Software changes constantly and continuously. It is often beneficial to record the progressive changes made to software, so that when any problems arise, it is possible to identify the change that might have caused the problem. Also, recording these changes enables recovery of the software as it was at any point of time. A version control system is used to track modifications to software. Version control systems (VCS) display when and where a change was made. In the case of multiple developers working on the same software system, version control systems also record which developer was responsible for the change. RCS, SCCS and CVS are examples of such version control systems, and they usually have a command-line interface. The widespread use of CVS has however given rise to a host of "CVS clients", which provide a two-dimensional graphical interface to CVS. While working with a version control system in two dimensions is a definite improvement over traditional command line interfaces, it is still not sufficient to display all the necessary information in a single view. Using three dimensions to display the information from a version control system like CVS is an effective and efficient way to represent multiple attributes in a single view. There are many advantages to using a third dimension for visualizing the version history and evolution of software. A three-dimensional visualization tool has been developed to provide insights into the structure and characteristics of the history of a software system. It demonstrates the benefits of three-dimensional visualization and illustrates a framework that can be used to automatically derive information from a version control system. / Master of Information Systems

Student Number : 0318263P - MA research report - Faculty of Humanities / This is an historical documentary about an individual’s remarkable journey, one which starts in Durban in 1957 and ends with the protagonist’s arrival in London later the same year before he would subsequently move to Oslo in 1961. The documentary is intended primarily for a South African television audience. As such, it is a history to be apprehended visually rather than in writing, and to a large and heterogeneous, though primarily South African audience. The documentary is actually about two journeys: the physical overland African passage to Europe with its various episodes, and the journey of an ambitious young adult from a humble and disadvantaged background with only a primary school education. It culminates with him gaining acceptance for study of medicine at a Norwegian university, where he would eventually qualify as a doctor and later as a psychiatrist. Though set against the backdrop of the emerging political opposition to apartheid, the documentary is a somewhat depoliticised personal history – the biographical narrative of an old man who accomplished something in his youth which altered his whole life. It is not primarily a political history, nor is it a narrative about the experience of exile. The documentary attempts to locate a historical and spatial context from where the protagonist emerged, but does not attempt to portray the history of South African Indians as a racial or cultural group, per se.

Visualizing atomic orbitals.

Magister Artium (Social Work) - MA(SW) / The researcher's concern for the topic was founded on the fact that previous research on child labour in Rwanda did not qualitatively explore the working and living conditions of child domestic workers in this specific contextual setting. The aim of the study therefore, was to explore the living and working conditions of child domestic workers in a contextual setting of Kigali city and its periphery. To achieve the objectives of this study, a qualitative approach was envisaged, utilizing a case study strategy. The population was selected among child domestic workers in four districts of Kigali city and its periphery. The criteria of selection and reaching participants were snowball sampling and purposive sampling techniques. Data was collected by means of a semi-structured interview with open-ended questions. The collected data was analyzed through a model that is presented as a spiral image including: Collecting and recording data; managing data; reading and writing memos; describing, classifying and interpreting; representing and visualizing (Creswell, 1998: 142-165). In order to increase trustworthiness, triangulation as a process that uses multiple perceptions to clarify meaning, was used through child workers themselves, their employers, neighbours and local authorities. Colleagues helped to verify translations from mother tongue into English. Participants, especially child domestic workers revealed that the main factors pushing them into the job market was poverty and family and socio-political conflicts. Findings concerning working and living conditions also indicate experiences of exploitation and maltreatment. It has also been revealed that most participants were ignorant about children's rights. Finally discussions allowed the researcher to discover what participants and especially child domestic participants were expecting in their future and suggestions of how child domestic work would be abolished.

"Many approaches to the visualization of multivariate data have been proposed to date. Pixel oriented techniques map each attribute value of the data to a single colored pixel, theoretically yielding the display of the maximum possible information at a time. A large number of pixel layout methods have been proposed, each of which enables users to perform their visual exploration tasks to varying degrees. Pixel oriented techniques typically maintain the global view of large amounts of data while still preserving the perception of small regions of interest, which makes them particularly interesting for visualizing very large multidimensional data sets. Pixel based methods also provide feedback on the given query by presenting not only the data items fulfilling the query but also the data that approximately fulfill the query. The goal of this thesis was to extend XmdvTool, a public domain multivariate data visualization package, to incorporate pixel based techniques and to explore their strengths and weaknesses. The main challenge here was to seamlessly apply the interaction and distortion techniques used in other visualization methods within XmdvTool to pixel based methods and investigate the capabilities made possible by fusing the various multivariate visualization techniques."

