http://popups.lib.uliege.be/1373-5411/index.php?id=1897 Publications of Auteurs Stefan Pickl fr 0 http://popups.lib.uliege.be/1373-5411/index.php?id=4641 A class of stochastic antagonistic positional games for Markov decision processes with average and expected total discounted costs optimization criteria are formu lated and studied. Saddle point conditions in the considered class of games that extend saddle point conditions for deterministic parity games are derived. Further more algorithms for determining the optimal stationary strategies of the players are proposed and grounded Mon, 14 Oct 2024 15:41:10 +0200 Thu, 17 Oct 2024 11:57:01 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=4641 http://popups.lib.uliege.be/1373-5411/index.php?id=4478 This paper presents a system dynamics model which shows that there seem to be rational reasons for hesitation to invest in resource-saving projects. In contrast to classical marketing approaches dealing with decreasing resource and product prices a new kind of follower advantages in a market of increasing resource prices may constitute a waiting game which in turn can significantly delay the deployment of sustainable technologies. This new kind of follower advantages and the related hesitation to introduce a potential resource-saving new technology may be significant when anticipating the market diffusion of such a technology or designing policy to foster green economy. A price shock of resources, as shown by model simulations, might be a possible way to switch back from such a waiting game to a preemption game. Fri, 11 Oct 2024 12:03:11 +0200 Fri, 11 Oct 2024 12:03:22 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=4478 http://popups.lib.uliege.be/1373-5411/index.php?id=4459 In this paper we present an innovative concept and prototype of a web platform which supports participatory modelling in the decision-making processes in the field of environmental modelling and simulation. Participatory modelling needs usually face-to-face participatory modelling sessions. In comparison to classical approaches, the platform presented in this paper shall facilitate web-based collaborative and cumulative modelling when such face-to-face sessions cannot be organised as often as desired. Successive iteration steps of the model development can thus be displayed interactively in a standard web browser together with comments and explanations made by the modeller. The platform strengthens the support of formal model construction and documentation on the one hand and reduces the effort of model re-publishing on the other hand. These approaches are discussed and characterised in the following contribution. Furthermore this platform shall be used to support participatory modelling and decision-making processes in the field of sustainable development, especially in the context of anticipatory systems Fri, 11 Oct 2024 11:14:16 +0200 Fri, 11 Oct 2024 11:14:28 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=4459 http://popups.lib.uliege.be/1373-5411/index.php?id=3192 A characterization of a simple Markov process based on a random graph theoretic structure is introduced. We propose a polynomial time algorithm for the calculation of a limit state matrix. The algorithm is based on two procedures which will be derived in this contribution. They exploit a distinguished decomposition principle of the underlying graph theoretic structure and the special property of an acyclic directed graph. Wed, 11 Sep 2024 17:01:24 +0200 Wed, 11 Sep 2024 17:01:55 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=3192 http://popups.lib.uliege.be/1373-5411/index.php?id=2950 Discrete multiobjective control problems with varying time of states transactions of dynamical system are formulated and studied. Nash equilibrium conditions for the considered problems are given and algorithms based on dynamic programming for determining optimal solutions in the sense of Nash and Pareto are proposed and proved. We exploit a certain (so-called) intelligent network structure to underline a constructive approach Tue, 03 Sep 2024 15:57:55 +0200 Tue, 03 Sep 2024 15:58:06 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=2950 http://popups.lib.uliege.be/1373-5411/index.php?id=1883 This article is a small survey and pioneering as a starting point for a longer research project : to utilize generalized semi-infinite optimization for purposes of prediction. Firstly, it reflects tbe analytical and inverse (intrinsic) behaviour of generalized semi-infinite optimization problems P(f,h,g,u,v) and presents interpretations of them from the viewpoint of anticipatory systems. These differentiable problems admit an infinite set Y(x) of inequality constraints y, which depends on the state x. Under suitable assumptions, we present global stability properties of the feasible set and corresponding structural stability properties of the entire optimization problem (Weber, 2002 ; Weber, 2003). The achieved results are a basis of algorithm design. In the course of explanation, the perturbational approach gives rise to reconstructions. By studying three applications of generalized semi-infinite optimization, secondly, we interpret these aspects of inverse problems in the sense of prediction. The three anticipatory systems are : (i) Reverse Chebycchev approximation, where we describe a given system by a neighbouring easier one as long as possible under some error tolerance. We begin by a motivating problem from chemical engineering and turn then to time-dependent systems. (ii) Time-minimal or -maximal optimization problems, where we want to pull or push the time-horizon of some process to present time or into the future. We mention global warming and turn to further kinds of biosystems. (iii) Computational biology, where we are concerned with prediction and stability of DNA microarray gene-expression patterns. Wed, 17 Jul 2024 12:56:01 +0200 Thu, 10 Oct 2024 16:49:39 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=1883