• 전기학회논문지P
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• 제64권3호
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• pp.193-198
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• 2015

A large number of vision applications rely on matching keypoints across images. Pedestrian detection is under constant pressure to increase both its quality and speed. Such progress allows for new application. A higher speed enables its inclusion into large systems with extensive subsequent processing, and its deployment in computationally constrained scenarios. In this paper, we focus on improving the speed of pedestrian detection using HOG(histogram of oriented gradient) and multi frame operation which is robust to illumination changes in cluttering images. The result of our simulation indicates that the detection rate and speed of the proposed method is much faster than that of conventional HOG and differential images.

• 전기학회논문지P
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• 제64권3호
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• pp.187-192
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• 2015

Detecting human in images is a challenging task owing to their variable appearance and the wide range of poses the they can adopt. The first need is a robust feature set that allows the human form to be discriminated cleanly, even in cluttered background under difficult illumination. A large number of vision application rely on matching keypoints across images. These days, the deployment of vision algorithms on smart phones and embedded device with low memory and computation complexity has even upped the ante: the goal is to make descriptors faster compute, more compact while remaining robust scale, rotation and noise. In this paper we focus on improving the speed of pedestrian(walking person) detection using Histogram of Oriented Gradient(HOG) descriptors provide excellent performance and tracking using kalman filter.

• Nuclear Engineering and Technology
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• 제30권1호
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• pp.17-25
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• 1998

Transport of carbon and boron impurity ions parallel to magnetic field lines in the tokamak SOL (scrape-off layer) is numerically investigated for a one-dimensional steady state. The spatial distributions of density and velocity of the impurity ions in a steady state are calculated by finite difference method for a single-fluid model. The calculated results show that among forces acting on SOL particles thermal force produced tv plasma temperature gradient is a principal force determining the feature of impurity distribution profiles in the tokamak edge. However, strong collisional friction forces appearing dominant in front of the diverter plate restrain impurity ion flows due to temperature gradients from moving toward the midplane. Consequently, the stagnation point develops in the impurity flow by these two forces near the diverter region, in which ion flows change their directions. Impurity ions turn out to be accumulated at the stagnation points, where peaked profiles of highly-ionized state ions are relatively predominant over those of low-ionized state ions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.749-752
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• 1998

Recognizing a human part becomes very important for applications which are based on the interaction between computers and their users. In this paper, we design and implement a system which recognizes and tracks a human head using a sequence of images. Difference images are used to easily extract feature vectors from images with very complex backgrounds. A human bhead is represented with an ellipse and recognized by searching for a maximum value from preprocessed gradient images. The method is developed by considering the fact that the tracking system should be real-time. The designed system not only shows an excellent performance for the normal up-right position of the head, but also for the cases of 360.deg. rotated head position, occluded images of heads, and tilted head positions.

• 정보처리학회논문지B
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• 제8B권2호
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• pp.215-222
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• 2001

본 논문에서는 새로운 형태 특징값으로서 형태 correlogram을 제안하고 이를 기반으로 한 효과적인 내용기반 영삼검색(content-based image retrieval) 방법을 제시한다. 기존읜 색상 correlogram은 색상 정보에 공간적인 정보를 부여함으로써 영상검색 성능을 향상시켰다. 그러나 이 특징값은 형태 정보를 포함하고 있지 않아서 색상이 다르면서 비슷한 윤곽선 형태를 갖는 물체의 검색에는 좋은 효과를 보이지 못한다.이 문제를 해결하기 위해 예지(edge)들의 correlogram인 형태(shape) correlogram을 제안한다. 색상 correlogram이 색상들의 거리에 따른 상관관계를 나타내는데 반해 형태 correlogram은 에지 각도들의 상관관게를 나타낸다. 형태 correlogram은 gradient 축과 각도 축을 가지는 2차원 특징 벡터(feature vector)로 표현된다. 각 축은 24개 빈(bin)으로 나뉘어져서 총 576개의 원소를 가지게 된다. 또한 본 논문에서는 형태 correlogram의 데이터 크기를 줄이고, 회전에 대해 불변인 특성을 가지게 하기 위해 투영(projected) 형태 correlogram을 제안한다. 실험결과를 통하여 본 논문에서 제안한 형태 correlogram과 투영 형태 correlogram을 사용한 영상검색 방법이 기존의 방법보다 성능면에서 우수함을 입증한다.

• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1845-1852
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• 2001

This paper deals with the experiment to obtain quantitative information about conditions of the interface between a water drop and surrounding oil. Velocity distributions in very close region of the interface are measured by introducing a new illumination technique and a telecentric lens. It enables precise measurements of velocity distributions in the close region to the interface. Although the measured velocity distributions exhibit strong influence from the solid wall of an experimental tube, the coincidence of inner and outside velocities on the interface is clearly confirmed for the clean interface. The shearing stresses on the interface, which are proportional to the velocity gradient normal to the interface, clearly show conditions of contaminated interface, which can be divided into two parts. From front stagnation point to somewhere near a separation point, the distribution of shearing stresses is well coincide with that of the Hadamard's analytical solution, while the distribution on the latter part of the interface sows quite different feature, which is supposed to be strongly influenced by contamination of the surface.

• 대한기계학회논문집B
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• 제31권1호
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• pp.40-50
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• 2007

The present contribution describes the application of elliptic-blending second moment closure to predict the gas cooling process of turbulent super-critical carbon dioxide flow in a square cross-sectioned duct. The gas cooling process under super-critical state experiences a drastic change in thermodynamic and transport properties. Redistributive terms in the Reynolds stress and turbulent heat flux equations are modeled by an elliptic-blending second moment closure in order to represent strongly non-homogeneous effects produced by the presence of walls. The main feature of Durbin's elliptic relaxation second moment closure that accounts for the nonlocal character of pressure-velocity gradient correlation and the near-wall inhomogeneity guaranteed by the elliptic blending second moment closure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권5호
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• pp.2171-2185
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• 2020

In order to judge that whether the vehicles in different images which are captured by surveillance cameras represent the same vehicle or not, we proposed a novel vehicle face recognition algorithm based on improved Nonnegative Matrix Factorization (NMF), different from traditional vehicle recognition algorithms, there are fewer effective features in vehicle face image than in whole vehicle image in general, which brings certain difficulty to recognition. The innovations mainly include the following two aspects: 1) we proposed a novel idea that the vehicle type can be determined by a few key regions of the vehicle face such as logo, grille and so on; 2) Through adding weight, sparseness and classification property constraints to the NMF model, we can acquire the effective feature bases that represent the key regions of vehicle face image. Experimental results show that the proposed algorithm not only achieve a high correct recognition rate, but also has a strong robustness to some non-cooperative factors such as illumination variation.

• Journal of Chest Surgery
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• 제27권4호
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• pp.313-317
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• 1994

Surgical treatment is possible for the obstructive form of hypertrophic cardiomyopathy and transaortic left ventricular septal myectomy and myotomy has been the procedure of choice. If coexisting intrinsic mitral valve disease exists, mitral valve replacement has been performed. But abnormal systolic anterior motion of anterior mitral leaflet[SAM] with intrinsic normal mitral valve disease is the typical feature of IHSS and we prefer not to replace mitral valve. 3 patients underwent transaortic myotomy and myectomy for IHSS with mitral regurgitation. 2 patients of them have coexisting intrinsic mitral valve diseases such as mitral valve vegetation and chorda rupture. Concomittent mitral valve replacement were performed. 1 patient shows SAM of mitral anterior leaflet but has intrinsic normal mitral valve morphologically and transepicardial echocardiogram and direct monitoring of pressure gradient during the operative procedure gives better information for subsided mitral regurgitation. Post operative course during the 12 months follow-up was uneventful.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2015년도 하계학술대회
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• pp.513-515
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• 2015

최근 지능형 차량과 ADAS(Advanced Driver Assistance System) 개발에 있어 차량 영상을 이용한 도로 정보 분석이 중요한 화두로 떠오르고 있다. 다양한 도로 정보 중에서 도로표지판 검출 및 판단은 차량 운행 환경을 파악할 수 있는 중요한 과정이 될 수 있다. 이에 본 논문에서는 차량 영상에서의 색상 정보를 이용하여 표지판의 후보 영역을 추출(Candidate Generation)하고, 후보 영상에 대한 HOG(Histogram of Gradient) 특징 분석을 통해 도로표지판 여부와 그 종류를 판단(Object Classification)하는 알고리즘을 구현하였다. 또한 구현 알고리즘은 실시간 처리가 가능한 속도를 보여주어 지능형 차량 또는 ADAS에서의 실제 적용이 가능하도록 하였다.