• 한국산업정보학회논문지
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• 제19권4호
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• pp.41-52
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• 2014

본 논문은 O링의 치수 측정에 있어 고가의 대 중형 머신비전 장비를 대체할 수 있는 소형 머신 비전 검사 장비에 기반한 O링 부품 내 외경 측정 알고리즘을 제안한다. 백라이트 조명하에 하나의 CCD 카메라를 이용하여 측정 평면으로 부터 영상을 획득하는 소형 머신 비전 검사장비에 의해 획득된 영상을 제안한 영상처리 기법 알고리즘을 이용하여 O링의 외경 및 내경치수를 측정한다. 치수 측정의 정확도를 높이기 위해 렌즈계 왜곡 보정과 원근 왜곡 보정을 소프트웨어적 기법으로 보정 하였고 O링 형상을 고려하여 타원정합 모델을 적용하였으며 보다 타원 정합의 신뢰성을 높이기 위해 RANSAC알고리즘을 적용하였다.

• 센서학회지
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• 제14권4호
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• pp.278-285
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• 2005

This paper describes techniques of camera calibration and artificial landmarks detection for the automatic charging of a mobile robot, equipped with a fish-eye camera in the direction of its operation for movement or surveillance purposes. For its identification from the surrounding environments, three landmarks employed with infrared LEDs, were installed at the charging station. When the robot reaches a certain point, a signal is sent to the LEDs for activation, which allows the robot to easily detect the landmarks using its vision camera. To eliminate the effects of the outside light interference during the process, a difference image was generated by comparing the two images taken when the LEDs are on and off respectively. A fish-eye lens was used for the vision camera of the robot but the wide-angle lens resulted in a significant image distortion. The radial lens distortion was corrected after linear perspective projection transformation based on the pin-hole model. In the experiment, the designed system showed sensing accuracy of ${\pm}10$ mm in position and ${\pm}1^{\circ}$ in orientation at the distance of 550 mm.

• 대한임베디드공학회논문지
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• 제18권3호
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• pp.117-124
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• 2023

In the machine vision inspection equipment, diameter measurement is important process in inspection of cylindrical object. However, machine vision inspection equipment requires complex algorithm processing such as camera distortion correction and perspective distortion correction, and the increase in processing time and cost required for precise diameter measurement. In this paper, we proposed the algorithm for diameter measurement of cylindrical object using the laser displacement sensor. In order to fit circle for given four input outer points, grid search algorithms using root-mean-square error and mean-absolute error are applied and compared. To solve the limitations of the grid search algorithm, we finally apply the singular-value-decomposition based circle fitting algorithm. In order to compare the performance of the algorithms, we generated the pseudo data of the outer points of the cylindrical object and applied each algorithm. As a result of the experiment, the grid search using root-mean-square error confirmed stable measurement results, but it was confirmed that real-time processing was difficult as the execution time was 10.8059 second. The execution time of mean-absolute error algorithm was greatly improved as 0.3639 second, but there was no weight according to the distance, so the result of algorithm is abnormal. On the other hand, the singular-value-decomposition method was not affected by the grid and could not only obtain precise detection results, but also confirmed a very good execution time of 0.6 millisecond.

• 한국항행학회논문지
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• 제23권6호
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• pp.522-525
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• 2019

기존 항행안전시설 지상점검의 한계점을 극복하기 위해서 한국공항공사는 항행안전시설 점검용 드론시스템을 개발하였다. 드론시스템을 이용한 항행안전시설 점검은 사용자(항공기) 입장에서 공중 전파신호를 점검할 수 있다 장점이 있다. 또한 드론은 항공기와 비교하여 비행경로가 자유롭고 비행속도의 제어가 용이하기 때문에 공중 전파신호를 보다 면밀히 점검할 수 있다. 최근 공항주변개발의 가속화에 따라 항행안전시설 전파신호의 품질저하에 대한 우려가 고조되고 있다. 이에 따라, 항행안전시설 전파왜곡현상을 분석하기 위해 드론을 활용한 전파환경조사를 진행하였다. 드론의 비행경로별 신호수신 시 항행전파신호가 왜곡되는 구간을 측정·분석하여 반사파가 발생되는 원점을 특정화하였다.

• 보건행정학회지
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• 제20권4호
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• pp.1-18
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• 2010

Much policy attention has been directed to the concentration of patients in large hospitals, especially in tertiary care hospitals. In order to address the problem, the government has enforced referral requirement for accessing care in tertiary care hospitals by denying insurance benefits to the patients who do not observe the requirement. This approach somehow has failed to produce expected effects although it still exists in theory. The concentration of patients in a certain type of providers results in the distortion of functional differentiation among various types of providers and vice versa. Thus the approaches for the alleviation of the problem should be directed to both patients and providers. However, policy approaches has so far focused on ways of directly affecting patients' choice of a provider neglecting the effects of providers. Based upon the observation, this paper has reviewed selected issues that should be considered in agenda setting for policies concerned with the concentration of patients in large hospitals or the distortion of functional differentiation among health care providers. A brief discussion of each of the issues suggests three general guidelines for the formulation and implementation of policies intended to address the problem. First, attention should be directed to both patients and providers. Secondly, it is necessary to employ diverse measures including regulation, incentives and administrative supports. Thirdly, some of the approaches should be planned from a long range perspective, for it often takes a long time to change some aspects of health care utilization and provision.