Nos últimos anos a utilização de pontos como primitiva gráfica básica vem mostrandose uma poderosa e versátil ferramenta para a computação gráfica. Considerável esforço de pesquisa vem sendo dedicado para encontrar formas eficientes de aquisição, representação, processamento, renderização e animação para conjuntos de pontos. As representações baseadas em pontos têm-se destacado como uma estratégia eficiente em computação desde que se tornou comum extrair modelos geométricos a partir de Scanners 3D, os quais geram grandes quantidades de pontos que aproximam a geometria do objeto. Este trabalho apresenta um conjunto de métodos para tratar a visibilidade aproximada para nuvens de pontos sem informação de conectividade e topologia. Primeiramente é proposto uma abordagem baseada em clusters para acelerar o operador de remoção de pontos proposto por Katz et al. A principal motivação para esta otimização é a possibilidade de conseguir um equilíbrio entre a velocidade e a qualidade do resultado. Também é apresentado uma técnica de renderização baseada em pontos acelerada por hardware chamada Surface Splatting. Esta abordagem utiliza mapeamento de textura com alpha blending para aproximar um filtro de reamostragem Elliptical Weighted Average no espaço de objeto. Juntamente com o Geometry Shader das modernas placas gráficas, produz de forma eficiente imagens de alta qualidade de superfícies amostradas por surfels. Por último é proposto um novo operador de remoção de pontos ocultos acelerado por hardware baseados na técnica de splatting juntamente com um operador morfológico de erosão modificado para reduzir o efeito de silhuetas no resultado final do operador. A motivação para a criação deste novo operador é a baixa eficiência demonstrada pelos métodos existentes para a utilização em aplicações em tempo real onde as nuvens de pontos são muito densas. Todas as técnicas apresentadas neste trabalho podem ser utilizadas em visualização científica com taxas interativas, em particular na visualização direta de geometria baseada em pontos. / In recent years the use of points as a fundamental graphics primitive has proved to be a powerful and versatile tool for computer graphics. Considerable research has been devoted to the efficient representation, modeling, processing, rendering and animation of point-sampled geometry. The point-based representation has gained increasing attention in computer graphics because 3D scanning systems easily extract large information from real-world objects. On the other hand, point sets are more flexible when compared to triangle meshes, because they are not required to maintain consistent topological information. This work presents a set of tools to determine the visibility and also to render a point-based geometry efficiently. Firstly, a cluster-based approach is proposed to speed up the hidden point removal operator proposed by Katz et al. The main idea of this study is to trade-off speed and quality in dynamic scenes of moving or deforming point clouds. After that, a hardware based point rendering technique called Surface Splatting is introduced. This approach uses the texture mapping with alpha blending and the Geometry Shader to approximate the Elliptical Weighted Average filter in object space. This efficient technique produces high quality images as surfel-based geometry. Finally, a new hidden point removal operator is presented. This operator, based on the splatting technique and also hardware accelerated, applies a morphological erosion operation in the depth buffer to reduce the silhouette effect in the final image. The motivation to develop a new operator is the low efficiency demonstrated by existing hidden point removal methods in real time applications, where the point cloud is very dense. All the techniques introduced in this work can be used in scientific visualization with interactive frame rates, particularly when visualizing point-based geometry sets.

The aim of this study is to generate a grounded theory that explains the content of teachers' and students' work with personal development dialogues and individual development plans using written assessments, all regulated in the national result-oriented curriculum for the Swedish compulsory school. Two secondary schools participated and data was collected on two occasions. Data consists of recorded personal development dialogues, which are informed by written assessments, and copies of the individual development plans written as a conclusion stating agreements between the teacher and student. All data was continuously compared and analyzed by using a grounded theory method. Underpinning the study are the premises of pragmatic philosophy and transactional theory that are assumed to shape the focus of the grounded theory approach and hence of teacher and student transactional strategies. It is argued that teachers' and students' primary concern is to establish result-oriented individualization. This is a means for cooperation in a mutual endeavor to establish improved results, guided by the phases of visible accountability and responsible awareness. By using strategies for planning, guiding, auditing and reflecting, new ways of managing individualization are developed. It is also suggested that a new professional approach has been developed, where teachers and students work in collaborative teams, continuously focusing on improving student results.

