305,687 research outputs found
Recent Results From the EU POF-PLUS Project: Multi-Gigabit Transmission Over 1 mm Core Diameter Plastic Optical Fibers
Full text linkRecent activity to achieve multi-gigabit transmission over 1 mm core diameter graded-index and step-index plastic optical fibers for distances up to 50 meters is reported in this paper. By employing a simple intensity-modulated direct-detection system with pulse amplitude or digital multi-tone modulation techniques, low-cost transceivers and easy to install large-core POFs, it is demonstrated that multi-gigabit transmission up to 10 Gbit/s over 1-mm core diameter POF infrastructure is feasible. The results presented in this paper were obtained in the EU FP7 POF-PLUS project, which focused on applications in different scenarios, such as in next-generation in-building residential networks and in datacom applications
In-home networks integrating high-capacity DMT data and DVB-T over large-core GI-POF
Full text link[EN] The low-cost in-home distribution of full-standard digital TV jointly with high-bitrate data using 50 m long 1 mm core diameter gradedindex plastic optical fiber (GI-POF) is proposed and experimentally demonstrated. Discrete multitone (DMT) modulation is demonstrated to provide an adaptive bitrate which can spectrally coexist with digital video broadcasting-terrestrial (DVB-T) signals in 470-862 MHz. A 3 Gb/s DMT signal and two DVB-T channels are generated, transmitted and received exhibiting excellent performance. © 2012 Optical Society of America.This work has been supported in part by the European Commission through the FP7 ICT-4-249142 FIVER project, and by the Spain project IPT-430000-2010-072 IT-HOGAR.Beltrán Ramírez, M.; Shi, Y.; Okonkwo, C.; Llorente Sáez, R.; Tangdiongga, E..; Koonen, T. (2012). In-home networks integrating high-capacity DMT data and DVB-T over large-core GI-POF. Optics Express. 20(28):29769-29775. https://doi.org/10.1364/OE.20.029769S29769297752028Koonen, A. M. J., van den Boom, H. P. A., Martinez, E. O., Pizzinat, A., Guignard, P., Lannoo, B., … Tangdiongga, E. (2011). Cost optimization of optical in-building networks. Optics Express, 19(26), B399. doi:10.1364/oe.19.00b39
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
Full text linkThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
Remote in-door Ranging System Using Impulse Radio Ultra Wideband RoF Techniques
No full textWe propose and experimentally demonstrate an Impulse-Radio Ultra-wideband Radioover-Fiber (IR-UWB-RoF) indoor ranging systems with sub-cm level accuracy. To minimize the cost of the system, reduce power consumption of receiver architecture and simultaneously achieve a better FCC-mask compliance, we employ a novel pulse shaping technique of IR-UWB pulse and an energy detector receiver architecture with a sub-sampling frequency capability. The effect of different fiber types (SMF and MMF) and fiber lengths on the ranging accuracy are studied using ToA ranging techniques.
The proposed system has a potential for low cost in-building networks application to provide indoor localization with excellent accuracy
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
40 GHz clock recovery from 640 Gbit/s OTDM signal using SOA-based phase comparator
No full textA 40 GHz clock with low jitter is recovered from a 640 Gbit/s optical time-division multiplexed (OTDM), single-polarised, return-to-zero PRBS data signal. The clock recovery circuit is an injection-locked loop which contains a 40 GHz Gunn oscillator, a 40 GHz pulse source, and a semiconductor optical amplifier (SOA) assisted by a filtered chirp as optical phase comparator
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