It is proved that the Green’s function of the simple random walk on a surface group of large genus decays exponentially in distance at the (inverse) spectral radius. It is also shown that Ancona’s inequalities extend to the spectral radius R, and therefore that the Martin boundary for R−potentials coincides with the natural geometric boundary S. This implies that the Green’s function obeys a po...

We prove that given a fixed radius r, the maximum density achieved by packings of the hyperbolic plane by radius r circles is the supremum of densities of “periodic packings” (those packings with cofinite symmetry). We also show that the maximal density function is continuous as a function of radius. Our investigations lead us to consider more general questions regarding the density of periodic...

We present an algorithm computing, for any first order differential equation L over the affine line and any (Berkovich) point t of this affine line, the p-adic radius of convergence RL(t) of the solutions of L near t. We do explicit computations for the equation (0.1) L(f) def = xf ′ − π(px + ax)f = 0 (πp−1 = −p). where a lies in some valued extension of Qp. For a = −1 and t = 0, a solution of ...

Pursuant to the high usage of rotating the disk in aircraft gas turbine engine, turbo pumps in oil and gas industries, steam and gas turbines in power plants, marine gas turbine and other industrial rotary machines designing and getting under the mechanical and thermal loading casued this design and analysis to be as a special significance. These disks are subjected to mechanical and thermal lo...

in this study, the stability problem of a circular orthotropic cylindrical shell under the effect of anaxial compression varying with a power function of time is considered. at first, the modified donnell typedynamic stability and compatibility equations are obtained using love’s shell theory. applying the galerkinmethod and rayleigh-ritz variational techniques to these equations and taking the...

in this paper, the deformation of a thick-walled circular cylindrical shell of incompressible isotropic elastic material is considered. the shell, which is made of three-term strain energy function is subjected to the combined external and axial loading pressure. in order to obtain the relevant eigenvalues, which is the main objective of the work, the incremental equilibrium equations are so...

This paper introduces a niching technique called GAS (S stands for species) which dynamically creates a subpopulation structure (taxonomic chart) using a radius function instead of a single radius, and a ‘cooling’ method similar to simulated annealing. GAS offers a solution to the niche radius problem with the help of these techniques. A method based on the speed of species is presented for det...

This paper deals with the reconstruction of smooth, flexible, flat surfaces isometrically embedded in 3D when observed from uncalibrated camera images. It provides a cost function which captures the global geometry of the problem. The input data consists of a sequence of matched feature points (i.e. known correspondence), but the algorithm allows for missing data so that all points do not need ...

A solution is given for the frictionless indentation of an elastic half-space by a flat-ended cylindrical punch with a central circular recess, when the load is large enough to establish a circular region of contact in the recess. The problem is reduced to two simultaneous Fredholm equations using the method of complex potentials due to Green and Collins. Results are presented for the relations...