1,721,010 research outputs found
Experimental Activities to Support Future Space-based High Throughput Communication Infrastructures
No full textModulation instability and conservation of energy:toward a new model
Full text linkL'articolo analizza la propagazione in regime nonlineare di un segnale ottico CW in presenza di una "piccola" perturbazione. In letteratura sono presenti lavori che specificano i parametri fisici che regolano l'interazione tra il segnale CW e la perturbazione ma non si hanno indicazioni relative ai limiti di applicabilità dei modelli proposti. Obiettivo principale di questo lavoro è rappresentato dalla definizione dei parametri che "attivano" l'instabilità di modulazione e regolano il regime di propagazione nonlineare. A tal fine, il regime di propagazione nonlineare è analizzato vincolandolo al principio di conservazione dell'energia
Tropospheric Scintillation and Simultaneous Rain Attenuation at 19.7 GHz and 39.4 GHz for Tito Scalo and Spino d'Adda
No full textChodsigoa parca G. M. Allen 1923
No full text170. Lowe’s Brown-toothed Shrew Chodsigoa parca French: Musaraigne étriquée / German: Lowe-Braunzahnspitzmaus / Spanish: Musarana de dientes marrones de Lowe Other common names: Lowe's Shrew Taxonomy. Chodsigoa smithii parca G. M. Allen, 1923, “Ho-mu-shu Pass [= Hong- mushu, Baoshan], western Yunnan, Chi- na, 8000 feet [= 2438 m].” Chodsigoa parca used to include furva as a subspecies, which has been re-elevated to full species. Chodsigoa parca has been split into two species, and eastern populations were recognized as a new species, C. hoffmanmni. Taxonomic status of subspecies lowei needs to be reassessed. Two subspecies recognized. Subspecies and Distribution. C.p.parcaG.M.Allen,1923—SWChina(Yunnan),NE&EMyanmar,andNThailand,WoftheMekongRiver. C. p. lower Osgood, 1932 — known only from the type locality in Chapa (= Sa Pa), Lao Cai Province, NW Vietnam. Descriptive notes. Head-body 62-77 mm, tail 77-99 mm, hindfoot 15-18 mm. No specific data are available for body weight. Condylo-incisive lengths are 20-1-20-9 mm, and tooth rows are 8-6-9 mm. Lowe’s Brown-toothed Shrew is similar to Hoffmann’s Brown-toothed Shrew (C. hoffmanni) but larger. Dorsal pelageis slate-gray, and ventral pelageis palerslate-gray. Tail is longer than head-body length and bicolored; its dorsal surface is brown, and ventral surface is creamy white. Tuft of slightly longer hair occurs on tip oftail. Braincase is dome-shaped. Rostrum tapers gradually in premaxillary region. There are three upper unicuspids. Habitat. Moist forests at elevations of 1500-3000 m. In western Yunnan, Lowe’s Browntoothed Shrew is most common at elevations of 2400-2600 m in evergreen broadleaved forest. Food and Feeding. No information. Breeding. No information. Activity patterns. Most Lowe’s Brown-toothed Shrews were captured at night. It is well adapted for running and jumping. Movements, Home range and Social organization. No information. Status and Conservation. Classified as Least Concern on The IUCN Red List. In northern Myanmar (= Burma), Lowe’s Brown-toothed Shrew is threatened by deforestation. Presumably, populations are not declining in south-western China and northern Thailand. Bibliography. Chen Zhongzheng et al. (2017), Hoffmann (1985).Published as part of Russell A. Mittermeier & Don E. Wilson, 2018, Soricidae, pp. 332-551 in Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona :Lynx Edicions on page 454, DOI: 10.5281/zenodo.687084
Optical packet network with limited-range wavelength conversion: a novel formalization of the optimal scheduling problem
No full textWe consider synchronous optical packet networks formed by switches equipped with a complete-set of limited-range wavelength converters. On these networks, we dealt with scheduling algorithm that maximizes the switch throughput.
So far, previous literature works have formalized this scheduling problem as the finding of a maximum bipartite matching (MBM) in a convex graph. The MBM formalization has collected several follow-ups, mainly focused on measuring switch-level performance. We revise the MBM formalization by measuring network-level performance. Surprisingly, we find out that when optical switches are cascaded, MBM formalization has two not negligible lacks: i) a useless degradation of optical signal quality; ii) a tendency in shifting optical packets toward lower wavelengths, thus increasing the occurrence of wavelength contention.
To solve these issues, we propose a novel formalization of the scheduling problem as the finding of a maximum bipartite matching with minimum edges weights (MW-MBM). We show that MW-MBM outperforms MBM in terms of both network throughput and optical signal to noise ratio. Performance evaluation is carried out by means of NS2 simulator that we extend to toughly model optical components (e.g., SOA FWM wavelength converter). The simulator is provided as open-source
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
The Alphasat Propagation Experiment: Interim Results from ASI and NASA Ground Stations
No full textThis contribution presents results obtained from the Italian ground stations in the frame of the Alphasat propagation experiment. Yearly statistics of the atmospheric attenuation as inferred from the received beacon signals (19.7 and 39.4 GHz) are reported and discussed for the two receiving stations installed in Spino d’Adda and Milan, whose experimental data are also combined to evaluate the advantage that would originate from a two-station diversity configuration
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
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