• 제목/요약/키워드: geometric transformation

검색결과 241건 처리시간 0.026초

A Corner Matching Algorithm with Uncertainty Handling Capability

  • Lee, Kil-jae;Zeungnam Bien
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1997년도 춘계학술대회 학술발표 논문집
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    • pp.228-233
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    • 1997
  • An efficient corner matching algorithm is developed to minimize the amount of calculation. To reduce the amount of calculation, all available information from a corner detector is used to make model. This information has uncertainties due to discretization noise and geometric distortion, and this is represented by fuzzy rule base which can represent and handle the uncertainties. Form fuzzy inference procedure, a matched segment list is extracted, and resulted segment list is used to calculate the transformation between object of model and scene. To reduce the false hypotheses, a vote and re-vote method is developed. Also an auto tuning scheme of the fuzzy rule base is developed to find out the uncertainties of features from recognized results automatically. To show the effectiveness of the developed algorithm, experiments are conducted for images of real electronic components.

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전구 자동화 생산기계용 바렐 캠의 형상설계에 관한 연구 (A Study on Design of Barrel Cam for Automatic Bulb Production Machine)

  • 김종수;윤호업
    • 연구논문집
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    • 통권33호
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    • pp.89-97
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    • 2003
  • A barrel cam is used as a very important part of an index drive unit. The index drive unit must have an intermittent-rotational motion. The barrel typed cam and roller gear mechanism has the advantages of high reliability to perform a prescribed motion of a follower. This paper proposes a new method for the shape design of the barrel cam and also a CAD program is developed by using the proposed method. As defined in this paper, the relative velocity method for the shape design calculates the relative velocity of the follower versus cam at a center of roller, and then detemines a contact point by using the geometric relationships and the kinematic constraints, where the direction of the relative velocity must be parallel to a common tangential line at the contact point of two independent bodies, i.e. the cam and the follower. Then, the shape of the cam is defined by the coordinate transformation of the trace of the contact points. This paper presents shape design of the barrel cam in order to prove the accuracy of the proposed methods

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호모그래피행렬을 이용한 노면검출 (Ground Plane Detection Using Homography Matrix)

  • 이기용;이준웅
    • 제어로봇시스템학회논문지
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    • 제17권10호
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    • pp.983-988
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    • 2011
  • This paper presents a robust method for ground plane detection in vision-based applications based on a monocular sequence of images with a non-stationary camera. The proposed method, which is based on the reliable estimation of the homography between two frames taken from the sequence, aims at designing a practical system to detect road surface from traffic scenes. The homography is computed using a feature matching approach, which often gives rise to inaccurate matches or undesirable matches from out of the ground plane. Hence, the proposed homography estimation minimizes the effects from erroneous feature matching by the evaluation of the difference between the predicted and the observed matrices. The method is successfully demonstrated for the detection of road surface performed on experiments to fill an information void area taken place from geometric transformation applied to captured images by an in-vehicle camera system.

Unifying Method for Computing the Circumcircles of Three Circles

  • Kim, Deok-Soo;Kim, Dong-Uk;Sugihara, Kokichi
    • International Journal of CAD/CAM
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    • 제2권1호
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    • pp.45-54
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    • 2002
  • Given a set of three generator circles in a plane, we want to find a circumcircle of these generators. This problem is a part of well-known Apollonius' $10^{th}$ Problem and is frequently encountered in various geometric computations such as the Voronoi diagram for circles. It turns out that this seemingly trivial problem is not at all easy to solve in a general setting. In addition, there can be several degenerate configurations of the generators. For example, there may not exist any circumcircle, or there could be one or two circumcircle(s) depending on the generator configuration. Sometimes, a circumcircle itself may degenerate to a line. We show that the problem can be reduced to a point location problem among the regions bounded by two lines and two transformed circles via $M{\ddot{o}}bius$ transformations in a complex space. The presented algorithm is simple and the required computation is negligible. In addition, several degenerate cases are all incorporated into a unified framework.

Mapping Within-field Variability Using Airborne Imaging Systems: A Case Study from Missouri Precision Agriculture

  • Hong, S.Y.;Sudduth, K.A.;Kitchen, N.R.;Palm, H.L.;Wiebold, W.J.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1049-1051
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    • 2003
  • This study investigated the use of airborne image data to provide estimates of within -field variability in soil properties and crop growth as an alternative to extensive field data collection. Hyperspectral and multispectral images were acquired in 2000, 2001, and 2002 for central Missouri experimental fields. Data were converted to reflectance using chemically-treated reference tarps with known reflectance levels. Geometric distortion of the hyperspectral pushbroom sensor images was corrected with a rubber sheeting transformation. Statistical analyses were used to relate image data to field-measured soil properties and crop characteristics. Results showed that this approach has potential; however, it is important to address a number of implementation issues to insure quality data and accurate interpretations.

