Traffic monitoring and modeling for Intersection Safety

NARCIS (Netherlands)

Pyykönen, P.; Molinier, M.; Klunder, G.A.

2010-01-01

The INTERSAFE-2 project aims to develop and demonstrate a Cooperative Intersection Safety System that is able to significantly reduce injury and fatal accidents at intersections. The cooperative sensor data fusion is based on state-of-the-art and advanced on-board sensors for object recognition and

Contributory factors to traffic crashes at signalized intersections in Hong Kong.

Science.gov (United States)

Wong, S C; Sze, N N; Li, Y C

2007-11-01

Efficient geometric design and signal timing not only improve operational performance at signalized intersections by expanding capacity and reducing traffic delays, but also result in an appreciable reduction in traffic conflicts, and thus better road safety. Information on the incidence of crashes, traffic flow, geometric design, road environment, and traffic control at 262 signalized intersections in Hong Kong during 2002 and 2003 are incorporated into a crash prediction model. Poisson regression and negative binomial regression are used to quantify the influence of possible contributory factors on the incidence of killed and severe injury (KSI) crashes and slight injury crashes, respectively, while possible interventions by traffic flow are controlled. The results for the incidence of slight injury crashes reveal that the road environment, degree of curvature, and presence of tram stops are significant factors, and that traffic volume has a diminishing effect on the crash risk. The presence of tram stops, number of pedestrian streams, road environment, proportion of commercial vehicles, average lane width, and degree of curvature increase the risk of KSI crashes, but the effect of traffic volume is negligible.

Traffic Safety of Older Drivers in Various Types of Road Intersections

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Tomaž Tollazzi

2010-05-01

Full Text Available In industrialized countries people over 50 years of age represent a rapidly growing part of population. Their lifestyle is also becoming more active, which means that the percentage of older drivers in the population of all drivers is also increasing. Many different studies have shown that elderly drivers are more frequently involved in specific types of accidents, especially at intersections. In the past 15 years there was a trend of increasing popularity of roundabouts in Slovenia. Their introduction was generally supported by the arguments of increased traffic-flow capacity and traffic safety as well. The studies on which these arguments are based were performed with an “ideal” type of driver in mind; the one that fully understands new rules and reacts correctly in all situations that may occur at such intersections, where there are no light signals to guide them. An elderly person does not necessarily conform to that ideal and if the percentage of elderly drivers became significant, the premises of the above mentioned studies may not be correct anymore which in turn implies that their results could also be questioned. The present study concentrated on the evaluation of traffic safety of elderly drivers, at various types of intersection, from their own perspective. Various statistical analyses of obtained data were performed. The most important finding was that we may claim, with high degree of probability, that the average person of the age of over 60 feels more unsafe at double-lane roundabouts than they would feel had the same intersection been equipped with traffic lights. Elderly traffic participants will always cause more accidents or participate in them due to hazardous factors. Challenge, arising from many different studies and researches, is in studying what measures and solutions can reduce the risk for elderly participants. KEYWORDS: traffic safety, road intersections, roundabouts, elderly people, older drivers

Signal treatments to reduce heavy vehicle crash-risk at metropolitan highway intersections.

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Archer, Jeffery; Young, William

2009-05-01

Heavy vehicle red-light running at intersections is a common safety problem that has severe consequences. This paper investigates alternative signal treatments that address this issue. A micro-simulation analysis approach was adopted as a precursor to a field trial. The simulation model emulated traffic conditions at a known problem intersection and provided a baseline measure to compare the effects of: an extension of amber time; an extension of green for heavy vehicles detected in the dilemma zone at the onset of amber; an extension of the all-red safety-clearance time based on the detection of vehicles considered likely to run the red light at two detector locations during amber; an extension of the all-red safety-clearance time based on the detection of potential red-light runners during amber or red; and a combination of the second and fourth alternatives. Results suggested safety improvements for all treatments. An extension of amber provided the best safety effect but is known to be prone to behavioural adaptation effects and wastes traffic movement time unnecessarily. A green extension for heavy vehicles detected in the dilemma zone and an all-red extension for potential red-light runners were deemed to provide a sustainable safety improvement and operational efficiency.

Statistical modeling of total crash frequency at highway intersections

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Arash M. Roshandeh

2016-04-01

Full Text Available Intersection-related crashes are associated with high proportion of accidents involving drivers, occupants, pedestrians, and cyclists. In general, the purpose of intersection safety analysis is to determine the impact of safety-related variables on pedestrians, cyclists and vehicles, so as to facilitate the design of effective and efficient countermeasure strategies to improve safety at intersections. This study investigates the effects of traffic, environmental, intersection geometric and pavement-related characteristics on total crash frequencies at intersections. A random-parameter Poisson model was used with crash data from 357 signalized intersections in Chicago from 2004 to 2010. The results indicate that out of the identified factors, evening peak period traffic volume, pavement condition, and unlighted intersections have the greatest effects on crash frequencies. Overall, the results seek to suggest that, in order to improve effective highway-related safety countermeasures at intersections, significant attention must be focused on ensuring that pavements are adequately maintained and intersections should be well lighted. It needs to be mentioned that, projects could be implemented at and around the study intersections during the study period (7 years, which could affect the crash frequency over the time. This is an important variable which could be a part of the future studies to investigate the impacts of safety-related works at intersections and their marginal effects on crash frequency at signalized intersections.

Rural expressway intersection safety toolbox : desktop reference.

Science.gov (United States)

2011-06-01

This document is intended to be a guide for planning-level decisions concerning safety : issues and subsequent potential improvements at rural expressway intersections. It is : NOT a design guide. It simply presents the gamut of safety treatment opti...

Comparison of proposed countermeasures for dilemma zone at signalized intersections based on cellular automata simulations.

Science.gov (United States)

Wu, Yina; Abdel-Aty, Mohamed; Ding, Yaoxian; Jia, Bin; Shi, Qi; Yan, Xuedong

2018-07-01

The Type II dilemma zone describes the road segment to a signalized intersection where drivers have difficulties to decide either stop or go at the onset of yellow signal. Such phenomenon can result in an increased crash risk at signalized intersections. Different types of warning systems have been proposed to help drivers make decisions. Although the warning systems help to improve drivers' behavior, they also have several disadvantages such as increasing rear-end crashes or red-light running (RLR) violations. In this study, a new warning system called pavement marking with auxiliary countermeasure (PMAIC) is proposed to reduce the dilemma zone and enhance the traffic safety at signalized intersections. The proposed warning system integrates the pavement marking and flashing yellow system which can provide drivers with better suggestions about stop/go decisions based on their arriving time and speed. In order to evaluate the performance of the proposed warning system, this paper presents a cellular automata (CA) simulation study. The CA simulations are conducted for four different scenarios in total, including the typical intersection without warning system, the intersection with flashing green countermeasure, the intersection with pavement marking, and the intersection with the PMAIC warning system. Before the specific CA simulation analysis, a logistic regression model is calibrated based on field video data to predict drivers' general stop/go decisions. Also, the rules of vehicle movements in the CA models under the influence by different warning systems are proposed. The proxy indicators of rear-end crash and potential RLR violations were estimated and used to evaluate safety levels for the different scenarios. The simulation results showed that the PMAIC countermeasure consistently offered best performance to reduce rear-end crash and RLR violation. Meanwhile, the results indicate that the flashing-green countermeasure could not effectively reduce either rear

Modeling Left-Turn Driving Behavior at Signalized Intersections with Mixed Traffic Conditions

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Hong Li

2016-01-01

Full Text Available In many developing countries, mixed traffic is the most common type of urban transportation; traffic of this type faces many major problems in traffic engineering, such as conflicts, inefficiency, and security issues. This paper focuses on the traffic engineering concerns on the driving behavior of left-turning vehicles caused by different degrees of pedestrian violations. The traffic characteristics of left-turning vehicles and pedestrians in the affected region at a signalized intersection were analyzed and a cellular-automata-based “following-conflict” driving behavior model that mainly addresses four basic behavior modes was proposed to study the conflict and behavior mechanisms of left-turning vehicles by mathematic methodologies. Four basic driving behavior modes were reproduced in computer simulations, and a logit model of the behavior mode choice was also developed to analyze the relative share of each behavior mode. Finally, the microscopic characteristics of driving behaviors and the macroscopic parameters of traffic flow in the affected region were all determined. These data are important reference for geometry and capacity design for signalized intersections. The simulation results show that the proposed models are valid and can be used to represent the behavior of left-turning vehicles in the case of conflicts with illegally crossing pedestrians. These results will have potential applications on improving traffic safety and traffic capacity at signalized intersections with mixed traffic conditions.

Assessment at Al-Ameer signalized intersection in Samawa city

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Joni Hasan

2018-01-01

Full Text Available The aim of this paper is to evaluate traffic performance of Al-Ameer signalized intersection in Samawa city, which fits with the prevailing conditions and geometric properties of the intersection. The technique of video recording has used for collection the traffic volume data for all approaches. These data are abstracted from video films. SYNCHRO 8 software was used to evaluate and analyze the intersection and choose the best suggestion. The evaluation process result showed that the intersection is operated with level of service (LOS F. By suggestion of several strategies which vary from signal optimization to geometric improvements. The best solution has been found by suggestion an overpass at the east-west direction, and the level of service has improved from (LOS F to (LOS C, this result is considered an acceptable and economical solution for the existing problems at intersection.

Driving Simulator study for intelligent cooperative intersection safety system (IRIS)

NARCIS (Netherlands)

Vreeswijk, J.; Schendzielorz, T.; Mathias, P.; Feenstra, P.

2008-01-01

About forty percent of all accidents occur at intersections. The Intelligent Cooperative Intersection Safety system (IRIS), as part of the European research project SAFESPOT, is a roadside application and aims at minimizing the number of accidents at controlled and uncontrolled intersections. IRIS

Intersection signal control multi-objective optimization based on genetic algorithm

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Zhanhong Zhou

2014-04-01

Full Text Available A signal control intersection increases not only vehicle delay, but also vehicle emissions and fuel consumption in that area. Because more and more fuel and air pollution problems arise recently, an intersection signal control optimization method which aims at reducing vehicle emissions, fuel consumption and vehicle delay is required heavily. This paper proposed a signal control multi-object optimization method to reduce vehicle emissions, fuel consumption and vehicle delay simultaneously at an intersection. The optimization method combined the Paramics microscopic traffic simulation software, Comprehensive Modal Emissions Model (CMEM, and genetic algorithm. An intersection in Haizhu District, Guangzhou, was taken for a case study. The result of the case study shows the optimal timing scheme obtained from this method is better than the Webster timing scheme.

Signal Timing Optimization Based on Fuzzy Compromise Programming for Isolated Signalized Intersection

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Dexin Yu

2016-01-01

Full Text Available In order to optimize the signal timing for isolated intersection, a new method based on fuzzy programming approach is proposed in this paper. Considering the whole operation efficiency of the intersection comprehensively, traffic capacity, vehicle cycle delay, cycle stops, and exhaust emission are chosen as optimization goals to establish a multiobjective function first. Then fuzzy compromise programming approach is employed to give different weight coefficients to various optimization objectives for different traffic flow ratios states. And then the multiobjective function is converted to a single objective function. By using genetic algorithm, the optimized signal cycle and effective green time can be obtained. Finally, the performance of the traditional method and new method proposed in this paper is compared and analyzed through VISSIM software. It can be concluded that the signal timing optimized in this paper can effectively reduce vehicle delays and stops, which can improve traffic capacity of the intersection as well.

Characteristics of turn signal use at intersections in baseline naturalistic driving.

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Sullivan, John M; Bao, Shan; Goudy, Roy; Konet, Heather

2015-01-01

The purpose of this study was to determine whether a driver's use of turn signals is sufficiently reliable to forecast a vehicle's future path around an intersection, when detailed information about the intersection is unavailable. Naturalistic observations of turn signal use among 108 drivers on surface streets were extracted from the baseline portion of a field operational test of a safety system. Left and right turns that resulted in heading changes of between 70 and 110° and turn radii between 18 and 90 m were selected from the dataset. The odds that a driver would signal a turn were modeled as a function of road type, turn direction, presence of a forward vehicle, whether the vehicle stopped before the turn, and driver age and gender. Overall, 25 percent of left turns and 29 percent of right turns were not signaled. Road type, turn direction, and presence of a forward vehicle were found to influence the odds that a turn is signaled, while gender and age of the driver did not. The results suggest that situational factors like road type and turn direction are more powerful predictors of whether a turn will be signaled than either age or gender. Signaling on major and minor surface roads was about 5 times more likely than on local roads and 1.5 times more likely when a forward vehicle was present, suggesting a possible effect of traffic volume. It was concluded that turn signal activation alone may be insufficiently reliable to forecast a driver's path. Copyright © 2014 Elsevier Ltd. All rights reserved.

Micro-simulation of vehicle conflicts involving right-turn vehicles at signalized intersections based on cellular automata.

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Chai, C; Wong, Y D

2014-02-01

At intersection, vehicles coming from different directions conflict with each other. Improper geometric design and signal settings at signalized intersection will increase occurrence of conflicts between road users and results in a reduction of the safety level. This study established a cellular automata (CA) model to simulate vehicular interactions involving right-turn vehicles (as similar to left-turn vehicles in US). Through various simulation scenarios for four case cross-intersections, the relationships between conflict occurrences involving right-turn vehicles with traffic volume and right-turn movement control strategies are analyzed. Impacts of traffic volume, permissive right-turn compared to red-amber-green (RAG) arrow, shared straight-through and right-turn lane as well as signal setting are estimated from simulation results. The simulation model is found to be able to provide reasonable assessment of conflicts through comparison of existed simulation approach and observed accidents. Through the proposed approach, prediction models for occurrences and severity of vehicle conflicts can be developed for various geometric layouts and traffic control strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Traffic design and signal timing of staggered intersections based on a sorting strategy

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Zhengyi Cai

2016-04-01

Full Text Available A staggered intersection is a special type of intersection in a road network. Its geographical characteristics consist of two T-legged intersections that cause the lost time per cycle to become longer than at cross intersections under conventional signal control, thus leading to low intersection efficiency. This article shows that the problem can be eliminated at the left–right type of staggered intersection by channelization and signal phasing, based on a sorting strategy and pre-signal, which reduce the amount of lost time during the signal cycle using the split distance as the sorting area. VISSIM was used to model and analyze the proposed method as well as the conventional method for comparison purposes. The simulation revealed that the proposed method reduced the average delays and maximum queue lengths in each movement and for the entire intersection, both in the peak hours and in the off-peak hour.

Intersection signal control multi-objective optimization based on genetic algorithm

OpenAIRE

Zhanhong Zhou; Ming Cai

2014-01-01

A signal control intersection increases not only vehicle delay, but also vehicle emissions and fuel consumption in that area. Because more and more fuel and air pollution problems arise recently, an intersection signal control optimization method which aims at reducing vehicle emissions, fuel consumption and vehicle delay is required heavily. This paper proposed a signal control multi-object optimization method to reduce vehicle emissions, fuel consumption and vehicle delay simultaneously at ...

Empirical Analysis and Modeling of Stop-Line Crossing Time and Speed at Signalized Intersections

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Keshuang Tang

2016-12-01

Full Text Available In China, a flashing green (FG indication of 3 s followed by a yellow (Y indication of 3 s is commonly applied to end the green phase at signalized intersections. Stop-line crossing behavior of drivers during such a phase transition period significantly influences safety performance of signalized intersections. The objective of this study is thus to empirically analyze and model drivers’ stop-line crossing time and speed in response to the specific phase transition period of FG and Y. High-resolution trajectories for 1465 vehicles were collected at three rural high-speed intersections with a speed limit of 80 km/h and two urban intersections with a speed limit of 50 km/h in Shanghai. With the vehicle trajectory data, statistical analyses were performed to look into the general characteristics of stop-line crossing time and speed at the two types of intersections. A multinomial logit model and a multiple linear regression model were then developed to predict the stop-line crossing patterns and speeds respectively. It was found that the percentage of stop-line crossings during the Y interval is remarkably higher and the stop-line crossing time is approximately 0.7 s longer at the urban intersections, as compared with the rural intersections. In addition, approaching speed and distance to the stop-line at the onset of FG as well as area type significantly affect the percentages of stop-line crossings during the FG and Y intervals. Vehicle type and stop-line crossing pattern were found to significantly influence the stop-line crossing speed, in addition to the above factors. The red-light-running seems to occur more frequently at the large intersections with a long cycle length.

A speed guidance strategy for multiple signalized intersections based on car-following model

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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.

Research on the Method of Setting Waiting Area for Non-motor Vehicle at Signal Control Intersection

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Wang Yun Xia

2018-01-01

Full Text Available Electric bicycle has become an indispensable important component of the transportation system. The fact is that traffic organization and channelizing design of signal control intersection is not intensive, which cannot adapt to the current traffic demand of non-motor vehicle, such as unclear traffic rules and poor visibility, thus the traffic safety of non-motor vehicle is not optimistic. Therefore, it is necessary to study on traffic organization method based on the demand of non-motor vehicle, which can provide certain theoretical basis for traffic administrative department to make policy and traffic design. This article focuses on the method of setting waiting area for non-motor vehicle at signal control intersection, including the advantages, disadvantages and the applicable conditions.

Safety effectiveness of pavement design treatment at intersections: Left turning vehicles and pedestrians on crosswalks

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Hasina Iasmin

2016-07-01

Full Text Available Pedestrians are the most vulnerable road users as they are more exposed than other road users. Pedestrian safety at road intersections still remains the most vital and yet unsolved issue. One of the critical points in pedestrian safety is the occurrence of accidents between left-turning vehicle and pedestrians on crosswalks at signalized intersections. A crosswalk is a place designated for pedestrians and cyclists to cross vehicular roads safely. Drivers are expected to give priority to pedestrians or cyclists during interactions between them on the crosswalk. If a driver exhibits non-yielding behavior, the interaction will turn into a collision. This study examined the safety effect of three crosswalks designed with different materials such as red-colored material or brick pavement based on a safety performance study. The safety performance study considered left-turning driver's gap acceptance behavior and the severity of traffic conflict events between left-turning vehicles and pedestrians. The results of the study indicates that using brick pavement on a crosswalk increases the safety level of the crosswalk. Drivers at such crosswalks are more acquiescent to the priority rule.

Influential factors of red-light running at signalized intersection and prediction using a rare events logistic regression model.

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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.

Differences in passenger car and large truck involved crash frequencies at urban signalized intersections: an exploratory analysis.

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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.

Modeling traffic accidents at signalized intersections in the city of Norfolk, VA.

Science.gov (United States)

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...

The Research of Vehicle Acceleration at Signalized Intersections

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Vuk Bogdanović

2013-02-01

Full Text Available Vehicle acceleration is an important parameter used in planning various road elements, traffic signalization, geometric elements of an intersection, signal plans of traffic lights, etc. The knowledge of vehicle acceleration values is also necessary in using simulation softwares for more accurate analysis of the total situation at an intersection, on a road section or in a traffic network. In a lot of earlier studies, acceleration values were analysed and defined, mostly in optimal conditions for traffic functioning. However, values of almost all traffic flow parameters have been changed over time, due to changes in driving-dynamic vehicle characteristics, pneumatic tyres, material used for building road surface, etc. Besides, local environment influence and changes in drivers’ behaviour also significantly affect values of this parameter. According to HCM, it is advisable to perform local research for all values of the parameters recommended within the framework of this handbook, and to adapt their values to local conditions as well. The results of measuring the values of vehicles acceleration at signalized intersections in Novi Sad, Serbia, have been shown in this paper, using the procedure based on video recording processing.

