arXiv subjects

Francisco J. Uribe

Publications and source records attributed to Francisco J. Uribe.

3 recordsLinked to original sources

arXiv2018

Protocol for Energy-Efficiency using Robust Control on WSN

The present work analyzes the feasibility of obtaining a single controller (robust), with theoretical guarantees of stability and performance, valid for a total set of network configurations in designed the controller for an uncertain success probability obtain the protocol for Energy-Efficiency in Networked Control System NCS. In particular, this work investigates the performance degradation, in terms of the $\mathcal{H}_{\infty}$ guaranteed cost, between optimal controller design (precisely known probability) and the sub-optimal controller design (robust to probability uncertainties). The feasibility of the proposed methodology is validated by a numerical example.

eess.SY↗

arXiv2011

Maxwell and Cattaneo's Time-Delay Ideas Applied to Shockwaves and the Rayleigh-Benard Problem

We apply Maxwell and Cattaneo's relaxation approaches to the analysis of strong shockwaves in a two-dimensional viscous heat-conducting fluid. Good agreement results for reasonable values of Maxwell's relaxation times. Instability results if the viscous relaxation time is too large. These relaxation terms have negligible effects on slower-paced subsonic problems, as is shown here for two-roll and four-roll Rayleigh-Benard flows.

physics.flu-dyn↗

arXiv2010

Flexible Macroscopic Models for Dense-Fluid Shockwaves: Partitioning Heat and Work; Delaying Stress and Heat Flux; Two-Temperature Thermal Relaxation

Macroscopic models which distinguish the longitudinal and transverse temperatures can provide improved descriptions of the microscopic shock structures as revealed by molecular dynamics simulations. Additionally, we can include three relaxation times in the models, two based on Maxwell's viscoelasticity and its Cattaneo-equation analog for heat flow, and a third thermal, based on the Krook-Boltzmann equation. This approach can replicate the observed lags of stress (which lags behind the strain rate) and heat flux (which lags behind the temperature gradient), as well as the eventual equilibration of the two temperatures. For profile stability the time lags cannot be too large. By partitioning the longitudinal and transverse contributions of work and heat and including a tensor heat conductivity and bulk viscosity, all the qualitative microscopic features of strong simple-fluid shockwave structures can be reproduced.

cond-mat.stat-mech↗