• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.87-94
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• 2006

Grid computing has been developed for resolving large-scaled computing problems through geographically distributed heterogeneous resources. In order to guarantee effective and reliable job processing, grid computing needs resource scheduling model. So, we propose a resource performance measurement scheduling model which allocates job to resources with resource performance measurement. We assess resources using resource performance measurement formula, and implement the resource performance measurement scheduling model in DEVS simulation modeling.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.285-292
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• 2019

Path planning is an important problem to solve in robotics and there has been many related studies so far. In the previous research, we proposed the Heterogeneous-Ants-Based Path Planner (HAB-PP) for the global path planning of mobile robots. The conventional path planners using grid map had discrete state transitions that constrain the only movement of an agent to multiples of 45 degrees. The HAB-PP provided the smoother path using the heterogeneous ants unlike the conventional path planners based on Ant Colony Optimization (ACO) algorithm. The planner, however, has the problem that the optimization of the path once found is fast but it takes a lot of time to find the first path to the goal point. Also, the HAB-PP often falls into a local optimum solution. To solve these problems, this paper proposes an improved ant-inspired path planner using the Rapidly-exploring Random Tree-star ($RRT^*$). The key ideas are to use $RRT^*$ as the characteristic of another heterogeneous ant and to share the information for the found path through the pheromone field. The comparative simulations with several scenarios verify the performance of the improved HAB-PP.

• Journal of KIISE:Information Networking
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• v.31 no.5
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• pp.450-459
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• 2004

This paper studies the collective communication in the grid computing environment, which is characterized by the combination of heterogeneous networks as well as uneven, long communication delay. Efficient collective communication requires communication schedule, which in turn requires network information. When the network information is not accurate or network faults occur, the performance of collective communication can be markedly degraded. This paper proposes TTCC(Two-Tree Collective Communication) for scheduling collective communication in the grid. It Provides an efficient and reliable schedule even In this unfavorable network condition by maintaining two disjoint communication trees. Benefits of the proposed method are manifested via simulation, where the performance degradation with TTCC is much slower than those using conventional scheduling algorithms.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.97-106
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• 2002

Grid makes it possible to cooperate with other network area by sharing and using distributed resources. In order to manage effectively large-scale Grid network resources, Grid NOC needs monitoring architecture that can manage distributed resources in one time. Being restricted within specific managing area, conventional network management system has limitation in extension of managing area and in general management of heterogeneous resource. In this paper, we design a monitoring architecture that can take in the situation and has scalability. In the monitoring architecture the network areas publish information in a common directory service, and then Grid NOC can connect to the network areas directly by using this information. Therefore, it makes us possible to manage overall large-scale resource of Grid network reducing load.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.4
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• pp.90-99
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• 2002

Grid makes it possible to cooperate with other network area by sharing and using distributed resources. In order to manage effectively large-scale Grid network resources, Grid NOC needs monitoring architecture that can manage distributed resources in one time. Being restricted within specific managing area conventional network management system has limitation in extension of managing area and in general management of heterogeneous resource. In this paper, we design a monitoring architecture that can take in the situation and has scalability. In the monitoring architecture the network areas publish information in a common directory service, and then Grid NOC can connect to the network areas directly by using this information. Therefore, it makes us possible to manage overall large-scale resource of Grid network reducing load.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1103-1106
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• 2008

Data Grid is a kind of Grid computing provides the cooperative environment through the distributed data sharing, and can manage the massive data easily and efficiently. We designed and implemented Globus Toolkit4 (GT4) based database access and integration service (GDAIS). This service was implemented as Grid service for run on the GT4 which is Grid middleware. And it provides functions which are automatic registration of database in virtual organization, distributed query service, and the unified user interface. Also this system can use components which are provided from GT4. Therefore it can improve the efficiency to distribute and manage databases, can easily access and integrate of the distributed heterogeneous data in Grid environments.

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.33-42
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• 2016

Spacer grids play an important role in maintaining the proper form of the fuel assembly structure and ensuring the safety of reactor core design. This study applies the Monte Carlo method to the analysis of the neutronics effects of spacer grids in a typical pressurized water reactor (PWR). The core problem used to analyze the neutronics effects of spacer grids is a modified version of Korea Advanced Institute of Science and Technology benchmark problem 1B, based on an Advanced Power Reactor 1400 (APR1400) core model. The spacer grids are modeled and added to this test problem in various ways. Then, by running MCNP5 for all cases of spacer grid modeling, some important numerical results, such as the effective multiplication factor, the spatial distributions of neutron flux, and its energy spectrum are obtained. The numerical results of each case of spacer grid modeling are analyzed and compared to assess which type has more advantages in accuracy of numerical results and effectiveness in terms of geometry building. The conclusion is that the most realistic modeling for Monte Carlo calculation is the "volume-preserving" streamlined heterogeneous spacer grids, but the "banded" dissolution spacer grids modeling is a more practical yet accurate model for routine (deterministic) analysis.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.137-142
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• 2008

In this paper, we describe TIGRIS Grid MPI Service, which is 4he WS-Resource Framework (WSRF) based services to enable an MPI job to be executed on Grid environments. It covers heterogeneous compute resources and diverse MPI libraries. The main functionalities are as follows. First, it allows an MPI user to seamlessly launch a job without knowing how to use the specific MPI library. Secondly, it executes an MPI job on the cross-site resources by supporting the Grid-enabled MPI library such as MPICH-G2. Thirdly, it enables the user to launch a job using the source code without compiling. The service is implemented on top of the services of Globus Toolkit. We provide the user interface as a web portal and CLI(Command Line Interface).

• 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.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2001.06a
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• pp.151-152
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• 2001

A common problem of the model simulations of the land surface - atmosphere interaction is to choose the appropriate spatial scale and resolution at which the simulations are to be performed. The accuracy of energy and water exchange predictions between the land surface and the atmosphere in regional and global scale atmospheric models is mainly influenced by: model simplifications applied to describe the spatial heterogeneity of land surface properties within individual grid cells; ignoring the variability of sub-grid properties (e.g. relief, vegetation, soils), and; lacks of necessary input meteorological and biophysical data.(omitted)