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A Decision Support System (DSS) based on intelligent agents was developed to help in operation of the Granollers WWTP (NE of Spain). The DSS has been performing real-time support to the operation of the facility since September 1999. The assessment of the DSS performance at the end of 2000 showed an 80% of accuracy in the diagnosis of the process state. However, about 12% of the situations were not identified, while 8% were wrong identifications. In addition, some practical caveats of the system were reported by the operators of the facility. To reduce the number of wrongly identified process states, as well as to improve DSS performance in general, a significant revision and upgrade of the system was recently proposed. To guarantee real-time identification of problems related to clarifiers, numerical modeling of a secondary settler was added in the diagnosis level. In addition, a new local weighting technique was used to assign specific weights to specific values of the variables, which improves performance of the retrieval of similar experiences in the case-based reasoning system. Also, to avoid misdiagnosis, a minimum percentage value of similarity was added in the reasoning cycle. If the similarity value for a case falls below minimum, the case is not considered similar to the current one and is not retrieved. Finally, two new levels have been added to support the operator in the definition of the action plan, specifying the list of tasks to be carried out to solve the problem.

Document Type: Research Article


Publication date: January 1, 2002

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  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

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