Evidence is presented that in the early stages of design or composition the mental processes used by artists for visual invention require a different type of support from those used for visualising a nearly complete object. Most research into machine visualisation has as its goal the production of realistic images which simulate the light pattern presented to the retina by real objects. In contrast sketch attributes preserve the results of cognitive processing which can be used interactively to amplify visual thought. The traditional attributes of sketches include many types of indeterminacy which may reflect the artist's need to be "vague". Drawing on contemporary theories of visual cognition and neuroscience this study discusses in detail the evidence for the following functions which are better served by rough sketches than by the very realistic imagery favoured in machine visualising systems. 1. Sketches are intermediate representational types which facilitate the mental translation between descriptive and depictive modes of representing visual thought. 2. Sketch attributes exploit automatic processes of perceptual retrieval and object recognition to improve the availability of tacit knowledge for visual invention. 3. Sketches are percept-image hybrids. The incomplete physical attributes of sketches elicit and stabilise a stream of super-imposed mental images which amplify inventive thought. 4. By segregating and isolating meaningful components of visual experience, sketches may assist the user to attend selectively to a limited part of a visual task, freeing otherwise over-loaded cognitive resources for visual thought. 5. Sequences of sketches and sketching acts support the short term episodic memory for cognitive actions. This assists creativity, providing voluntary control over highly practised mental processes which can otherwise become stereotyped. An attempt is made to unite the five hypothetical functions. Drawing on the Baddeley and Hitch model of working memory, it is speculated that the five functions may be related to a limited capacity monitoring mechanism which makes tacit visual knowledge explicitly available for conscious control and manipulation. It is suggested that the resources available to the human brain for imagining nonexistent objects are a cultural adaptation of visual mechanisms which evolved in early hominids for responding to confusing or incomplete stimuli from immediately present objects and events. Sketches are cultural inventions which artificially mimic aspects of such stimuli in order to capture these shared resources for the different purpose of imagining objects which do not yet exist. Finally the implications of the theory for the design of improved machine systems is discussed. The untidy attributes of traditional sketches are revealed to include cultural inventions which serve subtle cognitive functions. However traditional media have many short-comings which it should be possible to correct with new technology. Existing machine systems for sketching tend to imitate nonselectively the media bound properties of sketches without regard to the functions they serve. This may prove to be a mistake. It is concluded that new system designs are needed in which meaningfully structured data and specialised imagery amplify without interference or replacement the impressive but limited creative resources of the visual brain.

Nos últimos anos a utilização de pontos como primitiva gráfica básica vem mostrandose uma poderosa e versátil ferramenta para a computação gráfica. Considerável esforço de pesquisa vem sendo dedicado para encontrar formas eficientes de aquisição, representação, processamento, renderização e animação para conjuntos de pontos. As representações baseadas em pontos têm-se destacado como uma estratégia eficiente em computação desde que se tornou comum extrair modelos geométricos a partir de Scanners 3D, os quais geram grandes quantidades de pontos que aproximam a geometria do objeto. Este trabalho apresenta um conjunto de métodos para tratar a visibilidade aproximada para nuvens de pontos sem informação de conectividade e topologia. Primeiramente é proposto uma abordagem baseada em clusters para acelerar o operador de remoção de pontos proposto por Katz et al. A principal motivação para esta otimização é a possibilidade de conseguir um equilíbrio entre a velocidade e a qualidade do resultado. Também é apresentado uma técnica de renderização baseada em pontos acelerada por hardware chamada Surface Splatting. Esta abordagem utiliza mapeamento de textura com alpha blending para aproximar um filtro de reamostragem Elliptical Weighted Average no espaço de objeto. Juntamente com o Geometry Shader das modernas placas gráficas, produz de forma eficiente imagens de alta qualidade de superfícies amostradas por surfels. Por último é proposto um novo operador de remoção de pontos ocultos acelerado por hardware baseados na técnica de splatting juntamente com um operador morfológico de erosão modificado para reduzir o efeito de silhuetas no resultado final do operador. A motivação para a criação deste novo operador é a baixa eficiência demonstrada pelos métodos existentes para a utilização em aplicações em tempo real onde as nuvens de pontos são muito densas. Todas as técnicas apresentadas neste trabalho podem ser utilizadas em visualização científica com taxas interativas, em particular na visualização direta de geometria baseada em pontos. / In recent years the use of points as a fundamental graphics primitive has proved to be a powerful and versatile tool for computer graphics. Considerable research has been devoted to the efficient representation, modeling, processing, rendering and animation of point-sampled geometry. The point-based representation has gained increasing attention in computer graphics because 3D scanning systems easily extract large information from real-world objects. On the other hand, point sets are more flexible when compared to triangle meshes, because they are not required to maintain consistent topological information. This work presents a set of tools to determine the visibility and also to render a point-based geometry efficiently. Firstly, a cluster-based approach is proposed to speed up the hidden point removal operator proposed by Katz et al. The main idea of this study is to trade-off speed and quality in dynamic scenes of moving or deforming point clouds. After that, a hardware based point rendering technique called Surface Splatting is introduced. This approach uses the texture mapping with alpha blending and the Geometry Shader to approximate the Elliptical Weighted Average filter in object space. This efficient technique produces high quality images as surfel-based geometry. Finally, a new hidden point removal operator is presented. This operator, based on the splatting technique and also hardware accelerated, applies a morphological erosion operation in the depth buffer to reduce the silhouette effect in the final image. The motivation to develop a new operator is the low efficiency demonstrated by existing hidden point removal methods in real time applications, where the point cloud is very dense. All the techniques introduced in this work can be used in scientific visualization with interactive frame rates, particularly when visualizing point-based geometry sets.

