The Experts below are selected from a list of 2331 Experts worldwide ranked by ideXlab platform
Marcelo D. Fragoso - One of the best experts on this subject based on the ideXlab platform.
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CDC - Output-feedback robust control of continuous-time Infinite Markov jump linear systems
49th IEEE Conference on Decision and Control (CDC), 2010Co-Authors: Marcos G. Todorov, Marcelo D. FragosoAbstract:This paper addresses the robust H 2 guaranteed cost control of continuous-time Markov jump linear systems, in the dynamic output feedback scenario. It is assumed that the jump process takes values in a Countably Infinite Set. In the finite case, an adjoint approach to the robust control of MJLS in face of linear structured uncertainty is developed. A numerical example, regarding the robust control of the coupling between two damped oscillators, illustrates the applicability of the proposed results.
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CDC - On the state-feedback robust control of continuous-time Infinite Markov jump linear systems
49th IEEE Conference on Decision and Control (CDC), 2010Co-Authors: Marcos G. Todorov, Marcelo D. FragosoAbstract:This paper addresses the robust H 2 guaranteed cost control of continuous-time Markov jump linear systems with transition parameters taking values in a Countably Infinite Set. In the finite case, an adjoint approach to the robust control of MJLS in face of linear structured uncertainty is developed. Regarding the scenario of uncertain transition rates of the Markov process, the design of robust controllers is characterized by uncertainty-dependent linear matrix inequality problems. The main results are applied to the robust control of an underactuated robotic manipulator system.
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ECC - Robust stability and stabilization of discrete-time Infinite Markov jump linear systems
2009 European Control Conference (ECC), 2009Co-Authors: Marcos G. Todorov, Marcelo D. FragosoAbstract:This paper addresses the problems of robust stability and stabilization of discrete-time linear systems with Markov jump parameters taking values in a Countably Infinite Set. We consider the problem of robustness against complex multiperturbations, which extends the Setting currently encountered in the literature. By means of the introduction of block-diagonal scaling techniques, we show how less conservative robust stability margins and robust controllers can be obtained by the solution of linear matrix inequality problems. The effectiveness of the main results is illustrated with a numerical example.
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ECC - Robust stability and stabilization of continuous-time Infinite Markov jump linear systems
2009 European Control Conference (ECC), 2009Co-Authors: Marcos G. Todorov, Marcelo D. FragosoAbstract:This paper addresses the robust stability and stabilization problems for a class of continuous-time linear systems with Markov jump parameters taking values in a Countably Infinite Set. We consider the problem of robustness against various classes of parametric uncertainty, which extends previous results in the literature. By means of the introduction of novel scaling techniques, it is shown how less conservative robust stability margins and robust controllers can be obtained by the solution of linear matrix inequality problems. The effectiveness of the obtained results is illustrated with a numerical example.
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Optimal Control for Continuous-Time Linear Quadratic Problems with Infinite Markov Jump Parameters
SIAM Journal on Control and Optimization, 2001Co-Authors: Marcelo D. Fragoso, J. BaczynskiAbstract:The subject matter of this paper is the optimal control problem for continuous-time linear systems subject to Markovian jumps in the parameters and the usual Infinite-time horizon quadratic cost. What essentially distinguishes our problem from previous ones, inter alia, is that the Markov chain takes values on a Countably Infinite Set. To tackle our problem, we make use of powerful tools from semigroup theory in Banach space and a decomplexification technique. The solution for the problem relies, in part, on the study of a Countably Infinite Set of coupled algebraic Riccati equations (ICARE). Conditions for existence and uniqueness of a positive semidefinite solution of the ICARE are obtained via the extended concepts of stochastic stabilizability (SS) and stochastic detectability (SD). These concepts are couched into the theory of operators in Banach space and, parallel to the classical linear quadratic (LQ) case, bound up with the spectrum of a certain Infinite dimensional linear operator.
Dang H. Nguyen - One of the best experts on this subject based on the ideXlab platform.
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Recurrence and Ergodicity of Switching Diffusions with Past-Dependent Switching Having a Countable State Space
Potential Analysis, 2018Co-Authors: Dang H. NguyenAbstract:This work focuses on recurrence and ergodicity of switching diffusions consisting of continuous and discrete components, in which the discrete component takes values in a Countably Infinite Set and the rates of switching at current time depend on the value of the continuous component over an interval including certain past history. Sufficient conditions for recurrence and ergodicity are given. Moreover, the relationship between systems of partial differential equations and recurrence when the switching is past-independent is established under suitable conditions.
