• 한국해안해양공학회지
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• 제14권4호
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• pp.282-285
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• 2002

본 연구에서 선형파 이론을 사용하여 파랑변형을 예측할 경우 소멸파 성분의 역학적인 크기를 정량화 하는 작업을 하였다. 즉, 진행파 성분뿐만 아니라 소멸파의 영향을 받는성분의 운동에너지와 위치에너지를 유도하였다. 소멸파 성분에는 진행파와 소멸파의 합성 성분, 서로 같은 소멸파의 합성 성분, 서로 다른 소멸파의 합성 성분으로 구성되어 있다. 수평길이 당 소멸파의 에너지 성분은 수명길이가 커짐에 따라 기하급수적으로 감소한다.

• Journal of applied mathematics & informatics
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• 제32권1_2호
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• pp.285-295
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• 2014

In the setting of semidenite linear complementarity problems on $S^n$, we focus on the Stein Transformation $S_A(X)\;:=X-AXA^T$, and show that $S_A$ is (strictly) monotone if and only if ${\nu}_r(UAU^T{\circ}\;UAU^T)$(<)${\leq}1$, for all orthogonal matrices U where ${\circ}$ is the Hadamard product and ${\nu}_r$ is the real numerical radius. In particular, we show that if ${\rho}(A)$ < 1 and ${\nu}_r(UAU^T{\circ}\;UAU^T){\leq}1$, then SDLCP($S_A$, Q) has a unique solution for all $Q{\in}S^n$. In an attempt to characterize the GUS-property of a nonmonotone $S_A$, we give an instance of a nonnormal $2{\times}2$ matrix A such that SDLCP($S_A$, Q) has a unique solution for Q either a diagonal or a symmetric positive or negative semidenite matrix. We show that this particular $S_A$ has the $P^{\prime}_2$-property.

• 대한전자공학회논문지
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• 제20권2호
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• pp.41-51
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• 1983

선형변환기법을 이용하여 사다리형태의 수동여파회로를 능동화하는데 있어서 새로운 방식을 제시하였다. 전압과 전류영역으로 나타내는 회로망변수를 선형변환메이트릭스의 사용으로 새로운 영역의 변수로 바꾸어서 회로를 능동화하는 과정에서 종전의 방법은 개개의 리액턴스소자에 대해서 선형변환을 적용하는데 비하여 본연구에서는 병렬과 직렬의 두개의 리액턴스소자에 동시에 선형변환을 적용함으로써 회로능동화에 소요되는 연산증폭기의 개수를 여파기의 차수와 같도록 줄일수 있었다. 저역통과여파기의 경우. 선형변환메이트릭스를 적절하게 선택함으로써 사다리형회로의 리액턴스소자의 배치여하에 관계없이 규칙적이며 단계적인 회로능동화를 가능하게 하였다. 이 방법에 따라 5차 Chebyshev 저역통과여파회로를 능동화한 다음 이론치에 매우 근사한 주파수특성을 측정으로 얻음으로써 이 방식의 타당성을 입증하였다.

• 한국해안해양공학회지
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• 제15권1호
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• pp.51-58
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• 2003

본 연구에서 선형파 이론을 사용하여 파랑변형을 예측할 경우 소멸파 성분의 역학적인 크기를 정량화 하는 작업을 하였다. 두 계단 위로 파랑이 전파하는 경우 고유함수 전개법을 사용하여 반사파와 통과파의 진폭을 진행파와 소멸파 성분 별로 구한 다음 진행파 대비 소멸파 에너지의 중요성이 크게 나타나는 조건을 찾아보았다. 그 결과 앞 계단에서의 상대수심이 k$_1$h$_1$＝0.11$\pi$이고.수심의 비 h$_2$/h$_1$이 0에 가까울 때 소멸파 에너지가 가장 크게 나타남을 알 수 있었다.

