• Title/Summary/Keyword: bezier curve

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Development of an Effective Walking System for a Hexapod Robot on Uneven Terrain (오프로드 환경에서 효율적인 6족 로봇 보행 시스템 개발)

  • Kim, Jun Woo;Lee, Gi Won;Lee, Suk Gyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.12
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    • pp.1152-1159
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    • 2013
  • This paper proposes an effective walking system for a hexapod robot on uneven terrain. To overcome the deficiencies of two-pair walking systems, which are effective on even terrain, the use of only three legs changes the steps required for movement. The proposed system receives feedback data from switches attached to the bottom of the legs and gyro sensor to carry out stable walking using the Bezier curve algorithm. From the coordinates of the Bezier curve, which guarantees the circular motion of legs, the motor's angle value can be obtained using inverse kinematics. The angle values are sent to each motor though RS-485 communication. If a switch is pushed by the surface during navigation in the Bezier curve pattern, the robot is designed to change its circular course. Through the changed course, each leg can be located on an optimal surface and the wobble phenomenon is reduced by using a normal vector algorithm. The simulation and experiment results show the efficiency of the proposed algorithm.

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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Extraction of Intima and Adventitia using Bezier Curve on IVUS Image (IVUS 영상에서 베지어 곡선을 이용한 내막과 외막 추출)

  • Moon, A-Seong;Kim, Yeong-Wan;Kang, Yong Hoon;Kim, Kwang-Baek
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2020.01a
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    • pp.29-31
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    • 2020
  • 제안된 방법은 외막의 경계선을 추출하기 위해 Max-Min 이진화를 적용하여 외막을 추출 한 후에 삼각 함수의 각도 값을 이용하여 외막의 경계점을 추출한다. 추출한 경계점들을 Bezier Curve 기법을 적용하여 외막의 경계점들을 연결하여 외막의 경계선을 추출한다. 그리고 내막 영역을 추출하기 위해 외막 영역을 ROI 영역으로 추출한다. 추출된 ROI 영역을 오목 파라볼라 기법을 적용하여 내막의 영역을 강조한다. 내막영역이 강조된 ROI 영역에 평균 이진화를 적용하여 내막의 영역을 추출한다. 추출된 영역에서 잡음을 제거하기 위해 내막 영역만 Labeling 기법을 적용한다. 제안된 방법을 IVUS 영상을 대상으로 실험한 결과, 내막과 외막간의 포함관계의 정도에 따라 환자의 수술 여부 결정에 대한 외막과 내막의 각 넓이 정보를 개관적으로 제공할 수 있는 가능성을 확인하였다.

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Modeling of Blend Surfaces by Bezier Surface Patches (비지어곡면에 의한 블렌드곡면의 모델링)

  • 주상윤
    • Korean Journal of Computational Design and Engineering
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    • v.2 no.2
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    • pp.122-129
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    • 1997
  • Ball rolling blending is a popular technique for blending between parametric surfaces. The ball rolling blend surface is conceptually a trajectory of a ball rolling between two base sufaces. It is constructed by sweeping a circular arc along a ball contact curve pair. Since a ball rolling blend surfaces does not have a polynomial form like a Bezier surface patch, it is impossible to apply this method directly to a commercial CAD/CAM system. In this paper an algorithm is developed to approximate a ball rolling blend surface into Bezier surface patches. Least square method is applied to obtain proper Bezier surface patches under a given tolerance. The Bezier surface patches have degree three or more and guarantee VC1-continuity.

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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.

A Design Optimization Study of Blunt Nose Hypersonic Flight Vehicle Using Surface Heat-transfer and Drag Minimization (표면열전달과 항력을 고려한 극초음속 비행체 선두부 최적형상설계)

  • Lim S.;Seo J. I.;Song D. J.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.10a
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    • pp.197-201
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    • 2004
  • A design optimization of Sphere-Cone blunt nose hypersonic flight vehicle has been studied by using upwind Navier-Stokes method and numerical optimization method. Heat transfer coefficient and drag coefficient are selected as objective function or design constraint. Control points of Bezier curve are considered as design variable.

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A study on a design for a centrifugal pump impeller shape (원심펌프 회전차 형상 설계에 대한 연구)

  • 김진환
    • Journal of Ocean Engineering and Technology
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    • v.11 no.4
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    • pp.213-220
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    • 1997
  • In this study, a design for a shape of centrifugal pump impeller has been performed using a p.c. under a Windows environment. Interaction between a user and a computer has been easily established using the Visual Basic. In determining an outer diameter of an impeller, steps are divided into two, a basic computational step and a refinment step. In this way user can enter his/her experience at the refinment step and hence can expect to lessen the nonlinear nature inherent to the design. In determining a shape of a side view of an impeller, the Bezier cubic curve has been used, and it can be seen that the Bezier cubic curves are well suited in the shape design under a Windows environment. By simply manipulating the four control points, one can generate various cubic curves among which one is selected. Also, a simple method, which can determine the curved position of an impeller vane, has been developed. These data can be used for final CAD drawings.

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Aircraft Position Prediction and Shadow Zone Penetration Control Using Bezier Curve (베지에 곡선을 이용한 항공기 위치 예측 및 음영 지역 진입 제어 방법)

  • Jeong, Jae-Soon;Roh, Byeong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.11
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    • pp.1011-1022
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    • 2014
  • Currently, the wireless network environment of air node is constructed mainly of ground relay station. However, as the Korean Peninsula is composed of 70% mountainous region, there are multiple shadow zones. This is calling for effective measures to prevent aircraft from losing communication link during low-mid altitude missions. In this article we propose the utilization of Bezier Curve for estimation of aircraft flight path and control method for entering shadow zone. This method successfully estimated aircraft track, and analyzed the existence, disseminated the warning, and took measures to avoid the shadow zone before entering. This article, suggested after simulated experiments, proves that the method enables seamless communication during air operations.