Existence of geodesics for the Lorentz metric of a stationary gravitational field
Existence of minimal energy configurations of nematic liquid crystals with variable degree of orientation.
Existence of minimizers for some non convex one-dimensional integrals.
Existence of minimizers of free autonomous variational problems via solvability of constrained ones
Existence of solutions of minimization problems with an increasing cost function and porosity.
Existence of solutions to weak nonlinear bilevel problems via MinSup and d.c. problems
In this paper, which is an extension of [4], we first show the existence of solutions to a class of Min Sup problems with linked constraints, which satisfy a certain property. Then, we apply our result to a class of weak nonlinear bilevel problems. Furthermore, for such a class of bilevel problems, we give a relationship with appropriate d.c. problems concerning the existence of solutions.
Existence theorems for moving boundary optimization problems
Explicit Construction of Piecewise Affine Mappings with Constraints
We construct explicitly piecewise affine mappings u:ℝ ⁿ → ℝ ⁿ with affine boundary data satisfying the constraint div u = 0. As an application of the construction we give short and direct proofs of the main approximation lemmas with constraints in convex integration theory. Our approach provides direct proofs avoiding approximation by smooth mappings and works in all dimensions n ≥ 2. After a slight modification of our construction, the constraint div u = 0 can be turned into det Du = 1, giving...
Explicit formulae of distributions and densities of characteristics of a dynamic advertising and pricing model
We analyze the optimal sales process of a stochastic advertising and pricing model with constant demand elasticities. We derive explicit formulae of the densities of the (optimal) sales times and (optimal) prices when a fixed finite number of units of a product are to be sold during a finite sales period or an infinite one. Furthermore, for any time t the exact distribution of the inventory, i.e. the number of unsold items, at t is determined and will be expressed in terms of elementary functions....
Exponential stability of Timoshenko beam system with delay terms in boundary feedbacks*
In this paper, the stability of a Timoshenko beam with time delays in the boundary input is studied. The system is fixed at the left end, and at the other end there are feedback controllers, in which time delays exist. We prove that this closed loop system is well-posed. By the complete spectral analysis, we show that there is a sequence of eigenvectors and generalized eigenvectors of the system operator that forms a Riesz basis for the state Hilbert space. Hence the system satisfies the spectrum...
Exponential stability of Timoshenko beam system with delay terms in boundary feedbacks*
In this paper, the stability of a Timoshenko beam with time delays in the boundary input is studied. The system is fixed at the left end, and at the other end there are feedback controllers, in which time delays exist. We prove that this closed loop system is well-posed. By the complete spectral analysis, we show that there is a sequence of eigenvectors and generalized eigenvectors of the system operator that forms a Riesz basis for the state Hilbert space. Hence the system satisfies the spectrum...
Extended well-posedness for quasivariational inequalities.
Extrema constrained by curves.
Extrema with constraints on points and/or velocities.
Feedback Nash equilibria in optimal taxation problems
A well-known result in public economics is that capital income should not be taxed in the long run. This result has been derived using necessary optimality conditions for an appropriate dynamic Stackelberg game. In this paper we consider three models of dynamic taxation in continuous time and suggest a method for calculating their feedback Nash equilibria based on a sufficient condition for optimality. We show that the optimal tax on capital income is generally different from zero.
Finite-dimensionality of information states in optimal control of stochastic systems: a Lie algebraic approach
In this paper we introduce the sufficient statistic algebra which is responsible for propagating the sufficient statistic, or information state, in the optimal control of stochastic systems. Certain Lie algebraic methods widely used in nonlinear control theory, are then employed to derive finite- dimensional controllers. The sufficient statistic algebra enables us to determine a priori whether there exist finite-dimensional controllers; it also enables us to classify all finite-dimensional controllers....
First and Second Order Necessary Optimality Conditions for Discrete Optimal Control Problems
First integrals for problems of calculus of variations on locally convex spaces.
First Integrals in the Discrete Variational Calculus
First variation of the general curvature-dependent surface energy
We consider general surface energies, which are weighted integrals over a closed surface with a weight function depending on the position, the unit normal and the mean curvature of the surface. Energies of this form have applications in many areas, such as materials science, biology and image processing. Often one is interested in finding a surface that minimizes such an energy, which entails finding its first variation with respect to perturbations of the surface. We present a concise derivation...