Motivated by the numerical solution of the linearized incompressible Navier–Stokes equations, we study threshold incomplete LU factorizations for non-symmetric saddle point matrices. The resulting preconditioners are used to accelerate the convergence of a Krylov subspace method applied to finite element discretizations of fluid dynamics problems in three space dimensions. The paper presents an...

We have developed a model for the impact of the hydrogen-induced piezoelectric effect on the threshold voltage of InP HEMTs and GaAs PHEMTs. We have used two-dimensional (2-D) finite element simulations to calculate the mechanical stress caused by a Ti-containing metal gate that has expanded due to hydrogen absorption. This has allowed us to map the 2-D piezoelectric charge distribution in the ...

Memristive systems, namely, resistive systems with memory, are currently attracting considerable attention. Here we show that even the simplest one-dimensional network formed by the most common memristive elements with voltage threshold bears nontrivial physical properties. In particular, by taking into account the single element variability we find (1) dynamical acceleration and slowing down o...

The information transmitted through a parallel summing array of noisy threshold elements with a common threshold is considered. In particular, using theoretical and numerical analysis, a recently reported [N. G. Stocks, Phys. Rev. Lett. 84, 2310 (2000)] form of stochastic resonance, termed suprathreshold stochastic resonance (SSR), is studied in detail. SSR is observed to occur in arrays with t...

We present a unified framework to deal with threshold functions for the existence of certain combinatorial structures in random sets. More precisely, let M · x = 0 be a linear system of r equations and m variables, and A a random set on [n] where each element is chosen independently with the same probability. We show that, under certain conditions, there exists a threshold function for the prop...

The paper offers a new methodology of designing in CMOS technology analogdigital artificial neurons learnable to arbitrary logical threshold functions of some number of variables. The problems of functional ability, implementability restrictions, noise stability, and refreshment of the learned state are formulated and solved. Some functional problems in experiments on teaching an artificial neu...

For marine mammals, auditory perception plays a critical role in a variety of acoustically mediated behaviors, such as communication, foraging, social interactions, and avoidance of predators. Although auditory perception involves many other factors beyond merely hearing or detecting sounds, sound detection is a required element for perception. As with many other processes, sound detection may ...

to evaluate the effect of different rates of nitrogen fertilizer on competitive ability of canola (okapi cv.) in interference with wild mustard, a split-plot experiment based on a randomized complete block design with 3 replications was carried out at agricultural faculty of bu-ali sina university, in 2008-2009. 4 levels of nitrogen fertilization (100, 150, 200 and 250 kg n ha-1) were assigned ...

farming organic vegetable and crops have grown as a market desiring commodity. weed control in farms has been costly and laborous and it has always been hard to achieve a proper weeding. a few chemicals are commonly applied in organic farming. thermal weeding with flame burners seems a good solution; however, it has its own drawbacks, such as; damaging the main crops, low performance, being inf...