• 제목/요약/키워드: Geometrical features

검색결과 225건 처리시간 0.027초

2차원 LRF의 Raw Sensor Data로부터 추출된 다른 타입의 기하학적 특징 (Extraction of Different Types of Geometrical Features from Raw Sensor Data of Two-dimensional LRF)

  • 염서군;무경;원조;한창수
    • 제어로봇시스템학회논문지
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    • 제21권3호
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    • pp.265-275
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    • 2015
  • This paper describes extraction methods of five different types of geometrical features (line, arc, corner, polynomial curve, NURBS curve) from the obtained raw data by using a two-dimensional laser range finder (LRF). Natural features with their covariance matrices play a key role in the realization of feature-based simultaneous localization and mapping (SLAM), which can be used to represent the environment and correct the pose of mobile robot. The covariance matrices of these geometrical features are derived in detail based on the raw sensor data and the uncertainty of LRF. Several comparison are made and discussed to highlight the advantages and drawbacks of each type of geometrical feature. Finally, the extracted features from raw sensor data obtained by using a LRF in an indoor environment are used to validate the proposed extraction methods.

농산물 및 미립자의 기하학적 특성 분석을 위한 컴퓨터 시각 시스템(II) -기하학적 특성 분석 알고리즘- (Computer Vision System for Analysis of Geometrical Characteristics of Agricultural Products and Microscopic Particles(II) -Algorithms for Geometrical Feature Analysis-)

  • 이종환;노상하
    • Journal of Biosystems Engineering
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    • 제17권2호
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    • pp.143-155
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    • 1992
  • The aim of this study is to develop a general purpose algorithm for analyzing geometrical features of agricultural products and microscopic particles regardless of their numbers, shapes and positions with a computer vision system. Primarily, boundary informations of an image were obtained by Scan Line Coding and Scan & Chain Coding methods and then with these informations, geometrical features such as area, perimeter, lengths, widths, centroid, major and minor axes, equivalent circle diameter, number of individual objects, etc, were analyzed. The algorithms developed in this study was evaluated with test images consisting of a number of randomly generated ellipsoids or a few synthesized diagrams having different features. The result was successful in terms of accuracy.

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CMM의 기하학적 제품규격 (Geometrical Product Specifications for Coordinate Measuring Machines)

  • 최성운
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2007년도 추계학술대회
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    • pp.319-322
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    • 2007
  • This paper presents geometrical product specifications of acceptance and verification tests for coordinate measuring machines(CMM). These specifications include vocabulary, measuring size, rotary table with fourth axis, scanning measuring mode, multiple-stylus probing systems, measuring, and, estimation of errors in computing Gaussian associated features.

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Estimating 3-D surface geometrical features on the basis of surface curvature consistency

  • Zha, H.B.;Muramatsu, S.;Nagata, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.54-59
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    • 1993
  • This paper presents a method of estimating 3-D surface geometrical features that are necessary for 3-D object recognition and image interpretation. The features, such as surface needle maps and curvatures, are computed from range or intensity images. In general, the range and intensity images are prone to noises, and hence the features computed by differentiation calculi on such a noisy image are hardly applicable to industrial recognition tasks. In our approach, we try to obtain a more accurate estimate of the features by using a least-squares minimization procedure subject to local curvature consistency constraints. The algorithm is robust with respect to noises and is completely independent of the viewpoint at which the image is taken. The performance of the ajgoritlim is evaluated using both synthetic data and real intensity images.

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이동로봇의 위치 추정을 위한 스케일 불변 특징점 추출 및 거리 측정에 관한 연구 (A Study on Scale-Invariant Features Extraction and Distance Measurement for Localization of Mobile Robot)

  • 정대섭;장문석;유제군;이응혁;심재홍
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.625-627
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    • 2005
  • Existent distance measurement that use camera is method that use both Stereo Camera and Monocular Camera, There is shortcoming that method that use Stereo Camera is sensitive in effect of a lot of expenses and environment variables, and method that use Monocular Camera are big computational complexity and error. In this study, reduce expense and error using Monocular Camera and I suggest algorithm that measure distance, Extract features using scale Invariant features Transform(SIFT) for distance measurement, and this measures distance through features matching and geometrical analysis, Proposed method proves measuring distance with wall by geometrical analysis free wall through feature point abstraction and matching.

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현대주거의 기하조작에 의한 보이드 공간의 생성과 친환경적 특성에 관한 연구 (A Study on Formation of Void Space by Geometric Method and Environment-friendly Characteristics in Contemporary Housing)

  • 이동기
    • 한국주거학회논문집
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    • 제21권6호
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    • pp.131-141
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    • 2010
  • This study is aimed to grasp the spatial characteristics exhibited in the modern housing architecture from the aspect of a geometrical manipulation, which transforms basic geometrical shapes and persue the formative diversity, to identify and verify the various characteristics of spatial structure in modern housing architecture. In this regard, this paper analyze and identify the influences of the void spaces that are created by geometrical manipulations on housing architecture, in terms of morphological and environmental aspects. Theoretical approaches define the concept of geometrical manipulation according to the characteristics of residence and examine the spatial features of void spaces. Additionally, case studies result in the classification of void spaces that are created by geometrical manipulation. Furthermore, to understand environment-friendly characteristics of the void space, the researcher elicited the factors that can affect environment friendly housing from previous studies, and analyzed their correlation between those factors and the void spaces that are classified.

