A design of a strongly stable generalized predictive control using coprime factorization approach

This paper proposes a new generalized predictive control (GPC) having new design parameters. In selecting the design parameters, the controller becomes a strongly stable GPC, that is, not only the closed-loop system is stable, but also the controller itself is stable. The parameters are introduced by applying the coprime factorization approach and comparing Youla parametrization of stabilizing compensators to the controller by the standard GPC</p

Numerical simulations studies of the convective instability onset in a supercritical fluid

Numerical simulation studies in 2D with the addition of noise are reported for the convection of a supercritical fluid,3He, in a Rayleigh-Be'nard cell where the fluid parameters and cell height L are the same as in published laboratory experiments. The noise addition is to accelerate the instability onset after starting the heat flow across the fluid, so as to bring simulations into better agreement with experimental observations. Homogeneous temperature noise and spatial lateral periodic temperature variations in the top plate were programmed into the simulations. A speed-up in the instability onset was obtained, which was most effective through the spatial temperature variations with a period of 2L, close to the wavelength of a pair of convections rolls. For a small amplitude of 0.5 microK, this perturbation gave a semiquantitative agreement with experimental observations. Results for various noise amplitudes are presented and discussed in relation to predictions by El Khouri and Carle`s.Comment: 6 pages (2-column format) 4 figures, Proceedings of NASA2004 workshop, Solvang,C

Weyl law for open systems with sharply divided mixed phase space

A generalization of the Weyl law to systems with a sharply divided mixed phase space is proposed. The ansatz is composed of the usual Weyl term which counts the number of states in regular islands and a term associated with sticky regions in phase space. For a piecewise linear map, we numerically check the validity of our hypothesis, and find good agreement not only for the case with a sharply divided phase space, but also for the case where tiny island chains surround the main regular island. For the latter case, a non-trivial power law exponent appears in the survival probability of classical escaping orbits, which may provide a clue to develop the Weyl law for more generic mixed systems.Comment: 8 pages, 14 figure

A Fundamental Limit of Measurement Imposed by the Elementary Interactions

Quantum information theory is closely related to quantum measurement theory because one must perform measurement to obtain information on a quantum system. Among many possible limits of quantum measurement, the simplest ones were derived directly from the uncertainty principles. However, such simple limits are not the only limits. I here suggest a new limit which comes from the forms and the strengths of the elementary interactions. Namely, there are only four types of elementary interactions in nature; their forms are determined by the gauge invariance (and symmetry breaking), and their coupling constants (in the low-energy regime) have definite values. I point out that this leads to a new fundamental limit of quantum measurements. Furthermore, this fundamental limit imposes the fundamental limits of getting information on, preparing, and controlling quantum systems.Comment: 10 pages including 1 figure. Proc. 3rd Tohwa Univ. Int. Conf. Statistical Physics (Fukuoka, Japan, 1999) to be published from AI

Approaches to QCD phase diagram; effective models, strong-coupling lattice QCD, and compact stars

The outline of the two lectures given in "Dense Matter School 2015" is presented. After an overview on the relevance of the phase diagram to heavy-ion collisions and compact star phenomena, I show some basic formulae to discuss the QCD phase diagram in the mean field treatment of the Nambu-Jona-Lasinio model. Next, I introduce the strong-coupling lattice QCD, which is one of the promising methods to access the QCD phase diagram including the first order phase boundary. In the last part, I discuss the QCD phase diagram in asymmetric matter, which should be formed in compact star phenomena.Comment: Lecture given at Helmholtz International Summer School "Dense Matter 2015", 29 June-11 July 2015 and the 15th International Conference on Strageness in Quark Matter (SQM 2015), 6-11 July 2015, Dubna, Russia. 12 pages, 10 figures. Some typos are corrected in v