scholarly journals Determination of a Hysteresis Model Parameters with the Use of Different Evolutionary Methods for an Innovative Hysteresis Model

Mathematics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 201 ◽  
Author(s):  
Marko Jesenik ◽  
Marjan Mernik ◽  
Mladen Trlep
Keyword(s):  
Mathematical Expression ◽  
Optimization Method ◽  
Precise Determination ◽  
Model Material ◽  
Model Parameters ◽  
Magnetization Process ◽  
Hysteresis Model ◽  
Bee Colony ◽  
Two Parameters

For precise modeling of electromagnetic devices, we have to model material hysteresis. A Genetic Algorithm, Differential Evolution with three different strategies, teaching–learning-based optimization and Artificial Bee Colony, were used for testing seven different modified mathematical expressions, and the best combination of mathematical expression and solving method was used for hysteresis modeling. The parameters of the hysteresis model were determined based on the measured major hysteresis loop and first-order reversal curves. The model offers a simple determination of the magnetization procedure in the areas between measured curves, with the only correction of two parameters based on only two known points in the magnetization process. It was tested on two very different magnetic materials, and results show good agreement between the measured and calculated curves. The calculated curves between the measured curves have correct shapes. The main difference between our model and other models is that, in our model, each measured curve, major and reversal, is described with different parameters. The magnetization process between measured curves is described according to the nearest measured curve, and this ensures the best fit for each measured curve. In other models, there is mainly only one curve, a major hysteresis or magnetization curve, used for the determination of the parameters, and all other curves are then dependent on this curve. Results confirm that the evolutionary optimization method offers a reliable procedure for precise determination of the parameters.

Nauwkeurige methode voor de aanwasbepaling van het grondvlak met behulp van de Pressler-boor

1968 ◽  
Vol 12 ◽  
Author(s):  
R. Goossens
Keyword(s):  
Basal Area ◽  
Precise Determination ◽  
Maximum Diameter ◽  
Precise Method ◽  
Maximum Radius ◽  
The Core ◽  
Two Parameters

A precise method for the determination of the increment of the  basal area using the PressIer bore. Refering to  previous research showing that the basal area of the corsica pine could be  characterized by an ellips, we present in this paper a precise method for the  determination of the increment of the basal area. In this method we determine  the direction of the maximum diameter, we measure this diameter and we take a  core in one of the points of tangency of the caliper with the measured tree.  The determination of the diameter perpendicular to the maximum diameter  finishes the work wich is to be done in the forest. From the classical  measurements effectuated on the core and from the measured diameters we can  then determine the form (V) and the excentricity (e). Substituting these two  parameters in the formula 2 or 2', we can also calculate the error of a  radius measured on the core with respect to the representative radius, This  error with them allow us to correct the measured value of the minimum or the  maximum radius and we will be able to do a precise determination of the  increment.

scholarly journals The seven sisters DANCe

2018 ◽  
Vol 612 ◽  
pp. A70 ◽  
Author(s):  
J. Olivares ◽  
E. Moraux ◽  
L. M. Sarro ◽  
H. Bouy ◽  
A. Berihuete ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Model Comparison ◽  
Precise Determination ◽  
Model Parameters ◽  
Data Sets ◽  
Adequate Model ◽  
Comparison Results ◽  
Bayesian Evidence ◽  
Mass Segregation

Context. Membership analyses of the DANCe and Tycho + DANCe data sets provide the largest and least contaminated sample of Pleiades candidate members to date. Aims. We aim at reassessing the different proposals for the number surface density of the Pleiades in the light of the new and most complete list of candidate members, and inferring the parameters of the most adequate model. Methods. We compute the Bayesian evidence and Bayes Factors for variations of the classical radial models. These include elliptical symmetry, and luminosity segregation. As a by-product of the model comparison, we obtain posterior distributions for each set of model parameters. Results. We find that the model comparison results depend on the spatial extent of the region used for the analysis. For a circle of 11.5 parsecs around the cluster centre (the most homogeneous and complete region), we find no compelling reason to abandon King’s model, although the Generalised King model introduced here has slightly better fitting properties. Furthermore, we find strong evidence against radially symmetric models when compared to the elliptic extensions. Finally, we find that including mass segregation in the form of luminosity segregation in the J band is strongly supported in all our models. Conclusions. We have put the question of the projected spatial distribution of the Pleiades cluster on a solid probabilistic framework, and inferred its properties using the most exhaustive and least contaminated list of Pleiades candidate members available to date. Our results suggest however that this sample may still lack about 20% of the expected number of cluster members. Therefore, this study should be revised when the completeness and homogeneity of the data can be extended beyond the 11.5 parsecs limit. Such a study will allow for more precise determination of the Pleiades spatial distribution, its tidal radius, ellipticity, number of objects and total mass.

