Tracer Flux Balance at an Urban Canyon Intersection
NASA Astrophysics Data System (ADS)
Carpentieri, Matteo; Robins, Alan G.
2010-05-01
Despite their importance for pollutant dispersion in urban areas, the special features of dispersion at street intersections are rarely taken into account by operational air quality models. Several previous studies have demonstrated the complex flow patterns that occur at street intersections, even with simple geometry. This study presents results from wind-tunnel experiments on a reduced scale model of a complex but realistic urban intersection, located in central London. Tracer concentration measurements were used to derive three-dimensional maps of the concentration field within the intersection. In combination with a previous study (Carpentieri et al., Boundary-Layer Meteorol 133:277-296, 2009) where the velocity field was measured in the same model, a methodology for the calculation of the mean tracer flux balance at the intersection was developed and applied. The calculation highlighted several limitations of current state-of-the-art canyon dispersion models, arising mainly from the complex geometry of the intersection. Despite its limitations, the proposed methodology could be further developed in order to derive, assess and implement street intersection dispersion models for complex urban areas.
Michigan urban trunkline intersections safety performance functions (SPFs) development and support.
DOT National Transportation Integrated Search
2015-06-01
This study involves the development of safety performance functions (SPFs) for signalized and stop-controlled intersections : located along urban and suburban arterials in the state of Michigan. Extensive databases were developed that resulted in the...
Safety analysis of urban arterials at the meso level.
Li, Jia; Wang, Xuesong
2017-11-01
Urban arterials form the main structure of street networks. They typically have multiple lanes, high traffic volume, and high crash frequency. Classical crash prediction models investigate the relationship between arterial characteristics and traffic safety by treating road segments and intersections as isolated units. This micro-level analysis does not work when examining urban arterial crashes because signal spacing is typically short for urban arterials, and there are interactions between intersections and road segments that classical models do not accommodate. Signal spacing also has safety effects on both intersections and road segments that classical models cannot fully account for because they allocate crashes separately to intersections and road segments. In addition, classical models do not consider the impact on arterial safety of the immediately surrounding street network pattern. This study proposes a new modeling methodology that will offer an integrated treatment of intersections and road segments by combining signalized intersections and their adjacent road segments into a single unit based on road geometric design characteristics and operational conditions. These are called meso-level units because they offer an analytical approach between micro and macro. The safety effects of signal spacing and street network pattern were estimated for this study based on 118 meso-level units obtained from 21 urban arterials in Shanghai, and were examined using CAR (conditional auto regressive) models that corrected for spatial correlation among the units within individual arterials. Results showed shorter arterial signal spacing was associated with higher total and PDO (property damage only) crashes, while arterials with a greater number of parallel roads were associated with lower total, PDO, and injury crashes. The findings from this study can be used in the traffic safety planning, design, and management of urban arterials. Copyright © 2017 Elsevier Ltd. All rights reserved.
Assessment of statewide intersection safety performance.
DOT National Transportation Integrated Search
2011-06-01
This report summarizes the results of an analysis of the safety performance of Oregons intersections. Following a pilot : study, a database of 500 intersections randomly sampled from around the state of Oregon in both urban and rural : environment...
Wind tunnel measurements of pollutant turbulent fluxes in urban intersections
NASA Astrophysics Data System (ADS)
Carpentieri, Matteo; Hayden, Paul; Robins, Alan G.
2012-01-01
Wind tunnel experiments have been carried out at the EnFlo laboratory to measure mean and turbulent tracer fluxes in geometries of real street canyon intersections. The work was part of the major DAPPLE project, focussing on the area surrounding the intersection between Marylebone Road and Gloucester Place in Central London, UK. Understanding flow and dispersion in urban streets is a very important issue for air quality management and planning, and turbulent mass exchange processes are important phenomena that are very often neglected in urban modelling studies. The adopted methodology involved the combined use of laser Doppler anemometry and tracer concentration measurements. This methodology was applied to quantify the mean and turbulent flow and dispersion fields within several street canyon intersections. Vertical profiles of turbulent tracer flux were also measured. The technique, despite a number of limitations, proved reliable and allowed tracer balance calculations to be undertaken in the selected street canyon intersections. The experience gained in this work will enable much more precise studies in the future as issues affecting the accuracy of the experimental technique have been identified and resolved.
Gauvin, Lise; Plante, Céline; Fournier, Michel; Morency, Catherine
2012-01-01
Objectives. We examined the extent to which differential traffic volume and road geometry can explain social inequalities in pedestrian, cyclist, and motor vehicle occupant injuries across wealthy and poor urban areas. Methods. We performed a multilevel observational study of all road users injured over 5 years (n = 19 568) at intersections (n = 17 498) in a large urban area (Island of Montreal, Canada). We considered intersection-level (traffic estimates, major roads, number of legs) and area-level (population density, commuting travel modes, household income) characteristics in multilevel Poisson regressions that nested intersections in 506 census tracts. Results. There were significantly more injured pedestrians, cyclists, and motor vehicle occupants at intersections in the poorest than in the richest areas. Controlling for traffic volume, intersection geometry, and pedestrian and cyclist volumes greatly attenuated the event rate ratios between intersections in the poorest and richest areas for injured pedestrians (−70%), cyclists (−44%), and motor vehicle occupants (−44%). Conclusions. Roadway environment can explain a substantial portion of the excess rate of road traffic injuries in the poorest urban areas. PMID:22515869
An analysis of urban collisions using an artificial intelligence model.
Mussone, L; Ferrari, A; Oneta, M
1999-11-01
Traditional studies on road accidents estimate the effect of variables (such as vehicular flows, road geometry, vehicular characteristics), and the calculation of the number of accidents. A descriptive statistical analysis of the accidents (those used in the model) over the period 1992-1995 is proposed. The paper describes an alternative method based on the use of artificial neural networks (ANN) in order to work out a model that relates to the analysis of vehicular accidents in Milan. The degree of danger of urban intersections using different scenarios is quantified by the ANN model. Methodology is the first result, which allows us to tackle the modelling of urban vehicular accidents by the innovative use of ANN. Other results deal with model outputs: intersection complexity may determine a higher accident index depending on the regulation of intersection. The highest index for running over of pedestrian occurs at non-signalised intersections at night-time.
DOT National Transportation Integrated Search
2015-04-01
This research examined the safety and operational effects of roadway lane width on mid-block segments between : signalized intersections as well as on signalized intersection approaches in the urban environments of Lincoln and Omaha, : Nebraska. In t...
Air quality assessment at a congested urban intersection
DOT National Transportation Integrated Search
2000-09-01
The deficient transportation system of Beirut results in significant economic losses for the city and causes severe traffic congestion in the urban areas. Proposals have been made for grade separations at some of the worst congested intersections. Th...
Evaluation of Urban Freight Deliveries using Microsimulation and Surrogate Safety Measures
DOT National Transportation Integrated Search
2018-02-01
Freight deliveries on signalized urban streets are known to cause lane blockages during deliveries. When delivery vehicles block lanes of traffic near signalized intersections, the capacity of the intersection is affected. Current practice is for tra...
Sustainable intersection control to accommodate urban freight mobility.
DOT National Transportation Integrated Search
2009-08-01
In this research, we studied green extension of a two-phased vehicleactuated signal at an isolated : intersection between two one-way streets. The green phase is extended by a preset time interval, referred to : as critical gap, from the time of a...
A speed guidance strategy for multiple signalized intersections based on car-following model
NASA Astrophysics Data System (ADS)
Tang, Tie-Qiao; Yi, Zhi-Yan; Zhang, Jian; Wang, Tao; Leng, Jun-Qiang
2018-04-01
Signalized intersection has great roles in urban traffic system. The signal infrastructure and the driving behavior near the intersection are paramount factors that have significant impacts on traffic flow and energy consumption. In this paper, a speed guidance strategy is introduced into a car-following model to study the driving behavior and the fuel consumption in a single-lane road with multiple signalized intersections. The numerical results indicate that the proposed model can reduce the fuel consumption and the average stop times. The findings provide insightful guidance for the eco-driving strategies near the signalized intersections.
DOT National Transportation Integrated Search
2011-12-01
Pedestrian countdown timers are becoming common at urban and suburban intersections. The added information that : pedestrian countdown timers provide to pedestrians can also be used by approaching drivers. A before-and-after case study : on the effec...
Multiliteracies and Family Language Policy in an Urban Inuit Community
ERIC Educational Resources Information Center
Patrick, Donna; Budach, Gabriele; Muckpaloo, Igah
2013-01-01
This study investigates the intersection of family language policy with Indigenous multiliteracies and urban Indigeneity. It documents a grassroots Inuit literacy initiative in Ottawa, Canada and considers literacy practices among Inuit at a local Inuit educational centre, where maintaining connections between urban Inuit and their homeland…
Project SisterCircle: Risk, Intersectionality, and Intervening in Urban Schools
ERIC Educational Resources Information Center
Williams, Wendi; Karlin, Thomas; Wallace, Deidre
2012-01-01
Adolescent Black/African descent and Latina girls in urban environments are at heightened risk for the negative consequences of sexual risk. Intervention programming that accounts for the intersection of adolescent girls' racial/ethnic cultural experiences and gender are likely to be most effective in minimizing their vulnerability for sexual…
Improved traffic operations through real-time data collection and control.
DOT National Transportation Integrated Search
2016-05-01
Intersections are a major source of delay in urban networks, and reservation-based intersection control for : autonomous vehicles has great potential to improve intersection throughput. However, despite the high : flexibility in reservations, existin...
Time-series analysis to study the impact of an intersection on dispersion along a street canyon.
Richmond-Bryant, Jennifer; Eisner, Alfred D; Hahn, Intaek; Fortune, Christopher R; Drake-Richman, Zora E; Brixey, Laurie A; Talih, M; Wiener, Russell W; Ellenson, William D
2009-12-01
This paper presents data analysis from the Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) study to assess the transport of ultrafine particulate matter (PM) across urban intersections. Experiments were performed in a street canyon perpendicular to a highway in Brooklyn, NY, USA. Real-time ultrafine PM samplers were positioned on either side of an intersection at multiple locations along a street to collect time-series number concentration data. Meteorology equipment was positioned within the street canyon and at an upstream background site to measure wind speed and direction. Time-series analysis was performed on the PM data to compute a transport velocity along the direction of the street for the cases where background winds were parallel and perpendicular to the street. The data were analyzed for sampler pairs located (1) on opposite sides of the intersection and (2) on the same block. The time-series analysis demonstrated along-street transport, including across the intersection when background winds were parallel to the street canyon and there was minimal transport and no communication across the intersection when background winds were perpendicular to the street canyon. Low but significant values of the cross-correlation function (CCF) underscore the turbulent nature of plume transport along the street canyon. The low correlations suggest that flow switching around corners or traffic-induced turbulence at the intersection may have aided dilution of the PM plume from the highway. This observation supports similar findings in the literature. Furthermore, the time-series analysis methodology applied in this study is introduced as a technique for studying spatiotemporal variation in the urban microscale environment.
Dong, Chunjiao; Clarke, David B; Richards, Stephen H; Huang, Baoshan
2014-01-01
The influence of intersection features on safety has been examined extensively because intersections experience a relatively large proportion of motor vehicle conflicts and crashes. Although there are distinct differences between passenger cars and large trucks-size, operating characteristics, dimensions, and weight-modeling crash counts across vehicle types is rarely addressed. This paper develops and presents a multivariate regression model of crash frequencies by collision vehicle type using crash data for urban signalized intersections in Tennessee. In addition, the performance of univariate Poisson-lognormal (UVPLN), multivariate Poisson (MVP), and multivariate Poisson-lognormal (MVPLN) regression models in establishing the relationship between crashes, traffic factors, and geometric design of roadway intersections is investigated. Bayesian methods are used to estimate the unknown parameters of these models. The evaluation results suggest that the MVPLN model possesses most of the desirable statistical properties in developing the relationships. Compared to the UVPLN and MVP models, the MVPLN model better identifies significant factors and predicts crash frequencies. The findings suggest that traffic volume, truck percentage, lighting condition, and intersection angle significantly affect intersection safety. Important differences in car, car-truck, and truck crash frequencies with respect to various risk factors were found to exist between models. The paper provides some new or more comprehensive observations that have not been covered in previous studies. Copyright © 2013 Elsevier Ltd. All rights reserved.
Research notes : adjustment of driver behavior to an urban multilane roundabout.
DOT National Transportation Integrated Search
2007-06-01
In June of 2006, the City of Springfield, Oregon began construction of the first multi-lane urban roundabout in Oregon. The five-legged roundabout replaced an existing T intersection that was controlled by a traffic light. A study was conducted...
Safety analysis of urban signalized intersections under mixed traffic.
S, Anjana; M V L R, Anjaneyulu
2015-02-01
This study examined the crash causative factors of signalized intersections under mixed traffic using advanced statistical models. Hierarchical Poisson regression and logistic regression models were developed to predict the crash frequency and severity of signalized intersection approaches. The prediction models helped to develop general safety countermeasures for signalized intersections. The study shows that exclusive left turn lanes and countdown timers are beneficial for improving the safety of signalized intersections. Safety is also influenced by the presence of a surveillance camera, green time, median width, traffic volume, and proportion of two wheelers in the traffic stream. The factors that influence the severity of crashes were also identified in this study. As a practical application, the safe values of deviation of green time provided from design green time, with varying traffic volume, is presented in this study. This is a useful tool for setting the appropriate green time for a signalized intersection approach with variations in the traffic volume. Copyright © 2014 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Swartz, Leslie, Ed.; Warner, Linda, Ed.; Grossman, David L., Ed.
This publication presents a sampling of the writings of participants in the Intersections Project, a professional development program to bridge gap between multicultural and global education for urban schools that involved four participating entities, each with a local project that focused on Asia and Asian Americans. The project was specifically…
The trend of road traffic crashes at urban signalised intersection
NASA Astrophysics Data System (ADS)
Farhana Nasarrudin, Nurul; Razelan, Intan Suhana Mohd
2018-04-01
Road traffic crash is one of the main contributing factors for deaths in the world. Intersection is listed as the second road type which road crashes occurred frequently. Hence, the traffic light was installed to minimise the road crashes at intersection. However, the crashes are still occurring and arising. The objective of this study was to exhibit the trend of road crashes at the signalised intersections. The data of road crashes for the past 6 years were analysed using descriptive analysis. The results showed that the road traffic crashes at three- and four-legged signalised intersection recorded the increasing trend. In conclusion, this finding shows that the road traffic crashes for these types of signalised intersection in Malaysia is rising. It is also one the contributors to the increasing number of crashes in Malaysia. This finding will encourage the local authority to conduct awareness programs on the safety at the signalised intersection.
Evaluating the Safety In Numbers effect for pedestrians at urban intersections.
Murphy, Brendan; Levinson, David M; Owen, Andrew
2017-09-01
Assessment of collision risk between pedestrians and automobiles offers a powerful and informative tool in urban planning applications, and can be leveraged to inform proper placement of improvements and treatment projects to improve pedestrian safety. Such assessment can be performed using existing datasets of crashes, pedestrian counts, and automobile traffic flows to identify intersections or corridors characterized by elevated collision risks to pedestrians. The Safety In Numbers phenomenon, which refers to the observable effect that pedestrian safety is positively correlated with increased pedestrian traffic in a given area (i.e. that the individual per-pedestrian risk of a collision decreases with additional pedestrians), is a readily observed phenomenon that has been studied previously, though its directional causality is not yet known. A sample of 488 intersections in Minneapolis were analyzed, and statistically-significant log-linear relationships between pedestrian traffic flows and the per-pedestrian crash risk were found, indicating the Safety In Numbers effect. Potential planning applications of this analysis framework towards improving pedestrian safety in urban environments are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.
Three-Dimensional Mapping of Air Flow at an Urban Canyon Intersection
NASA Astrophysics Data System (ADS)
Carpentieri, Matteo; Robins, Alan G.; Baldi, Sandro
2009-11-01
In this experimental work both qualitative (flow visualisation) and quantitative (laser Doppler anemometry) methods were applied in a wind tunnel in order to describe the complex three-dimensional flow field in a real environment (a street canyon intersection). The main aim was an examination of the mean flow, turbulence and flow pathlines characterising a complex three-dimensional urban location. The experiments highlighted the complexity of the observed flows, particularly in the upwind region of the intersection. In this complex and realistic situation some details of the upwind flow, such as the presence of two tall towers, play an important role in defining the flow field within the intersection, particularly at roof level. This effect is likely to have a strong influence on the mass exchange mechanism between the canopy flow and the air aloft, and therefore the distribution of pollutants. This strong interaction between the flows inside and outside the urban canopy is currently neglected in most state-of-the-art local scale dispersion models.
Salmon, Paul M; Lenne, Michael G; Walker, Guy H; Stanton, Neville A; Filtness, Ashleigh
2014-01-01
Collisions between different types of road users at intersections form a substantial component of the road toll. This paper presents an analysis of driver, cyclist, motorcyclist and pedestrian behaviour at intersections that involved the application of an integrated suite of ergonomics methods, the Event Analysis of Systemic Teamwork (EAST) framework, to on-road study data. EAST was used to analyse behaviour at three intersections using data derived from an on-road study of driver, cyclist, motorcyclist and pedestrian behaviour. The analysis shows the differences in behaviour and cognition across the different road user groups and pinpoints instances where this may be creating conflicts between different road users. The role of intersection design in creating these differences in behaviour and resulting conflicts is discussed. It is concluded that currently intersections are not designed in a way that supports behaviour across the four forms of road user studied. Interventions designed to improve intersection safety are discussed. Practitioner Summary: Intersection safety currently represents a key road safety issue worldwide. This paper presents a novel application of a framework of ergonomics methods for studying differences in road user behaviour at intersections. The findings support development of interventions that consider all road users as opposed to one group in isolation.
Ghavami, Negin; Peplau, Letitia Anne
2018-05-01
Heterosexual urban middle school students' (N = 1,757) stereotypes about gender typicality, intelligence, and aggression were assessed. Students (M age = 12.36 years) rated Facebook-like profiles of peers who varied by gender, ethnicity, and sexual orientation. Several hypotheses about how the gender, ethnicity, and sexual orientation of target peers intersect to shape stereotypes were tested. As predicted, a peer's sexual orientation determined stereotypes of gender typicality, with gay and lesbian students viewed as most atypical. As expected, ethnicity shaped stereotypes of intelligence, with Asian American students seen as most intelligent. Gender, ethnicity, and sexual orientation independently and jointly affected stereotypes of aggression. These results demonstrate the value of an intersectional approach to the study of stereotypes. Implications for future research and practice are offered. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.
Chen, Chen; Xie, Yuanchang
2016-06-01
Annual Average Daily Traffic (AADT) is often considered as a main covariate for predicting crash frequencies at urban and suburban intersections. A linear functional form is typically assumed for the Safety Performance Function (SPF) to describe the relationship between the natural logarithm of expected crash frequency and covariates derived from AADTs. Such a linearity assumption has been questioned by many researchers. This study applies Generalized Additive Models (GAMs) and Piecewise Linear Negative Binomial (PLNB) regression models to fit intersection crash data. Various covariates derived from minor-and major-approach AADTs are considered. Three different dependent variables are modeled, which are total multiple-vehicle crashes, rear-end crashes, and angle crashes. The modeling results suggest that a nonlinear functional form may be more appropriate. Also, the results show that it is important to take into consideration the joint safety effects of multiple covariates. Additionally, it is found that the ratio of minor to major-approach AADT has a varying impact on intersection safety and deserves further investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.
DOT National Transportation Integrated Search
2011-03-01
This report analyzes data from the 2006-2007 Oregon Road User Fee Pilot Program to assess if and how urban form variables correlate with travel behavior changes that participants made in response to the mileage fee program. The study tested the impac...
ERIC Educational Resources Information Center
McCready, Lance T.
2010-01-01
What's it like for Black male students who are openly gay or "gender non-conforming" to navigate the social geography of urban schools? In the tradition of critical ethnographies of schooling, Lance T. McCready mobilizes feminist theories of intersectionality to explore the voices of Black gay male students and their teachers in a…
The impact of iterated games on traffic flow at noncontrolled intersections
NASA Astrophysics Data System (ADS)
Zhao, Chao; Jia, Ning
2015-05-01
Intersections without signal control widely exist in urban road networks. This paper studied the traffic flow in a noncontrolled intersection within an iterated game framework. We assume drivers have learning ability and can repetitively adjust their strategies (to give way or to rush through) in the intersection according to memories. A cellular automata model is applied to investigate the characteristics of the traffic flow. Numerical experiments indicate two main findings. First, the traffic flow experiences a "volcano-shaped" fundamental diagram with three different phases. Second, most drivers choose to give way in the intersection, but the aggressive drivers cannot be completely eliminated, which is coincident with field observations. Analysis are also given out to explain the observed phenomena. These findings allow deeper insight of the real-world bottleneck traffic flow.
ERIC Educational Resources Information Center
Gastic, Billie
2012-01-01
This study examined the association between having a gay or lesbian friend and urban students' attitudes about sexual minorities. Results indicate that females were more likely than males to express supportive views about gays and lesbians. The contours of these sex differences were distinct by race/ethnicity. Black males and females differed more…
At the cross-roads: an on-road examination of driving errors at intersections.
Young, Kristie L; Salmon, Paul M; Lenné, Michael G
2013-09-01
A significant proportion of road trauma occurs at intersections. Understanding the nature of driving errors at intersections therefore has the potential to lead to significant injury reductions. To further understand how the complexity of modern intersections shapes behaviour of these errors are compared to errors made mid-block, and the role of wider systems failures in intersection error causation is investigated in an on-road study. Twenty-five participants drove a pre-determined urban route incorporating 25 intersections. Two in-vehicle observers recorded the errors made while a range of other data was collected, including driver verbal protocols, video, driver eye glance behaviour and vehicle data (e.g., speed, braking and lane position). Participants also completed a post-trial cognitive task analysis interview. Participants were found to make 39 specific error types, with speeding violations the most common. Participants made significantly more errors at intersections compared to mid-block, with misjudgement, action and perceptual/observation errors more commonly observed at intersections. Traffic signal configuration was found to play a key role in intersection error causation, with drivers making more errors at partially signalised compared to fully signalised intersections. Copyright © 2012 Elsevier Ltd. All rights reserved.
Development of next generation intersection control.
DOT National Transportation Integrated Search
2013-03-01
A reservation-based autonomous intersection control system, named Autonomous Control of Urban : TrAffic (ACUTA), was developed as a part of this research effort. ACUTA allows centralized management : of autonomous vehicles within a certain distance f...
Mori, Midori; Horino, Sadao; Kitajima, Sou; Ueyama, Masaru; Ebara, Takeshi; Itani, Toru
2008-11-01
This paper aims to assess quantitatively the actual visual environment of uncontrolled urban downtown intersections in Japan in relation to frequently occurring crossing collisions and to discuss the safety countermeasures for them. In Field Study 1 dealing with direct visibility, our ultra-wide-angle photograph analysis revealed that most of the right/left-ward visible range at 11 intersections were insufficient to check safety, and the quality of direct visibility was closely associated with causing crossing collisions. The countermeasures to reduce a blind area were determined to be a top priority. In Field Study 2 dealing with indirect visibility, more than half of the 25 traffic convex mirrors had marked shortcomings for preventive safety, and ergonomics guidelines ensuring indirect visibility were proposed for installing traffic convex mirrors. Low-cost/low-technology-oriented countermeasures are highly recommended to obtain clear/sufficient images of crucial information satisfying drivers' requirements on traffic convex mirrors in accordance with those ergonomics guidelines was highly recommended. Crossing collisions could be prevented by improvement of poor direct and indirect visibility.
Bar-Gera, H; Musicant, O; Schechtman, E; Ze'evi, T
2016-11-01
The yellow signal driver behavior, reflecting the dilemma zone behavior, is analyzed using naturalistic data from digital enforcement cameras. The key variable in the analysis is the entrance time after the yellow onset, and its distribution. This distribution can assist in determining two critical outcomes: the safety outcome related to red-light-running angle accidents, and the efficiency outcome. The connection to other approaches for evaluating the yellow signal driver behavior is also discussed. The dataset was obtained from 37 digital enforcement cameras at non-urban signalized intersections in Israel, over a period of nearly two years. The data contain more than 200 million vehicle entrances, of which 2.3% (∼5million vehicles) entered the intersection during the yellow phase. In all non-urban signalized intersections in Israel the green phase ends with 3s of flashing green, followed by 3s of yellow. In most non-urban signalized roads in Israel the posted speed limit is 90km/h. Our analysis focuses on crossings during the yellow phase and the first 1.5s of the red phase. The analysis method consists of two stages. In the first stage we tested whether the frequency of crossings is constant at the beginning of the yellow phase. We found that the pattern was stable (i.e., the frequencies were constant) at 18 intersections, nearly stable at 13 intersections and unstable at 6 intersections. In addition to the 6 intersections with unstable patterns, two other outlying intersections were excluded from subsequent analysis. Logistic regression models were fitted for each of the remaining 29 intersection. We examined both standard (exponential) logistic regression and four parameters logistic regression. The results show a clear advantage for the former. The estimated parameters show that the time when the frequency of crossing reduces to half ranges from1.7 to 2.3s after yellow onset. The duration of the reduction of the relative frequency from 0.9 to 0.1 ranged from 1.9 to 2.9s. Copyright © 2015 Elsevier Ltd. All rights reserved.
Traffic Feasibility Study for a Grade Separator at a Busy Intersection in Vellore
NASA Astrophysics Data System (ADS)
Vasantha Kumar, S.; Gulati, Himanshu; Arora, Shivam
2017-11-01
One of the byproduct of urbanization is traffic congestion and before suggesting any solutions to reduce congestion, understanding the present context becomes very important. Study of traffic volumes at busy intersections to find the percentage composition of different vehicle types, directional distribution and peak hour traffic volume is a first step towards understanding the present context of traffic. Hence in the present study, one of the busy intersections in Vellore, namely, Gandhi nagar intersection in Vellore-Katpadi road was selected and traffic flow data was collected using video surveys. It was found that at the selected intersection, the two wheelers and three wheelers alone share 80% of the total traffic when compared to other vehicle types. Nearly 700 trucks and multi axle trailers were observed to pass through the intersection during the analysis period of five hours. That is, on an average 2 trucks/multi axle trailers were passing through the intersection in each minute. As like in other major cities, entry of trucks and other heavy vehicles such as multi axle trailers into the city needs to be banned during peak hours for smooth flow of traffic within city limits. A highest hourly volume of 6939 PCU’s was observed between 4 and 5 pm at the selected intersection. By assuming a 10% uniform traffic growth every year, it was found that after about 4 years, i.e., in 2019, the traffic volume at the intersection may reach 10,000 PCU’s and may warrant for a grade separator or interchange at the intersection.
Development of warrants for installation of dual right-turn lanes at signalized intersections.
DOT National Transportation Integrated Search
2012-04-01
Right-turn lanes provide space for the deceleration and storage of right-turn vehicles, and separate turning vehicles : from through movements. Dual right-turn lanes are increasingly used at urban intersections primarily for two : reasons: (1) to acc...
ERIC Educational Resources Information Center
Cahill, Kevin
2018-01-01
This paper draws on a three-year critical ethnography which interrogated intersections of social class, school and identity in an urban Irish community. The focus here is on the psycho-spatial disidentifications, inscriptions and class fractioning enacted throughout the school and community of Portown by a cohort of succeeding students from this…
The research of single intersection sensor signal control based on section data
NASA Astrophysics Data System (ADS)
Liu, Yunxiang; Huang, Yue; Wang, Hao
2016-12-01
Propose a sensing signal intersection control design electronic license based on the design by setting the intersection readers to interact with active electronic tags equipped vehicles, vehicle information obtained on the road section. In the vehicle detection sensor may control the green density as evaluation criteria are extended when the vehicle is higher than the threshold, the green density continuity, whereas the switching phases. Induction showed improved control strategy can achieve real-time traffic signal control effectively in high saturation intersection, to overcome the traditional sensor control failure at high saturation drawbacks and improve the utilization of urban Intersection comparative analysis by simulation.
Intersectional inequalities in immunization in India, 1992-93 to 2005-06: a progress assessment.
Joe, William
2015-05-01
Immunization in India is marked with stark disparities across gender, caste, wealth and place of residence with severe shortfalls among those disadvantaged in more than one dimension. In this regard, an explicit recognition of intersectionality and intersectional inequalities has 2-fold relevance; one, being the pathway of health inequality and the other being its role as a deterrent of progress particularly at higher (better) levels of health. Against this backdrop, this study examines intersectional inequalities in immunization in India and also suggests a level-sensitive progress assessment method. The study uses group analogue of Gini coefficient for highlighting the magnitude of intersectional inequality and for comprehending its association with immunization level. The results unravel the plight of vulnerable intersectional groups and draw attention to disquieting shortfalls among female SCST (scheduled castes and tribes) children from rural areas. There is also some evidence to indicate leveraging among rural males in matters of immunization and it is further discerned that such gender advantage is greater among rural non-SCST community than the rural SCST group. In concluding, the study calls for intensive immunization planning to improve coverage among vulnerable communities in both rural and urban areas. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2014; all rights reserved.
NASA Astrophysics Data System (ADS)
Bargegol, Iraj; Hamze Hosseini, Seyyed; Jahangir Samet, Mehdi
2017-10-01
Nowadays, urban roundabouts are one of the most popular types of intersections that have grown highly all over the world. Thus, the accurate and engineering design of these types of intersections has a significant effect on improving their traffic performance. The capacity is one of the important traffic parameters in different intersections, which represents the maximum volume of vehicles entering the roundabouts. There are two general methods for determining the capacity of intersections including the use of analytical models such as gap acceptance model and the use of empirical methods (regression model). In the present paper, using the collected data such as entry and circulating volume, both accepted and rejected gaps were studied for three urban roundabouts and the capacity model have been determined by the use of analytical method. After implementation of the data, they became consistent and homogeneous in four different groups and the most optimized range of critical gaps as well as the follow up time were separately determined for each of these groups by using conventional methods such as Sigloch, Raff, Wu, and Harder and according to statistical analyses with a confidence level of 95%. From the obtained results, a range of 3.03 - 3.32 s for critical gap of the studied roundabouts and the range of 1.3 - 1.7 s for follow up time could be mentioned. It was used from the theory of gap acceptance in order to determine urban roundabouts capacity model, in which these gaps have a random nature and follow negative exponential distribution and by conducting this analysis (also has been used by Sigloch), some relations were obtained for determining the capacity of the roundabouts according to the impact of circulating volume and drivers’ behaviour. The results indicate that the maximum capacity of the roundabouts in the microscopic models is equal to 2400 veh/h, when the circulating flow rate is reached zero. Moreover, according to the obtained capacity model, the circulating flow never falls down to zero in the case that it reaches its peak value.
Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner.
An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai
2016-07-20
There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation.
Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner
An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai
2016-01-01
There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation. PMID:27447640
Wang, Jung-Han; Abdel-Aty, Mohamed; Wang, Ling
2017-07-01
There have been plenty of studies intended to use different methods, for example, empirical Bayes before-after methods, to get accurate estimation of CMFs. All of them have different assumptions toward crash count if there was no treatment. Additionally, another major assumption is that multiple sites share the same true CMF. Under this assumption, the CMF at an individual intersection is randomly drawn from a normally distributed population of CMFs at all intersections. Since CMFs are non-zero values, the population of all CMFs might not follow normal distributions, and even if it does, the true mean of CMFs at some intersections may be different from that at others. Therefore, a bootstrap method based on before-after empirical Bayes theory was proposed to estimate CMFs, but it did not make distributional assumptions. This bootstrap procedure has the added benefit of producing a measure of CMF stability. Furthermore, based on the bootstrapped CMF, a new CMF precision rating method was proposed to evaluate the reliability of CMFs. This study chose 29 urban four-legged intersections as treated sites, and their controls were changed from stop-controlled to signal-controlled. Meanwhile, 124 urban four-legged stop-controlled intersections were selected as reference sites. At first, different safety performance functions (SPFs) were applied to five crash categories, and it was found that each crash category had different optimal SPF form. Then, the CMFs of these five crash categories were estimated using the bootstrap empirical Bayes method. The results of the bootstrapped method showed that signalization significantly decreased Angle+Left-Turn crashes, and its CMF had the highest precision. While, the CMF for Rear-End crashes was unreliable. For KABCO, KABC, and KAB crashes, their CMFs were proved to be reliable for the majority of intersections, but the estimated effect of signalization may be not accurate at some sites. Copyright © 2017 Elsevier Ltd. All rights reserved.
DOT National Transportation Integrated Search
2001-04-28
An Institute of Transportation Engineers (ITE) test at 122 standard four-leg intersections in Long Island, NY, shows that retiming the length of the yellow/red phases of traffic signals can reduce serious and reportable accidents ($1,000-plus damage ...
Numerical simulation on pollutant dispersion from vehicle exhaust in street configurations.
Yassin, Mohamed F; Kellnerová, R; Janour, Z
2009-09-01
The impact of the street configurations on pollutants dispersion from vehicles exhausts within urban canyons was numerically investigated using a computational fluid dynamics (CFD) model. Three-dimensional flow and dispersion of gaseous pollutants were modeled using standard kappa - epsilon turbulence model, which was numerically solved based on Reynolds-averaged Navier-Stokes equations by the commercial CFD code FLUENT. The concentration fields in the urban canyons were examined in three cases of street configurations: (1) a regular-shaped intersection, (2) a T-shaped intersection and (3) a Skew-shaped crossing intersection. Vehicle emissions were simulated as double line sources along the street. The numerical model was validated against wind tunnel results in order to optimize the turbulence model. Numerical predictions agreed reasonably well with wind tunnel results. The results obtained indicate that the mean horizontal velocity was very small in the center near the lower region of street canyon. The lowest turbulent kinetic energy was found at the separation and reattachment points associated with the corner of the down part of the upwind and downwind buildings in the street canyon. The pollutant concentration at the upwind side in the regular-shaped street intersection was higher than that in the T-shaped and Skew-shaped street intersections. Moreover, the results reveal that the street intersections are important factors to predict the flow patterns and pollutant dispersion in street canyon.
Adaptive Urban Signal Control and Integration (AUSCI) : evaluation final report
DOT National Transportation Integrated Search
2000-10-01
This report presents an evaluation of the Adaptive Urban Signal Control and Integration (AUSCI) Intelligent Transportation System (ITS) Field Operational Test in Minneapolis, Minnesota. The project involved a 56-intersection portion of Minneapolis, e...
Child safety seat and safety belt use among urban travelers.
DOT National Transportation Integrated Search
1984-01-01
During nine days in June 1977 and nine in June 1983, four major metropolitan areas of Virginia were surveyed to determine whether safety restraints were being used by urban travelers. Observers stationed at selected signalized intersections displayed...
Wu, Lina; Ci, Yusheng; Chu, Jiangwei; Zhang, Hongsheng
2015-01-01
The calculating method for fuel consumption (FC) was put forward and calibrated and the characteristics of the fuel consumption on intersections were analyzed based on 18 groups of vehicular operating data which were acquired from the test experiment of a single vehicle along the urban arterial roads in Harbin, China. The results obtained show that 50.36% of the fuel consumption for the test vehicle was used at the area of intersections compared with 28.9% of the influencing distance and 68.5% of the running time; and 78.4% of them was burnt at the stages of acceleration and idling. Meanwhile, the type (c) of the vehicular operating status was illustrated to be the worst way of reducing fuel consumption, the causes were analyzed and four improvement strategies were put forward. PMID:26367012
Adjustment of driver behavior to an urban multi-lane roundabout.
DOT National Transportation Integrated Search
2007-05-01
In the summer of 2006, the city of Springfield, Oregon installed the first urban multi-lane roundabout in the state. It was hypothesized that after installation, speed variability on approaches to the intersection would decrease from the values with ...
2015-01-01
A traditional traffic signal control system is established based on vehicular delay, queue length, saturation and other indicators. However, due to the increasing severity of urban environmental pollution issues and the development of a resource-saving and environmentally friendly social philosophy, the development of low-carbon and energy-efficient urban transport is required. This paper first defines vehicular trajectories and the calculation of vehicular emissions based on VSP. Next, a regression analysis method is used to quantify the relationship between vehicular emissions and delay, and a traffic signal control model is established to reduce emissions and delay using the enumeration method combined with saturation constraints. Finally, one typical intersection of Changchun is selected to verify the model proposed in this paper; its performance efficiency is also compared using simulations in VISSIM. The results of this study show that the proposed model can significantly reduce vehicle delay and traffic emissions simultaneously. PMID:26720095
Lin, Ciyun; Gong, Bowen; Qu, Xin
2015-01-01
A traditional traffic signal control system is established based on vehicular delay, queue length, saturation and other indicators. However, due to the increasing severity of urban environmental pollution issues and the development of a resource-saving and environmentally friendly social philosophy, the development of low-carbon and energy-efficient urban transport is required. This paper first defines vehicular trajectories and the calculation of vehicular emissions based on VSP. Next, a regression analysis method is used to quantify the relationship between vehicular emissions and delay, and a traffic signal control model is established to reduce emissions and delay using the enumeration method combined with saturation constraints. Finally, one typical intersection of Changchun is selected to verify the model proposed in this paper; its performance efficiency is also compared using simulations in VISSIM. The results of this study show that the proposed model can significantly reduce vehicle delay and traffic emissions simultaneously.
DOT National Transportation Integrated Search
2010-07-01
This report documents the results of a study on evaluating three major video imaging vehicle detection systems (VIVDS) currently deployed in Nevadas urban areas. The report first provides a brief review of the features and functions of some major ...
The Intersection of Race, Culture, Language, and Disability: Implications for Urban Education
ERIC Educational Resources Information Center
Blanchett, Wanda J.; Klingner, Janette K.; Harry, Beth
2009-01-01
To date, few researchers have sought to examine the effect of issues of race, culture, language, and disability, let alone to look specifically at the intersection of these issues, as it relates to special education identification, special education service delivery, and students of color's access to an equitable education. Thus, this article will…
ERIC Educational Resources Information Center
Scribner, Samantha M. Paredes; Fernández, Erica
2017-01-01
This article presents results from community-engaged research conducted with Latinx immigrant parents advocating for their students and themselves in and around an urban school engaged in multiple reforms, in a context affected by anti-immigrant policies and sentiments. The authors analyzed the intersection of organizing narratives related to…
Ferlatte, Olivier; Salway, Travis; Hankivsky, Olena; Trussler, Terry; Oliffe, John L; Marchand, Rick
2017-09-08
This study draws from intersectionality to describe variations in recent suicide attempts (RSA) among gay and bisexual men (GBM) across sociodemographics. Using survey data, logistic regression modeling explored RSA in two analytical stages: (1) the individual effects of each sociodemographic were measured; (2) two-way interaction terms between sociodemographics were tested and added to the models created in stage A. In stage A, only education and income achieved significance. In stage B, the study found that (a) education and income interacted significantly such that the odds of RSA increased for those with a lower income and a lower education; (b) sexual orientation and partnership status interacted, resulting in decreased odds among bisexual men in heterosexual partnerships; and (c) income and education interacted with geography; the effects of these variables were significant only among urban men. These findings suggest that GBM are at unequal risk of RSA according to intersecting sociodemographics.
ERIC Educational Resources Information Center
Morgan, Lorraine S.
2011-01-01
Studies continue to reveal major concerns with discipline issues, such as referrals, detentions, and suspensions, involving Latino/Hispanic students. This problem particularly affects immigrant students in urban neighborhoods that may be characterized by high poverty and crime rates. The purpose of this study was to explore the intersection of…
Kukačka, Libor; Nosek, Štĕpán; Kellnerová, Radka; Jurčáková, Klára; Jaňour, Zbyněk
2012-01-01
The objective of this study is to determine processes of pollution ventilation in the X-shaped street intersection in an idealized symmetric urban area for the changing approach flow direction. A unique experimental setup for simultaneous wind tunnel measurement of the flow velocity and the tracer gas concentration in a high temporal resolution is assembled. Advective horizontal and vertical scalar fluxes are computed from averaged measured velocity and concentration data within the street intersection. Vertical advective and turbulent scalar fluxes are computed from synchronized velocity and concentration signals measured in the plane above the intersection. All the results are obtained for five approach flow directions. The influence of the approach flow on the advective and turbulent fluxes is determined. The contribution of the advective and turbulent flux to the ventilation is discussed. Wind direction with the best dispersive conditions in the area is found. The quadrant analysis is applied to the synchronized signals of velocity and concentration fluctuation to determine events with the dominant contribution to the momentum flux and turbulent scalar flux. PMID:22649290
Kukačka, Libor; Nosek, Štĕpán; Kellnerová, Radka; Jurčáková, Klára; Jaňour, Zbyněk
2012-01-01
The objective of this study is to determine processes of pollution ventilation in the X-shaped street intersection in an idealized symmetric urban area for the changing approach flow direction. A unique experimental setup for simultaneous wind tunnel measurement of the flow velocity and the tracer gas concentration in a high temporal resolution is assembled. Advective horizontal and vertical scalar fluxes are computed from averaged measured velocity and concentration data within the street intersection. Vertical advective and turbulent scalar fluxes are computed from synchronized velocity and concentration signals measured in the plane above the intersection. All the results are obtained for five approach flow directions. The influence of the approach flow on the advective and turbulent fluxes is determined. The contribution of the advective and turbulent flux to the ventilation is discussed. Wind direction with the best dispersive conditions in the area is found. The quadrant analysis is applied to the synchronized signals of velocity and concentration fluctuation to determine events with the dominant contribution to the momentum flux and turbulent scalar flux.
NOx profile around a signalized intersection of busy roadway
NASA Astrophysics Data System (ADS)
Kim, Kyung Hwan; Lee, Seung-Bok; Woo, Sung Ho; Bae, Gwi-Nam
2014-11-01
The NOx pollution profile around a signalized intersection of a busy roadway was investigated to understand the effect of traffic control on urban air pollution. Traffic flow patterns were classified into three categories of quasi-cruising, a combination of deceleration and acceleration, and a combination of deceleration, idling, and acceleration. The spatial distribution of air pollution levels around an intersection could be represented as a quasi-normal distribution, whose peak height was aggravated by increased emissions due to transient driving patterns. The peak concentration of NOx around the signalized intersection for the deceleration, idling, and acceleration category was five times higher than that for the quasi-cruising category. Severe levels of NOx pollution tailed off approximately 400 m from the center of the intersection. Approximately 200-1000 ppb of additional NOx was observed when traffic was decelerating, idling, and accelerating within the intersection zone, resulting in high exposure levels for pedestrians around the intersection. We propose a fluctuating horizontal distribution of motor vehicle-induced air pollutants as a function of time.
DOT National Transportation Integrated Search
2016-09-30
field study was performed at 40 uncontrolled midblock crosswalks and 26 signalized intersections on low-speed roadways selected from the areas surrounding three major urban college campuses across lower Michigan. An array of existing traffic control ...
Poverty and elimination of urban health disparities: challenge and opportunity.
Thomas, Stephen B; Quinn, Sandra Crouse
2008-01-01
The aim of this article is to examine the intersection of race and poverty, two critical factors fueling persistent racial and ethnic health disparities among urban populations. From the morass of social determinants that shape the health of racial and ethnic communities in our urban centers, we will offer promising practices and potential solutions to eliminating racial and ethnic health disparities.
Child safety seat and safety belt use among urban travelers : results of the 1985 survey.
DOT National Transportation Integrated Search
1986-01-01
During nine days in June 1983, 1984, and 1985, four major metropolitan areas of Virginia were surveyed to determine the extent to which safety restraints were being used by urban travelers. Observers stationed at selected signalized intersections dis...
Child safety seat and safety belt use among urban travelers : results of the 1983-1986 surveys.
DOT National Transportation Integrated Search
1986-01-01
The four major metropolitan areas of Virginia were surveyed to determine the extent to which safety restraints were being used by urban travelers. Observers were stationed at selected signalized intersections and displayed to stopped motorists a clip...
Child safety seat and safety belt use among urban travelers : results of the 1984 survey.
DOT National Transportation Integrated Search
1985-01-01
During nine days in June 1983 and nine in June 1984, four major metropolitan areas of Virginia were surveyed to determine whether safety restraints were being used by urban travelers. Observers stationed at selected signalized intersections displayed...
Literacy as Social Action in City Debate
ERIC Educational Resources Information Center
Cridland-Hughes, Susan
2012-01-01
This study examines critical literacy and the intersections of oral, aural, written, and performative literate practices in City Debate, an afterschool program dedicated to providing debate instruction to students in a major Southeastern city. Previous research into definitions and beliefs about literacy in an urban debate program over its twenty…
Choi, Wonsik; Ranasinghe, Dilhara; DeShazo, J R; Kim, Jae-Jin; Paulson, Suzanne E
2018-02-01
Epidemiological studies have shown that exposure to traffic-related pollutants increases incidence of adverse health outcomes. Transit users in cities across the globe commonly spend 15-45 min or more waiting at transit stops each day, often at locations with high levels of pollution from traffic. Here, we investigate the characteristics of concentration profiles of ultrafine particles (UFP) with 5 m spatial resolution across intersections, to determine the best place to site transit stops to minimize exposures. Cross-intersection UFP profiles were derived from 1744 profiles covering 90 m before and after each intersection center with a mobile monitoring platform. Measurements were made at 10 signalized intersections located at six urban sites, each with a distinct built environment, during both mornings and afternoons. Measurements were made within 1.5 m of the sidewalk and approximately at breathing height (1.5 m above ground level) to approximate sidewalk exposures. UFP profiles were strongly influenced by high emissions from vehicle stops and accelerations, and peaked within 30 m of intersection centers; from there concentrations decreased sharply with distance. Peak concentrations averaged about 90% higher than the minima along the block. They were accompanied by more frequent and larger transient concentration spikes, increasing the chance of people near the intersection being exposed to both short-term extremely high concentration spikes and higher average concentrations. The decays are somewhat larger before the intersection than after the intersection, however as siting transit stops after intersections is preferred for smooth traffic flow, we focus on after the intersection. Simple time-duration exposure calculations combined with breathing rates suggest moving a bus stop from 20 to 40-50 m after the intersection can reduce transit-users' exposure levels to total UFP substantially, in proportion to the reciprocal of the magnitude of elevation at the intersection. Copyright © 2017 Elsevier Ltd. All rights reserved.
Shannon, Geordan D; Motta, Angelica; Cáceres, Carlos F; Skordis-Worrall, Jolene; Bowie, Diana; Prost, Audrey
In the Peruvian Amazon, historical events of colonization and political marginalization intersect with identities of ethnicity, class and geography in the construction of gender and health inequities. Gender-based inequalities can manifest in poor health outcomes via discriminatory practices, healthcare system imbalances, inequities in health research, and differential exposures and vulnerabilities to diseases. Structural violence is a comprehensive framework to explain the mechanisms by which social forces such as poverty, racism and gender inequity become embodied as individual experiences and health outcomes, and thus may be a useful tool in structuring an intersectional analysis of gender and health inequities in Amazonian Peru. The aim of this paper is to explore the intersection of gender inequities with other social inequalities in the production of health and disease in Peru's Amazon using a structural violence approach. Exploratory qualitative research was performed in two Loreto settings - urban Iquitos and the rural Lower Napo River region - between March and November 2015. This included participant observation with prolonged stays in the community, 46 semi-structured individual interviews and three group discussions. Thematic analysis was performed to identify emerging themes related to gender inequalities in health and healthcare and how these intersect with layered social disadvantages in the reproduction of health and illness. We employed a structural violence approach to construct an intersectional analysis of gender and health inequities in Amazonian Peru. Our findings were arranged into five interrelated domains within a gender, structural violence and health model: gender as a symbolic institution, systemic gender-based violence, interpersonal violence, the social determinants of health, and other health outcomes. Each domain represents one aspect of the complex associations between gender, gender inequity and health. Through this model, we were able to explore: gender, health and intersectionality; structural violence; and to highlight particular local gender and health dynamics. Intersecting influences of poverty, ethnicity, geography and gender served as significant barriers to healthcare in both rural and urban settings.
Zangenehpour, Sohail; Strauss, Jillian; Miranda-Moreno, Luis F; Saunier, Nicolas
2016-01-01
Cities in North America have been building bicycle infrastructure, in particular cycle tracks, with the intention of promoting urban cycling and improving cyclist safety. These facilities have been built and expanded but very little research has been done to investigate the safety impacts of cycle tracks, in particular at intersections, where cyclists interact with turning motor-vehicles. Some safety research has looked at injury data and most have reached the conclusion that cycle tracks have positive effects of cyclist safety. The objective of this work is to investigate the safety effects of cycle tracks at signalized intersections using a case-control study. For this purpose, a video-based method is proposed for analyzing the post-encroachment time as a surrogate measure of the severity of the interactions between cyclists and turning vehicles travelling in the same direction. Using the city of Montreal as the case study, a sample of intersections with and without cycle tracks on the right and left sides of the road were carefully selected accounting for intersection geometry and traffic volumes. More than 90h of video were collected from 23 intersections and processed to obtain cyclist and motor-vehicle trajectories and interactions. After cyclist and motor-vehicle interactions were defined, ordered logit models with random effects were developed to evaluate the safety effects of cycle tracks at intersections. Based on the extracted data from the recorded videos, it was found that intersection approaches with cycle tracks on the right are safer than intersection approaches with no cycle track. However, intersections with cycle tracks on the left compared to no cycle tracks seem to be significantly safer. Results also identify that the likelihood of a cyclist being involved in a dangerous interaction increases with increasing turning vehicle flow and decreases as the size of the cyclist group arriving at the intersection increases. The results highlight the important role of cycle tracks and the factors that increase or decrease cyclist safety. Results need however to be confirmed using longer periods of video data. Copyright © 2015 Elsevier Ltd. All rights reserved.
Holly E. Bosley; Gene L. Brothers
2009-01-01
Both tourism researchers and urban planners use the term "tourist bubble" to describe a geographic area in a destination within which visitors operate. However, there is an interdisciplinary disparity in the conceptualization of the tourist bubble. This paper aims to more clearly describe the intersection of tourism and urban planning research, as well as to...
DOT National Transportation Integrated Search
1977-01-01
During nine days in late January 1974, four major metropolitan areas of the state of Virginia were surveyed in an effort to determine seat belt use by urban travelers. Observer-data collectors were stationed at selected signalized intersections. Moto...
DOT National Transportation Integrated Search
1978-01-01
During nine days in June 1977, four major metropolitan areas of the state of Virginia were surveyed to determine seat belt use by summer urban travelers. Observer-data collectors were stationed at selected signalized intersections. Motorists in the l...
Vehicular crash data used to rank intersections by injury crash frequency and severity.
Liu, Yi; Li, Zongzhi; Liu, Jingxian; Patel, Harshingar
2016-09-01
This article contains data on research conducted in "A double standard model for allocating limited emergency medical service vehicle resources ensuring service reliability" (Liu et al., 2016) [1]. The crash counts were sorted out from comprehensive crash records of over one thousand major signalized intersections in the city of Chicago from 2004 to 2010. For each intersection, vehicular crashes were counted by crash severity levels, including fatal, injury Types A, B, and C for major, moderate, and minor injury levels, property damage only (PDO), and unknown. The crash data was further used to rank intersections by equivalent injury crash frequency. The top 200 intersections with the highest number of crash occurrences identified based on crash frequency- and severity-based scenarios are shared in this brief. The provided data would be a valuable source for research in urban traffic safety analysis and could also be utilized to examine the effectiveness of traffic safety improvement planning and programming, intersection design enhancement, incident and emergency management, and law enforcement strategies.
The Intersection of Race and Gender in School Leadership for Three Black Female Principals
ERIC Educational Resources Information Center
Reed, Latish Cherie
2012-01-01
Using four assumptions of Black feminism, this qualitative study describes the practice of three African-American female principals in predominantly African-American, urban high schools. First, in general, the principals seemed to understand their experiences as part of a larger historical context. Second, given the shared racial and gender…
Teaching Urban Ecology: Environmental Studies and the Pedagogy of Intersectionality
ERIC Educational Resources Information Center
Di Chiro, Giovanna
2006-01-01
Despite the recognition by early champions of the environmental movement in the United States that humans and the diverse ecosystems in which they live are indivisible, many environmental education policies and programs have tended to uphold the categorical distinction between "nature" and "culture" (e.g., Sessions; Soule and Press). In the late…
Zhao, Jing; Yun, Meiping; Zhang, H Michael; Yang, Xiaoguang
2015-08-01
With the worsening of urban traffic congestion in large cities around the world, researchers have been looking for unconventional designs and/or controls to squeeze more capacity out of intersections, the most common bottlenecks of the road network. One of these innovative intersection designs, known as the exit-lanes for left-turn (EFL), opens up exit-lanes to be used by left-turn traffic with the help of an additional traffic light installed at the median opening (the pre-signal). This paper studies how drivers respond to EFL intersections with a series of driving simulator experiments. In our experiments, 64 drivers were recruited and divided into two groups. One group is trained to use the EFL while the other group is not. In addition, four scenarios were considered with different sign and marking designs and traffic conditions in the experiments. Results indicate that drivers show certain amount of confusion and hesitation when encountering an EFL intersection for the first time. They can be overcome, however, by increasing exposure through driver education or by cue provided from other vehicles. Moreover, drivers unfamiliar with EFL operation can make a left turn using the conventional left-turn lanes as usual. The EFL operation is not likely to pose any serious safety risk of the intersection in real life operations. Copyright © 2015 Elsevier Ltd. All rights reserved.
Reliability of drivers in urban intersections.
Gstalter, Herbert; Fastenmeier, Wolfgang
2010-01-01
The concept of human reliability has been widely used in industrial settings by human factors experts to optimise the person-task fit. Reliability is estimated by the probability that a task will successfully be completed by personnel in a given stage of system operation. Human Reliability Analysis (HRA) is a technique used to calculate human error probabilities as the ratio of errors committed to the number of opportunities for that error. To transfer this notion to the measurement of car driver reliability the following components are necessary: a taxonomy of driving tasks, a definition of correct behaviour in each of these tasks, a list of errors as deviations from the correct actions and an adequate observation method to register errors and opportunities for these errors. Use of the SAFE-task analysis procedure recently made it possible to derive driver errors directly from the normative analysis of behavioural requirements. Driver reliability estimates could be used to compare groups of tasks (e.g. different types of intersections with their respective regulations) as well as groups of drivers' or individual drivers' aptitudes. This approach was tested in a field study with 62 drivers of different age groups. The subjects drove an instrumented car and had to complete an urban test route, the main features of which were 18 intersections representing six different driving tasks. The subjects were accompanied by two trained observers who recorded driver errors using standardized observation sheets. Results indicate that error indices often vary between both the age group of drivers and the type of driving task. The highest error indices occurred in the non-signalised intersection tasks and the roundabout, which exactly equals the corresponding ratings of task complexity from the SAFE analysis. A comparison of age groups clearly shows the disadvantage of older drivers, whose error indices in nearly all tasks are significantly higher than those of the other groups. The vast majority of these errors could be explained by high task load in the intersections, as they represent difficult tasks. The discussion shows how reliability estimates can be used in a constructive way to propose changes in car design, intersection layout and regulation as well as driver training.
Peters, Zachary J; Hatzenbuehler, Mark L; Davidson, Leslie L
2017-01-01
Research is just beginning to explore the intersection of bullying and relationship violence. The relationship between these forms of youth aggression has yet to be examined in diverse urban centers, including New York City (NYC). This study seeks to identify intersections of joint victimization from bullying and electronic bullying (e-bullying) with physical relationship violence (pRV). This study examines data from the NYC Youth Risk Behavior Survey (YRBS), a representative sample of NYC public high school students, to assess the concurrent victimization from bullying at school and e-bullying with pRV, operationalized as physical violence by a dating partner in the past 12 months. Students who reported being bullied at school and e-bullied had increased odds (bullied: OR = 2.5, 95% CI [2.1, 2.9]; e-bullied: OR = 3.0, 95% CI [2.6, 3.5]) of also being victimized by pRV compared with those who did not report being bullied or e-bullied. In logistic regression models, being bullied at school and being e-bullied remained significant predictors of students' odds of reporting pRV (bullied: AOR = 2.6, 95% CI [2.2, 3.1]; e-bullied: AOR = 3.0, 95% CI [2.5, 3.6]) while controlling for race, gender, sexual orientation, and age. This research is the first to assess the intersection of victimization from bullying and e-bullying with pRV in a large, diverse, random sample of urban high school students. In this sample, students who report being bullied or e-bullied are more likely also to report pRV than students who have not been bullied or e-bullied. This research has potential implications for educators, adolescent health and social service providers, and policy makers to tailor programs and enact policies that jointly address bullying and pRV. Future studies are needed to longitudinally assess both victimization from and perpetration of bullying and pRV. © The Author(s) 2015.
Modelling Pollutant Dispersion in a Street Network
NASA Astrophysics Data System (ADS)
Salem, N. Ben; Garbero, V.; Salizzoni, P.; Lamaison, G.; Soulhac, L.
2015-04-01
This study constitutes a further step in the analysis of the performances of a street network model to simulate atmospheric pollutant dispersion in urban areas. The model, named SIRANE, is based on the decomposition of the urban atmosphere into two sub-domains: the urban boundary layer, whose dynamics is assumed to be well established, and the urban canopy, represented as a series of interconnected boxes. Parametric laws govern the mass exchanges between the boxes under the assumption that the pollutant dispersion within the canopy can be fully simulated by modelling three main bulk transfer phenomena: channelling along street axes, transfers at street intersections, and vertical exchange between street canyons and the overlying atmosphere. Here, we aim to evaluate the reliability of the parametrizations adopted to simulate these phenomena, by focusing on their possible dependence on the external wind direction. To this end, we test the model against concentration measurements within an idealized urban district whose geometrical layout closely matches the street network represented in SIRANE. The analysis is performed for an urban array with a fixed geometry and a varying wind incidence angle. The results show that the model provides generally good results with the reference parametrizations adopted in SIRANE and that its performances are quite robust for a wide range of the model parameters. This proves the reliability of the street network approach in simulating pollutant dispersion in densely built city districts. The results also show that the model performances may be improved by considering a dependence of the wind fluctuations at street intersections and of the vertical exchange velocity on the direction of the incident wind. This opens the way for further investigations to clarify the dependence of these parameters on wind direction and street aspect ratios.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aziz, H. M. Abdul; Ukkusuri, Satish V.
