1,720,961 research outputs found
Search for long-lived charged particles using large specific ionisation and time-of-flight in 140 fb of pp collisions at = 13 TeV with the ATLAS detector
No full textParticles with lifetimes exceeding a few ns arise in a broad spectrum of beyond-Standard Model scenarios. This poster presents a search for massive, charged, long-lived particles exploiting 140 fb−1 of pp collision data collected by the ATLAS experiment between the years 2015-2018. Since these particles are expected to move significantly slower than the speed of light, they leave anomalously large ionisation losses in the pixel detector. The measured ionisation is used to reconstruct the particle’s mass. A complementary mass determination is provided by a time-of-flight measurement with the hadronic calorimeter. Two search strategies are employed. One targets single long-lived charged particles with large transverse momentum, large specific ionisation loss in the pixel detector and the time of flight measured with the hadronic calorimeter inconsistent with the speed of light. The second strategy is optimized for pair-produced, charged long-lived particles with large transverse momenta and large specific ionisation losses in the pixel detector. This analysis is sensitive to particle masses ranging from 200 GeV to 3 TeV and lifetimes greater than about 3 ns. The results are interpreted in the context of slepton, chargino and gluino models, and the resulting production cross-section limits are the most stringent to date for detector-unstable charged long-lived particles with lifetimes exceeding 3 ns
The ATLAS ITk Pixel Detector. The biggest challenges from design to construction.
No full textAs a part of the ATLAS Phase-II upgrade, the current Inner Detector of the experiment will be replaced with a new all-silicon Inner Tracker (ITk) designed to face the challenging environment associated with the high number of collisions per bunch crossing expected during the High-Luminosity phase of the Large Hadron Collider. Along the lifetime of this project, from design to prototyping stages, many difficulties have been encountered and unforeseen problems had to be solved. In this proceeding, an overview of the ITk pixel detector layout and the most demanding tasks faced with up to now are described
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
Переходность и непереходность норвежского глагола
Get PDFИсследование посвящено переходности норвежского глагола. Работа включает обзор и классификацию основных направлений изучения явлений переходности и лабильности, а также подробный анализ норвежского языкового материала и предлагает возможные перспективы изучения переходных, непереходных и лабильных глаголов норвежского языка. Особое внимание уделяется изменениям, происходящим в модели управления норвежских глаголов.The research is dedicated to the notion of transitivity of the Norwegian verb. The paper features an overview and a classification of the main contexts of transitivity and lability studies as well as a detailed analysis of the Norwegian language material and suggests possible perspectives for studying Norwegian transitive, intransitive and labile verbs. The research pays special attention to the changes happening in the government pattern of the Norwegian verbs
Изменения глагольного управления в современном норвежском языке
Get PDFВ работе представлено исследование изменений глагольного управления в современном норвежском языке. В ней описаны такие типы колебаний в составе глагольных конструкций, как опущение актанта, возникновение новых пермутативов, сдвиги в употреблении предлогов и механизмы лабилизации. Модели изменений классифицированы по семантико-синтаксическому принципу.The paper presents a study of changes of verb government patterns in modern Norwegian. It describes such types of fluctuations in pattern structure as actant omission, emergence of new permutatives, shifts in the use of prepositions and mechanisms of labilization. The models of changes are classified on the semantico-syntactic basis
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
The ATLAS ITk Pixel Detector. The biggest challenges from design to construction
No full textIn the HL-LHC era, the radiation is expected to reach unprecedented values, with non- ionizing fluence of 1e16 neq/cm2 and ionizing dose of 5 MGy. To cope with the resulting increase in occupancy, bandwidth, and radiation damage, the current ATLAS Inner Detector is replaced by an all-silicon system. The Pixel Detector will consist of five-barrel layers and a number of rings, resulting in about 13 m2 of instrumented area. The ITk pixel system has been very carefully designed including three different flavours of silicon hybrid detectors equipped with novel ASICS and data transmission chains. A new serial powering scheme has also been developed to minimize the amount of material in the detector. Along the lifetime of this project from design to prototyping (current) stages many challenges have been encountered and unforeseen problems have to be solved. In this contribution, an overview of the ITk pixel detector layout and the most challenging tasks resolved by now will be shown. From the mechanical point of view, the detector’s structure has to be robust and light providing support to the whole system, including local supports for modules and electronics, cables to power the detector and to drive the data in and out of the volume and cooling. All material and structures are designed to withstand all the possible conditions and cycles along the life of the detector. A customized cooling system will allow the operation of the detector at -35 C. Therefore, the detector will be exposed to a large number of temperature cycles that will stress it. Prototypes of mechanical supports systems at different stages of the project are tested and qualified. The environmental conditions at different locations within the pixel system will be monitored and linked to an interlock system that will protect the detector from major damages in case of any malfunction. Achieving that requires that the operation conditions of every pixel module are monitored by a Detector Control System (DCS). Due to the HL-LHC collisions rate, the data needs to be driven form the front-end chip to the opto-electrical conversion system with high-speed transmission parallel lines (TwinAx cables) running at 1.28 Gb/s per data link. An Optosystem features custom designed radiation-hard electronics devoted to signal equalization, aggregation (to 10.24 Gb/s) and opto-electrical conversion. Regarding the active part of the system, the pixel modules have gone through an extensive R&D program to identify what sensor technologies and thicknesses will be used in the final detector to achieve the best possible tracking performance. Prototypes have been already loaded on demonstrators and are going through exhaustive testing and qualification campaigns. The highlights of this effort together with the outcome can be expected within this contribution. At the end of this contribution the audience will get a good understanding of the status of the ATLAS-ITk pixel project and what have been the biggest challenges faced up to the day of this presentation and what are the major ones that we still have to overcome
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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