1,721,741 research outputs found
Muon trigger with fast Neural Networks on FPGA, a demonstrator
No full textThe online reconstruction of muon tracks in High Energy Physics experiments is a highly demanding task, typically performed on reconfigurable digital circuits, such as FPGAs. Complex analytical algorithms are executed in a quasi-real-time environment to identify, select, and reconstruct local tracks in often noise-rich environments. A novel approach to the generation of local triggers based on a hybrid combination of Artificial Neural Networks and analytical methods is proposed, targeting the muon reconstruction for drift tube detectors. The proposed algorithm exploits Neural Networks to solve otherwise computationally expensive analytical tasks for the unique identification of coherent signals and the removal of geometrical ambiguities. The proposed approach is deployed on state-of-the-art FPGA and its performances are evaluated on simulation and on data collected from cosmic rays
40 MHz triggerless readout of the CMS Drift Tube muon detector
Full text linkThe Level -1 trigger scouting system of the CMS experiment aims at intercepting the intermediate data produced by the L1 trigger processors before the final trigger decision. This system can be complemented by adding the raw stream of data collected from the detector front-end, whenever the throughput is manageable. In this work, the triggerless readout of the CMS Drift Tubes (DT) detector is presented. This is realized by reading a sector of the DT which has been equipped with the preproduction of Phase -2 upgrade front-end boards. A Xilinx VCU118 acts as a concentrator of the Phase -2 demonstrator lpGBT links and transmits data to a server via 100G TCP/IP. First results coming from a test -stand mimicking the sector demonstrator are shown
A horizontally scalable online processing system for trigger-less data acquisition
No full textThe vast majority of high energy physics experiments rely on data acquisition and hardware-based trigger systems performing a number of stringent selections before storing data for offline analysis. The online reconstruction and selection performed at the trigger level are bound to the synchronous nature of the data acquisition system, resulting in a trade-off between the amount of data collected and the complexity of the online reconstruction performed. Exotic physics processes, such as long-lived and slow-moving particles, are rarely targeted by online triggers as they require complex and nonstandard online reconstruction, usually incompatible with the time constraints of most data acquisition systems. The online trigger selection can thus impact as one of the main limiting factors to the experimental reach for exotic signatures. Alternative data acquisition solutions based on the continuous and asynchronous processing of the stream of data from the detectors are therefore foreseeable as a way to extend the experimental physics reach. Trigger-less data readout systems, paired with efficient streaming data processing solutions, can provide a viable alternative. In this document, an end-to-end implementation of a fully trigger-less data acquisition and online data processing system is discussed. An easily scalable and deployable implementation of such an architecture is proposed, based on open-source distributed computing frameworks capable of performing asynchronous online processing of streaming data. The proposed schema can be suitable for deployment as a fully integrated data acquisition system for small-scale experimental apparatus, or to complement the trigger-based data acquisition systems of larger experiments. A muon telescope setup consisting of a set of gaseous detectors is used as the experimental development testbed in this work, and a fully integrated online processing pipeline deployed on cloud computing resources is implemented and described
Trigger-less readout and unbiased data quality monitoring of the CMS drift tubes muon detector
Full text linkThe CMS experiment 40 MHz data scouting project is aimed at intercepting the data produced at the level of the detectors' front-end without the filters induced by hardware-based triggers. A first implementation is realized by the trigger-less reading and processing of a fraction of the Drift Tube (DT) muon detector, equipped with a preliminary version of the so-called Phase-2 Upgrade on-detector electronics boards. The data are transferred via high-speed optical links to back-end boards independently from the central experiment data acquisition (DAQ), permitting real-time detector status monitoring via receiving all the signals produced at the front-end level, and providing an unbiased estimate of the CMS DT hit-rate under various data-taking conditions
Toward electron self-localization in H2 gas: Multiple scattering effects on the electron drift mobility at low temperature and intermediate densities
No full textWe report here the first measurements of the electron drift mobility μ in gaseous H2 in the intermediate density range 0.5 × 1026 m−3 ≤ N ≤ 5 × 1026 m−3, at low temperature, T = 49.7 K and T = 29.7 K. In this range, the density is small enough to make the presence of electron states self-localized in bubbles negligible but, at the same time, is large enough for multiple scattering effects to alter the prediction of the classical kinetic theory for the mobility of quasi-free electrons. The analysis of the present data confirms the validity of the model we have developed to describe the quasi-free electron mobility in dense noble gases, which is based on the heuristic inclusion of multiple scattering effects in the classical kinetic theory
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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