Este trabalho avalia de maneira detalhada diferentes parâmetros para a definição de níveis de homogeneidade e heterogeneidade em sistemas computacionais distribuídos. O objetivo é analisar a eficiência da métrica GH - Grau de Heterogeneidade - em relação a diferentes perspectivas. Métricas encontradas na literatura e benchmarks de código aberto (reconhecidos pela comunidade científica) são utilizados para quantificar a heterogeneidade do sistema computacional. A métrica GH também é empregada no AMIGO, um ambiente de escalonamento real, para analisar a sua utilização em algoritmos de escalonamento de processos. Os principais resultados obtidos neste trabalho são: a comprovação da estabilidade da métrica GH para determinar o grau de heterogeneidade de plataformas computacionais distribuídas, o uso da métrica GH com sucesso em um ambiente de escalonamento real e o desenvolvimento de um algoritmo de escalonamento adaptativo. Sub-produtos deste trabalho são: um levantamento dos principais benchmarks com código aberto e livre disponíveis na literatura, os quais podem ser utilizados em trabalhos futuros no grupo de pesquisa e a continuidade do desenvolvimento do ambiente de escalonamento AMIGO / This work evaluates several parameters in a detailed way for the definition of homogeneity and heterogeneity levels in distributed computing systems. The objective is to analise the GH metric efficiency (heterogeneity degree) according to different perspectives. Metrics found in the literature and open source benchmarks (recognized by the scientific community) are both used to quantify the heterogeneity of the computational system. The GH metric is also employed in the AMIGO, a real scheduling environment, in order to evaluate its use in process scheduling algorithms. The main results obtained in this work are: the verification of the GH metric stability for determining the heterogeneity degree of distributed computing platforms; the use of the GH metric with success in a real scheduling environment and the development of an adaptive scheduling algorithm. By-products of this work are: the highlighting of the main benchmarks with open source available in the literature, which can be used in future works by the research group and the continuity of the development of the AMIGO

A universalização do acesso ao conteúdo disponibilizado em sistemas Web tem se tornado crucial para que todas as pessoas, independente de deficiências ou de outras restrições possam ter acesso a ele. Diversos estudos indicam que, apesar da instituição de leis federais sobre acessibilidade para conteúdo Web em diversos países, muitos sítios ainda apresentam problemas. A falta de conscientização das pessoas envolvidas em projetos de desenvolvimento Web sobre a acessibilidade e a não utilização de técnicas adequadas para desenvolvimento de aplicações têm um impacto considerável sobre a acessibilidade. Levantamentos foram realizados com o objetivo de identificar características dos desenvolvedores sobre o conhecimento e uso de técnicas para acessibilidade. Entretanto, os estudos realizados investigaram somente o uso de um conjunto restrito de técnicas e, além disso, também não investigaram a correlação entre as respostas obtidas pelos participantes e o nível de acessibilidade das páginas desenvolvidas por eles. Neste trabalho, propõe-se efetuar um levantamento sobre a percepção de acessibilidade e uso de técnicas para desenvolvimento de sistemas Web considerando acessibilidade com pessoas envolvidas em projetos de desenvolvimento Web no Brasil de diferentes áreas de atuação. Este levantamento foi acompanhado de avaliações de acessibilidade automatizadas com uso de métricas sobre sítios desenvolvidos pelos participantes, para verificar a influência dos fatores investigados na acessibilidade dos sítios e na percepção de acessibilidade dos participantes. O levantamento realizado contou com a participação de 613 participantes de todo o Brasil. Os resultados indicaram que no Brasil a percepção da acessibilidade por pessoas que participam de projetos de desenvolvimento Web ainda é bastante limitada. Mais do que promover o treinamento das pessoas envolvidas em projetos sobre questões técnicas, é necessário promover maior conscientização sobre a acessibilidade e sobre os problemas que pessoas com diferentes restrições e habilidades enfrentam ao utilizar a Web. / Universal access to content in Web based systems is an essential aspect to enable everyone to have access to it, regardless of disabilities or any other restrictions. Several studies indicate that, although federal legislation regarding to Web accessibility have been promulgated in many countries, accessibility is still an issue for many Web sites. The limited awareness of accessibility by people involved in Web development and the lack of appropriate use of development techniques in the development of applications have a deep impact on accessibility. A few surveys have been carried out to identify the main characteristics of Web developers regarding accessibility concepts and techniques for accessibility. However, the studies reported up to this date have only investigated the use of a restricted set of techniques by developers. Besides, they have not addressed the analysis of the correlation between the answers provided by the subjects and the accessibility level of their Web pages. The proposal of the work presented in this master\'s thesis is the development of a survey on the accessibility awareness and on the use of techniques for accessibility by people involved in the development of Web based systems. Automatic metric based accessibility evaluations on the Web sites developed by the subjects were carried out to support the investigation of the impacts that the issues investigated have on the Web pages accessibility and on the accessibility awareness. The survey was answered by 613 subjects from all Brazilian states. The results show that in Brazil the accessibility awareness is still very limited. Training people involved in Web projects on technical issues alone is not enough. It is necessary to promote a wider awareness of accessibility and of the problems people with different restrictions and abilities deal with when using the Web

