Hendrik Olivié

Optimizing Jan Jannink's Implementation of B + -tree deletion

In this note we propose optimization strategies for the B+-tree deletion algorithm. The optimizations are focused on even order B+-trees and on the reduction of the number of block accesses.

Adaptive navigational facilities in educational hypermedia

INTRODUCTION Hypermedia users with different goals and knowledge may be interested in different pieces of information and may use different links for navigation. Irrelevant information and links overload their working memories and screen [1]. In order to overcome this problem, it is possible to use information represented in a user model and then adapt the content and/or the links to be presented to that user. Adaptive hypermedia systems build such a model with the goal of personalizing hypermedia.

Towards the integration of a query mechanism and navigation for retrieval of data on multimedia documents

Traditionally, two paradigms are discerned with respect to data retrieval [3, 17]:1. A query mechanism enables the user to express conditions that characterize the data he is looking for. The Data Base Management System (DBMS) is responsible for retrieval of the data that satisfy these conditions.2. Navigation or browsing can be used to investigate the content of the database by following links between related data.We will start with a discussion of these paradigms in the first two sections. We will then explore how both approaches can be combined. Finally, a practical implementation of the advocated approach will be presented. The implemented prototype supports access to a database on multimedia material. A more elaborated discussion of our ideas and results in this area can be found in [16].

Hypermedia for open and flexible learning

Although there are many systems available for the creation and maintenance of course material for open and flexible learning, this task remains tedious and inefficient. In this paper we present a data model and a design paradigm for hypermedia courseware. We demonstrate an implementation of the model which makes use of the World Wide Web, and will be used to provide selfstudy courses to students of the university of Leuven.

Structured Hypermedia Authoring: A Simple Tool for the Design and Implementation of Structured Hypermedia Databases

In this paper a new hypermedia model is presented that avoids a number of traditional problems of hypermedia authoring, and facilitates the maintenance of links and the re-use of information resources. The model was inspired by problems we experienced while implementing a hypermedia self study course on computer science [Olivie 1993].

Object-oriented hypertext design: authoring for reuse

We present a new approach for the development of hypertext information systems that avoids a number of traditional hypermedia authoring problems, and facilitates the maintenance of links and the reuse of information resources. The model is set-based, and integrates features from object-oriented software design models. This helps authors to make a comprehensive (and comprehensible) design before starting an implementation. We also briefly describe an authoring system that implements this model, and which uses an existing relational database system to store documents, links and meta-information.