Open Access Original Research Article

Generating New Flexible Lifetime Class of Distributions Based on Competing Risks and Frailty Models

M. M. E. Abd El-Monsef, M. M. El-Awady

Asian Journal of Probability and Statistics, Page 1-19
DOI: 10.9734/ajpas/2021/v12i130277

New classes of continuous distributions have been generated, in the last decad, based on a compounding procedure arises on a latent competing risks problem. This procedure assumes the homogeneity between the population individuals. In this paper, a new lifetime distribution is generated, assuming the heterogeneity at both population and individual levels, called Extended Gamma Gompertz (EGG) distribution. This distribution shows very desirable exibility of its hazard function. Some properties of the proposed distribution are given. Maximum likelihood estimation technique is used to estimate the parameters. A simulation study is performed to examine the performance of the proposed model. Finally, application to a real data set is given to exemplify the utility of the EGG distribution.

Open Access Original Research Article

Class of Tests Based on Subsample Quantiles for Two-sample Scale Problem

Shashank D. Shindhe, Sharada V. Bhat, Parameshwar V. Pandit

Asian Journal of Probability and Statistics, Page 20-33
DOI: 10.9734/ajpas/2021/v12i130276

A class of distribution-free tests based on U-statistics with its kernel being function of subsample quantiles is proposed for a two-sample scale problem. The proposed class of tests is a general class of tests that includes numerous members which explore information from the tails of the distributions and tests resistant to outliers. This class of tests includes many existing classes of tests as its subclasses. The distribution of the proposed class of tests is derived and its relevance is discussed. One of its members, which is resistant to outliers in -sample is investigated in detail.

Open Access Original Research Article

Generalized Exponential Power Distribution with Application to Complete and Censored Data

M. M. E. Abd El-Monsef, M. M. El-Awady

Asian Journal of Probability and Statistics, Page 34-55
DOI: 10.9734/ajpas/2021/v12i130278

The exponential power distribution (EP) is a lifetime model that can exhibit increasing and bathtub hazard rate function. This paper proposed a generalization of EP distribution, named generalized exponential power (GEP) distribution. Some properties of GEP distribution will be investigated. Recurrence relations for single moments of generalized ordered statistics from GEP distribution are established and used for characterizing the GEP distribution. Estimation of the model parameters are derived using maximum likelihood method based on complete sample, type I, type II and random censored samples. A simulation study is performed in order to examine the accuracy of the maximum likelihood estimators of the model parameters. Three applications to real data, two with censored data, are provided in order to show the superiority of the proposed model to other models.

Open Access Original Research Article

Two-Parameter Nwikpe (TPAN) Distribution with Application

Barinaadaa John Nwikpe, Isaac Didi Essi

Asian Journal of Probability and Statistics, Page 56-67
DOI: 10.9734/ajpas/2021/v12i130279

A new two-parameter continuous distribution called the Two-Parameter Nwikpe (TPAN) distribution is derived in this paper. The new distribution is a mixture of gamma and exponential distributions. A few statistical properties of the new probability distribution have been derived. The shape of its density for different values of the parameters has also been established.  The first four crude moments, the second and third moments about the mean of the new distribution were derived using the method of moment generating function. Other statistical properties derived include; the distribution of order statistics, coefficient of variation and coefficient of skewness. The parameters of the new distribution were estimated using maximum likelihood method. The flexibility of the Two-Parameter Nwikpe (TPAN) distribution was shown by fitting the distribution to three real life data sets. The goodness of fit shows that the new distribution outperforms the one parameter exponential, Shanker and Amarendra distributions for the data sets used for this study.

Open Access Original Research Article

Road Traffic Offences in Nigeria: An Empirical Analysis using Buys-Ballot Approach

K. C. N. Dozie, C.C Ibebuogu

Asian Journal of Probability and Statistics, Page 68-78
DOI: 10.9734/ajpas/2021/v12i130280

Road traffic offences in time series analysis when trend-cycle component is quadratic is discussed in this study. The study is to investigate the variance stability, trend pattern, seasonal indices and suitable model for decomposition of study data. The study shows that, the series is seasonal with evidence of upward trend or downward trend. There is an upsurge of the series in the months of March, August and November and a drop in January, June and December. The periodic standard deviations are stable while the seasonal standard deviations differ, suggesting that the series requires transformation to make the seasonal indices additive.