We present that EPA-MOVES (Motor Vehicle Emission Simulator) is often integrated with traffic simulators to assess emission levels of large-scale urban networks with signalized intersections. High variations in speed profiles exist in the context of congested urban networks with signalized intersections. The traditional average-speed-based emission estimation technique with EPA-MOVES provides faster execution while underestimates the emissions in most cases because of ignoring the speed variation at congested networks with signalized intersections. In contrast, the atomic second-by-second speed profile (i.e., the trajectory of each vehicle)-based technique provides accurate emissions at the cost of excessive computational power and time. We addressed thismore » issue by developing a novel method to determine the link-driving-schedules (LDSs) for the EPA-MOVES tool. Our research developed a hierarchical clustering technique with dynamic time warping similarity measures (HC-DTW) to find the LDS for EPA-MOVES that is capable of producing emission estimates better than the average-speed-based technique with execution time faster than the atomic speed profile approach. We applied the HC-DTW on a sample data from a signalized corridor and found that HC-DTW can significantly reduce computational time without compromising the accuracy. The developed technique in this research can substantially contribute to the EPA-MOVES-based emission estimation process for large-scale urban transportation network by reducing the computational time with reasonably accurate estimates. This method is highly appropriate for transportation networks with higher variation in speed such as signalized intersections. Lastly, experimental results show error difference ranging from 2% to 8% for most pollutants except PM 10.« less
Aziz, H. M. Abdul; Ukkusuri, Satish V.
2017-06-29
We present that EPA-MOVES (Motor Vehicle Emission Simulator) is often integrated with traffic simulators to assess emission levels of large-scale urban networks with signalized intersections. High variations in speed profiles exist in the context of congested urban networks with signalized intersections. The traditional average-speed-based emission estimation technique with EPA-MOVES provides faster execution while underestimates the emissions in most cases because of ignoring the speed variation at congested networks with signalized intersections. In contrast, the atomic second-by-second speed profile (i.e., the trajectory of each vehicle)-based technique provides accurate emissions at the cost of excessive computational power and time. We addressed thismore » issue by developing a novel method to determine the link-driving-schedules (LDSs) for the EPA-MOVES tool. Our research developed a hierarchical clustering technique with dynamic time warping similarity measures (HC-DTW) to find the LDS for EPA-MOVES that is capable of producing emission estimates better than the average-speed-based technique with execution time faster than the atomic speed profile approach. We applied the HC-DTW on a sample data from a signalized corridor and found that HC-DTW can significantly reduce computational time without compromising the accuracy. The developed technique in this research can substantially contribute to the EPA-MOVES-based emission estimation process for large-scale urban transportation network by reducing the computational time with reasonably accurate estimates. This method is highly appropriate for transportation networks with higher variation in speed such as signalized intersections. Lastly, experimental results show error difference ranging from 2% to 8% for most pollutants except PM 10.« less
Neighborhood design and walking trips in ten U.S. metropolitan areas.
Boer, Rob; Zheng, Yuhui; Overton, Adrian; Ridgeway, Gregory K; Cohen, Deborah A
2007-04-01
Despite substantial evidence for neighborhood characteristics correlating with walking, so far there has been limited attention to possible practical implications for neighborhood design. This study investigates to what extent design guidelines are likely to stimulate walking. Four of the New Urbanism Smart Scorecard criteria and two other measures were tested for their influence on walking. Data were obtained from the 1995 National Personal Transportation Survey, U.S. Census 2000, and InfoUSA. Propensity-score methodology was used to control for potential confounders. Higher levels of business diversity and higher percentages of four-way intersections were associated with more walking. For example, the odds ratio (OR) for walking in a neighborhood with four business types present compared to three business types was 1.24 (confidence interval [CI] 1.07-1.44) and neighborhoods with 50%-74% four-way intersections had an OR for walking of 1.4 (CI 1.09-1.78) relative to those with 25%-49% four-way intersections. The effects of housing density on walking are mixed. Higher parking pressure and older median housing age did not significantly affect walking after covariate adjustment. Block length did not appear to be associated with walking. When considering the New Urbanism Smart Scorecard from the perspective walking, some, but not all, of its criteria that appear to have a correlation with walking are likely to be useful for designing walkable communities.
Performing the Grade: Urban Latino Youth, Gender Performance, and Academic Success
ERIC Educational Resources Information Center
Foiles Sifuentes, A. M.
2015-01-01
This article examines the intersection of race, gender, class, and academic success through an ethnographic case study in a Texas charter high school. The 98% working-class, Latino student population was exposed to an array of stigmas ascribed to their persons based on negative social stereotypes of race, ethnicity, gender, and class due to the…
Critical Media Literacy in Middle School: Exploring the Politics of Representation
ERIC Educational Resources Information Center
Gainer, Jesse S.
2010-01-01
This article explores issues of critical media literacy with middle school students in an urban setting in the United States. The author focuses on data from a qualitative study engaging students in the reading and writing of video texts. The article examines intersections of issues relating to the "crisis of representation" in social science…
Shannon, Geordan D.; Motta, Angelica; Cáceres, Carlos F.; Skordis-Worrall, Jolene; Bowie, Diana; Prost, Audrey
2017-01-01
ABSTRACT Background: In the Peruvian Amazon, historical events of colonization and political marginalization intersect with identities of ethnicity, class and geography in the construction of gender and health inequities. Gender-based inequalities can manifest in poor health outcomes via discriminatory practices, healthcare system imbalances, inequities in health research, and differential exposures and vulnerabilities to diseases. Structural violence is a comprehensive framework to explain the mechanisms by which social forces such as poverty, racism and gender inequity become embodied as individual experiences and health outcomes, and thus may be a useful tool in structuring an intersectional analysis of gender and health inequities in Amazonian Peru. Objective: The aim of this paper is to explore the intersection of gender inequities with other social inequalities in the production of health and disease in Peru’s Amazon using a structural violence approach. Design: Exploratory qualitative research was performed in two Loreto settings – urban Iquitos and the rural Lower Napo River region – between March and November 2015. This included participant observation with prolonged stays in the community, 46 semi-structured individual interviews and three group discussions. Thematic analysis was performed to identify emerging themes related to gender inequalities in health and healthcare and how these intersect with layered social disadvantages in the reproduction of health and illness. We employed a structural violence approach to construct an intersectional analysis of gender and health inequities in Amazonian Peru. Results: Our findings were arranged into five interrelated domains within a gender, structural violence and health model: gender as a symbolic institution, systemic gender-based violence, interpersonal violence, the social determinants of health, and other health outcomes. Each domain represents one aspect of the complex associations between gender, gender inequity and health. Through this model, we were able to explore: gender, health and intersectionality; structural violence; and to highlight particular local gender and health dynamics. Intersecting influences of poverty, ethnicity, geography and gender served as significant barriers to healthcare in both rural and urban settings. PMID:28640664
Wu, Tong; Perrings, Charles; Kinzig, Ann; Collins, James P; Minteer, Ben A; Daszak, Peter
2017-02-01
Three interrelated world trends may be exacerbating emerging zoonotic risks: income growth, urbanization, and globalization. Income growth is associated with rising animal protein consumption in developing countries, which increases the conversion of wild lands to livestock production, and hence the probability of zoonotic emergence. Urbanization implies the greater concentration and connectedness of people, which increases the speed at which new infections are spread. Globalization-the closer integration of the world economy-has facilitated pathogen spread among countries through the growth of trade and travel. High-risk areas for the emergence and spread of infectious disease are where these three trends intersect with predisposing socioecological conditions including the presence of wild disease reservoirs, agricultural practices that increase contact between wildlife and livestock, and cultural practices that increase contact between humans, wildlife, and livestock. Such an intersection occurs in China, which has been a "cradle" of zoonoses from the Black Death to avian influenza and SARS. Disease management in China is thus critical to the mitigation of global zoonotic risks.
Driving with hemianopia: IV. Head scanning and detection at intersections in a simulator.
Bowers, Alex R; Ananyev, Egor; Mandel, Aaron J; Goldstein, Robert B; Peli, Eli
2014-03-13
Using a driving simulator, we examined the effects of homonymous hemianopia (HH) on head scanning behaviors at intersections and evaluated the role of inadequate head scanning in detection failures. Fourteen people with complete HH and without cognitive decline or visual neglect and 12 normally sighted (NV) current drivers participated. They drove in an urban environment following predetermined routes, which included multiple intersections. Head scanning behaviors were quantified at T-intersections (n = 32) with a stop or yield sign. Participants also performed a pedestrian detection task. The relationship between head scanning and detection was examined at 10 intersections. For HH drivers, the first scan was more likely to be toward the blind than the seeing hemifield. They also made a greater proportion of head scans overall to the blind side than did the NV drivers to the corresponding side (P = 0.003). However, head scan magnitudes of HH drivers were smaller than those of the NV group (P < 0.001). Drivers with HH had impaired detection of blind-side pedestrians due either to not scanning in the direction of the pedestrian or to an insufficient scan magnitude (left HH detected only 46% and right HH 8% at the extreme left and right of the intersection, respectively). Drivers with HH demonstrated compensatory head scan patterns, but not scan magnitudes. Inadequate scanning resulted in blind-side detection failures, which might place HH drivers at increased risk for collisions at intersections. Scanning training tailored to specific problem areas identified in this study might be beneficial.
NASA Astrophysics Data System (ADS)
Vîlcan, A.; Neagu, E.; Badarau Suster, H.; Boroiu, A. A.
2017-10-01
Road traffic congestion has become a daily phenomenon in the central area of Pitesti in the peak traffic periods. In order to achieve the mobility plan of Pitesti, an important stage is the diagnostic analysis of the road traffic. For this purpose, the urban road network was formalized through a graph containing the most important 40 intersections and traffic measurements were made at all these intersections and on the main roads connecting the peri-urban area. The data obtained by traffic macrosimulation confirmed the overloading of the street network during peak traffic hours and the analyzes made for various road traffic organization scenarios have shown that there are sustainable solutions for urban mobility only if the road network is fundamentally reconfigured (a belt outside the city and a median ring). Thus, the necessity of realizing the road passage in the Prundu neighbourhood and the finishing of the city belt by realizing the “detour West” of the city is argued. The importance of the work is that it brings scientific arguments for the realization of these road infrastructure projects, integrated in the urban mobility plan, which will base the development strategy of the Pitesti municipality.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Yue J.; Malikopoulos, Andreas; Cassandras, Christos G.
We address the problem of coordinating online a continuous flow of connected and automated vehicles (CAVs) crossing two adjacent intersections in an urban area. We present a decentralized optimal control framework whose solution yields for each vehicle the optimal acceleration/deceleration at any time in the sense of minimizing fuel consumption. The solu- tion, when it exists, allows the vehicles to cross the intersections without the use of traffic lights, without creating congestion on the connecting road, and under the hard safety constraint of collision avoidance. The effectiveness of the proposed solution is validated through simulation considering two intersections located inmore » downtown Boston, and it is shown that coordination of CAVs can reduce significantly both fuel consumption and travel time.« less
Devlin, Anna; McGillivray, Jane; Charlton, Judith; Lowndes, Georgia; Etienne, Virginie
2012-11-01
While there is a large body of research indicating that individuals with moderate to severe dementia are unfit to drive, relatively little is known about the driving performance of older drivers with mild cognitive impairment (MCI). The aim of the current study was to examine the driving performance of older drivers with MCI on approach to intersections, and to investigate how their healthy counterparts perform on the same driving tasks using a portable driving simulator. Fourteen drivers with MCI and 14 age-matched healthy older drivers (aged 65-87 years) completed a 10-min simulator drive in an urban environment. The simulator drive consisted of stop-sign controlled and signal-controlled intersections. Drivers were required to stop at the stop-sign controlled intersections and to decide whether or not to proceed through a critical light change at the signal-controlled intersections. The specific performance measures included; approach speed, number of brake applications on approach to the intersection (either excessive or minimal), failure to comply with stop signs, and slower braking response times on approach to a critical light change. MCI patients in our sample performed more poorly than controls across a number of variables. However, because the trends failed to reach statistical significance it will be important to replicate the study using a larger sample to qualify whether the results can be generalised to the broader population. Copyright © 2012 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Sampson, Carrie R.
2017-01-01
Community-based organizations have long influenced education reforms, and urban areas are especially vulnerable to community work that transcends racial and economic boundaries. The purpose of this study is to explore how The League of Women Voters of Las Vegas Valley, a mostly White, middle-upper-class women's organization, worked to pursue one…
"They Think We Don't Have the Knowledge": The Intersection of Autism and Race
ERIC Educational Resources Information Center
Hetherington, Susan Ames
2012-01-01
The purpose of this study was to explore the experiences of African American mothers of children with an autism diagnosis as they negotiated an urban district special education system. Beginning with the question, "How do the dual oppressions of race and disability impact African American mothers of children with autism and their relationship…
Joseph G. Champ; Daniel R. Williams; Katie Knotek
2009-01-01
A lack of research on the conceptual intersection of leisure, place and wildland fire and its role in identity prompted this exploratory study. The purpose of this research was to gather evidence regarding how people negotiate identities under the threat of wildland fire. Qualitative interviews with 16 homeowners and recreationists who value leisure activities in...
Technology-related distracted walking behaviours in Manhattan's most dangerous intersections.
Basch, Corey H; Ethan, Danna; Rajan, Sonali; Basch, Charles E
2014-10-01
Use of mobile devices has been cited as a distraction while driving, and more recently, among pedestrians crossing urban streets. In 2010, over half of New York City traffic fatalities were pedestrians. The aim of this study was to estimate the prevalence of distracted walking due to pedestrians' use of headphones, mobile phones, or both. Data were gathered by direct observations at the 10 intersections in Manhattan with the highest frequency of pedestrian-motor vehicle collisions. More than 1 in 4 of the >3500 pedestrians observed were distracted by mobile electronic devices while crossing during the 'walk' (28.8%) and 'don't walk' (26.3%) signals. Poisson regression analyses established there was a significant difference in individuals talking on a mobile device during the 'walk' signal versus the 'don't walk' signal; however, no other significant differences in other distracted walking behaviours were observed. This study contributes to the emerging literature on distracted walking behaviour by pedestrians in busy urban areas and can help to inform pedestrian-focused safety efforts. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
NASA Astrophysics Data System (ADS)
Kim, Youngseob; Wu, You; Seigneur, Christian; Roustan, Yelva
2018-02-01
A new multi-scale model of urban air pollution is presented. This model combines a chemistry-transport model (CTM) that includes a comprehensive treatment of atmospheric chemistry and transport on spatial scales down to 1 km and a street-network model that describes the atmospheric concentrations of pollutants in an urban street network. The street-network model is the Model of Urban Network of Intersecting Canyons and Highways (MUNICH), which consists of two main components: a street-canyon component and a street-intersection component. MUNICH is coupled to the Polair3D CTM of the Polyphemus air quality modeling platform to constitute the Street-in-Grid (SinG) model. MUNICH is used to simulate the concentrations of the chemical species in the urban canopy, which is located in the lowest layer of Polair3D, and the simulation of pollutant concentrations above rooftops is performed with Polair3D. Interactions between MUNICH and Polair3D occur at roof level and depend on a vertical mass transfer coefficient that is a function of atmospheric turbulence. SinG is used to simulate the concentrations of nitrogen oxides (NOx) and ozone (O3) in a Paris suburb. Simulated concentrations are compared to NOx concentrations measured at two monitoring stations within a street canyon. SinG shows better performance than MUNICH for nitrogen dioxide (NO2) concentrations. However, both SinG and MUNICH underestimate NOx. For the case study considered, the model performance for NOx concentrations is not sensitive to using a complex chemistry model in MUNICH and the Leighton NO-NO2-O3 set of reactions is sufficient.
Multi-scale modeling of urban air pollution: development of a Street-in-Grid model
NASA Astrophysics Data System (ADS)
Kim, Youngseob; Wu, You; Seigneur, Christian; Roustan, Yelva
2016-04-01
A new multi-scale model of urban air pollution is presented. This model combines a chemical-transport model (CTM) that includes a comprehensive treatment of atmospheric chemistry and transport at spatial scales greater than 1 km and a street-network model that describes the atmospheric concentrations of pollutants in an urban street network. The street-network model is based on the general formulation of the SIRANE model and consists of two main components: a street-canyon component and a street-intersection component. The street-canyon component calculates the mass transfer velocity at the top of the street canyon (roof top) and the mean wind velocity within the street canyon. The estimation of the mass transfer velocity depends on the intensity of the standard deviation of the vertical velocity at roof top. The effect of various formulations of this mass transfer velocity on the pollutant transport at roof-top level is examined. The street-intersection component calculates the mass transfer from a given street to other streets across the intersection. These mass transfer rates among the streets are calculated using the mean wind velocity calculated for each street and are balanced so that the total incoming flow rate is equal to the total outgoing flow rate from the intersection including the flow between the intersection and the overlying atmosphere at roof top. In the default option, the Leighton photostationary cycle among ozone (O3) and nitrogen oxides (NO and NO2) is used to represent the chemical reactions within the street network. However, the influence of volatile organic compounds (VOC) on the pollutant concentrations increases when the nitrogen oxides (NOx) concentrations are low. To account for the possible VOC influence on street-canyon chemistry, the CB05 chemical kinetic mechanism, which includes 35 VOC model species, is implemented in this street-network model. A sensitivity study is conducted to assess the uncertainties associated with the use of the Leighton cycle chemistry. The street-network model is coupled to the CTM Polair3D of the Polyphemus air quality modeling platform to constitute a Street-in-Grid (SinG) model. The street-network model is used to simulate the concentrations of the chemical species in the lowest layer in the urban area and the simulation for the upper layers is then performed by Polair3D. Interactions between the street-network model and the host CTM occur at roof-top and depend on the vertical mass transfer described above. The SinG model is used to simulate the concentrations of gas-phase pollutants (O3 and NOx) in a Paris suburb. The emission data for each street that are needed for the street-network model were obtained from a dynamic traffic model. Topographic data, such as street length/width and building height, were obtained from a geographic database (BD TOPO). Simulated concentrations are compared to concentrations measured at two monitoring stations that were located on each side of a large avenue.
A theoretical framework for the episodic-urban air quality management plan ( e-UAQMP)
NASA Astrophysics Data System (ADS)
Gokhale, Sharad; Khare, Mukesh
The present research proposes the local urban air quality management plan which combines two different modelling approaches (hybrid model) and possesses an improved predictive ability including the 'probabilistic exceedances over norms' and their 'frequency of occurrences' and so termed, herein, as episodic-urban air quality management plan ( e-UAQMP). The e-UAQMP deals with the consequences of 'extreme' concentrations of pollutant, mainly occurring at urban 'hotspots' e.g. traffic junctions, intersections and signalized roadways and are also influenced by complexities of traffic generated 'wake' effects. The e-UAQMP (based on probabilistic approach), also acts as an efficient preventive measure to predict the 'probability of exceedances' so as to prepare a successful policy responses in relation to the protection of urban environment as well as disseminating information to its sensitive 'receptors'. The e-UAQMP may be tailored to the requirements of the local area for the policy implementation programmes. The importance of such policy-making framework in the context of current air pollution 'episodes' in urban environments is discussed. The hybrid model that is based on both deterministic and stochastic based approaches predicting the 'average' as well as 'extreme' concentration distribution of air pollutants together in form of probability has been used at two air quality control regions (AQCRs) in the Delhi city, India, in formulating and executing the e-UAQMP— first, the income tax office (ITO), one of the busiest signalized traffic intersection and second, the Sirifort, one of the busiest signalized roadways.
Control of Networked Traffic Flow Distribution - A Stochastic Distribution System Perspective
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Hong; Aziz, H M Abdul; Young, Stan
Networked traffic flow is a common scenario for urban transportation, where the distribution of vehicle queues either at controlled intersections or highway segments reflect the smoothness of the traffic flow in the network. At signalized intersections, the traffic queues are controlled by traffic signal control settings and effective traffic lights control would realize both smooth traffic flow and minimize fuel consumption. Funded by the Energy Efficient Mobility Systems (EEMS) program of the Vehicle Technologies Office of the US Department of Energy, we performed a preliminary investigation on the modelling and control framework in context of urban network of signalized intersections.more » In specific, we developed a recursive input-output traffic queueing models. The queue formation can be modeled as a stochastic process where the number of vehicles entering each intersection is a random number. Further, we proposed a preliminary B-Spline stochastic model for a one-way single-lane corridor traffic system based on theory of stochastic distribution control.. It has been shown that the developed stochastic model would provide the optimal probability density function (PDF) of the traffic queueing length as a dynamic function of the traffic signal setting parameters. Based upon such a stochastic distribution model, we have proposed a preliminary closed loop framework on stochastic distribution control for the traffic queueing system to make the traffic queueing length PDF follow a target PDF that potentially realizes the smooth traffic flow distribution in a concerned corridor.« less
Missouri Highway Safety Manual Recalibration
DOT National Transportation Integrated Search
2018-05-01
The Highway Safety Manual (HSM) is a national manual for analyzing the highway safety of various facilities, including rural roads, urban arterials, freeways, and intersections. The HSM was first published in 2010, and a 2014 supplement addressed fre...
Growth Type and Functional Trajectories: An Empirical Study of Urban Expansion in Nanjing, China
Yuan, Feng
2016-01-01
Drawing upon the Landsat satellite images of Nanjing from 1985, 1995, 2001, 2007, and 2013, this paper integrates the convex hull analysis and common edge analysis at double scales, and develops a comprehensive matrix analysis to distinguish the different types of urban land expansion. The results show that Nanjing experienced rapid urban expansion, dominated by a mix of residential and manufacturing land from 1985 to 2013, which in turn has promoted Nanjing’s shift from a compact mononuclear city to a polycentric one. Spatial patterns of three specific types of growth, namely infilling, extension, and enclave were quite different in four consecutive periods. These patterns result primarily from the existing topographic constraints, as well as government-oriented urban planning and policies. By intersecting the function maps, we also reveal the functional evolution of newly-developed urban land. Moreover, both self-enhancing and mutual promotion of the newly developed functions are surveyed over the last decade. Our study confirms that the integration of a multi-scale method and multi-perspective analysis, such as the spatiotemporal patterns and functional evolution, helps us to better understand the rapid urban growth in China. PMID:26845155
Bus Stops and Pedestrian-Motor Vehicle Collisions in Lima, Peru: A Matched Case-Control Study
Quistberg, D. Alex; Koepsell, Thomas D.; Johnston, Brian D.; Boyle, Linda Ng; Miranda, J. Jaime; Ebel, Beth E.
2015-01-01
Objective To evaluate the relationship between bus stop characteristics and pedestrian-motor vehicle collisions. Design Matched case-control study where the units of study were pedestrian crossing. Setting Random sample of 11 police commissaries in Lima, Peru. Data collection occurred from February, 2011 to September, 2011. Participants 97 intersection cases representing 1,134 collisions and 40 mid-block cases representing 469 collisions that occurred between October, 2010 and January, 2011 and their matched controls. Main Exposures Presence of a bus stop and specific bus stop characteristics. Main Outcome Occurrence of a pedestrian-motor vehicle collision. Results Intersections with bus stops were three times more likely to have a pedestrian-vehicle collision (OR 3.28, 95% CI 1.53-7.03), relative to intersections without bus stops. Both formal and informal bus stops were associated with a higher odds of a collision at intersections (OR 6.23, 95% CI 1.76-22.0 and OR 2.98, 1.37-6.49). At mid-block sites, bus stops on a bus-dedicated transit lane were also associated with collision risk (OR 2.36, 95% CI 1.02-5.42). All bus stops were located prior to the intersection, contrary to practices in most high income countries. Conclusions In urban Lima, the presence of a bus stop was associated with a three-fold increase in risk of a pedestrian collision. The highly competitive environment among bus companies may provide an economic incentive for risky practices such as dropping off passengers in the middle of traffic and jockeying for position with other buses. Bus stop placement should be considered to improve pedestrian safety. PMID:24357516
NASA Astrophysics Data System (ADS)
He, Hong-di; Lu, Wei-Zhen; Xue, Yu
2009-12-01
At urban traffic intersections, vehicles frequently stop with idling engines during the red-light period and speed up rapidly during the green-light period. The changes of driving patterns (i.e., idle, acceleration, deceleration and cruising patterns) generally produce uncertain emission. Additionally, the movement of pedestrians and the influence of wind further result in the random dispersion of pollutants. It is, therefore, too complex to simulate the effects of such dynamics on the resulting emission using conventional deterministic causal models. For this reason, a modified semi-empirical box model for predicting the PM 10 concentrations on roadsides is proposed in this paper. The model constitutes three parts, i.e., traffic, emission and dispersion components. The traffic component is developed using a generalized force traffic model to obtain the instantaneous velocity and acceleration when vehicles move through intersections. Hence the distribution of vehicle emission in street canyon during the green-light period is calculated. Then the dispersion component is investigated using a semi-empirical box model combining average wind speed, box height and background concentrations. With these considerations, the proposed model is applied and evaluated using measured data at a busy traffic intersection in Mong Kok, Hong Kong. In order to test the performance of the model, two situations, i.e., the data sets within a sunny day and between two sunny days, were selected to examine the model performance. The predicted values are generally well coincident with the observed data during different time slots except several values are overestimated or underestimated. Moreover, two types of vehicles, i.e., buses and petrol cars, are separately taken into account in the study. Buses are verified to contribute most to the emission in street canyons, which may be useful in evaluating the impact of vehicle emissions on the ambient air quality when there is a significant change in a specific vehicular population.
Road Traffic Noise Exposure and Hearing Impairment Among Traffic Policemen in Surat, Western India
NASA Astrophysics Data System (ADS)
Tandel, B. N.; Macwan, J. E. M.
2017-06-01
Among all of the sources responsible for noise pollution, traffic related sources are of great environmental concern and increasing level of discomfort in urban areas with increasing traffic concentration. It will be a larger and serious problem in the future, if effective precautions are not taken addressed and attended to. Hence, a study was undertaken to measure the levels of road traffic noise at major intersections of Surat city, located in Western India and assess the hearing impairment among the exposed group of population i.e. the traffic policemen. Manual noise measurements and vehicle counts were performed at three of the busiest traffic intersections in the city for a period of 12 h. Audiometric screening was done on 46 policemen working at these intersections to determine the occurrence of hearing impairment. At all the three intersections, Leq measured was well above the permissible levels of 65 dBA for daytime. The Lmax recorded for three intersections were 84.6 dBA (07:36 pm), 87.3 dBA (06:32 pm) and 85.6 dBA (11:41 am). Audiometric screening showed that only 10 policemen (22%) had normal hearing. Slight, moderate and severe hearing impairment was recorded among 13 (28%), 18 (39%) and 5 (11%) policemen respectively. Of the total 46 policemen, none had profound impairment (deafness, hearing loss >81 dB). Of the 36 policemen having hearing impairment, 27 had bilateral impairment.
Cyclist Path Choices Through Shared Space Intersections in England
DOT National Transportation Integrated Search
2016-07-01
In the last several years, there has been growing worldwide interest in making streets safer for all users pedestrians, cyclists, and motorists. One approach, shared space, is a traffic calming technique as well as urban design concept. This techn...
False capacity for lane drops : final report.
DOT National Transportation Integrated Search
2005-02-01
Lane drops downstream of signalized intersections are found on many urban and suburban streets and highways. Since : drivers tend to avoid using the short lane due to the potential for stressful merges downstream of the signal, the short lane is : ty...
ERIC Educational Resources Information Center
Obiero, Judith A.
2012-01-01
The adoption of Free Primary Education in 2003 has expanded access to millions of children in Kenya. However, large numbers of children are still out of school. The majority of the out-of-school children belong to ethnic minority groups and the rural and urban poor, who live in abject poverty. This situation is disturbing given that free primary…
On the problem of boundaries and scaling for urban street networks
Masucci, A. Paolo; Arcaute, Elsa; Hatna, Erez; Stanilov, Kiril; Batty, Michael
2015-01-01
Urban morphology has presented significant intellectual challenges to mathematicians and physicists ever since the eighteenth century, when Euler first explored the famous Königsberg bridges problem. Many important regularities and scaling laws have been observed in urban studies, including Zipf's law and Gibrat's law, rendering cities attractive systems for analysis within statistical physics. Nevertheless, a broad consensus on how cities and their boundaries are defined is still lacking. Applying an elementary clustering technique to the street intersection space, we show that growth curves for the maximum cluster size of the largest cities in the UK and in California collapse to a single curve, namely the logistic. Subsequently, by introducing the concept of the condensation threshold, we show that natural boundaries of cities can be well defined in a universal way. This allows us to study and discuss systematically some of the regularities that are present in cities. We show that some scaling laws present consistent behaviour in space and time, thus suggesting the presence of common principles at the basis of the evolution of urban systems. PMID:26468071
On the problem of boundaries and scaling for urban street networks.
Masucci, A Paolo; Arcaute, Elsa; Hatna, Erez; Stanilov, Kiril; Batty, Michael
2015-10-06
Urban morphology has presented significant intellectual challenges to mathematicians and physicists ever since the eighteenth century, when Euler first explored the famous Königsberg bridges problem. Many important regularities and scaling laws have been observed in urban studies, including Zipf's law and Gibrat's law, rendering cities attractive systems for analysis within statistical physics. Nevertheless, a broad consensus on how cities and their boundaries are defined is still lacking. Applying an elementary clustering technique to the street intersection space, we show that growth curves for the maximum cluster size of the largest cities in the UK and in California collapse to a single curve, namely the logistic. Subsequently, by introducing the concept of the condensation threshold, we show that natural boundaries of cities can be well defined in a universal way. This allows us to study and discuss systematically some of the regularities that are present in cities. We show that some scaling laws present consistent behaviour in space and time, thus suggesting the presence of common principles at the basis of the evolution of urban systems. © 2015 The Authors.
Kershaw, Paul; Forer, Barry
2010-05-01
Given data limitations, neighborhood effects scholarship relies heavily on administrative data to measure area-level constructs. We provide new evidence to guide the selection of indicators from routinely collected sources, focusing on effects on early child development. Informed by an analytic paradigm attuned to the intersection of race, class, and sex, along with population-level data in British Columbia, Canada, our findings signal the need for greater precision when choosing variables in place of the now dominant approaches for measuring constructs like income/wealth, employment, family structure and race/ethnicity. We also provide new evidence about which area-level variables associate with the different domains of child development, as well as how area-level associations vary across urban and rural contexts. Copyright 2009 Elsevier Ltd. All rights reserved.
Feasibility study on intersection in North Sumatera
NASA Astrophysics Data System (ADS)
Hastuty, I. P.; Sembiring, I. S.; Anas, R.; Lubis, A. S.
2018-02-01
Traffic congestion is one of the problems faced by big cities, One of them is Binjai city and Medan city in North Sumatera. One of the causes of congestion is intersection of roads with highway and roads with railroads. To ensure the smooth movement of vehicles, technical handling at the intersection is needed. Therefore, it is necessary to pre-study the feasibility of level crossing in Binjai and Medan to be able to assess the investment needs and the level of importance of road development in the region. The development of transportation infrastructure and facilities is based on the thought of improving the transportation network system. The necessity of systemical integrated transportation system handling is needed in creating a transportation efficiency. The purpose of this study is to identify and prioritize the needs of the railway crossings. The objective which we want to be achieved is to obtain a document that contains technical, economic and environmental ability indicators as a reference in the feasibility and planning studies. The methodology used is collecting the primary data, secondary data, introduction of study area as the initial analysis of the problem. From the study it can be concluded that the existence of railway interchange will move the movement through traffic so it will not interfere the movement of traffic within urban areas and it keeps the national road network performance is still good.
A mobile phone system to find crosswalks for visually impaired pedestrians
Shen, Huiying; Chan, Kee-Yip; Coughlan, James; Brabyn, John
2010-01-01
Urban intersections are the most dangerous parts of a blind or visually impaired pedestrian’s travel. A prerequisite for safely crossing an intersection is entering the crosswalk in the right direction and avoiding the danger of straying outside the crosswalk. This paper presents a proof of concept system that seeks to provide such alignment information. The system consists of a standard mobile phone with built-in camera that uses computer vision algorithms to detect any crosswalk visible in the camera’s field of view; audio feedback from the phone then helps the user align him/herself to it. Our prototype implementation on a Nokia mobile phone runs in about one second per image, and is intended for eventual use in a mobile phone system that will aid blind and visually impaired pedestrians in navigating traffic intersections. PMID:20411035
The safety of urban cycle tracks: a review of the literature.
Thomas, Beth; DeRobertis, Michelle
2013-03-01
Cycling has to be a safe activity, and perceived as such, if bicycle trips by all populations are to increase and the public health benefits are to be realized. A key characteristic of developed countries with a high cycling mode share is their provision of cycle tracks--separated bikeways along city streets--on major routes. This literature review therefore sought to examine studies of cycle tracks from different countries in order elucidate the safety of these facilities relative to cycling in the street and to point to areas where further research is needed. The review indicates that one-way cycle tracks are generally safer at intersections than two-way and that, when effective intersection treatments are employed, constructing cycle tracks on busy streets reduces collisions and injuries. The evidence also suggests that, when controlling for exposure and including all collision types, building one-way cycle tracks reduces injury severity even when such intersection treatments are not employed. However, the extent of this effect has not been well examined, as very few studies both look at severity and control for exposure. Future studies of the safety of cycle tracks and associated intersection treatments should focus foremost on examining injury severity, while controlling for exposure. In the U.S., where the obesity epidemic and its health consequences and costs are well documented, the benefits of increased cycling should be a focus of research and policy development in order to provide the infrastructure needed to attract people to cycling while minimizing injuries. Copyright © 2013 Elsevier Ltd. All rights reserved.
Wu, Qiong; Zhang, Guohui; Ci, Yusheng; Wu, Lina; Tarefder, Rafiqul A; Alcántara, Adélamar Dely
2016-05-18
Teenage drivers are more likely to be involved in severely incapacitating and fatal crashes compared to adult drivers. Moreover, because two thirds of urban vehicle miles traveled are on signal-controlled roadways, significant research efforts are needed to investigate intersection-related teenage driver injury severities and their contributing factors in terms of driver behavior, vehicle-infrastructure interactions, environmental characteristics, roadway geometric features, and traffic compositions. Therefore, this study aims to explore the characteristic differences between teenage and adult drivers in intersection-related crashes, identify the significant contributing attributes, and analyze their impacts on driver injury severities. Using crash data collected in New Mexico from 2010 to 2011, 2 multinomial logit regression models were developed to analyze injury severities for teenage and adult drivers, respectively. Elasticity analyses and transferability tests were conducted to better understand the quantitative impacts of these factors and the teenage driver injury severity model's generality. The results showed that although many of the same contributing factors were found to be significant in the both teenage and adult driver models, certain different attributes must be distinguished to specifically develop effective safety solutions for the 2 driver groups. The research findings are helpful to better understand teenage crash uniqueness and develop cost-effective solutions to reduce intersection-related teenage injury severities and facilitate driver injury mitigation research.
DOT National Transportation Integrated Search
2001-02-01
The Minnesota data system includes the following basic files: Accident data (Accident File, Vehicle File, Occupant File); Roadlog File; Reference Post File; Traffic File; Intersection File; Bridge (Structures) File; and RR Grade Crossing File. For ea...
NASA Astrophysics Data System (ADS)
Adeniran, J. A.; Yusuf, R. O.; Olajire, A. A.
2017-10-01
This study aims to determine the seasonal variations and composition of suspended particulate matter in different sizes PM1.0, PM2.5, PM10 and the total suspended particles (TSP) emitted at major intra-urban traffic intersections (TIs) of Ilorin metropolis. The concentration levels of PM (PM1.0, PM2.5, PM10) obtained at the TIs during the rush hours (45.1, 77.9, and 513 μg/m3) are higher than the levels obtained for the non-rush hour periods (42.3, 62.7, and 390 μg/m3). The average on-road respiratory deposition dose (RDD) rates of PM1.0, PM2.5 and PM10 during the dry period at TIs types was found to be about 24%, 9% and 25% higher than those obtained during the wet period. Based on EF values calculated, Pb and Zn were anthropogenically-derived while Fe, Mn, Cr, Cu and Mg were of crustal source. Principal component analysis (PCA) has been applied to a set of PM data in order to determine the contribution of different sources. It was found that the main principal factors extracted from particulate emission data were related to exhaust and non-exhaust emissions such as tyre wears, oil and fuel combustion sources.
Tiwary, Abhishek; Robins, Alan; Namdeo, Anil; Bell, Margaret
2011-07-01
This paper reviews the state of knowledge on modelling air flow and concentration fields at road intersections. The first part covers the available literature from the past two decades on experimental (both field and wind tunnel) and modelling activities in order to provide insight into the physical basis of flow behaviour at a typical cross-street intersection. This is followed by a review of associated investigations of the impact of traffic-generated localised turbulence on the concentration fields due to emissions from vehicles. There is a discussion on the role of adequate characterisation of vehicle-induced turbulence in making predictions using hybrid models, combining the merits of conventional approaches with information obtained from more detailed modelling. This concludes that, despite advancements in computational techniques, there are crucial knowledge gaps affecting the parameterisations used in current models for individual exposure. This is specifically relevant to the growing impetus on walking and cycling activities on urban roads in the context of current drives for sustainable transport and healthy living. Due to inherently longer travel times involved during such trips, compared to automotive transport, pedestrians and cyclists are subjected to higher levels of exposure to emissions. Current modelling tools seem to under-predict this exposure because of limitations in their design and in the empirical parameters employed. Copyright © 2011 Elsevier Ltd. All rights reserved.
Syphard, Alexandra D.; Keeley, Jon E.; Brennan, Teresa J.
2011-01-01
As wildfires have increased in frequency and extent, so have the number of homes developed in the wildland-urban interface. In California, the predominant approach to mitigating fire risk is construction of fuel breaks, but there has been little empirical study of their role in controlling large fires.We constructed a spatial database of fuel breaks on the Los Padres National Forest in southern California to better understand characteristics of fuel breaks that affect the behaviour of large fires and to map where fires and fuel breaks most commonly intersect. We evaluated whether fires stopped or crossed over fuel breaks over a 28-year period and compared the outcomes with physical characteristics of the sites, weather and firefighting activities during the fire event. Many fuel breaks never intersected fires, but others intersected several, primarily in historically fire-prone areas. Fires stopped at fuel breaks 46% of the time, almost invariably owing to fire suppression activities. Firefighter access to treatments, smaller fires and longer fuel breaks were significant direct influences, and younger vegetation and fuel break maintenance indirectly improved the outcome by facilitating firefighter access. This study illustrates the importance of strategic location of fuel breaks because they have been most effective where they provided access for firefighting activities.
Schlossberg, Marc; Johnson-Shelton, Deb; Evers, Cody; Moreno, Geraldine
Researchers use measures of street connectivity to assess neighborhood walkability and many studies show a relationship between neighborhood design and walking activity. Yet, the core of those connectivity measures are based on constructs designed for analyzing automobile mobility - the street network - not pedestrian movement. This paper examines the effect of a finer grained characterization of street connectivity and illustrates the idea using parent ratings of street and intersection walkability for children throughout a suburban school district in Oregon. Several policy and practice recommendations are presented, including a discussion that extends Michael Southworth's (1993; 2005) foundational representation of streets and the walkable city using a refined, more pedestrian-centered approach to visualizing connectivity and walkable urban form.
Sexism and Permanent Exclusion from School
ERIC Educational Resources Information Center
Carlile, Anna
2009-01-01
Focussing on narratives collected during a two year participant observation research project in the children's services department of an urban local authority, this article addresses the intersection between incidents of permanent exclusion from school and assumptions made on the basis of a young person's gender. The article considers gendered…
Vera-Villarroel, Pablo; Contreras, Daniela; Lillo, Sebastián; Beyle, Christian; Segovia, Ariel; Rojo, Natalia; Moreno, Sandra; Oyarzo, Francisco
2016-01-01
The perception of colour and its subjective effects are key issues to designing safe and enjoyable bike lanes. This paper addresses the relationship between the colours of bike lane interventions-in particular pavement painting and intersection design-and the subjective evaluation of liking, visual saliency, and perceived safety related to such an intervention. Utilising images of three real bike lane intersections modified by software to change their colour (five in total), this study recruited 538 participants to assess their perception of all fifteen colour-design combinations. A multivariate analysis of covariance (MANCOVA) with the Bonferroni post hoc test was performed to assess the effect of the main conditions (colour and design) on the dependent variables (liking towards the intervention, level of visual saliency of the intersection, and perceived safety of the bike lane). The results showed that the colour red was more positively associated to the outcome variables, followed by yellow and blue. Additionally, it was observed that the effect of colour widely outweighs the effect of design, suggesting that the right choice and use of colour would increase the effectiveness on bike-lanes pavement interventions. Limitations and future directions are discussed.
Yu, Bo; Chen, Yuren; Wang, Ruiyun; Dong, Yongjie
2016-10-01
Turning right has a significant impact on urban road traffic safety. Driving into the curve inappropriately or with improper turning speed often leads to a series of potential accidents and hidden dangers. For a long time, the design speed at intersections has been used to determine the physical radius of curbs and channelization, and drivers are expected to drive in accordance with the design speed. However, a large number of real vehicle tests show that for the road without an exclusive right-turn lane, there is not a good correlation between the physical radius of curbs and the turning right speeds. In this paper, shape parameters of the driver's visual lane model are put forward and they have relatively high correlations with right-turn speeds. Hence, an evaluation method about safety reliability of turning right from urban major roads onto minor ones based on driver's visual perception is proposed. For existing roads, the evaluation object could be real driving videos; for those under construction roads, the evaluation object could be visual scenes obtained from a driving simulation device. Findings in this research will make a contribution to the optimization of right-turn design at intersections and lead to the development of auxiliary driving technology. Copyright © 2015 Elsevier Ltd. All rights reserved.
Achieving Passive Localization with Traffic Light Schedules in Urban Road Sensor Networks
Niu, Qiang; Yang, Xu; Gao, Shouwan; Chen, Pengpeng; Chan, Shibing
2016-01-01
Localization is crucial for the monitoring applications of cities, such as road monitoring, environment surveillance, vehicle tracking, etc. In urban road sensor networks, sensors are often sparely deployed due to the hardware cost. Under this sparse deployment, sensors cannot communicate with each other via ranging hardware or one-hop connectivity, rendering the existing localization solutions ineffective. To address this issue, this paper proposes a novel Traffic Lights Schedule-based localization algorithm (TLS), which is built on the fact that vehicles move through the intersection with a known traffic light schedule. We can first obtain the law by binary vehicle detection time stamps and describe the law as a matrix, called a detection matrix. At the same time, we can also use the known traffic light information to construct the matrices, which can be formed as a collection called a known matrix collection. The detection matrix is then matched in the known matrix collection for identifying where sensors are located on urban roads. We evaluate our algorithm by extensive simulation. The results show that the localization accuracy of intersection sensors can reach more than 90%. In addition, we compare it with a state-of-the-art algorithm and prove that it has a wider operational region. PMID:27735871
Resilience and efficiency in transportation networks
Ganin, Alexander A.; Kitsak, Maksim; Marchese, Dayton; Keisler, Jeffrey M.; Seager, Thomas; Linkov, Igor
2017-01-01
Urban transportation systems are vulnerable to congestion, accidents, weather, special events, and other costly delays. Whereas typical policy responses prioritize reduction of delays under normal conditions to improve the efficiency of urban road systems, analytic support for investments that improve resilience (defined as system recovery from additional disruptions) is still scarce. In this effort, we represent paved roads as a transportation network by mapping intersections to nodes and road segments between the intersections to links. We built road networks for 40 of the urban areas defined by the U.S. Census Bureau. We developed and calibrated a model to evaluate traffic delays using link loads. The loads may be regarded as traffic-based centrality measures, estimating the number of individuals using corresponding road segments. Efficiency was estimated as the average annual delay per peak-period auto commuter, and modeled results were found to be close to observed data, with the notable exception of New York City. Resilience was estimated as the change in efficiency resulting from roadway disruptions and was found to vary between cities, with increased delays due to a 5% random loss of road linkages ranging from 9.5% in Los Angeles to 56.0% in San Francisco. The results demonstrate that many urban road systems that operate inefficiently under normal conditions are nevertheless resilient to disruption, whereas some more efficient cities are more fragile. The implication is that resilience, not just efficiency, should be considered explicitly in roadway project selection and justify investment opportunities related to disaster and other disruptions. PMID:29291243
Mereish, Ethan H.; Bradford, Judith B.
2014-01-01
Objective: Research has documented that sexual minorities are at greater risk for substance use than heterosexuals. However, there are limited studies and mixed findings when investigating these health disparities among racial and ethnic minority samples. We used an intersectionality framework to examine disparities in lifetime substance use problems between heterosexual and sexual minority men and women and within sexual minority groups among a racially diverse sample. Method: A nonprobability sample of heterosexual (n = 1,091) and sexual minority (n = 1,465) patients from an urban community health center ranged in age from 18 to 72 years. Participants completed a brief patient survey and reported demographic information and history of lifetime substance use problems. Logistic regressions analyses were used to examine interactions between and among sexual orientation, gender, and race. Results: We found a significant three-way interaction among sexual orientation, gender, and race. Sexual minorities had a greater risk of self-reported lifetime substance use problems than heterosexuals, with nuanced gender and racial differences. Of greatest note, sexual minority women of color had greater risks than heterosexual women of color and than White sexual minority women. Sexual minority men of color did not differ in their risk when compared with heterosexual men of color, and they had lower risk than White sexual minority men. Conclusions: The results of this study demonstrate that an intersectionality framework is crucial to clearly identify lifetime substance use disparities between racially diverse sexual minority and heterosexual men and women. Future research, treatment, and policy should use intersectionality approaches when addressing substance use disparities. PMID:24411810
Gokhale, Sharad; Raokhande, Namita
2008-05-01
There are several models that can be used to evaluate roadside air quality. The comparison of the operational performance of different models pertinent to local conditions is desirable so that the model that performs best can be identified. Three air quality models, namely the 'modified General Finite Line Source Model' (M-GFLSM) of particulates, the 'California Line Source' (CALINE3) model, and the 'California Line Source for Queuing & Hot Spot Calculations' (CAL3QHC) model have been identified for evaluating the air quality at one of the busiest traffic intersections in the city of Guwahati. These models have been evaluated statistically with the vehicle-derived airborne particulate mass emissions in two sizes, i.e. PM10 and PM2.5, the prevailing meteorology and the temporal distribution of the measured daily average PM10 and PM2.5 concentrations in wintertime. The study has shown that the CAL3QHC model would make better predictions compared to other models for varied meteorology and traffic conditions. The detailed study reveals that the agreements between the measured and the modeled PM10 and PM2.5 concentrations have been reasonably good for CALINE3 and CAL3QHC models. Further detailed analysis shows that the CAL3QHC model performed well compared to the CALINE3. The monthly performance measures have also led to the similar results. These two models have also outperformed for a class of wind speed velocities except for low winds (<1 m s(-1)), for which, the M-GFLSM model has shown the tendency of better performance for PM10. Nevertheless, the CAL3QHC model has outperformed for both the particulate sizes and for all the wind classes, which therefore can be optional for air quality assessment at urban traffic intersections.
Lessons Learned: Research within an Urban, African American District
ERIC Educational Resources Information Center
Scott, Kimberly Ann
2012-01-01
For an African American female researcher whose race, class, and gender work as oppressive intersecting units shaping my contextualized experiences, meaning-making, and self-definition, the implications of my work with African American communities are complicated. In this article, I draw on culturally sensitive research practices, critical race…
Racial Counternarratives and Latina Epistemologies in Relational Organizing
ERIC Educational Resources Information Center
Bonilla, Christopher Milk
2014-01-01
This paper describes the perceptions and actions of working-class Latina family leaders as they promote their epistemological values during the community organizing of a "huerta" (vegetable garden) in an urban bilingual school. I focus on how their racial counternarratives are embedded in the intersected oppression of their local context…
A Social History of Media, Technology and Schooling
ERIC Educational Resources Information Center
Domine, Vanessa
2009-01-01
This article explores the literature in the intersecting fields of media, technology and schooling in the United States across the past two centuries. It organizes the research from a social-historical perspective through a fictionalized interview with an archetypal third-generation urban public school teacher. This topography illustrates the…
Rudolph, Abby E; Young, April M; Havens, Jennifer R
2017-11-01
Analyses that link contextual factors with individual-level data can improve our understanding of the "risk environment"; however, the accuracy of information provided by participants about locations where illegal/stigmatized behaviors occur may be influenced by privacy/confidentiality concerns that may vary by setting and/or data collection approach. We recruited thirty-five persons who use drugs from a rural Appalachian town and a Mid-Atlantic city to participate in in-depth interviews. Through thematic analyses, we identified and compared privacy/confidentiality concerns associated with two survey methods that (1) collect self-reported addresses/cross-streets and (2) use an interactive web-based map to find/confirm locations in rural and urban settings. Concerns differed more by setting than between methods. For example, (1) rural participants valued interviewer rapport and protections provided by the Certificate of Confidentiality more; (2) locations considered to be sensitive differed in rural (i.e., others' homes) and urban (i.e., where drugs were used) settings; and (3) urban participants were more likely to view providing cross-streets as an acceptable alternative to providing exact addresses for sensitive locations and to prefer the web-based map approach. Rural-urban differences in privacy/confidentiality concerns reflect contextual differences (i.e., where drugs are used/purchased, population density, and prior drug-related arrests). Strategies to alleviate concerns include: (1) obtain a Certificate of Confidentiality, (2) collect geographic data at the scale necessary for proposed analyses, and (3) permit participants to provide intersections/landmarks in close proximity to actual locations rather than exact addresses or to skip questions where providing an intersection/landmark would not obfuscate the actual address. Copyright © 2017 Elsevier Ltd. All rights reserved.
Bowleg, Lisa; English, Devin; del Rio-Gonzalez, Ana Maria; Burkholder, Gary J.; Teti, Michelle; Tschann, Jeanne M.
2015-01-01
Although extensive research documents that Black people in the U.S. frequently experience social discrimination, most of this research aggregates these experiences primarily or exclusively by race. Consequently, empirical gaps exist about the psychosocial costs and benefits of Black men’s experiences at the intersection of race and gender. Informed by intersectionality, a theoretical framework that highlights how multiple social identities intersect to reflect interlocking social-structural inequality, this study addresses these gaps with the qualitative development and quantitative test of the Black Men’s Experiences Scale (BMES). The BMES assesses Black men’s negative experiences with overt discrimination and microaggressions, as well their positive evaluations of what it means to be Black men. First, we conducted focus groups and individual interviews with Black men to develop the BMES. Next, we tested the BMES with 578 predominantly low-income urban Black men between the ages of 18 and 44. Exploratory factor analysis suggested a 12-item, 3-factor solution that explained 63.7% of the variance. We labeled the subscales: Overt Discrimination, Microaggressions, and Positives: Black Men. Confirmatory factor analysis supported the three-factor solution. As hypothesized, the BMES’s subscales correlated with measures of racial discrimination, depression, resilience, and social class at the neighborhood-level. Preliminary evidence suggests that the BMES is a reliable and valid measure of Black men’s experiences at the intersection of race and gender. PMID:27087786
Bowleg, Lisa; English, Devin; Del Rio-Gonzalez, Ana Maria; Burkholder, Gary J; Teti, Michelle; Tschann, Jeanne M
2016-04-01
Although extensive research documents that Black people in the U.S. frequently experience social discrimination, most of this research aggregates these experiences primarily or exclusively by race. Consequently, empirical gaps exist about the psychosocial costs and benefits of Black men's experiences at the intersection of race and gender. Informed by intersectionality, a theoretical framework that highlights how multiple social identities intersect to reflect interlocking social-structural inequality, this study addresses these gaps with the qualitative development and quantitative test of the Black Men's Experiences Scale (BMES). The BMES assesses Black men's negative experiences with overt discrimination and microaggressions, as well their positive evaluations of what it means to be Black men. First, we conducted focus groups and individual interviews with Black men to develop the BMES. Next, we tested the BMES with 578 predominantly low-income urban Black men between the ages of 18 and 44. Exploratory factor analysis suggested a 12-item, 3-factor solution that explained 63.7% of the variance. We labeled the subscales: Overt Discrimination, Microaggressions, and Positives: Black Men . Confirmatory factor analysis supported the three-factor solution. As hypothesized, the BMES's subscales correlated with measures of racial discrimination, depression, resilience, and social class at the neighborhood-level. Preliminary evidence suggests that the BMES is a reliable and valid measure of Black men's experiences at the intersection of race and gender.
Koohsari, Mohammad Javad; Sugiyama, Takemi; Shibata, Ai; Ishii, Kaori; Liao, Yung; Hanibuchi, Tomoya; Owen, Neville; Oka, Koichiro
2017-05-01
We examined whether street layout -a key urban design element- is associated with walking and sedentary behaviors in the context of a non-Western country; and, whether such associations differ between an urban and a rural area. In 2011, 1076 middle-to-older aged adults living in an urban and a rural area of Japan reported their walking and sedentary (sitting) behaviors. Two objective measures of street layout (intersection density and street integration) were calculated. Participants exposed to more-connected street layouts were more likely to walk for commuting and for errands, to meet physical activity recommendations through walking for commuting, and less likely to drive. These relationships differed between the urban and the rural area. This shows that previous findings from Western countries on associations of street connectivity with travel behaviors may also be applicable to Japan. Copyright © 2017 Elsevier Ltd. All rights reserved.
Activist Literacies: Validating Aboriginality through Visual and Literary Identity Texts
ERIC Educational Resources Information Center
Montero, M. Kristiina; Bice-Zaugg, Cassandra; Marsh, Makwa Oshkwenh-Adam Cyril John; Cummins, Jim
2013-01-01
Framed at the intersection of activist and Indigenous research methodologies, this article explores the way two First Nations senior high school students made sense of their visual and literary identity texts (Cummins & Early, 2011). An Ojibwe artist-in-residence at an urban secondary school in southwestern Ontario and a university-based…
ERIC Educational Resources Information Center
Dallavis, Christian
2013-01-01
This article explores the intersection of culturally responsive pedagogy and faith-based schooling. The author presents a portion of a larger ethnographic research project conducted at a Catholic elementary school that serves a predominantly Latino population in urban Chicago. This work contributes to theories of culturally responsive education by…
Increased stormwater flows are a direct result of urbanization and the consequent increase in the proportion of land area under impervious surface. Due to its contribution to abnormally high stream flows and its role as a carrier of pollutants that degrade water quality, exc...
DOT National Transportation Integrated Search
2014-01-01
Rail lines present two major challenges to the : roadways they intersect: potential for collisions : and increased congestion. In addition, congestion : can contribute collision hazards when drivers are : impatient or vehicles are prevented from clea...
Living and Learning at the Intersection: Student Homelessness and Complex Policy Environments
ERIC Educational Resources Information Center
Pavlakis, Alexandra E.
2014-01-01
In urban districts, homeless and highly mobile students are an important contributor to achievement disparities-and their numbers are rising. To date there has been little inquiry into how broader education and housing policies shape the schooling experiences of homeless and highly mobile families. Using semi-structured interviews with 132 key…
ERIC Educational Resources Information Center
Lee, Jo-Anne; De Finney, Sandrina
2004-01-01
This chapter examines the use of popular theatre as a methodology to investigate racialized minority girls' processes of identity formation and experiences of exclusion and belonging in predominantly white, urban Victoria, B.C., Canada. The article draws on transnational feminist frameworks that emphasize intersectionality and locality to…
Wallace, Brandy Harris; Reese, Ashante M; Chard, Sarah; Roth, Erin G; Quinn, Charlene; Eckert, J Kevin
2017-04-01
African Americans experience high rates of type 2 diabetes mellitus (T2D). Self-management strategies, such as medication adherence, are key to mitigating negative T2D outcomes. This article addresses a gap in the literature by examining the intersections of drug abuse histories and medication adherence among urban, older African Americans with T2D. In-depth interview data were collected as part of a larger ethnographic study examining the subjective experience of T2D among urban older adults. Two representative focal cases were selected and thematic analysis performed to illustrate how former illicit drug addicts perceive prescription medication usage. Narratives reveal that participants are displeased about having to take prescription drugs and are making lifestyle changes to reduce medication usage and maintain sobriety. Previous drug abuse not only complicates medication adherence but is also a significant part of how older African Americans who are former drug users frame their understanding of T2D more broadly.
LCA as a Tool to Evaluate Green Infrastructure's Environmental Performance
NASA Astrophysics Data System (ADS)
Catalano De Sousa, M.; Erispaha, A.; Spatari, S.; Montalto, F.
2011-12-01
Decentralized approaches to managing urban stormwater through use of green infrastructure (GI) often lead to system-wide efficiency gains within the urban watershed's energy supply system. These efficiencies lead to direct greenhouse gas (GHG) emissions savings, and also restore some ecosystem functions within the urban landscape. We developed a consequential life cycle assessment (LCA) model to estimate the life cycle energy, global warming potential (GWP), and payback times for each if GI were applied within a select neighborhood in New York City. We applied the SIMAPRO LCA software and the economic input-output LCA (EIO-LCA) tool developed by Carnegie Mellon University. The results showed that for a new intersection installation highlighted in this study a conventional infrastructure construction would emit and use approximately 3 times more for both CO2 and energy than a design using GI. Two GI benefits were analyzed with regards to retrofitting the existing intersection. The first was related to the savings in energy and CO2 at the Waste Water Treatment Plant via runoff reduction accrued from GI use. The second benefit was related to the avoided environmental costs associated with an additional new grey infrastructure installation needed to prevent CSO in case of no GI implementation. The first benefit indicated a high payback time for a GI installation in terms of CO2 and energy demand (80 and 90 years respectively) and suggest a slow energy and carbon recovery time. However, concerning to the second benefit, GI proved to be a sustainable alternative considering the high CO2 releases (429 MTE) and energy demand (5.5 TJ) associated with a grey infrastructure construction.