Pedestrian Safety Treatments for Signalized Intersections : Training Course Development

Science.gov (United States)

2017-11-01

When drivers make left turns during a permissive turn phase, they must yield to pedestrians as well as oncoming through vehicles. Left-turning drivers sometimes overlook pedestrians in the crosswalk while watching the opposing intersection approach. ...

MOTORCYCLE CRASH PREDICTION MODEL FOR NON-SIGNALIZED INTERSECTIONS

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S. HARNEN

2003-01-01

Full Text Available This paper attempts to develop a prediction model for motorcycle crashes at non-signalized intersections on urban roads in Malaysia. The Generalized Linear Modeling approach was used to develop the model. The final model revealed that an increase in motorcycle and non-motorcycle flows entering an intersection is associated with an increase in motorcycle crashes. Non-motorcycle flow on major road had the greatest effect on the probability of motorcycle crashes. Approach speed, lane width, number of lanes, shoulder width and land use were also found to be significant in explaining motorcycle crashes. The model should assist traffic engineers to decide the need for appropriate intersection treatment that specifically designed for non-exclusive motorcycle lane facilities.

An Adaptive Model for Calculating the Correlation Degree of Multiple Adjacent Signalized Intersections

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Linhong Wang

2013-01-01

Full Text Available As an important component of the urban adaptive traffic control system, subarea partition algorithm divides the road network into some small subareas and then determines the optimal signal control mode for each signalized intersection. Correlation model is the core of subarea partition algorithm because it can quantify the correlation degree of adjacent signalized intersections and decides whether these intersections can be grouped into one subarea. In most cases, there are more than two intersections in one subarea. However, current researches only focus on the correlation model for two adjacent intersections. The objective of this study is to develop a model which can calculate the correlation degree of multiple intersections adaptively. The cycle lengths, link lengths, number of intersections, and path flow between upstream and downstream coordinated phases were selected as the contributing factors of the correlation model. Their jointly impacts on the performance of the coordinated control mode relative to the isolated control mode were further studied using numerical experiments. The paper then proposed a correlation index (CI as an alternative to relative performance. The relationship between CI and the four contributing factors was established in order to predict the correlation, which determined whether adjacent intersections could be partitioned into one subarea. A value of 0 was set as the threshold of CI. If CI was larger than 0, multiple intersections could be partitioned into one subarea; otherwise, they should be separated. Finally, case studies were conducted in a real-life signalized network to evaluate the performance of the model. The results show that the CI simulates the relative performance well and could be a reliable index for subarea partition.

Intelligent Agent Based Traffic Signal Control on Isolated Intersections

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Daniela Koltovska

2014-08-01

Full Text Available The purpose of this paper is to develop an adaptive signal control strategy on isolated urban intersections. An innovative approach to defining the set of states dependent on the actual and primarily observed parameters has been introduced. ?he Q–learning algorithm has been applied. The developed self-learning adaptive signal strategy has been tested on a re?l intersection. The intelligent agent results have been compared to those in cases of fixed-time and actuated control. Regarding the average total delay, the total number of stops and the total throughput, the best results have been obtained for unknown traffic demand and over-capacity.

Street Intersection Characteristics and Their Impacts on Perceived Bicycling Safety

Science.gov (United States)

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 driver cognitive failures and driving errors on right-turn filtering movement at signalized road intersections based on Fuzzy Cellular Automata (FCA) model.

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Chai, Chen; Wong, Yiik Diew; Wang, Xuesong

2017-07-01

This paper proposes a simulation-based approach to estimate safety impact of driver cognitive failures and driving errors. Fuzzy Logic, which involves linguistic terms and uncertainty, is incorporated with Cellular Automata model to simulate decision-making process of right-turn filtering movement at signalized intersections. Simulation experiments are conducted to estimate the relationships between cognitive failures and driving errors with safety performance. Simulation results show Different types of cognitive failures are found to have varied relationship with driving errors and safety performance. For right-turn filtering movement, cognitive failures are more likely to result in driving errors with denser conflicting traffic stream. Moreover, different driving errors are found to have different safety impacts. The study serves to provide a novel approach to linguistically assess cognitions and replicate decision-making procedures of the individual driver. Compare to crash analysis, the proposed FCA model allows quantitative estimation of particular cognitive failures, and the impact of cognitions on driving errors and safety performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Safety effects of traffic signing for left turn flashing yellow arrow signals.

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Schattler, Kerrie L; Gulla, Cody J; Wallenfang, Travis J; Burdett, Beau A; Lund, Jessica A

2015-02-01

In 2010, the left turn flashing yellow arrow (FYA) signal displays were installed at signalized intersections on state routes in the Peoria, Illinois, area. Supplemental traffic signs with text "Left Turn Yield on Flashing Yellow Arrow" were mounted on the mast arm adjacent to the left turn signal at over half of the FYA installations. The purpose of this paper is to present the results of the effectiveness evaluation of the FYA supplemental sign on safety. Analyses are presented on the effects of the FYA supplemental sign for all drivers and a subset of drivers age 65 and older. A crash-based comparison of 164 FYA approaches including 90 approaches with the sign and 74 approaches without the sign showed greater crash reductions when the supplemental FYA sign was present. The results also showed that crashes involving drivers age 65 and older did not experience the same magnitudes of crash reductions as compared to all drivers. The findings of this research indicate that supplemental FYA signs may help in improving safety for left-turning vehicles during the permissive interval. Thus, it is recommended that supplemental signs be used when initially implementing the FYA, and that effort to educate the driving public on new traffic control be made to further improve safety at signalized intersections. Copyright © 2014. Published by Elsevier Ltd.

Evaluating the Impacts of Red Light Camera Deployment on Intersection Traffic Safety

Science.gov (United States)

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...

Analysis of Crossing Speed of the Pedestrians in Marked and Unmarked Crosswalks in the Signalized and Un-Signalized Intersections (Case Study: Rasht city)

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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.

Vehicle speed guidance strategy at signalized intersection based on cooperative vehicle infrastructure system

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Fengyuan JIA

2017-10-01

Full Text Available In order to reduce stopping time of vehicle at a signalized intersection, aiming at the difficulty, even the impossibility to obtain real-time queue length of intersection in third and fourth-tier cities in China sometimes, a speed guidance strategy based on cooperative vehicle infrastructure system is put forward and studied. For validating the strategy, the traffic signal timing data of the intersection at Hengshan Road and North Fengming Lake Road in Wuhu is collected by a vehicular traffic signal reminder system which is designed. The simulation experiments using the acquired data are done by software VISSIM. The simulation results demonstrate that the strategy under high and low traffic flow can effectively decrease the link travel-time, reducing average ratio is 9.2 % and 13.0 %, respectively, and the effect under low traffic flow is better than that under high traffic flow. The strategy improves efficiency of traffic at a signalized intersection and provides an idea for the application of vehicle speed guidance based on cooperative vehicle infrastructure system.

Delays at signalized intersections with exhaustive traffic control

NARCIS (Netherlands)

Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

2012-01-01

In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions.

EVALUATING THE CONTRIBUTION OF PHYSICAL PARAMETERS ON THE SAFETY OF UNSIGNALIZED INTERSECTIONS

Directory of Open Access Journals (Sweden)

A. AHMED

2015-05-01

Full Text Available Safety of any particular Road way facility cannot be attributed to set of parameters specific to a certain domain. Unsignalized intersections are no exceptions, thus, making them an important area of study. This paper presents the results of the analysis of four parameters, namely road width, traffic control, lane marking and landuse; and their sub-class on the safety of unsignalized intersections. The raw accident data was obtained from MIROS (Malaysian Institute of Road Safety Research. It was then reduced for descriptive analysis. Hypothesis testing was performed to assess the significance of all parameters and severity analysis was done to accomplish micro scale examination of each sub-class. The results show that landuse and lane marking are statistically significant. They are important variables to predict accidents whereas traffic control and road width are not significant. Intersections located in city with single line lane marking having no control and major road width greater than 9 meters were found to have the highest severity indices.

A new traffic control design method for large networks with signalized intersections

Science.gov (United States)

Leininger, G. G.; Colony, D. C.; Seldner, K.

1979-01-01

The paper presents a traffic control design technique for application to large traffic networks with signalized intersections. It is shown that the design method adopts a macroscopic viewpoint to establish a new traffic modelling procedure in which vehicle platoons are subdivided into main stream queues and turning queues. Optimization of the signal splits minimizes queue lengths in the steady state condition and improves traffic flow conditions, from the viewpoint of the traveling public. Finally, an application of the design method to a traffic network with thirty-three signalized intersections is used to demonstrate the effectiveness of the proposed technique.

Determination of safety specifications as for criticality in pipelines systems with intersection

International Nuclear Information System (INIS)

Santos, R. dos; Vellozo, S.O.

1982-01-01

By the Monte Carlo method, criticality calculations were done for pipelines with several types of reflexion and configurations, filled with solution of plutonium nitrate, with 100 per cent of weight of Pu-239 isotope, in water. From the more simple pipeline intersection condition, type T, an intersection type cross and Double cross are studied. A second central column is aded. The intersections are studied in the minimal, nominal and maximal reflexion condition. Critical safety values are presented for some systems. (E.G.) [pt

Delay-based Passenger Car Equivalent at Signalized Intersections in Iran

Directory of Open Access Journals (Sweden)

Habibollah Nassiri

2017-04-01

Full Text Available Due to their different sizes and operational characteristics, vehicles other than passenger cars have a different influence on traffic operations especially at intersections. The passenger car equivalent (PCE is the parameter that shows how many passenger cars must be substituted for a specific heavy vehicle to represent its influence on traffic operation. PCE is commonly estimated using headway-based methods that consider the excess headway utilized by heavy vehicles. In this research, the PCE was estimated based on the delay parameter at three signalized intersections in Tehran, Iran. The data collected were traffic volume, travel time for each movement, signalization, and geometric design information. These data were analysed and three different models, one for each intersection, were constructed and calibrated using TRAF-NETSIM simulation software for unsaturated traffic conditions. PCE was estimated under different scenarios and the number of approach movements at each intersection. The results showed that for approaches with only one movement, PCE varies from 1.1 to 1.65. Similarly, for approaches with two and three movements, the PCE varies from 1.07 to 1.99 and from 0.76 to 3.6, respectively. In addition, a general model was developed for predicting PCE for intersections with all of the movements considered. The results obtained from this model showed that the average PCE of 1.5 is similar to the value recommended by the HCM (Highway Capacity Manual 1985. However, the predicted PCE value of 1.9 for saturated threshold is closer to the PCE value of 2 which was recommended by the HCM 2000 and HCM 2010.

Waiting Endurance Time Estimation of Electric Two-Wheelers at Signalized Intersections

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Mei Huan

2014-01-01

Full Text Available The paper proposed a model for estimating waiting endurance times of electric two-wheelers at signalized intersections using survival analysis method. Waiting duration times were collected by video cameras and they were assigned as censored and uncensored data to distinguish between normal crossing and red-light running behavior. A Cox proportional hazard model was introduced, and variables revealing personal characteristics and traffic conditions were defined as covariates to describe the effects of internal and external factors. Empirical results show that riders do not want to wait too long to cross intersections. As signal waiting time increases, electric two-wheelers get impatient and violate the traffic signal. There are 12.8% of electric two-wheelers with negligible wait time. 25.0% of electric two-wheelers are generally nonrisk takers who can obey the traffic rules after waiting for 100 seconds. Half of electric two-wheelers cannot endure 49.0 seconds or longer at red-light phase. Red phase time, motor vehicle volume, and conformity behavior have important effects on riders’ waiting times. Waiting endurance times would decrease with the longer red-phase time, the lower traffic volume, or the bigger number of other riders who run against the red light. The proposed model may be applicable in the design, management and control of signalized intersections in other developing cities.

Waiting endurance time estimation of electric two-wheelers at signalized intersections.

Science.gov (United States)

Huan, Mei; Yang, Xiao-bao

2014-01-01

The paper proposed a model for estimating waiting endurance times of electric two-wheelers at signalized intersections using survival analysis method. Waiting duration times were collected by video cameras and they were assigned as censored and uncensored data to distinguish between normal crossing and red-light running behavior. A Cox proportional hazard model was introduced, and variables revealing personal characteristics and traffic conditions were defined as covariates to describe the effects of internal and external factors. Empirical results show that riders do not want to wait too long to cross intersections. As signal waiting time increases, electric two-wheelers get impatient and violate the traffic signal. There are 12.8% of electric two-wheelers with negligible wait time. 25.0% of electric two-wheelers are generally nonrisk takers who can obey the traffic rules after waiting for 100 seconds. Half of electric two-wheelers cannot endure 49.0 seconds or longer at red-light phase. Red phase time, motor vehicle volume, and conformity behavior have important effects on riders' waiting times. Waiting endurance times would decrease with the longer red-phase time, the lower traffic volume, or the bigger number of other riders who run against the red light. The proposed model may be applicable in the design, management and control of signalized intersections in other developing cities.

Evaluation of Red Light Camera Enforcement at Signalized Intersections

Directory of Open Access Journals (Sweden)

Abdulrahman AlJanahi

2007-12-01

Full Text Available The study attempts to find the effectiveness of adopting red light cameras in reducing red light violators. An experimental approach was adopted to investigate the use of red light cameras at signalized intersections in the Kingdom of Bahrain. The study locations were divided into three groups. The first group was related to the approaches monitored with red light cameras. The second group was related to approaches without red light cameras, but located within an intersection that had one of its approaches monitored with red light cameras. The third group was related to intersection approaches located at intersection without red light cameras (controlled sites. A methodology was developed for data collection. The data were then tested statistically by Z-test using proportion methods to compare the proportion of red light violations occurring at different sites. The study found that the proportion of red light violators at approaches monitored with red light cameras was significantly less than those at the controlled sites for most of the time. Approaches without red light cameras located within intersections having red light cameras showed, in general, fewer violations than controlled sites, but the results were not significant for all times of the day. The study reveals that red light cameras have a positive effect on reducing red light violations. However, these conclusions need further evaluations to justify their safe and economic use.

Safety Impacts of Push-Button and Countdown Timer on Nonmotorized Traffic at Intersections

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Bei Zhou

2014-01-01

Full Text Available This paper applies the random parameters negative binominal model to investigate safety impacts of push-button and countdown timer on pedestrians and cyclists at urban intersections. To account for possible unobserved heterogeneity which could vary from one intersection to another, random parameters model is introduced. A simulation-based maximum likelihood method using Halton draws is applied to estimate the maximum likelihood of random parameters in the model. Dataset containing pedestrians’ and cyclists’ crash data of 1,001 intersections from Chicago is utilized to establish the statistical relationship between crash frequencies and potential impact factors. LIMDEP (Version 9.0 statistical package is utilized for modeling. The parameter estimation results indicate that existence of push-button and countdown timer could significantly reduce crash frequencies of pedestrians and cyclists at intersections. Increasing number of through traffic lanes, left turn lanes, and ratio of major direction AADT to minor direction AADT, tend to increase crash frequencies. Annual average daily left turn traffic has a negative impact on pedestrians’ safety, but its impact on cyclists’ crash frequency is statistically insignificant at 90% confidence level. The results of current study could provide important insights for nonmotorized traffic safety improvement projects in both planning and operational levels.

Investigation of new vehicle detectors for high-speed signalized intersections.

Science.gov (United States)

2015-09-01

Early indications from the use of the newest vehicle detectors for high-speed signalized intersections : suggested that they perform well as replacements for the Texas Department of Transportations : (TxDOTs) legacy systems, but this early conc...

Road Impedance Model Study under the Control of Intersection Signal

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Yunlin Luo

2015-01-01

Full Text Available Road traffic impedance model is a difficult and critical point in urban traffic assignment and route guidance. The paper takes a signalized intersection as the research object. On the basis of traditional traffic wave theory including the implementation of traffic wave model and the analysis of vehicles’ gathering and dissipating, the road traffic impedance model is researched by determining the basic travel time and waiting delay time. Numerical example results have proved that the proposed model in this paper has received better calculation performance compared to existing model, especially in flat hours. The values of mean absolute percentage error (MAPE and mean absolute deviation (MAD are separately reduced by 3.78% and 2.62 s. It shows that the proposed model has feasibility and availability in road traffic impedance under intersection signal.

A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy.

Directory of Open Access Journals (Sweden)

Yiming Bie

Full Text Available 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.

A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy.

Science.gov (United States)

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.

An empirical Bayes safety evaluation of tram/streetcar signal and lane priority measures in Melbourne.

Science.gov (United States)

Naznin, Farhana; Currie, Graham; Sarvi, Majid; Logan, David

2016-01-01

Streetcars/tram systems are growing worldwide, and many are given priority to increase speed and reliability performance in mixed traffic conditions. Research related to the road safety impact of tram priority is limited. This study explores the road safety impacts of tram priority measures including lane and intersection/signal priority measures. A before-after crash study was conducted using the empirical Bayes (EB) method to provide more accurate crash impact estimates by accounting for wider crash trends and regression to the mean effects. Before-after crash data for 29 intersections with tram signal priority and 23 arterials with tram lane priority in Melbourne, Australia, were analyzed to evaluate the road safety impact of tram priority. The EB before-after analysis results indicated a statistically significant adjusted crash reduction rate of 16.4% after implementation of tram priority measures. Signal priority measures were found to reduce crashes by 13.9% and lane priority by 19.4%. A disaggregate level simple before-after analysis indicated reductions in total and serious crashes as well as vehicle-, pedestrian-, and motorcycle-involved crashes. In addition, reductions in on-path crashes, pedestrian-involved crashes, and collisions among vehicles moving in the same and opposite directions and all other specific crash types were found after tram priority implementation. Results suggest that streetcar/tram priority measures result in safety benefits for all road users, including vehicles, pedestrians, and cyclists. Policy implications and areas for future research are discussed.

Influence of the cognitive workload on bicycle safety at four-legged intersections

DEFF Research Database (Denmark)

Kveladze, Irma; Agerholm, Niels

2018-01-01

is the influence of workload capacity on bicyclists spatial behaviour in a natural environment of four-legged intersections. Method: Due to the traffic safety of test participants, the study is divided in two phases. In the first phase, the actual physical environment of the four-legged intersection and bicyclists......-legged intersection. The eye tracking glasses will be used to make video and audio recording of visible field of where or how long bicyclists are allocating their visual attention while riding a bicycle and facing obstacles when crossing the four-legged intersection. On the second phase, a bicycle riding simulator...... riding task. This will allow to understand the allocation of bicyclists attention between primary and secondary tasks, to reveal the limit of the information processing capacity during biking. Results expected: Two experimental results will be incorporated to gain in-depth knowledge on bicycle accidents...

