• 한국전기전자재료학회논문지
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• 제22권12호
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• pp.1084-1088
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• 2009

The measurement of dynamic stagger in electric railways is one of the key test parameters to increase speed and maintain safety in electric railways. This paper is introduces a non-contact optical-based measuring instrument of a catenary system in electric railways. The instrument is implemented by utilizing a CCD (Charge Coupled Device) camera installed on the roof of a vehicle for vision acquisition and image processing techniques including the Canny edge detector and the Hough transform to detect contact wires and calculate dynamic stagger. To check the validity of our approach for the intended application, we measured stagger of a overhead wire of a Korea Tilting Train (TTX). The non-contact optical-based measurement system proposed in this paper performs real-time stagger measurement of an activated high-voltage contact wire. By results of this paper, the instrument should be applied to assess performance and reliability of newly developed electric railway vehicles.

• 한국항공우주학회지
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• 제37권3호
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• pp.267-274
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• 2009

최근 무인 항공기(Unmanned Aerial Vehicle, UAV)는 다양한 임무수행이 가능한 무인 시스템이라는 점에서 크게 주목받고 있다. 특히 정찰, 추적 등의 임무는 영상을 이용하여 임무 수행이 이루어진다. 소형 무인 항공기의 경우 중량과 비용을 고려하여 단안 영상을 이용하는 임무 수행 연구가 활발하게 이루어지고 있다. 그러나 실제 지표면과 목표물이 고도 차이를 가지고 있어, 영상의 상대깊이를 고려하지 않은 3차원 거리는 임무 수행 시 오차 요인으로 작용 할 수 있다. 본 연구에서는 상대 깊이 추정을 위한 평균이동 알고리즘, 광류, 부분 공간법에 관하여 차례로 제시한다. 평균이동 알고리즘은 영상 내 목표물 추적과 관심영역을 결정하며 광류는 영상의 자기를 이용한 영상 이동 정보를 포함한다. 마지막으로 부분 공간법은 영상안의 움직임을 추정하며 각 영역의 상대깊이를 결정한다.

• 한국생산제조학회지
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• 제5권2호
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• pp.57-62
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• 1996

Basically, the idea underlying most edge-detection technique is the computation of a local derivative operator used for edge detection in gray level image. This concept can be easily illustrated with the aid of object which shows an image of a simple lilght on a dark background, Using the gray level profile along a horizontal scan line of the image. the first and second derivatives of it were acquired. This study is to develop an automatic measuring system based on the digital image processing which can be applied to the real time measurement of the characteristics of the ultra-thin thickness. The experimental results indicate that the developed automatic inspection can be applied in real situation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2729-2731
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• 2001

In this paper, we studied on the real-time environment map building for the mobile robot navigation using the stereo camera system. Distance measurement are necessary to build the environment map. We used a area-based stereo matching for the distance measurement with the stereo camera system. To reduce the computation time, we used DSP processor on the vision board, took a suitable area size for stereo matching, and used hierarchical search method. Using the fast acquired distance values, the environment map was built.

• 제어로봇시스템학회논문지
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• 제21권2호
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• pp.81-86
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• 2015

GPS position errors were corrected for guidance of autonomous vehicles. From the vision, we can obtain the lateral distance from the center of lane and the angle difference between the left and right detected line. By using a controller which makes these two measurements zero, a lane following system can be easily implemented. However, the problem is that if there's no lane, such as crossroad, the guidance system of autonomous vehicle does not work. In addition, Line detection has problems working on curved areas. In this case, the lateral distance measurement has an error because of a modeling mismatch. For this reason, we propose GPS error correction filter based on curve-modeled lane detection and evaluated the performance applying it to an autonomous vehicle at the test site.

• 농촌지도와개발
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• 제13권2호
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• pp.235-249
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• 2006

The objective of this study was to investigate the developmental level of Rural Women Leaders Federation(RWLF) which is one of the major rural women`s association in Korea. The writers designed organization measurement tool based on the reviews on the related studies and gather data from 191 memberships of RWLF through the mail questionnaire and interviews. The major findings were as follows; First, the findings shows us this organization as transition period from identification stage to expanded growth stage in developmental stage of rural women's organizations. Second, this organization focus on share of members decision making and leadership style rather than organization`s vision, strategy or organization level. In other words, this organization focus on human relations aspect rather than internal aspect of organization system. Third, this organization has high level of social evaluation of the organization, even if it has low level of personal compensation or individua's social performance. In conclusion, as long-term view-point, it is needed to help them to promote their self-control of survival ability to improve organization's vision, strategy, differentiation for achieving organizational goals. And it also needed to prepare educational programs to increase Rural Women's leadership capability understanding of organizational characteristics and its operation abilities.

