In 1991, a long term UBV -photometry campaign of four Wolf-Rayet stars was started using the 60 cm telescope of the National Astronomical Observatory Rozhen, Bulgaria. Here we report on our observational results and discuss the light variations. The star WR137 was observed during 1991 1998. No indications of eclipses were found, though random light variations with small amplitudes exist, which ...

–In contrast to conventional generators, self-excited induction generators are found to be most suitable machines for wind energy conversion in remote and windy areas due to many advantages over grid connected machines. However such machines exhibits poor performance in terms of voltage and frequency under frequent variations of operating speeds, which is a common feature in wind energy convers...

The spectrum of the Wolf-Rayet (WR) star WR 63 contains spectral lines two different O stars that show regular radial velocity (RV) variations with amplitudes ~160 and ~225 km/s on a ~4.03 d period. light-curve shows narrow eclipses are 0.2 mag deep same period as RV changes. On other hand, our data no significant for lines. Those findings compatible being triple system composed non-interacting...

NASA Glenn Research Center, in collaboration with the aerospace industry and academia, has begun the development of technology for a future hybrid-wing body electric airplane with a turboelectric distributed propulsion (TeDP) system. It is essential to design a subscale system to emulate the TeDP power grid, which would enable rapid analysis and demonstration of the proof-of-concept of the TeDP...

We present practical poisoning and name-server blocking attacks on standard DNS resolvers, by off-path, spoofing adversaries. Our attacks exploit large DNS responses that cause IP fragmentation; such long responses are increasingly common, mainly due to the use of DNSSEC. In common scenarios, where DNSSEC is partially or incorrectly deployed, our poisoning attacks allow ‘complete’ domain hijack...

This paper proposes an approach to determine the gain of closed loop flux observer for an induction machine with respect to robustness and stability criteria. In the companion paper, a sensitivity analysis of flux observer has pointed out the influence of the sampling rate and the parameters mismatch. From this study, an accurate observer can be deduced. The analytical results are checked exper...

Rethinking Linking: Breathing New Life into OpenURL In this issue of Library Technology Reports, authors Cindi Trainor and Jason Price revisit OpenURL and library linking. The OpenURL framework for context-sensitive linking has been in use for a decade, during which library collections and users' behaviors have undergone radical change. This report examines how libraries can make use of web usa...

DetermininO" the numhe r of responde rs following a search is basically two-ste p op!'r lion ~equenced by the con trol pulse~, 1'.\, and E \' ,,: !) c\' gates Lhe Y vector out to t he A"-A J!J~ inputs to the tree, A,,, ,, al t he root (If Lhe tree th e n co nt a ins the va lue of OHing , '5, y, which is t rn por rily stored in the combinatorial logic and s to re block, Simulla­ rte(,usly, the "...