Nos últimos anos a utilização de pontos como primitiva gráfica básica vem mostrandose uma poderosa e versátil ferramenta para a computação gráfica. Considerável esforço de pesquisa vem sendo dedicado para encontrar formas eficientes de aquisição, representação, processamento, renderização e animação para conjuntos de pontos. As representações baseadas em pontos têm-se destacado como uma estratégia eficiente em computação desde que se tornou comum extrair modelos geométricos a partir de Scanners 3D, os quais geram grandes quantidades de pontos que aproximam a geometria do objeto. Este trabalho apresenta um conjunto de métodos para tratar a visibilidade aproximada para nuvens de pontos sem informação de conectividade e topologia. Primeiramente é proposto uma abordagem baseada em clusters para acelerar o operador de remoção de pontos proposto por Katz et al. A principal motivação para esta otimização é a possibilidade de conseguir um equilíbrio entre a velocidade e a qualidade do resultado. Também é apresentado uma técnica de renderização baseada em pontos acelerada por hardware chamada Surface Splatting. Esta abordagem utiliza mapeamento de textura com alpha blending para aproximar um filtro de reamostragem Elliptical Weighted Average no espaço de objeto. Juntamente com o Geometry Shader das modernas placas gráficas, produz de forma eficiente imagens de alta qualidade de superfícies amostradas por surfels. Por último é proposto um novo operador de remoção de pontos ocultos acelerado por hardware baseados na técnica de splatting juntamente com um operador morfológico de erosão modificado para reduzir o efeito de silhuetas no resultado final do operador. A motivação para a criação deste novo operador é a baixa eficiência demonstrada pelos métodos existentes para a utilização em aplicações em tempo real onde as nuvens de pontos são muito densas. Todas as técnicas apresentadas neste trabalho podem ser utilizadas em visualização científica com taxas interativas, em particular na visualização direta de geometria baseada em pontos. / In recent years the use of points as a fundamental graphics primitive has proved to be a powerful and versatile tool for computer graphics. Considerable research has been devoted to the efficient representation, modeling, processing, rendering and animation of point-sampled geometry. The point-based representation has gained increasing attention in computer graphics because 3D scanning systems easily extract large information from real-world objects. On the other hand, point sets are more flexible when compared to triangle meshes, because they are not required to maintain consistent topological information. This work presents a set of tools to determine the visibility and also to render a point-based geometry efficiently. Firstly, a cluster-based approach is proposed to speed up the hidden point removal operator proposed by Katz et al. The main idea of this study is to trade-off speed and quality in dynamic scenes of moving or deforming point clouds. After that, a hardware based point rendering technique called Surface Splatting is introduced. This approach uses the texture mapping with alpha blending and the Geometry Shader to approximate the Elliptical Weighted Average filter in object space. This efficient technique produces high quality images as surfel-based geometry. Finally, a new hidden point removal operator is presented. This operator, based on the splatting technique and also hardware accelerated, applies a morphological erosion operation in the depth buffer to reduce the silhouette effect in the final image. The motivation to develop a new operator is the low efficiency demonstrated by existing hidden point removal methods in real time applications, where the point cloud is very dense. All the techniques introduced in this work can be used in scientific visualization with interactive frame rates, particularly when visualizing point-based geometry sets.