• Title/Summary/Keyword: Cubic spline interpolation

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Comparison of the Results of Finite Difference Method in One-Dimensional Advection-Dispersion Equation (유한차분 모형에 의한 일차원 이송-확산방정식 계산결과의 비교)

  • 이희영;이재철
    • Water for future
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    • v.28 no.4
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    • pp.125-136
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    • 1995
  • ELM, a characteristic line based method, was applied to advection-dispersion equation, and the results obtained were compared with those of Eulerian schemes(Stone-Brian and QUICKEST). The calculation methods consisted of Lagrangian interpolation scheme and cubic spline interpolation scheme for the advection calculation, and the Crank-Nicholson scheme for the dispersion calculation. The results of numerical methods were as follows: (1) for Gaussian hill: ELM, using Lagrangian interpolation scheme, gave the most accurate computational result, ELM, using cubic spline interpolation scheme, and QUICKEST scheme gave numerical damping for Peclet number 50. Stone-Brian scheme gave phase shift introduced in the numerical solution for Peclet number 10 and 50. (2) for advanced front: All schemes gave accurate computational results for Peclet number 1 and 4. ELM, Lagrangian interpolation scheme, and Stone,Brian scheme gave dissipation error and ELM, using cubic spline interpolation scheme, and QUICKEST scheme gave numerical oscillation for Peclet number 50.

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Comparison of Channel Estimation Schemes for Digital Broadcasting System in a Mobile Environment (이동 환경에서 디지털 방송 시스템을 위한 채널 추정 기법의 성능 비교)

  • Kim, Ki-Nam;Kim, Jin-Ho;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
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    • v.9 no.1
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    • pp.41-47
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    • 2005
  • In this paper, the performances of various channel estimation schemes for DVB-H system are investigated. The linear interpolation, the second order interpolation, the cubic spline interpolation, and the time-domain interpolation, which are used in frequency domain, are chosen as the channel estimation schemes. We derived the performances of Mean Square Error (MSE), Bit Error Rate (BER), and the complexity of calculation in Rayleigh and Rician fading channel through computer simulations. From the simulation results, the cubic spline interpolation shows the best performance under high $E_b/N_0$ environments.

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Reconstruction of the Undersampled Photoplethysmogram with Various Interpolation Methods (보간 방법에 따른 언더샘플링된 광용적맥파 복원 가능성 평가)

  • Shin, Hangsik;Kim, Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.8
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    • pp.1418-1423
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    • 2016
  • The purpose of this research is to investigate the effect of sampling frequency on the photoplethysmography (PPG) and to evaluate the performance of interpolation methods for under-sampled PPG. We generated down-sampled PPG using 10 kHz-sampled PPG then evaluated waveshape changes with correlation coefficient. Correlation coefficient was significantly decreased at 50 Hz or below sampling frequency. We interpolated the down-sampled PPG using four interpolation method-linear, nearest, cubic spline and piecewise cubic Hermitt interpolation polynomial - then evaluated interpolation performance. As a result, it was shown that PPG waveform that was sampled over 20 Hz could be reconstructed by interpolation. Among interpolation methods, cubic spline interpolation showed the highest performance. However, every interpolation method has no or less effect on 5 Hz sampled PPG.

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

  • Chang, Dong-Eon;Chung, Tae-Sang
    • Proceedings of the KIEE Conference
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    • 1998.11b
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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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Fuzzy System Representation of the Spline Interpolation for differentiable functions

  • Moon, Byung-Soo
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.358-363
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    • 1998
  • An algorithm for representing the cubic spline interpolation of differentiable functions by a fuzzy system is presented in this paper. The cubic B-spline functions which form a basis for the interpolation function are used as the fuzzy sets for input fuzzification. The ordinal number of the coefficient cKL in the list of the coefficient cij's as sorted in increasing order, is taken to be the output fuzzy set number in the (k, l) th entry of the fuzzy rule table. Spike functions are used for the output fuzzy sets, with cij's as support boundaries after they are sorted. An algorithm to compute the support boundaries explicitly without solving the matrix equation involved is included, along with a few properties of the fuzzy rule matrix for the designed fuzzy system.

