• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.758-765
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• 1999

Shape-preserving property is the important method that controls the complex free form curve/surface. Interpolation method for the existed Shape-Preservation had problems that it has needed the minimization of a curvature-related functions for calculating single-valued data. Solving this problem, in this paper, it proposed to the algorithm of generalizing C piecewise parametric cubic that has shape-preserving property for both Single-value data and Multivalue data. When there are the arbitrary tangents and two data, including shape-preserving property, this proposed method gets piecewise parametric cubic polynomial by checking the relation between the shape-preserving property and then calculates efficiently the control points using that. Also, it controls the initial shape using curvature distribution on curve segments.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.144-153
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• 2007

In order to generate the input data for rapid prototyping, a new approach which is based on the implicit surface interpolation method is presented. In the method a surface is reconstructed by creating smooth implicit surface from unorganized cloud of points through which the surface should pass. In the method an implicit surface is defined by the adaptive local shape functions including quadratic polynomial function, cubic polynomial function and RBF(Radial Basis Function). By the reconstruction of a surface, various types of error in raw STL file including degenerated triangles, undesirable holes with complex shapes and overlaps between triangles can be eliminated automatically. In order to get the slicing data for rapid prototyping an efficient intersection algorithm between implicit surface and plane is developed. For the direct usage for rapid prototyping, a robust transformation algorithm for the generation of complete STL data of solid type is also suggested.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.671-678
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• 2006

This article proposes a smooth path generation and time scheduling method for general tasks defined by non-smooth path segments in industrial robotic applications. This method utilizes a simple 3rd order polynomial function for smooth interpolation between non-smooth path segments, so that entire task can effectively maintain constant line speed of operation. A predictor-corrector type numerical mapping technique, which correlates time based speed profile to the smoothed path in Cartesian space, is also provided. Finally simulation results show the feasibility of the proposed algorithm.

• Journal of computational fluids engineering
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• v.20 no.4
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• pp.44-50
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• 2015

The computational efficiency of flow simulations with Multi-resolution analysis (MRA) was enhanced via the boundary treatment of the computational domain. In MRA, an adaptive dataset to a solution is constructed through data decomposition with interpolating polynomial and thresholding. During the decomposition process, the basis points of interpolation should exceed the boundary of the computational domain. In order to resolve this problem, the weight coefficients of interpolating polynomial were adjusted near the boundaries. By this boundary treatment, the computational efficiency of MRA was enhanced while the numerical accuracy of a solution was unchanged. This modified MRA was applied to two-dimensional steady Euler equations and the enhancement of computational efficiency and the maintenance of numerical accuracy were assessed.

• 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.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.235-240
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• 2015

A decimation chain for multi-standard reconfigurable radios is presented for 900-MHz and 1,900-MHz dual-band cellular standards with a data interpolator based on the Lagrange method for adjusting the variable data rate to a fixed data rate appropriate for each standard. The two proposed configurations are analyzed and compared to provide insight into aliasing and the signal bandwidth by means of a newly introduced measure called interpolation error. The average interpolation error is reduced as the ratio of the sampling frequency to the signal BW is increased. The decimation chain and the multi-rate analog-to-digital converter are simulated to compute the interpolation error and the output signal-to-noise ratio. Further, a method to operate the above-mentioned chain under a compressed mode of operation is proposed in order to guarantee continuous packet connectivity for inter-radio-access technologies. The presented decimation chain can be applied to LTE, WCDMA, GSM multi-mode multi-band digital front-end which will ultimately lead to the software-defined radio.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.459-463
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• 1997

In this paper, we present the elimination of ECG artifact from the polysomnographic EEG and EOG. The idea of this method is that the ECG synchronized EEG segment is detected from ECG and regard samples of that segment a missing signal. After this, we used two interpolation methods to recover the missing segment. One is the Lagrange Polynomial Interpolation Method and the other is the Least Square Error AR Interpolation method. We tested those methods by applying to simulated signals. AR methods works well enough to reject the artifact about 10% of the main artifact level. We practically applied to real EEG and EOG signals. We also developed the algorithm to detect whether the artifact level is high or not. If the artifact level is high, then the interpolations are applied.

• Current Optics and Photonics
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• v.7 no.5
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• pp.518-528
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• 2023

As an effective means of remotely detecting the spectral information of the object, the spectral calibration for the Savart polarization interference imaging spectrometer (SPIIS) is a basis and prerequisite of information quantification, and its experimental calibration scheme is firstly proposed in this paper. In order to evaluate the accuracy of the spectral information acquisition, the linear interpolation, cubic spline interpolation, and piecewise cubic interpolation algorithms are adopted, and the precision of the quadratic polynomial fitting is the highest, whose fitting error is better than 5.8642 nm in the wavelength range of [500 nm, 820 nm]. Besides, the inversed value of the spectral resolution for the monochromatic light is greater than the theoretical value, and the deviation between them becomes larger with the wavelength increasing, which is mainly caused by the structural design of the SPIIS, together with the rationality of the spectral restoration algorithm and the selection of the maximum optical path difference (OPD). This work demonstrates that the SPIIS has achieved high performance assuring the feasibility of its practical use in various fields.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.3
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• pp.295-304
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• 2008

This paper comprises two specific objectives. The first is to examine the applicability of Ordinary Kriging interpolation(OK) to finite element method that is based on variogram modeling in conjunction with different allowable limits of separation distance. The second is to investigate the accuracy according to theoretical variograms such as polynomial, Gauss, and spherical models. For this purpose, the weighted least square method is applied to obtain the estimated new stress field from the stress data at the Gauss points. The weight factor is determined by experimental and theoretical variograms for interpolation of stress data apart from the conventional interpolation methods that use an equal weight factor. The validity of the proposed approach has been tested by analyzing two numerical examples. It is noted that the numerical results by Gauss model using 25% allowable limit of separation distance show an excellent agreement with theoretical solutions in literature.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.5 no.1
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• pp.47-53
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• 2001

A problem of approximation by irrational splines is considered. These splines have a constant curvature between interpolation nodes and need only one additional boundary condition for derivatives, which should be set only at one of two boundary nodes, that is impossible for usual polynomial splines required boundary conditions at both boundary nodal points. Some estimations for numerical differentiation and rounding error analysis are presented.