• International Journal of Korean Welding Society
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• 제1권2호
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• pp.23-29
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• 2001

In this study, a preview-sensing visual sensor system is constructed far weld seam tracking in GMA welding. The visual sensor system consists of a CCD camera, a diode laser system with a cylindrical lens, and a band-pass-filter to overcome the degrading of image due to spatters and/or arc light. Among the image processing methods, Hough transform method is compared with the central difference method from a viewpoint of the capability for extracting the accurate feature position. As a result, it was revealed that Hough transform method can more accurately extract the feature positions and it can be applied to real time weld seam tracking. Image processing which includes Hough transform method is carried out to extract straight lines that express laser stripe. After extracting the lines, weld joint position and edge points are determined by intersecting the lines. Even though the image includes a spatter trace on it, it is possible to recognize the position of weld joint. Weld seam tracking was precisely implemented with adopting Hough transform method, and it is possible to track the weld seam in the case of offset angle is in the region of $\pm$ $15^{\circ}$.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
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• pp.256-256
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• 2004

• 한국정보통신학회논문지
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• 제6권7호
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• pp.1126-1132
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• 2002

In this paper, we propose a new scheme of motion tracking based on fuzzy inference (Fl) and wavelet transform (WT) from image sequences. First, we present a WT to segment a feature extraction of dynamic image . The coefficient matrix for 2-level DWT tent to be clustered around the location of Important features in the images, such as edge discontinuities, peaks, and corners. But these features are time varying owing to the environment conditions. Second, to reduce the spatio-temperal error, We develop a fuzzy inference algorithm. Some experiments are performed 0 testify the validity and applicability of the proposed system As a result, proposed method is relatively simple compared with the traditional space domain method. It is also well suited for motion tracking under the conditions of variation of illumination.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.100.3-100
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• 2002

This paper presents the method for detection and tracking of multiple humans robustly in mobile platform. The perception of human is performed in real time through the processing of images acquired from a moving stereo vision system. We performed multi-cue integration such as human shape, skin color and depth information to detect and track each human in moving background scene. Human shape is measured by edge-based template matching on distance transformed image. Improving robustness for human detection, we apply the human face skin color in HSV color space. And we could increase the accuracy and the robustness in both detection and tracking by applying random sampling stochastic estimati...

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.421-422
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• 2006

Using the still image through the camera reports which the moving object tracking system. Moving object direction detected to compare the two difference images. And base block set at moving object. Matching area set current difference image. The edge image of prior frame and current frame implement the moving object tracking system to block matching.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.217-221
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• 2002

In this paper, we propose a new scheme of motion tracking based on fuzzy inference (FI)and wavelet transform (WT) from image sequences. First, we present a WT to segment a feature extraction of dynamic image . The coefficient matrix for 2-level DWT tent to be clustered around the location of important features in the images, such as edge discontinuities, peaks, and corners. But these features are time varying owing to the environment conditions. Second, to reduce the spatio-temporal error, We develop a fuzzy inference algorithm. Some experiments are peformed to testify the validity and applicability of the proposed system. As a result, proposed method is relatively simple compared with the traditional space domain method. It is also well suited for motion tracking under the conditions of variation of illumination.

• 대한산업공학회지
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• 제18권2호
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• pp.83-97
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• 1992

A new approach, to seam tracking for robotic are welding is proposed. In this approach, the weld model is a snapshot image and the acquired image is analyzed and compared to the welding database which contains CAD data, weld positions, weld parameters, etc. This paper presents a fast and robust algorithm for the Hough Transform. This modified Hough Transform(MHT) algorithm uses the least-squares regression analysis method in order to approximate the edge lines more precisely, and leads to a significant reduction in both computation and storage. In comparison with the conventional seam tracking methods, this new approach has the advantages of low cost, continuous welding, and various type welding.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.205-208
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• 2006

본 논문은 이동물체의 영상에 대해 움직임을 감지하고 그 위치를 추적하는 감시시스템에 관한 연구이다. 물체의 움직임은 움직임이 없는 배경영상과 변화하는 영상간의 차 영상으로 감지하고 에지 검출과 움직임 벡터를 이용하여 움직임을 추적한다 실험결과 이동영상의 움직임 위치를 정확하게 추적하고 물체의 침입 유무를 판단할 수 있었다.

• Journal of Welding and Joining
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• 제17권3호
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• pp.71-78
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• 1999

The welded metal bellows is commonly manufactured by welding pairs of washer-shaped discs of thin sheet metal stamped from strip stock in thickness from 0.025 to 0.254 mm. The discs, or diaphragms, are formed with mating circumferential corrugations. In this study, the diaphragms were welded by using a CW Nd: YAG laser to form metal bellows. The bellows was fixed on a jig and compressed axially, while Cu-rings were installed between belows edges for intimate contact of edges. The difference between the inner diameter of bellows and jig shaft causes an eccentricity, while the tolerance between motor shaft and jig shaft causes a wobble type motion. A vision sensor which is based on the optical triangulation was used for seam tracking. An image processing algorithm which can distinguish the image by bellows edge from that by Cu-ring was developed. The geometric relationship which describes the eccentricity and wobble type motion was modeled. The seam tracking using the image processing algorithm and the geometric modeling was performed successfully.

• 한국정보과학회논문지:소프트웨어및응용
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• 제37권1호
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• pp.80-84
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• 2010

손 추적 기술은 인간과 기계와의 효율적인 의사소통을 위한 손동작 인식 기술의 핵심 기반 기술이다. 최근의 손 추적 연구는 3차원 손 모델을 이용한 연구 방향에 초점을 맞추고 있고, 기존의 2차원 손 모델을 이용한 방법보다 강인한 추적 성능을 보이고 있다. 본 논문에서는 결합된 파티클 필터에 기반한 새로운 3차원 손 추적 방법을 제안한다. 이는 전역적 손 형상과 지역적 손가락 움직임을 분리하여 추정하고, 각각의 추정 결과를 서로의 사전 정보로 이용하여 기존의 방법보다 빠르고 강인한 추적을 가능하게 한다. 또한, 추적 성능 향상을 위해 색상과 에지를 함께 고려한 다중 증거 결합 방법을 적용한다. 실험결과, 제안하는 방법은 복잡한 배경이나 동작에서도 강인한 추적 결과를 보였다.