1,721,098 research outputs found
Osservazioni su Cesarione
Full text linkStudio storico sul ruolo di Cesare nell'ascesa di Cleopatra e sul contesto biografico e storico del figlio Tolemeo Cesare
ArUco marker-based displacement measurement technique: Uncertainty analysis
No full textThe displacement response of structures can provide important information regarding their behaviours. Since image-based measurements have been considerably improved in recent years, in this research, a fiducial marker-based approach is exploited and a displacement measurement technique is proposed. With this method, an industrial camera can be used to measure the displacement of a structure through the detection of an ArUco marker. Acomparison with an established reference technique has been carried out. The uncertainty due to repeatability measurement and the relevance of the acquisition and environmental parameters on the measurement results were researched
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
Comprehensive characterization of mechanical and physical properties of PLA structures printed by FFF-3D-printing process in different directions
Full text linkThe industrial interest in additive manufacturing (AM) techniques is currently increasing for the realization of functional mechanical components. For this reason, the structural simulation of parts or complete structures made using this new manufacturing technique is gaining considerable importance. To realise accurate finite element models for the purpose of predicting the dynamic or static behaviour of the component printed and avoid unexpected failures, it is necessary to be aware of some mechanical and physical properties of the print material. Unfortunately, in the literature, it is very difficult to find all the data necessary to perform static or dynamic simulations of 3D printed parts. In this context, this activity aims to determine all these mechanical and physical properties for parts made in White-Pearl Polylactic-acid (PLA) Ultimaker filament using the Fused Filament Fabrication (FFF) technique. A set of printing parameters was chosen and kept constant in all tests which, based on literature data, maximizes the static strength and the fatigue limit of the component. Only the building direction was varied to increase the applicability of the obtained results to any geometry. The main results found for the horizontally moulded specimens (representing the best constructive solution) are the Ultimate Tensile Strength equal to 57.15 MPa, the elastic modulus 2606 MPa, the fatigue limit evaluated at 2 × 10 6 cycles equal to 13.5 MPa, the damping and density of the material of 0.008 dimensionless value and 1.1246 g/cm3, respectively. Only thanks to the obtained results, finite element models can be developed for reliable static and dynamic analysis
Suction system vapour velocity map estimation through SIFT-based alghoritm
Full text linkMeasurement of velocity fields is a fundamental topic in uid dynamics. Imagebased analysis methods such as Particle Image Velocimetry or Laser Doppler Velocimetry are usually used. However, these techniques need complex instrumentation and particular test conditions. In this work, a computer vision-based approach is developed in order to obtain vapour velocity field map in effective, robust and economic way. Moreover, iterative ltering algorithm is applied to improve the results. The implemented method is tested on a suction system for domestic use, and the obtained velocity maps are validated by hot-wire anemometry, leading to totally comparable results, both in terms of profile and mean velocity. Uncertainty analysis shows acceptable results, considering the random nature of the phenomenon
Thermoelasticity-based modal damage identification
No full textThe response of linear dynamic structures can be decomposed into modal components, where each natural frequency is also represented by a corresponding mode shape and damping ratio. While vibration-fatigue-damage identification was recently expanded using modal decomposition, this research proposes a modal-decomposition-based thermoelastic damage identification method. With the proposed method, a thermal camera can be used to identify the damage intensity of a particular mode shape. The proposed method is presented using a randomly excited structure exposed to multiaxial loads. With this, the intensity of a particular fatigue source is clearly related to the underlying structural dynamics
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