Document representation is important for computer-based text processing. Good document representations must include at least the most salient concepts of the document. Documents exist in a multidimensional space that difficult the identification of what concepts to include. A current problem is to measure the effectiveness of the different strategies that have been proposed to accomplish this task. As a contribution towards this goal, this dissertation studied the visual inter-document relationship in a dimensionally reduced space. The same treatment was done on full text and on three document representations. Two of the representations were based on the assumption that the salient features in a document set follow the chi-distribution in the whole document set. The third document representation identified features through a novel method. A Coefficient of Variability was calculated by normalizing the Cartesian distance of the discriminating value in the relevant and the non-relevant document subsets. Also, the local dictionary method was used. Cosine similarity values measured the inter-document distance in the information space and formed a matrix to serve as input to the Multi-Dimensional Scale (MDS) procedure. A Precision-Recall procedure was averaged across all treatments to statistically compare them. Treatments were not found to be statistically the same and the null hypotheses were rejected.

As bandwidth constraints on LAN/WAN environments decrease, the demand for distributed services will continue to increase. In particular, the proliferation of user-level applications requiring high-capacity distributed file storage systems will demand that such services be universally available. At the same time, the advent of high-speed networks have made the deployment of application and communication solutions based upon an Intelligent Mobile Agent (IMA) framework practical. Agents have proven to present an ideal development paradigm for the creation of autonomous large-scale distributed systems, and an agent-based communication scheme would facilitate the creation of independently administered distributed file services. This thesis thus outlines an architecture for such a distributed file system based upon an IMA communication framework.

“A picture is worth a thousand words”. If this proverb were taken literally we all know that every person interprets images or photos differently in terms of its content. This is due to the semantics contained in these images. Content-based image retrieval has become a vast area of research in order to successfully describe and retrieve images according to the content. In military applications, intelligence images such as those obtained by the defence intelligence group are taken (mostly on film), developed and then manually annotated thereafter. These photos are then stored in a filing system according to certain attributes such as the location, content etc. To retrieve these images at a later stage might take days or even weeks to locate. Thus, the need for a digital annotation system has arisen. The images of the military contain various military vehicles and buildings that need to be detected, described and stored in a database. For our research we want to look at the effects that the rotation and elevation angle of an object in an image has on the retrieval performance. We chose model cars in order to be able to control the environment the photos were taken in such as the background, lighting, distance between the objects, and the camera etc. There are also a wide variety of shapes and colours of these models to obtain and work with. We look at the MPEG-7 descriptor schemes that are recommended by the MPEG group for video and image retrieval as well as implement three of them. For the military it could be required that when the defence intelligence group is in the field, that the images be directly transmitted via satellite to the headquarters. We have therefore included the JPEG2000 standard which gives a compression performance increase of 20% over the original JPEG standard. It is also capable to transmit images wirelessly as well as securely. Including the MPEG-7 descriptors that we have implemented, we have also implemented the fuzzy histogram and colour correlogram descriptors. For our experimentation we implemented a series of experiments in order to determine the effects that rotation and elevation has on our model vehicle images. Observations are made when each vehicle is considered separately and when the vehicles are described and combined into a single database. After the experiments are done we look at the descriptors and determine which adjustments could be made in order to improve the retrieval performance thereof. / Dr. W.A. Clarke

D.Litt. et Phil. / The practice of medicine changes constantly and rapidly. Consequently, it is difficult for clinicians to learn about innovations, given the vast quantity of information available. Evidence-based medicine (EBM) is the process by which practitioners turn clinical problems into questions, and then systematically integrate personal clinical expertise with the best available external evidence as the basis for clinical decisions. To practice EBM, the practitioner is required to search the literature for relevant material, and then to synthesise knowledge and apply findings to each patient. Clinicians require fast and specific access to multiple data sources, but the availability of electronic full text documents has substantially exacerbated the lack of time to read the clinical literature owing to the demands of clinical practice, and is further compounded by the fact that the Web contains much health-related misinformation. Clinicians therefore require a means of searching the literature that will enhance the retrieval of accurate and evaluated clinical data from ranked resources, whereby the most relevant information is retrieved first from the most likely source. Strong correlations exist between four primary steps in EBM, and the formula commonly used in search strategy design in the field of information seeking. The similarities inherent in these steps suggest that an evidence-based approach to information seeking might enable endusers in the health professions to enhance their searching skills and to translate the clinical question into an appropriate information-seeking strategy. A main problem and two sub-problems were investigated, namely whether: · a Web-based EBM information-seeking model could be designed to enhance the information-seeking skills of healthcare practitioners · it was possible to design an information-seeking model more closely aligned with the clinical decision-making model familiar to healthcare practitioners · it was possible to design such a model in a manner that could further enhance the translation of the clinical question into an appropriate information-seeking strategy. Various models in medicine and the domain of information seeking were investigated. It was found that the model of the clinical decision-making process accorded with all six phases of the information-seeking process (ISP), whereas other information-seeking models only addressed the ISP from the formulation of the problem onwards, thus ignoring prior stages of initiation, selection and exploration in the ISP. A Web-based EBM information-seeking model (Model C) was devised and tested for compatibility against a general Web-based information-seeking model, and was found to be valid. Model C was further empirically assessed against a Web site design methodology, and was again found to be compatible. A unique approach to EBM information seeking is thus offered by Model C, which incorporates all aspects of the clinical-decision-making metaphor, as well as the “PICO” EBM filters (Patient/Problem, Intervention, Comparative Intervention and Outcome), into a facet analysis template for the design of a clinical search strategy. Prior to selection of the EBM information resource, Model C further allows for the ranking of each resource and for the design of individual browsing and/or analytical search strategies, as appropriate, so as to enhance EBM information seeking amongst healthcare practitioners.

