this study seeks to examine how a company can select the best intermediary for its marketing channels with minimum of criteria and time. a theoretical framework is proposed based on the most important tasks of intermediary and the criteria to measure them. there are four basic tasks and thirty criteria in three independent levels. subsequently, an exploratory case study in iranian food industry...

It is well known that most PDE problems defined over an axisymmetric domain can be efficiently solved by a Fourier based solution method. However, for many applications, the underlying computational domain is not entirely axisymmetric, but has one or several major axisymmetric subdomains. For such problems, an axisymmetric analysis method is not applicable, and a straightforward one can be inef...

Increasing observations are becoming available about a relatively weak, but persistent, non-axisymmetric magnetic field co-existing with the dominant axisymmetric field on the Sun. It indicates that the non-axisymmetric magnetic field plays an important role in the origin of solar activity. A linear non-axisymmetric α − Ω dynamo model is set up to discuss the characteristics of the axisymmetric...

Observations show that solar activity is distributed non-axisymmetrically, concentrating at “preferred longitudes”. This indicates the important role of non-axisymmetric magnetic fields in the origin of solar activity. We investigate the generation of the non-axisymmetric fields and their coupling with axisymmetric solar magnetic field. Our kinematic generation (dynamo) model operating in a sph...

The purpose of this study is to determine more accurately the marginal stability condition for axisymmetric waves since it is believed that an unstable axisymmetric wave could affect the amplification of spiral waves. An axisymmetric wave with a gradient term of velocity dispersion ( surface density ) is derived. Analysis of this axisymmetric wave with a gradient term for our own galaxy shows t...

Context. The MHD instabilities can generate complex field topologies even if the initial field configuration is a very simple one. Aims. We consider the stability properties of magnetic configurations containing a toroidal and an axial field. In this paper, we concentrate mainly on the behavior of non-axisymmetric perturbations in axisymmetric magnetic configurations. Methods. The stability is ...

An efficient approach to the geometry optimization problem of a non-axisymmetric flow channel is discussed. The method combines geometrical transformation with computational fluid dynamics solver, multi-objective genetic algorithm, and response surface. This approach, through modifications simplifications allows transforming into axisymmetric one in some specific devices i.e., scroll distributo...

The aim of this article is to model and analyze an unsteady axisymmetric flow of non-conducting, Newtonian fluid squeezed between two circular plates passing through porous medium channel with slip boundary condition. A single fourth order nonlinear ordinary differential equation is obtained using similarity transformation. The resulting boundary value problem is solved using Homotopy Perturbat...