Collaborative ontology-based information indexing and retrieval
Ιωάννης Τζίτζικας · 2002
An information system like the Web is a continuously evolving system consisting of multiple heterogeneous information sources, covering a wide domain of discourse, and a huge number of users (human or software) with diverse characteristics and needs, that produce and consume information.The challenge nowadays is to build a scalable information infrastructure enabling the e ective, accurate, content-based retrieval of information, in a way that adapts to the characteristics and interests of the users.The aim of this work is to propose formally sound methods for building such an information network based on ontologies which are widely used and are easy to grasp by ordinary Web users.The main results of this work are: A n o vel scheme for indexing and retrieving objects according to multiple aspects or facets.First of all I would like t o thank my advisor, Professor Panos Constantopoulos, for supervising and supporting my research e orts, both at MSc and the PhD level.I am really very grateful to my advisor and now close friend Professor Nicolas Spyratos, for giving me the opportunity t o w ork with him, for the endless discussions which often escape the narrow framework of this thesis and was touching almost all aspects of life.He has a remarkably clear way of thinking and his is full of energy.I w i l l n e v er forget him, he is a professor of life!I wish to him and his family the very best.I would also like to thank the members of my dissertation committee from the University of Crete and ICS-FORTH, Professors Dimitris Plexousakis, and Vassilis Christophides as well as the external members, Professors Manolis Koubarakis, Yannis Ioannidis, and Timos Sellis for their helpful comments and questions.Many thanks to all former and current m e m bers of the Information Systems