M.Comm. / An operational information model is adapted in this study to suit the current municipal applications. Problems arising from the current changing environment will have to be dealt with to ensure future success of municipalities. A control centre forms the basis of the model from where the relevant information can be supplied to employees in a robust form for outdoor use. The information is updated regularly and control measures are in place for issuing of the information. The effective management of the system will ensure that functions such as training, reporting, safety, labour relations, etc. are optimally implemented.

M.A. / CD-ROM products provide access to information by means of different modes of interaction, often on the same database. Although command language is still widely recognized as the interaction mode which retrieves the most relevant references, it is regarded as difficult to use because of its complex structure. More user friendly modes, for example, menu and direct manipulation are viewed as being more accessible to the up-and-coming end-user. The purpose of this study was to determine by means of an empirical study whether the retrieval effectiveness between two modes of interaction on the same database differed significantly. A literature survey pointed out the unique characteristics of existing modes. It was also established that the traditional measures of retrieval effectiveness through relevance and precision could not be applied in this research. A method was devised in which the results of the two modes were compared. The empirical study was done on the command and form fill-in modes of Wilson Business Abstracts. Total results retrieved through each mode were compared, as well as the ease of entering the search by means of appropriate search facilities for each mode. The results of the research revealed that the presence of unique search facilities in a mode results in better retrieval effectiveness. Searches in both modes also require specific ways of input for optimum quality retrieval and thus has implications for intensive training in search methods.

University of Macau / Faculty of Social Sciences. / Department of Communication

University of Macau / Faculty of Social Sciences. / Department of Sociology

by Eldous, Chan Hon Meng. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves B1-B7.

Lin Wai-yip. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 114-123). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Information Extraction --- p.1 / Chapter 1.2 --- IE from Semi-structured Documents --- p.3 / Chapter 1.3 --- Thesis Contributions --- p.7 / Chapter 1.4 --- Thesis Organization --- p.9 / Chapter 2 --- Related Work --- p.11 / Chapter 2.1 --- Existing Approaches --- p.11 / Chapter 2.2 --- Limitations of Existing Approaches --- p.18 / Chapter 2.3 --- Our HISER Approach --- p.20 / Chapter 3 --- System Overview --- p.23 / Chapter 3.1 --- Hierarchical record Structure and Extraction Rule learning (HISER) --- p.23 / Chapter 3.2 --- Hierarchical Record Structure --- p.29 / Chapter 3.3 --- Extraction Rule --- p.29 / Chapter 3.4 --- Wrapper Adaptation --- p.32 / Chapter 4 --- Automatic Hierarchical Record Structure Construction --- p.34 / Chapter 4.1 --- Motivation --- p.34 / Chapter 4.2 --- Hierarchical Record Structure Representation --- p.36 / Chapter 4.3 --- Constructing Hierarchical Record Structure --- p.38 / Chapter 5 --- Extraction Rule Induction --- p.43 / Chapter 5.1 --- Rule Representation --- p.43 / Chapter 5.2 --- Extraction Rule Induction Algorithm --- p.47 / Chapter 6 --- Experimental Results of Wrapper Learning --- p.54 / Chapter 6.1 --- Experimental Methodology --- p.54 / Chapter 6.2 --- Results on Electronic Appliance Catalogs --- p.56 / Chapter 6.3 --- Results on Book Catalogs --- p.60 / Chapter 6.4 --- Results on Seminar Announcements --- p.62 / Chapter 7 --- Adapting Wrappers to Unseen Information Sources --- p.69 / Chapter 7.1 --- Motivation --- p.69 / Chapter 7.2 --- Support Vector Machines --- p.72 / Chapter 7.3 --- Feature Selection --- p.76 / Chapter 7.4 --- Automatic Annotation of Training Examples --- p.80 / Chapter 7.4.1 --- Building SVM Models --- p.81 / Chapter 7.4.2 --- Seeking Potential Training Example Candidates --- p.82 / Chapter 7.4.3 --- Classifying Potential Training Examples --- p.84 / Chapter 8 --- Experimental Results of Wrapper Adaptation --- p.86 / Chapter 8.1 --- Experimental Methodology --- p.86 / Chapter 8.2 --- Results on Electronic Appliance Catalogs --- p.89 / Chapter 8.3 --- Results on Book Catalogs --- p.93 / Chapter 9 --- Conclusions and Future Work --- p.97 / Chapter 9.1 --- Conclusions --- p.97 / Chapter 9.2 --- Future Work --- p.100 / Chapter A --- Sample Experimental Pages --- p.101 / Chapter B --- Detailed Experimental Results of Wrapper Adaptation of HISER --- p.109 / Bibliography --- p.114