• 대한원격탐사학회지
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• 제2권1호
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• pp.3-11
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• 1986

The current methods of estimating contest distribution function in contextual clarifier are to "classify and count", GTGM (ground-truth-guided-method) and unbiased estimator. In this paper we propose a new contextual classifier echoes context distribution is replaced by context probability that is estimated from transition probability. The classification accuracy increases considerably compared with the classical one.

• 한국소음진동공학회논문집
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• 제17권9호
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• pp.805-812
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• 2007

This paper present a robust controller design method based on the estimation of velocity disturbance to construct a robust fine seek control system. A loop gain adjustment algorithm is introduced to accurately estimate the velocity disturbance in spite of the uncertainties of fine actuator. A weighting function is optimally selected from a minimum fine seek open-loop gain, calculated by estimating the velocity disturbance. A robust fine seek controller is designed by considering a robust $H_{\infty}$ control problem using the weighting function. The proposed controller design method is applied to the fine seek control system of a DVD rewritable drive and is evaluated through the experimental results.

• 한국유체기계학회 논문집
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• 제7권2호
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• pp.7-13
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• 2004

In an attempt to solve multiobjective optimization problems, weighted sum method is most widely used for the advantage that a designer can consider the relative significance of each object functions by weight values but it can be highly sensitive to weight vector and occasionally yield a deviated optimum from the relative weighting values designer designated because the multiobjective function has the form of simple sum of the product of the weighting values and the object functions in traditional approach. To search the design solution agree well to the designer's weighting values, we proposed new multiobjective function which was the functional of each normalized objective functions and considered to find the design solution comparing the distance between the characteristic line and the ideal optimum. In this study, proposed multiobjective function was applied to design high efficiency and low noise axial flow fan and the result shows this approach is effective for the case that the quality of the design can be highly affected by the designer's subjectiveness represented as weighting values in multiobjective design optimization process.

• 한국광학회지
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• 제9권6호
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• pp.417-422
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• 1998

쌍안정 TN LCD를 매트릭스 어드레싱 구동을 할 때 패널 파라미터와 구동 파형을 최적화하는 방법을 제시하였다. 쌍안정 TN 액정 셀에서 데이터 전압이 광 수위칭 특성에 미치는 영향을 측정하였고 이를 이론적으로 모델링 하였다. 스위칭에 데이터 전압이 미치는 영향을 고려하기 위해 시간의 함수로써 weighting 함수를 도입하였다. Weighting 함수를 알아내면 최소의 데이터 펄스폭을 계산함으로써 멀티플렉싱 구동을 위한 최대의 구동 라인 수를 계산할 수 있다. 또한 패널 파라미터(예, d/p)를 변화 시키면서 테스트 셀을 구동하면 고속 동작을 위한 파라미터를 최적화할 수 있다. 이로부터 이론적 예측과 실험 결과가 잘 일치하는 것을 확인하였다.

• 한국음향학회지
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• 제20권5호
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• pp.48-53
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• 2001

LPC분석 기반 화자 확인에서 잔여성분(residue) 예측은 보통 무시되고, LPCC(LPC-cepstrum)만이 특징 파라미터로 사용된다. 본 연구에서는 잔여성분으로부터 추출된 예측파라미터인 잔여 켑스트럼(residual cepstrum)을 LPCC와 함께 여러 환경에서 구축된 데이터 베이스에서 화자특징 파라미터로 사용하였다. 또한, 잔여 켑스트럼에 포함되어있는 화자 고유성분인 피치(pitch)성분에 큰 가중치(weighting)를 줌으로써 화자간 변이(inter-speaker variation)가 커지도록 하는 가중치 함수를 제안한다. 실험 결과, LPCC만을 특징 파라미터로 사용하였을 경우보다 잔여 켑스트럼 (RCEP)과 LPCC를 동시에 사용했을 경우 약 6％가량의 인식 오류율이 향상 되었으며, 제안한 가중치 함수를 적용한 잔여 켑스트럼 (RCEP)과 LPCC를 동시에 사용했을 경우 인식 오류율이 가중치를 주지 않은 경우보다 약 2.45％가량 개선되었다.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.227-242
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• 2015

This paper proposes a weighting factor optimization method in predictive control algorithm for torque ripple reduction in an induction motor fed by an indirect matrix converter (IMC). In this paper, the torque ripple behavior is analyzed to validate the proposed weighting factor optimization method in the predictive control platform and shows the effectiveness of the system. Therefore, an optimization method is adopted here to calculate the optimum weighting factor corresponds to minimum torque ripple and is compared with the results of conventional weighting factor based predictive control algorithm. The predictive control algorithm selects the optimum switching state that minimizes a cost function based on optimized weighting factor to actuate the indirect matrix converter. The conventional and introduced weighting factor optimization method in predictive control algorithm are validated through simulations and experimental validation in DS1104 R&D controller platform and show the potential control, tracking of variables with their respective references and consequently reduces the torque ripple.

• 충청수학회지
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• 제27권3호
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• pp.513-521
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• 2014

Via extension of the classical double-Newton method, we propose high-order family of two-point methods in this paper. Theoretical and computational properties of the proposed methods are fully investigated along with a main theorem describing methodology and convergence analysis. Typical numerical examples are thoroughly treated to verify the underlying theory.

• 한국해양공학회지
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• 제13권1호통권31호
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• pp.39-50
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• 1999

특이 가중함수로 표현된 shepard interpolant와 일관조건을 사용하여 무요소법 형성함수를 도출하였다. 따라서 통상의 EFGM(Element Free Galerkin Method)과는 달리 변위로 주어지는 경계조건을 자연스럽게 부과할 수 있다. 수치계산 예로서 외팔보 문제를 다루었는데 보이론과 비교하여 매우 잘 맞는 결과를 보여주고, 유한요소법과의 결합도 자연스럽게 이루어짐을 보인다. 또 penny-shaped 균열을 다루는데, 응력확대계수는 균열 표면의 변위로부처 직접 계산하여 해석해와 비교한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.577-580
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• 1996

LQ-servo is a stability-robustness guaranteed multivariable controller design method based on the LQR structure to improve command following performance with output feedback. In this paper, a new type of PI controller based on LQ-servo is introduced. Then, Command following performance is improved using the limiting behavior of the control gain and weighting factors on the low frequency part of design parameter Q that is the state weighting matrix in the cost function.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.639-642
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• 1998

This paper proposes a new wide-band beamforming which has guassian weighting. For the prupose of measurement this beam is formed by using all sensors toghether, not octave-by-octave. Weighting is applied to each sensor before time-delay compensation as a frequency-dependent function. As the resutls of the simulation of the proosed algorithm for nested linear array having 17 sensors for each octave, it is confirmed that beam can be formed with all sensors together and uniform directivity index can be achieved by proposed algorithm.