Disturbance Decoupling in Dynamic Games

A theory for disturbance decoupling problems has been well developed in the area of geometric control theory. The aim of the present study is to introduce disturbance decoupling problems in a dynamic game context. For this purpose, techniques from geometric control theory are applied. Necessary and sufficient conditions are derived for the solvability of the disturbance decoupling problems introduced here. Consequently, for a given game, the players can easily check if these problems are solvable or not.Disturbance decoupling;differential games;robust controlled invariance

Moving Horizon Control in Dynamic Games

We consider a continuous time system influenced by different agents who adopt moving horizon control. The well known Nash equilibrium concept is used to define two solution concepts fitting in the moving horizon structure. One of them is analyzed in more detail in the class of linear quadratic games. The (dis)advantages of moving horizon control are illustrated by means of a government debt stabilization model.

TACOP: A Cognitive Agent for a Naval Training Simulation Environment

The full version of this paper appeared in: Doesburg, W. A. van, Heuvelink, A., and Broek, E. L. van den (2005). TACOP: A cognitive agent for a naval training simulation environment. In M. Pechoucek, D. Steiner, and S. Thompson (Eds.), Proceedings of the Industry Track of the Fourth International Joint Conference on Autonomous Agents and Multi-Agent Systems (AAMAS-05), p.34-41. July 25-29, Utrecht, The Netherlands

A Game Theoretic Approach to Linear Systems with L2-bounded Disturbances

The aim of the present study is to construct a state feedback controller for a given linear system that minimizes the worst-case effect of an L2 -bounded disturbance. Our setting is different from the usual framework of H -theory in that we consider nonzero initial conditions. The situation is modeled in a game theoretical framework, in which the controller designer acts as a minimizing player, and the uncertainty as a maximizing player. We show that a saddle-point equilibrium exists and find an optimal controller.

A Game Theoretic Approach to Linear Systems with L2-bounded Disturbances

The aim of the present study is to construct a state feedback controller for a given linear system that minimizes the worst-case effect of an L2 -bounded disturbance. Our setting is different from the usual framework of H -theory in that we consider nonzero initial conditions. The situation is modeled in a game theoretical framework, in which the controller designer acts as a minimizing player, and the uncertainty as a maximizing player. We show that a saddle-point equilibrium exists and find an optimal controller.Linear uncertain systems;game theory;algebraic Riccati equations

Cyclosporin in atopic dermatitis: A multicentre placebo-controlled study

The efficacy of cyclosporin (Sandimmun®) given in a daily dose of 5 mg/kg for 6 weeks in severe atopic dermatitis was confirmed in this double-blind, placebo-controlled, short-term study. Of the 46 patients included in the study, 23 were randomized to receive cyclosporin and 23 to receive placebo. Four of the 23 patients (17%) on cyclosporin, and 14 of the 23 patients (61%) who received placebo, discontinued the trial because of inefficacy. All patients who discontinued the trial were assessed following the principle the principle of ‘intention to treat’. Compared with the baseline, the mean scores for disease severity [6-area, total body severity assessment (TBSA)] improved by 55%, and the mean scores for extent of disease [rule-of-nines area assessment (RoNAA)] improved by 40%, in patients treated with cyclosporin. Nine of the patients who received cyclosporin and completed the study (n=14) had an individual reduction of disease severity (TBSA) of 75% or more, and in three patients this reduction was nearly 100%. In the placebo group, a mean worsening of disease severity (4%) and of extent of the disease (25%), compared with the baseline, was observed al week 6. Patients' and investigators' mean scores for the overall efficacy were similar, and showed a statistically significant difference in favour of cyclosporin. Two patients on cyclosporin developed hypertension during therapy, and one of these withdrew from the study. At the end of the trial, no statistically significant differences in the systolic or diastolic blood pressures were observed between the two groups. In the cyclosporin group, the increases in the values of serum creatinine and bilirubin at week 6, compared with the respective values at the baseline, were statistically significantly different from those in the placebo group, but all values normalized in the post-treatment period. Cyclosporin can be a safe and very effective treatment in episodes of severe atopic dermatitis, provided that the recommended guidelines for its administration are strictly observed