Search results for "Simulation."
showing 10 items of 4779 documents
The shortest-path problem with resource constraints with -loop elimination and its application to the capacitated arc-routing problem
2014
Abstract In many branch-and-price algorithms, the column generation subproblem consists of computing feasible constrained paths. In the capacitated arc-routing problem (CARP), elementarity constraints concerning the edges to be serviced and additional constraints resulting from the branch-and-bound process together impose two types of loop-elimination constraints. To fulfill the former constraints, it is common practice to rely on a relaxation where loops are allowed. In a k-loop elimination approach all loops of length k and smaller are forbidden. Following Bode and Irnich (2012) for solving the CARP, branching on followers and non-followers is the only known approach to guarantee integer …
A robust and efficient method for obtaining the complex modes in inhomogeneously filled waveguides
2003
In this paper, we present a computational simulation of the complex wave propagation in inhomogeneously filled waveguides with lossless and lossy dielectrics. We use a biorthonormal-basis method as a numerical technique. The behavior of complex modes in different waveguides whose characterization with other methods involves some difficulties is analyzed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 218–222, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10875
On the chemiluminescence emission of luminol: protic and aprotic solvents and encapsulation to improve the properties in aqueous solution.
2020
Luminol is a popular molecule that is currently gaining further interest due to its potential role for non-invasive cancer treatments. Design of more efficient derivatives in this context would benefit from a clear knowledge on the origin of the distinct intensity and spectroscopic properties in protic and aprotic solvents observed experimentally, which are still not rationalized. By efficiently combining molecular dynamics, quantum methodologies based on density functional theory and multiconfigurational quantum chemistry and hybrid approaches, and developing herein a computational approach for accurately determining "molar negative extinction (or gain) coefficients of emission", we firstl…
The Lyapunov dimension formula for the global attractor of the Lorenz system
2015
The exact Lyapunov dimension formula for the Lorenz system has been analytically obtained first due to G.A.Leonov in 2002 under certain restrictions on parameters, permitting classical values. He used the construction technique of special Lyapunov-type functions developed by him in 1991 year. Later it was shown that the consideration of larger class of Lyapunov-type functions permits proving the validity of this formula for all parameters of the system such that all the equilibria of the system are hyperbolically unstable. In the present work it is proved the validity of the formula for Lyapunov dimension for a wider variety of parameters values, which include all parameters satisfying the …
-Infinity robust controller design for the synchronization of master-slave chaotic systems with disturbance input
2012
Published version of an article from the journal: Modeling, Identification and Control. Also available from the publisher: http://dx.doi.org/10.4173/mic.2012.1.3 This paper is concerned with the robust control problems for the synchronization of master-slave chaotic systems with disturbance input. By constructing a series of Lyapunov functions, novel H1 robust syn- chronization controllers are designed, whose control regulation possess the characteristic of simpleness and explicitness. Finally, numerical simulations are provided to demonstrate the e ectiveness of the proposed techniques.
A nonlinear observer for rotor flux estimation considering magnetic saturation effects in induction motor drives
2015
This paper proposes a non-linear observer for In- duction Machine (IM) drives which takes into consideration the saturation effects. The non-linear observer is based on an original formulation of the dynamic model of the IM taking into consideration the magnetic saturation of the iron core. A Lyapunov based convergence analysis is proposed in order to suitably compute the observer gain guaranteeing the stability of the observer. The proposed non-linear observer has been tested in numerical simulation and experimentally on a suitably developed test set-up. Its behaviour has been compared to that obtained with a classic Full-Order Luenberger Observer (FOLO) in variable flux working conditions…
Adaptive predictor control for stabilizing pressure in a managed pressure drilling system under time-delay
2016
Abstract In this paper, we address adaptive predictor feedback design for a simplified ODE drilling system in the presence of unknown parameter, disturbance and time-delay. The main objective is to stabilize the bottomhole pressure at a critical depth at a desired set-point directly. The time-delay in the transmission line of the drilling systems is considered. The stabilization of the dynamic system and the asymptotic tracking are demonstrated by the proposed predictor control, where the adaptation employs Lyapunov update law design with normalization. The proposed method is evaluated using a high fidelity drilling simulator and cases from a North Sea drilling operation are simulated. The …
Adaptive Neural Stabilizing Controller for a Class of Mismatched Uncertain Nonlinear Systems by State and Output Feedback
2015
In this paper, first, an adaptive neural network (NN) state-feedback controller for a class of nonlinear systems with mismatched uncertainties is proposed. By using a radial basis function NN (RBFNN), a bound of unknown nonlinear functions is approximated so that no information about the upper bound of mismatched uncertainties is required. Then, an observer-based adaptive controller based on RBFNN is designed to stabilize uncertain nonlinear systems with immeasurable states. The state-feedback and observer-based controllers are based on Lyapunov and strictly positive real-Lyapunov stability theory, respectively, and it is shown that the asymptotic convergence of the closed-loop system to ze…
FPGA Implementation Of Diffusive Realization For A Distributed Control Operator
2010
International audience; We focus on the question of real-time computation for optimal distributed filtering or control applicable to MEMS Arrays. We present an algorithm for the realization of a linear operator solution to a functional equation through its application to a Lyapunov operatorial equation associated to the heat equation in one dimension. It is based on the diffusive realization, and turns to be well suited for fined grained parallel computer architecture as Field Programmable Gate Arrays (FPGA). An effective FPGA implementation has been successfully carried out. Here, we report the main implementation steps and the final measured performances.
Chaos synchronization for a class of chaotic systems via H<inf>&#x221E;</inf> control technique
2013
In this paper, the robust synchronization control for a class of chaotic systems is studied. Based on linear matrix inequality techniques and Lyapunov stability theory, a novel H∝ robust synchronization controller is designed for the possible application in real engineering. Finally, some numerical simulations are included to demonstrate the effectiveness of the proposed techniques.