• KCID journal
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• v.21 no.1
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• pp.127-140
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• 2014

Recently drastic climate changes(e.g., extreme floods and droughts) are often taking place around the world. Even an increase in uncertainty, population, and mega cities has caused drastic changes in water recycle process. As in other countries, Korea has faced some issues relevant to water security. In response to these changes, Smart Water Grid(SWG) system combining the current water resources management with ICT (Information and Communications Technology) is considered as a new paradigm for the Korean water resources management. This study aims to explore and identify influential factors contributing to the SWG system's application to analyze the importance and role of those factors, and then to offer a policy suggestion for the successful application of the SWG system along with legislative improvements in Korea. In this study, we looked at different barriers related to the SWG application and also the complicated Korean water laws, enacted by different ministries and in order to efficiently apply the SWG system to the current Korean water resources management structures. This study employed qualitative research methods to analyze and identify the priorities of the tasks to be implemented by analyzing conditions for the SWG application, especially related to multi water sources and micro water grid, because legal and institutional measures can be more important to manage conflicts between different stakeholders once the SWG enters a phase of standardization and commercialization from its development stage.

• Journal of computational fluids engineering
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• v.20 no.1
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• pp.26-31
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• 2015

A grid generation program for specific problems is introduced. The program allows users to easily generate grid system for specific geometry such as an airfoil, cylinder, wedge, flat plate, and nozzle. Generating grid system for those problems can be proceeded with minimum user inputs such as geometry-defining parameters and grid-defining parameters. By using this program learning stage for preprocessing of CFD application can be efficiently shorten and novice students can learn and acquire experience by trying out grid generation and CFD solution by themselves.

• 연구논문집
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• s.25
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• pp.67-76
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• 1995

A grid generation algorithm associated with turbomachinery cascade flow fields has been developed. The present grid generation system consists of four separate modules. The system input is made of the results of the preliminary design, i.e., flow-path, aerodynamic conditions along the spanwise direction, and the blade profile data. The grid generation method generates a series of two-dimensional grids in the blade-to-blade passage to build up the three-¬dimensional grid, The numerical algorithm adopts the combination of the algebraic and elliptic method to create the internal grids efficiently and quickly. The resultant grids generated from each module of the system are used as the preprocessor for the performance prediction of the turbomachinery blade using Naveir-Stokes method in addition to the blade surface modelling for CAD data. For purposes of illustration, the grid generation system is applied to several complex geometries inculding a turbine rotor with and without a tip flow grid. Application to the blade design of the LP compressor was demonstrated to be very reliable and practical in support of design activities. This customized system are coupled strongly with the design procedure and reduces the man-hours required to predict the aerodynamic performance of the turbomachinery cascades using the CFD technique.

• Journal of computational fluids engineering
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• v.12 no.4
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• pp.68-73
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• 2007

Computational Fluid Dynamics (CFD) approach is now playing an important role in the engineering process in these days. Generating proper grid system in time for the region of interest is prerequisite for the efficient numerical calculation of flow physics using CFD approach. Grid generation is, however, usually considered as a major obstacle for a routine and successful application of numerical approaches in the engineering process. CFD approach based on the unstructured grid system is gaining popularity due to its simplicity and efficiency for generating grid system compared to the structured grid approaches, especially for complex geometries. In this paper an automated triangular surface grid generation using CAD(Computer Aided Design) surface data is proposed. According to the present method, the CAD surface data imported in the STL(Stereo-lithography) format is processed to identify feature edges defining the topology and geometry of the surface shape first. When the feature edges are identified, node points along the edges are distributed. The initial fronts which connect those feature edge nodes are constructed and then they are advanced along the CAD surface data inward until the surface is fully covered by triangular surface grid cells using Advancing Front Method. It is found that this approach can be implemented in an automated way successfully saving man-hours and reducing human-errors in generating triangular surface grid system.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.91-100
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• 2005