Data abstraction techniques are widely used in multiresolution visualization systems to reduce visual clutter and facilitate analysis from overview to detail. However, analysts are usually unaware of how well the abstracted data represent the original dataset, which can impact the reliability of results gleaned from the abstractions. In this thesis, we define three types of data abstraction quality measures for computing the degree to which the abstraction conveys the original dataset: the Histogram Difference Measure, the Nearest Neighbor Measure and Statistical Measure. They have been integrated within XmdvTool, a public-domain multiresolution visualization system for multivariate data analysis that supports sampling as well as clustering to simplify data. Several interactive operations are provided, including adjusting the data abstraction level, changing selected regions, and setting the acceptable data abstraction quality level. Conducting these operations, analysts can select an optimal data abstraction level. We did an evaluation to check how well the data abstraction measures conform to the data abstraction quality perceived by users. We adjusted the data abstraction measures based on the results of the evaluation. We also experimented on the measures with different distance methods and different computing mechanisms, in order to find the optimal variation from many variations of each type of measure. Finally, we developed two case studies to demonstrate how analysts can compare different abstraction methods using the measures to see how well relative data density and outliers are maintained, and then select an abstraction method that meets the requirement of their analytic tasks.

Today`s continuously growing Internet requires users and network applications to have knowledge of network metrics. This knowledge is critical for decision making during the usage of network applications. This thesis studies application related network metrics. The major approach in this work is to examine the traffic between a simulated user and network applications. We use the historical data collected from previous usage of network applications to make predictions for future usage of those applications. We also use the historical data obtained from a given application to make predictions about another application. Prediction mechanisms require us to make parameter choices so that certain weights can be placed on historical data versus current data. We study these different choices and use the values from our best experimental results. From these studies we conclude that our data prediction is quite accurate and remains stable over a range of parameter choices. The use of shared routing paths between users and network applications are explored in the performance prediction of applications. Only some servers at the same locations show similar prediction results. The network applications studied are also varied, including web, streaming, DNS, etc. We see whether sharing information obtained from different applications can be used to make predictions of application performance. However, we observe limited success in predictions across applications.

One role of forensic anthropologists is to create a biological profile to help identify remains. This includes estimating ancestry. Many morphological and metrical methods of ancestry estimation have been created and utilized. This study was aimed at created a simple, metrical analysis of dental arch size and shape to aid in ancestry estimation. Maximum length and width of over 700 dental casts (both maxillary and mandibular) were recorded and statistically analyzed by one-way ANOVA. Measurements were taken using points on teeth rather than on the fragile bone of the maxilla and mandible. It was found that ancestry does affect the size of the maxillary arch but not the mandibular one, but discriminant function analysis showed that ancestry estimation is not possible with the present set of data for either the maxilla or the mandible. Further research will need to be conducted with larger sample sizes of certain populations in order to improve ancestry estimation using this method.

Os rumos atuais da competição e da tecnologia justificam a crescente utilização de indicadores para a gestão dos recursos produtivos nas organizações industriais. Nesta linha de pensamento, o presente trabalho discorre sobre as principais abordagens relacionadas com gestão competitiva, construção de indicadores e métodos de custeio, disponíveis na literatura. Com base no modelo gerencial do Prof. Nigel Slack, para agregar vantagem competitiva na manufatura, é desenvolvido um sistema de indicadores integrados para a gestão do custeio e das atividades de manutenção. O modelo de gestão é validado por intermédio de um estudo de caso real e os resultados obtidos demonstram a eficácia do sistema de indicadores no monitoramento das atividades de manutenção nas empresas industriais. / The current trend in terms of world-wide competition and technological skills justify the increasing utilization of constant up-to-date information and decision-making data in manufacturing organizations. Accordingly, this work discusses the major contributions related to a world-class management, performance metrics and costing methods. Based on Nigel Slack’s management model proposed to increase competitiveness, an inter-related performance metrics system is developed, aiming to reduce maintenance cost and to improve the overall maintenance activities management. The management techniques proposed in this research is validated by its application in a real manufacturing company, selected for a case-study. This research shows that the data collected allows statistical analysis and helps a plant management team to get important conclusions about the effectiveness of the performance metrics proposed for maintenance management.

