• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.383-393
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• 2010

DVC (Distributed Video Coding) allows us to explore the video statistics at the decoder side, resulting in a less complex encoder and more complex decoder. In this approach, it is important to generate a good prediction to the current Wyner-Ziv frame, called side information, which plays a crucial role in the overall performance of a DVC system. Conventional MCFI (motion compensated frame interpolation) techniques, which explore temporal correlations between neighbor frames of the current frame, preform the block-based or object-based motion estimation, but, they do not include the basis frame for the Wyner-Ziv frame. This paper proposes an efficient way to get better side information, by finding the average frame between neighbor frames and by comparing adaptively the candidate blocks. Through computer simulations, it is shown that the proposed method can improve the performance up to 0.4dB and provide better subjective and objective visual qualities in Wyner-Ziv CODEC.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.6
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• pp.532-540
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• 2008

Recently there are growing interests in calculating aerodynamic characteristics of aircraft configurations with structural deformation using the FSI(Fluid-Structure Interaction) system in which CFD(Computational Fluid Dynamics) and CSD(Computational Structure Dynamics) modules are coupled. In this paper the FSI system comprised of CAD, CFD, CSD, VSI(Volume Spline Interpolation) and grid deformation modules was constructed in order to investigate aerodynamic characteristics of the deformed shape. In the process VSI and grid generation modules are developed to combine CSD and CFD routines and to regenerate the aerodynamic grids for the deformed shape, respectively. For the CFD and CSD analysis, commercial programs FLUENT and NASTRAN were used. As a test model, DLR-F4 wing configuration was chosen and its aerodynamic characteristics were calculated by applying the static FSI system. It was shown that lift and drag coefficients of the wing at mach number 0.75 are reduced to 20.26% and 18.5%, respectively, owing to the structural deformation.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.136-140
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• 2011

Satellites industry has been developing with the commercial and military needs. Because power system of satellites is very important to survival operation and hard to test, increasing reliability is very critical. Especially LEO small satellites are very sensitive to power system, effective stabilization control is important. Because of various need of load condition, converter design are complicated. Therefore this paper introduced general modeling of LEO small satellite converter system and analyzed stabilization control design. The performance prediction of LEO small satellites power system is typically critical. Because of verity controller and rectification value, it is hard to computation and test implementation. So, this approach has merit that will reduce cost and make more reliable system. Furthermore, it can be constraint of converter specification and controller design. This paper will examine generation a modeling of LEO small satellites power converting system, and a possible guide line to design reliable controller which optimizing power converters of LEO small satellite.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.1-6
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• 2013

Three Surface cracks are among the more common flaws in aircraft and pressure vessel components. Accurate stress intensity analyses and crack growth rate data of surface-cracked components are needed for reliable prediction of their fatigue life and fracture strengths. Three Dimensional finite element method (FEM) was used to obtain the stress intensity factor for surface cracks existing in structures. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Nodes are generated by bucket method, and quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. To examine accuracy and efficiency of the present system, the stress intensity factor for a semi-elliptical surface crack in cylindrical structures subjected to pressure is calculated. Analysis results by present system showed good agreement with those by ASME equation and Raju-Newman's equation.

• The Journal of Engineering Research
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• v.5 no.1
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• pp.89-107
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• 2004

This study has tried to develop the modified DRASTIC Model by supplying the parameters, such as structural lineament density and landuse, into conventional DRASTIC model, and to predict the potential of groundwater contamination using GIS in Whanam 2 Area, Gyeonggi Province, Korea. Since the aquifers in Korea is generally through the joints of rock-mass in hydrogeological environment, lineament density affects to the behavior of groundwater and contaminated plumes directly, and land-use reflect the effect of point or non-point source of contamination indirectly. For the statistical analysis, lattice layers of each parameter were generated, and then level of confidence was assessed by analyzing each correlation coefficient. Composite contamination map was achieved as a final result by comparing modified DRASTIC potential and the amount of generation load of several contaminant sources logically. The result could suggest the predictability of the area of contamination potential on the respects of hydrogeological aspect and water quality.

• Journal of Korea Water Resources Association
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• v.46 no.5
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• pp.439-447
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• 2013

The applicability of the parameter map of the Modified Bartlett-Lewis Rectangular Pulse (MBLRP) model for the Korean Peninsula was assessed from the perspective of flood prediction. The design rainfalls estimated from the MBLRP model were smaller than those from observed values by 5% to 40%, and the degree of underestimation of design rainfall increases with the increase of the recurrence interval of the design rainfall. The design floods at a virtual watershed estimated using the simulated rainfall time series based on MBLRP model were also smaller than those derived from the observed rainfall time series by 20% to 45%. The degree of underestimation of design flood increases with the increase of the recurrence interval of the design flood.

