1,720,967 research outputs found
On the finitization of Priorean linear time
No full textA labelled sequent calculus for Priorean linear time is defined through the method of internalization of the possible-worlds semantics into the syntax. The calculus enjoys desirable structural properties, such as syntactic cut elimination, but requires an infinitary mathematical rule stating that between any two points there are only finitely many points. By replacing the infinitary rule with two weaker finitary rules a system for non-standard discrete frames is obtained. A conservativity result for an appropriate fragment of the original calculus is proved syntactically
Equality in the presence of apartness : an application of structural proof analysis to intuitionistic axiomatics
No full textThe theories of apartness, equality, and n-stable equality are presented through contraction- and cut-free sequent calculi. By methods of proof analysis, a purely proof-theoretic characterization of the equality fragment of apartness is obtained
Proof Analysis in Temporal Logic
Full text linkThe logic of time is one of the most interesting modal logics, and its importance is widely acknowledged both for philosophical and formal reasons.
In this thesis, we apply the method of internalisation of Kripke-style semantics into the syntax of sequent calculus to the proof-theoretical analysis of temporal logics.
Sequent systems for different flows of time are obtained as modular extensions of a basic temporal calculus, through the addition of appropriate mathematical rules that correspond to the properties of temporal frames: a general and uniform treatment is thus achieved for a wide range of temporal logics. All the calculi enjoy remarkable structural properties, in particular are contraction and cut free.
Linear discrete time is analysed by means of two infinitary calculi. The first is obtained by means of a rule with infinitely many premises, and the second through a new definition of provability which admits, under certain conditions, derivation trees with infinite branches.
The first calculus enjoys the desired structural properties, but the presence of an infinitary rule is harmful for proof analysis. Two finitary systems are identified by replacing the infinitary rule with a weaker finitary rule, and by bounding the number of its premises, respectively. Corresponding, somehow complementary, conservativity results are proved with respect to adequate fragments of the original calculus.
The second calculus stems from a closure algorithm which exploits the fixed-point equations
for temporal operators and gives saturated sets of closure formulas from a given formula.
Finitisation is obtained in the form of an upper bound to the proof-search procedure, and decidability follows as a major consequence
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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