• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.193-203
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• 2015

In this study, effects of buildings and topography on observation environment of weather stations located on mountainous terrain in metropolitan areas are investigated using a computational fluid dynamics (CFD) model. In order to investigate the characteristics of flow pattern around the weather stations, geographic information system (GIS) data are used to construct surface boundary input data of the CFD model. In order to evaluate effects of buildings and topography on wind speed and direction at three weather stations located in Deajeon, Busan, and Gwangju., target areas around the weather stations are selected and 16 cases with different inflow directions for each target area are considered. The simulated wind speed and direction at the weather stations are compared with those of inflow. As a whole, wind speed at the weather stations decreases due to drag effects of the buildings and topography in the upwind regions. This study shows that GIS data and the CFD model are successfully applicable to evaluation of observation environment for weather stations.

• Journal of Korea Water Resources Association
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• v.38 no.2
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• pp.121-131
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• 2005

In this study, a flood routing model is used for analyzing change of flood stage induced by various factors. The results by using the past cross section measurement data showed the minimum error in case of accurate measurement of cross section as well as reasonable boundary condition of model. In analyzing the rise of flood stage of main stream considering Inflow magnitude of tributary, it showed that the larger the flow magnitude is, the smaller the variance of stage is. The results of analysis in the tidal effect at Wolgot are that the tidal effect influence the stage profile into upstream in case of normal discharge of main stream and tributary but doesn't influence it even with maximum flood tide in case of project flood. Finally, when the various hydraulic factors are considered in numerical analysis, more systematic and realistic flood forecast system is able to be performed.

• Nuclear Engineering and Technology
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• v.42 no.5
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• pp.576-581
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• 2010

KAERI (Korea Atomic Energy Research Institute) fabricated MOX (Mixed Oxide) fuel pellets as a cooperation project with PSI (Paul Scherrer Institut) for an irradiation test in the Halden reactor. The MOX pellets were fitted into fuel rods that included instrumentation for measurement in IFE (Institutt for Energiteknikk). The fuel rods were assembled into the test rig and irradiated in the Halden reactor up to 50 MWd/kgHM. The irradiated fuel rods were transported to the IFE, where ceramography was carried out. The fuel rods were cut transversely at the relatively higher burn-up locations and then the radial cross sections were observed. Micrographs were analyzed using an image analysis program and grain sizes along the radial direction were measured by the linear intercept method. Radial cracks in the irradiated MOX were observed that were generally circumferentially closed at the pellet periphery and open in the hot central region. A circumferential crack was formed along the boundary between the dark central and the outer regions. The inner surface of the cladding was covered with an oxide layer. Pu-rich spots were observed in the outer region of the fuel pellets. The spots were surrounded by many small pores and contained some big pores inside. Metallic fission product precipitates were observed mainly in the central region and in the inside of the Pu spots. The average areal fractions of the metallic precipitates at the radial cross section were 0.41% for rod 6 and 0.32% for rod 3. In the periphery, pore density smaller than 2 ${\mu}m$ was higher than that of the other regions. The grain growth occurred from 10 ${\mu}m$ to 12 ${\mu}m$ in the central region of rod 6 during irradiation.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.63-74
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• 2018

As part of the Four Major Rivers Restoration Project, multifunctional weirs have been constructed in the rivers and operated for river-level management. As the weirs play a role in draining water from tributaries, the aim of this study was to determine the influence of the weirs on the water level of the Nam River, which is one of the Nakdong River's tributaries. Self-organizing maps (SOMs) and a locally weighted scatterplot smoothing (LOWESS) technique were applied to analyze the patterns and trends of water level and quality of the Nakdong River, considering the operation of the Changnyeong-Haman weir, which is located where the Nam River flows into the Nakdong River. The software program HEC-RAS was used to find the boundary points where the water is well drained. Per the study results at the monitoring points ranging between the junction of the two rivers and 17.5 km upstream toward the Nam River, the multifunctional weir influenced the water level at the Geoyrong and Daesan observation stations on the Nam River and the water quality based on automatic monitoring at the Chilseo station on the Nakdong River was affected strongly by the Nakdong River and partly by the Nam River.

