• 제어로봇시스템학회논문지
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• 제14권3호
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• pp.236-241
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• 2008

This paper presents a method to recognize the plane regions for movement of walking robots. When the autonomous agencies using stereo camera or laser scanning sensor is under unknown 3D environment, the mobile agency has to detect the plane regions to decide the moving direction and perform the given tasks. In this paper, we propose a very fast method for plane detection using normal vector of a triangle by 3 vertices defined on a small circular region. To reduce the effect of noises and outliers, the triangle rotates with respect to the center position of the circular region and generates a series of triangles with different normal vectors based on different three points on the boundary of the circular region. The vectors for several triangles are normalized and then median direction of the normal vectors is used to test the planarity of the circular region. The method is very fast and we prove the performance of algorithm for real range data obtained from a stereo camera system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.228-230
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• 2002

We present a new low power scan testing and test data compression method for System-On-a-Chip (SOC). The don't cares in unspecified scan vectors are mapped to binary values for low power and encoded by adaptive encoding method for higher compression. Also, the scan-in direction of scan vectors is determined for low power. Experimental results for full-scanned versions of ISCAS 89 benchmark circuits show that the proposed method has both low power and higher compression.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.462-464
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• 1992

In this paper, an extraction of depth intonation in pattern using neural network is presented. All the 3D images represent the depth information in grey pixels. This pixels which have analog values translated digital values. Because of the noise and distortion in pattern, we use the normalization in learning and recalling the patterns. Our method has eight direction vectors and slopes for pattern. Also, we use potential to obtain the mean slope and direction vectors of given 3D patches. The higher level of deduction finding the global depth information is also carried out by using neural network.

• 대한전자공학회논문지SP
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• 제39권3호
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• pp.78-87
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• 2002

본 논문은 MPEG 비디오에서 나타나는 여러 예측 형태의 움직임 벡터를 프레임 타입에 관계없이 단일 예측방향만을 갖도록 새롭게 추정하여 비디오 영상물의 분석에 직접적으로 활용하는 방안에 대해 제시하고 있다. 또한 재추정된 각 프레임에서의 움직임 벡터를 이용한 비디오 시퀀스 내에서의 객체 추출 및 추적 기법 등에 대해서도 새롭게 제안하였다. 제안된 알고리즘은 압축 영상에 대한 전체적인 복원과정을 거치지 않고, 압축 비디오 영역으로부터 쉽게 추출될 수 있는 매크로 블록 영역 상에서 수행되었으며, 실험 결과는 제안된 방법의 높은 성능을 잘 나타내어 주고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.161-163
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• 2005

In this paper, we propose an efficient motion vector recovery algorithm for the new coding standard H.264, which makes use of the Lagrange interpolation formula. In H.264/AVC, a 16$\times$16 macroblock can be divided into different block shapes for motion estimation, and each block has its own motion vector. In the natural video the motion vector is likely to move in the same direction, hence the neighboring motion vectors are correlative. Because the motion vector in H.264 covers smaller area than previous coding standards, the correlation between neighboring motion vectors increases. We can use the Lagrange interpolation formula to constitute a polynomial that describes the motion tendency of motion vectors, and use this polynomial to recover the lost motion vector. The simulation result shows that our algorithm can efficiently improve the visual quality of the corrupted video.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.485-490
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• 1999

Wind vector information over the ocean is currently obtained using multiple beam scatterometer data. The scatterometers on ERS-1/2 generate wind vector information with a spatial resolution of 50km and accuracies of $\pm$2m/s in wind speed and $\pm$20$^{\circ}$ in wind direction. Synthetic aperture radar (SAR) data over the ocean have the potential of providing wind vector information independent of weather conditions with finer resolution. Finer resolution wind vector information can often be useful particularly in coastal regions where the scatterometer wind information is often corrupted because of the lower resolution system characteristics which is often contaminated by the signal returns from the coastal areas or ice in the case of arctic environments. In this paper we tested CMOD_4 and CMOD_IFR2 algorithms for extracting the wind vector from SAR data. These algorithms require precise estimation of normalized radar cross-section and wind direction from the SAR data and the local incidence angle. The CMOD series algorithms were developed for the C-band, VV-Polarized SAR data, typically for the ERS SAR data. Since RADARSAT operates at the same C-band but with HH-Polarization, the CMOD series algorithms should not be used directly. As a preliminary approach of resolving with this problem, we applied the polarization ratio between the HH and VV polarizations in the wind vectors estimation. Two test areas, one in front of Inchon and several sites around Jeju island were selected and investigated for wind vector estimation. The new results were compared with the wind vectors obtained from CMOD algorithms. The wind vector results agree well with the observed wind speed data. However the estimation of wind direction agree with the observed wind direction only when the wind speed is greater than approximately 3.0m/s.

