1,720,983 research outputs found
Human mobility from theory to practice: Data, models and applications
Full text linkThe inclusion of tracking technologies in personal devices opened the doors to the analysis of large sets of mobility data like GPS traces and call detail records. This tutorial presents an overview of both modeling principles of human mobility and machine learning models applicable to specific problems. We review the state of the art of five main aspects in human mobility: (1) human mobility data landscape; (2) key measures of individual and collective mobility; (3) generative models at the level of individual, population and mixture of the two; (4) next location prediction algorithms; (5) applications for social good. For each aspect, we show experiments and simulations using the Python library "scikit-mobility" developed by the presenters of the tutorial
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
Nuove prospettive per la definizione della struttura ottimale delle foreste
No full textLa comprensione delle leggi che regolano la dinamica delle foreste è obiettivo primario dell'ecologia forestale ed ha, contestualmente, grande importanza applicativa. Infatti, poter predire la distribuzione diametrica della foresta sulla base di relazioni fisiologiche, non empiriche, consentirebbe al selvicoltore di poter disporre di uno strumento operativo di indirizzo degli interventi essenziale per poter mimare le dinamiche naturali delle foresta (come prevede la selvicoltura naturalistica). In questo lavoro viene presentata la prospettiva di poter predire la relazione di self-thinning (autodiradamento naturale) delle foreste ossia la variazione di densità (N/ha) in relazione alla variazione della dimensione dei singoli individui delle diverse coorti (utilizzando l'altezza come variabile indipendente). Il modello si basa su alcuni assunti circa la variazione dimensionale degli individui (ossia lo scaling del volume della chioma in relazione all'altezza, h) e circa la piena l'utilizzazione delle risorse e dello spazio da parte della comunità vegetale. Si dimostra che la curva di variazione di densità in funzione dell'altezza (o del diametro) è tipicamente una funzione potenza (Y=a*Xb) ma solo per un intervallo di circa un ordine di grandezza. In relazione al superamento di una cosiddetta altezza caratteristica (hc) la funzione decresce esponenzialmente (cut-off) perché essendo limitate le risorse anche la dimensione massima degli individui non può essere infinita (finite size scaling). In foreste pluviali tropicali (dataset BCI) l'esponente della relazione di self-thinning nel tratto di decrescenza a potenza è b=-3 se la densità viene messa in relazione all'altezza degli individui. Siccome anche il volume della chioma (Vc), ossia l'area fogliare, scala con una potenza di 3 rispetto all'h (Vc h3) ne deriva che le diverse coorti di alberi utilizzano la stessa energia indipendentemente dalla dimensione dei singoli individui della coorte dimostrando cosi il principio dell'equivalenza energetica (energy equivalence principle). L'esponente b, da cui dipende la variazione proporzionale del numero di individui in funzione della dimensione (altezza o diametro), sembra essere dipendente unicamente dalla caratteristiche di variazione strutturale del singolo individuo. Esso infatti assume lo stesso valore (ma con segno negativo) rispetto all'esponente di scala di Vc vs h. In questo modo sembra possibile predire la curva "ottimale" di popolamento sulla base delle caratteristiche fisiologiche degli individui che compongono il popolamento. Applicazioni in foreste pluviali tropicali, in foreste paranaturali della Romania (abetine miste) e in popolamenti di alta quota sulle Alpi Nord-Orientali (larici-cembreti) sembrano confermare che la variazione relativa della massa fogliare degli individui determini la dinamica di autodiradamento della comunità
RIABILITAZIONE VOCALE IN UN SOGGETTO SOTTOPOSTO A INTERVENTO DI FARINGO-LARINGO-ESOFAGECTOMIA CON TRASPOSIZIONE DELLO STOMACO
No full textkoamabayili/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
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