Grid computing is widely applicable to various fields of industry including process control and manufacturing, military command and control, transportation management, and so on. In a viewpoint of application area, grid computing can be classified to three aspects that are computational grid, data grid and access grid. This paper focuses on computational grid which handles complex and large-scale computing problems. Computational grid is characterized by system dynamics which handles a variety of processors and jobs on continuous time. To solve problems of system complexity and reliability due to complex system dynamics, computational grid needs scheduling policies that allocate various jobs to proper processors and decide processing orders of allocated jobs. This paper proposes a service prediction-based job scheduling model and present its scheduling algorithm that is applicable for computational grid. The service prediction-based job scheduling model can minimize overall system execution time since the model predicts the next processing time of each processing component and distributes a job to a processing component with minimum processing time. This paper implements the job scheduling model on the DEVS modeling and simulation environment and evaluates its efficiency and reliability. Empirical results, which are compared to conventional scheduling policies, show the usefulness of service prediction-based job scheduling.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.29-33
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• 2005

Grid computing is widely applicable to various fields of industry including process control and manufacturing, military command and control, transportation management, and so on. In a viewpoint of application area, grid computing can be classified to three aspects that are computational grid, data grid and access grid. This paper focuses on computational grid which handles complex and large-scale computing problems. Computational grid is characterized by system dynamics which handles a variety of processors and jobs on continuous time. To solve problems of system complexity and reliability due to complex system dynamics, computational grid needs scheduling policies that allocate various jobs to proper processors and decide processing orders of allocated jobs. This paper proposes the service prediction-based job scheduling model and present its algorithm that is applicable for computational grid. The service prediction-based job scheduling model can minimize overall system execution time since the model predicts a processing time of each processing component and distributes a job to processing component with minimum processing time. This paper implements the job scheduling model on the DEVSJAVA modeling and simulation environment and simulates with a case study to evaluate its efficiency and reliability Empirical results, which are compared to the conventional scheduling policies such as the random scheduling and the round-robin scheduling, show the usefulness of service prediction-based job scheduling.

• The KIPS Transactions:PartA
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• v.15A no.3
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• pp.151-154
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• 2008

A middleware in grid computing environment is required to support seamless on-demand services over diverse resource situations in order to meet various user requirements [1]. Since grid computing applications need situation-aware middleware services in this environment. In this paper, we propose a semantic middleware architecture to support dynamic software component reconfiguration based fault and service ontology to provide fault-tolerance in a grid computing environment. Our middleware includes autonomic management to detect faults, analyze causes of them, and plan semantically meaningful strategies to recover from the failure using pre-defined fault and service ontology trees. We implemented a referenced prototype, Web-service based Application Execution Environment(Wapee), as a proof-of-concept, and showed the efficiency in runtime recovery.

• Journal of Digital Contents Society
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• v.14 no.2
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• pp.171-178
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• 2013

Desktop grid computing is the computing paradigm that can execute large-scale computing jobs using the desktop resources with heterogeneity and volatility. However, such the computing environment can not guarantee the stability and reliability of task execution because the desktop resources with different performance can freely participate and leave in task execution. Therefore, in this paper, we design resource grouping scheme using k-means clustering algorithm with an aim to provide desktop grid computing with the stability and reliability of task execution. Moreover, we conduct resource grouping using the execution log data of actual desktop grid systems and present application methods of desktop resource groups to fault-tolerance.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.165-171
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• 2005

High speed computer, large scale storage device and high speed computer network are computing infrastructure which we can easily access to in these days. However, many computer simulations in natural or applied science such as molecular simulation require more computing power as well as larger scale of storage. Grid computing which is a next generation of distributed computing environment, is one of solution for the new requirements. Even though many researches have been going on Grid computing, those are oriented to communication interface and protocols, and middleware like globus tool kits[2, 3]. Therefore research on application level platform or application itself is yet premature and it makes real users be difficult to utilize Grid system for their research. In this paper, we suggest a new user environment and an abstract job model for simulation experiments on MGrid(Molecular Simulation Grid). It will make users be able to utilize Grid resources efficiently and reliably.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1455-1461
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• 2015

Micro Grid is a new concept of electrical grid to solve several problems of Mega-Grid and it is under research and development at the national level around the world. With this background, Micro Grid Common Platform has been developed for interoperability technology of devices-systems in Micro Grid and securing enabler for new market. For supporting business models, Micro Grid Common Platform provides electric power information to Third-Party licensee via Open API function. Licensee, who want to develop electric power application by connecting to Micro Grid Common Platform, needs IDE(Integrated Development Environment) for service development and distribution. The paper proposes a service development tool for developing applications of Micro Grid Common Platform as a PaaS (Platform as a Service).