نتایج جستجو برای: underground structures

تعداد نتایج: 468821  

2008
M. Li J. Z. Chen S. J. Mao W. Xiong

Many coal mine companies have established underground safety monitor and control systems. However, the safety management information can only be displayed on the 2D maps or as reports. In this paper, a new method that combines the VR technologies with underground mine safety monitoring technologies was explored. A desktop virtual reality program for underground coal mine, called VRLane, was dev...

2013
Gad Degani Gal Levy

This study examined the effect of underground water on reproductionand growth-related hormones in blue gourami males under non-reproductive and reproductive conditions. An increase in the percentage of males building nests under the highest percentage of underground water were compared to fish that maintained a lower percentage of underground water in the first two days. The % Gonado-somatic in...

Journal: :Physical Communication 2010
Mehmet C. Vuran Ian F. Akyildiz

Wireless underground sensor networks (WUSNs) constitute one of the promising application areas of the recently developed wireless sensor networking techniques. The main difference between WUSNs and the terrestrial wireless sensor networks is the communication medium. The propagation characteristics of electromagnetic (EM) waves in soil and the significant differences between propagation in air ...

2016
D. Lynas

Studies conducted on surface coal mining equipment have identified whole-body vibration as a significant hazard. Operators of underground mobile equipment, particularly shuttle cars and transport vehicles, are likely to be exposed to significant levels of whole-body vibration. To date, measuring whole-body vibration from underground mining mobile equipment has been difficult due to the strict g...

Journal: :British journal of industrial medicine 1992
A W Musk I L Rouse B Rivera N H de Klerk J C McNulty

Respiratory symptoms, spirometry, and transfer factor were measured in 208 non-smoking Western Australian underground goldminers (mean age 32) to identify the presence of respiratory abnormalities resulting from underground work. These subjects were part of a larger group of 771 subjects attending for statutory periodic chest x ray examinations in the industry. They had worked underground for a...

2012
Hariom Agrawal

Researchers have worked on routing issues for adhoc-networks, VANET’s, and Wireless Sensor Networks in a normal scenario; recently there has been a recent trend towards the study on underground wireless networks and proposals for design and development for Wireless Underground Sensor Networks. This paper highlights the concept of wireless underground sensor network in the coal mine environment,...

2012
A. G. Lazaropoulos

A complete methodology is employed to determine the transmission characteristics of low-voltage/broadband over power lines (LV/BPL) channels associated with underground power distribution networks, in the light of the multiconductor transmission line (MTL) theory. The established bottom-up approach, already used to treat overhead and underground MV/BPL transmission, is extended to analyze BPL t...

Journal: :JCP 2013
Xiaoqing Yu Pute Wu Ning Wang Wenting Han Zenglin Zhang

Wireless underground sensor networks (WUSN) are a natural extension of the wireless sensor networks (WSN) phenomenon to the underground environment. In this work, experimental measurements are presented at the frequency of 433 MHz, which show a good agreement with the theoretical studies. Experiments are run to examine the received signal strength and the packet error rate for aboveground-to-un...

2008
J. Larsson

During the last decade, mining companies and mobile equipment manufacturers have pursued improved efficiency, productivity, and safety in underground mining operations by automating some of the functions of underground vehicles. This paper describes the implementation and successful field testing of a new infrastructureless guidance system for autonomous tramming of centre-articulated undergrou...

Recently, the non-destructive methods have become of interest to the scientists in various fields. One of these method is Ground Penetration Radar (GPR), which can provide a valuable information from underground structures in a friendly environment and cost-effective way. To increase the signal-to-noise (S/N) ratio of the GPR data, multi-fold acquisition is performed, and the Common-Mid-Points ...

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