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Stability of Regime-Switching Diffusion Systems with Discrete States Belonging to a Countable Set
SIAM Journal on Control and Optimization, 2018Co-Authors: Dang H. Nguyen, George YinAbstract:This work focuses on the stability of regime-switching diffusions consisting of continuous and discrete components, in which the discrete component switches in a Countably Infinite Set and its swit...
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Recurrence for switching diffusion with past dependent switching and countable state space
Mathematical Control & Related Fields, 2018Co-Authors: Dang H. Nguyen, George YinAbstract:This work continues and substantially extends our recent work on switching diffusions with the switching processes that depend on the past states and that take values in a countable state space. That is, the discrete component of the two-component process takes values in a Countably Infinite Set and its switching rate at current time depends on the value of the continuous component involving past history. This paper focuses on recurrence, positive recurrence, and weak stabilization of such systems. In particular, the paper aims to providing more verifiable conditions on recurrence and positive recurrence and related issues. Assuming that the system is linearizable, it provides feasible conditions focusing on the coefficients of the systems for positive recurrence. Then linear feedback controls for weak stabilization are considered. Some illustrative examples are also given.
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Stability of Regime-Switching Diffusion Systems with Discrete States Belonging to a Countable Set
arXiv: Probability, 2017Co-Authors: Dang H. Nguyen, George YinAbstract:This work focuses on stability of regime-switching diffusions consisting of continuous and discrete components, in which the discrete component switches in a Countably Infinite Set and its switching rates at current time depend on the continuous component. In contrast to the existing approach, this work provides more practically viable approach with more feasible conditions for stability. A classical approach for asymptotic stabilityusing Lyapunov function techniques shows the Lyapunov function evaluated at the solution process goes to 0 as time $t\to \infty$. A distinctive feature of this paper is to obtain estimates of path-wise rates of convergence, which pinpoints how fast the aforementioned convergence to 0 taking place. Finally, some examples are given to illustrate our findings.
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CDC - Switching diffusion with past dependent switching and countable switching space: Existence and uniqueness of solutions, recurrence, and weak stabilization
2017 IEEE 56th Annual Conference on Decision and Control (CDC), 2017Co-Authors: Dang H. Nguyen, George YinAbstract:This work is an extension of our recent paper published in SIAM Journal on Control and Optimization. Starting with the Setup in [11], this paper focuses on positive recurrence and weak stabilization of regime-switching diffusion consisting of continuous and discrete components, in which the discrete component switches in a Countably Infinite Set and its switching rates at current time depend on the past value of the continuous component. After presenting the existence and uniqueness of solutions of switching diffusions, the paper departs from [11] and concentrates on recurrence and related issues. Assuming that the system is linearizable, this work provides more feasible conditions on the coefficients of the systems for positive recurrence. Then we obtain linear feedback controls for weak stabilization. Some illustrative examples are also given.
Baxter J. Erik - One of the best experts on this subject based on the ideXlab platform.
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Dyonic black holes in $\mathfrak{su}(\infty)$ anti-de Sitter Einstein-Yang-Mills theory, characterised by an Infinite Set of global charges
'IOP Publishing', 2019Co-Authors: Baxter J. ErikAbstract:We here investigate static, spherically symmetric solutions to $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory with a negative cosmological constant $\Lambda$ in the case of dyonic solutions, which possess a non-trivial electric sector of the gauge field. We are able to find non-trivial solutions to this system, and show that some may be uniquely characterised by a Countably Infinite Set of global charges, which may have implications for Bizon's modified `No Hair' theorem.Comment: 38 pages, 4 figure
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Stable furry black holes in $\mathfrak{su}(\infty)$ anti-de Sitter Einstein-Yang-Mills theory, characterised by an infinitude of global charges
2019Co-Authors: Baxter J. ErikAbstract:We present solutions to classical field equations for purely magnetic $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory in asymptotically Anti-de Sitter space. These solutions are found to be stable under linear, time-dependent perturbations. Recent work has also shown that these solutions may in general be uniquely characterized by a Countably Infinite Set of asymptotically measured, gauge-invariant charges. In light of this discovery, we revisit Bizon's `modified No-Hair conjecture', and suggest a new version that accommodates these solutions.Comment: 10 pages, 4 figure
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Globally regular solutions to dyonic anti-de Sitter $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory -- Existence and characterising charges
2019Co-Authors: Baxter J. ErikAbstract:In this work, we find new static, spherically symmetric, dyonic, globally regular exact solutions to $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory with a negative cosmological constant $\Lambda$, in the regime that $|\Lambda|$ is very large. In this regime, we also prove that dyonic globally regular solutions may be uniquely characterised by a Countably Infinite Set of effective global charges; and that dyon solutions may be distinguished from dyonic black hole solutions to the same field equations by their ADM masses. These solutions have potential modelling applications for certain exotic gravitational objects.Comment: 34 pages; 4 figure