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Geometrical Comparisons between Rigorous Sensor Model and Rational Function Model for Quickbird Images

  • Teo, Tee-Ann;Chen, Liang-Chien
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.750-752
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    • 2003
  • The objective of this investigation is to compare the geometric precision of Rigorous Sensor Model and Rational Function Model for QuickBird images. In rigorous sensor model, we use the on-board data and ground control points to fit an orbit; then, a least squares filtering technique is applied to collocate the orbit. In rational function model, we first use the rational polynomial coefficients provided by the satellite company. Then the systematic bias of the coefficients is compensated by an affine transformation using ground control points. Experimental results indicate that, the RFM provides a good approximation in the position accuracy.

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자동 착유시스템을 위한 다관절 로봇 머니퓰레이터의 기구학적 분석 (Kinematics Analysis of the Milti-joint Robot Manipulator for an Automatic Milking System)

  • 김웅;이대원
    • 한국축산시설환경학회지
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    • 제13권3호
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    • pp.179-186
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    • 2007
  • The purpose of this study was kinematics analysis of the multi-joint robot manipulator for an automatic milking system. The multi-joint robot manipulator was consisted of one perpendicular link and four revolution links to attach simultaneously four teat cups to four teats of a milking cow. The local coordinates of each joints on the robot manipulator was given for kinematics analysis. The transformation of manipulator was able to be given by kinematics using Denavit-Hatenberg parameters. The value of inverse kinematics which was solved by two geometric solution methods. The kinematics solutions was verified by AutoCAD, MATLAB, simulation program was developed using Visual C++.

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Elastoplastic nonlinear behavior of planar steel gabled frame

  • Moghaddam, Sina Heyrani;Masoodi, Amir R.
    • Advances in Computational Design
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    • 제4권4호
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    • pp.397-413
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    • 2019
  • In this paper, static nonlinear analysis of gable frame is performed using OpenSees software. Both geometric and material nonlinearities are considered in analyses. To consider large displacements, co-rotational coordinate transformation is used in software. The effects of symmetric and asymmetric support conditions including clamped and simple supports are studied. On the other hand, the material nonlinearity is reflected on analyses using Giuffre-Menegotto-Pinto steel material. Note that strain hardening characteristics are also considered in this model. Moreover, I-shaped cross-section is assumed for all members. The results are provided for different geometry properties of gable frame including shallow and deep inclined roof. It should be added that buckling and post-buckling behaviors of gable frame are investigated using related equilibrium paths. A comparison study is also implemented on the responses of buckling loads obtained for different support and geometry conditions. To trace snap-through paths completely, a displacement control method entitled arc-length is utilized. Findings show the capability of proposed model in nonlinear analysis of gable frames.

INVARIANT GRAPH AND RANDOM BONY ATTRACTORS

  • Fateme Helen Ghane;Maryam Rabiee;Marzie Zaj
    • 대한수학회지
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    • 제60권2호
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    • pp.255-271
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    • 2023
  • In this paper, we deal with random attractors for dynamical systems forced by a deterministic noise. These kind of systems are modeled as skew products where the dynamics of the forcing process are described by the base transformation. Here, we consider skew products over the Bernoulli shift with the unit interval fiber. We study the geometric structure of maximal attractors, the orbit stability and stability of mixing of these skew products under random perturbations of the fiber maps. We show that there exists an open set U in the space of such skew products so that any skew product belonging to this set admits an attractor which is either a continuous invariant graph or a bony graph attractor. These skew products have negative fiber Lyapunov exponents and their fiber maps are non-uniformly contracting, hence the non-uniform contraction rates are measured by Lyapnnov exponents. Furthermore, each skew product of U admits an invariant ergodic measure whose support is contained in that attractor. Additionally, we show that the invariant measure for the perturbed system is continuous in the Hutchinson metric.

대화형 인쇄물 구현을 위한 기하변형과 잡음에 강인한 원형 점 패턴코드의 설계와 인식 알고리즘 구현 (Design and Implementation of Circular Dot Pattern Code (CDPC) and Its Recognition Algorithm which is robust to Geometric Distortion and Noise)

  • 심재연;김성환
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2011년도 추계학술발표대회
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    • pp.1166-1169
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    • 2011
  • In this paper, we design a Circle dot Code, In our scheme, we design a dot patterns for increasing maximum capacity and also for increasing robustness to Affine Transformation. Our code Can be extended according number of data circle. We use three data circle vision code. In this type code, after acquiring camera images for the Circle dot Codes, and perform error correction decoding using four position symbols and six CRC symbols. We perform graph based dot code analysis which determines the topological distance between dot pixels. Our code can be bridged the real world and ubiquitous computing environment.