1,721,069 research outputs found
Unsupervised anomaly detection on multiprocess event time-series
No full textLAUREA MAGISTRALEStabilire se i dati osservati siano anomali o meno è un task importante che è stato ampiamente studiato in letteratura, e diventa un problema ancora più complesso se combinato con una alta dimensionalità dei dati e con una moltitudine di processi indipendenti che generano i pattern da analizzare. Il lavoro presentato in questa tesi utilizza una data-driven pipeline per la identificazione di un recurrent auto-encoder per l'analisi senza supervisione di serie di eventi ad alta dimensionalità generati da molteplici e variabili processi che interagiscono con un sistema. L'analisi di log files che registrato gli eventi di interazione tra gli utenti e l'infrastruttura radio di accesso alla rete è stata impiegata come caso di studio reale per il problema identificato. Il lavoro propone una pipeline che gestisce la rappresentazione complessa dei dati e la definizione e settaggio del modello per identificazione delle anomalie, senza basarsi su nessuna conoscenza specifica di dominio e quindi potenzialmente adattabile a diversi contesti. Il modello è stato implementato in quattro varianti differenti che sono state valutate sia con dati normali che anomali, in parte raccolti da celle reali e in parte generati tramite la simulazione di comportamenti anomali. I risultati mostrano l'applicabilità del modello per la classificazione di eventi e sequenze anomale nel contesto descritto, e la loro più dettagliata analisi fornisce interessanti interpretazioni riguardo la differenza tra i vari modelli, le loro limitazioni e punti di forza.Establishing whether the observed data are anomalous or not is an important task that has been widely investigated in literature, and it becomes an even more complex prob- lem if combined with high dimensional representations and multiple sources independently generating the patterns to be analyzed. The work presented in this master thesis em- ploys a data-driven pipeline for the definition of a recur- rent auto-encoder architecture to analyze, in an unsuper- vised fashion, high-dimensional event time-series generated by multiple and variable processes interacting with a sys- tem. The analysis of log files that record events of inter- action between users and the radio network infrastructure is employed as real-world case-study for the given prob- lem. The work proposes a pipeline, to deal with the com- plex representation of the data source and the definition and tuning of the anomaly detection model, that is based on no domain-specific knowledge and can thus be adapted to different problem settings. The model has been imple- mented in four different variants that have been evaluated over both normal and anomalous data, gathered partially from real network cells and partially from the simulation of anomalous behaviours. The results show the applicability of the model for the detection of anomalous sequences and events in the described setting, and their deeper interpreta- tion gives insights about the difference between the variants of the model and thus, their limitations and strong points
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
Evaluating resource bundle derivatives for multi-agent negotiation of resource allocation
No full textConsider continuous negotiations where the goal is to obtain exactly one complete bundle of resources and there exists alternative bundles that solve the task. This paper presents a market-based model of this negotiation that does not require commitment and decommitment during the negotiation phase. A negotation goal is represented by a graph, called a resource network. Goals are achieved by obtaining resources along one path in the graph. The resource network model can be applied to electronic commerce with agents trading bandwidth in all-or-nothing deals, and for agents that want to combine simple goods into more complex goods
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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