Cogent Mathematics 

About: Cogent Mathematics is an academic journal. The journal publishes majorly in the area(s): Convex function & Nonlinear system. Over the lifetime, 277 publications have been published receiving 1362 citations.

Interval-valued Pythagorean fuzzy geometric aggregation operators and their application to group decision making problem

Abstract: There are many aggregation operators have been defined up to date, but in this work, we define the interval valued Pythagorean fuzzy weighted geometric (IPFWG) operator, the interval-valued Pythago...

A defense against the alleged unreliability of difference scores

Abstract: Based on a classical true score theory (classical test theory, CTT) equation, indicating that as the observed correlation between two tests increases, the reliability of the difference scores decreases, researchers have concluded that difference scores are unreliable. But CTT shows that the reliabilities of the two tests and the true correlation between them influence the observed correlation and previous analyses have not taken the true correlation sufficiently into account. In turn, the reliability of difference scores depends on the interaction of the reliabilities of the individual tests and their true correlation when the variances of the tests are equal, and on a more complicated interaction between them and the deviation ratio when the variances of the tests are not equal. The upshot is that difference scores likely are more reliable, on more occasions, than researchers have realized. I show how researchers can predict what the reliability of the difference scores is likely to be, to aid in...

The improved F-expansion method with Riccati equation and its applications in mathematical physics

Abstract: The improved F-expansion method combined with Riccati equation is one of the most effective analytical methods in finding the exact traveling wave solutions to non-linear evolution equations in mat...

Effect of viscous dissipation on hydromagnetic fluid flow and heat transfer of nanofluid over an exponentially stretching sheet with fluid-particle suspension

Abstract: This paper considers the problem of steady, boundary layer flow and heat transfer of a nanofluid with fluid-particle suspension over an exponentially stretching surface in the presence of transverse magnetic field and viscous dissipation. The stretching velocity and wall temperature are assumed to vary according to specific exponential form. The governing equations in partial forms are reduced to a system of coupled non-linear ordinary differential equations using suitable similarity transformations. An effective Runge–Kutta–Fehlberg (RKF-45) is used to solve the obtained differential equations with the help of a symbolic software MAPLE. The effects of flow parameters—such as nanofluid interaction parameter, magnetic parameter, solid volume fraction of nanoparticle parameter, Prandtl number and Eckert number—on the flow field and heat-transfer characteristics were obtained and are tabulated. Useful discussions were carried out with the help of plotted graphs and tables. Under the limiting cases, c...

Exact traveling wave solutions for the generalized Hirota-Satsuma couple KdV system using the exp(−φ(ξ))-expansion method

Abstract: In this research, we find the exact traveling wave solutions involving parameters of the generalized Hirota-Satsuma couple KdV system according to the exp(-φ(ξ))-expansion method and when these parameters are taken to be special values we can obtain the solitary wave solutions which is derived from the exact traveling wave solutions. It is shown that the proposed method provides a more powerful mathematical tool for constructing exact traveling wave solutions for many other nonlinear evolution equations.