preprint numerics no. 1/2008 norwegian university of science and technology trondheim, norway We present a temporal splitting scheme for the semi-discrete convection-diffusion equation and the semi-discrete incompressible Navier-Stokes equations in time-depedent geometries. The proposed splitting scheme can be considered as an extension of the OIF-method proposed in [22] in the sense that it ca...

We introduce a new variant of the Goemans-Williamson (GW) scheme for the Prize-Collecting Steiner Tree Problem (PCST). Motivated by applications in signal processing, the focus of our contribution is to construct a very fast algorithm for the PCST problem that still achieves a provable approximation guarantee. Our overall algorithm runs in time O(dm logn) on a graph with m edges, where all edge...

an internal ballistics model has been developed for performance prediction of a solid propellant rocket motor. inthis model a 1-d unsteady euler equation with source terms is considered. the flow is assumed as a non-reacting mixture of perfect gases with space and time varying thermo physical properties. the governing equations in the combustion chamber are solved numerically by using the stege...

Two-dimensional Euler equations have been solved on an unstructured grid. An upwind finite volume scheme, based on Roe's flux difference splitting method, is used to discretize the equations. Using advancing front method, an initial Delaunay triangulation has been made. The adaptation procedure involves mesh enrichment coarsening in regions of flow with high low gradients of flow properties, ac...

In this paper we are going to study the gas evolution dynamics of the exact and approximate Riemann solvers, e.g., the Flux Vector Splitting (FVS) and the Flux Difference Splitting (FDS) schemes. Since the FVS scheme and the Kinetic Flux Vector Splitting (KFVS) scheme have the same physical mechanism and similar flux function, based on the analysis of the discretized KFVS scheme the weakness an...

Motivated by applications in Asian option pricing, optimal commodity trading etc., we propose a splitting scheme for fully nonlinear degenerate parabolic PDEs. The splitting scheme generalizes the probabilistic scheme of Fahim, Touzi and Warin [13] to the degenerate case. General convergence as well as rate of convergence are obtained under reasonable conditions. In particular, it can be used f...

A forward-in-time splitting method for integrating the elastic equations is presented. A second-order Runge– Kutta time integrator (RK2) for the large-time-step integration is combined with the forward–backward scheme in a manner similar to the Klemp and Wilhelmson method. The new scheme produces fully second-order-accurate integrations for advection and gravity wave propagation. The RK2 scheme...

In this paper we restrict every set splitting problem to the special case in which every set has just three elements. This restricted version is also NP-complete. Then, we introduce a general conversion from any set splitting problem to 3-set splitting. Then we introduce a randomize algorithm, and we use Markov chain model for run time complexity analysis of this algorithm. In the last section ...

In this paper, the secrecy problem in the state dependent causal cognitive interference channel is studied. The channel state is non-causally known at the cognitive encoder. The message of the cognitive encoder must be kept secret from the primary receiver. We use a coding scheme which is a combination of compress-and-forward strategy with Marton coding, Gel’fand-Pinsker coding and Wyner’s wire...

A numerical scheme based on an operator splitting method and a dense output event location algorithm is proposed to integrate a diffusiondissolution/precipitation chemical initial-boundary value problem with jumping nonlinearities. The numerical analysis of the scheme is carried out and it is proved to be of order 2 in time. This global order estimate is illustrated numerically on a test case.