The internal circadian rhythms of cells and organisms coordinate their physiological properties to the prevailing 24-h cycle of light and dark on earth. The mechanisms generating circadian rhythms have four defining characteristics: they oscillate endogenously with period close to 24 h, entrain to external signals, suffer phase shifts by aberrant pulses of light or temperature, and compensate f...

the focus of studies in the field of passive walking has often been on straight walking, while less attention has been paid to the field of turning motions. in this paper, the passive motions of a finite width rimless wheel as the simplest 3d model of passive biped walkers was investigated with a focus on turning motions. for this purpose, the hybrid model of the system consisting of continuous...

in this paper, we introduce fractional order of a planar fractional prey-predator system with a nonmonotonic functional response and anti-predator behaviour such that the adult preys can attack vulnerable predators. we analyze the existence and stability of all possibleequilibria. numerical simulations reveal that anti-predator behaviour notonly makes the coexistence of the prey and predator po...

This paper aims at proposing robust methods to optimize nonlinear energy sinks (NES) used for the mitigation of friction-induced vibrations due mode coupling instabilities. The study is based on a mechanical system composed two NES coupled well-known two-degrees-of-freedom Hultèn’s model. In such an unstable with NES, it usual observe discontinuity in steady-state amplitude profile which separa...

Robust performance controller design for duty-cycle controlled series resonant converter (SRC) is proposed in this paper. The uncertainties of the converter are analyzed with load variation and power circuit components tolerances are taken into consideration. Additionally, a nominal performance (NP) controller is designed. Closed-loop system is simulated with Orcad and simulation results of r...

In this paper we give sufficient conditions to ensure uniqueness of limit cycles for a class of planar vector fields. We also exhibit a class of examples with exactly one limit cycle.

We study quadratic perturbations of the integrable system (1 + x)dH, where H = (x2 + y2)/2. We prove that the first three Melnikov functions associated to the perturbed system give rise at most to three limit cycles.