9,907 research outputs found
A Convex Approach to Hydrodynamic Analysis
We study stability and input-state analysis of three dimensional (3D)
incompressible, viscous flows with invariance in one direction. By taking
advantage of this invariance property, we propose a class of Lyapunov and
storage functionals. We then consider exponential stability, induced L2-norms,
and input-to-state stability (ISS). For streamwise constant flows, we formulate
conditions based on matrix inequalities. We show that in the case of polynomial
laminar flow profiles the matrix inequalities can be checked via convex
optimization. The proposed method is illustrated by an example of rotating
Couette flow.Comment: Preliminary version submitted to 54rd IEEE Conference on Decision and
Control, Dec. 15-18, 2015, Osaka, Japa
Constructing solutions for a kinetic model of angiogenesis in annular domains
We prove existence and stability of solutions for a model of angiogenesis set
in an annular region. Branching, anastomosis and extension of blood vessel tips
are described by an integrodifferential kinetic equation of Fokker-Planck type
supplemented with nonlocal boundary conditions and coupled to a diffusion
problem with Neumann boundary conditions through the force field created by the
tumor induced angiogenic factor and the flux of vessel tips. Our technique
exploits balance equations, estimates of velocity decay and compactness results
for kinetic operators, combined with gradient estimates of heat kernels for
Neumann problems in non convex domains.Comment: to appear in Applied Mathematical Modellin
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