1,720,958 research outputs found
Querying and Navigating a Database of Images With the Magical Objects of the Wizard Zurlino
No full textThis work is part of a research targeted at experimenting the use of physical artifacts for the retrieval of multimedia information. Tangible interfaces – that couple physical artifacts to digital data – are described in different research works, and a number of studies focus on tangibles for children. In spite of that, most of the work done for the kids is related to gaming or learning. This work is focused on a less explored domain, that of the access to information systems. We propose a tangible interface for enabling preschoolers to query and navigate multimedia information. The approach was tested with a class of 27 preschoolers, that where engaged in a game with the magical objects of the wizard Zurlino. The experiment gave us interesting insights about the suitability of the system for preschool children, its ease of use and the need for support by educators
Mapping Physical Objects to Digital Functions: A Tangible Interface for Querying and Navigating a Multimedia Database
No full textIn this work we propose a set of guidelines for tangible interfaces (TUI) for mapping physical objects and digital functions. These guidelines emphasize an aspect that has been only partly analyzed so far in TUI research: the role of the object shape as a means for suggesting how to manipulate the artifacts. The peculiarity of the proposal - general enough to be used for different application domains - is the mapping to discrete and continuous digital functions based on the type of surfaces that define the physical artifacts of the interface. The application of the guidelines to a widely diffused task, the query and navigation of a multimedia database, and its evaluation with a class of students gave us interesting insights about the appropriateness of the mapping and its learnability
Assessing the frequency support provided by DFIG wind turbines according to current standards
No full textNowadays, wind turbines commonly installed in new plants include a power converter. This allows these generators to operate in a variable speed range with the aim of maximizing the primary source exploitation. On the other hand, the presence of a converter implies a partial decoupling from the grid. Several studies have been carried out to enhance the ability of wind turbines in supporting frequency stability in the case of network events, and some grid codes recently include these regulating functions as required specifications. This work presents a novel control system applied to a Doubly Fed Induction Generator to make it compliant with present Italian standards. In order to characterize the role of wind turbines in supporting network frequency, several simulations have been carried out in the DIgSILENT PowerFactory environment. Main advantages and disadvantages are identified and discussed, depending on both the wind turbine operating conditions and the characteristics of the required stabilizing contribution
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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