The Experts below are selected from a list of 29724 Experts worldwide ranked by ideXlab platform
Ajith Abraham - One of the best experts on this subject based on the ideXlab platform.
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hybrid metaheuristic algorithm for job scheduling on Computational Grids
Informatica (lithuanian Academy of Sciences), 2013Co-Authors: Zahra Pooranian, Mohammad Shojafar, Reza Tavoli, Mukesh Singhal, Ajith AbrahamAbstract:The dynamic nature of grid resources and the demands of users produce complexity in the grid scheduling problem that cannot be addressed by deterministic algorithms with polynomial complexity. One of the best methods for grid scheduling is the genetic algorithm (GA); the simple and parallel features of this algorithm make it applicable to several optimization problems. A GA searches the problem space globally and is unable to search locally. Therefore, scholars have investigated combining GAs with other meta-heuristic methods to resolve the local search problem. This is the focus of the present contribution, where we have developed a new hybrid scheduling algorithm GGA that combines GA and the gravitational emulation local search (GELS) algorithm. The noteworthy feature of the proposed optimal scheduler is that it decreases runtime and the number of submitted tasks whose deadlines are missed. A comparison of the performance of our proposed joint optimal scheduler to similar methods shows that it produces more optimal computation time.
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scheduling jobs on Computational Grids using a fuzzy particle swarm optimization algorithm
Future Generation Computer Systems, 2010Co-Authors: Hongbo Liu, Ajith Abraham, Aboul Ella HassanienAbstract:Grid computing is a Computational framework used to meet growing Computational demands. This paper introduces a novel approach based on Particle Swarm Optimization (PSO) for scheduling jobs on Computational Grids. The representations of the position and velocity of the particles in conventional PSO is extended from the real vectors to fuzzy matrices. The proposed approach is to dynamically generate an optimal schedule so as to complete the tasks within a minimum period of time as well as utilizing the resources in an efficient way. We evaluate the performance of the proposed PSO algorithm with a Genetic Algorithm (GA) and Simulated Annealing (SA) approach. Empirical results illustrate that an important advantage of the PSO algorithm is its speed of convergence and the ability to obtain faster and feasible schedules.
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Computational models and heuristic methods for grid scheduling problems
Future Generation Computer Systems, 2010Co-Authors: Fatos Xhafa, Ajith AbrahamAbstract:In this paper we survey Computational models for Grid scheduling problems and their resolution using heuristic and meta-heuristic approaches. Scheduling problems are at the heart of any Grid-like Computational system. Different types of scheduling based on different criteria, such as static versus dynamic environment, multi-objectivity, adaptivity, etc., are identified. Then, heuristic and meta-heuristic methods for scheduling in Grids are presented. The paper reveals the complexity of the scheduling problem in Computational Grids when compared to scheduling in classical parallel and distributed systems and shows the usefulness of heuristic and meta-heuristic approaches for the design of efficient Grid schedulers. We also discuss on requirements for a modular Grid scheduling and its integration with Grid architecture.
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an auction method for resource allocation in Computational Grids
Future Generation Computer Systems, 2010Co-Authors: Hesam Izakian, Ajith Abraham, Behrouz Tork LadaniAbstract:A Computational grid is composed of a set of resource consumers and resources providers. Usually these entities are independent and making decisions autonomously based on their policies and resource allocation in such systems is a challenging problem. In such systems using market-like techniques for this problem regulates the supply and demand for resources, provides an incentive for providers, and motivates the users to trade-off between deadline, budget, and the required level of quality of service. In this paper, we introduce a continuous double auction method (CDA) for grid resource allocation in which resources are considered as provider agents and users as consumer agents. In our proposed method these entities are allowed to participate in a grid independently and make decisions autonomously. We study this method in terms of economic efficiency and system performance. Experimental results illustrate that the proposed method is efficient in terms of successful execution rates, resource utilization rates and fair profit allocation.
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nature s heuristics for scheduling jobs on Computational Grids
International Conference on Advanced Computing, 2000Co-Authors: Ajith Abraham, Rajkumar Buyya, Baikunth NathAbstract:Computational Grid (Grid Computing) is a new paradigm that will drive the computing arena in the new millennium. Unification of globally remote and diverse resources, coupled with the increasing Computational needs for Grand Challenge Applications (GCA) and accelerated growth of the Internet and communication technology will further fuel the development of global Computational power Grids. In this paper, we attempt to address the scheduling of jobs to the geographically distributed computing resources. Conventional wisdom in the field of scheduling is that scheduling problems exhibit such richness and variety that no single scheduling method is sufficient. Heuristics derived from the nature has demonstrated a surprising degree of effectiveness and generality for handling combinatorial optimization problems. This paper begins with an introduction of Computational Grids followed by a brief description of the three nature's heuristics namely Genetic Algorithm (GA), Simulated Annealing (SA) and Tabu Search (TS). Experimental results using GA are included. We further demonstrate the hybridized usage of the above algorithms that can be applied in a Computational grid environment for job scheduling.
