Underground utility tunnels (UUTs) are convenient for the integrated management of various infrastructure facilities. They ensure effective control underground facilities and reduce occupied space. However, aging UUTs require preventive measures fire safety. The fundamental problems in operating frequent occurrence mold, corrosion, damage caused to finishing materials owing inadequate waterproo...

A sealed atmosphere in a mined-out area of an underground coal mine is simply a volume with homogeneous composition governed by boundary conditions. This paper presents a mathematical model based upon the conservation of mass principle that describes the flow of air (nitrogen and oxygen), methane and carbon dioxide into and out of a sealed atmosphere and the time-dependent changes in gas concen...

Airport ground lighting (AGL) systems provide visual reference to aircrafts during airport operations. In AGL systems, constant current regulators feed a beacon circuit supplied through isolation transformers. Component modeling is necessary to simulate AGL systems, and thus characterize and predict their behavior. This paper presents an isolation transformer model including transformer core sa...

Microorganisms influence the chemical and physical properties of subsurface environments and thus represent an important control on the fate and environmental impact of CO2 that leaks into aquifers from deep storage reservoirs. How leakage will influence microbial populations over long time scales is largely unknown. This study uses natural analog sites to investigate the long-term impact of CO...

A Wireless Underground Sensor Network (WUSN) is a network of wireless sensor devices in which all sensor devices are deployed completely underground (network sinks or any devices specifically for relay between sensors and a sink may be aboveground). These networks can be utilized to monitor the underground environment, especially soil conditions and aboveground events, such as the presence of p...

Wireless underground sensor networks (WUSNs) can enable many important applications such as intelligent agriculture, pipeline fault diagnosis, mine disaster rescue, concealed border patrol, crude oil exploration, among others. The key challenge to realize WUSNs is the wireless communication in underground environments. Most existing wireless communication systems utilize the dipole antenna to t...

The cadastral system provides land ownership information by registering and representing land boundaries on a map. The current cadastral system in Korea, however, focuses mainly on the management of 2D land-surface boundaries. It is not yet possible to provide efficient or reliable land administration, as this 2D system cannot support or manage land information on 3D properties (including archi...

Underground railway stations are known to have elevated particulate matter (PM) loads compared to ambient air. As these particles are derived from metal-rich sources and transition metals may pose a risk to health by virtue of their ability to catalyze generation of reactive oxygen species (ROS), their potential enrichment in underground environments is a source of concern. Compared to coarse (...

A wireless underground sensor network (WUSN) is defined as a network of wireless sensor devices in which all sensor devices are deployed completely underground (network sinks or any devices specifically for relay between sensors and a sink may be aboveground). In hybrid wireless underground sensor network (HWUSN), communication between nodes is implemented from underground-to-air or air-to-unde...