In this work, we model the optical constants of three organic materials using a modified Lorentz oscillator model. We have analysed the impact of the choice of the objective or merit function, which is employed for model parameter estimation, on the modelling of the optical constants. The objective function for model parameter determination should be chosen in such a manner that discrepancies b...

Clinicians and experimentalists routinely estimate vagal-cardiac nerve traffic from respiratory sinus arrhythmia. However, evidence suggests that sympathetic mechanisms may also modulate respiratory sinus arrhythmia. Our study examined modulation of respiratory sinus arrhythmia by sympathetic outflow. We measured R-R interval spectral power in 10 volunteers that breathed sequentially at 13 freq...

We propose a method for detecting the presence of a synchronization of a self-sustained oscillator by external driving with linearly varying frequency. The method is based on a continuous wavelet transform of the signals of the self-sustained oscillator and external force and allows one to distinguish the case of true synchronization from the case of spurious synchronization caused by linear mi...

Interaction between a membrane oscillator generated by voltage-dependent ion channels and an intracellular calcium signal oscillator was present in the earliest models (1984 to 1985) using representations of the sarcoplasmic reticulum. Oscillatory release of calcium is inherent in the calcium-induced calcium release process. Those historical results fully support the synthesis proposed in the a...

in this study a new minimum lumped electrical model of total circulatory system through numerical solutions to approximate the response of the human circulatory system was presented. among five existent ventricular elastances as activity function of heart pumps, a more accurate model was chosen as well as the operation of baroreflex system to accommodate variations in heart rate and systemic va...

in this work, time domain analysis is used to solve adler’s equation in order to obtain the required time, for an oscillator under external injection, reaching the steady-state condition. mathematical approach has been applied to fully describe the transient of frequency acquisition in injection-locked lc and ring oscillators considering their time-varying nature. then, the analysis is verified...