1,635 research outputs found
On the nature of the torus in the complex Lorenz equations.
The complex Lorenz equations are a nonlinear fifth-order set of physically derived differential equations which exhibit an exact analytic limit cycle which subsequently bifurcates to a torus. In this paper we build upon previously derived results to examine a connection between this torus at high and low r1 bifurcation parameter) and between zero and nonzero r2(complexity parameter); in so doing, we are able to gain insight on the effect of the rotational invariance of the system, and on how extra weak dispersion (r2 ≠0) affects the chaotic behavior of the real Lorenz system (which describes a weakly dissipative, dispersive instability)
A delay recruitment model of the cardiovascular control system.
Copyright will be owned by Springer. We develop a nonlinear delay-differential equation for the human cardiovascular control system, and use it to explore blood pressure and heart rate variability under short-term baroreflex control. The model incorporates an intrinsically stable heart rate in the absence of nervous control, and features baroreflex influence on both heart rate and peripheral resistance. Analytical simplifications of the model allow a general investigation of the rĂ´les played by gain and delay, and the effects of ageing.
A Dichotomy Theorem for Circular Colouring Reconfiguration
The "reconfiguration problem" for circular colourings asks, given two
-colourings and of a graph , is it possible to transform
into by changing the colour of one vertex at a time such that every
intermediate mapping is a -colouring? We show that this problem can be
solved in polynomial time for and is PSPACE-complete for
. This generalizes a known dichotomy theorem for reconfiguring
classical graph colourings.Comment: 22 pages, 5 figure
Job Mismatches and Labour Market Outcomes: Panel Evidence on Australian University Graduates
The interpretation of graduate mismatch manifested either as overeducation or as overskilling remains problematical. This paper uses annual panel information on both educational and skills mismatches uniquely found in the HILDA survey to analyse the relationship of both mismatches with pay, job satisfaction and job mobility. We find that overeducation and overskilling are distinct phenomena with different labour market outcomes and that their combination results in the most severe negative labour market outcomes. Using panel methodology reduces strongly the size of many relevant coefficients, questioning previous cross-section results and suggesting the presence of considerable unobserved heterogeneity which varies by gender.overeducation, overskilling, wages, satisfaction, mobility
Quantum Frequency Translation of Single-Photon States in Photonic Crystal Fiber
We experimentally demonstrate frequency translation of a nonclassical optical
field via the Bragg scattering four-wave mixing process in a photonic crystal
fiber (PCF). The high nonlinearity and the ability to control dispersion in PCF
enable efficient translation between photon channels within the visible
to-near-infrared spectral range, useful in quantum networks. Heralded single
photons at 683 nm were translated to 659 nm with an efficiency of percent. Second-order correlation measurements on the 683-nm and 659-nm
fields yielded and respectively, showing the nonclassical nature of both fields.Comment: 5 pages, 3 figure
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