Dynamics of skewness and kurtosis of dangerous environmental parameters in the event of fire

Abstract

The object of this study is the dynamics of skewness and kurtosis of the selective distribution of dangerous parameters of the gas environment in the current time when materials are ignited. The theoretical substantiation of the methodology for determining the dynamics of skewness and kurtosis based on a sample of an arbitrary size of dangerous parameters of the gas medium moving in the current time of observation has been performed. Thresholds for current skewness and kurtosis are determined depending on sample size and null hypothesis significance levels. The procedure makes it possible to investigate the peculiarities of the dynamics of skewness and kurtosis and to identify moments of time for which alternative hypotheses (stability of parameter dynamics) are valid. Laboratory experiments were conducted to study the dynamics of skewness and kurtosis in terms of carbon monoxide concentration, smoke density, and the temperature of the gas environment during the ignition of alcohol and textiles. The results indicate that the investigated dangerous parameters are generally not Gaussian in the observation interval. It was found that the nature of the dynamics of measures of the current sample distributions of dangerous parameters depends on the type of ignition material and the dangerous parameter. It was established that in the absence of ignition, the dynamics of skewness and kurtosis of dangerous parameters is characterized by different directional skewness and kurtosis. In the event of ignition, the dynamics of skewness and kurtosis are fluctuating (from –4 to 18), which indicates the instability of the development of the dangerous parameter over time. The specified procedure creates an opportunity to detect the instability of the development of a dangerous parameter, which in practice makes it possible to detect the occurrence of fires (with a given reliability) in order to eliminate them and prevent the occurrence of a fire