one parallel solution. It is oriented to a general network, where each processor manages data and tasks and shares them with the others to optimise common resources utilisation. In this context, a Virtual Sharing Memory (VSM) is used and an efficient load balancing strategy can be implemented. With this approach, the amount of messages in the network tends to increase and strategies to reduce them are needed. Schemes to optimise remote accesses to data have been developed, namely a special type of multicast message addressing named InPathTo. © Springer-Verlag Berlin Heidelberg 1997.

Abstract

Abstract
Distributed systems emerged in the last decade as a more efficient way of sharing networked resources, allowing cooperating processes to be executed in remote computers with possibly distinct architectures and operating systems. This paper presents the motivations that may lead to the usage of distributed architectures in the support of telecommunications services, particularly multimedia services. It also gives an overview of one distributed architecture, ANSA, which was used to implement a prototype of a distributed multimedia service, briefly described.

Abstract
Technical advances in communication networks and terminal equipment make possible the provision of a wide range of new and appealing telecommunication services. However, the increasing user demand and the strong market competition require that the creation of those services is efficient and fast, and that they have attractive interfaces. The complexity of networks and distributed systems, which support those services, renders the usage of formal specification languages, such as SDL, almost mandatory in their development. According to some authors, fifty percent of the total time necessary to develop applications is spent in building and testing graphical interfaces for different platforms. In this paper, an efficient methodology to create graphical interfaces for telecommunication services specified in SDL is presented.

Abstract
One of the most-used rendering algorithms in Computer Graphics is the Ray-Tracing. The ''standard'' (Whited like) Ray-Tracing(1) is a good rendering algorithm but with a drawback: the time necessary to produce an image is too large (several hours of CPU time are necessary to make a good picture of a moderately sophisticated 3D scene) and the image is only ready to be observed at the end of processing. This kind of situation is difficult to accept in systems where interactivity is the first goal. ''Increasing Realism'' In Ray-Tracing tries to avoid the problem by supplying the user with a preview of the final image. This preview can be calculated in a considerably shorter time but permits that, with some margin of error, the user can imagine (even see, sometimes) some final effects. With more processing time the image quality continues improving without loss of previous results. The user can, at any time, interrupt the session if the image does not match what he wants. Simultaneously with the above idea, it is necessary to accelerate image production. Parallelism is then justified by the need of more processing power. The aim of this text is to describe the Interactive Ray-Tracing Algorithm implementation, using a parallel architecture based on Transputers. An overview of the architecture used is presented and the main parallel processes and related problems are discussed.