• Atmosphere
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• v.21 no.2
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• pp.197-208
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• 2011

The objective of this study is to describe the short-range forecast system of the Korea Air Force (KAF) and to verificate its performace in 2009 summer. The KAF weather prediction model system, based on the Weather Research and Forecasting (WRF) model (i.e., the KAF-WRF), is configured with a parent domain overs East Asia and two nested domains with the finest horizontal grid size of 2 km. Each domain covers the Korean peninsula and South Korea, respectively. The model is integrated for 84 hour 4 times a day with the initial and boundary conditions from National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) data. A quantitative verification system is constructed for the East Asia and Korean peninsula domains. Verification variables for the East Asia domain are 500 hPa temperature, wind and geopotential height fields, and the skill score is calculated using the difference between the analysis data from the NCEP GFS model and the forecast data of the KAF-WRF model results. Accuracy of precipitation for the Korean penisula domain is examined using the contingency table that is made of the KAF-WRF model results and the KMA (Korea Meteorological Administraion) AWS (Automatic Weather Station) data. Using the verification system, the operational model and parallel model with updated version of the WRF model and improved physics process are quantitatively evaluated for the 2009 summer. Over the East Aisa region, the parallel experimental model shows the better performance than the operation model. Errors of the experimental model in 500 hPa geopotential height near the Tibetan plateau are smaller than errors in the operational model. Over the Korean peninsula, verification of precipitation prediction skills shows that the performance of the operational model is better than that of the experimental one in simulating light precipitation. However, performance of experimental one is generally better than that of operational one, in prediction.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.113-121
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• 2013

It has been known that edges of forest fire areas play significant roles in post-fire change of forest ecosystem and recovery process. The purpose of this study was to analyze the relationships between edge formation of burned forests and landscape characteristics with consideration on spatial autocorrelation. Samcheok fire site burned in 2000 was selected as the study area. Seven hundred fifty three of 500 $m^2$ grid cells were generated for measuring landscape characteristics. This study used the topographic variables including slop, elevation, topographic wetness index, solar radiation index and proportions of fuel and land use types. In delineating landscape characteristics correlation analysis with modified t-test were performed for exploring the relationships between edge formation and landscape characteristics. The results indicated that edge formation of burned forests was positively correlated with most variables including TWI, SRI, water, paddy, developed, farm, grass, bare soil, and negatively related with elevation, slope and all fuel types. Especially TWI (r=0.437) showed a strong positive correlation with edge formation. According to the results, edge of burned forests were likely formed when proportions of heterogeneous land use types were high with mild slope and low elevation.

• Journal of the Korean GEO-environmental Society
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• v.14 no.7
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• pp.39-50
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• 2013

Crib wall is one of the segmental grid retaining walls using headers and stretchers to establish the framework of the wall. In this method, grids formed by the intersection of headers and stretchers are generally filled with the gravel to maintain the weight of the wall. Therefore, the construction can be carried out with higher speed and much economically when compared with the concrete retaining wall. Furthermore, it has high drain capacity, and environmentally friendly aspects also have been pointed out because the possibility of the planting at the front of the wall. However, in the wooden crib wall method, the relative movement between the individual headers and stretchers was generally recognized, and stress redistribution in the gravel filling was also observed when subjected to the external loading and self-weight of filling. In this study, it was analyzed fracture types and causes of wooden crib wall through detailed investigation and analysis of a large crib wall construction site. As a results, it occurred the damage in the members of 5.7% in a total of 2,315 locations and the damage of header occurred in the members of a header 80.2%. The 65.7% of the damaged header are concentrated in the lower part of crib wall. Therefore, it was analyzed the differences of fracture types and causes of wooden crib wall depending on the installation position and the kinds of members. It is considered basically the members of various forms of distortion and the grain affecting.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.2
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• pp.1-25
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• 2009

