176,902 research outputs found
Measurement results of transmit delay diversity for DVB-T networks
This paper describes work carried out by Brunel University and Broadreach systems (UK) to quantify the advantages that can be achieved if transmit diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial performed during the winter of 2007/2008 in Uxbridge (UK) is described. The transmissions were performed in the 730 MHz frequency band with a DVB-T transmitter and a mean power of 18.4 dBW. Transmit delay diversity has been observed to deliver significant reception improvement in automotive- non line of sight situations
On-Line Instruction-checking in Pipelined Microprocessors
Microprocessors performances have increased by more than five orders of magnitude in the last three decades. As technology scales down, these components become inherently unreliable posing major design and test challenges. This paper proposes an instruction-checking architecture to detect erroneous instruction executions caused by both permanent and transient errors in the internal logic of a microprocessor. Monitoring the correct activation sequence of a set of predefined microprocessor control/status signals allow distinguishing between correctly and not correctly executed instruction
New species, combinations, synonymies, and records of Clytini (Coleoptera: Cerambycidae)
Megacyllene (Megacyllene) cryptofrasciata n. sp. from Argentina is described and illustrated. M. quinquefasciata (Melzer, 1931), and Megacyllene rotundicollis Zajciw, 1963 are transferred from the subgenus Megacyllene Casey 1912 to Sierracyllene Tippmann, 1960. Megacyllene (SierracylZene) tafivallensis n. sp. is described from northwestern Argentina. Dexithea spixii (Laporte & Gory, 1836), and Plagionotus latreillei (Laporte & Gory, 1836) are transferred to Megacyllene (sensu stricto), excluding Dexithea, and Plagionotus from the South American fauna of Clytini. Neoclytus famelicus (Burmeister, 1865) is synonymized with N. ypsilon Chevrolat, 1861. Additional new records of Clytini from Argentina, Paraguay, and Ecuador are also presented here. A key for subgenera and species of Megacyllene is included, with distribution maps for Argentina and nearby countries
The genus Erlandia Aurivillius, 1904 (Coleoptera: Cerambycidae) in Argentina, with the description of a new species
The genus Erlandia (Cerambycinae: Erlandiini) was described by Aurivillius in 1904, containing a single species, Erlandia inopinata, distributed in Bolivia, Argentina, and Paraguay. Anew species, E. megacephala, from Argentina is described, and illustrated here. A key and distribution map of both species are provided, with a generic diagnosis using characters of both species
Correlation established between heat transfer and ultrasonic transmission properties of copper braze bonds
Measuring and correlating the thermal conductivity and ultrasonic transmission of seven hot-brazed-bonded copper plates established a relationship between heat transfer and ultrasonic transmission properties of the bonds. This relationship permits the prediction of heat transfer characteristics from ultrasonic transmission tests
Addenda and omissions to the catalogue and checklist of the Cerambycidae and Disteniidae (Coleoptera) of the Western hemisphere
The Catalogue (Monne, 1993-1994) and Checklist (Monne and Giesbert, 1995) of the Cerambycidae and Disteniidae of the Western Hemisphere represents a necessary, and valuable tool since recompilation of Blackwelder (1946) was made. Species with references (omissions), and without them (new records) are given for some countries
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