1,720,962 research outputs found
A probabilistic AI-based pedestrian volume estimation model for street-level urban management
No full textAs analyzing and controlling human movements is a key task in urban planning and management process, decision-makers have developed the computer-aided methodologies for pedestrian volume estimation. However, the existing pedestrian volume estimation studies have faced several constraints, such as the high cost of manual counting. This study aims to develop a street-level pedestrian volume estimation model by utilizing a computeraided approach to evaluate data acquired through closed-circuit television (CCTV). We employ spatial characteristics and pedestrian volume data derived from sensed points to estimate pedestrian volumes on unsensed streets. The Bayesian Neural Network (BNN)-based model exhibited the best performance for the pedestrian volume estimation, with a mean hourly error of 21.305 individuals for 10-fold cross-validation and total 77.394 individuals for test estimation on four streets representing diverse pedestrian volume, surpassing the performance of regression and deep neural network (DNN)-based models. The BNN-based model also exhibits considerable performance in terms of estimating the hourly pedestrian volumes of entire streets within the study site (i.e., Bukchon Hanok Village in Seoul), and we examine the potential of the stochastic model to assess the uncertainty of a probabilistic artificial intelligence (AI) model. Additionally, a scenario-based test that assumes two specific road control situations presents a numeric and visual aid for predicting the aftermath of an urban management policy. The methodology proposed in this study can contribute to the exploitation of computeraided techniques and trustworthy AI for supporting decision-making processes, thereby providing urban planners with more quantitative evidence.
Vision-based Overhead Front Point Recognition of Vehicles for Traffic Safety Analysis
No full textPedestrian-vehicle accidents are the cause of many human injuries and deaths. To address this challenge, vision-based traffic systems have focused on detecting traffic-related objects' behaviors, such as vehicle position and velocity relative to pedestrians. In this paper, we propose a new and simple model for effectively recognizing overhead front point of vehicles, while only using a single stationary camera capturing from an oblique angle. The proposed system uses faster R-CNN model for detecting object bounding box and mask, projects the mask's extreme points down to find the car's ground front point, and transforms these coordinates from oblique to overhead frame of reference. Our experimental result shows that this method is effective for recognizing overhead front point of car (accuracy: 92.4%) within a certain tolerance. © 2018 Copyright is held by the owner/author(s). Publication rights licensed to ACM
Characteristics of Urban Areas Related to Natural Surveillance and Children's Sense of Safety: Focusing on Street Lights, Cctvs, and Spatial Configuration
No full textThe study asks if the urban facilities related to natural surveillance can explain the children’s perception of ‘dangerous’ places. The degree to which people feel safe got attention from the researchers since it encourages or discourages physical activities (Bennet et al., 2007). The increased natural surveillance is one of the key factors to make a city not only actually safer but also allow people to feel safe. Children, as objects with independent needs from the adults’ instructions, show more or less physical activity due to their perception of a particular space (Min & Lee, 2006). The relationship between various environmental variables and children's perception is being interested in researchers, yet the studies often targeted children’s certain activities or places. This study is in line with previous studies studying the relationship between urban environment and perception of children but differentiates itself as it focuses on how the urban facilities related to natural surveillances would affect children’s perceived safety. Targeting an elementary school and its surrounding areas, two main methods were used in the study. First, we conducted a survey to figure out the locations and reasons of places where children actually feel dangerous about the streets around the school. Second, we performed statistical analysis with the physical factors of the streets in relation to children’s perceptions. Independent variables were the number of street lights, the number of CCTVs, and the average integration value of streets by the space syntax according to the top reasons why children think the place is dangerous. The dependent variable was the number of ‘dangerous’ places that children think. We counted and calculated the values of each variable using a 30-meter by 30-meter grid as a unit of analysis. The statistical analysis shows the average integration value a positive correlation with the number of dangerous places that children think. This shows that higher pedestrian volumes may affect children noticing the places dangerous, which is different from the previous studies. We think it may be related to other pedestrian-related reasons. For example, high integration means there would be a lot of people on the streets, not only the good people but also bad people who can put kids in danger. Additionally, the street lights and CCTVs show very low relation to the children’s sense of safety. This is an important finding to investigate the difference between adults' and children’s perceptions of safety on streets in the future. This study may have some limitations in that the number of variables is small and the variables should be more verified whether it represents the survey results well. The increased variety of variables and their proper selection would be covered in the future study
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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