140 research outputs found

    An integral formula for L^2-eigenfunctions of a fourth order Bessel-type differential operator

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    We find an explicit integral formula for the eigenfunctions of a fourth order differential operator against the kernel involving two Bessel functions. Our formula establishes the relation between K-types in two different realizations of the minimal representation of the indefinite orthogonal group, namely the L^2-model and the conformal model

    SOME ASPECTS OF ENERGY SAVING OF BURDEN MATERIAL IN THE BLAST FURNACE

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    To determine the possibility of self-stabilization effect for burden surface texture and gas flow in operating blast furnace under the proper conditions was experimentally proved for the first time, as well as the reasons of the effect disruption

    Radio-over-fibre technologies arising from the Building the future Optical Network in Europe (BONE) project

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    [EN] This study describes a wide range of salient radio-over-fibre system issues. Impulse radio and multiband ultra-wideband signal distribution over both single-mode fibre and multi-mode fibre (MMF) implementations are considered. Carrier frequencies ranging from 3.1 to 10.6 GHz, up to 60 GHz, are featured, and the use of microring laser transmitters is discussed. A cost-performance comparative analysis of competing distributed antenna system topologies is presented, and a theoretical approach to understanding the factors underlying radio-over-MMF performance for within-building applications is discussed. Finally, techniques to minimise thermal impacts on performance are described and novel energy-efficient schemes are introduced. Overall, this study provides a snap-shot of research being undertaken by European institutes involved in the Building the future Optical Network in Europe (BONE) project.The work described in this paper was carried out with the support of the EU-FP7 Network of Excellence BONE project.Parker, M.; Walker, SD.; Llorente, R.; Morant, M.; Beltrán, M.; Möllers, I.; Jäger, D.... (2010). Radio-over-fibre technologies arising from the Building the future Optical Network in Europe (BONE) project. IET Optoelectronics. 4(6):247-259. https://doi.org/10.1049/iet-opt.2009.0062S24725946http://www.ftthcouncil.euGomes, N. J., Morant, M., Alphones, A., Cabon, B., Mitchell, J. E., Lethien, C., … Iezekiel, S. (2009). Radio-over-fiber transport for the support of wireless broadband services [Invited]. Journal of Optical Networking, 8(2), 156. doi:10.1364/jon.8.000156Thakur, M. P., Quinlan, T. J., Bock, C., Walker, S. D., Toycan, M., Dudley, S. E. M., … Ben-Ezra, Y. (2009). 480-Mbps, Bi-Directional, Ultra-Wideband Radio-Over-Fiber Transmission Using a 1308/1564-nm Reflective Electro-Absorption Transducer and Commercially Available VCSELs. Journal of Lightwave Technology, 27(3), 266-272. doi:10.1109/jlt.2008.2005644ECMA-368 International Standard: ‘High rate ultra wideband PHY and MAC standard’, December 2008FCC 02-48: ‘Revision of part 15 of the commission's rules regarding ultra-wideband transmission systems’, April 2002ECC∕DEC∕(06)04: ‘On the harmonised conditions for devices using ultra-wideband (UWB) technology in bands below 10.6 GHz’, March 2006ETSI EN 302 065 V1.1.1 (2008-02): ‘Electromagnetic compatibility and radio spectrum matters (ERM); ultra wideband (UWB) technologies for communication purposes; harmonized EN covering the essential requirements of article 3.2 of the R&TTE Directive’, February 2008WiMedia Alliance: Worldwide regulatory status [online]. Available at: http://www.wimedia.orgMikroulis, S., Simos, H., Roditi, E., & Syvridis, D. (2005). Ultrafast all-optical AND logic operation based on four-wave mixing in a passive InGaAsP-InP microring resonator. IEEE Photonics Technology Letters, 17(9), 1878-1880. doi:10.1109/lpt.2005.853260Argyris, A., Hamacher, M., Chlouverakis, K. E., Bogris, A., & Syvridis, D. (2008). Photonic Integrated Device for Chaos Applications in Communications. Physical Review Letters, 100(19). doi:10.1103/physrevlett.100.194101Win, M. Z., & Scholtz, R. A. (1998). On the robustness of ultra-wide bandwidth signals in dense multipath environments. IEEE Communications Letters, 2(2), 51-53. doi:10.1109/4234.660801Flatman, A.: In-premises optical fibre installed base analysis to 2007. Presented at the IEEE 802.3 10GbE over FDDI Grade Fibre Study Group, Orlando, FL, March 2004Raddatz, L., & White, I. H. (1999). Overcoming the modal bandwidth limitation of multimode fiber by using passband modulation. IEEE Photonics Technology Letters, 11(2), 266-268. doi:10.1109/68.740725Hartmann, P., Xin Qian, Wonfor, A., Penty, R. V., & White, I. H. (2005). 1-20 GHz Directly Modulated Radio over MMF Link. 2005 International Topical Meeting on Microwave Photonics. doi:10.1109/mwp.2005.203548Kanprachar, S., & Jacobs, I. (2003). Diversity coding for subcarrier multiplexing on multimode fibers. IEEE Transactions on Communications, 51(9), 1546-1553. doi:10.1109/tcomm.2003.816981Gasulla, I., & Capmany, J. (2006). Transfer function of multimode fiber links using an electric field propagation model: Application to Radio over Fibre Systems. Optics Express, 14(20), 9051. doi:10.1364/oe.14.009051Al-Raweshidy, H., and Komaki, S.: ‘Radio over fiber technologies for mobile communication networks’, (Artech House 2002)Sauer, M., Kobyakov, A., & George, J. (2007). Radio Over Fiber for Picocellular Network Architectures. Journal of Lightwave Technology, 25(11), 3301-3320. doi:10.1109/jlt.2007.906822Gomes, N. J., Nkansah, A., & Wake, D. (2008). Radio-Over-MMF Techniques—Part I: RF to Microwave Frequency Systems. Journal of Lightwave Technology, 26(15), 2388-2395. doi:10.1109/jlt.2008.925624Rajan, G., Semenova, Y., Pengfei Wang, & Farrell, G. (2009). Temperature-Induced Instabilities in Macro-Bend Fiber Based Wavelength Measurement Systems. Journal of Lightwave Technology, 27(10), 1355-1361. doi:10.1109/jlt.2009.2014081Montalvo, J., Vázquez, C., & Montero, D. S. (2006). CWDM self-referencing sensor network based on ring resonators in reflective configuration. Optics Express, 14(11), 4601. doi:10.1364/oe.14.00460

    Urbanization in Iron Age Europe:Trajectories, patterns, and social dynamics

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