IEEE Trans Antennas Propag

At the ultrahigh frequencies common to portable radios, tunnels such as mine entries are often modeled by hollow dielectric waveguides. The roughness condition of the tunnel walls has an influence on radio propagation, and therefore should be taken into account when an accurate power prediction is needed. This paper investigates how wall roughness affects radio propagation in tunnels, and presents a unified ray tracing and modal method for modeling radio propagation in tunnels with rough walls. First, general analytical formulas for modeling the influence of the wall roughness are derived, based on the modal method and the ray tracing method, respectively. Second, the equivalence of the ray tracing and modal methods in the presence of wall roughnesses is mathematically proved, by showing that the ray tracing-based analytical formula can converge to the modal-based formula through the Poisson summation formula. The derivation and findings are verified by simulation results based on ray tracing and modal methods.CC999999/Intramural CDC HHS/United States2017-09-19T00:00:00Z28935995PMC560325

Bibliography of communication and research products 2014

This publication is a compendium of NIOSH publications and reports produced during calendar year 2014. Citations are listed by category including: I. Journal Articles; II. Book or Book Chapters; III. NIOSH Numbered Publications; IV. Proceedings; V. Abstracts; VI. Control Technology Reports; VII. Fatality Assessment and Control Evaluation Reports; VIII. Fire Fighter Fatality Investigation and Prevention Reports; and, VIII. Health Hazard Evaluation Reports; IX. Ebola Interim Guidance Products. Author and National Occupational Research Agenda (NORA) indexes are also included.Suggested citation: NIOSH [2015]. NIOSH bibliography of communication and research products 2014. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2015-112.NIOSHTIC No 20046111Foreword -- Introduction -- Journal articles -- Books or book chapters -- NIOSH numbered products -- Proceedings -- Abstracts -- Control technology reports -- Fatality assessment and control evaluation reports -- Fire fighter fatality investigation and prevention reports -- Health hazard evaluation reports -- Ebola interim guidance products -- Author index -- National Occupational Research Agenda (NORA) index