1,721,128 research outputs found
Virtual assessment of structural health monitoring techniques for wind turbines using vibration data
No full textOperational Modal Analysis (OMA), also known as output-only modal analysis, allows identifying modal parameters only by using the response measurements of the structure in operational conditions when the input forces cannot be measured. This information can then be used to improve numerical models in order to monitor the operating and structural conditions of the system. This is a critical aspect both for condition monitoring and maintenance of large wind turbines, particularly in the off-shore sector where operation and maintenance represent a high percentage of total costs.
The availability of commercial numerical aeroelastic simulation codes simulating the response of wind turbines in operation can be used as a virtual design and verification tool. Effects of design modifications and variations in the environmental and structural conditions can all be simulated using these tools. However, experimental test campaigns should be able to provide accurate and reliable data with which the model can be updated and be more representative of the real response. Thus, the improvement of these simulation models is strongly related to the improvement of the current Operational Modal Analysis (OMA) modal parameter estimation techniques. The main issue for these methods is that, due to blade rotation, force periodicity and the presence of control surfaces which modify continuously the system configuration, most of the applicability assumptions of OMA are violated. In this paper, some preliminary assessments on how to combine numerical and experimental techniques for Structural Health Monitoring (SHM) of wind turbines are investigated
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Variability in Composite Structure Vibration Measurement and Numerical Model Updating
No full textThis paper presents an overview of the composite engineering projects. Research objectives,
scope of the performed tests, computational activities and main project results will be highlighted.
The main goal of this multidisciplinary projects is to investigate the dynamic properties of fibre
reinforced composite structure. Non-destructive experimental and numerical simulation methods
were applied. The test results were used in two ways: for the identification of the mechanical
properties of the structure and for non- deterministic updating the Finite Element Model according
to range of experimental models obtained from test. In the experimental part the different test
configurations were taken into account. The sources of the test data variabilities were the
excitation and measurement technique applied for investigated object. The former was performed
by means of the random and harmonic, single and multi point excitation while the latter was
contact and non-contact acceleration and velocity measurement. Non deterministic model
updating and verification & validation included uncertainties of its parameters by means of interval
and stochastic methods. An optimisation technique for test (sensor number and location) was
applied. A number of variable test modal models were statistically assessed to investigate impact
of variability source onto modal model parameters
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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