Analysis of methodologies for determination of DEM input parameters

2021 ◽  
Author(s):  
Rondinelli M. Lima ◽  
Rodolfo J. Brandao ◽  
Raphael L. Santos ◽  
Claudio R. Duarte ◽  
Marcos A. S. Barrozo
Keyword(s):  
Input Parameters

Device Modeling of a-Si:H Alloy Solar Cells: Calibration Procedure for Determination of Model Input Parameters

1998 ◽  
Vol 507 ◽  
Author(s):  
M. Zeman ◽  
R.A.C.M.M. Van Swaaij ◽  
E. Schroten ◽  
L.L.A. Vosteen ◽  
J.W. Metselaar
Keyword(s):  
Solar Cell ◽  
Material Properties ◽  
Calibration Procedure ◽  
Model Parameters ◽  
Model Input ◽  
A Value ◽  
Input Parameters ◽  
Simulated Material ◽  
Good Agreement

ABSTRACTA calibration procedure for determining the model input parameters of standard a-Si:H layers, which comprise a single junction a-Si:H solar cell, is presented. The calibration procedure consists of: i) deposition of the separate layers, ii) measurement of the material properties, iii) fitting the model parameters to match the measured properties, iv) simulation of test devices and comparison with experimental results. The inverse modeling procedure was used to extract values of the most influential model parameters by fitting the simulated material properties to the measured ones. In case of doped layers the extracted values of the characteristic energies of exponentially decaying tail states are much higher than the values reported in literature. Using the extracted values of model parameters a good agreement between the measured and calculated characteristics of a reference solar cell was reached. The presented procedure could not solve directly an important issue concerning a value of the mobility gap in a-Si:H alloys.

Modelling of tribological responses of composites using integrated ANN-GA technique

2020 ◽  
pp. 002199832096052
Author(s):  
Santanu Sardar ◽  
Swati Dey ◽  
Debdulal Das
Keyword(s):  
Optimization Technique ◽  
Matrix Composites ◽  
Large Numbers ◽  
Wide Range ◽  
Input Parameters ◽  
Input Variables ◽  
Velocity Input ◽  
Abrasive Size

In the present article, artificial neural networks (ANNs) and genetic algorithm (GA) methodology were integrated to model tribological characteristics of stir-cast Al-Zn-Mg-Cu matrix composites under two-body abrasion considering large numbers of experimentally generated results. Tribo-responses of wear rate (Wrt), coefficient of friction (COF) and roughness of abraded surface (RAS) were evaluated under wide range of intrinsic ( i.e., particle quantity) and extrinsic ( i.e., abrasive size, load, distance and velocity) input parameters. Characteristics of Wrt, COF and RAS are often mutually contradictory in nature and so, multi-objective optimization technique becomes imperative for selection and design of machine components. Accordingly, those were optimized through Pareto solutions. Sensitivity of different factors was analyzed on each of the tribo-performances and validated via experimental evidences. Amongst the input variables, particle quantity and abrasive size dominated significantly over other variables except load which imparted modest influences. The role of various input parameters was explained through determination of different micromechanisms via exhaustive post wear characterizations, microstructural and surface topography attributes. Lowest values of Wrt and COF with a modest value of RAS were identified at 15 ± 2 wt.% particle quantity.

APPLICATION OF RELEVANCE VECTOR MACHINE IN SEISMIC ATTENUATION PREDICTION

2007 ◽  
Vol 01 (04) ◽  
pp. 299-309 ◽  
Author(s):  
PIJUSH SAMUI
Keyword(s):  
Sensitivity Analysis ◽  
Information Content ◽  
Relevance Vector Machine ◽  
Seismic Attenuation ◽  
Rock Properties ◽  
Input Parameters ◽  
Practical Tool ◽  
Data Sensitivity

The recently introduced relevance vector machine (RVM) technique is applied to predict seismic attenuation based on rock properties. The RVM provides much sparser regressors without compromising performance, and kernel bases give a small but worthwhile improvement in performance. It evades complexity by producing models that have structure and as a result parameterization process that is appropriate to the information content of the data. Sensitivity analysis has been also performed to investigate the importance of each of the input parameters. The results show that RVM approach has the potential to be a practical tool for determination of seismic attenuation.

Determination of Material Parameters for Nonlinear Analysis of Reinforced Concrete

2017 ◽  
Vol 738 ◽  
pp. 140-150
Author(s):  
Jan Kubosek ◽  
Jana Vaskova
Keyword(s):  
Tensile Strength ◽  
Nonlinear Analysis ◽  
Unknown Input ◽  
Nonlinear Behaviour ◽  
Material Parameters ◽  
Model Code ◽  
Input Parameters ◽  
Loading Case ◽  
Compressive Strength Of Concrete

The aim of the paper is a nonlinear analysis of concrete structures. For these type of tasks is an important suitable choice of model input parameters and concrete. Especially if the analysis is preceding the results of an experiment, which can determine the exact properties of concrete. The following properties of concrete are needed for nonlinear analysis: tensile strength and compressive strength of concrete. There are more procedures how to determine some unknown input parameters. The paper presents some approaches to calculating and selecting parameters, which are based primarily on the recommendations of the Model Code and professional articles. Specifically, the numerical analysis performed in our developed program which allows observing a nonlinear behaviour of concrete at loading case.

scholarly journals Formulation of the membership function and determination of the input of fuzzy loads in the structural fuzzy analyzing problem

2007 ◽  
Vol 29 (2) ◽  
pp. 117-126
Author(s):  
Nguyen Van Pho
Keyword(s):  
Membership Function ◽  
Input Parameter ◽  
Design Standards ◽  
Input Parameters ◽  
Triangular Membership Function ◽  
Probabilistic Density Function ◽  
Fuzzy Parameters ◽  
Selection Of ◽  
The Membership Function

The fuzzy analyzing process consists of different steps. In this paper, the author considers only the method for formulation of the membership function of fuzzy loads acting on the structure. Based on the membership function of fuzzy loads, the combinations of deterministic of the regression analyzing process will be determined. The membership function of fuzzy loads is selected by the triangular membership function. It is in conformity with the concept on selection of loads in the design standards. The combination of inputs for the analyzing process will be determined, based on the number of present times of the value of input parameters (including the deterministic parameters, fuzzy parameters and the random ones) in the schema of analysis. The number of present times of input parameters is either proportional to value of the corresponding membership function or to the value of the probabilistic density function. A method for determining the appropriate combination of deterministic inputs so that each input parameter will present only one time in each combination is proposed. To illustrate the proposed method, an example on the determination of input combinations of tornado's velocity in Vietnam is presented.

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