1,720,960 research outputs found
Mapping Passenger Trajectories to Train Schedules - industrial paper
No full textAn important task in transportation studies is to accurately map a given set of trajectories representing moving individuals onto specific means of transportation, like trains or buses. In this paper, we consider the following problem: given a trajectory representing train stations visited by a passenger during a trip and a train schedule, extract the set of trains that have been taken by the individual during the trip. Specifically, we introduce a novel algorithm based on a Generalized Suffix Tree (GST) to efficiently link passenger trajectories to train schedules, addressing challenges like large data volumes and noisy input trajectories. Our method constructs a GST from train schedules and allows for integrating multiple schedules into a single searchable structure, enabling rapid and precise matching of trajectories to train routes. Although we use trains as an example, the approach can be used for other means like buses or trams. To analyze our solution, we construct a synthetic dataset of passenger trajectories built over the Italian train schedule; the dataset contains trajectories with and without transfers and with noise both in timestamps and station identifiers. The experimental analysis shows that our solution perfectly reconstructs noiseless trajectories even with transfers, and achieves an accuracy of at least 86% with noisy data
Assessing veracity of big data: An in-depth evaluation process from the comparison of Mobile phone traces and groundtruth data in traffic monitoring
Full text linkVeracity is a critical dimension of Big Data, as it is related to the quality of data. Its role is even more important when Big Data are supposed to be a counterpart or a substitute of official data. While the former is usually unstructured and the collecting procedures are unsupervised, the latter is collected in accordance to strict and rigorous methodologies. Mobile phone traces, alternatively called Cellphone Big Data (CBD), can be ascribed among the most popular Big Data typology in transportation analyses, even if they are affected by some biases. This research effort is aimed to contribute to the discussion on Big Data and to shed light on the need of a rigorous assessment of the dataset quality. An in-depth evaluation process was carried out with the comparison of CBD to groundtruth data, namely traffic-related data collected by Anas S.p.A. – Gruppo Ferrovie dello Stato Italiane along a major Italian trunk road. What emerges from this paper is the sensitiveness of CBD to some variables related to both cinematic characteristics of traffic, mobile phone network characteristics and the traffic condition, namely the vehicle occupancy rate
Towards a Fair and Comprehensive Evaluation of Walkable Accessibility and Attractivity in the 15 Min City Scenario Based on Demographic Data
No full textAccessibility and the so-called ‘15 min city’ paradigm are critical dimensions in agendas involving urban policies. However, when interested in accounting for accessibility from a formal perspective, researchers and practitioners should use pertinent indicators. Additionally, most of the indicators focus on the number of facilities reachable within a given time window, while the counterpart of the latter, i.e., as a measure of attractiveness, such as the number of users that can reach that given area, is not evaluated explicitly. In this paper, a comprehensive method able to capture accessibility and attractivity simultaneously will be presented. The formulation is based on a refinement of the gravity model. As the main input, the actual number of residents was used and included in the computation. Therefore, the resulting values of accessibility and attractivity are intended to represent the real status of different degrees of walkable accessibility in urban areas. As a test field, three Italian cities were explored. The method proposed and discussed throughout the paper is aimed at providing an operative tool for planners, as well as for private stakeholders, when they are in charge of evaluating the degree of ‘walkable’ accessibility. Furthermore, the use of open and standardized data is intended to be a main strength of the proposed methodology, as it can be easily replicated in other contexts
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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