• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.753-757
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• 2008

In this paper, we propose a new scheduling strategy for dynamic programming in Grid environment. The key idea of this scheme is to reduce the execution time of a job by dividing the dynamic table based on the locality of table and allocating jobs to nodes which minimize network latency. This scheme obtains optimal concurrency by constructing the dynamic table using a distributed top down method. Through simulation, we show that the proposed Grid strategy improves the performance of Grid environment compared to previous branch-bound strategies.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.107-110
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• 2002

A grid computing environment is one in which applications can be built over multiple resource nodes at widespread geographic locations. Grid environments seek to integrate and enable access to widely distributed compute resources. The compute resources in a grid environment are typically heterogeneous, with varying qualify and availability Hence, how computations are allocated to individual resources is extremely important in the design of a grid. This paper j\ulcorners concerned with resource management for metacomputing. We describe a resource management architecture using the two-level resource broker.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.71-77
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• 2002

The grid technology is believed to be the next generation research tool for both computational and experimental scientists. With advanced network technologies and middleware, geographically distributed facilities can be tightly connected to provided a huge amount of resources or remote accessibility, In this paper, an overview of grid technology will be introduced with an emphasis in application to computational fluid dynamics. The computational fluid dynamics, which involves solution of partial differential equations, is basically limited by the computing power, With the grid technology, virtually unlimited resources are provided. The schematic structure of middleware and grid environment, as well as some preliminary results are presented.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.224-226
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• 2005

Grid computing enables the fundamental computing shift from a localized resource computing model to a fully-distributed virtual organization with shared resources. In the grid computing environment, grid users usually get access rights by mapping their credential to local account. The mapped total account is temporally belongs to grid user. So, data on the secondary storage, which is produced by grid operation, can increase the load of system administration or can issue grid user's privacy. In this paper, we design a data management system for grid user to cover these problems. This system implements template account mechanism and manages local grid data.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.49-56
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• 2007

This paper deals with grid job allocation and grid resource scheduling to provide a stable and quicker job processing service to grid users. In this paper, we proposed a fuzzy logic-based grid job scheduling model for an effective job scheduling in computational grid environment. The fuzzy logic-based grid job scheduling model measures resource efficiency of all grid resources by a fuzzy logic system based on diverse input parameters like CPU speed and network latency and divides resources into several groups by resource efficiency. And, the model allocates jobs to resources of a group with the highest resource efficiency. For performance evaluation, we implemented the fuzzy logic-based grid job scheduling model on the DEVS modeling and simulation environment and measured reduction rates of turnaround time, job loss, and communication messages in comparison with existing job scheduling models such as the random scheduling model and the MCT(Minimum Completion time) model. Experiment results that the proposed model is useful to improve the QoS of the grid job processing service.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_1
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• pp.23-28
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• 2001

A new numerical weather prediction and dispersion model, the Operational Multi-scale Environment model with Grid Adaptivity(OMEGA) including an embedded Atmospheric Dispersion Model(ADM), is introduced as a next generation atmospheric simulation system for real-time hazard predictions, such as severe weather or the transport of hazardous release. OMEGA is based on an unstructured grid that can facilitate a continuously varying horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from 20 -30 meters in the boundary layer to 1 km in the free atmosphere. OMEGA is also naturally scale spanning and time. In particular, the unstructured grid cells in the horizontal dimension can increase the local resolution to better capture the topography or important physical features of the atmospheric circulation and cloud dynamics. This means the OMEGA can readily adapt its grid to a stationary surface, terrain features, or dynamic features in an evolving weather pattern. While adaptive numerical techniques have yet to be extensively applied in atmospheric models, the OMEGA model is the first to exploit the adaptive nature of an unstructured gridding technique for atmospheric simulation and real-time hazard prediction. The purpose of this paper is to provide a detailed description of the OMEGA model, the OMEGA system, and a detailed comparison of OMEGA forecast results with observed data.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.47-50
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• 2005

The Grid'[1] means the collaboration of computing and experimental resources in dispersed organizations by high-speed network. It has been paid much attention for an unlimited number of potential resources available and the easiness to build collaborative environments among multiple disciplines. However, the difficulty in establishing the environments and accessing and utilizing the resources has prevented application scientists from conducting Grid computing. Thus, the present study focuses on building PSE(Problem Solving Environment) which assists application researchers to easily access and utilize the Grid. The Cactus toolkit, originally developed by astrophysicists, is used as a base frame for Grid PSE. Some modules are newly developed and modified for CFD(Computational Fluid Dynamics) analysis. Simultaneously, a web portal, Grid-One portal, is built for remote monitoring/control and job migration. Cactus frame through the web portal service has been applied to various CFD problems, demonstrating that the developed PSE is valuable for large-scaled applications on the Grid.

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.19-26
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• 2007

In recent rears. web portal system has received much attention as a user interface for the grid environment. Grid system uses symmetric key for authenticating user identity while the traditional portal system does a password-based authentication. Regarding this, many researches are progressing to integrate portal accounts with symmetric key. Specially. researches such as GAMA and PURSE are active and those focus on easy usability for users who familiar with password-based authentication. However the protection of data and resources is a critical issue in Grid environment, because those are shared through a wide-area network. In this paper, we suggest a new authentication mechanism which unify authentication mechanisms between portal system and grid service by using symmetric key. It will improve a security level in UI layer as much as in grid service.

• The KIPS Transactions:PartA
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• v.12A no.2 s.92
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• pp.161-170
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• 2005

Grid makes a virtual high-performance computing resource by connecting geographically distributed heterogeneous resources. Building access control system is an important factor In the grid environment In this paper, we design and implement a grid access control system based on Globus Toolkit, which is one of the popular grid middleware. Especially, to guarantee the site autonomy for resource provider, we use several environment configuration files. Moreover, we design and implement PGAM to produce more detail and diverse information to ease the development of value added services.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.228-231
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• 2015

In power system research fields, one of current key issues is the construction and commercialization of micro grid site which is called green island, carbon zero island, energy independent island, building micro grid, etc. and various affiliated technologies have been being vigorously developed to realize. In addition, various researches about electric vehicles (EVs) are in progress and it is expected to penetrate rapidly with the next a few years. Some new load models should be developed integrating with electric vehicle loads because the EVs' deployment could cause the change of load composition rate on power system planning and operations. EVs are also resources for micro grid as well as distributed generation and demand response so that various supply and demand side resources should be considered for micro grid researches. In this paper, the load composition rate of residential sectors is prospected considering the deployment of EVs and the resource configuration of micro grid is optimized based on net present cost. In the optimization, the load patten of case studies includes EV's charging characteristics and various cases are simulated comparing micro grid environment and normal condition. HOMER is used to compare various cases and economic effects.