1,721,003 research outputs found
An acoustic emission based structural health monitoring approach to damage development in solid railway axles
Full text linkThe in-service safety of railway axles is a very important engineering challenge, as it has a large impact not only from the economic point of view of the railway operator, but it has cascading effects on supply chains, loss of work productivity, and, in the most serious cases, loss of life. It is, therefore, vital that the structural integrity of such components is known, during their lifecycle, with the highest possible accuracy via precise modelling, reliable inspections and, more recently but still at research level, effective condition monitoring. With a focus on solid freight axles, the research investigates the applicability of Acoustic Emission as a structural health monitoring approach for determining the in-service condition of a full-scale axle. A fatigue crack propagation test is carried out in the lab subjecting the axle to many repetitions of a block load sequence defined from real service measurements. Acoustic Emission data are continuously recorded during the test, whilst crack size is periodically measured by conventional non-destructive techniques. Eventually, a first-approximation correlation is highlighted between Acoustic Emission data, post-processed by a machine-learning algorithm, and crack propagation ones
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
Bilateral skin temperature drop and warm sensibility decrease following modulation of body part ownership through mirror-box illusion
No full textThe implicit and explicit awareness of owning a body and its parts is a constant accompaniment in our everyday life and our interaction with the outside world. The way in which we build and maintain a coherent sense of body ownership is not fully understood. It has been postulated that the integration between exteroceptive, interoceptive, and proprioceptive signals may play a fundamental role in the sense of body ownership. For instance, studies on healthy subjects and brain-damaged patients have suggested that alterations in the sense of body ownership are coupled with autonomic signal changes, such as thermoregulatory reactions. However, the available evidence is conflicting, possibly due to shortcomings in the experimental paradigm that previous studies have adopted. In this study, we explore the relationship between body ownership, thermoregulation, and thermal sensitivity through a novel application of the mirror-box illusion paradigm, overcoming some of the limitations of previous studies. We find a bilateral decrease in hand skin temperature, together with reduced thermal sensitivity for warm thermal stimuli following the induction of the illusion of ownership towards the participant's reflected hand. These findings demonstrate the importance of the orchestration of exteroceptive (e.g., visual), autonomic (e.g., body temperature) and proprioceptive (e.g., position and movement of the body) signals in maintaining a coherent sense of body ownership
Exploring the Interaction Between Handedness and Body Parts Ownership by Means of the Implicit Association Test
No full textThe experience of owning a body is built upon the integration of exteroceptive, interoceptive, and proprioceptive signals. Recently, it has been suggested that motor signals could be particularly important in producing the feeling of body part ownership. One thus may hypothesize that the strength of this feeling may not be spatially uniform; rather, it could vary as a function of the degree by which different body parts are involved in motor behavior. Given that our dominant hand plays a leading role in our motor behavior, we hypothesized that it could be more strongly associated with one’s self compared to its non-dominant counterpart. To explore whether this possible asymmetry manifests as a stronger implicit association of the right hand (vs left hand) with the self, we administered the Implicit Association Test to a group of 70 healthy individuals. To control whether this asymmetric association is human-body specific, we further tested whether a similar asymmetry characterizes the association between a right (vs left) animal body part with the concept of self, in an independent sample of subjects (N = 70, 140 subjects total). Our results revealed a linear relationship between the magnitude of the implicit association between the right hand with the self and the subject’s handedness. In detail, the strength of this association increased as a function of hand preference. Critically, the handedness score did not predict the association of the right-animal body part with the self. These findings suggest that, in healthy individuals, the dominant and non-dominant hands are differently perceived at an implicit level as belonging to the self. We argue that such asymmetry may stem from the different roles that the two hands play in our adaptive motor behavior
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
Strain energy density approach as fatigue assessment of Ti6Al4V specimens machined by WEDM single step technology
Full text linkThe present paper summarizes the results from force-controlled fatigue tests performed on Ti6Al4V specimens machined by wire electrical discharge machining (WEDM) single step technology. For this aim, blunt V-notched specimens with various notch root radii and un-notched “dog bone” specimens are considered. The fatigue behaviour of this alloy machined by WEDM single step technology is an extremely important issue but, despite this, the literature on this topic is very poor and the effect of geometrical discontinuities on the fatigue life of has still to be investigated. Fatigue data, generated by testing a total number of 62 specimen, are re-analysed by means of the Strain Energy Density (SED) method, investigating the possibility to use this method following a numerical approach. Estimation of the critical radius is performed on the basis of finite element analysis to overcome the lack of knowledge of the material properties often related to the machining process. Thanks to the SED method, it is possible to summarize in a single scatter-band all the collected fatigue data, independently of the specimen geometry. The proposed numerical approach is capable to reduce the scatter index compared to the actual procedure with modest extra effort, also solving the issue related to the geometry selection for the critical radius identification. The method is successfully validated by assessing the fatigue life of specimens with two notch geometries not considered during the critical radius identification. © 2022 The Author(s
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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