37 research outputs found
Generalized Group Actions in a Global Setting
We study generalized group actions on differentiable manifolds in the
Colombeau framework, extending previous work on flows of generalized vector
fields and symmetry group analysis of generalized solutions. As an application,
we analyze group invariant generalized functions in this setting
Distributed order fractional constitutive stress-strain relation in wave propagation modeling
Distributed order fractional model of viscoelastic body is used in order to
describe wave propagation in infinite media. Existence and uniqueness of
fundamental solution to the generalized Cauchy problem, corresponding to
fractional wave equation, is studied. The explicit form of fundamental solution
is calculated, and wave propagation speed, arising from solution's support, is
found to be connected with the material properties at initial time instant.
Existence and uniqueness of the fundamental solutions to the fractional wave
equations corresponding to four thermodynamically acceptable classes of linear
fractional constitutive models, as well as to power type distributed order
model, are established and explicit forms of the corresponding fundamental
solutions are obtained
Control theory for nonlinear fractional dispersive systems
We consider a terminal control problem for processes governed by a nonlinear
system of fractional ODEs. In order to show existence of the control, we first
consider the linear counterpart of the system and reprove a number of classical
theorems in the fractional setting (representation of the solution through the
Gramian type matrix, Kalman's principle, equivalence of the controllability and
observability). We are then in the position to use a fixed point theorem
approach and various techniques from the fractional calculus theory to get the
desired result