• 전기학회논문지
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• 제67권7호
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• pp.976-980
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• 2018

The traction power system is configured to transmit electricity to the vehicles through mechanical contact between the OCL (Overhead Contact Line) and the pantograph. The system measures the current collection performance of the OCL, or the OCL installation condition is examined through maintenance for commercial operation. Maintenance continues to check the conditions through visual inspection by walking and inspection vehicles. The current collection performance is divided into the percentage of arcing(%), the contact force, and the uplift. The percentage of arcing is composed of a vision based system and used to verify the performance of a new OCL. However, it is not always possible to measure the current collection performance during commercial operation, and maintenance based on human resources can not be replaced. This paper presents the minimum performance condition of video devices in the current collection system of commercial vehicles. In addition, a continuous arcing was measured, and current collection performance was examined on the traction power system at the 250 km/h. It was analyzed with a minimum duration of arc of 1 ms. The frame rate is then shown by comparing the number of frames in the image at the time intervals of the number of the arcing. It is expected that the result of this study can be used for examining the minimum performance of video devices depending on their purpose.

• 한국정밀공학회지
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• 제21권10호
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• pp.154-161
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• 2004

An experimental method for measuring side-necking deformation near a crack-tip is described. It is based on Stereoscopic Digital Speckle Photography and Digital Image Correlation, and it is simple and robust to mechanical vibration inherent to a hydraulic material test system. The validity and accuracy are evaluated through a calibration fur rigid body translation. A case study has been performed for a CT specimen made of a ductile steel and the three dimensional profiles of the side-necked region are presented as the load increases. Also, the details of the procedure and the surface treatment are discussed.

• 해양환경안전학회지
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• 제17권2호
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• pp.131-136
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• 2011

컴퓨터 비젼을 이용한 항행선박의 항적을 계산하고 교통량을 측정하는 방법은 해양사고의 예방관점에서 사고발생 가능성 여부를 예측해 볼 수 있는 유용한 방법이다. 본 연구에서는 컴퓨터 비젼을 이용하여 영상축소, 미분연산자, 최대 최소값 등을 이용하여 선박을 인식한 후 실세계 상에서의 좌표 값을 계산하여 실시간 항적을 전자 해도에 표시함으로서 해상 구조물과의 충돌여부를 직접 육안으로 확인 할 수 있는 알고리즘을 개발하였다. 본 연구에서 개발된 알고리즘은 영역 정보를 기반으로 개발되었기 때문에 점 정보에 의존하고 있는 기존 레이더 시스템의 단점을 보완하는 장점을 지니고 있다.

• Smart Structures and Systems
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• 제19권6호
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• pp.679-694
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• 2017

The complexity, enlargement and irregularity of structures and multi-directional dynamic loads acting on the structures can lead to unexpected structural behavior, such as torsion. Continuous torsion of the structure causes unexpected changes in the structure's stress distribution, reduces the performance of the structural members, and shortens the structure's lifespan. Therefore, a method of monitoring the torsional behavior is required to ensure structural safety. Structural torsion typically occurs accompanied by displacement, but no model has yet been developed to measure this type of structural response. This research proposes a model for measuring dynamic torsional response of structure accompanied by displacement and for identifying the torsional modal parameter using vision-based displacement measurement equipment, a motion capture system (MCS). In the present model, dynamic torsional responses including pure rotation and translation displacements are measured and used to calculate the torsional angle and displacements. To apply the proposed model, vibration tests for a shear-type structure were performed. The torsional responses were obtained from measured dynamic displacements. The torsional angle and displacements obtained by the proposed model using MCS were compared with the torsional response measured using laser displacement sensors (LDSs), which have been widely used for displacement measurement. In addition, torsional modal parameters were obtained using the dynamic torsional angle and displacements obtained from the tests.