Este trabalho avalia de maneira detalhada diferentes parâmetros para a definição de níveis de homogeneidade e heterogeneidade em sistemas computacionais distribuídos. O objetivo é analisar a eficiência da métrica GH - Grau de Heterogeneidade - em relação a diferentes perspectivas. Métricas encontradas na literatura e benchmarks de código aberto (reconhecidos pela comunidade científica) são utilizados para quantificar a heterogeneidade do sistema computacional. A métrica GH também é empregada no AMIGO, um ambiente de escalonamento real, para analisar a sua utilização em algoritmos de escalonamento de processos. Os principais resultados obtidos neste trabalho são: a comprovação da estabilidade da métrica GH para determinar o grau de heterogeneidade de plataformas computacionais distribuídas, o uso da métrica GH com sucesso em um ambiente de escalonamento real e o desenvolvimento de um algoritmo de escalonamento adaptativo. Sub-produtos deste trabalho são: um levantamento dos principais benchmarks com código aberto e livre disponíveis na literatura, os quais podem ser utilizados em trabalhos futuros no grupo de pesquisa e a continuidade do desenvolvimento do ambiente de escalonamento AMIGO / This work evaluates several parameters in a detailed way for the definition of homogeneity and heterogeneity levels in distributed computing systems. The objective is to analise the GH metric efficiency (heterogeneity degree) according to different perspectives. Metrics found in the literature and open source benchmarks (recognized by the scientific community) are both used to quantify the heterogeneity of the computational system. The GH metric is also employed in the AMIGO, a real scheduling environment, in order to evaluate its use in process scheduling algorithms. The main results obtained in this work are: the verification of the GH metric stability for determining the heterogeneity degree of distributed computing platforms; the use of the GH metric with success in a real scheduling environment and the development of an adaptive scheduling algorithm. By-products of this work are: the highlighting of the main benchmarks with open source available in the literature, which can be used in future works by the research group and the continuity of the development of the AMIGO

Nesse trabalho apresentaremos alguns exemplos clássicos que evidenciam as diferenças entre a geometria Riemanniana e a semi-Riemanniana (Lorentziana) quanto à completude de geodésicas. Para isso, revisitaremos conceitos básicos de Geometria, seguido de uma introdução aos espaços vetoriais de Lorentz e um estudo inicial sobre o grupo de Lorentz. Nos capítulos finais discutiremos sobre completude de geodésicas e como se distanciam do caso Riemanniano. / In this work we intend to present some classical examples that display the differences between Riemannian and semi-Riemannian (Lorentzian) geometry in relation to the completeness of geodesics. For this, we will revisit basic Geometry concepts followed by an introduction to the vector spaces of Lorentz and a simple study on the Lorentz group. In the final chapters we will discuss about the completeness of geodesics and how it distances itself from the Riemannian case.

