• Title/Summary/Keyword: S-transform

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A functionally graded magneto-thermoelastic half space with memory-dependent derivatives heat transfer

  • Ezzat, Magdy A.;El-Bary, Alaa A.
    • Steel and Composite Structures
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    • v.25 no.2
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    • pp.177-186
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    • 2017
  • In this work, the model of magneto-thermoelasticity based on memory-dependent derivative (MDD) is applied to a one-dimensional thermal shock problem for a functionally graded half-space whose surface is assumed to be traction free and subjected to an arbitrary thermal loading. The $Lam{\acute{e}}^{\prime}s$ modulii are taken as functions of the vertical distance from the surface of thermoelastic perfect conducting medium in the presence of a uniform magnetic field. Laplace transform and the perturbation techniques are used to derive the solution in the Laplace transform domain. A numerical method is employed for the inversion of the Laplace transforms. The effects of the time-delay on the temperature, stress and displacement distribution for different linear forms of Kernel functions are discussed. Numerical results are represented graphically and discussed.

Embedded System-Based Fast Fourier Transform Method for Measuring Water Content in Crude Oil

  • Shuqi Jia;Xiaolei Wang;Zhe Kan
    • Journal of Information Processing Systems
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    • v.20 no.3
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    • pp.399-408
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    • 2024
  • The moisture content of crude oil notably affects various aspects of oil production, storage, transportation, and exploration. However, accurately measuring this moisture content is challenging because of numerous influencing factors, leading to a lack of precision in existing detection methods. This inadequacy hinders the progress of China's petroleum industry. To overcome these challenges, this paper proposes a conductivity-based method for measuring crude oil moisture content. By employing an embedded system, we designed a sensor comprising five electrodes. Additionally, we developed signal excitation and signal processing circuits. Moreover, a software program was designed to analyze and compute the output signal using fast Fourier transform operations. This facilitated the identification of flow patterns, computation of relevant flow rates, and establishment of correlation rates based on frequency spectral characteristics. Based on experimental results, we established a functional relationship between measurement parameters and crude oil moisture content. This study enhanced the precision of moisture content measurement, thereby addressing existing limitations and fostering the advancement of China's petroleum industry.

A Model-Based Image Steganography Method Using Watson's Visual Model

  • Fakhredanesh, Mohammad;Safabakhsh, Reza;Rahmati, Mohammad
    • ETRI Journal
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    • v.36 no.3
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    • pp.479-489
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    • 2014
  • This paper presents a model-based image steganography method based on Watson's visual model. Model-based steganography assumes a model for cover image statistics. This approach, however, has some weaknesses, including perceptual detectability. We propose to use Watson's visual model to improve perceptual undetectability of model-based steganography. The proposed method prevents visually perceptible changes during embedding. First, the maximum acceptable change in each discrete cosine transform coefficient is extracted based on Watson's visual model. Then, a model is fitted to a low-precision histogram of such coefficients and the message bits are encoded to this model. Finally, the encoded message bits are embedded in those coefficients whose maximum possible changes are visually imperceptible. Experimental results show that changes resulting from the proposed method are perceptually undetectable, whereas model-based steganography retains perceptually detectable changes. This perceptual undetectability is achieved while the perceptual quality - based on the structural similarity measure - and the security - based on two steganalysis methods - do not show any significant changes.

GENERALIZATION OF EXTENDED APPELL'S AND LAURICELLA'S HYPERGEOMETRIC FUNCTIONS

  • Khan, N.U.;Ghayasuddin, M.
    • Honam Mathematical Journal
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    • v.37 no.1
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    • pp.113-126
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    • 2015
  • Recently, Liu and Wang generalized Appell's and Lauricella's hypergeometric functions. Motivated by the work of Liu and Wang, the main object of this paper is to present new generalizations of Appell's and Lauricella's hypergeometric functions. Some integral representations, transformation formulae, differential formulae and recurrence relations are obtained for these new generalized Appell's and Lauricella's functions.

SEMIGROUP OF LIPSCHITZ OPERATORS

  • Lee, Young S.
    • Korean Journal of Mathematics
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    • v.14 no.2
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    • pp.273-280
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    • 2006
  • Lipschitzian semigroup is a semigroup of Lipschitz operators which contains $C_0$ semigroup and nonlinear semigroup. In this paper, we establish the cannonical exponential formula of Lipschitzian semigroup from its Lie generator and the approximation theorem by Laplace transform approach to Lipschitzian semigroup.

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