1,721,029 research outputs found
MASS MANAGEMENT OF A HIGH ENERGY-EFFICIENT BATTERY ELECTRIC VEHICLE
No full textThe paper presents a detailed analysis of the mass-induced power demand of an ultra-efficient battery electric vehicle. The vehicle belongs to a special class of lightweight quadricycles, designed for participating to efficiency competitions. The influence of reducing the mass of the entire vehicle and the mass of the wheels on the vehicle energy consumption is assessed. A sensitivity analysis is performed by exploiting a “tank-to-wheel” multi-physics model of the vehicle. The model includes the main vehicle subsystems and the principal sources of power dissipation are modelled. A three-step sensitivity analysis is carried out: firstly, the influence of the mass reduction on the energy saving is analysed for two different race tracks; then, two different driving behaviour on the same track are compared; finally, the potential energy saving due to actual lightweighting interventions performed on the vehicle is computed. In this phase, secondary mass reduction effects (battery downsizing) are included in the simulation. Results are expressed in terms of Energy Reduction Value (ERV), a parameter widely used in the literature to quantify the correlation between mass reduction and energy saving. The vehicle studied in this paper shows an ERV due to vehicle mass reduction ranging from 0.23 to 0.36 kWh/(100 km∙100 kg), while wheel lightweighting leads to an ERV ranging from 1.03 to 1.74 kWh/(100 km∙100 kg)
Crystallization of peralkaline rhyolitic magmas: Rheological implications for the Pantelleria system
No full textBeams on elastic foundation: A variable reduction approach for nonlinear contact problems
Full text linkBeams on elastic foundations are applied to a vast number of engineering problems. Several elastic foundation models are available, from the simplest Winkler element with one parameter to complex models with more parameters and nonlinear characteristics. Analytical and numerical approaches have been developed in the literature for the solution of this problem, often specialized for a particular application. In this paper, a novel numerical approach that can be applied to any combination of beam and foundation models is presented. The method is based on independent meshes for the beam and for the foundation. The independent discretization of the foundation opens the possibility to model any kind of foundation behaviour, including nonlinearities, discontinuities and space-dependent properties. The two meshes are then connected by a variable reduction approach, formulated by standard finite element procedures. Such an approach allows to refine the discretization of the foundation without affecting the dimension of the solving system, i.e. with a limited effect on the computational time. Additionally, a relevant advantage of the presented method is that, contrary to most approaches described in the literature, gaps between the beam and the foundation can be straightforwardly included by an energy-based formulation. Examples of applications to linear, nonlinear, and foundation with gaps are reported in the paper. This innovative approach not only simplifies the modelling process but also offers significant computational advantages, making it a versatile and efficient tool for a wide range of engineering applications involving beam–foundation interactions
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
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