• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.37-42
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• 2004

Information Quality Challenge ·Incomplete business process ·Islands of data ·Escalating costs ·No planned information architecture(omitted)

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1738-1743
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• 2008

Environmental issue is one of the key factors to industry area using fossil fuels, because it accelerates the global warming. So it is supposed to reduce greenhouse gases around the developed nations of the world at times go. This issue is especially for the power industry. Under this background, MicroGrid system that consists of Distributed Energy Resources (DER) system, such as natural power system (wind, solar) and fuel-cell, co-generation, also known as CHP (Combined heat and power), has been developed greatly during the last 10 years. This paper adopts optimal model using GAMS to develop methods for conducting an integrated assessment of MicroGrid system.

• IE interfaces
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• v.25 no.4
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• pp.441-449
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• 2012

Solar PV(photovoltaic) is paid great attention to as a possible renewable energy source to overcome recent global energy crisis. However to be a viable alternative energy source compared with fossil fuel, its market competitiveness should be attained. Grid parity is one of effective measure of market competitiveness of renewable energy. In this paper, we forecast the grid parity timing of solar PV energy in Korea using two factor learning curve model. Two factors considered in the present model are production capacity and technological improvement. As a result, it is forecasted that the grid parity will be achieved in 2019 in Korea.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.4
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• pp.368-374
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• 2011

Recently, the ship vibration analysis technique has been well set up by using FEM. The methods considering the hydrodynamic added mass and damping of the fluid surrounding a floating ship have been well developed, so that they can be calculated by using the commercial package FEM programs such as MSC/NASTRAN, ADINA and ANSYS. Especially, MSC/NASTRAN has the functions to consider the fluid in tanks(MFLUID) and to solve the Fluid-Structure Interaction(FSI) problem(DMAP). In this study, the global ship vibration with considering the added mass distributed at the grid points on the wetted shell surface is introduced to. In the new method, the velocity potentials of the fluid surrounding a floating ship are calculated by solving the Lapalce equation using the Boundary Element Method(BEM), and the point mass is obtained by integrating the potentials at the points. Then, the global vibration analyses of the ship structure with distributed added mass on the wetted surface are carried out for an oil/chemical tanker. During the future sea trial, the results will be confirmed by measurement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2497-2506
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• 2010

Smart power grid is targeting to improve grid operation by integrating existing power IT technologies in the jeju smart grid field test. Real-time two-way communication and interoperability in power grid are essential to smart power grid. Adopting smart grid will increase security vulnerabilities in power grid by increasing the number of wireless sensors and the chances of the external exposure of communication networks. In addition, hackers can cause chaos in the power grid system with eavesdropping and forgery attacks in communication networks. Smart power grid is one of the most important systems in deploying smart grid, and it is important to design security system systematically since smart grid can be seriously damaged when problem occurs. In this paper, local and global smart grid security standard and security vulnerabilities in power grid are reviewed, and 2 level smart grid service model is proposed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.115-123
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• 2005

Quantitative understanding of spatial characteristics of the study site is a prerequisite to investigate water and carbon cycles in agricultural and forest ecosystems, particularly with complex, heterogeneous landscapes. The spatial characteristics of variables related with topography, vegetation and soil in Gwangneung forest watershed are quantified in this study. To characterize topography, information on elevation, slope and aspect extracted from DEM is analyzed. For vegetation and soil, a land-cover map classified from LANDSAT TM images is used. Four satellite images are selected to represent different seasons (30 June 1999, 4 September 2000, 23 September 2001 and 14 February 2002). As a flux index for CO₂ and water vapor, normalized difference vegetation index (NDVI) is calculated from satellite images for three different grid sizes: MODIS grid (7km x 7km), intensive observation grid (3km x 3km), and unit grid (1km x 1km). Then, these data are analyzed to quantify the spatial scale of heterogeneity based on semivariogram analysis. As expected, the scale of heterogeneity decreases as the grid size decreases and are sensitive to seasonal changes in vegetation. For the two unit grids where the two 40 m flux towers are located, the spatial scale of heterogeneity ranges from 200 to 1,000m, which correspond well to the climatology of the computed tower flux footprint.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.183-190
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• 2019

