this paper examines the historical development of operations research (or) and represents different or methods (methodologies) developed during its lifetime. then, considering thomas kuhn’s paradigm model of scientific development as a basis for our work, the former and current status of or are analyzed and the future trend is discussed.

Orbital-free density functional theory as an extension of traditional Thomas-Fermi theory has attracted a lot of interest in the past decade because of developments in both more accurate kinetic energy functionals and highly efficient numerical methodology. In this paper, we developed a conjugate-gradient method for the numerical solution of spin-dependent extended Thomas-Fermi equation by inco...

Patients with pectus carinatum are at risk for a disturbed body image and reduced quality of life. Until recently, treatment required surgical reconstruction. A growing body of literature, however, now supports the use of orthotic bracing as a nonoperative alternative in select patients. This article reviews the current literature and describes the evaluation and management of children with pec...

In the White House, among journalists, and for many political practitioners, the idea of a major “political realignment” that might dramatically reshape the face of American politics remains as tantalizing as ever. But among historians and political scientists, no one needs a weatherman to tell which way the wind is blowing. The long-venerated “realignment” approach to election analysis develop...

7 Davis, J.A., Construction of relative difference sets in p-groups, Discrete Mathematics 103 (1992) 7-15. Jungnickel (1982) and Elliot and Butson (1966) have shown that (pi+ , p, pi+•, pi) relative difference sets exist in the elementary abelian p-group case (p an odd prime) and many 2-groups for the case p = 2. This paper provides two new constructions of relative difference sets with these p...