691 research outputs found
Congruences of models of elliptic curves
Let O_K be a discrete valuation ring with field of fractions K and perfect
residue field. Let E be an elliptic curve over K, let L/K be a finite Galois
extension and let O_L be the integral closure of O_K in L. Denote by X' the
minimal regular model of E_L over O_L. We show that the special fibers of the
minimal Weierstrass model and the minimal regular model of E over O_K are
determined by the infinitesimal fiber X'_m together with the action of
Gal(L/K), when m is big enough (depending on the minimal discriminant of E and
the different of L/K).Comment: Minor changes.To appear in J. London Math. So
Data-Driven Robust Control of Unknown MIMO Nonlinear System Subject to Input Saturations and Disturbances
This paper presented a new data-driven robust control scheme for unknown nonlinear systems in the presence of input saturation and external disturbances. According to the input and output data of the nonlinear system, a recurrent neural network (RNN) data-driven model is established to reconstruct the dynamics of the nonlinear system. An adaptive output-feedback controller is developed to approximate the unknown disturbances and a novel input saturation compensation method is used to attenuate the effect of the input saturation. Under the proposed adaptive control scheme, the uniformly ultimately bounded convergence of all the signals of the closed-loop nonlinear system is guaranteed via Lyapunov analysis. The simulation results are given to show the effectiveness of the proposed data-driven robust controller
Uncertainty analysis of environmental loads response for fixed offshore platform in climate change condition
Peer Reviewe
CRYSTAL STRUCTURES AND FERROELECTRIC BEHAVIOUR OF EPITAXIAL BISMUTH FERRITE THIN FILMS.
Ph.DDOCTOR OF PHILOSOPH
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