• 한국멀티미디어학회논문지
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• 제20권11호
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• pp.1720-1728
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• 2017

Active shape model is widely used in the field of image processing especially on arbitrary meaningful shape extraction from single gray level image. Cootes et. al. showed efficient detection of variable shape from image by using covariance and mean shape from learning. There are two stages of learning and testing. Hahn applied enhanced shape alignment method rather than using Cootes's rotation and scale scheme. Hahn did not modified the profile itself. In this paper, the method using directional one dimensional profile is proposed to enhance Cootes's one dimensional profile and the shape alignment algorithm of Hahn is combined. The performance of the proposed method was superior to Cootes's and Hahn's. Average landmark estimation error for each image was 27.72 pixels and 39.46 for Cootes's and 33.73 for Hahn's each.

• 한국컴퓨터정보학회논문지
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• 제9권3호
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• pp.95-102
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• 2004

본 논문에서는 작은 형태정보의 차이를 감지할 수 있고 부분적인 입력 패턴도 효과적으로 검색할 수 있는 윤곽선 정보를 기반으로 하는 GHT와 다중 해상도 검색 방법을 제안한다. 제안된 방법은 부분적인 에지 정보를 효율적으로 사용할 수 있고 작은 형태변화를 구분할 수 있어서 도검과 같은 유사한 물체를 효과적으로 구분할 수 있다. 또한, 에지 리스트를 이용한 다중 해상도 에지 생성과 계층적인 패턴 정합을 통해서 신속하고 정확한 검색을 가능하게 한다. 실험 결과, 제안된 방법은 도검과 같은 임의 물체에 대해 높은 검색율을 보였다.

• 한국정밀공학회지
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• 제22권9호
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• pp.77-84
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• 2005

In most vision applications, we are frequently confronted with determining the position of object continuously. Generally, intertwined processes ire needed for target tracking, composed with tracking and control process. Each of these processes can be studied independently. In case of actual implementation we must consider the interaction between them to achieve robust performance. In this paper, the robust real time visual tracking in complex background is considered. A common approach to increase robustness of a tracking system is to use known geometric models (CAD model etc.) or to attach the marker. In case an object has arbitrary shape or it is difficult to attach the marker to object, we present a method to track the target easily as we set up the color and shape for a part of object previously. Robust detection can be achieved by integrating voting-based visual cues. Kalman filter is used to estimate the motion of moving object in 3D space, and this algorithm is tested in a pan/tilt robot system. Experimental results show that fusion of cues and motion estimation in a tracking system has a robust performance.

• 센서학회지
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• 제11권4호
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• pp.200-208
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• 2002

This paper represents the development of an array-type flexible tactile sensor using PVDF(polyvinylidene fluoride) film and flexible circuitry. The tactile sensor which has $8{\times}8$ taxels is made by using PVDF film and FPC(flexible printed circuit) technique. Experimental results on static and dynamic properties are obtained by applying arbitrary forces and frequencies generated by the shaker. In the static characteristics, the threshold and the linearity of the sensor are investigated. Also dynamic response of the sensor subjected to the variable frequencies is examined. The signals of a contact force to the tactile sensor are sensed and processed in the DSP system in which the signals are digitalized and filtered. Finally, the signals are integrated for taking the force profile. The processed signals of the outputs of the sensor are visualized on a personal computer, the shape and force distribution of the contacted object are obtained using two and three-dimensional image in real time. The reasonable performance for the detection of contact state is verified through the experiment.

• 한국의류산업학회지
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• 제12권5호
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• pp.582-590
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• 2010

Garment design needs an iterative manipulation of 2D patterns to generate a final sloper. Traditionally there have been two kinds of design methodologies such as the flat pattern method and the pattern draping method. But today, it is possible to combine the advantages from the two methods due to the realistic cloth simulation techniques. We devised a new garment design system which starts from 3D initial drape simulation result and then modifies the garment by editing the 2D flat patterns synchronously. With this interactive methodology using real-time pattern deformation technique, the designer can freely change a pattern shape by watching its 3D outlook in real-time. Also the final garment data were given relative coordinates with respect to the human anthropometric feature points detected by an automatic body feature detection algorithm. Using the relative human body coordinate system, the final garments can be re-used to an arbitrary body data without repositioning in the drape simulation. A female shirt was used for an example and a 3D body scan data was used for an illustration of the feature point detection algorithm.

