Results 11 to 20 of about 26,492,778 (291)

Uncertainty Analysis of Neutron Diffusion Eigenvalue Problem Based on Reduced-order Model

open access: yesYuanzineng kexue jishu, 2023
In order to improve the efficiency of core physical uncertainty analysis based on sampling statistics, the proper orthogonal decomposition (POD) and Galerkin projection method were combined to study the application feasibility of reduced-order model ...
In order to improve the efficiency of core physical uncertainty analysis based on sampling statistics, the proper orthogonal decomposition (POD) and Galerkin projection method were combined to study the application feasibility of reduced-order model based on POD-Galerkin method in core physical uncertainty analysis. The two-dimensional two group TWIGL benchmark question was taken as the research object, the key variation characteristics of the core flux distribution were extracted under the finite perturbation of the group constants of each material region, and the full-order neutron diffusion problem was projected on the variation characteristics to establish a reduced-order neutron diffusion model. The reduced-order model was used to replace the full-order model to carry out the uncertainty analysis of the group constants of the material region. The results show that the bias of the mathematical expectation of keff calculated by reduced-order and full-order models is close to 1 pcm. In addition, compared with the calculation time required for uncertainty analysis of full-order model, the analysis time of reduced-order model (including the calculation time of the full-order model required for the construction of reduced-order model) is only 11.48%, which greatly improves the efficiency of uncertainty analysis. The biases of mathematical expectation of keff calculated by reduced-order and full-order models based on Latin hypercube sampling and simple random sampling are less than 8 pcm, and under the same sample size, the bias from the Latin hypercube sampling result is smaller. From the TWIGL benchmark test results, under the same sample size, Latin hypercube sampling method is more recommended for POD-Galerkin reduced-order model.
doaj   +2 more sources

Reduced-order modelling for high-speed aerial weapon aerodynamics [PDF]

open access: yes, 2008
In this work a high-fidelity low-cost surrogate of a computational fluid dynamics analysis tool was developed. This computational tool is composed of general and physics- based approximation methods by which three dimensional high-speed aerodynamic ...
Mifsud, Michael
core   +7 more sources

An Artificial Compression Reduced Order Model [PDF]

open access: yesSIAM Journal on Numerical Analysis, 2020
We propose a novel artificial compression, reduced order model (AC-ROM) for the numerical simulation of viscous incompressible fluid flows. The new AC-ROM provides approximations not only for velocity, but also for pressure, which is needed to calculate forces on bodies in the flow and to connect the simulation parameters with pressure data. The new AC-
Victor P. DeCaria   +4 more
openaire   +3 more sources

Reduced-order modeling of hidden dynamics [PDF]

open access: yes2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2016
5 pages, 2 ...
Héas, Patrick, Herzet, Cédric
openaire   +4 more sources

Reduced-order modelling numerical homogenization [PDF]

open access: yesPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2014
A general framework to combine numerical homogenization and reduced-order modelling techniques for partial differential equations (PDEs) with multiple scales is described. Numerical homogenization methods are usually efficient to approximate the effective solution of PDEs with multiple scales.
Abdulle Assyr, Bai Yun
openaire   +3 more sources

Model reduction based on regional pole and covariance equivalentrealizations [PDF]

open access: yes, 1999
Copyright [1999] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services.
Wang, Z, Unbehauen, H
core   +4 more sources

Experimental Study of the Transient Behavior of a Wind Turbine Wake Following Yaw Actuation

open access: yesEnergies, 2023
Wind tunnel experiments were performed to investigate the response of a wind turbine model immersed in a replicated atmospheric boundary layer to dynamic changes in the yaw angle.
Derek Micheletto   +2 more
doaj   +1 more source

Convolutional Autoencoders for Reduced-Order Modeling

open access: yesCoRR, 2021
In the construction of reduced-order models for dynamical systems, linear projection methods, such as proper orthogonal decompositions, are commonly employed. However, for many dynamical systems, the lower dimensional representation of the state space can most accurately be described by a \textit{nonlinear} manifold.
Sreeram Venkat   +2 more
openaire   +2 more sources

IGBT Temperature Field Monitoring Based on Reduced-order Model

open access: yesCES Transactions on Electrical Machines and Systems, 2023
With the rapid development of the world economy, IGBT has been widely used in motor drive and electric energy conversion. In order to timely detect the fatigue damage of IGBT, it is necessary to monitor the junction temperature of IGBT.
Ziyu Zhou   +5 more
doaj   +1 more source

Laguerre-Gram reduced-order modeling [PDF]

open access: yesIEEE Transactions on Automatic Control, 2005
We present an efficient model reduction procedure based on the Laguerre description of the system to be approximated. Using a one-order operator defined in the Laplace domain we construct a pencil of functions and formulate the problem as the minimization of the L/sub /spl infin///sup 2/(/spl Ropf//sup +/) criterion. The use of a weight function in the
Ahmed Amghayrir   +4 more
openaire   +2 more sources

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