• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.83.6-83
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• 2002

$\textbullet$ Disturbance observer $\textbullet$ Performance enhancement $\textbullet$ LFT formulation $\textbullet$ Structured singular value $\textbullet$ Maximum bandwidth of DOB $\textbullet$ DVD experiments $\textbullet$ Robust stable disturbance observer

• 충청수학회지
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• 제2권1호
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• pp.9-14
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• 1989

Certain type of singular two point boundary value problem is studied. This contains a wider class of differential equations than [5]. An example is provided for comparison with earlier results.

• 한국전산구조공학회논문집
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• 제24권5호
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• pp.481-489
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• 2011

본 논문에서는 트러스 구조 해석에 있어서 기존의 하중법을 특이값 분해로 정식화 한 새로운 하중법을 제안하였다. 하중법은 유한요소법을 이용한 트러스 구조 해석법과 달리 접근 방법이 쉬우며 어려운 구조적 개념이 필요하지 않아 일반적인 트러스 구조 해석에서 주로 사용된다. 또한 트러스 및 핀-조인트 골조와 같은 골조 시스템의 구조 해석에도 적용할 수 있어 매우 효과적인 방법이다. 하지만 하중법은 많은 수식을 통해 구조 해석을 수행하여야 하므로 이로 인해 수치상의 오류가 발생할 수 있다. 따라서 본 연구에서는 이러한 문제점을 보완하기 위하여 기존의 하중법에서 사용하던 수식을 특이값 분해로 정식화 한 새로운 하중법을 제안하였다. 이 방법을 사용하여 트러스 구조물을 해석할 경우 기존의 하중법의 기본개념을 그대로 이용하면서도 복잡한 수식을 사용하지 않고 해석을 수행할 수 있으므로 매우 효율적인 방법이다.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.729-739
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• 2015

An algorithm for fault detection and classification method for wide-area protection in Korean transmission systems is proposed. The modeling of 345-kV and 765-kV Korean power system transmission networks using the Electro Magnetic Transient Program - Restructured Version (EMTP-RV) is presented and the algorithm for fault detection and classification in transmission lines is developed. The proposed algorithm uses the Wavelet Transform (WT) and Singular Value Decomposition (SVD). The Singular value of Approximation coefficient (SA) and part Sum of Detail coefficient (SD) are introduced. The characteristics of the SA and SD at the fault conditions are analyzed and used in the algorithm for fault detection and classification. The validation of the proposed algorithm is verified by various simulation results.

• 한국통신학회논문지
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• 제38A권11호
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• pp.928-937
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• 2013

본 논문은 특이값 분해와 영상 피라미드를 이용한 새로운 대비 개선 방법을 제안한다. 제안된 방법은 다음과 같이 네 단계로 진행 된다. 먼저 전역 명암대비와 지역적 디테일을 향상시키기 위해 영상 피라미드를 이용하여 영상을 기저영상과 세부영상들로 분해한다. 전역 명암대비 향상은 특이값 분해를 이용하여 영상 전체의 명암대비를 향상시키고, 지역적 디테일 향상은 가중치를 이용하여 개선시킨다. 영상 합성은 영상의 컬러 일관성을 유지하기 위해 컬러와 명암성분들을 결합한다. 실험 결과를 통해 제안된 방법은 기존의 방법들보다 영상의 세부 정보를 강화하면서 전체적인 명암대비 개선을 보인다.

• 한국자기학회지
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• 제17권6호
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• pp.259-264
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• 2007

본 논문에서는 모델 함정에 의해 발생하는 정 자기장 신호 특성을 수학적으로 모델링하는 방법에 대해 기술하고 있다. 특정 위치에 설치된 자기센서들에 의해 계측된 자기장 신호 값들로 부터 특이치 분해(singular value decomposition) 방법을 이용한 등가 자기원 다이폴 모델링 기법을 제안하였으며, 제안된 기법의 타당성은 비자성 자기실험실에서 측정된 자기장 값들과의 비교를 통해 성공적으로 검증되었다. 본 논문에서 제안된 기법은 모델 함정 뿐 만 아니라 실 함정에서의 다양한 심도 변화에 따른 정 자기장 신호 분포 특성 예측 시 직접 활용이 가능하다.