Analysis on influencing factors and decision-making of pedestrian crossing at intersections

Science.gov (United States)

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.

Eco-Approach and Departure System for Left-Turn Vehicles at a Fixed-Time Signalized Intersection

Directory of Open Access Journals (Sweden)

Huifu Jiang

2018-01-01

Full Text Available This research proposed an eco-approach and departure system for left-turn vehicles at a fixed-time signalized intersection. This system gives higher priority to enhancing traffic safety than improving mobility and fuel efficiency, and optimizes the entire traffic consisted of connected and automated vehicles (CAVs and conventional human-driven vehicles by providing ecological speed trajectories for left-turn CAVs. All the ecological speed trajectories are offline optimized before the implementation of system. The speed trajectory optimization is constructed in Pontryagin’s Minimum Principle structure. The before and after evaluation of the proposed system shows the percentage of vehicles that drive pass the intersection at safe speed increases by 2.14% to 45.65%, fuel consumption benefits range 0.53% to 18.44%, emission benefits range from 0.57% to 15.69%, no significant throughput benefits is observed. The proposed system significantly enhances the traffic safety and improves the fuel efficiency and emission reduction of left-turn vehicles with no adverse effect on mobility, and has a good robustness against the randomness of traffic. The investigation also indicates that the computation time of proposed system is greatly reduced compared to previous eco-driving system with online speed optimization. The computation time is up to 0.01 s. The proposed system is ready for real-time application.

An Eco-Driving Advisory System for Continuous Signalized Intersections by Vehicular Ad Hoc Network

Directory of Open Access Journals (Sweden)

Wei-Hsun Lee

2018-01-01

Full Text Available With the vehicular ad hoc network (VANET technology which support vehicle-to-vehicle (V2V and vehicle to road side unit (V2R/R2V communications, vehicles can preview the intersection signal plan such as signal countdown message. In this paper, an ecodriving advisory system (EDAS is proposed to reduce CO2 emissions and energy consumption by letting the vehicle continuously pass through multiple intersections with the minimum possibilities of stops. We extend the isolated intersection model to multiple continuous intersections scenario. A hybrid method combining three strategies including maximized throughput model (MTM, smooth speed model (SSM, and minimized acceleration and deceleration (MinADM is designed, and it is compared with related works maximized throughput model (MaxTM, open traffic light control model (OTLCM, and predictive cruise control (PCC models. Some issues for the practical application including safe car following, queue clearing, and gliding mode are discussed and conquered. Simulation results show that the proposed model outperforms OTLCM 25.1%~81.2% in the isolated intersection scenario for the CO2 emissions and 20.5%~84.3% in averaged travel time. It also performs better than the compared PCC model in CO2 emissions (19.9%~31.2% as well as travel time (24.5%~35.9% in the multiple intersections scenario.

Road safety audit for the intersection of US 59 and IA 9 in Osceola County, Iowa.

Science.gov (United States)

2012-03-01

The Iowa Department of Transportation (DOT) requested a road safety audit (RSA) of the US 59/IA 9 intersection in northwestern Iowa, just south of the Minnesota border, to assess intersection environmental issues and crash history and recommend appro...

Drivers' smart advisory system improves driving performance at STOP sign intersections

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Qing Li

2017-06-01

Full Text Available STOP signs are often physically blocked by obstacles at the corner, forming a safety threat. To enhance the safety at an un-signalized intersection like a STOP sign intersection, a radio frequency identification (RFID based drivers smart advisory system (DSAS was developed, which provides drivers with an earlier warning message when they are approaching an un-signalized intersection. In this research, a pilot field test was conducted with the DSAS alarm on an approach towards a STOP sign intersection in a residential area in Houston, Texas. The designed test route covers all turning movements, including left turn, through movement, and right turn. GPS units recorded test drivers' driving behaviors. A self-developed MATLAB program and statistically significant difference t-test were applied to analyze the impacts of the DSAS messages on drivers' driving performance, in terms of approaching speed profile, acceleration/deceleration rates, braking distance, and possible extra vehicle emissions induced by the introduction of the DSAS message. Drivers' preference on the DSAS was investigated by a designed survey questionnaire among test drivers. Results showed that the DSAS alarm was able to induce drivers to drive significantly slower to approach a STOP sign intersection, perform smaller fluctuation in acceleration/deceleration rates, and be more aware of a coming STOP sign indicated by decelerating earlier. All test drivers preferred to follow the DSAS alarm on roads for a safety concern. Further, the DSAS alarm caused the reduction in emission rates through movement. For a general observation, more road tests with more participants and different test routes were recommended.

Estimation of fuel loss due to idling of vehicles at a signalized intersection in Chennai, India

Science.gov (United States)

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.

State-Space Equations and the First-Phase Algorithm for Signal Control of Single Intersections

Institute of Scientific and Technical Information of China (English)

LI Jinyuan; PAN Xin; WANG Xiqin

2007-01-01

State-space equations were applied to formulate the queuing and delay of traffic at a single intersection in this paper. The signal control of a single intersection was then modeled as a discrete-time optimal control problem, with consideration of the constraints of stream conflicts, saturation flow rate, minimum green time, and maximum green time. The problem cannot be solved directly due to the nonlinear constraints.However, the results of qualitative analysis were used to develop a first-phase signal control algorithm. Simulation results show that the algorithm substantially reduces the total delay compared to fixed-time control.

Effects of turning and through lane sharing on traffic performance at intersections

Science.gov (United States)

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.

AERIS : Eco-Vehicle Speed Control at Signalized Intersections Using I2V Communication

Science.gov (United States)

2012-06-01

This report concentrates on a velocity advisory tool, or decision support system, for vehicles approaching an intersection using communication capabilities between the infrastructure and vehicles. The system uses available signal change information, ...

Safety analysis of urban arterials at the meso level.

Science.gov (United States)

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

Saturation flow versus green time at two-stage signal controlled intersections

Directory of Open Access Journals (Sweden)

A. Boumediene

2009-12-01

Full Text Available Intersections are the key components of road networks considerably affecting capacity. As flow levels and experience have increased over the years, methods and means have been developed to cope with growing demand for traffic at road junctions. Among various traffic control devices and techniques developed to cope with conflicting movements, traffic signals create artificial gaps to accommodate the impeded traffic streams. The majority of parameters that govern signalised intersection control and operations such as a degree of saturation, delays, queue lengths, the level of service etc. are very sensitive to saturation flow. Therefore, it is essential to reliably evaluate saturation flow for correctly setting traffic signals to avoid unnecessary delays and conflicts. Generally, almost all guidelines support the constancy of saturation flow irrespective of green time duration. This paper presents the results of field studies carried out to enable the performance of signalised intersections to be compared at different green time durations. It was found that saturation flow decreased slightly with growing green time. Reduction corresponded to between 2 and 5 pcus/gh per second of green time. However, the analyses of the discharge rate during the successive time intervals of 6-seconds showed a substantial reduction of 10% to 13% in saturation flow levels after 36 seconds of green time compared to those relating to 6–36 seconds range. No reduction in saturation flow levels was detected at the sites where only green periods of 44 seconds or less were implemented.

Safety and Convergence Analysis of Intersecting Aircraft Flows Under Decentralized Collision Avoidance

Science.gov (United States)

Dallal, Ahmed H.

Safety is an essential requirement for air traffic management and control systems. Aircraft are not allowed to get closer to each other than a specified safety distance, to avoid any conflicts and collisions between aircraft. Forecast analysis predicts a tremendous increase in the number of flights. Subsequently, automated tools are needed to help air traffic controllers resolve air born conflicts. In this dissertation, we consider the problem of conflict resolution of aircraft flows with the assumption that aircraft are flowing through a fixed specified control volume at a constant speed. In this regard, several centralized and decentralized resolution rules have been proposed for path planning and conflict avoidance. For the case of two intersecting flows, we introduce the concept of conflict touches, and a collaborative decentralized conflict resolution rule is then proposed and analyzed for two intersecting flows. The proposed rule is also able to resolved airborne conflicts that resulted from resolving another conflict via the domino effect. We study the safety conditions under the proposed conflict resolution and collision avoidance rule. Then, we use Lyapunov analysis to analytically prove the convergence of conflict resolution dynamics under the proposed rule. The analysis show that, under the proposed conflict resolution rule, the system of intersecting aircraft flows is guaranteed to converge to safe, conflict free, trajectories within a bounded time. Simulations are provided to verify the analytically derived conclusions and study the convergence of the conflict resolution dynamics at different encounter angles. Simulation results show that lateral deviations taken by aircraft in each flow, to resolve conflicts, are bounded, and aircraft converged to safe and conflict free trajectories, within a finite time.

Evaluation of the dispersion effect in through movement bicycles at signalized intersection via cellular automata simulation

Science.gov (United States)

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.

Multiobjective Traffic Signal Control Model for Intersection Based on Dynamic Turning Movements Estimation

Directory of Open Access Journals (Sweden)

Pengpeng Jiao

2014-01-01

Full Text Available The real-time traffic signal control for intersection requires dynamic turning movements as the basic input data. It is impossible to detect dynamic turning movements directly through current traffic surveillance systems, but dynamic origin-destination (O-D estimation can obtain it. However, the combined models of dynamic O-D estimation and real-time traffic signal control are rare in the literature. A framework for the multiobjective traffic signal control model for intersection based on dynamic O-D estimation (MSC-DODE is presented. A state-space model using Kalman filtering is first formulated to estimate the dynamic turning movements; then a revised sequential Kalman filtering algorithm is designed to solve the model, and the root mean square error and mean percentage error are used to evaluate the accuracy of estimated dynamic turning proportions. Furthermore, a multiobjective traffic signal control model is put forward to achieve real-time signal control parameters and evaluation indices. Finally, based on practical survey data, the evaluation indices from MSC-DODE are compared with those from Webster method. The actual and estimated turning movements are further input into MSC-DODE, respectively, and results are also compared. Case studies show that results of MSC-DODE are better than those of Webster method and are very close to unavailable actual values.

Vehicular crash data used to rank intersections by injury crash frequency and severity

Directory of Open Access Journals (Sweden)

Yi Liu

2016-09-01

Full Text Available 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.

Development of an in-vehicle intersection collision countermeasure

Science.gov (United States)

Pierowicz, John A.

1997-02-01

Intersection collisions constitute approximately twenty-six percent of all accidents in the United States. Because of their complexity, and demands on the perceptual and decision making abilities of the driver, intersections present an increased risk of collisions between automobiles. This situation provides an opportunity to apply advanced sensor and processing capabilities to prevent these collisions. A program to determine the characteristics of intersection collisions and identify potential countermeasures will be described. This program, sponsored by the National Highway Traffic Safety Administration, utilized accident data to develop a taxonomy of intersection crashes. This taxonomy was used to develop a concept for an intersection collision avoidance countermeasure. The concept utilizes in-vehicle position, dynamic status, and millimeter wave radar system and an in-vehicle computer system to provide inputs to an intersection collision avoidance algorithm. Detection of potential violation of traffic control device, or proceeding into the intersection with inadequate gap will lead to the presentation of a warning to the driver. These warnings are presented to the driver primarily via a head-up display and haptic feedback. Roadside to vehicle communication provides information regarding phased traffic signal information. Active control of the vehicle's brake and steering systems are described. Progress in the development of the systems will be presented along with the schedule of future activities.

Influences of motorcycle rider and driver characteristics and road environment on red light running behavior at signalized intersections.

Science.gov (United States)

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.

Spatial database for intersections.

Science.gov (United States)

2015-08-01

Deciding which intersections in the state of Kentucky warrant safety improvements requires a comprehensive inventory : with information on every intersection in the public roadway network. The Kentucky Transportation Cabinet (KYTC) : had previously c...

DESIGNING AN EFFECTIVE INTERSECTION USING CAD ENVIRONMENT

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CRISAN George-Horea

2017-05-01

Full Text Available Ensuring the safety and streamline in road traffic are very important aims, with regard to the nowadays people mobility level. Road infrastructure is an essential element that can meet these requirements. Thus, it is proposed to develop an effective model of intersection by using CAD software tools. This type of intersection can be successfully used on almost any category of roads, increasing road traffic safety, reducing passing times through the intersection and in the same time, reducing conflict points and increase the intersection capacity.

Safety effects of exclusive and concurrent signal phasing for pedestrian crossing.

Science.gov (United States)

Zhang, Yaohua; Mamun, Sha A; Ivan, John N; Ravishanker, Nalini; Haque, Khademul

2015-10-01

This paper describes the estimation of pedestrian crash count and vehicle interaction severity prediction models for a sample of signalized intersections in Connecticut with either concurrent or exclusive pedestrian phasing. With concurrent phasing, pedestrians cross at the same time as motor vehicle traffic in the same direction receives a green phase, while with exclusive phasing, pedestrians cross during their own phase when all motor vehicle traffic on all approaches is stopped. Pedestrians crossing at each intersection were observed and classified according to the severity of interactions with motor vehicles. Observation intersections were selected to represent both types of signal phasing while controlling for other physical characteristics. In the nonlinear mixed models for interaction severity, pedestrians crossing on the walk signal at an exclusive signal experienced lower interaction severity compared to those crossing on the green light with concurrent phasing; however, pedestrians crossing on a green light where an exclusive phase was available experienced higher interaction severity. Intersections with concurrent phasing have fewer total pedestrian crashes than those with exclusive phasing but more crashes at higher severity levels. It is recommended that exclusive pedestrian phasing only be used at locations where pedestrians are more likely to comply. Copyright © 2015. Published by Elsevier Ltd.

Influence of dimension box differences and time differences during operations of red box for motorcycles at signalized intersection

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Mulyadi, Agah Muhammad

2017-11-01

Performance of signalized intersection has declined due to a large number of motorcycles. The number of motorcycles reached 98.2 million units and the composition of motorcycles has reached around 81.7% of the total composition of vehicles in Indonesia (AISI, 2017). To solve that problem, the red box for motorcycles are provided at the signalized intersection. Red box for the motorcycle at signalized intersections was developed from the concept of Advance Stop Line (ASL) for bicycles. The Red Box was developed to split the queue between motorcycles and other vehicles when waiting at red light. This paper aims to evaluate the influence of the red box dimension and red time operation differences. The survey was conducted as many as 30 cycles of traffic signals per day. The data were analyzed using software IBM SPSS Statistics 20 by using Analysis of Variance (ANOVA) to obtain p-value (significant). The analysis shows that there are insignificant influences between the occupancy rates to the dimension of Red Box. Furthermore, that there is a significant difference that shows the dependency of only motorcycles in the Red Box Area towards red time operation.

Best response game of traffic on road network of non-signalized intersections

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Yao, Wang; Jia, Ning; Zhong, Shiquan; Li, Liying

2018-01-01

This paper studies the traffic flow in a grid road network with non-signalized intersections. The nature of the drivers in the network is simulated such that they play an iterative snowdrift game with other drivers. A cellular automata model is applied to study the characteristics of the traffic flow and the evolution of the behaviour of the drivers during the game. The drivers use best-response as their strategy to update rules. Three major findings are revealed. First, the cooperation rate in simulation experiences staircase-shaped drop as cost to benefit ratio r increases, and cooperation rate can be derived analytically as a function of cost to benefit ratio r. Second, we find that higher cooperation rate corresponds to higher average speed, lower density and higher flow. This reveals that defectors deteriorate the efficiency of traffic on non-signalized intersections. Third, the system experiences more randomness when the density is low because the drivers will not have much opportunity to update strategy when the density is low. These findings help to show how the strategy of drivers in a traffic network evolves and how their interactions influence the overall performance of the traffic system.

Human-like motion planning model for driving in signalized intersections

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Yanlei Gu

2017-10-01

Full Text Available Highly automated and fully autonomous vehicles are much more likely to be accepted if they react in the same way as human drivers do, especially in a hybrid traffic situation, which allows autonomous vehicles and human-driven vehicles to share the same road. This paper proposes a human-like motion planning model to represent how human drivers assess environments and operate vehicles in signalized intersections. The developed model consists of a pedestrian intention detection model, gap detection model, and vehicle control model. These three submodels are individually responsible for situation assessment, decision making, and action, and also depend on each other in the process of motion planning. In addition, these submodels are constructed and learned on the basis of human drivers' data collected from real traffic environments. To verify the effectiveness of the proposed motion planning model, we compared the proposed model with actual human driver and pedestrian data. The experimental results showed that our proposed model and actual human driver behaviors are highly similar with respect to gap acceptance in intersections.

A simulator-based analysis of engineering treatments for right-hook bicycle crashes at signalized intersections.

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Warner, Jennifer; Hurwitz, David S; Monsere, Christopher M; Fleskes, Kayla

2017-07-01

A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures - regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design - at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections with a shared right-turn and through lane. Changes in driver performance in response to treatments were measured in a high-fidelity driving simulator. Twenty-eight participants each completed 22 right-turn maneuvers. A partially counterbalanced experimental design exposed drivers to critical scenarios, which had been determined in a previous experiment. For each turn, driver performance measures, including visual attention, crash avoidance, and potential crash severity, were collected. A total of 75 incidents (47 near-collisions and 28 collisions) were observed during the 616 right turns. All treatments had some positive effect on measured driver performance with respect to the right-turn vehicle conflicts. Further work is required to map the magnitude of these changes in driver performance to crash-based outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

V2I-based startup assistance system at signalized intersections

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Jianqiang Wang

2015-08-01

Full Text Available Traffic delays are caused by unskilled vehicle operation and driver distraction during the startup process at signalized intersections. To address this issue, we propose a V2I-based driver assistance system that can acquire the current traffic signal status and provide drivers with startup assistance. This article presents the proposed system’s architecture and an assistance algorithm, which contains two types of driver assistance methods: startup prompting and automatic startup control. The automatic startup control method, based on fuzzy logic control, is validated in simulation tests. We also implement startup prompting using a prototype system and validate its performance in field tests. The test results suggest that the proposed assistance algorithm can help drivers start up their vehicles with less delay, which will significantly improve traffic efficiency.

An extended car-following model at un-signalized intersections under V2V communication environment

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Wang, Tao; Li, Peng

2018-01-01

An extended car-following model is proposed in this paper to analyze the impacts of V2V (vehicle to vehicle) communication on the micro driving behavior at the un-signalized intersection. A four-leg un-signalized intersection with twelve streams (left-turn, through movement, and right turn from each leg) is used. The effect of the guidance strategy on the reduction of the rate of stops and total delay is explored by comparing the proposed model and the traditional FVD car-following model. The numerical results illustrate that potential conflicts between vehicles can be predicted and some stops can be avoided by decelerating in advance. The driving comfort and traffic efficiency can be improved accordingly. More benefits could be obtained under the long communication range, low to medium traffic density, and simple traffic pattern conditions. PMID:29425243

Effects of countdown timers on driver behavior after the yellow onset at Chinese intersections.

Science.gov (United States)

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.

