• Title/Summary/Keyword: spline curve

검색결과 205건 처리시간 0.024초

GA를 이용한 Form parameter 방법에 의한 초기선형 생성 (Preliminary Hull Form Generation by Form Parameter Method using GA)

  • 김수영;신성철;신경엽
    • 한국지능시스템학회논문지
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    • 제12권1호
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    • pp.44-51
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    • 2002
  • 본 연구는 선형 생성을 위하여 목적함수로서 fairness 기준을 도입하고 설계변수를 B-spline 곡선의 조정점으로 하며 설계자에 의해서 주어지는 기하학적 제약조건을 만족하도록 하는 최적화를 수행하도록 하였다 본 연구에서는 최적화 방법으로서 GA(Genetic Algorithm)와 최적성 기준(optimality criteria)을 병행하였다.

공구경 보정을 이용한 2차원 자유곡선의 가공 (Machining of 2D Parametric Spline Using Cutter Radius Compensation)

  • 신하용;정회민;곽영수
    • 산업공학
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    • 제8권3호
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    • pp.133-139
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    • 1995
  • Free from curves and surfaces are frequently used in designing engineering products such as car, ship, airplane, and hosing of electronic households. In many aspect, it is very nice to use the cutter radius compensation function of CNC controller when contour machining a 2-dimensional curve. However, if the 2D curve is a parametric spline, it is not easy to apply the cutter radius compensation function of CNC controller to the NC data obtained from many commercial CAM system. This is mainly due to the error magnification effect when offsetting line segments with inevitable round-off error at their vertices. Proposed in this paper is an approach to contour machining a 2D parametric spline while using cutter radius compensation. Some implementation results are included.

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동적 프로그래밍에 의한 활성 윤곽선의 B-스플라인 표현 (B-Spline Representation of Active Contours by Dynamic Programming)

  • 김동근
    • 한국정보처리학회논문지
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    • 제6권7호
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    • pp.1962-1969
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    • 1999
  • 활성 윤곽선은 내부 에너지와 외부에너지에 의해 조절되는 형태 변형이 가능한 에너지 최소화 곡선이다. 내부 에너지는 곡선을 부드럽게 유지하기 위한 제약 조건이고, 외부 지는 곡선을 영상 특징 쪽으로 이끈다. 활성 윤곽선이 제어 점에 의한 B-스플라인 표현은 많은 장점을 갖는다. Mentet[3] 등은 유한 차분 법에 의한 활성 윤곽선이 B-스플라인 표현을 제안하였다. 본 논문에서는 활성 윤곽선을 구간별 3차 B-스플라인으로 표현하고, 이 모델의 에너지를 최소로 하는 제어 점을 찾기 위한 방법으로 동적 프로그래밍을 사용한 방법을 제안한다. 제안된 방법은 유한 차분 법에 의한 B-스플라인 방법에 비해 간단하고 효과적이다.

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허미트 보간을 이용한 곡률 연속 현길이 스플라인 곡면 ($VC^2$ Chord-Length Spline Surface Using Hermite Interpolant)

  • 전차수;주상윤;전명길
    • 대한산업공학회지
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    • 제20권1호
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    • pp.87-98
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    • 1994
  • This paper describes a method of constructing VC2 Chord-length spline surface from semi-evenly spaced 3D point array. The suface uses Hermite interpolant as Ferguson surface, and it is an extention of chord-length spline curve to surface The proposed surface may be widely used in interpolating smoothly 3D point data obtaind by measurement or engineering design.

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ASMOD와 혼합 곡선 근사법을 이용한 SAC의 생성 (Generation of SAC using a ASMOD and a Hybrid curve approximation)

  • 김현철;이경선;김수영
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
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    • pp.435-438
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    • 1997
  • This paper presents the process generating a SAC(Sectional Area Cure) by using ASMOD(Adaptive Spline Modeling of Observation Data). That is, we define SACs of real ships as B-spline curves by a hybrid cure approximation(which is the combination method of a B-spline fitting method and a genetic algorithm) and accumulate a database of control points. Then we let ASMOD learn from the correlation principal dimensions with control points.

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Inclinometer-based method to monitor displacement of high-rise buildings

  • Xiong, Hai-Bei;Cao, Ji-Xing;Zhang, Feng-Liang
    • Structural Monitoring and Maintenance
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    • 제5권1호
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    • pp.111-127
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    • 2018
  • Horizontal displacement of high-rise building is an essential index for assessing the structural performance and safety. In this paper, a novel inclinometer-based method is proposed to address this issue and an algorithm based on three spline interpolation principle is presented to estimate the horizontal displacement of high-rise buildings. In this method, the whole structure is divided into different elements by different measured points. The story drift angle curve of each element is modeled as a three spline curve. The horizontal displacement can be estimated after integration of the story drift angle curve. A numerical example is designed to verify the proposed method and the result shows this method can effectively estimate the horizontal displacement with high accuracy. After that, this method is applied to a practical slender structure - Shanghai Tower. Nature frequencies identification and deformation monitoring are conducted from the signal of inclinometers. It is concluded that inclinometer-based technology can not only be used for spectrum analysis and modal identification, but also for monitoring deformation of the whole structure. This inclinometer-based technology provides a novel method for future structural health monitoring.