Economic Design of the Specification for Geometrical Quality Characteristic

  • Ma, Yizhong;Zhao, Fengyu;Xu, Jichao
    • International Journal of Quality Innovation
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    • 제2권1호
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    • pp.50-57
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    • 2001
  • The economic design of specification limits must be determined on an economic basis where we minimize total loss to society, which consists of both the producer and the consumer. Economic specification limits have been developed based on the assumption that the quality characteristic is normally distributed. Unfortunately, the assumption is not to meet some practical cases. In this paper, some non-normal distributions are considered for quality characteristic with geometrical features. An economic model for selecting the optimum specification limits on the basis of minimizing total cost is introduced. A case study is presented to illustrate the application in practice.

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피부색 정보와 얼굴의 구조적 특징 분석을 통한 얼굴 영상 인식 시스템 (Human Face Recognition System Based on Skin Color Informations and Geometrical Feature Analysis of Face)

  • 이응주
    • 융합신호처리학회논문지
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    • 제1권1호
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    • pp.42-48
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    • 2000
  • 본 논문에서는 칼라 CCD 카메라로부터 입력된 얼굴 영상에서 피부색 정보와 눈, 코, 입 등의 얼굴 영역 특징 자 및 턱 선의 선형 적 특징을 이용한 얼굴 영상 인식 알고리즘을 제안하져다. 제안한 알고리즘에서는 인간의 시각 체계와 비교적 유사한 HSI 좌표계 상에서 피부색에 대한 색상 정보와 명암값 정보를 함께 이용함으로써 얼굴영역 추출의 효율을 높였고, 인종에 따라 적응적인 추출이 가능하도록 하였다. 또한 추출된 얼굴 영역에서 얼굴 인식율 개선을 위해 눈, 코, 입 등의 구조적 위치정보와 턱선의 선형적인 특징값을 이용하여 얼굴 인식율을 개선하였다. 제안한 알고리즘에서는 기존의 명암 정보를 이용하는 방법과는 달리 색상 정보와 명암 정보를 함께 이용함으로써 정확한 얼굴영역의 검출이 가긍하였으며 인식 방법에 있어서 구조적 특징자 외에 턱선의 선형적인 관계값을 이용함으로써 인식 효율을 개선하였다.

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마들렌느 비오네의 작품에 나타난 기하학적 특성에 관한 연구 (A Study on the Characteristics of Geometry in Madeleine Vionnet´s Works)

  • 유수경;김의경
    • 복식문화연구
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    • 제10권6호
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    • pp.763-780
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    • 2002
  • The aim of this research is to analyze Vionnet´s geometric features, which can be regarded as the key formative beauty among the external characteristics of her works. and to thereby establish the theory that her works emitted a time-transcending life force because they were patterns designed based on a geometrical frame of mind. To prove such argument, studies to understand the basic geometrical aspects appearing in her works will be made by taking a look at the general features of geometry, viewing Vionnet´s philosophy for designing, and examining the geometric cutting methods. The period covered in this paper will center mainly on dresses Vionnet made from her very active days in the fashion sector, 1919. till when she retired from the fashion industry, around 1939. What's outstanding about Vionnet´s geometric principle expressed in her works is the unique cutting method that acknowledges the silhouette of the human body as a cubic or three-dimensions concept, through insight of the human body, the mechanics of the materials, and geometry. Vionnet introduced a simple and elegant design by combining geometric figure cuts, such as rectan히es. quadrants, and triangles. Moreover, she created a new sewing structure that plans everything about the materials to the tiniest detail, resulting in producing a softer style With this, Vionnet showed the geometrical correlation can bring about harmony and the beauty of ideal proportion, forming the source of eternal beauty. As discussed so fu, the geometrical characteristics appearing in Vionnet´s works are marked such as spirals, zig-zag lines, asymmetries. panels, gradation, golden proportion, and the mobius-band.

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전극 함몰형 고효율 실리콘 태양전지에서의 texturing 효과 (Texturing Effects on High Efficiency Silicon Buried Contact Solar Cell)

  • 지일환;조영현;이수홍
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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    • pp.172-176
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    • 1995
  • Schemes to trap weakly absorbed light into the cell have played an important role in improving the efficiency of both amorphous and crystlline silicon solar cells. One class of scheme relies on randomizing the direction of light within the cell by use of Lambertian(diffuse)surfaces. A second class of scheme relies on the use fo well defined geometrical features to control the direction of light wihin the cell, Widly used geometrical features in crystalline silicon solar cells are the square based pyramids and V-shaped grooves formed in (100) orientated surfaces by intersecting(III) crystallographic planes exposed by anisotropic etching. 18.5% conversion efficiency of Buried Contact Solar Cell with pyramidally textured surface has been achieved. 18.5% efficiency of silicon solar cell is one the highest record in the world The efficieny of cell without textured surface was 16.6%, When adapting textured surface to the Cell, the efficiency has been improved over 12%.

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