This paper considers the closed-loop control of electrically stimulated muscle using simultaneous pulse width and frequency modulation. Previous work has experimentally demonstrated good feedback regulation of muscle force using fixed parameter and an adaptive controller modulating pulse width. In this work, it is shown how the addition of pulse frequency… (More)
Optical fiber sensors offer unprecedented features, the most unique of which is the ability of monitoring variations of the observed physical field with spatial continuity along the fiber. These distributed optical fiber sensors are based on the scattering processes that originate from the interaction between light and matter. Among the three different… (More)
We show analytically how periodic spinning affects the polarization mode dispersion of a fiber in three different practical regimes that are determined by the values of three length scales: the beat length, the birefringence correlation length, and the spin period. We determine in which limits the spin is effective in reducing the mean differential group… (More)
—Polarization-mode dispersion (PMD) is a serious impairment for high-bit-rate optical telecommunication systems. It is known that spinning the fiber during the drawing process drastically reduces the PMD. However, the analysis of pulse propagation through a randomly birefringent spun fiber is still at an early stage. In this paper, we derive an analytical… (More)
Approvazione verbale riunione precedente Il Direttore porta all'approvazione del Collegio il verbale della seduta del Collegio del 25/01/2011. Il Collegio approva all'unanimità.
La riunione, convocata con posta elettronica del 6 dicembre 2013 (All. A), si è tenuta nell'Aula Magna " Antonio Lepschy " DEI/A, Dipartimento di Ingegneria dell'Informazione. Segretario il Prof. Carlo Ferrari.
—We consider the two Wai–Menyuk models of birefrin-gence in periodically spun fibers, and we show that the differential group delay differs significantly for the two models when the spin period approaches or exceeds the fiber beat length. When the fiber correlation length is large, we explain this difference quantitatively, and we explain it qualitatively… (More)
—Spun fibers are increasingly used in telecommunica-tion systems because their polarization-mode dispersion (PMD) is lower than that in unspun fibers. In this paper, we investigate the effects of a periodic spin on the PMD of fibers with randomly varying birefringence. Numerical simulations show that when the spin period is of the same order as or larger… (More)