Almeida E.P.L.,Av. Torquato Tapajos |
Chaves F.S.,Av. Torquato Tapajos |
Vieira R.D.,SCS Quadra 01 |
Iida R.F.,Av. Torquato Tapajos
Analog Integrated Circuits and Signal Processing | Year: 2014
The use of TV white spaces as an alternative to overcome spectrum scarcity is a huge opportunity for new telecommunication systems and services. While being attractive for its desirable propagation characteristics, this part of the spectrum imposes a major difficulty from design and regulatory perspectives: how to optimize the use of spectrum and to ensure the protection of primary users, TV systems for example, at the same time. This paper discusses strategies to be adopted by geo-location database operators to calculate adaptive maximum permitted power levels for secondary devices, according to permissible levels of interference into the digital terrestrial television primary system. © 2013 Springer Science+Business Media New York.
Diaz F.,National University of La Plata |
Torreias S.R.S.,Av. Torquato Tapajos |
Spinelli G.R.,National University of La Plata |
Ronderos M.M.,National University of La Plata
Acta Entomologica Musei Nationalis Pragae | Year: 2014
A new species, Dasyhelea pseudopollinosa Díaz & Ronderos sp. nov., is described from Brazil, illustrated and photographed as pupae and male and female adults. The male of D. paulistana Forattini & Rabello, 1957 is described for the first time, and the pupa and female adult are redescribed. Pupae of both species were collected from mats of floating fern leaves (Salviniaceae and Azollaceae) in Brazil and Argentina, and exhibit a respiratory organ which is thick at the base and tapering to a sharp apex, and segment 9 with elongate, slender apicolateral process. Diffe rences between the two species are established, and they are also compared with Nearctic congeners that have the same kind of pupa: D. pollinosa Wirth, 1952, D. traverae Thomsen, 1935, and D. chani Wirth & Linley, 1990. © 2014, National Museum/Narodni muzeum. All rights reserved.