A disorder-dependent Gaussian variational approach is applied to the problem of a d dimensional polymer chain in a random medium (or potential). Two classes of variational solutions are obtained. For d < 2, these two classes may be interpreted as domain and domain wall. The critical exponent ν describing the polymer width is ν = 1 (4−d) (domain solution) or ν = 3 (d+4) (domain wall solution). T...

Network processors utilize a special unit for the classification of the received packets according to their characteristics. The classification of packets is currently the most processor intensive portion of network processing which has to be performed at wire speed. Currently, network processors use Content Addressable Memories (CAM), for classification of thousands of flow identifiers in ATM ...

We have studied a model of a random walk in a quenched random environment. In addition to featuring anomalous diffusion and localization, for special regimes of disorder parameters the particle density decomposes into multi-Gaussian structure while its cumulative distribution is normal. We explain the observed fine structure of the density and point out its significance to experiments.

We consider solutions of a scalar reaction-diffusion equation of the ignition type with a random, stationary and ergodic reaction rate. We show that solutions of the Cauchy problem spread with a deterministic rate in the long time limit. We also establish existence of generalized random traveling waves and of transition fronts in general heterogeneous media.

2014 The propagation of a front (we use the model of a forest fire) in a bidimensional random lattice is studied for several different types of interactions. We obtain the corresponding critical concentrations and critical exponents calculated by means of the finite size scaling conjecture. These exponents are expressed in terms of the fractal dimension of the infinite cluster and of the spread...

We consider acoustic pulse propagation in inhomogeneous media over relatively long propagation distances. Our main objective is to characterize the spreading of the travelling pulse due to microscale variations in the medium parameters. The pulse is generated by a point source and the medium is modelled by a smooth three-dimensional background that is modulated by stratified random fluctuations...

We study mission-critical networking in wireless communication networks, where network users are subject to critical events such as emergencies and crises. If a critical event occurs to a user, the user needs to send necessary information for help as early as possible. However, most existing medium access control (MAC) protocols are not adequate to meet the urgent need for information transmiss...

We examined laser action in a two-dimensional amplifying and scattering medium consisting of random array of dye-doped plastic fiber. When the excitation pulse energy was increased, the parallel emission component to the fiber first reached the laser threshold showing spectral collapse, and then further increase in the excitation pulse energy resulted in the subsequent laser action in the perpe...

The differential equation for the fourth-order statistical moment of the field of a finite beam propagating in a statistically homogeneous and isotropic two-dimensional random medium is solved numerically. Results are presented for the variance and covariance of irradiance scintillations of a Gaussian beam that propagates in a medium with a Gaussian correlation function. It is shown that the ra...

A randomly pinned elastic medium in two dimensions is modeled by a disordered fully-packed loop model. The energetics of disorderinduced dislocations is studied using exact and polynomial algorithms from combinatorial optimization. Dislocations are found to become unbound at large scale, and the elastic phase is thus unstable giving evidence for the absence of a Bragg glass in two dimensions. R...