1,721,572 research outputs found
OCDM systems with PSK and QAM codes
No full textA multiport encoder/decoder can simultaneously generate multiple PSK optical codes, and it has been effectively used in asynchronous, spectrally efficient access networks. To increase the system flexibility, as well as the number of simultaneous IoT signals, we introduce novel multi-level QAM orthogonal optical codes that are generated by the multiport encoder/decoder using optical phase modulators. The QPSK modulator simultaneously operates for data modulation and orthogonal code generation. The code orthogonality is improved, compared to conventional PSK codes, and we analyze the performance of 16-code × 10 GSymbol/s, OOK-, DPSK- and DQPSK-modulated OCDM systems, using conventional PSK and the proposed QAM codes
Coarse-graining Scale And Effectiveness Of Hydrodynamic Modeling
No full textSome basic questions about the hydrodynamical approach to relativistic heavy-ion collisions are discussed aiming to clarify how far we can go with such an approach to extract useful information on the properties and dynamics of the QCD matter created. We emphasize the importance of the coarsegraining scale required for the hydrodynamic modeling which determines the space-time resolution and the associated limitations of collective flow observables. We show that certain kinds of observables can indicate the degree of inhomogeneity of the initial condition under less stringent condition than the local thermal equilibrium subjected to the coarse-graining scale compatible to the scenario. © Società Italiana di Fisica / Springer-Verlag 2012.4811112Ackermann, K.H., (2001) Phys. Rev. Lett, 86, p. 402Adams, J., (2005) Nucl. Phys. A, 757, p. 102Adcox, K., (2005) Nucl. Phys. A, 757, p. 184Back, B.B., (2005) Phys. Rev. C, 72, p. 051901Afanasiev, S., (2009) Phys. Rev. C, 80, p. 024909Landau, L.D., Lifshitz, E.M., (1959) Fluid Mechanics, , Pergamon, New YorkElze, H.-T., Hama, Y., Kodama, T., Makler, M., Rafelski, J., (1999) J. Phys. G Nucl. Part. Phys, 25, p. 1935Koide, T., Kodama, T., (2012) J. Phys. A Math. Theor, 45, p. 255204Hama, Y., Kodama, T., Socolowski Jr., O., (2005) Braz. J. Phys, 35, p. 24Andrade, R.P.G., Grassi, F., Hama, Y., Kodama, T., Qian, W.L., (2008) Phys. Rev. Lett, 101, p. 112301Mota, P., Kodama, T., (2012) Progr. Theor. Phys. Suppl, 193, p. 315Denicol, G.S., Holopainen, H., Huovinen, P., Niemi, H., Molner, E., Rischke, D., in preparationStöcker, H., (2005) Nucl. Phys. A, 750, p. 121Casalderrey-Solana, J., Shuryak, E.V., Teaney, D., (2006) Nucl. Phys. A, 774, p. 577Denicol, G.S., Kodama, T., Koide, T., Mota, P., (2008) Phys. Rev. C, 78, p. 034901Csernai, L.P., Strottman, D.D., Anderlik, C., (2012) Phys. Rev. C, 85, p. 054901Paiva, S., Hama, Y., Kodama, T., (1997) Phys. Rev. C, 55, p. 1455Aguiar, C.E., Hama, Y., Kodama, T., Osada, T., (2002) Nucl. Phys. A, 698, p. 639Andrade, R., Grassi, F., Hama, Y., Kodama, T., Socolowski, O., (2006) Phys. Rev. Lett, 97, p. 202302Andrade, R., Grassi, F., Hama, Y., Kodama, T., Socolowski Jr., O., (2007) Braz. J. Phys, 37, p. 717Takahashi, J., Tavares, B.M., Qian, W.L., Andrade, R., Grassi, F., Hama, Y., Kodama, T., Xu, N., (2009) Phys. Rev. Lett, 103, p. 242301Wang, D.J., Csernai, L.P., Strottman, D., Anderlik, C., Cheng, Y., (2012) QGP flow fluctuations and the characteristics of higher moments, , arXiv:1205.4934Qiu, Z., Shen, C., Heinz, U., (2012) Phys. Lett. B, 707, p. 151Alver, B., Roland, G., (2010) Phys. Rev. C, 81, p. 054905Teaney, D., Yan, L., (2011) Phys. Rev. C, 83, p. 064904Schenke, B., Tribedy, P., Venugopalan, R., (2012) Phys. Rev. Lett, 108, p. 252301Dumitru, A., Nara, Y., (2012) Phys. Rev. C, 85, p. 034907Mota, P., Kodama, T., Koide, T., Takahashi, J., (2011) Nucl. Phys. A, 862-863, p. 188Drescher, H.J., Liu, F.M., Ostapchenko, S., Pierog, T., Werner, K., (2002) Phys. Rev. C, 65, p. 054902Schenke, B., Jeon, S., Gale, C., (2012) Phys. Rev. C, 85, p. 02490
Secure DPSK-based M-ary block-ciphered multicarrier optical communication
No full textTo improve the physical-layer data confidentiality in short-reach optical networks, we have proposed an M-ary blockciphered system using an optical code multiplexing approach. In a previous system, each optical code (OC), that corresponds to a frequency subcarrier, was mapped onto one of the log2M bits, and the computational security is related to the correspondence between the bit-block and the OC, and the number of possible combinations equates M!. However, this system presents two critical issues (1) Computational Security: the number M of OCs that can be generated by an optical arrayed waveguide grating (AWG) is limited, due to the port number and the subcarrier crosstalk. (2) Physical security: a careful differential analysis of the corresponding time waveform, optical power, and/or optical spectrum can be used to identify the symbol pattern. To mitigate the effects of interchannel interference, we propose a new differential phase-shift keying (DPSK)-based multi-dimensional M-ary block ciphering system, that assigns binary phase difference patterns to adjacent symbols and demonstrate a 16-dimensional 216-ary ciphered system. In addition, to increase the M-ary number, without increasing the number of OCs, we consider also a differential quadrature phase-shift keying (DQPSK)-based multi-dimensional M-ary block ciphered system and demonstrate a 16-dimensional 232-ary ciphered system
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
Effects of aeration on tropane alkaloid production by transformed root of Atropa belladonna in flask cultures.
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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
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