Author(s): L. S. Vamvakeridouluroudia

Linked Author(s):

Keywords: Water supply networks; Optimization; Genetic algorithms; Fuzzy reasoninglinguistic variables; Small water tanks

Abstract: Extension and partial renewal of an urban water supply and distribution network is a complex optimization problem, for which genetic algorithms are frequently used, because it is very difficult to solve using classical optimization methods. In genetic algorithms, usually constraints are taken into consideration using penalty functions. In this paper, fuzzy reasoning is introduced for constraint handling and feasibility checks, so that penalty functions are replaced by the total aggregated membership function to the set of feasible solutions. Linguistic variables, such as [AROUND], [STRICTLY], [TOO] are used to simulate diversity of tolerance for each constraint bound in a flexible and constructive way, without the need to predefine specific numeric “penalties” for constraint violation. The general theoretical approach is presented, together with an application of the model to the main water supply network of the city of Halkis. Moreover, an original approach to the mathematical simulation of small existing tanks is introduced, for which linguistic variables and fuzzy reasoning are appropriate. The paper includes also a discussion on the advantages and possibilities of linguistic variables, while pointing out sensitivity to the use of various fuzzy operators for membership functions and aggregation.

DOI:

Year: 2003