Coordinated signal control for arterial intersections using fuzzy logic

Science.gov (United States)

Kermanian, Davood; Zare, Assef; Balochian, Saeed

2013-09-01

Every day growth of the vehicles has become one of the biggest problems of urbanism especially in major cities. This can waste people's time, increase the fuel consumption, air pollution, and increase the density of cars and vehicles. Fuzzy controllers have been widely used in many consumer products and industrial applications with success over the past two decades. This article proposes a comprehensive model of urban traffic network using state space equations and then using Fuzzy Logic Tool Box and SIMULINK Program MATLAB a fuzzy controller in order to optimize and coordinate signal control at two intersections at an arterial road. The fuzzy controller decides to extend, early cut or terminate a signal phase and phase sequence to ensure smooth flow of traffic with minimal waiting time and length of queue. Results show that the performance of the proposed traffic controller at novel fuzzy model is better that of conventional controllers under normal and abnormal traffic conditions.

An Optimization Model of Multi-Intersection Signal Control for Trunk Road under Collaborative Information

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Xun Li

2017-01-01

Full Text Available We proposed a signal control optimization model for urban main trunk line intersections. Four-phase intersection was analyzed and modeled based on the Cell Transmission Model (CTM. CTM and signal control model in our study had both been improved for multi-intersections by three-phase theory and information-exchanging. To achieve a real-time application, an improved genetic algorithm (GA was proposed finally, the DISCO traffic simulation software was used for numerical simulation experiment, and comparisons with the standard GA and CTM were reported in this paper. Experimental results indicate that our searching time is less than that of SGA by 38%, and our method needs only 1/3 iteration time of SGA. According to our DISCO traffic simulation processing, compared with SGA, if the input traffic flow is changed from free phase to synchronized phase, for example, less than 900 vel/h, the delay time can reduce to 87.99% by our method, and the minimum delay time is 77.76% of existing method. Furthermore, if input traffic volume is increased to 1200 vel/h or more at the synchronized phase, the summary and minimum values of average delay time are reduced to 81.16% and 75.83%, respectively, and the average delay time is reduced to 17.72 seconds.

Aging road user studies of intersection safety : lab and simulator-based studies of crosswalk markings and flashing yellow arrow comprehension -- phase 2 : [summary].

Science.gov (United States)

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...

Analysis of Emission Effects Related to Drivers' Compliance Rates for Cooperative Vehicle-Infrastructure System at Signalized Intersections.

Science.gov (United States)

Liao, Ruohua; Chen, Xumei; Yu, Lei; Sun, Xiaofei

2018-01-12

Unknown remaining time of signal phase at a signalized intersection generally results in extra accelerations and decelerations that increase variations of operating conditions and thus emissions. A cooperative vehicle-infrastructure system can reduce unnecessary speed changes by establishing communications between vehicles and the signal infrastructure. However, the environmental benefits largely depend on drivers' compliance behaviors. To quantify the effects of drivers' compliance rates on emissions, this study applied VISSIM 5.20 (Planung Transport Verkehr AG, Karlsruhe, Germany) to develop a simulation model for a signalized intersection, in which light duty vehicles were equipped with a cooperative vehicle-infrastructure system. A vehicle-specific power (VSP)-based model was used to estimate emissions. Based on simulation data, the effects of different compliance rates on VSP distributions, emission factors, and total emissions were analyzed. The results show the higher compliance rate decreases the proportion of VSP bin = 0, which means that the frequencies of braking and idling were lower and light duty vehicles ran more smoothly at the intersection if more light duty vehicles complied with the cooperative vehicle-infrastructure system, and emission factors for light duty vehicles decreased significantly as the compliance rate increased. The case study shows higher total emission reductions were observed with higher compliance rate for all of CO₂, NO x , HC, and CO emissions. CO₂ was reduced most significantly, decreased by 16% and 22% with compliance rates of 0.3 and 0.7, respectively.

Analysis of Emission Effects Related to Drivers’ Compliance Rates for Cooperative Vehicle-Infrastructure System at Signalized Intersections

Science.gov (United States)

Liao, Ruohua; Yu, Lei; Sun, Xiaofei

2018-01-01

Unknown remaining time of signal phase at a signalized intersection generally results in extra accelerations and decelerations that increase variations of operating conditions and thus emissions. A cooperative vehicle-infrastructure system can reduce unnecessary speed changes by establishing communications between vehicles and the signal infrastructure. However, the environmental benefits largely depend on drivers’ compliance behaviors. To quantify the effects of drivers’ compliance rates on emissions, this study applied VISSIM 5.20 (Planung Transport Verkehr AG, Karlsruhe, Germany) to develop a simulation model for a signalized intersection, in which light duty vehicles were equipped with a cooperative vehicle-infrastructure system. A vehicle-specific power (VSP)-based model was used to estimate emissions. Based on simulation data, the effects of different compliance rates on VSP distributions, emission factors, and total emissions were analyzed. The results show the higher compliance rate decreases the proportion of VSP bin = 0, which means that the frequencies of braking and idling were lower and light duty vehicles ran more smoothly at the intersection if more light duty vehicles complied with the cooperative vehicle-infrastructure system, and emission factors for light duty vehicles decreased significantly as the compliance rate increased. The case study shows higher total emission reductions were observed with higher compliance rate for all of CO2, NOx, HC, and CO emissions. CO2 was reduced most significantly, decreased by 16% and 22% with compliance rates of 0.3 and 0.7, respectively. PMID:29329214

Analysis of Emission Effects Related to Drivers’ Compliance Rates for Cooperative Vehicle-Infrastructure System at Signalized Intersections

Directory of Open Access Journals (Sweden)

Ruohua Liao

2018-01-01

Full Text Available Unknown remaining time of signal phase at a signalized intersection generally results in extra accelerations and decelerations that increase variations of operating conditions and thus emissions. A cooperative vehicle-infrastructure system can reduce unnecessary speed changes by establishing communications between vehicles and the signal infrastructure. However, the environmental benefits largely depend on drivers’ compliance behaviors. To quantify the effects of drivers’ compliance rates on emissions, this study applied VISSIM 5.20 (Planung Transport Verkehr AG, Karlsruhe, Germany to develop a simulation model for a signalized intersection, in which light duty vehicles were equipped with a cooperative vehicle-infrastructure system. A vehicle-specific power (VSP-based model was used to estimate emissions. Based on simulation data, the effects of different compliance rates on VSP distributions, emission factors, and total emissions were analyzed. The results show the higher compliance rate decreases the proportion of VSP bin = 0, which means that the frequencies of braking and idling were lower and light duty vehicles ran more smoothly at the intersection if more light duty vehicles complied with the cooperative vehicle-infrastructure system, and emission factors for light duty vehicles decreased significantly as the compliance rate increased. The case study shows higher total emission reductions were observed with higher compliance rate for all of CO2, NOx, HC, and CO emissions. CO2 was reduced most significantly, decreased by 16% and 22% with compliance rates of 0.3 and 0.7, respectively.

A PREDICTIVE STUDY: CARBON MONOXIDE EMISSION MODELING AT A SIGNALIZED INTERSECTION

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FREDDY WEE LIANG KHO

2014-02-01

Full Text Available CAL3QHC dispersion model was used to predict the present and future carbonmonoxide (CO levels at a busy signalized intersection. This study attempted to identify CO “hot-spots” at nearby areas of the intersection during typical A.M. and P.M. peak hours. The CO concentration “hot-spots” had been identified at 101 Commercial Park and the simulated maximum 1-hour Time-Weighted Average (1-h TWA ground level CO concentrations of 18.3 ppm and 18.6 ppm had been observed during A.M. and P.M. peaks, respectively in year 2006. This study shows that there would be no significant increment in CO level for year 2014 although a substantial increase in the number of vehicles is assumed to affect CO levels. It was also found that CO levels would be well below the Malaysian Ambient Air Quality Guideline of 30 ppm (1-h TWA. Comparisons between the measured and simulated CO levels using quantitative data analysis technique and statistical methods indicated that CAL3QHC dispersion model correlated well with measured data.

Operation, analysis, and design of signalized intersections : a module for the introductory course in transportation engineering.

Science.gov (United States)

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...

Safety Evaluation of Destination Lighting at Stop-Controlled Cross Intersections

Science.gov (United States)

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...

Calculation of vehicle delay at signal-controlled intersections with adaptive traffic control algorithm

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Andronov Roman

2018-01-01

Full Text Available By widely introducing information technology tools in the field of traffic control, it is possible to increase the capacity of hubs and reduce vehicle delays. Adaptive traffic light control is one of such tools. Its effectiveness can be assessed through traffic flow simulation. The aim of this study is to create a simulation model of a signal-controlled intersection that can be used to assess the effectiveness of adaptive control in various traffic situations, including the presence or absence of pedestrian traffic through an intersection. The model is based on a numerical experiment conducted using the Monte Carlo method. As a result of the study, vehicle delays, queue length and duration of traffic light cycles are calculated subject to different intensities of incoming traffic flows, and the presence or absence of pedestrian traffic.

Exposure to lateral collision in signalized intersections with protected left turn under different traffic control strategies.

Science.gov (United States)

Midenet, Sophie; Saunier, Nicolas; Boillot, Florence

2011-11-01

This paper proposes an original definition of the exposure to lateral collision in signalized intersections and discusses the results of a real world experiment. This exposure is defined as the duration of situations where the stream that is given the right-of-way goes through the conflict zone while road users are waiting in the cross-traffic approach. This measure, obtained from video sensors, makes it possible to compare different operating conditions such as different traffic signal strategies. The data from a real world experiment is used, where the adaptive real-time strategy CRONOS (ContRol Of Networks by Optimization of Switchovers) and a time-plan strategy with vehicle-actuated ranges alternately controlled an isolated intersection near Paris. Hourly samples with similar traffic volumes are compared and the exposure to lateral collision is different in various areas of the intersection and various traffic conditions for the two strategies. The total exposure under peak hour traffic conditions drops by roughly 5 min/h with the CRONOS strategy compared to the time-plan strategy, which occurs mostly on entry streams. The results are analyzed through the decomposition of cycles in phase sequences and recommendations are made for traffic control strategies. Copyright © 2011 Elsevier Ltd. All rights reserved.

Exploring stop-go decision zones at rural high-speed intersections with flashing green signal and insufficient yellow time in China.

Science.gov (United States)

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.

Meeting the global demand of sports safety: the intersection of science and policy in sports safety.

Science.gov (United States)

Timpka, Toomas; Finch, Caroline F; Goulet, Claude; Noakes, Tim; Yammine, Kaissar

2008-01-01

Sports and physical activity are transforming, and being transformed by, the societies in which they are practised. From the perspectives of both competitive and non-competitive sports, the complexity of their integration into today's society has led to neither sports federations nor governments being able to manage the safety problem alone. In other words, these agencies, whilst promoting sport and physical activity, deliver policy and practices in an uncoordinated way that largely ignores the need for a concurrent overall policy for sports safety. This article reviews and analyses the possibility of developing an overall sports safety policy from a global viewpoint. Firstly, we describe the role of sports in today's societies and the context within which much sport is delivered. We then discuss global issues related to injury prevention and safety in sports, with practical relevance to this important sector, including an analysis of critical policy issues necessary for the future development of the area and significant safety gains for all. We argue that there is a need to establish the sports injury problem as a critical component of general global health policy agendas, and to introduce sports safety as a mandatory component of all sustainable sports organizations. We conclude that the establishment of an explicit intersection between science and policy making is necessary for the future development of sports and the necessary safety gains required for all participants around the world. The Safe Sports International safety promotion programme is outlined as an example of an international organization active within this arena.

Using Traffic Conflict Method in Evaluating Traffic Safety at the Reconstructed Intersection

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Zdravko Bukljaš

2002-05-01

Full Text Available As part of organised social system, traffic is subjected togeneral social tendency towards adequate safety and sustainabilityof relations in such a system, probabilistically marked bythe risk of danger. Inte1polation of subjective factor facilitatesthe occwTence of negative phenomena. Road traffic system ischaracterised by extremely massive participation in traffic, contributingthus to a greater possibility of negative features characteristicfor imperfect human mechanism. This is precisely thereason why this paper deals with the problem of traffic safety onthe concrete example of the intersection between the SavskaStreet and the Slavonska and LjubljanskaAvenues over the periodof time prior to constmcting the new unde1pass solution,and the period of time immediately after the construction workswere completed. The used data have been provided by the TrafficPolice Department - Lucko.

Next generation safety performance monitoring at signalized intersections using connected vehicle technology.

Science.gov (United States)

2014-08-01

Crash-based safety evaluation is often hampered by randomness, lack of timeliness, and rarity of crash : occurrences. This is particularly the case for technology-driven safety improvement projects that are : frequently updated or replaced by newer o...

Effect of Pedestrians on the Saturation Flow Rate of Right Turn Movements at Signalized Intersection - Case Study from Rasht City

Science.gov (United States)

Roshani, Mostafa; Bargegol, Iraj

2017-10-01

Saturation flow rate is one of the important items in the analysis of the capacity of signalized intersections that are affected by some factors. Pedestrian crossing on signalized intersection is one of the factors which influence the vehicles flow. In addition, the released researches determined that the greatest impact of pedestrian on the saturation flow occurred in the Conflict zone where the highest chance of the encounter of pedestrians and vehicles has in turning movements. The purpose of this paper is to estimate the saturation flow rate considering the effect of a pedestrian on right turn movements of the signalized intersections in Rasht city. For this goal, 6 signalized intersections with 90 cycles of reviews were selected for the estimation of saturation flow rate by the microscopic method and also 3 right turn lanes containing radius differences with 70 cycles of reviews were collected for the investigation of the pedestrians’ effects. Each phase of right turn lanes cycle was divided in the pieces of 10-second period which was totally 476 sample volumes of considered pedestrians and vehicles at that period. Only 101 samples of those were ranged as saturated conditions. Finally, using different regression models, the best relationship between pedestrian’s volume and right turning vehicles flow parameters was evaluated. The results indicate that there is a primarily linear relationship between pedestrian volume and right turning vehicles flow with R2=0.6261. According to this regression model with the increase in pedestrians, saturation flow rate will be reduced. In addition, by comparing the adjustment factor obtained in the present study and other studies, it was found that the effect of pedestrians on the right-turn movements in Rasht city is less than the rest of the world.

Multiobjective optimization model of intersection signal timing considering emissions based on field data: A case study of Beijing.

Science.gov (United States)

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.

A study of pedestrian compliance with traffic signals for exclusive and concurrent phasing.

Science.gov (United States)

Ivan, John N; McKernan, Kevin; Zhang, Yaohua; Ravishanker, Nalini; Mamun, Sha A

2017-01-01

This paper describes a comparison of pedestrian compliance at traffic signals with two types of pedestrian phasing: concurrent, where both pedestrians and vehicular traffic are directed to move in the same directions at the same time, and exclusive, where pedestrians are directed to move during their own dedicated phase while all vehicular traffic is stopped. Exclusive phasing is usually perceived to be safer, especially by senior and disabled advocacy groups, although these safety benefits depend upon pedestrians waiting for the walk signal. This paper investigates whether or not there are differences between pedestrian compliance at signals with exclusive pedestrian phasing and those with concurrent phasing and whether these differences continue to exist when compliance at exclusive phasing signals is evaluated as if they had concurrent phasing. Pedestrian behavior was observed at 42 signalized intersections in central Connecticut with both concurrent and exclusive pedestrian phasing. Binary regression models were estimated to predict pedestrian compliance as a function of the pedestrian phasing type and other intersection characteristics, such as vehicular and pedestrian volume, crossing distance and speed limit. We found that pedestrian compliance is significantly higher at intersections with concurrent pedestrian phasing than at those with exclusive pedestrian phasing, but this difference is not significant when compliance at exclusive phase intersections is evaluated as if it had concurrent phasing. This suggests that pedestrians treat exclusive phase intersections as though they have concurrent phasing, rendering the safety benefits of exclusive pedestrian phasing elusive. No differences were observed for senior or non-senior pedestrians. Published by Elsevier Ltd.

A Signal Coordination Control Based on Traversing Empty between Mid-Block Street Crossing and Intersection

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Changjiang Zheng

2012-01-01

Full Text Available To solve the problem in pedestrian Mid-Block street crossing, the method of signal coordination control between mid-block street crossing and intersection is researched in this paper. The paper proposes to use “distance-flow rate-time” graph as the tool for building coordination control system model which is for different situations of traffic control. Through alternating the linear optimization model, the system outputs the distribution of signal timing and system operational factors (delays in vehicles and mid-block street crossing. Finally, taking one section on the Taiping North Road in Nanjing as an example, the signal coordination control is carried out. And the results which are delays in the vehicles and mid-block street crossing are compared to those in the current distribution of signal timing.

Extended MRI findings of intersection syndrome

International Nuclear Information System (INIS)

Lee, Roger P.; Hatem, Stephen F.; Recht, Michael P.

2009-01-01

The symptoms and physical findings of intersection syndrome have been well described in the clinical medical literature. However, the magnetic resonance imaging (MRI) findings in patients with intersection syndrome of the forearm have only recently been described in a small number of patients. We review our experience with imaging of intersection syndrome, describe previously unreported MRI findings, and emphasize modifications to MRI protocols for its evaluation. Institutional review board approval was obtained for this retrospective review of patients with MRI findings consistent with intersection syndrome of the forearm during the period from January 2004 to September 2006. Six patients were identified, three males and three females, with an average age of 39.3 years. The MRI examinations were reviewed to assess signal abnormalities within and adjacent to the first and second dorsal extensor tendon compartments (DETC): tendinosis, peritendinous edema or fluid, muscle edema, subcutaneous edema, and juxtacortical edema. The overall longitudinal extent of signal alterations was measured as well as the distance from Lister's tubercle to the crossover of the first and second DETC. Review of the MRIs showed increased intrasubstance tendon signal suggesting tendinosis in two of the six patients, peritendinous edema or fluid in all six patients, muscle edema in five of the six patients, and subcutaneous edema in three of the six patients. Juxtacortical edema was seen in one patient. Peritendinous edema or fluid extended distally beyond the radiocarpal joint in three of the six patients. The average distance from Lister's tubercle to the crossover of the first and second DETC was 3.95 cm, in keeping with recently published data. Intersection syndrome is an uncommon MRI diagnosis. In addition to the previously described MRI findings of edema adjacent to the first or second DETC, possibly with proximal extension and subcutaneous edema, we have identified additional

Optimization of Signal Timing of Intersections by Internal Metering of Queue Time Ratio of Vehicles in Network Scale

Directory of Open Access Journals (Sweden)

Mina Ghanbarikarekani

2016-06-01

Full Text Available Optimization of signal timing in urban network is usually done by minimizing the delay times or queue lengths. Sincethe effect of each intersection on the whole network is not considered in the mentioned methods, traffic congestion may occur in network links. Therefore, this paper has aimed to provide a timing optimization algorithm for traffic signals using internal timing policy based on balancing queue time ratio of vehicles in network links. In the proposed algorithm, the difference between the real queue time ratio and the optimum one for each link of intersection was minimized. To evaluate the efficiency of the proposed algorithm on traffic performance, the proposed algorithm was applied in a hypothetical network. By comparing the simulating software outputs, before and after implementing the algorithm, it was concluded that the queue time ratio algorithm has improved the traffic parameters by increasing the flow as well as reducing the delay time and density of the network.

Evaluation of j-turn intersection design performance in Missouri.

Science.gov (United States)

2013-12-01

Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections with : minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is the ...