Objectives : The purpose of this study was to investigate the effects of Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang, YGKT) and electrical acupuncture treatment in spinal cord injury(SCI)-induced rats. Methods : The subjects were divided into 5 groups ; Normal, Control-no treatment after SCI, Experimental I(Exp. I)-taken with YGKT 500 mg/kg $0.5m{\ell}$ daily after SCI. Experimental II(Exp. II)-taken with electrical acupuncture after SCI and Experimental III(Exp. III)-taken with YGKT 500 mg/kg $0.5m{\ell}$ and electrical acupuncture after SCI. After each operation, the present author observed cytological changes, the motor behavior recovery and nerve regeneration by analysis of the motor behavior tests, EMG, hematological(AST, ALT, WBC), histological and immunological changes. Rats were tested by Motor behavior test at 1st, 3rd, 7th, 14th and 21st day. Results : 1. All the experimental groups were improved compared with control group in the motor behavior tests including Tarlov test, Basso-Beattle-Bresnahan locomotor rating scale, modified inclined plane test, open field test, grid walk test and narrow beam test. Especially Exp. III was significantly improved among other groups. 2. In EMG test, H and M wave were significantly increased in Exp. III. 3. All the experimental groups were significantly decreased compared with control group in AST, ALT and WBC. 4. NGF, BDNF and Trk B of spinal cord gray matter in all the experimental groups were increased compared with control group. Especially, Exp. III was more effective. 5. In histological observations, muscle contraction and denaturation of gastrocnemius muscle of all the experimental groups were inhibited. Especially, those of Exp. III was more effective. On the observations of liver and kidney, cell atrophy and apoptosis of all the experimental groups were decreased compared with control group. Especially, those of Exp. III was more effective. Conclusions : It can be suggested that YGKT and electrical acupuncture may improve motor behavior, EMG, hematological, histological and immunological findings in SCI-induced rats. Especially, combination of these two treatments will be somewhat better in spinal nerve recovery and motor function improvement.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.2
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• pp.27-49
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• 2009

Objectives : The purpose of this study was to investigate the effects of Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang) and Cervi Cornu Parvum pharmaco-acupuncture in Spinal Cord Injury(SCI)-induced rats. Methods : The subjects were divided into 5 groups ; Normal, Control no treatment after SCI, Experimental I taken with Yanghyuljanggeungunbo-tang (Yangxuezhuangjinjianbu-tang) 500 mg/kg $0.5m{\ell}$ daily after inducing SCI. Experimental II taken with Cervi Cornu Parvum pharmaco-acupuncture at Taegye(KI3) and $Yangnungch{\acute{o}}n$(GB34) after inducing SCI and Experimental III taken with Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang) 500 mg/kg $0.5m{\ell}$ and Cervi Cornu Parvum pharmaco-acupuncture at KI3 and GB34 to SCI-induced rats. After each operation, the present author observed the motor behavior recovery and nerve regeneration by analysis of the motor behavior tests, EMG, hematological(AST, ALT, WBC), histological and immunological changes. Rats were tested at modified Tarlov test at the 1st, 2nd, 3rd, 4th day, and Motor behavior test at 1st, 3rd, 7th, 14th, 21st day. Results : Results are as follows. 1. All the experimental groups were improved compared with control group in the motor behavior tests including Tarlov test, Basso-Beattle-Bresnahan locomotor rating scale, modified inclined plane test, open field test, grid walk test and narrow beam test. Especially Experimental III was improved significantly among other groups. 2. In EMG test, H wave appeared weak only in Experimental III. And M wave was increased significantly in Experimental III. 3. All the experimental groups were significantly decreased compared with control group in serum AST, serum ALT and serum WBC tests. 4. significantly decreased in Tumor Necrosis Factor-${\alpha}$ test compared with the first day of SCI. 5. Muscle contraction and denaturation of all the experimental groups were inhibited in histological observations of gastrocnemius muscle. Especially, those of experimental III was more effective. 6. NGF and BDNF of spinal cord gray matter in all the experimental groups were increased compared with control group. Especially, those of experimental III was more effective. Conclusions : As above, it can be suggested that Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang) and Cervi Cornu Parvum pharmaco-acupuncture may improve motor behavior, EMG, hematological, histological and immunological findings in Spinal Cord Injury(SCI)-induced rats. Especially, effects will be somewhat better in combination of these two treatments.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.278-284
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• 2002

To examine the global gene expression of osteoclastogenesis-related genes in RAW 264.7 and its differentiated OCLs through the use of Atlas Mouse cDNA Array 2.1 membranes printed with 1176 well-characterized mouse genes involved in biology. Both samples were screened in parallel using cDNA expression arrays. The array results were additionally validated using RT-PCR. The results of cDNA arrays showed that 6 genes were up-regulated >2.5-fold (PKC beta II. POMC, PTEN, etc) and 16 genes were down-regulated >2.5-fold (Osteopontin, Cyclin D1, Cathepsin C, PTMA, etc) in both samples at the mRNA level. RT-PCR analysis of PKC beta II of these differentially expressed genes gave result consistent with cDNA array findings. The result of osteoclastogenesis showed that the PKC beta II gene was overexpressed in OCLs compared with RAW264.7 cell line. Osteoclastogenesis-related genes are differentially expressed in RAW264.7 cell line and its differentiated OCLs. its gene overexpression correlates with osteoclast differentiation in RAW264.7 cell line.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.246-252
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• 2018

