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Grid

About: Grid is a(n) research topic. Over the lifetime, 54335 publication(s) have been published within this topic receiving 787790 citation(s).

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Journal ArticleDOI: 10.1126/SCIENCE.1212741
18 Nov 2011-Science
Abstract: The increasing interest in energy storage for the grid can be attributed to multiple factors, including the capital costs of managing peak demands, the investments needed for grid reliability, and the integration of renewable energy sources. Although existing energy storage is dominated by pumped hydroelectric, there is the recognition that battery systems can offer a number of high-value opportunities, provided that lower costs can be obtained. The battery systems reviewed here include sodium-sulfur batteries that are commercially available for grid applications, redox-flow batteries that offer low cost, and lithium-ion batteries whose development for commercial electronics and electric vehicles is being applied to grid storage.

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Topics: Grid energy storage (67%), Intermittent energy source (65%), Energy storage (63%) ...read more

8,906 Citations


Journal ArticleDOI: 10.1177/109434200101500302
Ian Foster1, Carl Kesselman2, Steven Tuecke1Institutions (2)
01 Aug 2001-
Abstract: "Grid" computing has emerged as an important new field, distinguished from conventional distributed computing by its focus on large-scale resource sharing, innovative applications, and, in some cases, high performance orientation. In this article, the authors define this new field. First, they review the "Grid problem," which is defined as flexible, secure, coordinated resource sharing among dynamic collections of individuals, institutions, and resources--what is referred to as virtual organizations. In such settings, unique authentication, authorization, resource access, resource discovery, and other challenges are encountered. It is this class of problem that is addressed by Grid technologies. Next, the authors present an extensible and open Grid architecture, in which protocols, services, application programming interfaces, and software development kits are categorized according to their roles in enabling resource sharing. The authors describe requirements that they believe any such mechanisms must satisfy and discuss the importance of defining a compact set of intergrid protocols to enable interoperability among different Grid systems. Finally, the authors discuss how Grid technologies relate to other contemporary technologies, including enterprise integration, application service provider, storage service provider, and peer-to-peer computing. They maintain that Grid concepts and technologies complement and have much to contribute to these other approaches.

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Topics: Open Grid Services Architecture (69%), Semantic grid (67%), Grid computing (67%) ...read more

6,686 Citations


Open accessJournal ArticleDOI: 10.1088/0953-8984/21/8/084204
Wenjie Tang1, E. Sanville2, Graeme Henkelman1Institutions (2)
Abstract: A computational method for partitioning a charge density grid into Bader volumes is presented which is efficient, robust, and scales linearly with the number of grid points. The partitioning algorithm follows the steepest ascent paths along the charge density gradient from grid point to grid point until a charge density maximum is reached. In this paper, we describe how accurate off-lattice ascent paths can be represented with respect to the grid points. This improvement maintains the efficient linear scaling of an earlier version of the algorithm, and eliminates a tendency for the Bader surfaces to be aligned along the grid directions. As the algorithm assigns grid points to charge density maxima, subsequent paths are terminated when they reach previously assigned grid points. It is this grid-based approach which gives the algorithm its efficiency, and allows for the analysis of the large grids generated from plane-wave-based density functional theory calculations.

