“…Over the past years, laborious research on the development of strategies for efficient sensor placement has been conducted (for reviews, see the papers (Kubrusly and Malebranche, 1985;Uciński, 1992;Uciński, 2000;van de Wal and de Jager, 2001) and the comprehensive monographs Uciński, 1999)). Nevertheless, although the need for systematic methods was widely recognized, most techniques communicated by various authors usually rely on an exhaustive search over a predefined set of candidates and the combinatorial nature of the design problem is taken into account very occasionally (van de Wal and de Jager, 2001).…”