• Title/Summary/Keyword: Interpolation accuracy

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An Enhancement of Ultrasonic Based Map-building Using Newton Interpolation (뉴턴 보간법을 이용한 초음파센서 기반의 맵빌딩 개선)

  • Choi, Kyung-Sik;Choi, Jung-Won;Lee, Suk-Gyu
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.8
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    • pp.62-71
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    • 2009
  • In mobile robotics, ultrasonic sensors became one of the most popular devices for collision avoidance and navigation primarily due to data robustness, the easy availability of low-cost systems, their compact size, simple circuits, and their ease in interfacing with computers. However, ultrasonic sonic sensors are subject to noise which results in inaccuracy of mapping and localization of the robot. This paper introduces a new approach to enhance environmental maps based on ultrasonic range data using linear interpolation and Newton interpolation. The simulation and experimental results show that the proposed method improves of the accuracy of the map through better distance estimation between the mobile robot and obstacles.

Development of an Efficient Line Search Method by Using the Sequential Polynomial Approximation (순차적 다항식 근사화를 적용한 효율적 선탐색기법의 개발)

  • 김민수;최동훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.2
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    • pp.433-442
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    • 1995
  • For the line search of a multi-variable optimization, an efficient algorithm is presented. The algorithm sequentially employs several polynomial approximations such as 2-point quadratic interpolation, 3-point cubic interpolation/extrapolation and 4-point cubic interpolation/extrapolation. The order of polynomial function is automatically increased for improving the accuracy of approximation. The method of approximation (interpolation or extrapolation) is automatically switched by checking the slope information of the sample points. Also, for selecting the initial step length along the descent vector, a new approach is presented. The performance of the proposed method is examined by solving typical test problems such as mathematical problems, mechanical design problems and dynamic response problems.

The Estimation of The Block Pulse Series by The Lagrange's Second Order Interpolation Polynomial (Lagrange 이차 보간 다항식을 이용한 블록 펄스 급수 추정)

  • Kim, Tai-Hoon;Lee, Hae-Ki
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.6
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    • pp.235-240
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    • 2002
  • This paper presents a new method for estimating the block pulse series coefficients by using the Lagrange's second order interpolation polynomial. Block pulse functions have been used in a variety of fields such as the analysis and controller design of the systems. When the block pulse functions are used, it is necessary to find the more exact value of the block pulse series coefficients. But these coefficients have been estimated by the mean of the adjacent discrete values, and the result is not sufficient when the values are changing extremely. In this paper, the method for improving the accuracy of the block pulse series coefficients by using the Lagrange's second order interpolation polynomial is presented.

Improving Dimension Reduction Method Using Kriging Interpolation (Kriging 보간법을 사용한 개선된 차원감소법)

  • Choi, Joo-Ho;Choi, Chang-Hyun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.135-140
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    • 2007
  • In this paper, an Improved Dimension Reduction(IDR) method is proposed for uncertainty quantification that employes Kriging interpolation technic. It has been acknowledged that the DR method is accurate and efficient for assessing statistical moments and reliability due to the sensitivity free feature. However, the DR method has a number of drawbacks such as instability and inaccuracy for problems with increased nonlineality. In this paper, improved DR is implanted by three steps. First, the Kriging interpolation method is used to accurately approximate the responses. Second, 2N+1 and 4N+1 ADOEs are proposed to maintain high accuracy of the method for UQ analysis. Third, numerical integration scheme is used with accurate but free response values at any set of integration points of the surrogated model.

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Estimation of Daily Solar Radiation at the Missing Point for Water Quality Impact Assessment in Nakdong River Watershed: Comparison of Modified Angstrom Model and Transmittance interpolation Model (수질 영향평가 신뢰수준 향상을 위한 낙동강 유역 미관측 지점에서의 일사량 추정: 수정형 Angstrom모형과 투과율모형의 비교)

  • Lee, Khil-Ha
    • Journal of Environmental Impact Assessment
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    • v.21 no.1
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    • pp.219-227
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    • 2012
  • Daily solar radiation is essential for water resources planning and environmental impact assessment. However, radiation data is not commonly available in Korea other than in big cities, and there has been no direct measurement for rural areas where water resources planning and environmental impact assessment is usually most needed. In general, missing radiation data is estimated from nearby regional stations within a certain distance, and this study compared two dominant methods (modified Angstrom equation and transmittance interpolation method) at six stations in Nakdong River watershed area. Two methods shows a similar level of accuracy but the transmittance interpolation method is likely to be superior in that there is no need for any measurement element since the modified Angstrom equation require the sunshine hour measurement. This study will contribute to improve water resource and water quality management in Nakdong River watershed.