Bin Wang - One of the best experts on this subject based on the ideXlab platform.
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advection errors in an orthogonal terrain following coordinate idealized experiments
Chinese Science Bulletin, 2015Co-Authors: Li Yiyuan, Bin Wang, L I Jinxi, Xun ZouAbstract:The orthogonal curvilinear terrain-following coordinate (OS-coordinate) can create smooth vertical layers and orthogonal vertical Computational Grids, therefore reducing the advection errors in the classic terrain-following coordinate. The reduction of advection errors by the OS-coordinate had been validated by the idealized experiments using one kind of terrain and one kind of resolution. We have implemented two more types of 2D linear advection experiments to further analyze the advection errors of the OS-coordinate. The first experiment is to use three kinds of terrain which are one-crest, three-crest, and five-crest wavelike terrain (multi-mountain experiment). And the second experiment is to use five different horizontal (vertical) resolutions (multi-resolution experiment). In both types of the experiments, we compare the advection errors in the OS-coordinate with those in the corresponding hybrid terrainfollowing coordinate (HS-coordinate) to investigate the effect of the OS-coordinate on reducing the advection errors. For the multimountain experiment, the advection errors in the OS-coordinate and those in the HS-coordinate are almost the same in one-crest terrain experiments. And in the three-crest terrain experiments, the advection errors in the OS-coordinate are slightly smaller than those in the HS-coordinate. However, in the five-crest terrain experiment (complex terrain), the advection errors in the OS-coordinate are much reduced comparing with those in the HS-coordinate. This reason is that the OS-coordinate creates the orthogonal Computational Grids while the HS-coordinate creates the non-orthogonal Computational Grids. And the differences between these two Grids are most significant in the five-crest terrain experiments. Moreover, the differences between these two Grids actually represent the different quality of them. This indicates that the OS-coordinate can reduce the advection errors comparing with the corresponding hybrid terrain-following coordinate above the complex terrain, through improving the quality of the vertical Computational Grids. For the multi-resolution experiments, the advection errors in the OS-coordinate are always smaller than those in the HS-coordinate, and more importantly, the higher the vertical resolution is, the greater the reduction of the advection errors by the OS-coordinate is. All the results obtained by the idealized experiments in this paper indicate that the OS-coordinate may reduce the advection errors near the complex terrain in a high-resolution model.
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an orthogonal terrain following coordinate and its preliminary tests using 2 d idealized advection experiments
Geoscientific Model Development, 2014Co-Authors: Bin Wang, Donghai Wang, Lianhui DongAbstract:Abstract. We have designed an orthogonal curvilinear terrain-following coordinate (the orthogonal σ coordinate, or the OS coordinate) to reduce the advection errors in the classic σ coordinate. First, we rotate the basis vectors of the z coordinate in a specific way in order to obtain the orthogonal, terrain-following basis vectors of the OS coordinate, and then add a rotation parameter b to each rotation angle to create the smoother vertical levels of the OS coordinate with increasing height. Second, we solve the corresponding definition of each OS coordinate through its basis vectors; and then solve the 3-D coordinate surfaces of the OS coordinate numerically, therefore the Computational Grids created by the OS coordinate are not exactly orthogonal and its orthogonality is dependent on the accuracy of a numerical method. Third, through choosing a proper b, we can significantly smooth the vertical levels of the OS coordinate over a steep terrain, and, more importantly, we can create the orthogonal, terrain-following Computational Grids in the vertical through the orthogonal basis vectors of the OS coordinate, which can reduce the advection errors better than the corresponding hybrid σ coordinate. However, the convergence of the grid lines in the OS coordinate over orography restricts the time step and increases the numerical errors. We demonstrate the advantages and the drawbacks of the OS coordinate relative to the hybrid σ coordinate using two sets of 2-D linear advection experiments.
R Schneider - One of the best experts on this subject based on the ideXlab platform.
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arbitrary high order finite volume methods for electromagnetic wave propagation
Computer Physics Communications, 2006Co-Authors: Thomas Schwartzkopff, Frieder Lorcher, Clausdieter Munz, R SchneiderAbstract:Problems in electromagnetic wave propagation often require high accuracy approximations with low resolution Computational Grids. For non-stationary problems such schemes should possess the same approximation order in space and time. In the present article we propose for electromagnetic applications an explicit class of robust finite-volume (FV) schemes for the Maxwell equations. To achieve high accuracy we combine the FV method with the so-called ADER approach resulting in schemes which are arbitrary high order accurate in space and time. Numerical results and convergence investigations are shown for two and three-dimensional test cases on Cartesian Grids, where the used FV-ADER schemes are up to 8th order accurate in both space and time.
