• Title/Summary/Keyword: Domain-inversion

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Transversely isotropic thin circular plate with multi-dual-phase lag heat transfer

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.343-351
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    • 2020
  • The present research deals with the multi-dual-phase-lags thermoelasticity theory for thermoelastic behavior of transversely isotropic thermoelastic thin circular plate The Laplace and Hankel transform techniques have been used to find the solution of the problem. The displacement components, stress components, and conductive temperature distribution are computed in the transformed domain with the radial distance and further determined in the physical domain using numerical inversion techniques. The effect of rotation and two temperature are depicted graphically on the resulting quantities.

Analysis of One-Dimensional Transient Heat Conduction Problems using Hybrid Laplace Transform/finite Element Method (라플라스 변환과 유한요소법의 결합에 의한 1차원 과도 열전도 문제 해석)

  • Song, Byoung-Chul;Jung, Hae-Duk;Lee, Ki-Sik
    • Proceedings of the KIEE Conference
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    • 1997.07a
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    • pp.309-311
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    • 1997
  • In this paper, it is proposed that a algorithm which is applicable to the transient analysis by combined use of the Laplace transform and the finite element method. The proposed method removes the time terms using the Laplace transform and then solves the associated equation with the finite element method. The solution which is solved at frequency domain is transformed into time domain by use of the Laplace inversion. To verify proposed algorithm, heat conduction problem is analysed and found a good agreement with analytic solution.

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Microwave Imaging of a Perfectly Conducting Cylinder by Using Modified Newton's Algorithm in the Angular Spectral Domain (각 스펙트럼 영역에서 개선된 Newton 알고리듬을 이용한 완전도체의 역산란 방법)

  • 박선규;박정석;라정웅
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.6
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    • pp.34-44
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    • 1994
  • In this paper, an iterative inversion method in angular spectral domain is presented for microwave imaging of a perfectly conducting cylinder. Angular spectra are calculated from measured far-field scattered fields. And then both the propagating modes and the evanescent modes are defined. The center and initial shape of an unknown conductor may be obtained by the characteristics of angular spectra and the total scattering cross section (TSCS). Finally, the orignal shape is reconstructed by the modified Newton algorithm. By using well estimated initial shape the local minima can be avoided, which might appear when the nonlinear equation is solved with Newton algorithm. It is shown to be robust to noise in scattered fields via numerical examples by keeping only the propagating modes and filtering out the evanescent modes.

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Dynamic stress intensity factors for two parallel cracks in an infinite orthotropic plate subject to an impact load

  • Itou, Shouetsu
    • Structural Engineering and Mechanics
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    • v.33 no.6
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    • pp.697-708
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    • 2009
  • Stresses are solved for two parallel cracks in an infinite orthotropic plate during passage of incoming shock stress waves normal to their surfaces. Fourier transformations were used to reduce the boundary conditions with respect to the cracks to two pairs of dual integral equations in the Laplace domain. To solve these equations, the differences in the crack surface displacements were expanded to a series of functions that are zero outside the cracks. The unknown coefficients in the series were solved using the Schmidt method so as to satisfy the conditions inside the cracks. The stress intensity factors were defined in the Laplace domain and were inverted numerically to physical space. Dynamic stress intensity factors were calculated numerically for selected crack configurations.

High-Quality and Robust Reversible Data Hiding by Coefficient Shifting Algorithm

  • Yang, Ching-Yu;Lin, Chih-Hung
    • ETRI Journal
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    • v.34 no.3
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    • pp.429-438
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    • 2012
  • This study presents two reversible data hiding schemes based on the coefficient shifting (CS) algorithm. The first scheme uses the CS algorithm with a mean predictor in the spatial domain to provide a large payload while minimizing distortion. To guard against manipulations, the second scheme uses a robust version of the CS algorithm with feature embedding implemented in the integer wavelet transform domain. Simulations demonstrate that both the payload and peak signal-to-noise ratio generated by the CS algorithm with a mean predictor are better than those generated by existing techniques. In addition, the marked images generated by the variant of the CS algorithm are robust to various manipulations created by JPEG2000 compression, JPEG compression, noise additions, (edge) sharpening, low-pass filtering, bit truncation, brightness, contrast, (color) quantization, winding, zigzag and poster edge distortion, and inversion.