Automated Announcements of Approaching Emergency Vehicles
NASA Technical Reports Server (NTRS)
Bachelder, Aaron; Foster, Conrad
2006-01-01
Street intersections that are equipped with traffic lights would also be equipped with means for generating audible announcements of approaching emergency vehicles, according to a proposal. The means to generate the announcements would be implemented in the intersection- based subsystems of emergency traffic-light-preemption systems like those described in the two immediately preceding articles and in "Systems Would Preempt Traffic Lights for Emergency Vehicles" (NPO-30573), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 36. Preempting traffic lights is not, by itself, sufficient to warn pedestrians at affected intersections that emergency vehicles are approaching. Automated visual displays that warn of approaching emergency vehicles can be helpful as a supplement to preemption of traffic lights, but experience teaches that for a variety of reasons, pedestrians often do not see such displays. Moreover, in noisy and crowded urban settings, the lights and sirens on emergency vehicles are often not noticed until a few seconds before the vehicles arrive. According to the proposal, the traffic-light preemption subsystem at each intersection would generate an audible announcement for example, emergency vehicle approaching, please clear intersection whenever a preemption was triggered. The subsystem would estimate the time of arrival of an approaching emergency vehicle by use of vehicle identity, position, and time data from one or more sources that could include units connected to traffic loops and/or transponders connected to diagnostic and navigation systems in participating emergency vehicles. The intersection-based subsystem would then start the announcement far enough in advance to enable pedestrians to leave the roadway before any emergency vehicles arrive.
A bicycle safety index for evaluating urban street facilities.
Asadi-Shekari, Zohreh; Moeinaddini, Mehdi; Zaly Shah, Muhammad
2015-01-01
The objectives of this research are to conceptualize the Bicycle Safety Index (BSI) that considers all parts of the street and to propose a universal guideline with microscale details. A point system method comparing existing safety facilities to a defined standard is proposed to estimate the BSI. Two streets in Singapore and Malaysia are chosen to examine this model. The majority of previous measurements to evaluate street conditions for cyclists usually cannot cover all parts of streets, including segments and intersections. Previous models also did not consider all safety indicators and cycling facilities at a microlevel in particular. This study introduces a new concept of a practical BSI to complete previous studies using its practical, easy-to-follow, point system-based outputs. This practical model can be used in different urban settings to estimate the level of safety for cycling and suggest some improvements based on the standards.
NASA Astrophysics Data System (ADS)
Inomata, Satoshi; Fujitani, Yuji; Fushimi, Akihiro; Tanimoto, Hiroshi; Sekimoto, Kanako; Yamada, Hiroyuki
2014-10-01
Field measurements of seven nitro-organic compounds including nitromethane and ten related volatile organic compounds were carried out using proton-transfer-reaction mass spectrometry at a busy intersection of an urban city, Kawasaki, Japan from 26th February to 6th March, 2011. Among the nitro-organic compounds, nitromethane was usually observed along with air pollutants emitted from automobiles. The mixing ratios of nitromethane varied substantially and sometimes clearly varied at an approximately constant interval. The interval corresponded to the cycle of the traffic signals at the intersection and the regular peaks of nitromethane concentrations were caused by emissions from diesel trucks running with high speed. In addition to the regular peaks, sharp increases of nitromethane concentrations were often observed irregularly from diesel trucks accelerating in front of the measurement site. For other nitro-organic compounds such as nitrophenol, nitrocresol, dihydroxynitrobenzene, nitrobenzene, nitrotoluene, and nitronaphthalene, most of the data fluctuated within the detection limits.
Vera-Villarroel, Pablo; Contreras, Daniela; Lillo, Sebastián; Segovia, Ariel; Rojo, Natalia; Moreno, Sandra; Oyarzo, Francisco
2016-01-01
The perception of colour and its subjective effects are key issues to designing safe and enjoyable bike lanes. This paper addresses the relationship between the colours of bike lane interventions—in particular pavement painting and intersection design—and the subjective evaluation of liking, visual saliency, and perceived safety related to such an intervention. Utilising images of three real bike lane intersections modified by software to change their colour (five in total), this study recruited 538 participants to assess their perception of all fifteen colour-design combinations. A multivariate analysis of covariance (MANCOVA) with the Bonferroni post hoc test was performed to assess the effect of the main conditions (colour and design) on the dependent variables (liking towards the intervention, level of visual saliency of the intersection, and perceived safety of the bike lane). The results showed that the colour red was more positively associated to the outcome variables, followed by yellow and blue. Additionally, it was observed that the effect of colour widely outweighs the effect of design, suggesting that the right choice and use of colour would increase the effectiveness on bike-lanes pavement interventions. Limitations and future directions are discussed. PMID:27548562
Coaxial Compound Helicopter for Confined Urban Operations
NASA Technical Reports Server (NTRS)
Johnson, Wayne; Elmore, Joshua F.; Keen, Ernest B.; Gallaher, Andrew T.; Nunez, Gerardo F.
2016-01-01
A rotorcraft was designed for military operations in a confined urban environment. The specifications included major increases in useful load, range, and speed relative current aircraft capabilities, with a size constraint based on the dimensions of urban streets and intersections. Analysis showed that this combination of requirements is best satisfied by a coaxial main-rotor configuration, with lift compounding to off-load the rotors at high speed, and ducted fans under the rotor disk for propulsion. The baseline design is described, and the aircraft performance is summarized for utility, attack, MEDEVAC, and cargo delivery missions. The impact on size and performance is examined for a number of excursions, including lift-offset main rotors. Technology development required to achieve this advance in capability is recommended.
ERIC Educational Resources Information Center
Ngotho, Muthoni; Fincham, Robert; Quinn, Nevil
2004-01-01
This paper focuses on the need to further environmental education research within a context in which local government, local business and tertiary institutions are viewed as interlinked components of the development process. Research and interaction with local stakeholders offers an opportunity to chart a path that intersects and then fuses…
ERIC Educational Resources Information Center
Kazeem, Aramide; Jensen, Leif; Stokes, C. Shannon
2010-01-01
This article presents a research which examines the impact of religion, gender, and parental socioeconomic status on school attendance in Nigeria. Researchers found that both gender and parental socioeconomic status have significant impacts on school attendance. Although gender is an important determinant of school attendance, indicators of…
Whose Language Is Legit? Intersections of Race, Ethnicity, and Language
ERIC Educational Resources Information Center
Zisselsberger, Margarita; Collins, Kristina
2016-01-01
This case describes St. Lucy School, a K-8 elementary school in a mid-sized urban center. St. Lucy has traditionally served African American students. In the past 10 years, the neighborhood has experienced a significant shift in population, such that many Latino/a families are now entering the school. In response to these changes, the school…
Response to Evaluation Field Building in South Asia: Reflections, Anecdotes, and Questions
ERIC Educational Resources Information Center
King, Jean A.
2010-01-01
The author is increasingly sensitive to the Venn diagram of overlapping expertise in which program evaluation intersects a content area such as public health, urban education, or--in the case of Katherine Hay--international development. Many evaluators practice in these areas of overlap, experts in the evaluation of a specific domain. Given her…
ERIC Educational Resources Information Center
Cheng, Li; Tan, Mei; Liu, Zhengkui
2015-01-01
China has been undergoing great social change due to its new focus on urbanization and globalization. Such change has had a tremendous adverse impact on the living conditions of millions of young children, simultaneously generating new interest in children's creativity development. The intersection of these two issues has important implications…
Probation and Head Lice: The Intersection of Corrections and Education
ERIC Educational Resources Information Center
Kronick, Robert F.
2006-01-01
The critical incident that drove this article involved a single mother who was on probation for drug offenses. Her two daughters were sent home from their Title I urban elementary school on a frequent basis because of head lice. This situation prompted several questions: Can we and should we be able to legislate and enforce cleanliness? Is…
NASA Astrophysics Data System (ADS)
Ramesh, Adepu; Ashritha, Kilari; Kumar, Molugaram
2018-04-01
Walking has always been a prime source of human mobility for short distance travel. Traffic congestion has become a major problem for safe pedestrian crossing in most of the metropolitan cities. This has emphasized for providing a sufficient pedestrian gap for safe crossing on urban road. The present works aims in understanding factors that influence pedestrian crossing behaviour. Four locations were chosen for identification of pedestrian crossing behaviour, gap characteristics, waiting time etc., in Hyderabad city. From the study it was observed that pedestrian behaviour and crossing patterns are different and is influenced by land use pattern. A gap acceptance model was developed from the data for improving pedestrian safety at mid-block location; the model was validated using the existing data. Pedestrian delay was estimated at intersection using Highway Capacity Manual (HCM). It was observed that field delays are less when compared to delay arrived from HCM method.
Grasser, Gerlinde; Van Dyck, Delfien; Titze, Sylvia; Stronegger, Willibald
2013-08-01
The aim of this study was to investigate which GIS-based measures of walkability (density, land-use mix, connectivity and walkability indexes) in urban and suburban neighbourhoods are used in research and which of them are consistently associated with walking and cycling for transport, overall active transportation and weight-related measures in adults. A systematic review of English publications using PubMed, Science Direct, Active Living Research Literature Database, the Transportation Research Information Service and reference lists was conducted. The search terms utilised were synonyms for GIS in combination with synonyms for the outcomes. Thirty-four publications based on 19 different studies were eligible. Walkability measures such as gross population density, intersection density and walkability indexes most consistently correlated with measures of physical activity for transport. Results on weight-related measures were inconsistent. More research is needed to determine whether walkability is an appropriate measure for predicting weight-related measures and overall active transportation. As most of the consistent correlates, gross population density, intersection density and the walkability indexes have the potential to be used in planning and monitoring.
Population-Adjusted Street Connectivity, Urbanicity and Risk of Obesity in the U.S
Wang, Fahui; Wen, Ming; Xu, Yanqing
2013-01-01
Street connectivity, defined as the number of (3-way or more) intersections per area unit, is an important index of built environments as a proxy for walkability in a neighborhood. This paper examines its geographic variations across the rural-urban continuum (urbanicity), major racial-ethnic groups and various poverty levels. The population-adjusted street connectivity index is proposed as a better measure than the regular index for a large area such as county due to likely concentration of population in limited space within the large area. Based on the data from the Behavioral Risk Factor Surveillance System (BRFSS), this paper uses multilevel modeling to analyze its association with physical activity and obesity while controlling for various individual and county-level variables. Analysis of data subsets indicates that the influences of individual and county-level variables on obesity risk vary across areas of different urbanization levels. The positive influence of street connectivity on obesity control is limited to the more but not the mostly urbanized areas. This demonstrates the value of obesogenic environment research in different geographic settings, helps us reconcile and synthesize some seemingly contradictory results reported in different studies, and also promotes that effective policies need to be highly sensitive to the diversity of demographic groups and geographically adaptable. PMID:23667278
Sauvons le Luxembourg: urban greenspace as private domain and public battleground, 1865-1867.
Hopkins, Richard S
2011-01-01
This article examines the way in which public response to a municipal proposal concerning greenspace reduction in Paris during the Second Empire reflected not only political antipathy but also an ever-increasing understanding of public urban greenspace as part of the private domain. By examining archival records concerning the proposal, essays, newspaper accounts, and memoirs, this article argues that a particular proprietary sensibility, fomented by expansive public greenspace development in Paris, intersected with extant social constructs and political tensions to create a public, coordinated, and sustained challenge to the authoritarian regime. Thus, the battle over the Luxembourg Garden became more than just a fight to prevent a reduction in size of a particular public urban greenspace. Rather, public debate surrounding alteration of this garden underscores the extent to which public greenspace, in general, was urban space that blurred the public—private boundary and presented unique opportunities for community formation, social integration, and political action.
Spatial connectivity, scaling, and temporal trajectories as emergent urban stormwater impacts
NASA Astrophysics Data System (ADS)
Jovanovic, T.; Gironas, J. A.; Hale, R. L.; Mejia, A.
2016-12-01
Urban watersheds are structurally complex systems comprised of multiple components (e.g., streets, pipes, ponds, vegetated swales, wetlands, riparian corridors, etc.). These multiple engineered components interact in unanticipated and nontrivial ways with topographic conditions, climate variability, land use/land cover changes, and the underlying eco-hydrogeomorphic dynamics. Such interactions can result in emergent urban stormwater impacts with cascading effects that can negatively influence the overall functioning of the urban watershed. For example, the interaction among many detention ponds has been shown, in some situations, to synchronize flow volumes and ultimately lead to downstream flow amplifications and increased pollutant mobilization. Additionally, interactions occur at multiple temporal and spatial scales requiring that urban stormwater dynamics be represented at the long-term temporal (decadal) and across spatial scales (from the single lot to the watershed scale). In this study, we develop and implement an event-based, high-resolution, network hydro-engineering model (NHEM), and demonstrate an approach to reconstruct the long-term regional infrastructure and land use/land cover conditions of an urban watershed. As the study area, we select an urban watershed in the metropolitan area of Scottsdale, Arizona. Using the reconstructed landscapes to drive the NHEM, we find that distinct surficial, hydrologic connectivity patterns result from the intersection of hydrologic processes, infrastructure, and land use/land cover arrangements. These spatial patters, in turn, exhibit scaling characteristics. For example, the scaling of urban watershed dispersion mechanisms shows altered scaling exponents with respect to pre-urban conditions. For example, the scaling exponent associated with geomorphic dispersion tends to increase for urban conditions, reflecting increased surficial path heterogeneity. Both the connectivity and scaling results can be used to delineate impact trajectories (i.e. the evolution of spatially referenced impacts over time). We find that the impact trajectories provide insight about the urban stormwater sustainability of watersheds as well as clues about the potential imprint of socio-environmental feedbacks in the evolutionary dynamics.
Validity of Walk Score® as a measure of neighborhood walkability in Japan.
Koohsari, Mohammad Javad; Sugiyama, Takemi; Hanibuchi, Tomoya; Shibata, Ai; Ishii, Kaori; Liao, Yung; Oka, Koichiro
2018-03-01
Objective measures of environmental attributes have been used to understand how neighborhood environments relate to physical activity. However, this method relies on detailed spatial data, which are often not easily available. Walk Score® is a free, publicly available web-based tool that shows how walkable a given location is based on objectively-derived proximity to several types of local destinations and street connectivity. To date, several studies have tested the concurrent validity of Walk Score as a measure of neighborhood walkability in the USA and Canada. However, it is unknown whether Walk Score is a valid measure in other regions. The current study examined how Walk Score is correlated with objectively-derived attributes of neighborhood walkability, for residential addresses in Japan. Walk Scores were obtained for 1072 residential addresses in urban and rural areas in Japan. Five environmental attributes (residential density, intersection density, number of local destinations, sidewalk availability, and access to public transportation) were calculated using geographic information systems for each address. Pearson's correlation coefficients between Walk Score and these environmental attributes were calculated (conducted in May 2017). Significant positive correlations were observed between Walk Score and environmental attributes relevant to walking. Walk Score was most closely associated with intersection density ( r = 0.82) and with the number of local destinations ( r = 0.77). Walk Score appears to be a valid measure of neighborhood walkability in Japan. Walk Score will allow urban designers and public health practitioners to identify walkability of local areas without relying on detailed geographic data.
ERIC Educational Resources Information Center
Price, Jeremy F.; McNeill, Katherine L.
2013-01-01
As knowledge of and familiarity with science becomes an increasingly important aspect of contemporary life and citizenship, efforts have been made to make the science curriculum a “lived” curriculum (Hurd, 2000), one that reaches out to the lives, communities, and experiences of students. In this research around a high school urban ecology…
Building the Future on Knowledge
ERIC Educational Resources Information Center
Principal Leadership, 2005
2005-01-01
Deep in a heavily Latino section of urban East Los Angeles, at the intersection of Knights Lane and Kings Row, approximately 2,300 high school students go about the business of school with a sense of purpose and resolve. The majesty of the San Gabriel Mountains can be seen to the north of this vast 40-acre campus, the stark poverty of a housing…
ERIC Educational Resources Information Center
Tan, Edna; Calabrese Barton, Angela
2018-01-01
We investigated how community ethnography as a pedagogy approach to STEM-rich making supported youth makers from two low-income urban communities engaged in sustained STEM-rich making towards making a difference in their communities. Data is drawn from two-year long ethnographic data across two community-based, youth making programs. We highlight…
ERIC Educational Resources Information Center
Palmer, Deborah; Henderson, Kathryn; Wall, Dorothy; Zúñiga, Christian E.; Berthelsen, Stefan
2016-01-01
This article documents and interrogates top-down district-wide implementation of a two-way dual language bilingual education (DLBE) program in a large urban district. We carried out a language policy ethnography to explore the way two schools' teams of third grade teachers worked together to negotiate the intersection of DLBE implementation and…
USDA-ARS?s Scientific Manuscript database
Aquaculture, which is growing 3-5 times faster than terrestrial agriculture, will play an important role to meet future global food production needs. However, 80% of global sewage production is returned to the environment untreated. In developing nations, these non-traditional waters of diverse qual...
Cities of Consumption: The Impact of Corporate Practices on the Health of Urban Populations
Galea, Sandro
2008-01-01
The increasing concentration of the world’s population in cities and the growing accumulation of political and economic power by corporations create new threats to health and opportunities for improving global health. By considering the intersection of these two fundamental social determinants of well-being, we elucidate some of the mechanisms by which they influence the health of urban populations. After reviewing the changing historical impact of corporations on cities, we focus on the growth of consumption as a leading cause of mortality and morbidity and describe how the food, tobacco, automobile, and other industries promote unhealthy behaviors and lifestyles in urban settings. Cities are also sites for developing alternatives to unhealthy corporate practices, and we assess strategies used to modify practices that harm health. PMID:18437582
Kou, Weibin; Chen, Xumei; Yu, Lei; Gong, Huibo
2018-04-18
Most existing signal timing models are aimed to minimize the total delay and stops at intersections, without considering environmental factors. This paper analyzes the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. First, considering the different operating modes of cruising, acceleration, deceleration, and idling, field data of emissions and Global Positioning System (GPS) are collected to estimate emission rates for heavy-duty and light-duty vehicles. Second, multiobjective signal timing optimization model is established based on a genetic algorithm to minimize delay, stops, and emissions. Finally, a case study is conducted in Beijing. Nine scenarios are designed considering different weights of emission and traffic efficiency. The results compared with those using Highway Capacity Manual (HCM) 2010 show that signal timing optimized by the model proposed in this paper can decrease vehicles delay and emissions more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development. Vehicle emissions are heavily at signal intersections in urban area. The multiobjective signal timing optimization model is proposed considering the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. The results indicate that signal timing optimized by the model proposed in this paper can decrease vehicle emissions and delays more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development.
NASA Astrophysics Data System (ADS)
Furman, Melina Gabriela
The current scenario in American education shows a large achievement and opportunity gap in science between urban children in poverty and more privileged youth. Research has shown that one essential factor that accounts for this gap is the shortage of qualified science teachers in urban schools. Teaching science in a high poverty school presents unique challenges to beginner teachers. Limited resources and support and a significant cultural divide with their students are some of the common problems that cause many novice teachers to quit their jobs or to start enacting what has been described as "the pedagogy of poverty." In this study I looked at the case of the Urban Science Education Fellows Program. This program aimed to prepare preservice teachers (i.e. "fellows") to enact socially just science pedagogies in urban classrooms. I conducted qualitative case studies of three fellows. Fellows worked over one year with science teachers in middle-school classrooms in order to develop transformative action research studies. My analysis focused on how fellows coauthored hybrid spaces within these studies that challenged the typical ways science was taught and learned in their classrooms towards a vision of socially just teaching. By coauthoring these hybrid spaces, fellows developed grounded generativity, i.e. a capacity to create new teaching scenarios rooted in the pragmatic realities of an authentic classroom setting. Grounded generativity included building upon their pedagogical beliefs in order to improvise pedagogies with others, repositioning themselves and their students differently in the classroom and constructing symbols of possibility to guide their practice. I proposed authentic play as the mechanism that enabled fellows to coauthor hybrid spaces. Authentic play involved contexts of moderate risk and of distributed expertise and required fellows to be positioned at the intersection of the margins and the center of the classroom community of practice. In all, this study demonstrates that engaging in classroom reform can support preservice teachers in developing specialized tools to teach science in urban classrooms.
Li, F.; Fisher, K; Brownson, R.; Bosworth, M.
2005-01-01
Objective: To examine the relation between built environment factors (representing several dimensions of urban form of neighbourhoods) and walking activity at both the neighbourhood level and the resident level, in an older adult sample. Design, setting, participants: A cross sectional, multilevel design with neighbourhoods as the primary sampling unit and senior residents as the secondary unit. Five hundred and seventy seven residents (mean age = 74 years, SD = 6.3 years) participated in the survey, which was conducted among 56 city defined neighbourhoods in Portland, Oregon, USA. Neighbourhood level variables were constructed using geographical information systems. Resident level variables consisted of a mix of self reports and geocoded data on the built environment. Main outcome measure: Self reported neighbourhood walking. Main results: A positive relation was found between built environment factors (density of places of employment, household density, green and open spaces for recreation, number of street intersections) and walking activity at the neighbourhood level. At the resident level, perceptions of safety for walking and number of nearby recreational facilities were positively related to high levels of walking activity. A significant interaction was observed between number of street intersections and perceptions of safety from traffic. Conclusions: Certain neighbourhood built environment characteristics related to urban form were positively associated with walking activity in the neighbourhoods of senior residents. Public health promotion of walking activity/urban mobility and the design of interventions need to consider the contribution of neighbourhood level built environment influences. PMID:15965138
The intersection of everyday life and group prenatal care for women in two urban clinics.
Novick, Gina; Sadler, Lois S; Knafl, Kathleen A; Groce, Nora Ellen; Kennedy, Holly Powell
2012-05-01
Women from vulnerable populations encounter challenging circumstances that generate stress and may adversely affect their health. Group prenatal care (GPNC) incorporates features that address social stressors, and has been demonstrated to improve pregnancy outcomes and prenatal care experiences. In this qualitative study, we describe the complex circumstances in the lives of women receiving care in two urban clinics and how GPNC attenuated them. Stressors included problems with transportation and child care, demanding jobs, poverty, homelessness, difficult relationships with partners, limited family support, and frustrating health care experiences. Receiving prenatal care in groups allowed women to strengthen relationships with significant others, gain social support, and develop meaningful relationships with group leaders. By eliminating waits and providing the opportunity to participate in care, GPNC also offered sanctuary from frustrations encountered in receiving individual care. Reducing such stressors may help improve pregnancy outcomes; however, more evidence is needed on mechanisms underlying these effects.
Assessment of the impacts of vehicular pollution on urban air quality.
Ghose, Mrinal K; Paul, R; Banerjee, S K
2004-01-01
Air quality crisis in cities is mainly due to vehicular emissions. Owing to the expanding economic base Indian cities are growing at a faster rate. Transportation systems are increasing everywhere and the improved technology is insufficient to counteract growth. The effect of vehicular emission on urban air quality and human health has been described. A survey has been conducted in an Indian mega city to evaluate the status of air pollution at traffic intersections and the unique problem arising out of vehicular emissions in the study area has been narrated. Approach for the selection of the air monitoring stations, methodology adopted for data collection and the results have been discussed. Vulnerability analysis (VA) has been carried out to identify the zones at what pollution stress. Options for reducing mobile source emission have been discussed and a strategic air quality management plan has been proposed to mitigate the air pollution in the city.
Parametric laws to model urban pollutant dispersion with a street network approach
NASA Astrophysics Data System (ADS)
Soulhac, L.; Salizzoni, P.; Mejean, P.; Perkins, R. J.
2013-03-01
This study discusses the reliability of the street network approach for pollutant dispersion modelling in urban areas. This is essentially based on a box model, with parametric relations that explicitly model the main phenomena that contribute to the street canyon ventilation: the mass exchanges between the street and the atmosphere, the pollutant advection along the street axes and the pollutant transfer at street intersections. In the first part of the paper the focus is on the development of a model for the bulk transfer street/atmosphere, which represents the main ventilation mechanisms for wind direction that are almost perpendicular to the axis of the street. We then discuss the role of the advective transfer along the street axis on its ventilation, depending on the length of the street and the direction of the external wind. Finally we evaluate the performances of a box model integrating parametric exchange laws for these transfer phenomena. To that purpose we compare the prediction of the model to wind tunnel experiments of pollutant dispersion within a street canyon placed in an idealised urban district.
The influence of the infrastructure characteristics in urban road accidents occurrence.
Vieira Gomes, Sandra
2013-11-01
This paper summarizes the result of a study regarding the creation of tools that can be used in intervention methods in the planning and management of urban road networks in Portugal. The first tool relates the creation of a geocoded database of road accidents occurred in Lisbon between 2004 and 2007, which allowed the definition of digital maps, with the possibility of a wide range of consultations and crossing of information. The second tool concerns the development of models to estimate the frequency of accidents on urban networks, according to different desegregations: road element (intersections and segments); type of accident (accidents with and without pedestrians); and inclusion of explanatory variables related to the road environment. Several methods were used to assess the goodness of fit of the developed models, allowing more robust conclusions. This work aims to contribute to the scientific knowledge of accidents phenomenon in Portugal, with detailed and accurate information on the factors affecting its occurrence. This allows to explicitly include safety aspects in planning and road management tasks. Copyright © 2013 Elsevier Ltd. All rights reserved.
Tachikawa, Tomoko; Hashimoto, Shusa
2007-12-01
The results of questionnaire and interview surveys conducted in Mitaka and Musashino cities are presented for investigating of residents' evaluation of their urban environment, particularly regarding its attractiveness. A special attention was paid to residents' evaluation with regard to anxiety associated with traffic accidents and urban crimes. The urban infrastructure and residents' responses were examined using a Geographic Information System (GIS). Attractiveness associated with the urban environment was classified into two categories: "attractiveness in daily life" and "attractiveness in non-daily life." The residents valued opportunities for relaxing and living in comfort. In non-daily life, the residents specifically valued improved living conditions and harmony between the natural environment and commercial facilities. They attributed crime anxiety to trees, narrow streets, obstructed views, dark areas and a gloomy atmosphere. Residents regarded violent crimes as being prevalent, but considered trespassing and property crimes infrequent. The residents' anxiety about traffic accidents was caused by reckless driving habits, narrow streets, lack of separation between roadway and pedestrians' ways, heavy traffic, and obstructed views. Residents cited main roads and intersections as locations of anxiety, which concurred with frequent accidents.
NASA Astrophysics Data System (ADS)
Albright, C. M.; Traver, R.; Wadzuk, B.
2017-12-01
Analysis of local-to-regional climate data is critical in understanding how changing patterns in rainfall and other atmospheric conditions can affect urban hydrology. Urbanization has caused hydrologic and ecologic modifications to our land surfaces, and altered the dynamics of urban water cycle in complex ways. Green infrastructure (GI) systems, in their simplest form, reduce runoff and flooding, prevent combined sewer overflows and improve quality of receiving waters. However, when viewed through a more holistic lens, GI systems sit at the nexus of hydrology, climate and energy, yet are rarely designed to account for the impacts of these intersections. We must assess urban hydrologic systems beyond their response to a single event or design storm, incorporating multiple temporal scales and all hydrologic processes. This is of utmost importance to design and characterization of urban GI systems because the resilience of these systems will be dictated by their ability to adapt to future behavior of extreme weather patterns and climate. In this study, we characterize long-term hydrologic conditions in Philadelphia to identify periods of record that are most representative of regional climate characteristics, including a representative rainfall year and longer representative periods. Utility of these datasets will be demonstrated by showing that GI systems are able to sustain effective performance for most expected annual precipitation events. Connections between atmospheric (precipitation and temperature) patterns, GI systems and potential removal mechanisms in the urban hydrologic cycle will be presented for Philadelphia and cities with similar climate characteristics. Establishing such connections is critically needed to not only validate what is already known about urban GI, but more importantly, to advance theory and practice by linking the hydrologic benefits of urban GI to broader concepts such as risk, mitigation of extreme events and sustainable communities.
NASA Astrophysics Data System (ADS)
Chen, Jie; Li, Ming; Jiang, Rui; Hu, Mao-Bin
2017-09-01
In a real traffic system, information feedback has already been proven to be a good way to alleviate traffic jams. However, due to the massive traffic information of real system, the procedure is often difficult in practice. In this paper, we study the effects of the amount of feedback information based on a cellular automaton model of urban traffic. What we found most interesting is that when providing the traffic information of a part of a road to travelers, the performance of the system will be better than that providing the road's full traffic information. From this basis, we can provide more effective routing strategy with less information. We demonstrate that only providing the traffic information of about first half road from upstream to downstream can maximize the traffic capacity of the system. We also give an explanation for these phenomena by studying the distribution pattern of vehicles and the detailed turning environment at the intersections. The effects of the traffic light period are also provided.
Knight, Kelly R; Lopez, Andrea M; Comfort, Megan; Shumway, Martha; Cohen, Jennifer; Riley, Elise D
2014-05-01
Due to the significantly high levels of comorbid substance use and mental health diagnosis among urban poor populations, examining the intersection of drug policy and place requires a consideration of the role of housing in drug user mental health. In San Francisco, geographic boundedness and progressive health and housing polices have coalesced to make single room occupancy hotels (SROs) a key urban built environment used to house poor populations with co-occurring drug use and mental health issues. Unstably housed women who use illicit drugs have high rates of lifetime and current trauma, which manifests in disproportionately high rates of post-traumatic stress disorder (PTSD), anxiety, and depression when compared to stably housed women. We report data from a qualitative interview study (n=30) and four years of ethnography conducted with housing policy makers and unstably housed women who use drugs and live in SROs. Women in the study lived in a range of SRO built environments, from publicly funded, newly built SROs to privately owned, dilapidated buildings, which presented a rich opportunity for ethnographic comparison. Applying Rhodes et al.'s framework of socio-structural vulnerability, we explore how SROs can operate as "mental health risk environments" in which macro-structural factors (housing policies shaping the built environment) interact with meso-level factors (social relations within SROs) and micro-level, behavioral coping strategies to impact women's mental health. The degree to which SRO built environments were "trauma-sensitive" at the macro level significantly influenced women's mental health at meso- and micro-levels. Women who were living in SROs which exacerbated fear and anxiety attempted, with limited success, to deploy strategies on the meso- and micro-level to manage their mental health symptoms. Study findings underscore the importance of housing polices which consider substance use in the context of current and cumulative trauma experiences in order to improve quality of life and mental health for unstably housed women. Copyright © 2013 Elsevier B.V. All rights reserved.
Knight, Knight R.; Lopez, Andrea M.; Comfort, Megan; Shumway, Martha; Cohen, Jennifer; Riley, Elise
2014-01-01
Due to the significantly high levels of comorbid substance use and mental health diagnosis among urban poor populations, examining the intersection of drug policy and place requires a consideration of the role of housing in drug user mental health. In San Francisco, geographic boundedness and progressive health and housing polices have coalesced to make single room occupancy hotels (SROs) a key urban built environment used to house poor populations with co-occurring drug use and mental health issues. Unstably housed women who use illicit drugs have high rates of lifetime and current trauma, which manifests in disproportionately high rates of post-traumatic stress disorder (PTSD), anxiety, and depression when compared to stably housed women. We report data from a qualitative interview study (n=30) and four years of ethnography conducted with housing policy makers and unstably housed women who use drugs and live in SROs. Women in the study lived in a range of SRO built environments, from publicly-funded, newly built SROs to privately-owned, dilapidated buildings, which presented a rich opportunity for ethnographic comparison. Applying Rhodes et al.’s framework of socio-structural vulnerability, we explore how SROs can operate as “mental health risk environments” in which macro-structural factors (housing policies shaping the built environment) interact with meso-level factors (social relations within SROs) and micro-level, behavioral coping strategies to impact women’s mental health. The degree to which SRO built environments were “trauma-sensitive” at the macro level significantly influenced women’s mental health at meso- and micro- levels. Women who were living in SROs which exacerbated fear and anxiety attempted, with limited success, to deploy strategies on the meso- and micro- level to manage their mental health symptoms. Study findings underscore the importance of housing polices which consider substance use in the context of current and cumulative trauma experiences in order to improve quality of life and mental health for unstably housed women. PMID:24411945
ERIC Educational Resources Information Center
Knight-Diop, Michelle
2011-01-01
The author takes up the invitation to engage in the dialogue on the imperatives for civic engagement in teacher education at the intersections of youth, immigration, and globalization in urban contexts--especially when given that many of the youth in K-12 schools are immigrants or children of immigrants. The first imperative considers the…
ERIC Educational Resources Information Center
Grimes, Nicole K.
2013-01-01
A growing body of teacher identity-based research has begun to embrace that the development of self-understanding about being a teacher is critical to learning how to teach. Construction of a professional teacher identity requires much more beyond mere content, skills and a foundational pedagogy. It also includes an intersection of the personal…
ERIC Educational Resources Information Center
Baker, Bruce D.
2011-01-01
This article applies the education cost function methodology in order to estimate additional costs associated with black student concentration and with alternative, race-neutral measures of urban poverty. Recent research highlights the continued importance of the role of race in educational outcomes, and how the intersection of peer group effects…
ERIC Educational Resources Information Center
Kearl, Benjamin Kelsey
2014-01-01
Through an interpretive analysis of how high school American history textbooks depict the urban-riots of the late-1960s, in this article the author discusses how textbooks incorporate and abject official knowledge related to the intersections of race and poverty. Incorporation is related with Raymond Williams' theory of the selective tradition and…
Hartmann, William E.; Wendt, Dennis C.; Saftner, Melissa A.; Marcus, John; Momper, Sandra L.
2014-01-01
The U.S. has witnessed significant growth among urban AI populations in recent decades, and concerns have been raised that these populations face equal or greater degrees of disadvantage than their reservation counterparts. Surprisingly little urban AI research or community work has been documented in the literature, and even less has been written about the influences of urban settings on community-based work with these populations. Given the deep commitments of community psychology to empowering disadvantaged groups and understanding the impact of contextual factors on the lives of individuals and groups, community psychologists are well suited to fill these gaps in the literature. Toward informing such efforts, this work offers multidisciplinary insights from distinct idiographic accounts of community-based behavioral health research with urban AI populations. Accounts are offered by three researchers and one urban AI community organization staff member, and particular attention is given to issues of community heterogeneity, geography, membership, and collaboration. Each first-person account provides “lessons learned” from the urban context in which the research occurred. Together, these accounts suggest several important areas of consideration in research with urban AIs, some of which also seem relevant to reservation-based work. Finally, the potential role of research as a tool of empowerment for urban AI populations is emphasized, suggesting future research attend to the intersections of identity, sense of community, and empowerment in urban AI populations. PMID:24659391
NASA Astrophysics Data System (ADS)
Orlando, P.; Vo, D.; Giossi, C.; George, L.
2017-12-01
With the world-wide increase in urbanization and the increasing usage of combustion vehicles in urban areas, traffic-related air pollution is a growing health hazard. However, there are limited studies that examine the spatial and temporal impacts of traffic-related pollutants within cities. In particular, there are few studies that look at traffic management and its potential for pollution mitigation. In a previous study we examined roadway pollution and traffic parameters with one roadway station instrumented with standard measurement instruments. With the advent of low-cost air pollution sensors, we have expanded our work by observing multiple sites within a neighborhood to understand spatial and temporal exposures. We have deployed a high-density sensor network around urban arterial corridors in SE Portland, Oregon. This network consisted of ten nodes measuring CO, NO, NO2 and O3, and ten nodes measuring CO, CO2, VOC and PM2.5. The co-location of standard measurement instruments provided insight towards the utility of our low-cost sensor network, as the different nodes varied in cost, and potentially in quality. We have identified near-real-time temporal trends and local-scale spatial patterns during the summer of 2017. Meteorological and traffic data were included to further characterize these patterns, exploring the potential for pollution mitigation.
The Science of Middle Nature (Invited)
NASA Astrophysics Data System (ADS)
Pataki, D. E.; Pincetl, S.; Hinners, S.
2013-12-01
In the field of biogeochemistry, urbanization is often considered as an 'alteration' or 'disturbance' to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the 'middle nature' proposed by Cosgrove (1993), which serves a purpose of 'actively transforming nature into culture.' It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles and Salt Lake City from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native species, maximizing carbon sequestration, or minimizing human disturbance. Rather, in our project the discourse is shifting away from the ecosystem services framework, and towards a shared vision for middle nature as the intersection between nature as we have traditionally valued it outside of the city, and its integral role in urban culture, design, function, and quality of life.
NASA Astrophysics Data System (ADS)
Pataki, D. E.; Pincetl, S.
2012-12-01
In the field of biogeochemistry, urbanization is often considered as an "alteration" or "disturbance" to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the "middle nature" proposed by Cosgrove (1993), which serves a purpose of "actively transforming nature into culture." It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native species, maximizing carbon sequestration, or minimizing human disturbance. Rather, in our project the discourse is shifting away from the ecosystem services framework, and towards a shared vision for middle nature as the intersection between nature as we have traditionally valued it outside of the city, and its integral role in urban culture, design, function, and quality of life.
Senn, Theresa E; Carey, Michael P; Vanable, Peter A
2010-07-01
High rates of psychosocial and health problems have been identified among patients attending sexually transmitted disease (STD) clinics, who are disproportionately urban, have low income, and are racial/ethnic minorities. This study sought to determine whether these problems co-occurred and whether they indicated the presence of a syndemic. Patients (N = 1557, 46% female, 64% African American) attending an urban STD clinic completed a computerized survey assessing childhood sexual abuse (CSA), depressive symptoms, binge drinking, marijuana use, intimate partner violence (IPV), and sexual risk behavior. Medical records were reviewed to determine incident STD diagnosis. The psychosocial and health problems were interrelated. Endorsing more psychosocial problems was associated with a greater likelihood of having multiple sexual partners and STD diagnosis. Interactions between CSA and marijuana use and between CSA and IPV predicted STD diagnosis. Numerous psychosocial and health problems co-occur among urban STD clinic patients. There was some evidence of a syngergistic relationship (i.e., a syndemic) between these conditions, resulting in worsened sexual health outcomes. Health care needs to be multidisciplinary to address the multiple psychosocial and health problems faced by STD clinic patients. Research needs to identify factors that may underlie these comorbid conditions.
"They come in peasants and leave citizens": urban villages and the making of Shenzhen, China.
Bach, Jonathan
2010-01-01
This essay examines the ongoing process of postsocialist transformation at the intersection of cultural and economic forces in an urban environment through the example of the so-called "urban villages"(chengzhongcun) in Shenzhen, China, a booming southern Chinese city and former Special Economic Zone next to Hong Kong. This essay ethnographically examines the role of former rural collectives encircled by a city that has exploded from farmland to an export-driven city of over 14 million people in little over one generation. These villages form an internal other that is both the antithesis and the condition of possibility for Shenzhen city. By co-opting the market economy in ways that weave them into the fabric of the contemporary global city, the villages become as much an experiment as the Special Economic Zone itself. This essay analyzes the urban-rural divide as complicit in each other's continued production and effacement and explores how village and city exploit the ambiguities of their juxtaposition in the making of Shenzhen.
Caldwell, Julia T; Ford, Chandra L; Wallace, Steven P; Wang, May C; Takahashi, Lois M
2016-08-01
To examine whether living in a rural versus urban area differentially exposes populations to social conditions associated with disparities in access to health care. We linked Medical Expenditure Panel Survey (2005-2010) data to geographic data from the American Community Survey (2005-2009) and Area Health Resource File (2010). We categorized census tracts as rural and urban by using the Rural-Urban Commuting Area Codes. Respondent sample sizes ranged from 49 839 to 105 306. Outcomes were access to a usual source of health care, cholesterol screening, cervical screening, dental visit within recommended intervals, and health care needs met. African Americans in rural areas had lower odds of cholesterol screening (odds ratio[OR] = 0.37; 95% confidence interval[CI] = 0.25, 0.57) and cervical screening (OR = 0.48; 95% CI = 0.29, 0.80) than African Americans in urban areas. Whites had fewer screenings and dental visits in rural versus urban areas. There were mixed results for which racial/ethnic group had better access. Rural status confers additional disadvantage for most of the health care use measures, independently of poverty and health care supply.
Sexual Violence Among College Students Attending a Nonresidential Campus.
Solinas-Saunders, Monica
2018-03-01
Using the empirical powers of theories of intersectionality, the study investigates the association between students' demographics (such as gender identity, race, ethnicity, age, and socioeconomic status) and sexual violence victimization. An anonymous survey was employed to collect data from a cluster random sample of 966 students attending face-to-face courses at a midsize urban nonresidential campus. The empirical findings suggest that being older and female are the only statistically significant factors in the analysis. As the first attempt to focus on students attending nonresidential programs in the United States, the study presents implications for policy and program implementation to include issues pertinent to students' diversity to better respond to students' risk of victimization.
Large-Scale Urban Localisation with a Pushbroom LIDAR
2012-10-01
the sole means of gen- erating full 6-DOF poses from a previously-surveyed workspace. In this approach, Normalised Information Distance is used as the...vehicle to have good knowledge of its position at system- initialization. We now turn to an overview of the use of point-based registration methods for...combination of reference vertices, and provides a convenient representation for the intersection test . Using this parametric representation, the coordinates
Kennedy, Angie C; Bybee, Deborah; Kulkarni, Shanti J; Archer, Gretchen
2012-11-01
Guided by an intersectional feminist perspective, we examined sexual victimization, witnessing intimate partner violence (IPV) in the family, and familial physical abuse among a sample of 180 urban African American adolescent women. We used cluster analysis to better understand the profiles of cumulative victimization, and the relationships between profiles and IPV victimization and personal exposure to the sex trade. Just under one third of the sample reported sexual victimization, with cooccurrence with both forms of family violence common. The cluster profile with high levels of severe family violence was associated with the highest rate of IPV victimization and sex trade exposure.
Street floods in Metro Manila and possible solutions.
Lagmay, Alfredo Mahar; Mendoza, Jerico; Cipriano, Fatima; Delmendo, Patricia Anne; Lacsamana, Micah Nieves; Moises, Marc Anthony; Pellejera, Nicanor; Punay, Kenneth Niño; Sabio, Glenn; Santos, Laurize; Serrano, Jonathan; Taniza, Herbert James; Tingin, Neil Eneri
2017-09-01
Urban floods from thunderstorms cause severe problems in Metro Manila due to road traffic. Using Light Detection and Ranging (LiDAR)-derived topography, flood simulations and anecdotal reports, the root of surface flood problems in Metro Manila is identified. Majority of flood-prone areas are along the intersection of creeks and streets located in topographic lows. When creeks overflow or when rapidly accumulated street flood does not drain fast enough to the nearest stream channel, the intersecting road also gets flooded. Possible solutions include the elevation of roads or construction of well-designed drainage structures leading to the creeks. Proposed solutions to the flood problem of Metro Manila may avoid paralyzing traffic problems due to short-lived rain events, which according to Japan International Cooperation Agency (JICA) cost the Philippine economy 2.4billionpesos/day. Copyright © 2017. Published by Elsevier B.V.
White, Jonah
2011-01-01
Objectives. Few studies have considered the sociohistorical intersection of environmental injustice and gentrification; a gap addressed by this case study of Seattle, Washington. This study explored the advantages of integrating air toxic risk screening with gentrification research to enhance proximity and health equity analysis methodologies. It was hypothesized that Seattle's industrial air toxic exposure risk was unevenly dispersed, that gentrification stratified the city's neighborhoods, and that the inequities of both converged. Methods. Spatial characterizations of air toxic pollution risk exposures from 1990 to 2007 were combined with longitudinal cluster analysis of census block groups in Seattle, Washington, from 1990 to 2000. Results. A cluster of air toxic exposure inequality and socioeconomic inequity converged in 1 area of south central Seattle. Minority and working class residents were more concentrated in the same neighborhoods near Seattle's worst industrial pollution risks. Conclusions. Not all pollution was distributed equally in a dynamic urban landscape. Using techniques to examine skewed riskscapes and socioeconomic urban geographies provided a foundation for future research on the connections among environmental health hazard sources, socially vulnerable neighborhoods, and health inequity. PMID:21836115
Abel, Troy D; White, Jonah
2011-12-01
Few studies have considered the sociohistorical intersection of environmental injustice and gentrification; a gap addressed by this case study of Seattle, Washington. This study explored the advantages of integrating air toxic risk screening with gentrification research to enhance proximity and health equity analysis methodologies. It was hypothesized that Seattle's industrial air toxic exposure risk was unevenly dispersed, that gentrification stratified the city's neighborhoods, and that the inequities of both converged. Spatial characterizations of air toxic pollution risk exposures from 1990 to 2007 were combined with longitudinal cluster analysis of census block groups in Seattle, Washington, from 1990 to 2000. A cluster of air toxic exposure inequality and socioeconomic inequity converged in 1 area of south central Seattle. Minority and working class residents were more concentrated in the same neighborhoods near Seattle's worst industrial pollution risks. Not all pollution was distributed equally in a dynamic urban landscape. Using techniques to examine skewed riskscapes and socioeconomic urban geographies provided a foundation for future research on the connections among environmental health hazard sources, socially vulnerable neighborhoods, and health inequity.
Dong, Chunjiao; Clarke, David B; Yan, Xuedong; Khattak, Asad; Huang, Baoshan
2014-09-01
Crash data are collected through police reports and integrated with road inventory data for further analysis. Integrated police reports and inventory data yield correlated multivariate data for roadway entities (e.g., segments or intersections). Analysis of such data reveals important relationships that can help focus on high-risk situations and coming up with safety countermeasures. To understand relationships between crash frequencies and associated variables, while taking full advantage of the available data, multivariate random-parameters models are appropriate since they can simultaneously consider the correlation among the specific crash types and account for unobserved heterogeneity. However, a key issue that arises with correlated multivariate data is the number of crash-free samples increases, as crash counts have many categories. In this paper, we describe a multivariate random-parameters zero-inflated negative binomial (MRZINB) regression model for jointly modeling crash counts. The full Bayesian method is employed to estimate the model parameters. Crash frequencies at urban signalized intersections in Tennessee are analyzed. The paper investigates the performance of MZINB and MRZINB regression models in establishing the relationship between crash frequencies, pavement conditions, traffic factors, and geometric design features of roadway intersections. Compared to the MZINB model, the MRZINB model identifies additional statistically significant factors and provides better goodness of fit in developing the relationships. The empirical results show that MRZINB model possesses most of the desirable statistical properties in terms of its ability to accommodate unobserved heterogeneity and excess zero counts in correlated data. Notably, in the random-parameters MZINB model, the estimated parameters vary significantly across intersections for different crash types. Copyright © 2014 Elsevier Ltd. All rights reserved.
Stumm, F.; Chu, A.; Joesten, P.K.; Lane, J.W.
2007-01-01
Advanced borehole-geophysical methods were used to assess the geohydrology of fractured crystalline bedrock in 31 of 64 boreholes on the southern part of Manhattan Island, NY in preparation of the construction of a new water tunnel. The study area is located in a highly urbanized part of New York City. The boreholes penetrated gneiss, schist, and other crystalline bedrock that has an overall southwest-to northwest-dipping foliation. Most of the fractures intersected are nearly horizontal or have moderate- to high-angle northwest or eastward dip azimuths. Heat-pulse flowmeter logs obtained under nonpumping (ambient) and pumping conditions, together with other geophysical logs, delineated transmissive fracture zones in each borehole. Water-level and flowmeter data suggest the fractured-rock ground-water-flow system is interconnected. The 60 MHz directional borehole-radar logs delineated the location and orientation of several radar reflectors that did not intersect the projection of the borehole. A total of 53 faults intersected by the boreholes have mean orientation populations of N12??W, 66??W and N11??W, 70??E. A total of 77 transmissive fractures delineated using the heat-pulse flowmeter have mean orientations of N11??E, 14??SE (majority) and N23??E, 57??NW (minority). The transmissivity of the bedrock boreholes ranged from 0.7 to 870 feet squared (ft2) per day (0.07 to 81 metres squared (m2) per day). ?? 2007 Nanjing Institute of Geophysical Prospecting.
NASA Astrophysics Data System (ADS)
Vardoulakis, Sotiris; Solazzo, Efisio; Lumbreras, Julio
2011-09-01
Automatic monitoring networks have the ability of capturing air pollution episodes, as well as short- and long-term air quality trends in urban areas that can be used in epidemiological studies. However, due to practical constraints (e.g. cost and bulk of equipment), the use of automatic analysers is restricted to a limited number of roadside and background locations within a city. As a result, certain localised air pollution hotspots may be overlooked or overemphasised, especially near heavily trafficked street canyons and intersections. This has implications for compliance with regulatory standards and may cause exposure misclassification in epidemiological studies. Apart from automatic analysers, low cost passive diffusion tubes can be used to characterise the spatial variability of air pollution in urban areas. In this study, BTEX, NO 2 and O 3 data from a one-year passive sampling survey were used to characterise the intra-urban and street scale spatial variability of traffic-related pollutants in Birmingham (UK). In addition, continuous monitoring of NO 2, NO x, O 3, CO, SO 2, PM 10 and PM 2.5 from three permanent monitoring sites was used to identify seasonal and annual pollution patterns. The passive sampling measurements allowed us to evaluate the representativeness of a permanent roadside monitoring site that has recorded some of the highest NO 2 and PM 10 concentrations in Birmingham in recent years. Dispersion modelling was also used to gain further insight into pollutant sources and dispersion characteristics at this location. The strong spatial concentration gradients observed in busy streets, as well as the differences between roadside and urban background levels highlight the importance of appropriate positioning of air quality monitoring equipment in cities.
DOT National Transportation Integrated Search
2003-08-01
The objective of this study were to develop a database of intersections, match traffic crashes to these intersections, calculate rates for intersections, and identify intersections with the highest crash rates. A procedure was used to: a) identify in...
Urban local air quality management framework for non-attainment areas in Indian cities.
Gulia, Sunil; Nagendra, S M Shiva; Barnes, Jo; Khare, Mukesh
2018-04-01
Increasing urban air pollution level in Indian cities is one of the major concerns for policy makers due to its impact on public health. The growth in population and increase in associated motorised road transport demand is one of the major causes of increasing air pollution in most urban areas along with other sources e.g., road dust, construction dust, biomass burning etc. The present study documents the development of an urban local air quality management (ULAQM) framework at urban hotspots (non-attainment area) and a pathway for the flow of information from goal setting to policy making. The ULAQM also includes assessment and management of air pollution episodic conditions at these hotspots, which currently available city/regional-scale air quality management plans do not address. The prediction of extreme pollutant concentrations using a hybrid model differentiates the ULAQM from other existing air quality management plans. The developed ULAQM framework has been applied and validated at one of the busiest traffic intersections in Delhi and Chennai cities. Various scenarios have been tested targeting the effective reductions in elevated levels of NO x and PM 2.5 concentrations. The results indicate that a developed ULAQM framework is capable of providing an evidence-based graded action to reduce ambient pollution levels within the specified standard level at pre-identified locations. The ULAQM framework methodology is generalised and therefore can be applied to other non-attainment areas of the country. Copyright © 2017 Elsevier B.V. All rights reserved.
Choi, Jaisung; Tay, Richard; Kim, Sangyoup; Jeong, Seungwon
2017-11-01
Ageing drivers experience a higher risk of intersection crashes because of their decrease in driving efficiency, including the decline in cognitive ability, head and neck flexibility, and visual acuity. Although several studies have been conducted to examine the factors associated with ageing driver crashes at intersections, little research has been conducted to examine the differences in the factors related to ageing drivers' turning paths and intersection geometric features. This study aims to improve the safety of ageing drivers at intersections by identifying the maneuvers that are risky for them and tracking their turning movements at selected intersections. We find that ageing drivers experience more crashes at intersections than younger drivers, especially crashes involving turning movements. Furthermore, ageing drivers experience more crashes at unchannelized intersections compared to channelized intersections. In addition, this study finds that ageing drivers exhibit greater and more inconsistent offsets during turning movements compared to those of younger drivers at both channelized and unchannelized intersections. Ageing drivers also tend to make relatively sharper or tighter turns than younger drivers. Hence, transportation engineers and road safety professionals should consider appropriate countermeasures to reduce the risks of crashes involving ageing drivers at intersections. Copyright © 2017 Elsevier Ltd. All rights reserved.
Research on conflict detection algorithm in 3D visualization environment of urban rail transit line
NASA Astrophysics Data System (ADS)
Wang, Li; Xiong, Jing; You, Kuokuo
2017-03-01
In this paper, a method of collision detection is introduced, and the theory of three-dimensional modeling of underground buildings and urban rail lines is realized by rapidly extracting the buildings that are in conflict with the track area in the 3D visualization environment. According to the characteristics of the buildings, CSG and B-rep are used to model the buildings based on CSG and B-rep. On the basis of studying the modeling characteristics, this paper proposes to use the AABB level bounding volume method to detect the first conflict and improve the detection efficiency, and then use the triangular rapid intersection detection algorithm to detect the conflict, and finally determine whether the building collides with the track area. Through the algorithm of this paper, we can quickly extract buildings colliding with the influence area of the track line, so as to help the line design, choose the best route and calculate the cost of land acquisition in the three-dimensional visualization environment.
NASA Astrophysics Data System (ADS)
Rivera Maulucci, Maria S.
2011-06-01
One of the central challenges globalization and immigration present to education is how to construct school language policies, procedures, and curricula to support academic success of immigrant youth. This case-study compares and contrasts language experience narratives along Elena's developmental trajectory of becoming an urban science teacher. Elena reflects upon her early language experiences and her more recent experiences as a preservice science teacher in elementary dual language classrooms. The findings from Elena's early schooling experiences provide an analysis of the linkages between Elena's developing English proficiency, her Spanish proficiency, and her autobiographical reasoning. Elena's experiences as a preservice teacher in two elementary dual language classrooms indicates ways in which those experiences helped to reframe her views about the intersections between language learning and science learning. I propose the language experience narrative, as a subset of the life story, as a way to understand how preservice teachers reconstruct past language experiences, connect to the present, and anticipate future language practices.
Patterns of productive activity engagement among older adults in urban China.
Liu, Huiying; Lou, Wei Qun
2016-12-01
This study aims to identify patterns of productive activity engagement among older adults in urban China. Once patterns are identified, we further explore how a set of individual characteristics is associated with these patterns. Using data from the 2011 baseline survey of the China Health and Retirement Longitudinal Study (CHARLS), we performed a latent class analysis (LCA) on a national representative sample of adults aged 60 years and over ( N = 3019). A specified range of productive activity indicators that fit the context of urban China was used for performing LCA (including working, grandchildren's care, parental care, spousal care, informal helping, and formal volunteering). A multinomial logistic regression was used to assess whether individual characteristics are associated with the identified patterns. The results indicated that a four-class model fit the data well, with the interpretable set of classes: spouse carer (51.2 %), working grandparents (21.7 %), multifaceted contributor (16.6 %), and light-engaged volunteer (10.5 %). Age, gender, education, number of children, proximity with the nearest child, household composition and functional status contributed to differentiating these classes. This study captured the reality of productive engagement among older adults by drawing attention to how multiple productive activities intersect in later-life stages. Our findings have implications for policy-makers, health care practitioners, and community advocates to develop programs that facilitate this aging population in assuming meaningful productive activities.
Cohen, Alison Klebanoff; Schuchter, Joseph W
2013-04-01
Inequities in education, the urban environment, and health co-exist and mutually reinforce each other. Educators, planners, and public health practitioners share commitments to place-based, participatory, youth-focused, and equitable work. They also have shared goals of building community resilience, social capital, and civic engagement. Interdisciplinary programs that embody these shared values and work towards these shared goals are emerging, including school-based health centers, full-service community schools, community health centers, Promise Neighborhoods, and Choice Neighborhoods. The intersection of these three fields represents an opportunity to intervene on social determinants of health. More collaborative research and practice across public health, education, and planning should build from the shared values identified to continue to address these common goals.
Personal Air Pollution Exposure Monitoring using Low Cost Sensors in Chennai City
NASA Astrophysics Data System (ADS)
Reddy Yasa, Pavan; Shiva, Nagendra S. N.
2016-04-01
Air quality in many cities is deteriorating due to rapid urbanization and motorization. In the past, most of the health impacts studies in the urban areas have considered stationary air quality monitoring station data for health impact assessment. Since, there exist a spatial and temporal variation of air quality because of rapid change in land use pattern and complex interaction between emission sources and meteorological conditions, the human exposure assessment using stationary data may not provide realistic information. In such cases low cost sensors monitoring is viable in providing both spatial and temporal variations of air pollutant concentrations. In the present study an attempt has been made to use low cost sensor for monitoring the personal exposure to the two criteria pollutants CO and PM2.5 at 3 different locations of Chennai city. Maximum and minimum concentrations of CO and PM2.5 were found to be 5.4ppm, 0.8ppm and 534.8μg/m3, 1.9μg/m3 respectively. Results showed high concentrations near the intersection and low concentrations in the straight road.
Ford, Chandra L.; Wallace, Steven P.; Wang, May C.; Takahashi, Lois M.
2016-01-01
Objectives. To examine whether living in a rural versus urban area differentially exposes populations to social conditions associated with disparities in access to health care. Methods. We linked Medical Expenditure Panel Survey (2005–2010) data to geographic data from the American Community Survey (2005–2009) and Area Health Resource File (2010). We categorized census tracts as rural and urban by using the Rural–Urban Commuting Area Codes. Respondent sample sizes ranged from 49 839 to 105 306. Outcomes were access to a usual source of health care, cholesterol screening, cervical screening, dental visit within recommended intervals, and health care needs met. Results. African Americans in rural areas had lower odds of cholesterol screening (odds ratio[OR] = 0.37; 95% confidence interval[CI] = 0.25, 0.57) and cervical screening (OR = 0.48; 95% CI = 0.29, 0.80) than African Americans in urban areas. Whites had fewer screenings and dental visits in rural versus urban areas. There were mixed results for which racial/ethnic group had better access. Conclusions. Rural status confers additional disadvantage for most of the health care use measures, independently of poverty and health care supply. PMID:27310341
NASA Astrophysics Data System (ADS)
Aksoy, Erman; Yıldırım, Şahin
2017-10-01
The existence or endurance of the city is determined by social, economic, cultural, and technological factors. Therefore, transportation connections become physical signifiers of the relation between two spaces. Nevertheless, the potential for change in transportation is more dynamic when compared to other factors. Change in the infrastructure and systems of transportation become evident at the urban scale more rapidly. In addition to leading to the formation of new cities or to socio-cultural and economic development in the already-existent cities, this dynamic structure may also cause the decrease in economic power, and even the desertion of settlements. Furthermore, it functions as a leading, even determining, parameter in the formation of space, thereby in economic and social development. The fact that, throughout history, centres of communication and commerce were established at intersection, stopping and lodging points of transportation links and/or their development into residential areas attests to this interaction. In the commercial centres and life of the city, the effects of regional transportation networks and technologies surface relatively. By means of the analytical method, this study focuses on how, within the history of settlements, population increases due to the choice of location based on transportation and strategic significance, and how urban functions vary accordingly. As such, the interaction between urban development and transportation links for the Ancient City of Tios will be analysed, and the signifiers for urban development will be designated.
