Farkas' lemma of alternative
Fast and heteroclinic solutions for a second order ODE.
Favorable classes of mappings and multimappings in nonlinear analysis and optimization.
Feedback in state constrained optimal control
An optimal control problem is studied, in which the state is required to remain in a compact set . A control feedback law is constructed which, for given , produces -optimal trajectories that satisfy the state constraint universally with respect to all initial conditions in . The construction relies upon a constraint removal technique which utilizes geometric properties of inner approximations of and a related trajectory tracking result. The control feedback is shown to possess a robustness...
Feedback in state constrained optimal control
An optimal control problem is studied, in which the state is required to remain in a compact set S. A control feedback law is constructed which, for given ε > 0, produces ε-optimal trajectories that satisfy the state constraint universally with respect to all initial conditions in S. The construction relies upon a constraint removal technique which utilizes geometric properties of inner approximations of S and a related trajectory tracking result. The control feedback is shown to possess a robustness...
Fenomeni di concentrazione per energie di tipo Ginzburg-Landau
Si discute il comportamento asintotico di energie di tipo Ginzburg-Landau, per funzioni da in , e sotto l'ipotesi che l'esponente di crescita sia strettamente maggiore di . In particolare, si illustra un risultato di compattezza e di -convergenza, rispetto a una opportuna topologia sui Jacobiani, visti come correnti -dimensionali. L'energia limite è definita sulla classe degli -bordi interi , e la sua densità dipende localmente dalla molteplicità di tramite una famiglia di costanti di...
Fictitious domain/mixed finite element approach for a class of optimal shape design problems
Filippov Lemma for matrix fourth order differential inclusions
In the paper we give an analogue of the Filippov Lemma for the fourth order differential inclusions y = y”” - (A² + B²)y” + A²B²y ∈ F(t,y), (*) with the initial conditions y(0) = y’(0) = y”(0) = y”’(0) = 0, (**) where the matrices are commutative and the multifunction is Lipschitz continuous in y with a t-independent constant l < ||A||²||B||². Main theorem. Assume that y₀ ∈ W4,1
Finding common solutions of a variational inequality, a general system of variational inequalities, and a fixed-point problem via a hybrid extragradient method.
Finding global minima with a filled function approach for non-smooth global optimization.
Finite element analysis for unilateral problems with obstacles on the boundary
Finite element analysis of unilateral problems with obstacles on the boundary is given. Provided the exact solution is smooth enough, we obtain the rate of convergence for the case of one and two (lower and upper) obstacles on the boundary. At the end of this paper the proof of convergence without any regularity assumptions on the exact solution is given.
Finite element approximation of the volume-matching problem.
Finite element approximations of a glaciology problem
In this paper we study a model problem describing the movement of a glacier under Glen’s flow law and investigated by Colinge and Rappaz [Colinge and Rappaz, ESAIM: M2AN 33 (1999) 395–406]. We establish error estimates for finite element approximation using the results of Chow [Chow, SIAM J. Numer. Analysis 29 (1992) 769–780] and Liu and Barrett [Liu and Barrett, SIAM J. Numer. Analysis 33 (1996) 98–106] and give an analysis of the convergence of the successive approximations used in [Colinge and...
Finite element approximations of a glaciology problem
In this paper we study a model problem describing the movement of a glacier under Glen's flow law and investigated by Colinge and Rappaz [Colinge and Rappaz, ESAIM: M2AN33 (1999) 395–406]. We establish error estimates for finite element approximation using the results of Chow [Chow, SIAM J. Numer. Analysis29 (1992) 769–780] and Liu and Barrett [Liu and Barrett, SIAM J. Numer. Analysis33 (1996) 98–106] and give an analysis of the convergence of the successive approximations used in [Colinge and...
Finite element estimates for a class of nonlinear variational inequalities.
Finite Element Solution of Nonlinear Elliptic Problems.
Finite-difference approximation of energies in fracture mechanics
Finite-differences discretizations of the Mumford-Shah functional
Finite-differences discretizations of the mumford-shah functional
About two years ago, Gobbino [21] gave a proof of a De Giorgi's conjecture on the approximation of the Mumford-Shah energy by means of finite-differences based non-local functionals. In this work, we introduce a discretized version of De Giorgi's approximation, that may be seen as a generalization of Blake and Zisserman's “weak membrane” energy (first introduced in the image segmentation framework). A simple adaptation of Gobbino's results allows us to compute the Γ-limit of this discrete functional...
Finite-step relaxed hybrid steepest-descent methods for variational inequalities.