4,484 research outputs found

    HotGrid: Graduated Access to Grid-based Science Gateways

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    We describe the idea of a Science Gateway, an application-specific task wrapped as a web service, and some examples of these that are being implemented on the US TeraGrid cyberinfrastructure. We also describe HotGrid, a means of providing simple, immediate access to the Grid through one of these gateways, which we hope will broaden the use of the Grid, drawing in a wide community of users. The secondary purpose of HotGrid is to acclimate a science community to the concepts of certificate use. Our system provides these weakly authenticated users with immediate power to use the Grid resources for science, but without the dangerous power of running arbitrary code. We describe the implementation of these Science Gateways with the Clarens secure web server

    SOAP Services with Clarens: Guide for Developers and Administrators

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    The Clarens application server enables secure, asynchronous SOAP services to run on a Grid cluster such as one of those of the TeraGrid. There is a Client, who wants to use the service and understands the application domain enough to form a reasonable service request; a Developer, who is a power-user of the TeraGrid, who understands both Clarens and the application domain, and creates and deploys a service on a TeraGrid head node; and there is a Root system administrator, who controls the Clarens installation and the cluster on which it runs. The purpose of this document is to provide all of the information a service developer needs to know in order to deploy a Clarens service, with information also provided for the system administrator of the Clarens installation. First we discuss how each of the three roles see the service

    Embers in the Ashes: Apocalyptic Horror and the Creative Process

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    A thesis submitted alongside a published work of fiction for the qualification of PhD (by Publication) at the University of Huddersfield. The essay reflects upon the conception, development and revision of One (2009), a novel of apocalyptic fiction. The peculiar creative process attendant to this sub-genre is explored with reference to various external global socio-political forces. Comparisons with analogous texts are made, and an assessment offered as to where One stands both as a unique document and as a supplement to a deep-rooted tradition of literature

    Population Genetics of Rice Rats (Oryzomys palustris) at the Northern Edge of the Species Range

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    The marsh rice rat (Oryzomys sp.) is a semiaquatic rodent native to wetlands in the southeastern United States. The northwestern-most part of the rice rat’s range extends to Illinois where rice rats are found in wetlands across the southern part of the state. Recent studies have shown that rice rats in the United States can be divided into two species: O. palustris and O. texensis, but the taxonomic status of rice rats in Southern Illinois is unclear. To resolve this, I sequenced cytochrome-b and the control region, two regions of mitochondrial DNA, for 16 rice rats and constructed a phylogeny using these new sequences and previously obtained O. palustris and O. texensis sequences. In contrast to previous morphological assessments, I found that rice rats in Southern Illinois should be classified as O. texensis. This would extend the range of O. texensis north and west from its current extent. Further investigation using nuclear loci will be needed to confirm this classification

    Canonical Completeness in Lattice-Based Languages for Attribute-Based Access Control

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    The study of canonically complete attribute-based access control (ABAC) languages is relatively new. A canonically complete language is useful as it is functionally complete and provides a "normal form" for policies. However, previous work on canonically complete ABAC languages requires that the set of authorization decisions is totally ordered, which does not accurately reflect the intuition behind the use of the allow, deny and not-applicable decisions in access control. A number of recent ABAC languages use a fourth value and the set of authorization decisions is partially ordered. In this paper, we show how canonical completeness in multi-valued logics can be extended to the case where the set of truth values forms a lattice. This enables us to investigate the canonical completeness of logics having a partially ordered set of truth values, such as Belnap logic, and show that ABAC languages based on Belnap logic, such as PBel, are not canonically complete. We then construct a canonically complete four-valued logic using connections between the generators of the symmetric group (defined over the set of decisions) and unary operators in a canonically suitable logic. Finally, we propose a new authorization language PTaCL4â©˝\text{PTaCL}_{\sf 4}^{\leqslant}, an extension of PTaCL, which incorporates a lattice-ordered decision set and is canonically complete. We then discuss how the advantages of PTaCL4â©˝\text{PTaCL}_{\sf 4}^{\leqslant} can be leveraged within the framework of XACML

    On Completeness in Languages for Attribute-Based Access Control

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    Attribute Expressions, Policy Tables and Attribute-Based Access Control

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