Area Measurement of Organism Image using Super Sampling and Interpolation (수퍼 샘플링과 보간을 이용한 생물조직 영상의 면적 측정)

  • Choi, Sun-Wan;Yu, Suk-Hyun
    • Journal of Korea Multimedia Society
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    • v.17 no.10
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    • pp.1150-1159
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    • 2014
  • This paper proposes a method for extracting tissue cells from an organism image by an electron microscope and getting the whole cell number and the area from the cell. In general, the difference between the cell color and the background is used to extract tissue cell. However, there may be a problem when overlapped cells are seen as a single cell. To solve the problem, we split them by using cell size and curvature. This method has a 99% accuracy rate. To measure the cell area, we compute two areas, the inside and boundary of the cell. The inside is simply calculated by the number of pixels. The cell boundary is obtained by applying super sampling, linear interpolation, and cubic spline interpolation. It improves the error rate, 18%, 19%, and 120% respectively, in comparison to the counting method that counts a pixel area as 1.

Application of Spatial Interpolation to Rainfall Data (강우자료에 대한 공간보간 기법의 적용)

  • Cho Hong-Lae;Jeong Jong-Chul
    • Spatial Information Research
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    • v.14 no.1 s.36
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    • pp.29-41
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    • 2006
  • Geostatistical data are obtained only at selected sites even though they are potentially available at any location In a continuous surface. Therefore it is necessary to estimate the unknown values at unsampled locations based on observations. In this study we compared the accuracy of 5 spatial interpolation methods: local trend surface, IDW, RBF, ordinary kriging, universal kriging. These interpolation methods were applied to annual rainfall data. As the results of validation tests, universal kriging with gaussian variogram model showed the best accuracy in comparison with other interpolation methods. In the case of kriging, the predicted values were more accurate and within a more narrow range than other methods. In contrast with kriging, local trend surface analysis, IDW and RBF showed the wide range of predicted values and abrupt changes between neighbors.

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Comparative analysis of methods for digital simulation (디지털 전산모사를 위한 방법론 비교분석)

  • Yi, Dokkyun;Park, Jieun
    • Journal of Digital Convergence
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    • v.13 no.9
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    • pp.209-218
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    • 2015
  • Computer simulation plays an important role for a theoretical foundation in convergence technology and the interpolation is to know the unknown values from known values on grid points. Therefore it is an important problem to select an interpolation method for digital simulation. The aim of this paper is to compare analysis of interpolation methods for digital simulation. we test six different interpolation methods namely: Quartic-Lagrangian, Cubic Spline, Fourier, Hermit, PWENO and SL-WENO. Through digital simulation of a linear advection equation, we analyse pros and cons for each method. In order to compare performance, we introduce accuracy computing and Error functions. The accuracy computing is used well-known $L^1-norm$ and the Error functions are dispersion function, dissipation function and total error function. High-order methods well apply to computer simulation, unfortunately, side-effects (Oscillation) happen.

Rational finite element method for plane orthotropic elastic problems

  • Mao, Ling;Yao, Weian;Gao, Qiang;Zhong, Wanxie
    • Structural Engineering and Mechanics
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    • v.51 no.6
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    • pp.923-937
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    • 2014
  • The rational finite element method is different from the standard finite element method, which is constructed using basic solutions of the governing differential equations as interpolation functions in the elements. Therefore, it is superior to the isoparametric approach because of its obvious physical meaning and accuracy; it has successfully been applied to the isotropic elasticity problem. In this paper, the formulation of rational finite elements for plane orthotropic elasticity problems is deduced. This method is formulated directly in the physical domain with full consideration of the requirements of the patch test. Based on the number of element nodes and the interpolation functions, different approaches are applied with complete polynomial interpolation functions. Then, two special stiffness matrixes of elements with four and five nodes are deduced as a representative application. In addition, some typical numerical examples are considered to evaluate the performance of the elements. The numerical results demonstrate that the present method has a high level of accuracy and is an effective technique for solving plane orthotropic elasticity problems.

A Study on the Point Rainfall Interpolation Method : 2. Accuracy Analysis of the Methods (결측 강우량 보정방법에 관한 연구: 2. 방법론별 정확도 분석)

  • Kim Eung-Seok;Baek Chun-Woo;Lee Jung-Ho;Park Moo-Jong;Jo Deok-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.4
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    • pp.690-696
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    • 2006
  • This study applies the methods proposed in this issue[1] to the 11 rainfall gauging stations of the Pyongchang area. Also, this study analyzes the error range of each interpolation method, and considers spatial distribution according to the number of gauging station. As the results, the linear programming methods shows the best minimum error. However, this method might be difficult to apply in the field because of need for programming. Comparatively, the inverse distance method shows more simple and accurate results than the linear programming one. The result of this study could contribute to the increase of accuracy for the filling of missing rainfall data.

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