1,720,954 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
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
Suspicious objects classification for illegal landfills discovery in remote sensing images
No full textLAUREA MAGISTRALEIl problema della gestione dei rifiuti ha recentemente acquisito rilevanza a livello mondiale, con una risonanza sia economica che sociale in ogni Paese. Una delle criticità più preoccupanti è costituita dalle discariche abusive, ovvero nello scarico incontrollato di rifiuti nell'ambiente. Dagli anni '70, con l'ulteriore sviluppo della tecnologia, la necessità di monitorare in maniera automatica questi tipi di fenomeni è aumentata, portando i ricercatori a esplorare molte possibili opzioni. Finora, però, non è stato possibile andare oltre a tecniche semiautomatiche, che richiedono sempre l'intervento umano. La combinazione delle immagini satellitari con i sistemi di informazione geografica (GIS) è stata esaminata in lungo e in largo per molto tempo. Nonostante abbia prodotto ottimi risultati, queste tecniche non hanno mai permesso di raggiungere la totale indipendenza dalle competenze umane. Un deciso miglioramento verso i sistemi completamente automatici è stato ottenuto con l'adozione di tecniche di Deep Learning, in particolare le Convolutional Neural Networks (CNN). In questo contesto, gli esperimenti attuali si concentrano sulla classificazione automatica delle immagini.
L'obiettivo di questa ricerca è sfruttare una delle reti neurali già utilizzate in questo campo (ResNet50) per estendere ulteriormente le capacità di monitoraggio di sistemi automatici, consentendo la classificazione di diverse tipologie di oggetti che caratterizzano le discariche illegali. Inizialmente l'architettura ResNet50 è stata utilizzata per risolvere la classificazione di tipo multilabel, e quindi per riconoscere la presenza (anche contemporanea) di oggetti appartenenti a diverse classi. Il modello proposto ha raggiunto un F1 score del 81% in media sul test set. Successivamente, con il classificatore allenato sono state prodotte le Class Activation Maps (CAMs), al fine di identificare le regioni delle immagini che appartengono ai diversi tipi di rifiuti. I risultati ottenuti sono stati valutati quantitativamente utilizzando metriche personalizzate basate sul calcolo dell'Intersection over Union, e qualitativamente guardando effettivamente i box di delimitazione ottenuti.The problem of waste management has recently gained worldwide relevance, having both an economic and social resonance in every country. One of the most concerning issues is constituted by illegal dumping, consisting of the uncontrolled discharge of waste into the environment. From the 1970s, with the further development of technology, the need for automatic procedures to monitor these types of phenomena increased over and over, bringing researchers to explore many possible options. Until now, however, it has been not possible to go beyond semi-automatic techniques, always requiring human intervention. In particular, the combination of satellite images with geographic information systems (GIS) has been examined far and wide for a long time. Even if it produced very good results, as anticipated, it has never allowed achieving total independence from human expertise. A decisive improvement towards fully automatic systems has been obtained with the adoption of Deep Learning techniques, in particular Convolutional Neural Networks (CNNs). In this context, current experiments focus on the automatic classification of images.
The goal of this research is to exploit one of the neural networks already used in this field, the ResNet50 architecture, to further extend the monitoring capabilities of automatic systems, allowing them to also account for the classification and localization of different types of objects characterizing Illegal Landfills. In particular, firstly the ResNet50 architecture has been used to solve the multilabel classification task, consisting in the recognition of the presence (even concurrently) of the considered classes in the given images. The proposed model reached an F1 score of 81% on average on the test set. From the trained classifier, Class Activation Maps (CAMs) were produced and analyzed to identify the regions of the images belonging to the different waste types. The obtained results have been evaluated quantitatively using custom metrics based on the calculation of the Intersection over Union, and qualitatively by actually looking at the obtained bounding boxes, thus understanding the practical relevance of the achieved results
Efficiency analysis of a railway system : modelling and validation
Get PDFLAUREA MAGISTRALEIl lavoro svolto mira alla realizzazione di un modello in ambiente Matlab e Simulink che possa simulare un sistema ferroviario, in particolare per quanto riguarda le sue variabili elettriche, di modo da avere uno strumento adeguato a studiare e analizzare il comportamento di un veicolo ferroviario in condizioni di funzionamento nominale, ma soprattutto per saggiare l’impatto sulla linea ferroviaria che potrebbe prevedere l’adozione di componenti innovative atte a ridurre i consumi energetici e le conseguenti emissioni inquinanti nell’attuale scenario di riduzione di impatto ambientale. Uno dei punti chiave è quello di avere un modello che sia il più possibile flessibile e adattabile a situazioni differenti da quelle di iniziale progettazione, di modo che l’implementazione di nuovi componenti sia la più rapida possibile.
Pertanto, si inizierà mostrando l’attuale stato dell’arte della tecnologia ferroviaria, con particolare riferimento alle linee alimentate in corrente continua a 3000V, essendo questa la tecnologia prevalente in Italia. Verranno perciò analizzate le sue principali componenti, dalle sottostazioni elettriche che l’alimentano, ai treni che ne rappresentano gli utilizzatori maggiori, senza trascurare la catenaria attraverso cui tutti i gli elementi sono collegati. Verrà inoltre dedicato un breve spazio anche alla tecnologia relativa alle linee ad alta velocità e capacità, alimentata da un sistema in corrente alternata monofase.
In seguito, verrà descritta la modellazione dei varî componenti che andranno a costituire il modello stesso ponendo attenzione alle ipotesi realizzative e motivandole; quindi verranno esposte alcune strategie atte a ridurre il consumo energetico dell’intera infrastruttura agendo sul recupero dell’energia rigenerata dai treni in frenata e attualmente poco riutilizzata.
Infine, dopoché il modello sarà stato validato e i suoi risultati verificati, verranno mostrate alcune simulazioni che riguardano l’applicazione di due strategie di riduzione dei consumi e i conseguenti effetti che hanno sulle variabili elettriche in gioco.The work aim is the definition of a model in Matlab and Simulink environment which could simulate a railway system, in particular for what concerns its electrical variables, in order to have an appropriate instrument for studying and analysing the behaviour of a railway vehicle in nominal functioning conditions, but above all to determine the impact on the railway line which may implement innovative components suitable for the reduction of energetic consumptions and the consequent polluting emissions, in the actual scenario of reduction of environmental impact. One of the key points is to have a model which is as flexible as possible and adaptable to situations different from the ones of initial design, in order to make immediate the implementation of new components.
Therefore, it will be firstly shown the actual state of art of railway technology, with a particular attention to the 3000V DC lines, which is the predominant technology in Italy. Hence it will be analysed its principal components, from the electric substation which power it, to the trains which represent the predominant utilizers, without neglecting the catenary through which all the elements are linked. Moreover, it will be dedicated a short paragraph even to high velocity and high capacity lines, powered by a monophase AC system.
Then it will be described the modelling of the different components which constitute the model itself, with a certain attention at realization hypotheses and justifying them; in a second time it will be exposed some strategies which could reduce the energetic consumptions of the entire infrastructure, acting on the recovery of the energy regenerated by trains during braking and currently underutilized.
Finally, after that the model will have been validated and its results verified, it will be shown some simulations regarding the application of two reduction strategies and the corresponding effects on consumption and on the electrical variables at stake
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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