title: A Hybrid Approach for Efficient Modeling of Medium-Frequency Propagation in Coal Mines.
abstract: An efficient procedure for modeling medium frequency (MF) communications in coal mines is introduced. In particular, a hybrid approach is formulated and demonstrated utilizing ideal transmission line equations to model MF propagation in combination with full-wave sections used for accurate simulation of local antenna-line coupling and other near-field effects. This work confirms that the hybrid method accurately models signal propagation from a source to a load for various system geometries and material compositions, while significantly reducing computation time. With such dramatic improvement to solution times, it becomes feasible to perform large-scale optimizations with the primary motivation of improving communications in coal mines both for daily operations and emergency response. Furthermore, it is demonstrated that the hybrid approach is suitable for modeling and optimizing large communication networks in coal mines that may otherwise be intractable to simulate using traditional full-wave techniques such as moment methods or finite-element analysis.
authors.affiliation: Pennsylvania State University, University Park, PA 16802 USA.
authors.forename: Donovan E
authors.initials: DE
authors.lastname: Brocker
authors.affiliation: Pennsylvania State University, University Park, PA 16802 USA.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Sieber
authors.affiliation: National Institute for Occupational Safety and Health, Pittsburgh, PA 15236 USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Waynert
authors.affiliation: National Institute for Occupational Safety and Health, Pittsburgh, PA 15236 USA.
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Li
authors.affiliation: Pennsylvania State University, University Park, PA 16802 USA.
authors.forename: Pingjuan L
authors.initials: PL
authors.lastname: Werner
authors.affiliation: Pennsylvania State University, University Park, PA 16802 USA.
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Werner
keywords: Coal mines; communication network optimization; medium frequency (MF); propagation; transmission lines (TLs)