The internal circadian clock and sleep-wake homeostasis regulate the timing of human brain function, physiology, and behavior so that wakefulness and its associated functions are optimal during the solar day and that sleep and its related functions are optimal at night. The maintenance of a normal phase relationship between the internal circadian clock, sleep-wake homeostasis, and the light-dar...

We present the principles of variable pure polarization rotators based on the accumulation of a geometric phase that is obtained by coiling a beam of light via discrete reflections. They consist of two pseudo rotators in series. By changing the angle between the pseudo rotators the geometric phase acquired by the light is varied. We describe in detail two important examples: the variable-angle ...

For the specification of phase-noise requirements for the front-end of a HiperLAN/2 system we investigated available literature on the subject. Literature differed in several aspects. One aspect is in the type of phase-noise used (Wiener phase-noise or small-angle phase noise). A Wiener phase-noise based analysis leads to contradictions with the type of analysis normally used in the solid state...

This paper presents the implementation and characteristic analysis of a drive system for a three-phase permanent magnet motor with independent excitation winding that is applicable for electric bicycles. The design features improves the phase current waveform, output power, and torque by using advance angle control. This adjusts the phase angle of each phase current in relation to back EMF. In ...

Cationic waterborne polyurethane as a new dispersing polymer was synthesized by using relatively hydrophilic polyols. Dispersing cationic polyurethane (DCPU) nanocomposites were prepared using isophorone diisocyanate (IPDI), polyethylene glycol (PEG) with different molecular weights (Mn=200, 400, 600,and1000 g/mol), N-methyl diethanolamine (MDEA), dibutyltin dilaurate (DBTDL) and different perc...