1,720,968 research outputs found
Determination of physical properties of high-energy hadronic interactions from the - anticorrelation
Get PDFSeit der Entdeckung der kosmischen Strahlung Anfang des 20. Jahrhunderts wurden viele Experimente entwickelt, um sie direkt oder anhand der Luftschauer zu studieren, die sie beim Eintritt in die Erdatmosphäre erzeugen. Das größte Observatorium zur Erfassung von Luftschauern ist das Pierre-Auger-Observatorium in Malargüe, Argentinien. Hier werden viele Fragen der Astro- und Teilchenphysik behandelt. Da kosmische Strahlung Energien abdeckt, die weit über denen liegen, die in künstlichen Beschleunigern erreichbar sind, stellen sie hervorragende und einzigartige Objekete dar, an denen man physikalische Eigenschaften bei höchsten Energien studieren kann.
Wenn ein Luftschauer die Atmosphäre durchquert, wächst die Anzahl der in ihm enthaltenen Teilchen. Gleichzeitig nehmen ihre Energien ab. Wenn diese tief genug sind, zerfallen die Teilchen oder werden in der Atmosphäre absorbiert, was die Zahl der Teilchen wieder verringert. Dies ergibt eine Position maximaler Entwicklung . Hadronisch wechselwirkende Teilchen bringen Myonen hervor, die am Boden gemessen werden können. Diese Zahl zusammen mit sind Observablen, die in Auger gemessen werden und eine aussagekräftige Antikorrelation aufweisen.
In der vorliegenden Arbeit wird diese Antikorrelation studiert. Es wird ein analytisches Modell entwickelt, das diese als Funktion von Parametern wiedergibt, die die hadronische Multiplizität, den hadronischen Energieanteil und die Inelastizität der ersten Interaktion beschreiben, zusammen mit entsprechenden effektiven Parametern, die für den gesamten Schauer repräsentativ sind.
Dieses Modell wird dann anhand künstlicher neuronaler Netze weiter verbessert. Hierfür werden Werte der Parameter und Observablen von Simulationen benutzt, die mit CONEX durchgeführt wurden. Das resultierende Modell hängt nicht von dem während der Simulation verwendeten Hochenergie-Wechselwirkungsmodell ab. Schließlich wird ein Modell mit reduziertem Parametersatz auf einen Datensatz von Auger angewendet. Die Verteilungen der hadronischen Multiplizität und des hadronischen Energieanteils der ersten Wechselwirkung und die der effektiven Inelastizität werden diesem Datensatz entnommen. Sie zeigen, dass die Multiplizität und der Energieanteil der ersten Wechselwirkung in aktuellen Modellen, die für Simulationen verwendet werden, im Allgemeinen zu niedrig sind
Data analysis of the Pierre Auger observatory and its upgrades
Get PDFEl proyecto se propone avanzar en el conocimiento de propiedades de los rayos cósmicos de mayor energía a partir del análisis de las mediciones del Observatorio Pierre Auger, instalado en Malargüe, Mendoza, de cuya colaboración internacional los investigadores involucrados forman parte activa. El plan de trabajo incluye análisis de datos, su interpretación en términos de modelos astrofísicos, y el perfeccionamiento de técnicas de reconstrucción de los eventos observados, tanto con los detectores originales como con las extensiones que están actualmente en proceso de construcción, instalación y calibración.This project aims at advancing our knowledge of the properties of cosmic rays with the highest energies based on the analysis of measurements performed with the Pierre Auger Observatory, located in Malargüe, Mendoza, Argentina. The researchers involved in this project form active part of the international collaboration operating the Observatory. The research plan includes data analysis, its interpretation in terms of astrophysical models, and the improvement of techniques to reconstruct the observed cosmic ray events, both with the original detectors as well as with the upgrades currently being built, installed and calibrated
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
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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