• Title/Summary/Keyword: distance measure

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Local Collision Avoidance of Multiple Robots Using Avoidability Measure and Relative Distance

  • Ko, Nak-Yong;Seo, Dong-Jin;Kim, Koung-Suk
    • Journal of Mechanical Science and Technology
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    • v.18 no.1
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    • pp.132-144
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    • 2004
  • This paper presents a new method driving multiple robots to their goal position without collision. To consider the movement of the robots in a work area, we adopt the concept of avoidability measure. The avoidability measure figures the degree of how easily a robot can avoid other robots considering the velocity of the robots. To implement the concept to avoid collision among multiple robots, relative distance between the robots is proposed. The relative distance is a virtual distance between robots indicating the threat of collision between the robots. Based on the relative distance, the method calculates repulsive force against a robot from the other robots. Also, attractive force toward the goal position is calculated in terms of the relative distance. These repulsive force and attractive force are added to form the driving force for robot motion. The proposed method is simulated for several cases. The results show that the proposed method steers robots to open space anticipating the approach of other robots. In contrast, since the usual potential field method initiates avoidance motion later than the proposed method, it sometimes fails preventing collision or causes hasty motion to avoid other robots. The proposed method works as a local collision-free motion coordination method in conjunction with higher level of task planning and path planning method for multiple robots to do a collaborative job.

Fuzzy Entropy Construction based on Similarity Measure (유사측도에 기반한 퍼지 엔트로피구성)

  • Park, Wook-Je;Park, Hyun-Jeong;Lee, Sang-H
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2007.11a
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    • pp.366-369
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    • 2007
  • In this paper we derived fuzzy entropy that is based on similarity measure. Similarity measure represents the degree of similarity between two informations, those informations characteristics are not important. First we construct similarity measure between two informations, and derived entropy functions with obtained similarity measure. Obtained entropy is verified with proof. With the help of one-to-one similarity is also obtained through distance measure, this similarity measure is also proved in our paper.

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On the Measurement of the Depth and Distance from the Defocused Imagesusing the Regularization Method (비초점화 영상에서 정칙화법을 이용한 깊이 및 거리 계측)

  • 차국찬;김종수
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.6
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    • pp.886-898
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    • 1995
  • One of the ways to measure the distance in the computer vision is to use the focus and defocus. There are two methods in this way. The first method is caculating the distance from the focused images in a point (MMDFP: the method measuring the distance to the focal plane). The second method is to measure the distance from the difference of the camera parameters, in other words, the apertures of the focal planes, of two images with having the different parameters (MMDCI: the method to measure the distance by comparing two images). The problem of the existing methods in MMDFP is to decide the thresholding vaue on detecting the most optimally focused object in the defocused image. In this case, it could be solved by comparing only the error energy in 3x3 window between two images. In MMDCI, the difficulty is the influence of the deflection effect. Therefor, to minimize its influence, we utilize two differently focused images instead of different aperture images in this paper. At the first, the amount of defocusing between two images is measured through the introduction of regularization and then the distance from the camera to the objects is caculated by the new equation measuring the distance. In the results of simulation, we see the fact to be able to measure the distance from two differently defocused images, and for our approach to be robuster than the method using the different aperture in the noisy image.

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Distance measure between intuitionistic fuzzy sets and its application to pattern recognition

  • Park, Jin-Han;Lim, Ki-Moon;Kwun, Young-Chel
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.4
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    • pp.556-561
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    • 2009
  • In this paper, we propose new method to calculate the distance between intuitionistic fuzzy sets(IFSs) based on the three dimensional representation of IFSs and analyze the relations of similarity measure and distance measure of IFSs. Finally, we apply the proposed measures to pattern recognitions.

Analysis of Fuzzy Entropy and Similarity Measure for Non Convex Membership Functions

  • Lee, Sang-H.;Kim, Sang-Jin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.1
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    • pp.4-9
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    • 2009
  • Fuzzy entropy is designed for non convex fuzzy membership function using well known Hamming distance measure. Design procedure of convex fuzzy membership function is represented through distance measure, furthermore characteristic analysis for non convex function are also illustrated. Proof of proposed fuzzy entropy is discussed, and entropy computation is illustrated.