scholarly journals Restriction in the determination of the Jiles-Atherton hysteresis model parameters

2017 ◽  
Vol 442 ◽  
pp. 8-14 ◽  
Author(s):  
J.B. Padilha ◽  
P. Kuo-Peng ◽  
N. Sadowski ◽  
J.V. Leite ◽  
N.J. Batistela
Keyword(s):  
Model Parameters ◽  
Hysteresis Model

scholarly journals CKM PARAMETERS AND RARE B DECAYS

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1683-1696 ◽  
Author(s):  
FRANCESCO FORTI
Keyword(s):  
B Meson ◽  
New Physics ◽  
Precise Determination ◽  
Model Parameters ◽  
B Decays ◽  
Unitarity Triangle ◽  
Indirect Determination ◽  
Radiative Transitions ◽  
First Time

Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the loop diagrams. In this paper the recent measurements performed in this area by BABAR and Belle will be presented. The direct measurement of the angle α is for the first time as precise as the indirect determination. The precision of the |Vub| determination has improved significantly with respect to previous measurement. New limits on B → τν decays are presented, as well as updated measurements on b → s radiative transitions and a new observation of b → dγ transition made by Belle.

scholarly journals Multi-Step Magnetization Process of Gd-Co/Co/Cu/Co Thermo-Sensitive Spin Valves

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 351 ◽  
Author(s):  
Andrei Svalov ◽  
Iñaki Orue ◽  
Galina Kurlyandskaya
Keyword(s):  
Hysteresis Loop ◽  
Magnetic Structure ◽  
Functional Properties ◽  
Critical Field ◽  
Spin Valve ◽  
Precise Determination ◽  
Magnetization Process ◽  
Magnetic Type ◽  
Characteristic Values

Magnetic and magnetoresistive properties of the Gd-Co/Co/Cu/Co magnetic type multilayered sensitive spin valve were studied as a function of temperature. It is shown that the appearance of a non-collinear magnetic structure significantly affects the shape of the magnetoresistive hysteresis loop. The characteristic values of the critical field related to the appearance of non-collinear structure depend on the temperature of the spin valve. The obtained results can serve as a basis for the improvements of functional properties and expanding the application areas of magnetic multilayered sensitive elements of the spin valve type; for example, for precise determination of the position of the object.

Optimal Placement of Viscoelastic Dampers Represented by the Classical and Fractional Rheological Models

2013 ◽  
pp. 50-84
Author(s):  
Roman Lewandowski ◽  
Zdzislaw Pawlak
Keyword(s):  
Mathematical Formulation ◽  
Optimization Method ◽  
Sequential Optimization ◽  
Optimal Placement ◽  
Model Parameters ◽  
Swarm Optimization ◽  
Rheological Models ◽  
Viscoelastic Dampers ◽  
Optimal Values

The problems of the optimal location of viscoelastic (VE) dampers and determination of the optimal values of parameters of dampers are considered in this chapter. The optimal distributions of dampers in buildings are found for various objective functions. The optimization problem is solved using the sequential optimization method and the particle swarm optimization method. The properties of VE dampers are described using the rheological models with fractional derivatives. These models have an ability to correctly describe the behaviour of VE dampers using a small number of model parameters. Moreover, generalized classical rheological models of VE dampers are also taken into account. A mathematical formulation of the problem of dynamics of structures with VE dampers, modelled by the classical and fractional rheological models is presented. The results obtained from numerical calculation are also discussed in detail.

Hysteretic Mapping of Structural Wood Systems

1997 ◽  
Author(s):  
G. C. Foliente ◽  
F. Ma
Keyword(s):  
Realistic Model ◽  
Model Parameters ◽  
Structural Systems ◽  
Hysteresis Model ◽  
Cyclic Tests ◽  
Wood Structures ◽  
Principal Source ◽  
Identification Techniques ◽  
Stochastic Loads

Abstract Any realistic model of structural wood systems must account for the equivalent hysteresis, which is the principal source of internal energy dissipation. Thus, determination of model parameters for hysteresis should be a first step in dynamic analysis. This paper presents a plan to use system identification techniques to estimate hysteresis model parameters for wood joints and structural systems from the extensive base of experimental data on cyclic tests that have been collected over the years around the world. A smoothly varying hysteresis loop, which represents an extension of the Bouc-Wen model, can be generated to bring about pinching as well as stiffness and strength degradation. The identified models will be used to study the dynamic response of single and multi-degree-of-freedom wood structures subjected to both deterministic and stochastic loads.

Sign in / Sign up

Export Citation Format

Share Document