Proximity to Fast-Food Outlets and Supermarkets as Predictors of Fast-Food Dining Frequency.
Athens, Jessica K; Duncan, Dustin T; Elbel, Brian
2016-08-01
This study used cross-sectional data to test the independent relationship of proximity to chain fast-food outlets and proximity to full-service supermarkets on the frequency of mealtime dining at fast-food outlets in two major urban areas, using three approaches to define access. Interactions between presence of a supermarket and presence of fast-food outlets as predictors of fast-food dining were also tested. Residential intersections for respondents in point-of-purchase and random-digit-dial telephone surveys of adults in Philadelphia, PA, and Baltimore, MD, were geocoded. The count of fast-food outlets and supermarkets within quarter-mile, half-mile, and 1-mile street network buffers around each respondent's intersection was calculated, as well as distance to the nearest fast-food outlet and supermarket. These variables were regressed on weekly fast-food dining frequency to determine whether proximity to fast food and supermarkets had independent and joint effects on fast-food dining. The effect of access to supermarkets and chain fast-food outlets varied by study population. Among telephone survey respondents, supermarket access was the only significant predictor of fast-food dining frequency. Point-of-purchase respondents were generally unaffected by proximity to either supermarkets or fast-food outlets. However, ≥1 fast-food outlet within a 1-mile buffer was an independent predictor of consuming more fast-food meals among point-of-purchase respondents. At the quarter-mile distance, ≥1 supermarket was predictive of fewer fast-food meals. Supermarket access was associated with less fast-food dining among telephone respondents, whereas access to fast-food outlets were associated with more fast-food visits among survey respondents identified at point-of-purchase. This study adds to the existing literature on geographic determinants of fast-food dining behavior among urban adults in the general population and those who regularly consume fast food. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.
Harris, M Anne; Reynolds, Conor C O; Winters, Meghan; Cripton, Peter A; Shen, Hui; Chipman, Mary L; Cusimano, Michael D; Babul, Shelina; Brubacher, Jeffrey R; Friedman, Steven M; Hunte, Garth; Monro, Melody; Vernich, Lee; Teschke, Kay
2013-01-01
Background This study examined the impact of transportation infrastructure at intersection and non-intersection locations on bicycling injury risk. Methods In Vancouver and Toronto, we studied adult cyclists who were injured and treated at a hospital emergency department. A case–crossover design compared the infrastructure of injury and control sites within each injured bicyclist's route. Intersection injury sites (N=210) were compared to randomly selected intersection control sites (N=272). Non-intersection injury sites (N=478) were compared to randomly selected non-intersection control sites (N=801). Results At intersections, the types of routes meeting and the intersection design influenced safety. Intersections of two local streets (no demarcated traffic lanes) had approximately one-fifth the risk (adjusted OR 0.19, 95% CI 0.05 to 0.66) of intersections of two major streets (more than two traffic lanes). Motor vehicle speeds less than 30 km/h also reduced risk (adjusted OR 0.52, 95% CI 0.29 to 0.92). Traffic circles (small roundabouts) on local streets increased the risk of these otherwise safe intersections (adjusted OR 7.98, 95% CI 1.79 to 35.6). At non-intersection locations, very low risks were found for cycle tracks (bike lanes physically separated from motor vehicle traffic; adjusted OR 0.05, 95% CI 0.01 to 0.59) and local streets with diverters that reduce motor vehicle traffic (adjusted OR 0.04, 95% CI 0.003 to 0.60). Downhill grades increased risks at both intersections and non-intersections. Conclusions These results provide guidance for transportation planners and engineers: at local street intersections, traditional stops are safer than traffic circles, and at non-intersections, cycle tracks alongside major streets and traffic diversion from local streets are safer than no bicycle infrastructure. PMID:23411678
DOT National Transportation Integrated Search
2005-02-25
This study developed a GIS-based Intersection Inventory System (GIS-IIS) for the signalized : intersections on the state-maintained highway system of IDOT District 6. GIS-IIS is a tool to have an : easy access to intersection inventory data, photogra...
Associations of leisure-time sitting in cars with neighborhood walkability.
Koohsari, Mohammad Javad; Sugiyama, Takemi; Kaczynski, Andrew T; Owen, Neville
2014-08-01
Too much sitting, including time spent sitting in cars, is associated with poor health outcomes. Identifying the built-environment attributes that may reduce vehicular sitting time can inform future initiatives linking the public health, urban design, and transportation sectors. Data collected in 2003-2004 from adult residents (n = 2521) of Adelaide, Australia were used. Logistic regression analyses examined associations of prolonged time spent sitting in cars during leisure time (30 min/day or more) with neighborhood walkability and its components (dwelling density; intersection density; land use mix; net retail area ratio). Lower overall walkability was significantly associated with a higher odds (OR = 1.43, 95% CI: 1.21-1.70) of spending prolonged time in cars. For analyses with walkability components, lower net retail area ratio, lower residential density, and lower intersection density were significantly associated with prolonged sitting in cars. This study found that residents of high walkable neighborhoods tended to spend less time sitting in cars. In particular, higher net retail area ratio, an indicator of tightly spaced commercial areas, was strongly associated with less time in cars. Policy and planning initiatives to reduce car use require further evidence, particularly on the influence of neighborhood retail areas.
Suicide Risk Among College Student. The Intersection of Sexual Orientation and Race.
Shadick, Richard; Backus Dagirmanjian, Faedra; Barbot, Baptiste
2015-01-01
Research on young adults in the general population has identified a relationship between sexual minority identification and risk for suicide. Differential rates of suicidal ideation and attempts have also been found across racial and ethnic groups. This study examined risk for suicide among university students, based on membership in one or more marginalized groups (sexual minority and racial minority identification). Data were collected from first-year college students (N = 4,345) at an urban university. Structural equation modeling was employed to model a suicidality construct, based on which a "risk for suicide" category system was derived. Chi-square and logistic regression analyses were then conducted to estimate the relationship between the background variables of interest and suicide risk. Students who identified as lesbian, gay, or bisexual (LGB) were associated with higher suicide risk than their heterosexual peers. Students of color were slightly less at risk than their heterosexual peers. However, LGB students of color were associated with elevated suicide risk relative to heterosexual peers. Results indicate that belonging to multiple marginalized groups may increase one's risk for suicide, though these effects are not simply additive. Findings highlight the complexity of the intersection between marginalized identities and suicidality.
van der Riet, Mary; Nicholson, Tamaryn Jane
2014-01-01
Individuals' perceptions of risk have implications for whether and how they engage with protective strategies. This study investigated how sexual risk, specifically HIV and pregnancy and responsibility for these risks were constructed in discussions across five groups of youth in KwaZulu-Natal, South Africa. The qualitative study used focus groups and interviews with a sample of 28 tertiary level students and 7 peri-urban youth. The constructions of risk intersected with raced and gendered narratives around sexual risk and responsibility. These constructions were used by the participants to assign and displace responsibility for the risks of HIV and pregnancy, rendering some groups immune to these risks. This constitutes a form of stigmatisation and also has implications for participants' prevention practices.
NASA Astrophysics Data System (ADS)
Butzer, Karl W.
2008-10-01
Geoarchaeology is a growing subfield of cross-disciplinary research at the intersection between geomorphology, environmental history, and archaeology. This prospective essay does not aim to analyze the nature or evolution of geoarachaeology, or to review available techniques and methods. Instead it addresses challenges. Exciting challenges confront geoarchaeology in the form of persistent problems that demand satisfactory solutions, despite improving skills and innovative technologies. Drawing from the full record of human history, a number of practical issues can be highlighted to explicate these challenges: Open-air archaeological sites are the main object of study for the Early to Mid-Pleistocene, even though they represent open systems that raise fundamental questions about archaeo-taphonomic integrity. How were sites buried and then modified by selective preservation, horizontal or vertical disturbance, and the role of carnivores? Is it possible to determine the degree to which such sites accurately record prehistoric human behavior, prior to the Late Pleistocene when hearths and living structures lend better definition to occupation surfaces? Can non-primary open-air sites also shed light on human activities and environmental history? Cave sites have long been favored by archaeologists because of the impression that they represent relatively complete and undisturbed archaeostratigraphic sequences. But serious problems also exist here in regard to the nature of accumulation and the sources of mineral and biogenic sediments in what were open systems, liable to disturbance, despite comparatively low-energy processes. Less familiar are urban and other architectural sites, where processes of formation and degradation mimic natural sedimentation and erosion. Such a geoarchaeology can be highly informative for urban processes, demographic cycles, or the intersection between sites and their surrounding landscapes. Spatial components of geoarchaeological research need more systematic consideration, for locational strategies and with an appreciation that site presence or absence allows a more dynamic modeling of settlement and procurement strategies. Regional settlement expansion and contraction may also inform on mosaic evolution or Pleistocene dispersals, including the Out of Africa hypothesis. Finally, multiple themes connected with environmental degradation during Holocene times may open new windows to examine specific problems by objective criteria, so contributing to a wider academic discourse about long-term trends, the interfingering of climatic and land-use factors in cause-and-effect dilemmas, or the construction of future scenarios in an era of accelerating planetary change. The focus of archaeology is shifting to later ranges of prehistory so that geoarchaeologists now have a mandate to engage more directly with urban, spatial, and degradation issues. This should be met with a broader and more inclusive agenda, one that optimizes on expertise with historical geomorphology and environmental history, but in collaboration with archaeologists and other social scientists. That would sustain a more prominent role for geoarchaeology in the university curriculum.
NASA Astrophysics Data System (ADS)
Sandric, Ionut; Onose, Diana; Vanau, Gabriel; Ioja, Cristian
2016-04-01
The present study is focusing on the identification of urban heat island in Bucharest using both remote sensing products and low cost temperature sensors. The urban heat island in Bucharest was analyzed through a network of sensors located in 56 points (47 inside the administrative boundary of the city, 9 outside) 2009-2011. The network lost progressively its initial density, but was reformed during a new phase, 2013-2015. Time series satellite images from MODIS were intersected with the sensors for both phases. Statistical analysis were conducted to identify the temporal and spatial pattern of extreme temperatures in Bucharest. Several environmental factors like albedou, presence and absence of vegetation were used to fit a regression model between MODIS satellite products sensors in order to upscale the temperatures values recorded by MODIS For Bucharest, an important role for air temperature values in urban environments proved to have the local environmental conditions that leads to differences in air temperature at Bucharest city scale between 3-5 °C (both in the summer and in the winter). The UHI maps shows a good correlation with the presence of green areas. Differences in air temperature between higher tree density areas and isolated trees can reach much higher values, averages over 24 h periods still are in the 3-5 °C range The results have been obtained within the project UCLIMESA (Urban Heat Island Monitoring under Present and Future Climate), ongoing between 2013 and 2015 in the framework of the Programme for Research-DevelopmentInnovation for Space Technology and Advanced Research (STAR), administrated by the Romanian Space Agency Keywords: time series, urban heat island
ERIC Educational Resources Information Center
Gao, Lijun
2015-01-01
An information point was defined in this study as any object, structure, or activity located outside of a traveling vehicle that could potentially attract the visual attention of the driver. Saturation flow rates were studied for three pairs of signalized intersections in Toledo, Ohio. Each pair of intersections consisted of one intersection with…
Effects of digital countdown timer on intersection safety and efficiency: A systematic review.
Fu, Chuanyun; Zhang, Yaping; Qi, Weiwei; Cheng, Shaowu
2016-01-01
To investigate the available evidence referring to the effectiveness of digital countdown timers (DCTs) in improving the safety and operational efficiency of signalized intersection. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines. Relevant literature was searched from electronic databases using key terms. Based on study selection and methodological quality assessment, 14 studies were included in the review. Findings of the studies were synthesized in a narrative analysis. Three types of DCT had different effects on intersection safety and operational efficiency. Green signal countdown timers (GSCTs) reduced red light violations, type I dilemma zone distributions, and rear-end collision likelihood but increased crossing after yellow onset and had mixed impacts on type II dilemma zone distributions and intersection capacity. In contrast, red signal countdown timers (RSCTs) increased intersection capacity, although their effectiveness in reducing red light violations dissipated over time. Likewise, continuous countdown timers (CCTs) significantly enhanced intersection capacity but had mixed influences on red light violations and crossing after yellow onset. Due to the limited and inconsistent evidence regarding DCTs' effects on intersection safety and efficiency, it is not sufficient to recommend any type of DCT to be installed at signalized intersections to improve safety and operational efficiency. Nevertheless, it is apparent that both RSCTs and CCTs enhance intersection capacity, though their impacts on intersection safety are unclear. Future studies need to further verify those anticipated safe and operational benefits of DCTs with enriched field observation data.
Stable isotopes reveal links between human food inputs and urban ant diets.
Penick, Clint A; Savage, Amy M; Dunn, Robert R
2015-05-07
The amount of energy consumed within an average city block is an order of magnitude higher than that consumed in any other ecosystem over a similar area. This is driven by human food inputs, but the consequence of these resources for urban animal populations is poorly understood. We investigated the role of human foods in ant diets across an urbanization gradient in Manhattan using carbon and nitrogen stable isotopes. We found that some-but not all-ant species living in Manhattan's most urbanized habitats had δ(13)C signatures associated with processed human foods. In particular, pavement ants (Tetramorium sp. E) had increased levels of δ(13)C similar to δ(13)C levels in human fast foods. The magnitude of this effect was positively correlated with urbanization. By contrast, we detected no differences in δ(15)N, suggesting Tetramorium feeds at the same trophic level despite shifting to human foods. This pattern persisted across the broader ant community; species in traffic islands used human resources more than park species. Our results demonstrate that the degree urban ants exploit human resources changes across the city and among species, and this variation could play a key role in community structure and ecosystem processes where human and animal food webs intersect. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
NASA Astrophysics Data System (ADS)
Goel, Anju; Kumar, Prashant
2014-11-01
Signalised traffic intersections (TIs) are considered as pollution hot-spots in urban areas, but the knowledge of fundamental drivers governing emission, dispersion and exposure to vehicle-emitted nanoparticles (represented by particle number concentration, PNC) at TIs is yet to be established. A number of following key factors, which are important for developing an emission and exposure framework for nanoparticles at TIs, are critically evaluated as a part of this review article. In particular, (i) how do traffic- and wind-flow features affect emission and dispersion of nanoparticles? (ii) What levels of PNCs can be typically expected under diverse signal- and traffic-conditions? (iii) How does the traffic driving condition affect the particle number (PN) emissions and the particle number emission factors (PNEF)? (iv) What is the relative importance of particle transformation processes in affecting the PNCs? (v) What are important considerations for the dispersion modelling of nanoparticles? (vi) What is extent of exposure at TIs with respect to other locations in urban settings? (vii) What are the gaps in current knowledge on this topic where the future research should focus? We found that the accurate consideration of dynamic traffic flow features at TIs is essential for reliable estimates of PN emissions. Wind flow features at TIs are generally complex to generalise. Only a few field studies have monitored PNCs at TIs until now, reporting over an order of magnitude larger peak PNCs (0.7-5.4 × 105 cm-3) compared with average PNCs at typical roadsides (˜0.3 × 105 cm-3). The PN emission and thus the PNEFs can be up to an order of magnitude higher during acceleration compared with steady speed conditions. The time scale analysis suggests nucleation as the fastest transformation process, followed by dilution, deposition, coagulation and condensation. Consideration of appropriate flow features, PNEFs and transformation processes emerged as important parameters for reliable modelling of PNCs at TIs. Computation of respiratory deposition doses (RDD) based on the available PNC data suggest that the peak RDD at TIs can be up to 12-times higher compared with average RDD at urban roadsides. Systematic field and modelling studies are needed to develop a sound understanding of the emissions, dispersion and exposure of nanoparticles at the TIs.
Durbin, Anna; Moineddin, Rahim; Lin, Elizabeth; Steele, Leah S; Glazier, Richard H
2015-01-01
Objective While newcomers are often disproportionately concentrated in disadvantaged areas, little attention is given to the effects of immigrants’ postimmigration context on their mental health and care use. Intersectionality theory suggests that understanding the full impact of disadvantage requires considering the effects of interacting factors. This study assessed the inter-relationship between recent immigration status, living in deprived areas and service use for non-psychotic mental health disorders. Study design Matched population-based cross-sectional study. Setting Ontario, Canada, where healthcare use data for 1999–2012 were linked to immigration data and area-based material deprivation scores. Participants Immigrants in urban Ontario, and their age-matched and sex-matched long-term residents (a group of Canadian-born or long-term immigrants, n=501 417 pairs). Primary and secondary outcome measures For immigrants and matched long-term residents, contact with primary care, psychiatric care and hospital care (emergency department visits or inpatient admissions) for non-psychotic mental health disorders was followed for 5 years and examined using conditional logistic regression models. Intersectionality was investigated by including a material deprivation quintile by immigrant status (immigrant vs long-term resident) interaction. Results Recent immigrants in urban Ontario were more likely than long-term residents to live in most deprived quintiles (immigrants—males: 22.8%, females: 22.3%; long-term residents—both sexes: 13.1%, p<0.001). Living in more deprived circumstances was associated with greater use of mental health services, but increases were smaller for immigrants than for long-term residents. Immigrants used less mental health services than long-term residents. Conclusions This study adds to existing research by suggesting that immigrant status and deprivation have a combined effect on recent immigrants’ care use for non-psychotic mental health disorders. In settings where immigrants are over-represented in deprived areas, policymakers focused on increasing immigrants’ access of mental health services should broadly address the influence of structural and cultural factors beyond the disadvantage. PMID:25770230
Intersectionality, Race-Gender Subordination, and Education
ERIC Educational Resources Information Center
Harris, Angela; Leonardo, Zeus
2018-01-01
In this chapter, we unpack "intersectionality as an analytical framework." First, we cite Black Lives Matter as an impetus for discussing intersectionality's current traction. Second, we review the genealogy of "intersectionality" beginning with Kimberlé Crenshaw's formulation, which brought a Black Studies provocation into…
Lessons learned from combined experimental and numerical modelling of urban floods
NASA Astrophysics Data System (ADS)
Archambeau, Pierre; Bruwier, Martin; Finaud-Guyot, Pascal; Erpicum, Sébastien; Pirotton, Michel; Dewals, Benjamin
2017-04-01
Field data for validating hydraulic models remain scarce. They are often limited to inundation extents and water marks, which provide little insights into the dynamic features of the flow in urbanized floodplains, such as the discharge partition in-between the streets and the velocity fields. To address this issue, a unique experimental setup representing a whole urban district was built in the laboratory ICube in Strasbourg and the state-of-the-art shallow-water model Wolf 2D was tested against the experimental measurements (Arrault et al. 2016). The numerical model was also used to extend and refine the analysis of the laboratory observations. The experimental model (5 m × 5 m) represents a square urban district with a total of 14 streets of different widths and 49 intersections (crossroads). The inflow discharge can be controlled in each street individually and the outflow discharges were measured downstream of each street. The numerical model Wolf was developed at the University of Liege and has been extensively used in flood risk research (Beckers et al. 2013, Bruwier et al. 2015, Detrembleur et al. 2015). Several lessons could be learned from this combined experimental and numerical analysis. First, we found that the discharge partition in-between the streets is primarily controlled by the street widths. Second, although the standard shallow-water equations reproduce satisfactorily most of the flow characteristics, adding a turbulence model improves the prediction of the shape and length of the flow recirculations in the streets. Yet, this has little influence on the discharge partition because the computed recirculation widths are hardly affected by the turbulence model. The experiments and the numerical model also show that the water depths in the streets remain fairly constant in-between two intersections, while they drop suddenly downstream of each intersection as a result of complex flow interactions at the intersections. This hints that friction has little influence on the water depths obtained in the experiments. However, tailored numerical tests demonstrate that this is a direct consequence of the distorted nature of the experimental setup. Indeed, the ratio between the water depth and the street width is close to 1 in the experiments, while it would be at least one order of magnitude lower in real-world conditions, even for extreme floods. Finally, remote sensing data, such as digital elevation models, are generally available on a regular grid, which makes it convenient to use also a Cartesian grid for hydraulic modelling. We show here that the discretization of the geometry of the buildings on such a Cartesian grid has a major influence on the modelling accuracy (overestimation of the overall flow resistance). An extended shallow-water model based on non-isotropic porosity parameters is shown to improve substantially the prediction of the discharge partition in-between the streets. It is therefore considered as a valuable tool to advance urban flood modelling in practice. From the lessons learned here, we recommend that future research focuses on the design and exploitation of a less distorted experimental model, as well as on the analysis of extra flow processes such as transient conditions and interactions between overland flow and pressurized flow in underground passages. References Arrault, A., Finaud-Guyot, P., Archambeau, P., Bruwier, M., Erpicum, S., Pirotton, M., & Dewals, B. (2016). Hydrodynamics of long-duration urban ?oods: experiments and numerical modelling. Natural Hazards & Earth System Sciences, 16, 1413-1429. Beckers, A., Dewals, B., Erpicum, S., Dujardin, S., Detrembleur, S., Teller, J., Pirotton, M., & Archambeau, P. (2013). Contribution of land use changes to future flood damage along the river Meuse in the Walloon region. Natural Hazards & Earth System Sciences, 13, 2301-2318. Bruwier, M., Erpicum, S., Pirotton, M., Archambeau, P., & Dewals, B. (2015). Assessing the operation rules of a reservoir system based on a detailed modelling chain. Natural Hazards & Earth System Sciences, 15, 365-379. Detrembleur, S., Stilmant, F., Dewals, B., Erpicum, S., Archambeau, P., & Pirotton, M. (2015). Impacts of climate change on future flood damage on the river Meuse, with a distributed uncertainty analysis. Natural Hazards, 77(3), 1533-1549. Acknowledgement Part of this research was funded through the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation.
Prediction of Particle Concentration using Traffic Emission Model
NASA Astrophysics Data System (ADS)
He, Hong-di; Lu, Jane Wei-zhen
2010-05-01
Vehicle emission is regarded as one of major sources of air pollution in urban area. Much attention has been addressed on it especially at traffic intersection. At intersection, vehicles frequently stop with idling engine during the red time and speed-up rapidly in the green time, which result in a high velocity fluctuation and produce extra pollutants to the surrounding air. To deeply understand such process, a semi-empirical model for predicting the changing effect of traffic flow patterns on particulate concentrations is proposed. The performance of the model is evaluated using the correlation coefficient and other parameters. From the results, the correlation coefficients in morning and afternoon data were found to be 0.86 an 0.73 respectively, which implies that the semi-empirical model for morning and afternoon data are 86% and 73% error free. Due to less affected by possible factors such as traffic volume and movement of pedestrian, the dispersion of the particulate matter in the morning is smaller and then contributes to higher performance than that in the afternoon.
Policies on pets for healthy cities: a conceptual framework
Rock, Melanie J.; Adams, Cindy L.; Degeling, Chris; Massolo, Alessandro; McCormack, Gavin R.
2015-01-01
Drawing on the One Health concept, and integrating a dual focus on public policy and practices of caring from the Ottawa Charter for Health Promotion, we outline a conceptual framework to help guide the development and assessment of local governments' policies on pets. This framework emphasizes well-being in human populations, while recognizing that these outcomes relate to the well-being of non-human animals. Five intersecting spheres of activity, each associated with local governments' jurisdiction over pets, are presented: (i) preventing threats and nuisances from pets, (ii) meeting pets' emotional and physical needs, (iii) procuring pets ethically, (iv) providing pets with veterinary services and (v) licensing and identifying pets. This conceptual framework acknowledges the tenets of previous health promotion frameworks, including overlapping and intersecting influences. At the same time, this framework proposes to advance our understanding of health promotion and, more broadly, population health by underscoring interdependence between people and pets as well as the dynamism of urbanized ecologies. PMID:24694682
Intersectional perspective in elderly care.
Cuesta, Marta; Rämgård, Margareta
2016-01-01
Earlier research has shown that power relationships at workplaces are constructed by power structures. Processes related to power always influence the working conditions for (in this study in elderly care) the working groups involved. Power structures are central for intersectional analysis, in the sense that the intersectional perspective highlights aspects such as gender and ethnicity (subjective dimensions) and interrelates them to processes of power (objective dimension). This qualitative study aims to explore in what way an intersectional perspective could contribute to increased knowledge of power structures in a nursing home where the employees were mostly immigrants from different countries. By using reflexive dialogues related to an intersectional perspective, new knowledge which contributes to the employees' well-being could develop. Narrative analysis was the method used to conduct this study. Through a multi-stage focus group on six occasions over 6 months, the staff were engaged in intersectional and critical reflections about power relationship with the researchers, by identifying patterns in their professional activities that could be connected to their subjectivities (gender, ethnicity, etc.). The result of this study presents three themes that express the staff's experiences and connect these experiences to structural discrimination. 1) Intersectionality, knowledge, and experiences of professionalism; 2) Intersectionality, knowledge, and experiences of collaboration; and 3) Intersectionality, knowledge, and experiences of discrimination. The result demonstrates that an intersectional perspective reinforces the involved abilities, during the conversations, into being clear about, for example, their experiences of discrimination, and consequently developing a better understanding of their professionalism and collaboration. Such deeper reflections became possible through a process of consciousness raising, strengthening the employee's self-confidence, in a positive way.
Intersectional perspective in elderly care
Cuesta, Marta; Rämgård, Margareta
2016-01-01
Earlier research has shown that power relationships at workplaces are constructed by power structures. Processes related to power always influence the working conditions for (in this study in elderly care) the working groups involved. Power structures are central for intersectional analysis, in the sense that the intersectional perspective highlights aspects such as gender and ethnicity (subjective dimensions) and interrelates them to processes of power (objective dimension). This qualitative study aims to explore in what way an intersectional perspective could contribute to increased knowledge of power structures in a nursing home where the employees were mostly immigrants from different countries. By using reflexive dialogues related to an intersectional perspective, new knowledge which contributes to the employees’ well-being could develop. Narrative analysis was the method used to conduct this study. Through a multi-stage focus group on six occasions over 6 months, the staff were engaged in intersectional and critical reflections about power relationship with the researchers, by identifying patterns in their professional activities that could be connected to their subjectivities (gender, ethnicity, etc.). The result of this study presents three themes that express the staff's experiences and connect these experiences to structural discrimination. 1) Intersectionality, knowledge, and experiences of professionalism; 2) Intersectionality, knowledge, and experiences of collaboration; and 3) Intersectionality, knowledge, and experiences of discrimination. The result demonstrates that an intersectional perspective reinforces the involved abilities, during the conversations, into being clear about, for example, their experiences of discrimination, and consequently developing a better understanding of their professionalism and collaboration. Such deeper reflections became possible through a process of consciousness raising, strengthening the employee's self-confidence, in a positive way. PMID:27167554
Hahn, Intaek; Wiener, Russell W; Richmond-Bryant, Jennifer; Brixey, Laurie A; Henkle, Stacy W
2009-12-01
The Brooklyn traffic real-time ambient pollutant penetration and environmental dispersion (B-TRAPPED) study was a multidisciplinary field research project that investigated the transport, dispersion, and infiltration processes of traffic emission particulate matter (PM) pollutants in a near-highway urban residential area. The urban PM transport, dispersion, and infiltration processes were described mathematically in a theoretical model that was constructed to develop the experimental objectives of the B-TRAPPED study. In the study, simultaneous and continuous time-series PM concentration and meteorological data collected at multiple outdoor and indoor monitoring locations were used to characterize both temporal and spatial patterns of the PM concentration movements within microscale distances (<500 m) from the highway. Objectives of the study included (1) characterizing the temporal and spatial PM concentration fluctuation and distribution patterns in the urban street canyon; (2) investigating the effects of urban structures such as a tall building or an intersection on the transport and dispersion of PM; (3) studying the influence of meteorological variables on the transport, dispersion, and infiltration processes; (4) characterizing the relationships between the building parameters and the infiltration mechanisms; (5) establishing a cause-and-effect relationship between outdoor-released PM and indoor PM concentrations and identifying the dominant mechanisms involved in the infiltration process; (6) evaluating the effectiveness of a shelter-in-place area for protection against outdoor-released PM pollutants; and (7) understanding the predominant airflow and pollutant dispersion patterns within the neighborhood using wind tunnel and CFD simulations. The 10 papers in this first set of papers presenting the results from the B-TRAPPED study address these objectives. This paper describes the theoretical background and models representing the interrelated processes of transport, dispersion, and infiltration. The theoretical solution for the relationship between the time-dependent indoor PM concentration and the initial PM concentration at the outdoor source was obtained. The theoretical models and solutions helped us to identify important parameters in the processes of transport, dispersion, and infiltration. The B-TRAPPED study field experiments were then designed to investigate these parameters in the hope of better understanding urban PM pollutant behaviors.
Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections
Azpilicueta, Leyre; López-Iturri, Peio; Aguirre, Erik; Martínez, Carlos; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco
2016-01-01
With the growing demand of Intelligent Transportation Systems (ITS) for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs) deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network. PMID:27455270
Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections.
Azpilicueta, Leyre; López-Iturri, Peio; Aguirre, Erik; Martínez, Carlos; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco
2016-07-22
With the growing demand of Intelligent Transportation Systems (ITS) for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs) deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network.
An integrated material metabolism model for stocks of urban road system in Beijing, China.
Guo, Zhen; Hu, Dan; Zhang, Fuhua; Huang, Guolong; Xiao, Qiang
2014-02-01
Rapid urbanization has greatly altered the urban metabolism of material and energy. As a significant part of the infrastructure, urban roads are being rapidly developed worldwide. Quantitative analysis of metabolic processes on urban road systems, especially the scale, composition and spatial distribution of their stocks, could help to assess the resource appropriation and potential environmental impacts, as well as improve urban metabolism models. In this paper, an integrated model, which covered all types of roads, intersection structures and ancillary facilities, was built for calculating the material stocks of urban road systems. Based on a bottom-up method, the total stocks were disassembled into a number of stock parts rather than obtained by input-output data, which provided an approach promoting data availability and inner structure understanding. The combination with GIS enabled the model to tackle the complex structures of road networks and avoid double counting. In the case study of Beijing, the following results are shown: 1) The total stocks for the entire road system reached 159 million tons, of which nearly 80% was stored in roads, and 20% in ancillary facilities. 2) Macadam was the largest stock (111 million tons), while stone mastic asphalt, polyurethane plastics, and atactic polypropylene accounted for smaller components of the overall system. 3) The stock per unit area of pedestrian overcrossing was higher than that of the other stock units in the entire system, and its steel stocks reached 0.49 t/m(2), which was 10 times as high as that in interchanges. 4) The high stock areas were mainly distributed in ring-shaped and radial expressways, as well as in major interchanges. 5) Expressways and arterials were excessively emphasized, while minor roads were relatively ignored. However, the variation of cross-sectional thickness in branches and neighborhood roads will have a significant impact on the scale of material stocks in the entire road system. © 2013.
Landscaping of highway medians and roadway safety at unsignalized intersections.
Chen, Hongyun; Fabregas, Aldo; Lin, Pei-Sung
2016-05-01
Well-planted and maintained landscaping can help reduce driving stress, provide better visual quality, and decrease over speeding, thus improving roadway safety. Florida Department of Transportation (FDOT) Standard Index (SI-546) is one of the more demanding standards in the U.S. for landscaping design criteria at highway medians near intersections. The purposes of this study were to (1) empirically evaluate the safety results of SI-546 at unsignalized intersections and (2) quantify the impacts of geometrics, traffic, and landscaping design features on total crashes and injury plus fatal crashes. The studied unsignalized intersections were divided into (1) those without median trees near intersections, (2) those with median trees near intersections that were compliant with SI-546, and (3) those with median trees near intersections that were non-compliant with SI-546. A total of 72 intersections were selected, for which five-year crash data from 2006-2010 were collected. The sites that were compliant with SI-546 showed the best safety performance in terms of the lowest crash counts and crash rates. Four crash predictive models-two for total crashes and two for injury crashes-were developed. The results indicated that improperly planted and maintained median trees near highway intersections can increase the total number of crashes and injury plus fatal crashes at a 90% confidence level; no significant difference could be found in crash rates between sites that were compliant with SI-546 and sites without trees. All other conditions remaining the same, an intersection with trees that was not compliant with SI-546 had 63% more crashes and almost doubled injury plus fatal crashes than those at intersections without trees. The study indicates that appropriate landscaping in highway medians near intersections can be an engineering technology that not only improves roadway environmental quality but also maintains intersection safety. Copyright © 2016. Published by Elsevier Ltd.
Johnson, Marilyn; Newstead, Stuart; Charlton, Judith; Oxley, Jennifer
2011-01-01
This study determined the rate and associated factors of red light infringement among urban commuter cyclists. A cross-sectional observational study was conducted using a covert video camera to record cyclists at 10 sites across metropolitan Melbourne, Australia from October 2008 to April 2009. In total, 4225 cyclists faced a red light and 6.9% were non-compliant. The main predictive factor for infringement was direction of travel, cyclists turning left (traffic travels on the left-side in Australia) had 28.3 times the relative odds of infringement compared to cyclists who continued straight through the intersection. Presence of other road users had a deterrent effect with the odds of infringement lower when a vehicle travelling in the same direction was present (OR=0.39, 95% CI 0.28-0.53) or when other cyclists were present (OR=0.26, 95% CI 0.19-0.36). Findings suggest that some cyclists do not perceive turning left against a red signal to be unsafe and the opportunity to ride through the red light during low cross traffic times influences the likelihood of infringement. Copyright © 2010 Elsevier Ltd. All rights reserved.
Collins, Pamela Y; von Unger, Hella; Armbrister, Adria
2008-08-01
Inner city women with severe mental illness may carry multiple stigmatized statuses. In some contexts these include having a mental illness, being a member of an ethnic minority group, being an immigrant, being poor, and being a woman who does not live up to gendered expectations. These potentially stigmatizing identities influence both the way women's sexuality is viewed and their risk for HIV infection. This qualitative study applies the concept of intersectionality to facilitate understanding of how these multiple identities intersect to influence women's sexuality and HIV risk. We report the firsthand accounts of 24 Latina women living with severe mental illness in New York City. In examining the interlocking domains of these women's sexual lives, we find that the women seek identities that define them in opposition to the stigmatizing label of "loca" (Spanish for crazy) and bestow respect and dignity. These identities have unfolded through the additional themes of "good girls" and "church ladies". Therefore, in spite of their association with the "loca", the women also identify with faith and religion ("church ladies") and uphold more traditional gender norms ("good girls") that are often undermined by the realities of life with a severe mental illness and the stigma attached to it. However, the participants fall short of their gender ideals and engage in sexual relationships that they experience as disempowering and unsatisfying. The effects of their multiple identities as poor Latina women living with severe mental illness in an urban ethnic minority community are not always additive, but the interlocking effects can facilitate increased HIV risks. Interventions should acknowledge women's multiple layers of vulnerability, both individual and structural, and stress women's empowerment in and beyond the sexual realm.
Factors associated with civilian drivers involved in crashes with emergency vehicles.
Drucker, Christopher; Gerberich, Susan G; Manser, Michael P; Alexander, Bruce H; Church, Timothy R; Ryan, Andrew D; Becic, Ensar
2013-06-01
Motor vehicle crashes involving civilian and emergency vehicles (EVs) have been a known problem that contributes to fatal and nonfatal injuries; however, characteristics associated with civilian drivers have not been examined adequately. This study used data from The National Highway Traffic Safety Administration's Fatality Analysis Reporting System and the National Automotive Sampling System General Estimates System to identify driver, roadway, environmental, and crash factors, and consequences for civilian drivers involved in fatal and nonfatal crashes with in-use and in-transport EVs. In general, drivers involved in emergency-civilian crashes (ECCs) were more often driving: straight through intersections (vs. same direction) of four-points or more (vs. not at intersection); where traffic signals were present (vs. no traffic control device); and at night (vs. midday). For nonfatal ECCs, drivers were more often driving: distracted (vs. not distracted); with vision obstructed by external objects (vs. no obstruction); on dark but lighted roads (vs. daylight); and in opposite directions (vs. same directions) of the EVs. Consequences included increased risk of injury (vs. no injury) and receiving traffic violations (vs. no violation). Fatal ECCs were associated with driving on urban roads (vs. rural), although these types of crashes were less likely to occur on dark roads (vs. daylight). The findings of this study suggest drivers may have difficulties in visually detecting EVs in different environments. Copyright © 2013 Elsevier Ltd. All rights reserved.
Evaluation of the cost-effectiveness of illumination as a safety treatment at rural intersections.
DOT National Transportation Integrated Search
2016-09-01
This research study seeks to improve current understanding of the relationship between rural intersection safety and different illumination levels. It uses three parallel studies: a survey of rural intersection illumination practices among US state d...
Evaluation of intersection countermeasures on high-speed rural multi-lane facilities.
DOT National Transportation Integrated Search
2012-01-01
The primary objective of this study is the evaluation of the effectiveness of several proposed safety : treatments at two intersections in Habersham County, Georgia. The intersections selected for this study had high : crash rates leading to a Georgi...
NASA Astrophysics Data System (ADS)
Pierini, N.; Vivoni, E. R.; Schreiner-McGraw, A.; Lopez-Castrillo, I.
2015-12-01
The urbanization process transforms a natural landscape into a built environment with many engineered surfaces, leading to significant impacts on surface energy and water fluxes across multiple spatial and temporal scales. Nevertheless, the effects of different urban land covers on energy and water fluxes has been rarely quantified across the large varieties of construction materials, landscaping and vegetation types, and industrial, commercial and residential areas in cities. In this study, we deployed a mobile eddy covariance tower at three different locations in the Phoenix, Arizona, metropolitan area to capture a variety of urban land covers. The three locations each represent a common urban class in Phoenix: 1) a dense, xeric landscape (gravel cover and native plants with drip-irrigation systems near tall buildings); 2) a high-density urban site (asphalt-paved parking lot near a high-traffic intersection); and 3) a suburban mesic landscape (sprinkler-irrigated turf grass in a suburban neighborhood). At each site, we measured meteorological variables, including air temperature and relative humidity at three heights, precipitation and pressure, surface temperature, and soil moisture and temperature (where applicable), to complement the eddy covariance measurements of radiation, energy, carbon dioxide and water vapor fluxes. We evaluated the tower footprint at each site to characterize the contributing surface area to the flux measurements, including engineered and landscaping elements, as a function of time for each deployment. The different sites allowed us to compare how turbulent fluxes of water vapor and carbon dioxide vary for these representative urban land covers, in particular with respect to the role of precipitation events and irrigation. While the deployments covered different seasons, from winter to summer in 2015, the variety of daily conditions allowed quantification of the differential response to precipitation events during the winter, pre-monsoon, and monsoon seasons in relation to irrigation input or lack thereof. As desert urban areas continue to grow worldwide, it is essential to gain an improved understanding of how the energy and water balances vary across the built environment and their implications on urban climate, energy, hydrologic conditions, and air quality.
Krüsi, Andrea; Kerr, Thomas; Taylor, Christina; Rhodes, Tim; Shannon, Kate
2016-09-01
In Vancouver, Canada, there has been a continuous shift in the policing of sex work away from arresting sex workers, which led to the implementation of a policing strategy that explicitly prioritised the safety of sex workers and continued to target sex workers' clients. We conducted semi-structured interviews with 26 cisgender and five transgender women street-based sex workers about their working conditions. Data were analysed thematically and by drawing on concepts of structural stigma and vulnerability. Our results indicated that despite police rhetoric of prioritising the safety of sex workers, participants were denied their citizenship rights for police protection by virtue of their 'risky' occupation and were thus responsiblised for sex work related violence. Our findings further suggest that sex workers' interactions with neighbourhood residents were predominantly shaped by a discourse of sex workers as a 'risky' presence in the urban landscape and police took swift action in removing sex workers in the case of complaints. This study highlights that intersecting regimes of stigmatisation and criminalisation continued to undermine sex workers citizenship rights to police protection and legal recourse and perpetuated labour conditions that render sex workers at increased risk for violence and poor health. © 2016 Foundation for the Sociology of Health & Illness.
Krüsi, Andrea; Kerr, Tthomas; Taylor, Christina; Rhodes, Tim; Shannon, Kate
2016-01-01
In Vancouver, Canada, there has been a continuous shift in the policing of sex work away from arresting sex workers, which led to the implementation of a policing strategy that explicitly prioritized the safety of sex workers and continued to target sex workers’ clients. We conducted semi-structured interviews with 26 cisgender and 5 transgender women street-based sex workers about their working conditions. Data were analysed thematically and by drawing on concepts of structural stigma and vulnerability. Our results indicated that despite police rhetoric of prioritizing the safety of sex workers, participants were denied their citizenship rights for police protection by virtue of their ‘risky’ occupation and where thus responsiblised for sex work related violence. Our findings further suggest that sex workers’ interactions with neighbourhood residents were predominantly shaped by a discourse of sex workers as a ‘risky’ presence in the urban landscape and police took swift action in removing sex workers in case of complaints. This study highlights that intersecting regimes of stigmatization and criminalization continued to undermine sex workers citizenship rights to police protection and legal recourse and perpetuated labour conditions that render sex workers at increased risk for violence and poor health. PMID:27113456
SIG Contribution in the Making of Geotechnical Maps in Urban Areas
NASA Astrophysics Data System (ADS)
Monteiro, António; Pais, Luís Andrade; Rodrigues, Carlos; Carvalho, Paulo
2017-10-01
The use of Geographic Information Systems (GIS) has spread to several science areas, from oceanography to geotechnics. Its application in the urban mapping was intensified in the last century, which allowed a great development, due to the use of geographic database, new analysis tools and, more recently, free open source software. Geotechnical cartography struggle with a permanent and large environment re-organization in urban area, due to new building construction, trenching and the drilling of sampling wells and holes. This creates an extra important and largest volume of data at any pre-existence geological map. The main problem results on the fact that the natural environment is covered with buildings and communications system. The purpose of this work is to create a viable geographic information base for geotechnical mapping through a free GIS computer program and open source, with non-traditional cartographic sources, giving preference to open platforms. QGIS was used as software and “Google Maps”, “Bing Maps” and “OpenStreetMap” were applied as cartographic sources using the “OpenLayers plugin” module. Finally, we also pretend to identify and delimit the degree of granite’s change and fracturing areas using a “Streetview” platform. This model has cartographic input which are a geological map study area, open cartographic web archives and the use of “Streetview” platform. The output has several layouts, such as topography intersection (roads, borders, etc.), with geological map and the bordering area of Guarda Urban Zone. The use of this platform types decrease the collect data time and, sometimes, a careful observation of pictures that were taken during excavations may reveal important details for geological mapping in the study area.
An Intersectional Perspective on Access to HIV-Related Healthcare for Transgender Women
Lacombe-Duncan, Ashley
2016-01-01
Abstract Transgender women experience decreased access to HIV-related healthcare relative to cisgender people, in part due to pervasive transphobia in healthcare. This perspective describes intersectionality as a salient theoretical approach to understanding this disparity, moving beyond transphobia to explore how intersecting systems of oppression, including cisnormativity, sexism/transmisogyny, classism, racism, and HIV-related, gender nonconformity, substance use, and sex work stigma influence HIV-related healthcare access for transgender women living with HIV. This perspective concludes with a discussion of how intersectionality-informed studies can be enhanced through studying underexplored intersections and bringing attention to women's resiliency and empowerment. PMID:29159304
2014-01-01
In 21st-century public health, rapid urbanization and mental health disorders are a growing global concern. The relationship between diet, brain function and the risk of mental disorders has been the subject of intense research in recent years. In this review, we examine some of the potential socioeconomic and environmental challenges detracting from the traditional dietary patterns that might otherwise support positive mental health. In the context of urban expansion, climate change, cultural and technological changes and the global industrialization and ultraprocessing of food, findings related to nutrition and mental health are connected to some of the most pressing issues of our time. The research is also of relevance to matters of biophysiological anthropology. We explore some aspects of a potential evolutionary mismatch between our ancestral past (Paleolithic, Neolithic) and the contemporary nutritional environment. Changes related to dietary acid load, advanced glycation end products and microbiota (via dietary choices and cooking practices) may be of relevance to depression, anxiety and other mental disorders. In particular, the results of emerging studies demonstrate the importance of prenatal and early childhood dietary practices within the developmental origins of health and disease concept. There is still much work to be done before these population studies and their mirrored advances in bench research can provide translation to clinical medicine and public health policy. However, the clear message is that in the midst of a looming global epidemic, we ignore nutrition at our peril. PMID:25060574
A Persistent Disparity: Smoking in Rural Sexual and Gender Minorities.
Bennett, Keisa; McElroy, Jane A; Johnson, Andrew O; Munk, Niki; Everett, Kevin D
2015-03-01
Sexual and gender minorities (SGM) smoke cigarettes at higher rates than the general population. Historically, research in SGM health issues was conducted in urban populations and recent population-based studies seldom have sufficient SGM participants to distinguish urban from rural. Given that rural populations also tend to have a smoking disparity, and that many SGM live in rural areas, it is vitally important to understand the intersection of rural residence, SGM identity, and smoking. This study analyzes the patterns of smoking in urban and rural SGM in a large sample. We conducted an analysis of 4280 adult participants in the Out, Proud, and Healthy project with complete data on SGM status, smoking status, and zip code. Surveys were conducted at 6 Missouri Pride Festivals and online in 2012. Analysis involved descriptive and bivariate methods, and multivariable logistic regression. We used GIS mapping to demonstrate the dispersion of rural SGM participants. SGM had higher smoking proportion than the non-SGM recruited from these settings. In the multivariable model, SGM identity conferred 1.35 times the odds of being a current smoker when controlled for covariates. Rural residence was not independently significant, demonstrating the persistence of the smoking disparity in rural SGM. Mapping revealed widespread distribution of SGM in rural areas. The SGM smoking disparity persists among rural SGM. These communities would benefit from continued research into interventions targeting both SGM and rural tobacco control measures. Recruitment at Pride Festivals may provide a venue for reaching rural SGM for intervention.
Logan, Alan C; Jacka, Felice N
2014-07-24
In 21st-century public health, rapid urbanization and mental health disorders are a growing global concern. The relationship between diet, brain function and the risk of mental disorders has been the subject of intense research in recent years. In this review, we examine some of the potential socioeconomic and environmental challenges detracting from the traditional dietary patterns that might otherwise support positive mental health. In the context of urban expansion, climate change, cultural and technological changes and the global industrialization and ultraprocessing of food, findings related to nutrition and mental health are connected to some of the most pressing issues of our time. The research is also of relevance to matters of biophysiological anthropology. We explore some aspects of a potential evolutionary mismatch between our ancestral past (Paleolithic, Neolithic) and the contemporary nutritional environment. Changes related to dietary acid load, advanced glycation end products and microbiota (via dietary choices and cooking practices) may be of relevance to depression, anxiety and other mental disorders. In particular, the results of emerging studies demonstrate the importance of prenatal and early childhood dietary practices within the developmental origins of health and disease concept. There is still much work to be done before these population studies and their mirrored advances in bench research can provide translation to clinical medicine and public health policy. However, the clear message is that in the midst of a looming global epidemic, we ignore nutrition at our peril.
Proposal of a Roundabout Solution within a Particular Traflc Operation
NASA Astrophysics Data System (ADS)
Ližbetin, Ján; Stopka, Ondrej
2016-11-01
This paper presents the practical solution of the transport telematics elements within a particular traffic operation when providing a transport and logistics services. A roundabout helps to increase the fluency and safety of transport and logistics services in cities and urban areas, however, the positive effect can be achieved only after determining the proper intersection parameters. Based on a survey performed in a real traffic situation, the practical application of roundabout in the city of Pilsen is processed in the most important part of the paper.
The model SIRANE for atmospheric urban pollutant dispersion; part I, presentation of the model
NASA Astrophysics Data System (ADS)
Soulhac, Lionel; Salizzoni, Pietro; Cierco, F.-X.; Perkins, Richard
2011-12-01
In order to control and manage urban air quality, public authorities require an integrated approach that incorporates direct measurements and modelling of mean pollutant concentrations. These have to be performed by means of operational modelling tools, that simulate the transport of pollutants within and above the urban canopy over a large number of streets. The operational models must be able to assess rapidly a large variety of situations and with limited computing resources. SIRANE is an operational urban dispersion model based on a simplified description of the urban geometry that adopts parametric relations for the pollutant transfer phenomena within and out of the urban canopy. The streets in a city district are modelled as a network of connected street segments. The flow within each street is driven by the component of the external wind parallel to the street, and the pollutant is assumed to be uniformly mixed within the street. The model contains three main mechanisms for transport in and out of a street: advection along the street axis, diffusion across the interface between the street and the overlying air flow and exchanges with other streets at street intersections. The dispersion of pollutants advected or diffused out of the streets is taken into account using a Gaussian plume model, with the standard deviations σ y and σ z parameterised by the similarity theory. The input data for the final model are the urban geometry, the meteorological parameters, the background concentration of pollutants advected into the model domain by the wind and the emissions within each street in the network.
Induced gravity on intersecting brane worlds. II. Cosmology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Corradini, Olindo; Koyama, Kazuya; Tasinato, Gianmassimo
2008-12-15
We explore cosmology of intersecting brane worlds with induced gravity on the branes. We find the cosmological equations that control the evolution of a moving codimension-one brane and a codimension-two brane that sits at the intersection. We study the Friedmann equation at the intersection, finding new contributions from the six-dimensional bulk. These higher dimensional contributions allow us to find new examples of self-accelerating configurations for the codimension-two brane at the intersection and we discuss their features.
NASA Astrophysics Data System (ADS)
Parracino, Stefano; Richetta, Maria; Gelfusa, Michela; Malizia, Andrea; Bellecci, Carlo; De Leo, Leonardo; Perrimezzi, Carlo; Fin, Alessandro; Forin, Marco; Giappicucci, Francesca; Grion, Massimo; Marchese, Giuseppe; Gaudio, Pasquale
2016-10-01
Urban air pollution causes deleterious effects on human health and the environment. To meet stringent standards imposed by the European Commission, advanced measurement methods are required. Remote sensing techniques, such as light detection and ranging (LiDAR), can be a valuable option for evaluating particulate matter (PM), emitted by vehicles in urban traffic, with high sensitivity and in shorter time intervals. Since air quality problems persist not only in large urban areas, a measuring campaign was specifically performed in a suburban area of Crotone, Italy, using both a compact LiDAR system and conventional instruments for real-time vehicle emissions monitoring along a congested road. First results reported in this paper show a strong dependence between variations of LiDAR backscattering signals and traffic-related air pollution levels. Moreover, time-resolved LiDAR data averaged in limited regions, directly above conventional monitoring stations at the border of an intersection, were found to be linearly correlated to the PM concentration levels with a correlation coefficient between 0.75 and 0.84.
Investigation of the impact of low cost traffic engineering measures on road safety in urban areas.
Yannis, George; Kondyli, Alexandra; Georgopoulou, Xenia
2014-01-01
This paper investigates the impact of low cost traffic engineering measures (LCTEMs) on the improvement of road safety in urban areas. A number of such measures were considered, such as speed humps, woonerfs, raised intersections and other traffic calming measures, which have been implemented on one-way, one-lane roads in the Municipality of Neo Psychiko in the Greater Athens Area. Data were analysed using the before-and-after safety analysis methodology with large control group. The selected control group comprised of two Municipalities in the Athens Greater Area, which present similar road network and land use characteristics with the area considered. The application of the methodology showed that the total number of crashes presented a statistically significant reduction, which can be possibly attributed to the introduction of LCTEMs. This reduction concerns passenger cars and single-vehicle crashes and is possibly due to the behavioural improvement of drivers of 25 years old or more. The results of this research are very useful for the identification of the appropriate low cost traffic engineering countermeasures for road safety problems in urban areas.
DOT National Transportation Integrated Search
2014-10-01
Nearly half of all traffic-related fatalities occur : at intersections, so engineering intersections : for greater safety remains a priority for the : Florida Department of Transportation (FDOT). : Engineering in this case must take into accoun...
Urban form relationships with walk trip frequency and distance among youth.
Frank, Lawrence; Kerr, Jacqueline; Chapman, Jim; Sallis, James
2007-01-01
To assess the relationship among objectively measured urban form variables, age, and walking in youth. Cross-sectional analyses of travel diary data mapped against urban form characteristics within a 1-km buffer of participant's place of residence. Setting. Youth in the Atlanta, Georgia region with selection stratified by income, household size, and residential density. A total of 3161 5- to 20-year-olds who completed 2-day travel diaries. Diaries of those under 15 years were completed by a parent or legal guardian. Walking distances were calculated from a 2-day travel diary. Residential density, intersection density, land use mix, and commercial and recreation space were assessed within a 1-km network distance around residences. Analysis. Logistic regression analyses were performed for each urban form variable by age groups controlling for the demographic variables. All variables were then entered simultaneously into an analysis of the whole sample. All five urban form variables tested were related to walking. Recreation space was the only variables associated with walking across the four different age groups. All the urban form variables were related to walking in the 12 to 15 years age cohort. For this group, the odds of walking were 3. 7 times greater for those in highest- versus lowest-density tertile and 2.6 times greater for those with at least one commercial and 2.5 times greater for those with at least one recreational destination within 1 km from home. In the analysis of the full sample, number of cars, recreation space, and residential density were most strongly related to walking. Access to recreation or open space was the most important urban form variable related to walking for all age groups. Children aged 12 to 15 years old may be particularly influenced by urban form.
Application of Foldcore Sandwich Structures in Helicopter Subfloor Energy Absorption Structure
NASA Astrophysics Data System (ADS)
Zhou, H. Z.; Wang, Z. J.
2017-10-01
The intersection element is an important part of the helicopter subfloor structure. The numerical simulation model of the intersection element is established and the crush simulation is conducted. The simulation results agree well with the experiment results. In order to improve the buffering capacity and energy-absorbing capacity, the intersection element is redesigned. The skin and the floor in the intersection element are replaced with foldcore sandwich structures. The new intersection element is studied using the same simulation method as the typical intersection element. The analysis result shows that foldcore can improve the buffering capacity and the energy-absorbing capacity, and reduce the structure mass.
Complex Road Intersection Modelling Based on Low-Frequency GPS Track Data
NASA Astrophysics Data System (ADS)
Huang, J.; Deng, M.; Zhang, Y.; Liu, H.
2017-09-01
It is widely accepted that digital map becomes an indispensable guide for human daily traveling. Traditional road network maps are produced in the time-consuming and labour-intensive ways, such as digitizing printed maps and extraction from remote sensing images. At present, a large number of GPS trajectory data collected by floating vehicles makes it a reality to extract high-detailed and up-to-date road network information. Road intersections are often accident-prone areas and very critical to route planning and the connectivity of road networks is mainly determined by the topological geometry of road intersections. A few studies paid attention on detecting complex road intersections and mining the attached traffic information (e.g., connectivity, topology and turning restriction) from massive GPS traces. To the authors' knowledge, recent studies mainly used high frequency (1 s sampling rate) trajectory data to detect the crossroads regions or extract rough intersection models. It is still difficult to make use of low frequency (20-100 s) and easily available trajectory data to modelling complex road intersections geometrically and semantically. The paper thus attempts to construct precise models for complex road intersection by using low frequency GPS traces. We propose to firstly extract the complex road intersections by a LCSS-based (Longest Common Subsequence) trajectory clustering method, then delineate the geometry shapes of complex road intersections by a K-segment principle curve algorithm, and finally infer the traffic constraint rules inside the complex intersections.
Bowleg, Lisa
2012-07-01
Intersectionality is a theoretical framework that posits that multiple social categories (e.g., race, ethnicity, gender, sexual orientation, socioeconomic status) intersect at the micro level of individual experience to reflect multiple interlocking systems of privilege and oppression at the macro, social-structural level (e.g., racism, sexism, heterosexism). Public health's commitment to social justice makes it a natural fit with intersectionality's focus on multiple historically oppressed populations. Yet despite a plethora of research focused on these populations, public health studies that reflect intersectionality in their theoretical frameworks, designs, analyses, or interpretations are rare. Accordingly, I describe the history and central tenets of intersectionality, address some theoretical and methodological challenges, and highlight the benefits of intersectionality for public health theory, research, and policy.
NASA Astrophysics Data System (ADS)
Shao, M.; Zhao, G.; Gao, H.
2017-12-01
Texas, the fastest growing state in the US, has seen significant land cover/land use change due to urbanization over the past decades. With most of the region being arid/semi-arid, water issues are unprecedentedly pressing. Among the 15 major river basins, two adjacent river basins located in south-central Texas—the San Antonio River Basin (SARB) and the Guadalupe River Basin (GRB)—form an ideal testbed for evaluating the impacts of urbanization on both hydrological processes and water resources. These two basins are similar in size and in climate pattern, but differ in terms of urbanization progress. In SARB, where the city of San Antonio is located, the impervious area has increased from 0.6% (1929) to 7.8% (2011). In contrast, there is little land cover change in the GRB. With regard to the underground components, both basins intersect with the Edward Aquifer (more than 15% of basin area in both cases). The Edward Aquifer acts as one of the major municipal water supplies for San Antonio, and as the water source for local agricultural uses (and for the surrounding habitat). This aquifer has the characteristic of being highly sensitive to changes in surface water conditions, like the descending trend of the underground water table due to over exploitation. In this study, a distributed hydrologic model—DHSVM (the Distributed Hydrology Soil Vegetation Model)—is used to compare the hydrologic characteristics (and their impacts on water resources) over the two basins. With a 200m spatial resolution, the model is calibrated and validated during the historical period over both basins. The objectives of the comparisons are two-fold: First, the urbanization effects on peak flows are evaluated for selected extreme rainfall events; Second, the Edward Aquifer recharge rate from surface water under flood and/or drought conditions within the two basins is analyzed. Furthermore, future urbanization scenarios are tested to provide information relevant to decision making.