To signal or not to signal: that should not be the question.

Science.gov (United States)

Faw, Harold W

2013-10-01

The purpose of the present research was to examine rates of turn signal use, a positive and potentially valuable means by which drivers can communicate. A second purpose was to explore factors that might impact these rates, including the modeling influence of other drivers. A series of observations involving more than 5600 vehicles making turns were recorded at a variety of intersections in British Columbia, Canada. Though the occurrence of signal use varied widely, ranging from a low of 54% to a high of 95%, the overall rate was 76%. Drivers used turn signals significantly less often when making right as compared with left turns, when traffic volume was higher, and when a designated turning lane was provided. In addition, compared with drivers following another vehicle not using signals, those following a vehicle with turn signals on were significantly more likely to activate their turn signals, suggesting a possible modeling effect. Both internal and external influences on turn signal use by drivers were considered. External factors explored in this research included direction of turn, traffic volume, intersection configuration, and the example of other drivers. It was concluded that the practice of signaling turns merits more research attention, since consistent use of signals is a potential contributor to enhanced safety for all road users. Copyright © 2013 Elsevier Ltd. All rights reserved.

Exploring the impact of signal types and adjacent vehicles on drivers' choices after the onset of yellow

Science.gov (United States)

Bao, Ji; Chen, Qun; Luo, Dandan; Wu, Yuli; Liang, Zuli

2018-06-01

Drivers' choices at signalized intersections may be made in great uncertainty after the onset of yellow, which creates potential hazards for road safety. These choices are analyzed and modeled based on field observations at three comparable signalized intersections in Changsha, China. The results show that intersections without monitoring devices widen the indecision zone, which can increase the risk of rear-end collisions and the uncertainty of drivers' decision-making. In addition, drivers are more likely to stop during the yellow interval at intersections equipped with a green signal countdown device (GSCD) than at those with a green signal flashing device (GSFD). Subsequently, according to the results of a binary logistic regression model (BLRM), drivers' decision making at the onset of the yellow indication is greatly influenced by the vehicle's spot speed, the distance to the stop line, and signal and monitoring devices. The presence of an adjacent vehicle with a short space headway can particularly motivate the following driver to make a go-decision after the first driver chooses to pass the intersection. However, a stop-decision by a driver in an adjacent lane can also prompt the following driver to stop.

Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design

Science.gov (United States)

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

Signal Control for Reducing Vehicle NOx and CO2 Emissions Based on Prediction of Arrival Traffic Flows at Intersections

Science.gov (United States)

Oda, Toshihiko

Nitrogen oxide (NOx) and carbon dioxide (CO2) emissions from vehicles have been increasing every year because of the growing number of vehicles, and they cause serious environmental problems such as air pollution and global warming. To alleviate these problems, this paper proposes a new traffic signal control method for reducing vehicle NOx and CO2 emissions on arterial roads. To this end, we first model the amount of vehicle emissions as a function of the traffic delay and the number of stops at intersections. This step is necessary because it is difficult to obtain the amount of emissions directly using traffic control systems. Second, we introduce a signal control model in which the control parameters are continuously updated on the basis of predictions of arrival traffic flows at intersections. The signal timings are calculated in such a manner so as to minimize the weighted sum of the two emissions, which depend on the traffic flow. To evaluate the validity of this method, simulation experiments are carried out on an arterial road. The experiments show that the proposed method significantly outperforms existing methods in reducing both the emissions and travel time.

Determining of the Parking Manoeuvre and the Taxi Blockage Adjustment Factor for the Saturation Flow Rate at the Outlet Legs of Signalized Intersections: Case Study from Rasht City (Iran)

Science.gov (United States)

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.

Deployment and Field Evaluation of In-Vehicle Traffic Signal Advisory System (ITSAS

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Joyoung Lee

2017-06-01

Full Text Available This research evaluates the impact of In-vehicle Signal Advisory System (ITSAS on signalized arterial. ITSAS provides individual drivers equipped with a mobile communication device with advisory speed information enabling to minimize the time delay and fuel consumption when crossing intersection. Given the instantaneous vehicular driving information, such as position, speed, and acceleration rate, ITSAS produces advisory speed information by taking into consideration the traffic signal changes at a downstream intersection. The advisory speed information includes not only an optimal speed range updated every 300-ft for individual drivers but also a descriptive message to warn drivers stop to ensure safety at the downstream intersection. Unlike other similar Connected Vehicles applications for intersection management, ITSAS does not require Roadside Equipment (RSE to disseminate the advisory speed information as it is designed to exploit commercial cellular network service (i.e., 3G and 4G-LTE. Thus, ITSAS can be easily plugged into existing traffic control management system to rapidly conduct its implementation without significant additional cost. This research presents the field evaluations of ITSAS on a signalized corridor in New Jersey, which discovered significant travel time savings for the equipped vehicle.

Simulation of queue length and vehicle delays on signal-controlled intersection

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Leverents Evgeny

2018-01-01

Full Text Available The extensive use of information technology in the field of traffic control will increase the traffic capacity of intersection points and transports. To assess the efficacy of changing options for the road traffic organization or the reorganization of intersection points, you need to know the average delay in vehicles and the length of the queue. The adaptive traffic light control is one of such tools. Simulation modeling of traffic flows use for the definition of its work. The aim of this work is to create a simulation model of controlled intersection, which can evaluate the efficiency of the application the adaptive regulation in various traffic situations, including the availability or deficiency of pedestrian traffic through the intersection. The numerical experiment in in the model pass with using of the Monte Carlo method, which can to draw a conclusion about the calculated parameter on the basis of the result of the reproduction of the calculation model.

Lighting levels for isolated intersections : leading to safety improvements : final report.

Science.gov (United States)

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...

Evaluation of countermeasures for red light running by traffic simulator-based surrogate safety measures.

Science.gov (United States)

Lee, Changju; So, Jaehyun Jason; Ma, Jiaqi

2018-01-02

The conflicts among motorists entering a signalized intersection with the red light indication have become a national safety issue. Because of its sensitivity, efforts have been made to investigate the possible causes and effectiveness of countermeasures using comparison sites and/or before-and-after studies. Nevertheless, these approaches are ineffective when comparison sites cannot be found, or crash data sets are not readily available or not reliable for statistical analysis. Considering the random nature of red light running (RLR) crashes, an inventive approach regardless of data availability is necessary to evaluate the effectiveness of each countermeasure face to face. The aims of this research are to (1) review erstwhile literature related to red light running and traffic safety models; (2) propose a practical methodology for evaluation of RLR countermeasures with a microscopic traffic simulation model and surrogate safety assessment model (SSAM); (3) apply the proposed methodology to actual signalized intersection in Virginia, with the most prevalent scenarios-increasing the yellow signal interval duration, installing an advance warning sign, and an RLR camera; and (4) analyze the relative effectiveness by RLR frequency and the number of conflicts (rear-end and crossing). All scenarios show a reduction in RLR frequency (-7.8, -45.5, and -52.4%, respectively), but only increasing the yellow signal interval duration results in a reduced total number of conflicts (-11.3%; a surrogate safety measure of possible RLR-related crashes). An RLR camera makes the greatest reduction (-60.9%) in crossing conflicts (a surrogate safety measure of possible angle crashes), whereas increasing the yellow signal interval duration results in only a 12.8% reduction of rear-end conflicts (a surrogate safety measure of possible rear-end crash). Although increasing the yellow signal interval duration is advantageous because this reduces the total conflicts (a possibility of total

Cross-comparison of three surrogate safety methods to diagnose cyclist safety problems at intersections in Norway.

Science.gov (United States)

Laureshyn, Aliaksei; Goede, Maartje de; Saunier, Nicolas; Fyhri, Aslak

2017-08-01

Relying on accident records as the main data source for studying cyclists' safety has many drawbacks, such as high degree of under-reporting, the lack of accident details and particularly of information about the interaction processes that led to the accident. It is also an ethical problem as one has to wait for accidents to happen in order to make a statement about cyclists' (un-)safety. In this perspective, the use of surrogate safety measures based on actual observations in traffic is very promising. In this study we used video data from three intersections in Norway that were all independently analysed using three methods: the Swedish traffic conflict technique (Swedish TCT), the Dutch conflict technique (DOCTOR) and the probabilistic surrogate measures of safety (PSMS) technique developed in Canada. The first two methods are based on manual detection and counting of critical events in traffic (traffic conflicts), while the third considers probabilities of multiple trajectories for each interaction and delivers a density map of potential collision points per site. Due to extensive use of microscopic data, PSMS technique relies heavily on automated tracking of the road users in video. Across the three sites, the methods show similarities or are at least "compatible" with the accident records. The two conflict techniques agree quite well for the number, type and location of conflicts, but some differences with no obvious explanation are also found. PSMS reports many more safety-relevant interactions including less severe events. The location of the potential collision points is compatible with what the conflict techniques suggest, but the possibly significant share of false alarms due to inaccurate trajectories extracted from video complicates the comparison. The tested techniques still require enhancement, with respect to better adjustment to analysis of the situations involving cyclists (and vulnerable road users in general) and further validation. However, we

"Highly processed, highly packaged, very unhealthy. But they are low risk": exploring intersections between community food security and food safety.

Science.gov (United States)

Speed, Kelsey A; Meyer, Samantha B; Hanning, Rhona M; Majowicz, Shannon E

2017-10-01

Food insecurity and foodborne disease are important issues in Canada, and the public health actions taken to address them can be conceptualized as factors shaping the food environment. Given emerging evidence that these two areas may interrelate, the objective of this study was to explore ways in which community food security efforts and food safety practices (and the population health issues they aim to address) may intersect in British Columbia, Canada, and interpret what this might mean for conceptualizing and attaining healthier food environments. We conducted 14 key informant interviews with practitioners working in community food security and food safety in British Columbia, and used qualitative descriptive analysis to identify examples of intersections between the sectors. Participants identified four key ways that the two sectors intersect. They identified (1) how their daily practices to promote safe or healthy food could be helped or hindered by the activities of the other sector; (2) that historically disjointed policies that do not consider multiple health outcomes related to food may complicate the interrelationship; (3) that the relationship of these sectors is also affected by the fact that specific types of food products, such as fresh produce, can be considered both risky and beneficial; and (4) that both sectors are working towards the same goal of improved population health, albeit viewing it through slightly different lenses. Food security and food safety connect in several ways, with implications for characterizing and improving Canadian food environments. Collaboration across separated public health areas related to food is needed when designing new programs or policies aimed at changing the way Canadians eat.

"Highly processed, highly packaged, very unhealthy. But they are low risk": exploring intersections between community food security and food safety

Directory of Open Access Journals (Sweden)

Kelsey A. Speed

2017-10-01

Full Text Available Introduction: Food insecurity and foodborne disease are important issues in Canada, and the public health actions taken to address them can be conceptualized as factors shaping the food environment. Given emerging evidence that these two areas may interrelate, the objective of this study was to explore ways in which community food security efforts and food safety practices (and the population health issues they aim to address may intersect in British Columbia, Canada, and interpret what this might mean for conceptualizing and attaining healthier food environments. Methods: We conducted 14 key informant interviews with practitioners working in community food security and food safety in British Columbia, and used qualitative descriptive analysis to identify examples of intersections between the sectors. Results: Participants identified four key ways that the two sectors intersect. They identified (1 how their daily practices to promote safe or healthy food could be helped or hindered by the activities of the other sector; (2 that historically disjointed policies that do not consider multiple health outcomes related to food may complicate the interrelationship; (3 that the relationship of these sectors is also affected by the fact that specific types of food products, such as fresh produce, can be considered both risky and beneficial; and (4 that both sectors are working towards the same goal of improved population health, albeit viewing it through slightly different lenses. Conclusion: Food security and food safety connect in several ways, with implications for characterizing and improving Canadian food environments. Collaboration across separated public health areas related to food is needed when designing new programs or policies aimed at changing the way Canadians eat.

Dynamic Eco-Driving Speed Guidance at Signalized Intersections: Multivehicle Driving Simulator Based Experimental Study

Directory of Open Access Journals (Sweden)

Peng Chen

2018-01-01

Full Text Available Variations in vehicle fuel consumption and gas emissions are usually associated with changes in cruise speed and the aggressiveness of drivers’ acceleration/deceleration, especially at traffic signals. In an attempt to enhance vehicle fuel efficiency on arterials, this study developed a dynamic eco-driving speed guidance strategy (DESGS using real-time signal timing and vehicle positioning information in a connected vehicle (CV environment. DESGS mainly aims to optimize the fuel/emission speed profiles for vehicles approaching signalized intersections. An optimization-based rolling horizon and a dynamic programming approach were proposed to track the optimal guided velocity for individual vehicles along the travel segment. In addition, a vehicle specific power (VSP based approach was integrated into DESGS to estimate the fuel consumption and CO2 emissions. To evaluate the effectiveness of the overall strategy, 15 experienced drivers were recruited to participate in interactive speed guidance experiments using multivehicle driving simulators. It was found that compared to vehicles without speed guidance, those with DESGS had a significantly reduced number of stops and approximately 25% less fuel consumption and CO2 emissions.

Low Emissions and Delay Optimization for an Isolated Signalized Intersection Based on Vehicular Trajectories.

Science.gov (United States)

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.

Intersection carbon monoxide modeling

International Nuclear Information System (INIS)

Zamurs, J.

1990-01-01

In this note the author discusses the need for better air quality mobile source models near roadways and intersections. To develop the improved models, a better understanding of emissions and their relation to ambient concentrations is necessary. The database for the modal model indicates that vehicles do have different emission levels for different engine operating modes. If the modal approach is used information is needed on traffic signal phasing, queue lengths, delay times, acceleration rates, deceleration rates, capacity, etc. Dispersion estimates using current air quality models may be inaccurate because the models do not take into account intersecting traffic streams, multiple buildings of varying setbacks, height, and spacing

Evaluation of j-turn intersection design performance in Missouri, final report.

Science.gov (United States)

2013-12-01

Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections : with minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is : th...

How the choice of safety performance function affects the identification of important crash prediction variables.

Science.gov (United States)

Wang, Ketong; Simandl, Jenna K; Porter, Michael D; Graettinger, Andrew J; Smith, Randy K

2016-03-01

Across the nation, researchers and transportation engineers are developing safety performance functions (SPFs) to predict crash rates and develop crash modification factors to improve traffic safety at roadway segments and intersections. Generalized linear models (GLMs), such as Poisson or negative binomial regression, are most commonly used to develop SPFs with annual average daily traffic as the primary roadway characteristic to predict crashes. However, while more complex to interpret, data mining models such as boosted regression trees have improved upon GLMs crash prediction performance due to their ability to handle more data characteristics, accommodate non-linearities, and include interaction effects between the characteristics. An intersection data inventory of 36 safety relevant parameters for three- and four-legged non-signalized intersections along state routes in Alabama was used to study the importance of intersection characteristics on crash rate and the interaction effects between key characteristics. Four different SPFs were investigated and compared: Poisson regression, negative binomial regression, regularized generalized linear model, and boosted regression trees. The models did not agree on which intersection characteristics were most related to the crash rate. The boosted regression tree model significantly outperformed the other models and identified several intersection characteristics as having strong interaction effects. Copyright © 2015 Elsevier Ltd. All rights reserved.

“Highly processed, highly packaged, very unhealthy. But they are low risk”: exploring intersections between community food security and food safety

Science.gov (United States)

Kelsey A., Speed; Samantha B., Meyer; Rhona M., Hanning; Shannon E., Majowicz

2017-01-01

Abstract Introduction: Food insecurity and foodborne disease are important issues in Canada, and the public health actions taken to address them can be conceptualized as factors shaping the food environment. Given emerging evidence that these two areas may interrelate, the objective of this study was to explore ways in which community food security efforts and food safety practices (and the population health issues they aim to address) may intersect in British Columbia, Canada, and interpret what this might mean for conceptualizing and attaining healthier food environments. Methods: We conducted 14 key informant interviews with practitioners working in community food security and food safety in British Columbia, and used qualitative descriptive analysis to identify examples of intersections between the sectors. Results: Participants identified four key ways that the two sectors intersect. They identified (1) how their daily practices to promote safe or healthy food could be helped or hindered by the activities of the other sector; (2) that historically disjointed policies that do not consider multiple health outcomes related to food may complicate the interrelationship; (3) that the relationship of these sectors is also affected by the fact that specific types of food products, such as fresh produce, can be considered both risky and beneficial; and (4) that both sectors are working towards the same goal of improved population health, albeit viewing it through slightly different lenses. Conclusion: Food security and food safety connect in several ways, with implications for characterizing and improving Canadian food environments. Collaboration across separated public health areas related to food is needed when designing new programs or policies aimed at changing the way Canadians eat. PMID:29043759

Stimulated Raman signals at conical intersections: Ab initio surface hopping simulation protocol with direct propagation of the nuclear wave function

International Nuclear Information System (INIS)

Kowalewski, Markus; Mukamel, Shaul

2015-01-01

Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings

Stimulated Raman signals at conical intersections: Ab initio surface hopping simulation protocol with direct propagation of the nuclear wave function

Energy Technology Data Exchange (ETDEWEB)

Kowalewski, Markus, E-mail: mkowalew@uci.edu; Mukamel, Shaul, E-mail: smukamel@uci.edu [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

2015-07-28

Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings.

Turning movements, vehicle offsets and ageing drivers driving behaviour at channelized and unchannelized intersections.

Science.gov (United States)

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.

Low Emissions and Delay Optimization for an Isolated Signalized Intersection Based on Vehicular Trajectories.

Directory of Open Access Journals (Sweden)

Ciyun Lin

Full Text Available 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.

Self-Localization at Street Intersections.

Science.gov (United States)

Fusco, Giovanni; Shen, Huiying; Coughlan, James M

2014-05-01

There is growing interest among smartphone users in the ability to determine their precise location in their environment for a variety of applications related to wayfinding, travel and shopping. While GPS provides valuable self-localization estimates, its accuracy is limited to approximately 10 meters in most urban locations. This paper focuses on the self-localization needs of blind or visually impaired travelers, who are faced with the challenge of negotiating street intersections. These travelers need more precise self-localization to help them align themselves properly to crosswalks, signal lights and other features such as walk light pushbuttons. We demonstrate a novel computer vision-based localization approach that is tailored to the street intersection domain. Unlike most work on computer vision-based localization techniques, which typically assume the presence of detailed, high-quality 3D models of urban environments, our technique harnesses the availability of simple, ubiquitous satellite imagery (e.g., Google Maps) to create simple maps of each intersection. Not only does this technique scale naturally to the great majority of street intersections in urban areas, but it has the added advantage of incorporating the specific metric information that blind or visually impaired travelers need, namely, the locations of intersection features such as crosswalks. Key to our approach is the integration of IMU (inertial measurement unit) information with geometric information obtained from image panorama stitchings. Finally, we evaluate the localization performance of our algorithm on a dataset of intersection panoramas, demonstrating the feasibility of our approach.

