Articles

Edge Maximal Graphs Containing No Specific Wheels

Let k ≥ 4 be a positive integer. Let G(n;W_k) denote the class of graphs on n vertices containing no wheel W_k as a subgraph. In this paper, we study the following: (1) Edge maximal graphs containing no odd wheels. Furthermore, we characterize the extremal graphs. (2) The edge maximal graph containing no even wheels. (3) The edge maximal graph containing no specific even wheels.

Rings on Torsion-Free Groups of Rank One and Two

This paper gives a survey about the possible rings which may be de-fined over torsion-free groups of rank one and two. In fact, we give a list of such rings which have been studied by some mathematicians over the past decades. In particular, we give a review of the authors' studies to determine such rings.

A. Najafizadeh

A. M. Aghdam

JJMS, 2015, 8(2), 121-154 

The principle of finding an integrating factor for a none exact differential equations is extended to equations of second order. If the second order equation is not exact, under certain conditions, an integrating factor exists that transforms it to an exact one. In this paper we give explicit forms for integrating factors of the second order differential equations.

Rami Al-Ahmad

M. Al-Jararha

H. Al Mefleh

N. Selvanayaki

Gnanambal Ilango

Extension of Cerone's Generalizations of Steffensen's Inequality

The aim of this paper is to extend Cerone's generalization of Ste-ffensen's inequality to positive finite measures and to give weaker conditions for obtained extension. Further, our intension is to obtain extensions of known generalizations of Steffensen's inequality in order to allow bounds that involve any two subintervals using measure theoretic aspects.

Julije Jaksetic

Josip Pecaric

Ksenija Smoljak Kalamir