Development of a framework for evaluating yellow timing at signalized intersections.
DOT National Transportation Integrated Search
2011-02-01
Studies show that the proper design of clearance intervals has significant implications for intersection safety. For : example, in 2001, approximately 218,000 red-light-running crashes occurred at signalized intersections in the United States. : Thes...
ERIC Educational Resources Information Center
Forrester, Sommer H.
2018-01-01
The purpose of this study was to examine the complexities of instrumental music teacher knowledge as they relate to the intersection between instrumental music teaching and conducting, and to explore how participants describe and perceive these intersections. The key research question guiding this study was, How do high school instrumental music…
Investigating the Intersection of Poverty and Race in Gifted Education Journals: A 15-Year Analysis
ERIC Educational Resources Information Center
Goings, Ramon B.; Ford, Donna Y.
2018-01-01
Using a two-phase content analysis approach, this study examined how education scholars have discussed the intersection of giftedness, race, and poverty in gifted academic journals from 2000 to 2015. Specifically, the authors explored the following questions: (a) What are the characteristics of studies published that explore the intersection of…
Modeling traffic accidents at signalized intersections in the city of Norfolk, VA.
DOT National Transportation Integrated Search
2010-12-31
This study was an attempt to apply a proactive approach using traffic pattern and signalized intersection characteristics to predict accident rates at signalized intersections in a citys arterial network. An earlier analysis of accident data at se...
Policies on pets for healthy cities: a conceptual framework.
Rock, Melanie J; Adams, Cindy L; Degeling, Chris; Massolo, Alessandro; McCormack, Gavin R
2015-12-01
Drawing on the One Health concept, and integrating a dual focus on public policy and practices of caring from the Ottawa Charter for Health Promotion, we outline a conceptual framework to help guide the development and assessment of local governments' policies on pets. This framework emphasizes well-being in human populations, while recognizing that these outcomes relate to the well-being of non-human animals. Five intersecting spheres of activity, each associated with local governments' jurisdiction over pets, are presented: (i) preventing threats and nuisances from pets, (ii) meeting pets' emotional and physical needs, (iii) procuring pets ethically, (iv) providing pets with veterinary services and (v) licensing and identifying pets. This conceptual framework acknowledges the tenets of previous health promotion frameworks, including overlapping and intersecting influences. At the same time, this framework proposes to advance our understanding of health promotion and, more broadly, population health by underscoring interdependence between people and pets as well as the dynamism of urbanized ecologies. © The Author (2014). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Line segment extraction for large scale unorganized point clouds
NASA Astrophysics Data System (ADS)
Lin, Yangbin; Wang, Cheng; Cheng, Jun; Chen, Bili; Jia, Fukai; Chen, Zhonggui; Li, Jonathan
2015-04-01
Line segment detection in images is already a well-investigated topic, although it has received considerably less attention in 3D point clouds. Benefiting from current LiDAR devices, large-scale point clouds are becoming increasingly common. Most human-made objects have flat surfaces. Line segments that occur where pairs of planes intersect give important information regarding the geometric content of point clouds, which is especially useful for automatic building reconstruction and segmentation. This paper proposes a novel method that is capable of accurately extracting plane intersection line segments from large-scale raw scan points. The 3D line-support region, namely, a point set near a straight linear structure, is extracted simultaneously. The 3D line-support region is fitted by our Line-Segment-Half-Planes (LSHP) structure, which provides a geometric constraint for a line segment, making the line segment more reliable and accurate. We demonstrate our method on the point clouds of large-scale, complex, real-world scenes acquired by LiDAR devices. We also demonstrate the application of 3D line-support regions and their LSHP structures on urban scene abstraction.
Low-cost mobile air pollution monitoring in urban environments: a pilot study in Lubbock, Texas.
McKercher, Grant R; Vanos, Jennifer K
2018-06-01
The complex nature of air pollution in urban areas prevents traditional monitoring techniques from obtaining measurements representative of true human exposure. The current study assessed the capability of low-cost mobile monitors to acquire useful data in a city without a monitoring network in place (Lubbock, Texas) using a bicycle platform. The monitoring campaign resulted in 30 days of data along a 13.4 km fixed concentric route. Due to high sensitivities to airflow, the apparent wind velocity was accounted for throughout the route. The data were also normalized into percentiles in order to visualize spatial patterns. The highest estimated pollution levels were located near frequently busy intersections and roads; however, sensor issues resulted in lower confidence. Additional research is needed concerning the appropriate use of low-cost metal oxide sensors for citizen science applications, as measurements can be misleading if the user is unaware of sensors specifications. The simultaneous use of several low-cost mobile platforms, rather than a single platform, as well as the use of high-end cases, are recommended to create a more robust spatial analysis. The issues addressed from this research are important to understand for accurate and beneficial application of low-cost gaseous monitors for citizen science.
Besser, Lilah M; Rodriguez, Daniel A; McDonald, Noreen; Kukull, Walter A; Fitzpatrick, Annette L; Rapp, Stephen R; Seeman, Teresa
2018-03-01
Preliminary studies suggest that neighborhood social and built environment (BE) characteristics may affect cognition in older adults. Older adults are particularly vulnerable to the neighborhood environment due to a decreasing range of routine travel with increasing age. We examined if multiple neighborhood BE characteristics are cross-sectionally associated with cognition in a diverse sample of older adults, and if the BE-cognition associations vary by individual-level demographics. The sample included 4539 participants from the Multi-Ethnic Study of Atherosclerosis. Multivariable linear regression was used to examine the associations between five BE measures and four cognitive measures, and effect modification by individual-level education and race/ethnicity. In the overall sample, increasing social destination density, walking destination density, and intersection density were associated with worse overall cognition, whereas increasing proportion of land dedicated to retail was associated with better processing speed. Effect modification results suggest that the association between urban density and worse cognition may be limited to or strongest in those of non-white race/ethnicity. Although an increase in neighborhood retail destinations was associated with better cognition in the overall sample, these results suggest that certain BE characteristics in dense urban environments may have a disproportionately negative association with cognition in vulnerable populations. However, our findings must be replicated in longitudinal studies and other regional samples. Copyright © 2018 Elsevier Ltd. All rights reserved.
Lighting levels for isolated intersections : leading to safety improvements : final report.
DOT National Transportation Integrated Search
2015-01-01
A number of studies have linked the benefits of roadway lighting to a reduction in crash rates at night for a variety : of roadway types including rural intersections. Assessing the effectiveness of intersection lighting has primarily : relied upon c...
Islam, Samantha; Brown, Joshua
2017-11-01
The research described in this paper explored the factors contributing to the injury severity resulting from the motorcycle at-fault accidents in rural and urban areas in Alabama. Given the occurrence of a motorcycle at-fault crash, random parameter logit models of injury severity (with possible outcomes of fatal, major, minor, and possible or no injury) were estimated. The estimated models identified a variety of statistically significant factors influencing the injury severities resulting from motorcycle at-fault crashes. According to these models, some variables were found to be significant only in one model (rural or urban) but not in the other one. For example, variables such as clear weather, young motorcyclists, and roadway without light were found significant only in the rural model. On the other hand, variables such as older female motorcyclists, horizontal curve and at intersection were found significant only in the urban model. In addition, some variables (such as, motorcyclists under influence of alcohol, non-usage of helmet, high speed roadways, etc.) were found significant in both models. Also, estimation findings showed that two parameters (clear weather and roadway without light) in the rural model and one parameter (on weekend) in the urban model could be modeled as random parameters indicating their varying influences on the injury severity due to unobserved effects. Based on the results obtained, this paper discusses the effects of different variables on injury severities resulting from rural and urban motorcycle at-fault crashes and their possible explanations. Copyright © 2017 Elsevier Ltd. All rights reserved.
Bauer, Greta R
2014-06-01
Intersectionality theory, developed to address the non-additivity of effects of sex/gender and race/ethnicity but extendable to other domains, allows for the potential to study health and disease at different intersections of identity, social position, processes of oppression or privilege, and policies or institutional practices. Intersectionality has the potential to enrich population health research through improved validity and greater attention to both heterogeneity of effects and causal processes producing health inequalities. Moreover, intersectional population health research may serve to both test and generate new theories. Nevertheless, its implementation within health research to date has been primarily through qualitative research. In this paper, challenges to incorporation of intersectionality into population health research are identified or expanded upon. These include: 1) confusion of quantitative terms used metaphorically in theoretical work with similar-sounding statistical methods; 2) the question of whether all intersectional positions are of equal value, or even of sufficient value for study; 3) distinguishing between intersecting identities, social positions, processes, and policies or other structural factors; 4) reflecting embodiment in how processes of oppression and privilege are measured and analysed; 5) understanding and utilizing appropriate scale for interactions in regression models; 6) structuring interaction or risk modification to best convey effects, and; 7) avoiding assumptions of equidistance or single level in the design of analyses. Addressing these challenges throughout the processes of conceptualizing and planning research and in conducting analyses has the potential to improve researchers' ability to more specifically document inequalities at varying intersectional positions, and to study the potential individual- and group-level causes that may drive these observed inequalities. A greater and more thoughtful incorporation of intersectionality can promote the creation of evidence that is directly useful in population-level interventions such as policy changes, or that is specific enough to be applicable within the social contexts of affected communities. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.
Integrating intersectionality and biomedicine in health disparities research.
Kelly, Ursula A
2009-01-01
Persisting health disparities have lead to calls for an increase in health research to address them. Biomedical scientists call for research that stratifies individual indicators associated with health disparities, for example, ethnicity. Feminist social scientists recommend feminist intersectionality research. Intersectionality is the multiplicative effect of inequalities experienced by nondominant marginalized groups, for example, ethnic minorities, women, and the poor. The elimination of health disparities necessitates integration of both paradigms in health research. This study provides a practical application of the integration of biomedical and feminist intersectionality paradigms in nursing research, using a psychiatric intervention study with battered Latino women as an example.
Evaluating the Impacts of Red Light Camera Deployment on Intersection Traffic Safety
DOT National Transportation Integrated Search
2018-06-01
Red-light cameras (RLC) are a popular countermeasure to reduce red-light running and improve intersection safety. Studies show that the reduction in side impact crashes at RLC intersections are often accompanied by no-change or an increase in the num...
DOT National Transportation Integrated Search
1998-09-01
This project included a background literature synthesis and observational field study. The research goals were to document driving problems and errors at intersections, for older drivers using their own cars to travel familiar and unfamiliar routes, ...
Evaluation and analysis of noise levels at traffic intersections of Nagpur city, India.
Vijay, Ritesh; Popat, Rishabh; Pisode, Mayur; Sharma, Asheesh; Manoj, Kumar; Chakrabarti, T; Gupta, Rajesh
2013-04-01
The objective of the present study was to monitor and assess the noise levels at traffic intersections in Napgur city under heterogenic traffic activities. For this, traffic volume and noise level were measured at intersections on highways, major roads andring road during morning and evening peak hours. Traffic volume was categorized in light, medium and heavy vehicles while noise levels were measured for Lmin, Lmax, Leq , L10 and L90. Equivalent noise was observed in the range of 71.3 to 79.3 dB(A) at the traffic intersections. Due to heterogenic traffic conditions and activities at the intersection like honking, idling, gear noise, bearing noise, breaking noise, tyre-road noise and exhaust noise, no correlation was established between traffic volume and observed noise levels except West High Court road. A strong correlation was found at West High Court road due to controlled traffic flow and less impact of heavy vehicles. Impact of noisy vehicles on general traffic was also assessed at the traffic intersections based on noise pollution levels and traffic noise index. The study suggests that control measures are required at the traffic intersections to minimize noise pollution levels.
NASA Astrophysics Data System (ADS)
Stoll, R., II; Christen, A.; Mahaffee, W.; Salesky, S.; Therias, A.; Caitlin, S.
2016-12-01
Pollution in the form of small particles has a strong impact on a wide variety of urban processes that play an important role in the function of urban ecosystems and ultimately human health and well-being. As a result, a substantial body of research exists on the sources, sinks, and transport characteristics of urban particulate matter. Most of the existing experimental work examining point sources employed gases (e.g., SF6) as the working medium. Furthermore, the focus of most studies has been on the dispersion of pollutants far from the source location. Here, our focus is on the turbulent dispersion of heavy particles in the near source region of a suburban neighborhood. To this end, we conducted a series of heavy particle releases in the Sunset neighborhood of Vancouver, Canada during June, 2017. The particles where dispersed from a near ground point source at two different locations. The Sunset neighborhood is composed mostly of single dwelling detached houses and has been used in numerous previous urban studies. One of the release points was just upwind of a 4-way intersection and the other in the middle of a contiguous block of houses. Each location had a significant density of trees. A minimum of four different successful release events were conducted at each site. During each release, fluorescing micro particles (mean diameter approx. 30 micron) were released from ultrasonic atomizer nozzles for a duration of approximately 20 minutes. The particles where sampled at 50 locations (1.5 m height) in the area downwind of the release over distances from 1-15 times the mean canopy height ( 6 m) using rotating impaction traps. In addition to the 50 sampler locations, instantaneous wind velocities were measured with eight sonic anemometers distributed horizontally and vertically throughout the release area. The resulting particle plume distributions indicate a strong impact of local urban form in the near source region and a high degree of sensitivity to the local wind direction measured from the sonic anemometers. In addition to presenting the experimental data, initial comparisons to a Lagrangian particle dispersion model driven by a mass consistent diagnostic wind field will be presented.
NASA Astrophysics Data System (ADS)
Stoll, R., II; Christen, A.; Mahaffee, W.; Salesky, S.; Therias, A.; Caitlin, S.
2017-12-01
Pollution in the form of small particles has a strong impact on a wide variety of urban processes that play an important role in the function of urban ecosystems and ultimately human health and well-being. As a result, a substantial body of research exists on the sources, sinks, and transport characteristics of urban particulate matter. Most of the existing experimental work examining point sources employed gases (e.g., SF6) as the working medium. Furthermore, the focus of most studies has been on the dispersion of pollutants far from the source location. Here, our focus is on the turbulent dispersion of heavy particles in the near source region of a suburban neighborhood. To this end, we conducted a series of heavy particle releases in the Sunset neighborhood of Vancouver, Canada during June, 2017. The particles where dispersed from a near ground point source at two different locations. The Sunset neighborhood is composed mostly of single dwelling detached houses and has been used in numerous previous urban studies. One of the release points was just upwind of a 4-way intersection and the other in the middle of a contiguous block of houses. Each location had a significant density of trees. A minimum of four different successful release events were conducted at each site. During each release, fluorescing micro particles (mean diameter approx. 30 micron) were released from ultrasonic atomizer nozzles for a duration of approximately 20 minutes. The particles where sampled at 50 locations (1.5 m height) in the area downwind of the release over distances from 1-15 times the mean canopy height ( 6 m) using rotating impaction traps. In addition to the 50 sampler locations, instantaneous wind velocities were measured with eight sonic anemometers distributed horizontally and vertically throughout the release area. The resulting particle plume distributions indicate a strong impact of local urban form in the near source region and a high degree of sensitivity to the local wind direction measured from the sonic anemometers. In addition to presenting the experimental data, initial comparisons to a Lagrangian particle dispersion model driven by a mass consistent diagnostic wind field will be presented.
The Effect of Gender and Race Intersectionality on Student Learning Outcomes in Engineering
ERIC Educational Resources Information Center
Ro, Hyun Kyoung; Loya, Karla I.
2015-01-01
Women and underrepresented minorities in traditionally White and male-dominated disciplines tend to report lower learning outcomes than their White peers. Adopting a feminist intersectionality framework, this study looks at the intersections of gender and race to investigate differences in self-assessed learning outcomes in engineering…
ERIC Educational Resources Information Center
Armstrong, Denise; Mitchell, Coral
2017-01-01
This qualitative study used a critical intersectional lens to examine how two black female Canadian principals negotiated their professional identities in administrative contexts. Both principals encountered gender and race-related pressures to fit normative expectations of administrators as white males. Navigating their intersecting identities…
DOT National Transportation Integrated Search
1987-10-01
A review of the literature and a state-of-the-practice survey were conducted of procedures relating to the addition of through lanes at intersections. The capacity and level of service change at the intersection is of interest, since the reduction in...
Intersectionality research in counseling psychology.
Grzanka, Patrick R; Santos, Carlos E; Moradi, Bonnie
2017-10-01
This article introduces the special section on intersectionality research in counseling psychology. Across the 4 manuscripts that constitute this special section, a clear theme emerges: a need to return to the roots and politics of intersectionality. Importantly, the 2 empirical articles in this special section (Jerald, Cole, Ward, & Avery, 2017; Lewis, Williams, Peppers, & Gadson, 2017) are studies of Black women's experiences: a return, so to speak, to the subject positions and social locations from which intersectionality emanates. Shin et al. (2017) explore why this focus on Black feminist thought and social justice is so important by highlighting the persistent weaknesses in how much research published in leading counseling psychology journals has tended to use intersectionality as a way to talk about multiple identities, rather than as a framework for critiquing systemic, intersecting forms of oppression and privilege. Shin and colleagues also point to the possibilities intersectionality affords us when scholars realize the transformative potential of this critical framework. Answers to this call for transformative practices are foregrounded in Moradi and Grzanka's (2017) contribution, which surveys the interdisciplinary literature on intersectionality and presents a series of guidelines for using intersectionality responsibly. We close with a discussion of issues concerning the applications of intersectionality to counseling psychology research that spans beyond the contributions of each manuscript in this special section. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
National occupant protection use survey : controlled intersection study
DOT National Transportation Integrated Search
1995-05-01
In late 1994, NHTSA conducted the National Occupant Protection Use Survey : (NOPUS). NOPUS is composed of three separate studies: the moving traffic study : which provides information on overall shoulder belt use, the controlled : intersection study ...
Modeling and formal analysis of urban road traffic
NASA Astrophysics Data System (ADS)
Avram, Camelia; Machado, José; Aştilean, Adina
2013-10-01
Modern life in cities leads to complex urban traffic road and, sometimes, to go from one point to another, in a city, is a hard and very complex task. The use of assisted systems for helping drivers on their task of reaching the desired destination is being common, mainly systems like GPS location systems or other similar systems. The main gap of those systems is that they are not able to assist drivers when some unexpected changes occur, like accidents, or another unexpected situations. In this context, it would be desirable to have a dynamic system to inform the drivers, about everything that is happening "online". This work is inserted in this context and the work presented here is one part of a bigger project that has, as main goal, to be a dynamic system for assisting drivers under hard conditions of urban road traffic. In this paper is modeled, and formally analyzed, the intersection of four street segments, in order to take some considerations about this subject. This paper presents the model of the considered system, using timed automata formalism. The validation and verification of the road traffic model it is realized using UPPAAL model-checker.
Mean and turbulent mass flux measurements in an idealised street network.
Carpentieri, Matteo; Robins, Alan G; Hayden, Paul; Santi, Edoardo
2018-03-01
Pollutant mass fluxes are rarely measured in the laboratory, especially their turbulent component. They play a major role in the dispersion of gases in urban areas and modern mathematical models often attempt some sort of parametrisation. An experimental technique to measure mean and turbulent fluxes in an idealised urban array was developed and applied to improve our understanding of how the fluxes are distributed in a dense street canyon network. As expected, horizontal advective scalar fluxes were found to be dominant compared with the turbulent components. This is an important result because it reduces the complexity in developing parametrisations for street network models. On the other hand, vertical mean and turbulent fluxes appear to be approximately of the same order of magnitude. Building height variability does not appear to affect the exchange process significantly, while the presence of isolated taller buildings upwind of the area of interest does. One of the most interesting results, again, is the fact that even very simple and regular geometries lead to complex advective patterns at intersections: parametrisations derived from measurements in simpler geometries are unlikely to capture the full complexity of a real urban area. Copyright © 2017 Elsevier Ltd. All rights reserved.
Streets and stages: urban renewal and the arts after World War II.
Foulkes, Julia L
2010-01-01
Lincoln Center for the Performing Arts in Manhattan and the revitalization of the Brooklyn Academy of Music in Brooklyn offer insights into the intersection of arts and urbanization after World War II. This intra-city comparison shows the aggrandizing pull of the international arena in the shaping of Lincoln Center and the arts it featured in contrast to the local focus and debate that transformed how BAM fit into its Brooklyn neighborhood. The performing arts, bound as they are to a moment fused in space and time, reveal the making of place within grandiose formal buildings as well as outside on the streets that surround them—and it is, perhaps, that tensile connection between stages and streets that informs the relevancy of both the institution and the arts it features. At a time when the suburbs pulled more and more people, the arts provided a counterforce in cities, as magnet and stimulus. The arts were used as compensation for the demolition and re-building of a neighborhood in urban renewal, but they also exposed the more complex social dynamics that underpinned the transformation of the mid-20th century American city from a segregated to a multi-faceted place.
Moradi, Bonnie; Grzanka, Patrick R
2017-10-01
The increasing popularity of the concept of intersectionality in the social sciences, including in psychology, represents an opportunity to reflect on the state of stewardship of this concept, its roots, and its promise. In this context, the authors aim to promote responsible stewardship of intersectionality and to tip the momentum of intersectionality's flourishing toward fuller use and engagement of its roots and promise for understanding and challenging dynamics of power, privilege, and oppression. To this end, this article provides a set of guidelines for reflection and action. The authors organize these guidelines along 3 major formulations of intersectionality: intersectionality as a field of study, as analytic strategy or disposition, and as critical praxis for social justice. Ultimately, the authors call for expanding the use of intersectionality toward fuller engagement with its roots in Black feminist thought, its current interdisciplinary richness and potential, and its central aims to challenge and transform structures and systems of power, privilege, and oppression. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Intersecting surface defects and two-dimensional CFT
NASA Astrophysics Data System (ADS)
Gomis, Jaume; Le Floch, Bruno; Pan, Yiwen; Peelaers, Wolfger
2017-08-01
We initiate the study of intersecting surface operators/defects in 4D quantum field theories (QFTs). We characterize these defects by coupled 4D/2D/0D theories constructed by coupling the degrees of freedom localized at a point and on intersecting surfaces in spacetime to each other and to the 4D QFT. We construct supersymmetric intersecting surface defects preserving just two supercharges in N =2 gauge theories. These defects are amenable to exact analysis by localization of the partition function of the underlying 4D/2D/0D QFT. We identify the 4D/2D/0D QFTs that describe intersecting surface operators in N =2 gauge theories realized by intersecting M2 branes ending on N M5 branes wrapping a Riemann surface. We conjecture and provide evidence for an explicit equivalence between the squashed four-sphere partition function of these intersecting defects and correlation functions in Liouville/Toda CFT with the insertion of arbitrary degenerate vertex operators, which are labeled by two representations of S U (N ).
Requirements of a system to reduce car-to-vulnerable road user crashes in urban intersections.
Habibovic, Azra; Davidsson, Johan
2011-07-01
Intersection crashes between cars and vulnerable road users (VRUs), such as pedestrians and bicyclists, often result in injuries and fatalities. Advanced driver assistance systems (ADASs) can prevent, or mitigate, these crashes. To derive functional requirements for such systems, an understanding of the underlying contributing factors and the context in which the crashes occur is essential. The aim of this study is to use microscopic and macroscopic crash data to explore the potential of information and warning providing ADASs, and then to derive functional sensor, collision detection, and human-machine interface (HMI) requirements. The microscopic data were obtained from the European project SafetyNet. Causation charts describing contributing factors for 60 car-to-VRU crashes had been compiled and were then also aggregated using the SafetyNet Accident Causation System (SNACS). The macroscopic data were obtained from the Swedish national crash database, STRADA. A total of 9702 crashes were analyzed. The results show that the most frequent contributing factor to the crashes was the drivers' failure to observe VRUs due to reduced visibility, reduced awareness, and/or insufficient comprehension. An ADAS should therefore help drivers to observe the VRUs in time and to enhance their ability to interpret the development of events in the near future. The system should include a combination of imminent and cautionary collision warnings, with additional support in the form of information about intersection geometry and traffic regulations. The warnings should be deployed via an in-vehicle HMI and according to the likelihood of crash risk. The system should be able to operate under a variety of weather and light conditions. It should have the capacity to support drivers when their view is obstructed by physical objects. To address problems that vehicle-based sensors may face in this regard, the use of cooperative systems is recommended. Copyright © 2011 Elsevier Ltd. All rights reserved.
Geochemical Legacies and the Future Health of Cities: An Analysis of two Neurotoxins in Urban Soils
NASA Astrophysics Data System (ADS)
Filippelli, G. M.; Risch, M.
2015-12-01
The past and future of cities are inextricably linked, a linkage that can be seen clearly in the long-term impacts of urban geochemical legacies. As loci of population as well as the means of employment and industry to support these populations, cities have a long history of co-locating contaminating practices and people, sometimes with negative implications for human health. Working at the intersection between geochemical processes, communities, and human health is critical to grapple with environmental legacies and to support healthy, sustainable, and growing urban populations. An emerging area of environmental health research is to understand the impacts of chronic exposures and exposure mixtures—these impacts are very poorly studied, yet have materialized as perhaps the greatest threat to large-scale population health. Acute exposure to lead (Pb), a powerful neurotoxin to which children are particularly susceptible, has largely been eliminated in the U.S. and other countries through policy-based restrictions on leaded gasoline and lead-based paints. But these legacy Pb sources are still around in the form of surface soil Pb contamination, a common problem in cities and one that has only recently emerged as a pernicious and widespread chronic exposure mechanism in cities. Some urban soils are also contaminated with another neurotoxin, mercury (Hg), although very little work has been done to understand human exposures to low levels of this element in soils. The most documented human exposure to Hg is through fish consumption, so eating fish caught in urban areas presents risks for above average dietary Hg exposure. The potential double impact of chronic exposure to these two neurotoxins is pronounced in cities. Many aspects of the dose-response curves for individual elements and mixtures are poorly understood, especially at lower levels, leaving unanswered several interesting and provocative questions about environmental impacts on neurological and developmental disorders.
NASA Astrophysics Data System (ADS)
Jiang, Ping; Wen, Zhiping; Sha, Weiming; Chen, Guixing
2017-05-01
Turbulent flow and its interaction with a sea breeze front (SBF) over an urban-like coast with a regular block array were investigated using a building-resolving computational fluid dynamics model. It was found that during daytime with an offshore ambient flow, streaky turbulent structures tended to grow within the convective boundary layer (CBL) over a warm urban surface ahead of the SBF. The structures were organized as streamwise streaks at an interval of a few hundred meters, which initiated at the rooftop level with strong wind shear and strengthens in the CBL with moderate buoyancy. The streaks then interacted with the onshore-propagating SBF as it made landfall. The SBF, which was initially characterized as a shallow and quasi-linear feature over the sea, developed three-dimensional structures with intensified updrafts at an elevated frontal head after landfall. Frontal updrafts were locally enhanced at intersections where the streaks merged with the SBF, which greatly increased turbulent fluxes at the front. The frontal line was irregular because of merging, tilting, and transformation effects of vorticity associated with streaky structures. Inland penetration of the SBF was slowed by the frictional effect of urban-like surfaces and turbulent flow on land. The overall SBF intensity weakened after the interaction with turbulent flow. These findings aid understanding of local weather over coastal cities during typical sea breeze conditions.
The Intersection of Gender and Age: An Exploration
ERIC Educational Resources Information Center
Gander, Michelle
2014-01-01
The understanding of gender inequality for women entering work has not been subject to significant research or theorizing. This small study indicated that young women entering the workplace are subject to direct discrimination and by using an intersectionality approach this paper proposes that the intersection of gender and young age results in…
Cargos Rotate at Microtubule Intersections during Intracellular Trafficking.
Gao, Yuan; Anthony, Stephen M; Yu, Yanqi; Yi, Yi; Yu, Yan
2018-06-19
Intracellular cargos are transported by molecular motors along actin and microtubules, but how their dynamics depends on the complex structure of the cytoskeletal network remains unclear. In this study, we investigated this longstanding question by measuring simultaneously the rotational and translational dynamics of cargos at microtubule intersections in living cells. We engineered two-faced particles that are fluorescent on one hemisphere and opaque on the other and used their optical anisotropy to report the rotation of cargos. We show that cargos undergo brief episodes of unidirectional and rapid rotation while pausing at microtubule intersections. Probability and amplitude of the cargo rotation depend on the geometry of the intersecting filaments. The cargo rotation is not random motion due to detachment from microtubules, as revealed by statistical analyses of the translational and rotational dynamics. Instead, it is an active rotation driven by motor proteins. Although cargos are known to pause at microtubule intersections, this study reveals a different dimension of dynamics at this seemingly static state and, more importantly, provides direct evidence showing the correlation between cargo rotation and the geometry of underlying microtubule intersections. Copyright © 2018 Biophysical Society. All rights reserved.
NASA Astrophysics Data System (ADS)
Behbahani, Hamid; Najafi Moghaddam Gilani, Vahid; Jahangir Samet, Mehdi; Salehfard, Reza
2017-10-01
Pedestrians affect the traffic in the signalized and un-signalized intersections. Therefore, identifying the behavioural features of the pedestrians is of great importance and may result in better designing facilities for them. In this study, by shooting the four intersections in Rasht for 15 hours and inventory from 4568 pedestrians, crossing speed of the pedestrians in the marked crosswalks and unmarked crosswalks was evaluated and analysed. Results showed that pedestrians‧ crossing speed in the marked crosswalks is higher than their crossing speed in the unmarked crosswalks in both signalized and un-signalized intersections. Moreover, in the unmarked crosswalks in the signalized intersections, 15th percentile speed of male pedestrians, female pedestrians and group of pedestrians’ decrease 6.4%, 5.4% and 12.2%, respectively, compared with the 15th percentile speed in the marked crosswalks. Above-mentioned values in the unmarked crosswalks in the un-signalized intersections for male pedestrians, female pedestrians, and group of pedestrians decrease 1.2%, 3.8%, and 1.4%, respectively.
Etherington, Nicole; Baker, Linda
2016-03-07
Empirical studies on the impact of intimate partner violence (IPV) on children have burgeoned over the last three decades. Notably absent from existing approaches to studying children exposed to IPV, however, is attention to how various positionalities intersect to impact the experiences of children and their families. In fact, while the importance of an intersectional framework for understanding IPV has been discussed for over two decades, little or no attention has been given to issues of children's exposure to IPV. In this article, we examine the current state of the literature on children exposed to IPV through an exploratory meta-analysis, finding limited application of intersectionality and a focus on discrete categories of difference. We then demonstrate why and how an intersectional framework should be applied to children exposed to IPV, with specific strategies for research and policy. We suggest a child-centered approach that recognizes diversity among children exposed to IPV, extending the challenge to traditional "one-size-fits-all" models to include an intersectionality-informed stance. © The Author(s) 2016.
The Benefit Impact of Air Pollution Reduction Through ATCS Implementation at Intersections
NASA Astrophysics Data System (ADS)
Budihardjo, Mochamad Arief; Huboyo, Haryono Setiyo; Samadikun, Budi Prasetyo
2018-02-01
The field study in five intersections that had ATCS, such as Krapyak, Tugu Muda, Polda, Bangkong and Fatmawati were done to investigate the effectivity of air pollution reduction. The study was done by estimating the differences between the vehicle speed due to the cycle duration of green light by field observation and video recording in each intersection. In five intersections that had been observed, the percentage of fuel consumption savings for two-wheeled vehicles were between 15 - 18%, meanwhile for four-wheel vehicles were between 30 - 46%. Based on the calculation that adopt the emission factor from CORINAIR and USEPA emission, the emission reduction based on pollutant types were TSP (12-17%), NOx (22-36%), CO (15-25%), HC (16-28%) and SO2 (22-35%). The result to the vehicles' speed that passed the intersections through ATCS has also indicated that the ATCS could increase vehicle speed and consequently reduce the emission.
Sacchi, Emanuele; Sayed, Tarek; El-Basyouny, Karim
2016-09-01
Recently, important advances in road safety statistics have been brought about by methods able to address issues other than the choice of the best error structure for modeling crash data. In particular, accounting for spatial and temporal interdependence, i.e., the notion that the collision occurrence of a site or unit times depend on those of others, has become an important issue that needs further research. Overall, autoregressive models can be used for this purpose as they can specify that the output variable depends on its own previous values and on a stochastic term. Spatial effects have been investigated and applied mostly in the context of developing safety performance functions (SPFs) to relate crash occurrence to highway characteristics. Hence, there is a need for studies that attempt to estimate the effectiveness of safety countermeasures by including the spatial interdependence of road sites within the context of an observational before-after (BA) study. Moreover, the combination of temporal dynamics and spatial effects on crash frequency has not been explored in depth for SPF development. Therefore, the main goal of this research was to carry out a BA study accounting for spatial effects and temporal dynamics in evaluating the effectiveness of a road safety treatment. The countermeasure analyzed was the installation of traffic signals at unsignalized urban/suburban intersections in British Columbia (Canada). The full Bayes approach was selected as the statistical framework to develop the models. The results demonstrated that zone variation was a major component of total crash variability and that spatial effects were alleviated by clustering intersections together. Finally, the methodology used also allowed estimation of the treatment's effectiveness in the form of crash modification factors and functions with time trends. Copyright © 2016 Elsevier Ltd. All rights reserved.
Vanlaar, Ward; Robertson, Robyn; Marcoux, Kyla
2014-01-01
The objective of this study was to evaluate the impact of Winnipeg's photo enforcement safety program on speeding, i.e., "speed on green", and red-light running behavior at intersections as well as on crashes resulting from these behaviors. ARIMA time series analyses regarding crashes related to red-light running (right-angle crashes and rear-end crashes) and crashes related to speeding (injury crashes and property damage only crashes) occurring at intersections were conducted using monthly crash counts from 1994 to 2008. A quasi-experimental intersection camera experiment was also conducted using roadside data on speeding and red-light running behavior at intersections. These data were analyzed using logistic regression analysis. The time series analyses showed that for crashes related to red-light running, there had been a 46% decrease in right-angle crashes at camera intersections, but that there had also been an initial 42% increase in rear-end crashes. For crashes related to speeding, analyses revealed that the installation of cameras was not associated with increases or decreases in crashes. Results of the intersection camera experiment show that there were significantly fewer red light running violations at intersections after installation of cameras and that photo enforcement had a protective effect on speeding behavior at intersections. However, the data also suggest photo enforcement may be less effective in preventing serious speeding violations at intersections. Overall, Winnipeg's photo enforcement safety program had a positive net effect on traffic safety. Results from both the ARIMA time series and the quasi-experimental design corroborate one another. However, the protective effect of photo enforcement is not equally pronounced across different conditions so further monitoring is required to improve the delivery of this measure. Results from this study as well as limitations are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.
Refined open intersection numbers and the Kontsevich-Penner matrix model
NASA Astrophysics Data System (ADS)
Alexandrov, Alexander; Buryak, Alexandr; Tessler, Ran J.
2017-03-01
A study of the intersection theory on the moduli space of Riemann surfaces with boundary was recently initiated in a work of R. Pandharipande, J.P. Solomon and the third author, where they introduced open intersection numbers in genus 0. Their construction was later generalized to all genera by J.P. Solomon and the third author. In this paper we consider a refinement of the open intersection numbers by distinguishing contributions from surfaces with different numbers of boundary components, and we calculate all these numbers. We then construct a matrix model for the generating series of the refined open intersection numbers and conjecture that it is equivalent to the Kontsevich-Penner matrix model. An evidence for the conjecture is presented. Another refinement of the open intersection numbers, which describes the distribution of the boundary marked points on the boundary components, is also discussed.
NASA Astrophysics Data System (ADS)
Sanzana, Pedro; Gironas, Jorge; Braud, Isabelle; Branger, Flora; Rodriguez, Fabrice; Vargas, Ximena; Hitschfeld, Nancy; Francisco Munoz, Jose
2016-04-01
In addition to land use changes, the process of urbanization can modify the direction of the surface and sub-surface flows, generating complex environments and increasing the types of connectivity between pervious and impervious areas. Thus, hydrological pathways in urban and periurban areas are significantly affected by artificial elements like channels, pipes, streets and other elements of storm water systems. This work presents Geo-PUMMA, a new GIS toolbox to generate vectorial meshes for distributed hydrological modeling and extract the drainage network in urban and periurban terrain. Geo-PUMMA gathers spatial information maps (e.g. cadastral, soil types, geology and digital elevation models) to produce Hydrological Response Units (HRU) and Urban Hydrological Elements (UHE). Geo-PUMMA includes tools to improve the initial mesh derived from GIS layers intersection in order to respect geometrical constraints, which ensures numerical stability while preserving the shape of the initial HRUs and minimizing the small elements to lower computing times. The geometrical constraints taken into account include: elements convexity, limitation of the number of sliver elements (e.g. roads) and of very small or very large elements. This toolbox allows the representation of basins at small scales (0.1-10km2), as it takes into account the hydrological connectivity of the main elements explicitly, and improves the representation of water pathways compared with classical raster approaches. Geo-PUMMA also allows the extraction of basin morphologic properties such as the width function, the area function and the imperviousness function. We applied this new toolbox to two periurban catchments: the Mercier catchment located near Lyon, France, and the Estero El Guindo catchment located in the Andean piedmont in the Maipo River, Chile. We use the capability of Geo-PUMMA to generate three different meshes. The first one is the initial mesh derived from the direct intersection of GIS layers. The second one is based on fine triangulation of HRUs and is considered the best one we can obtain (reference mesh). The third one is the recommended mesh, preserving the shape of the initial HRUs and limiting the number of elements. The representation of the drainage network and its morphological properties is compared between the three meshes. This comparison shows that the drainage network representation is particularly improved at small to medium spatial scales when using the recommended meshes (i.e. 120-150 m for the El Guindo catchment and 80-150 m for the Mercier catchment). The results also show that the recommended mesh correctly represents the main features of the drainage network as compared to the reference mesh. KEYWORDS: GRASS-GIS, Computer-assisted mesh generation, periurban catchments
Adams, Marc A; Frank, Lawrence D; Schipperijn, Jasper; Smith, Graham; Chapman, James; Christiansen, Lars B; Coffee, Neil; Salvo, Deborah; du Toit, Lorinne; Dygrýn, Jan; Hino, Adriano Akira Ferreira; Lai, Poh-chin; Mavoa, Suzanne; Pinzón, José David; Van de Weghe, Nico; Cerin, Ester; Davey, Rachel; Macfarlane, Duncan; Owen, Neville; Sallis, James F
2014-10-25
The World Health Organization recommends strategies to improve urban design, public transportation, and recreation facilities to facilitate physical activity for non-communicable disease prevention for an increasingly urbanized global population. Most evidence supporting environmental associations with physical activity comes from single countries or regions with limited variation in urban form. This paper documents variation in comparable built environment features across countries from diverse regions. The International Physical Activity and the Environment Network (IPEN) study of adults aimed to measure the full range of variation in the built environment using geographic information systems (GIS) across 12 countries on 5 continents. Investigators in Australia, Belgium, Brazil, Colombia, the Czech Republic, Denmark, China, Mexico, New Zealand, Spain, the United Kingdom, and the United States followed a common research protocol to develop internationally comparable measures. Using detailed instructions, GIS-based measures included features such as walkability (i.e., residential density, street connectivity, mix of land uses), and access to public transit, parks, and private recreation facilities around each participant's residential address using 1-km and 500-m street network buffers. Eleven of 12 countries and 15 cities had objective GIS data on built environment features. We observed a 38-fold difference in median residential densities, a 5-fold difference in median intersection densities and an 18-fold difference in median park densities. Hong Kong had the highest and North Shore, New Zealand had the lowest median walkability index values, representing a difference of 9 standard deviations in GIS-measured walkability. Results show that comparable measures can be created across a range of cultural settings revealing profound global differences in urban form relevant to physical activity. These measures allow cities to be ranked more precisely than previously possible. The highly variable measures of urban form will be used to explain individuals' physical activity, sedentary behaviors, body mass index, and other health outcomes on an international basis. Present measures provide the ability to estimate dose-response relationships from projected changes to the built environment that would otherwise be impossible.
ERIC Educational Resources Information Center
Vaccaro, Annemarie
2017-01-01
This article offers an intersectional critical race feminist analysis of student silence in a diverse university classroom. Findings from a case study with six Women of Color and four White women revealed students remained silent because they felt their complicated intersectional realities did not fit with the acceptable classroom…
Validating a driving simulator using surrogate safety measures.
Yan, Xuedong; Abdel-Aty, Mohamed; Radwan, Essam; Wang, Xuesong; Chilakapati, Praveen
2008-01-01
Traffic crash statistics and previous research have shown an increased risk of traffic crashes at signalized intersections. How to diagnose safety problems and develop effective countermeasures to reduce crash rate at intersections is a key task for traffic engineers and researchers. This study aims at investigating whether the driving simulator can be used as a valid tool to assess traffic safety at signalized intersections. In support of the research objective, this simulator validity study was conducted from two perspectives, a traffic parameter (speed) and a safety parameter (crash history). A signalized intersection with as many important features (including roadway geometries, traffic control devices, intersection surroundings, and buildings) was replicated into a high-fidelity driving simulator. A driving simulator experiment with eight scenarios at the intersection were conducted to determine if the subjects' speed behavior and traffic risk patterns in the driving simulator were similar to what were found at the real intersection. The experiment results showed that speed data observed from the field and in the simulator experiment both follow normal distributions and have equal means for each intersection approach, which validated the driving simulator in absolute terms. Furthermore, this study used an innovative approach of using surrogate safety measures from the simulator to contrast with the crash analysis for the field data. The simulator experiment results indicated that compared to the right-turn lane with the low rear-end crash history record (2 crashes), subjects showed a series of more risky behaviors at the right-turn lane with the high rear-end crash history record (16 crashes), including higher deceleration rate (1.80+/-1.20 m/s(2) versus 0.80+/-0.65 m/s(2)), higher non-stop right-turn rate on red (81.67% versus 57.63%), higher right-turn speed as stop line (18.38+/-8.90 km/h versus 14.68+/-6.04 km/h), shorter following distance (30.19+/-13.43 m versus 35.58+/-13.41 m), and higher rear-end probability (9/59=0.153 versus 2/60=0.033). Therefore, the relative validity of driving simulator was well established for the traffic safety studies at signalized intersections.
Vision-Based Georeferencing of GPR in Urban Areas
Barzaghi, Riccardo; Cazzaniga, Noemi Emanuela; Pagliari, Diana; Pinto, Livio
2016-01-01
Ground Penetrating Radar (GPR) surveying is widely used to gather accurate knowledge about the geometry and position of underground utilities. The sensor arrays need to be coupled to an accurate positioning system, like a geodetic-grade Global Navigation Satellite System (GNSS) device. However, in urban areas this approach is not always feasible because GNSS accuracy can be substantially degraded due to the presence of buildings, trees, tunnels, etc. In this work, a photogrammetric (vision-based) method for GPR georeferencing is presented. The method can be summarized in three main steps: tie point extraction from the images acquired during the survey, computation of approximate camera extrinsic parameters and finally a refinement of the parameter estimation using a rigorous implementation of the collinearity equations. A test under operational conditions is described, where accuracy of a few centimeters has been achieved. The results demonstrate that the solution was robust enough for recovering vehicle trajectories even in critical situations, such as poorly textured framed surfaces, short baselines, and low intersection angles. PMID:26805842
Determinants of spikes in ultrafine particle concentration whilst commuting by bus
NASA Astrophysics Data System (ADS)
Lim, Shanon; Dirks, Kim N.; Salmond, Jennifer A.; Xie, Shanju
2015-07-01
This paper examines concentration of ultrafine particles (UFPs) based on data collected using high-resolution UFP monitors whilst travelling by bus during rush hour along three different urban routes in Auckland, New Zealand. The factors influencing in-bus UFP concentration were assessed using a combination of spatial, statistical and GIS analysis techniques to determine both spatial and temporal variability. Results from 68 bus trips showed that concentrations varied more within a route than between on a given day, despite differences in urban morphology, land use and traffic densities between routes. A number of trips were characterised by periods of very rapid increases in UFPs (concentration 'spikes'), followed by slow declines. Trips which recorded at least one spike (an increase of greater than 10,000 pt/cm3) resulted in significantly higher mean concentrations. Spikes in UFPs were significantly more likely to occur when travelling at low speeds and when passengers were alighting and boarding at bus stops close to traffic light intersections.
Crosswalk markings and the risk of pedestrian-motor vehicle collisions in older pedestrians.
Koepsell, Thomas; McCloskey, Lon; Wolf, Marsha; Moudon, Anne Vernez; Buchner, David; Kraus, Jess; Patterson, Matthew
2002-11-06
Motor vehicles struck and killed 4739 pedestrians in the United States in the year 2000. Older pedestrians are at especially high risk. To determine whether crosswalk markings at urban intersections influence the risk of injury to older pedestrians. Case-control study in which the units of study were crossing locations. Six cities in Washington and California, with case accrual from February 1995 through January 1999. A total of 282 case sites were street-crossing locations at an intersection where a pedestrian aged 65 years or older had been struck by a motor vehicle while crossing the street; 564 control sites were other nearby crossings that were matched to case sites based on street classification. Trained observers recorded environmental characteristics, vehicular traffic flow and speed, and pedestrian use at each site on the same day of the week and time of day as when the case event had occurred. Risk of pedestrian-motor vehicle collision involving an older pedestrian. After adjusting for pedestrian flow, vehicle flow, crossing length, and signalization, risk of a pedestrian-motor vehicle collision was 2.1-fold greater (95% confidence interval, 1.1-4.0) at sites with a marked crosswalk. Almost all of the excess risk was due to 3.6-fold (95% confidence interval, 1.7-7.9) higher risk associated with marked crosswalks at sites with no traffic signal or stop sign. Crosswalk markings appear associated with increased risk of pedestrian-motor vehicle collision to older pedestrians at sites where no signal or stop sign is present to halt traffic.
Expanding the Therapy Paradigm with Queer Couples: A Relational Intersectional Lens.
Addison, Sheila M; Coolhart, Deborah
2015-09-01
North American and global cultures in general-and the field of Couple and Family Therapy in particular-have made significant strides toward recognizing and validating LGBTQ identities and relationships. However, clinical assessment and conceptualization of queer couples still lack the complexity needed to encompass the issues involved in treatment. Existing literature provides clinicians a basic understanding of queer couples and the dynamics that make them unique from nonqueer couples. However, much of this knowledge has been normed on White middle-class couples and has rarely included couples with transgender or bisexual members. This article invites clinicians and researchers to apply a feminist model of intersectionality to understand queer couples. Our proposed intersectional lens considers multiple axes of identity and power and their interrelationships (Crenshaw, 1989, 1991). We argue that intersectionality is important for understanding all identities, whether privileged or marginalized (Falicov, 2003). This application of the concept of intersectionality is unique in its relational focus, emphasizing how partners' complex individual identities overlap with and intersect with one another. Additionally, this lens considers how the therapists' and clients' multidimensional identities intersect. Three case studies are presented to illustrate application of the intersectional lens. In each case, exploring the partners' multiple social locations, their influences on one another, and the therapist's intersections of identity all proved critical to the direction of therapy. © 2015 Family Process Institute.
Multilane Traffic Flow Modeling Using Cellular Automata Theory
NASA Astrophysics Data System (ADS)
Chechina, Antonina; Churbanova, Natalia; Trapeznikova, Marina
2018-02-01
The paper deals with the mathematical modeling of traffic flows on urban road networks using microscopic approach. The model is based on the cellular automata theory and presents a generalization of the Nagel-Schreckenberg model to a multilane case. The created program package allows to simulate traffic on various types of road fragments (T or X type intersection, strait road elements, etc.) and on road networks that consist of these elements. Besides that, it allows to predict the consequences of various decisions regarding road infrastructure changes, such as: number of lanes increasing/decreasing, putting new traffic lights into operation, building new roads, entrances/exits, road junctions.
Arita, Chikashi; Foulaadvand, M Ebrahim; Santen, Ludger
2017-03-01
We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.
NASA Astrophysics Data System (ADS)
Arita, Chikashi; Foulaadvand, M. Ebrahim; Santen, Ludger
2017-03-01
We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.
NASA Astrophysics Data System (ADS)
HuaZhi, Zhou; ZhiJin, Wang
2017-11-01
The intersection element is an important part of the helicopter subfloor structure. In order to improve the crashworthiness properties, the floor and the skin of the intersection element are replaced with foldcore sandwich structures. Foldcore is a kind of high-energy absorption structure. Compared with original structure, the new intersection element shows better buffering capacity and energy-absorption capacity. To reduce structure’s mass while maintaining the crashworthiness requirements satisfied, optimization of the intersection element geometric parameters is conducted. An optimization method using NSGA-II and Anisotropic Kriging is used. A significant CPU time saving can be obtained by replacing numerical model with Anisotropic Kriging surrogate model. The operation allows 17.15% reduce of the intersection element mass.
Cooperative and Integrated Vehicle and Intersection Control for Energy Efficiency (CIVIC-E²)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hou, Yunfei; Seliman, Salaheldeen M. S.; Wang, Enshu
Recent advances in connected vehicle technologies enable vehicles and signal controllers to cooperate and improve the traffic management at intersections. This paper explores the opportunity for cooperative and integrated vehicle and intersection control for energy efficiency (CIVIC-E 2) to contribute to a more sustainable transportation system. We propose a two-level approach that jointly optimizes the traffic signal timing and vehicles' approach speed, with the objective being to minimize total energy consumption for all vehicles passing through an isolated intersection. More specifically, at the intersection level, a dynamic programming algorithm is designed to find the optimal signal timing by explicitly consideringmore » the arrival time and energy profile of each vehicle. At the vehicle level, a model predictive control strategy is adopted to ensure that vehicles pass through the intersection in a timely fashion. Our simulation study has shown that the proposed CIVIC-E 2 system can significantly improve intersection performance under various traffic conditions. Compared with conventional fixed-time and actuated signal control strategies, the proposed algorithm can reduce energy consumption and queue length by up to 31% and 95%, respectively.« less
Cooperative and Integrated Vehicle and Intersection Control for Energy Efficiency (CIVIC-E²)
Hou, Yunfei; Seliman, Salaheldeen M. S.; Wang, Enshu; ...
2018-02-15
Recent advances in connected vehicle technologies enable vehicles and signal controllers to cooperate and improve the traffic management at intersections. This paper explores the opportunity for cooperative and integrated vehicle and intersection control for energy efficiency (CIVIC-E 2) to contribute to a more sustainable transportation system. We propose a two-level approach that jointly optimizes the traffic signal timing and vehicles' approach speed, with the objective being to minimize total energy consumption for all vehicles passing through an isolated intersection. More specifically, at the intersection level, a dynamic programming algorithm is designed to find the optimal signal timing by explicitly consideringmore » the arrival time and energy profile of each vehicle. At the vehicle level, a model predictive control strategy is adopted to ensure that vehicles pass through the intersection in a timely fashion. Our simulation study has shown that the proposed CIVIC-E 2 system can significantly improve intersection performance under various traffic conditions. Compared with conventional fixed-time and actuated signal control strategies, the proposed algorithm can reduce energy consumption and queue length by up to 31% and 95%, respectively.« less
Buck, Christoph; Kneib, Thomas; Tkaczick, Tobias; Konstabel, Kenn; Pigeot, Iris
2015-12-22
Built environment studies provide broad evidence that urban characteristics influence physical activity (PA). However, findings are still difficult to compare, due to inconsistent measures assessing urban point characteristics and varying definitions of spatial scale. Both were found to influence the strength of the association between the built environment and PA. We simultaneously evaluated the effect of kernel approaches and network-distances to investigate the association between urban characteristics and physical activity depending on spatial scale and intensity measure. We assessed urban measures of point characteristics such as intersections, public transit stations, and public open spaces in ego-centered network-dependent neighborhoods based on geographical data of one German study region of the IDEFICS study. We calculated point intensities using the simple intensity and kernel approaches based on fixed bandwidths, cross-validated bandwidths including isotropic and anisotropic kernel functions and considering adaptive bandwidths that adjust for residential density. We distinguished six network-distances from 500 m up to 2 km to calculate each intensity measure. A log-gamma regression model was used to investigate the effect of each urban measure on moderate-to-vigorous physical activity (MVPA) of 400 2- to 9.9-year old children who participated in the IDEFICS study. Models were stratified by sex and age groups, i.e. pre-school children (2 to <6 years) and school children (6-9.9 years), and were adjusted for age, body mass index (BMI), education and safety concerns of parents, season and valid weartime of accelerometers. Association between intensity measures and MVPA strongly differed by network-distance, with stronger effects found for larger network-distances. Simple intensity revealed smaller effect estimates and smaller goodness-of-fit compared to kernel approaches. Smallest variation in effect estimates over network-distances was found for kernel intensity measures based on isotropic and anisotropic cross-validated bandwidth selection. We found a strong variation in the association between the built environment and PA of children based on the choice of intensity measure and network-distance. Kernel intensity measures provided stable results over various scales and improved the assessment compared to the simple intensity measure. Considering different spatial scales and kernel intensity methods might reduce methodological limitations in assessing opportunities for PA in the built environment.
Revitalizing sociology: urban life and mental illness between history and the present.
Fitzgerald, Des; Rose, Nikolas; Singh, Ilina
2016-03-01
This paper proposes a re-thinking of the relationship between sociology and the biological sciences. Tracing lines of connection between the history of sociology and the contemporary landscape of biology, the paper argues for a reconfiguration of this relationship beyond popular rhetorics of 'biologization' or 'medicalization'. At the heart of the paper is a claim that, today, there are some potent new frames for re-imagining the traffic between sociological and biological research - even for 'revitalizing' the sociological enterprise as such. The paper threads this argument through one empirical case: the relationship between urban life and mental illness. In its first section, it shows how this relationship enlivened both early psychiatric epidemiology, and some forms of the new discipline of sociology; it then traces the historical division of these sciences, as the sociological investment in psychiatric questions waned, and 'the social' become marginalized within an increasingly 'biological' psychiatry. In its third section, however, the paper shows how this relationship has lately been revivified, but now by a nuanced epigenetic and neurobiological attention to the links between mental health and urban life. What role can sociology play here? In its final section, the paper shows how this older sociology, with its lively interest in the psychiatric and neurobiological vicissitudes of urban social life, can be our guide in helping to identify intersections between sociological and biological attention. With a new century now underway, the paper concludes by suggesting that the relationship between urban life and mental illness may prove a core testing-ground for a 'revitalized' sociology. © London School of Economics and Political Science 2016.
Egan, James E.; Kurtz, Steven P.; Latkin, Carl; Chen, Minxing; Tobin, Karin; Yang, Cui; Koblin, Beryl A.
2011-01-01
Adopting socioecological, intersectionality, and lifecourse theoretical frameworks may enhance our understanding of the production of syndemic adverse health outcomes among gay, bisexual and other men who have sex with men (MSM). From this perspective, we present preliminary data from three related studies that suggest ways in which social contexts may influence the health of MSM. The first study, using cross-sectional data, looked at migration of MSM to the gay resort area of South Florida, and found that amount of time lived in the area was associated with risk behaviors and HIV infection. The second study, using qualitative interviews, observed complex interactions between neighborhood-level social environments and individual-level racial and sexual identity among MSM in New York City. The third study, using egocentric network analysis with a sample of African American MSM in Baltimore, found that sexual partners were more likely to be found through face-to-face means than the Internet. They also observed that those who co-resided with a sex partner had larger networks of people to depend on for social and financial support, but had the same size sexual networks as those who did not live with a partner. Overall, these findings suggest the need for further investigation into the role of macro-level social forces on the emotional, behavioral, and physical health of urban MSM. PMID:21369730
The design of traffic signal coordinated control
NASA Astrophysics Data System (ADS)
Guo, Xueting; Sun, Hongsheng; Wang, Xifu
2017-05-01
Traffic as the tertiary industry is an important pillar industry to support the normal development of the economy. But now China's road traffic development and economic development has shown a great imbalance and fault phenomenon, which greatly inhibited the normal development of China's economy. Now in many large and medium-sized cities in China are implementing green belt construction. The so-called green band is when the road conditions to meet the conditions for the establishment of the green band, the sections of the intersection of several planning to a traffic coordination control system, so that when the driver at a specific speed can be achieved without stopping the continuous Through the intersection. Green belt can effectively reduce the delay and queuing length of vehicle driving, the normal function of urban roads and reduce the economic losses caused by traffic congestion is a great help. In this paper, the theoretical basis of the design of the coordinated control system is described. Secondly, the green time offset is calculated by the analytic method and the green band is established. And then the VISSIM software is used to simulate the traffic system before and after the improvement. Finally, the results of the two simulations are compared.
NASA Astrophysics Data System (ADS)
Yagüe, Carlos; Román-Cascón, Carlos; Sastre, Mariano; Maqueda, Gregorio; Arrillaga, Jon A.; Artiñano, Begoña; Díaz-Ramiro, Elías; Gómez-Moreno, Francisco J.; Borge, Rafael; Narros, Adolfo; Pérez, Javier; Quaassdorff, Christina
2017-04-01
Air pollution is a major problem in the city of Madrid during weak synoptic forcing, since the presence of atmospheric stability conditions often develops night surface-based thermal inversions and subsidence inversions during daytime for several consecutive days, reaching high levels of NOx and Particulate Matter (PM) concentration. In this context, the TECNAIRE-CM (Innovative technologies for the assessment and improvement of urban air quality) research project has developed two field campaigns along 2015 (winter and summer) in a hot spot in the city of Madrid (Fernández Ladreda square). This hot spot includes one important intersection of different streets and also the start of the A42 motorway, which crosses down the square through a tunnel of about 150 m length. Besides, the location has numerous traffic lights and a lot of pedestrians walking in the vicinity. In addition to direct measurements related to air quality, data from different meteorological variables were recorded in order to characterize the atmospheric conditions. Moreover, two sonic anemometers where deployed to carry out a micrometeorological assessment of physical processes that take place in the urban atmospheric surface layer (TKE, friction velocity and sensible heat flux were evaluated). The evolution of the turbulence will be analyzed and compared for both campaigns (winter and summer), searching for the key seasonal differences as well as the importance of the different scales influencing the diffusion of pollutants (from multi resolution flux decomposition -MRFD- analysis). Specific case studies corresponding to high levels of pollution will be studied in detailed, to understand local pollution dynamics under the influence of both high traffic density and low turbulence situations. This work has been financed by Madrid Regional Research Plan through TECNAIRE (P2013/MAE-2972).
