Mine Working Face Gas Prediction Based on Weighted LS-SVM

2011 ◽  
pp. 639-647 ◽  
Author(s):  
Tiezhu Qiao ◽  
Meiying Qiao
Keyword(s):  
Mine Working ◽  
Working Face

scholarly journals Interference Mitigation for Visible Light Communications in Underground Mines Using Angle Diversity Receivers

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 367 ◽  
Author(s):  
Pablo Palacios Játiva ◽  
Milton Román Cañizares ◽  
Cesar A. Azurdia-Meza ◽  
David Zabala-Blanco ◽  
Ali Dehghan Firoozabadi ◽  
...  
Keyword(s):  
Visible Light ◽  
Mine Working ◽  
Channel Model ◽  
Underground Mining ◽  
Cumulative Distribution ◽  
Line Of Sight ◽  
Delay Spread ◽  
Noise Power ◽  
Working Face ◽  
Angle Diversity

This paper proposes two solutions based on angle diversity receivers (ADRs) to mitigate inter-cell interference (ICI) in underground mining visible light communication (VLC) systems, one of them is a novel approach. A realistic VLC system based on two underground mining scenarios, termed as mining roadway and mine working face, is developed and modeled. A channel model based on the direct component in line-of-sight (LoS) and reflections of non-line-of-sight (NLoS) links is considered, as well as thermal and shot noises. The design and mathematical models of a pyramid distribution and a new hemi-dodecahedral distribution are addressed in detail. The performances of these approaches, accompanied by signal combining schemes, are evaluated with the baseline of a single photo-diode in reception. Results show that the minimum lighting standards established in both scenarios are met. As expected, the root-mean-square delay spread decreases as the distance between the transmitters and receivers increases. Furthermore, the hemi-dodecahedron ADR in conjunction with the maximum ratio combining (MRC) scheme, presents the best performance in the evaluated VLC system, with a maximum user data rate of 250 Mbps in mining roadway and 120 Mbps in mine working face, received energy per bit/noise power of 32 dB and 23 dB, respectively, when the bit error rate corresponds to 10 − 4 , and finally, values of 120 dB in mining roadway and 118 dB in mine working face for signal-to-interference-plus-noise ratio are observed in a cumulative distribution function.

Technology Research on Rapid Excavation of Large Section Super-Long Coal Roadway

2014 ◽  
Vol 1010-1012 ◽  
pp. 1560-1563
Author(s):  
Sheng Kai Liang
Keyword(s):  
Mine Working ◽  
Social Benefit ◽  
Labor Intensity ◽  
Technology Research ◽  
Large Section ◽  
Coal Roadway ◽  
Working Face ◽  
Section Area ◽  
Rapid Excavation ◽  
Design Construction

The design construction length of conveyance roadway of the mine working face is nearly 5000m and the section area of driving is 18m2, belongs to large section super-long coal roadway. Through advanced mechanized supporting facilities tunneling construction and using reasonable support pattern and labor organization, it ensured the safety of workers, reduced the labor intensity, and realized the safety and rapid excavation with 440m/month. The economic and social benefit is obviously. It could provide reference meaning for other large section coal roadway rapid excavation at home and abroad.

Water Probe in Coal Mine Working Face

2013 ◽  
Vol 734-737 ◽  
pp. 888-891
Author(s):  
Chen Shi
Keyword(s):  
Hydraulic Conductivity ◽  
Coal Mining ◽  
Coal Mine ◽  
Mine Working ◽  
Mine Water ◽  
Theoretical Calculations ◽  
Drainage System ◽  
Water Inflow ◽  
Interference Method ◽  
Working Face

Water probe in coal mine working face is an important part of the work of Mine Water. When the mine working face close to the aquifer hydraulic conductivity faults, underground rivers, caves and hydraulic conductivity collapse columns; extractive damaging effects, water probe should be done. However, the calculation of water inflow face probe has no feasible way. This paper discussed the theoretical calculations to explore water drilling inflow well group interference method and provides the basis for provision of drainage system for the coal mining enterprises.

scholarly journals Modification of the roof bolt support technology in the conditions of increasing coal mining intensity

2019 ◽  
Vol 109 ◽  
pp. 00042 ◽  
Author(s):  
Oleksandr Krukovskyi ◽  
Yurii Bulich ◽  
Yuliia Zemlianaia
Keyword(s):  
Coal Mining ◽  
Mine Working ◽  
Stable State ◽  
Roof Bolt ◽  
Suggested Approach ◽  
Roof Bolting ◽  
Working Face ◽  
The Face ◽  
Mine Workings ◽  
Host Rocks

The modification of the technology roof bolt supporting of mine workings in the conditions of increasing the coal mining intensity has been made. The technological schemes have been developed for the phased construction of roof bolting and frame support. This schemes make it possible to temporarily postpone the setting of frames in the mine working face, reduce the time and labour intensity for covering with a grid of the mine working arch and setting the bolts, as well as to increase the safety. The analysis of changes in the stress state of the border massif during the phased construction of roof bolting and frame support has been made. It is shown that the technology of phased construction of roof bolting and frame support ensures the maintaining a stable state of host rocks. In addition, the time between the extraction of the coal-rock mass and the setting of the primary support, as well as the distance between the face and the first row of roof bolts has been reduced to a minimum. The suggested approach makes possible to ensure the rate of preparatory mine workings development that are necessary for the intensification coal mining.

scholarly journals Coal Wall and Roof Segmentation in the Coal Mine Working Face Based on Dynamic Graph Convolution Neural Networks

ACS Omega ◽  
2021 ◽  
Author(s):  
Zhizhong Xing ◽  
Shuanfeng Zhao ◽  
Wei Guo ◽  
Xiaojun Guo ◽  
Shenquan Wang ◽  
...  
Keyword(s):  
Neural Networks ◽  
Coal Mine ◽  
Mine Working ◽  
Dynamic Graph ◽  
Convolution Neural Networks ◽  
Working Face ◽  
Coal Wall

Simulation of a methane fire event at a coal mine working face with consideration of ventilation curtain damage

Transactions ◽  
2016 ◽  
Vol 340 (1) ◽  
pp. 120-126
Author(s):  
A. Haghighat ◽  
K. Luxbacher ◽  
B. Lattimer
Keyword(s):  
Coal Mine ◽  
Mine Working ◽  
Fire Event ◽  
Working Face
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