In this paper, the friction drag force of 3D submerged body is investigated by considering the surface roughness, the first grid height, and the Reynolds number using open CFD source code, OpenFOAM 4.0. A procedure for estimating drag components by CFD code is set up and suggested in this study. In the 3D submerged body, because of the form factor in the 3D computations, the friction resistance with the small roughness of $12{\mu}m$ obtains different result with the smooth wall. As the Reynolds number increased, the boundary layer becomes thinner and the fiction resistance tends to decrease. In the computations for the effect of y+, the friction resistance and wall shear stress are excessively predicted when the y+ value deviates from the log layer. This is presumably because the boundary layer becomes thicker and the turbulence energy is excessively predicted in the nose due to the increase in y+ value. As the roughness increases, the boundary layer becomes thicker and the turbulence kinetic energy on the surface increases. From this study, the drag estimation method, considering the roughness by numerical analysis for ships or offshore structures, can be provided by using the suggested the y+ value and surface roughness with wall function.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1809-1815
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• 2008

This experiment simulated the fire driven flow of an underground station through parallel processing method. Fire analysis program FDS(Fire Dynamics Simulation), using LES(Large Eddy Simulation), has been used and a 6-node parallel cluster, each node with 3.0Ghz_2set installed, has been used for parallel computation. Simulation model was based on the Kwangju-geumnan subway station. Underground station, and the total time for simulation was set at 600s. First, the whole underground passage was divided to 1-Mesh and 8-Mesh in order to compare the parallel computation of a single CPU and Multi-CPU. With matrix numbers($15{\times}10^6$) more than what a single CPU can handle, fire driven flow from the center of the platform and the subway itself was analyzed. As a result, there seemed to be almost no difference between the single CPU's result and the Multi-CPU's ones. $3{\times}10^6$ grid point one employed to test the computing time with 2CPU and 7CPU computation were computable two times and fire times faster than 1CPU respectively. In this study it was confirmed that CPU could be overcome by using parallel computation.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.3
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• pp.77-84
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• 2015

The key objective of this research is to review the effectiveness of spatial regression to identify the influencing factors of spatial distribution patterns of floating population. To this end, global and local spatial autocorrelation test were performed using seoul floating population survey(2014) data. The result of Moran's I and Getis-Ord $Gi^*$ as used in the analysis derived spatial heterogeneity and spatial similarities of floating population patterns in a statistically significant range. Accordingly, Geographically Weighted Regression was applied to identify the relationship between land use attributes and population floating. Urbanization area, green tract of land of micro land cover data were aggregated in to $400m{\times}400m$ grid boundary of Seoul. Additionally public transportation variables such as intersection density transit accessibility, road density and pedestrian passage density were adopted as transit environmental factors. As a result, the GWR model derived more improved results than Ordinary Least Square(OLS) regression model. Furthermore, the spatial variation of applied local effect of independent variables for the floating population distributions.

• Geophysics and Geophysical Exploration
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• v.9 no.3
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• pp.241-249
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• 2006

Due to the long tectonic history and the very complex geologic formations in Korea, the anisotropic characteristics of subsurface material may often change very greatly and locally. The algorithms commonly used, however, may not give sufficiently precise computational results of traveltime data particularly for the complex and strong anisotropic model, since they are based on the two-dimensional (2D) earth and/or weak anisotropy assumptions. This study is intended to develope a three-dimensional (3D) modeling algorithm to precisely calculate the first arrival time in the complex anisotropic media. Considering the complex geology of Korea, we assume 3D TTI (tilted transversely isotropy) medium having the arbitrary symmetry axis. The algorithm includes the 2D non-linear interpolation scheme to calculate the traveltimes inside the grid and the 3D traveltime mapping to fill the 3D model with first arrival times. The weak anisotropy assumption, moreover, can be overcome through devising a numerical approach of the steepest descent method in the calculation of minimum traveltime, instead of using approximate solution. The performance of the algorithm developed in this study is demonstrated by the comparison of the analytic and numerical solutions for the homogeneous anisotropic earth as well as through the numerical experiment for the two layer model whose anisotropic properties are greatly different each other. We expect that the developed modeling algorithm can be used in the development of processing and inversion schemes of seismic data acquired in strongly anisotropic environment, such as migration, velocity analysis, cross-well tomography and so on.