Please read the abstract in the section 00front of this document / Dissertation (MSc)--University of Pretoria, 2007. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted

Image and video quality evaluation is very important. In applications involving signal transmission, the Reduced- or No-Reference quality metrics are generally more practical than the Full-Reference metrics. Digital watermarking based quality evaluation emerges as a potential Reduced- or No-Reference quality metric, which estimates signal quality by assessing the degradation of the embedded watermark. Since the watermark contains a small amount of information compared to the cover signal, performing accurate signal quality evaluation is a challenging task. Meanwhile, the watermarking process causes signal quality loss. To address these problems, in this thesis, a framework for image and video quality evaluation is proposed based on semi-fragile and adaptive watermarking. In this framework, adaptive watermark embedding strength is assigned by examining the signal quality degradation characteristics. The "Ideal Mapping Curve" is experimentally generated to relate watermark degradation to signal degradation so that the watermark degradation can be used to estimate the quality of distorted signals. With the proposed framework, a quantization based scheme is first implemented in DWT domain. In this scheme, the adaptive watermark embedding strengths are optimized by iteratively testing the image degradation characteristics under JPEG compression. This iterative process provides high accuracy for quality evaluation. However, it results in relatively high computational complexity. As an improvement, a tree structure based scheme is proposed to assign adaptive watermark embedding strengths by pre-estimating the signal degradation characteristics, which greatly improves the computational efficiency. The SPIHT tree structure and HVS masking are used to guide the watermark embedding, which greatly reduces the signal quality loss caused by watermark embedding. Experimental results show that the tree structure based scheme can evaluate image and video quality with high accuracy in terms of PSNR, wPSNR, JND, SSIM and VIF under JPEG compression, JPEG2000 compression, Gaussian low-pass filtering, Gaussian noise distortion, H.264 compression and packet loss related distortion.

Estudos indicam que a utilização de aplicativos educacionais móveis vêm crescendo continuamente, possibilitando a alunos e professores maior flexibilidade e comodidade na execução de atividades e práticas educacionais. Embora várias instituições já tenham aderido à modalidade de aprendizagem móvel (m-learning), sua adoção ainda traz problemas e desafios organizacionais, culturais e tecnológicos. Um destes problemas consiste em como avaliar adequadamente a qualidade dos aplicativos educacionais desenvolvidos. De fato, os métodos existentes para avaliação da qualidade de software ainda são muito genéricos, não contemplando aspectos específicos aos contextos pedagógico e móvel. Nesse cenário, o presente trabalho apresenta o método MoLEva, desenvolvido para avaliar a qualidade de aplicativos educacionais móveis. O método tem como base a norma ISO/IEC 25000, sendo composto por: (i) modelo de qualidade; (ii) métricas; e (iii) critérios de julgamento. Para validar o método, foram realizados dois estudos de caso; o primeiro consistiu na aplicação do MoLEva para avaliar o aplicativo do ENEM; o segundo consistiu na aplicação do método para avaliação de aplicativos para o ensino de idiomas. A partir dos resultados obtidos, foi possível identificar problemas e pontos de melhoria nos aplicativos avaliados. Além disso, os estudos de caso conduzidos forneceram bons indicativos a respeito da viabilidade de uso do método MoLEva na avaliação de aplicativos educacionais móveis. / Studies indicate that the use of mobile learning applications has grown continuously, allowing students and teachers greater flexibility and convenience in the execution of educational activities and practices. Although several institutions have already adhered to the mobile learning (m-learning) modality, their adoption still brings organizational, cultural and technological problems and challenges. One of these problems is how to adequately evaluated the quality of the mobile learning applications developed. In fact, existing methods for evaluating software quality are still very generic, not considering aspects specific to the pedagogical and mobile contexts. In this scenario, the present work presents the MoLEva method, developed to evaluate the quality of mobile learning applications. The method is based on the ISO / IEC 25000 standard, being composed of: (i) quality model; (ii) metrics; and (iii) criteria of judgment. To validate the method, two case studies were performed; the first consisted of applying MoLEva to evaluate the ENEM application; the second consisted of applying the method for evaluating applications for language teaching. From the obtained results, it was possible to identify problems and improvement points in the evaluated applications. In addition, the case studies conducted provided good indications regarding the feasibility of using the MoLEva method in evaluating mobile learning applications.

