A vulnerability analysis of possible use in security studies is presented. The analysis of the London underground network suggests that the stations bombed on 7 July, 2005 may not have been chosen randomly. From the viewpoint of effectively disturbing the transport system, nearly the best choice was made out of roughly 3 million possible combinations for attacking three stations. By comparing t...

Designing a proper acoustical environment--indispensable to speech recognition--in long enclosures is difficult. Although there is some literature on the acoustical conditions in underground stations, there is still little information about methods that make estimation of correct reverberation conditions possible. This paper discusses the assessment of the reverberation conditions of undergroun...

Underground vehicular ad-hoc networks are indorsing wireless networks because they can realize many goals such as improving the driving safety and monitoring the emergency alerts in underground environments (i.e., road tunnels). It is necessary for vehicular nodes to recognize their positions to achieve these goals. However, Global Positioning System (GPS) devices cannot operate in underground ...

We examine the reduction in London Underground passenger journeys in response to the July 2005 bombings. Using entrance data for London Underground stations between 2001 and 2007, we incorporate demand and supply factors in a multivariate time-series regression model to estimate changes in passenger journeys between different Underground lines. We find that passenger journeys fell by an average...

Utilizing only the vertical muon intensity of the Gaisser parameterization of the muon flux at the surface and propagating this energy spectrum underground according to statistical ionization and radiative energy losses, it is possible to calculate the underground muon intensity Crouch curve. In addition, the primary spectral index of the Gaisser parameterization can be adjusted from E to E sim...

the increasing rate of urbanization and rate of population growth over the 20th century has led to various problems such as traffic congestion, air pollution, and lack of open and green spaces that have affected the cities and their citizen's life. this condition has led to increasing demands for more land use, homes, and work places, more public transport and mass transit systems and mode...

ground penetrating radar (gpr) and magnetic methods were used at ghasr-e-shirin town in kermanshah province, southwest of iran for detecting a series of large ancient (ca 1500 years) underground cavities (tagh). the area of study is a historical monument which is named as emarat e khosro. radar and total intensity magnetic field measurements have been done on the eastern part of the complex, wh...

To provide more reasonable references for remedying underground water, fuel leak was simulated by establishing an experimental model of a porous-aquifer sand tank with the same size as that of the actual tank and by monitoring the underground water. In the tank, traditional gasoline and ethyl alcohol gasoline were poured. This study was conducted to achieve better understanding of the migration...

The lack of accurate maps of subsurface utilities and other underground hazards often causes accidents, project delays and increased project cost. Subsurface Utility Engineering (SUE) is an engineering process utilizing state-of-the-art technology to accurately identify, characterize, and map underground utilities and installations prior to the design of new highways and structures or the insta...

This work introduces the concept of a Wireless Underground Sensor Network (WUSN). WUSNs can be used to monitor a variety of conditions, such as soil properties for agricultural applications and toxic substances for environmental monitoring. Unlike existing methods of monitoring underground conditions, which rely on buried sensors connected via wire to the surface, WUSN devices are deployed comp...