Applying Bayesian hierarchical models to examine motorcycle crashes at signalized intersections.
Haque, Md Mazharul; Chin, Hoong Chor; Huang, Helai
2010-01-01
Motorcycles are overrepresented in road traffic crashes and particularly vulnerable at signalized intersections. The objective of this study is to identify causal factors affecting the motorcycle crashes at both four-legged and T signalized intersections. Treating the data in time-series cross-section panels, this study explores different Hierarchical Poisson models and found that the model allowing autoregressive lag-1 dependence specification in the error term is the most suitable. Results show that the number of lanes at the four-legged signalized intersections significantly increases motorcycle crashes largely because of the higher exposure resulting from higher motorcycle accumulation at the stop line. Furthermore, the presence of a wide median and an uncontrolled left-turn lane at major roadways of four-legged intersections exacerbate this potential hazard. For T signalized intersections, the presence of exclusive right-turn lane at both major and minor roadways and an uncontrolled left-turn lane at major roadways increases motorcycle crashes. Motorcycle crashes increase on high-speed roadways because they are more vulnerable and less likely to react in time during conflicts. The presence of red light cameras reduces motorcycle crashes significantly for both four-legged and T intersections. With the red light camera, motorcycles are less exposed to conflicts because it is observed that they are more disciplined in queuing at the stop line and less likely to jump start at the start of green.
ERIC Educational Resources Information Center
Museus, Samuel D.
2011-01-01
In this article, the author discusses how researchers can use mixed-methods approaches and intersectional analyses to understand college access among first-generation Asian American and Pacific Islanders (AAPIs). First, he discusses the utility of mixed-methods approaches and intersectionality research in studying college access. Then, he…
Guo, Yanyong; Li, Zhibin; Wu, Yao; Xu, Chengcheng
2018-06-01
Bicyclists running the red light at crossing facilities increase the potential of colliding with motor vehicles. Exploring the contributing factors could improve the prediction of running red-light probability and develop countermeasures to reduce such behaviors. However, individuals could have unobserved heterogeneities in running a red light, which make the accurate prediction more challenging. Traditional models assume that factor parameters are fixed and cannot capture the varying impacts on red-light running behaviors. In this study, we employed the full Bayesian random parameters logistic regression approach to account for the unobserved heterogeneous effects. Two types of crossing facilities were considered which were the signalized intersection crosswalks and the road segment crosswalks. Electric and conventional bikes were distinguished in the modeling. Data were collected from 16 crosswalks in urban area of Nanjing, China. Factors such as individual characteristics, road geometric design, environmental features, and traffic variables were examined. Model comparison indicates that the full Bayesian random parameters logistic regression approach is statistically superior to the standard logistic regression model. More red-light runners are predicted at signalized intersection crosswalks than at road segment crosswalks. Factors affecting red-light running behaviors are gender, age, bike type, road width, presence of raised median, separation width, signal type, green ratio, bike and vehicle volume, and average vehicle speed. Factors associated with the unobserved heterogeneity are gender, bike type, signal type, separation width, and bike volume. Copyright © 2018 Elsevier Ltd. All rights reserved.
Nosek, Štěpán; Kukačka, Libor; Jurčáková, Klára; Kellnerová, Radka; Jaňour, Zbyněk
2017-08-01
This paper presents an extension of our previous wind-tunnel study (Nosek et al., 2016) in which we highlighted the need for investigation of the removal mechanisms of traffic pollution from all openings of a 3D street canyon. The extension represents the pollution flux (turbulent and advective) measurements at the lateral openings of three different 3D street canyons for the winds perpendicular and oblique to the along-canyon axis. The pollution was simulated by emitting a passive gas (ethane) from a homogeneous ground-level line source positioned along the centreline of the investigated street canyons. The street canyons were formed by courtyard-type buildings of two different regular urban-array models. The first model has a uniform building roof height, while the second model has a non-uniform roof height along each building's wall. The mean flow and concentration fields at the canyons' lateral openings confirm the findings of other studies that the buildings' roof-height variability at the intersections plays an important role in the dispersion of the traffic pollutants within the canyons. For the perpendicular wind, the non-uniform roof-height canyon appreciably removes or entrains the pollutant through its lateral openings, contrary to the uniform canyon, where the pollutant was removed primarily through the top. The analysis of the turbulent mass transport revealed that the coherent flow structures of the lateral momentum transport correlate with the ventilation processes at the lateral openings of all studied canyons. These flow structures coincide at the same areas and hence simultaneously transport the pollutant in opposite directions. Copyright © 2017 Elsevier Ltd. All rights reserved.
Elkington, Katherine S; Peters, Zachary; Choi, C Jean; Bucek, Amelia; Leu, Cheng-Shiun; Abrams, Elaine J; Mellins, Claude A
2017-11-22
We examined the role of youth HIV status and other key factors on past-year arrest in perinatally HIV-exposed but uninfected (PHIV-) and perinatally HIV-infected (PHIV+) youth using data from a multi-site study of psychosocial behaviors in PHIV-exposed urban youth (N = 340; 61% PHIV+; 51% female; ages 9-16 at baseline). Youth and caregivers were administered 5 interviews, spanning approximately 7.5 years. Using longitudinal logistic mixed-effect models, we explored the association between past year arrest, internal [e.g., substance use disorder (SUD)] and external (e.g., neighborhood arrest rates) contextual factors, and social-regulation processes (e.g., in-school/work). Arrest rates increased from 2.6 to 19.7% across follow-ups; there were no differences in arrest over time by HIV status. In the final model, odds of arrest were greater for youth who were male, with SUD, ≥ 18 years old, with high levels of city stress, and neither in school nor employed. PHIV-exposed, urban youth have much higher rates of arrest than national samples. Lack of differences in arrest by HIV status suggests key contextual factors are more important in promoting arrest.
The influence of traffic signal solutions on self-reported road-crossing behavior.
Di Stasi, Leandro L; Megías, Alberto; Cándido, Antonio; Maldonado, Antonio; Catena, Andrés
2015-01-07
Injury to pedestrians is a major safety hazard in many countries. Since the beginning of the last century, modern cities have been designed around the use of motor vehicles despite the unfavourable interactions between the vehicles and pedestrians. This push towards urbanization resulted in a substantial number of crashes and fatalities involving pedestrians every day, all over the world. Thus, improving the design of urban cities and townships is a pressing issue for modern society. The study presented here provides a characterization of pedestrian safety problems, with the emphasis on signalized crosswalks (i.e. traffic signal) design solutions. We tested the impact of seven different traffic light configurations (steady [green, yellow, and red], flashing [green, yellow, and red], and light off) on pedestrian self-reported road-crossing behavior, using a 11-point scale -ranging from 0 ("I never cross in this situation") to 10 ("I always cross in this situation"). Results showed that mandatory solutions (steady green vs. steady red) are the best solutions to avoid unsafe pedestrian behaviors while crossing controlled intersections (frequency of crossing: Mgreen = 9.4 ± 1 vs. Mred = 2.6 ± 2). These findings offer important guidelines for the design of future traffic signals for encouraging a pedestrian/transit-friendly environment.
Methods Used in EnviroAtlas to Assess Urban Natural ...
Previous studies have positively correlated human exposures to natural features with health promoting outcomes such as increased physical activity, improved cognitive function, increased social engagement, and reduced ambient air pollution. When using remotely-sensed data to investigate these relationships, researchers must first identify an appropriate spatial resolution to characterize exposures. However, metric development has often been limited by the lack of fine-scale land cover data, especially across multiple communities. As a result, researchers commonly use coarse resolution imagery. EnviroAtlas, a U.S. Environmental Protection Agency web-based ecosystem services mapping tool, has developed 1-meter resolution land cover data across 16 diverse U.S. Census Urban Areas using aerial photography and supplemental data. Research maps derived from these foundational data include percent tree cover along busy roads, percent tree cover and green space along walkable streets, and percent natural vegetation bordering water bodies. EnviroAtlas has also developed multiple smoothed “heat maps” of proximity to specific types of features at every 1m point; these include total green space, tree cover, and water within 50m, 500m, and 1,000m buffers; walking distance to the nearest park entrance; and intersection density as an indicator of neighborhood walkability.EnviroAtlas variables are available to external researchers, public health professionals and planners t
Cheng, Li; Tan, Mei; Liu, Zhengkui
2015-01-01
China has been undergoing great social change due to its new focus on urbanization and globalization. Such change has had a tremendous adverse impact on the living conditions of millions of young children, simultaneously generating new interest in children's creativity development. The intersection of these two issues has important implications for China's future as it brings together one of China's core cultural values-"success in adversity"-the importance of creativity, and very real social and economic needs. "Success in adversity" reflects the strongly held belief that individuals who suffer adverse environments can rise to excellence and success through persistence, effort, and creativity. In this article, we briefly explore the historical sources of this belief and how it is closely related to the Chinese conception of creativity. We then present some studies on the creativity of some of China's migrant children. Findings show that while migrant children as a group may not generally exhibit higher creativity than their urban peers as hypothesized, indications of resilience and creative potential suggest that the notion of success in adversity may contribute to the positive development of China's migrant children more substantially when it is informed by research and augmented by research-supported policy. © 2015 Wiley Periodicals, Inc.
Experimental Study of Pollutant Dispersion Within a Network of Streets
NASA Astrophysics Data System (ADS)
Garbero, Valeria; Salizzoni, Pietro; Soulhac, Lionel
2010-09-01
We investigate the dispersion of a passive scalar within an idealised urban district made up of a building-like obstacle array. We focus on a street network in which the lateral dimension of the buildings exceeds the street width, a geometry representative of many European cities. To investigate the effect of different geometries and wind directions upon the pollutant dispersion process, we have performed a series of wind-tunnel experiments. Concentration measurements of a passive tracer have enabled us to infer the main features characterising its dispersion within the street network. We describe this by focusing on the roles of different transfer processes. These are the channelling of the tracer along the street axes, the mixing at street intersections, and the mass exchange between the streets and the overlying atmospheric flow. Our experiments provide evidence of the dependence of these processes on the geometrical properties of the array and the direction of the overlying atmospheric flow.
Song, Guohua; Zhou, Xixi; Yu, Lei
2015-05-01
The intersection is one of the biggest emission points for buses and also the high exposure site for people. Several traffic performance indexes have been developed and widely used for intersection evaluations. However, few studies have focused on the relationship between these indexes and emissions at intersections. This paper intends to propose a model that relates emissions to the two commonly used measures of effectiveness (i.e. delay time and number of stops) by using bus activity data and emission data at intersections. First, with a large number of field instantaneous emission data and corresponding activity data collected by the Portable Emission Measurement System (PEMS), emission rates are derived for different vehicle specific power (VSP) bins. Then, 2002 sets of trajectory data, an equivalent of about 140,000 sets of second-by-second activity data, are obtained from Global Position Systems (GPSs)-equipped diesel buses in Beijing. The delay and the emission factors of each trajectory are estimated. Then, by using baseline emission factors for two types of intersections, e.g. the Arterial @ Arterial Intersection and the Arterial @ Collector, delay correction factors are calculated for the two types of intersections at different congestion levels. Finally, delay correction models are established for adjusting emission factors for each type of intersections and different numbers of stops. A comparative analysis between estimated and field emission factors demonstrates that the delay correction model is reliable. Copyright © 2015 Elsevier B.V. All rights reserved.
2012-01-01
Intersectionality is a theoretical framework that posits that multiple social categories (e.g., race, ethnicity, gender, sexual orientation, socioeconomic status) intersect at the micro level of individual experience to reflect multiple interlocking systems of privilege and oppression at the macro, social-structural level (e.g., racism, sexism, heterosexism). Public health’s commitment to social justice makes it a natural fit with intersectionality’s focus on multiple historically oppressed populations. Yet despite a plethora of research focused on these populations, public health studies that reflect intersectionality in their theoretical frameworks, designs, analyses, or interpretations are rare. Accordingly, I describe the history and central tenets of intersectionality, address some theoretical and methodological challenges, and highlight the benefits of intersectionality for public health theory, research, and policy. PMID:22594719
Increasing motorist compliance and caution at stop signs.
Van Houten, R; Retting, R A
2001-01-01
This study evaluated strategies to improve motorist compliance and caution at three stop-sign-controlled intersections with a history of motor vehicle crashes. The primary intervention was a light-emitting diode (LED) sign that featured animated eyes scanning left and right to prompt drivers to look left and right for approaching traffic. Data were scored from videotape on the percentage of drivers coming to a complete stop and the percentage of drivers looking right before entering the intersection. Observational data were collected on the percentage of right-angle conflicts (defined as braking suddenly or swerving from the path to avoid an intersection crash). The introduction of the LED sign according to a multiple baseline across the three intersections was associated with an increase in the percentage of vehicles coming to a complete stop at all three intersections and a small increase in the percentage of drivers looking right before entering the intersections. Conflicts between vehicles on the major and minor road were also reduced following the introduction of the animated eyes prompt. PMID:11421311
Intersection assistance: a safe solution for older drivers?
Dotzauer, Mandy; Caljouw, Simone R; de Waard, Dick; Brouwer, Wiebo H
2013-10-01
Within the next few decades, the number of older drivers operating a vehicle will increase rapidly (Eurostat, 2011). As age increases so does physical vulnerability, age-related impairments, and the risk of being involved in a fatal crashes. Older drivers experience problems in driving situations that require divided attention and decision making under time pressure as reflected by their overrepresentation in at-fault crashes on intersections. Advanced Driver Assistance Systems (ADAS) especially designed to support older drivers crossing intersections might counteract these difficulties. In a longer-term driving simulator study, the effects of an intersection assistant on driving were evaluated. 18 older drivers (M=71.44 years) returned repeatedly completing a ride either with or without a support system in a driving simulator. In order to test the intersection assistance, eight intersections were depicted for further analyses. Results show that ADAS affects driving. Equipped with ADAS, drivers allocated more attention to the road center rather than the left and right, crossed intersections in shorter time, engaged in higher speeds, and crossed more often with a critical time-to-collision (TTC) value. The implications of results are discussed in terms of behavioral adaptation and safety. Copyright © 2013 Elsevier Ltd. All rights reserved.
Gkiouleka, Anna; Huijts, Tim; Beckfield, Jason; Bambra, Clare
2018-03-01
This essay brings together intersectionality and institutional approaches to health inequalities, suggesting an integrative analytical framework that accounts for the complexity of the intertwined influence of both individual social positioning and institutional stratification on health. This essay therefore advances the emerging scholarship on the relevance of intersectionality to health inequalities research. We argue that intersectionality provides a strong analytical tool for an integrated understanding of health inequalities beyond the purely socioeconomic by addressing the multiple layers of privilege and disadvantage, including race, migration and ethnicity, gender and sexuality. We further demonstrate how integrating intersectionality with institutional approaches allows for the study of institutions as heterogeneous entities that impact on the production of social privilege and disadvantage beyond just socioeconomic (re)distribution. This leads to an understanding of the interaction of the macro and the micro facets of the politics of health. Finally, we set out a research agenda considering the interplay/intersections between individuals and institutions and involving a series of methodological implications for research - arguing that quantitative designs can incorporate an intersectional institutional approach. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
Complicating Counterspaces: Intersectionality and the Michigan Womyn's Music Festival.
McConnell, Elizabeth A; Todd, Nathan R; Odahl-Ruan, Charlynn; Shattell, Mona
2016-06-01
The counterspaces framework articulated by Case and Hunter (2012), follows from community psychology's long-standing interest in the potential for settings to promote well-being and liberatory responses to oppression. This framework proposes that certain settings (i.e., "counterspaces") facilitate a specific set of processes that promote the well-being of marginalized groups. We argue that an intersectional analysis is crucial to understand whether and how counterspaces achieve these goals. We draw from literature on safe spaces and present a case study of the Michigan Womyn's Music Festival (Michfest) to illustrate the value of an intersectional analysis and explore how these processes operate. Based on 20 in-person interviews, 23 responses to an online survey, and ethnographic field notes, we show how Michfest was characterized by a particular intersection of identities at the setting level, and intersectional diversity complicated experiences at the individual level. Moreover, intersectional identities provided opportunities for dialogue and change at the setting level, including the creation of counterspaces within counterspaces. Overall, we demonstrate the need to attend to intersectionality in counterspaces, and more broadly in how we conceptualize settings in community psychology. © Society for Community Research and Action 2016.
A century of sprawl in the United States
Barrington-Leigh, Christopher; Millard-Ball, Adam
2015-01-01
The urban street network is one of the most permanent features of cities. Once laid down, the pattern of streets determines urban form and the level of sprawl for decades to come. We present a high-resolution time series of urban sprawl, as measured through street network connectivity, in the United States from 1920 to 2012. Sprawl started well before private car ownership was dominant and grew steadily until the mid-1990s. Over the last two decades, however, new streets have become significantly more connected and grid-like; the peak in street-network sprawl in the United States occurred in ∼1994. By one measure of connectivity, the mean nodal degree of intersections, sprawl fell by ∼9% between 1994 and 2012. We analyze spatial variation in these changes and demonstrate the persistence of sprawl. Places that were built with a low-connectivity street network tend to stay that way, even as the network expands. We also find suggestive evidence that local government policies impact sprawl, as the largest increases in connectivity have occurred in places with policies to promote gridded streets and similar New Urbanist design principles. We provide for public use a county-level version of our street-network sprawl dataset comprising a time series of nearly 100 y. PMID:26080422
A century of sprawl in the United States.
Barrington-Leigh, Christopher; Millard-Ball, Adam
2015-07-07
The urban street network is one of the most permanent features of cities. Once laid down, the pattern of streets determines urban form and the level of sprawl for decades to come. We present a high-resolution time series of urban sprawl, as measured through street network connectivity, in the United States from 1920 to 2012. Sprawl started well before private car ownership was dominant and grew steadily until the mid-1990s. Over the last two decades, however, new streets have become significantly more connected and grid-like; the peak in street-network sprawl in the United States occurred in ∼ 1994. By one measure of connectivity, the mean nodal degree of intersections, sprawl fell by ∼ 9% between 1994 and 2012. We analyze spatial variation in these changes and demonstrate the persistence of sprawl. Places that were built with a low-connectivity street network tend to stay that way, even as the network expands. We also find suggestive evidence that local government policies impact sprawl, as the largest increases in connectivity have occurred in places with policies to promote gridded streets and similar New Urbanist design principles. We provide for public use a county-level version of our street-network sprawl dataset comprising a time series of nearly 100 y.
Generic patterns in the evolution of urban water networks: Evidence from a large Asian city
NASA Astrophysics Data System (ADS)
Krueger, Elisabeth; Klinkhamer, Christopher; Urich, Christian; Zhan, Xianyuan; Rao, P. Suresh C.
2017-03-01
We examine high-resolution urban infrastructure data using every pipe for the water distribution network (WDN) and sanitary sewer network (SSN) in a large Asian city (≈4 million residents) to explore the structure as well as the spatial and temporal evolution of these infrastructure networks. Network data were spatially disaggregated into multiple subnets to examine intracity topological differences for functional zones of the WDN and SSN, and time-stamped SSN data were examined to understand network evolution over several decades as the city expanded. Graphs were generated using a dual-mapping technique (Hierarchical Intersection Continuity Negotiation), which emphasizes the functional attributes of these networks. Network graphs for WDNs and SSNs are characterized by several network topological metrics, and a double Pareto (power-law) model approximates the node-degree distributions of both water infrastructure networks (WDN and SSN), across spatial and hierarchical scales relevant to urban settings, and throughout their temporal evolution over several decades. These results indicate that generic mechanisms govern the networks' evolution, similar to those of scale-free networks found in nature. Deviations from the general topological patterns are indicative of (1) incomplete establishment of network hierarchies and functional network evolution, (2) capacity for growth (expansion) or densification (e.g., in-fill), and (3) likely network vulnerabilities. We discuss the implications of our findings for the (re-)design of urban infrastructure networks to enhance their resilience to external and internal threats.
Bie, Yiming; Wang, Yinhai
2017-01-01
To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios. PMID:28531198
Bie, Yiming; Liu, Zhiyuan; Wang, Yinhai
2017-01-01
To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios.
10 Best resources on… intersectionality with an emphasis on low- and middle-income countries.
Larson, Elizabeth; George, Asha; Morgan, Rosemary; Poteat, Tonia
2016-10-01
Intersectionality has emerged as an important framework for understanding and responding to health inequities by making visible the fluid and interconnected structures of power that create them. It promotes an understanding of the dynamic nature of the privileges and disadvantages that permeate health systems and affect health. It considers the interaction of different social stratifiers (e.g. 'race'/ethnicity, indigeneity, gender, class, sexuality, geography, age, disability/ability, migration status, religion) and the power structures that underpin them at multiple levels. In doing so, it is a departure from previous health inequalities research that looked at these forms of social stratification in isolation from one another or in an additive manner. Despite its potential use and long history in other disciplines, intersectionality is uncommonly used in health systems research in low- and middle-income countries (LMICs). To orient readers to intersectionality theory and research, we first define intersectionality and describe its role in public health, and then we review resources on intersectionality. We found that applications in public health mostly increased after 2009, with only 14 out of 86 articles focused on LMICs. To arrive at 10 best resources, we selected articles based on the proportion of the article that was devoted to intersectionality, the strength of the intersectionality analysis, and its relevance to LMICs. The first four resources explain intersectionality as a methodology. The subsequent six articles apply intersectionality to research in LMIC with quantitative and qualitative analysis. We provide examples from India, Swaziland, Uganda and Mexico. Topics for the studies range from HIV, violence and sexual abuse to immunization and the use of health entitlements. Through these 10 resources, we hope to spark interest and open a needed conversation on the importance and use of intersectional analysis in LMICs as part of understanding people-centred health systems. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Wu, Jianqing; Xu, Hao
2017-12-01
Understanding driver behavior is important for traffic safety and operation, especially at intersections where different traffic movements conflict. While most driver-behavior studies are based on simulation, this paper documents the analysis of driver-behavior at signalized intersections with the SHRP 2 Naturalistic Driving Study (NDS) data. This study analyzes the different influencing factors on the operation (speed control) and observation of right-turn drivers. A total of 300 NDS trips at six signalized intersections were used, including the NDS time-series sensor data, the forward videos and driver face videos. Different factors of drivers, vehicles, roads and environments were studied for their influence on driver behavior. An influencing index function was developed and the index was calculated for each influencing factor to quantitatively describe its influencing level. The influencing index was applied to prioritize the factors, which facilitates development and selection of safety countermeasures to improve intersection safety. Drivers' speed control was analyzed under different conditions with consideration of the prioritized influencing factors. Vehicle type, traffic signal status, conflicting traffic, conflicting pedestrian and driver age group were identified as the five major influencing factors on driver observation. This research revealed that drivers have high acceleration and low observation frequency under Right-Turn-On-Red (RTOR), which constituted potential danger for other roadway users, especially for pedestrians. As speed has a direct influence on crash rates and severities, the revealed speed patterns of the different situations also benefit selection of safety countermeasures at signalized intersections. Published by Elsevier Ltd.
Comparing the role of fuel breaks across southern California national forests
Syphard, Alexandra D.; Keeley, Jon E.; Brennan, Teresa J.
2011-01-01
Fuel treatment of wildland vegetation is the primary approach advocated for mitigating fire risk at the wildland-urban interface (WUI), but little systematic research has been conducted to understand what role fuel treatments play in controlling large fires, which factors influence this role, or how the role of fuel treatments may vary over space and time. We assembled a spatial database of fuel breaks and fires from the last 30 years in four southern California national forests to better understand which factors are consistently important for fuel breaks in the control of large fires. We also explored which landscape features influence where fires and fuel breaks are most likely to intersect. The relative importance of significant factors explaining fuel break outcome and number of fire and fuel break intersections varied among the forests, which reflects high levels of regional landscape diversity. Nevertheless, several factors were consistently important across all the forests. In general, fuel breaks played an important role in controlling large fires only when they facilitated fire management, primarily by providing access for firefighting activities. Fire weather and fuel break maintenance were also consistently important. Models and maps predicting where fuel breaks and fires are most likely to intersect performed well in the regions where the models were developed, but these models did not extend well to other regions, reflecting how the environmental controls of fire regimes vary even within a single ecoregion. Nevertheless, similar mapping methods could be adopted in different landscapes to help with strategic location of fuel breaks. Strategic location of fuel breaks should also account for access points near communities, where fire protection is most important.
The kids at Hamilton Elementary School: Purposes and practices for co-opting science
NASA Astrophysics Data System (ADS)
Ortiz, Loaiza
The purpose of this study was to explore youth's purposes and motivations for engaging in science through the lens of science practices. The construct of science practices allowed me to see science in youths' lives in a holistic way, shaped by social, political, historical, economic and cultural forces. The framework for understanding urban youths' science practices is grounded in the intersections of critical and feminist theory, sociocultural learning theories, especially as applied in research in urban science education, and recent work in critical literacy studies. As I explored the answers to my research questions---(1) When 5th grade youth, living in predominantly Latino communities struggling with urban poverty, engage in science how and why do they co-opt science in ways that result in changes in participation in science? (2) What are the science practices that facilitate youths' coopting of science? And how are those practices framed by context (school, out-of-school), content (LiFE curriculum), and funds of knowledge? (3) In what ways are science practices expressions of youths' scientific literacy? And (4) In what ways do youth use science practices as tools for expressing identities and agency?---I engaged in feminist ethnography with embedded case studies. Data were collected in 2004 in school and in out of school settings. I recorded numerous informal conversations, interviews, and observations both during after-school and students' regular science and non-science classes. Findings describe how and why students co-opted science for purposes that make sense for their lives. These purposes included gaining and activating resources, building and maintaining social relationships, bridging home and school knowledge, positioning themselves with authority, and constructing science identities. Findings also explored what practices facilitated youth's co-opting of science. I highlighted three practices: making ideas public, storytelling and prioritizing and using evidence. Finally, I present an in-depth analysis of the science practice of storytelling. Analysis revealed that students engaged in storytelling to facilitate co-opting of science by: allowing them to change the discourse of the science classroom, to seek legitimacy, and to position themselves with authority. I end with implications for urban science education, teacher education and for future research.
Computer Generated Pictorial Stores Management Displays for Fighter Aircraft.
1983-05-01
questionnaire rating-scale data. KRISHNAIAH FINITE INTERSECTION TESTS (FITs) - A set of tests conducted after significant MANOVA results are found to...the Social Sciences (SPSS) (Reference 2). To further examine significant performance differences, the Krishnaiah Finite Intersection Test (FIT), a...New York: McGraw-Hill Book Company, 1975. 3. C. M. Cox, P. R. Krishnaiah , J. C. Lee, J. M. Reising, and F. J. Schuurman, A study on Finite Intersection
Jensupakarn, Auearree; Kanitpong, Kunnawee
2018-04-01
In Thailand, red light running is considered as one of the most dangerous behaviors at intersection. Red light running (RLR) behavior is the failure to obey the traffic control signal. However, motorcycle riders and car drivers who are running through red lights could be influenced by human factors or road environment at intersection. RLR could be advertent or inadvertent behavior influenced by many factors. Little research study has been done to evaluate the contributing factors influencing the red-light violation behavior. This study aims to determine the factors influencing the red light running behavior including human characteristics, physical condition of intersection, traffic signal operation, and traffic condition. A total of 92 intersections were observed in Chiang Mai, Nakhon Ratchasima, and Chonburi, the major provinces in each region of Thailand. In addition, the socio-economic characteristics of red light runners were obtained from self-reported questionnaire survey. The Binary Logistic Regression and the Multiple Linear Regression models were used to determine the characteristics of red light runners and the factors influencing rates of red light running respectively. The results from this study can help to understand the characteristics of red light runners and factors affecting them to run red lights. For motorcycle riders and car drivers, age, gender, occupation, driving license, helmet/seatbelt use, and the probability to be penalized when running the red light significantly affect RLR behavior. In addition, the results indicated that vehicle travelling direction, time of day, existence of turning lane, number of lanes, lane width, intersection sight distance, type of traffic signal pole, type of traffic signal operation, length of yellow time interval, approaching speed, distance from intersection warning sign to stop line, and pavement roughness significantly affect RLR rates. Copyright © 2018 Elsevier Ltd. All rights reserved.
Heat Sink Welding for Preventing Hot Cracking in Alloy 2195 Intersection Welds: A Feasibility Study
NASA Technical Reports Server (NTRS)
Yang, Yu-Ping; Dong, Pingsha; Rogers, Patrick
2000-01-01
Two concepts, stationary cooling and trailing cooling, were proposed to prevent weld intersection cracking. Finite element analysis was used to demonstrate the potential effectiveness of those two concepts. Both stationary and trailing heat sink setups were proposed for preventing intersection cracking. The cooling media could be liquid nitrogen, or pressured air knife. Welding experiments on the small test panel with the localized heat sink confirmed the feasibility of using such a stationary cooling technique. The required cooling was achieved in this test panel. Systematic welding experiments should be conducted in the future to validate and refine the heat sink technique for preventing intersection cracking.
The role of intersection and street design on severity of bicycle-motor vehicle crashes
Verma, Santosh; Mekary, Rania A; Courtney, Theodore K; Christiani, David C
2017-01-01
Background Safety concerns are a major barrier to cycling. Intersection and street design variables such as intersection angles and street width might contribute to the severity of crashes and the safety concerns. In this study we examined whether these design variables were associated with bicycle-motor vehicle crashes (BMVC) severity. Methods Using the geographical information system and latitudes/longitudes recorded by the police using a global positioning device, we extracted intersection angles, street width, bicycle facilities, posted speed limits and annual average daily traffic from 3266 BMVC data from New York City police records. Additional variables about BMVC, including age and sex of the bicyclist, time of the day, road surface conditions, road character, vehicle type and injury severity, were obtained from police reports. Injury severity was classified as severe (incapacitating or killed) or non-severe (non-incapacitating, possible injury). The associations between injury severity and environment design variables were examined using multivariate log-binomial regression model. Findings Compared with crashes at orthogonal intersections, crashes at non-orthogonal intersections had 1.37 times (95% CI 1.05 to 1.80) and non-intersection street segments had 1.31 times (95% CI 1.01 to 1.70) higher risk of a severe injury. Crashes that involved a truck or a bus were twice as likely to result in a severe injury outcome; street width was not significantly associated with injury severity. Conclusion Crashes at non-orthogonal intersections and non-intersection segments are more likely to result in higher injury severity. The findings can be used to improve road design and develop effective safety interventions. PMID:27881469
Investigating the Intersection of Race and Histories in the Classroom
ERIC Educational Resources Information Center
Martell, Christopher C.
2012-01-01
In this practitioner research study, a social studies teacher examined the intersection between his students' race/ethnicity and their experiences learning history. Using the theory of culturally relevant pedagogy as a lens, this study employed mixed methods, analyzing teacher journaling, classroom artifacts, and student reflections, as well as…
NASA Astrophysics Data System (ADS)
Fallah-Shorshani, Masoud; Shekarrizfard, Maryam; Hatzopoulou, Marianne
2017-03-01
The development and use of dispersion models that simulate traffic-related air pollution in urban areas has risen significantly in support of air pollution exposure research. In order to accurately estimate population exposure, it is important to generate concentration surfaces that take into account near-road concentrations as well as the transport of pollutants throughout an urban region. In this paper, an integrated modelling chain was developed to simulate ambient Nitrogen Dioxide (NO2) in a dense urban neighbourhood while taking into account traffic emissions, the regional background, and the transport of pollutants within the urban canopy. For this purpose, we developed a hybrid configuration including 1) a street canyon model, which simulates pollutant transfer along streets and intersections, taking into account the geometry of buildings and other obstacles, and 2) a Gaussian puff model, which resolves the transport of contaminants at the top of the urban canopy and accounts for regional meteorology. Each dispersion model was validated against measured concentrations and compared against the hybrid configuration. Our results demonstrate that the hybrid approach significantly improves the output of each model on its own. An underestimation appears clearly for the Gaussian model and street-canyon model compared to observed data. This is due to ignoring the building effect by the Gaussian model and undermining the contribution of other roads by the canyon model. The hybrid approach reduced the RMSE (of observed vs. predicted concentrations) by 16%-25% compared to each model on its own, and increased FAC2 (fraction of predictions within a factor of two of the observations) by 10%-34%.
"I have seen the future": selling the unsustainable city.
Hayden, Dolores
2012-01-01
Seventy years ago, General Motors’ Highways and Horizons exhibit at the World’s Fair, designed by Norman Bel Geddes and Eero Saarinen, promoted demand for cars and federal highways without any concern for environmental sustainability, the theme of our 2010 conference. The main exhibit included a sequence of four parts (entrance ramps, map lobby, Futurama ride, and “intersection of 1960”) where the viewer’s perception of spatial scale was manipulated. Setha M. Low’s theory of “embodied space” helps decode why movement through these diverse spaces influenced millions of Americans’ views of transportation and urban form, a promotional success yet to be equaled by advocates of environmental sustainability.
Beyond dichotomies: Gender and intersecting inequalities in climate change studies.
Djoudi, Houria; Locatelli, Bruno; Vaast, Chloe; Asher, Kiran; Brockhaus, Maria; Basnett Sijapati, Bimbika
2016-12-01
Climate change and related adaptation strategies have gender-differentiated impacts. This paper reviews how gender is framed in 41 papers on climate change adaptation through an intersectionality lens. The main findings show that while intersectional analysis has demonstrated many advantages for a comprehensive study of gender, it has not yet entered the field of climate change and gender. In climate change studies, gender is mostly handled in a men-versus-women dichotomy and little or no attention has been paid to power and social and political relations. These gaps which are echoed in other domains of development and gender research depict a 'feminization of vulnerability' and reinforce a 'victimization' discourse within climate change studies. We argue that a critical intersectional assessment would contribute to unveil agency and emancipatory pathways in the adaptation process by providing a better understanding of how the differential impacts of climate change shape, and are shaped by, the complex power dynamics of existing social and political relations.
Multiphase flow in geometrically simple fracture intersections
Basagaoglu, H.; Meakin, P.; Green, C.T.; Mathew, M.; ,
2006-01-01
A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to study gravity-driven flow in geometrically simple fracture intersections. Simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-film flow on smooth and undulating solid surfaces. Qualitative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.
Estimation of fuel loss due to idling of vehicles at a signalized intersection in Chennai, India
NASA Astrophysics Data System (ADS)
Vasantha Kumar, S.; Gulati, Himanshu; Arora, Shivam
2017-11-01
The vehicles while waiting at signalized intersections are generally found to be in idling condition, i.e., not switching off their vehicles during red times. This phenomenon of idling of vehicles during red times at signalized intersections may lead to huge economic loss as lot of fuel is consumed by vehicles when they are in idling condition. The situation may even be worse in countries like India as different vehicle types consume varying amount of fuel. Only limited studies have been reported on estimation of fuel loss due to idling of vehicles in India. In the present study, one of the busy intersections in Chennai, namely, Tidel Park Junction in Rajiv Gandhi salai was considered. Data collection was carried out in one approach road of the intersection during morning and evening peak hours on a typical working day by manually noting down the red timings of each cycle and the corresponding number of two-wheelers, three-wheelers, passenger cars, light commercial vehicles (LCV) and heavy motorized vehicles (HMV) that were in idling mode. Using the fuel consumption values of various vehicles types suggested by Central Road Research Institute (CRRI), the total fuel loss during the study period was found to be Rs. 4,93,849/-. The installation of red timers, synchronization of signals, use of non-motorized transport for short trips and public awareness are some of the measures which government need to focus to save the fuel wasted at signalized intersections in major cities of India.
Ghanipoor Machiani, Sahar; Abbas, Montasir
2016-11-01
Drivers' indecisiveness in dilemma zones (DZ) could result in crash-prone situations at signalized intersections. DZ is to the area ahead of an intersection in which drivers encounter a dilemma regarding whether to stop or proceed through the intersection when the signal turns yellow. An improper decision to stop by the leading driver, combined with the following driver deciding to go, can result in a rear-end collision, unless the following driver recognizes a collision is imminent and adjusts his or her behavior at or shortly after the onset of yellow. Considering the significance of DZ-related crashes, a comprehensive safety measure is needed to characterize the level of safety at signalized intersections. In this study, a novel safety surrogate measure was developed utilizing real-time radar field data. This new measure, called safety surrogate histogram (SSH), captures the degree and frequency of DZ-related conflicts at each intersection approach. SSH includes detailed information regarding the possibility of crashes, because it is calculated based on the vehicles conflicts. An example illustrating the application of the new methodology at two study sites in Virginia is presented and discussed, and a comparison is provided between SSH and other DZ-related safety surrogate measures mentioned in the literature. The results of the study reveal the efficacy of the SSH as complementary to existing surrogate measures. Copyright © 2015 Elsevier Ltd. All rights reserved.
Traffic signal design and simulation for vulnerable road users safety and bus preemption
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lo, Shih-Ching; Huang, Hsieh-Chu
Mostly, pedestrian car accidents occurred at a signalized interaction is because pedestrians cannot across the intersection safely within the green light. From the viewpoint of pedestrian, there might have two reasons. The first one is pedestrians cannot speed up to across the intersection, such as the elders. The other reason is pedestrians do not sense that the signal phase is going to change and their right-of-way is going to be lost. Developing signal logic to protect pedestrian, who is crossing an intersection is the first purpose of this study. In addition, to improve the reliability and reduce delay of publicmore » transportation service is the second purpose. Therefore, bus preemption is also considered in the designed signal logic. In this study, the traffic data of the intersection of Chong-Qing North Road and Min-Zu West Road, Taipei, Taiwan, is employed to calibrate and validate the signal logic by simulation. VISSIM 5.20, which is a microscopic traffic simulation software, is employed to simulate the signal logic. From the simulated results, the signal logic presented in this study can protect pedestrians crossing the intersection successfully. The design of bus preemption can reduce the average delay. However, the pedestrian safety and bus preemption signal will influence the average delay of cars largely. Thus, whether applying the pedestrian safety and bus preemption signal logic to an intersection or not should be evaluated carefully.« less
Kidd, Sean A; Virdee, Gursharan; Krupa, Terry; Burnham, Darrell; Hemingway, Dawn; Margolin, Indrani; Patterson, Michelle; Zabkiewicz, Denise
2013-01-01
Objective This study was undertaken to examine the role of gender as it relates to access to housing among individuals with severe mental illness (SMI) in Canada. Design An exploratory, qualitative approach was used to assess the perspectives of Canadian housing experts. The focus of inquiry was on the role of gender and associated intersections (eg, ethnicity) in pathways to housing access and housing needs for individuals with SMI. Setting A purposeful sampling strategy was undertaken to access respondents across all Canadian geographic regions, with diversity across settings (urban and rural) and service sectors (hospital based and community based). Participants –29 individuals (6 men and 23 women) considered to be experts in a housing service context as it pertains to SMI were recruited. On average, participants had worked for 15 years in services that specialised in the support and delivery of housing services to people with SMI. Measures Semistructured interviews with participants focused on the role gender plays in access to housing in their specific context. Barriers and facilitators were examined as were intersections with other relevant factors, such as ethnicity, poverty and parenthood. Quantitative ratings of housing accessibility as a function of gender were also collected. Results Participants across geographic contexts described a lack of shelter facilities for women, leading to a reliance on exploitative circumstances. Other findings included a compounding of discrimination for ethnic minority women, the unique resource problems faced in rural contexts, and the difficulties that attend access to shelter and housing for parents with SMI. Conclusions These findings suggest that, along with a generally poor availability of housing stock for individuals with SMI, access problems are compounded by a lack of attention to the unique needs and illness trajectories that attend gender. PMID:23794544
Stormwater management and ecosystem services: a review
NASA Astrophysics Data System (ADS)
Prudencio, Liana; Null, Sarah E.
2018-03-01
Researchers and water managers have turned to green stormwater infrastructure, such as bioswales, retention basins, wetlands, rain gardens, and urban green spaces to reduce flooding, augment surface water supplies, recharge groundwater, and improve water quality. It is increasingly clear that green stormwater infrastructure not only controls stormwater volume and timing, but also promotes ecosystem services, which are the benefits that ecosystems provide to humans. Yet there has been little synthesis focused on understanding how green stormwater management affects ecosystem services. The objectives of this paper are to review and synthesize published literature on ecosystem services and green stormwater infrastructure and identify gaps in research and understanding, establishing a foundation for research at the intersection of ecosystems services and green stormwater management. We reviewed 170 publications on stormwater management and ecosystem services, and summarized the state-of-the-science categorized by the four types of ecosystem services. Major findings show that: (1) most research was conducted at the parcel-scale and should expand to larger scales to more closely understand green stormwater infrastructure impacts, (2) nearly a third of papers developed frameworks for implementing green stormwater infrastructure and highlighted barriers, (3) papers discussed ecosystem services, but less than 40% quantified ecosystem services, (4) no geographic trends emerged, indicating interest in applying green stormwater infrastructure across different contexts, (5) studies increasingly integrate engineering, physical science, and social science approaches for holistic understanding, and (6) standardizing green stormwater infrastructure terminology would provide a more cohesive field of study than the diverse and often redundant terminology currently in use. We recommend that future research provide metrics and quantify ecosystem services, integrate disciplines to measure ecosystem services from green stormwater infrastructure, and better incorporate stormwater management into environmental policy. Our conclusions outline promising future research directions at the intersection of stormwater management and ecosystem services.
Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections
Xiang, Yun; Li, Zhibin; Wang, Wei; Chen, Jingxu; Wang, Hao; Li, Ye
2016-01-01
Median U-turn intersection treatment (MUTIT) has been considered an alternative measure to reduce congestion and traffic conflict at intersection areas. The MUTIT is sometimes difficult to implement in the field because it requires wide median on arterials for U-turn vehicles. The objective of this study is to introduce an unconventional U-turn treatment (UUT) for intersections which requires less median space but is also effective. The UUT has a dual-bay design with different turning radiuses for small and large vehicles. The VISSIM simulation model was developed to evaluate the operational features of the UUT. The model was calibrated using data collected from intersections in China. The capacity, delay and number of stops were evaluated and compared with the direct-left-turn (DLT) for the same intersections. The results showed that the UUT significantly improved the operations at intersection areas, especially when volume/capacity ratio is small, and ratio of left-turn to through traffic is small. With the UUT, the capacity is increased by 9.81% to 10.38%, vehicle delay is decreased by 18.5% to 40.1%, and number of stops is decreased by 23.19% to 36.62%, when volume/capacity ratio is less than 0.50. The study also found that traffic efficiency could be further improved when the UUT is designed in conjunction with signal control. In the case, the UUT plus signalized control increases the capacity by 25% to 26.02%, decreases vehicle delay by 50.5% to 55.8%, and reduces number of stops by 69.5%, compared with the traditional DLT. PMID:27467127
Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections.
Xiang, Yun; Li, Zhibin; Wang, Wei; Chen, Jingxu; Wang, Hao; Li, Ye
2016-01-01
Median U-turn intersection treatment (MUTIT) has been considered an alternative measure to reduce congestion and traffic conflict at intersection areas. The MUTIT is sometimes difficult to implement in the field because it requires wide median on arterials for U-turn vehicles. The objective of this study is to introduce an unconventional U-turn treatment (UUT) for intersections which requires less median space but is also effective. The UUT has a dual-bay design with different turning radiuses for small and large vehicles. The VISSIM simulation model was developed to evaluate the operational features of the UUT. The model was calibrated using data collected from intersections in China. The capacity, delay and number of stops were evaluated and compared with the direct-left-turn (DLT) for the same intersections. The results showed that the UUT significantly improved the operations at intersection areas, especially when volume/capacity ratio is small, and ratio of left-turn to through traffic is small. With the UUT, the capacity is increased by 9.81% to 10.38%, vehicle delay is decreased by 18.5% to 40.1%, and number of stops is decreased by 23.19% to 36.62%, when volume/capacity ratio is less than 0.50. The study also found that traffic efficiency could be further improved when the UUT is designed in conjunction with signal control. In the case, the UUT plus signalized control increases the capacity by 25% to 26.02%, decreases vehicle delay by 50.5% to 55.8%, and reduces number of stops by 69.5%, compared with the traditional DLT.
Empowered Intersectionality among Black Female K-12 Leaders: A Transcendental Phenomenological Study
ERIC Educational Resources Information Center
McNeal, Carla
2017-01-01
Black female school leaders remain underrepresented as educational leaders in the K-12 context as marginalizing factors persist in the field. The purpose of this transcendental phenomenological study was to explore the lived experiences of Black female school leaders through the lens of intersectionality. For this research study, intersectionality…
ERIC Educational Resources Information Center
Schlund-Vials, Cathy J.
2011-01-01
Focused on comparative ethnic studies and intersectionality, the author commences with a discussion about Barack Obama's historic inauguration and the Asian American literature classroom. This essay argues that courses, programs, and departments focused on ethnicity, race, gender, class, and sexuality remain important precisely because they…
NASA Astrophysics Data System (ADS)
Chester, M.; Grimm, N. B.; Redman, C.; Miller, T.; McPherson, T.; Munoz-Erickson, T.; Chandler, D. G.
2015-12-01
Climate change is widely considered one of the greatest challenges to global sustainability, with extreme events being the most immediate way that people experience this phenomenon. Urban areas are particularly vulnerable to these events given their location, concentration of people, and increasingly complex and interdependent infrastructure. We are developing a conceptual framework for urban social-ecological-technological systems (SETS) that will allow researchers and practitioners to assess how infrastructure can be resilient, provide ecosystem services, improve social well being, and exploit new technologies in ways that benefit urban populations. The framework integrates the three domains of social and equity issues, environmental quality and protection, and technical/engineering aspects, to form a concept of infrastructure that occurs at the intersection of the domains. Examples show how the more common socioecological systems and socially sensitive engineering approaches that fail to incorporate the third dimension may elevate vulnerability to climate-related disaster. The SETS conceptual framework bridges currently siloed social science, environmental science, and engineering approaches to significantly advance research into the structure, function, and emergent properties of SETS. Extreme events like heat waves in Phoenix; coastal and urban flooding in the wake of superstorm Sandy and following hurricanes in Miami, FL; drought in Mexico; and urban flooding in Baltimore, Portland, San Juan PR, Syracuse, and Valdivia, Chile provide examples of the impacts of and vulnerability to extreme events that demand a new approach. The infrastructure of the future must be resilient, leverage ecosystem services, improve social well being, and exploit new technologies in ways that benefit all segments of urban populations and are appropriate to the particular urban contexts. These contexts are defined not only by the biophysical environment but also by culture and institutions of each place. We apply the SETS conceptual framework to nine western hemisphere cities in diverse settings, presenting hypotheses about the relative efficacy of strategies for resilient SETS infrastructure in cities contrasting in event type, biophysical setting, and cultural and institutional contexts.
Wemrell, Maria; Mulinari, Shai; Merlo, Juan
2017-03-01
Intersectionality theory can contribute to epidemiology and public health by furthering understanding of power dynamics driving production of health disparities, and increasing knowledge about heterogeneities within, and overlap between, social categories. Drawing on McCall, we relate the first of these potential contributions to categorical intersectionality and the second to anti-categorical intersectionality. Both approaches are used in study of risk of ischemic heart disease (IHD), based on register data on 3.6 million adults residing in Sweden by 2010, followed for three years. Categorical intersectionality is here coupled with between-group differences in average risk calculation, as we use intersectional categorizations while estimating odds ratios through logistic regressions. The anti-categorical approach is operationalized through measurement of discriminatory accuracy (DA), i.e., capacity to accurately categorize individuals with or without a certain outcome, through computation of the area under the curve (AUC). Our results show substantial differences in average risk between intersectional groupings. The DA of social categorizations is found to be low, however, due to outcome variability within and overlap between categories. We argue that measures of DA should be used for proper interpretation of differences in average risk between social (or any other) categories. Tension between average between-group risk and the DA of categorizations, which can be related to categorical and anti-categorical intersectional analyses, should be made explicit and discussed to a larger degree in epidemiology and public health. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Sun, Shufang; Crooks, Natasha; Kemnitz, Rebecca; Westergaard, Ryan P
2018-06-12
Both the HIV epidemic and incarceration disproportionately affect Black men in the United States. A critical period for incarcerated Black men living with HIV/AIDS is re-entry into the community, which is often associated with adverse health outcomes. Additionally, Black men living with HIV/AIDS involved in the criminal justice system are burdened by multiple, intersecting disadvantaged identities and social positions. This study aimed to examine community re-entry experiences among Black men living with HIV/AIDS from an intersectional perspective. In-depth, semi-structured interviews were conducted with 16 incarcerated Black men in Wisconsin, at pre-release from prison and six months after re-entry. Thematic analysis guided by intersectionality theory was used to analyze interview transcripts. Seven emerged themes included Intersectional Identities and Social Positions, Family Support, Neighborhood Violence, Relationship with Law Enforcement, Employment, Mental Health Concerns, and Medical Care and Medication Management. Intersecting identities and social positions interact with factors at multiple levels to inform health and HIV care. A conceptual framework was developed to illustrate relationships among themes. Findings demonstrate the relevance of intersectionality theory in HIV care with Black men involved in criminal justice system. Incorporating a social-ecological perspective into intersectionality framework could be useful in theoretical and empirical research. Disenfranchised communities may particularly benefit from interventions that address community- and systemic-level issues. Copyright © 2018 Elsevier Ltd. All rights reserved.
Conical intersection in a bilirubin model A possible pathway for phototherapy of neonatal jaundice
NASA Astrophysics Data System (ADS)
Zietz, Burkhard; Blomgren, Fredrik
2006-03-01
Phototherapy of neonatal jaundice involves Z- E-isomerisation around an exocyclic double bond in bilirubin. Our results of a CASSCF study on dipyrrinone, a bilirubin model, show a conical intersection between the ground and first excited singlet states associated with the Z- E-isomerisation. The conical intersection, located ca. 50 kJ/mol below the Franck-Condon-point, together with the S 1 minimum, ca. 50 kJ/mol below the conical intersection, are able to explain the available time-resolved spectroscopic data (the very short lifetime of the initially excited state and transient 'dark state' intermediate) as well as bilirubin's very low fluorescence quantum yield and the medium-efficient photoisomerisation reaction.
Design, analysis, and testing of a metal matrix composite web/flange intersection
NASA Technical Reports Server (NTRS)
Biggers, S. B.; Knight, N. F., Jr.; Moran, S. G.; Olliffe, R.
1992-01-01
An experimental and analytical program to study the local design details of a typical T-shaped web/flange intersection made from a metal matrix composite is described. Loads creating flange bending were applied to specimens having different designs and boundary conditions. Finite element analyses were conducted on models of the test specimens to predict the structural response. The analyses correctly predict failure load, mode, and location in the fillet material in the intersection region of the web and the flange when specimen quality is good. The test program shows the importance of fabrication quality in the intersection region. The full-scale test program that led to the investigation of this local detail is also described.
Research notes : safety at high-speed intersections.
DOT National Transportation Integrated Search
2010-04-01
A 2010 study for ODOT by researchers at the Oregon State University School of Civil and Construction Engineering titled, Evaluating Safety and Operations of High-Speed Signalized Intersections, examined effective means for improving safety at isolate...
Quad City Intersection Traffic Accident Study: 1993 Data
DOT National Transportation Integrated Search
1996-03-01
Accident information is an important factor from which to work towards the : regional Transportation System Management (TSM) objective of improving the : safety of the local transportation system. The 1993 Quad City Intersection : Traffic Accident Re...
Stepfamilies: The Intersection of Culture, Context, and Biology.
ERIC Educational Resources Information Center
Bray, James
1999-01-01
Discusses five areas concerning Heatherington et al.'s study: nature and nurture issues; deviance versus normative behavior in stepfamilies; context and meaning in different types of families; intersecting developmental trajectories; and gender differences. (JPB)
Gupta, A K; Nag, Subhankar; Mukhopadhyay, U K
2006-04-01
In this study, the relationship between inhalable particulate (PM(10)), fine particulate (PM(2.5)), coarse particles (PM(2.5 - 10)) and meteorological parameters such as temperature, relative humidity, solar radiation, wind speed were statistically analyzed and modelled for urban area of Kolkata during winter months of 2003-2004. Ambient air quality was monitored with a sampling frequency of twenty-four hours at three monitoring sites located near traffic intersections and in an industrial area. The monitoring sites were located 3-5 m above ground near highly trafficked and congested areas. The 24 h average PM(10) and PM(2.5) samples were collected using Thermo-Andersen high volume samplers and exposed filter papers were extracted and analysed for benzene soluble organic fraction. The ratios between PM(2.5) and PM(10) were found to be in the range of 0.6 to 0.92 and the highest ratio was found in the most polluted urban site. Statistical analysis has shown a strong positive correlation between PM(10) and PM(2.5) and inverse correlation was observed between particulate matter (PM(10) and PM(2.5)) and wind speed. Statistical analysis of air quality data shows that PM(10) and PM(2.5) are showing poor correlation with temperature, relative humidity and solar radiation. Regression equations for PM(10) and PM(2.5) and meteorological parameters were developed. The organic fraction of particulate matter soluble in benzene is an indication of poly aromatic hydrocarbon (PAH) concentration present in particulate matter. The relationship between the benzene soluble organic fraction (BSOF) of inhalable particulate (PM(10)) and fine particulate (PM(2.5)) were analysed for urban area of Kolkata. Significant positive correlation was observed between benzene soluble organic fraction of PM(10) (BSM10) and benzene soluble organic fraction of PM(2.5) (BSM2.5). Regression equations for BSM10 and BSM2.5 were developed.
Browning, Christopher R.; Soller, Brian
2014-01-01
Many scholars, policy analysts, and practitioners agree that neighborhoods are important contexts for urban youth. Yet, despite decades of research, our knowledge of why and how neighborhoods influence the day-to-day lives of youth is still emerging. Theories about neighborhood effects largely assume that neighborhoods operate to influence youth through exposure-based mechanisms. Extant theoretical approaches, however, have neglected the processes by which neighborhood socioeconomic contexts influence the routine spatial exposures—or activity spaces—of urban residents. In this article, we argue that exposure to organizations, institutions, and other settings that characterize individual activity spaces is a key mechanism through which neighborhoods influence youth outcomes. Moreover, we hypothesize that aggregate patterns of shared local exposure—captured by the concept of ecological networks—are influenced by neighborhood socioeconomic characteristics and are independently consequential for neighborhood youth. Neighborhoods in which residents intersect in space more extensively as a result of routine conventional activities will exhibit higher levels of social capital relevant to youth well-being, including (1) familiarity, (2) beneficial (weak) social ties, (3) trust, (4) shared expectations for pro-social youth behavior (collective efficacy), and (5) the capacity for consistent monitoring of public space. We then consider the implications of ecological networks for understanding the complexities of contextual exposure. We specifically discuss the role of embeddedness in ecological communities—that is, clusters of actors and locations that intersect at higher rates—for understanding contextual influences that are inadequately captured by geographically defined neighborhoods. We conclude with an overview of new approaches to data collection that incorporate insights from an activity-space and ecological-network perspective on neighborhood and contextual influences on youth. Our approach offers (1) a new theoretical approach to understanding the links between neighborhood socioeconomic characteristics and youth-relevant dimensions of neighborhood social capital; (2) a basis for conceptualizing contextual influences that vary within, or extend beyond, traditionally understood geographic neighborhoods; and (3) a suite of methodological tools and resources to address the mechanisms of contextual influence more precisely. Research into the causes and consequences of urban neighborhood routine activity structures will illuminate the social processes accounting for compromised youth outcomes in disadvantaged neighborhoods and enhance the capacity for effective youth-oriented interventions. PMID:25105172
Effects of countdown timers on driver behavior after the yellow onset at Chinese intersections.
Long, Kejun; Han, Lee D; Yang, Qiang
2011-10-01
Few studies have focused on the effect of countdown timers at signalized intersections in China, where such timers are widely deployed for their perceived benefits of increased safety and capacity. This study examines the effect of countdown timers on driver behavior during the yellow interval. Signal phasing and traffic operations were videotaped at 4 comparable signalized intersections under normal conditions. Microscopic details were extracted manually at 25 Hz to yield 24 h of data on onset time of the yellow, onset time of the red, driver location and actions after the onset of the yellow, red light-running violations, etc. For comparable intersections with and without countdown timers, driver behavior measured by driver decision (stop or go) and vehicle entry time (when the vehicle crosses the stop line) were analyzed using binary logistical regression (BLR) and a nonparametric test, respectively. The results suggest that countdown timers can indeed influence driver behaviors, in terms of decisions to stop or cross the intersection as well as the distribution of vehicle entry times. There was a strong correlation between the presence of countdown timers and an increase in red light violations. Countdown timers may lead to increased entrance into the intersection during the later portions of the yellow and even the red. This alarming finding calls for further research as well as for serious consideration before the field deployment of countdown timers.
How Student Teachers (Don't) Talk about Race: An Intersectional Analysis
ERIC Educational Resources Information Center
Young, Kathryn S.
