1,721,401 research outputs found
A Petri net view of covalent bonds
Full text linkIn nature and chemistry the interactions among elements often form bonds and among them covalent bonds are relevant, involving the sharing of electrons. Another relevant and compelling facet of calculi modelling covalent bonds is that certain steps in reactions are the result of concerting different activities, possibly reversing some of them. Starting from a calculus for covalent bonds, we investigate on how it can be done in a compositional fashion and how it can be encoded in suitable Petri nets. The outcome gives us a compositional covalent bond calculus and a truly distributed implementation. On these results it is possible to build a behavioural equivalence among terms.Fil: Melgratti, Hernan Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Mezzina, Claudio Antares. Università Degli Studi Di Urbino Carlo Bo; ItaliaFil: Pinna, G. Michele. Università degli Studi di Cagliari; Itali
Petri nets and dynamic causality for service-oriented computations
No full textWhen dealing with service oriented computations the dependencies among the various distributed activities may be complex and difficult to represent statically. Recently Event Structures where the causality may change dynamically have been introduced and have been related with many other kind of Event Structures (with a particular focus on expressivity). In this paper we relate them to a kind of (labeled) Petri net which turns out to cover these new Event Structures. This relationship empowers the usage of all the available verification tools based on Petri nets, giving practical and usable means for the verification of the complex and distributed system whose behavior is modeled by this kind of event structures
Synthesis of Tricyclic Condensed Rings Incorporating the Pyrazole or Isoxazole Moieties Bonded to a 4-Piperidinyl Substituent
No full textIn this paper we report the synthesis of new compounds based on the pyrazole and isoxazole framework fused to a cycloalkene unit, and bearing as a substituent the 1-piperidinyl group as new examples of potential antipsychotic molecules. The general synthesis involves the acylation of a chloro-substituted cyclic ketone with a 1-substituted piperidine-4-carboxylate derivative, followed by heterocyclization of the formed 1,3-dioxo compound with a hydrazine or hydroxylamine
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
La Meccanizzazione della raccolta del mirto
Full text linkThe plant of the myrtle in past has been always considered one marginal cultivation and of
insufficient interest. Only in the last five years it has been knowledge the economic
importance for the demanded crescent of liquor of myrtle, product up to now nearly
exclusively in Sardinia. Therefore, new sensibility has been developed one and a greater
knowledge of the importance of a deepened study more of the cultivation from the biological
point of view and the point of view of one rations mechanized harvester of the berries. The
aim of the work was that one to characterize an harvester of the berries from the plant,
avoiding the damaging of the plant and above all of the fruits that influenced on the quality of
the finished product. In this present study they are evidences the comparison between some
tests of harvest in turn to obtained and carried out with two different types of harvesters some
in relation to the ransom of the plants
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