Andre Ribes - One of the best experts on this subject based on the ideXlab platform.
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a parallel corba component model for numerical code coupling
IEEE International Conference on High Performance Computing Data and Analytics, 2003Co-Authors: Christian Pérez, Andre RibesAbstract:The fast growth of high bandwidth wide area networks has allowed the building of Computational Grids, which are constituted of PC clusters and/or parallel machines. Computational Grids enable the design of new numerical simulation applications. For example, it is now feasible to couple several scientific codes to obtain a multi-physic application. In order to handle the complexity of such aplications, software component technology appears very appealing. However, most current software component models do not provide any support to transparently and efficiently embed parallel codes into components. This paper deals with GridCCM, an extension to the CORBA Common Object Request Broker Architecture Component Model to support parallel components. The feasibility of the model is evaluated thanks to its implementation on top of two CCM prototypes. Preliminary performance results are very good; there is no significant overhead while aggregating the network bandwidth capability of a parallel component.
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a parallel corba component model for numerical code coupling
Grid Computing, 2002Co-Authors: Christian Pérez, Andre RibesAbstract:The fast growth of high bandwidth wide area networks has allowed the building of Computational Grids, which are constituted of PC clusters and/or parallel machines. Computational Grids enable the design of new numerical simulation applications. For example, it is now feasible to couple several scientific codes to obtain a multi-physic application. In order to handle the complexity of such applications, software component technology appears very appealing. However, most current software component models provide no support to transparently and efficiently embed parallel codes into components. This paper describes a first study of GridCCM, an extension to the CORBA Component Model to support parallel components. The feasibility of the model is evaluated thanks to its implementation on top of two CCM prototypes. Preliminary performance results show that bandwidth is efficiently aggregated.
Christian Pérez - One of the best experts on this subject based on the ideXlab platform.
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generic application description model toward automatic deployment of applications on Computational Grids
Grid Computing, 2005Co-Authors: Sebastien Lacour, Christian Pérez, Thierry PriolAbstract:Computational Grids promise to deliver a huge computer power as transparently as the electric power grid supplies electricity. Thus, applications need to be automatically deployed on Computational Grids. However, various types of applications may be run on a grid, so it may not be wise to design an automatic deployment tool for each specific programming model. This paper promotes a generic application description model which can express several specific application descriptions. Translating a specific application description into our generic description is a simple task. Then, developing new planning algorithms and re-using them for different application types will be much easier. Moreover, our generic description model allows to deploy applications based on a programming model combining several models, as parallel components encompass component-based and parallel programming models for instance. Our generic description model is implemented in an automatic deployment tool which can deploy CCM and MPICH-G2 applications.
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a parallel corba component model for numerical code coupling
IEEE International Conference on High Performance Computing Data and Analytics, 2003Co-Authors: Christian Pérez, Andre RibesAbstract:The fast growth of high bandwidth wide area networks has allowed the building of Computational Grids, which are constituted of PC clusters and/or parallel machines. Computational Grids enable the design of new numerical simulation applications. For example, it is now feasible to couple several scientific codes to obtain a multi-physic application. In order to handle the complexity of such aplications, software component technology appears very appealing. However, most current software component models do not provide any support to transparently and efficiently embed parallel codes into components. This paper deals with GridCCM, an extension to the CORBA Common Object Request Broker Architecture Component Model to support parallel components. The feasibility of the model is evaluated thanks to its implementation on top of two CCM prototypes. Preliminary performance results are very good; there is no significant overhead while aggregating the network bandwidth capability of a parallel component.
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a parallel corba component model for numerical code coupling
Grid Computing, 2002Co-Authors: Christian Pérez, Andre RibesAbstract:The fast growth of high bandwidth wide area networks has allowed the building of Computational Grids, which are constituted of PC clusters and/or parallel machines. Computational Grids enable the design of new numerical simulation applications. For example, it is now feasible to couple several scientific codes to obtain a multi-physic application. In order to handle the complexity of such applications, software component technology appears very appealing. However, most current software component models provide no support to transparently and efficiently embed parallel codes into components. This paper describes a first study of GridCCM, an extension to the CORBA Component Model to support parallel components. The feasibility of the model is evaluated thanks to its implementation on top of two CCM prototypes. Preliminary performance results show that bandwidth is efficiently aggregated.