• Title/Summary/Keyword: Scattered points

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A Method for Modifying a Surface Model with Nonuniform Scattered Constraint Points (불균일 이산 구속조건을 만족시키는 곡면 모델의 변형 방법)

  • Kim, S.H.;Song, S.J.
    • Korean Journal of Computational Design and Engineering
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    • v.12 no.1
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    • pp.58-73
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    • 2007
  • This paper described a method for the construction of a surface through a set of nonuniform scattered points. When the shift vectors of some points as constraints on the original surface are given, those of the other points should be computed to make the new surface. To keep up the look-see and smoothness with the original surfaces, the proper relationship should be formulated between the shifts of the constraint points and those of the other points. Vector fields for 3 dimensional shift of a point on the surface are made based in the constraint shifts. Vector fields for 3 dimensional shift of a point on the surface are made based on the constraint shifts. Multilevel B-spline approximation technique was used to construct the vector field. The technique uses coarse-to-fine hierarchy of control lattices. The developed method was applied to shoe sole design system especially for grading. Using this system, a shoe sole can be modified effectively.

ON $\mathcal{I}$-SCATTERED SPACES

  • Li, Zhaowen;Lu, Shizhan
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.3
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    • pp.667-680
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    • 2014
  • In this paper, $\mathcal{I}$-scattered spaces are introduced, and their characterizations and properties are given. We prove that (X, ${\tau}$) is scattered if and only if (X, ${\tau}$, $\mathcal{I}$) is $\mathcal{I}$-scattered for any ideal $\mathcal{I}$ on X.

Numerical Analysis on the Signal Characteristics for Scattered Far-field of Ultrasonic SH-Wave by the Internal Cavity (재료내 기공결함에 의한 SH형 초음파 원거리 산란장의 신호특성에 대한 수치해석)

  • Lee, Jun-Hyeon;Lee, Seo-Il;Park, Yun-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.1 s.173
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    • pp.163-172
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    • 2000
  • In this study, the scattered far-field due to a cavity embedded in infinite media subjected to the incident SH-wave was calculated by the boundary element method. The effects of cavity shape and distance between internal cavity and internal point in infinite media were considered. The scattered far-field of the frequency domain was transformed into the signal of the time domain by using the Inverse Fast Fourier Transform(IFFT). It was found that the amplitude of scattered signal in time domain decreased with the increase of the distance between the detecting points of ultrasonic scattered field and the center of internal cavity in media. In addition, the time delay was clearly found in time domain waveform as the distance between the detecting points of ultrasonic scattered field and the center of internal cavity was gradually increased.

QUASI-INTERPOLATORY APPROXIMATION SCHEME FOR MULTIVARIATE SCATTERED DATA

  • Yoon, Jung-Ho
    • Journal of applied mathematics & informatics
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    • v.29 no.3_4
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    • pp.713-719
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    • 2011
  • The problem of approximation from a set of scattered data arises in a wide range of applied mathematics and scientific applications. In this study, we present a quasi-interpolatory approximation scheme for scattered data approximation problem, which reproduces a certain space of polynomials. The proposed scheme is local in the sense that for an evaluation point, the contribution of a data value to the approximating value is decreasing rapidly as the distance between two data points is increasing.

Volume Modeling of Scattered Data based on Weighted Alpha Shapes (가중치 알파 쉐이프를 기반으로 하는 산포된 자료의 볼륨 모델링)

  • Paik Jung-Min;Lee Kun
    • The KIPS Transactions:PartA
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    • v.13A no.3 s.100
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    • pp.267-274
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    • 2006
  • This paper describes a method to achieve different level of detail for the given volumetric data by assigning weight for the given data points. The relation between wavelet transformation and alpha shape was investigated to define the different level of resolution. Scattered data are defined as a collection of data that have little specified connectivity between data points. The quality of interpolant in volumetric trivariate space depends not only on the distribution of the data points in ${\Re}^3$, but also on the data value (intensity). We can improve the quality of an approximation by using wavelet coefficient as weight for the corresponding data points.

