title: UVisP: User-centric visualization of data provenance with gestalt principles

authors: Garae, Jeffery

subjects: computer science

abstract: The need to understand and track files (and inherently, data) in cloud computing systems is in high demand. Over the past years, the use of logs and data representation using graphs have become the main method for tracking and relating information to the cloud users. While being used, tracking related information with 'data provenance' (i.e. series of chronicles and the derivation history of data on metadata) is the new trend for cloud users. However, there is still much room for improving data activity representation in cloud systems for end-users. We propose 'User-centric Visualization of data provenance with Gestalt (UVisP)', a novel user-centric visualization technique for data provenance. This technique aims to facilitate the missing link between data movements in cloud computing environments and the end-users uncertain queries over their files security and life cycle within cloud systems. The proof of concept for the UVisP technique integrates an open-source visualization API with Gestalt's theory of perception to provide a range of user-centric provenance visualizations. UVisP allows users to transform and visualize provenance (logs) with implicit prior knowledge of 'Gestalt's theory of perception.' We presented the initial development of the UVisP technique and our results show that the integration of Gestalt and 'perceptual key(s)' in provenance visualization allows end-users to enhance their visualizing capabilities, to extract useful knowledge and understand the visualizations better.

text: UVisP: User-centric visualization of data provenance with gestalt principles The need to understand and track files (and inherently, data) in cloud computing systems is in high demand. Over the past years, the use of logs and data representation using graphs have become the main method for tracking and relating information to the cloud users. While being used, tracking related information with 'data provenance' (i.e. series of chronicles and the derivation history of data on metadata) is the new trend for cloud users. However, there is still much room for improving data activity representation in cloud systems for end-users. We propose 'User-centric Visualization of data provenance with Gestalt (UVisP)', a novel user-centric visualization technique for data provenance. This technique aims to facilitate the missing link between data movements in cloud computing environments and the end-users uncertain queries over their files security and life cycle within cloud systems. The proof of concept for the UVisP technique integrates an open-source visualization API with Gestalt's theory of perception to provide a range of user-centric provenance visualizations. UVisP allows users to transform and visualize provenance (logs) with implicit prior knowledge of 'Gestalt's theory of perception.' We presented the initial development of the UVisP technique and our results show that the integration of Gestalt and 'perceptual key(s)' in provenance visualization allows end-users to enhance their visualizing capabilities, to extract useful knowledge and understand the visualizations better.

year: 2016

title: A numerical study of diffusive cosmic-ray transport with adiabatic focusing

authors: Litvinenko, Yuri E.

subjects: cosmic rays

abstract: Focused particle transport in a nonuniform large-scale magnetic field is investigated numerically in the case of isotropic pitch-angle scattering. Evolving particle density profiles and distribution moments are computed from solutions of a system of stochastic differential equations, equivalent to the original Fokker-Planck equation for the particle distribution. Conflicting analytical predictions for the transport coefficients in the diffusion limit, independently calculated by Beeck & Wibberenz and Shalchi, are compared with the numerical results. The reasons for the discrepancies among the analytical and numerical treatments, as well as the general limitations of the diffusion model, are discussed. The telegraph equation, derived in a higher-order expansion of the particle distribution function, is shown to describe the particle transport much more accurately than the diffusion model, especially ahead of a moving density pulse.

text: A numerical study of diffusive cosmic-ray transport with adiabatic focusing Focused particle transport in a nonuniform large-scale magnetic field is investigated numerically in the case of isotropic pitch-angle scattering. Evolving particle density profiles and distribution moments are computed from solutions of a system of stochastic differential equations, equivalent to the original Fokker-Planck equation for the particle distribution. Conflicting analytical predictions for the transport coefficients in the diffusion limit, independently calculated by Beeck & Wibberenz and Shalchi, are compared with the numerical results. The reasons for the discrepancies among the analytical and numerical treatments, as well as the general limitations of the diffusion model, are discussed. The telegraph equation, derived in a higher-order expansion of the particle distribution function, is shown to describe the particle transport much more accurately than the diffusion model, especially ahead of a moving density pulse.

year: 2013

title: Biological flora of New Zealand 11. Eleochairs spacelata, kuta, paopao, bamboo spike sedge.

authors: Kapa, Mieke M

subjects: cultural

abstract: Information relevant to the ecology and morphology of Eleocharis sphacelata (Cyperaceae) available through published and unpublished sources is assembled and reviewed. Eleocharis sphacelata is a freshwater wetland sedge found growing at the edge of lake margins, swamps, lagoons, and bogs within New Zealand, Australia, and Papua New Guinea. It is a perennial rhizomatous herb, with tall green cylindrical culms rising from submerged rhizomes generally buried under water in aerobic soils. A tendency to dominate the deepwater margins makes E. sphacelata crucial to the ecology of this habitat as a source of food, shelter, and protection for invertebrates, birds, and fish. Eleocharis sphacelata is commonly named giant spike-rush, kuta, or paopao. Māori have traditionally used the plant for clothing and warm coverings within whare (houses). Recent interest comes from its use in restoration plantings and constructed wetlands.

text: Biological flora of New Zealand 11. Eleochairs spacelata, kuta, paopao, bamboo spike sedge. Information relevant to the ecology and morphology of Eleocharis sphacelata (Cyperaceae) available through published and unpublished sources is assembled and reviewed. Eleocharis sphacelata is a freshwater wetland sedge found growing at the edge of lake margins, swamps, lagoons, and bogs within New Zealand, Australia, and Papua New Guinea. It is a perennial rhizomatous herb, with tall green cylindrical culms rising from submerged rhizomes generally buried under water in aerobic soils. A tendency to dominate the deepwater margins makes E. sphacelata crucial to the ecology of this habitat as a source of food, shelter, and protection for invertebrates, birds, and fish. Eleocharis sphacelata is commonly named giant spike-rush, kuta, or paopao. Māori have traditionally used the plant for clothing and warm coverings within whare (houses). Recent interest comes from its use in restoration plantings and constructed wetlands.

year: 2009