133 research outputs found
Oscillation death in coupled counter-rotating identical nonlinear oscillators
We study oscillatory and oscillation suppressed phases in coupled
counter-rotating nonlinear oscillators. We demonstrate the existence of limit
cycle, amplitude death, and oscillation death, and also clarify the Hopf,
pitchfork, and infinite period bifurcations between them. Especially, the
oscillation death is a new type of oscillation suppressions of which the
inhomogeneous steady states are neutrally stable. We discuss the robust neutral
stability of the oscillation death in non-conservative systems via the
anti-PT-symmetric phase transitions at exceptional points in terms of
non-Hermitian systems.Comment: 7 pages, 4 figure
Time Delay Effect on the Love Dynamical Model
We investigate the effect of time delay on the dynamical model of love. The
local stability analysis proves that the time delay on the return function can
cause a Hopf bifurcation and a cyclic love dynamics. The condition for the
occurrence of the Hopf bifurcation is also clarified. Through a numerical
bifurcation analysis, we confirm the theoretical predictions on the Hopf
bifurcation and obtain a universal bifurcation structure consisting of a
supercritical Hopf bifurcation and a cascade of period-doubling bifurcations,
i.e., a period doubling route to chaos.Comment: To appear in Journal of Korean Physical Societ
Amplitude death in a ring of nonidentical nonlinear oscillators with unidirectional coupling
We study the collective behaviors in a ring of coupled nonidentical nonlinear
oscillators with unidirectional coupling, of which natural frequencies are
distributed in a random way. We find the amplitude death phenomena in the case
of unidirectional couplings and discuss the differences between the cases of
bidirectional and unidirectional couplings. There are three main differences;
there exists neither partial amplitude death nor local clustering behavior but
oblique line structure which represents directional signal flow on the
spatio-temporal patterns in the unidirectional coupling case. The
unidirectional coupling has the advantage of easily obtaining global amplitude
death in a ring of coupled oscillators with randomly distributed natural
frequency. Finally, we explain the results using the eigenvalue analysis of
Jacobian matrix at the origin and also discuss the transition of dynamical
behavior coming from connection structure as coupling strength increases.Comment: 14 pages, 11 figure
Chaotic universe in the z=2 Hovava-Lifshitz gravity
The deformed z=2 Horava-Lifshitz gravity with coupling constant w leads to a
nonrelativistic "mixmaster" cosmological model. The potential of theory is
given by the sum of IR and UV potentials in the ADM Hamiltonian formalism. It
turns out that adding the UV-potential cannot suppress chaotic behaviors
existing in the IR-potential.Comment: 7 pages, 5 figures, version to appear in PR
Palladium Catalysts for Dehydrogenation of Ammonia Borane with Preferential B−H Activation
Cationic Pd(II) complexes catalyzed the dehydrogenation of ammonia borane in the most efficient manner with the release of 2.0 equiv of H_2 in less than 60 s at 25 °C. Most of the hydrogen atoms were obtained from the boron atom of the ammonia borane. The first step of the dehydrogenation reaction was elaborated using density functional theory calculations
Comparison of postoperative changes in the distal and proximal segments between conventional and sliding mini-plate fixation following mandibular setback
The purpose of the present study was to evaluate the postoperative three-dimensional (3D) changes in the proximal segments after mandibular setback sagittal split ramus osteotomy and to compare the changes between the conventional mini-plate fixation and semi-rigid sliding plate fixation
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