A gas outburst risk level prediction method, based on the Whale Optimization Algorithm (WOA) Improved Extreme Learning Machine (ELM), is proposed to predict coal and hazard more accurately. Based this recommendations are given according with help of Case-Based Reasoning (CBR) method. Firstly, we analyze accident reports accidents, select index, construct index system by combining prevention con...

We present Spitzer Space Telescope observations of V1647 Ori, the outburst-ing source lighting McNeil's nebula, taken near the optical peak of the outburst in early March 2004. The source is easily detected in all Spitzer imaging bands from 3.6-70 µm. The fluxes at all wavelengths are roughly a factor of 15 brighter than pre-outburst levels; we measure a bolometric luminosity of 44 L ⊙. We posi...

Abstract Although a series of hypotheses have been proposed, the mechanism underlying coal and gas outburst remains unclear. Given low-index outbursts encountered in mining practice, we attempt to explore this using multiphysics coupling model considering effects strength mass transfer on failure. Based force analysis ahead heading face, risk identification index C m critical criterion ( ? 1) i...

We present a 4 year light curve of a cataclysmic variable in M22, based on an analysis of accumulated data from the MOA microlensing survey. The position of the star coincides with that of a transient event observed by HST in 1999, originally attributed to microlensing but later suspected to be a dwarf nova outburst. Two outburst episodes, one in 2002 and one in 2003, with ∆I ∼ 3 are seen in th...

We present optical and infrared monitoring of the 2005 outburst of the halo black hole X-ray transient XTE J1118+480. We measured a total outburst amplitude of ∼ 5.7±0.1 mag in the R band and ∼ 5 mag in the infrared J, H and K s bands. The hardness ratio HR2 (5-12 keV/3-5 keV) from the RXTE/ASM data is 1.53±0.02 at the peak of the outburst indicating a hard spectrum. Both the shape of the light...

The comparative analysis of coal samples under different gas occurrence conditions systematically reveals the pore structure characteristics and outburst seams. functional relationship between R0,max Kc was clarified using mathematical statistical methods, fractal seams were analyzed on basis modified mercury pressure data analysis. results show that is consistent with y = 1.59x−0.48, when inle...

For the first time we have performed a detailed study of the X-ray, optical and infrared light curves and an intercomparison between these wavelengths (including radio) of the 1975/1976 outburst of the famous black-hole transient A0620−00 (Nova Mon 1975, V616Mon). We also investigated the optical behaviour up to a year after the main outburst. This study enabled us to find some new features, wh...