Browsing Mathematics, Statistics, and Physics by Title

Spectral methods solution of the Navier-Stokes equations for steady viscous flows

Vargas, German A. (Wichita State University, 2009-05)

A combination of Spectral Methods and Finite Differences will be used to solve the Navier-Stokes equations for a viscous flow past a circular cylinder and past symmetric Joukowski airfoils. Different discretizations of ...

Spherically invariant vector random fields in space and time

Du, Juan; Ma, Chunsheng (IEEE, 2011-12)

This paper is concerned with spherically invariant or elliptically contoured vector random fields in space and/or time, which are formulated as scale mixtures of vector Gaussian random fields. While a spherically invariant ...

A stability analysis of the harmonic continuation

Elcrat, Alan R.; Isakov, Victor; Kropf, Everett; Stewart, Darrell Anne (IOP PUBLISHING LTD, 2012-07)

We consider the Cauchy problem for harmonic functions outside some disc in the plane with the Cauchy data on an interval. We obtain simple formulae for singular values of the operator solving this Cauchy problem and ...

Stability and the inverse gravimetry problem with minimal data

Isakov, Victor; Titi, Aseel (e Gruyter Open Ltd, 2020-10-11)

The inverse problem in gravimetry is to find a domain ð • inside the reference domain ω from boundary measurements of gravitational force outside ω. We found that about five parameters of the unknown ð • can be stably ...

Stability estimates and explicit formulas for the inverse problem of determining the boundary condition from discrete data

Ingle, William Nathan (Wichita State University. Graduate School, 2011-05-04)

Stability estimates for inverse problems of some elliptic equations

Ingle, William Nathan (Wichita State University, 2011-12)

In this dissertation we obtain new Carleman formulas for the solution of the Cauchy problem for equations P u = h, in Ω, u|E = f , where E ⊂ ∂Ω and | E | > 0. Our elliptic operator is of the form P = [ [2∂¯ 0 ; ...

Stability of continuation and obstacle problems in acoustic and electromagnetic scattering

Subbarayappa, Deepak Aralumallige (Wichita State University, 2010-12)

Study of the Cauchy problem for Helmholtz equation is motivated by the inverse scattering theory and more generally by remote sensing. In this dissertation the increased stability of the Cauchy problem for Helmholtz ...

Stability of coupled strings vibration system due to different boundary conditions

Sarhangi, G.R.; Najafi, M.; Wang, H. (IEEE, 1993-06-02)

We study the rate of convergence of a coupled wave systems under two different boundary conditions, energy absorbing in two ends for one and free or fixed boundary controls in two ends for the other one. We will observe ...

Stability of inviscid vortices behind a circular cylinder

Elcrat, Alan R.; Fornberg, Bengt; Miller, Kenneth G. (American Physical Society, 2005-11-21)

In a previous work (JFM 409(2000), 13-27 famillies of vortex patches in equilibrium with flow past a circular cylinder which is uniform at infinity were found using iterations for a nonlinear Poisson equation. These included ...

The stabilization of a linearized self-excited wave equation by an energy absorbing boundary

Sarhangi, G.R.; Najafi, M.; Wang, H. (IEEE, 1992-06-24)

We study the linrized self-excited wave quation tt - A £ -P(s) tg=0, where P(s)>0, P(r)eL(f), in a bounded domain 0cRI with smooth bounar r whee boun y dampig is prst. coniering the prtii Fr 1r.).of he bouM~ ron which ...

Stationary and isotropic vector random fields on spheres

Ma, Chunsheng (Springer, 2012-08)

This paper presents the characterization of the covariance matrix function of a Gaussian or second-order elliptically contoured vector random field on the sphere which is stationary, isotropic, and mean square continuous. ...

Stationary random fields in space and time with rational spectral densities

Ma, Chunsheng (IEEE, 2007-03)

This paper introduces three spatio–temporal stationary random fields with simple correlation functions and rational spectral densities. The correlation functions have similar forms, but are defined on different space–time ...

Stationary time series resulting from certain positive definite kernels and simulation via high-order vector autoregressive models

Ma, Nicholas (Wichita State University, 2013-05)

Vector auto-regressive models have traditionally been used to model and forecast multivariate time series data, predicting future values based on previous observations. In this thesis, we introduce some multivariate time ...