This paper introduces a near-tip grid refinement and explores its usefulness in the crack analysis by the natural element method(NEM). As a sort of local h-refinement in finite element method(FEM), a NEM grid is locally refined around the crack tip showing high stress singularity. This local grid refinement is completed in two steps in which grid points are added and Delaunay triangles sharing the crack tip node are divided. A plane strain rectangular plate with symmetric edge cracks is simulated to validate the proposed local grid refinement and to examine its usefulness in the crack analysis. The crack analysis is also simulated using a uniform NEM grid for comparison. Unlike the uniform grid, the refined grid provides near-tip stress distributions similar to the analytic solutions and the fine grid. In addition, the refined grid shows higher convergence than the uniform grid, the global relative error to the total number of grid points.

• Atmosphere
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• v.28 no.2
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• pp.223-232
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• 2018

The Global-Korean aviation Turbulence Guidance (G-KTG) system is developed using the operational Global Data Assimilation and Prediction System of Korea Meteorological Administration with 17-km horizontal grid spacing. The G-KTG system provides an integrated solution of various clear-air turbulence (CAT) diagnostics and mountain-wave induced turbulence (MWT) diagnostics for low [below 10 kft (3.05 km)], middle [10 kft (3.05 km) - 20 kft (6.10 km)], and upper [20 kft (6.10 km) - 50 kft (15.24 km)] levels. Individual CAT and MWT diagnostics in the G-KTG are converted to a 1/3 power of energy dissipation rate (EDR). 12-h forecast of the G-KTG is evaluated using 6-month period (2016.06~2016.11) of in-situ EDR observation data. The forecast skill is calculated by area under curve (AUC) where the curve is drawn by pairs of probabilities of detection of "yes" for moderate-or-greater-level turbulence events and "no" for null-level turbulence events. The AUCs of G-KTG for the upper, middle, and lower levels are 0.79, 0.69, and 0.63, respectively. Comparison of the upper-level G-KTG with the regional-KTG in East Asia reveals that the forecast skill of the G-KTG (AUC = 0.77) is similar to that of the regional-KTG (AUC = 0.79) using the Regional Data Assimilation and Prediction System with 12-km horizontal grid spacing.

• 전기의세계
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• v.60 no.11
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• pp.56-63
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• 2011

In the face of global warming and resource depletion, a smart grid has been suggested as one way of contributing to abating the environment problems and increasing energy efficiency. Smart grids utilize renewable energy which has intermittent and irregular output power depending on weather conditions. In order to maintain stability and reliability of the power system, smart grids need to have complementary measures for the possible unstable system conditions. Cogenerating systems such as Combined Heat and Power(CHP) can be one good solution as it has capability of instantly increasing or decreasing output power. Therefore, this paper investigates the connectivity between Combined Heat and Power systems and smart grid technologies. The smart grid national roadmap formulated by South Korea Ministry of Knowledge and Economy and 'IEC Smart Grid Standardization Roadmap' are analyzed to extract related components of the smart grid for the CHP connection. Also, case studies on demonstration projects for smart grids with CHP systems completed or currently being implementing in the world are presented.

• Journal of Information Processing Systems
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• v.7 no.2
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• pp.299-320
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• 2011

The overhead of processing fine-grain tasks on a grid induces the need for batch processing or task group deployment in order to minimise overall application turnaround time. When deciding the granularity of a batch, the processing requirements of each task should be considered as well as the utilisation constraints of the interconnecting network and the designated resources. However, the dynamic nature of a grid requires the batch size to be adaptable to the latest grid status. In this paper, we describe the policies and the specific techniques involved in the batch resizing process. We explain the nuts and bolts of these techniques in order to maximise the resulting benefits of batch processing. We conduct experiments to determine the nature of the policies and techniques in response to a real grid environment. The techniques are further investigated to highlight the important parameters for obtaining the appropriate task granularity for a grid resource.