in this paper, a model based on gmdh type neural network, is used to predict gas price in the spot market while using oil spot market price, gas spot market price, gas future market price, oil future market price and average temperature of the weather. the results suggest that gmdh neural network model, according to the root mean squared error (rmse) and direction statistics (dstat) statistics ...

An Ant Colony Optimization (ACO) algorithm is proposed for optimal tree-structured natural gas distribution network. Design of pipelines, facilities, and equipment systems are necessary tasks to configure an optimal natural gas network. A mixed integer programming model is formulated to minimize the total cost in the network. The aim is to optimize pipe diameter sizes so that the location-alloc...

Considering the high costs of the implementation and maintenance of gas distribution networks in urban areas, optimal design of such networks is vital. Today, urban gas networks are implemented within a tree structure. These networks receive gas from City Gate Stations (CGS) and deliver it to the consumers. This study presents a comprehensive model based on Mixed Integer Nonlinear Programming (...

In resilience-based frameworks, optimizing the repair strategy and approaches is important for recovery of function gas network systems (GNS) water (WNS). According to resilience quantification results GNS WNS a real example urban city in China, potential impact utilizing different sequences repair/replacement was investigated. First, Monte Carlo simulation-based method proposed search optimal ...

introduction the urban population experienced rapid growth in the recent decades, particularly between 1975 and 2000 when it has reached from 1.5 to more than 2 billion people. by turn of the century; half of the world's populations are concentrated in cities. this would severely affect the quality of life in urban areas. accordingly, cities will be faced with significant challenges in inf...

Natural gas (NG) is one of the widely used domestic fuels in most of the countries, and because of economical and environmental advantages, its consumption is continuously increasing. As a result, complex piping systems are being installed to transport and distribute the gas for end users. Pipelines carrying NG are a significant source of hazard for their adjacent society. The risk of this haza...