• 전자공학회논문지S
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• 제34S권12호
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• pp.70-80
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• 1997

This paper proposes a hierarchical Hausdorff distance (HD) matching algorithm baased on coarse-to-fine approach. It reduces the computational complexity greatly by using the pyramidal structures consisting of distance transform (DT) and edge pyramids. Also, inthe proposed hierarchical HD matching, a thresholding method is presented to find an optimal matching position with small error, in which the threshold values are determined by using the property between adjacent level of a DT map pyramid. By computer simulation, the performance of the conventional and proposed hierarchical HD matching algorithms is compared in therms of the matching position for binary images containing uniform noise.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3095-3097
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• 1999

A New path planning using modified DT(distance transform) algorithm for a remote mobile robot is proposed. The weakness of DT algorithm is that the generated path is not the best path of all possible paths. Modified DT algorithm proposed can compensate for the weakness of DT algorithm, but the operating time of the proposed is longer than that of DT algorithm.

• 한국음향학회지
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• 제19권5호
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• pp.27-34
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• 2000

This paper deals with speech enhancement methods using the wavelet transform. A cycle-spinning scheme and undecimated wavelet transform are used for denoising of speech signals, and then their results are compared with that of the conventional wavelet transform. We apply soft-thresholding technique for removing additive background noise from noisy speech. The symlets 8-tap wavelet and pyramid algorithm are used for the wavelet transform. Performance assessments based on average SNR, cepstral distance and informal subjective listening test are carried out. Experimental results demonstrate that both cycle-spinning denoising(CSD) method and undecimated wavelet denoising(CWD) method outperform conventional wavelet denoising(UWD) method in objective performance measure as welt as subjective listening test. The two methods also show less "clicks" that usually appears in the neighborhood of signal discontinuities.

• 한국정보과학회논문지:시스템및이론
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• 제37권2호
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• pp.103-109
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• 2010

문자열에 대한 편집 거리 문제는 하나의 문자열을 다른 문자열로 변환할 때 필요한 최소한의 연산의 개수를 구하는 문제이다. 편집 거리 문제는 오랫동안 연구가 진행되어 왔으며, 영어와 같이 1차원 문자열에 대해서는 최적해를 찾는 여러 가지 알고리즘이 개발되어 왔다. 그러나 한글 또는 한자와 같이 좀 더 복잡한 언어에 대한 편집 거리에 대해서는 많은 연구가 진행되지 못했다. 본 논문에서는 한글이 갖는 특징을 반영한 편집 거리를 정의하고, 한글 문자열에 대한 편집 거리를 구하는 알고리즘을 제안한다.

• 전자공학회논문지
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• 제53권7호
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• pp.67-77
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• 2016

본 논문에서는 변형된 하우스더프 거리 (MDH: Modified Hausdorff Distance)를 이용한 눈 개폐 감지 알고리즘을 제안한다. 제안하는 알고리즘은 얼굴 검출과 눈 개폐 감지로 크게 구분된다. 얼굴 영역의 검출을 위하여 고정 크기의 영역 내에서 픽셀 값을 이용하는 지역 구조특성의 MCT (Modified Census Transform)특징기반 방법을 사용하였다. 이후, 검출된 얼굴 영역 내에서 MHD를 이용하여 눈의 위치 및 개폐를 판단한다. 얼굴 검출의 처리절차는 먼저, 오프라인에서 다양한 얼굴 영상에 대해 MCT 이미지를 생성하고, 이를 기반으로 PCA를 이용하여 기준이 되는 특징벡터들을 추출한다. 다음으로, 온라인에서는 입력되는 실험 영상 내에서 새롭게 추출된 특징벡터들과 기준이 되는 특징 벡터들 간의 유클리드 거리를 이용하여 얼굴 영역을 검출하는 순서로 진행된다. 이후, 검출된 얼굴 영역 내에서 MHD 기반의 눈 영역 검출과 템플릿 매칭을 수행하여 눈의 개폐를 감지한다. 제안하는 방법의 성능 검증을 위하여 그레이 스케일 영상 (30FPS, $320{\times}180$)을 입력으로 실험을 수행한 결과, 눈 계폐 검출율에서 평균 94.04%의 정확도를 달성하였다.

• 대한전기학회논문지
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• 제41권3호
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• pp.219-226
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• 1992

In this study, Kalman filtering theory is applied to the estimation of symmetrical components from fault voltage and current signal when it comes to faults with the power system. An algorithm for estimating fault location accurately and quickly by calculating the symmetrical components from the extracted fundamental voltage phasor and current phasor is presented. Also, to confirm the validity of digital distance relaying techniques using Kalman filtering, the experimental results obtained by using the digital simulation of power system is shown.

• 전기학회논문지P
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• 제65권1호
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• pp.66-71
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• 2016

According to the development of depth sensing devices and depth estimation technology, depth information becomes more important for object detection in computer vision. In terms of recognition rate, pedestrian detection methods have been improved more accurately. However, the methods makes slower detection time. So, many researches have overcome this problem by using GPU. Here, we propose a real-time pedestrian detection algorithm that does not rely on GPU. First, the depth-weighted distance map is used for detecting expected human regions. Next, human detection is performed on the regions. The performance for the proposed approach is evaluated and compared with the previous methods. We show that proposed method can detect human about 7 times faster than conventional ones.

• 전기학회논문지
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• 제57권12호
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• pp.2139-2146
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• 2008

This paper presents a numerical algorithm for fault location estimation which used to data from both end of the transmission line. The proposed algorithm is also based on the synchronized voltage and current phasor measured from the PMUs(Phasor Measurement Units) in the time-domain. This paper has separated from two part of with/without shunt capacitance(short/long distance). Most fault was arc one-ground fault which is 75% over [1]. so most study focused with it. In this paper, the numerical algorithm has calculated to distance for ground fault and line-line fault. In this paper, the algorithm is given with/without shunt capacitance using II parameter line model, simple impedance model and estimated using DFT(Discrete Fourier Transform) and the LES(Least Error Squares Method). To verify the validity of the proposed algorithm, the EMTP(Electro- Magnetic Transient Program) and MATLAB did used.

• 대한전기학회논문지:전력기술부문A
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• 제51권8호
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• pp.371-378
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• 2002

This paper presents the rapid and accurate algorithm for fault detection and location estimation in the transmission line. This algorithm uses wavelet transform for fault detection and harmonics elimination and utilizes least square error method for fault impedance estimation. Wavelet transform decomposes fault signals into high frequence component Dl and low frequence component A3. The former is used for fault phase detection and fault types classification and the latter is used for harmonics elimination. After fault detection, an adaptive data window technique using LSE estimates fault impedance. It can find a optimal data window length and estimate fault impedance rapidly, because it changes the length according to the fault disturbance. To prove the performance of the algorithm, the authors test relaying signals obtained from EMTP simulation. Test results show that the proposed algorithm estimates fault location within a half cycle after fault irrelevant to fault types and various fault conditions.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.859-868
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• 2012

A new fault location algorithm based on stationary wavelet transform and its verification experiment results are described for HVDC submarine cables in this paper. For wavelet based fault location algorithm, firstly, 4th level approximation coefficients decomposed by wavelet transform function are superimposed by correlation, then the distance to the fault point is calculated by time delay between the first incident signal and the second reflected signal. For the verification of this algorithm, the real experiments based on various fault conditions and return types of fault current are performed at HVDC submarine cable test yard located in KEPCO(Korea Electric Power Corporation) Power Testing Center of South Korea. It proves that the fault location method proposed in this paper is very simple but very quick and accurate for HVDC submarine cable fault location.