Computing and Information Systems - Theses
Permanent URI for this collection
Search Results
1 - 4 of 4
-
ItemThe production of meaningful route directions using landmark extraction( 2006-11)In order for automated navigation systems to operate effectively, the route instructions they produce must be clear, concise and easily understood by users. Thequality and coherence of route instructions may be improved via landmark chunking, whereby a turning instruction is given with reference to a nearby landmark. In order to incorporate a landmark within a coherent sentence, it is necessary to first understand how that landmark is conceptualised by travellers — whether it is perceived as point-like, line-like or area-like. This conceptualisation determines which prepositions and verbs are appropriate when referring to the landmark. This thesis investigates the viability of automatically classifying the conceptualisation of landmarks relative to a given city context. First, we construct a web-based annotation interface to solicit gold-standard judgements from expert annotators over a set of landmarks for three major cities (Melbourne, Hamburg and Tokyo). We then experiment with the use of web data to learn the default conceptualisation of those landmarks, analysing their occurrence in a fixed set of lexico-syntactic patterns. Based on this, we develop two automated landmark classifiers and evaluate them against the gold standard annotations,investigating patterns of convergence or divergence in landmark categorisation.
-
ItemAnalysis and prediction of user behaviour in a museum environment( 2006)Visitors to a museum enter an environment with a wealth of information. However not all of this information may be located in physical form. It may be accessible through an online web-site and available for download, or this information could be presented by a tour guide that leads you through the museum. Neither of these sources of information allow a visitor to deviate from a set path. If a visitor leaves a guided tour, they will not have access to the resource that is supplying them with the extra information. If they deviate from a downloaded tour, they again will not have the correct information sheets for an exhibit that is not directly on their tour. The solution is to create a Recommender System based on the conceptual similarity of the exhibits. This system creates a dynamic tour through the museum for a given visitor by recommending exhibits that the visitor is interested in. Conceptual similarity of exhibits can be comprised of elements including the physical proximity, the semantic content of the exhibit, and the opinions of previous visitors. By using a combination of these similarities, we have produced a system that recommends relevant exhibits in 51% of test cases.
-
ItemAdaptive psychophysical procedures and Ulam's game( 2006-10)The problem of finding the threshold of a psychometric function is of major interest to researchers in the field of psychophysics, and has applications in many areas of medical diagnosis, particularly those dealing with perception, such as optometry and hearing tests. This problem is closely related to other problems in computer science, such as search with errors, however most existing literature does not make this link. This thesis provides a review of existing algorithms for finding the threshold, with an emphasis on identifying the types of problems for which each algorithm is useful. We also address a number of issues which are not adequately covered in the literature. These include choosing an appropriate loss function to evaluate the performance of an algorithm for a given problem, as well as relating the problem of finding the threshold to binary search with errors problems in computer science. Finally, this research presents a new algorithm for finding the threshold of a psychometric function, ENT-FIRST, which results in improved performance compared to many existing algorithms.
-
ItemComputational gene finding in the human malaria parasite Plasmodium vivax( 2006-10)Different approaches to genome annotation are reviewed and compared with reference based annotation using GeneMapper in the human malaria parasite Plasmodium vivax. It is found that the latter approach does not achieve sensitivity and specificity as high as those for some ab initio techniques. Potential reasons for this are identified and discussed. As part of the process of using GeneMapper, codon substitution matrices are constructed and examined. This leads to the discovery of evidence from which we derive a conjecture regarding Plasmodium evolution.