• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.2833-2835
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• 1999

이 논문에서는 임의의 시스템 동정에 사용되는 적응필터의 계수를 최적화시키는 방법으로 광범위하게 사용되어지고 있는 기존의 적응 알고리즘인 Least Mean Square(LMS)방법과 최근들어 다양한 최적화 문제에 응용되고 있는 유전자 알고리즘(GA)을 합성한 하이브리드 형태의 적응 알고리즘을 사용한다. 이 알고리즘은 TIR 필터를 설계하는데 있어, 경사하강법의 개념을 사용함으로써 야기되는 지역 수렴문제의 단점을 보완하기 위해, 미분과 같은 결정론적인 규칙없이 단지 확률적인 연산자만으로 진행하는 유전자 알고리즘을 이용한다. 그리고 유전자 알고리즘에 있어서 확률적인 연산을 사용함으로써 발생하는 많은 계산량과 느린 수렴속도 문제를 LMS의 경사하강법을 이용하여 보완한다. 이처럼 유전자 알고리즘이 지닌 장점과 LMS 알고리즘이 갖는 장점을 이용하여 각 알고리즘이 지니는 단점을 서로 보완함으로써 알고리즘의 성능을 향상시키고 이 향상된 알고리즘을 이용하여 최적 필터계수를 찾는다 이렇게 얻은 필터계수값을 이용하여 적응 필터의 성능을 확인 평가한다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.8 no.3
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• pp.151-157
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• 1979

A general solution for temperature distribution And heat transfer for a uniform straight fin is yen. Thermal conductivity and heat transfer coefficient between the fin and the surrounding fluid can be arbitrary functions of temperature. Minimum weight conditions for a rectangular fin are analyzed, Numerical results for some special cases are given in graphical forms.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2A
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• pp.179-186
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• 2008

To analyzing the validity for using the stiffness ratio in evaluating edge stiffness effect of the composite girder bridges, modification factors are analyzed with changing girder spacing. The relation between stiffness ratio, loading type, girder spacing and modification factors is analyzed. From the results of comparing modification factors analyzed from the field loading test and the established design method with the modification factor analyzed from this study, it was concluded that evaluating the edge stiffness effect using stiffness ratio is possible.

• 어항어장
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• s.44
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• pp.67-75
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• 1998

본 연구의 목적은 서로 다른 형태를 갖는 피복블록의 형상에 따른 Hudson식의 안정계수 값들과 양압력의 관계를 방파제의 안정성과 연계 해석하여, 방파제 단면설계에 있어서 피복블록의 선택 및 소요중량 산정에 효과적으로 이용하고자 한다.

• Journal of KIISE:Software and Applications
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• v.30 no.5_6
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• pp.454-460
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• 2003

In this paper, we propose an efficient method for recognizing human lips. Based on Point Distribution Model, a lip shape is represented as a set of points. We calculate a lip model and the distribution of shape parameters using Principle Component Analysis and Gaussian mixture, respectively. The Expectation Maximization algorithm is used to determine the maximum likelihood parameter of Gaussian mixture. The lip contour model is derived by using the gray value changes at each point and in regions around the point and used to search the lip shape in a image. The experiments have been performed for many images, and show very encouraging result.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.2 s.308
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• pp.72-80
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• 2006

In this paper, we propose a new descriptor for 3D model retrieval based on shape information. The proposed method consists of two steps including ray casting method and spherical harmonic function, considering geometric properties of model. In the ray casting method, an adaptive sampling is performed for external shape information. By increasing shape information included in the descriptor, we improve the discriminating power of the proposed descriptor. The coefficients of spherical harmonic function are adaptively calculated, considering geometric frequency characteristics. This makes the descriptor more compact and concise without decreasing the retrieval performance. By combining two methods, we achieve more improved retrieval results.

• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.1-10
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• 2002

Flow computations around forward sweep wing small aircraft have been conducted in this study. The main-wing of the forward-wing small aircraft is composed of two planforms: the inboard wing section with backward sweep angle which is known as strake and the outboard wing section with forward sweep angle. The geometrical discontinuity or kink generated by the combination of these two different planforms requires detailed flow analysis around wing. Four different solvers were used to calculate aerodynamic data and the accuracy of each method is examined. For the convenience of grid generation over the aircraft geometry, the overset grid method was applied. Through this calculation, the basic aerodynamic data of the forward-wing aircraft were provided and the aerodynamic characteristics of the wing is expounded.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1345-1346
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• 2006

본 논문에서는 솔레노이드 형태의 칩 인덕터와 나선형태의 박막 인덕터에 대하여 주파수 특성을 비교 분석하여 장 단점을 정의하고자 한다. 솔레노이드형 RF 칩 인덕터는 $1.0mm{\times}0.5mm{\times}0.5mm$의 크기에 11nH의 인덕턴스를 가질 수 있도록 6회 권선하였다. 나선형 박막 인덕터는 $213{\mu}m{\times}250{\mu}m{\times}304{\mu}m$의 크기에 11nH의 인덕턴스를 가질 수 있도록 7회 권선하였다. 시뮬레이션을 위하여 AnSoft사의 HFSS를 이용하였으며, 이 결과 솔레노이드형 RF 칩 인덕터는 2GHz에서 77 정도의 품질계수와 5.6GHz의 SRF를 가진다. 반면 나선형 박막 인덕터는 2GHz에서 14 정도의 품질계수와 4.5GHz의 SRF를 가진다. 성능면에서는 솔레노이드형 RF 칩 인덕터가 우수한 특성을 나타내었으나 크기를 감소시키는데 제한을 받으므로, 향후 소형 경량화를 위하여 박막 인덕터의 개발은 필수적이며, 성능을 더욱 향상시키기 위하여 나선형태와 재료의 개발이 필수적이라 하겠다.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.1
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• pp.90-99
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• 2002

The prediction of stress intensity factor(SIF) is one of the most important factors to analyse the propagation behavior of cracks in hull structural members. Up to now, however, simplified prediction method of SIF has not yet been established for the cracks experienced in large complex structures. As a first step to predict crack propagation behavior in a ship structure with very large structural redundancies, simplified SIF prediction formulas for various crack shapes were derived based on the results of the stress analysis under a non-crack condition in this study. The adequacy of the proposed method was then verified in comparison with other experimental and analysis results.

• Journal of the Korea Society of Computer and Information
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• v.3 no.3
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• pp.73-81
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• 1998

In this paper suggest for methods disease region feature extraction of medical image using wavelet. In the preprocessing, the shape informations of medical image are selected by performing the discrete wavelet transform(DWT) with four level coefficient matrix. In this approach, based on the characteristics of the coefficient matrix, 96 feature parameters are calculated as follows: Firstly. obtaining 32 feature parameters which have the characteristics of low frequency from the parameters according to the horizontal high frequency are calculated from the coefficient matrix of horizontal high frequency. In the third place, 16 vertical feature parameters are also calculated using the same kind of procedure with respect to the vertical high frequency. Finally, 32 feature parameters of diagonal high frequency are obtained from the coefficient matrix of diagonal high frequency. Consequently, 96 feature aprameters extracted. Using suggest algorithm in this paper will, implamentation can automatic recognition system, increasing efficiency of picture achieve communication system.