역공학 기반 5축 신발 러핑용 CAM 시스템 개발 (Development of CAM system for 5-axis automatic roughing machine Based on Reverse Engineering)

  • 김화영;손성민;안중환;강동배
    • 한국정밀공학회지
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    • 제22권7호
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    • pp.122-129
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    • 2005
  • Shoe with leather upper such as safety and golf shoe requires a roughing process where the upper is roughed fur helping outsole to be cemented well. It is an important and basic process for production of leather shoe but is not automated yet. Thus, there are problems that the defect rate is high and the quality of roughed surface is not uniform. In order to solve such problems, the interest in automation of roughing process is being increased and this paper introduces CAM system for 5-axis automatic roughing machine as one part of automation of roughing process. The CAM system developed interpolates a B-spline curve using points measured from the Roughing Path Measurement System. The B-spline curve is used to generate the tool path and orientation data fer a roughing tool which has not only stiffness but also flexibility to rough the inclined surface efficiently. For productivity, the upper of shoe is machined by side of the roughing tool and tool offset is applied to the roughing tool for machining of inclined surface. The generated NC code was applied to 5-axis polishing machine for the test. The upper of shoe was roughed well along the roughing path data from CAM and the roughed surface was proper fur cementing of the outsole.

비축대칭 H-형 및 U-형상의 압출금형 곡면의 자동생성 (Automatic Surface Generation for Extrusion Die of Non-symmetric H- and U-shaped Sections)

  • 임종훈;유동진;양동열
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 추계학술대회논문집
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    • pp.318-321
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    • 2003
  • In order to generate the extrusion die surface of non-symmetric H- and U-shaped sections, an automatic surface construction method based on B-spline surface and scalar field theory is proposed in this study. The isothermal lines and stream lines designed in the scalar field are introduced to find the control points which are used in constructing B-spline surfaces. Intersected points between the isothermal lines and stream lines are used to construct B-spline surfaces. The inlet and outlet profiles are precisely described with B-spline curves by using the centripetal method for uniform parameterization. The extrusion die surface is generated by using the cubic curve interpolation in the u- and v-directions. A quantitative measure for the control of surface is suggested by introducing the tangential vectors at the inlet and outlet sections.

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복잡한 형상의 압출금형 곡면의 자동생성 (Automatic Surface Generation for Extrusion Die of Complicated Sections)

  • 임종훈;유동진;권혁홍;양동열
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 추계학술대회논문집
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    • pp.197-200
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    • 2003
  • An automatic surface construction method based on B-spline surface and scalar field theory is proposed to generate the extrusion die surface of complicated sections in this paper. The isothermal lines and stream lines designed in the scalar field are introduced to find the control points which are used in constructing B-spline surfaces. Intersected points between the isothermal lines and stream lines are used to construct B-spline surfaces. The inlet and outlet profiles are precisely described with B-spline curves by using the centripetal method for uniform parameterization. The extrusion die surface is generated by using the cubic curve interpolation in the u- and v-directions. A quantitative measure for the control of surface is suggested by introducing the tangential vectors at the inlet and outlet sections.

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비축대칭 H-형 및 U-형상의 압출금형 곡면의 자동생성 (Automatic Surface Generation for Extrusion Die of Non-symmetric H-and U-shaped sections)

  • 유동진;임종훈;양동열
    • 소성∙가공
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    • 제12권6호
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    • pp.572-581
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    • 2003
  • In this paper, an automatic surface construction method based on B-spline surface and scalar field theory is proposed to generate the extrusion die surface of non-symmetric H-and U-shaped sections. The isothermal lines and stream lines designed in the scalar field are introduced to find the control points which are used in constructing B-spline surfaces. Intersected points between the isothermal lines and stream lines are used to construct B-spline surfaces. The inlet and outlet profiles are precisely described with B-spline curves by using the centripetal method for uniform parameterization. The extrusion die surface is generated by using the cubic curve interpolation in the u-and v-directions. A quantitative measure for the control of surface is suggested by introducing the tangential vectors at the inlet and outlet sections. To verify the validity of the proposed method, automatic surface generation is carried out for extrusion die of non-symmetric H-and U-shaped sections.