During the last years, the Internet Application (Remote Flexible Control and Instrumentation, Telecontrol...) has retained the attention of Control researchers for modeling and studying the congestion control of TCP/IP (Transfer Control Protocol/Internet Protocol) networks. The controllers proposed in the literature such as RED (Random Early Detection) or PID (Proportional Integrate Derivative)...

The H∞ control problem for linear discrete-time descriptor systems which are of high index and possibly non-regular is considered. The goal is to compute a descriptor feedback such that the closed loop system is stable, causal, and H∞ norm bounded by a prescibed real number. In a recent solution of this problem, where causality is established by a preliminary feedback and where stability and H∞...

Let φ(z) = (φ1(z), · · · , φn(z)) be a holomorphic self-map of Bn and ψ(z) a holomorphic function on Bn, and H(Bn) the class of all holomorphic functions on Bn, where Bn is the unit ball of C , the weight composition operator Wψ,φ is defined by Wψ,φ = ψf(φ) for f ∈ H(Bn). In this paper we estimate the essential norm for the weighted composition operator Wψ,φ acting from the Hardy space H to H (...

We develop the convergence analysis for a numerical scheme proposed for approximating the solution of the elliptic problem L u = − ∂ ∂xi aij(x/ ) ∂ ∂xj u = f in Ω, u = 0 on ∂Ω, where the matrix a(y) = (aij(y)) is symmetric positive definite and periodic with period Y . The major goal is to develop a numerical scheme capturing the solution oscillations in the scale on a mesh size h > (or h >> )....

In this paper we study the rotational form of the pressure-correction method that was proposed in [19]. We show that the rotational form of the algorithm provides better accuracy in terms of the H-norm of the velocity and of the L-norm of the pressure than the standard form.

A fast algorithm for the computation of the optimally frequency-dependent scaled H 1-norm of a nite dimensional LTI system is presented. It is well known that this quantity is an upper bound to the \-norm"; furthermore, it was recently shown to play a special role in the context of slowly time-varying uncertainty. Numerical experimentation suggests that the algorithm generally converges quadrat...

This work gives an affirmative answer to a long time research problem. The weighted L projection is of optimal order in approximation measured in the weighted L norm, and stable in the weighted semi-H norm, independent of the jump of the constant weights, in 2D and 3D finite element spaces.

This paper presents an iterative two-step LMI method for improving the H 1 model error compared to Hankel norm reduction. The improvement of the Hankel norm reduced model is usually not signii-cant, typically a few percents only. For practical use the LMI reduction scheme is usually not worthwhile , but it can be interresting from the theoretical and principal point of view.

We define a new finite element method for a steady state elliptic problem with discontinuous diffusion coefficients where the meshes are not aligned with the interface. We prove optimal error estimates in the L norm and H weighted semi-norm independent of the contrast between the coefficients. Numerical experiments validating our theoretical findings are provided.

In this paper, norm estimates are obtained for the problem of minimal-norm tangential interpolation by vector-valued analytic functions in weighted H spaces, expressed in terms of the Carleson constants of related scalar measures. Applications are given to the notion of p-controllability properties of linear semigroup systems and controllability by functions in certain Sobolev spaces.