• Journal of Industrial Technology
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• v.10
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• pp.15-20
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• 1990

A parallel processing algorithm for discrete Kalman filter, which is one of the most commonly used filtering technique in modern control, signal processing, and communication, is proposed. Previously proposed parallel algorithms to decrease the number of computations needed in the Kalman filter are the hierachical structures by distributed processing of measurements, or the systolic structures to disperse the computational burden. In this paper, a new parallel Kalman filter employing a structure similar to recursive doubling is proposed. Estimated values of state variables by the new algorithm converge with two times faster data processing speed than that of the conventional Kalman filter. Moreover it maintains the optimality of the conventional Kalman filter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.994-1000
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• 2014

This paper considers the problem of continuous and discrete time dissipative filter design method for the singular systems with polytopic uncertainties. Two bounded real lemmas (BRL) for the robust filters of dissipative singular systems along with the polytopic uncertainties are proposed on the basis of Lyapunov criterion. The sufficient conditions for both continuous and discrete time dissipative filter design methods are derived using the obtained BRL by linear matrix inequality (LMI) approach. Finally, the validities of the proposed methods are shown by numerical examples.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.139-144
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• 2001

Insulation aging diagnosis system provides early warning regarding electrical equipment defect. Early warning is very important in that it can avoid great losses resulting from unexpected shutdown of the production line. Since relations of insulation aging and partial discharge dynamics are non-linear, it is very difficult to provide early warning in an electrical equipment. In this paper, we propose the design method of insulation aging diagnosis system that use a magnetic wave and acoustic signal to diagnoses an electrical equipment. Proposed system measures the partial discharge on-line from DAS(Data Acquisition System) and acquires 2D patterns from analyzing it. For filtering the noise contained in sensor signals we used ICA algorithms. Using this data, design of the neuro-fuzzy model that diagnoses an electrical equipment is investigated. Validity of the new method is asserted by numerical simulation.

• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.148-154
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• 2009

In recent days, large-sized flat-panel display (FPD) has been increasingly applied to computer monitors and TVs. Mura defects, appearing as low contrast or non-uniform brightness region, sometimes occur in manufacturing of the Thin-Film Transistor Liquid-Crystal Displays (TFT-LCD). Implementation of automatic Mura inspection methods is necessary for TFT-LCD production. Various existing Mura detection methods based on regression diagnostics, surface fitting and data transformation have been presented with good performance. This paper proposes an efficient Mura detection method that is based on a regression diagnostics using studentized residuals for automatic Mura inspection of FPD. The input image is estimated by a linear model and then the studentized residuals are calculated for filtering Mura regions. After image dilation, the proposed threshold is determined for detecting the non-uniform brightness region in TFT-LCD by means of monitoring the every pixel in the image. The experimental results obtained from several test images are used to illustrate the effectiveness and efficiency of the proposed method for Mura detection.

• Earthquakes and Structures
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• v.15 no.5
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• pp.565-581
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• 2018

This paper proposes a new analytical formulation for computing the seismic input at various levels of a structure in terms of floor response spectra. The approach, which neglects the dynamic interaction between primary structure and secondary element, is particularly useful for the seismic assessment of secondary and non-structural elements. The proposed formulation has a robust theoretical basis and it is based on few meaningful dynamic parameters of the main building. The method has been validated in the linear and nonlinear behavior of the main building through results coming from both experimental tests (available in literature) and parametric numerical analyses. The conditions, for which the Floor Spectrum Approach and its simplified assumptions are valid, have been derived in terms of specific interval ratios between the mass of the secondary element and the participant mass of the main structure. Finally, a practice-oriented formulation has been derived, which could be easily implementable also at code level.

• Journal of Intelligence and Information Systems
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• v.3 no.1
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• pp.47-68
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• 1997

This paper discusses a method of modified Elman network(1990) for nonlinear predictions and its a, pp.ication to forecasting daily exchange rate returns. The method consists of two stages that take advantages of both time domain filter and modified feedback networks. The first stage straightforwardly employs the filtering technique to remove extreme noise. In the second stage neural networks are designed to take the feedback from both hidden-layer units and the deviation of outputs from target values during learning. This combined feedback can be exploited to transfer unconsidered information on errors into the network system and, consequently, would improve predictions. The method a, pp.ars to dominate linear ARMA models and standard dynamic neural networks in one-step-ahead forecasting exchange rate returns.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.4-5
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• 2012

원거리에서의 얼굴 식별은 낮은 영상 해상도를 비롯하여 블러와 잡음으로 인한 어려움이 크다. 더욱이 모바일 장치에서 실시간 처리를 하기 위하여 느린 수행속도와 제한된 메모리 등 모바일 계산환경을 필히 고려하여야 한다. 본 논문은 모바일 환경에서 주파수 영역의 정합 필터를 이용한 얼굴 식별 방법을 제안한다. 얼굴 식별은 선형(linear) 및 위상(phase-only) 필터, 순차적인 검증 단계를 이용하여 수행된다. 얼굴 후보 윈도우 영역은 선형 필터와 위상 필터를 수행하여 검출하고 순차적인 검증 단계는 피부색 테스트와 경계 마스크 필터링 테스트로 구성한다. 제안된 방법은 Android 플랫폼에서 Java을 이용하여 모바일 폰에서 개발하였다. 예비실험 결과는 모바일 환경에서 얼굴 식별이 실시간으로 성공적으로 수행될 수 있음을 보인다.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.233-236
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• 2005

Polarization filtering based on the multicomponent complex trace analysis method is performed to reject Rayleigh waves and to enhance S waves. To test the polarization filter, synthetic seismic data were constructed for a simple two-layer model based on the finite difference method. Rayleigh waves with elliptic motion are eliminated effectively and P and S waves with linear motions are well separated each other.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.152-155
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• 1994

The presence of joint elasticity or the arm flexibility causes low damped oscillatory position error along a desired trajectory. We utilize a stochastic model for describing the fast dynamics and the approximation error. A second order shaping filter is synthesized such that its spectrum matches that of the fast dynamics. Augmenting the state vector of slow part with that of shaping filter, we obtain a nonlinear dynamics to which a Gaussian white noise is injected. This modeling approach leads us to the design of an extended Kalman filter(KEF) and a linear quadratic Gaussian(LQG) control scheme. We present the simulation results of this control method. The simulation results show us that our Kalman filtering approach is one of prospective methods in controlling the flexible arms.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.105-108
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• 1996

In this paper, we present an interpolation schema for image resolution enhancement using fuzzy logic. Proposed algorithm can recover both low and high frequency information in image data. In general, interpolation techniques are based on linear operators which are essentially details in the original image. In our fuzzy approach, the operator itself balances the strength of its sharpening and noise suppressing components according to the properties of the input image data. The proposed interpolation algorithm is performed in three step. First logic reasoning is applied to coarsely interpret the high frequency information. These results are combined to obtain the optical output. Using our approach, resolution of the original image can be applied to various kind of image processing topics such as image enhancement, subpixel edge detection, and filtering.