• Title/Summary/Keyword: Higher Order

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Higher-order solutions for generalized canonical correlation analysis

  • Kang, Hyuncheol
    • Communications for Statistical Applications and Methods
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    • v.26 no.3
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    • pp.305-313
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    • 2019
  • Generalized canonical correlation analysis (GCCA) extends the canonical correlation analysis (CCA) to the case of more than two sets of variables and there have been many studies on how two-set canonical solutions can be generalized. In this paper, we derive certain stationary equations which can lead the higher-order solutions of several GCCA methods and suggest a type of iterative procedure to obtain the canonical coefficients. In addition, with some numerical examples we present the methods for graphical display, which are useful to interpret the GCCA results obtained.

Analysis of Corneal Higher-order Aberrations after Myopic Refractive Surgery

  • Kim, Jeong-mee
    • Current Optics and Photonics
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    • v.3 no.1
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    • pp.72-77
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    • 2019
  • This study was performed to analyze the optical aberrations of the cornea induced by myopic refractive surgery. Corneal total higher-order aberrations, spherical aberration and coma for 4-mm and 6-mm pupils were measured using a wave-front analyzer. The amount of aberrations of the oblate corneal optics by the achieved correction was found to be larger than for the prolate corneal shape with complete eye, in an emmetropia control group. The change in corneal shape acts as an optical factor that degrades the quality of the retinal image; it seems to be one of the important factors related to quality of vision.

Blow-up of Solutions for Higher-order Nonlinear Kirchhoff-type Equation with Degenerate Damping and Source

  • Kang, Yong Han;Park, Jong-Yeoul
    • Kyungpook Mathematical Journal
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    • v.61 no.1
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    • pp.1-10
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    • 2021
  • This paper is concerned the finite time blow-up of solution for higher-order nonlinear Kirchhoff-type equation with a degenerate term and a source term. By an appropriate Lyapunov inequality, we prove the finite time blow-up of solution for equation (1.1) as a suitable conditions and the initial data satisfying ||Dmu0|| > B-(p+2)/(p-2q), E(0) < E1.

Spline finite strip method incorporating different plate theories for thick piezoelectric composite plates

  • Akhras, G.;Li, W.C.
    • Smart Structures and Systems
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    • v.5 no.5
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    • pp.531-546
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    • 2009
  • In the present analysis, the spline finite strip with higher-order shear deformation is formulated for the static analysis of piezoelectric composite plates. The proposed method incorporates Reddy's third-order shear deformation theory, Touratier's "Sine" model, Afaq's exponential model, Cho's higher-order zigzag laminate theory, as well as the classic plate theory and the first-order plate theory. Thus, the analysis can be conducted based on any of the above-mentioned theories. The selection of a specific method is done by simply changing a few terms in a 2 by 2 square matrix and the results, obtained according to different plate theories, can be compared to each other. Numerical examples are presented for piezoelectric composite plates subjected to mechanical loading. The results based on different shear deformation theories are compared with the three-dimensional solutions. The behaviours of piezoelectric composite plates with different length-to-thickness ratios, fibre orientations, and boundary conditions are also investigated in these examples.

Buckling Analysis of Laminated Composite Plate and Shell Structures considering a Higher-Order Shear Deformation (고차전단변형을 고려한 복합적층판 및 쉘구조의 좌굴해석)

  • Lee, Won Hong;Yoon, Seok Ho;Han, Seong Cheon
    • Journal of Korean Society of Steel Construction
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    • v.9 no.1 s.30
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    • pp.3-11
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    • 1997
  • Laminated composite shells exhibit properties comsiderably different from those of the single-layer shell. Thus, to obtain the more accurate solutions to laminated composite shells ptoblems, effects of shear strain should be condidered in analysis of them. A higher-order shear deformation theory requires no shear correction coefficients. This theory is used to determine the buckling loads of elastic shells. The theory accounts for parabolic distribution of the transverse shear through the thickness of the shell and rotary inertia. Exact solutions of simply-supported shells are obtained and the results are compared with the exact solutions of the first-order shear deformation theory, and the classical theory. The present theory predicts the buckling loads more accurately when compared to the first -order and classical theory.

