• 제목/요약/키워드: cubic spline

검색결과 259건 처리시간 0.027초

SOFM과 LAM을 이용한 영상 보간에 관한 연구 (A Study on Image Interpolation Using SOFM and LAM)

  • 장동언;정태상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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    • pp.640-642
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    • 1998
  • When resampling an image to a new set of coordinates, there is often a noticeable loss in image quality. The interpolation kernel determines the quality of interpolation. In this paper, We think two interpolation methods: cubic-spline method, neural net method, at first study given interpolation method using spline and then present new interpolation methon using SOFM and LAM(neural net method), finally compare the performance of several interpolation methods including replication, bilinear, spline and new methods.

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Spline Surface Approximation for Computing Pit Excavation Volume with the Free Boundary Conditions

  • Jaechil Yoo;Lee, Seung-Hoon;Mun, Du-Yeoul
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2002년도 창립 20주년기념 국제학술대회
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    • pp.229-238
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    • 2002
  • The calculation of earthwork plays a major role in plan or design of many civil engineering projects, and thus it has become very important to improve the accuracy of earthwork calculation. In this paper, we propose an algorithm of finding a cubic spline surface with the free boundary conditions, which interpolates the given three dimensional data, by using B-spline and an accurate method to estimate pit-excavation volume. The proposed method should be of interest to surveyors especially concerned with accuracy of volume computations. We present some computational results showing that our proposed method provides good accuracy.

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Spline Surface Approximation for Computing Pit Excavation Volume with the Free Boundary Conditions

  • Yoo, Jae-Chil;Lee, Seung-Hoon;Mun, Du-Yeoul
    • Korean Journal of Geomatics
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    • 제2권1호
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    • pp.25-29
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    • 2002
  • The calculation of earthwork plays a major role in plan or design of many civil engineering projects, and thus it has become very important to improve the accuracy of earthwork calculation. In this paper, we propose an algorithm for finding a cubic spline surface with the free boundary conditions, which interpolates the given three dimensional data, by using B-spline and an accurate method to estimate pit-excavation volume. The proposed method should be of interest to surveyors especially concerned with accuracy of volume computations. We present some computational results showing that our proposed method provides good accuracy.

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B 스플라인 보간을 이용한 고화질 볼륨 가시화 (High quality volume visualization using B-spline interpolation)

  • 신용하;계희원
    • 한국컴퓨터그래픽스학회논문지
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    • 제22권3호
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    • pp.1-9
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    • 2016
  • 볼륨 가시화의 샘플링 단계에서는 보통 선형 보간이 사용된다. 선형 보간은 일반적으로 좋은 화질의 영상을 생성하지만 의료영상 소프트웨어는 높은 화질의 영상이 필요하기 때문에 경우에 따라 높은 기대에 미치지 못한다. 본 연구는 샘플링 단계에서 B 스플라인을 기반으로 하는 삼차 보간을 수행한다. 기존의 B 스플라인은 제어점을 지나지 않는 근사 함수이므로, 본 연구는 제어점을 이동하여 생성된 곡선이 원래의 제어점을 지나도록 하였다. 가시화 단계에서는 속도를 향상하기 위해 빈공간 도약을 적용 가능하다. 빈공간을 파악하기 위해서는 각 블록에 대한 최대값과 최소값을 계산해야 한다. B 스플라인은 볼록포 성질이 있어서, 제어점의 값을 최대값과 최소값으로 사용할 수 있다. 그 결과로 삼차 보간 기반의 볼륨 가시화가 대화적 속도로 가능하다.

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.

체공형 부양선(Aerostat) 개념설계

  • 이융교;김동민;염찬홍
    • 항공우주기술
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    • 제4권1호
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    • pp.31-38
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    • 2005
  • 체공형 부양선인 Aerostat에 대한 개념설계를 수행하였다. 기존의 풍동 시험자료를 참조하여, 정적 종안정성을 확보하기 위한 Aerostat의 외형 설계를 수행하였다. 주어진 동체형상과 길이에 대한 표면적 및 부피는 Cubic Spline을 이용하여 수치적으로 계산하였고, 반복계산을 통하여 동체의 길이를 결정하였다. 개념설계를 위한 케이블 장력과 중량, 그리고 임무장비 무게를 산정하였다. 중량과 임무고도 등과 같은 중요한 설계 변수에 대한 민감도를 분석하였으며, 그 결과로서 30m급의 Aerostat 시스템에 대한 개념 설계결과를 제시하였다.

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