• 제어로봇시스템학회논문지
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• 제12권2호
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• pp.93-100
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• 2006

In this paper, a new-type Extended Kalman Filter (EKF) is proposed as a robust nonlinear filter for a stochastic nonlinear system. The original EKF is widely used for various nonlinear system applications. But it is fragile to its estimation errors because they give rise to linearization errors that affect the system mode1 as the modeling errors. The linearization errors are nonlinear functions of the estimation errors therefore it is very difficult to obtain the accurate error covariance of the EKF using the linear form. The inaccurately estimated error covariance hinders the EKF from being a sub-optimal estimator. The proposed filter tries to obtain the upper bound of the error covariance tolerating the uncertainty of the error covariance instead of trying to obtain the accurate one. It treats the linearization errors as uncertain modeling errors that can be handled by the robust linear filtering. In order to be more robust to the estimation errors than the original EKF, the proposed filter minimizes the upper bound like the robust linear filter that is applied to the linear model with uncertainty. The in-flight alignment problem of the inertial navigation system with GPS position measurements is a good example that the proposed robust filter is applicable to. The simulation results show the efficiency of the proposed filter in the robustness to initial estimation errors of the filter.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1989년도 봄 학술발표회 논문집
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• pp.66-70
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• 1989

Methods for identification of modal properties of linear structures are presented. The extended Kalman filtering technique is empolyed. The state equation is formulated by two different ways, namely by the time domain and frequency domain approaches. Verifications are carried out by using simulated records of ground acceleration and structural response. Then the techniques are applied to the estimation of modal parameters of a scaled model for a 3-story building which is installed on a shaking table.

• The Journal of the Acoustical Society of Korea
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• 제22권1E호
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• pp.43-48
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• 2003

The effects of linear acoustic channels have been analyzed and compensated at mel-frequency feature domain. Unlike popular RASTA filtering our approach incorporates separate filters for each mel-frequency band, which results in better recognition performance for heavy-reverberated speeches.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.947-950
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• 1998

Geological structures such as fault and fracture patterns provide important information about preliminary exploration of mineralized areas and geological characterization. We apply a filtering method taking the sun's azimuth angle into account to a shaded relief image derived from a digital elevation model (DEM), by which even linear edges extending parallel to the sun direction can be effectively extracted. Then, Generalized Hough tranform is applied to extract lineanments which correspond to fault and fracture patterns.

• 제어로봇시스템학회논문지
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• 제9권6호
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• pp.413-419
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• 2003

The objective of this paper is to survey and put in perspective the existing methods of dynamic filter development. This includes theories and practices for linear and nonlinear filters, multiple model filters, and data association methods for tracking in multitarget environment. The presentation of this paper is motivated by recent surge of interest in the area of designing feedback control systems with reduced number of sensors, detection and identification of abrupt changes, and multitarget tracking in clutter. It is hoped to be useful in view of the need to take a grasp of existing techniques before using them in practice and developing new techniques.

• 대한의용생체공학회:의공학회지
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• 제8권2호
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• pp.205-214
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• 1987

In this paper, a mathmatical model for the purpose of QRS detection is considered in the case of the occurence of nonoverlappjng pulse-shaped waveforms corrupted with white noise. The number of waveform, the arrival times, amplitudes, and widths of QRS complexes are regarded as random variables. The joint MAP estimation of all the unknown Quantities consists of linear filtering followed by an optimization procedure. Because the optimization procedure is time-consuming, this procedure is modified so that a threshold test is obtained.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.484-489
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• 1992

The inference of fuzzy controller can be considered a mapping from the controller input to membership value. The membership value, a kind of weight, has a role to decide if the input is appropriate to the rule. The membership function is described by several values, which are decided by a learning method. The learning method is adopted from adaptive filtering theory. The simulation shows the proposed fuzzy controller can learn linear and nonlinear functions. the structure of the proposed fuzzy controller becomes a kind of neural network.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.690-693
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• 1987

Base-line wandering and 60Hz noise in ECG are removed by linear phase FIR filter. The important problem in FIR filtering is to reduce the number of impulse response coefficients. It can be reduced by symmetrical impulse response. The ripple is improved by window function .omega.(n). And the determination of filter accuracy is proposed by PRD(percent rms difference) algorithm.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 춘계학술대회 학술발표 논문집
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• pp.73-76
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• 2000

문서 분류나 여과 문제에서 양의 학습 데이터의 부족은 성능 저하의 주요 원인이 된다. 이런 경우 여러 학습 알고리즘이 문제의 특성을 제대로 파악하지 못한다. 본 논문에서는 부스팅 기법을 도입하여 이 문제를 접근해 보았다. 부스팅 기법은 약한 능력을 보유한 학습 알고리즘을 부스팅 과정을 통해 궁극적으로 강력한 성능을 얻을 수 있게 해준다. 간단한 선형 퍼셉트론에 부스팅 기법을 도입하여 문서 여과에 적용하였다. 제안된 알고리즘을 Reuters-21578 문서 집합에 적용한 결과, 재현률 측면에서 다층 신경망보다 우수한 성능을 보였고 특히 양의 학습 데이터가 부족한 문제의 경우 탁월한 결과를 얻을 수 있었다.

• 영어어문교육
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• 제8권2호
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• pp.91-104
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• 2003

The purpose of this paper is to show that when we consider the analytical ways of Dissimilation, it becomes clear that it is insufficient to deal with it in just linear and nonlinear ways. Thus within a new framework to be introduced in this paper, Harmonic Phonology, we will reanalyze the phenomenon. We will also consider how the Obligatory Contour Principle (hereinafter, OCP) is used as both rule trigger and rule blocker in rule application, and works as a universal constraint, that is, a filtering device of ill formed representation. As we also consider it under the new framework, we can show the application position and motivation of rules appropriately and represent the phenomenon synthetically. (Yosu National University)