1,720,962 research outputs found
Analysis of the carbon footprint of freight transport in the mass market retail sector: a case study in Campania (Italy)
No full textImpacts of truck platooning on the multimodal freight transport market: An exploratory assessment on a case study in Italy
No full textTruck platooning is expected to significantly affect road freight transport performances, although in the long term due to technological and operational issues still to address. Furthermore, truck platooning could be introduced with increasing levels of automation, corresponding to different technologies and operational costs. In parallel, various Countries promote freight-related infrastructural plans pursuing a modal shift from the road towards more sustainable modes (railways, sea shipping, inland waterways). The planning horizon of such infrastructures probably overlaps, at least partially, with a non-negligible market penetration of truck platooning. In this framework, the paper aims to explore the extent of a system-wide competition between existing freight modes and truck platooning, through an exploratory analysis of the potential market of truck platooning in Italy. The study is based on a comparative analysis of the cost of various freight modes, leveraging a multimodal nationwide freight supply model. Forty different scenarios have been modelled, with different assumptions on the input variables including three levels of automation. Results show that truck platooning could be highly competitive with respect to rail transport for medium to large distances. Competition with conventional road transport is significant as well, with a large contestable market share between truck platooning and traditional road freight,
especially on medium to long distances, whilst maritime transport starts competing with truck
platooning only in the case of (at least partially) unmanned truck platooning operations. The size of truck platoons impacts appreciably on results only with a manned leader truck and unmanned
followers. Based on the above results it would be appropriate to consider track platooning as a
new freight transport mode
Choice probabilities and correlations in closed-form route choice models: Specifications and drawbacks
No full textThis paper investigates the performance – in terms of choice probabilities and correlations – of existing and new specifications of closed-form route choice models with flexible correlation patterns, namely the Link Nested Logit (LNL), the Paired Combinatorial Logit (PCL) and the more recent Combination of Nested Logit (CoNL) models. Following a consolidated track in the literature, choice probabilities and correlations of the Multinomial Probit
(MNP) model are taken as targets. Laboratory experiments on small/medium-size networks are illustrated, also leveraging a procedure for practical calculation of correlations of any GEV models. Results show that models with inherent limitations in the coverage of the domain of feasible correlations yield unsatisfactory performance, whilst the specifications of the CoNL proposed in the paper appear the best in fitting both MNP correlations and probabilities. The performance of the models is appreciably ameliorated by introducing lower bounds to the
nesting parameters. Overall, the paper provides guides for the practical application of tested models
New freight transport incentive to achieve modal shift targets: Methodology and application to Italy
Get PDFThis study illustrates a new freight transport incentive for achieving modal shift targets. The proposed incentives
are jointly designed for all non-road modes within an optimization framework, varying by origin–destination pair
to maximize effectiveness while adhering to budget constraints and market competition regulations. This
approach addresses the limitations and side effects of existing incentive schemes. Methodological issues related
to the formulation and solution of the optimization problem are discussed, and a specific heuristic algorithm is
presented to apply the proposed approach to large-scale instances. The viability of the proposed approach is
demonstrated with an example of a multimodal freight system in Italy, considering various assumptions on
freight mode choice and cargo values of time. The results show that the proposed approach outperforms
nationwide incentive schemes
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Incentives to freight railway undertakings compensating for infrastructural gaps: Methodology and practical application to Italy
No full textThe paper illustrates an incentive scheme to freight railway undertakings, proportional to the infrastructural gaps they experience on the rail network with respect to optimal performances in terms of loading gauge, length and weight. The proposed incentive is equitable and provided on an origin-destination pair basis, as opposed to the watering-can principle underlying current incentives schemes. In practice, it can be simply dispensed as a discount of the access charge the railway undertakings should pay to the rail network infrastructure manager. It also differs by type of train, to account for their different infrastructural needs, and can be adjusted on a yearly basis to account for ongoing network improvements. The main methodological challenge lies in the quantification of the infrastructural gap, defined as the difference of the unit transport costs in the current and in the optimal scenario, as a consequence of the non-additivity of concerned costs. For this aim, a specific procedure is illustrated and applied to the railway intermodal transport in Italy, to show the feasibility of the approach and highlight the differences with respect to the current incentive schemes
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