Browsing Τμήμα Μαθηματικών και Στατιστικής / Department of Mathematics and Statistics by Subject "Eigenvalues and eigenfunctions"
Now showing items 1-8 of 8
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Article
Adaptive control of a class of slowly time varying systems with modeling uncertainties
(2005)In a recent work, a new linear adaptive controller based on certainty-equivalence and backstepping design, which promises a level of transient and asymptotic performance comparable to that of the tuning functions adaptive ...
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Article
Adaptive LQ control with anti-windup augmentation to optimize UAV performance in autonomous soaring applications
(2008)The performance of a glider can be considerably improved by means of soaring and optimization of its trajectory. Recent advances in the area of static soaring assume known linear glider dynamics and no actuator saturation ...
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Article
Comparison of spectral and finite element methods applied to the study of the core-annular flow in an undulating tube
(2002)A Galerkin/finite element and a pseudo-spectral method, in conjunction with the primitive (velocity-pressure) and streamfunction-vorticity formulations, are tested for solving the two-phase flow in a tube, which has a ...
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Article
Differential invariants for quasi-linear and semi-linear wave-type equations
(2008)In this paper, we consider the class of wave-type equations utt = f (x, t, u) uxx + g (x, t, u, ux, ut) and two special cases of it. We derive the equivalence transformations for these equations and using these transformations, ...
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Conference Object
Eigenvalue estimates on bakry–Émery manifolds
(Springer Verlag, 2015)We demonstrate lower bounds for the eigenvalues of compact Bakry– Émery manifolds with and without boundary. The lower bounds for the first eigenvalue rely on a generalized maximum principle which allows gradient estimates ...
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Article
Parameter convergence of a new class of adaptive controllers
(1996)A new class of adaptive control schemes for minimum-phase linear time invariant (LTI) systems has recently been developed using nonlinear design techniques which guarantee improved transient performance in addition to ...
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Conference Object
A robust adaptive control design for gliders subject to actuator saturation nonlinearities
(2007)Range, endurance and cross-country speed of a glider can be considerably improved by efficient soaring methods. Recent static soaring research assumes known linear glider dynamics which do not change with flight conditions, ...
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Article
Start-up and cessation Newtonian Poiseuille and Couette flows with dynamic wall slip
(2015)Analytical solutions are derived for the start-up and cessation Newtonian Poiseuille and Couette flows with wall slip obeying a dynamic slip model. This slip equation allows for a relaxation time in the development of wall ...