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Conversion between Decrement Models using Cubic Spline (삼차 스플라인 보간법을 활용한 탈퇴율 전환방법)

  • Kim, Ju Kyung;Lee, Hangsuck
    • The Korean Journal of Applied Statistics
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    • v.26 no.3
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    • pp.549-568
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    • 2013
  • This paper discusses conversion methods between multiple decrement models and associated single decrement models. One of most popular assumptions on fractional age is UDD(uniform distribution of decrement) or constant force of mortality in actuarial practice. Instead of these assumptions, this paper suggests cubic spline interpolation to approximate the distribution of fractional age with the continuous force of decrements. Conversion formulas are derived. The comparisons of these two methods based on the numerical data show that the cubic spline interpolation approach is more accurate.

AN ERROR BOUND ANALYSIS FOR CUBIC SPLINE APPROXIMATION OF CONIC SECTION

  • Ahn, Young-Joon
    • Communications of the Korean Mathematical Society
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    • v.17 no.4
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    • pp.741-754
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    • 2002
  • In this paper we present an error bound for cubic spline approximation of conic section curve. We compare it to the error bound proposed by Floater [1]. The error estimating function proposed in this paper is sharper than Floater's at the mid-point of parameter, which means the overall error bound is sharper than Floater's if the estimating function has the maximum at the midpoint.

Analysis for computing heat conduction and fluid problems using cubic B-spline function (3차 B-spline 함수를 이용한 열전도 및 유체문제의 해석)

  • Kim, Eun-Pil
    • Journal of computational fluids engineering
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    • v.3 no.2
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    • pp.1-8
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    • 1998
  • We make use of cubic B-spline interpolation function in two cases: heat conduction and fluid flow problems. Cubic B-spline test function is employed because it is superior to approximation of linear and non-linear problems. We investigated the accuracy of the numerical formulation and focused on the position of the breakpoints within the computational domain. When the domain is divided by partitions of equal space, the results show poor accuracy. For the case of a heat conduction problem this partition can not reflect the temperature gradient which is rapidly changed near the wall. To correct the problem, we have more grid points near the wall or the region which has a rapid change of variables. When we applied the unequally spaced breakpoints, the results show high accuracy. Based on the comparison of the linear problem, we extended to the highly non-linear fluid flow problems.

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Performance Analysis of Channel Estimation Schemes for MF Band Digital Radio Broadcasting System (MF 대역 디지털 라디오 방송 시스템을 위한 채널 추정 기법의 성능 분석)

  • 송정훈;김기남;노재성;조성준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.2
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    • pp.217-222
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    • 2004
  • In this paper, the efficient channel estimation schemes for DRM system(AM band digital radio broadcasting standard) are investigated. In frequency domain, by means of the linear interpolation, the second order interpolation, cubic spline interpolation, and time domain interpolation, the channel impulse response is estimated respectively to compensate the attenuation due to the fading. And in time domain, the frequency channel impulse response is averaged to reduce the attenuation due to the AWGN. By the simulation, the performance of MSE, BER and the complexity of calculation is compared and analyzed for each interpolation scheme.

FLIGHT TRAJECTORY CONTOLLER FOR NONLINEAR MANEUVER(GENERATION OF A DESIRED TRAJECTORY BY SPLINE THEORY)

  • Baba, Yoriaki;Takano, Hiroyuki;Sano, Masaki
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.376-379
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    • 1995
  • To force an aircraft to track the specified path, the generation of the smooth desired trajectory is essential. In this paper, the cubic spline function is used to generate the trajectory which passes through the specified intercept points. The simulation results show that the desired trajectory generated by the spline interpolation is very smooth and the aircraft tracks it with small position errors.

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