Discussion of "Analysis of Water Distribution System under Uncertainty Based on Genetic Algorithm and Trapezoid Fuzzy Membership".

The range of pipe roughness values in both cases (triangular and trapezoidal) at the 0 HT <math display="inline" overflow="scroll" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi> </mi><mtext>-</mtext><mi>cut</mi></mrow></math> ht level is the same, i.e., 110 to 130. For example, the minimum and maximum values obtained by the authors for HT <math display="inline" overflow="scroll" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>Q</mi><mn>2</mn></msub></mrow></math> ht are 8.88 and HT <math display="inline" overflow="scroll" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>19.01</mn><mtext> </mtext><mi mathvariant="normal">L</mi><mo stretchy="false">/</mo><mi mathvariant="normal">s</mi></mrow></math> ht , while Sivakumar et al. ([5]) reported 5.81 and HT <math display="inline" overflow="scroll" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>20.14</mn><mtext> </mtext><mi mathvariant="normal">L</mi><mo stretchy="false">/</mo><mi mathvariant="normal">s</mi></mrow></math> ht . Because the range of pipe roughness values at the 0 HT <math display="inline" overflow="scroll" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi> </mi><mtext>-</mtext><mi>cut</mi></mrow></math> ht level in both triangular and trapezoidal cases is the same, MFs of pipe discharges and nodal heads at the 0 HT <math display="inline" overflow="scroll" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi> </mi><mtext>-</mtext><mi>cut</mi></mrow></math> ht level should be identical. However, for other HT <math display="inline" overflow="scroll" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi> </mi><mtext>-</mtext><mi>cut</mi></mrow></math> ht levels, these are different. [Extracted from the article]