1,720,969 research outputs found
Auralisation of train pass-bys for virtual reality demonstration of combined noise mitigation measures
No full textRailway noise can be reduced by various mitigation measures and combinations thereof. However, it is difficult to assess their combined effects and to communicate the options to stakeholders. For this, auralisation is a promising technique that can support communication and decision-making, and enable psychoacoustic evaluations. This paper presents a new physics-based auralisation model for train pass-bys that considers combined mitigation measures. The measures include acoustic rail grinding, avoidance of wheel flats, wheel and rail dampers, rail shields, mini barriers and classical noise barriers. Pass-by parameters such as train type, speed, track design and observer location can be selected. The proposed model includes contributions from rolling noise, impact noise, traction, auxiliary systems, and aerodynamic noise. The main novelty of this work lies in the improved time-domain synthesis of rolling noise. The sound radiated by each wheelset is modelled by multiple moving point sources. For the sound radiated by the track, a new hybrid model is proposed that consists of a combination of moving and fixed equivalent sources, reflecting the structural wave propagation in the rails. Separate source contributions for radial and axial wheel vibration, vertical and lateral rail vibration and sleeper vibration are considered using TWINS-based computations and an improved description of rolling damping. First comparisons of synthesised and recorded train pass-bys showed a very good agreement and a high degree of realism. The auralisations were coupled to an immersive virtual reality environment that allows for an interactive audio-visual experience of different train pass-by scenarios and to demonstrate noise mitigation options. The presented models were implemented in two software tools that are described in this paper and made available. The tools have already been successfully used in public demonstrations at international exhibitions and information events for residents
Auralisation of combined mitigation measures in railway pass-by noise
No full textTo reduce noise exposure along railway lines various combinations of noise mitigation measures can be considered. However, predicting and assessing their effects is non-trivial and the potential need for multiple measures is difficult to communicate to stakeholders. Auralisation is a promising tool that can help to support communication and decision-making, and enable psychoacoustic evaluations. This paper presents developments of a physics-based auralisation model for train pass-bys that allows various mitigation measures to be included. The work is conducted within the European research project SILVARSTAR. The proposed model includes contribution from rolling noise, impact noise, traction, auxiliary systems, and aerodynamic noise. It is physically based and allows a direct assessment of pass-by parameters such as speed, roughness, wheel flats and track design. Based on the TWINS model, five structural transfer paths for rolling noise are considered to integrate mitigation measures such as wheel and rail dampers. Shielding by noise barriers is simulated with analytical models. Reflection at different ground types is considered and can account for track embankments. The results can be coupled to an immersive Virtual Reality environment, by first panning the synthesised sounds to a small virtual speaker array and subsequently dynamic binaural rendering for headphones
VR demonstration of railway noise mitigation using auralised train pass-bys
No full textIn the European project SILVARSTAR, a new tool for the demonstration of railway noise mitigation measures was developed. The tool allows for an interactive, immersive audio-visual experience of different train pass-by scenarios. Different train types, speeds and tracks can be simulated within different virtual environments. The user can activate a set of mitigation measures and switch in real time between variants. The tool offers nine different mitigation measures, such as barriers, dampers, acoustic rail grinding, and as well as their combinations. The train pass-by sounds are auralised using physics-based synthesis. For rolling noise, structural transfer functions for the sleepers, the rails and the wheelsets are predicted using the TWINS model. The track contributions are modelled as a combination of distributed fixed and moving equivalent sources, whereas each wheelset is represented by a series of vertically stacked moving point sources. The pass-by sound synthesis was validated by comparisons with field measurements. At public international exhibitions, the VR system consisting of the newly developed auralisation and VR software, and commercial VR hardware has been attested to have high credibility and quality
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
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