1,720,961 research outputs found
Simulating effects of a human-based maintenance on production lines: a case from the pharmaceutical industry
No full textThe authors propose a theoretical approach aiming at identifying stochastic variables which mainly affect system performance. The approach is firstly applied to a theoretical case of stochastic variables defined in [0,1] range, distributed according to Beta probability density function.
A general conclusion achieved relies on the system attitude in smoothing or boosting stochastic variability of system performance, given stochastic variability of independent system variables. The attitude mainly relies on deterministic relationship between system performance and system variables.
The approach is applied to an industrial case consisting of a production line of sterile syringes. The aim of the management was to identify work stations requiring improvements on maintenance performance in order to increase system availability.
System availability has been evaluated by simulation. A simulation model coded by ARENA® was built up. Results outline the capability of the approach proposed in identifying most sensitive relationship between system availability and time to repair
Simulating effects of a human-based maintenance on production lines: a case from the pharmaceutical industry
No full textThe authors propose a theoretical approach aiming at identifying stochastic variables which mainly affect system performance. The approach is firstly applied to a theoretical case of stochastic variables defined in [0,1] range, distributed according to Beta probability density function.
A general conclusion achieved relies on the system attitude in smoothing or boosting stochastic variability of system performance, given stochastic variability of independent system variables. The attitude mainly relies on deterministic relationship between system performance and system variables.
The approach is applied to an industrial case consisting of a production line of sterile syringes. The aim of the management was to identify work stations requiring improvements on maintenance performance in order to increase system availability.
System availability has been evaluated by simulation. A simulation model coded by ARENA® was built up. Results outline the capability of the approach proposed in identifying most sensitive relationship between system availability and time to repair
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
Group Momentum Space and Hopf Algebra Symmetries of Point Particles Coupled to 2+1 Gravity
Full text linkWe present an in-depth investigation of the SL(2,R) momentum space describing point particles coupled to Einstein gravity in three space-time dimensions. We introduce different sets of coordinates on the group manifold and discuss their properties under Lorentz transformations. In particular we show how a certain set of coordinates exhibits an upper bound on the energy under deformed Lorentz boosts which saturate at the Planck energy. We discuss how this deformed symmetry framework is generally described by a quantum deformation of the Poincaré group: the quantum double of SL(2,R). We then illustrate how the space of functions on the group manifold momentum space has a dual representation on a non-commutative space of coordinates via a (quantum) group Fourier transform. In this context we explore the connection between Weyl maps and different notions of (quantum) group Fourier transform appeared in the literature in the past years and establish relations between them
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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