Results 251 to 260 of about 604,375 (292)

Radio Map of the Andromeda Galaxy

Science, 1964
The University of Illinois radio telescope has resolved the 610.5 Mcy/sec disk component of radio emission from the large galaxy M 31 into several discrete concentrations. In two cases, these correspond to the crossing of the optical major axis by spiral arms. A spur of emission extends southeast from the galaxy near the minor axis.
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Radio Maps of Maffei 2

Nature Physical Science, 1972
KEEN interest has been aroused by the newly discovered objects1 Maffei 1 and 2, which are believed to be nearby galaxies. There is no detectable radio emission2 from Maffei 1, which is probably an E3 or E4 galaxy, but Maffei 2 (at l = 136°, b = 0°) has been studied both in the radio continuum3–7 and the 21 cm hydrogen line6,7 with the conclusions that (
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Distributed estimation for Radio Environment Map in cognitive radio networks

Proceedings of the 33rd Chinese Control Conference, 2014
Radio Environment Map (REM) is a map that indicates the radio signal strength (RSS) over a finite geographical region. It enables cognitive radio (CR) users to opportunistically access to the spectrum unoccupied by the primary users (PUs) who are licensed to use specific spectrum.
Jianzhi Liu, Hui Han, Cailian Chen, Li'an Li, Xinping Guan   +4 more
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Small-cells radio resource management based on Radio Environmental Maps

2014 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), 2014
Recent advances in cognitive radio have identified the small-cells among the most promising future wireless networking scenarios. Utilizing radio context information, smallcells should perform the most optimal radio resource management (RRM) to maximize performances and minimize inter-cell interference.
Daniel Denkovski, Valentin Rakovic, Marko Angjelicinoski, Vladimir Atanasovski, Liljana Gavrilovska   +4 more
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Sensor placement algorithm for radio environment map construction in cognitive radio networks

2014 IEEE Wireless Communications and Networking Conference (WCNC), 2014
In cognitive radio, current trend is to utilize geolocation database for TV bands. Considering more dynamic bands in terms of primary user activity, however, necessitates the use of Radio Environment Map (REM), which is an advanced knowledge base that stores live multidomain information on the entities in the network and the environment.
H Birkan Yilmaz, Chan-Byoung Chae, Tugcu, Tuna   +2 more
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Mapping the Radio KC community

Ecquid Novi: African Journalism Studies, 2004
South African community radio was established as one means of addressing the need for local participation in the public sphere. The model of community radio outlined in legislation does not, however, offer enough guidance for how such participation will be achieved on a day-to-day basis, and many geographically-based stations face serious problems in ...
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Radio Maps of QSOs in Clusters

Publications of the Astronomical Society of the Pacific, 1998
We present 20 cm and 6 cm maps of 38 QSOs observed in the B configuration of the VLA. The maps are snapshots used in the discussion of the effects of cluster environment on radio properties of QSOs by Hutchings et al. We display maps of all QSOs from the sample of 43 that have significant structure.
J. B. Hutchings, A. Dewey, D. Chaytor, S. Ryneveld, A. C. Gower, E. Ellingson   +5 more
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Radio Maps for Fingerprinting in Indoor Positioning

2019
In spite of all the efforts done by researchers, today we still do not have a universal and ubiquitous solution for indoor positioning. Fingerprinting is one of the most well-known technologies used to build indoor positioning systems, using the radio signals to determine the user or device location, exploring the principle that each location has a ...
Meneses, Filipe, Moreira, Adriano, Costa, António, Nicolau, Maria João   +3 more
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Secure crowdsourced radio environment map construction

2017 IEEE 25th International Conference on Network Protocols (ICNP), 2017
Database-driven Dynamic Spectrum Sharing (DSS) is the de-facto technical paradigm adopted by Federal Communications Commission (FCC) for increasing spectrum efficiency. In such a system, a geo-location database administrator (DBA) maintains spectrum availability information over its service region whereby to determines whether a secondary user can ...
Yidan Hu, Rui Zhang
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Practical radio environment mapping with geostatistics

2012 IEEE International Symposium on Dynamic Spectrum Access Networks, 2012
In this paper we present results from the first application of robust geostatistical modeling techniques to radio environment and coverage mapping of wireless networks. We perform our analysis of these methods with a case study mapping the coverage of a 2.5 GHz WiMax network at the University of Colorado, Boulder.
Caleb Phillips, Michael Ton, Douglas Sicker, Dirk Grunwald   +3 more
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