Combined Prediction Model of Gas Concentration Based on Indicators Dynamic Optimization and Bi-LSTMs.

In order to accurately predict the gas concentration, find out the gas abnormal emission in advance, and take effective measures to reduce the gas concentration in time, this paper analyzes multivariate monitoring data and proposes a new dynamic combined prediction method of gas concentration. Spearman's rank correlation coefficient is applied for the dynamic optimization of prediction indicators. The time series and spatial topology features of the optimized indicators are extracted and input into the combined prediction model of gas concentration based on indicators dynamic optimization and Bi-LSTMs (Bi-directional Long Short-term Memory), which can predict the gas concentration for the next 30 min.

Investigation of coal and gas outburst risk by microseismic monitoring.

In order to improve the monitoring and prediction of coal and gas outburst, this paper proposes a new method for dynamic regional prediction of coal and gas outburst using microseismic (MS) monitoring. The theoretical basis of this method is presented. An index evaluation system was established and applied, based on which field tests were carried out in a coal mine.

The roles of foam ceramics in suppression of gas explosion overpressure and quenching of flame propagation.

In order to substantially suppress the shock waves resulting from gas explosions in coal mines as well as to reveal the mechanism of explosion flame quenching by foam ceramics, a rectangular explosion test pipe was designed, which has a 200mm × 200mm cross-section and is similar in shape to the roadways in coal mines. Explosion flame propagation characteristics in empty pipe and in the presence of Al(2)O(3) and SiC foam ceramics were experimentally investigated. To obtain direct observations, the flame propagation was photographed by a high-speed camera.

Longitudinal relationship between economic development and occupational accidents in China.

The relativity between economic development and occupational accidents is a debated topic. Compared with the development courses of both economic development and occupational accidents in China during 1953-2008, this paper used statistic methods such as Granger causality test, cointegration test and impulse response function based on the vector autoregression model to investigate the relativity between economic development and occupational accidents in China from 1953 to 2008. Owing to fluctuation and growth scale characteristics of economic development, two dimensions including economic cycle and economic scale were divided.