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This thesis deals with the issue of influence of storage conditions on the quality of conventional fly ashes which are produced by combustion of lignite. These ashes were stockpiled for long time. A borehole for sampling was made in the fly ash stock-pile. Total depth of the borehole was 20 m. Samples of fly ashes taken from every single meter were analyzed and next mechanical properties and the volume stability of materials containing these fly ashes were tested. The quality of fly ashes especially with respect to the possibility to use them as components of pastes, mortars and concretes as pozzolanic admixture or fine filler was evaluated.

This study explores the consequences for a historically black university (HBU) of the South African state’s focus on routine and strategic quality evaluation within a policy framework that views higher education as a lever for social change and economic development. It analyses the changing nature of academic work and probes the motivations and understandings of institutional managers and academics in an attempt to explain their responses to policy requirements. The theory of the Evaluative State is employed to examine the nature and consequences of overzealous responsiveness by a historically black university in transition in South Africa. It suggests that the changing relationship between state and university is characterised by contradictions and ambivalence, a result of the interplay between a strong sense of loyalty to the state on the one hand and a recognition of the failure of the state to recognise and reward achievements valued by the HBU. This study suggests that state steering, through the use of output evaluation and efficiency-directed performance indicators, has resulted in failure to achieve central policy goals of development, equity and social justice. The study is guided by one main research question: How do academics in a historically black South African university in transition engage with and implement internal and external quality assurance processes and policies? The literature review reveals significant gaps in understanding the consequences of the rise of the Evaluative State in higher education. A major limitation has been a lack of focus on higher education systems in developing countries and on the consequences of imposing neo-liberal frameworks upon local realities which require redress to remedy historically constructed economic and social disadvantage. The descriptions of academics and institutional managers that emerge in this study highlight stark differences between the two groups in perceptions of and approaches to quality improvement and university work. Significantly, institutional history, context and mission emerge as strong factors shaping academics’ and managers’ responses to change, factors that have largely been disregarded by state policy which focuses more on output achievement than on input variables. / Thesis (PhD)--University of Pretoria, 2010. / Education Management and Policy Studies / unrestricted

Background. Secondary motion is a principle of animation, it is movement that occurs as a result of other movement, such as swinging hair or clothes. In 3D animation, such as in games, it is often simulated instead of animated manually. In game projects with time limitations, it can be interesting to know to what degree these simulations impact the visual quality in order to decide whether they should be prioritized. It is also interesting to know how the results of various methods compare to each other. To simulate in real-time means that physics simulations are running during gameplay. Baked animations on the other hand are simulations that have already been processed and saved as animation data, they are less dynamic but also less performance intensive. Objectives. The aim of this thesis is to evaluate the impact of three sets of animations by conducting a survey where each set is compared. The three sets are: animations that feature real-time simulations, baked simulations and ones without simulation. The goal is to acquire a metric from the comparisons that can give an insight to the visual quality impact of each method. Methods. Three animation sets were created. Then, a survey was conducted using a questionnaire that featured side by side video comparisons of the animation sets. The videos featured a stylized character running, walking, or jumping through an empty environment. Pairwise similarity judgements were done by asking the participants to rate each video compared to each other. The results from the questionnaire were analyzed using a method that is a part of the analytical hierarchy process. The data from each comparison was averaged, put into pairwise comparison matrices, and then used to calculate priority vectors. The level of consistency of the comparisons were also calculated. Results. The priority vectors show the ratios of how each animation set were preferred compared to each other. In the priority vector for all animations combined, the set without simulations ranked at twenty-four percent, the real-time set ranked at thirty-three percent and the baked set ranked the highest at forty-three percent. The comparisons were calculated to have a very high consistency, which strengthens the result. Conclusions. The results show the impact that adding simulated secondary motion has. The simulations appear to improve the visual quality, but the margin is not extreme. The calculated ratios could be used to argue for or against a game project’s prioritization of secondary motion simulations depending on the project’s time constraints and access to preexisting methods of simulation. It should be noted that the format of video comparisons did not showcase all the advantages of each method such as creation accessibility, technical performance or dynamicity. As such, it is uncertain how fair the comparisons of the baked and real-time simulations are in a more general sense. Nevertheless, the results are considered to give at least a partial insight into how these methods compare.

