• Title/Summary/Keyword: Laplace distribution

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Fractional order GL model on thermoelastic interaction in porous media due to pulse heat flux

  • Alzahrani, Faris S.;Abbas, Ibrahim A.
    • Geomechanics and Engineering
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    • v.23 no.3
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    • pp.217-225
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    • 2020
  • In this paper, the thermoelastic interactions in a two-dimension porous body are studied. This problem is solved by using the Green and Lindsay (GL) generalized thermoelasticity model under fractional time derivative. The derived approaches are estimated. with numeral results which are applied to the porous mediums in simplifying geometrical. The bounding plane surface of the present half-space continuum is subjected to a pulse heat flux. We use the Laplace-Fourier transforms methods with the eigenvalues approach to solve the problem. The numerical solutions for the field functions are obtained numerically using the numerical Laplace inversion technique. The effects of the fractional parameter and the thermal relaxation times on the temperature field, the displacement field, the change in volume fraction field of voids distribution and the stress fields have been calculated and displayed graphically and the obtained results are discussed.

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.

AWGN Removal using Laplace Distribution and Weighted Mask (라플라스 분포와 가중치 마스크를 이용한 AWGN 제거)

  • Park, Hwa-Jung;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.12
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    • pp.1846-1852
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    • 2021
  • In modern society, various digital devices are being distributed in a wide range of fields due to the fourth industrial revolution and the development of IoT technology. However, noise is generated in the process of acquiring or transmitting an image, and not only damages the information, but also affects the system, causing errors and incorrect operation. AWGN is a representative noise among image noise. As a method for removing noise, prior research has been conducted, and among them, AF, A-TMF, and MF are the representative methods. Existing filters have a disadvantage that smoothing occurs in areas with high frequency components because it is difficult to consider the characteristics of images. Therefore, the proposed algorithm calculates the standard deviation distribution to effectively eliminate noise even in the high frequency domain, and then calculates the final output by applying the probability density function weight of the Laplace distribution using the curve fitting method.

A Study on the Posterior Density under the Bayes-empirical Bayes Models

  • Sohn, Joong-K.Sohn;Kim, Heon-Joo-Kim
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.215-223
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    • 1996
  • By using Tukey's generalized lambda distribution, appoximate posterior density is derived under the Bayes-empirical Bayes model. The sensitivity of posterior distribution to the hyperprior distribution is examined by using Tukey's generalized lambda distriburion which approximate many well-knmown distributions. Based upon Monte Varlo simulation studies it can be said that posterior distribution is sensitive to the cariance of the prior distribution and to the symmetry of the hyperprior distribution. Also posterior distribution is approximately obtained by using the following methods : Lindley method, Laplace method and Gibbs sampler method.

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Fourier Series Approximation for the Generalized Baumgartner Statistic

  • Ha, Hyung-Tae
    • Communications for Statistical Applications and Methods
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    • v.19 no.3
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    • pp.451-457
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    • 2012
  • Baumgartner et al. (1998) proposed a novel statistical test for the null hypothesis that two independently drawn samples of data originate from the same population, and Murakami (2006) generalized the test statistic for more than two samples. Whereas the expressions of the exact density and distribution functions of the generalized Baumgartner statistic are not yet found, the characteristic function of its limiting distribution has been obtained. Due to the development of computational power, the Fourier series approximation can be readily utilized to accurately and efficiently approximate its density function based on its Laplace transform. Numerical examples show that the Fourier series method provides an accurate approximation for statistical quantities of the generalized Baumgartner statistic.

On testing NBUL aging class of life distribution

  • Hassan, M.Kh.;El-Din, M.M. Mohie;Abu-Youssef, S.E.
    • International Journal of Reliability and Applications
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    • v.15 no.1
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    • pp.1-9
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    • 2014
  • Let X and $X_t$ denote the lifetime and the residual life at age t, respectively. X is said to be a NBUL (new better than used in Laplace transform order) random variable if $X_t$ is smaller than X in Laplace order, i.e., $X_t{\leq}_{LT}X$. We propose a new test statistics for testing exponentiality versus NBUL class of life distribution. The tests by Hollender and Proschan (1975) and the generalized Hollender and Proschan test by Ains and Mitra (2011) are considered as special cases of the our of test statistics. Our proposed test statistics is simple, consistent and asymptotically normal. Efficiency and powers of the test statistics for some commonly used distributions in reliability are discussed. Finally, real examples are presented to illustrate the theoretical results.

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Photothermoelastic interactions under Moore-Gibson-Thompson thermoelasticity

  • Kumar, Rajneesh;Sharma, Nidhi;Chopra, Supriya
    • Coupled systems mechanics
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    • v.11 no.5
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    • pp.459-483
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    • 2022
  • In the present work, a new photothermoelastic model based on Moore-Gibson-Thompson theory has been constructed. The governing equationsfor orthotropic photothermoelastic plate are simplified for two-dimension model. Laplace and Fourier transforms are employed after converting the system of equations into dimensionless form. The problem is examined due to various specified sources. Moving normal force, ramp type thermal source and carrier density periodic loading are taken to explore the application of the assumed model. Various field quantities like displacements, stresses, temperature distribution and carrier density distribution are obtained in the transformed domain. The problem is validated by numerical computation for a given material and numerical obtained results are depicted in form of graphs to show the impact of varioustheories of thermoelasticity along with impact of moving velocity, ramp type and periodic loading parameters. Some special cases are also explored. The results obtained in this paper can be used to design various semiconductor elements during the coupled thermal, plasma and elastic wave and otherfieldsin thematerialscience, physical engineering.

The Comparative Study based on Gompertz Software Reliability Model of Shape Parameter (곰페르츠형 형상모수에 근거한 소프트웨어 신뢰성모형에 대한 비교연구)

  • Shin, Hyun Cheul;Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.2
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    • pp.29-36
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    • 2014
  • Finite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the Gompertz distribution reliability model, which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination$(R^2)$, for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing fixed shape parameter of the Gompertz distribution was employed. This analysis of failure data compared with the Gompertz distribution model of shape parameter. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the proposed Gompertz model is more efficient in terms of reliability in this area. Thus, Gompertz model can also be used as an alternative model. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can was helped.

A Study on the Characteristic of Twisted Nematic Liquid Crystal Cell by Three Dimensional Finite Element Method (3차원 유한요소법을 이용한 TN 모드 액정 셀 특성 분석 연구)

  • 정주식;윤상호;이철수;윤석인;원태영
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.12
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    • pp.1071-1079
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    • 2002
  • This paper reports a methodology and application lot calculating distribution of the director in a liquid crystal cell by a numerical technique. To calculate distribution of the director, we applied a three dimensional finite element method (FEM) and calculated the distributions of electric potential and director in the liquid crystal cell. We have considered the free-energy density in the bulk of liquid crystal cell and calculated the switching property by the Ericksen-Leslie equation and the Laplace equation. We have calculated the optical transmission with distribution of the director by Berreman's method and confirmed the threshold voltage and the response time.

LOSS PROBABILITY IN THE PH/M/1/K QUEUE

  • Kim, Jeong-Sim
    • Journal of applied mathematics & informatics
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    • v.24 no.1_2
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    • pp.529-534
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    • 2007
  • We obtain an explicit expression of the loss probability for the PR/M/1/K queue when the offered load is strictly less than one.