This paper and the accompanying project Amechan explore the construction of 'virtual' identity on the Internet. It explores historic art trails and how they lead to the new frontier of web art, moving from the traditional arts to television, video to the Internet. It explores the need for alternative forms of art practice and art dissemination in contemporary society and it looks at what makes web art unique. It also explores the alternate realms of reality; our physical world, and the new world of the virtual. And how this has affected our notions of self, privacy, and narrative. And finally, it explains the construction of the Amechan site, both theoretically and practically. The paper has been divided into three parts. The first sites the work within current art practices. The second places Amechan into the context of the author's art practice. The third section looks at the elements and themes contained within the Amechan site, which was a serialized 'homepage' created by a fictional character, a diaristic narrative of image and text. The site initially ran from February 1-July 31, 1999. The section also discusses the ideas that have informed the site in less discernible ways. It looks at the theoretical and practical concerns of creating and maintaining the site for the 6 months it was initially operating, and at the site as 'installation'. It also introduces an email correspondence between the fictional character of 'Amechan' and an unknown correspondent. / Master of Arts

Cette thèse porte sur l'indexation et l'interrogation de pages Web. Dans ce cadre, nous proposons un nouveau modèle : BlockWeb, qui s'appuie sur une décomposition de pages Web en une hiérarchie de blocs visuels. Ce modèle prend en compte, l'importance visuelle de chaque bloc et la perméabilité des blocs au contenu de leurs blocs voisins dans la page. Les avantages de cette décomposition sont multiples en terme d'indexation et d'interrogation. Elle permet notamment d'effectuer une interrogation à une granularité plus fine que la page : les blocs les plus similaires à une requête peuvent être renvoyés à la place de la page complète. Une page est représentée sous forme d'un graphe acyclique orienté dont chaque nœud est associé à un bloc et étiqueté par l'importance de ce bloc et chaque arc est étiqueté la perméabilité du bloc cible au bloc source. Afin de construire ce graphe à partir de la représentation en arbre de blocs d'une page, nous proposons un nouveau langage : XIML (acronyme de XML Indexing Management Language), qui est un langage de règles à la façon de XSLT. Nous avons expérimenté notre modèle sur deux applications distinctes : la recherche du meilleur point d'entrée sur un corpus d'articles de journaux électroniques et l'indexation et la recherche d'images sur un corpus de la campagne d'ImagEval 2006. Nous en présentons les résultats. / This thesis is about indexing and querying Web pages. We propose a new model called BlockWeb, based on the decomposition of Web pages into a hierarchy of visual blocks. This model takes in account the visual importance of each block as well as the permeability of block's content to their neighbor blocks on the page. Splitting up a page into blocks has several advantages in terms of indexing and querying. It allows to query the system with a finer granularity than the whole page: the most similar blocks to the query can be returned instead of the whole page. A page is modeled as a directed acyclic graph, the IP graph, where each node is associated with a block and is labeled by the coefficient of importance of this block and each arc is labeled by the coefficient of permeability of the target node content to the source node content. In order to build this graph from the bloc tree representation of a page, we propose a new language : XIML (acronym for XML Indexing Management Language), a rule based language like XSLT. The model has been assessed on two distinct dataset: finding the best entry point in a dataset of electronic newspaper articles, and images indexing and querying in a dataset drawn from web pages of the ImagEval 2006 campaign. We present the results of these experiments.