1,721,111 research outputs found
Babel: sito bibliografico sull'opera di Edgar Morin
No full textThe Babel project started at CeRCo (Research Centre on Antropology and Epistemology of Complexity, University of Bergamo, Italy) in october 2003. It is intended to collect Edgar Morin's whole bibliography in a free access web resource.
The Babel data base contains now 872 bibliographic records. Future work includes collecting all other references of Edgar Morin's publications, in all languages and formats; and storing a number of full texts yielded by the Author
Glauber dynamics on nonamenable graphs: boundary conditions and mixing time
Full text linkWe study the stochastic Ising model on finite graphs with n vertices and bounded degree and analyze the effect of boundary conditions on the mixing time. We show that for all low enough temperatures, the spectral gap of the dynamics with (+)-boundary condition on a class of nonamenable graphs, is strictly positive uniformly in n. This implies that the mixing time grows at most linearly in n. The class of graphs we consider includes hyperbolic graphs with sufficiently high degree, where the best upper bound on the mixing time of the free boundary dynamics is polynomial in n, with exponent growing with the inverse temperature. In addition, we construct a graph in this class, for which the mixing time in the free boundary case is exponentially large in n. This provides a first example where the mixing time jumps from exponential to linear in n while passing from free to (+)- boundary condition. These results extend the analysis of Martinelli, Sinclair and Weitz to a wider class of nonamenable graphs
Renewable Energies in Between Landscape and Landmark: Case Studies
No full textWhen do renewable energies become architecture and landscape?
When can they be considered a plus for a landscape?
These are the key questions of the study carried out by the local unit of the Politecnico di Milano as part of the Program of National Interest (PRIN) financed by the Ministry of Education, University and Research .
After the identification of an organized information system, several case studies were analysed and this led to a first classification of the energy systems, based on the size, source, power, ... it was then studied a method that could allow to define which system, more than others, could be positive and appropriate for a given territory. Many are, in fact, the techniques for the analysis and management of the impact that changes can have on a man-made system: multidimensional investigations, multi-criteria , multivariate analysis , complex assessments borrowed from landscape ecology .
All these techniques, however, seem to assume that the landscape is an unmodifiable good to be preserved and that any human action, especially related to energy systems, should be related to the production of the minimum possible impact. The starting point here wants to be different, as different is the concept of landscape and different is the idea of Energy Systems (ES), considered not as just plants, but as indivisible union of the plant with its support and its functions and therefore with the place in which it is located. In this sense, the ES has all the features to be considered a landmark, as marker of land and reference point. (Golledge 1987)
Metastability in the reversible inclusion process
Full text linkWe study the condensation regime of the finite reversible inclusion process, i.e., the inclusion process on a finite graph SS with an underlying random walk that admits a reversible measure. We assume that the random walk kernel is irreducible and its reversible measure takes maximum value on a subset of vertices S⋆⊆SS⋆⊆S. We consider initial conditions corresponding to a single condensate that is localized on one of those vertices and study the metastable (or tunneling) dynamics. We find that, if the random walk restricted to S⋆S⋆ is irreducible, then there exists a single time-scale for the condensate motion. In this case we compute this typical time-scale and characterize the law of the (properly rescaled) limiting process. If the restriction of the random walk to S⋆S⋆ has several connected components, a metastability scenario with multiple time-scales emerges. We prove such a scenario, involving two additional time-scales, in a one-dimensional setting with two metastable states and nearest-neighbor jumps
Informatica umanistica
No full textIntroduzione all'informatica per studenti di corsi di laurea umanistici.
Elementi di base di hadware e software e di telematica; approfondimenti sull'uso di strumenti informatici per la ricerca di informazioni, per la linguistica computazionale, per la gestione dei beni culturali
Sharp asymptotics for metastability in the random eld Curie-Weiss model
Full text linkIn this paper we study the metastable behavior of one of the simplest disordered spin system, the random field Curie-Weiss model. We will show how the potential theoretic approach can be used to prove sharp estimates on capacities and metastable exit times also in the case when the distribution of the random field is continuous. Previous work was restricted to the case when the random field takes only finitely many values, which allowed the reduction to a finite dimensional problem using lumping techniques. Here we produce the first genuine sharp estimates in a context where entropy is important
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
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