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On Carleman estimates for elliptic and parabolic operators. Applications to unique continuation and control of parabolic equations∗∗∗

Jérôme Le Rousseau, Gilles Lebeau (2012)

ESAIM: Control, Optimisation and Calculus of Variations

Local and global Carleman estimates play a central role in the study of some partial differential equations regarding questions such as unique continuation and controllability. We survey and prove such estimates in the case of elliptic and parabolic operators by means of semi-classical microlocal techniques. Optimality results for these estimates and some of their consequences are presented. We point out the connexion of these optimality results to the local phase-space geometry after conjugation...

On characterization of the solution set in case of generalized semiflow

Zdeněk Beran (2009)

Kybernetika

In the paper, a possible characterization of a chaotic behavior for the generalized semiflows in finite time is presented. As a main result, it is proven that under specific conditions there is at least one trajectory of generalized semiflow, which lies inside an arbitrary covering of the solution set. The trajectory mutually connects each subset of the covering. A connection with symbolic dynamical systems is mentioned and a possible numerical method of analysis of dynamical behavior is outlined....

On classification with missing data using rough-neuro-fuzzy systems

Robert K. Nowicki (2010)

International Journal of Applied Mathematics and Computer Science

The paper presents a new approach to fuzzy classification in the case of missing data. Rough-fuzzy sets are incorporated into logical type neuro-fuzzy structures and a rough-neuro-fuzzy classifier is derived. Theorems which allow determining the structure of the rough-neuro-fuzzy classifier are given. Several experiments illustrating the performance of the roughneuro-fuzzy classifier working in the case of missing features are described.

On constrained controllability of dynamical systems with multiple delays in control

Beata Sikora (2005)

Applicationes Mathematicae

Linear, continuous dynamical systems with multiple delays in control are studied. Their relative and absolute controllability with constrained control is discussed. Definitions of various types of constrained relative and absolute controllability for linear systems with delays in control are introduced. Criteria of relative and absolute controllability with constrained control are established. Constraints on control values are considered. Mutual implications between constrained relative controllability...

On control problems of minimum time for Lagrangian systems similar to a swing. I. Convexity criteria for sets

Aldo Bressan, Monica Motta (1994)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

One establishes some convexity criteria for sets in R 2 . They will be applied in a further Note to treat the existence of solutions to minimum time problems for certain Lagrangian systems referred to two coordinates, one of which is used as a control. These problems regard the swing or the ski.

On control problems of minimum time for Lagrangian systems similar to a swing. II Application of convexity criteria to certain minimum time problems

Aldo Bressan, Monica Motta (1994)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

This Note is the Part II of a previous Note with the same title. One refers to holonomic systems Σ = A ⁢ ⋃ U with two degrees of freedom, where the part A can schemetize a swing or a pair of skis and U schemetizes whom uses A . The behaviour of U is characterized by a coordinate used as a control. Frictions and air resistance are neglected. One considers on Σ minimum time problems and one is interested in the existence of solutions. To this aim one determines a certain structural condition Γ which implies...

On control theory and its applications to certain problems for Lagrangian systems. On hyperimpulsive motions for these. II. Some purely mathematical considerations for hyper-impulsive motions. Applications to Lagrangian systems

Aldo Bressan (1988)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

See Summary in Note I. First, on the basis of some results in [2] or [5]-such as Lemmas 8.1 and 10.1-the general (mathematical) theorems on controllizability proved in Note I are quickly applied to (mechanic) Lagrangian systems. Second, in case Σ , χ and M satisfy conditions (11.7) when 𝒬 is a polynomial in γ ˙ , conditions (C)-i.e. (11.8) and (11.7) with 𝒬 ≡ 0 -are proved to be necessary for treating satisfactorily Σ 's hyper-impulsive motions (in which positions can suffer first order discontinuities)....

On control theory and its applications to certain problems for Lagrangian systems. On hyper-impulsive motions for these. III. Strengthening of the characterizations performed in parts I and II, for Lagrangian systems. An invariance property.

Aldo Bressan (1988)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

In [1] I and II various equivalence theorems are proved; e.g. an ODE ( ℰ ) ⁢ z ˙ = F ⁢ ( t , z , u , u ˙ ) ( ∈ ℝ m ) with a scalar control u = u ⁢ ( ⋅ ) is linear w.r.t. u ˙ iff ( α ) its solution z ⁢ ( u , ⋅ ) with given initial conditions (chosen arbitrarily) is continuous w.r.t. u in a certain sense, or iff ( β ) z ⁢

On delay-dependent robust stability under model transformation of some neutral systems

Salvador A. Rodríguez, Luc Dugard, Jean-Michel Dion, Jesús de León (2009)

Kybernetika

This paper focuses on the delay-dependent robust stability of linear neutral delay systems. The systems under consideration are described by functional differential equations, with norm bounded time varying nonlinear uncertainties in the "state" and norm bounded time varying quasi-linear uncertainties in the delayed "state" and in the difference operator. The stability analysis is performed via the Lyapunov-Krasovskii functional approach. Sufficient delay dependent conditions for robust stability...

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

Éric Busvelle, Jean-Paul Gauthier (2003)

ESAIM: Control, Optimisation and Calculus of Variations

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...

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

Éric Busvelle, Jean-Paul Gauthier (2010)

ESAIM: Control, Optimisation and Calculus of Variations

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...

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