1,720,987 research outputs found
Efficient Pedestrian and Bicycle Traffic Flow Estimation Combining Mobile-Sourced Data with Route Choice Prediction
No full textAccurate estimate of traffic flow measures like annual average daily traffic (AADT) is vital to making decisions about roadway planning, safety, maintenance, operation etc. Methodology to inexpensively obtain an accurate estimate of traffic flow especially for pedestrian and bicyclist traffic is lacking in the literature. High expenses of conducting household surveys and setting up traffic monitoring stations to collect data motivated us to look for cheaper solutions. In this study, we develop a methodology to inexpensively obtain a good estimate of pedestrian and bicyclist traffic flow from mobile data sources while avoiding the privacy issues associated with models based on household survey data. However, the accuracy of mobile data is unknown and may vary in different locations. To deal with erroneous data sources we use different techniques to estimate and keep improving an origin-destination (OD) matrix from the observed link flows to ultimately get the actual link flows. In our model, we enforce the consistency between the number of productions and attractions of trips for different regions with the OD-matrix. Using the network topology, we use trip distribution based on the gravity model to generate an initial OD-matrix. Then we use an optimization formulation to improve the initial OD-matrix so that the link flow obtained using the improved OD-matrix matches with the partially observable link flows. Furthermore, we present the performance of the solution algorithm for the Twin Cities' bicycle and pedestrian networks. We also compare the accuracy of our estimate with manually collected traffic flow data for the real networks.Barman, Simanta; Stern, Raphael; Levin, Michael W.; Lindsey, Greg. (2023). Efficient Pedestrian and Bicycle Traffic Flow Estimation Combining Mobile-Sourced Data with Route Choice Prediction. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/259068
Air travel data during the COVID-19 pandemic in the United States
No full textThe flight data contains flights within the Northeastern US and contains flight date, duration, origin, destination, airline, and aircraft registration. The aircraft registration information has been cross referenced with the Federal Aviation Administration (FAA) database to identify the aircraft type and seating configuration on that aircraft.
The dataset also contains normalized COVID-19 infection levels for each county in the five-state region of New York, Massachusetts, Connecticut, Rhode Island, and New Jersey. This data is presented as the proportion of infected people in each county on a day-by-day basis.This dataset contains flight data for all commercial flights in the Northeastern US during the COVID-19 pandemic, as well as code to calibrate and simulate an SEIR model that incorporates the flight data into the transmission process.Shang, Mingfeng; Pham, Joseph; Vrabac, Damir; Butler, Brooks; Paré, Philip E; Stern, Raphael. (2020). Air travel data during the COVID-19 pandemic in the United States. Retrieved from the University Digital Conservancy, https://doi.org/10.13020/r4mw-5017
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
Driver Comprehension of Flashing Yellow Arrows
No full textIn 2009, the FHWA's Manual on Uniform Traffic Control Devices (MUTCD) introduced the flashing yellow arrow (FYA) traffic signal as an alternative to circular green (CG) to indicate permitted left turns. The FYA is arguably a more intuitive indication that left turns are permitted but not protected and, in addition, the FYA signal heads can support time-of-day changes between protective and permissive left -turn phasing. In 2019, a Research Needs Statement stated that "Research is needed to examine driver comprehension of flashing yellow arrows in different light arrangements and the role of signage." Our objective in this project was to assess drivers' understanding of FYA signal indications and to see if the presence or absence of "Left Turn Yield" signs affect gap acceptance. This was accomplished by conducting an online survey of drivers regarding their understanding of FYA signals and by carrying out a field study of drivers' gap acceptance at a set of Twin Cities intersections.Davis, Gary A.; Stern, Raphael; Duhn, Melissa; Gao, Jingru. (2023). Driver Comprehension of Flashing Yellow Arrows. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/260835
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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