This work deals with the analysis of a decision-directed echo canceller working in a baseband d a t a communication link. This guided scheme, as known in self-adaptive equalization systems, introduces stable local minima in the error s u... more
The paper introduces a general class of neural networks where the neuron activations are modeled by discontinuous functions. The neural networks have an additive interconnecting structure and they include as particular cases the Hopfield... more
This paper presents a reinforcement learning algorithm and provides conditions for global convergence to Nash equilibria. For several reinforcement learning schemes, including the ones proposed here, excluding convergence to action... more
A globally convergent method for solving nonlinear equations without the differentiability condition
We give a general iterative method which computes the maximal real root Zm= of a one variable Lipschitzian function in a given interval. The method generates a monotonically decreasing sequence which converges towards Zm~x or demonstrates... more
In this paper, we use the resolvent operator and auxiliary principle techniques to suggest and analyze several iterative algorithms for solving mixed quasi variational inequalities and related problems. We study the convergence criteria... more
In this paper, an iterative algorithm to solve Algebraic Riccati Equations (ARE) arising from, for example, a standard H ∞ control problem is proposed. By constructing two sequences of positive semidefinite matrices, we reduce an ARE with... more
In this paper, an iterative algorithm to solve Algebraic Riccati Equations (ARE) arising from, for example, a standard H ∞ control problem is proposed. By constructing two sequences of positive semidefinite matrices, we reduce an ARE with... more
An iterative algorithm to solve Algebraic Riccati Equations with an indefinite quadratic term is proposed. The global convergence and local quadratic rate of convergence of the algorithm are guaranteed and a proof is given. Numerical... more
We present an algorithm for large-scale equality constrained optimization. The method is based on a characterization of inexact sequential quadratic pro- gramming (SQP) steps that can ensure global convergence of the algorithm it- erates.... more
We propose a globalization strategy for nonlinear constrained optimization. The method employs a "flexible" penalty function to promote convergence, where during each iteration the penalty parameter can be chosen as any number within a... more
This paper introduces an orthonormal version of the sliding-window Projection Approximation Subspace Tracker (PAST). The new algorithm guarantees the orthonormality of the signal subspace basis at each iteration. Moreover, it has the same... more
involves interactions between multiple human operators, procedures and technical systems, all of which are highly distributed. This yields that providing safety is more than making sure that each of the ATM elements functions properly... more
In the modern digital economy, optimal decision support systems, as well as machine learning systems, are becoming an integral part of production processes. Artificial neural network training as well as other engineering problems generate... more
Pattern search methods are a class of direct search methods for nonlinear optimization. Since the introduction of the original pattern search methods in the late 1950s and early 1960s, they have remained popular with users due to their... more
We discuss direct search methods for unconstrained optimization. We give a modern perspective on this classical family of derivative-free algorithms, focusing on the development of direct search methods during their golden age from 1960... more
In this paper we propose a model and numerical scheme for quantifying the motion of the phase transition front and the temperature fields in layered materials using boundary conditions of the third ...
