• Title/Summary/Keyword: Bezier 곡선

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Hypothesis Tests For Performances of a New Spline Interpolation Technique (신 스플라인보간법의 퍼포먼스 가설점정)

  • Yu, Ki-Yun
    • Journal of Korean Society for Geospatial Information Science
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    • v.7 no.1 s.13
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    • pp.29-40
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    • 1999
  • In vector GIS, natural linear entities (called linear entitles) are usually represented by a set of line segments. As an alternative of the line segments, curve segments can be used to represent the linear entities. The curve segments, as one-dimensional spatial objects, we generated by spline interpolation technique such as Bezier technique. In an effort to improve its accuracy in resembling the linear entities, the Bezier technique was modified generating a new technique (called New technique) (Kiyun, 1998). In this paper, validity of the New technique was tested. Test focused on answering two questions: (1) whether or not the curve segments from the New technique replace line segments so as to enhance the accuracy of representations of linear entities, and (2) whether or not the curve segments from the New technique represent the linear entities more accurately than curve segments from the Bezier technique. Answering these two questions entailed two hypothesis tests. For test data, a series of hydrologic lines on 7.5-minute USGS map series were selected. Test were done using t-test method and statistical inferences were made from the results. Test results indicated that curve segments from both the Bezier and New techniques represent the linear entities more accurately than the line segments do. In addition, curve segments from the New technique represent the linear entities more accurately than the line segments from the Bezier technique do at probability level 69% or higher.

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An Improvement of Navigation in Robot Soccer using Bezier Curve (베지어 곡선을 이용한 로봇 축구 항법의 개선)

  • Jung, Tae-Young;Lee, Gui-Hyung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.6
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    • pp.696-702
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    • 2015
  • This paper suggests a new method for making a navigation path by using Bezier curve in order to improve the navigation performance used to avoid obstacles during a robot soccer game. We analyzed the advantages and disadvantages of both vector-field and limit-cycle navigation methods, which are the mostly widely used navigation methods for avoiding obstacles. To improve the disadvantages of these methods, we propose a new design technique for generating a more proper path using Bezier curve and describe its advantages. Using computer simulations and experiments, we compare the performance of vector-field navigation with that of Bezier curve navigation. The results prove that the navigation performance using Bezier curve is relatively superior to the other method.

Degree Reduction and Computation of the Maximum Error of B$\'{e}$zier Curves (B$\'{e}$zier 곡선의 차수감소와 최대오차의 계산)

  • 김혁진
    • Journal of the Korea Society of Computer and Information
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    • v.4 no.4
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    • pp.25-33
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    • 1999
  • Exchanging parametric curves and surfaces between different geometric modeling systems often require degree reductions to approximate the curves and surfaces to the degree of supporting systems within the given tolerance. This paper is a research for approximate conversion of a degree reduction methods for Bezier curves in the data exchange between the different systems. Our approximate conversion is implemented that shows the experimental results with the others to reduce the degree from the given degree n to n-1 for the Bezier curves about the different degree reductions.

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Trajectory Generation of Two Wheeled Mobile Robot using Bezier Curve (Bezier 곡선을 이용한 이륜 구동 로봇의 경로 생성)

  • Cho, Gyu-Sang
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2472-2474
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    • 2002
  • This paper describe a trajectory generation method for a two-wheeled mobile robot using cubic Bezier curve. It is proposed that the method to determine the location of control points which mainly affect the shape of curve, and constrains for two-wheeled mobile are examined. Simulation results show its traceability of the trajectory of mobile robot.

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Nonparametric estimation of the derivative of function via the Bezier curve (베지에 곡선을 이용한 함수의 미분에 대한 비모수적 추정)

  • 김충락;정미선;김형순
    • The Korean Journal of Applied Statistics
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    • v.11 no.1
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    • pp.193-204
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    • 1998
  • It is quite that we have to estimate the derivative of the regression function. The Bezier curve, rarely known to statisticians, is very popular in computer graphics area. In this paper, we use nonparametric method via the Bezier curve, and apply this method to real data set. This method seems to be very easy to compute and can be easily applied to other smoothing techniques.

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The Detection of Inflection Points on Planar Rational $B\'{e}zier$ Curves (평면 유리 $B\'{e}zier$곡선상의 변곡점 계산법)

  • 김덕수;이형주;장태범
    • Korean Journal of Computational Design and Engineering
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    • v.4 no.4
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    • pp.312-317
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    • 1999
  • An inflection point on a curve is a point where the curvature vanishes. An inflection point is useful for various geometric operations such as the approximation of curves and intersection points between curves or curve approximations. An inflection point on planar Bezier curves can be easily detected using a hodograph and a derivative of hodograph, since the closed from of hodograph is known. In the case of rational Bezier curves, for the detection of inflection point, it is needed to use the first and the second derivatives have higher degree and are more complex than those of non-rational Bezier curvet. This paper presents three methods to detect inflection points of rational Bezier curves. Since the algorithms avoid explicit derivations of the first and the second derivatives of rational Bezier curve to generate polynomial of relatively lower degree, they turn out to be rather efficient. Presented also in this paper is the theoretical analysis of the performances of the algorithms as well as the experimental result.

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Facial Detection using Haar-like Feature and Bezier Curve (Haar-like와 베지어 곡선을 이용한 얼굴 성분 검출)

  • An, Kyeoung-Jun;Lee, Sang-Yong
    • Journal of Digital Convergence
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    • v.11 no.9
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    • pp.311-318
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    • 2013
  • For face detection techniques, the correctness of detection decreases with different lightings and backgrounds so such requires new methods and techniques. This study has aimed to obtain data for reasoning human emotional information by analyzing the components of the eyes and mouth that are critical in expressing emotions. To do this, existing problems in detecting face are addressed and a detection method that has a high detection rate and fast processing speed good at detecting environmental elements is proposed. This method must detect a specific part (eyes and a mouth) by using Haar-like Feature technique with the application of an integral image. After which, binaries detect elements based on color information, dividing the face zone and skin zone. To generate correct shape, the shape of detected elements is generated by using a bezier curve-a curve generation algorithm. To evaluate the performance of the proposed method, an experiment was conducted by using data in the Face Recognition Homepage. The result showed that Haar-like technique and bezier curve method were able to detect face elements more elaborately.