Download the full-sized PDF of An ontology-driven concept-based information retrieval approach for web documentsDownload the full-sized PDF



Permanent link (DOI):


Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Graduate Studies and Research, Faculty of


This file is in the following collections:

Theses and Dissertations

An ontology-driven concept-based information retrieval approach for web documents Open Access


Other title
concept-based system
information retrieval
Type of item
Degree grantor
University of Alberta
Author or creator
Li, Zhan
Supervisor and department
Reformat, Marek (Electrical and Computer Engineering)
Examining committee member and department
Pedrycz, Witold (Electrical and Computer Engineering)
Szymanski, Jozef (Civil and Environmental Engineering)
Kreinovich, Vladik (Computing Science)
Zhao, Vicky (Electrical and Computer Engineering)
Musilek, Petr (Electrical and Computer Engineering)
Department of Electrical and Computer Engineering

Date accepted
Graduation date
Doctor of Philosophy
Degree level
Building computer agents that can utilize the meanings in the text of Web documents is a promising extension of current search technology. Concept-based information retrieval applies "intelligent" agents to identify Web documents that match user queries. A new concept-based information retrieval framework, Hybrid Ontology-based Textual Information Retrieval (HOTIR), is introduced in this thesis. HOTIR accepts conventional keyword-based queries, translates them into concept-based queries, enriches definitions of concepts with supplementary knowledge from a knowledge base, and ranks documents by aggregating "equivalent" concepts identified in them. The concept-based queries in HOTIR are organized in a hierarchy of concepts (HofC) and definitions of concepts are added from a knowledge base to enhance their meanings. The knowledge base is a modified ontology (ModOnt) that can enrich the HofC with concept definitions in the form of related-concepts, terms, their importance values, and their relations. The ModOnt relies on an adaptive assignment of term importance (AATI) scheme that continuously updates the importance of terms/concepts using Web documents. The identified concepts in a Web document that match those in the HofC are evaluated using ordered weighted averaging (OWA) operators, and documents are ranked according to the degree to which they satisfy the HofC. The case studies and experiments presented in the thesis are designed to validate the performance of HOTIR.
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 2807161
Last modified: 2015:10:12 19:28:35-06:00
Filename: thesis_ZhanLi_FGSR.pdf
Original checksum: 86b2c23dc0ef253050a16a1c104d1ffc
Well formed: true
Valid: true
Page count: 171
Activity of users you follow
User Activity Date