1,721,017 research outputs found
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
Datenbasierte Abschätzung der Energieskala hadronisch zerfallender Tau-Leptonen zur Steigerung der Sensitivität einer Higgs-Analyse im Kanal qq-->qqH-->qqtautau-->qq lnu hnu mit dem ATLAS Detektor
No full textVariations 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
Search for Standard Model Decays in the Lepton-Hadron Final State in Proton-Proton Collisions with the ATLAS Detector at the LHC
No full textThis thesis presents a search for Standard Model (SM) Higgs boson decays to a pair of tau leptons in the lepton-hadron final state with the ATLAS detector at the Large Hadron Collider (LHC). The analysis is based on proton-proton collision data recorded during Run 1 of the LHC, corresponding to integrated luminosities of 4.5 fb and 20.3 fb at centre-of-mass energies of 7 TeV and 8 TeV, respectively. Background events from various SM processes contribute to the selected event sample at a high rate. Their contribution is efficiently separated from the expected Higgs boson signal by using boosted decision trees (BDT) in two analysis categories, which are enriched in events emerging from vector boson fusion and gluon fusion processes. The expected number of events from background processes is modelled using data-driven estimation techniques. The signal contribution is measured using a maximum likelihood fit of the BDT output distributions. An excess of events over the expected level of background events is found and corresponds to an observed (expected) significance of 2.3 (2.4) standard deviations at a Higgs boson mass hypothesis of 125 GeV. The signal strength normalised to the Standard Model expectation is measured to be . A combined analysis of all tau-tau final states rejects the background-only hypothesis at a level of 4.5 standard deviations at GeV, while a significance of 3.5 standard deviations is expected. This provides evidence for the direct coupling of the recently discovered Higgs boson to tau leptons. The measured normalised signal strength of is consistent with the predicted Yukawa coupling strength in the Standard Model
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
Suche nach Standardmodell H->tau^+tau^- Zerfällen im Lepton-Hadron Endzustand in Proton-Proton Kollisionen mit dem ATLAS Detektor am LHC
No full textThis thesis presents a search for Standard Model (SM) Higgs boson decays to a pair of tau leptons in the lepton-hadron final state with the ATLAS detector at the Large Hadron Collider (LHC).
The analysis is based on proton-proton collision data recorded during Run 1 of the LHC, corresponding to integrated luminosities of 4.5 fb^-1 and 20.3 fb^-1 at centre-of-mass energies of 7 TeV and 8 TeV, respectively.
Background events from various SM processes contribute to the selected event sample at a high rate.
Their contribution is efficiently separated from the expected Higgs boson signal by using boosted decision trees (BDT) in two analysis categories, which are enriched in events emerging from vector boson fusion and gluon fusion processes.
The expected number of events from background processes is modelled using data-driven estimation techniques.
The signal contribution is measured using a maximum likelihood fit of the BDT output distributions.
An excess of events over the expected level of background events is found and corresponds to an observed (expected) significance of 2.3 (2.4) standard deviations at a Higgs boson mass hypothesis of 125 GeV. The signal strength normalised to the Standard Model expectation is measured to be 0.98+0.5-0.5.
A combined analysis of all tau-tau final states rejects the background-only hypothesis at a level of 4.5 standard deviations at m_H=125 GeV, while a significance of 3.5 standard deviations is expected.
This provides evidence for the direct coupling of the recently discovered Higgs boson to tau leptons.
The measured normalised signal strength of 1.4+0.43-0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model.
Die vorliegende Dissertation stellt eine Suche nach Standardmodell (SM) Higgs Boson Zerfällen in ein Tau-Leptonen-Paar im Lepton-Hadron Endzustand vor. Die Analyse basiert auf einem Datensatz von Proton-Proton Kollisionen von 4.5 fb^-1 und 20.3 fb^-1 bei Schwerpunktsenergien von 7 bzw. 8 TeV, aufgenommen vom ATLAS Detektor am Large-Hadron-Collider (LHC).
Untergrundereignisse aus verschiedensten SM Prozessen tragen den größten Anteil zum selektierten Ereignissample bei.
Um diese Ereignisse effizient von den erwarteten Higgs Boson Signalereignissen zu trennen, werden Boosted Decision Trees (BDT) in zwei Ereignisskategorien verwendet, welche in Ereignissen aus Vektor Boson Fusion und Gluon Fusions Prozessen angereichert sind.
Die Untergrunderwartung wird mittels datenbasierter Methoden abgeschätzt und der Beitrag von Higgs Boson Signalereignissen in einem Maximum Likelihood Fit der BDT Verteilungen gemessen.
Ein Überschuss von Ereignissen über dem erwarteten Untergrund mit einer statistischen Signifikanz von 2.3 Standardabweichungen bei einer Higgs Boson Massenhypothese von m_H=125 GeV wird beobachtet. Die auf die Standardmodell Erwartung normierte Signalstärke beträgt 0.98+0.5-0.5.
In einer kombinierten Analyse aller Tau-Tau Endzustände kann die Untergrundhypothese mit einer Signifikanz von 4.5 Standardabweichungen ausgeschlossen werden, bei einer erwarteten Signifikanz von 3.5 Standardabweichungen.
Dies stellt eine Evidenz für die direkte Kopplung des kürzlich entdeckten Higgs Bosons an Tau Leptonen dar.
Die gemessene relative Signalstärke ist 1.4+0.43-0.37 und damit in guter Übereinstimmung mit der Yukawa Kopplungsstärke im Standardmodell
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