A Novel Frechet-Type Probability Distribution: Its Properties and Applications

In this article, a new lifetime model, referred to as modified Frechet–Rayleigh distribution (MFRD), is developed by accommodating an additional parameter in Rayleigh distribution on the basis of the modified Frechet method. Numerous statistical properties of the suggested model are derived and discussed. The technique of maximum likelihood (ML) estimation is adopted to get estimates of the parameters. The suggested model is very flexible and has the capability to model datasets having both monotonic and nonmonotonic failure rates. The proposed model is applied on two real datasets for checking its performance in comparison with available well-known models. The suggested model has shown outclass performance in comparison with the available versions of the Rayleigh distribution used in the literature.

On the frequency module of the hull of a primitive substitution tiling

Understanding the properties of tilings is of increasing relevance to the study of aperiodic tilings and tiling spaces. This work considers the statistical properties of the hull of a primitive substitution tiling, where the hull is the family of all substitution tilings with respect to the substitution. A method is presented on how to arrive at the frequency module of the hull of a primitive substitution tiling (the minimal {\bb Z}-module, where {\bb Z} is the set of integers) containing the absolute frequency of each of its patches. The method involves deriving the tiling's edge types and vertex stars; in the process, a new substitution is introduced on a reconstructed set of prototiles.

Variations in meteorological floods during summer monsoon over India

In this study, rainfall data of 31 mteorological sub-divisioins in India for 113 years (1875-1987) have been used to develop a flood index and statistical properties of the Index are discussed. Relationship of the index with the seasonal rainfall, number of depressions and El-N/no phenomenon are examined. The study revealed that 1971-80 decade, had more number of flood years than the drought years. The flood index was found to be significantly related to flood situation over India. It IS difficult to associate any particular phase of the quasi-biennial oscillations (QBO) with occurrence of floods.

The Novel Bivariate Distribution: Statistical Properties and Real Data Applications

This article proposes a novel class of bivariate distributions that are completely defined by stating their conditionals as Poisson exponential distributions. Numerous statistical properties of this distribution are also examined here, including the conditional probability mass function (PMF) and moments of the new class. The techniques of maximum likelihood and pseudolikelihood are used to estimate the model parameters. Additionally, the effectiveness of the bivariate Poisson exponential conditional (BPEC) distribution is compared to that of the bivariate Poisson conditional (BPC), the bivariate Poisson (BP), the bivariate Poisson–Lindley (BPL), and the bivariate negative binomial (BNB) distributions using a real-world dataset. The findings of Akaike information criterion (AIC) and Bayesian information criterion (BIC) reveal that the BPEC distribution performs better than the other distributions considered in this study. As a result, the authors claim that this distribution may be used to fit dependent and overspread count data.

Frequency analysis of δ Scuti stars towards the Galactic bulge

We have performed a frequency analysis of 10,092 δ Scuti-type stars detected in the fourth phase of the Optical Gravitational Lensing Experiment (OGLE) towards the Galactic bulge, which is the most numerous homogeneous sample of δ Scuti stars observed so far. The main goal was to search for stars pulsating in at least two radial modes simultaneously. We have found 3083 candidates for such stars, which is the largest set obtained to date. Among them, 2655 stars pulsate in two radial modes, 414 stars pulsate in three radial modes, and 14 stars pulsate in four radial modes at the same time. We report the identification of 221 δ Scuti stars pulsating in the fundamental mode, first overtone, and third overtone simultaneously. We show the most populated Petersen and Bailey diagrams and discuss statistical properties of the identified frequencies based on this numerous sample. Additionally, we present theoretical predictions of period ratios for δ Scuti stars pulsating in overtones from the fourth to the seventh.

An extensive extension of exponentiated exponential distribution using alpha power transformation – statistical properties and applications in engineering science

In this article, an extension of exponentiated exponential distribution is familiarized by adding an extra parameter to the parent distribution using alpha power technique. The new distribution obtained is referred to as Alpha Power Exponentiated Exponential Distribution. Various statistical properties of the proposed distribution like mean, variance, central and non-central moments, reliability functions and entropies have been derived. Two real life data sets have been applied to check the flexibility of the proposed model. The new density model introduced provides the better fit when compared with other related statistical models.