• 대한임베디드공학회논문지
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• 제18권3호
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• pp.117-124
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• 2023

In the machine vision inspection equipment, diameter measurement is important process in inspection of cylindrical object. However, machine vision inspection equipment requires complex algorithm processing such as camera distortion correction and perspective distortion correction, and the increase in processing time and cost required for precise diameter measurement. In this paper, we proposed the algorithm for diameter measurement of cylindrical object using the laser displacement sensor. In order to fit circle for given four input outer points, grid search algorithms using root-mean-square error and mean-absolute error are applied and compared. To solve the limitations of the grid search algorithm, we finally apply the singular-value-decomposition based circle fitting algorithm. In order to compare the performance of the algorithms, we generated the pseudo data of the outer points of the cylindrical object and applied each algorithm. As a result of the experiment, the grid search using root-mean-square error confirmed stable measurement results, but it was confirmed that real-time processing was difficult as the execution time was 10.8059 second. The execution time of mean-absolute error algorithm was greatly improved as 0.3639 second, but there was no weight according to the distance, so the result of algorithm is abnormal. On the other hand, the singular-value-decomposition method was not affected by the grid and could not only obtain precise detection results, but also confirmed a very good execution time of 0.6 millisecond.

• Journal of applied mathematics & informatics
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• 제27권3_4호
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• pp.501-515
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• 2009

A second order nonlinear ordinary differential equation is obtained by solving the initial-boundary value problem of a class of elas-todynamics equations, which models the radially symmetric motion of a incompressible hyper-elastic solid sphere under a suddenly applied surface tensile load. Some new conclusions are presented. All existence conditions of nonzero solutions of the ordinary differential equation, which describes cavity formation and motion in the interior of the sphere, are presented. It is proved that the differential equation has singular periodic solutions only when the surface tensile load exceeds a critical value, in this case, a cavity would form in the interior of the sphere and the motion of the cavity with time would present a class of singular periodic oscillations, otherwise, the sphere remains a solid one. To better understand the results obtained in this paper, the modified Varga material is considered simultaneously as an example, and numerical simulations are given.

• 전기학회논문지
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• 제58권5호
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• pp.1041-1046
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• 2009

In this paper, we proposed a robust watermark scheme for image based on SVD(Singular Value Transform) and Triplet. First, the original image is decomposed by using 3-level DWT, and then used the singular values changed for embedding and extracting of the watermark sequence in LL3 band. Since the matrix of singular values is not easily altered with various signal processing noises, the embedded watermark sequence has the ability to withstand various signal processing noise attacks. Nevertheless, this method does not guarantee geometric transformation(such as rotation, cropping, etc.) because the geometric transformation changes the matrix size. In this case, the watermark sequence cannot be extracted. To compensate for the above weaknesses, a method which uses the triplet for embedding a barcode image watermark in the middle of frequency band is proposed. In order to generate the barcode image watermark, the pattern of the watermark sequence embedded in a LL3 band is used. According to this method, the watermark information can be extracted from attacked images.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.223-227
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• 2021

A treatment based on the algebraic operations on fuzzy numbers is used to replace the fuzzy problem into an equivalent crisp one. The finite difference technique is used to replace the continuous boundary value problem (BVP) of arbitrary order 1<α≤2, with fuzzy boundary parameters into an equivalent crisp (algebraic or differential) system. Three numerical examples with different behaviors are considered to illustrate the treatment of the singular perturbed case with different fractional orders of the BVP (α=1.8, α=1.9) as well as the classical second order (α=2). The calculated fuzzy solutions are compared with the crisp solutions of the singular perturbed BVP using triangular membership function (r-cut representation in parametric form) for different values of the singular perturbed parameter (ε=0.8, ε=0.9, ε=1.0). Results are illustrated graphically for the different values of the included parameters.