The seismic wavefield propagating along the recently instrumented Pacific-North American plate boundary (California) displays remarkable variation, with regional shear waves arriving at coastal stations up to 20 seconds earlier than equidistant stations in eastern California. Broadband modeling of this data reveals that coastal paths sample fast upper mantle typical of Miocene-aged ocean plate ...

We will consider the feedback stabilization of a class of in£nite dimensional systems by using boundary control, i.e. control inputs are applied at the boundaries of such systems. Such systems usually possess an internal energy, and along their solutions a conservation of energy equation hold. By utilizing this relation, we will prove various stability results. We will also give an example on t...

The paper addresses the boundary control of a nonlinear diffusion system submitted to Neumann actuation. The control law is designed in the framework of geometric control theory using directly the nonlinear partial differential equation model without any previous reduction. First, an equivalent linear model using the Cole-Hopf transformation is obtained, then the manipulated variable is inserte...

Abstract— The classical Stefan problem is a linear onedimensional heat equation with a free boundary at one end, modelling a column of liquid (e.g. water) in contact with an infinite strip of solid (ice). Given the fixed boundary conditions, the column temperature and free boundary motion can be uniquely determined. In the inverse problem, one specifies the free boundary motion, say from one st...

Consider a partial differential equation (PDE) of evolution type, such as the wave equation or the heat equation. Assume now that you can influence the behavior of the solution by setting the boundary conditions as you please. This is boundary control in a broad sense. A substantial amount of literature exists in the area of theoretical results concerning control of partial differential equatio...

In this paper, we consider the solution of optimal control problem for hyperdiffusion equation involving boundary function of continuous time variable in its cost function. A specific direct approach based on infinite series of Fourier expansion in space and temporal integration by parts for analytical solution is proposed to solve optimal boundary control for hyperdiffusion equation. The time ...

The problem of suppressing the slugging phenomenon is investigated. Industrial oil facilities such as gas-lifted wells and offshore production oil-risers are examples of systems where occurs such phenomenon. To study this problem, we consider that these systems are written as a set of 3 × 3 hyperbolic partial differential equations of balance laws, where the control variable appears at the boun...

In this thesis we study optimal boundary control problems in energy spaces, their construction of robust preconditioners and applications to arterial blood flow. More precisely we first consider the unconstrained optimal Dirichlet and Neumann boundary control problems for the Poisson equation as a model problem. In both cases it turns out that the control can be eliminated and thus a variationa...

We show that a finite dimensional strictly passive linear controller exponentially stabilizes a large class of partial differential equations which are actuated through its boundaries on a one dimensional spatial domain. This is achieved by extending existing results on exponential stability of boundary control system with static boundary control to the case with dynamic boundary control. The a...

When fluid flow in a pipeline is suddenly halted, a pressure surge or wave is created within the pipeline. This phenomenon, called water hammer, can cause major damage to pipelines, including pipeline ruptures. In this paper, we model the problem of mitigating water hammer during valve closure by an optimal boundary control problem involving a nonlinear hyperbolic PDE system that describes the ...