1,721,033 research outputs found
La valutazione per pensare il lavoro pedagogico
No full textCome si valuta all'interno dei servizi educativi oggi? Quali intrecci si generano tra l'atto del valutare e quello dell'educare? In un momento storico in cui valutare è divenuta una pratica diffusa, può la valutazione pensare la complessità del lavoro educativo che si attua ei servizi e sostenere il sapere pedagogico che matura al suo interno? Il testo elabora, in chiave critica i principali risultati della ricerca PRIN 2009- politiche e culture della valutazione
Areas and limits of employment of portable EDXRF equipment for in situ investigations
No full textThe use of mobile spectrometers in the archaeometric study of ancient artefacts has become a very common practice over the
past few years. It docs open methodological questions on the employment of such techniques in a non-destructive manner, i.e. avoiding the damage of the artifact. Some additional methodological questions come by (i) the use of such instrumentation for diagnostic scopes (in which a different approach to the measurement is required) and (ii) the use of the spectrometers in systematic analysis on big number of artefacts, stored in several museums (during experimental campaigns).
This paper's aim is to discuss some of this questions, on the basis of the experience in the use of mobile (or Field Portable) systems for Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopy that we have harvested in the last years.
Our conclusions mainly regard the precision of measures, which is related both to the positioning of the spectrometer and to the instrument's instability. Also we deal with the more complex problem of the object's matrix not being homogeneous and of how this can affect the response of the measuring system.
Moreover, it is discussed the more general question of the use of portable spectrometers and, consequently, of the meaning one can give to the results so obtained. As a matter of fact the use of such systems, which have an intrinsic analytic potential, in a non-destructive manner, frequently creates ambiguities that have not been, sometimes, taken into account with attention by the investigators.
Finally some ideas arc traced on the development of ethodologies which favor a better use of such spectroscopic systems for the analysis of ancient artefacts
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
Strutture compressive pellicolari e tettonica distensiva nei Monti Ernici sud-occidentali (Appennino centrale)
No full textRazors, Horse Bits or Axes; Search of the Different Composition in Common Use Bronze Villanovan Objects (VIII-VII Century BC, Italy) by Multivariate Analysis
No full textOne of the main issues still not resolved is to what extent casters were capable to change the composition of the bronze objects in order to meet the demands of the "market". To face this problem it is necessary to study a large number of items produced by a single foundry with modern analytical techniques. The discovery of a Dolium at the end of 1800, buried near a furnace containing more than 14,000 pieces of bronze objects allowed performing compositional analysis on virtually every item of daily use. The objects were found in central Italy near Bologna in the so called "ripostiglio di San Francesco" ("hoard of San Francesco"). 431 measurements were carried out using portable energy dispersive x-ray fluorescence analysis (EDXRF). Abundance of the main elements (Cu, Sn, Pb, Fe, Sb, Ag, As) in the bronze alloy was analysed on 229 objects, after their brushing in order to remove the "patina" of oxidation. On 126 objects a single point was analysed ( with measurement repetition), while on 155 objects two or more points were investigated. The research objects were chosen among the 14,000 pieces by museum curators and were grouped in 15 categories based on a visual and functional study. The complete data set was studied by chemometric analyses with Explorative Data Analysis techniques. The results of this preliminary study could not identify a clear correlation between composition and destination of use. However, some of the technical aspects of the fusion process were highlighted by this research
Appraisal of the new approach to the archaeometric study of ancient metal artifacts by the use of movable EDXRF equipments
No full textThe capability of the new generation EDXRF portable equipment offers a unique possibility to study the technology of production and to reconstruct the casting history of metal artefact.
The most important improvement in the EDXRF system development is the use of small and portable X ray tubes and non cryogenic detectors having similar performance of the traditional cryogenic ones.
Another very important contribution to the in-field use of the EDXRF technique has been the development of software specifically engineered for in-situ acquisition and data analysis and storage data managing.
One of the finalities of the present archaeometric research is to support the hypothesis on ancient metallurgical technologies with statistical significant set of data obtainable only with a large number of measurement on many artifacts. This large amount of data implies the choice of a proper statistical approach.
This work will show the method actively in use discussing the most relevant points that make possible the use of EDXRF in the study of big sets of metallic samples.
Several extensive examples campaigns will be listed (bronze samples from the Archeological Civic Museum in Bologna and from the Archeological Museum in Chieti and golden samples from the Archaeological Museum in Athens
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