1,721,529 research outputs found
Nonlinear Dynamics and Fiber Optics Group at Instituto de Óptica “Daza de Valdes del CSIC: Experimental research lines
No full text11 pags., 10 figs. -- Ejemplar dedicado a: Óptica no lineaSe presenta y describen las líneas de trabajo experimentales que se vienen cultivando en el Grupo de
investigación en Dinámica no Lineal y Fibras ópticas, recientemente creado en el Instituto de Óptica
del CSIC.We present the experimental lines developed in last years in the Nonlinear Dynamics and Fiber
Optics Group (NDFO) of the Optics Institute “Daza de Valdés” (IO-CSIC).Agradecemos la ayuda al Ministerio de Ciencia y
Tecnología a través de los proyectos TEC2009-
14423-C02-01, TEC2009-14423-C02-02 y
TEC2008-5791, al Ministerio de Fomento a
través del proyecto MIFFO (FOM-07/77) y de la
Comunidad de Madrid a través del proyecto
FACTOTEM2 (S2009/ESP-1781). S. MartinLópez y J. Nuño agradecen al Ministerio de Ciencia y Tecnología por su contrato “Juan de la
Cierva” y beca FPI, respectivamente. Xabier
Angulo-Vinuesa agradece el apoyo económico de
ICYF S.A.Peer reviewe
Raman-assisted Brillouin optical time-domain analysis with sub-meter resolution over 100 km
Full text linkSub-meter resolution in long-distance Brillouin Optical Time Domain Analysis (BOTDA) cannot be trivially achieved due to several issues including: resolution-uncertainty trade-offs, self-phase modulation, fiber attenuation, depletion, etc. In this paper we show that combining Raman assistance, differential pulse-width pair (DPP) measurements and a novel numerical de-noising procedure, we could obtain sub-meter resolution Brillouin optical time-domain analysis over a range of 100 km. We successfully demonstrate the detection of a 0.5 meter hot-spot in the position of worst contrast along the fiber. © 2012 Optical Society of America.This work was supported in part by the Spanish Ministry of Science and Innovation through projects TEC2009-14423-C02-01 and TEC2009-14423-C02-02 and the Comunidad de Madrid through project FACTOTEM-2. Sonia Martin-Lopez acknowledges funding from the Spanish Ministry of Science and Innovation through a “Juan de la Cierva” contract.Peer Reviewe
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
Variations 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
Raman-assisted Brillouin distributed temperature sensor over 100 km featuring 2 m resolution and 1.2 °c uncertainty
Full text linkRaman assistance in distributed sensors based on Brillouin optical time-domain analysis can significantly extend the measurement distance. In this paper, we have developed a 2 m resolution long-range Brillouin distributed sensor that reaches 100 km using first-order Raman assistance. The estimated uncertainty in temperature discrimination is 1.2 °C, even for the position of worst contrast. The parameters used in the experiment are supported by a simple analytical model of the required values, considering the main limitations of the setup. © 2012 IEEE.This work was supported in part by the Spanish
Ministry of Science and Innovation through Project TEC2009-14423-C02-01
and Project TEC2009-14423-C02-02, the Ministerio de Fomento through
projects MIFFO (FOM-07/77) and IFZONE (FOM 39/08), and the Comunidad
de Madrid through project FACTOTEM2.Peer Reviewe
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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