1,720,960 research outputs found
The Parma University Campus as major trip attractor. Traffic microsimulation for modelling vehicle access scenarios
No full textUniversity campuses are multi-modal and major trip attractors, facing strong interactions of several transport modes within a unique system. Although campuses may share common features, they have different transport needs. The development of policies that encourage active mobility and transit service and the improvement of road infrastructures are main strategies to accomplish sustainable transportation goals. While many universities devote efforts to reducing drive-alone commute trips, private vehicles often remain the most affordable and convenient choice for many employees and students. In addition to discourage or apply strict restrictions to vehicular traffic, the optimization of the inbound and outbound flows is a necessary approach to reduce congestion and safety issues on and near campus Micro-simulation models are increasingly popular for examining these complex traffic problems at detail level, emulating traffic behavior in a transport network over time and space to predict a system performance. In this perspective, the article describes the case study of the mitigation of motorized traffic problems of the University Campus of Parma (Italy), which is implementing multiple sustainability strategies towards modal shift to non-motorized systems and optimization of public transport. Specifically, a traffic micro-simulation modelling was implemented to study the vehicle access at the main entrance to the Campus delimited area from the public road network via a multi-lane roundabout. Different scenarios, that do not involve any investment in infrastructure but only interventions in the management of the scheduled educational activities and services, were presented for increasing the users' safety and level of service. Following a description of the software calibration process and its validation to match the locally observed conditions, some operational solutions based on the re-planning of the lesson timetable were presented to reduce the current congestion levels within the campus and in its vicinity during peak hours
The odour fingerprint of bitumen
No full textBitumen is a very complex material with chemical composition and properties highly dependent on the crude oil source and refinery processes. Several analytical procedures were developed to understand the relationship between bitumen composition, microstructure and physical properties. Nevertheless, these techniques are expensive, time-consuming and involve significant drawbacks. Moreover, advanced research and industrial research have often different purposes and timing perspectives. Several bitumen operators require simpler and more suitable techniques for research and technology development, production and acceptance control and above all polymer modification. This necessity has led the authors to propose a new approach based on the artificial olfactory system (AOS), also known as electronic nose or e-nose. AOS is an instrument consisting of an array of partially selective sensors coupled to a suitable pattern-recognition system capable of recognising complex odours. The warm-up study highlighted the possibility of AOS to discriminate, already at room temperature without the need of sample pre-treatments, between bitumen produced with different origin crude oils and to verify the production stability in the same plant. Thus, these results indicate that the e-nose method may be used for quality assurance and quality control applications and for the fingerprinting of bitumen, showing a number of advantages over classical analytical instruments
Early age evolution of rheological properties of over-stabilized bitumen emulsion-cement pastes
No full textThis paper focuses on the early age evolution of consistency and rheological properties of fresh bitumen emulsion-cement (BEC) pastes. The tested BEC pastes were fabricated using a Portland limestone cement and an over-stabilized bitumen emulsion and were characterized by water to cement ratio ranging between 0.33 and 1 and by bitumen to cement ratio ranging between 0 and 1. The testing plan included the measurement of sedimentation tendency, setting time and evolution of viscosity with increasing storage time. Rheological measurements were also carried out on bitumen emulsion-filler mastics prepared with a reference filler. Results showed that, regardless of water content, the initial and final setting time of BEC pastes increased when the proportion of bitumen with respect to cement was increased. When the total concentration of the dispersed phases was low, the increase in bitumen concentration with respect to cement led to a reduction in the rate of viscosity increase with storage time; on the other hand, when the total concentration of the dispersed phases was high the increase of storage time led to a change in the physical state of the pastes (from fluid to plastic) due to coalescence of bitumen droplets
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
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