• Structural Engineering and Mechanics
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• 제40권1호
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• pp.13-28
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• 2011

An effective method for detection linear flaws in plate structures via two-dimensional discrete wavelet transform is proposed in this study. The proposed method was applied to a four-fixed supported rectangular plate containing damage with arbitrary length, depth and location. Numerical results identifying the damage location are compared with the actual results to demonstrate the effectiveness of the proposed method. Also, a wavelet-based method presented for de-noising of mode shape of plate. Finally, the performance of the proposed method for de-noising and damage identification was verified using experimental data. Comparison between the location detected by the proposed method, and the plate's actual damage location revealed that the methodology can be used as an accessible and effective technique for damage identification of actual plate structures.

• 대한전자공학회논문지SP
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• 제42권4호
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• pp.21-30
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• 2005

본 논문에서는 B-snake 차선 모델을 이용한 차선 검출 및 추적에 관한 알고리즘을 제안한다. 제안된 이론의 특성은 첫째, 다른 알고리즘에 비해 직선, 굴곡이 있는 도로와 같은 보다 넓은 범위의 차선 구조의 표현이 가능하며, 또한 평면 도로의 평행 특성을 이용하여 그림자, 잡음 등에 강하고, 둘째, 잡음에 강한 CHEVP(Canny/Hough Estimation Vanish Point) 알고리즘을 사용하여 차선 위치의 초기값을 제공한다. 셋째, GYP(Gradient Vector Flow)와 최소 평균 제곱 에러를 이용하여 B-Snake 차선 모델에서 발생하는 외부의 힘을 줄여 차선 검출의 에러를 줄이고 차선 추적을 효과적으로 수행한다. 측정 실험 결과 도로영상을 날씨 별로 맑은 날, 흐린 날 그리고 비오는 날로 구분하여 본 알고리즘을 수행하였으며 95$\%$ 이상의 차선 검출률을 보였다.

• 대한기계학회논문집A
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• 제20권7호
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• pp.2205-2212
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• 1996

In order to move the body of a walking robot translationally, and step over the obstacles, the walking robot must have at least 3 degrees of freedom for each leg. Therefore each leg of the general walking robots can be composed of 3-link system with 3 revolute joints. In this paper, the colsed form of inverse kinimatic solutions is shown for this general 3R linkage. Moreover, in order to have efficient walking volume in rough terrain, the workspace of each log is obtained considering the twist angles and the offsets in D-H parameters. When we design a walking robot, the information of the walking volume is needed for planning desired trajectories of the feet effectively. Appropriate knowledge of the walking volume can also be used to maximize linear or angular velocity of minimize power of stress. However, since it is impossible to obrain the information of walking volume in 3-D space directly from the kinematic equations, the walking volume can be searched through the edge detection algorithm using the triangle tracer with closed from inverse kinematic solutions. In this study, we present the closed form inverse kinematic solutions for 3R linkage model, and the walking volume of 6 legged walking robot which is modeled after the darking bettle, Eleodes obscura sulcipennis, through the method of edge detection for an arbitrary 2 dimensional shape using triangle tracer.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1271-1276
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• 2020

The geometrical efficiency of a source-to-detector configuration is considered to be necessary in the calculation of the full energy peak efficiency, especially for NaI(Tl) and HPGe gamma-ray spectroscopy detectors. The geometrical efficiency depends on the solid angle subtended by the radioactive sources and the detector surfaces. The present work is basically concerned to establish a new mathematical approach for calculating the solid angle and geometrical efficiency, based on conversion of the geometrical solid angle of a non-axial radioactive point source with respect to a circular surface of the detector to a new equivalent geometry. The equivalent geometry consists of an axial radioactive point source with respect to an arbitrary elliptical surface that lies between the radioactive point source and the circular surface of the detector. This expression was extended to include coaxial radioactive circular disk source. The results were compared with a number of published data to explain how significant this work is in the efficiency calibration procedure for the γ-ray detection systems, especially in case of using isotropic radiating γ-ray sources in the form of point and disk shapes.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제12권1호
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• pp.60-65
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• 2012

This paper presents a method for occluded object based motion estimation and tracking system in dynamic image sequences using particle filter with 3D reconstruction. A unique characteristic of this study is its ability to cope with partial occlusion based continuous motion estimation using particle filter inspired from the mirror neuron system in human brain. To update a prior knowledge about the shape or motion of objects, firstly, fundamental 3D reconstruction based occlusion tracing method is applied and object landmarks are determined. And optical flow based motion vector is estimated from the movement of the landmarks. When arbitrary partial occlusions are occurred, the continuous motion of the hidden parts of object can be estimated by particle filter with optical flow. The resistance of the resulting estimation to partial occlusions enables the more accurate detection and handling of more severe occlusions.