Search results for "Observability"

Phase diagram of dirty two-band superconductors and observability of impurity-induced $s+is$ state

2016

We investigate the phase diagram of dirty two-band superconductors. This paper primarily focuses on the properties and observability of the time-reversal symmetry-breaking $s+is$ superconducting states, which can be generated in two-band superconductors by interband impurity scattering. We show that such states can appear in two distinct ways. First, according to a previously discussed scenario, the $s+is$ state can form as an intermediate phase at the impurity-driven crossover between $s_{\pm}$ and $s_{++}$ states. We show that there is a second scenario where domains of the $s+is$ state exists in the form of an isolated dome inside the $s_{\pm}$ domain, completely detached from the transi…

Quarks in Few Hadron Systems

1994

We make use of QCD-based quark models to analyze the observability of quark effects in few hadron systems. A hadron is described by a two phase picture. The dynamics of the interior (perturbative) phase consists of a mechanism to confine the elementary degrees of freedom and an asymptotic QGD type interaction. The dynamics of the exterior (non perturbative) phase is approximated by an effective mesonic lagrangian.

Unitary Transfer of Entanglement in Multipartite Two-Level Systems

2005

The dynamics of a system composed by two pairs of dipolarly coupled two-level atoms is exactly studied. We show that the initial entanglement stored in a couple of atoms not directly interacting is fully transferred to the other pair in a periodic way. The observability of this phenomenon in laboratory is briefly discussed both in terms of its temporal scale and of its stability against uncertainties in the geometrical parameters defining the physical system.

Advanced Motion Control in Induction Motor Systems - Modelling, Analysis and Control

Using a unified notation, this thesis collects and discusses the most important steps and issues in the design of estimation and control algorithms for induction motors. It contains many estimation and control algorithms. Their stability is analyzed and their performance is illustrated by simulations and experiments on the same induction motor. An intense and challenging collective research effort is carefully documented and analyzed, with the aim of providing and clarifying the basic intuition and tools required in the analysis and design of nonlinear feedback control algorithms. This material should be of specific interest to engineers who are engaged in the design of control algorithms f…

Analysis of pattern recognition by man using detection experiments.

1981

This paper addresses the problem of analyzing biological pattern recognition systems. As no complete analysis is possible due to limited observability, the theoretical part of the paper examines some principles of construction for recognition systems. The relations between measurable and characteristic variables of these systems are described. The results of the study are: 1. Human recognition systems can always be described by a model consisting of an analyzer (FA) and a linear classifier. 2. The linearity of the classifier places no limits on the universal validity of the model. The principle of organization of such a system may be put into effect in many different ways. 3. The analyzer f…

D-Optimal Design for Parameter Estimation in Discrete-Time Nonlinear Dynamic Systems

2012

Published version of an article from the journal: Mathematical Problems in Engineering. Also available from the publisher:http://dx.doi.org/10.1155/2012/296701 An optimal input design method for parameter estimation in a discrete-time nonlinear system is presented in the paper to improve the observability and identification precision of model parameters. Determinant of the information matrix is used as the criterion function which is generally a nonconvex function about the input signals to be designed. To avoid the locally optimizing problem, a randomized designmethod is proposed bywhich a globally optimizing test plan other than input signals may be obtained. Then the randomized design ca…

On determining unknown functions in differential systems, with an application to biological reactors.

2003

In this paper, we consider general nonlinear systems with observations, containing a (single) unknown function φ . We study the possibility to learn about this unknown function via the observations: if it is possible to determine the [values of the] unknown function from any experiment [on the set of states visited during the experiment], and for any arbitrary input function, on any time interval, we say that the system is “identifiable”. For systems without controls, we give a more or less complete picture of what happens for this identifiability property. This picture is very similar to the picture of the “observation theory” in [7]: Contrarily to the case of the observability property, i…

Convergence Analysis of Extended Kalman Filter for Sensorless Control of Induction Motor

2015

This paper deals with convergence analysis of the extended Kalman filters (EKFs) for sensorless motion control systems with induction motor (IM). An EKF is tuned according to a six-order discrete-time model of the IM, affected by system and measurement noises, obtained by applying a first-order Euler discretization to a six-order continuous-time model. Some properties of the discrete-time model have been explored. Among these properties, the observability property is relevant, which leads to conditions that can be directly linked with the working conditions of the machine. Starting from these properties, the convergence of the stochastic state estimation process, in mean square sense, has b…