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A Resource Management Architecture for Metacomputing Systems
, 1997
"... Metacomputing systems are intended to support remote and/or concurrent use of geographically distributed computational resources. Resource management in such systems is complicated by five concerns that do not typically arise in other situations: site autonomy and heterogeneous substrates at the ..."
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Cited by 465 (46 self)
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Metacomputing systems are intended to support remote and/or concurrent use of geographically distributed computational resources. Resource management in such systems is complicated by five concerns that do not typically arise in other situations: site autonomy and heterogeneous substrates at the resources, and application requirements for policy extensibility, coallocation, and online control. We describe a resource management architecture that addresses these concerns. This architecture distributes the resource management problem among distinct local manager, resource broker, and resource coallocator components and defines an extensible resource specification language to exchange information about requirements. We describe how these techniques have been implemented in the context of the Globus metacomputing toolkit and used to implement a variety of different resource management strategies. We report on our experiences applying our techniques in a large testbed, GUSTO, incorporating 15 sites, 330 computers, and 3600 processors.
High Performance Parametric Modeling with Nimrod/G: Killer Application for the Global Grid?
, 2000
"... This paper examines the role of parametric modeling as an application for the global computing grid, and explores some heuristics which make it possible to specify soft real time deadlines for larger computational experiments. We demonstrate the scheme with a case study utilizing the Globus toolkit ..."
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Cited by 286 (54 self)
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This paper examines the role of parametric modeling as an application for the global computing grid, and explores some heuristics which make it possible to specify soft real time deadlines for larger computational experiments. We demonstrate the scheme with a case study utilizing the Globus toolkit running on the GUSTO testbed. 1 Introduction Parametric computational experiments are becoming increasingly important in science and engineering as a means of exploring the behavior of complex systems. For example, an engineer may explore the behaviour of a wing by running a computational model of the airfoil multiple times while varying key parameters such as angle of attack, air speed, etc. The results of these multiple experiments yield a picture of how the wing behaves in different parts of parametric space. Over the past several years, we have developed a specialized parametric modeling system called Nimrod [1][2][3][17]. Nimrod uses a simple declarative parametric modeling language ...
A Directory Service for Configuring HighPerformance Distributed Computations
, 1997
"... Highperformance execution in distributed computing environments often requires careful selection and configuration not only of computers, networks, and other resources but also of the protocols and algorithms used by applications. Selection and configuration in turn require access to accurate, upt ..."
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Cited by 284 (56 self)
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Highperformance execution in distributed computing environments often requires careful selection and configuration not only of computers, networks, and other resources but also of the protocols and algorithms used by applications. Selection and configuration in turn require access to accurate, uptodate information on the structure and state of available resources. Unfortunately, no standard mechanism exists for organizing or accessing such information. Consequently, different tools and applications adopt ad hoc mechanisms, or they compromise their portability and performance by using default configurations. We propose a solution to this problem: a Metacomputing Directory Service that provides efficient and scalable access to diverse, dynamic, and distributed information about resource structure and state. We define an extensible data model to represent the information required for distributed computing, and we present a scalable, highperformance, distributed implementation. The dat...
A GridEnabled MPI: Message Passing in Heterogeneous Distributed Computing Systems
, 1998
"... Application development for highperformance distributed computing systems, or computational grids as they are sometimes called, requires "gridenabled" tools that hide mundane aspects of the heterogeneous grid environment without compromising performance. As part of an investigation of t ..."
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Cited by 122 (13 self)
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Application development for highperformance distributed computing systems, or computational grids as they are sometimes called, requires "gridenabled" tools that hide mundane aspects of the heterogeneous grid environment without compromising performance. As part of an investigation of these issues, we have developed MPICHG, a gridenabled implementation of the Message Passing Interface (MPI) that allows a user to run MPI programs across multiple computers at different sites using the same commands that would be usedonaparallel computer. This library extends the Argonne MPICH implementation of MPI to use services provided by the Globus grid toolkit. In this paper, we describe the MPICHG implementation and present preliminary performance results.
Structured Low Rank Approximation
 LINEAR ALGEBRA APPL
, 2002
"... This paper concerns the construction of a structured low rank matrix that is nearest to a given matrix. The notion of structured low rank approximation arises in various applications, ranging from signal enhancement to protein folding to computer algebra, where the empirical data collected in a matr ..."
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Cited by 16 (1 self)
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This paper concerns the construction of a structured low rank matrix that is nearest to a given matrix. The notion of structured low rank approximation arises in various applications, ranging from signal enhancement to protein folding to computer algebra, where the empirical data collected in a matrix do not maintain either the specified structure or the desirable rank as is expected in the original system. The task to retrieve useful information while maintaining the underlying physical feasibility often necessitates the search for a good structured lower rank approximation of the data matrix. This paper addresses some of the theoretical and numerical issues involved in the problem. Two procedures for constructing the nearest structured low rank matrix are proposed. The procedures are flexible enough that they can be applied to any lower rank, any linear structure, and any matrix norm in the measurement of nearness. The techniques can also be easily implemented by utilizing available optimization packages. The special case of symmetric Toeplitz structure using the Frobenius matrix norm is used to exemplify the ideas throughout the discussion. The concept, rather than the implementation details, is the main emphasis of the paper.
Structured Lower Rank Approximation
 Linear Algebra and Its Applications
, 1998
"... This paper discusses two general procedures for constructing the nearest approximation of a given matrix by one with any lower rank and any linear structure. Nearness can be measured in any matrix norm. Structured low rank matrices arise in various applications, including image enhancement and model ..."
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Cited by 1 (0 self)
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This paper discusses two general procedures for constructing the nearest approximation of a given matrix by one with any lower rank and any linear structure. Nearness can be measured in any matrix norm. Structured low rank matrices arise in various applications, including image enhancement and model reduction. In practice, the empirical data collected in the matrix often either do not maintain the specified structure or do not induce the desirable rank. It is therefore an important task to search for the nearest structured lower rank approximation of a given matrix. The techniques developed in this paper can easily be implemented for numerical computation. In particular, it is shown that the computations can be approached using efficient optimization packages. The special case of Toeplitz structure using the Frobenius matrix norm is discussed in detail to illustrate the ideas, and numerical tests are reported. The procedures developed herein can be generalized to consider a much broade...