Search results for "Computer Science::Systems and Control"
showing 10 items of 54 documents
MECHANISM DESIGN FOR OPTIMAL CONSENSUS PROBLEMS
2006
We consider stationary consensus protocols for networks of dynamic agents with fixed and switching topologies. At each time instant, each agent knows only its and its neighbors’ state, but must reach consensus on a group decision value that is function of all the agents’ initial state.We show that our protocol design is the solution of individual optimizations performed by the agents. This notion suggests a game theoretic interpretation of consensus problems as mechanism design problems. Under this perspective a supervisor entails the agents to reach a consensus by imposing individual objectives. We prove that such objectives can be chosen so that rational agents have a unique optimal proto…
Notice of Violation of IEEE Publication Principles: Robust Observer Design for Unknown Inputs Takagi–Sugeno Models
2013
This paper deals with the observer design for Takagi-Sugeno (T-S) fuzzy models subject to unknown inputs and disturbance affecting both states and outputs of the system. Sufficient conditions to design an unknown input T-S observer are given in linear matrix inequality (LMI) terms. Both continuous-time and discrete-time cases are studied. Relaxations are introduced by using intermediate variables. Extension to the case of unmeasured decision variables is also given. A numerical example is given to illustrate the effectiveness of the given results.
The approximate subdifferential of composite functions
1993
This paper deals with the approximate subdifferential chain rule in a Banach space. It establishes specific results when the real-valued function is locally Lipschitzian and the mapping is strongly compactly Lipschitzian.
The Lyapunov dimension, convergency and entropy for a dynamical model of Chua memristor circuit
2018
For the study of chaotic dynamics and dimension of attractors the concepts of the Lyapunov exponents was found useful and became widely spread. Such characteristics of chaotic behavior, as the Lyapunov dimension and the entropy rate, can be estimated via the Lyapunov exponents. In this work an analytical approach to the study of the Lyapunov dimension, convergency and entropy for a dynamical model of Chua memristor circuit is demonstrated.
Recent Advances in Static Output-Feedback Controller Design with Applications to Vibration Control of Large Structures
2014
Published version of an article in the journal: Modeling, Identification and Control. Also available from the publisher at: http://dx.doi.org/10.4173/mic.2014.3.4 Open Access In this paper, we present a novel two-step strategy for static output-feedback controller design. In the first step, an optimal state-feedback controller is obtained by means of a linear matrix inequality (LMI) formulation. In the second step, a transformation of the LMI variables is used to derive a suitable LMI formulation for the static output-feedback controller. This design strategy can be applied to a wide range of practical problems, including vibration control of large structures, control of oshore wind turbine…
H<inf>&#x221E;</inf> synchronization of Markovian jump master-slave systems with delay
2012
The problem of synchronization is investigated for a class of master-slave systems with time-varying delays and Markovian switching parameters. Using an appropriate Lyapunov-Krasovskii functional, a synchronization law which includes the master-slave parameters is established for designing a mode-dependent output feedback control law in terms of LMIs. A numerical example is given to show the effectiveness of the method.
Optical studies of gap, hopping energies, and the Anderson-Hubbard parameter in the zigzag-chain compoundSrCuO2
2001
We have investigated the electronic structure of the zig-zag ladder (chain) compound ${\mathrm{SrCuO}}_{2}$ combining polarized optical absorption, reflection, photoreflectance, and pseudo-dielectric-function measurements with the model calculations. These measurements yield an energy gap of 1.42 eV (1.77 eV) at 300 K along (perpendicular to) the Cu-O chains. We have found that the lowest-energy gap, the correlation gap, is temperature independent. The electronic structure of this oxide is calculated using both the local-spin-density approximation with gradient correction method and the tight-binding theory for the correlated electrons. The calculated density of electronic states for noncor…
Resonant rayleigh scattering in semiconductor structures
1995
A detailed study of the relative role played by localized and/or propagating intermediate excitonic states in, resonant Rayleigh scattering (RRS) is presented for a large set of GaAs quantum well (QW) and bulk structures. We show that the two kinds of states contribute to RRS through different mechanisms. We concluded that RRS occurs via localized states in QW heterostructures, very likely due to localization by the interface roughness, while bulk, crystals turn out to be better candidates for RRS via propagating states.
Constraints on millicharged dark matter and axionlike particles from timing of radio waves
2019
We derive novel constraints on millicharged dark matter and ultralight axion-like particles using pulsar timing and fast radio burst observations. Millicharged dark matter affects the dispersion measure of the time of arrival of radio pulses in a way analogous to free electrons. Light pseudo-scalar dark matter, on the other hand, causes the polarization angle of radio signals to oscillate. We show that current and future data can set strong constraints in both cases. For dark matter particles of charge $\epsilon e$, these constraints are ${\epsilon}/{m_{\rm milli}} \lesssim 10^{-8}{\rm eV}^{-1}$, for masses $m_{\rm milli}\gtrsim 10^{-6}\,$eV. For axion-like particles, the analysis of signal…
Dynamics for a simple graph using the U(N) framework for loop quantum gravity
2012
The implementation of the dynamics in loop quantum gravity (LQG) is still an open problem. Here, we discuss a tentative dynamics for the simplest class of graphs in LQG: Two vertices linked with an arbitrary number of edges. We find an interesting global U(N) symmetry in this model that selects the homogeneous/isotropic sector. Then, we propose a quantum Hamiltonian operator for this reduced sector. Finally, we introduce the spinor representation for LQG in order to propose a classical effective dynamics for this model.