Browsing MATH Research Publications by Issue Date
Now showing items 120 of 110

Pole placement by linear quadratic modification for continuous time systems
(IEEE, 19910626)This paper bridges the gap between linear quadratic solution and pole placement providing a simple criterion sucht that the resulting optimal gain places the closed loop eigenvalues at desired locations. The method has the ... 
Constrained pole placement by linear quadratic modification
(IEEE, 19910626)A noniterative method is introduced that will enable the designer to find an optmal one step state feedback controller. The controller will place the eigenvalues of the closed loop system in a specified disk. 
The stabilization of a linearized selfexcited wave equation by an energy absorbing boundary
(IEEE, 19920624)We study the linrized selfexcited 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 ... 
Numerical comparison of negative damping bounds in a specified domain when the wave speed varies
(IEEE, 19920624)The energy decay of a selfexcited wave equation utt  c2 Â¿ u  P(x)ut = 0 is studied where the wave speed c is greater than one, P(x) Â¿ 0, and P(x) LÂ¿(Â¿), Â¿ Â¿ Â¿ Rn. Moreover, the relationship between two bounds for ... 
Stability of coupled strings vibration system due to different boundary conditions
(IEEE, 19930602)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 ... 
On the asymptotic behavior of solutions of quasilinear elliptic equations
(SpringerVerlag, 20030101)The asymptotic behavior of solutions of secondorder quasilinear elliptic and nonhyperbolic partial differential equations defined on unbounded domains in R n contained in {(Xl, ..., Xn): Ix,~ I < ~(~/x~ +... + x~_ 1)} ... 
Lipschitz stability in the lateral Cauchy problem for elasticity system
(Kyoto University, 20030801)We consider the isotropic elasticity system: ρ∂2 t u − μ(Δu + ∇(∇Tu))−∇(λ∇Tu) − 3 X j=1 ∇μ · (∇uj + ∂ju)ej = 0 in Ω× (0, T) for the displacement vector u = (u1, u2, u3) depending on x ∈ Ω and t ∈ (0, T) where Ω ... 
Carleman estimates and applications to inverse problems
(Birkhäuser Verlag Basel/Switzerland, 2004)This review paper describes some general and recent results of possible interest for mathematicians studying or using uniqueness of the continuation or working on control theory or inverse problems for partial ... 
On the existence of convex classical solutions to a generalized PrandtlBatchelor free boundary problem
(Birkhäuser Verlag, Basel, 2004)Under reasonably general assumptions, we prove the existence of convex classical solutions for the PrandtlBatchelor free boundary problem in fluid dynamics, in which a flow of constant vorticity density is embedded in ... 
Spatial autoregression and related spatiotemporal models
(Elsevier Inc., 200401)We propose a spatial autoregressive randomfield of order p on the spatial domain Rd for pX2 in this paper, whose univariate margins are the continuoustime autoregression of order p on the real line, and introduce a class ... 
Consistent estimation of distributions with type II bias with applications in competing
(Institute of Mathematical Statistics, 200402)A random variable X is symmetric about 0 if X and X have the same distribution. There is a large literature on the estimation of a distribution function (DF) under the symmetry restriction and tests for checking this ... 
Annular capillary surfaces
(BirkhäuserVerlag, Basel, 20040501)The meniscus in a symmetric annular capillary tube is investigated. The contact angles on the inner and outer tube surface need not be the same. Existence and qualitative properties of solutions are obtained using an ... 
Increased stability in the continuation of solutions to the Helmholtz equation
(IOP Science, 20040503)In this paper we give analytical and numerical evidence of increasing stability in the Cauchy Problem for the Helmholtz equation when frequency is growing. This effect depends on convexity properties of the surface where ... 
Regularity of the heat operator on a manifold with cylindrical ends
(Pacific Journal of Mathematics at the University of California, 20040601)We study mapping properties of the heat operator etA of an mth order elliptic bdifferential operator in appropriately defined spaces of whole and fractional (Hölder) derivatives. An application is made to short time ... 
Uniqueness in one inverse problem for the elasticity system
(Plenum Publishing Corporation, 200407)We consider an inverse problem for the stationary elasticity system with constant Lam´e coefficients and a variable matrix coefficient depending on the spatial variables and frequency. The righthand side contains a ... 
The multilayer free boundary problem for the pLaplacian in convex domains
(European Mathematical Society, 20040821)The main result of this paper concerns existence of classical solutions to the multilayer Bernoulli free boundary problem with nonlinear joining conditions and the pLaplacian as gov erning operator. The present treatment ... 
Geometry of nonlinear connections
(Elsevier Science B.V., Amsterdam, 20040828)We show that locally diffeomorphic exponential maps can be defined for any secondorder differential equation, and give a (possibly nonlinear) covariant derivative for any (possibly nonlinear) connection. We introduce ... 
The use of the variogram in construction of stationary time series models
(Applied Probability Trust, 200412)This paper studies a class of stationary covariance models, in both the discrete and the continuoustime domains, which possess a simple functional form γ(τ + τ0) + γ(τ  τ0)  2γ(τ), where τ0 is a fixed lag and γ(τ) is ... 
Equilibrium configurations for a floating drop
(BirkhäuserVerlag, Basel, 20041201)If a drop of fluid of density ρ1 rests on the surface of a fluid of density ρ2 below a fluid of density ρ0, ρ0 < ρ1 < ρ2, the surface of the drop is made up of a sessile drop and an inverted sessile drop which match an ... 
SchwarzChristoffel mapping of multiply connected domains
(Springer Verlag, 20041201)A SchwarzChristoffel mapping formula is established for polygonal domains of finite connectivity m _> 2 thereby extending the results of Christoffel (1867) and Schwarz (1869) for m = 1 and Komatu (1945), m = 2. A ...