• 한국정보통신학회논문지
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• 제18권9호
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• pp.2209-2215
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• 2014

본 논문은 DOI방법을 개선한 디인터레이싱 방법을 제안한다. DOI방법은 강력한 인트라필드 기반의 디인터레이싱 기술이지만 긴 연산시간과 주기적인 패턴에서 방향을 잘못 찾는 문제를 가지고 있다. 이 문제를 해결하기 위해 기존의 전역검색 대신하여 2단계 검색을 하여 연산속도를 향상시키고 두 가지 과정을 추가하여 영상의 화질을 개선하는 방법을 제안한다. 첫 번째 단계로 잘못된 방향으로 찾은 공간벡터를 삭제하며 두 번째 단계로 찾지 못한 방향에 대한 공간 방향벡터를 삽입함으로써 제안된 방법에서 잘못 찾은 공간 방향벡터를 정확한 결과인지 재확인하여 픽셀의 보간에 사용할지 검사한다. ISO 실험 이미지를 이용하여 제안된 방법과 line evarage, edge-based line averaging, DOI, selective deinterlacing algorithm 등의 기존의 방법을 비교한 결과 제안된 방법이 객관적으로나 주관적으로 우 수하다는 것을 보였다.

• Journal of the Korean Statistical Society
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• 제27권4호
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• pp.471-483
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• 1998

The influence of observations on the misclassification probability in multiple discriminant analysis under the equal covariance assumption is investigated by the local influence method. Under an appropriate perturbation we can get information about influential observations and outliers by studying the curvatures and the associated direction vectors of the perturbation-formed surface of the misclassification probability. We show that the influence function method gives essentially the same information as the direction vector of the maximum slope. An illustrative example is given for the effectiveness of the local influence method.

• 한국통신학회논문지
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• 제34권1C호
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• pp.37-47
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• 2009

본 논문은 무선망과 같이 패킷 손실이 많은 환경에 H.264 부호화 영상이 전송될 때 복호기 단말기에서 손실된 움직임 벡터를 효율적으로 에러은닉 방법에 대하여 2가지를 제안한다. 첫째, 손실된 블록(매크로블록)에 대하여 후보벡터집합(candidate vector set)을 선정하는 방법으로는 손실된 블록에 인접한 주변 블록의 움직임벡터들의 높은 상관성을 착안하여 후보벡터를 선정한다. 이때 제안한 알고리즘은 주변 블록의 움직임벡터들 간에 거리를 이용하여 클러스터한다. 클리스터된 움직임 벡터 집합(클러스터 집합)에서 최적의 후보벡터 선택방법은 중앙값을 선택한다. 둘째, 손실된 블록의 최종의 후보벡터를 선정하는 방법으로는 후보벡터집합에서 주변에 인접한 픽셀간의 방향성을 고려하여 왜곡 값이 최소인 벡터를 후보벡터로 결정한다. 패킷이 손실되는 환경에서 실험한 결과, 제안한 에러 은닉 방법은 기존 방법에 비하여 후보벡터 개수가 평균적으로 $23%{\sim}61%$까지 감소하였고, 디코딩 시간이 평균적으로 $3{\sim}4$(sec) 감소하였다. 또한 화질에 대한 객관적 평가 기준인 PSNR은 평균적으로 기존 방법들과 거의 비슷하였다.

• Communications for Statistical Applications and Methods
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• 제8권3호
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• pp.875-883
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• 2001

We derive the asymptotic relative efficiencies in two special cases of Chaudhuri's estimators for the multivariate one sample problem. And we compare those two when observations are independent and identically distributed from a family of spherically symmetric distributions including normal distributions.