The effect of imperfections on surface critical properties is studied for Ising models with nearest– neighbour ferromagnetic couplings on simple cubic lattices. In particular, results of Monte Carlo simulations for flat, perfect surfaces are compared to those for flat surfaces with random, ’weak’ or ’strong’, interactions between neighbouring spins in the surface layer, and for surfaces with st...

CSMA (carrier sense multiple access) is random access protocol for multi-user data communication; it was development to be used in wired (Ethernet) systems, and eventually adopted as the main access scheme of wireless LANs. Because of some intrinsic imperfections and unpredictability of wireless channel, pure CSMA system can not completely use the channel resources; the methods offered in the 8...

We characterize optical wave propagation along line defects in two-dimensional arrays of air-holes in free-standing silicon slabs. The fabricated waveguides contain random variations in orientation of the photonic lattice elements which perturb the in-plane translational symmetry. The vertical slab symmetry is also broken by a tilt of the etched sidewalls. We discuss how these lattice imperfect...

This paper presents a worst case approach for robust geometry and topology optimization of plane frames with global stability constraint. Uncertainty is assumed to exist in the nodal locations cross-sectional areas, values objective constraint functions are relaxed quantile structural responses represented by order statistics given robustness confidence levels. In alleviate difficulty caused me...

The interaction behavior between local and global buckling modes in high-strength steel box-section columns has received limited research attention. Currently, there is a lack of validated equivalent geometric imperfection that can be effectively employed nonlinear plastic analysis to estimate the resistance. This aims find imperfections used geometrical materially using (GMNIA) resistance squa...

Recent studies on localized bulging in inflated membrane tubes have shown that the initiation pressure for the onset of localization is determined through a bifurcation condition. This kind of localization has also been shown to be much more sensitive to geometrical and material imperfections than classical sub-critical bifurcation into periodic patterns. We use these results to show that the i...

In engineering practice, longitudinal brace systems for column-braced are designed to resist both horizontal and vertical loads. previous experimental research on forces of intermediate height, only loads were considered. Hence, this paper presents a numerical simulation numerous subjected the simulation, second-order analysis was adopted, Monte Carlo method used incorporate randomness initial ...

the collapse of a compression member gives rise to decrease of the load carrying capacity of the member. to perform a nonlinear analysis, in addition to the precritical behavior, the post-critical behavior of the compression member also must be determined. in this study, because of certain advantages of the finite element method, this method has been selected to evaluate the axial load-axial di...