scholarly journals Solution Approaches for the Management of the Water Resources in Irrigation Water Systems with Fuzzy Costs

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2432 ◽  
Author(s):  
Raquel Sanchis ◽  
Manuel Díaz-Madroñero ◽  
P. Amparo López-Jiménez ◽  
Modesto Pérez-Sánchez
Keyword(s):  
Water Resources ◽  
Programming Model ◽  
Model Complexity ◽  
Water Networks ◽  
Mathematical Programming Model ◽  
Water Network ◽  
Fuzzy Methods ◽  
Operation Costs ◽  
Fuzzy Solution ◽  
Selection Of

Currently, the management of water networks is key to increase their sustainability. This fact implies that water managers have to develop tools that ease the decision-making process in order to improve the efficiency of irrigation networks, as well as their exploitation costs. The present research proposes a mathematical programming model to optimize the selection of the water sources and the volume over time in water networks, minimizing the operation costs as a function of the water demand and the reservoir capacity. The model, which is based on fuzzy methods, improves the evaluation performed by water managers when they have to decide about the acquisition of the water resources under uncertain costs. Different fuzzy solution approaches have been applied and assessed in terms of model complexity and computational efficiency, showing the solution accomplished for each one. A comparison between different methods was applied in a real water network, reaching a 20% total cost reduction for the best solution.

Methods for estimating water network rehabilitation needs

2003 ◽  
Vol 3 (1-2) ◽  
pp. 63-69 ◽  
Author(s):  
S. Sægrov ◽  
A. König ◽  
A. Mattick ◽  
J. Milina ◽  
J. Röstum ◽  
...  
Keyword(s):  
Water Networks ◽  
Water Network ◽  
Network Failure ◽  
Failure Frequency ◽  
Failure Distribution ◽  
Computer Based ◽  
Rehabilitation Needs ◽  
Network Rehabilitation ◽  
Selection Of

This paper comprises a brief overview of some of the computer-based methods for water network rehabilitation planning, which are currently applied in Norway. Examples from some Norwegian cities using tools for estimation of long-term rehabilitation needs, network serviceability, as well as methods for prediction of water network failure frequency and failure distribution, are presented. These tools have been shown to give important support to the planning of future investments on water networks and the selection of rehabilitation candidates.

Sectorisation of looped water networks with electromagnetic water meters

2014 ◽  
Vol 9 (2) ◽  
pp. 150-157
Author(s):  
Koral Wojciech
Keyword(s):  
Water Balance ◽  
Water Networks ◽  
Water Network ◽  
Automatic Meter Reading ◽  
Dead End ◽  
Water Meters ◽  
The Town

This paper describes the sectorisation of a water network, as operated by the water and sewage utility (PWiK Gliwice, Poland) with electromagnetic water-meters (battery powered). This solution allows supply of District Metered Areas (DMA) by a few points without ‘dead-end’ pipework and shows that the main problems of the Utility are small, hidden leaks. Additionally the paper describes a water balance for the town of Pyskowice (part of the Gliwice water network) where all water meters are read by radio (automatic meter reading – AMR).

Scheduling a Bus Fleet for Evacuation Planning Using Stop-Skipping Method

2021 ◽  
pp. 036119812110200
Author(s):  
Hu Zhao ◽  
Shumin Feng ◽  
Yusheng Ci
Keyword(s):  
Waiting Time ◽  
Ant Colony Algorithm ◽  
Programming Model ◽  
Peer To Peer ◽  
Mathematical Programming Model ◽  
Fleet Size ◽  
Bus Stop ◽  
Passenger Demand ◽  
Service Strategies ◽  
Bus System

Sudden passenger demand at a bus stop can lead to numerous passengers gathering at the stop, which can affect bus system operation. Bus system operators often deal with this problem by adopting peer-to-peer service, where empty buses are added to the fleet and dispatched directly to the stop where passengers are gathered (PG-stop). However, with this strategy, passengers at the PG-stop have a long waiting time to board a bus. Thus, this paper proposes a novel mathematical programming model to reduce the passenger waiting time at a bus stop. A more complete stop-skipping model that including four cases for passengers’ waiting time at bus stops is proposed in this study. The stop-skipping decision and fleet size are modeled as a dynamic program to obtain the optimal strategy that minimizes the passenger waiting time, and the optimization model is solved with an improved ant colony algorithm. The proposed strategy was implemented on a bus line in Harbin, China. The results show that, during the evacuation, using the stop-skipping strategy not only reduced the total waiting time for passengers but also decreased the proportion of passengers with a long waiting time (>6 min) at the stops. Compared with the habitual and peer-to-peer service strategies, the total waiting time for passengers is reduced by 31% and 23%, respectively. Additionally, the proportion of passengers with longer waiting time dropped to 43.19% by adopting the stop-skipping strategy, compared with 72.68% with the habitual strategy and 47.5% with the peer-to-peer service strategy.

scholarly journals A Mathematical Programming Model to Determine Objective Weights for the Interval Extension of TOPSIS

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Hai Shen ◽  
Lingyu Hu ◽  
Kin Keung Lai
Keyword(s):  
Mathematical Programming ◽  
Input Data ◽  
Programming Model ◽  
Multiple Criteria Decision Making ◽  
Decision Makers ◽  
Mathematical Programming Model ◽  
Topsis Method ◽  
Data Set ◽  
Interval Extension ◽  
Interval Valued

Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method has been extended in previous literature to consider the situation with interval input data. However, the weights associated with criteria are still subjectively assigned by decision makers. This paper develops a mathematical programming model to determine objective weights for the implementation of interval extension of TOPSIS. Our method not only takes into account the optimization of interval-valued Multiple Criteria Decision Making (MCDM) problems, but also determines the weights only based upon the data set itself. An illustrative example is performed to compare our results with that of existing literature.

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