• Title/Summary/Keyword: Ellipses

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Detection of Ellipses using Least Square Method (최소자승법을 이용한 타원의 검출)

  • 이주용;서요한;이웅기
    • Journal of the Korea Society of Computer and Information
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    • v.1 no.1
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    • pp.95-104
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    • 1996
  • The Hough transform Is a robust technique Which Is useful in defecting straight lines in an picture. However, the extension of the conventional Hough transform to recover circles and ellipses has been limited by slow speed and excessive memory .This paper presents a method of detecting ellipses from the Image by using Least Square Method. This method Is reduced calculation cost and memory requirement .When detecting ellipse. Instead of obtaining accumulation of Hough transform for determination of ellipse parameters. particular points containing geometric properties of ellipse are selected. Parameters of the ellipse are calculated by Least Square Method using those particular points.

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COMPUTATION OF THE HAUSDORFF DISTANCE BETWEEN TWO ELLIPSES

  • Kim, Ik-Sung
    • Honam Mathematical Journal
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    • v.38 no.4
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    • pp.833-847
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    • 2016
  • We are interested in the problem of finding the Hausdorff distance between two objects in ${\mathbb{R}}^2$, or in ${\mathbb{R}}^3$. In this paper, we develop an algorithm for computing the Hausdorff distance between two ellipses in ${\mathbb{R}}^3$. Our algorithm is mainly based on computing the distance between a point $u{\in}{\mathbb{R}}^3$ and a standard ellipse $E_s$, equipped with a pruning technique. This algorithm requires O(log M) operations, compared with O(M) operations for a direct method, to achieve a comparable accuracy. We give an example,and observe that the computational cost needed by our algorithm is only O(log M).

SURFACES FOLIATED BY ELLIPSES WITH CONSTANT GAUSSIAN CURVATURE IN EUCLIDEAN 3-SPACE

  • Ali, Ahmed T.;Hamdoon, Fathi M.
    • Korean Journal of Mathematics
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    • v.25 no.4
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    • pp.537-554
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    • 2017
  • In this paper, we study the surfaces foliated by ellipses in three dimensional Euclidean space ${\mathbf{E}}^3$. We prove the following results: (1) The surface foliated by an ellipse have constant Gaussian curvature K if and only if the surface is flat, i.e. K = 0. (2) The surface foliated by an ellipse is a flat if and only if it is a part of generalized cylinder or part of generalized cone.

Detection of Lines and Ellipses using Hough Transform (하프변환을 이용한 직선 및 타원 검출법)

  • Kim, Ha-Seok;Kim, Ran;Lee, Jung-Jae;Song, Chol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.10
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    • pp.1582-1589
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    • 1993
  • This paper presents a method of detecting lines and ellipses from the image by using Hough transform(HT) known as a robust line detection method against noise. Lines are first detected by conventional HT. Then points of the lines are eliminated to reduce the calculation cost and to ease detection of ellipses. For ellipse defection, parameters of the ellipse are calculated by Least Square Method using particular points that contain geometric properties of the ellipse, instead of accumlating Hough array. Circles are detected in the same way as ellipse detection.

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Study for Calculating Overlapped Areas of Ellipse Bumper with Real-time Weight (실시간 가중치를 갖는 타원형 범퍼의 겹치는 면적을 계산하기 위한 연구)

  • Gang, Sang-Geun;Yim, Jeong-Bin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2017.11a
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    • pp.262-265
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    • 2017
  • This study is to calculate the Real-Time Overlapped Area of ellipses with weight by Ship's Bumper Theory. In this paper, The Real-Time Overlapped Area of ellipses with weight can be used the important tool to feel the perceived risk evaluation by navigator. In this paper, through how to feel the risk of collision between the vessels in advance, We will study the technique to certify the perceived risk of collision from several different angles.

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Implementing 3-D Image Reconstruction Algorithms for Compton (컴프턴 카메라를 위한 3 차원 영상 재구성 알고리즘의 구현)

  • Lee, Mi-No;Lee, Soo-Jin
    • The Journal of Engineering Research
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    • v.8 no.1
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    • pp.51-57
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    • 2006
  • We propose efficient methods for implementing 3-D reconstruction algorithms for Compton camera. Since reconstructing Compton scattered data involves the surface integral over the cone associated with the measurement bin, it is crucial to develop a computationally efficient surface integration method. In this work we assume that a cone is made up of a series of ellipses (or circles) stacked up one o top of the other. In order to reduce computational burden for tracing ellipses formed by the intersection of a cone and an image plane, we construct a series of imaginary planes perpendicular to the cone axis so that each plane contains a circle, not an ellipse. In this case the surface integral can be performed by adding uniform samples along each circle. The experimental results demonstrate that our method using imaginary planes significantly improves computational efficiency while keeping reconstruction accuracy.

