1,721,367 research outputs found
A FPGA-based architecture for real-time cluster finding in the LHCb silicon pixel detector
Full text linkThe data acquisition system of the LHCb experiment has been substantially
upgraded for the LHC Run 3, with the unprecedented capability of reading out
and fully reconstructing all proton–proton collisions in real time, occurring
with an average rate of 30 MHz, for a total data flow of approximately
32 Tb/s. The high demand of computing power required by this task has
motivated a transition to a hybrid heterogeneous computing architecture,
where a farm of graphics cores, GPUs, is used in addition to general–purpose
processors, CPUs, to speed up the execution of reconstruction algorithms. In
a continuing effort to improve real–time processing capabilities of this new
DAQ system, also with a view to further luminosity increases in the future,
low–level, highly–parallelizable tasks are increasingly being addressed at the
earliest stages of the data acquisition chain, using special–purpose computing
accelerators. A promising solution is offered by custom–programmable FPGA
devices, that are well suited to perform high–volume computations with
high throughput and degree of parallelism, limited power consumption and
latency. In this context, a two–dimensional FPGA–friendly cluster–finder
algorithm has been developed to reconstruct hit positions in the new vertex
pixel detector (VELO) of the LHCb Upgrade experiment. The associated
firmware architecture, implemented in VHDL language, has been integrated
within the VELO readout, without the need for extra cards, as a further
enhancement of the DAQ system. This pre–processing allows the first level
of the software trigger to accept a 11% higher rate of events, as the ready–
made hit coordinates accelerate the track reconstruction, while leading to a
drop in electrical power consumption, as the FPGA implementation requires
O(50x) less power than the GPU one. The tracking performance of this novel
system, being indistinguishable from a full–fledged software implementation,
allows the raw pixel data to be dropped immediately at the readout level,
yielding the additional benefit of a 14% reduction in data flow. The clustering
architecture has been commissioned during the start of LHCb Run 3 and it
currently runs in real time during physics data taking, reconstructing VELO
hit coordinates on–the–fly at the LHC collision rate
“A little place in the neighbourhood of a great city”: Landscape and Environment in Walter Pater’s “The Child in the House”, “An English Poet” and “Emerald Uthwart”
Full text linkMy paper will consider the function of landscape in Walter Pater’s short narratives, focusing on three texts traditionally grouped together: “The Child in the House”, “An English Poet” and “Emerald Uthwart”. I will investigate the physical and visionary plenitude of the Paterian landscape through its synesthetic and mythopoeic imagery (gardens and flowers are among the most recurrent tropes in these ‘portraits’). Consequently, I will examine the peculiar dialectic and fusion, in these narratives, between human and natural environment, art and nature. Seen from this perspective, the still overlooked “An English Poet” suggests that Ruskin’s idea of nature may be juxtaposed to Pater’s and this may fruitfully add to the complex relationship between the two authors as well as to the subject of Victorian ecocriticism
«As ‘twere he». Alcune considerazioni sul ritratto fotografico nella cultura letteraria inglese del tardo Ottocento
Full text linkThis article investigates the simulacral dimension in the representation of photographic portraits in late-nineteenth century English literature. Its first two sections focus on Hardy’s photography-related poetry and prose, and show how, in these texts, photographic portraits operate as a ghostly surrogate for an absent person and/or much-desired body. This fetishization of photographic images, which Hardy shares with several other turn-of-the century poets and writers, is in tune with later theories of photography and simulacra, but also reflects contemporary cultural and aesthetic discourses related to technological innovations in the field of photography. The final section of the article argues that this ‘photographic’ simulacrum, which is often linked to amorous desire, may be viewed as a modern version of a long-established trope in Western literary culture, that is the internalised portrait of the beloved.Questo articolo indaga la dimensione simulacrale delle rappresentazioni di ritratti fotografici nella letteratura inglese del tardo Ottocento. Le prime due sezioni si concentrano sulle opere di Hardy legate alla fotografia e mostrano come in questi testi i ritratti fotografici svolgono la funzione di un surrogato spettrale di una persona assente e/o di un corpo oggetto del desiderio. Questa feticizzazione delle immagini fotografiche, che Hardy condivide con altri poeti e scrittori a cavallo tra fine Ottocento e primo Novecento, anticipa successive teorizzazioni sulla fotografia e il simulacro, ma riflette anche discorsi estetico-culturali dell'epoca connessi alle innovazioni tecnologiche nell'ambito della fotografia. L'ultima parte dell'articolo sostiene che questo simulacro 'fotografico', spesso associato al desiderio amoroso, può essere considerato una modernizzazione di un consolidato tropo della cultura letteraria Occidentale, il ritratto interiore dell'amato/a
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
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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