Η χρήση σημασιολογικών δικτύων για τη διαχείριση του περιεχομένου του παγκόσμιου ιστού

Abstract

This dissertation addresses the incorporation of a semantic network into a set of Web-based applications for the effective management of Web content. Semantic networks are a kind of machine readable dictionaries, which encode semantic information for the lemmas they contain, where the latter are stored in a tree structure. Semantic networks store their contents in a similar way to the organization that Web pages exhibit on the Web graph; a feature that makes semantic networks readily usable by several Web applications that aim at the efficient management of the proliferating and constantly changing Web data. After an overview of the techniques that have been employed for managing the Web content, we propose and implement a novel Web data management model, which relies on an enriched semantic network for locating semantic similarities in the context of distinct Web pages. Based on these similarities, our model attempts and successfully achieves the automatic and effective indexing, categorization and ranking of the numerous pages that are available on the Web. For demonstrating the potential of our Web data management model, we adopt the navigation model in Web thematic directories and we experimentally show the contribution of semantic networks throughout the construction of Web catalogs. More specifically, we study the contribution of semantic networks in: (i) determining and enriching the thematic categories of Web directories, (ii) processing and disambiguating the contents of Web pages, (iii) automatically improving the thematic categories of Web directories, (iv) ordering Web pages that have been assigned in the respective categories of a Web directory, (v) managing the contents of Web directories in a way that ensures the availability of useful Web data to the directories’ users, and (vi) searching for information in the contents of Web directories. The contribution of our model is certified by the experimental results that we obtained from a numerous of testing applications that we run in the framework of our study. Obtained results demonstrate the contribution of semantic networks in the effective management of the dynamically evolving Web content. The practical outcome of the research presented herein, besides offering a fully-fledge infrastructure for the efficient manipulation and organization of the Web data, it can play a key role in the development of numerous applications, such as text summarization, information extraction, topical-focused crawling, measuring the Web’s evolution, spam detection, and so forth.