• Title/Summary/Keyword: Empirical

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Empirical evaluations for predicting the damage of FRC wall subjected to close-in explosions

  • Duc-Kien Thai;Thai-Hoan Pham;Duy-Liem Nguyen;Tran Minh Tu;Phan Van Tien
    • Steel and Composite Structures
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    • v.49 no.1
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    • pp.65-79
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    • 2023
  • This paper presents a development of empirical evaluations, which can be used to evaluate the damage of fiber-reinforced concrete composites (FRC) wall subjected to close-in blast loads. For this development, a combined application of numerical simulation and machine learning approaches are employed. First, finite element modeling of FRC wall under blast loading is developed and verified using experimental data. Numerical analyses are then carried out to investigate the dynamic behavior of the FRC wall under blast loading. In addition, a data set of 384 samples on the damage of FRC wall due to blast loads is then produced in order to develop machine learning models. Second, three robust machine learning models of Random Forest (RF), Support Vector Machine (SVM), and Extreme Gradient Boosting (XGBoost) are employed to propose empirical evaluations for predicting the damage of FRC wall. The proposed empirical evaluations are very useful for practical evaluation and design of FRC wall subjected to blast loads.

Empirical Bayesian Multiple Comparisons with the Best

  • Kim, Woo-Chul;Hwang, Hyung-Tae
    • Journal of the Korean Statistical Society
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    • v.20 no.2
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    • pp.108-117
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    • 1991
  • A parametric empirical Bayes procedure is proposed and studied to compare treatments simultaneously with the best. Minimum Bayes risk lower bounds are derived for an additive loss function, and their relationship with Bayesian simultaneous confidence lower bounds is given. For the proposed empirical Bayes procedure, the nominal confidence level both in Bayesian sense and in frequentist's sense is shown to be controlled asymptotically. For practical implementation, a measure of significance similar to f-value is suggested with an illustrative example.

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Empirical Bayes Test for the Exponential Parameter with Censored Data

  • Wang, Lichun
    • Communications for Statistical Applications and Methods
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    • v.15 no.2
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    • pp.213-228
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    • 2008
  • Using a linear loss function, this paper considers the one-sided testing problem for the exponential distribution via the empirical Bayes(EB) approach. Based on right censored data, we propose an EB test for the exponential parameter and obtain its convergence rate and asymptotic optimality, firstly, under the condition that the censoring distribution is known and secondly, that it is unknown.

Hierarchical Order Statistics Filtering for Fast Bi-Dimensional Empirical Mode Decomposition

  • Semiz, Serkan;Celebi, Anil;Urhan, Oguzhan
    • ETRI Journal
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    • v.38 no.4
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    • pp.695-702
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    • 2016
  • A hierarchical approach for fast bi-dimensional empirical mode decomposition (B-EMD) is proposed. The presented approach utilizes an efficient window size determination scheme that enables the multi-level computation of the order statistics filter (OSF). Our detailed experiments show that the proposed OSF computation approach allows a significantly faster computation of an EMD without degrading the decomposition accuracy.

ON ALMOST SURE REPRESENTATIONS FOR LONG MEMORY SEQUENCES

  • Ho, Hwai-Chung
    • Journal of the Korean Mathematical Society
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    • v.35 no.3
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    • pp.741-753
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    • 1998
  • Let G(*) be a Borel function applied to a stationary long memory sequence {X$_{i}$} of standard Gaussian random variables. Focusing on the process {G(X$_{i}$)}, the present paper establishes the almost sure representation for the empirical quantile process, that is, Bahadur's representation, and for the empirical process with respect to sample mean. Statistical applications of the representations are also addressed.sed.

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Bayes and Empirical Bayes Estimation of the Scale Parameter of the Gamma Distribution under Balanced Loss Functions

  • Rezaeian, R.;Asgharzadeh, A.
    • Communications for Statistical Applications and Methods
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    • v.14 no.1
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    • pp.71-80
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    • 2007
  • The present paper investigates estimation of a scale parameter of a gamma distribution using a loss function that reflects both goodness of fit and precision of estimation. The Bayes and empirical Bayes estimators rotative to balanced loss functions (BLFs) are derived and optimality of some estimators are studied.

Parametric Empirical Bayes Estimators with Item-Censored Data

  • Choi, Dal-Woo
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.261-270
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    • 1997
  • This paper is proposed the parametric empirical Bayes(EB) confidence intervals which corrects the deficiencies in the naive EB confidence intervals of the scale parameter in the Weibull distribution under item-censoring scheme. In this case, the bootstrap EB confidence intervals are obtained by the parametric bootstrap introduced by Laird and Louis(1987). The comparisons among the bootstrap and the naive EB confidence intervals through Monte Carlo study are also presented.

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A NOTE ON WEAK CONVERGENCE OF EMPIRICAL PROCESSES FOR A STATIONARY PHI-MIXING SEQUENCE

  • Kim, Tae-Yoon;Kim, Jang-Han;Lee, Tai-Sup
    • Journal of the Korean Statistical Society
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    • v.32 no.2
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    • pp.203-211
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    • 2003
  • A new result of weak convergence of the empirical process is established for a stationary ${\phi}-mixing$ sequence of random variables, which relaxes the existing conditions on mixing coefficients. The result is basically obtained from bounds for even moments of sums of ${\phi}-mixing$ r.v.'s useful for handling triangular arrays with entries decreasing in size.

On the Performance of Empiricla Bayes Simultaneous Interval Estimates for All Pairwise Comparisons

  • Kim, Woo-Chul;Han, Kyung-Soo
    • Journal of the Korean Statistical Society
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    • v.24 no.1
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    • pp.161-181
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    • 1995
  • The goal of this article is to study the performances of various empirical Bayes simultaneous interval estimates for all pairwise comparisons. The considered empirical Bayes interval estimaters are those based on unbiased estimate, a hierarchical Bayes estimate and a constrained hierarchical Bayes estimate. Simulation results for small sample cases are given and an illustrative example is also provided.

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ON THE GOODNESS OF FIT TEST FOR DISCRETELY OBSERVED SAMPLE FROM DIFFUSION PROCESSES: DIVERGENCE MEASURE APPROACH

  • Lee, Sang-Yeol
    • Journal of the Korean Mathematical Society
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    • v.47 no.6
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    • pp.1137-1146
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    • 2010
  • In this paper, we study the divergence based goodness of fit test for partially observed sample from diffusion processes. In order to derive the limiting distribution of the test, we study the asymptotic behavior of the residual empirical process based on the observed sample. It is shown that the residual empirical process converges weakly to a Brownian bridge and the associated phi-divergence test has a chi-square limiting null distribution.