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Improving the eigenvalue using higher order elements without re-solving

  • Stephen, D.B.;Steven, G.P.
    • Structural Engineering and Mechanics
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    • v.5 no.4
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    • pp.385-398
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    • 1997
  • High order finite element have a greater convergence rate than low order finite elements, and in general produce more accurate results. These elements have the disadvantage of being more computationally expensive and often require a longer time to solve the finite element analysis. High order elements have been used in this paper to obtain a new eigenvalue solution with out re-solving the new model. The optimisation of the eigenvalue via the differentiation of the Rayleigh quotient has shown that the additional nodes associated with the higher order elements can be condensed out and solved using the original finite element solution. The higher order elements can then be used to calculate an improved eigenvalue for the finite element analysis.

A B-Spline Higher Order Panel Method Applied to the Radiation Wave Problem for a 2-D Body Oscillating on the Free Surface

  • Hong, D.C.;Lee, C.-S.
    • Journal of Ship and Ocean Technology
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    • v.3 no.4
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    • pp.1-14
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    • 1999
  • The improved Green integral equation using the Kelvin-type Green function in known free of irregular frequencies where the integral over the inner free surface integral is removed from the integral equation, resulting in an overdetermined integral equation. The solution of the overdetermined Green integral equation is shown identical with the solution of the improved Green integral equation Using the B-spline higher order panel method, the overdetermined equation is discretized in two different ways; one of the resulting linear system is square and the other is redundant. Numerical experiments show that the solutions of both are identical. Using the present methods, the exact values and higher derivatives of the potential at any place over the wetted surface of the body can be found with much fewer panels than low order panel method.

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Bending analysis of a single leaf flexure using higher-order beam theory

  • Nguyen, Nghia Huu;Lee, Dong-Yeon
    • Structural Engineering and Mechanics
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    • v.53 no.4
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    • pp.781-790
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    • 2015
  • We apply higher-order beam theory to analyze the deflections and stresses of a cantilevered single leaf flexure in bending. Our equations include shear deformation and the warping effect in bending. The results are compared with Euler-Bernoulli and Timoshenko beam theory, and are verified by finite element analysis (FEA). The results show that the higher-order beam theory is in a good agreement with the FEA results, with errors of less than 10%. These results indicate that the analysis of the deflections and stresses of a single leaf flexure should consider the shear and warping effects in bending to ensure high precision mechanism design.

Analysis of higher order composite beams by exact and finite element methods

  • He, Guang-Hui;Yang, Xiao
    • Structural Engineering and Mechanics
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    • v.53 no.4
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    • pp.625-644
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    • 2015
  • In this paper, a two-layer partial interaction composite beams model considering the higher order shear deformation of sub-elements is built. Then, the governing differential equations and boundary conditions for static analysis of linear elastic higher order composite beams are formulated by means of principle of minimum potential energy. Subsequently, analytical solutions for cantilever composite beams subjected to uniform load are presented by Laplace transform technique. As a comparison, FEM for this problem is also developed, and the results of the proposed FE program are in good agreement with the analytical ones which demonstrates the reliability of the presented exact and finite element methods. Finally, parametric studies are performed to investigate the influences of parameters including rigidity of shear connectors, ratio of shear modulus and slenderness ratio, on deflections of cantilever composite beams, internal forces and stresses. It is revealed that the interfacial slip has a major effect on the deflection, the distribution of internal forces and the stresses.

Bending analysis of functionally graded plates using new eight-unknown higher order shear deformation theory

  • Tu, Tran Minh;Quoc, Tran Huu;Long, Nguyen Van
    • Structural Engineering and Mechanics
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    • v.62 no.3
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    • pp.311-324
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    • 2017
  • In this paper a new eight-unknown higher order shear deformation theory is proposed for functionally graded (FG) material plates. The theory based on full twelve-unknown higher order shear deformation theory, simultaneously satisfy zeros transverse stresses at top and bottom surface of FG plates. Equations of motion are derived from principle of virtual displacement. Exact closed-form solutions are obtained for simply supported rectangular FG plates under uniform loading. The accuracy of present numerical results has been verified by comparing it with generalized shear deformation theory. The effect of power law index of functionally graded material, side-to-thickness ratio, and aspect ratio on static behavior of FG plates is investigated.