• Geophysics and Geophysical Exploration
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• v.2 no.3
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• pp.149-153
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• 1999

The study was performed as a part of 3-D exploration project of the South Con Son basin, where Korea National Oil Co. (KNOC) and SHELL Company are performing joint operation. In the structurally complex area, seismic facies or lap-out patterns, which are usually the tools for the conventional seismic stratigraphy developed by Exxon Group (Vail et at., 1977), are not easily identifiable. Therefore, stratigraphic informations are mainly extracted from seismic attribute maps of each sequence or systems tracts, and isopach maps in correlation with the stratigraphic information from the wells. The attribute maps of the sequence or systems tract boundaries and isopach map describe the variations of paleodepositional environments. The shape of the attribute maps of the boundaries is a reasonable description of the shape of the paleodepositional surface. With other maps such as isopach and structural maps, the variations of the parasequences in the systems tracts can be projected using the surface attribute maps. The reflection intensity attribute at each sequence or system tract boundary can be related to lithology, facies or porosity distributions. The azimuth attribute of source rock sequence can be used to identify the hydrocarbon migration patterns into the prospects. The overall risks of reservoir rocks, cap rocks, structure and hydrocarbon migrations were computed using the results of the study.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.8
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• pp.89-100
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• 2019

The purpose of this study is to critically review the repair works of Seokguram architecture and to search for its original form and space. Seokguram's architectural form has been transformed throughout three repair works. The first transformation occurred during the repair work of the Colonial Government in 1913-1915, and the second occurred during the repair work of the Colonial Government in 1920-1923. The repair work done by the Korean Government in 1961-1964 also caused a severe change in the architectural form and space of Seokguram architecture. The more the repair work was added to Seokguram, the more its original form flew away like a mirage. Through the three repair works, the spatial composition of Seokguram changed in the following directions: from ((front chamber + passageway) + main chamber) to (front chamber + (passageway + main chamber)) through the second repair work, from (front chamber + (passageway + main chamber)) to (front chamber + passageway + main chamber) through the last repair work. Although the compositional space hierarchy of Seokguram was maintained during the first repair work, the architectural form based on the dry method was changed to the form based on the wet method. The Korean government's repair work was a tragedy for the 'Seokguram conservation project' that the people who led the conservation process misunderstood the architectural nature of Seokguram.

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.2311-2320
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• 2022

The main outcomes of the experiments H2P6 performed in the thermal-hydraulics large-scale PANDA facility at PSI in the frame of the OECD/NEA HYMERES-2 project are presented in this article. The experiments of the H2P6 series consists of two PANDA tests characterized by the activation of three (H2P6_1) or one (H2P6_2) cooler(s) in an initially stratified and pressurized containment atmosphere. The initial stratification is defined by a helium-rich region located in the upper part of the vessel and a steam/air atmosphere in the lower part. The activation of the cooler(s) results i) in the condensation of the steam in the vicinity of the cooler(s), ii) the corresponding activation of large scale natural circulation currents in the vessel atmosphere, with the result of iii) the re-distribution and mixing of the Helium stratification initially located in the upper half of the vessel and iv) the continuous pressure decay. The initial helium layer represents hydrogen generated in a postulated severe accident. The main question to be answered by the experiments is whether or not the interaction of the different, localized cooler units would be important for the application of numerical methods. The paper describes the initial and boundary conditions and the experimental results of the H2P6 series with the suggestion of simple scaling laws for both experiments in terms of i) the temperature difference(s) across the cooler(s), ii) the transient steam and helium content and iii) the pressure decay in the vessel. The outcomes of this scaling indicate that the interaction between separate, closely localized units does not play a prominent role for the present experiments. It is therefore reasonable to model several units as one large component with equivalent heat transfer area and total water flow rate.

