1,721,107 research outputs found
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
Simplified analytical method for moment-curvature response of corroded prestressed concrete beams
No full textNowadays, the corrosion phenomenon is recognized as one of the main causes of
deterioration of reinforced and prestressed concrete (PC) structures. Several experimental and
numerical investigations have been proposed in the literature for the flexural and shear response
of reinforced concrete structures. However, the lack of simplified yet accurate analytical models
have been outlined, especially concerning the residual mechanical response of corroded pre stressed concrete members. To this aim, the present work focuses on the proposal of a simplified
analytical model for the flexural resistance of prestressed concrete beams - subjected to chloride induced corrosion - in terms of moment-curvature response. Firstly, the basic assumptions of the
approach and the validation against un-corroded PC beams are described by adopting a novel
stress-strain relationship for corroded strands previously proposed by the authors. Secondly, the
effect of the corrosion level on the moment-curvature response of deteriorated PC beams is in vestigated. Finally, outcomes are provided concerning: (i) the expected flexural failure mode, (ii)
the evaluation of useful parameters for the assessment of flexural and shear resistances - the latter
referring to the current formulation provided in the Model Code 201
The PARC_CL 2.1 crack model for reinforced concrete elements subjected to corrosion and long-term effects.
No full textDuring the service life, existing structures may suffer a combination of time-dependent effects, such as creep,
shrinkage and reinforcement corrosion. The corrosion deterioration can significantly affect the durability of
reinforced concrete (RC) elements causing premature concrete crushing, size reduction of reinforcement
cross-section, degradation of mechanical properties of steel and concrete, and stirrups rupture. Furthermore,
to ensure adequate safety and serviceability throughout the life of the structure, the prediction of long-term
strains, due to creep and shrinkage, is important. Creep and shrinkage have a considerable impact on the
performance of RC structures, affecting stress and strain distribution, increasing deflections and crack width.
For this reason, a nonlinear finite element approach, based on multi-layer shell elements and PARC_CL
2.0 crack model is presented in this paper. The PARC_CL 2.1 model is a fixed crack model developed at the
University of Parma and implemented in a FORTRAN subroutine UMAT for for ABAQUS that incorporates
cyclic constitutive laws of materials and the evolution of corrosion, shrinkage and creep over the time. The
effectiveness of the proposed model is validated through comparison with experimental data available in
literature
SCPS-model Validation Based on a Database of Naturally Corroded Prestressing Strands
No full textChloride-induced corrosion of prestressed concrete (PC) structures is worldwide recognized as a one of the main causes triggering the structural performance reduction of PC members over time. To ac-count for this issue, the accurate estimation of the mechanical properties decay of corroded prestressing reinforcement plays a crucial role. To provide model uncertainties estimation useful for reliable assess-ment of corroded PC members, the paper presents a further validation of the novel SCPS-model, based on an updated test database on naturally corroded strands collected by Authors from scientific literature. As revealed by the statistical analysis outcomes, the SCPS-model is confirmed as a useful tool for the daily engineering practice for the prediction of the residual tensile response of corroded strand
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
A deterministic event calculus for effective runtime verification
Full text linkRuntime verification (RV) is an effective technique for dynamically monitoring, even after deployment, properties that could be hardly verified statically. To this aim, specification formalims for RV have to reconcile expressive power and monitoring efficiency. We present an event calculus which provides a basis for the semantics and the implementation of RML, a domain specific language (DSL) for RV. The semantics of the calculus is based on a deterministic reduction strategy which allows concise specifications of non context-free properties, and their efficient verification at runtime
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