Development of a Robot's Visual System for Measuring Distance and Width of Object Algorism (로봇의 시각시스템을 위한 물체의 거리 및 크기측정 알고리즘 개발)

  • Kim, Hoi-In;Kim, Gab-Soon
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.2
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    • pp.88-92
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    • 2011
  • This paper looks at the development of the visual system of robots, and the development of image processing algorism to measure the size of an object and the distance from robot to an object for the visual system. Robots usually get the visual systems with a camera for measuring the size of an object and the distance to an object. The visual systems are accurately impossible the size and distance in case of that the locations of the systems is changed and the objects are not on the ground. Thus, in this paper, we developed robot's visual system to measure the size of an object and the distance to an object using two cameras and two-degree robot mechanism. And, we developed the image processing algorism to measure the size of an object and the distance from robot to an object for the visual system, and finally, carried out the characteristics test of the developed visual system. As a result, it is thought that the developed system could accurately measure the size of an object and the distance to an object.

Robust Oriented Hausdorff Measure for 2-D Object Matching (이차원 물체 정합을 위한 Robust Oriented Hausdorff Measure)

  • Sim, Dong-Gyu;Park, Rae-Hong
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.11
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    • pp.60-67
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    • 1999
  • This paper proposes a robust oriented Hausdorff measure (ROHM) for 20D object matching. The ROHM is introduced by replacing the distance concept of the conventional Hausdorff distance (HD) algorithm by the accumulation scheme of the Hough transform (HT). The proposed algorithm can be considered as the modified directed HT using the distance transform (DT). The orientation information at each pixel is also used for removing incorrect correspondences. Experiments with various test images show that the performance of the proposed algorithm is better than that of conventional HD algorithms considered.

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Grouping DNA sequences with similarity measure and application

  • Lee, Sanghyuk
    • Journal of the Korea Convergence Society
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    • v.4 no.3
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    • pp.35-41
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    • 2013
  • Grouping problem with similarities between DNA sequences are studied. The similaritymeasure and the distance measure showed the complementary characteristics. Distance measure can be obtained by complementing similarity measure, and vice versa. Similarity measure is derived and proved. Usefulness of the proposed similarity measure is applied to grouping problem of 25 cockroach DNA sequences. By calculation of DNA similarity, 25 cockroaches are clustered by four groups, and the results are compared with the previous neighbor-joining method.

Measure of Fuzziness with fuzzy entropy function

  • Lee, Sang-Hyuk;Kang, Keum-Boo;Kim, Sung shin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.5
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    • pp.642-647
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    • 2004
  • The relations of fuzzy entropy, distance measure, and similarity measure are discussed in this paper. For the purpose of reliable signal selection, the fuzzy entropy is proposed by a distance measure. Properness of the proposed entropy is verified by the definition of the entropy measure. Fourier and Wavelet transform are applied to the stator current signal to obtain the fault features of an induction motor. Membership functions for 3-phase currents are obtained by the Bootstrap method and Central Limit Theorem. Finally, the proposed entropy is applied to measure the fault signal of an induction machine, and the fuzzy entropy values of phase currents are illustrated.

Similarity Measure Construction for Non-Convex Fuzzy Membership Function (비 컨벡스 퍼지 소속함수에 대한 유사측도구성)

  • Park, Hyun-Jeong;Kim, Sung-Shin;Lee, Sang-H
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2007.11a
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    • pp.199-202
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    • 2007
  • The similarity measure is constructed for non-convex fuzzy membership function using well known Hamming distance measure. Comparison with convex fuzzy membership function is carried out, furthermore characteristic analysis for non-convex function are also illustrated. Proposed similarity measure is proved and the usefulness is verified through example. In example, usefulness of proposed similarity is pointed out.

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