1,720,960 research outputs found
Distilling information from present and future CMB datasets: the cases of large-scale polarization and lensing
No full textThe level of precision expected by future cosmic microwave background experiments makes it necessary to refine the techniques used to analyse the data. It becomes essential to understand how to maximise their information content. This can be done, either by developing techniques to reduce the noise level present in the data or by systematically studying the significance of different observations for a given model. In addition, it is possible to define new estimators to test their statistical properties. In this thesis, we initially show how it is possible to construct a pixel-based dataset that combines the WMAP and low-frequency \Planck\ large-scale polarization maps. After demonstrating its robustness, we derive constraints on the optical depth obtaining (68\% CL). Adding small-scale data, BAO and lensing we find (68\% CL). As a further topic, we show how it is possible to define new estimators to study the correlation between the orientation of the Galactic plane and the low-variance anomaly shown by large angle CMB temperature data. Through the use of random rotations, we show the stability of this anomaly at high Galactic latitudes, finding a significance of . Finally, we compare two main observables in CMB experiments: lensing and large-scale polarization. We show how the information carried by these two probes affects our ability to constrain the base CDM parameters. We extend the analyses considering also some of its most debated extensions, quantifying which future probe will play a crucial role in their characterisation.Il livello di precisione atteso dai futuri esperimenti sulla radiazione cosmica di fondo rende necessario il perfezionamento delle tecniche utilizzate per analizzare i dati. Diviene indispensabile capire come massimizzare il loro contenuto informativo. Questo pu\`o essere fatto sia sviluppando tecniche per ridurre del livello di rumore presente nei dati, sia tramite lo studio sistematico della significativit\`a delle diverse osservazioni per un determinato modello. In aggiunta, \`e possibile definire nuovi estimatori per testarne le propriet\`a statistiche. In questo lavoro di tesi, inizialmente mostriamo come sia possibile costruire un dataset nello spazio dei pixel che combini le mappe di polarizzazione su larga scala ottenute dalle misure a bassa frequenza di WMAP e \Planck. Dopo averne dimostrato la robustezza, deriviamo i vincoli sullo spessore ottico ottenendo un valore pari a (68\% CL). Aggiungendo misure derivanti dalle piccole scale, BAO e lensing troviamo un valore pari a (68\% CL). Come ulteriore argomento, facciamo vedere come sia possibile definire nuovi estimatori per studiare la correlazione tra l'orientazione del piano Galattico e l'abbassamento anomalo della varianza visto nei dati di temperatura della CMB su larga scala angolare. Tramite l'uso di rotazioni random mostriamo la stabilit\`a di questa anomalia ad alte latitudini Galattiche, trovando una significativit\`a di . Infine, compariamo due osservabili principali negli esperimenti di CMB: quella del lensing e quella della polarizzazione su larga scala. Mostriamo come l'informazione contenuta in queste due sonde influenzi la nostra capacit\`a di vincolare i parametri base del modello CDM. Estendiamo l'analisi considerando anche alcune delle sue estensioni pi\`u dibattute, quantificando quale sar\`a la sonda che giocher\`a un ruolo cruciale nella loro caratterizzazione
REDESIGN OF ENERGY ABSORBING CAR COMPONENT BY CRASH TEST SIMULATION
No full textThis paper deals with the redesign of a car energy absorbing systems (EAS) for low impact forces in an integrated virtual environment
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
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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