CONTROLLING TRAFFIC FLOW IN MULTILANE-ISOLATED INTERSECTION USING ANFIS APPROACH TECHNIQUES

Directory of Open Access Journals (Sweden)

G. R. LAI

2015-08-01

Full Text Available Many controllers have applied the Adaptive Neural-Fuzzy Inference System (ANFIS concept for optimizing the controller performance. However, there are less traffic signal controllers developed using the ANFIS concept. ANFIS traffic signal controller with its fuzzy rule base and its ability to learn from a set of sample data could improve the performance of Existing traffic signal controlling system to reduce traffic congestions at most of the busy traffic intersections in city such as Kuala Lumpur, Malaysia. The aim of this research is to develop an ANFIS traffic signals controller for multilane-isolated four approaches intersections in order to ease traffic congestions at traffic intersections. The new concept to generate sample data for ANFIS training is introduced in this research. The sample data is generated based on fuzzy rules and can be analysed using tree diagram. This controller is simulated on multilane-isolated traffic intersection model developed using M/M/1 queuing theory and its performance in terms of average waiting time, queue length and delay time are compared with traditional controllers and fuzzy controller. Simulation result shows that the average waiting time, queue length, and delay time of ANFIS traffic signal controller are the lowest as compared to the other three controllers. In conclusion, the efficiency and performance of ANFIS controller are much better than that of fuzzy and traditional controllers in different traffic volumes.

Estimation of red-light running frequency using high-resolution traffic and signal data.

Science.gov (United States)

Chen, Peng; Yu, Guizhen; Wu, Xinkai; Ren, Yilong; Li, Yueguang

2017-05-01

Red-light-running (RLR) emerges as a major cause that may lead to intersection-related crashes and endanger intersection safety. To reduce RLR violations, it's critical to identify the influential factors associated with RLR and estimate RLR frequency. Without resorting to video camera recordings, this study investigates this important issue by utilizing high-resolution traffic and signal event data collected from loop detectors at five intersections on Trunk Highway 55, Minneapolis, MN. First, a simple method is proposed to identify RLR by fully utilizing the information obtained from stop bar detectors, downstream entrance detectors and advance detectors. Using 12 months of event data, a total of 6550 RLR cases were identified. According to a definition of RLR frequency as the conditional probability of RLR on a certain traffic or signal condition (veh/1000veh), the relationships between RLR frequency and some influential factors including arriving time at advance detector, approaching speed, headway, gap to the preceding vehicle on adjacent lane, cycle length, geometric characteristics and even snowing weather were empirically investigated. Statistical analysis shows good agreement with the traffic engineering practice, e.g., RLR is most likely to occur on weekdays during peak periods under large traffic demands and longer signal cycles, and a total of 95.24% RLR events occurred within the first 1.5s after the onset of red phase. The findings confirmed that vehicles tend to run the red light when they are close to intersection during phase transition, and the vehicles following the leading vehicle with short headways also likely run the red light. Last, a simplified nonlinear regression model is proposed to estimate RLR frequency based on the data from advance detector. The study is expected to helpbetter understand RLR occurrence and further contribute to the future improvement of intersection safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

A full Bayes before-after study accounting for temporal and spatial effects: Evaluating the safety impact of new signal installations.

Science.gov (United States)

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.

Automation of a T-intersection using virtual platoons of cooperative autonomous vehicles

NARCIS (Netherlands)

Morales Medina, Alejandro; van de Wouw, N.; Nijmeijer, H.

2015-01-01

Both traffic throughput and the vehicle passenger safety can be increased by automating road intersections. We propose the virtual platooning concept to ensure a smooth, efficient and safe traffic flow through an automated intersection. The virtual platoon is formed by defining a virtual

Evaluation of Adaptive Signal Control Technology—Volume 2 : Comparison of Base Condition to the First Year After Implementation

Science.gov (United States)

2018-05-01

Field evaluation of adaptive signal control technologies (ASCT) is very important in understanding the systems contribution to safety and operational efficiency. Data were collected at six intersections along the Neil Street corridor in Champaign,...

The trend of road traffic crashes at urban signalised intersection

Science.gov (United States)

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.

Increasing Capacity of Intersections with Transit Priority

Directory of Open Access Journals (Sweden)

Yanxi Hao

2016-12-01

Full Text Available Dedicated bus lane (DBL and transit signal priority (TSP are two effective and low-cost ways of improving the reliability of transits. However, these strategies reduce the capacity of general traffic. This paper presents an integrated optimization (IO model to improve the performance of intersections with dedicated bus lanes. The IO model integrated geometry layout, main-signal timing, pre-signal timing and transit priority. The optimization problem is formulated as a Mix-Integer-Non-Linear-Program (MINLP that can be transformed into a Mix-Integer-Linear-Program (MILP and then solved by the standard branch-and-bound technique. The applicability of the IO model is tested through numerical experiment under different intersection layouts and traffic demands. A VISSIM micro simulation model was developed and used to evaluate the performance of the proposed IO model. The test results indicate that the proposed model can increase the capacity and reduce the delay of general traffic when providing priority to buses.

Intersection assistance: a safe solution for older drivers?

Science.gov (United States)

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.

Mixed Vehicle Flow At Signalized Intersection: Markov Chain Analysis

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Gertsbakh Ilya B.

2015-09-01

Full Text Available We assume that a Poisson flow of vehicles arrives at isolated signalized intersection, and each vehicle, independently of others, represents a random number X of passenger car units (PCU’s. We analyze numerically the stationary distribution of the queue process {Zn}, where Zn is the number of PCU’s in a queue at the beginning of the n-th red phase, n → ∞. We approximate the number Yn of PCU’s arriving during one red-green cycle by a two-parameter Negative Binomial Distribution (NBD. The well-known fact is that {Zn} follow an infinite-state Markov chain. We approximate its stationary distribution using a finite-state Markov chain. We show numerically that there is a strong dependence of the mean queue length E[Zn] in equilibrium on the input distribution of Yn and, in particular, on the ”over dispersion” parameter γ= Var[Yn]/E[Yn]. For Poisson input, γ = 1. γ > 1 indicates presence of heavy-tailed input. In reality it means that a relatively large ”portion” of PCU’s, considerably exceeding the average, may arrive with high probability during one red-green cycle. Empirical formulas are presented for an accurate estimation of mean queue length as a function of load and g of the input flow. Using the Markov chain technique, we analyze the mean ”virtual” delay time for a car which always arrives at the beginning of the red phase.

47 CFR 80.329 - Safety signals and messages.

Science.gov (United States)

2010-10-01

.... It must be sent before the call. (c) In radiotelephony, the safety signal consists of the word... signal and call must be sent on one of the international distress frequencies (2182 kHz or 156.8 MHz...

Analysis and methods of improvement of safety at high-speed rural intersections : appendix B.

Science.gov (United States)

2012-04-01

Since 2006, INDOT has been preparing an annual fivepercent report that identifies intersections and segments on Indiana state roads that require attention due to the excessive number and severity of crashes. Many of the identified intersections ar...

Intersection of neighbourhood structure, parenting and externalizing ...

African Journals Online (AJOL)

Little is known about parenting practices and how it intersects with neighbourhood structure and externalizing behaviour, in South Africa. This chapter presents the findings of parental reflections on neighbourhood structure and problem behaviours, which is one component of a study, that is situated within a child safety, ...

Technology-related distracted walking behaviours in Manhattan's most dangerous intersections.

Science.gov (United States)

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.

Intersection Group Dynamic Subdivision and Coordination at Intraregional Boundaries in Sudden Disaster

Directory of Open Access Journals (Sweden)

Ciyun Lin

2015-01-01

Full Text Available This paper aims at the traffic flow agglomeration effect characteristics and rapid evacuation requirement in sudden disaster; operation time of intraregional boundaries traffic signal coordination was presented firstly. Then intraregional boundaries intersection group dynamic subdivision and consolidation method based on relative similarity degree and similarity coefficient of adjacent intersections was put forward. As to make the traffic control strategy adapt to traffic condition of different intraregional boundaries intersection groups, this paper proposes an intraregional boundaries traffic signal coordination and optimization technology based on organic computing theory. Finally, this paper uses Delphi 7.0, MapX, and Oracle developing a software package, combined with Paramics V6 Simulator to validate the methods of this paper. The result shows that it can obviously improve disaster affected regional traffic signal control efficiency which reduces average traffic delay by 30–35%, decreases vehicle queue by more than 20% and reduces evacuation time more than 13.06%.

Distributed traffic signal control using fuzzy logic

Science.gov (United States)

Chiu, Stephen

1992-01-01

We present a distributed approach to traffic signal control, where the signal timing parameters at a given intersection are adjusted as functions of the local traffic condition and of the signal timing parameters at adjacent intersections. Thus, the signal timing parameters evolve dynamically using only local information to improve traffic flow. This distributed approach provides for a fault-tolerant, highly responsive traffic management system. The signal timing at an intersection is defined by three parameters: cycle time, phase split, and offset. We use fuzzy decision rules to adjust these three parameters based only on local information. The amount of change in the timing parameters during each cycle is limited to a small fraction of the current parameters to ensure smooth transition. We show the effectiveness of this method through simulation of the traffic flow in a network of controlled intersections.

Types of intersections.

NARCIS (Netherlands)

2015-01-01

There are many types of intersections in the Netherlands. In an inherently safe road traffic system, however, the number of intersection types needs to be limited, depending on the road types that intersect. The desired types of intersections do not always correspond with the recommendations in the

Revisiting Street Intersections Using Slot-Based Systems.

Directory of Open Access Journals (Sweden)

Remi Tachet

Full Text Available Since their appearance at the end of the 19th century, traffic lights have been the primary mode of granting access to road intersections. Today, this centuries-old technology is challenged by advances in intelligent transportation, which are opening the way to new solutions built upon slot-based systems similar to those commonly used in aerial traffic: what we call Slot-based Intersections (SIs. Despite simulation-based evidence of the potential benefits of SIs, a comprehensive, analytical framework to compare their relative performance with traffic lights is still lacking. Here, we develop such a framework. We approach the problem in a novel way, by generalizing classical queuing theory. Having defined safety conditions, we characterize capacity and delay of SIs. In the 2-road crossing configuration, we provide a capacity-optimal SI management system. For arbitrary intersection configurations, near-optimal solutions are developed. Results theoretically show that transitioning from a traffic light system to SI has the potential of doubling capacity and significantly reducing delays. This suggests a reduction of non-linear dynamics induced by intersection bottlenecks, with positive impact on the road network. Such findings can provide transportation engineers and planners with crucial insights as they prepare to manage the transition towards a more intelligent transportation infrastructure in cities.

“Bus Lane Within The Area Of Intersection” Method For Buses Priority On The Intersections

Directory of Open Access Journals (Sweden)

Vikovych Ihor

2015-12-01

Full Text Available The primary objective of this article is to formalize the “special bus lanes within the area of intersection” method that allows providing buses with space-time priority at signalized intersections (mostly of the isolated type, including those with no more than two traffic lanes in each direction at the approaches to the intersection. The article establishes the limits for efficient application of this method, and describes the results of a simulation experiment conducted in the VISSIM environment to investigate the functioning of the method on an actual intersection. The most critical phase of implementation of this method is to determine the optimum length of the special bus lane at the approach to the intersection. The optimum length of special bus lanes at the approaches to isolated or coordinated intersections is determined based on the maximum length of queued vehicles which is computed using the simulation models developed in the Objective-C language. The article covers the basic characteristics of those models, their structure and building principles, and also provides the model validation results. Simulation models can be used both for determination of the optimum length of special bus lanes at the approaches to signalized intersections and for analysis of intersection performance based on the maximum length of queued vehicles.

Grounded Intersectionality

DEFF Research Database (Denmark)

Marfelt, Mikkel Mouritz

2016-01-01

associated with intersectional research. The findings assist in positioning the proposed methodological framework within recent intersectional debates. Findings – The review shows a rise in intersectional publications since the birth of the “intersectionality” term in 1989. Moreover, the paper points to four...... oriented but still emphasizes stable concepts. Moreover, it does not give primacy to oppression. Finally, it adopts a critical stance on the nature of the macro, meso, and micro levels as dominant analytical perspectives. As a result, this paper focusses on the importance of intersectionality...

Choice of the control variables of an isolated intersection by graph colouring

Directory of Open Access Journals (Sweden)

Batanović Vladan

2015-01-01

Full Text Available This paper deals with the problem of grouping the traffic streams into some groups - signal groups on a signalized intersection. The fact that more traffic streams, which are not in a conflict, can be controlled by one sequence of traffic lights means that one control variable can be assigned to one signal group. Determination of the complete sets of signal groups, i.e. the groups of traffic streams on one intersection, controlled by one control variable is defined in this paper as a graphcoloring problem. The complete sets of signal groups are obtained by coloring the complement of the graph of identical indications. It is shown that the minimal number of signal groups in the complete set of signal groups is equal to the chromatic number of the complement of the graph with identical indications. The problem of finding all complete sets of signal groups with minimal cardinality, which is equal to the chromatic number, is formulated as a linear programming problem where the values of variables belong to set {0,1}.

Evaluation of pedestrian safety at intersections: A theoretical framework based on pedestrian-vehicle interaction patterns.

Science.gov (United States)

Ni, Ying; Wang, Menglong; Sun, Jian; Li, Keping

2016-11-01

Pedestrians are the most vulnerable road users, and pedestrian safety has become a major research focus in recent years. Regarding the quality and quantity issues with collision data, conflict analysis using surrogate safety measures has become a useful method to study pedestrian safety. However, given the inequality between pedestrians and vehicles in encounters and the multiple interactions between pedestrians and vehicles, it is insufficient to simply use the same indicator(s) or the same way to aggregate indicators for all conditions. In addition, behavioral factors cannot be neglected. To better use information extracted from trajectories for safety evaluation and pay more attention on effects of behavioral factors, this paper develops a more sophisticated framework for pedestrian conflict analysis that takes pedestrian-vehicle interactions into consideration. A concept of three interaction patterns has been proposed for the first time, namely "hard interaction," "no interaction," and "soft-interaction." Interactions have been categorized under one of these patterns by analyzing profiles of speed and conflict indicators during the whole interactive processes. In this paper, a support vector machine (SVM) approach has been adopted to classify severity levels for a dataset including 1144 events extracted from three intersections in Shanghai, China, followed by an analysis of variable importance. The results revealed that different conflict indicators have different contributions to indicating the severity level under various interaction patterns. Therefore, it is recommended either to use specific conflict indicators or to use weighted indicator aggregation for each interaction pattern when evaluating pedestrian safety. The implementation has been carried out at the fourth crosswalk, and the results indicate that the proposed method can achieve a higher accuracy and better robustness than conventional methods. Furthermore, the method is helpful for better

Sustainable intersection control to accommodate urban freight mobility.

Science.gov (United States)

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...

Assessing the 'system' in safe systems-based road designs: using cognitive work analysis to evaluate intersection designs.

Science.gov (United States)

Cornelissen, M; Salmon, P M; Stanton, N A; McClure, R

2015-01-01

While a safe systems approach has long been acknowledged as the underlying philosophy of contemporary road safety strategies, systemic applications are sparse. This article argues that systems-based methods from the discipline of Ergonomics have a key role to play in road transport design and evaluation. To demonstrate, the Cognitive Work Analysis framework was used to evaluate two road designs - a traditional Melbourne intersection and a cut-through design for future intersections based on road safety safe systems principles. The results demonstrate that, although the cut-through intersection appears different in layout from the traditional intersection, system constraints are not markedly different. Furthermore, the analyses demonstrated that redistribution of constraints in the cut-through intersection resulted in emergent behaviour, which was not anticipated and could prove problematic. Further, based on the lack of understanding of emergent behaviour, similar design induced problems are apparent across both intersections. Specifically, incompatibilities between infrastructure, vehicles and different road users were not dealt with by the proposed design changes. The importance of applying systems methods in the design and evaluation of road transport systems is discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mitigating gas emissions at signalised intersections using wireless vehicle detectors

Directory of Open Access Journals (Sweden)

Moses Kwasi Torkudzor

2015-09-01

Full Text Available Traffic congestion on roads wastes travel times and increases fuel consumption as well as gas emissions which are dangerous to human health. This has led to growing concern about environmental protection and energy conservation and a number of studies to increase fuel economy and reduce gas emissions. To increase travel times so as to reduce fuel consumption and gas emissions, traffic signals at intersections must be well implemented. It is therefore necessary to employ the current technology of wireless sensor networks to enhance the optimisation of the signalised intersections so as to address such a concern. In this study, a vehicular traffic control model was developed to optimise a signalised intersection, using wireless vehicle detectors. Real-time traffic volume gathered were analysed to obtain the peak hour traffic volume causing congestion. The intersection was modelled and simulated in Synchro7 as an actuated signalised model using results from the analysed data. The model for morning peak and evening peak periods gave optimal cycle lengths which result in the reduction of gas emissions, fuel consumption and delay at the intersection.

Dynamic all-red extension at signalized intersection : probabilistic modeling and algorithm.

Science.gov (United States)

2011-01-01

Red light running has been a major cause of intersection injuries and fatalities in the United : States. In 2004 alone, there were 8,619 fatal crashes and 848,000 crashes with people injured, all : caused by RLR. Under the U.S. Department of Transpor...

At the cross-roads: an on-road examination of driving errors at intersections.

Science.gov (United States)

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.

Delays at signalised intersections with exhaustive traffic control

NARCIS (Netherlands)

Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

2010-01-01

In this paper we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under Heavy Traffic (HT) conditions,

Delays at signalised intersections with exhaustive traffic control

NARCIS (Netherlands)

Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

2012-01-01

In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions.

Using the event analysis of systemic teamwork (EAST) to explore conflicts between different road user groups when making right hand turns at urban intersections.

Science.gov (United States)

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.

Modeling the dynamics of driver's dilemma zone perception using machine learning methods for safer intersection control.

Science.gov (United States)

2014-04-01

The "dilemma zone" (DZ) is defined as the area where drivers approaching a signalized intersection must decide to either proceed or stop at the onset of the yellow indication. Drivers that might perceive themselves to be too close to an intersection ...

Route-Based Signal Preemption Control of Emergency Vehicle

Directory of Open Access Journals (Sweden)

Haibo Mu

2018-01-01

Full Text Available This paper focuses on the signal preemption control of emergency vehicles (EV. A signal preemption control method based on route is proposed to reduce time delay of EV at intersections. According to the time at which EV is detected and the current phase of each intersection on the travelling route of EV, the calculation methods of the earliest start time and the latest start time of green light at each intersection are given. Consequently, the effective time range of green light at each intersection is determined in theory. A multiobjective programming model, whose objectives are the minimal residence time of EV at all intersections and the maximal passing numbers of general society vehicles, is presented. Finally, a simulation calculation is carried out. Calculation results indicate that, by adopting the signal preemption method based on route, the delay of EV is reduced and the number of society vehicles passing through the whole system is increased. The signal preemption control method of EV based on route can reduce the time delay of EV and improve the evacuation efficiency of the system.

A novel approach to modeling and predicting crash frequency at rural intersections by crash type and injury severity level.

Science.gov (United States)

2015-04-01

Safety at intersections is of significant interest to transportation professionals due to the large number of : possible conflicts that occur at those locations. In particular, rural intersections have been recognized as : one of the most hazardous l...