Effect of thermal conductivity on isotropic modified couple stress thermoelastic medium with two temperatures

  • Kaur, Harpreet;Lata, Parveen
    • Steel and Composite Structures
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    • v.34 no.2
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    • pp.309-319
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    • 2020
  • The objective is to study the deformation in a homogeneous isotropic modified couple stress thermoelastic medium with mass diffusion and with two temperatures due to a thermal source and mechanical force. Laplace and Fourier transform techniques are applied to obtain the solutions of the governing equations. The displacements, stress components, conductive temperature, mass concentration and couple stress are obtained in the transformed domain. Numerical inversion technique has been used to obtain the solutions in the physical domain. Isothermal boundary and insulated boundaryconditions are used to investigate the problem. Some special cases of interest are also deduced.

Time harmonic interactions in non local thermoelastic solid with two temperatures

  • Lata, Parveen;Singh, Sukhveer
    • Structural Engineering and Mechanics
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    • v.74 no.3
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    • pp.341-350
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    • 2020
  • The present investigation is concerned with two dimensional deformation in a non local thermoelastic solid with two temperatures due to time harmonic sources. The nonlocal thermoelastic solid is homogeneous with the effect of two temperature parameters. Fourier transforms are used to solve the problem. The bounding surface is subjected to concentrated and distributed sources. The analytical expressions of displacement, stress components and conductive temperature are obtained in the transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerical simulated results are depicted graphically to show the effect of nonlocal parameter and frequency on the components of displacements, stresses and conductive temperature. Some special cases are also deduced from the present investigation.

Effect of nonlocal parameter on nonlocal thermoelastic solid due to inclined load

  • Lata, Parveen;Singh, Sukhveer
    • Steel and Composite Structures
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    • v.33 no.1
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    • pp.123-131
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    • 2019
  • The present investigation is concerned with two dimensional deformation in a homogeneous nonlocal thermoelastic solid with two temperature. The nonlocal thermoelastic solid is subjected to inclined load. Laplace and Fourier transforms are used to solve the problem. The bounding surface is subjected to concentrated and distributed sources. The analytical expressions of displacement, stress components, temperature change are obtained in the transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerical simulated results are depicted graphically to show the effect of angle of inclination and nonlocal parameter on the components of displacements, stresses and conductive temperature. Some special cases are also deduced from the present investigation.

Effects of Hall current in a transversely isotropic magnetothermoelastic with and without energy dissipation due to normal force

  • Kumar, Rajneesh;Sharma, Nidhi;Lata, Parveen
    • Structural Engineering and Mechanics
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    • v.57 no.1
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    • pp.91-103
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    • 2016
  • This investigation is concerned with the disturbances in a homogeneous transversely isotropic thermoelastic rotating medium with two temperature, in the presence of the combined effects of Hall currents and magnetic field due to normal force of ramp type. The formulation is applied to the thermoelasticity theories developed by Green-Naghdi Theories of Type-II and Type-III. Laplace and Fourier transform technique is applied to solve the problem. The analytical expressions of displacements, stress components, temperature change and current density components are obtained in the transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerically simulated results are depicted graphically to show the effects of Hall current and anisotropy on the resulting quantities. Some special cases are also deduced from the present investigation.

Thermomechanical interactions in transversely isotropic thick circular plate with axisymmetric heat supply

  • Lata, Parveen;Kaur, Iqbal
    • Structural Engineering and Mechanics
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    • v.69 no.6
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    • pp.607-614
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    • 2019
  • The present investigation has focus on the study of deformation due to thermomechanical sources in a thick circular plate. The thick circular plate is homogeneous, transversely isotropic with two temperatures and without energy dissipation. The upper and lower surfaces of the thick circular plate are traction free. The Laplace and Hankel transform has been used for finding the general solution to the field equations. The analytical expressions of stresses, conductive temperature and displacement components are computed in the transformed domain. However, the resulting quantities are obtained in the physical domain by using numerical inversion technique. Numerically simulated results are illustrated graphically. The effects of two temperatures by considering different values of temperature parameters are shown on the various components. Some particular cases are also figured out from the present investigation.