• Proceedings of the KOSOMBE Conference
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• v.1994 no.05
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• pp.75-78
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• 1994

To represent the overall potential distribution on the entire scalp it is necessary to interpolate between sampled EEG(electroencephalogram) values, we describe a method to interpolate between scalp recorded EEG data which obtained from electrodes irregularly disposed on the scalp, using polynomial interpolation. This method can analyze the variance of source temporally or spatially and present continuous distributed topographic mapping of the EEG records. In the result, we obtained the overall potentials distribution on the entire scalp from the EEG records of a patient which was known to epilepsy.

• Steel and Composite Structures
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• v.9 no.5
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• pp.473-497
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• 2009

For the spatially coupled free vibration analysis of composite box beams resting on elastic foundation under the axial force, the exact solutions are presented by using the power series method based on the homogeneous form of simultaneous ordinary differential equations. The general vibrational theory for the composite box beam with arbitrary lamination is developed by introducing Vlasov°Øs assumption. Next, the equations of motion and force-displacement relationships are derived from the energy principle and explicit expressions for displacement parameters are presented based on power series expansions of displacement components. Finally, the dynamic stiffness matrix is calculated using force-displacement relationships. In addition, the finite element model based on the classical Hermitian interpolation polynomial is presented. To show the performances of the proposed dynamic stiffness matrix of composite box beam, the numerical solutions are presented and compared with the finite element solutions using the Hermitian beam elements and the results from other researchers. Particularly, the effects of the fiber orientation, the axial force, the elastic foundation, and the boundary condition on the vibrational behavior of composite box beam are investigated parametrically. Also the emphasis is given in showing the phenomenon of vibration mode change.

• Structural Engineering and Mechanics
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• v.23 no.3
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• pp.263-278
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• 2006

This work presents a time-truncation scheme, based on the Lagrange interpolation polynomial, for the solution of the two-dimensional scalar wave problem by the time-domain boundary element method. The aim is to reduce the number of stored matrices, due to the convolution integral performed from the initial time to the current time, and to keep a compromise between computational economy and efficiency and the numerical accuracy. In order to verify the accuracy of the proposed formulation, three examples are presented and discussed at the end of the article.

• Journal of the Korean Society for Railway
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• v.5 no.1
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• pp.40-47
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• 2002

In this study, and analytical method for ride sensitivity analysis of a train with non-linear suspension elements are proposed. Non-linear characteristics of springs and dampers for primary and secondary suspensions of a train are parameterized using polynomial interpolation. Vertical dynamic model of a three-body train running on straight rail with the predetermined roughness expressed in terms of spectral density function is set up and its equations of motion for ride analysis are derived. Using the direct differentiation method, sensitivity equations of the vertical dynamic model with respect to design parameters associated with non-linearity of suspensions are obtained. Based on the sensitivity analysis, improvement of ride is achieved by varying appropriate suspension parameters.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.969-976
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• 1999

This paper is concerned with the generation of a balancing trajectory for improving the walking performance. The balancing motion has been determined by solving a second -order differential equation. However, this method caused some difficulties in linearizing and approximating the equation and had restrictions on using various balancing trajectories. The proposed difficulties in linearizing and approximating the equation and had restrictions on using various balancing trajectories. The proposed method i this paper is based on the genetic algorithm for minimizing the motins of balancing joints, whose trajectories are generated by the fifth-order polynomial interpolation after planning leg trajectories. The real walking experiments are made on the biped robot IWR-III, developed by our Automatic Control Laboratory. The system has 8 degrees of freedom and the structure of three pitches in each leg, and one roll and one prismatic joint in the balancing joints. The experimental result shows the validity and applicability of the new proposed algorithm.

• Structural Engineering and Mechanics
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• v.33 no.5
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• pp.573-588
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• 2009

In this paper a four-node hybrid stress element is proposed for analysing arbitrarily shaped plates on a two parameter elastic foundation. The element is developed by combining a hybrid plate stress element and a soil element. The formulation is based on Hellinger-Reissner variational principle in which both inter element compatible boundary displacement and equilibrated stress fields for the plate as well as the foundation are chosen separately. This formulation also allows a low order polynomial interpolation functions. Numerical examples are presented to show that the validity and efficiency of the present element for the plate analysis resting on an elastic foundation. In these examples the effect of soil depth, interaction between closed plates on soil parameters, comparison with Winkler hypothesis is investigated.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.149-156
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• 2006

This paper presents a novel approach for constructing a piecewise triangular cubic polynomial surface with $C^1$ continuity around a common corner vertex. A $C^1$ continuity condition between two cubic triangular patches is first derived using mixed directional derivatives. An approach for constructing a surface with $C^1$ continuity around a corner is then developed. Our approach is easy and fast with the virtue of cubic reproduction, local shape controllability, $C^2$ continuous at the corner vertex. Some experimental results are presented to show the applicability and flexibility of the approach.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.774-778
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• 1996

Developed in this research is a surface modeling kernel for various CAD/CAM applications. Its internal surface representations are rational parametric polynomials, which are generalizations of nonrational Bezier, Ferguson, Coons and NURBS surface, and are very fast in evaluation. The kernel is designed under the OOP concepts and coded in C++ on PCs. The present implementation of the kernel supports surface construction methods, such as point data interpolation, skinning, sweeping and blending. It also has NURBS conversion routines and offers the IGES and ZES format for geometric information exchange. It includes some geometric processing routines, such as surface/surface intersection, curve/surface intersection, curve projection and so forth. We are continuing to work with the kernel and eventually develop a B-Rep based solid modeler.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.3 s.258
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• pp.300-305
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• 2007

Many practical flow problems are defined with the circular boundary. Fluid flows within a circular boundary are however susceptible to a singularity problem when the cylindrical coordinates are employed. To remove this singularity a method has been developed in this study which uses the local harmonic functions in discretization of derivatives as well as interpolation. This paper describes the basic reason for introducing the harmonic functions and the overall numerical methods. The numerical methods are evaluated in terms of the accuracy and the stability. The Lamb-dipole flow is selected as a test flow. We will see that the harmonic-function method indeed gives more accurate solutions than the conventional methods in which the polynomial functions are utilized.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.3 no.2
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• pp.11-17
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• 1985

In the three dimensional Cartesian Coordinate System such as the satellite geodesy the relationship of the geoid and the reference ellipsoid must be known. Therefore, the determination of geoidal heights is regarded as one of the most important problem in geodesy. This paper deals with determination of astro-geodetic geoid by the spherical surface polynomials interpolation method. The data that astronomical deflection of the vertical was published by National Geography Institute is applied. The map of geoidal heights is drawn out. This shows that Tokyo Datum have influenced on Korea.