Book of abstracts
The paper presents numerical verification and experimental results for the setpoint control of the nonholonomic mobile robot. The task is to move to the goal and reach it with desired orientation avoiding collisions with static obstacles.... more
This paper reviews the design challenges that current and future processors must face, with stringent power limits and high frequency targets, and the design methods required to overcome the above challenges and address the continuing... more
This article examines the development of the length of copyright protection in Russia. The copyright term has been subject to a number of extensions, the most significant of which took place in the post-Soviet period. This has led to the... more
The problem of constructing globally convergent, reduced-order observers for general nonlinear systems is addressed. It is shown that an asymptotic estimate of the unknown states can be obtained by rendering attractive an appropriately... more
We propose a new technique for minimization of convex functions not necessarily smooth. Our approach employs an equivalent constrained optimization problem and approximated linear programs obtained with cutting planes. At each iteration a... more
Center Discussion Papers are preliminary materials circulatErl to stinw.ate discussion and critical cament. References in plblications to Discussion Papers should be cleared with the author to protect the tentative character of these... more
The conventional concepts of invariance are extended in this article to include impulsive control systems represented by measure driven differential inclusions. Invariance conditions and some of their main features are derived. The... more
Min f (x) на M SI [h, g], где M SI [h, g] := { x ∈ IR n | h i (x) = 0 (i ∈ I), g(x, y) ≥ 0 (y ∈ Y (x)) }, в которой Y (x) = M F [u(x, •), v(x, •)] (x ∈ IR n) допустимые множества в смысле оптимизации с конечными ограничениями.... more
In this paper we investigate the global convergence of solutions of non-autonomous Hopfield neural network models with discrete time-varying delays, infinite distributed delays, and possible unbounded coefficient functions. Instead of... more
In this paper, based on projection technique Solodove and Svaiter (Reformulation: Nonsmooth, piecewise smooth, semismooth and smoothing methods; 355-369,1995), we propose a decent improved threeterm derivative free approach for solving... more
Noise is an unavoidable aspect of modern camera technology, causing a decline in the overall visual quality of the images. Efforts are underway to diminish noise without compromising essential image features like edges, corners, and other... more
Jump Markov linear systems are linear systems whose parameters evolve with time according to a finite-state Markov chain. Given a set of observations, our aim is to estimate the states of the finite-state Markov chain and the continuous... more
Conventional blind carrier recovery algorithms have been observed to show unstable behaviors for large constellation modulation schemes such as 64-QAM or 256-QAM. In this paper, we propose a new carrier tracking approach that has... more
Online identification of sinusoidal components is an important problem that occurs in active noise control, vibration suppression, on line health monitoring, and radar, sonar, and seismic applications. We adopt a new approach to this... more
We consider the problem of finding stationary Nash equilibria (NE) in a finite discounted general-sum stochastic game. We first generalize a non-linear optimization problem from Filar and Vrieze [2004] to a N-player setting and break down... more
We propose an implementable BFGS method for solving a nonsmooth convex optimization problem by converting the original objective function into a once continuously differentiable function by way of the Moreau-Yosida regularization. The... more
Technical reports from the Communications Systems group in Linköping are available by anonymous ftp at the address ftp.control.isy.liu.se. This report is contained in the file 2274.pdf.
Dans le but de déchiffrer l’évolution tectono-métamorphique des massifs de Belledonne, des Grandes Rousses et du Pelvoux nous avons effectué une étude multidisciplinaire (Structures, pétrologies, géochronologies, géochimies, et isotopes... more
Using Taylor's series we propose a modified secant relation to get a more accurate approximation of the second curvature of the objective function. Then, based on this modified secant relation we present a new BFGS method for solving... more
We consider a doubly-fed induction machine-controlled through the rotor voltage and connected to a variable local load-that acts as an energy-switching device between a local prime mover (a flywheel) and the electrical power network. The... more
At first sight, aiming for energy efficiency appears to penalize electricity carriers. A close look at electrical energy flow, from primary to final energy, reveals abysmally low efficiency, resulting from the generation mix, transmission... more
Following the approach proposed by Dai and Liao, we introduce two nonlinear conjugate gradient methods for unconstrained optimization problems. One of our proposed methods is based on a modified version of the secant equation proposed by... more
A new formulation is proposed for the estimation of transmissivity in confined aquifers based on head measurements. This formulation consists of a formulation which minimizes a weighted residual norm of the gradient of the measured and... more
In this works, we consider a system of variational inequality, which can be regarded as an extension of a primal-dual variational inequality system and involves multivalued mappings. The system does not possess monotonicity properties and... more
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more
It is well known that the sufficient descent condition is very important to the global convergence of the nonlinear conjugate gradient methods. Also, the direction generated by a conjugate gradient method may not be a descent direction.... more
It is well known that the sufficient descent condition is very important to the global convergence of the nonlinear conjugate gradient methods. Also, the direction generated by a conjugate gradient method may not be a descent direction.... more
Real life optimization often concerns difficult objective functions, in two aspects, namely that gradients are unavailable, and that evaluation of the objective function takes a long time. Such pro ...