Time Resolved Flow Quantification with MRI Using Phase Methods: A Linear Systems Approach

1995 ◽  
Vol 33 (3) ◽  
pp. 337-354 ◽  
Author(s):  
Frank Peeters ◽  
Robert Luypaert ◽  
Henri Eisendrath ◽  
Michel Osteaux
Keyword(s):  
Linear Systems ◽  
Systems Approach ◽  
Flow Quantification ◽  
Time Resolved

Linear systems approach to describing and classifying Fano resonances

2013 ◽  
Vol 87 (12) ◽  
Author(s):  
I. Avrutsky ◽  
R. Gibson ◽  
J. Sears ◽  
G. Khitrova ◽  
H. M. Gibbs ◽  
...  
Keyword(s):  
Linear Systems ◽  
Systems Approach ◽  
Fano Resonances

Linear systems approach to simulation of optical diffraction

1998 ◽  
Vol 37 (34) ◽  
pp. 7933 ◽  
Author(s):  
Andrew J. Lambert ◽  
Donald Fraser
Keyword(s):  
Linear Systems ◽  
Systems Approach ◽  
Optical Diffraction

scholarly journals Stability Analysis of Networked Control Systems Using a Switched Linear Systems Approach

2011 ◽  
Vol 56 (9) ◽  
pp. 2101-2115 ◽  
Author(s):  
M. C. F. Donkers ◽  
W. P. M. H. Heemels ◽  
Nathan van de Wouw ◽  
Laurentiu Hetel
Keyword(s):  
Stability Analysis ◽  
Control Systems ◽  
Linear Systems ◽  
Systems Approach ◽  
Networked Control Systems ◽  
Networked Control ◽  
Switched Linear Systems

scholarly journals THE LINEAR SYSTEMS APPROACH TO LINEAR RATIONAL EXPECTATIONS MODELS

2017 ◽  
Vol 34 (3) ◽  
pp. 628-658 ◽  
Author(s):  
Majid M. Al-Sadoon
Keyword(s):  
Linear Systems ◽  
Representation Theorem ◽  
Existence And Uniqueness ◽  
Rational Expectations ◽  
Systems Approach ◽  
Point Of View

This paper considers linear rational expectations models from the linear systems point of view. Using a generalization of the Wiener-Hopf factorization, the linear systems approach is able to furnish very simple conditions for existence and uniqueness of both particular and generic linear rational expectations models. To illustrate the applicability of this approach, the paper characterizes the structure of stationary and cointegrated solutions, including a generalization of Granger’s representation theorem.

Linear systems approach to the analysis of an induced drug removal process. Phenobarbital removal by oral activated charcoal

1986 ◽  
Vol 14 (1) ◽  
pp. 19-28 ◽  
Author(s):  
William R. Gillespie ◽  
Peter Veng-Pedersen ◽  
Mary J. Berg ◽  
Dorothy D. Schottelius
Keyword(s):  
Linear Systems ◽  
Activated Charcoal ◽  
Systems Approach ◽  
Removal Process ◽  
Drug Removal

In vivo and in vitro validation of aortic flow quantification by time-resolved three-dimensional velocity-encoded MRI

2012 ◽  
Vol 28 (8) ◽  
pp. 1999-2008 ◽  
Author(s):  
Fabian Rengier ◽  
Michael Delles ◽  
Roland Unterhinninghofen ◽  
Sebastian Ley ◽  
Matthias Müller-Eschner ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Aortic Flow ◽  
Flow Quantification ◽  
Time Resolved

Estimating large-scale structures in wall turbulence using linear models

2018 ◽  
Vol 842 ◽  
pp. 146-162 ◽  
Author(s):  
Simon J. Illingworth ◽  
Jason P. Monty ◽  
Ivan Marusic
Keyword(s):  
Linear Model ◽  
Large Scale ◽  
Eddy Viscosity ◽  
Linear Models ◽  
Systems Approach ◽  
Wall Turbulence ◽  
Linear Estimator ◽  
Small Scale ◽  
Spanwise Direction ◽  
Time Resolved

A dynamical systems approach is used to devise a linear estimation tool for channel flow at a friction Reynolds number of $Re_{\unicode[STIX]{x1D70F}}=1000$. The estimator uses time-resolved velocity measurements at a single wall-normal location to estimate the velocity field at other wall-normal locations (the data coming from direct numerical simulations). The estimation tool builds on the work of McKeon & Sharma (J. Fluid Mech., vol. 658, 2010, pp. 336–382) by using a Navier–Stokes-based linear model and treating any nonlinear terms as unknown forcings to an otherwise linear system. In this way nonlinearities are not ignored, but instead treated as an unknown model input. It is shown that, while the linear estimator qualitatively reproduces large-scale flow features, it tends to overpredict the amplitude of velocity fluctuations – particularly for structures that are long in the streamwise direction and thin in the spanwise direction. An alternative linear model is therefore formed in which a simple eddy viscosity is used to model the influence of the small-scale turbulent fluctuations on the large scales of interest. This modification improves the estimator performance significantly. Importantly, as well as improving the performance of the estimator, the linear model with eddy viscosity is also able to predict with reasonable accuracy the range of wavenumber pairs and the range of wall-normal heights over which the estimator will perform well.

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