As percepções sobre qualidade em educação no Brasil têm sido influenciadas por questões de acesso e permanência, e atualmente remetem à aprendizagem proporcionada pela formação escolar seja essa formação pautada por desempenho cognitivo em testes ou por sentidos mais abrangentes, como os fins que compõem o direito à educação conforme a CF/88. Se o Estado brasileiro é declaradamente o principal sujeito do dever de garantir tal direito, o qual se cumpre via políticas públicas (entre outros meios), nota-se que, por outro lado, políticas de avaliação e indicadores educacionais correlatos têm sido instrumentos em disputa e protagonistas de algumas tensões. Dentre elas, destaca-se que o indicador mais amplamente utilizado como padrão de qualidade no Brasil IDEB é composto por medidas de aprovação e desempenho cognitivo, e não permite avaliar adequadamente se certos fins da educação estão sendo garantidos pela oferta da educação básica. Sustentando, contudo, a pertinência do uso de indicadores como auxílio na garantia do padrão de qualidade da educação pública ainda que sublinhando dificuldades como a de acessar dimensões mais dificilmente quantificáveis da qualidade educacional, como formação de valores , este trabalho parte da ideia de que as dimensões da qualidade em educação são interligadas, e propõe a hipótese de que resultados educacionais pouco acessíveis a medidas sejam inferidos a partir de seus processos relativos. Tomando a formação para cidadania como caso ilustrativo dessa hipótese, a pesquisa busca identificar, a partir de referências conceituais e empíricas, processos educacionais relevantes à formação para cidadania, e destacar instrumentos com potencial para acessar de forma padronizada os processos apontados, de modo a constituir medidas que alimentem um eventual indicador de qualidade mais compreensivo quanto à magnitude do direito à educação. / The perceptions about educational quality in Brazil have been influenced by matters of access and permanence of students in the public systems, and currently they mostly refer to the learning provided by schooling whether this learning is taken in terms of tests scores or in broader senses, such as the educational purposes that comprise the right to education as stated by the Brazilian Constitution. The Brazilian State has a central role in ensuring this right, specially by the means of public policies (among others); it is noticeable, however, that public evaluation policies and related educational indicators have been involved in some controversies. One of these controversies pertains to the educational quality standard more widely used in Brazil IDEB; this indicator is composed by measures of approval and cognitive performance in tests, and does not adequately infer whether certain educational purposes are being guaranteed through public schooling. Nevertheless, this work sustain the relevance of indicators as a support to reach educational quality standards although stressing associated difficulties such as to quantify dimensions of educational quality less approachable by measures, as the formation of values. To cope with this question, it is assumed that the dimensions of educational quality are interconnected, and then proposed the hypothesis that educational outcomes less accessible by measures may be inferred from its related educational processes. This work will ascertain this hypothesis taking education for citizenship as an illustrative case. In this sense, it will identify, from conceptual and empirical references, educational processes relevant to education for citizenship, and highlight potential tools to access this processes in a standardized manner, to explore the possibility to provide measures that could compose a more comprehensive quality indicator concerning the magnitude of the right to education.

Diante da constante necessidade de funcionamento ininterrupto dos sistemas computacionais, das mais diversas organizações, é imperativo que existam meios de continuidade dos negócios e recuperação de desastres implantados, testados e prontos para serem invocados. Diante disso, torna-se essencial a existência de uma maneira de avaliar se as informações, os procedimentos e o nível do conhecimento dos colaboradores da organização estão adequados para enfrentar uma ocorrência inesperada e devastadora no ambiente computacional da organização. A presente tese propõe um modelo hierárquico para se representar e avaliar a qualidade dos Projetos de Planos de Continuidade de Negócios (PPCN) aplicados a sistemas computacionais. Este modelo apresenta o mapeamento das principais características que esses planos devem possuir, de acordo com as principais normas relativas ao tema (BS 25999, ABNT NBR ISO/IEC 27001 e ABNT NBR ISO/IEC 27002), as experiências de especialistas da área e dados reais dos usuários dos PPCNs obtidos por meio da utilização de questionários. É proposto neste trabalho, também, um Índice de Qualidade (IQ) para os PPCNs que permite a comparação de um PPCN existente com um PPCN ideal, identificando-se os pontos fracos nele existentes e munindo a organização com informações para a busca de soluções que resultarão na melhoria do PPCN atual. / Given the need for computer systems uninterrupted operation, for the most different organizations, it is imperative that business continuity and disaster recovery plans be already in place, tested and ready to be invoked. Given this, it is essential for there being a way to assess whether the information, procedures and organizations employees knowledge level are adequate to deal with an unexpected and devastating event in the organization\'s computing environment. This thesis proposes a hierarchical model to represent and assess the organizations computer systems Business Continuity Plan Project (BCPP) quality. This model maps the main features these plans should have, in accordance with the main standards related to this area (BS 25999, ISO/IEC 27001 and ISO/IEC 27002), specialists experience and real data from BCPPs users obtained from questionnaires. As a complementary proposal, a BCPP Quality Index (QI) is suggested, which will allow organizations to compare their existing BCPP against an ideal BCPP, identifying the gaps between these plans and providing the organization with information for seeking solutions that will result in the improvement of current BCPP.

