1,721,038 research outputs found
Intensity sensors multiplexing using a multiwavelength ring fiber laser with hybrid serial-tree configuration
No full textDual Stage Ytterbium Doped Fiber Laser in MOPA Configuration
No full textWe report the experimental demonstration of an Ytterbium doped fiber laser (YDFL) composed by two stages in cascade.
Two sorts of Ytterbium doped fiber (YDF) with different concentration have been used.
A proper characterization of the YDFs has been performed in order to find the optimum YDF length.
To this end, the output power and the slope-efficiency have been calculated and the signal amplification and the amplified spontaneous emission (ASE) spectra have been analyzed, which are strictly related to the absorption and emission cross-section of the YDF.
The first stage has been studied for both continuous wave (CW) and pulsed regime. The results show that by using an YDF with a high slope-efficiency, up to 66%, it is possible to reach an emitted peak power of 30 W in a pulsed regime
Remote PCF-based Multiplexing by using optical add-drop multiplexers
No full textA 100 km remote PCF micro-displacement sensor multiplexing system based on optical add-drop multiplexers (OADMs) has been experimentally demonstrated. The PCF sensors are placed in an OADM bus structure which is illuminated by a home-made tunable fiber optic ring laser. Four micro-displacement photonic crystal fiber (PCF) sensors based on a suspended core fiber inserted into a Sagnac loop filter are multiplexed. Furthermore, being the first proposal to solve this issue in PCF sensor multiplexing structures, these sensors can be referenced with an extra wavelength
Magnetic field sensor based on backscattered intensity using ferrofluid
No full textA magnetic field sensor based on backscattered intensity of a single mode fiber immersed in a ferrofluid is experimentally demonstrated. An OTDR system was used to interrogate the reflected power at the fiber end face, revealing more than 2 dB of modulation for magnetic field changes up to 1525 Gauss. The sensor showed the same response when used in remote and multiplexed configurations, demonstrating the high potential and versatility of this sensing approach
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
- …
