In the present paper, a class of stochastic Runge–Kutta methods containing the second order stochastic Runge–Kutta scheme due to E. Platen for the weak approximation of Itô stochastic differential equation systems with a multi-dimensional Wiener process is considered. Order 1 and order 2...

The phenomenon of ‘synchronization’ of physical diffusion is widely discussed in the physical literature. In this paper, we give a simple rigorous proof of the synchronization for a one-dimensional diffusion including the one-dimensional counterpart of a physical diffusion described by a...

We consider scalar stochastic differential equations of the formdXt=μ(Xt)dt+σ(Xt)dBt,X0=x0,where B is a standard Brownian motion. Suppose that the coefficients are such that the solution X possesses the (a, b)-invariance property for some interval (a,b)⊂R:Xt∈(a,b) for all t≥0 if...

A ‘standard’ second order weak Runge–Kutta method for a stochastic differential equation can be applied only in the case where the equation is understood in the Stratonovich sense. To adapt Runge–Kutta type methods for Itô equations, we propose to use a rather simple additional...

We consider a stochastic model of the two-dimensional chemostat as a diffusion process for the concentration of substrate and the concentration of biomass. The model allows for the washout phenomenon: the disappearance of the biomass inside the chemostat. We establish the Fokker–Planck...

Understanding the behaviour of market prices is not simple. Stock market prices tend to have complicated distributions with strong skewness and fat tails. One important step in forecasting tomorrow’s price is to estimate the volatility, i.e. how much tomorrow’s price is expected to differ...

An efficient methodology of estimation of parameters in the diffusion coefficient of the stochastic differential equation (SDE) is presented in this work. The methodology is based on the concept of quadratic variation of a stochastic process and on some classical numerical tools such as spline...

In this paper we study the initial boundary value problem of wave equations with nonlinear damping and source terms:utt−Δu+a|ut|m−1ut=b|u|p−1u,x∈Ω,t0,u(x,0)=u0(x),ut(x,0)=u1(x),x∈Ω,u(x,t)=0,x∈∂Ω,t≥0,where Ω⊂RN is a suitably smooth bounded domain. We prove that for any a0...