https://www.selleckchem.com/products/hs148.html On the other hand, the absence of firework during the Spring Festival in 2020 may explain the darker night skies. Finally, there is an evidence that the urban developments in Wuxi are degrading night sky quality.For the first time, ten frequentist estimation methods are considered on stress-strength reliability R = P(Y less then X) when X and Y are two independent Weibull distributions with the same shape parameter. The start point to estimate the parameter R is the maximum likelihood method. Other than the maximum likelihood method, a nine frequentist estimation methods are used to estimate R, namely least square, weighted least square, percentile, maximum product of spacing, minimum spacing absolute distance, minimum spacing absolute-log distance, method of Cramér-von Mises, Anderson-Darling and Right-tail Anderson-Darling. We also consider two parametric bootstrap confidence intervals of R. We compare the efficiency of the different proposed estimators by conducting an extensive Mont Carlo simulation study. The performance and the finite sample properties of the different estimators are compared in terms of relative biases and relative mean squared errors. The Mont Carlo simulation study revels that the percentile and maximum product of spacing methods are highly competitive with the other methods for small and large sample sizes. To show the applicability and the importance of the proposed estimators, we analyze one real data set. Sleep duration has been found to affect some reproductive phenotypes but fecundability has been rarely researched. We aim to evaluate the association between female/male sleep duration and the probability of conception in two representative populations. The present study uses two datasets, namely, a cross-sectional dataset of 9137 reproductive-age females in the US (National Health Interview Survey, NHIS) and a longitudinal dataset of 2687 reproductive-age females and their male mates in