118 research outputs found
On semi-Classical Questions Related to Signal Analysis
This study explores the reconstruction of a signal using spectral quantities
associated with some self-adjoint realization of an h-dependent Schr\"odinger
operator when the parameter h tends to 0. Theoretical results in semi-classical
analysis are proved. Some numerical results are also presented. We first
consider as a toy model the sech^2 function. Then we study a real signal given
by arterial blood pressure measurements. This approach seems to be very
promising in signal analysis. Indeed it provides new spectral quantities that
can give relevant information on some signals as it is the case for arterial
blood pressure signal
Mean-Field Stochastic Differential Game for Fine Alignment Control of Cooperative Optical Beam Systems
The deployment of autonomous optical link communication platforms that
benefit from mobility and optical data rates is essential in public safety
communications. However, maintaining an accurate line-of-sight and perfect
tracking between mobile platforms or unmanned aerial vehicles (UAVs) in
free-space remains challenging for cooperative optical communication due to the
underlying mechanical vibration and accidental shocks. Indeed, a misalignment
can result in optical channel disconnection, leading to connectivity loss. To
address this challenge, we propose a two-way optical link that coordinates
mobile UAVs' closed-loop fine beam tracking operation in a swarm architecture
to enhance terrestrial public safety communication systems. We study a dynamic
of the optical beam tracking games in which each agent's dynamic and cost
function are coupled with the other optical beam transceiver agents' states via
a mean-field term. We describe a line-of-sight stochastic cooperative beam
tracking communication through a mean field game paradigm that can provide
reliable network structure and persistent distributed connectivity and
communicability. We derive two optimal mean-field beam tracking control
frameworks through decentralized and centralized strategies. The solutions of
these strategies are derived from forward-backward ordinary differential
equations and rely on the linearity Hamilton-Jacobi-Bellman Fokker-Planck
(HJB-FP) equations and stochastic maximum principle. Furthermore, we
numerically compute the solution pair to the two joint equations using Newton
and fixed point iterations methods to verify the existence and uniqueness of
the equilibrium that drives the control to a Nash equilibrium for both
differential games
Reference Tracking AND Observer Design for Space-Fractional Partial Differential Equation Modeling Gas Pressures in Fractured Media
This paper considers a class of space fractional partial differential
equations (FPDEs) that describe gas pressures in fractured media. First, the
well-posedness, uniqueness, and the stability in of the
considered FPDEs are investigated. Then, the reference tracking problem is
studied to track the pressure gradient at a downstream location of a channel.
This requires manipulation of gas pressure at the downstream location and the
use of pressure measurements at an upstream location. To achiever this, the
backstepping approach is adapted to the space FPDEs. The key challenge in this
adaptation is the non-applicability of the Lyapunov theory which is typically
used to prove the stability of the target system as, the obtained target system
is fractional in space. In addition, a backstepping adaptive observer is
designed to jointly estimate both the system's state and the disturbance. The
stability of the closed loop (reference tracking controller/observer) is also
investigated. Finally, numerical simulations are given to evaluate the
efficiency of the proposed method.Comment: 37 pages, 9 figure
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