We consider an inverse heat conduction problem (IHCP) in a quarter plane. We want to know the distribution of surface temperature in a body from a measured temperature history at a fixed location inside the body. This is a severely ill-posed problem in the sense that the solution (if exists) does not depend continuously on the data. Eldén (1995) has used a difference method for solving this pro...

Several algorithms for introducing artificial dissipation into a central difference approximation to the Euler and Navier Stokes equations are considered. The focus of the paper is on the convective upwind and split pressure (CUSP) scheme, which is designed to support single interior point discrete shock waves. This scheme is analyzed and compared in detail with scalar and matrix dissipation (M...

We construct accurate central difference stencils for problems involving high frequency waves or multi-frequency solutions over long time intervals with a relatively coarse spatial mesh, and with an easily obtained bound on the dispersion error. This is done by demonstrating that the problem of constructing central difference stencils that have minimal dispersion error in the infinity norm can ...

saturation (ScvO2) and mixed venous saturation (SvO2) in 53 patients with severe sepsis [1]. For several reasons, however, we feel the authors’ broadly stated conclusion that ‘a positive (ScvO2 SvO2) value is not associated with improved outcome’ is unwarranted. First, in Figure 3 of their paper, graphing the number of measurements rather than the number of subjects is counterintuitive; your re...

In this paper, we present a new formulation using the ( ) time-domain electric-field integral equation TD EFIE to obtain a transient scattering response from arbitrarily shaped conducting bodies. The time deri ati e of the magnetic ector potential is approximated with a central finite difference, and the scalar potential is time a eraged by di iding it into two terms. This approach with an impl...

Discrete versions of basic inequalities in functional analysis such as the Sobolev inequality play key role in theoretical analysis of finite difference schemes. They have been shown for some simple difference operators, but are still left open for general operators, even including the standard central difference operators. In this paper, we propose a systematic approach for deriving such inequ...

In this note, we define the class of finite groups of Suzuki type, which are non–abelian groups of exponent 4 and class 2 with special properties. A group G of Suzuki type with |G| = 22s always possesses a non–trivial difference set. We show that if s is odd, G possesses a central difference set, whereas if s is even, G has no non–trivial central difference set.

This paper presents a modified numerical scheme for a class of Fractional Optimal Control Problems (FOCPs) formulated in Agrawal (2004) where a Fractional Derivative (FD) is defined in the Riemann-Liouville sense. In this scheme, the entire time domain is divided into several subdomains, and a fractional derivative (FDs) at a time node point is approximated using a modified Grünwald-Letnikov ap...

four explicit finite difference schemes, including lax-friedrichs, nessyahu-tadmor, lax-wendroff and lax-wendroff with a nonlinear filter are applied to solve water hammer equations. the schemes solve the equations in a reservoir-pipe-valve with an instantaneous and gradual closure of the valve boundary. the computational results are compared with those of the method of characteristics (moc), a...