2016-01-01
This study explores how student teacher talk about their students illuminates the identities ascribed to these same students. It uses a hybrid intersectional framework based on Disability Studies, Critical Race Theory, and Latino Critical Theory and methodologies (like examining majoritarian stories, counter-storytelling, coded talk, and…
"Two Totally Different People": Dissonance of Intersecting Identities in White College Women
ERIC Educational Resources Information Center
Dalpra, Abby; Vianden, Jörg
2017-01-01
This phenomenological study explored the intersecting privileged (racial) and oppressed (gender) identities of eight White college women. Through three interviews, this study aimed to understand how the participants experience socially conflicting identities. Findings indicated that the participants felt more connected to their gender than their…
DOT National Transportation Integrated Search
2012-04-01
The three studies included in the current report examine the transition from an infrastructure-based rural : intersection crossing assist system to one located inside a vehicle. The primary goals of the first study, conducted in : a simulator, were t...
Adapting an Evidence-Based HIV-Prevention Intervention for Women in Domestic Violence Shelters
Cavanaugh, Courtenay E.; Campbell, Jacquelyn; Braxton, Nikia; Harvey, Jenna; Wingood, Gina
2016-01-01
Objective Despite the documented intersection of intimate partner violence and HIV, there is a paucity of evidence-based HIV prevention interventions for female survivors of intimate partner violence in the United States. This paper describes the adaptation of an effective HIV prevention intervention, Sisters Informing Sisters about Topics on AIDS (SISTA), for women in domestic violence shelters and the steps taken to improve the adapted intervention’s implementation. Method The adaptation process was guided by the ADAPT-ITT framework and data collected from directors, direct client service providers, and residents of two domestic violence shelters located in urban areas, as well as topical experts. Results Eleven of 12 shelter staff (92%) reported that HIV interventions had never been implemented at their shelter and 64% reported they had not provided residents with educational brochures about HIV prevention. Changes made to adapt SISTA for this population and enhance the implementation of the intervention included reducing the intervention’s duration; adding education about the intersection of intimate partner violence, substance use, and HIV; and adding an HIV risk assessment and safety plan. Conclusions Next steps will include implementing the adapted intervention and evaluating its perceived acceptability and efficacy, and assessing whether contextual factors influence the intervention’s implementation. PMID:27398257
A Bandwidth-Efficient Dissemination Scheme of Non-Safety Information in Urban VANETs †
Garcia-Lozano, Estrella; Campo, Celeste; Garcia-Rubio, Carlos; Rodriguez-Carrion, Alicia
2016-01-01
The recent release of standards for vehicular communications will hasten the development of smart cities in the following years. Many applications for vehicular networks, such as blocked road warnings or advertising, will require multi-hop dissemination of information to all vehicles in a region of interest. However, these networks present special features and difficulties that may require special measures. The dissemination of information may cause broadcast storms. Urban scenarios are especially sensitive to broadcast storms because of the high density of vehicles in downtown areas. They also present numerous crossroads and signal blocking due to buildings, which make dissemination more difficult than in open, almost straight interurban roadways. In this article, we discuss several options to avoid the broadcast storm problem while trying to achieve the maximum coverage of the region of interest. Specifically, we evaluate through simulations different ways to detect and take advantage of intersections and a strategy based on store-carry-forward to overcome short disconnections between groups of vehicles. Our conclusions are varied, and we propose two different solutions, depending on the requirements of the application. PMID:27355956
A Bandwidth-Efficient Dissemination Scheme of Non-Safety Information in Urban VANETs.
Garcia-Lozano, Estrella; Campo, Celeste; Garcia-Rubio, Carlos; Rodriguez-Carrion, Alicia
2016-06-27
The recent release of standards for vehicular communications will hasten the development of smart cities in the following years. Many applications for vehicular networks, such as blocked road warnings or advertising, will require multi-hop dissemination of information to all vehicles in a region of interest. However, these networks present special features and difficulties that may require special measures. The dissemination of information may cause broadcast storms. Urban scenarios are especially sensitive to broadcast storms because of the high density of vehicles in downtown areas. They also present numerous crossroads and signal blocking due to buildings, which make dissemination more difficult than in open, almost straight interurban roadways. In this article, we discuss several options to avoid the broadcast storm problem while trying to achieve the maximum coverage of the region of interest. Specifically, we evaluate through simulations different ways to detect and take advantage of intersections and a strategy based on store-carry-forward to overcome short disconnections between groups of vehicles. Our conclusions are varied, and we propose two different solutions, depending on the requirements of the application.
Living in the city: school friendships, diversity and the middle classes.
Vincent, Carol; Neal, Sarah; Iqbal, Humera
2018-06-01
Much of the literature on the urban middle classes describes processes of both affiliation (often to the localities) and disaffiliation (often from some of the non-middle-class residents). In this paper, we consider this situation from a different position, drawing on research exploring whether and how children and adults living in diverse localities develop friendships with those different to themselves in terms of social class and ethnicity. This paper focuses on the interviews with the ethnically diverse, but predominantly white British, middle-class parent participants, considering their attitudes towards social and cultural difference. We emphasize the importance of highlighting inequalities that arise from social class and its intersection with ethnicity in analyses of complex urban populations. The paper's contribution is, first, to examine processes of clustering amongst the white British middle-class parents, particularly in relation to social class. Second, we contrast this process, and its moments of reflection and unease, with the more deliberate and purposeful efforts of one middle-class, Bangladeshi-origin mother who engages in active labour to facilitate relationships across social and ethnic difference. © London School of Economics and Political Science 2017.
Christiansen, Lars B; Cerin, Ester; Badland, Hannah; Kerr, Jacqueline; Davey, Rachel; Troelsen, Jens; van Dyck, Delfien; Mitáš, Josef; Schofield, Grant; Sugiyama, Takemi; Salvo, Deborah; Sarmiento, Olga L; Reis, Rodrigo; Adams, Marc; Frank, Larry; Sallis, James F
2016-12-01
Mounting evidence documents the importance of urban form for active travel, but international studies could strengthen the evidence. The aim of the study was to document the strength, shape, and generalizability of relations of objectively measured built environment variables with transport-related walking and cycling. This cross-sectional study maximized variation of environments and demographics by including multiple countries and by selecting adult participants living in neighborhoods based on higher and lower classifications of objectively measured walkability and socioeconomic status. Analyses were conducted on 12,181 adults aged 18-66 years, drawn from 14 cities across 10 countries worldwide. Frequency of transport-related walking and cycling over the last seven days was assessed by questionnaire and four objectively measured built environment variables were calculated. Associations of built environment variables with transport-related walking and cycling variables were estimated using generalized additive mixed models, and were tested for curvilinearity and study site moderation. We found positive associations of walking for transport with all the environmental attributes, but also found that the relationships was only linear for land use mix, but not for residential density, intersection density, and the number of parks. Our findings suggest that there may be optimum values in these attributes, beyond which higher densities or number of parks could have minor or even negative impact. Cycling for transport was associated linearly with residential density, intersection density (only for any cycling), and land use mix, but not with the number of parks. Across 14 diverse cities and countries, living in more densely populated areas, having a well-connected street network, more diverse land uses, and having more parks were positively associated with transport-related walking and/or cycling. Except for land-use-mix, all built environment variables had curvilinear relationships with walking, with a plateau in the relationship at higher levels of the scales.
Christiansen, Lars B.; Cerin, Ester; Badland, Hannah; Kerr, Jacqueline; Davey, Rachel; Troelsen, Jens; van Dyck, Delfien; Mitáš, Josef; Schofield, Grant; Sugiyama, Takemi; Salvo, Deborah; Sarmiento, Olga L.; Reis, Rodrigo; Adams, Marc; Frank, Larry; Sallis, James F.
2016-01-01
Introduction Mounting evidence documents the importance of urban form for active travel, but international studies could strengthen the evidence. The aim of the study was to document the strength, shape, and generalizability of relations of objectively measured built environment variables with transport-related walking and cycling. Methods This cross-sectional study maximized variation of environments and demographics by including multiple countries and by selecting adult participants living in neighborhoods based on higher and lower classifications of objectively measured walkability and socioeconomic status. Analyses were conducted on 12,181 adults aged 18–66 years, drawn from 14 cities across 10 countries worldwide. Frequency of transport-related walking and cycling over the last seven days was assessed by questionnaire and four objectively measured built environment variables were calculated. Associations of built environment variables with transport-related walking and cycling variables were estimated using generalized additive mixed models, and were tested for curvilinearity and study site moderation. Results We found positive associations of walking for transport with all the environmental attributes, but also found that the relationships was only linear for land use mix, but not for residential density, intersection density, and the number of parks. Our findings suggest that there may be optimum values in these attributes, beyond which higher densities or number of parks could have minor or even negative impact. Cycling for transport was associated linearly with residential density, intersection density (only for any cycling), and land use mix, but not with the number of parks. Conclusion Across 14 diverse cities and countries, living in more densely populated areas, having a well-connected street network, more diverse land uses, and having more parks were positively associated with transport-related walking and/or cycling. Except for land-use-mix, all built environment variables had curvilinear relationships with walking, with a plateau in the relationship at higher levels of the scales. PMID:28111613
Changes in crash risk following re-timing of traffic signal change intervals.
Retting, Richard A; Chapline, Janella F; Williams, Allan F
2002-03-01
More than I million motor vehicle crashes occur annually at signalized intersections in the USA. The principal method used to prevent crashes associated with routine changes in signal indications is employment of a traffic signal change interval--a brief yellow and all-red period that follows the green indication. No universal practice exists for selecting the duration of change intervals, and little is known about the influence of the duration of the change interval on crash risk. The purpose of this study was to estimate potential crash effects of modifying the duration of traffic signal change intervals to conform with values associated with a proposed recommended practice published by the Institute of Transportation Engineers. A sample of 122 intersections was identified and randomly assigned to experimental and control groups. Of 51 eligible experimental sites, 40 (78%) needed signal timing changes. For the 3-year period following implementation of signal timing changes, there was an 8% reduction in reportable crashes at experimental sites relative to those occurring at control sites (P = 0.08). For injury crashes, a 12% reduction at experimental sites relative to those occurring at control sites was found (P = 0.03). Pedestrian and bicycle crashes at experimental sites decreased 37% (P = 0.03) relative to controls. Given these results and the relatively low cost of re-timing traffic signals, modifying the duration of traffic signal change intervals to conform with values associated with the Institute of Transportation Engineers' proposed recommended practice should be strongly considered by transportation agencies to reduce the frequency of urban motor vehicle crashes.
Women's health care: the experiences and behaviors of rural and urban lesbians in the USA.
Barefoot, K Nikki; Warren, Jacob C; Smalley, K Bryant
2017-01-01
Previous research has consistently demonstrated that, in comparison to their cisgender heterosexual counterparts, lesbians face a multitude of women's healthcare-related disparities. However, very little research has been conducted that takes an intersectionality approach to examining the potential influences of rural-urban location on the health-related needs and experiences of lesbians. The purpose of this study was to quantitatively compare rural and urban lesbians' access to women's health care, experiences with women's healthcare providers (WHCPs), and preventive behavior using a large, diverse sample of lesbians from across the USA. A total of 895 (31.1% rural and 68.9% urban) lesbian-identified cisgender women (ie not transgender) from the USA participated in the current online study. As part of a larger parent study, participants were recruited from across the USA through email communication to lesbian, gay, bisexual, and transgender (LGBT)-focused organizations and online advertisements. Participants were asked to complete a series of questions related to their women's healthcare-related experiences and behaviors (ie access to care, experiences with WHCPs, and preventive behavior). A series of χ2 analyses were utilized in order to examine rural-urban differences across dependent variables. An examination of sexual risks revealed that relatively more rural lesbians reported at least one previous male sexual partner in comparison to the urban sample of lesbians (78.1% vs 69.1%, χ2(1, N=890)=7.56, p=0.006). A similarly low percentage of rural (42.4%) and urban (42.9%) lesbians reported that they have a WHCP that they see on a regular basis for preventive care. In terms of experiences with WHCP providers, relatively fewer rural lesbians indicated that their current WHCP had discussed/recommended the human papillomavirus (HPV) vaccination in comparison to urban lesbians (27.5% vs. 37.2%; χ2 (1, N=796)=7.24, p=0.007). No other rural-urban differences in experiences with WHCPs emerged - few rural and urban lesbians had been asked about their sexual orientation by their WHCP (38.8% and 45.0%, respectively), been provided with appropriate safe-sex education by their WHCP (21.4% and 25.3%), had their last HIV/sexually transmitted infection screening instigated by their WHCP (if applicable; 15.7% and 19.5%), and reported that their WHCP seems knowledgeable about lesbian health concerns (56.5% vs 54.6%). In terms of preventive behavior, significantly fewer rural lesbians aged 40 years or more had received a mammogram in the past 3 years (63.2% vs 83.2%; χ2(1, N=163)=8.36, p=0.004) when compared to their urban counterparts. No other significant rural-urban differences in preventive behaviors emerged. A similarly low percentage of rural and urban lesbians indicated that they have received the HPV vaccination (22.8% and 29.0%, respectively) and/or have had a HIV/STI screening (43.0% and 47.8%), Pap test (62.0% and 64.5%) or breast exam (59.2% and 62.8%), in the past 3 years. The current findings highlight that rural lesbians in the USA, in comparison to urban lesbians, may experience elevated health risks related to being more likely to have at least one previous male sexual partner, less likely to be recommended the HPV vaccination by a WHCP, and, for those 40 or older, less likely to receive routine mammogram screenings. Furthermore, rural lesbians appear to engage in similarly low rates of HPV vaccination and regular HIV/STI screenings, Pap tests, and clinical breast exams as their urban counterparts. Given the increased cervical and breast cancer risks associated with rural living, the current findings underscore the dire need for health promotion efforts aimed at increasing rural lesbians' engagement in routine pelvic and breast exams.
U-Turns at signalized intersections.
DOT National Transportation Integrated Search
2004-06-01
The objectives of the study were to examine the safety consequences from the installation of U-turns at signalized intersections in Kentucky and to develop a set of guidelines for using this alternative in the future. The literature review indicated ...
Intersection negotiation problems of older drivers. Volume 1
DOT National Transportation Integrated Search
1998-09-01
This project included a background literature synthesis and observational field study. The research goals were to document driving problems and errors at intersections, for older drivers using their own cars to travel familiar and unfamiliar routes, ...
[When and where motorcyclists have accidents and die in Belo Horizonte, Minas Gerais State, Brazil].
Diniz, Eugênio Paceli Hatem; Pinheiro, Letícia Cavalari; Proietti, Fernando Augusto
2015-12-01
The objective of this study was to analyze traffic accidents involving motorcycles in Belo Horizonte, Minas Gerais State, Brazil, from 2007 to 2011 and to identify clusters of high-risk and hazardous intersections in and around the city. Data were provided by the Military Police Brigade and the Emergency Medical Service (SAMU). Accident severity rates were used to identify critical intersections. Two techniques were used: kernel analysis and scan statistics (continuous Poisson model). High-risk clusters were located in the downtown area and on major thoroughfares. Surprisingly, the highest risk of accidents and death occurred not at intersections, but between them. Hazardous intersections are part of routes used to access regions around Greater Metropolitan Belo Horizonte. Two distinct trends in mortality rates and accidents were identified. Most motorcycle deaths occurred after 7:00 PM. The study concludes that there is an urgent need to improve motorcycle and public transportation routes.
Ni, Ying; Li, Keping
2014-01-01
Rear-end accidents are the most common accident type at signalized intersections, because the diversity of actions taken increases due to signal change. Green signal countdown devices (GSCDs), which have been widely installed in Asia, are thought to have the potential of improving capacity and reducing accidents, but some negative effects on intersection safety have been observed in practice; for example, an increase in rear-end accidents. A microscopic modeling approach was applied to estimate rear-end accident probability during the phase transition interval in the study. The rear-end accident probability is determined by the following probabilities: (1) a leading vehicle makes a "stop" decision, which was formulated by using a binary logistic model, and (2) the following vehicle fails to stop in the available stopping distance, which is closely related to the critical deceleration used by the leading vehicle. Based on the field observation carried out at 2 GSCD intersections and 2 NGSCD intersections (i.e., intersections without GSCD devices) along an arterial in Suzhou, the rear-end probabilities at GSCD and NGSCD intersections were calculated using Monte Carlo simulation. The results suggested that, on the one hand, GSCDs caused significantly negative safety effects during the flashing green interval, especially for vehicles in a zone ranging from 15 to 70 m; on the other hand, GSCD devices were helpful in reducing rear-end accidents during the yellow interval, especially in a zone from 0 to 50 m. GSCDs helped shorten indecision zones and reduce rear-end collisions near the stop line during the yellow interval, but they easily resulted in risky car following behavior and much higher rear-end collision probabilities at indecision zones during both flashing green and yellow intervals. GSCDs are recommended to be cautiously installed and education on safe driving behavior should be available.
Bowleg, Lisa; Teti, Michelle; Malebranche, David J; Tschann, Jeanne M
2013-01-01
This interview study, the initial qualitative phase of a larger mixed methods HIV prevention study focused on Black heterosexual men, used intersectionality as a theoretical framework to explore: (1) How a sample of Black heterosexual men describe and experience the multiple intersections of race, gender, and SES; and (2) How these descriptions reflected interlocking systems of social inequality for Black men at the social-structural level. Participants were 30 predominantly low-income self-identified Black heterosexual men between the ages of 18 and 44. Analyses highlighted four themes that demonstrate how participants' individual-level experiences as Black men reflect macro social-structural inequality: (1) racial discrimination and microaggressions; (2) unemployment; (3) incarceration; and (4) police surveillance and harassment. We discuss the study's findings within the context of social-structural factors that disproportionately and adversely impact Black men. We also highlight the implications of the intersectionality perspective for HIV prevention research and interventions for Black heterosexual men.
NASA Astrophysics Data System (ADS)
McNew-Birren, Jill; Hildebrand, Tyra; Belknap, Gabrielle
2017-02-01
Teach For America (TFA), a widespread and well-known route into the teaching profession, frequently partners with university-based education programs to prepare and certify its corps members. However, university-based teacher education programs frequently emphasize very different understandings of socially just education and priorities for training teachers from those of TFA. Accordingly, science teachers trained through TFA-university partnerships encounter conflicting understandings of science education, justice, and urban communities as they are introduced to teaching practice. In this ethnographic case study we explored the experiences and reactions of a cohort of TFA corps members in a science methods course as they engaged with TFA's perspective focused primarily on enhancing students' social mobility and the methods course emphasizing democratic equality through scientific engagement. The study considers intersections between TFA's approach to teacher preparation and sociocultural perspectives on equitable science teaching. The study also lends insight into the contradictions and challenges through which TFA science teachers develop understandings about their role as science teachers, purposes and goals of science education, and identities of the students and communities they serve.
Impact of eliminating fracture intersection nodes in multiphase compositional flow simulation
NASA Astrophysics Data System (ADS)
Walton, Kenneth M.; Unger, Andre J. A.; Ioannidis, Marios A.; Parker, Beth L.
2017-04-01
Algebraic elimination of nodes at discrete fracture intersections via the star-delta technique has proven to be a valuable tool for making multiphase numerical simulations more tractable and efficient. This study examines the assumptions of the star-delta technique and exposes its effects in a 3-D, multiphase context for advective and dispersive/diffusive fluxes. Key issues of relative permeability-saturation-capillary pressure (kr-S-Pc) and capillary barriers at fracture-fracture intersections are discussed. This study uses a multiphase compositional, finite difference numerical model in discrete fracture network (DFN) and discrete fracture-matrix (DFM) modes. It verifies that the numerical model replicates analytical solutions and performs adequately in convergence exercises (conservative and decaying tracer, one and two-phase flow, DFM and DFN domains). The study culminates in simulations of a two-phase laboratory experiment in which a fluid invades a simple fracture intersection. The experiment and simulations evoke different invading fluid flow paths by varying fracture apertures as oil invades water-filled fractures and as water invades air-filled fractures. Results indicate that the node elimination technique as implemented in numerical model correctly reproduces the long-term flow path of the invading fluid, but that short-term temporal effects of the capillary traps and barriers arising from the intersection node are lost.
Boateng, Richard Atta; Kwigizile, Valerian; Oh, Jun-Seok
2018-04-11
This study evaluated the safety impacts of PCSs with and without pushbuttons based on pedestrian crashes and pedestrian injuries in Michigan. This study used ten years of intersection data: five years before PCSs were installed and five years after they were installed, along with a comparison group, to evaluate the crash impacts of PCSs: at 107 intersections the PCS had a pushbutton and at 96 it did not. At these intersections, and at their comparison sites (where no PCS was installed), crash data (from 2004-2016) were examined, along with traffic and geometric characteristics, population, education and poverty levels data. Intersections where PCSs with pushbuttons have been installed showed a 29 percent reduction in total pedestrian crashes and a 30 percent reduction in fatal/injury pedestrian crashes. Further, when considering only pedestrians age 65 and below, these respective reductions are 33 and 35 percent. Intersections with PCSs but without pushbuttons did not show any significant change in any type of pedestrian crash. Although the Manual of Uniform Traffic Control Devices (FHWA, 2009) requires the use of PCSs at new traffic signal installations, this study suggests a safety benefit of installing PCSs with pushbutton at signals where a PCS without a pushbutton is present.
ERIC Educational Resources Information Center
Davis, Deanna Rachelle
2012-01-01
The purpose of this qualitative phenomenological study was to explore the intersectionality of race and gender for African American women through their lived experiences of how they developed into leaders. This research study was designed to determine how the intersection of race and gender identities contributed to the elements of leadership…
NASA Astrophysics Data System (ADS)
Malik, A.; Akbar, R.; Maryati, S.; Natalivan, P.
2018-05-01
Public space plays a role in defining the character of a city and is a valuable asset for a city and one of the indicators in assessing whether a city is considered successful or not. In the context of urban sociology, high-quality public spaces with well-maintained environments can improve the quality of the heterogeneous life of urban social communities by creating economic, social, or environmental value-added. Urban societies tend to be heterogeneous, individualistic, and characterized by high competition that often causes conflicts. Another reason for conflicts is the relatively high social differentiation because of the level of religious differences, customs, languages, and sociocultural aspects brought by immigrants from various regions. In the context of space, the city is a system that does not stand alone because internally the city is a unified system of functional activities in it. Meanwhile, externally, the city is influenced by its surrounding environment. As part of the public space, park has an important role in the environmental, aesthetic, recreational, psychological, social, educational, and economic aspects of the city. Public space can be understood as open spaces in urban areas, where everyone regardless their interests and backgrounds can be intersectional and have social contact and serve as an “urban regenerator” including educational functions through innovation and technological intervention. Moreover, park can also absorb carbon dioxide emissions, produce oxygen, improve air and water quality, regulate the microclimate, reduce noise, protect soil and water, and maintain biodiversity. However, many things cause the function of parks to decrease. One reason relates to the distribution of parks related to the characteristics of their location. Research has not seen many studies on the characteristics of locations in the planning of public space. The provision of public space should consider these location characteristics. This study will use a descriptive methodology, by first explaining the policy of public space provision, the existence of the reality of public space, its function and role, the park as public space, the time of visiting the park by the community, and the various problems that occur in it. This research will look at the characteristics of neighborhood parks based on the aspect of the location of park supply and the spatial policies of Bandung City. The analysis comprised ArcGIS (Geographic Information System) and direct observations to evaluate the locational characteristics of the area around the park by using the case study of Music Park and Pendawa Park.
Analysis of Driver Evasive Maneuvering Prior to Intersection Crashes Using Event Data Recorders.
Scanlon, John M; Kusano, Kristofer D; Gabler, Hampton C
2015-01-01
Intersection crashes account for over 4,500 fatalities in the United States each year. Intersection Advanced Driver Assistance Systems (I-ADAS) are emerging vehicle-based active safety systems that have the potential to help drivers safely navigate across intersections and prevent intersection crashes and injuries. The performance of an I-ADAS is expected to be highly dependent upon driver evasive maneuvering prior to an intersection crash. Little has been published, however, on the detailed evasive kinematics followed by drivers prior to real-world intersection crashes. The objective of this study was to characterize the frequency, timing, and kinematics of driver evasive maneuvers prior to intersection crashes. Event data recorders (EDRs) downloaded from vehicles involved in intersection crashes were investigated as part of NASS-CDS years 2001 to 2013. A total of 135 EDRs with precrash vehicle speed and braking application were downloaded to investigate evasive braking. A smaller subset of 59 EDRs that collected vehicle yaw rate was additionally analyzed to investigate evasive steering. Each vehicle was assigned to one of 3 precrash movement classifiers (traveling through the intersection, completely stopped, or rolling stop) based on the vehicle's calculated acceleration and observed velocity profile. To ensure that any significant steering input observed was an attempted evasive maneuver, the analysis excluded vehicles at intersections that were turning, driving on a curved road, or performing a lane change. Braking application at the last EDR-recorded time point was assumed to indicate evasive braking. A vehicle yaw rate greater than 4° per second was assumed to indicate an evasive steering maneuver. Drivers executed crash avoidance maneuvers in four-fifths of intersection crashes. A more detailed analysis of evasive braking frequency by precrash maneuver revealed that drivers performing complete or rolling stops (61.3%) braked less often than drivers traveling through the intersection without yielding (79.0%). After accounting for uncertainty in the timing of braking and steering data, the median evasive braking time was found to be between 0.5 to 1.5 s prior to impact, and the median initial evasive steering time was found to occur between 0.5 and 0.9 s prior to impact. The median average evasive braking deceleration for all cases was found to be 0.58 g. The median of the maximum evasive vehicle yaw rates was found to be 8.2° per second. Evasive steering direction was found to be most frequently in the direction of travel of the approaching vehicle. The majority of drivers involved in intersection crashes were alert enough to perform an evasive action. Most drivers used a combination of steering and braking to avoid a crash. The average driver attempted to steer and brake at approximately the same time prior to the crash.
NASA Astrophysics Data System (ADS)
Behbahani, Hamid; Jahangir Samet, Mehdi; Najafi Moghaddam Gilani, Vahid; Amini, Amir
2017-10-01
The presence of taxi stops within the area of signalized intersections at the outlet legs due to unnatural behaviour of the taxis, sudden change of lanes, parking manoeuvres activities and stopping the vehicle to discharge or pick up the passengers have led to reduction of saturation flow rate at the outlet leg of signalized intersections and increased delay as well as affecting the performance of a crossing lane. So far, in term of evaluating effective adjustment factors on saturation flow rate at the inlet legs of the signalized intersections, various studies have been carried out, however; there has not been any studies on effective adjustment factors on saturation flow rate at the inlet legs. Hence, the evaluating of the traffic effects of unique behaviours on the saturation flow rate of the outlet leg is very important. In this research the parking manoeuvre time and taxi blockage time were evaluated and analyzed based on the available lane width as well as determining the effective adjustment factors on the saturation flow rate using recording related data at four signalized intersections in Rasht city. The results show that the average parking manoeuvre time is a function of the lane width and is increased as the lane width is reduced. Also, it is suggested to use the values of 7.37 and 11.31 seconds, respectively for the average parking manoeuvre time and the average blockage time of taxies at the outlet legs of signalized intersections for the traffic designing in Rasht city.
Analysis on influencing factors and decision-making of pedestrian crossing at intersections
NASA Astrophysics Data System (ADS)
Liu, Likun; Wang, Ziyang
2017-10-01
The city signal intersection always has complex traffic flow and many traffic accidents. As vulnerable participants, the proportion of traffic accidents involving pedestrians remain high. And a lot of insecure crossing behavior seriously reduce the safety of the intersection. Therefore, it is necessary to carry out in-depth study on the traversing characteristics of pedestrians, reveal the inherent laws of pedestrian crossing, and then put forward targeted measures to improve pedestrian traffic environment, protect pedestrian crossing safety and improve traffic efficiency.
Matrix Models and A Proof of the Open Analog of Witten's Conjecture
NASA Astrophysics Data System (ADS)
Buryak, Alexandr; Tessler, Ran J.
2017-08-01
In a recent work, R. Pandharipande, J. P. Solomon and the second author have initiated a study of the intersection theory on the moduli space of Riemann surfaces with boundary. They conjectured that the generating series of the intersection numbers satisfies the open KdV equations. In this paper we prove this conjecture. Our proof goes through a matrix model and is based on a Kontsevich type combinatorial formula for the intersection numbers that was found by the second author.
Goodin, Burel R; Owens, Michael A; White, Dyan M; Strath, Larissa J; Gonzalez, Cesar; Rainey, Rachael L; Okunbor, Jennifer I; Heath, Sonya L; Turan, Janet M; Merlin, Jessica S
2018-05-30
"Intersectional health-related stigma" (IHRS) refers to stigma that arises at the convergence of multiple health conditions. People living with HIV (PLWH) and chronic pain have two highly stigmatized health conditions, and thus may be at especially high risk for internalizing these stigmas and consequently experiencing depression. This study examined the intersectionality of internalized HIV and chronic pain stigma in relation to depressive symptoms in a sample of PLWH and chronic pain. Sixty participants were recruited from an HIV clinic in the Southeastern United States. Chronic pain was defined as pain that has been present for at least three consecutive months, and that has been an ongoing problem for at least half the days in the past six months. All participants completed the HIV Stigma Mechanisms Scale, Internalized Stigma in Chronic Pain Scale, the Short-Form Brief Pain Inventory, and the Center for Epidemiological Studies - Depression Scale. Clinical data was collected from medical records. An intersectional HIV and chronic pain composite variable was created and participants were categorized as either high (28%), moderate (32%), or low (40%). Results revealed that intersectional HIV and chronic pain stigma was significantly associated with severity of depressive symptoms (p = .023). Pairwise contrasts revealed that participants with high (p = .009) and moderate (p = .033) intersectional stigma reported significantly greater mean depressive symptom severity than those with low intersectional stigma. Participants who reported the highest levels of internalized HIV and chronic pain stigma also reported the greatest severity of depressive symptoms. This suggests that the experience of both HIV and chronic pain stigma (i.e., IHRS) among PLWH and chronic pain may synergistically perpetuate negative mood in a more profound manner than experiencing either one stigma alone.
Ren, Yilong; Wang, Yunpeng; Wu, Xinkai; Yu, Guizhen; Ding, Chuan
2016-10-01
Red light running (RLR) has become a major safety concern at signalized intersection. To prevent RLR related crashes, it is critical to identify the factors that significantly impact the drivers' behaviors of RLR, and to predict potential RLR in real time. In this research, 9-month's RLR events extracted from high-resolution traffic data collected by loop detectors from three signalized intersections were applied to identify the factors that significantly affect RLR behaviors. The data analysis indicated that occupancy time, time gap, used yellow time, time left to yellow start, whether the preceding vehicle runs through the intersection during yellow, and whether there is a vehicle passing through the intersection on the adjacent lane were significantly factors for RLR behaviors. Furthermore, due to the rare events nature of RLR, a modified rare events logistic regression model was developed for RLR prediction. The rare events logistic regression method has been applied in many fields for rare events studies and shows impressive performance, but so far none of previous research has applied this method to study RLR. The results showed that the rare events logistic regression model performed significantly better than the standard logistic regression model. More importantly, the proposed RLR prediction method is purely based on loop detector data collected from a single advance loop detector located 400 feet away from stop-bar. This brings great potential for future field applications of the proposed method since loops have been widely implemented in many intersections and can collect data in real time. This research is expected to contribute to the improvement of intersection safety significantly. Copyright © 2016 Elsevier Ltd. All rights reserved.
Burket, S Rebekah; Sapozhnikova, Yelena; Zheng, J S; Chung, Shan Shan; Brooks, Bryan W
2018-05-23
Aquaculture, which is growing 3-5 times faster than terrestrial agriculture, will play an important role to meet future global food production needs. However, over 80% of global sewage production is returned to the environment untreated or poorly treated. In developing nations, these nontraditional waters of diverse quality are being recycled for aquaculture, yet chemical residues are differentially studied. Here, we examined pharmaceuticals, pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), and flame retardants in marine bivalves using isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) and low-pressure gas chromatography-tandem mass spectrometry (LP GC-MS/MS). Green-lipped mussels from the field and oysters from aquaculture net pens, which are harvested as food products, were collected adjacent to point source municipal wastewater and landfill leachate effluent discharges, respectively, in Hong Kong, the fourth most densely populated country in the world. Multiple classes of pharmaceutical, pesticides, PAHs, and phosphorus-based flame retardants were detected at low μg/kg levels. Acceptable servings per week indicated minimal risk for a number of chemicals; however, such calculations could not be performed for other contaminants of emerging concern. Future efforts are needed to better understand contaminant influences on marine bivalve populations and aquaculture product safety, particularly in rapidly urbanizing regions of developing countries with limited wastewater infrastructure.
Integrating intersection traffic signal data into a traffic monitoring program.
DOT National Transportation Integrated Search
2014-09-01
The objective of this study was to provide the Georgia Department of Transportation with : an evaluation of the feasibility of integrating intersection traffic signal data into a traffic : monitoring program. Some of the pertinent conclusions from th...
Statistical Models of At-Grade Intersection Accidents. Addendum.
DOT National Transportation Integrated Search
2000-03-01
This report is an addendum to the work published in FHWA-RD-96-125 titled Statistical Models of At-Grade Intersection Accidents. The objective of both research studies was to develop statistical models of the relationship between traffic accide...
Evaluation of bike boxes at signalized intersections.
DOT National Transportation Integrated Search
2011-01-01
This report presents a before-after study of bike boxes at 10 signalized intersections in Portland, Oregon. The bike boxes, also known as advanced stop lines or advanced stop boxes, were installed to increase visibility of cyclists and reduce conflic...
Street Intersection Characteristics and Their Impacts on Perceived Bicycling Safety
DOT National Transportation Integrated Search
2018-01-01
Safety concern is one of the core issues that deter people from bicycling in the US. Earlier studies have explored the associations between intersection design characteristics and bicyclist safety perceptions. Research shows that there are significan...
Safety evaluation of intersection conflict warning system.
DOT National Transportation Integrated Search
2016-06-01
FHWA organized a pooled fund study of 40 States to evaluate low-cost safety strategies as part of its strategic highway safety effort. One of the strategies selected for evaluation was intersection conflict warning systems (ICWSs). This strategy is i...
Co-location and Self-Similar Topologies of Urban Infrastructure Networks
NASA Astrophysics Data System (ADS)
Klinkhamer, Christopher; Zhan, Xianyuan; Ukkusuri, Satish; Elisabeth, Krueger; Paik, Kyungrock; Rao, Suresh
2016-04-01
The co-location of urban infrastructure is too obvious to be easily ignored. For reasons of practicality, reliability, and eminent domain, the spatial locations of many urban infrastructure networks, including drainage, sanitary sewers, and road networks, are well correlated. However, important questions dealing with correlations in the network topologies of differing infrastructure types remain unanswered. Here, we have extracted randomly distributed, nested subnets from the urban drainage, sanitary sewer, and road networks in two distinctly different cities: Amman, Jordan; and Indianapolis, USA. Network analyses were performed for each randomly chosen subnet (location and size), using a dual-mapping approach (Hierarchical Intersection Continuity Negotiation). Topological metrics for each infrastructure type were calculated and compared for all subnets in a given city. Despite large differences in the climate, governance, and populace of the two cities, and functional properties of the different infrastructure types, these infrastructure networks are shown to be highly spatially homogenous. Furthermore, strong correlations are found between topological metrics of differing types of surface and subsurface infrastructure networks. Also, the network topologies of each infrastructure type for both cities are shown to exhibit self-similar characteristics (i.e., power law node-degree distributions, [p(k) = ak-γ]. These findings can be used to assist city planners and engineers either expanding or retrofitting existing infrastructure, or in the case of developing countries, building new cities from the ground up. In addition, the self-similar nature of these infrastructure networks holds significant implications for the vulnerability of these critical infrastructure networks to external hazards and ways in which network resilience can be improved.
Infection, disease, and biosocial processes at the end of the Indus Civilization.
Robbins Schug, Gwen; Blevins, K Elaine; Cox, Brett; Gray, Kelsey; Mushrif-Tripathy, V
2013-01-01
In the third millennium B.C., the Indus Civilization flourished in northwest India and Pakistan. The late mature phase (2200-1900 B.C.) was characterized by long-distance exchange networks, planned urban settlements, sanitation facilities, standardized weights and measures, and a sphere of influence over 1,000,000 square kilometers of territory. Recent paleoclimate reconstructions from the Beas River Valley demonstrate hydro-climatic stress due to a weakened monsoon system may have impacted urban centers like Harappa by the end of the third millennium B.C. the impact of environmental change was compounded by concurrent disruptions to the regional interaction sphere. Climate, economic, and social changes contributed to the disintegration of this civilization after 1900 B.C. We assess evidence for paleopathology to infer the biological consequences of climate change and socio-economic disruption in the post-urban period at Harappa, one of the largest urban centers in the Indus Civilization. Bioarchaeological evidence demonstrates the prevalence of infection and infectious disease increased through time. Furthermore, the risk for infection and disease was uneven among burial communities. Corresponding mortuary differences suggest that socially and economically marginalized communities were most vulnerable in the context of climate uncertainty at Harappa. Combined with prior evidence for increasing levels of interpersonal violence, our data support a growing pathology of power at Harappa after 2000 B.C. Observations of the intersection between climate change and social processes in proto-historic cities offer valuable lessons about vulnerability, insecurity, and the long-term consequences of short-term strategies for coping with climate change.
Infection, Disease, and Biosocial Processes at the End of the Indus Civilization
Robbins Schug, Gwen; Blevins, K. Elaine; Cox, Brett; Gray, Kelsey; Mushrif-Tripathy, V.
2013-01-01
In the third millennium B.C., the Indus Civilization flourished in northwest India and Pakistan. The late mature phase (2200-1900 B.C.) was characterized by long-distance exchange networks, planned urban settlements, sanitation facilities, standardized weights and measures, and a sphere of influence over 1,000,000 square kilometers of territory. Recent paleoclimate reconstructions from the Beas River Valley demonstrate hydro-climatic stress due to a weakened monsoon system may have impacted urban centers like Harappa by the end of the third millennium B.C. the impact of environmental change was compounded by concurrent disruptions to the regional interaction sphere. Climate, economic, and social changes contributed to the disintegration of this civilization after 1900 B.C. We assess evidence for paleopathology to infer the biological consequences of climate change and socio-economic disruption in the post-urban period at Harappa, one of the largest urban centers in the Indus Civilization. Bioarchaeological evidence demonstrates the prevalence of infection and infectious disease increased through time. Furthermore, the risk for infection and disease was uneven among burial communities. Corresponding mortuary differences suggest that socially and economically marginalized communities were most vulnerable in the context of climate uncertainty at Harappa. Combined with prior evidence for increasing levels of interpersonal violence, our data support a growing pathology of power at Harappa after 2000 B.C. Observations of the intersection between climate change and social processes in proto-historic cities offer valuable lessons about vulnerability, insecurity, and the long-term consequences of short-term strategies for coping with climate change. PMID:24358372
NASA Astrophysics Data System (ADS)
Jin, Cheng-Jie; Wang, Wei; Jiang, Rui
2016-08-01
The proper setting of traffic signals at signalized intersections is one of the most important tasks in traffic control and management. This paper has evaluated the four-phase traffic signal plans at a four-leg intersection via cellular automaton simulations. Each leg consists of three lanes, an exclusive left-turn lane, a through lane, and a through/right-turn lane. For a comparison, we also evaluate the two-phase signal plan. The diagram of the intersection states in the space of inflow rate versus turning ratio has been presented, which exhibits four regions: In region I/II/III, congestion will propagate upstream and laterally and result in queue spillover with both signal plans/two-phase signal plan/four-phase signal plan, respectively. Therefore, neither signal plan works in region I, and only the four-phase signal plan/two-phase signal plan works in region II/III. In region IV, both signal plans work, but two-phase signal plan performs better in terms of average delays of vehicles. Finally, we study the diagram of the intersection states and average delays in the asymmetrical configurations.
Modeling Driver Behavior near Intersections in Hidden Markov Model
Li, Juan; He, Qinglian; Zhou, Hang; Guan, Yunlin; Dai, Wei
2016-01-01
Intersections are one of the major locations where safety is a big concern to drivers. Inappropriate driver behaviors in response to frequent changes when approaching intersections often lead to intersection-related crashes or collisions. Thus to better understand driver behaviors at intersections, especially in the dilemma zone, a Hidden Markov Model (HMM) is utilized in this study. With the discrete data processing, the observed dynamic data of vehicles are used for the inference of the Hidden Markov Model. The Baum-Welch (B-W) estimation algorithm is applied to calculate the vehicle state transition probability matrix and the observation probability matrix. When combined with the Forward algorithm, the most likely state of the driver can be obtained. Thus the model can be used to measure the stability and risk of driver behavior. It is found that drivers’ behaviors in the dilemma zone are of lower stability and higher risk compared with those in other regions around intersections. In addition to the B-W estimation algorithm, the Viterbi Algorithm is utilized to predict the potential dangers of vehicles. The results can be applied to driving assistance systems to warn drivers to avoid possible accidents. PMID:28009838
Johnson Shen, Megan; Freeman, Ryann; Karpiak, Stephen; Brennan-Ing, Mark; Seidel, Liz; Siegler, Eugenia L
2018-03-26
The present study examined the intersectionality of stigma across varying groups of older persons living with HIV (PWH). Four focus groups of older PWH (gay/bisexual men, heterosexual men, heterosexual and bisexualwomen, and Spanish-speaking) were audio-recorded and transcribed. Inductive thematic text analysis was used to identify qualitative themes. Five major themes emerged from the data: 1) disclosure of HIV status; 2) types of stigma experienced; 3) discrimination experienced; 4) other outcomes associated with experiencing stigma; and 5) influence of aging on social isolation experienced due to stigma. Findings indicate women did not suffer from the intersection of stigmas. Other groups suffered from the intersection of stigma due to HIV status and age (gay/bisexual males); HIV status and perceived stigma of sexual orientation or drug use (heterosexual males); and HIV status and culture/ethnicity (Spanish-speaking). Results indicate that many at-risk groups, including heterosexual men, homosexual men, and Spanish-speaking individuals, experience an intersection of stigma between aging and their sexuality, HIV status, or real or perceived drug use. Results highlight the need for HIV support, especially social support, to address intersection of stigmas for unique groups of individuals disproportionately affected by HIV.
Seng, Julia S; Lopez, William D; Sperlich, Mickey; Hamama, Lydia; Reed Meldrum, Caroline D
2012-12-01
Intersectionality is a term used to describe the intersecting effects of race, class, gender, and other marginalizing characteristics that contribute to social identity and affect health. Adverse health effects are thought to occur via social processes including discrimination and structural inequalities (i.e., reduced opportunities for education and income). Although intersectionality has been well-described conceptually, approaches to modeling it in quantitative studies of health outcomes are still emerging. Strategies to date have focused on modeling demographic characteristics as proxies for structural inequality. Our objective was to extend these methodological efforts by modeling intersectionality across three levels: structural, contextual, and interpersonal, consistent with a social-ecological framework. We conducted a secondary analysis of a database that included two components of a widely used survey instrument, the Everyday Discrimination Scale. We operationalized a meso- or interpersonal-level of intersectionality using two variables, the frequency score of discrimination experiences and the sum of characteristics listed as reasons for these (i.e., the person's race, ethnicity, gender, sexual orientation, nationality, religion, disability or pregnancy status, or physical appearance). We controlled for two structural inequality factors (low education, poverty) and three contextual factors (high crime neighborhood, racial minority status, and trauma exposures). The outcome variables we modeled were posttraumatic stress disorder symptoms and a quality of life index score. We used data from 619 women who completed the Everyday Discrimination Scale for a perinatal study in the U.S. state of Michigan. Statistical results indicated that the two interpersonal-level variables (i.e., number of marginalized identities, frequency of discrimination) explained 15% of variance in posttraumatic stress symptoms and 13% of variance in quality of life scores, improving the predictive value of the models over those using structural inequality and contextual factors alone. This study's results point to instrument development ideas to improve the statistical modeling of intersectionality in health and social science research. Copyright © 2012 Elsevier Ltd. All rights reserved.
Pedestrian Choice Behavior at Shopping Mall Intersections in China and the United States
ERIC Educational Resources Information Center
Bitgood, Stephen; Davey, Gareth; Huang, Xiaoyi; Fung, Holly
2013-01-01
Pedestrian navigation through public spaces reflects the nature of interaction between behavior and environment. This study compared pedestrian choice behavior at shopping mall intersections in China and the United States. The study found that in both countries (a) pedestrians chose movement patterns that involved the fewest steps and (b) there…
A Survey on Urban Traffic Management System Using Wireless Sensor Networks.
Nellore, Kapileswar; Hancke, Gerhard P
2016-01-27
Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs) have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT) of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research.
A Survey on Urban Traffic Management System Using Wireless Sensor Networks
Nellore, Kapileswar; Hancke, Gerhard P.
2016-01-01
Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs) have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT) of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research. PMID:26828489
Unsafe riding practice among electric bikers in Suzhou, China: an observational study
Yang, Jie; Hu, Yihe; Du, Wei; Powis, Brent; Ozanne-Smith, Joan; Liao, Yilan; Li, Ning; Wu, Ming
2014-01-01
Background Electric bike (E-bike)-related deaths have been increasing rapidly in China and such injuries may be partly attributable to unsafe riding practice. Objectives To describe potentially unsafe riding behaviours among electric bikers (E-bikers) and to investigate factors influencing these practices in China. Methods In September 2012, a cross-sectional observation study including a speed measurement component was conducted in Wuzhong (an urban district) and Zhangjiagang (a rural district) of Suzhou, Jiangsu Province, China. Hand-held radar speed metres were used to read travelling speeds of E-bikes and a pro forma observation checklist was used to collect data on road riding practice. Mixed-effect logistic regressions were used to calculate adjusted ORs and 95% CIs for the association between speeding, road rule violations and helmet use and their influencing factors. Results Among 800 E-bikes with a speed reading, 70.9% exceeded the designed speed limit of 20 km/h. Among a further 20 647 E-bikers observed, 38.3% did not comply with the road rules when entering intersections; and only 2.2% wore helmets. No regional variation was identified between urban and rural areas. Male E-bikers were associated with more speeding and road rule violations, whereas riding a pedal-equipped E-bike was associated with less road rule violations and less helmet use. Conclusions Unsafe riding practices such as speeding, road rule violations and lack of helmet use were commonplace among E-bikers, especially among men. The study findings indicate that measures aimed at improving E-bike safety are required in China. PMID:24435891
Kinney, P L; Aggarwal, M; Northridge, M E; Janssen, N A; Shepard, P
2000-03-01
Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increasing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter [less than/equal to] 2.5 micro in aerodynamic diameter (PM(2.5)) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentrations were related to local diesel traffic density. Eight-hour (1000-1800 hr) air samples for PM(2.5 )and elemental carbon (EC) were collected for 5 days in July 1996 on sidewalks adjacent to four geographically distinct Harlem intersections. Samples were taken using portable monitors worn by study staff. Simultaneous traffic counts for diesel trucks, buses, cars, and pedestrians were carried out at each intersection on [Greater/equal to] 2 of the 5 sampling days. Eight-hour diesel vehicle counts ranged from 61 to 2,467 across the four sites. Mean concentrations of PM(2.5) exhibited only modest site-to-site variation (37-47 microg/m(3)), reflecting the importance of broader regional sources of PM(2.5). In contrast, EC concentrations varied 4-fold across sites (from 1.5 to 6 microg/m(3)), and were associated with bus and truck counts on adjacent streets and, at one site, with the presence of a bus depot. A high correlation (r = 0.95) was observed between EC concentrations measured analytically and a blackness measurement based on PM(2.5) filter reflectance, suggesting the utility of the latter as a surrogate measure of DEP in future community-based studies. These results show that local diesel sources in Harlem create spatial variations in sidewalk concentrations of DEP. The study also demonstrates the feasibility of a new paradigm for community-based research involving full and active partnership between academic scientists and community-based organizations.
The odd couple: using biomedical and intersectional approaches to address health inequities
Hankivsky, Olena; Doyal, Lesley; Einstein, Gillian; Kelly, Ursula; Shim, Janet; Weber, Lynn; Repta, Robin
2017-01-01
ABSTRACT Background: Better understanding and addressing health inequities is a growing global priority. Objective: In this paper, we contribute to the literature examining complex relationships between biological and social dimensions in the field of health inequalities. Specifically, we explore the potential of intersectionality to advance current approaches to socio-biological entwinements. Design: We provide a brief overview of current approaches to combining both biological and social factors in a single study, and then investigate the contributions of an intersectional framework to such work. Results: We offer a number of concrete examples of how intersectionality has been used empirically to bring both biological and social factors together in the areas of HIV, post-traumatic stress disorder, female genital circumcision/mutilation/cutting, and cardiovascular disease. Conclusion: We argue that an intersectional approach can further research that integrates biological and social aspects of human lives and human health and ultimately generate better and more precise evidence for effective policies and practices aimed at tackling health inequities. PMID:28641056
The odd couple: using biomedical and intersectional approaches to address health inequities.
Hankivsky, Olena; Doyal, Lesley; Einstein, Gillian; Kelly, Ursula; Shim, Janet; Weber, Lynn; Repta, Robin
Better understanding and addressing health inequities is a growing global priority. In this paper, we contribute to the literature examining complex relationships between biological and social dimensions in the field of health inequalities. Specifically, we explore the potential of intersectionality to advance current approaches to socio-biological entwinements. We provide a brief overview of current approaches to combining both biological and social factors in a single study, and then investigate the contributions of an intersectional framework to such work. We offer a number of concrete examples of how intersectionality has been used empirically to bring both biological and social factors together in the areas of HIV, post-traumatic stress disorder, female genital circumcision/mutilation/cutting, and cardiovascular disease. We argue that an intersectional approach can further research that integrates biological and social aspects of human lives and human health and ultimately generate better and more precise evidence for effective policies and practices aimed at tackling health inequities.
DOT National Transportation Integrated Search
2005-11-01
The objective of this focus group study was to identify driver attitudes and behaviors related to intersection safety and to assess the likely impacts of new or existing infrastructure-based technologies/countermeasures. Four focus groups were conduc...
Implementation of a real-time intersection accident detection system (Phase 1).
DOT National Transportation Integrated Search
2004-10-01
The focus of this research is the feasibility study for the implementation of a real-time accident : detection system at intersections. After reviewing accident detection algorithms investigated in the prior : phase of the research, we explored schem...
Development of an interactive GIS based work zone traffic control tool.
DOT National Transportation Integrated Search
2013-08-01
The purpose of this study was to include consideration for intersections into the previously created GIS traffic control planning tool. Available data for making intersection control calculations were collected and integrated into the design of the t...
Low-cost safety measures at signalized intersections.
DOT National Transportation Integrated Search
2008-05-01
The objectives of this study were to: a) identify intersections with a high number of crashes involving a driver disregarding the traffic signal, b) identify types of low-cost safety measures which may be used as a countermeasure for red light runnin...
ERIC Educational Resources Information Center
Haskins, Natoya H.; Ziomek-Daigle, Jolie; Sewell, Cheryl; Crumb, Lonika; Appling, Brandee; Trepal, Heather
2016-01-01
Using phenomenological inquiry, this study explored the lived experiences and intersecting identities of 8 African American counselor educators who are mothers. Six themes were identified: race, professional strain, work-life balance, support, internalized success, and mothering pedagogy.
Development of data measurement techniques for traffic operations analysis at intersections
DOT National Transportation Integrated Search
1985-06-01
This study was undertaken for the purpose of developing intersection data collection methods and approaches which reflect the current needs of engineers and the state-of-the-art capabilities of available equipment. A literature review summarizes perv...
DOT National Transportation Integrated Search
2006-03-01
This document is an executive summary of the report "Driver attitudes and behaviors at intersections and potential effectiveness of engineering countermeasures", FHWA-HRT-05-078. The objective of the focus group study was to identify driver attitudes...
Multiuse trail intersection safety analysis: A crowdsourced data perspective.
Jestico, Ben; Nelson, Trisalyn A; Potter, Jason; Winters, Meghan
2017-06-01
Real and perceived concerns about cycling safety are a barrier to increased ridership in many cities. Many people prefer to bike on facilities separated from motor vehicles, such as multiuse trails. However, due to underreporting, cities lack data on bike collisions, especially along greenways and multiuse paths. We used a crowdsourced cycling incident dataset (2005-2016) from BikeMaps.org for the Capital Regional District (CRD), BC, Canada. Our goal was to identify design characteristics associated with unsafe intersections between multiuse trails and roads. 92.8% of mapped incidents occurred between 2014 and 2016. We extracted both collision and near miss incidents at intersections from BikeMaps.org. We conducted site observations at 32 intersections where a major multiuse trail intersected with roads. We compared attributes of reported incidents at multiuse trail-road intersections to those at road-road intersections. We then used negative binomial regression to model the relationship between the number of incidents and the infrastructure characteristics at multiuse trail-road intersections. We found a higher proportion of collisions (38%, or 17/45 total reports) at multiuse trail-road intersections compared to road-road intersections (23%, or 62/268 total reports). A higher proportion of incidents resulted in an injury at multiuse trail-road intersections compared to road-road intersections (33% versus 15%). Cycling volumes, vehicle volumes, and trail sight distance were all associated with incident frequency at multiuse trail-road intersections. Supplementing traditional crash records with crowdsourced cycling incident data provides valuable evidence on cycling safety at intersections between multiuse trails and roads, and more generally, when conflicts occur between diverse transportation modes. Copyright © 2017. Published by Elsevier Ltd.
DOT National Transportation Integrated Search
2016-05-01
Due to sun glare disturbances, drivers may encounter fatal threats on roadways, particularly at signalized intersections. Many studies have attempted to develop applicable solutions, such as avoiding sun positions, road geometric redirections, and we...
DOT National Transportation Integrated Search
2008-12-26
Dilemma zone at signalized intersection has been recognized as a major potential causing rearend : crashes, and has been widely studied by researches since it was initially proposed as the : GHM model in 1960. However, concepts conventionally defined...
Characterize dynamic dilemma zone and minimize its effect at signalized intersections.
DOT National Transportation Integrated Search
2008-12-26
Dilemma zone at signalized intersection has been recognized as a major potential causing rearend : and right-angle crashes, and has been widely studied by researches since it was initially : proposed as the GHM model in 1960. However, concepts conven...
A Study of the Traffic Safety at Reduced Conflict Intersections In Minnesota
DOT National Transportation Integrated Search
2017-05-23
In 2010, the Minnesota Department of Transportation installed the first Reduced Conflict Intersection (RCI) in the City of Willmar. Since 2010, seven more were constructed, with more planned. The RCI concept is gaining popularity in several states, i...
Repeated Challenge Studies: A Comparison of Union-Intersection Testing with Linear Modeling.
ERIC Educational Resources Information Center
Levine, Richard A.; Ohman, Pamela A.
1997-01-01
Challenge studies can be used to see whether there is a causal relationship between an agent of interest and a response. An approach based on union-intersection testing is presented that allows researchers to examine observations on a single subject and test the hypothesis of interest. An application using psychological data is presented. (SLD)
The Intersection of Imagery Ability, Imagery Use, and Learning Style: An Exploratory Study
ERIC Educational Resources Information Center
Bolles, Gina; Chatfield, Steven J.
2009-01-01
This study explores the intersection of the individual's imagery ability, imagery use in dance training and performance, and learning style. Thirty-four intermediate-level ballet and modern dance students at the University of Oregon completed the Movement Imagery Questionnaire-Revised (MIQ-R) and Kolb's Learning Style Inventory-3 (LSI-3). The four…
Sampling, testing and modeling particle size distribution in urban catch basins.
Garofalo, G; Carbone, M; Piro, P
2014-01-01
The study analyzed the particle size distribution of particulate matter (PM) retained in two catch basins located, respectively, near a parking lot and a traffic intersection with common high levels of traffic activity. Also, the treatment performance of a filter medium was evaluated by laboratory testing. The experimental treatment results and the field data were then used as inputs to a numerical model which described on a qualitative basis the hydrological response of the two catchments draining into each catch basin, respectively, and the quality of treatment provided by the filter during the measured rainfall. The results show that PM concentrations were on average around 300 mg/L (parking lot site) and 400 mg/L (road site) for the 10 rainfall-runoff events observed. PM with a particle diameter of <45 μm represented 40-50% of the total PM mass. The numerical model showed that a catch basin with a filter unit can remove 30 to 40% of the PM load depending on the storm characteristics.
Relationship of Stigma to HIV Risk Among Women with Mental Illness
Collins, Pamela Y.; Elkington, Katherine S.; von Unger, Hella; Sweetland, Annika; Wright, Eric R.; Zybert, Patricia A.
2009-01-01
Urban women with severe mental illness (SMI) are vulnerable to stigma and discrimination related to mental illness and other stigmatized labels. Stigma experiences may increase their risk for negative health outcomes, such as HIV infection. This study tests the relationship between perceived stigma and HIV risk behaviors among women with SMI. The authors interviewed 92 women attending community mental health programs using the Stigma of Psychiatric Illness and Sexuality Among Women Questionnaire. There were significant relationships between personal experiences of mental illness and substance use accompanying sexual intercourse; perceived ethnic stigma and having a riskier partner type; and experiences of discrimination and having a casual or sex-exchange partner. Higher scores on relationship stigma were associated with a greater number of sexual risk behaviors. The findings underscore the importance of exploring how stigma attached to mental illness intersects with other stigmatized labels to produce unique configurations of HIV risk. HIV risk reduction interventions and prevention research should integrate attention to stigmatized identities in the lives of women with SMI. PMID:19123772
Tang, Keshuang; Xu, Yanqing; Wang, Fen; Oguchi, Takashi
2016-10-01
The objective of this study is to empirically analyze and model the stop-go decision behavior of drivers at rural high-speed intersections in China, where a flashing green signal of 3s followed by a yellow signal of 3s is commonly applied to end a green phase. 1, 186 high-resolution vehicle trajectories were collected at four typical high-speed intersection approaches in Shanghai and used for the identification of actual stop-go decision zones and the modeling of stop-go decision behavior. Results indicate that the presence of flashing green significantly changed the theoretical decision zones based on the conventional Dilemma Zone theory. The actual stop-go decision zones at the study intersections were thus formulated and identified based on the empirical data. Binary Logistic model and Fuzzy Logic model were then developed to further explore the impacts of flashing green on the stop-go behavior of drivers. It was found that the Fuzzy Logic model could produce comparably good estimation results as compared to the traditional Binary Logistic models. The findings of this study could contribute the development of effective dilemma zone protection strategies, the improvement of stop-go decision model embedded in the microscopic traffic simulation software and the proper design of signal change and clearance intervals at high-speed intersections in China. Copyright © 2016 Elsevier Ltd. All rights reserved.