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  • Figure 7. The Bader surface in H2O is strongly dependent upon the orientation of the molecule with the on-grid method. This orientation dependence is due to the bias in the method which tends to orient the Bader surfaces along the grid directions. In the near-grid method, this bias is removed and the Bader surfaces are insensitive to the orientation of the molecule.
    Figure 7. The Bader surface in H2O is strongly dependent upon the orientation of the molecule with the on-grid method. This orientation dependence is due to the bias in the method which tends to orient the Bader surfaces along the grid directions. In the near-grid method, this bias is removed and the Bader surfaces are insensitive to the orientation of the molecule.
  • Figure 1. An illustration of the steepest ascent paths (a) on a charge density grid to find the Bader volumes using the on-grid analysis method. These ascent trajectories are constrained to the grid points, moving at each step to the neighboring grid point towards which the charge density gradient is maximized. Each trajectory either terminates at a new charge density maximum, mi , or at a grid point which has already been assigned. After all grid points are assigned (b), the set of points which terminate at each maximum (green to m1 and blue to m2) constitute that Bader volume. The Bader surfaces (red curved line) separate the volumes.
    Figure 1. An illustration of the steepest ascent paths (a) on a charge density grid to find the Bader volumes using the on-grid analysis method. These ascent trajectories are constrained to the grid points, moving at each step to the neighboring grid point towards which the charge density gradient is maximized. Each trajectory either terminates at a new charge density maximum, mi , or at a grid point which has already been assigned. After all grid points are assigned (b), the set of points which terminate at each maximum (green to m1 and blue to m2) constitute that Bader volume. The Bader surfaces (red curved line) separate the volumes.
  • Figure 2. Illustration of lattice bias in the on-grid method. The true dividing surface (red) runs parallel to the gradient lines, but the on-grid ascent trajectories follow the lattice direction along which the projection of the charge density gradient is maximized. Starting from the initial point, this direction is along +x and the trajectory moves from grid point to grid point in this direction. The error can be seen as the on-grid trajectory (straight blue arrows through the light-blue point) deviates from the true trajectory (solid blue curved arrow). The resulting dividing surface follows the x lattice direction instead of the true dividing surface.
    Figure 2. Illustration of lattice bias in the on-grid method. The true dividing surface (red) runs parallel to the gradient lines, but the on-grid ascent trajectories follow the lattice direction along which the projection of the charge density gradient is maximized. Starting from the initial point, this direction is along +x and the trajectory moves from grid point to grid point in this direction. The error can be seen as the on-grid trajectory (straight blue arrows through the light-blue point) deviates from the true trajectory (solid blue curved arrow). The resulting dividing surface follows the x lattice direction instead of the true dividing surface.
  • Figure 8. The calculated Bader charge on the O atom in a H2O molecule as it is rotated with respect to the charge density grid. The biased Bader surfaces in the on-grid method give rise to both systematic and orientation dependent errors as compared to the near-grid method, for which the Bader surfaces and O valance charge remain constant with orientation.
    Figure 8. The calculated Bader charge on the O atom in a H2O molecule as it is rotated with respect to the charge density grid. The biased Bader surfaces in the on-grid method give rise to both systematic and orientation dependent errors as compared to the near-grid method, for which the Bader surfaces and O valance charge remain constant with orientation.
  • Figure 9. Computer time required to analyze the charge density grid for the eight-atom NaCl cell with the near-grid algorithm. The computational cost scales linearly with the number of grid points in the charge density file, as with the on-grid method.
    Figure 9. Computer time required to analyze the charge density grid for the eight-atom NaCl cell with the near-grid algorithm. The computational cost scales linearly with the number of grid points in the charge density file, as with the on-grid method.
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Topics: Grid (57%), Charge density (51%)

4,300 Citations


Open accessJournal ArticleDOI: 10.1109/TIE.2006.881997
Abstract: Renewable energy sources like wind, sun, and hydro are seen as a reliable alternative to the traditional energy sources such as oil, natural gas, or coal. Distributed power generation systems (DPGSs) based on renewable energy sources experience a large development worldwide, with Germany, Denmark, Japan, and USA as leaders in the development in this field. Due to the increasing number of DPGSs connected to the utility network, new and stricter standards in respect to power quality, safe running, and islanding protection are issued. As a consequence, the control of distributed generation systems should be improved to meet the requirements for grid interconnection. This paper gives an overview of the structures for the DPGS based on fuel cell, photovoltaic, and wind turbines. In addition, control structures of the grid-side converter are presented, and the possibility of compensation for low-order harmonics is also discussed. Moreover, control strategies when running on grid faults are treated. This paper ends up with an overview of synchronization methods and a discussion about their importance in the control

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Topics: Distributed generation (66%), Intermittent energy source (63%), Wind power (63%) ...read more

4,134 Citations


Open accessPosted Content
Ian Foster1, Carl Kesselman2, Steven Tuecke1Institutions (2)
Abstract: "Grid" computing has emerged as an important new field, distinguished from conventional distributed computing by its focus on large-scale resource sharing, innovative applications, and, in some cases, high-performance orientation. In this article, we define this new field. First, we review the "Grid problem," which we define as flexible, secure, coordinated resource sharing among dynamic collections of individuals, institutions, and resources-what we refer to as virtual organizations. In such settings, we encounter unique authentication, authorization, resource access, resource discovery, and other challenges. It is this class of problem that is addressed by Grid technologies. Next, we present an extensible and open Grid architecture, in which protocols, services, application programming interfaces, and software development kits are categorized according to their roles in enabling resource sharing. We describe requirements that we believe any such mechanisms must satisfy, and we discuss the central role played by the intergrid protocols that enable interoperability among different Grid systems. Finally, we discuss how Grid technologies relate to other contemporary technologies, including enterprise integration, application service provider, storage service provider, and peer-to-peer computing. We maintain that Grid concepts and technologies complement and have much to contribute to these other approaches.

...read more

Topics: Grid (57%), Service provider (55%), Application service provider (55%) ...read more

3,595 Citations


Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202272
20212,243
20203,073
20193,277
20183,044
20172,914

Top Attributes

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Topic's top 5 most impactful authors

Bhim Singh

134 papers, 707 citations

Rajkumar Buyya

127 papers, 13.5K citations

Péter Kacsuk

122 papers, 2K citations

Ian Foster

84 papers, 21.4K citations

Thomas Fahringer

73 papers, 2.3K citations

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