Agent-based game theory modeling for driverless vehicles at intersections.

Science.gov (United States)

2013-02-01

This report presents three research efforts that were published in various journals. The first research effort presents a reactive-driving agent based algorithm for modeling driver left turn gap acceptance behavior at signalized intersections. This m...

Estimation of air quality improvement at road and street intersections

Energy Technology Data Exchange (ETDEWEB)

Hoeglund, P.G. [Royal Inst. of Technology, Stockholm (Sweden). Traffic and Transport Planning

1995-12-31

There has always been a very great problem to quantify the detrimental exhaust air pollution related to the traffic flow, especially at road and street intersections. Until now model calculations have been developed mainly for the links between the intersections. In an attempt to remedy this situation the author has developed a method of estimating emissions on the micro level from motor vehicles at intersections as a help for infrastructural design related to improved environmental conditions. Very parsimonious knowledge exists regarding the deceleration and acceleration patterns at road- and street intersections. Not many surveys are done neither in Sweden nor within other countries. Evidently, the need for knowledge regarding deceleration and acceleration behaviour on the micro level has until now not been given priority. In traffic safety related research studies have been done describing the drivers` deceleration and acceleration behaviour and the vehicles` braking performance. Those results give deceleration data for extreme situations and are not useful for describing normal decelerations and accelerations at road- and street intersections. Environment related problems within the traffic flow analysis are now accentuating the need for the studying of special deceleration and acceleration behaviours in combination with an alternative design of the road and street infrastructure. There is a big difference in different vehicles` amount of emitted exhaust pollutions during the passing of intersections depending on the vehicles` speed levels related to their deceleration and acceleration levels. (author)

Estimation of air quality improvement at road and street intersections

Energy Technology Data Exchange (ETDEWEB)

Hoeglund, P G [Royal Inst. of Technology, Stockholm (Sweden). Traffic and Transport Planning

1996-12-31

There has always been a very great problem to quantify the detrimental exhaust air pollution related to the traffic flow, especially at road and street intersections. Until now model calculations have been developed mainly for the links between the intersections. In an attempt to remedy this situation the author has developed a method of estimating emissions on the micro level from motor vehicles at intersections as a help for infrastructural design related to improved environmental conditions. Very parsimonious knowledge exists regarding the deceleration and acceleration patterns at road- and street intersections. Not many surveys are done neither in Sweden nor within other countries. Evidently, the need for knowledge regarding deceleration and acceleration behaviour on the micro level has until now not been given priority. In traffic safety related research studies have been done describing the drivers` deceleration and acceleration behaviour and the vehicles` braking performance. Those results give deceleration data for extreme situations and are not useful for describing normal decelerations and accelerations at road- and street intersections. Environment related problems within the traffic flow analysis are now accentuating the need for the studying of special deceleration and acceleration behaviours in combination with an alternative design of the road and street infrastructure. There is a big difference in different vehicles` amount of emitted exhaust pollutions during the passing of intersections depending on the vehicles` speed levels related to their deceleration and acceleration levels. (author)

PASSENGER CAR EQUIVALENT (PCE OF THROUGH VEHICLES AT SIGNALIZED INTERSECTIONS IN DHAKA METROPOLITAN CITY, BANGLADESH

Directory of Open Access Journals (Sweden)

Partha SAHA

2009-01-01

PCE currently used in Bangladesh is based on the values given in Geometric Design of Highways (MoC, 2001, which is the modification of the values given by Webster (1958 on the study performed in the United Kingdom in the 50's and 60's. But now-a-days, the situation is far different both for traffic and road user as the characteristics have changed from that time. Hence, in this paper an empirical study was carried out to determine the PCE of different types of vehicle that reflect the actual traffic conditions of Dhaka Metropolitan City. Data were collected from ten signalized intersections and the headway ratio method was used to estimate the PCE of different types of vehicle. The main vehicle compositions observed during the study period consist of passenger cars, auto-rickshaws, mini-buses and buses. The PCE obtained in this study were compared to the values established earlier. It was found that the estimated PCE are smaller than those being used in Bangladesh.

Implications of advanced warning messages on eliminating sun glare disturbances at signalized intersections

Directory of Open Access Journals (Sweden)

Qing Li

2016-08-01

Full Text Available Due to sun glare disturbances, drivers encounter fatal threats on roadways, particularly at signalized intersections. Many studies have attempted to develop applicable solutions, such as avoiding sun positions, applying road geometric re-directions, and wearing anti-glare glasses. None of these strategies have fully solved the problem. As one of the “Connected Vehicle” practices proposed by the U.S. Department of Transportation, advanced warning messages (AWMs are capable of providing wireless information about traffic controls. AWM acts as a supplement to conventional signs and signals, which can be blocked by obstacles or natural disturbances, such as sun glare. The drivers' smart advisory system (DSAS can provide drivers with AWM. Using a driving simulator this research explores the effects of DSAS messages on driving behaviors under sun glare disturbance. Statistical analyses were applied to assess (1 the negative impacts of sun glare, (2 the compensation of the DSAS AWM to sun glare effects, and (3 the improvement in driving performance due to DSAS AWM. Four performance indexes were measured, including (1 half kinetic energy speed, (2 mean approach speed, (3 brake response time, and (4 braking distance. The effects of the socio-demographic factors, such as gender, age, educational background, and driving experience were also studied. The analytical results illustrate that the DSAS can compensate for reduced visibility due to sun glare and improve driving performance to a normal visual situation, particularly for left turn and through movement.

Digital Signal Processing for In-Vehicle Systems and Safety

CERN Document Server

Boyraz, Pinar; Takeda, Kazuya; Abut, Hüseyin

2012-01-01

Compiled from papers of the 4th Biennial Workshop on DSP (Digital Signal Processing) for In-Vehicle Systems and Safety this edited collection features world-class experts from diverse fields focusing on integrating smart in-vehicle systems with human factors to enhance safety in automobiles. Digital Signal Processing for In-Vehicle Systems and Safety presents new approaches on how to reduce driver inattention and prevent road accidents. The material addresses DSP technologies in adaptive automobiles, in-vehicle dialogue systems, human machine interfaces, video and audio processing, and in-vehicle speech systems. The volume also features: Recent advances in Smart-Car technology – vehicles that take into account and conform to the driver Driver-vehicle interfaces that take into account the driving task and cognitive load of the driver Best practices for In-Vehicle Corpus Development and distribution Information on multi-sensor analysis and fusion techniques for robust driver monitoring and driver recognition ...

A Study of the Traffic Safety at Reduced Conflict Intersections In Minnesota

Science.gov (United States)

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...

Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections.

Science.gov (United States)

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.

The accuracy and timing of pedestrian warnings at intersections: the acceptance from drivers and their preferences

NARCIS (Netherlands)

de Boer, Josine; Chaziris, Antonios; Vreeswijk, Jacob Dirk; Bie, Jing; van Arem, Bart; Abadi, A.; Bauer e.a., D.

2010-01-01

The safety of vulnerable road users at traffic intersections is critical. Driver assistance systems can improve safety but have to rely on accurate detection of hazardous situations. Given the complexity of pedestrian movement, detection of pedestrian presence and prediction of their behaviour are

CONTROLLING TRAFFIC FLOW IN MULTILANE-ISOLATED INTERSECTION USING ANFIS APPROACH TECHNIQUES

OpenAIRE

G. R. LAI; A. CHE SOH; H. MD. SARKAN; R. Z. ABDUL RAHMAN; M. K. HASSAN

2015-01-01

Many controllers have applied the Adaptive Neural-Fuzzy Inference System (ANFIS) concept for optimizing the controller performance. However, there are less traffic signal controllers developed using the ANFIS concept. ANFIS traffic signal controller with its fuzzy rule base and its ability to learn from a set of sample data could improve the performance of Existing traffic signal controlling system to reduce traffic congestions at most of the busy traffic intersections in city such as Kuala L...

Exploratory multinomial logit model-based driver injury severity analyses for teenage and adult drivers in intersection-related crashes.

Science.gov (United States)

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.

EMPIRICAL STUDY ON USABILITY OF CROSSING SUPPORT SYSTEM FOR VISUALLY DISABLED AT SIGNALIZED INTERSECTION

Science.gov (United States)

Suzuki, Koji; Fujita, Motohiro; Matsuura, Kazuma; Fukuzono, Kazuyuki

This paper evaluates the adjustment process for crossing support system for visually disabled at signalized intersections with the use of pedestrian traffic signals in concert with visible light communication (VLC) technology through outdoor experiments. As for the experiments, we put a blindfold on sighted people by eye mask in order to analyze the behavior of acquired visually disabled. And we used a full-scale crosswalk which is taking into consideration the crossing slope, the bumps at the edge of a crosswalk between the roadway and the sidewalkand crosswalk line. From the results of the survey, it is found that repetitive use of the VLC system decreased the number of lost their bearings completely and ended up standing immobile and reduced the crossing time for each person. On the other hand, it is shown that the performance of our VLC system is nearly equal to the existing support system from the view point of crossing time and the number of standing immobile and we clarified the effect factor for guidance accuracy by the regression analyses. Then we broke test subjects down into patterns by cluster analysis, and explained the walking characteristics for each group as they used the VLC system. In addition, we conducted the additional surveys for the quasi-blind subjects who had difficulty walking by using VLC system and visually impaired users. As a result, it is revealed that guidance accuracy was improved by providing the information about their receiving movement at several points on crosswalk and the habit of their walks for each user.

Responding to vaccine safety signals during pandemic influenza: a modeling study.

Directory of Open Access Journals (Sweden)

Judith C Maro

Full Text Available Managing emerging vaccine safety signals during an influenza pandemic is challenging. Federal regulators must balance vaccine risks against benefits while maintaining public confidence in the public health system.We developed a multi-criteria decision analysis model to explore regulatory decision-making in the context of emerging vaccine safety signals during a pandemic. We simulated vaccine safety surveillance system capabilities and used an age-structured compartmental model to develop potential pandemic scenarios. We used an expert-derived multi-attribute utility function to evaluate potential regulatory responses by combining four outcome measures into a single measure of interest: 1 expected vaccination benefit from averted influenza; 2 expected vaccination risk from vaccine-associated febrile seizures; 3 expected vaccination risk from vaccine-associated Guillain-Barre Syndrome; and 4 expected change in vaccine-seeking behavior in future influenza seasons.Over multiple scenarios, risk communication, with or without suspension of vaccination of high-risk persons, were the consistently preferred regulatory responses over no action or general suspension when safety signals were detected during a pandemic influenza. On average, the expert panel valued near-term vaccine-related outcomes relative to long-term projected outcomes by 3:1. However, when decision-makers had minimal ability to influence near-term outcomes, the response was selected primarily by projected impacts on future vaccine-seeking behavior.The selected regulatory response depends on how quickly a vaccine safety signal is identified relative to the peak of the pandemic and the initiation of vaccination. Our analysis suggested two areas for future investment: efforts to improve the size and timeliness of the surveillance system and behavioral research to understand changes in vaccine-seeking behavior.

Differential use of danger and safety signals in an animal model of anxiety vulnerability: The behavioral economics of avoidance.

Science.gov (United States)

Spiegler, Kevin M; Fortress, Ashley M; Pang, Kevin C H

2018-03-02

Differential processing of danger and safety signals may underlie symptoms of anxiety disorders and posttraumatic stress disorder. One symptom common to these disorders is pathological avoidance. The present study examined whether danger and safety signals influence avoidance differently in anxiety-vulnerable Wistar-Kyoto (WKY) rats and Sprague Dawley (SD) rats. SD and WKY rats were tested in a novel progressive ratio avoidance task with and without danger or safety signals. Two components of reinforcement, hedonic value and motivation, were determined by fitting an exponentiated demand equation to the data. Hedonic value of avoidance did not differ between SD and WKY rats, but WKY rats had greater motivation to avoid than SD rats. Removal of the safety signal reduced motivation to avoid in SD, but not WKY, rats. Removal of the danger signal did not alter avoidance in either strain. When danger and safety signals were presented simultaneously, WKY rats responded to the danger signals, whereas SD rats responded to the safety signal. The results provide evidence that 1) safety signals enhance motivation to avoid in SD rats, 2) both danger and safety signals influence motivation in WKY rats, and 3) danger signals take precedence over safety signals when presented simultaneously in WKY rats. Thus, anxiety vulnerability is associated with preferential use of danger signals to motivate avoidance. The differential use of danger and safety signals has important implications for the etiology and treatment of pathological avoidance in anxiety disorders and posttraumatic stress disorder. Copyright © 2017. Published by Elsevier Inc.

Vehicular crash data used to rank intersections by injury crash frequency and severity

OpenAIRE

Liu, Yi; Li, Zongzhi; Liu, Jingxian; Patel, Harshingar

2016-01-01

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, modera...

Evaluating the Operational Features of an Unconventional Dual-Bay U-Turn Design for Intersections.

Directory of Open Access Journals (Sweden)

Yun Xiang

Full Text Available 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.

Predicting crash-relevant violations at stop sign-controlled intersections for the development of an intersection driver assistance system.

Science.gov (United States)

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

L'intersectionnalité contre l'intersection

NARCIS (Netherlands)

Chauvin, S.; Jaunait, A.

2015-01-01

Intersectionality against intersection. Is the notion of intersectionality doomed to being part of the problem it designates? Intersectionality theory was not developed to merely point at intersections but to capture subject positions made invisible by dominant systems of normative representation.

Vehicular traffic flow at an intersection with the possibility of turning

International Nuclear Information System (INIS)

Foulaadvand, M Ebrahim; Belbasi, Somayyeh

2011-01-01

We have developed a Nagel-Schreckenberg cellular automata model for describing a vehicular traffic flow at a single intersection. A set of traffic lights operating in a fixed-time scheme controls the traffic flow. An open boundary condition is applied to the streets each of which conducts a unidirectional flow. Streets are single lane and cars can turn upon reaching to the intersection with prescribed probabilities. Extensive Monte Carlo simulations are carried out to find the model flow characteristics. In particular, we investigate the flow dependence on signalization parameters, turning probabilities and input rates. It is shown that for each set of parameters, there exists a plateau region inside which the total outflow from the intersection remains almost constant. We also compute total waiting time of vehicles per cycle behind red lights for various control parameters.

Prediction equation for vehicle-pedestrian crash and safety analysis ...

African Journals Online (AJOL)

The occurrences of vehicle-pedestrian crashes at signalized intersections were investigated using a 3 year (2004-2006) crash records of 82 signalized intersections in Accra, Kumasi, Tema, Sekondi-Takoradi and Tamale. The data were analyzed using Micro-computer Accident Analysis Package. Traffic flow characteristics ...

Evaluating the impact of grade crossing safety factors through signal detection theory

Science.gov (United States)

2012-10-22

The purpose of this effort was to apply signal detection theory to descriptively model the impact : of five grade crossing safety factors to understand their effect on driver decision making. The : safety factors consisted of: improving commercial mo...

Evaluation of Urban Freight Deliveries using Microsimulation and Surrogate Safety Measures

Science.gov (United States)

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...

Intersectionality research in counseling psychology.

Science.gov (United States)

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).

INTERSECTIONAL DISCRIMINATION AGAINST CHILDREN

DEFF Research Database (Denmark)

Ravnbøl, Camilla Ida

This paper adds a perspective to existing research on child protection by engaging in a debate on intersectional discrimination and its relationship to child protection. The paper has a twofold objective, (1) to further establish intersectionality as a concept to address discrimination against...... children, and (2) to illustrate the importance of addressing intersectionality within rights-based programmes of child protection....

Effects of Countdown Signals in Red Phase on Drivers: A Comparative Study between Japan and Turkey

Directory of Open Access Journals (Sweden)

Ke Yu

2014-01-01

Full Text Available Countdown signals can be found in many countries; however, there are only a few researches that study the impact of the signals on driver behavior. In this study, we focus particularly on the behavior of drivers reacting to countdown signals when the signal shifted from red to green. Although the countdown signal can reduce startup delay, it also causes drivers premature start. This paper determines the factors influencing the behaviors of drivers on startup delay, premature start, and headway due to countdown signals. The analysis results are compared between Japan and Turkey. From our findings, we propose countermeasures to reduce the problems caused by the countdown signals which can be a guideline for implementation or modification of countdown-signalized intersections in many countries in order to increase safety of both drivers and pedestrians as well as drivers’ satisfactions.

New perspectives on occupational health and safety in immigrant populations: studying the intersection between immigrant background and gender.

Science.gov (United States)

Mousaid, Sarah; De Moortel, Deborah; Malmusi, Davide; Vanroelen, Christophe

2016-01-01

Few studies investigating health inequalities pay attention to the intersection between several social determinants of health. The purpose of this article is to examine the relation between perceptions of work-related health and safety risk (WHSR) and (1) immigrant background and (2) gender in the EU-15. The effects are controlled for educational attainment, the quality of work (QOW) and occupation. Pooled data from the European Social Survey 2004 and 2010 are used in this study. The sample is restricted to respondents of working age (16-65 years) (N = 17,468). The immigrants are divided into two groups according to their country of origin: (semi-)periphery and core countries. Both groups of immigrants are compared to natives. Additionally, the research population is stratified by gender. Descriptive statistics and logistic regression analyses are used. Core immigrants (both men and women) do not differ from natives in terms of QOW. (Semi-)periphery immigrants (both men and women) are employed in jobs with lower QOW. While no differences in WHSR are found among men, female immigrants (both (semi-)periphery and core) have significantly more WHSR compared to native women. Although WHSR is generally lower in women, (semi-)periphery women have a similar prevalence of WHSR as men. (Semi-)periphery immigrants are employed in lower quality jobs, while core immigrants do not differ from natives in that regard. Female immigrant workers--especially those from (semi-)periphery countries--have higher WHSR compared to native women. Our findings highlight the importance of an intersectional approach in the study of work-related health inequalities.

Proposition of delay model for signalized intersections with queueing theory analytical models usage

Directory of Open Access Journals (Sweden)

Grzegorz SIERPIŃSKI

2007-01-01

Full Text Available Time delay on intersections is a very important transport problem. Thearticle includes a proposition of time delay model. Variance of service times is considered by used average waiting time in queue for queuing system with compressed queuing processes usage as a part of proposed time delays model.

Missouri Highway Safety Manual Recalibration

Science.gov (United States)

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...

Study on Determination of Preceding Vehicle Motion State at the Traffic Lights Intersection

Directory of Open Access Journals (Sweden)

Cailin Wu

2014-10-01

Full Text Available In order to enhance the security of automotive safety systems and reduce traffic accidents in traffic lights intersection, In view of this, it is proposed to apply the distance measurement technology of binocular vision ranging in determination of preceding vehicle motion state at the traffic lights intersection, We study the determination of preceding vehicle motion state at the traffic lights intersection based on binocular vision. The system, which is divided into four steps, adopts the theory combining the binocular stereo vision principle and the triangulation principle. First of all, from different angles, image information with preceding vehicles and traffic lights, collected by two CCD cameras, is processed and positioned. Next, two pairs of corresponding feature matching points is obtained by using the stereo matching method. Furthermore, the distance between the cameras and the preceding vehicle, and the distance between the cameras and the traffic lights are determined, according to the camera calibration technique, the parallax disparity principle and the triangulation principle. Finally, the determination about the motion state of traffic lights intersection is determined according to the distance difference principle. Experimental results show that the design, with high measurement accuracy and application value, realize the determination of preceding vehicle’s motion state at traffic lights intersection.