J. Erik Baxter - One of the best experts on this subject based on the ideXlab platform.
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Dyonic black holes in $\mathfrak{su}(\infty)$ anti-de Sitter Einstein-Yang-Mills theory, characterised by an Infinite Set of global charges
Classical and Quantum Gravity, 2019Co-Authors: J. Erik BaxterAbstract:We here derive field equations for static, spherically symmetric, dyonic Einstein–Yang–Mills theory with a negative cosmological constant . We are able to find new non-trivial black hole solutions to this system in two regimes: where the gauge fields are small; and where . We also show that some may be uniquely characterised by a Countably Infinite Set of asymptotically-defined charges. This may have implications for Bizon's modified 'No Hair' conjecture.
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Stable furry black holes in $\mathfrak{su}(\infty)$ anti-de Sitter Einstein-Yang-Mills theory, characterised by an infinitude of global charges
arXiv: General Relativity and Quantum Cosmology, 2019Co-Authors: J. Erik BaxterAbstract:We present solutions to classical field equations for purely magnetic $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory in asymptotically Anti-de Sitter space. These solutions are found to be stable under linear, time-dependent perturbations. Recent work has also shown that these solutions may in general be uniquely characterized by a Countably Infinite Set of asymptotically measured, gauge-invariant charges. In light of this discovery, we revisit Bizon's `modified No-Hair conjecture', and suggest a new version that accommodates these solutions.
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Globally regular solutions to dyonic anti-de Sitter $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory -- Existence and characterising charges
arXiv: General Relativity and Quantum Cosmology, 2019Co-Authors: J. Erik BaxterAbstract:In this work, we find new static, spherically symmetric, dyonic, globally regular exact solutions to $\mathfrak{su}(\infty)$ Einstein-Yang-Mills theory with a negative cosmological constant $\Lambda$, in the regime that $|\Lambda|$ is very large. In this regime, we also prove that dyonic globally regular solutions may be uniquely characterised by a Countably Infinite Set of effective global charges; and that dyon solutions may be distinguished from dyonic black hole solutions to the same field equations by their ADM masses. These solutions have potential modelling applications for certain exotic gravitational objects.
O.l.v. Costa - One of the best experts on this subject based on the ideXlab platform.
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full informationh control for discrete time Infinite markov jump parameter systems
Journal of Mathematical Analysis and Applications, 1996Co-Authors: O.l.v. CostaAbstract:Abstract In this paper we consider the full information discrete-timeH∞-control problem for the class of linear systems with Markovian jumping parameters. The state-space of the Markov chain is assumed to take values in a Countably Infinite Set. Full information here means that the controller has access to both the state-variables and jump-variables. A necessary and sufficient condition for the existence of a feedback controller that makes the l 2-induced norm of the system less than a prespecified bound is obtained. This condition is written in terms of a Set of Infinite coupled algebraic Riccati equations.
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discrete time lq optimal control problems for Infinite markov jump parameter systems
IEEE Transactions on Automatic Control, 1995Co-Authors: O.l.v. Costa, Marcelo D. FragosoAbstract:Optimal control problems for discrete-time linear systems subject to Markovian jumps in the parameters are considered for the case in which the Markov chain takes values in a Countably Infinite Set. Two situations are considered: the noiseless case and the case in which an additive noise is appended to the model. The solution for these problems relies, in part, on the study of a Countably Infinite Set of coupled algebraic Riccati equations (ICARE). Conditions for existence and uniqueness of a positive semidefinite solution to the ICARE are obtained via the extended concepts of stochastic stabilizability (SS) and stochastic detectability (SD), which turn out to be equivalent to the spectral radius of certain Infinite dimensional linear operators in a Banach space being less than one. For the long-run average cost, SS and SD guarantee existence and uniqueness of a stationary measure and consequently existence of an optimal stationary control policy. Furthermore, an extension of a Lyapunov equation result is derived for the Countably Infinite Markov state-space case.
