2,992 research outputs found
Galactic Nonlinear Dynamic Model
We develop a model for spiral galaxies based on a nonlinear realization of
the Newtonian dynamics starting from the momentum and mass conservations in the
phase space. The radial solution exhibits a rotation curve in qualitative
accordance with the observational data.Comment: 6 pages, 1 figure. Talk given in the 7th Alexander Friedmann
International Seminar, June 29 to July 5, 2008, Joao Pessoa, PB, Brazi
Modal Analysis of Grid Connected Doubly-Fed Induction Generators
This paper presents the modal analysis of a gridconnected doubly fed induction generator (DFIG). The change in modal properties for different system parameters, operating points, and grid strengths are computed and observed. The results offer a better understanding of theDFIG intrinsic dynamics,which can also be useful for control design and model justification. Index Terms—Doubly fed induction generator, eigenvalue analysis, nonlinear dynamic model, small-signal stability.Published versio
Approximate dynamic model of a turbojet engine
An approximate dynamic nonlinear model of a turbojet engine is elaborated on as a tool in studying the aircraft control loop, with the turbojet engine treated as an actuating component. Approximate relationships linking the basic engine parameters and shaft speed are derived to simplify the problem, and to aid in constructing an approximate nonlinear dynamic model of turbojet engine performance useful for predicting aircraft motion
Thompson Sampling in Dynamic Systems for Contextual Bandit Problems
We consider the multiarm bandit problems in the timevarying dynamic system
for rich structural features. For the nonlinear dynamic model, we propose the
approximate inference for the posterior distributions based on Laplace
Approximation. For the context bandit problems, Thompson Sampling is adopted
based on the underlying posterior distributions of the parameters. More
specifically, we introduce the discount decays on the previous samples impact
and analyze the different decay rates with the underlying sample dynamics.
Consequently, the exploration and exploitation is adaptively tradeoff according
to the dynamics in the system.Comment: 22 pages, 10 figure
On a fractional order nonlinear dynamic model of a triadic relationship
In this paper, a fractional order nonlinear dynamic model of involving three person is introduced. The proposed model describes the dynamic behavior of an interrelation of three person under different structures. Stability analysis of the fractional-order nonlinear dynamic model of involving three person is studied using the fractional Routh-Hurwitz criteria. By using stability analysis on fractional order system, we obtain sufficient condition on the parameters for the locally asymptotically stable of equilibrium points. Finally, our results are validated by numerical simulations
Parameter identification for a robotic manipulator arm
The development is described of a nonlinear dynamic model for large oscillations of a robotic manipulator arm about a single joint. Optimization routines are formulated and implemented for the identification of electrical and physical parameters from dynamic data taken from an industrial robot arm. Special attention is given to the role of sensitivity in the formulation of robust models of this motion. The importance of actuator effects in the reduction of sensitivity is established and used to develop an electromechanical model of the manipulator system
Parameter identification and sensitivity analysis for a robotic manipulator arm
The development of a nonlinear dynamic model for large oscillations of a robotic manipulator arm about a single joint is described. Optimization routines are formulated and implemented for the identification of electrical and physical parameters from dynamic data taken from an industrial robot arm. Special attention is given to difficulties caused by the large sensitivity of the model with respect to unknown parameters. Performance of the parameter identification algorithm is improved by choosing a control input that allows actuator emf to be included in an electro-mechanical model of the manipulator system
Applications of inverse simulation to a nonlinear model of an underwater vehicle
Inverse simulation provides an important alternative
to conventional simulation and to more formal
mathematical techniques of model inversion. The
application of inverse simulation methods to a nonlinear
dynamic model of an unmanned underwater vehicle with
actuator limits is found to give rise to a number of
challenging problems. It is shown that this particular
problem requires, in common with other applications that
include hard nonlinearities in the model or discontinuities
in the required trajectory, can best be approached using a
search-based optimization algorithm for inverse
simulation in place of the more conventional Newton-
Raphson approach. Results show that meaningful inverse
simulation results can be obtained but that multi-solution
responses exist. Although the inverse solutions are not
unique they are shown to generate the required
trajectories when tested using conventional forward
simulation methods
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