What is it about?

This paper develops the integrated fuzzy analytical hierarchy process (AHP) with multidimensional scaling (MDS) approach to improve current methods for determining the optimal alternative. The integrated method incorporates the weights computed by AHP into the fuzzy matter- element, and allows evaluators to understand the relative importance of each index or criterion at a high level. This is followed by the MDS method to determine the optimal alternative directly through the coordinates associated with each alternative in a two-dimensional configuration. The method was evaluated via specific programming language software packages, and was applied to select natural wastewater treatment alternatives in a case study. Results indicate the stabilization pond was the optimal alternative among five natural wastewater treatment systems. Sensitivity analysis was conducted and reflects the importance of weighing on alternative selection.

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Why is it important?

The proposed methods have the following advantages compared with the conventional methods. Firstly, the fuzzy matter-element theory was applied to quantify qualitative indices and to normalize indices for AHP, as well as to quantify values of correlation degree after weighting each criterion and index. Accordingly, the fuzziness of indices is resolved. Secondly, MDS was performed, with the correlation degree, to present the ranking of wastewater treatment alternatives with the desirable configuration. This method provides a smart and direct way for alternative selection. Furthermore, sensitivity analysis with numerous scenarios can address the uncertainties and subjectivity of conventional AHP or other methods in determining weights. The


The application of the integrated evaluation method is expected to extend to the determination of other alternatives.

PhD Xiaoguang Ouyang
Chinese University of Hong Kong

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This page is a summary of: Development of the integrated fuzzy analytical hierarchy process with multidimensional scaling in selection of natural wastewater treatment alternatives, Ecological Engineering, January 2015, Elsevier, DOI: 10.1016/j.ecoleng.2014.11.006.
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