• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.203-204
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• 2010

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.1
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• pp.1-11
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• 1999

The three-dimensional laminar mixed convection flow between the conductive printed circuit boards. on which the heat generating rectangular blocks are uniformly distributed, has been examined in the present study. The flow and heat-transfer characteristics are assumed to be pseudo periodic in the streamwise direction and symmetric in the cross-stream direction. Using an algorithm of SIMPLER, the continuity equation. the Navier-Stokes equations and the energy equation are solved numerically in the three-dimensional domain Inside the channel. The convective derivative terms are discretized by the QUICK scheme to accurately capture the flow field. The flow and the heat transfer characteristics are thoroughly examined for various Re and Gr.

• The KIPS Transactions:PartB
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• v.10B no.3
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• pp.273-280
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• 2003

Recommender System can help users to find products to Purchase. A representative method for recommender systems is collaborative filtering (CF). It predict products that user may like based on a group of similar users. User information is based on user's ratings for products and similarities of users are measured by ratings. As user is increasing tremendously, the performance of the pure collaborative filtering is lowed because of high dimensionality and scarcity of data. We consider the effect of dimension deduction in collaborative filtering to cope with scarcity of data experimentally. We suggest that SVD improves the performance of collaborative filtering in comparison with pure collaborative filtering.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.3
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• pp.191-199
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• 2000

In this paper, a numerical analysis using the finite element method (FEM) is presented which models the eddy current testing (ECT) of tubes with 3-dimensional defects. For the description of 3-dimensional eddy current problems, the governing equation is derived from the Maxwell's equations. The 3-dimensional FEM formulation with hexahedral elements is carried out using the Galerkin weighted residual method. The INCONEL 600 steam generator tube with inner and outer diameter defects is adopted for the numerical analysis, and the ECT signal, which is the trajectory of the probe impedance, is calculated. For the verification of the numerical analysis method, results of numerical calculations and experiments are compared and they show good agreements. Based on this verification, several defect signals are predicted and their characteristics are investigated with the variation in the defect depth and the circumferential angle of the defect.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.670_671
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• 2009

This paper presents a optimum design process for static torque characteristics of the Claw-Poles PM Stepping Motor(CPSM). Since the shape of CPSM changes along with axial direction, CPSM should only be analyzed by 3D-FEM. But 3D-FEM needs too much computation time and computer resources. Therefore, it is essential to reduce the number of 3D-FEM analysis models. In this paper, two design factors which affect the static torque characteristics of CPSM were selected. Optimum design process was able to make progress by using Pattern Search Algorithm and 3D-FEM. Finally, optimized model was compared with a conventional model.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.844-845
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• 2011

스피리컬 전동기의 적용대상인 기존의 다자유도 시스템은 다수의 전동기를 동시에 제어해야 하므로 제어성과 전력공급면에서 단점을 갖는다. 하나의 전동기로 다 자유도 시스템을 구현할 수 있는 스피리컬 전동기는 출력 밀도 측면에서 영구자석을 이용한 형태의 연구가 주로 진행되고 있는데, 세계적으로 기초연구 단계에 있다. 스피리컬 영구자석형 전동기를 구현하기 위해서는 회전자를 지지하면서 3자유도 구현이 가능한 구조적인 설계, 3자유도의 전동력의 발생 메커니즘 설계, 3차원 전자장 해석 및 제어알고리즘 구현이 필요하다. 회전축이 기울여진 상황에서 회전자계를 발생시키는 식이 보고되고 있으나 회전형 전동기와 달리 공증된 회전자계 식이 없는 상황이다. 본 연구에서는 전류벡터를 이용한 회전자계 식에 대한 연구를 진행하였다.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.220-222
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• 1999

This paper presents a numerical analysis of the eddy current testing with cracked pipe using finite element method (FEM). ${\vec{A}},\;{\phi}-{\vec{A}}$ method is adopted for the formulation of 3-dimensional(3-D) FEM with the brick element. The cracks investigated here are the inner and outer surface of axial symmetry, 90 degree circular one. The algorithm of 3-D numerical analysis is employed for the axisymmetric pipe with the cracks. In order to verify the validity of 3-D numerical analysis, the results are compared with those of 2-D analysis with the same type of the model. The differential impedance is obtained by using energy method and its locus are various 8-shaped curves for each cracks. The ICCG method is used for the calculation of a matrix.

• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.210-213
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• 2000

In the closed range space, the parallel two CCD cameras are used to acquire a pair of stereo image. The acquired stereo image are computed with Wavelet Transform repeatedly and including the low frequency component, the image size of those are reduced. It is the pyramid structure. The optimum matching point is searched to the pixel. Then appling the optimum matching point to DLT, it extract the three - dimensional surface coordinate from a stereo image. The direct linear transformation(DLT) method is used to calibrate the stereo camera compute the coordinate on a three dimensional space. To find the parameters for the DLT method, 30 control points which marked on the cylinder type object are used. To improve the matching algorithm, the paper select the pyramid structure for Wavelet Transform. The acquired disparity information is used to represent the really three-dimensional surface coordinate.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.347-348
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• 2018

일본 뇌염 바이러스(Japanese encephalitis virus)는 작은빨간집모기(Culex spp.)를 매개로 사람에게 감염될 수 있으며, 인체에 치명적인 질병을 유발한다. 일본 뇌염 바이러스의 혈청형(serotype)은 1종류이지만, 유전형(genotype)은 5종류(GI, GII, GIII, GIV, GV)로 분류되고 있다. 현재 일본 뇌염 바이러스 백신은 아시아 지역에서 감염 빈도가 높은 유전형 3(GIII)에 대한 백신이며, 사백신(inactivated vaccine)과 약독화 백신(attenuated vaccine)이 주로 사용되고 있다. 본 연구에서는 기존 백신의 부작용을 줄이고 한계점을 개선하기 위하여, 생물정보학 데이터베이스를 활용한 접근법을 통해 펩타이드 백신 후보군을 선별하였다. 5가지의 유전형 중에서도 감염 빈도가 가장 높은 유전형 3(GIII) 및 최근 감염빈도가 서서히 늘어나고 있어 주의가 요구되고 있는 유전형 1(GI)을 연구 대상으로 선정하였다. 여러 종류의 생물정보학 데이터베이스를 활용하여 백신으로 활용가치가 높은 것으로 보고되고 있는 외피 단백질(envelope protein)에 대한 아미노산 상동성을 분석하고, 이를 바탕으로 공통 적용이 가능한 동시에 면역원성이 높은 펩타이드 3종을 백신 후보군으로 선별하였다. 더 나아가 이들의 3차원 구조 모델링을 통해 보다 백신으로 활용 가능성이 높은 펩타이드를 최종 도출하였다.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.99-113
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• 2018

Recently, global warming has widened the habitat of mosquitoes and infection chances for mosquito-borne diseases are increasing. Flavivirus is a typical mosquito-borne virus. Flaviviruses with a relatively high frequency of infection in Asian countries include Zika, Dengue, and Japanese encephalitis viruses. Although distinctive diagnosis of flaviviruses is required because the symptoms and therapeutic method differ, there is no diagnostic method that can distinguish them accurately yet. In this study, we propose distinctive diagnosis method of flaviviruses using informations and analysis tools constructed in bioinformatic databases. The envelope protein and non-structural protein 1 which are useful protein for the immuno-diagnostics of three flaviviruses were selected. Their homology was analyzed by multiple sequence alignments and epitope candidates consisting of 10-15 amino acids were selected. Finally two epitopes were suggested to be most useful by immunogenicity analysis and 3D structure prediction. These approaches and results are expected to be great value in the distinctive diagnosis of three flaviviruses with a high frequency of infection in Asian countries.