• 대한전자공학회논문지SP
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• 제39권4호
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• pp.429-441
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• 2002

본 논문은 실시간으로 3차원 공간상에서의 움직임 정보를 추출할 수 있는 입력 장치를 제안한다. 제안하는 3차원 입력 장치는 스테레오 카메라의 기하학적 구조와 색상, 움직임, 형태상의 특성을 이용하여 복잡한 환경에서 사전 카메라 캘리브레이션 없이 3차원 움직임 정보를 추출할 수 있다. 움직임 추출을 위해서 perspepctive projection 행렬과 perspective distortion 행렬을 이용한 스테레오 카메라의 기하학적 특성을 이용하며, 효과적인 좌우 영상의 특징점 추적 및 추출을 위해 색상 변환(Color transform)과 UPC(Unmatched Pixel Count) 및 이산 칼만 필터(Discrete Kalman Filter)의 효과적인 결합으로 이루어진 MAWUPC(Motion Adaptive Weighted Pixel Count)과 PCA(Principal Component Analysis)로 구성된 알고리즘을 제안한다. 추출된 3차원 공간상에서의 움직임은 가상환경에서의 가상 물체를 제어하거나 사용자 시점의 이동을 나타내는 인터페이스로 사용한다. 스테레오 비전을 이용한 입력 장치는 선으로 연결되지 않기 때문에 사용자가 가상환경에서 작업하기가 편리하며 몰입감을 높일 수 있는 등 보다 효율적인 상호작용을 가능하게 해준다.

• 한국실내디자인학회논문집
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• 제18권2호
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• pp.41-49
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• 2009

Contemporary design environment is formed with image-centered trend based on pluralism. In this point of view, enterprises' building lobbies are public places containing the equivocal meaning, actively utilizing light as a design element to express the image of enterprises' identifications. Light is an immaterial entity having unlimited possibilities and potentials on space. It also acts as media to activate spaces and create new images in connection with formative elements of space. This study is to figure out how lightings are expressed and affected the formative characteristics of office lobby spaces and activate the specific characteristics of spaces. As a result, we drew conclusions as follows. First, as state-of-the-art technology and media are introduced, light is expressed on spaces as floating, direction, rhythm, silhouette, metaphor and allusion, sense of depth and volume. Second, expressive aspects of light in lobby space are embodiment of light, substantiation of immateriality, standing of materiality from the perspective of spatial aesthetics, and distortion/transformation of shape, pluralism phenomena of space from the perspective of spatial structure. In this way, light on building lobbies which are greatly required design differentiation strategy, specializes space and also integrates all the designs as not only a functional element but also a mental, psychological, formative element. Consequently, light on lobby spaces induces communication between spaces and users, makes formative value of existence in itself, and presents the characteristics of differentiated enterprises' identities.

• 한국실내디자인학회논문집
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• 제23권4호
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• pp.63-71
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• 2014

Anamorphosis is highly favored in modern days as the atmosphere of pursuing unusual manners is growing while transformation and distortion of images are freely available. This research is to understand the affect of these distorted images on space designs and the close connection between anamorphosis and visual perceptions, and to identify the new perceptual phenomenon created through it, and the methods of expressing those. Four expressional methods were defined through the process of studying Anamorphosis based on its definition by Niceron, examining artworks such as paintings and photographs, and case-studying example spaces of visual perception experiments. Expressing anamorphosis through visual perceptions are broadly categorized to directional, dimensional, flatness, and optical. The analysis of 10 case projects suggests that the experimental spaces offer joys of finding and interpreting metaphorical forms and meanings caused by the four characteristic categories above. Also, they artificially show the boundaries between reality and virtual spaces in 2-dimensional or 3-dimensional spaces, and form hyper-boundaries, new experience, and an internal mechanism that is vague and chaotic. Therefore, this research concludes that anamorphosis which is a distorted perspective, is not only a simple measure to overcome perspectival errors, but is an existence suitable to the current era, that will extend its potential and value in spatial design.

• 한국정보통신학회논문지
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• 제19권1호
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• pp.201-207
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• 2015

스마트폰 카메라로 생성한 문서 이미지는 촬영 방법에 따라 일반 스캐너에 비해 회전 왜곡과 원근 왜곡이 발생한다. 본 논문에서는 MSER-b 통해 조명에 영향을 적게 받는 이미지를 생성하고 텍스트 이미지의 특성을 고려한 텍스트 영역 윤곽선 검출 기법을 제안하고 이를 통해 왜곡된 문서 이미지를 보정하여 프린터 품질의 이미지로 복원하였다. 그리고 제안한 기법의 성능 평가를 위해 현재 서비스되고 있는 타사의 제품과 비교하였으며, 다양한 왜곡에 대하여 효과적으로 처리가 가능함을 실험을 통해 보였다.

• 방송공학회논문지
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• 제22권4호
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• pp.448-461
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• 2017

본 논문에서는 교통관제용 CCTV로부터 촬영된 영상에서 교통 상황 분석을 위해 차량의 통행량 및 통행 속도를 획득하는 방법을 제안한다. 제안하는 방법은 촬영된 영상에 역 투영 사상(IPM, Inverse Perspective Mapping) 방법을 이용하여 카메라 각도에 따른 시각적 관점에서 기인한 왜곡을 제거하고, 차선 검출 알고리즘을 통해 1) 차량 통행량, 2) 차량 통행 속도를 측정할 소정 영역을 획득한다. 소정 영역에 대하여 광류(Optical flow) 기반 모션 추정을 이용하여 차량 통행량 및 통행 속도를 획득한다. 본 논문에서 제안한 방법을 지역별 다양한 CCTV 영상인 총 106,993 프레임, 약 세 시간 길이의 영상에 적용하여 88.94%의 검출 성능을 얻을 수 있었다.