Reduction of Uncertainties in Multidisciplinary Analysis Based on a Polynomial Chaos Sensitivity Study

Multidisciplinary analysis (MDA) is nowadays a powerful tool for analysis and optimization of complex systems. The present study is interested in the case where MDA involves feedback loops between disciplines (i.e., the output of a discipline is the input of another and vice versa). When the models for each discipline involve non-negligible modeling uncertainties, it is important to be able to efficiently propagate these uncertainties to the outputs of the MDA. The present study introduces a polynomial chaos expansion (PCE)-based approach to propagate modeling uncertainties in MDA. It is assumed that the response of each disciplinary solver is affected by an uncertainty modeled by a random field over the design and coupling variables space. A semi-intrusive PCE formulation of the problem is proposed to solve the corresponding nonlinear stochastic system. Application of the proposed method emphasizes an important particular case in which each disciplinary solver is replaced by a surrogate model (e.g., kriging). Three application problems are treated, which show that the proposed approach can approximate arbitrary (non-Gaussian) distributions very well at significantly reduced computational cost.

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Sensitivity study of dynamic systems using polynomial chaos

Reliability Engineering & System Safety ◽

10.1016/j.ress.2012.04.001 ◽

2012 ◽

Vol 104 ◽

pp. 15-26 ◽

Cited By ~ 33

Author(s):

Eduardo Haro Sandoval ◽

Floriane Anstett-Collin ◽

Michel Basset

Keyword(s):

Dynamic Systems ◽

Polynomial Chaos ◽

Sensitivity Study

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Uncertainty Propagation Using Polynomial Chaos Expansions for Extreme Sea Level Hazard Assessment: The Case of the Eastern Adriatic Meteotsunamis

Journal of Physical Oceanography ◽

10.1175/jpo-d-19-0147.1 ◽

2020 ◽

Vol 50 (4) ◽

pp. 1005-1021 ◽

Cited By ~ 1

Author(s):

Cléa Denamiel ◽

Xun Huan ◽

Jadranka Šepić ◽

Ivica Vilibić

Keyword(s):

Surrogate Model ◽

Polynomial Chaos ◽

Uncertainty Propagation ◽

Sensitivity Study ◽

Sea Levels ◽

Atmospheric Disturbances ◽

Stochastic Parameters ◽

Extreme Sea Levels ◽

Definition Of ◽

Polynomial Chaos Expansions

AbstractThis study quantifies the hazard associated with extreme sea levels due to eastern Adriatic meteotsunamis—long waves generated by traveling atmospheric disturbances—and assesses the sensitivity of the ocean response to the disturbances responsible for those events. In this spirit, a surrogate model of meteotsunami maximum elevation based on generalized polynomial chaos expansion (gPCE) methods, is implemented. The approach relies on the definition of a synthetic pressure disturbance—depending on six different stochastic parameters known to be important for meteotsunami generation, which is used as forcing to produce series of meteotsunami simulations defined with sparse grid methods (up to 10 689 used in this study). The surrogate model and the sensitivity study are then obtained with a pseudo-spectral approximation (PSA) method based on the chosen meteotsunami simulations. This study mainly presents the developed methodology and discusses the feasibility of implementing such gPCE-based surrogate models to assess the hazard and to study the sensitivity of meteorologically driven extreme sea levels.

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Sensitivity analysis for automotive EMC measurements using quasistatic Darwin model

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-02-2021-0054 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Arnold Bingler ◽

Sándor Bilicz ◽

Márk Csörnyei

Keyword(s):

Sensitivity Analysis ◽

Integral Equation ◽

Electromagnetic Compatibility ◽

Polynomial Chaos ◽

Low Cost ◽

Sensitivity Study ◽

Resonance Phenomenon ◽

Content Type ◽

Integral Equation Formulation ◽

Sensitivity Factors

Purpose The purpose of this paper is performing a global sensitivity analysis for automotive electromagnetic compatibility (EMC) measurements related to the CISPR 25 setup in order to examine the effect of the setup uncertainties on the resonance phenomenon. Design/methodology/approach An integral equation formulation is combined with Darwin model and special Green’s functions to model the configuration. The method of Sobol’ indices is used to gain sensitivity factors enhanced with a polynomial chaos metamodel. Findings The proposed model resulted in by orders of magnitude lower number of degrees of freedom and runtime compared to popular numerical methods, e.g. finite element method. The result of the sensitivity study is in good agreement with the underlying physical phenomena and improves the understanding of the resonances. Practical implications The fast model supplemented by the sensitivity factors can be used in EMC design and optimization. Originality/value The proposed method is original in the sense of combining a polynomial chaos metamodel with a low-cost integral equation model to reduce the computational demand for the sensitivity study.

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Race Difference in Auditory Sensitivity

Journal of Speech and Hearing Research ◽

10.1044/jshr.0704.389 ◽

1964 ◽

Vol 7 (4) ◽

pp. 389-393 ◽

Cited By ~ 3

Author(s):

David C. Shepherd ◽

Robert Goldstein ◽

Benjamin Rosenblüt

Keyword(s):

White Women ◽

White Men ◽

Sensitivity Study ◽

Auditory Sensitivity ◽

Race Difference ◽

Men And Women ◽

Auditory Thresholds ◽

Békésy Audiometry ◽

Method Of Adjustment ◽

Better Than

Two separate studies investigated race and sex differences in normal auditory sensitivity. Study I measured thresholds at 500, 1000, and 2000 cps of 23 white men, 26 white women, 21 negro men, and 24 negro women using the method of limits. In Study II thresholds of 10 white men, 10 white women, 10 negro men, and 10 negro women were measured at 1000 cps using four different stimulus conditions and the method of adjustment by means of Bekesy audiometry. Results indicated that the white men and women in Study I heard significantly better than their negro counterparts at 1000 and 2000 cps. There were no significant differences between the average thresholds measured at 1000 cps of the white and negro men in Study II. White women produced better auditory thresholds with three stimulus conditions and significantly more sensitive thresholds with the slow pulsed stimulus than did the negro women in Study II.

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