Safety evaluation of intersections with dynamic use of exit-lanes for left-turn using field data.
Zhao, Jing; Liu, Yue
2017-05-01
As a newly proposed unconventional intersection design, the exit-lanes for left-turn (EFL) intersection is found to be effective in increasing the intersection capacity with high level of application flexibility, especially under heavy left-turn traffic conditions. However, the operational safety of EFL is of most concern to the authority prior to its implementation. This paper evaluates the safety of the EFL intersections by studying the behavior of left-turn maneuvers using field data collected at 7 locations in China. A total of 22830 left-turn vehicles were captured, in which 9793 vehicles turned left using the mixed-usage area. Four potential safety problems, including the red-light violations, head-on collision risks, trapped vehicles, and rear-end crash risks, were discussed. Statistical analyses were carried out to compare the safety risk between the EFL intersection and the conventional one. Results indicate that the safety problems of EFL intersections mainly lie in higher percentages in red-light violations at the pre-signal (1.83% higher), wrong-way violation problems during the peak hours (the violation rate reaches up to 11.07%), and the lower travel speeds in the mixed-usage area (18.75% lower). Such risks can be counteracted, however, by providing more guiding information, installing cameras to investigate and punish violation maneuvers, and adjusting design parameter values for layout design and signal timing, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.
Intersecting surface defects and instanton partition functions
NASA Astrophysics Data System (ADS)
Pan, Yiwen; Peelaers, Wolfger
2017-07-01
We analyze intersecting surface defects inserted in interacting four-dimensional N=2 supersymmetric quantum field theories. We employ the realization of a class of such systems as the infrared fixed points of renormalization group flows from larger theories, triggered by perturbed Seiberg-Witten monopole-like configurations, to compute their partition functions. These results are cast into the form of a partition function of 4d/2d/0d coupled systems. Our computations provide concrete expressions for the instanton partition function in the presence of intersecting defects and we study the corresponding ADHM model.
Goodwin, L; Gazard, B; Aschan, L; MacCrimmon, S; Hotopf, M; Hatch, S L
2017-04-09
Inequalities in mental health are well documented using individual social statuses such as socioeconomic status (SES), ethnicity and migration status. However, few studies have taken an intersectional approach to investigate inequalities in mental health using latent class analysis (LCA). This study will examine the association between multiple indicator classes of social identity with common mental disorder (CMD). Data on CMD symptoms were assessed in a diverse inner London sample of 1052 participants in the second wave of the South East London Community Health study. LCA was used to define classes of social identity using multiple indicators of SES, ethnicity and migration status. Adjusted associations between CMD and both individual indicators and multiple indicators of social identity are presented. LCA identified six groups that were differentiated by varying levels of privilege and disadvantage based on multiple SES indicators. This intersectional approach highlighted nuanced differences in odds of CMD, with the economically inactive group with multiple levels of disadvantage most likely to have a CMD. Adding ethnicity and migration status further differentiated between groups. The migrant, economically inactive and White British, economically inactive classes both had increased odds of CMD. This is the first study to examine the intersections of SES, ethnicity and migration status with CMD using LCA. Results showed that both the migrant, economically inactive and the White British, economically inactive classes had a similarly high prevalence of CMD. Findings suggest that LCA is a useful methodology for investigating health inequalities by intersectional identities.
ERIC Educational Resources Information Center
Bramesfeld, Kosha D.; Good, Arla
2016-01-01
In this article, we present the results of two studies that evaluated an experiential intersectionality awareness activity, "C'est La Vie: The Game of Social Life." For Study 1 (N = 55), we content analyzed students' short answer responses about inequality written before and after playing "C'est La Vie." Study 2 compared a…
Characteristics of traffic flow at a non-signalized intersection in the framework of game theory
NASA Astrophysics Data System (ADS)
Fan, Hongqiang; Jia, Bin; Tian, Junfang; Yun, Lifen
2014-12-01
At a non-signalized intersection, some vehicles violate the traffic rules to pass the intersection as soon as possible. These behaviors may cause many traffic conflicts even traffic accidents. In this paper, a simulation model is proposed to research the effects of these behaviors at a non-signalized intersection. Vehicle’s movement is simulated by the cellular automaton (CA) model. The game theory is introduced for simulating the intersection dynamics. Two types of driver participate the game process: cooperator (C) and defector (D). The cooperator obey the traffic rules, but the defector does not. A transition process may occur when the cooperator is waiting before the intersection. The critical value of waiting time follows the Weibull distribution. One transition regime is found in the phase diagram. The simulation results illustrate the applicability of the proposed model and reveal a number of interesting insights into the intersection management, including that the existence of defectors is benefit for the capacity of intersection, but also reduce the safety of intersection.
Safety Effectiveness of Stop-Sign Beacons : A Cross-Sectional Study
DOT National Transportation Integrated Search
2018-02-02
Rural intersections account for 16% of fatalities in rural areas (IIHS 2016). Rural intersection crashes are frequently a result of drivers failing to yield to the right of way. Failure to yield right-of-way (FTYROW) may be due to speeding, which ...
The impact of general permissive right and left turn on red legislation in Virginia.
DOT National Transportation Integrated Search
1978-01-01
Right turn on red (RTOR) maneuvers have been permitted at signalized intersections in Virginia since 1972. However, until January 1, 1977, following a study requested by the General Assembly, the maneuver was restricted to intersections at which a si...
DOT National Transportation Integrated Search
2012-11-01
"This proof-of-concept study is to develop an automated data collection module for collection and management of : traffic data at signalized intersections controlled by the Arizona Department of Transportation (ADOT). The : objective of this proof-of...
Bowleg, Lisa; Teti, Michelle; Malebranche, David J.; Tschann, Jeanne M.
2012-01-01
This interview study, the initial qualitative phase of a larger mixed methods HIV prevention study focused on Black heterosexual men, used intersectionality as a theoretical framework to explore: (1) How a sample of Black heterosexual men describe and experience the multiple intersections of race, gender, and SES; and (2) How these descriptions reflected interlocking systems of social inequality for Black men at the social-structural level. Participants were 30 predominantly low-income self-identified Black heterosexual men between the ages of 18 and 44. Analyses highlighted four themes that demonstrate how participants’ individual-level experiences as Black men reflect macro social-structural inequality: (1) racial discrimination and microaggressions; (2) unemployment; (3) incarceration; and (4) police surveillance and harassment. We discuss the study’s findings within the context of social-structural factors that disproportionately and adversely impact Black men. We also highlight the implications of the intersectionality perspective for HIV prevention research and interventions for Black heterosexual men. PMID:23482810
Failure at Frame-Stringer Intersections in PRSEUS Panels
NASA Technical Reports Server (NTRS)
Jegley, Dawn C.
2012-01-01
NASA, the Air Force Research Laboratory and The Boeing Company have worked to develop new low-cost, light-weight composite structures for aircraft. A Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept has been developed which offers advantages over traditional metallic structures. In this concept a stitched carbon-epoxy material system has been developed with the potential for reducing the weight and cost of transport aircraft structure by eliminating fasteners, thereby reducing part count and labor. By adding unidirectional carbon rods to the top of stiffeners, the panel becomes more structurally efficient. This combination produces a more damage tolerant design. This study focuses on the intersection between the rod-stiffener and the foam-filled frame in a PRSEUS specimen. Compression loading is considered, which induces stress concentrations at the intersection point that can lead to failures. An experiment with accompanying analysis for a single-frame specimen is described, followed by a parametric study of simple reinforcements to reduce strains in the intersection region.
Detection and enforcement of failure-to-yield in an emergency vehicle preemption system
NASA Technical Reports Server (NTRS)
Bachelder, Aaron (Inventor); Wickline, Richard (Inventor)
2007-01-01
An intersection controlled by an intersection controller receives trigger signals from on-coming emergency vehicles responding to an emergency call. The intersection controller initiates surveillance of the intersection via cameras installed at the intersection in response to a received trigger signal. The surveillance may begin immediately upon receipt of the trigger signal from an emergency vehicle, or may wait until the intersection controller determines that the signaling emergency vehicle is in the field of view of the cameras at the intersection. Portions of the captured images are tagged by the intersection controller based on tag signals transmitted by the vehicle or based on detected traffic patterns that indicate a potential traffic violation. The captured images are downloaded to a processing facility that analyzes the images and automatically issues citations for captured traffic violations.
A feasibility study on the measurement of tree trunks in forests using multi-scale vertical images
NASA Astrophysics Data System (ADS)
Berveglieri, A.; Oliveira, R. O.; Tommaselli, A. M. G.
2014-06-01
The determination of the Diameter at Breast Height (DBH) is an important variable that contributes to several studies on forest, e.g., environmental monitoring, tree growth, volume of wood, and biomass estimation. This paper presents a preliminary technique for the measurement of tree trunks using terrestrial images collected with a panoramic camera in nadir view. A multi-scale model is generated with these images. Homologue points on the trunk surface are measured over the images and their ground coordinates are determined by intersection of rays. The resulting XY coordinates of each trunk, defining an arc shape, can be used as observations in a circle fitting by least squares. Then, the DBH of each trunk is calculated using an estimated radius. Experiments were performed in two urban forest areas to assess the approach. In comparison with direct measurements on the trunks taken with a measuring tape, the discrepancies presented a Root Mean Square Error (RMSE) of 1.8 cm with a standard deviation of 0.7 cm. These results demonstrate compatibility with manual measurements and confirm the feasibility of the proposed technique.
Study on Performance of Intersection Around The Underpass Using Micro Simulation Program
NASA Astrophysics Data System (ADS)
Arliansyah, J.; Bawono, R. T.
2018-03-01
In order to overcome the problems of congestion at the major intersections in Palembang City, there have been grade separation constructions in the form of flyover or underpass. One of them is the intersection of Patal Pusri Underpass. The smooth traffic due to the underpass construction needs to be balanced by the arrangement management at the intersections located close to the underpass to get the best network performance since both affect each other performance. The Taman Kenten and Seduduk Putih junctions which are just 569 and 226 meters from the underpass of Patal Pusri has to be analyzed for its needs of management and traffic arrangements to reduce its impact on the performance of the intersection of Patal Pusri or vice versa. Some alternatives of management and traffic arrangements were developed to get the best solutions and the Vissim 8.00 microsimulation program was used to evaluate the performance of intersections in the network where the compared parameters are the value of the queue length and average delay. The results of the analysis and the conducted modeling show that the best solution to optimize the performance of the two junctions are to make geometric changes and diversion of traffic flow at Seduduk Putih Junction and making geometric changes at Taman Kenten Junction.
NASA Technical Reports Server (NTRS)
Verosub, Kenneth L.; Brady, Roland H., III; Abrams, Michael
1989-01-01
Kinematic relationships at the intersection of the southern Death Valley and Garlock fault zones were examined to identify and delineate the eastern structural boundary between the Mojave and the Basin and Range geologic terrains, and to construct a model for the evolution of this boundary through time. In order to accomplish this, satellite imagery was combined with field investigations to study six areas in the vicinity of the intersection, or possible extensions, of the fault zones. The information gathered from these areas allows the test of various hypotheses that were proposed to explain the interaction between the Death Valley and Garlock fault zones.
NASA Astrophysics Data System (ADS)
Tay, A. C.; Lee, H. H.
2018-04-01
In this study, traffic survey was done at signalized intersection of both ends of an upgrading road during morning and afternoon peak hours throughout construction period. The intersections of Tudan Road located at Miri City in Sarawak State, Malaysia were chosen as study sites. The aim of this research was to investigate the traffic condition for the signalized intersections of a R3 secondary road that being upgrading to standard U5 dual carriageway during peak hours for construction and operation stages. Data collected from these sites were analyzed according to Highway Capacity Manual (HCM) 2010. From the results, the level-of-services (LOS) of Kuala Baram By Pass Road intersection improved from Level F to Level E at operation stage for weekday during peak hours in the morning. LOS of Lutong-Kuala Baram Road intersection at construction stage were Level C during peak hours in the morning and Level D during peak hours in the afternoon for weekends. However, the LOS during both peak hours for weekends were projected to improve to Level B at the operation stage. It proved that the road construction has affected LOS, and this temporary issue can be solved after the upgraded road is in operation.
DOT National Transportation Integrated Search
2016-02-01
Rural intersections account for 30% of crashes in rural areas and 6% of all fatal crashes, representing a significant but poorly : understood safety problem. Transportation agencies have traditionally implemented countermeasures to address rural inte...
DOT National Transportation Integrated Search
2005-05-01
The report presents the details of a study carried out to test and implement a dilemma zone protection technique at three high-speed closely-spaced intersections on Roosevelt Blvd in Middletown, Ohio.
DOT National Transportation Integrated Search
2008-12-01
Over the past six years, researchers from the University of Minnesota have studied the many ways in which transportation and technology intersect. Their work has explored these intersections from many perspectives, from ways intelligent transportatio...
Teaching Science from Cultural Points of Intersection
ERIC Educational Resources Information Center
Grimberg, Bruna Irene; Gummer, Edith
2013-01-01
This study focuses on a professional development program for science teachers near or on American Indian reservations in Montana. This program was framed by culturally relevant pedagogy premises and was characterized by instructional strategies and content foci resulting from the intersection between three cultures: tribal, science teaching, and…
ERIC Educational Resources Information Center
Harrison, Lisa
2017-01-01
The research presented uses intersectionality theory as a lens to study the racial identity construction of four African American young adolescent girls. The findings suggest that race was largely situated in a Black-White discourse for the girls in the study. When limited information was provided in home, school, and community settings, the…
ERIC Educational Resources Information Center
Ratnabalasuriar, Sheruni
2012-01-01
This study explores experiences of women as they pursue post-secondary computing education in various contexts. Using in-depth interviews, the current study employs qualitative methods and draws from an intersectional approach to focus on how the various barriers emerge for women in different types of computing cultures. In-depth interviews with…
ERIC Educational Resources Information Center
Ailshire, Jennifer A.; House, James S.
2011-01-01
The implications of recent weight gain trends for widening social disparities in body weight in the United States are unclear. Using an intersectional approach to studying inequality, and the longitudinal and nationally representative American's Changing Lives study (1986-2001/2002), we examine social disparities in body mass index trajectories…
Scanlon, John M; Sherony, Rini; Gabler, Hampton C
2016-09-01
Intersection crashes resulted in over 5,000 fatalities in the United States in 2014. Intersection Advanced Driver Assistance Systems (I-ADAS) are active safety systems that seek to help drivers safely traverse intersections. I-ADAS uses onboard sensors to detect oncoming vehicles and, in the event of an imminent crash, can either alert the driver or take autonomous evasive action. The objective of this study was to develop and evaluate a predictive model for detecting whether a stop sign violation was imminent. Passenger vehicle intersection approaches were extracted from a data set of typical driver behavior (100-Car Naturalistic Driving Study) and violations (event data recorders downloaded from real-world crashes) and were assigned weighting factors based on real-world frequency. A k-fold cross-validation procedure was then used to develop and evaluate 3 hypothetical stop sign warning algorithms (i.e., early, intermediate, and delayed) for detecting an impending violation during the intersection approach. Violation detection models were developed using logistic regression models that evaluate likelihood of a violation at various locations along the intersection approach. Two potential indicators of driver intent to stop-that is, required deceleration parameter (RDP) and brake application-were used to develop the predictive models. The earliest violation detection opportunity was then evaluated for each detection algorithm in order to (1) evaluate the violation detection accuracy and (2) compare braking demand versus maximum braking capabilities. A total of 38 violating and 658 nonviolating approaches were used in the analysis. All 3 algorithms were able to detect a violation at some point during the intersection approach. The early detection algorithm, as designed, was able to detect violations earlier than all other algorithms during the intersection approach but gave false alarms for 22.3% of approaches. In contrast, the delayed detection algorithm sacrificed some time for detecting violations but was able to substantially reduce false alarms to only 3.3% of all nonviolating approaches. Given good surface conditions (maximum braking capabilities = 0.8 g) and maximum effort, most drivers (55.3-71.1%) would be able to stop the vehicle regardless of the detection algorithm. However, given poor surface conditions (maximum braking capabilities = 0.4 g), few drivers (10.5-26.3%) would be able to stop the vehicle. Automatic emergency braking (AEB) would allow for early braking prior to driver reaction. If equipped with an AEB system, the results suggest that, even for the poor surface conditions scenario, over one half (55.3-65.8%) of the vehicles could have been stopped. This study demonstrates the potential of I-ADAS to incorporate a stop sign violation detection algorithm. Repeating the analysis on a larger, more extensive data set will allow for the development of a more comprehensive algorithm to further validate the findings.
Low-cost safety enhancements for stop-controlled and signalized intersections
DOT National Transportation Integrated Search
2009-05-01
The purpose of this document is to present information on suggested effective, low-cost intersection countermeasures developed using intersection safety research results and input from an intersection safety expert panel. These low-cost countermeasur...
Safety Evaluation of Destination Lighting at Stop-Controlled Cross Intersections
DOT National Transportation Integrated Search
2018-02-02
Unlit or inadequately lit intersections reduce the ability of drivers to recognize upcoming intersections during nighttime hours. Drivers also face difficulty in properly negotiating the intersection because lack of adequate lighting increases the li...
Guidelines for signal operations at intersections with wide medians.
DOT National Transportation Integrated Search
2010-03-01
The objective of this project is to evaluate the operations at signalized intersections with wide medians in : order to improve safety and efficiency. Intersections with wide medians are characterized by two : intersections and operate differently co...
NASA Astrophysics Data System (ADS)
LaViolette, Randall A.; Glass, Robert J.
2004-09-01
Under low flow conditions (where gravity and capillary forces dominate) within an unsaturated fracture network, fracture intersections act as capillary barriers to integrate flow from above and then release it as a pulse below. Water exiting a fracture intersection is often thought to enter the single connected fracture with the lowest invasion pressure. When the accumulated volume varies between intersections, the smaller volume intersections can be overloaded to cause all of the available fractures exiting an intersection to flow. We included the dynamic overloading process at fracture intersections within our previously discussed model where intersections were modeled as tipping buckets connected within a two-dimensional diamond lattice. With dynamic overloading, the flow behavior transitioned smoothly from diverging to converging flow with increasing overload parameter, as a consequence of a heterogeneous field, and they impose a dynamic structure where additional pathways activate or deactivate in time.
NASA Astrophysics Data System (ADS)
Jiang, Hang; Ma, Yongjian; Jiang, Lin; Chen, Guozhou; Wang, Dongwei
2018-05-01
At signalized intersection areas, bicycle traffic presents a dispersion feature which may influence the movements of vehicles during peak period. The primary objective of this study is to simulate the dispersion effect in through-movement bicycle traffic at intersection areas and evaluate its influence on through-movement traffic. A cellular automata (CA) model is developed and validated to simulate the operations of through-movement bicycle traffic departing from two types of intersection approaches. Simulation results show that bicycles benefit from the dispersion effect when they depart from the approach with an exclusive right-turn vehicle lane. But when bicycles travel from the approach with a shared right-turn and through vehicle lane, the dispersion effect will result in friction interference and block interference on through-movement vehicles. Bicycle interferences reduce the vehicle speed and increase the delay of through-movement vehicles. The policy implications in regard to the dispersion effect from two types of approaches are discussed to improve the performance of through-movement traffic operations at signalized intersections.
(En)gendering Racial Disparities in Health Trajectories: A Life Course and Intersectional Analysis.
Richardson, Liana J; Brown, Tyson H
2016-12-01
Historically, intersectionality has been an underutilized framework in sociological research on racial/ethnic and gender inequalities in health. To demonstrate its utility and importance, we conduct an intersectional analysis of the social stratification of health using the exemplar of hypertension-a health condition in which racial/ethnic and gender differences have been well-documented. Previous research has tended to examine these differences separately and ignore how the interaction of social status dimensions may influence health over time. Using seven waves of data from the Health and Retirement Study and multilevel logistic regression models, we found a multiplicative effect of race/ethnicity and gender on hypertension risk trajectories, consistent with both an intersectionality perspective and persistent inequality hypothesis. Group differences in past and contemporaneous socioeconomic and behavioral factors did not explain this effect.
Seedall, Ryan B; Holtrop, Kendal; Parra-Cardona, José Ruben
2014-04-01
In this study, we analyzed the amount of attention given to diversity, social justice, and an intersectional approach to social inequalities over an 8-year period (769 articles) in three family therapy journals. Overall, 28.1% of articles addressed at least one diversity issue, and a social justice framework was utilized in 48.1% of diversity articles. A systemic, intersectional approach to conceptualizing and analyzing multiple social inequalities was utilized in 17.6% of diversity articles. The most common goals addressed in diversity articles, articles using a social justice framework, and articles using an intersectional approach are also identified. Findings indicate that, despite important work being carried out, more work remains to further identify how addressing diversity issues can improve client outcomes. © 2013 American Association for Marriage and Family Therapy.
Effects of turning and through lane sharing on traffic performance at intersections
NASA Astrophysics Data System (ADS)
Li, Xiang; Sun, Jian-Qiao
2016-02-01
Turning vehicles strongly influence traffic flows at intersections. Effective regulation of turning vehicles is important to achieve better traffic performance. This paper studies the impact of lane sharing and turning signals on traffic performance at intersections by using cellular automata. Both right-turn and left-turn lane sharing are studied. Interactions between vehicles and pedestrians are considered. The transportation efficiency, road safety and energy economy are the traffic performance metrics. Extensive simulations are carried out to study the traffic performance indices. It is observed that shared turning lanes and permissive left-turn signal improve the transportation efficiency and reduce the fuel consumption in most cases, but the safety is usually sacrificed. It is not always beneficial for the through vehicles when they are allowed to be in the turning lanes.
Boysen, Guy; Ebersole, Ashley; Casner, Robert; Coston, Nykhala
2014-01-01
Research indicates that stereotypes can intersect. For example, the intersection of stereotypes about gender and mental disorders could result in perceptions of gendered mental disorders. In the current research, Studies 1 and 2 showed that people view specific disorders as being masculine or feminine. The masculine stereotype included antisocial personality disorder, addictions, and paraphilias. The feminine stereotype included eating disorders, histrionic personality disorder, body dysmorphia, and orgasmic disorder. In both studies, the perception of disorders as masculine was positively correlated with stigma. Study 3 showed that the positive correlation between masculinity and stigma also occurred when examining specific symptoms rather than full mental disorders. The findings provide further evidence for the intersection of stereotypes and indicate a novel factor in the understanding of stigma.
Design of a rotary for an uncontrolled multi-leg intersection in Chennai, India
NASA Astrophysics Data System (ADS)
Vasantha Kumar, S.; Gulati, Himanshu; Arora, Shivam
2017-11-01
One way to control the traffic at busy intersections is to construct a roundabout or rotary intersection, which is a special type of at-grade intersection, where all converging vehicles are forced to move round a central island in clock-wise direction. The present study aims to design a rotary for an uncontrolled multi leg intersection located in Royapetah in Chennai, India. The intersection has five approach roads with two-way traffic in all the approach roads and there is no signal or traffic police to control the traffic at present and hence experiences traffic chaos during peak hours. In order to design the rotary, it is essential to have the information on traffic volumes coming from the approach roads. For this, a video data collection was carried out for a duration of eight hours from 7.30 am to 11.30 am and from 2.30 pm to 6.30 pm on a typical working day using a handycam from the terrace of an apartment building located near the intersection. During data extraction stage, each 5 min. traffic volume was extracted for all the five classes of vehicles considered and were converted to passenger car units (PCU). The analysis of traffic data showed that during peak hour from 4.45 pm to 5.45 pm, the proportion of weaving traffic, i.e., ratio of sum of crossing streams to the total traffic on the weaving section was found to be 0.81. According to Indian road congress (IRC) guidelines, this proportion can take any value between 0.4 and 1 and in the present study, the calculated value is found to be within the prescribed range. Using the calculated values of average entry width of the rotary and width & length of weaving section, the practical capacity of the rotary was found to be 3020 PCUs which is well above the observed traffic volume of 2665 PCUs.
Seng, Julia S; Lopez, William D; Sperlich, Mickey; Hamama, Lydia; Meldrum, Caroline D Reed
2012-01-01
Intersectionality is a term used to describe the intersecting effects of race, class, gender, and other marginalizing characteristics that contribute to social identity and affect health. Adverse health effects are thought to occur via social processes including discrimination and structural inequalities (i.e., reduced opportunities for education and income). Although intersectionality has been well-described conceptually, approaches to modeling it in quantitative studies of health outcomes are still emerging. Strategies to date have focused on modeling demographic characteristics as proxies for structural inequality. Our objective was to extend these methodological efforts by modeling intersectionality across three levels: structural, contextual, and interpersonal, consistent with a social-ecological framework. We conducted a secondary analysis of a database that included two components of a widely used survey instrument, the Everyday Discrimination Scale. We operationalized a meso- or interpersonal-level of intersectionality using two variables, the frequency score of discrimination experiences and the sum of characteristics listed as reasons for these (i.e., the person’s race, ethnicity, gender, sexual orientation, nationality, religion, disability or pregnancy status, or physical appearance). We controlled for two structural inequality factors (low education, poverty) and three contextual factors (high crime neighborhood, racial minority status, and trauma exposures). The outcome variables we modeled were posttraumatic stress disorder symptoms and a quality of life index score. We used data from 619 women who completed the Everyday Discrimination Scale for a perinatal study in the U.S. state of Michigan. Statistical results indicated that the two interpersonal-level variables (i.e., number of marginalized identities, frequency of discrimination) explained 15% of variance in posttraumatic stress symptoms and 13% of variance in quality of life scores, improving the predictive value of the models over those using structural inequality and contextual factors alone. This study’s results point to instrument development ideas to improve the statistical modeling of intersectionality in health and social science research. PMID:23089613
Privileges and penalties in the legal profession: an intersectional analysis of career progression.
Tomlinson, Jennifer; Valizade, Danat; Muzio, Daniel; Charlwood, Andy; Aulakh, Sundeep
2018-04-26
Intersectionality theory is concerned with integrating social characteristics to better understanding complex human relations and inequalities in organizations and societies (McCall ). Recently, intersectionality research has taken a categorical and quantitative turn as scholars critically adopt but retain existing social categories to explain differences in labour market outcomes. A key contention is that social categories carry penalties or privileges and their intersection promotes or hinders the life chances of particular groups and individuals. An emergent debate is whether the intersection of disadvantaged characteristics (such as female gender or minority ethnic status) produce penalties that are additive, multiplicative or ameliorative. Research is inconclusive and as yet pays little attention to moderating factors such as employer type, size, geographic location or work profile. Drawing on administrative records for individuals qualified as solicitors in England and Wales, collected by the Solicitors Regulation Authority (SRA), combined with aggregated workforce data and firm characteristics of their law firms, we undertake a statistical analysis of the intersection of gender and ethnicity in the profession with a degree of precision and nuance not previously possible. In response to calls to broaden studies of inequalities and intersectionality beyond their effect on pay or income (Castilla ) we focus on career progression to partnership as our key measure of success. The original contribution of our study is twofold. First, we establish statistically different profiles of law firms, showing how the solicitors' profession is stratified by gender, ethnicity and socio-economic background, as well as the type of legal work undertaken by developing a model of socio-economic stratification in the profession. Second, we demonstrate that while penalties tend to be additive (i.e. the sum of the individual ethnic and gender penalties) this varies significantly by law firm profile and in some situations the effect is ameliorative. © London School of Economics and Political Science 2018.
Bell, Margaret Carol; Galatioto, Fabio; Giuffrè, Tullio; Tesoriere, Giovanni
2012-05-01
Building on previous research a conceptual framework, based on potential conflicts analysis, has provided a quantitative evaluation of 'proneness' to red-light running behaviour at urban signalised intersections of different geometric, flow and driver characteristics. The results provided evidence that commonly used violation rates could cause inappropriate evaluation of the extent of the red-light running phenomenon. Initially, an in-depth investigation of the functional form of the mathematical relationship between the potential and actual red-light runners was carried out. The application of the conceptual framework was tested on a signalised intersection in order to quantify the proneness to red-light running. For the particular junction studied proneness for daytime was found to be 0.17 north and 0.16 south for opposing main road approaches and 0.42 east and 0.59 west for the secondary approaches. Further investigations were carried out using a traffic microsimulation model, to explore those geometric features and traffic volumes (arrival patterns at the stop-line) that significantly affect red-light running. In this way the prediction capability of the proposed potential conflict model was improved. A degree of consistency in the measured and simulated red-light running was observed and the conceptual framework was tested through a sensitivity analysis applied to different stop-line positions and traffic volume variations. The microsimulation, although at its early stages of development, has shown promise in its ability to model unintentional red light running behaviour and following further work through application to other junctions, potentially provides a tool for evaluation of alternative junction designs on proneness. In brief, this paper proposes and applies a novel approach to model red-light running using a microsimulation and demonstrates consistency with the observed and theoretical results. Copyright © 2011 Elsevier Ltd. All rights reserved.
Macro-level safety analysis of pedestrian crashes in Shanghai, China.
Wang, Xuesong; Yang, Junguang; Lee, Chris; Ji, Zhuoran; You, Shikai
2016-11-01
Pedestrian safety has become one of the most important issues in the field of traffic safety. This study aims at investigating the association between pedestrian crash frequency and various predictor variables including roadway, socio-economic, and land-use features. The relationships were modeled using the data from 263 Traffic Analysis Zones (TAZs) within the urban area of Shanghai - the largest city in China. Since spatial correlation exists among the zonal-level data, Bayesian Conditional Autoregressive (CAR) models with seven different spatial weight features (i.e. (a) 0-1 first order, adjacency-based, (b) common boundary-length-based, (c) geometric centroid-distance-based, (d) crash-weighted centroid-distance-based, (e) land use type, adjacency-based, (f) land use intensity, adjacency-based, and (g) geometric centroid-distance-order) were developed to characterize the spatial correlations among TAZs. Model results indicated that the geometric centroid-distance-order spatial weight feature, which was introduced in macro-level safety analysis for the first time, outperformed all the other spatial weight features. Population was used as the surrogate for pedestrian exposure, and had a positive effect on pedestrian crashes. Other significant factors included length of major arterials, length of minor arterials, road density, average intersection spacing, percentage of 3-legged intersections, and area of TAZ. Pedestrian crashes were higher in TAZs with medium land use intensity than in TAZs with low and high land use intensity. Thus, higher priority should be given to TAZs with medium land use intensity to improve pedestrian safety. Overall, these findings can help transportation planners and managers understand the characteristics of pedestrian crashes and improve pedestrian safety. Copyright © 2016 Elsevier Ltd. All rights reserved.
Klems, Joseph P; Pennington, M Ross; Zordan, Christopher A; McFadden, Lauren; Johnston, Murray V
2011-07-01
High frequency spikes in ultrafine number concentration near a roadway intersection arise from motor vehicles that accelerate after a red light turns green. The present work describes a method to determine the contribution of motor vehicles to the total ambient ultrafine particle mass by correlating these number concentration spikes with fast changes in ultrafine particle chemical composition measured with the nano aerosol mass spectrometer, NAMS. Measurements were performed at an urban air quality monitoring site in Wilmington, Delaware during the summer and winter of 2009. Motor vehicles were found to contribute 48% of the ultrafine particle mass in the winter measurement period, but only 16% of the ultrafine particle mass in the summer period. Chemical composition profiles and contributions to the ultrafine particle mass of spark vs diesel vehicles were estimated by correlating still camera images, chemical composition and spike contribution at each time interval.. The spark and diesel contributions were roughly equal, but the uncertainty in the split was large. The distribution of emissions from individual vehicles was determined by correlating camera images with the spike contribution to particle number concentration at each time interval. A small percentage of motor vehicles were found to emit a disproportionally large concentration of ultrafine particles, and these high emitters included both spark ignition and diesel vehicles.
Intersectionality: An Arts-Based Approach to Student Awareness
ERIC Educational Resources Information Center
Edmonds, Leonard
2017-01-01
This study was designed to introduce specific activities/lessons to students in an online university gender and communication course. It was also designed to determine how participants made meaning of and felt about learning about intersectionality of gender and cultural identities, using arts-based data collection. Previous research on the…
DOT National Transportation Integrated Search
2001-11-01
A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is gener...
DOT National Transportation Integrated Search
2014-02-01
This report presents materials that can be used as the basis for a module on signalized intersections in the introductory : course in transportation engineering. The materials were developed based on studies of the work of students who took : this in...
Intersectional Identity Negotiation: The Case of Young Immigrant Children
ERIC Educational Resources Information Center
Compton-Lilly, Catherine; Papoi, Kristin; Venegas, Patricia; Hamman, Laura; Schwabenbauer, Briana
2017-01-01
We cast our lens on intersectional networks of identity negotiated by young children in immigrant families. Although some scholars discuss identity construction, we reference identity negotiation to capture the active, strategic, and agential work that we witnessed in our study. We begin by synthesizing relevant research on children's identity…
Ethnic, Gender and Class Intersections in British Women's Leadership Experiences
ERIC Educational Resources Information Center
Showunmi, Victoria; Atewologun, Doyin; Bebbington, Diane
2016-01-01
A qualitative study was conducted to examine how gender and ethnicity influenced leadership experiences of a mixed ethnic sample of British women. An intersectional framework was used which took the viewpoint that socio-demographic identities should be considered simultaneously in order to challenge universalist, gender and ethnic neutral…
DOT National Transportation Integrated Search
2016-12-21
The ability to accurately measure and cost-effectively collect traffic data at road intersections is needed to improve their safety and operations. This study investigates the feasibility of using laser ranging technology (LiDAR) for this purpose. Th...
Design and Evaluation of a Dynamic Dilemma Zone System for a High Speed Rural Intersection
DOT National Transportation Integrated Search
2012-08-01
The goal of this research was to develop a system that utilizes the dynamic detection technology and : to evaluate the performance of this system. The first step of this study was to select an intersection : experiencing a high frequency of crashes t...
DOT National Transportation Integrated Search
2013-11-01
Red light running has become a serious safety issue at signalized intersections throughout the : United States. One objective of this study was to identify the characteristics of red-light-running (RLR) : crashes and the drivers involved in those cra...
DOT National Transportation Integrated Search
2001-11-01
A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is gener...
Complicating Hetero-Femininities: Young Women, Sexualities and "Girl Power" at School
ERIC Educational Resources Information Center
Charles, Claire Elizabeth
2010-01-01
This paper is concerned with expanding knowledge of how femininity/sexuality intersections are constituted in secondary schools. Existing studies have drawn upon Judith Butler's notion of a "heterosexual matrix" in order to understand how intersections of femininity/sexuality are produced in schools through normative discourses of…
Six-Mile Corridor Economic Impact Study, Interstate 44 and Interstate 70 Corridor Summary
DOT National Transportation Integrated Search
2007-08-02
You've come a long way baby: Imagine an 89-percent drop in the number of accidents at your most dangerous intersections; a 100 percent decrease in the number of serious injuries at those same intersections, and 40- plus hours a year trimmed from the ...
Winchester, M S; BeLue, R; Oni, T; Wittwer-Backofen, U; Deobagkar, D; Onya, H; Samuels, T A; Matthews, S A; Stone, C; Airhihenbuwa, C
2016-04-21
In the current United Nations efforts to plan for post 2015-Millennium Development Goals, global partnership to address non-communicable diseases (NCDs) has become a critical goal to effectively respond to the complex global challenges of which inequity in health remains a persistent challenge. Building capacity in terms of well-equipped local researchers and service providers is a key to bridging the inequity in global health. Launched by Penn State University in 2014, the Pan University Network for Global Health responds to this need by bridging researchers at more than 10 universities across the globe. In this paper we outline our framework for international and interdisciplinary collaboration, as well the rationale for our research areas, including a review of these two themes. After its initial meeting, the network has established two central thematic priorities: 1) urbanization and health and 2) the intersection of infectious diseases and NCDs. The urban population in the global south will nearly double in 25 years (approx. 2 billion today to over 3.5 billion by 2040). Urban population growth will have a direct impact on global health, and this growth will be burdened with uneven development and the persistence of urban spatial inequality, including health disparities. The NCD burden, which includes conditions such as hypertension, stroke, and diabetes, is outstripping infectious disease in countries in the global south that are considered to be disproportionately burdened by infectious diseases. Addressing these two priorities demands an interdisciplinary and multi-institutional model to stimulate innovation and synergy that will influence the overall framing of research questions as well as the integration and coordination of research.
NASA Astrophysics Data System (ADS)
Borgie, Mireille; Ledoux, Frédéric; Dagher, Zeina; Verdin, Anthony; Cazier, Fabrice; Courcot, Lucie; Shirali, Pirouz; Greige-Gerges, Hélène; Courcot, Dominique
2016-11-01
Located on the eastern side of the Mediterranean Basin at the intersection of air masses circulating between three continents, the agglomeration of Beirut, capital of Lebanon is an important investigating area for air pollution and more studies are needed to elucidate the composition of the smallest particles classified as carcinogenic to humans. PM2.5-0.3 and PM0.3 samples were collected during the spring-summer period in an urban background site of Beirut, after a dust storm episode occurred, and their chemical composition was determined. Our findings showed that components formed by gas to particle conversion (SO42 - and NH4+) and related to combustion processes are mainly found in the PM0.3 fraction. Typical crustal (Ca2+, Fe, Ti, Mg2+), sea-salt (Na+, Cl-, Mg2+, Sr) species, and NO3- are mainly associated with the PM2.5-0.3 fraction. We have also evidenced that the dust episode which occurred in Lebanon in May 2011 originated from the Iraqian and Syrian deserts, which are the least studied, and had a direct influence on the composition of PM2.5-0.3 during the beginning of the first sampling period, and then an indirect and persistent influence by the re-suspension of deposited dust particles. Moreover, PAHs concentrations were much higher in PM0.3 than in PM2.5-0.3 and their composition appeared influenced by diesel (buses, trucks and generator sets) and gasoline (private cars) emissions.
Differential arrest and adhesion of tumor cells and microbeads in the microvasculature
Guo, Peng; Cai, Bin; Lei, Ming; Liu, Yang
2013-01-01
To investigate the mechanical mechanisms behind tumor cell arrest in the microvasculature, we injected fluorescently labeled human breast carcinoma cells or similarly sized rigid beads into the systemic circulation of a rat. Their arrest patterns in the microvasculature of mesentery were recorded and quantified. We found that 93% of rigid beads were arrested either at arteriole–capillary intersections or in capillaries. Only 3% were at the capillary–postcapillary venule intersections and in postcapillary venules. In contrast, most of the flexible tumor cells were either entrapped in capillaries or arrested at capillary or postcapillary venule–postcapillary venule intersections and in postcapillary venules. Only 12% of tumor cells were arrested at the arteriole–capillary intersections. The differential arrest and adhesion of tumor cells and microbeads in the microvasculature was confirmed by a χ2 test (p < 0.001). These results demonstrate that mechanical trapping was responsible for almost all the arrest of beads and half the arrest of tumor cells. Based on the measured geometry and blood flow velocities at the intersections, we also performed a numerical simulation using commercial software (ANSYS CFX 12.01) to depict the detailed distribution profiles of the velocity, shear rate, and vorticity at the intersections where tumor cells preferred to arrest and adhere. Simulation results reveal the presence of localized vorticity and shear rate regions at the turning points of the microvessel intersections, implying that hemodynamic factors play an important role in tumor cell arrest in the microcirculation. Our study helps elucidate long-debated issues related to the dominant factors in early-stage tumor hematogenous metastasis. PMID:23880911
Differential arrest and adhesion of tumor cells and microbeads in the microvasculature.
Guo, Peng; Cai, Bin; Lei, Ming; Liu, Yang; Fu, Bingmei M
2014-06-01
To investigate the mechanical mechanisms behind tumor cell arrest in the microvasculature, we injected fluorescently labeled human breast carcinoma cells or similarly sized rigid beads into the systemic circulation of a rat. Their arrest patterns in the microvasculature of mesentery were recorded and quantified. We found that 93% of rigid beads were arrested either at arteriole-capillary intersections or in capillaries. Only 3% were at the capillary-postcapillary venule intersections and in postcapillary venules. In contrast, most of the flexible tumor cells were either entrapped in capillaries or arrested at capillary or postcapillary venule-postcapillary venule intersections and in postcapillary venules. Only 12% of tumor cells were arrested at the arteriole-capillary intersections. The differential arrest and adhesion of tumor cells and microbeads in the microvasculature was confirmed by a χ(2) test (p < 0.001). These results demonstrate that mechanical trapping was responsible for almost all the arrest of beads and half the arrest of tumor cells. Based on the measured geometry and blood flow velocities at the intersections, we also performed a numerical simulation using commercial software (ANSYS CFX 12.01) to depict the detailed distribution profiles of the velocity, shear rate, and vorticity at the intersections where tumor cells preferred to arrest and adhere. Simulation results reveal the presence of localized vorticity and shear rate regions at the turning points of the microvessel intersections, implying that hemodynamic factors play an important role in tumor cell arrest in the microcirculation. Our study helps elucidate long-debated issues related to the dominant factors in early-stage tumor hematogenous metastasis.
McDonald, Catherine C; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas; Lee, Yi-Ching; Bonfiglio, Dana; Fisher, Donald L; Winston, Flaura K
Collisions at left turn intersections are among the most prevalent types of teen driver serious crashes, with inadequate surveillance as a key factor. Risk awareness perception training (RAPT) has shown effectiveness in improving hazard anticipation for latent hazards. The goal of this study was to determine if RAPT version 3 (RAPT-3) improved intersection turning behaviors among novice teen drivers when the hazards were not latent and frequent glancing to multiple locations at the intersection was needed. Teens aged 16-18 with ≤180 days of licensure were randomly assigned to: 1) an intervention group (n=18) that received RAPT-3 (Trained); or 2) a control group (n=19) that received no training (Untrained). Both groups completed RAPT-3 Baseline Assessment and the Trained group completed RAPT-3 Training and RAPT-3 Post Assessment. Training effects were evaluated on a driving simulator. Simulator ( gap selection errors and collisions ) and eye tracker ( traffic check errors) metrics from six left-turn stop sign controlled intersections in the Simulated Driving Assessment (SDA) were analyzed. The Trained group scored significantly higher in RAPT-3 Post Assessment than RAPT-3 Baseline Assessment (p< 0.0001). There were no significant differences in either traffic check and gap selection errors or collisions among Trained and Untrained teens in the SDA. Though Trained teens learned about hazard anticipation related to latent hazards, learning did not translate to performance differences in left-turn stop sign controlled intersections where the hazards were not latent. Our findings point to further research to better understand the challenges teens have with left turn intersections.
Physical activity in relation to urban environments in 14 cities worldwide: a cross-sectional study.
Sallis, James F; Cerin, Ester; Conway, Terry L; Adams, Marc A; Frank, Lawrence D; Pratt, Michael; Salvo, Deborah; Schipperijn, Jasper; Smith, Graham; Cain, Kelli L; Davey, Rachel; Kerr, Jacqueline; Lai, Poh-Chin; Mitáš, Josef; Reis, Rodrigo; Sarmiento, Olga L; Schofield, Grant; Troelsen, Jens; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Owen, Neville
2016-05-28
Physical inactivity is a global pandemic responsible for over 5 million deaths annually through its effects on multiple non-communicable diseases. We aimed to document how objectively measured attributes of the urban environment are related to objectively measured physical activity, in an international sample of adults. We based our analyses on the International Physical activity and Environment Network (IPEN) adult study, which was a coordinated, international, cross-sectional study. Participants were sampled from neighbourhoods with varied levels of walkability and socioeconomic status. The present analyses of data from the IPEN adult study included 6822 adults aged 18-66 years from 14 cities in ten countries on five continents. Indicators of walkability, public transport access, and park access were assessed in 1·0 km and 0·5 km street network buffers around each participant's residential address with geographic information systems. Mean daily minutes of moderate-to-vigorous-intensity physical activity were measured with 4-7 days of accelerometer monitoring. Associations between environmental attributes and physical activity were estimated using generalised additive mixed models with gamma variance and logarithmic link functions. Four of six environmental attributes were significantly, positively, and linearly related to physical activity in the single variable models: net residential density (exp[b] 1·006 [95% CI 1·003-1·009]; p=0·001), intersection density (1·069 [1·011-1·130]; p=0·019), public transport density (1·037 [1·018-1·056]; p=0·0007), and number of parks (1·146 [1·033-1·272]; p=0·010). Mixed land use and distance to nearest public transport point were not related to physical activity. The difference in physical activity between participants living in the most and least activity-friendly neighbourhoods ranged from 68 min/week to 89 min/week, which represents 45-59% of the 150 min/week recommended by guidelines. Design of urban environments has the potential to contribute substantially to physical activity. Similarity of findings across cities suggests the promise of engaging urban planning, transportation, and parks sectors in efforts to reduce the health burden of the global physical inactivity pandemic. Funding for coordination of the IPEN adult study, including the present analysis, was provided by the National Cancer Institute of National Institutes of Health (CA127296) with studies in each country funded by different sources. Copyright © 2016 Elsevier Ltd. All rights reserved.
DOT National Transportation Integrated Search
2000-09-01
Phase III of the Intersection Collision Avoidance Using ITS Countermeasures program developed testbed systems, implemented the systems on a vehicle, and performed testing to determine the potential effectiveness of this system in preventing intersect...
DOT National Transportation Integrated Search
2011-11-01
The intersection and mandatory movement lane control signs placed on intersection approaches are critical to : safe and efficient intersection operations. Ramp, frontage road, and cross-street approaches to interchanges : often widen at intersections...
Intersecting surface defects and instanton partition functions
Pan, Yiwen; Peelaers, Wolfger
2017-07-14
We analyze intersecting surface defects inserted in interacting four-dimensional N = 2 supersymmetric quantum field theories. We employ the realization of a class of such systems as the infrared xed points of renormalization group flows from larger theories, triggered by perturbed Seiberg-Witten monopole-like con gurations, to compute their partition functions. These results are cast into the form of a partition function of 4d/2d/0d coupled systems. In conclusion, our computations provide concrete expressions for the instanton partition function in the presence of intersecting defects and we study the corresponding ADHM model.
Viewing equitable practices through the lens of intersecting identities
NASA Astrophysics Data System (ADS)
Lyons, Renée; Dsouza, Nikeetha; Quigley, Cassie
2016-12-01
This review explores Archer, Dawson, Seakins, and Wong's "Disorienting, fun or meaningful? Disadvantaged families' experiences of a science museum visit" by examining the analytic frameworks guiding this study. To expand on Archer et al.'s use of feminist post-structuralist theories of identity we draw from the theory of intersectionality to provide a more robust framework for analyzing barriers to engagement within an informal learning space. Our response to this work ends by exploring the types of solutions generated from an intersectionality framework—solutions aimed at transforming institutional programs and practices to create more equitable spaces for learning.
Intersecting surface defects and instanton partition functions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pan, Yiwen; Peelaers, Wolfger
We analyze intersecting surface defects inserted in interacting four-dimensional N = 2 supersymmetric quantum field theories. We employ the realization of a class of such systems as the infrared xed points of renormalization group flows from larger theories, triggered by perturbed Seiberg-Witten monopole-like con gurations, to compute their partition functions. These results are cast into the form of a partition function of 4d/2d/0d coupled systems. In conclusion, our computations provide concrete expressions for the instanton partition function in the presence of intersecting defects and we study the corresponding ADHM model.
ERIC Educational Resources Information Center
Buchanan, Ian P.
2013-01-01
Using a critical race lens, this narrative study employs a focus group design to explore the intersections between black males, hip hop culture and schooling experiences. To provide a sociocultural grounding, this study first reviews the research literature around hip hop culture.s sociocultural development and its impact as a culture force that…
DOT National Transportation Integrated Search
2006-01-01
This project entailed the design, development, testing, and evaluation of intersection decision support (IDS) systems to address straight crossing path (SCP) intersection crashes. This type of intersection crash is responsible for more than 100,000 c...
Nahar, Papreen; Richters, Annemiek
2011-12-01
Research has documented that, around the world, women who are childless against their will suffer from an array of social, economic and emotional difficulties. The causes of this suffering are primarily related to their gender position in society and their gender identity. This paper addresses the impact of class differences on the gender-related suffering of childless women in the socially very hierarchically structured society of Bangladesh. The main method was gathering life histories of illiterate rural poor childless women and educated urban middle-class childless women. The rural childless women experience strong stigma in society, as their identity is devalued due to their inability to produce children. As a result, they suffer from feelings of guilt, role failure, loss of self-esteem, abandonment by the family, social isolation, and impoverishment. In contrast, because of their relatively high socio-economic status and good educational background, urban childless women have more opportunities to avail themselves of alternative social identities and thus avoid social isolation. Despite these differences, both groups of women lead frustrated lives, burdened with a deep sense of guilt for not being able to produce children.
Cities and regions in Britain through hierarchical percolation
NASA Astrophysics Data System (ADS)
Arcaute, Elsa; Molinero, Carlos; Hatna, Erez; Murcio, Roberto; Vargas-Ruiz, Camilo; Masucci, A. Paolo; Batty, Michael
2016-04-01
Urban systems present hierarchical structures at many different scales. These are observed as administrative regional delimitations which are the outcome of complex geographical, political and historical processes which leave almost indelible footprints on infrastructure such as the street network. In this work, we uncover a set of hierarchies in Britain at different scales using percolation theory on the street network and on its intersections which are the primary points of interaction and urban agglomeration. At the larger scales, the observed hierarchical structures can be interpreted as regional fractures of Britain, observed in various forms, from natural boundaries, such as National Parks, to regional divisions based on social class and wealth such as the well-known North-South divide. At smaller scales, cities are generated through recursive percolations on each of the emerging regional clusters. We examine the evolution of the morphology of the system as a whole, by measuring the fractal dimension of the clusters at each distance threshold in the percolation. We observe that this reaches a maximum plateau at a specific distance. The clusters defined at this distance threshold are in excellent correspondence with the boundaries of cities recovered from satellite images, and from previous methods using population density.
Sealing intersecting vane machines
Martin, Jedd N.; Chomyszak, Stephen M.
2005-06-07
The invention provides a toroidal intersecting vane machine incorporating intersecting rotors to form primary and secondary chambers whose porting configurations minimize friction and maximize efficiency. Specifically, it is an object of the invention to provide a toroidal intersecting vane machine that greatly reduces the frictional losses through intersecting surfaces without the need for external gearing by modifying the width of one or both tracks at the point of intermeshing. The inventions described herein relate to these improvements.
Sealing intersecting vane machines
Martin, Jedd N [Providence, RI; Chomyszak, Stephen M [Attleboro, MA
2007-06-05
The invention provides a toroidal intersecting vane machine incorporating intersecting rotors to form primary and secondary chambers whose porting configurations minimize friction and maximize efficiency. Specifically, it is an object of the invention to provide a toroidal intersecting vane machine that greatly reduces the frictional losses through intersecting surfaces without the need for external gearing by modifying the width of one or both tracks at the point of intermeshing. The inventions described herein relate to these improvements.
Justification of the Expediency of Creating Circular Intersections in Modern Cities
NASA Astrophysics Data System (ADS)
Vasilyeva, Elena; Sazonova, Tatiana
2017-10-01
The article resumes the principles of driving on Circular Intersections, which causes difficulties for some road users. Referring to certain foreign Traffic regulations, the author points out that such intersections are still stated imprecisely in Traffic regulations. Advantages and disadvantages of circular intersections as well as the expediency of their creation in the cities are considered in the article. The author offers to distinguish several types of circular intersections and claims that the most part of disadvantages listed in the article belong to circular intersections of the old type. On the contrary, the author presumes that creation of modern circular intersections will allow to regulate the planning of cities, make heavy traffic of transport possible while increasing the traffic safety at the same time, to improve the ecological situation of the city as well as its appearance, to carry out energy saving in the transport infrastructure of the city. All these aims could be feasible due to the creation of modern intersections of the Roundabout type.
Ethnic variation in gender-STEM stereotypes and STEM participation: an intersectional approach.
O'Brien, Laurie T; Blodorn, Alison; Adams, Glenn; Garcia, Donna M; Hammer, Elliott
2015-04-01
Stereotypes associating men and masculine traits with science, technology, engineering, and mathematics (STEM) fields are ubiquitous, but the relative strength of these stereotypes varies considerably across cultures. The present research applies an intersectional approach to understanding ethnic variation in gender-STEM stereotypes and STEM participation within an American university context. African American college women participated in STEM majors at higher rates than European American college women (Study 1, Study 2, and Study 4). Furthermore, African American women had weaker implicit gender-STEM stereotypes than European American women (Studies 2-4), and ethnic differences in implicit gender-STEM stereotypes partially mediated ethnic differences in STEM participation (Study 2 and Study 4). Although African American men had weaker implicit gender-STEM stereotypes than European American men (Study 4), ethnic differences between men in STEM participation were generally small (Study 1) or nonsignificant (Study 4). We discuss the implications of an intersectional approach for understanding the relationship between gender and STEM participation. (c) 2015 APA, all rights reserved).
Autonomous navigation of structured city roads
NASA Astrophysics Data System (ADS)
Aubert, Didier; Kluge, Karl C.; Thorpe, Chuck E.
1991-03-01
Autonomous road following is a domain which spans a range of complexity from poorly defined unmarked dirt roads to well defined well marked highly struc-. tured highways. The YARF system (for Yet Another Road Follower) is designed to operate in the middle of this range of complexity driving on urban streets. Our research program has focused on the use of feature- and situation-specific segmentation techniques driven by an explicit model of the appearance and geometry of the road features in the environment. We report results in robust detection of white and yellow painted stripes fitting a road model to detected feature locations to determine vehicle position and local road geometry and automatic location of road features in an initial image. We also describe our planned extensions to include intersection navigation.
NASA Astrophysics Data System (ADS)
Zaccheo, T. S.; Pernini, T.; Dobler, J. T.; Blume, N.; Braun, M.
2017-12-01
This work highlights the use of the greenhouse-gas laser imaging tomography experiment (GreenLITETM) data in conjunction with a sparse tomography approach to identify and quantify both urban and industrial sources of CO2 and CH4. The GreenLITETM system provides a user-defined set of time-sequenced intersecting chords or integrated column measurements at a fixed height through a quasi-horizontal plane of interest. This plane, with unobstructed views along the lines of sight, may range from complex industrial facilities to a small city scale or urban sector. The continuous time phased absorption measurements are converted to column concentrations and combined with a plume based model to estimate the 2-D distribution of gas concentration over extended areas ranging from 0.04-25 km2. Finally, these 2-D maps of concentration are combined with ancillary meteorological and atmospheric data to identify potential emission sources and provide first order estimates of their associated fluxes. In this presentation, we will provide a brief overview of the systems and results from both controlled release experiments and a long-term system deployment in Paris, FR. These results provide a quantitative assessment of the system's ability to detect and estimate CO2 and CH4 sources, and demonstrate its ability to perform long-term autonomous monitoring and quantification of either persistent or sporadic emissions that may have both health and safety as well as environmental impacts.
Thermal Analysis of the European XFEL Intersection Control Rack
NASA Astrophysics Data System (ADS)
Concha, P.; Vazquez, C.
2014-04-01
The three undulator segments of the European X-ray Free Electron Laser contain a total of 88 intersections cells. Each intersection accommodates a quadrupole magnet on top of a high precision X-Y positioning table, a beam position monitor, four air coil correctors and a phase shifter. The Intersection Control Rack is an electrical cabinet containing the necessary electronics to control both the quadrupole and the phase shifter movements (which are stepper motor based) with a repeatability of less than 1 um and 10 um, respectively. Four different cabinets have been extensively tested to ensure that they meet specifications. These tests include a thermal analysis to study position measurements dependence on the temperature. This paper introduces a description of the thermal issue, analyses the causes and consequences of heating, presents the results of the different tests performed, and concludes the best design and operating conditions to achieve a good performance.
On classical de Sitter and Minkowski solutions with intersecting branes
NASA Astrophysics Data System (ADS)
Andriot, David
2018-03-01
Motivated by the connection of string theory to cosmology or particle physics, we study solutions of type II supergravities having a four-dimensional de Sitter or Minkowski space-time, with intersecting D p -branes and orientifold O p -planes. Only few such solutions are known, and we aim at a better characterisation. Modulo a few restrictions, we prove that there exists no classical de Sitter solution for any combination of D 3/ O 3 and D 7/ O 7, while we derive interesting constraints for intersecting D 5/ O 5 or D 6/ O 6, or combinations of D 4/ O 4 and D 8/ O 8. Concerning classical Minkowski solutions, we understand some typical features, and propose a solution ansatz. Overall, a central information appears to be the way intersecting D p / O p overlap each other, a point we focus on.
Self-control of traffic lights and vehicle flows in urban road networks
NASA Astrophysics Data System (ADS)
Lämmer, Stefan; Helbing, Dirk
2008-04-01
Based on fluid-dynamic and many-particle (car-following) simulations of traffic flows in (urban) networks, we study the problem of coordinating incompatible traffic flows at intersections. Inspired by the observation of self-organized oscillations of pedestrian flows at bottlenecks, we propose a self-organization approach to traffic light control. The problem can be treated as a multi-agent problem with interactions between vehicles and traffic lights. Specifically, our approach assumes a priority-based control of traffic lights by the vehicle flows themselves, taking into account short-sighted anticipation of vehicle flows and platoons. The considered local interactions lead to emergent coordination patterns such as 'green waves' and achieve an efficient, decentralized traffic light control. While the proposed self-control adapts flexibly to local flow conditions and often leads to non-cyclical switching patterns with changing service sequences of different traffic flows, an almost periodic service may evolve under certain conditions and suggests the existence of a spontaneous synchronization of traffic lights despite the varying delays due to variable vehicle queues and travel times. The self-organized traffic light control is based on an optimization and a stabilization rule, each of which performs poorly at high utilizations of the road network, while their proper combination reaches a superior performance. The result is a considerable reduction not only in the average travel times, but also of their variation. Similar control approaches could be applied to the coordination of logistic and production processes.