"I know but one freedom, and that is the freedom of the mind" Antoine de Saint-Exupery. Web metrics offer significant potential for online businesses to incorporate high-quality, real-time information into their strategic marketing decision-making (SDM) process. This SDM process is affected by the firm�s strategic direction, which is critical for web businesses. A review of the widely researched strategy and SDM literature identified that managers use extensive information to support and improve strategic decisions and make informed decisions. Offline SDM processes might be appropriate for the online environment but the limited literature on web metrics has not researched information needs for online SDM. Even though web metrics can be a valuable tool for web businesses to inform strategic marketing decisions, and their collection might be less expensive and easier than offline measures, virtually no published research has combined web metrics and SDM concepts into one research project. To address this gap in the literature, the thesis investigated the differences and commonalities of online and offline SDM process approaches, the use of web metrics categories for online SDM stages, and the issues encountered during that process through four research questions. A preliminary conceptual model based on the literature review was refined through preliminary research, which addressed the research questions and investigated the current state of web metrics. After investigating various methodologies, a multi-stage qualitative methodology was selected. The use of qualitative methods represents a contribution to knowledge regarding methodological approaches to online research. Four stages within the online SDM process were shown to benefit from the use of web metrics: the setting of priorities, the setting of objectives, the pretest stage and the review stage. The results identified the similarity of online and offline SDM processes; demonstrated that Traffic, Transactions, Customer Feedback and Consumer Behaviour categories provide basic metrics used by most companies; identified the Environment, Technology, Business Results and Campaigns categories as supplementary categories that are applied according to the marketing objectives; and investigated the results based on different types of companies (website classification, channel focus, size and cluster association). Three clusters were identified that relate to the strategic importance of the website and web metrics. Modifying the initial conceptual model, six issues were distinguished that affect the use of web metrics: the adoption and use of web metrics by managers; the integration of multiple sources of metrics; the establishment of industry benchmarks; data quality; the differences to offline measures; as well as resource constraints that interfere with the appropriate web metrics analysis. Links to offline marketing strategy literature and established business concepts were explored and explanations provided where the results confirmed or modified these concepts. Using qualitative methods, the research assisted in building theory of web metrics and online SDM processes. The results show that offline theories apply to the online environment and conventional concepts provide guidance for online processes. Dynamic aspects of strategy relate to the online environment, and qualitative research methods appear suitable for online research. Publications during this research project: Weischedel, B., Matear, S. and Deans, K. R. (2003) The Use of E-metrics in Strategic Marketing Decisions - A Preliminary Investigation. Business Excellence �03 - 1st International Conference on Performance Measures, Benchmarking and Best Practices in the New Economy, Guimaraes, Portugal; June 10-13, 2003. Weischedel, B., Deans, K. R. and Matear, S. (2004) Emetrics - An Empirical Study of Marketing Performance Measures for Web Businesses. Performance Measurement Association Conference 2004, Edinburgh, UK; July 28-30, 2004. Weischedel, B., Matear, S. and Deans, K. R. (2005) "A Qualitative Approach to Investigating Online Strategic Decision-Making" Qualitative Market Research, Vol. 8 No 1, pp. 61-76. Weischedel, B., Matear, S. and Deans, K. R. (2005) "The Use of Emetrics in Strategic Marketing Decisions - A Preliminary Investigation" International Journal of Internet Marketing and Advertising, Vol. 2 Nos 1/2, p. 109-125.

Electronically displayed images are becoming increasingly important as an interface between man and information systems. Lengthy periods of intense observation are no longer unusual. There is a growing awareness that specific demands should be made on displayed images in order to achieve an optimum match with the perceptual properties of the human visual system. These demands may vary greatly, depending on the task for which the displayed image is to be used and the ambient conditions. Optimal image specifications are clearly not the same for a home TV, a radar signal monitor or an infrared targeting image display. There is, therefore, a growing need for means of objective measurement of image quality, where "image quality" is used in a very broad sense and is defined in the thesis, but includes any impact of image properties on human performance in relation to specified visual tasks. The aim of this thesis is to consolidate and comment on the image measure literatures, and to find through experiment the salient properties of electronically displayed real world complex imagery that impacts on human performance. These experiments were carried out for well specified visual tasks (of real relevance), and the appropriate application of image measures to this imagery, to predict human performance, was considered. An introduction to certain aspects of image quality measures is given, and clutter metrics are integrated into this concept. A very brief and basic introduction to the human visual system (HVS) is given, with some basic models. The literature on image measures is analysed, with a resulting classification of image measures, according to which features they were attempting to quantify. A series of experiments were performed to evaluate the effects of image properties on human performance, using appropriate measures of performance. The concept of image similarity was explored, by objectively measuring the subjective perception of imagery of the same scene, as obtained through different sensors, and which underwent different luminance transformations. Controlled degradations were introduced, by using image compression. Both still and video compression were used to investigate both spatial and temporal aspects of HVS processing. The effects of various compression schemes on human target acquisition performance were quantified. A study was carried out to determine the "local" extent, to which the clutter around a target, affects its detectability. It was found in this case, that the excepted wisdom, of setting the local domain (support of the metric) to twice the expected target size, was incorrect. The local extent of clutter was found to be much greater, with this having implications for the application of clutter metrics. An image quality metric called the gradient energy measure (GEM), for quantifying the affect of filtering on Nuclear Medicine derived images, was developed and evaluated. This proved to be a reliable measure of image smoothing and noise level, which in preliminary studies agreed with human perception. The final study discussed in this thesis determined the performance of human image analysts, in terms of their receiver-operating characteristic, when using Synthetic Aperture Radar (SAR) derived images in the surveillance context. In particular, the effects of target contrast and background clutter on human analyst target detection performance were quantified. In the final chapter, suggestions to extend the work of this thesis are made, and in this context a system to predict human visual performance, based on input imagery, is proposed. This system intelligently uses image metrics based on the particular visual task and human expectations and human visual system performance parameters. / Thesis (Ph.D.)--Medical School; School of Computer Science, 1999.