theory and praxis

This paper offers a review of technological developments regarding massive storage devices and the emergence of new streaming services for audio and video on-demand. While the capacity of storage devices has been increasing exponentially, the price of a stored bit has been falling at an even faster rate. Audio and video files can be stored on-line in personal computers and computer networks. Accessing this information requires new type of databases capable of handling special types of queries: access through annotations and metadata, access by similarity, and access by feature search. Databases with in-built streaming capabilities would be extremely useful for transmitting the information to the end user, while providing at the same time consistency checks, indexing, reporting, and querying features. They should also be fast and scalable. This paper reviews recent academic and industrial projects, and describes an implementation of a streaming video servlet based on the Oracle SQL database, its Binary Large Object storage data type, and the Java Database Connectivity interface

Learning Algorithms with an Electronic Chalkboard over the Web

Abstract. This paper describes a system for the animation of algorithms on an electronic chalkboard. The instructor teaching an algorithm can enter data directly through a drawing- the algorithm then makes use of this data, for exampIe numbers, or the image of a graph. The drawing becomes alive. The result is a more natural way of teaching and starting algorithmic animations. The paper also describeshow to couple a sign and handwritingrecognitionengine with the animation system. The lecturer can then write programs using her own handwriting, and the prograrnsruns. All animations can be enriched with sound and explanationsfrom the lecturer and can be posted to the Web.