Master's Thesis -- This research looks at distributed web search as an alternative to the current centralized web search paradigm. We assume that web sites, or peers, can index a collection consisting of local content, but possibly also content from other web sites. Peers cooperate with a broker by sending a part of their index. Receiving indices from many peers, the broker gains a global overview of the peers’ content. When a user poses a query to a broker, the broker selects a few peers to which it forwards the query. Selected peers should be promising to create a good result set with many relevant documents. The result sets are merged at the broker and sent to the user. This research focuses on collection selection, which corresponds to the selection of the most promising peers. The use of highly discriminative keys is employed as a strategy to select those peers. A highly discriminative key is a term set which is an index entry at the broker. The key is highly discriminative with respect to the collections because the posting lists pointing to the collections are relatively small. Query-driven indexing is applied to reduce the index size by only storing index entries that are part of popular queries. A PageRank-like algorithm is also tested to assign scores to collections that can be used for ranking. Sander Bockting February 16, 2009 collection_selection_for_distributed_web_search-v1-online.pdf 1.275 KB Accepted for DIR-2008 Workshop -- Studies on information retrieval for children are not yet common. As young children possess a limited vocabulary and limited intellectual power, they may experience more difficulty in fulfilling their information need than adults. This paper presents an image retrieval user interface that is specifically designed for children. The interface uses relevance feedback and has been evaluated by letting children perform different search tasks. The tasks were performed using two interfaces; a more traditional interface – acting as a control interface – and the relevance feedback interface. One of the remarkable results of this study is that children did not favor relevance feedback controls over traditional navigational controls. Sander Bockting, Matthijs Ooms, Djoerd Hiemstra, Paul van der Vet and Theo Huibers April 14, 2008 evaluating_relevance_feedback-_an_image_retrieval_interface_for_children.pdf 730 KB Enterprise Architects have many tools at their disposal to develop and design their architectures. Some of them enable the architect to model security policies for their architectures. ArchiMate in combination with the ArchiPonder extension is one of them. However, the latter does not have the capabilities to formally verify the modeled security. This paper shows the feasibility of formally verifying security in architectures designed and visualized with ArchiPonder. Sander Bockting January 12, 2007 formal_verification_of_security_models-a_feasibility_study_v2.pdf 1005 KB In this paper, a preliminary model is proposed for a semantic translation service using ontologies. Messages can be encoded using an ontology. The model provides the user with the interfaces and tools to translate these messages using ontologies and mappings, that can be pointed out by the user. Currently, all techniques exist to actually build such a system, but to obtain real good results, mapping techniques need to be further improved. Sander Bockting June 1, 2005 semantic_translation_service_using_ontologies.pdf 289 KB Localisatie / plaatsbepaling met behulp van Wireless LAN (WLAN). Sander Bockting, Niek Hoogma, Matthijs Ooms, Gerben Oostra, Viet Yen Nguyen March 21, 2004 FriendFinder.pdf 635 KB Eindopdracht van het bovenstaande vak. Voor deze opdracht dienden de vliegprestaties van een Boeing MD-11 doorgerekend te worden. Sander Bockting and Edwin Tangenberg February 3, 2004 inleidingluchtvaarttechniek.pdf 522 KB Een (fictieve) opdracht van het Rathenau Instituut om een technology assessment naar de digitale leeromgeving te doen. Hoewel de opdracht fictief was, zijn de resultaten van het onderzoek wel degelijk bruikbaar. Sander Bockting, Jasper Bragt, Maurice Liebregt, Peter Oost June 13, 2003 digitale_leeromgeving.pdf 536 KB Een fictieve opdracht om in een groep van 15 personen, als bedrijf, een proposal voor een ICT-infrastructuur van een scholengemeenschap op te stellen. Geentronics Projectgroup May 7, 2003 iwa_verslag.pdf 196 KB