Gibson Lam

Streaming Multimedia Delivery in Web Services Based E-Learning Platforms

The use of streaming multimedia has become more and more common as the content of e-learning material. The distribution of the material is typically achieved by a dedicated streaming server. There are several proprietary technologies that can act as the streaming server but there is a lack of standardized approach for this purpose. Recently importance has been placed on the interoperability and reusability of learning material by making use of standards such as SCORM and web services. In this paper we propose a service oriented architecture for the delivery of multimedia content which is interoperable and reusable. We model this delivery by extending current web service standards, and we briefly discuss the use of such web service resources in SCORM.

A SOAP-Based Streaming Content Delivery Framework for Multimedia Web Services

Web services provide efficient development and deployment of interoperable and reusable applications. Multimedia Web services is an implementation of multimedia applications within the Web services framework. However, current Web services standards are not sufficient to cater for multimedia streaming, the commonly used delivery method for large multimedia objects. In this paper, a SOAP-based streaming content delivery framework for multimedia Web services is proposed. The framework uses an extension of existing SOAP standards which allows streaming content to be transmitted between two SOAP nodes over the HTTP protocol. The extension includes a new SOAP streaming message exchange pattern and its corresponding SOAP HTTP binding. The proposed framework is capable of delivering quality adaptive multimedia content to users with heterogeneous configurations and requirements. By incorporating a proxy server between the service provider and requester the efficiency of the content delivery can be improved using multimedia caching.

Ray tracing surfaces of revolution: an old problem with a new perspective

We present a new subdivision scheme that is shown to improve the performance of ray tracing surfaces of revolution over Kajiyas (1983) classical work. This is based on a monotonic interval partitioning of a generatrix of a surface of revolution. The algorithm has a search complexity upper bound of O(log(m n)) for m monotonic intervals and n subdivisions for each interval and runs up to three times faster on large scenes. This method also suggests a novel hybrid bounding volume scheme that reduces this number of intersection tests between a ray and the actual object surface.

The gong system: web-based learning for multiple languages, with special support for the Yale representation of Cantonese

This paper introduces the Gong system, an Internet-based voice board system designed primarily for language learners which includes special support for Cantonese. The Gong system is a client/server design which may be used to complement or, in some contexts, to replace face to face learning. The system supports Unicode input, storage and display of multiple character sets. Furthermore, we have developed a unique storage and display method for the Yale romanized representation of Cantonese, which is the most popular written method used for teaching Cantonese.