This paper presents a novel control method to improve the efficiency of low-voltage DC-DC converters at light loads. Pulse Width Modulation (PWM) converters have poor efficiencies at light loads, while pulse frequency modulation (PFM) control is more efficient for the same cases. Switching losses constitute a major portion of the total power loss at light loads. To decrease the switching losses...

A common method to study the dynamic behavior of macroeconomic variables is using linear time series models; however, they are unable to explain nonlinear behavior of the series. Given the dependency between stock market and derivatives, the behavior of the underlying asset price can be modeled using Markov switching process properties and the economic regime significance. In this paper, a two-...

the large amount of computation necessary for obtaining time optimal solution for moving a manipulator on specified path has made it impossible to introduce an on line time optimal control algorithm. most of this computational burden is due to calculation of switching points. in this paper a learning algorithm is proposed for finding the switching points. the method, which can be used for both ...

one of the most controversial and unresolved questions in bilingual first language acquisition (henceforth bfla) is whether bilingual children develop one mixed or two independent linguistic systems. many scholars in the lield of bfla arc in tavor of the one-system hypothesis (leopold 1970; swain and wesche, 1975; volterra and tacschner, j 987; grosjean, 1982; tacschncr, 1983: mclaughlin, 1984:...

VAR support should be supplied as close to the load as possible to minimize transmission losses. For voltage control and for improvement of total power factor in a distribution system the circuit- breaker switched capacitor banks can be used. The problems with this solution are the voltage steps caused by the large sizes of the capacitor banks as well as the transients caused on insertion. Thyr...

We solve the coupled mode equations governing the chalcogenide nonlinear fiber Bragg gratings (FBGs) numerically, and obtain the bistability characteristics. The characteristics of the chalcogenide nonlinear FBGs such as: switching threshold intensity, bistability interval and on-off switching ratio are studied. The effects of FBG length and its third order nonlinear refractive index on FBG cha...