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Ellipse-Stacking Methods for Image Reconstruction in Compton Cameras (컴프턴 카메라 영상재구성을 위한 타원 누적법)

  • Lee, Mi-No;Lee, Soo-Jin;Kim, Soo-Mee;Lee, Jae-Sung
    • Journal of Biomedical Engineering Research
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    • v.28 no.4
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    • pp.520-529
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    • 2007
  • An efficient method for implementing image reconstruction algorithms for Compton cameras is presented. Since Compton scattering formula establishes a cone surface from which the incident photon must have originated, it is crucial to implement a computationally efficient cone-surface integration method for image reconstruction. In this paper we assume that a cone is made up of a series of ellipses (or circles) stacked up one on top of the other. In order to reduce computational burden for tracing ellipses formed by the intersection of a cone and an image plane, we propose a new method using a series of imaginary planes perpendicular to the cone axis so that each plane contains a circle, not an ellipse. In this case the cone surface integral can be performed by simply accumulating the circles along the cone axis. To reduce the computational cost of tracing circles, only one of the circles in the cone is traced and the rest are determined by using simple trigonometric ratios. For our experiments, we used the three different schemes for tracing ellipses; (i) using the samples generated by the ellipse equation, (ii) using the fixed number of samples along a circle on the imaginary plane, and (iii) using the fixed sampling interval along a circle on the imaginary plane. We then compared performance of the above three methods by applying them to the two reconstruction algorithms - the simple back-projection method and the expectation-maximization algorithm. The experimental results demonstrate that our proposed methods (ii) and (iii) using imaginary planes significantly improve reconstruction accuracy as well as computational efficiency.

Hand Gesture Recognition Algorithm Robust to Complex Image (복잡한 영상에 강인한 손동작 인식 방법)

  • Park, Sang-Yun;Lee, Eung-Joo
    • Journal of Korea Multimedia Society
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    • v.13 no.7
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    • pp.1000-1015
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    • 2010
  • In this paper, we propose a novel algorithm for hand gesture recognition. The hand detection method is based on human skin color, and we use the boundary energy information to locate the hand region accurately, then the moment method will be employed to locate the hand palm center. Hand gesture recognition can be separated into 2 step: firstly, the hand posture recognition: we employ the parallel NNs to deal with problem of hand posture recognition, pattern of a hand posture can be extracted by utilize the fitting ellipses method, which separates the detected hand region by 12 ellipses and calculates the white pixels rate in ellipse line. the pattern will be input to the NNs with 12 input nodes, the NNs contains 4 output nodes, each output node out a value within 0~1, the posture is then represented by composed of the 4 output codes. Secondly, the hand gesture tracking and recognition: we employed the Kalman filter to predict the position information of gesture to create the position sequence, distance relationship between positions will be used to confirm the gesture. The simulation have been performed on Windows XP to evaluate the efficiency of the algorithm, for recognizing the hand posture, we used 300 training images to train the recognizing machine and used 200 images to test the machine, the correct number is up to 194. And for testing the hand tracking recognition part, we make 1200 times gesture (each gesture 400 times), the total correct number is 1002 times. These results shows that the proposed gesture recognition algorithm can achieve an endurable job for detecting the hand and its' gesture.

Study on the grammatical characteristics and fallacy of translation in the sentences of Donguibogam by Heo Jun - Focused on Tangaekpean(湯液篇) in Donguibogam "東醫寶鑑" - ("동의보감(東醫寶鑑)"에 쓰여진 허준(許浚) 문장(文章)의 문법적(文法的) 특성(特性)과 번역서(飜譯書)의 오류(誤謬) - "탕액편(湯液篇)"을 중심(中心)으로 -)

  • Kim, Yong-Han;Kim, Eun-Ha
    • Journal of Korean Medical classics
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    • v.24 no.6
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    • pp.111-124
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    • 2011
  • The objectives of this study are to look into the grammatical characteristics and find misinterpretations on the translation books. 1. Sentences characteristics 1) Lots of ellipses of grammatical parts can be found such as conjunction, postposition, particle, Coverb, and focus on the parts which has practical meaning such as noun, pronoun, verb, adjective in the sentences. 2) Some predicates are skipped in the later phrases which has contradictive concepts against them of former phrases. 3) Pure Korean word order is exposed especially in complement. 2. Translation fallacy 1) There is fallacy in the sentences omitted paratactic conjunction as follows (1) mistranslation based on the wrong concept of the context between equal relation and subordinate relation. (2) failure on setting up the period, (3) misunderstanding equal relation as cause relation. 2) Some singular phrases, which are condition relation, were analyzed as plural phrases in the sentences omitted connection conjunction. 3) Ellipses of postposition obstruct understanding the difference between modifier and modificand in some sentences. 4) Some cause relation phrases were translated as equality relation due to lack of recognition of ellipsis of coverbs.

Study for VTS Operating Using Bumper Contact point by Bumper Thery (범퍼이론을 사용한 선박접근 인식을 이용한 선박관제기법 연구)

  • Gang, Sang geun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2019.11a
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    • pp.26-27
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    • 2019
  • This study is to calculate the Real-Time contact point of ellipses between the vessels ships by Ship's Bumper Theory. The Real-Time contact point of ship's bumper ellipses can be used the important tool to feel the perceived risk evaluation of ship's collision risk by VTS operator. In this paper, The warning information to feel the risk of collision between the vessels in advance is able to help them for VTS operation, We will study the technique to certify the perceived risk of collision from several different angles by programming.

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