International Journal of Mathematics and Statistics 

About: International Journal of Mathematics and Statistics is an academic journal. The journal publishes majorly in the area(s): Estimator & Computer science. It has an ISSN identifier of 0973-8347. Over the lifetime, 160 publications have been published receiving 824 citations. The journal is also known as: IJMS.

Ulam Stability for the Orthogonally General Euler - Lagrange Type Functional Equation

Abstract: In this paper, J. M. Rassias introduces the general Euler Lagrange type functional equation of the form.

Comparing Two Samples from an Individual Likert Question

Abstract: For two independent samples there is much debate in the literature whether parametric or non-parametric methods should be used for the comparison of Likert question responses. The comparison of paired responses has received less attention in the literature. In this paper, parametric and non-parametric tests are assessed in the comparison of two samples from a paired design on a five point Likert question. The tests considered are the independent samples t-test, the Mann-Whitney test, the paired samples t-test and the Wilcoxon test. Pratt’s modified Wilcoxon test for dealing with zero differences is also included. The Type I error rate and power of the test statistics are assessed using Monte-Carlo methods. The parameters varied are; sample size, correlation between paired observations, and the distribution of the responses. The results show that the independent samples t-test and the Mann-Whitney test are not Type I error robust when there is correlation between the two groups compared. Pratt’s test more closely maintains the Type I error rate than the standard Wilcoxon test does. The paired samples t-test is Type I error robust across the simulation design. As the correlation between the paired samples increases, the power of the test statistics making use of the paired information increases. The paired samples t-test is more powerful than Pratt’s test when the correlation is weak. The power differential between the test statistics is exacerbated when sample sizes are small. Assuming equally spaced categories on a five point Likert item, the paired samples t-test is not inappropriate.

Fixed Point Theorems for Some Multivalued Generalized Contractions in B-Metric Spaces

Abstract: The purpose of this paper is to develop a fixed point theory for multivalued generalized contractions in complete b-metric spaces.

Zografos–Balakrishnan Burr XII Distribution: Regression Modeling and Applications

Abstract: In this paper, we propose a new three-parameter model called the Zografos–Balakrishnan Burr XII distribution, which extends the Burr XII model. The new density function is expressed as a linear mixture of Burr XII densities. Explicit expressions for some of its mathematical and statistical characteristics including the ordinary and incomplete moments, quantile, cumulants, generating functions and order statistics are derived. We propose a log-linear regression model using a new distribution, the log Zografos–Balakrishnan BXII distribution. The maximum likelihood method is used to estimate the model parameters. Simulation results to assess the performance of the maximum likelihood estimation is discussed. The proposed model is shown to provide better fits than some nested and non nested models by using five real data sets. We hope that the proposed model will attract wider applications in areas such as survival and lifetime data, meteorology, hydrology, engineering and others.

Common fixed point results for mappings satisfying (psi, phi) -weak contractions in ordered partial metric spaces

Abstract: In this paper, we extend a result of Stojan Radenovic and Zoran Kadelburg [Generalized weak contractions in partially ordered metric spaces, Computers and Mathematics with Applications 60 (2010), 1776-1783] to ordered partial metric spaces. Besides, we present an example illustrating our result and we deduce a fixed point theorem involving contractions of integral type.