• 제목/요약/키워드: line segments

검색결과 340건 처리시간 0.028초

누적 센서 데이터 갱신을 이용한 아크/라인 세그먼트 기반 SLAM (Arc/Line Segments-based SLAM by Updating Accumulated Sensor Data)

  • 염서군;최윤성;무경;한창수
    • 제어로봇시스템학회논문지
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    • 제21권10호
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    • pp.936-943
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    • 2015
  • This paper presents arc/line segments-based Simultaneous Localization and Mapping (SLAM) by updating accumulated laser sensor data with a mobile robot moving in an unknown environment. For each scan, the sensor data in the set are stored by a small constant number of parameters that can recover the necessary information contained in the raw data of the group. The arc and line segments are then extracted according to different limit values, but based on the same parameters. If two segments, whether they are homogenous features or not, from two scans are matched successfully, the new segment is extracted from the union set with combined data information obtained by means of summing the equivalent parameters of these two sets, not combining the features directly. The covariance matrixes of the segments are also updated and calculated synchronously employing the same parameters. The experiment results obtained in an irregular indoor environment show the good performance of the proposed method.

마할라노비스 거리와 기하학적 파라메터에 의한 표적의 인식 (Target Identification using the Mahalanobis Distance and Geometric Parameters)

  • 이준웅;권인소
    • 제어로봇시스템학회논문지
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    • 제5권7호
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    • pp.814-820
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    • 1999
  • We propose a target identification algorithm for visual tracking. Target identification is realized by finding out corresponding line segments to the hypothesized model segments of the target. The key idea is the combination of the Mahalanobis distance with the geometrical relationship between model segments and extracted line segments.

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Simplified Representation of Image Contour

  • Yoo, Suk Won
    • International Journal of Advanced Culture Technology
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    • 제6권4호
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    • pp.317-322
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    • 2018
  • We use edge detection technique for the input image to extract the entire edges of the object in the image and then select only the edges that construct the outline of the object. By examining the positional relation between these pixels composing the outline, a simplified version of the outline of the object in the input image is generated by removing unnecessary pixels while maintaining the condition of connection of the outline. For each pixel constituting the outline, its direction is calculated by examining the positional relation with the next pixel. Then, we group the consecutive pixels with same direction into one and then change them to a line segment instead of a point. Among those line segments composing the outline of the object, a line segment whose length is smaller than a predefined minimum length of acceptable line segment is removed by merging it into one of the adjacent line segments. As a result, an outline composed of line segments of over a certain length is obtained through this process.

예산배분을 위한 철도선로구간의 노후도 평가 (Deterioration Evaluation of Railway Line Segments for Budget Distribution)

  • 김성호;최찬용;나희승
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1802-1809
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    • 2011
  • A distribution method of limited budget for rail line facility improvement is to use investment priorities of rail line segments based on their deterioration. In this paper we present an evaluation method of rail line segment deterioration which can be used to distribute limited budget. Rail line facilities include rail track, crossing, road bed, bridge, tunnel. These facilities deterioration and line shape can affect line segment deterioration. Deterioration evaluation method we present is a weighted sum of each component deterioration scores. The component weight can be obtained from experts using analytic hierarchy process.

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3-D Reconstruction of Buildings using 3-D Line Grouping for Urban Modeling

  • Jung, Young-Kee
    • Journal of information and communication convergence engineering
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    • 제7권1호
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    • pp.1-6
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    • 2009
  • In order to obtain a 3-D urban model, an abstraction of the surface model is required. This paper describes works on the 3D reconstruction and modeling by the grouping 3D line segments extracted from the stereo matching of edges, which is derived from multiple images. The grouping is achieved by conditions of degrees and distances between lines. Building objects are determined by the junction combinations of the grouped line segments. The proposed algorithm demonstrates effective results of 3D reconstruction of buildings with 2D aerial images.

허쉬슈프렁병 환아의 무신경절 장관에서 Neural Cell Adhesion Molecule (NCAM) 과 Glial Cell Line-Derived Neurotrophic Factor (GDNF)의 발현 (Expression of Neural Cell Adhesion Molecule (NCAM) and Glial Cell Line-Derived Neurotrophic Factor (GDNF) in Aganglionic Bowel of Hirschsprung's Disease)