• Atmosphere
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• v.31 no.5
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• pp.637-656
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• 2021

The United States has been known as the world's major producer of crops such as wheat, corn, and soybeans. Therefore, using meteorological long-term forecast data to project reliable crop yields in the United States is important for planning domestic food policies. The current study is part of an effort to improve the seasonal predictability of regional-scale precipitation across the United States for estimating crop production in the country. For the purpose, a dynamic downscaling method using Weather Research and Forecasting (WRF) model is utilized. The WRF simulation covers the crop-growing period (March to October) during 2000-2020. The initial and lateral boundary conditions of WRF are derived from the Pusan National University Coupled General Circulation Model (PNU CGCM), a participant model of Asia-Pacific Economic Cooperation Climate Center (APCC) Long-Term Multi-Model Ensemble Prediction System. For bias correction of downscaled daily precipitation, empirical quantile mapping (EQM) is applied. The downscaled data set without and with correction are called WRF_UC and WRF_C, respectively. In terms of mean precipitation, the EQM effectively reduces the wet biases over most of the United States and improves the spatial correlation coefficient with observation. The daily precipitation of WRF_C shows the better performance in terms of frequency and extreme precipitation intensity compared to WRF_UC. In addition, WRF_C shows a more reasonable performance in predicting drought frequency according to intensity than WRF_UC.

• Information Systems Review
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• v.10 no.3
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• pp.207-222
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• 2008

In recent business environment, we realize that MIS is taking important role in which it has been involved. However, we are having difficulty to find out the identity of MIS in business studies since MIS is derived from Micro Economics, Operations Research, Computer Science and so on. And there is no clear boundary in order to classify with other business area in consisting curriculums. Furthermore, IT staffs in the field are facing difficulties to utilize what they have learned MIS curriculums provided from business studies. In this research, we would like to present implications for development of market oriented MIS curriculums, which can be the actual needs of IT fields, through analysis of System Integration project for recent three years, analysis of IT capability based on the survey of IT consultants and analysis of application S/W technology trend in global vendor referred to "MIS Curriculum: The Current State of the Art and a Proposed Future Model (Lee et al, 2007)". As enterprise application software technology develop, the system integration can be achieved through special system solutions such as ERP, CRM, SCM, BI, etc. We also have acknowledged that solution consultants who have the ability of packaged S/W application are in demand since S/W vendors have become larger and more practical through M&A. Therefore, we have come to a conclusion regarding new direction of curriculum for increasing human power in IT industry which we demonstrated in detail through this research.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.61-68
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• 2010

A magnetotelluric (MT) survey has been performed to delineate deeply extended fracture systems at the geothermal field in Seokmo Island, Korea. To assist interpretation of the MT data, geological surveying and well logging of existing wells were also performed. The surface geology of the island shows Cretaceous and Jurassic granite in the north and Precambrian schist in the south. The geothermal regime has been found along the boundary between the schist and Cretaceous granite. Because of the deep circulation along the fracture system, geothermal gradient of the target area exceeds $45^{\circ}C/km$, which is much higher than the average geothermal gradient in Korea. 2D and 3D inversions of MT data clearly showed a very conductive anomaly, which is interpreted as a fracture system bearing saline water that extends at least down to 1.5 km depth and is inclined eastwards. After drilling down to the depth of 1280 m, more than 4000 tons/day of geothermal water overflowed with temperature higher than $70^{\circ}C$. This water showed very similar chemical composition and temperature to those from another existing well, so that they can be considered to have the same origin; i.e. from the same fracture system. A new geothermal project for combined heat and power generation was launched in 2009 in Seokmo Island, based on the survey. Additional geophysical investigations including MT surveys to cover a wider area, seismic reflection surveys, borehole surveys, and well logging of more than 20 existing boreholes will be conducted.