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This paper addresses the problem of model-based global stability analysis of discrete-time Takagi-Sugeno multiregional dynamic output controllers with static antiwindup filters. The presented analyses are reduced to the problem of a feasibility study of the Linear Matrix Inequalities (LMIs), derived based on Lyapunov stability theory. Two sets of LMIs are considered candidate derived from the classical common quadratic Lyapunov function, which may in some cases be too conservative, and a fuzzy Lyapunov function candidate, which has been proven to significantly reduce the conservatism level, although at the cost of increasing the number of LMIs. Two numerical examples illustrate the main result.

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This article addresses the problem of drinking water distribution system (DWDS) security in the terms of water quality which in the era of terrorist threat is of high importance to the public. The contribution of this paper is the development of the so called security module to extend a multi-species water quality model. This gives an insight to the situation in DWDS not only under normal operational conditions but also in case of a malicious attack on water quality. Moreover the security inputs are formally introduced to the model structure. This module enables simulation of both bacterial and/or chemical water contamination in DWDS environment. Previously defined inputs are utilised in proposed experiments by an attacking agent to influence the DWDS quality. The purpose of model development is to enable water scientists and water authorities to simulate the contamination propagation pathways and mechanisms throughout the network without omitting the 'natural' water chemistry effects. A simple simulation example for the exemplary DWDS illustrates the model performance for two distinct contamination scenarios.

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