• Biomolecules & Therapeutics
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• v.25 no.3
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• pp.296-307
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• 2017

In spite of frequent usage of primary human foreskin keratinocytes (HFKs) in the study of skin biology, senescence-induced block-age of in vitro proliferation has been a big hurdle for their effective utilization. In order to overcome this passage limitation, we first isolated ten HFK lines from circumcision patients and successfully immortalized four of them via a retroviral transduction of high-risk human papillomavirus (HPV) E6 and E7 oncogenes. We confirmed expression of a keratinocyte marker protein, keratin 14 and two viral oncoproteins in these immortalized HFKs. We also observed their robust responsiveness to various exogenous stimuli, which was evidenced by increased mRNA expression of epithelial differentiation markers and pro-inflammatory genes in response to three reactive chemicals. In addition, their applicability to cytotoxicity assessment turned out to be comparable to that of HaCaT cells. Finally, we confirmed their differentiation capacity by construction of well-stratified three dimensional skin cultures. These newly established immortalized HFKs will be valuable tools not only for generation of in vitro skin disease models but also for prediction of potential toxicities of various cosmetic chemicals.

• Journal of Korea Multimedia Society
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• v.3 no.2
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• pp.201-208
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• 2000

In this paper We describe an algorithm which is devised for 4he partition o# the input space and the generation of fuzzy rules by the fuzzy entropy and tested with the time series prediction problem using Mackey-Glass chaotic time series. This method divides the input space into several fuzzy regions and assigns a degree of each of the generated rules for the partitioned subspaces from the given data using the Shannon function and fuzzy entropy function generating the optimal knowledge base without the irrelevant rules. In this scheme the basic idea of the fuzzy neural network is to realize the fuzzy rules base and the process of reasoning by neural network and to make the corresponding parameters of the fuzzy control rules be adapted by the steepest descent algorithm. The Proposed algorithm has been naturally derived by means of the synergistic combination of the approximative approach and the descriptive approach. Each output of the rule's consequences has expressed with its connection weights in order to minimize the system parameters and reduce its complexities.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.525-525
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• 2015

국립기상과학원은 국가 물관리를 효율적으로 지원하기 위하여 TOPLATS(TOPmodel based Land-Atmosphere Transfer Scheme) 지면모델 기반을 활용한 전국 수문기상 분석 및 예측정보 생산체계를 구축하였다. TOPLATS 지면모델에서는 토양, 식생 등을 표현하기 위한 다양한 매개변수들이 사용되고 있으며, 그 중에서도 토양 속성과 관련 매개변수들은 토양수분, 증발산 등의 수문기상요소 생산에 큰 영향을 미치고 있어 현실적인 토양 특성에 대한 고려가 요구된다. 본 연구는 국립농업과학원의 토양도 정보를 이용하여 TOPLATS 지면모델에서 요구되는 토양 속성 및 관련 매개변수를 산정하고 이를 모델에 적용하고자 하였다. TOPLATS 모델에 사용되는 토양 매개변수는 총 22개 이며, 본 연구에서는 국립농업과학원에서 제공한 총 405개의 토양통에 대한 매개변수를 각각 산정하였다. TOPLATS 모델을 강제하기 위한 기상자료는 동네예보 분석자료, KLAPS(Korea Local Analysis and Prediction System) 분석자료, 입사 단 장파 복사량은 ASOS 관측자료를 기반으로 한 5km 해상도의 남한 격자자료이며, 2010~2013년 기간의 토양수분, 증발산량에 대한 검증 연구를 수행하였다. 본 연구의 결과는 기존의 11개 토양속성정보로 산출된 결과와 비교 분석하여 추후 제시할 예정이며, 본 연구에서 산출된 국내 토양 특성을 반영한 고해상도 수문기상정보는 향후 홍수 예측 및 가뭄 평가에 활용 할 수 있을 것으로 기대된다.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.72-80
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• 2010

The main thrust of this paper is to investigate a practical way of generating the monthly averaged daily horizontal solar radiation in Korea. For estimating the horizontal solar radiation, the clearness index($K_T$) and the clearness number($C_N$) which are required for the use of Liu and Jordan's model and ASHRAE Clear Sky model were derived based on the measured weather data. Third-order polynomials returning $K_T$ and��$C_N$ for a given location were derived as a function of cloud amount, month, date, latitude and longitude. The predicted monthly averaged daily horizontal solar radiation values were compared with those acquired from the established design weather data. The MBE(Mean Bias Error) and RMSE (Root Mean Squares for Error) between the predicted values and the measured data were near zero. It means that the suggested third-order polynomials for $K_T$ and $C_N$ have good applicability to Liu and Jordan's model and ASHRAE Clear Sky model.