  • 오정탁;한애리;손석우;최승훈;한석주;황의호;양우익
    • Advances in pediatric surgery
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    • 제7권1호
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    • pp.15-20
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    • 2001
  • The pathophysiology of Hirschsprung's disease (HD) is not fully understood, but recent studies have disclosed that neural cell adhesion molecule (NCAM) and glial cell line-derived neurotrophic factor (GDNF) play important roles in the formation of aganglionic bowel of Hirschsprung's disease. To evaluate the roles of NCAM and GDNF in HD, immunohistochemical analysis was performed using formalin-fixed and paraffin-embedded tissue sections. On the basis of the results, we tried to evaluate them as diagnostic markers. The specimens were obtained from 7 patients with HD who underwent modified Duhamel operation. The diagnosis was based on the clinical findings and the absence of ganglion cells in the nerve plexuses by routine microscopy. NCAM immunoreactivity was found in the nerve plexuses and scattered nerve fibers in the smooth muscle layers of ganglionic segments. In aganglionic segments, the number of NCAM positive nerve fibers in the smooth muscle layers was significantly reduced compared with ganglionic segments. In two cases the nerve plexuses in aganglionic segments, NCAM was negligible. The smooth muscle cells showed diffuse immunoreactivity for GDNF and the staining intensity was not different in the aganglionic and ganglionic segments. However, higher expression of GDNF in the nerve plexus of the ganglionic segments was noted comparing to aganglionic segments. These data suggest that both NCAM and GDNF may play important roles in pathogenesis of Hirschsprung's disease and immunohistochemical staining for NCAM can be used as an ancillary diagnostic tool for HD.

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3D Building Reconstructions for Urban Modeling using Line Junction Features

  • Lee, Kyu-Won
    • Journal of information and communication convergence engineering
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    • 제5권1호
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    • pp.78-82
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    • 2007
  • This paper propose a building reconstruction method of urban area for a 3D GIS with stereo images. The 3D reconstruction is performed by the grouping 3D line segments extracted from the stereo matching of salient edges which are derived from multiple images. The grouping is achieved by conditions of degrees and distances between lines. Building objects are determined by the junction combinations of the grouped line segments. The proposed algorithm demonstrates effective results of 3D reconstruction of buildings with 2D aerial images.

정형체의 투사 선분의 오차 최소화에 의한 영상기반 모델링 (Image-based Modeling by Minimizing Projection Error of Primitive Edges)

  • 박종승
    • 정보처리학회논문지B
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    • 제12B권5호
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    • pp.567-576
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    • 2005
  • 다중영상으로부터 투사 선분을 이용하여 3D 모델을 생성하고 각 면의 텍스쳐를 획득하는 구조 복원 기법을 제안한다 사용자는 매우 단순한 절차를 통해 정확한 3D 모델 데이터를 획득할 수 있다. 모델 파라메터 추정을 위해 내재된 비선형 최적화 방법은 사용자 지정 영상 선분과 모델의 투사 선분의 거리를 최소화하는 방법에 기반하고 있다. 모델링 기법의 기능적 주요 목표는 형상이 포함된 다중 영상으로부터 그 형상의 3차원 구조를 복원하고 각 면의 텍스쳐를 생성하는 것이다. 본 연구에서는 3D 정형체를 사용하여 사용의 편리성을 증대시킬 수 있고 정형체의 파라메터의 오차를 최소화하여 복원된 구조의 정확성을 높이는 방법을 제시한다. 제안된 방법은 유한 선분에 기반한 오차 함수를 도입하여 무한 직선에 기반한 방법보다 정확한 모델링이 가능하다. 제안된 방법을 다양한 실제 영상에 적용한 실험 결과를 제시하고 다중 영상기반 모델링 도구의 개발 과정에서의 기술적인 문제점과 해결책을 기술한다.

그리드지도의 방향정보를 이용한 형상지도 작성 (Feature based Map Building by using Orientation Information in a Grid Map)

  • 강승균;임종환
    • 한국정밀공학회지
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    • 제22권12호
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    • pp.61-69
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    • 2005
  • This paper presents an efficient method of extracting line segments from the occupancy grids in a grid map. The grid map is composed of 2-D grids that have both the occupancy and orientation probabilities using sonar sensors. We evaluate the orientation information of every grid when the occupancy probability of the grid is updated from sonar range data. To find the shape of an object in the map from orientation information, the orientations are clustered into several groups according to their values. The line segments are, then, extracted from the clusters based on Hough transform. Finally, a feature-based map is built with these line segments. The proposed method is illustrated with the results produced by sets of experiments in an indoor environment.

윤곽선의 선분 근사화를 활용한 양팔 화가 로봇의 개발 (Development of a Dual-Arm Drawing Robot using Line Segment Approximation of Image Edges)

  • 김정규;이상필;정혜림;조혜경
    • 로봇학회논문지
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    • 제9권3호
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    • pp.140-146
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    • 2014
  • This paper introduces a dual-arm robot painter system which is capable of sketching a camera-captured image with short line segments. To express various curved edges in the image by combining line segments, we first apply edge detection algorithm to the entire image, split the edged image into small boxed pieces, and then apply Hough Transformation to each piece so that the edges inside the piece can be approximated with short line segments. To draw the picture within a reasonable time, we designed a simple dual-arm robot system and controlled both arms concurrently according to linear interpolation algorithm. From the experiments, we could verify that simple linear motions can describe various images effectively with a unique brush style.