Healthy and sick individuals (A and B particles) diffuse independently with diffusion constants D A and D B. Sick individuals upon encounter infect healthy ones (at rate k), but may also spontaneously recover (at rate 1/τ). The propagation of the epidemic therefore couples to the fluctuations in the total population density. Global extinction occurs below a critical value ρ c of the spatially a...

ABSTRACT: For nonlinear functions f of a random vector Y , E[ f ( Y )] and f (E[ Y ]) usually differ. Consequently the mathematical expectation of Y is not intrinsic: when we change coordinate systems, it is not invariant.This article is about a fundamental and hitherto neglected property of random vectors of the form , where X ( t ) is the value at time t of a diffusion process X : namely that...

We study the problem of statistical inference of continuous-time diffusion processes, and develop methods for modeling threshold diffusion processes in particular. We derive the limiting properties of the quasi-likelihood estimator. We also propose a quasi-likelihood ratio test statistic for testing threshold diffusion process against linear alternative. We begin in Chapter 1 with an introducti...

in this paper, carbon nanotubes (cnts) were added into chitosan (cs) hydrogels in the form of chitosan modified cnts (cs-cnts) composites to prepare carbon nanotubes hydrogels (cnts-gel). the products, named cs-mwcnts, were characterized by scanning electron microscope (sem) and fourier transform infrared (ftir) spectroscopy. swelling properties and effect of ph on controlled release performanc...

the transport properties of liquids and gases through polymeric materialsplay a very important role in some areas of industrial applications. in thisstudy, natural rubber (nr)/caco3 composites were prepared by melt mixingmethod. by equilibrium swelling test, the transport process of toluene in the prepared natural rubber composites was investigated. the diffusion and transport of toluene throug...

This paper studies the innovation diffusion problemwith the affection of urbanization, proposing a dynamical innovation diffusion model with fuzzy coefficient, and uses the shifting rate of people from rural areas stepping into urban areas to show the process of urbanization. The numerical simulation shows the diffusion process for telephones in China with Genetic Algorithms and this model is e...

Abstract: activity gas diffusion process has been investigated in this research. Effects of coating temperature and aluminumconcentration in powder mixture on formation mechanism were studied using optical and scanning electronmicroscopes, EDS and X-ray diffraction (XRD) techniques. For this purpose two different packs containing 1 and 2wt% aluminum powder, were used for coating the samples at ...

In this paper, carbon nanotubes (CNTs) were added into chitosan (CS) hydrogels in the form of chitosan modified CNTs (CS-CNTs) composites to prepare carbon nanotubes hydrogels (CNTs-GEL). The products, named CS-MWCNTs, were characterized by scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Swelling properties and effect of pH on controlled release performanc...