A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

This report summarizes the work of the National Fusion Collaboratory (NFC) Project to develop a persistent infrastructure to enable scientific collaboration for magnetic fusion research. The original objective of the NFC project was to develop and deploy a national FES Grid (FusionGrid) that would be a system for secure sharing of computation, visualization, and data resources over the Internet. The goal of FusionGrid was to allow scientists at remote sites to participate as fully in experiments and computational activities as if they were working on site thereby creating a unified virtual organization of the geographically dispersed U.S. fusion community. The vision for FusionGrid was that experimental and simulation data, computer codes, analysis routines, visualization tools, and remote collaboration tools are to be thought of as network services. In this model, an application service provider (ASP provides and maintains software resources as well as the necessary hardware resources. The project would create a robust, user-friendly collaborative software environment and make it available to the US FES community. This Grid's resources would be protected by a shared security infrastructure including strong authentication to identify users and authorization to allow stakeholders to control their own resources. In this environment, access to services is stressed rather than data or software portability

Study and modeling of the effects of form and growth on coat pattern formation through reaction diffusion

Modelos de reação-difusão são amplamente usados na simulação de formação de padrões em seres vivos, sendo aplicados tanto como explicação destes fenômenos quanto para a geração de texturas em computação gráfica. No entanto, poucos estudos levam em conta a influência da forma da superfície sobre o padrão resultante. Neste trabalho realizamos simulações com o modelo de reação-difusão não-linear de Turing em superfícies bidimensionais utilizando diferentes parâmetros e formatos de superfície. Nossos resultados mostram que a forma possui um efeito relevante sobre o padrão final resultante, permitindo a transição de pintas para listras, a alteração da estabilidade e da robustez do sistema, e a obtenção de padrões geometricamente regulares.Reaction-diffusion models are widely used for simulations of biological pattern formation, finding applications both as an explanation of these phenomena as well as a method for texture generation. However, few studies take into account the influence of the surface shape on the resulting pattern. In this work we performed simulations with the nonlinear reaction-diffusion model of Turing in bidimensional surfaces using different parameters and surface shapes. Our results show that shape has a relevant effect over the resulting pattern, allowing the transition of spots to stripes, alterations of system stability and robustness, and synthesis of geometrically regular patterns

A Visual Approach to Analysis of Stress Tensor Fields

We present a visual approach for the exploration of stress tensor fields. In contrast to common tensor visualization methods that only provide a single view to the tensor field, we pursue the idea of providing various perspectives onto the data in attribute and object space. Especially in the context of stress tensors, advanced tensor visualization methods have a young tradition. Thus, we propose a combination of visualization techniques domain experts are used to with statistical views of tensor attributes. The application of this concept to tensor fields was achieved by extending the notion of shape space. It provides an intuitive way of finding tensor invariants that represent relevant physical properties. Using brushing techniques, the user can select features in attribute space, which are mapped to displayable entities in a three-dimensional hybrid visualization in object space. Volume rendering serves as context, while glyphs encode the whole tensor information in focus regions. Tensorlines can be included to emphasize directionally coherent features in the tensor field. We show that the benefit of such a multi-perspective approach is manifold. Foremost, it provides easy access to the complexity of tensor data. Moreover, including well-known analysis tools, such as Mohr diagrams, users can familiarize themselves gradually with novel visualization methods. Finally, by employing a focus-driven hybrid rendering, we significantly reduce clutter, which was a major problem of other three-dimensional tensor visualization methods

Estudo e Modelagem dos Efeitos da Forma e do Crescimento em Processos de Formação de Padrões de Pelagem via Reação-Difusão

Modelos de reação-difusão são amplamente usados na simulação de formação de padrõesem seres vivos, sendo aplicados tanto como explicação destes fenômenos quantopara a geração de texturas em computação gráfica. No entanto, poucos estudos levamem conta a influência da forma da superfície sobre o padrão resultante. Neste trabalhorealizamos simulações com o modelo de reação-difusão não-linear de Turing emsuperfícies bidimensionais utilizando diferentes parâmetros e formatos de superfície.Nossos resultados mostram que a forma possui um efeito relevante sobre o padrão finalresultante, permitindo a transição de pintas para listras, a alteração da estabilidadee da robustez do sistema, e a obtenção de padrões geometricamente regulares.

A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion

This report summarizes the work of the National Fusion Collaboratory (NFC) Project to develop a persistent infrastructure to enable scientific collaboration for magnetic fusion research. The original objective of the NFC project was to develop and deploy a national FES Grid (FusionGrid) that would be a system for secure sharing of computation, visualization, and data resources over the Internet. The goal of FusionGrid was to allow scientists at remote sites to participate as fully in experiments and computational activities as if they were working on site thereby creating a unified virtual organization of the geographically dispersed U.S. fusion community. The vision for FusionGrid was that experimental and simulation data, computer codes, analysis routines, visualization tools, and remote collaboration tools are to be thought of as network services. In this model, an application service provider (ASP provides and maintains software resources as well as the necessary hardware resources. The project would create a robust, user-friendly collaborative software environment and make it available to the US FES community. This Grid's resources would be protected by a shared security infrastructure including strong authentication to identify users and authorization to allow stakeholders to control their own resources. In this environment, access to services is stressed rather than data or software portability