• Title/Summary/Keyword: Series solutions

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A DOUBLY ROBUSTIFIED ESTIMATING FUNCTION FOR ARCH TIME SERIES MODELS

  • Kim, Sahm;Hwang, S.Y.
    • Journal of the Korean Statistical Society
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    • v.36 no.3
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    • pp.387-395
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    • 2007
  • We propose a doubly robustified estimating function for the estimation of parameters in the context of ARCH models. We investigate asymptotic properties of estimators obtained as solutions of robust estimating equations. A simulation study shows that robust estimator from specified doubly robustified estimating equation provides better performance than conventional robust estimators especially under heavy-tailed distributions of innovation errors.

A Novel Analytic Approach for the Forward Kinematics of the 3-6-type Stewart Platform using Tetrahedron Configurations (사면체 조합을 이용한 3-6형태의 스튜어트 플랫폼의 정기구학의 새로운 해석법)

  • 송세경;권동수
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.430-430
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    • 2000
  • This paper presents a new analytic approach using tetrahedrons to determine the forward kinematics of the 3-6-type Stewart platform. By using of the tetrahedral geometry, this approach has the advantage of greatly reducing the complexity of formulation and the computational burden required by the conventional methods which have been solved the forward kinematics with three unknown angles. As a result, this approach allows a significant abbreviation in the formulations and provides an easier means of obtaining the solutions. The proposed method is well verified through a series of numerical simulation.

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Analysis of the Steel Deck Bridges using the Finite Strip Method (유한대판법을 사용한 강상판 교량의 해석)

  • 최창근;홍현석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.77-84
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    • 1998
  • The finite strip method is presented for the analysis of steel deck bridges. Like the Pelikan-Esslinger design method for the steel deck bridges, steel deck is treated as an equivalent orthotropic plate. In the presented method, the deck is discretised by finite strips in the longitudinal direction and the effect of main girder or floor beam deflection can also be accounted for. In this method, the terms of harmonic series at elastically support such as transverse floor or diaphragm in steel deck become coupled. Solutions of this method are compared with other available analytical and numerical solution, and good agreement is observed.

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Synthesis ad Self-assembled Multilayer Film Fabrication via Layer-by-layer Deposition of Water-soluble Aromatic Polyimines

  • Lee, Taek-Seung;Kim, Jae-Hyeon;Kumar, Jayant;Tripathy, Sukant
    • Proceedings of the Korean Fiber Society Conference
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    • 1997.10a
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    • pp.71-75
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    • 1997
  • A new series of water-soluble conjugated aromatic polyimines containing sulfonate groups have been synthesized via polycondensation reaction between diamines and dialdehydes at room temperature. Self-assembled multilayer films consisting each polyimine as a polyanion and poly(diallyldimethylammonium hydrochloride) as a polycation were fabricated successfully by alternate deposition in corresponding aqueous solutions.

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Development of a Consistently Formulated General Order Nodal Method for Solving the Three-Dimensional Multi -Group Neutron Kinetic Equations

  • Kim, H.D.
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.137-141
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    • 1996
  • A new general high order consistent nodal method for solving the 3-D multigroup neutron kinetic equations in (x-y-z) geometry has been derived by expending the flux in a multiple polynomial series for the space variables by without the quadratic fit approximations of the transverse leakage and for the time variable and using a weighted-integral technique. The derived equation set is consistent mathematically, and therefore, we can expect very accurate solutions and less computing time since we can use coarse meshes in time variable as well as in spatial variables and the solution would converge exactly in fine mesh limit.

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Finite strain nonlinear longitudinal vibration of nanorods

  • Eren, Mehmet;Aydogdu, Metin
    • Advances in nano research
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    • v.6 no.4
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    • pp.323-337
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    • 2018
  • The nonlinear free vibration of a nanorod subjected to finite strain is investigated. The governing equation of motion in material configuration in terms of displacement is determined. By means of Galerkin method, the Fourier series solutions satisfying some typical boundary conditions are determined. The amplitude-frequency relationship and interaction between the modes are studied. The effects of nonlocal elasticity are shown for different length of nanotubes and nonlocal parameter. The results show that nonlocal effects lead to additional internal modal interaction for nanorod vibrations.