• Journal of the Korean Statistical Society
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• 제25권2호
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• pp.217-233
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• 1996

This paper gives a rigorous proof of an asymptotic result about bias and variance for a transformation-based nonparametric regression estimator proposed by Park et al (1995).

• Communications for Statistical Applications and Methods
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• 제5권3호
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• pp.581-589
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• 1998

An algorithm is proposed for the $L_1$-estimation with linear equality and inequality constraints in linear regression model. The algorithm employs a linear scaling transformation to obtain the optimal solution of linear programming type problem. And a special scheme is used to maintain the feasibility of the updated solution at each iteration. The convergence of the proposed algorithm is proved. In addition, the updating and orthogonal decomposition techniques are employed to improve the computational efficiency and numerical stability.

• 대한전기학회논문지
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• 제40권9호
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• pp.920-928
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• 1991

This paper proposes a design procedure based on the LQG/LTR (Linear Quadratic Gaussian/ Loop Transfer Recovery) method for a launch vehicle. Continuous-discrete type LQG/LTR compensators are designed using the e-transformation to overcome numerical problems occurring in the process of discretization. The e-LQG/LTR compensator using the e-transformation is compared width the z-LQG/LTR compensator using the z-transformation. The performance of the overall system controlled by the compensator is evaluated via simulations, which show that the discretization error problem is resolved and the control performances are satisfactory in the proposed compensator.

• The Journal of the Acoustical Society of Korea
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• 제22권4E호
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• pp.150-154
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• 2003

The distortion effects of microphones have been analyzed and compensated at mel-frequency feature domain. Unlike popular bias removal algorithms a linear transformation of mel-frequency spectrum is incorporated. Although a diagonal matrix transformation is sufficient for medium-quality microphones, a full-matrix transform is required for low-quality microphones with severe nonlinearity. Proposed compensation algorithms are tested with HTIMIT database, which resulted in about 5 percents improvements in recognition rate over conventional CMS algorithm.

• 한국CDE학회논문집
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• 제12권5호
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• pp.354-365
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• 2007

We present novel methods to generate a sequence of shapes that represents the pattern of morphological development or transformation of Bezier curves. The presented methods utilize the intrinsic geometric structures of a Bezier curve that are derived from rib and fan decomposition (RFD). Morphological development based on RFD shows a characteristic pattern of structural growth of a Bezier curve, which is the direct consequence of development path defined by fans. Morphological transformation based RFD utilizes development patterns of source and target curves to mimic the theory of evolutionary developmental biology: although the source and target curves are quite different in shapes, we can easily find similarities in their younger shapes, which makes it easier to set up feature correspondences for blending them. We also show that further controls on base transformation for intensity of feature blending, and extrapolation can compensate the immaturity of blended curves. We demonstrate the experimental results where transformation patterns are smoother and have unique geometric style that cannot be generated using conventional methods based on multi-linear blending.

• International Journal of Aeronautical and Space Sciences
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• 제13권4호
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• pp.458-467
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• 2012

In this study, the linear viscoelastic response of a rectangular laminated plate is investigated. The viscoelastic properties, expressed by two basic spring-dashpot models, that is Kelvin and Maxwell models, is assumed in the range to investigate the influence of viscoelastic coefficients to mechanical behavior. In the present study, viscoelastic responses are performed for two popular equivalent single-layered theories, such as the first-order shear deformation theory (FSDT) and third-order shear deformation theory (TSDT). Compliance and relaxation modulus of time-dependent viscoelastic behavior are approximately determined by Prony series. The constitutive equation for linear viscoelastic material as the Boltzmann superposition integral equation is simplified by the convolution theorem of Laplace transformation to avoid direct time integration as well as to improve both accuracy and computational efficiency. The viscoelastic responses of composite laminates in the real time domain are obtained by applying the inverse Laplace transformation. The numerical results of viscoelastic phenomena such as creep, cyclic creep and recovery creep are presented.