Vibration of double-graphene sheet-system is considered in this study. Graphene sheets are coupled by Pasternak elastic medium. Classic and Mindlin plate theories are utilized for modeling the coupled system. Upper sheet carries a moving mass. Governing equations are derived using energy method and Hamilton’s principle considering surface stress effects and nonlocal parameter.  Using Galerkin m...

In this paper, surface effects including surface elasticity, surface stress and surface density, on the free vibration analysis of Euler-Bernoulli and Timoshenko nanobeams are considered using nonlocal elasticity theory. To this end, the balance conditions between nanobeam bulk and its surfaces are considered to be satisfied assuming a linear variation for the component of the normal stress thr...

In general the importance of functional traits is increasing in all dairy cattle populations over the last decade. Beside udder and fertility problems claw and foot disorders are main involuntary culling reasons. Linear description of feet and leg traits in the frame of conformation scoring didn’t reduce claw and leg problems as expected. Therefore new ways of data recording should be establish...

Although each statistical unit on which measurements are taken is unique typically there is not enough information available to account totally for its uniqueness. Therefore heterogeneity among units has to be limited by structural assumptions. One classical approach is to use random effects models, which assume that heterogeneity can be described by distributional assumptions. However, inferen...

Meta-analysis is a standard statistical method used to combine the conclusions of individual studies that are related and the results of single study alone can not answered to deal with issues. The data are summarized by one or more outcome measure estimates along with their standard errors. The multivariate model and the variations between studies are not considered in most articles. Here we d...

This paper sheds some light on the problems associated with random effects gravity approaches. Arguments for the superiority of a fixed effects model are given both along intuitive and econometric lines based on a Hausman test.  2000 Elsevier Science S.A. All rights reserved.

This paper uses data drawn from the English Football League to model separate hazard rates for club managers for the 2001/2, 2002/3 and 2003/4 seasons. On average over the three seasons, approximately one-third of managers involuntarily exited employment status with their club. We model the hazard using a standard logistic model exploiting information on the spell at risk rather than the indivi...

In this study, the free vibration behavior of rotating nanobeam is studied.  Surface effects on the vibration frequencies of nanobeam are considered. To incorporate surface effects, Gurtin–Murdoch model is proposed to satisfy the surface balance equations of the continuum surface elasticity. Differential quadrature method is employed and in order to establish the accuracy and applicability of t...

In this article, surface stress and nonlocal effects on the biaxial and uniaxial buckling of rectangular silver nanoplates embedded in elastic media are investigated using finite difference method (FDM). The uniform temperature change is utilized to study thermal effect. The surface energy effects are taken into account using the Gurtin-Murdoch’s theory. Using the principle of virtual work, the...