Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 69 for “"limit-cycles"”.
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Limit Cycles and Dynamics of Rumor Models
<p>This thesis discusses limit cycles and behavior of rumor models. The first part presents the deterministic Daley-Kendall model (DK) with arrivals and departures and comparison of the Susceptibles, Infectives and Removed (SIR) model and the DK model. The second result is a part of the qualitative …
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Suppression of Limit Cycles in Digital Filters
The injection of randan dither to suppress limit cycle oscillations in second-order direct form digital filter sections is discussed. Three types of dither signal are used: uniformly distributed random dither, binary randan dither and bandstop dither. All the limit cycles in the second-order filter …
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On the maximum number of limit cycles of certain polynomial Lienard equations
We consider the Lienard equation of the form$$\ddot x + \epsilon f(x)\dot x + x\sp{2m+1} = 0,\eqno(1)\cr$$which is equivalent to the planar system$$\eqalignno{\dot x &= y&\enspace\cr \dot{y} &= -x\sp{2m+1} - \epsilon f(x)y,&(2)\cr}$$where m is a nonnegative integer, f is a real polynomial and …
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Analytical and numerical study of the unstable limit cycles of walking droplets
Recent studies have shown that a vibrating fluid bath can support a bouncing droplet, generating a pilot wave which propels the droplet into horizontal motion. Walking droplets have been demonstrated not only to follow linear trajectories, but to exhibit a range of rich dynamical behavior, …
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Coexistence of Slow Magnetoacoustic Waves and Thermal Limit Cycles in a Coronal Bright Point
… with slow magnetoacoustic waves and thermal limit cycles, respectively. Time–distance maps along an oscillation region reveal counter-propagating short-period waves propagating at acoustic speeds and long-period waves at a speed an order of magnitude slower. The simultaneity of oscillations …
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Using Stable Limit Cycles to Model p53-Mdm2 Protein Interactions in the Presence of DNA Damage
… periodic solutions resulting from stable limit cycles. We establish conditions for existence and stability of these limit cycles, and we validate this model using four data sets of the p53-Mdm2 interaction. To improve model performance, we apply a two-step method where Fourier series are …
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Stability analysis and control for bipedal locomotion using energy methods
In this thesis, we investigate the stability of limit cycles of passive dynamic walking. The formation process of the limit cycles is approached from the view of energy interaction. We introduce for the first time the notion of the energy portrait analysis originated from the phase portrait. The …
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Methods for Analysis of Nonlinear Thermoacoustic Systems
… from a stable fixed point to a stable limit cycle, via an unstable limit cycle. The practical stability of the Rijke tube was investigated when the system is forced by stochastic noise. Low levels of noise result in triggering much before the linear stability limit. Stochastic stability …
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Monomial Dynamical Systems over Finite Fields
… be described by monomials, information about the limit cycles can be obtained from the monomials themselves. In particular, this work contains sufficient and necessary conditions for a monomial dynamical system to have only fixed points as limit cycles.
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A computer assisted approach to Hilbert's 16th problem
… mention examples of cubic systems having eleven limit cycles and the cubic systems of Lienard type. In Chapter 6, we apply parameter-continuation method to compute the limit cycle bifurcation diagram for quadratic systems of special interest, whose limit cycles can not be determined with the …
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Modal interactions in shell dynamics
… the fixed-point solutions are unstable and limit cycles exist. Some limit cycles experience symmetry-breaking (pitchfork) bifurcation followed by an infinite cascade of period-doubling bifurcations culminating in chaos. Other limit cycles lose stability through cyclic-fold bifurcations …
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Some Extensions of Poincaré-Bendixson Theory Applied to a Resonant Converter.
In this thesis existence and uniqueness of limit cycles are shown for a resonant converter, by extending Poincaré-Bendixson theory to non-smooth vector fields. We discuss relevant control theory and the role of simulations.
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Studies of Vortex Breakdown and its Stability in a Confined Cylindrical Container
… mode competition between two axisymmetric limit cycles, vortex breakdown oscillation control and effects of modulation of the rotating endwall on the flow state. The experiment confirms the existence of an S-shape vortex structure and a spiral-type vortex breakdown. For the study on mode …
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Modeling and Control of Multiphase DC -Dc Converters With Linkages to Hybrid Control
… that can drive the state between two valid limit cycles in a finite amount of time, with a finite number of switch transitions. Sufficient but conservative algebraic conditions for deadbeat controllability of piecewise linear hybrid systems with finite state-vector dimension are presented.
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Exploring global dynamics in a low order model of parallel shear flow
… find homoclinic and heteroclinic connections of limit cycles in the parameter space surrounding the it. We use a matrix-free manifold computation method to find a homoclinic orbit of limit cycles. Finally we will discuss a method to continue the homoclinic orbit.
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Inverse Problems in Hybrid Systems With Application to Power Systems
… of power systems, performance in the form of limit cycle behavior is undesirable as it deteriorates the quality of supply. At a lower voltage level, hybrid limit cycles are primarily induced due to the interaction between switching devices. Locating such a behavior is another inverse problem …
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On threshold models over finite networks
… this end, we establish that the agents behavior cycles among different actions in the limit and provide three sets of results. We first characterize the limiting behavioral properties of the dynamics. We determine the length of the limit cycles and reveal bounds on the time steps required to …
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Geometric control and motion planning for three-dimensional bipedal locomotion
… planning applications that have previously been limited to inefficient quasi-static walkers. In order to produce exponentially stable hybrid limit cycles, we exploit system energetics, symmetry, and passivity through the energy-shaping method of controlled geometric reduction. This decouples a …
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