1,721,002 research outputs found
A Comparison of Distribution-Free Control Charts
No full textIn this study the statistical properties of several non-parametric control charts are investigated and
compared. It is considered the problem of monitoring data streams when the distributional form of the
monitored data is the generalized inverse Gaussian distribution. Two simulation studies are performed to
assess the performance of the monitoring algorithms in various scenarios. The aim is to identify the most
suitable monitoring algorithm considering jointly the ability in detecting shifts in location and/or scale and
the percentage of missed alarms
A joint use of monitoring and forecasting methods to detect change points in daily hospitalizations
No full textSurveillance of hospitalization trends is a crucial task in health care and life sciences, especially during periods of a health emergency, such as
those occurred in the recent pandemic. A good surveillance system supports decisions towards an optimal allocation of human, technical and
economic resources and allows the development of better and innovative health policies. Under this framework, change points analysis represents a useful statistical tool to monitor the temporal trends in hospitalization, able to detect changes in the evolution of a phenomenon by estimating the corresponding time location. In particular, change point algorithms, such as control charts, can discern substantive causes of directional variation, from other causes of variation, i.e. random fluctuations around a baseline trend. The prediction of a trend is analogously a challenging objective, as it anticipates a change and, thus, further supports better decision-making processes towards early and more effective solutions. Statistical literature provides a large set of proper methods able to fulfil this aim. The monitoring methods and the forecasting techniques of time series are combined into a unique set of statistical tools proposed to detect change points in the trend of daily hospitalizations and applied to the forecast of COVID hospitalization in the Emilia Romagna region
Non-parametric study of the radioxenon data distribution, measured at the noble gas stations of the International Monitoring System of the CTBTO
No full textThe aim of this work is to apply a non-parametric statistical methodology to the radioxenon activity
concentrations measured at noble gas stations of the International Monitoring System of the
CTBTO, in order to investigate the radioxenon atmospheric background and the radioxenon anomalous
values. The proposed non-parametric statistical methodology does not require any assumption
on the underlying probability distribution of the raw data. The suggested method, based on Recursive
Segmentation and Permutation (RS/P), allows to detect single or multiple mean and/or scale
shifts
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
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