Using the set point concept to allow water distribution system skeletonization preserving water quality constraints

[EN] Water distribution networks were included in the catalogue of critical infrastructures by different institutions as the European Council. One of the vulnerabilities of a water distribution networks consists of the contamination due to accidental or provoked events. Therefore, it is increasingly common to develop water quality models which allow the study of these threats. Many hydraulic models use algorithms with a high computational cost. Therefore, any strategy to accelerate these algorithms is an important contribution to the problem. This paper proposes a method to simplify branched areas of the network without losing information regarding water quality.This article has been possible inside the actions developed by the researchers of UPV involved in the project “Mejora de las técnicas de llenado y operación de redes de abastecimiento de agua (OPERAGUA)”. The number reference of the project is DPI2009-13674.Martínez-Solano, FJ.; Iglesias Rey, PL.; Mora Meliá, D.; Fuertes Miquel, VS. (2014). Using the set point concept to allow water distribution system skeletonization preserving water quality constraints. Procedia Engineering. 2014(89):213-219. https://doi.org/10.1016/j.proeng.2014.11.179S21321920148

TSP Cuts Which Do Not Conform to the Template Paradigm

The first computer implementation of the Dantzig-Fulkerson-Johnson cutting-plane method for solving the traveling salesman problem, written by Martin, used subtour inequalities as well as cutting planes of Gomory's type. The practice of looking for and using cuts that match prescribed templates in conjunction with Gomory cuts was continued in computer codes of Miliotis, Land, and Fleischmann. Grötschel, Padberg, and Hong advocated a different policy, where the template paradigm is the only source of cuts; furthermore, they argued for drawing the templates exclusively from the set of linear inequalities that induce facets of the TSP polytope. These policies were adopted in the work of Crowder and Padberg, in the work of Grötschel and Holland, and in the work of Padberg and Rinaldi; their computer codes produced the most impressive computational TSP successes of the nineteen eighties. Eventually, the template paradigm became the standard frame of reference for cutting planes in the TSP. The purpose of this paper is to describe a technique for finding cuts that disdains all understanding of the TSP polytope and bashes on regardless of all prescribed templates. Combining this technique with the traditional template approach was a crucial step in our solutions of a 13,509-city TSP instance and a 15,112-city TSP instance