Soft Computing Techniques

The increasing expansion of population and lack of enough urban space for construction and development of transportation infrastructures have doubled the role of long tunnels as the main solution for this problems. Nowadays, the mechanized excavation technology by tunnel boring machines is a fast, safe and cheap way compared to other tunneling methods. Given the variability of conditions in urban environments and high compliance of the technological situation of ground with excavation machines and also high costs for selection of wrong machines, the selection of an appropriate type of excavation machine has become an important challenge in the mechanized tunneling projects. There are various methods for determining an excavation machine in tunneling projects, among which the use of soft computing techniques to match experimental concepts with scientific one has a special place. Therefore. In this research, by studying factors influencing the selection of excavation machine and using opinions of experts in this area, the significance of these factors is determined, and by using soft computing techniques such as TOPSIS method and Fuzzy Delphi Analytic Hierarchy (FDAHP), which is one of the mostly used methods in multi-criteria decision making method, an appropriate excavation machine for line 7 of Tehran subway project (eastern-western section) in Iran is investigated and selected. Results obtained from studies showed that considering important criteria including the environmental and geological characteristics of the site, environmental issues and problems, applicability of the method, economic condition and project completion time, the use of earth pressure balance machine was the best choice for excavation of line 7 of Tehran subway.

The world has been beset with fears of future global overpopulation overwhelming the earth’s ecological system and producing shortages of energy, resources, water and food. The sustainability has been a major long-term concern, climate change is thought to be causing a warming of the planet, an increased incidence of extreme weather events, a reduction in agricultural yields, melting the ice caps, and rising sea levels which will eventually cause flooding of low lying islands and coastal districts. As a result, there is dire need for population checks in the world. The causes of overpopulation are attributed to cultural beliefs, lack of sex and population education, religious beliefs etc. The effects of overpopulation include mass poverty, increased death rate, unemployment, etc. It becomes eminent that some measures should be put in place to address this global issue. Some past measures included equipping and funding public and special libraries to disseminate population control in...