Publications with Abstracts by Alfred Hübler (1995)

1. * C. Wargitsch, A. Hübler, System Identification with Stochastic Resonance, Center for Complex Systems Research, Beckman Institute Il Nuovo Cimiento 17D, 969-976 (1995)
   Abstract: We study the impact of noise to the entrainment of undamped nonlinear oscillator to resonant driving forces. We find that the power consumption is large at a certain noise level. In addition we find that power consumption drops significantly if the forcing function is off-resonant. We discuss possible applications for system identification.

   Reprint

2. * F. Yamaguchi, K. Kawamura, A. Hübler, Sudden Drop of Dissipation in Field-Coupled Quantum Dot Resistors, Jpn. J. Appl. Phys. 34, L 105-108 (1995)
   Abstract: We propose a novel device where energy loss accompanied by current flow through a resistor is recovered, and therefore Joule heat production is exclusively low. This "energy-recovery effect" is caused by dynamical transition due to electronic coherent interference, namely Coulomb interaction within specially designed coupled quantum dots. We study the characteristics of this device as a resistor. We find sudden drop of energy dissipation due to current flow as a function of electrochemical potential of the reservoir which is coupled to the quantum dots. In addition, we show that resistance of the device depends on the strength of the Coulomb interaction.

   Reprint

3. * C. Wargitsch, A. Hübler, Resonances of Nonlinear Oscillators, Phys.Rev.E 51 1508-1519 (1995)
   Abstract: We show that nonlinear oscillators have a large response to special aperiodic driving forces. If these forces are selected to minimize the driving effort of a given terminal energy, these forces are given by the time-reflected transient of the unperturbed dynamics (the "principle of the dynamical key"). We provide a proof of this principle. We find that these optimal forcing functions have very similar dynamics for several different norms. We present a quantitative comparison of the energy transfer for sinusoidal and optimal driving forces. We find that aperiodic driving forces are most effective for large nonlinearity and small friction. We show that this optimal control is stable for several important systems.

   Reprint

4. * L.E. Arsenault, A. Hübler, Dynamics of Damped Coupled Oscillators Near Resonance, Phys.Rev.E 51, 3561-3571 (1995)
   Abstract: We study the dynamics of two conservative oscillators with perturbations from a linear displacement coupling and non-Hamiltonian forces such as damping. We examine the dynamics of these systems when they are near the primary resonance using secular perturbation theory. We show that near resonance a large class of driven oscillators and two coupled oscillators can be transformed to the same ordinary differential equations (ODEs). This common typ of dynamics near the resonance is a generalization of the standard Hamiltonian dynamics of two coupled conservative oscillators. We derive expressions for the parameters in these ODEs. From these parameters, we derive analytical expressions for the linear fixed point behavior of these oscillators near resonance. We find a relation between the amplitude frequency coupling of the oscillators and their phase-locking behavior. In particular, we show, that two hard oscillators lock in phase and two soft oscillators lock out of phase. We compare our theoretical predictions with computer simulations of two examples: a sinusoidally driven X³ force oscillator and two coupled van der Pol oscillators with X³ force.

   Reprint

5. * R. Mettin, W. Lauterborn, A. Hübler, A. Scheeline, W. Lauterborn, Parametric Entrainment Control of Chaotic Systems, Phys.Rev.E 51, 4065-4075 (1995)
   Abstract: We apply a generalized approach for model-based nonfeedback control to chaotic systems where parametric dependence on the control forces is included. The existing formalism is extended for our purpose. For chaotic iterated maps and ordinary differential equations, we obtain entrainment to stationary, periodic, and aperiodic goal dynamics. Applicability to general resonance spectroscopy is demonstrated.

   Reprint