Existe na indústria o interesse em utilizar as informações da tomografia computadorizada a fim de conhecer o interior (i) dos objetos industriais fabricados ou (ii) das máquinas e seus meios de produção. Nestes casos, a tomografia tem como finalidade (a) controlar a qualidade do produto final e (b) otimizar a produção, contribuindo na fase piloto dos projetos e na análise da qualidade dos meios sem interromper a produção. O contínuo controle de qualidade dos meios de produção é a chave mestra para garantir a qualidade e a competitividade dos produtos. O Centro de Tecnologia das Radiações (CTR), do Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP) vem desenvolvendo esta tecnologia para fins de análises de processos industriais há algum tempo. Atualmente, o laboratório tem desenvolvido três gerações de tomógrafos: (i) primeira geração; (ii) terceira geração; e (iii) tomógrafo Instant Non-Scanning. Os algoritmos de reconstrução de imagens tomográficas tem uma importância relevante para o funcionamento ideal desta tecnologia. Nesta tese, foram desenvolvidos e analisados os algoritmos de reconstrução de imagens tomográficas para serem implementados aos protocolos experimentais dos tomógrafos. Os métodos de reconstrução de imagem analítico e iterativo foram desenvolvidos utilizando o software Matlab® r2013b. Os algoritmos iterativos apresentaram imagens com melhor resolução espacial comparado com as obtidas pelo método analítico. Entretanto as imagens por método analítico apresentaram menos ruídos. O tempo para obtenção de imagem pelo método iterativo é relativamente elevado, e aumenta conforme aumenta a matriz de pixels da imagem. Já o método analítico fornece imagens instantâneas. Para as reconstruções de imagens utilizando o tomógrafo Instant Non-Scanning, as imagens pelo método analítico não apresentaram qualidade de imagem satisfatória comparada aos métodos iterativos. / There is an interest in the industry to use the CT information in order to know the interior (i) of the manufactured industrial objects or (ii) the machines and their means of production. In these cases, the purpose of the tomography systems is to (a) control the quality of the final product and (b) to optimize production, contributing to the pilot phase of the projects and to analyze the quality of the means without interrupting he line production. Continuous quality assurance of the means of production is the key to ensuring product quality and competitiveness. The Radiation Technology Center of the Nuclear and Energy Research Institute (IPEN/CNEN-SP) has been developing this technology for the purpose of industrial analysis. Currently the laboratory has developed three generations of tomography systems: (i) first generation; (ii) third generation; and (iii) Instant Non-Scanning tomography. The algorithms for the reconstruction of tomographic images are of relevant importance for the optimal functioning of this technology. In this PhD thesis, the reconstruction algorithms of tomographic images were developed and analyzed to be implemented to the tomography systems developed. The analytical and iterative image reconstruction methods were developed using the software Matlab® r2013b. The iterative algorithms presented images with better spatial resolution compared to those obtained by the analytical method; however the images of the analytical method presented be less image noisy. The time to obtain the image by the iterative method is high, and increases as the image matrix increases, while the analytical method provides fast images. For images reconstructions using the Instant Non-Scanning tomography system, the images by the analytical method did not present satisfactory image quality compared to the iterative methods.