Numerical Solutions of Fractional Differential Equations with Variable Coefficients by Taylor Basis Functions

  • Kammanee, Athassawat
    • Kyungpook Mathematical Journal
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    • v.61 no.2
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    • pp.383-393
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    • 2021
  • In this paper, numerical techniques are presented for solving initial value problems of fractional differential equations with variable coefficients. The method is derived by applying a Taylor vector approximation. Moreover, the operational matrix of fractional integration of a Taylor vector is provided in order to transform the continuous equations into a system of algebraic equations. Furthermore, numerical examples demonstrate that this method is applicable and accurate.

Exact Solutions for Vibration and Buckling of An SS-C-SS-C Rectangular Plate Loaded by Linearly Varying In-plane Stresse (등변분포 평면응력을 받는 SS-C-SS-C 직사각형 판의 진동과 좌굴의 엄밀해)

  • 강재훈;심현주;장경호
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.1
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    • pp.56-63
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    • 2004
  • Exact solutions are presented for the free vibration and buckling of rectangular plates haying two opposite edges ( x=0 and a) simply supported and the other two ( y=0 and b) clamped, with the simply supported edges subjected to a linearly varying normal stress $\sigma$$_{x}$=- $N_{0}$[1-a(y/b)]/h, where h is the plate thickness. By assuming the transverse displacement ( w) to vary as sin(m$\pi$x/a), the governing partial differential equation of motion is reduced to an ordinary differential equation in y with variable coefficients. for which an exact solution is obtained as a power series (the method of Frobenius). Applying the clamped boundary conditions at y=0 and byields the frequency determinant. Buckling loads arise as the frequencies approach zero. A careful study of the convergence of the power series is made. Buckling loads are determined for loading parameters a= 0, 0.5, 1, 1.5. 2, for which a=2 is a pure in-plane bending moment. Comparisons are made with published buckling loads for a= 0, 1, 2 obtained by the method of integration of the differential equation (a=0) or the method of energy (a=1, 2). Novel results are presented for the free vibration frequencies of rectangular plates with aspect ratios a/b =0.5, 1, 2 when a=2, with load intensities $N_{0}$ / $N_{cr}$ =0, 0.5, 0.8, 0.95, 1. where $N_{cr}$ is the critical buckling load of the plate. Contour plots of buckling and free vibration mode shapes ate also shown.shown.

The Solution of Mild-Slope Equation using Power Series (멱급수를 이용한 완경사 방정식의 해)

  • Jung, Tae-Hwa;Lee, Seung-Oh;Park, Jin-Ho;Cho, Yong-Sik
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.1
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    • pp.133-138
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    • 2008
  • To analyze incident waves traveling from the deep ocean is very important in that it is based on resolving problems occurred in coastal areas. In general, numerical models and analytical solutions are used to analyze wave transformation. Although a numerical model can be applied to various bottoms and wave conditions, it may have some cumbersome numerical errors. On the other hand, an analytical solution has an advantage of obtaining the solution quickly and accurately without numerical errors. The analytical solution can, however, be utilized only for specific conditions. In this study, the analytical solution of the mild-slope equation has been developed. It can be applied to various conditions combing a numerical technique and an analytical approach while minimizing the numerical errors. As a result of comparing the obtained solutions in this study with those of the previously developed numerical model, A good agreement was observed.

Effect of Concentration Polarization on The Pervaporation of Aqueous Chlorinated-Organic Solution (유기염화물 수용액의 투과증발에 미치는 농도분극의 영향)

  • Cho, Min-Suk;Kim, Seung-Jai;Kim, Jin-Hwan
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.698-703
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    • 1998
  • The pervaporation experiments of aqueous solutions of trichloroethylene (TCE) and chlorobenzene (CB) through the silicone rubber (polydimethylsiloxane, PDMS) membrane were carried out and the effect of concentration polarization on the separation characteristics was investigated. The resistance-in-series model was used to explain the boundary layer resistance. It was clear that the concentration polarization phenomenon had a significant effect on the permeation behavior in the pervaporation separation of the trace organic chlorides from aqueous solutions. With the same membrane thickness, the permeation of TCE, which has a stronger affinity for the PDMS, appeared to be more influenced by the boundary layer resistance than that of CB. The effect of boundary layer resistance was reduced and the membrane resistance became dominant with increasing membrane thickness at a given hydrodynamic condition. The separation factor was increased to approach the intrinsic separation factor of the membrane with its thickness.

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