659,927 research outputs found
Condor services for the Global Grid:interoperability between Condor and OGSA
In order for existing grid middleware to remain viable it is important to investigate their potentialfor integration with emerging grid standards and architectural schemes. The Open Grid ServicesArchitecture (OGSA), developed by the Globus Alliance and based on standard XML-based webservices technology, was the first attempt to identify the architectural components required tomigrate towards standardized global grid service delivery. This paper presents an investigation intothe integration of Condor, a widely adopted and sophisticated high-throughput computing softwarepackage, and OGSA; with the aim of bringing Condor in line with advances in Grid computing andprovide the Grid community with a mature suite of high-throughput computing job and resourcemanagement services. This report identifies mappings between elements of the OGSA and Condorinfrastructures, potential areas of conflict, and defines a set of complementary architectural optionsby which individual Condor services can be exposed as OGSA Grid services, in order to achieve aseamless integration of Condor resources in a standardized grid environment
Grid Integration of Robotic Telescopes
Robotic telescopes and grid technology have made significant progress in
recent years. Both innovations offer important advantages over conventional
technologies, particularly in combination with one another. Here, we introduce
robotic telescopes used by the Astrophysical Institute Potsdam as ideal
instruments for building a robotic telescope network. We also discuss the grid
architecture and protocols facilitating the network integration that is being
developed by the German AstroGrid-D project. Finally, we present three user
interfaces employed for this purpose.Comment: 4 pages, 5 Figures, refereed proceedings of "Hot-wiring the Transient
Universe", June 2007 (Tucson); version 2 including latex geometry package as
recommended by arXiv and minor changes as requested by AN except removal of
two figure
Spherical Harmonic Decomposition on a Cubic Grid
A method is described by which a function defined on a cubic grid (as from a
finite difference solution of a partial differential equation) can be resolved
into spherical harmonic components at some fixed radius. This has applications
to the treatment of boundary conditions imposed at radii larger than the size
of the grid, following Abrahams, Rezzola, Rupright et al.(gr-qc/9709082}. In
the method described here, the interpolation of the grid data to the
integration 2-sphere is combined in the same step as the integrations to
extract the spherical harmonic amplitudes, which become sums over grid points.
Coordinates adapted to the integration sphere are not needed.Comment: 5 pages, LaTeX uses cjour.cls (supplied
Recommended from our members
ASEAN grid flexibility: Preparedness for grid integration of renewable energy
In 2015, ASEAN established a goal of increasing its renewable energy share in its energy portfolio from approximately 13–23% by 2025. Renewable electricity, especially intermittent and variable sources, presents challenges for grid operators due to the uncertain timing and quantity of electricity supply. Grid flexibility, the electric grid's ability to respond to changing demands and supply, now stands a key resource in responding to these uncertainties while maximizing the cost-effective role of clean energy. We develop and apply a grid flexibility assessment tool to assess ASEAN's current grid flexibility using six quantitative indicators: grid reliability, electricity market access; load profile ramp capacity; quality of forecasting tools; proportion of electricity generation from natural gas; and renewable energy diversity. We find that ASEAN nations cluster into three groups: better; moderately; and the least prepared nations. We develop an analytical ramp rate calculator to quantify expected load ramps for ASEAN in an integrated ASEAN Power Grid scenario. The lack of forecasting systems and limited electricity market access represent key weaknesses and areas where dramatic improvements can become cost-effective means to increase regional grid flexibility. As ASEAN pursues renewable energy targets, regional cooperation remains essential to address identified challenges. Member nations need to increase grid flexibility capacity to adequately prepare for higher penetrations of renewable electricity and lower overall system costs
A Concept for Attribute-Based Authorization on D-Grid Resources
In Germany's D-Grid project numerous Grid communities are working together to provide a common overarching Grid infrastructure. The major aims of D-Grid are the integration of existing Grid deployments and their interoperability. The challenge lies in the heterogeneity of the current implementations: three Grid middleware stacks and different Virtual Organization management approaches have to be embraced to achieve the intended goals. In this article we focus oil the implementation of an attribute-based authorization infrastructure that not only leverages the well-known VO attributes but also campus attributes managed by a Shibboleth federation
Grid Integration Costs of Fluctuating Renewable Energy Sources
The grid integration of intermittent Renewable Energy Sources (RES) causes
costs for grid operators due to forecast uncertainty and the resulting
production schedule mismatches. These so-called profile service costs are
marginal cost components and can be understood as an insurance fee against RES
production schedule uncertainty that the system operator incurs due to the
obligation to always provide sufficient control reserve capacity for power
imbalance mitigation. This paper studies the situation for the German power
system and the existing German RES support schemes. The profile service costs
incurred by German Transmission System Operators (TSOs) are quantified and
means for cost reduction are discussed. In general, profile service costs are
dependent on the RES prediction error and the specific workings of the power
markets via which the prediction error is balanced. This paper shows both how
the prediction error can be reduced in daily operation as well as how profile
service costs can be reduced via optimization against power markets and/or
active curtailment of RES generation.Comment: Accepted for SUSTECH 2014, Portland, Oregon, USA, July 201
User oriented access to secure biomedical resources through the grid
The life science domain is typified by heterogeneous data sets that are evolving at an exponential rate. Numerous post-genomic databases and areas of post-genomic life science research have been established and are being actively explored. Whilst many of these databases are public and freely accessible, it is often the case that researchers have data that is not so freely available and access to this data needs to be strictly controlled when distributed collaborative research is undertaken. Grid technologies provide one mechanism by which access to and integration of federated data sets is possible. Combining such data access and integration technologies with fine grained security infrastructures facilitates the establishment of virtual organisations (VO). However experience has shown that the general research (non-Grid) community are not comfortable with the Grid and its associated security models based upon public key infrastructures (PKIs). The Internet2 Shibboleth technology helps to overcome this through users only having to log in to their home site to gain access to resources across a VO – or in Shibboleth terminology a federation. In this paper we outline how we have applied the combination of Grid technologies, advanced security infrastructures and the Internet2 Shibboleth technology in several biomedical projects to provide a user-oriented model for secure access to and usage of Grid resources. We believe that this model may well become the de facto mechanism for undertaking e-Research on the Grid across numerous domains including the life sciences
From access and integration to mining of secure genomic data sets across the grid
The UK Department of Trade and Industry (DTI) funded BRIDGES project (Biomedical Research Informatics Delivered by Grid Enabled Services) has developed a Grid infrastructure to support cardiovascular research. This includes the provision of a compute Grid and a data Grid infrastructure with security at its heart. In this paper we focus on the BRIDGES data Grid. A primary aim of the BRIDGES data Grid is to help control the complexity in access to and integration of a myriad of genomic data sets through simple Grid based tools. We outline these tools, how they are delivered to the end user scientists. We also describe how these tools are to be extended in the BBSRC funded Grid Enabled Microarray Expression Profile Search (GEMEPS) to support a richer vocabulary of search capabilities to support mining of microarray data sets. As with BRIDGES, fine grain Grid security underpins GEMEPS
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