A Study of Triangular Surface Interpolant for Scattered 3D points (불규칙한 3차원 상의 점군들에 대한 삼각곡면 보간에 관한 연구)

  • Ju, Sang-Yoon
    • Journal of Korean Institute of Industrial Engineers
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    • v.19 no.2
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    • pp.75-82
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    • 1993
  • This paper deals with a systematic procedure for constructing a triangular composite surface which is interpolated from given scattered 3-D points. The procedure consists of a triangulation, construction of curve net, and interpolation of triangular patches. An obtained surface is composed of cubic triangular patches, which are $G^1$ continuous to adjacent other patches.

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An interpolation method of b-spline surface for hull form design

  • Jung, Hyung-Bae
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.2 no.4
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    • pp.195-199
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    • 2010
  • This paper addresses the problem of B-spline surface interpolation of scattered points for a hull form design, which are not arbitrarily scattered, but can be arranged in a series of contours permitting variable number of points in the contours. A new approach that allows different parameter value for each point on the same contour has been adopted. The usefulness and quality of the interpolation has been demonstrated with some experimental results.

Characteristics of Acoustic Impulse Response of Submerged Cylindrical Objects as Elements of Target-Scattered Echo (표적신호 시뮬레이션 요소로서 원통형 몰수체의 충격응답의 특성)

  • Kim, Jae-Soo;Seong, Nak-Jin;Lee, Sang-Young;Kim, Kang;Yu, Myong-Jong;Cho, Woon-Hyun
    • The Journal of the Acoustical Society of Korea
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    • v.13 no.2E
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    • pp.5-13
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    • 1994
  • Simulation of the target-scattered echo requires the understanding of scattering mechanism at the highlight points. In this paper, the basic assumption of Highlight Model is reviewed through the analyzed data obtained in the acoustic water tank experiment. The analysis shows that the scattering mechanism involves pulse elongation and frequency shift as elements of target-scattered echo, and that the internal structures affect the temporal response of the target-scattered echo significantly. The band-limited impulse response or Green's function due to the diffraction from highlight points of internal structures is not mere delta function, but acts like a filter, which causes frequency shift and is elongated in time.

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The Generation of Free-Form Surface using Scattered Data Interpolation (분산 데이터 보간을 이용한 자유 형태 곡면 생성방법)

  • Lee, A-Ri;Park, Cheol-Ho;Sim, Jae-Hong
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.9
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    • pp.2504-2511
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    • 1999
  • This paper proposes the scattered data interpolation as an efficient method that is designed for free-form surface. Data interpolation is an essential method of designing for various objects. For the generating free-form surface of complexity construction, the existing method had problems to represent flat area and sharp corner edge, in presenting objects with computing the weight of control points. For solving this problem, we proposes the generating method of new approximation surfaces, using scattered data interpolation. This method obtains B-Spline basis function which calculates main curvature, having optimized value in variable area, on given control points and changed objects, and then computes the changing rate the approximating data, using it's value. We also present this method that generates smoother free-form surface, using the scattered data interpolation with minimum weight.

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Phase Shifts of Bound State Waves Scattered at Classical Turning Points: Morse Potential

  • Sun, Ho-Sung
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1717-1722
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    • 2005
  • The analytical transfer matrix method suggests a new quantization condition for calculating bound state eigenenergies exactly. In the quantization condition, the phase shifts of bound state wave functions scattered at classical turning points are explicitly introduced. We calculate the phase shifts of eigenfunctions of the Morse potential with various boundary conditions in order to understand the physical meaning of phase shifts. The Morse potential is known to adequately describe the interaction energy between two atoms and, therefore, it is frequently used to determine the vibrational energy levels of diatomic molecules. The variation of Morse potential eigenenergies influenced upon by changing boundary conditions is also investigated.