A Two-Stage Fuzzy Logic Control Method of Traffic Signal Based on Traffic Urgency Degree

OpenAIRE

Yan Ge

2014-01-01

City intersection traffic signal control is an important method to improve the efficiency of road network and alleviate traffic congestion. This paper researches traffic signal fuzzy control method on a single intersection. A two-stage traffic signal control method based on traffic urgency degree is proposed according to two-stage fuzzy inference on single intersection. At the first stage, calculate traffic urgency degree for all red phases using traffic urgency evaluation module and select t...

Analysis and methods of improvement of safety at high-speed rural intersections [technical summary].

Science.gov (United States)

2012-01-01

INTRODUCTION: Since 2006, INDOT has been preparing an annual fivepercent : report that identifies intersections and segments : on Indiana state roads that require attention due to the : excessive number and severity of crashes. Many of the : identifi...

Intersectional perspective in elderly care.

Science.gov (United States)

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

Intersectional perspective in elderly care

Directory of Open Access Journals (Sweden)

Marta Cuesta

2016-05-01

Full Text Available 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

Intersectional perspective in elderly care

Science.gov (United States)

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

Development of Evaluation Technology for Detection of Axial Crack at Eggcrate Intersection of Steam Generator Tube

International Nuclear Information System (INIS)

Choi, Myung Sik; Hur, Do Haeng; Kim, Kyung Mo; Han, Jung Ho; Lee, Deok Hyun; Song, Myung Ho

2011-01-01

The occurrence of outer diameter (OD) axial stress corrosion crack at egg crate intersection of steam generator tube in operating power plant is inspected primarily by the eddy current test using bobbin coil probe. Therefore, the characteristics of the bobbin coil signal from the axial crack at egg crate intersection of steam generator tube should be understood for the accurate and earlier detection of the crack. In this study, the mockup assembly simulating the steam generator tube with OD axial stress corrosion crack and tube support egg crate was manufactured, and the characteristics of bobbin coil eddy current signal was examined in order to extract the improved evaluation technique for the detection of the crack

Continuous and Discrete-Time Optimal Controls for an Isolated Signalized Intersection

Directory of Open Access Journals (Sweden)

Jiyuan Tan

2017-01-01

Full Text Available A classical control problem for an isolated oversaturated intersection is revisited with a focus on the optimal control policy to minimize total delay. The difference and connection between existing continuous-time planning models and recently proposed discrete-time planning models are studied. A gradient descent algorithm is proposed to convert the optimal control plan of the continuous-time model to the plan of the discrete-time model in many cases. Analytic proof and numerical tests for the algorithm are also presented. The findings shed light on the links between two kinds of models.

Behavioral adaptation of young and older drivers to an intersection crossing advisory system

NARCIS (Netherlands)

Dotzauer, Mandy; de Waard, Dick; Caljouw, Simone R.; Poehler, Gloria; Brouwer, Wiebo H.

An advanced driver assistance system (ADAS) provided information about the right of way regulation and safety to cross an upcoming intersection. Effects were studied in a longer-term study involving 18 healthy older drivers between the ages of 65 and 82 years and 18 healthy young drivers between the

The study of envorinmental state on road intersections based on emissions of car engines in Zhytomyr

Directory of Open Access Journals (Sweden)

Titarenko V.

2016-08-01

Full Text Available This paper presents results of the studies of environmental conditions on road intersections based on car engine emissions in Zhitomir. Statistical methods were used to determine the intensity of traffic flows based on transport emissions according to video monitoring records. Intersections with the highest intensity of traffic flows, where there is a high risk of car emissions accumulation above the applicable standard, were chosen for the assessment of ecological sustainability. Calculation of pollution was done for the intersection of Nebesnoi Sotni street and M. Grushevskogo street. The results of calculation were compared with the limit of affordable concentration and conclusions that emphasize difficulty of the problem and the emergence of its solving. The system of ecological safety in Zhitomir requires significant improvements taking into account the exceeding of factual values of pollution over normative values. Recommendations concerning of ecological sustainability of intersections can be developed through the optimization of traffic flows with the use of intellectual traffic systems.

Remote infrared signage evaluation for transit stations and intersections.

Science.gov (United States)

Crandall, W; Brabyn, J; Bentzen, B L; Myers, L

1999-10-01

Opportunities for education and employment depend upon effective and independent travel. For mainstream society, this is accomplished to a large extent by printed signs. People who are print disabled, visually impaired, or totally blind are at a disadvantage because they do not have access to signage. Remote infrared signage, such as the Talking Signs (TS) system, provides a solution to this need by labeling the environment for distant viewing. The system uses a transmitting "sign" and a hand-held receiver to tell people about their surroundings. In a seamless infrared signage environment, a visually impaired traveler could: walk safely across an intersection to an ATM or fare machine, from fare machine to bus stop, from bus stop to bus; from bus to building, from building to elevator, from elevator to office, from office to restroom, and so forth. This paper focuses on two problems that are among the most challenging and dangerous faced by blind travelers: negotiating complex transit stations and controlled intersections. We report on human factors studies of TS in these critical tasks, examining such issues as how much training is needed to use the system, its impact on performance and safety, benefits for different population subgroups and user opinions of its value. Results indicate that blind people can quickly and easily learn to use remote infrared signage effectively, and that its use improves travel safety, efficiency, and independence.

Optimal Signal Design for Mixed Equilibrium Networks with Autonomous and Regular Vehicles

Directory of Open Access Journals (Sweden)

Nan Jiang

2017-01-01

Full Text Available A signal design problem is studied for efficiently managing autonomous vehicles (AVs and regular vehicles (RVs simultaneously in transportation networks. AVs and RVs move on separate lanes and two types of vehicles share the green times at the same intersections. The signal design problem is formulated as a bilevel program. The lower-level model describes a mixed equilibrium where autonomous vehicles follow the Cournot-Nash (CN principle and RVs follow the user equilibrium (UE principle. In the upper-level model, signal timings are optimized at signalized intersections to allocate appropriate green times to both autonomous and RVs to minimize system travel cost. The sensitivity analysis based method is used to solve the bilevel optimization model. Various signal control strategies are evaluated through numerical examples and some insightful findings are obtained. It was found that the number of phases at intersections should be reduced for the optimal control of the AVs and RVs in the mixed networks. More importantly, incorporating AVs into the transportation network would improve the system performance due to the value of AV technologies in reducing random delays at intersections. Meanwhile, travelers prefer to choose AVs when the networks turn to be congested.

Modeling electric bicycle's lane-changing and retrograde behaviors

Science.gov (United States)

Tang, Tie-Qiao; Luo, Xiao-Feng; Zhang, Jian; Chen, Liang

2018-01-01

Recently, electric bicycle (EB) has been one important traffic tool due to its own merits. However, EB's motion behaviors (especially at a signalized/non-signalized intersection) are more complex than those of vehicle since it always has lane-changing and retrograde behaviors. In this paper, we propose a model to explore EB's lane-changing and retrograde behaviors on a road with a signalized intersection. The numerical results indicate that the proposed model can qualitatively describe each EB's lane-changing and retrograde behaviors near a signalized intersection, and that lane-changing and retrograde behaviors have prominent impacts on the signalized intersection (i.e., prominent jams and congestions occur). The above results show that EB should be controlled as a vehicle, i.e., lane-changing and retrograde behaviors at a signalized intersection should strictly be prohibited to improve the operational efficiency and traffic safety at the signalized intersection.

EJWS retrospective on intersectionality

NARCIS (Netherlands)

Davis, K.E.; Zarkov, Dubravka

2017-01-01

The EJWS has been at the forefront of debates about intersectionality in Europe. In the past two decades, the journal has published countless articles on intersectionality as theory, methodology, and political framework for doing critical feminist research. We have selected some of these articles

Intersectionality, Race-Gender Subordination, and Education

Science.gov (United States)

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…

A Fully-Distributed Heuristic Algorithm for Control of Autonomous Vehicle Movements at Isolated Intersections

Directory of Open Access Journals (Sweden)

Abdallah A. Hassan

2014-12-01

Full Text Available Optimizing autonomous vehicle movements through roadway intersections is a challenging problem. It has been demonstrated in the literature that traditional traffic control, such as traffic signal and stop sign control are not optimal especially for heavy traffic demand levels. Alternatively, centralized autonomous vehicle control strategies are costly and not scalable given that the ability of a central controller to track and schedule the movement of hundreds of vehicles in real-time is questionable. Consequently, in this paper a fully distributed algorithm is proposed where vehicles in the vicinity of an intersection continuously cooperate with each other to develop a schedule that allows them to safely proceed through the intersection while incurring minimum delay. Unlike other distributed approaches described in the literature, the wireless communication constraints are considered in the design of the control algorithm. Specifically, the proposed algorithm requires vehicles heading to an intersection to communicate only with neighboring vehicles, while the lead vehicles on each approach lane share information to develop a complete intersection utilization schedule. The scheduling rotates between vehicles to identify higher traffic volumes and favor vehicles coming from heavier lanes to minimize the overall intersection delay. The simulated experiments show significant reductions in the average delay using the proposed approach compared to other methods reported in the literature and reduction in the maximum delay experienced by a vehicle especially in cases of heavy traffic demand levels.

Changes in Drivers’ Visual Performance during the Collision Avoidance Process as a Function of Different Field of Views at Intersections

Science.gov (United States)

Yan, Xuedong; Zhang, Xinran; Zhang, Yuting; Li, Xiaomeng; Yang, Zhuo

2016-01-01

The intersection field of view (IFOV) indicates an extent that the visual information can be observed by drivers. It has been found that further enhancing IFOV can significantly improve emergent collision avoidance performance at intersections, such as faster brake reaction time, smaller deceleration rate, and lower traffic crash involvement risk. However, it is not known how IFOV affects drivers’ eye movements, visual attention and the relationship between visual searching and traffic safety. In this study, a driving simulation experiment was conducted to uncover the changes in drivers’ visual performance during the collision avoidance process as a function of different field of views at an intersection by using an eye tracking system. The experimental results showed that drivers’ ability in identifying the potential hazard in terms of visual searching was significantly affected by different IFOV conditions. As the IFOVs increased, drivers had longer gaze duration (GD) and more number of gazes (NG) in the intersection surrounding areas and paid more visual attention to capture critical visual information on the emerging conflict vehicle, thus leading to a better collision avoidance performance and a lower crash risk. It was also found that female drivers had a better visual performance and a lower crash rate than male drivers. From the perspective of drivers’ visual performance, the results strengthened the evidence that further increasing intersection sight distance standards should be encouraged for enhancing traffic safety. PMID:27716824

Exploring Class-Based Intersectionality

Science.gov (United States)

Block, David; Corona, Victor

2014-01-01

This paper argues that language, culture and identity researchers need to take the intersectionality of identity inscriptions seriously and, further to this, that an intersectional approach which emanates from an interest in social class provides a productive way to examine the lives and experience of individuals living in multicultural societies.…

Where to locate transit stops: Cross-intersection profiles of ultrafine particles and implications for pedestrian exposure.

Science.gov (United States)

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

Studying the Safety Impact of Autonomous Vehicles Using Simulation-Based Surrogate Safety Measures

Directory of Open Access Journals (Sweden)

Mark Mario Morando

2018-01-01

Full Text Available Autonomous vehicle (AV technology has advanced rapidly in recent years with some automated features already available in vehicles on the market. AVs are expected to reduce traffic crashes as the majority of crashes are related to driver errors, fatigue, alcohol, or drugs. However, very little research has been conducted to estimate the safety impact of AVs. This paper aims to investigate the safety impacts of AVs using a simulation-based surrogate safety measure approach. To this end, safety impacts are explored through the number of conflicts extracted from the VISSIM traffic microsimulator using the Surrogate Safety Assessment Model (SSAM. Behaviours of human-driven vehicles (HVs and AVs (level 4 automation are modelled within the VISSIM’s car-following model. The safety investigation is conducted for two case studies, that is, a signalised intersection and a roundabout, under various AV penetration rates. Results suggest that AVs improve safety significantly with high penetration rates, even when they travel with shorter headways to improve road capacity and reduce delay. For the signalised intersection, AVs reduce the number of conflicts by 20% to 65% with the AV penetration rates of between 50% and 100% (statistically significant at p<0.05. For the roundabout, the number of conflicts is reduced by 29% to 64% with the 100% AV penetration rate (statistically significant at p<0.05.

30 CFR 57.7055 - Intersecting holes.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intersecting holes. 57.7055 Section 57.7055... Jet Piercing Drilling-Surface and Underground § 57.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives, blasting agents...

UpSet: Visualization of Intersecting Sets

Science.gov (United States)

Lex, Alexander; Gehlenborg, Nils; Strobelt, Hendrik; Vuillemot, Romain; Pfister, Hanspeter

2016-01-01

Understanding relationships between sets is an important analysis task that has received widespread attention in the visualization community. The major challenge in this context is the combinatorial explosion of the number of set intersections if the number of sets exceeds a trivial threshold. In this paper we introduce UpSet, a novel visualization technique for the quantitative analysis of sets, their intersections, and aggregates of intersections. UpSet is focused on creating task-driven aggregates, communicating the size and properties of aggregates and intersections, and a duality between the visualization of the elements in a dataset and their set membership. UpSet visualizes set intersections in a matrix layout and introduces aggregates based on groupings and queries. The matrix layout enables the effective representation of associated data, such as the number of elements in the aggregates and intersections, as well as additional summary statistics derived from subset or element attributes. Sorting according to various measures enables a task-driven analysis of relevant intersections and aggregates. The elements represented in the sets and their associated attributes are visualized in a separate view. Queries based on containment in specific intersections, aggregates or driven by attribute filters are propagated between both views. We also introduce several advanced visual encodings and interaction methods to overcome the problems of varying scales and to address scalability. UpSet is web-based and open source. We demonstrate its general utility in multiple use cases from various domains. PMID:26356912

Pedestrian signalization and the risk of pedestrian-motor vehicle collisions in Lima, Peru.

Science.gov (United States)

Quistberg, D Alex; Koepsell, Thomas D; Boyle, Linda Ng; Miranda, J Jaime; Johnston, Brian D; Ebel, Beth E

2014-09-01

Safe walking environments are essential for protecting pedestrians and promoting physical activity. In Peru, pedestrians comprise over three-quarters of road fatality victims. Pedestrian signalization plays an important role managing pedestrian and vehicle traffic and may help improve pedestrian safety. We examined the relationship between pedestrian-motor vehicle collisions and the presence of visible traffic signals, pedestrian signals, and signal timing to determine whether these countermeasures improved pedestrian safety. A matched case-control design was used where the units of study were crossing locations. We randomly sampled 97 control-matched collisions (weighted N=1134) at intersections occurring from October, 2010 to January, 2011 in Lima. Each case-control pair was matched on proximity, street classification, and number of lanes. Sites were visited between February, 2011 and September, 2011. Each analysis accounted for sampling weight and matching and was adjusted for vehicle and pedestrian traffic flow, crossing width, and mean vehicle speed. Collisions were more common where a phased pedestrian signal (green or red-light signal) was present compared to no signalization (odds ratio [OR] 8.88, 95% Confidence Interval [CI] 1.32-59.6). A longer pedestrian-specific signal duration was associated with collision risk (OR 5.31, 95% CI 1.02-9.60 per 15-s interval). Collisions occurred more commonly in the presence of any signalization visible to pedestrians or pedestrian-specific signalization, though these associations were not statistically significant. Signalization efforts were not associated with lower risk for pedestrians; rather, they were associated with an increased risk of pedestrian-vehicle collisions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of Driver Evasive Maneuvering Prior to Intersection Crashes Using Event Data Recorders.

Science.gov (United States)

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

Estimating Safety Effects of Green-Man Countdown Devices at Signalized Pedestrian Crosswalk Based on Cellular Automata

Directory of Open Access Journals (Sweden)

Chen Chai

2017-01-01

Full Text Available Safety effects of Green-Man Countdown Device (GMCD at signalized pedestrian crosswalks are evaluated. Pedestrian behavior at GMCD and non-GMCD crosswalks is observed and analyzed. A microsimulation model is developed based on field observations to estimate safety performance. Simulation outputs allow analysts to assess the impacts of GMCD at various conditions with different geometric layout, traffic and pedestrian volumes, and the green time. According to simulation results, it is found that the safety impact of GMCD is affected by traffic condition as well as different time duration within green-man signal phase. In general, GMCD increases average walking velocity, especially during the last few seconds. The installation of GMCD improves safety performance generally, especially at more crowded crossings. Conflict severity is increased during last 10 s after GMCD installation. Findings from this study suggest that the current practice, which is to install GMCD at more crowded crosswalks or near the school zone, is effective. Moreover, at crosswalks with GMCD, longer all red signal phase is suggested to improve pedestrian safety during intergreen period.

Pedestrians´and cyclists´effect on capacity of right turn movement at signalized intersections

DEFF Research Database (Denmark)

Jørgensen, N O; Aagaard, Pierre E.; Rysgaard, Rikke

1998-01-01

Observations from 4 intersections in Copenhagen are used to formulate a model for the delays which right turning car traffic experience due to straight ahead going pedestrians and cyclists. The empirical data are used to formulate a simulation model which allows estimation of delays in cases...

30 CFR 56.7055 - Intersecting holes.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intersecting holes. 56.7055 Section 56.7055... Piercing Drilling § 56.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives blasting agents, or detonators. [56 FR 46508, Sept...

Traffic Signal Cycle Lengths

Data.gov (United States)

Town of Chapel Hill, North Carolina — Traffic signal location list for the town of Chapel Hill. This data set includes light cycle information as well as as intersection information.The Town of Chapel...

Development of a portable bicycle/pedestrian monitoring system for safety enhancement

Science.gov (United States)

Usher, Colin; Daley, W. D. R.

2015-03-01

Pedestrians involved in roadway accidents account for nearly 12 percent of all traffic fatalities and 59,000 injuries each year. Most injuries occur when pedestrians attempt to cross roads, and there have been noted differences in accident rates midblock vs. at intersections. Collecting data on pedestrian behavior is a time consuming manual process that is prone to error. This leads to a lack of quality information to guide the proper design of lane markings and traffic signals to enhance pedestrian safety. Researchers at the Georgia Tech Research Institute are developing and testing an automated system that can be rapidly deployed for data collection to support the analysis of pedestrian behavior at intersections and midblock crossings with and without traffic signals. This system will analyze the collected video data to automatically identify and characterize the number of pedestrians and their behavior. It consists of a mobile trailer with four high definition pan-tilt cameras for data collection. The software is custom designed and uses state of the art commercial pedestrian detection algorithms. We will be presenting the system hardware and software design, challenges, and results from the preliminary system testing. Preliminary results indicate the ability to provide representative quantitative data on pedestrian motion data more efficiently than current techniques.

A Cooperative Traffic Control of Vehicle–Intersection (CTCVI) for the Reduction of Traffic Delays and Fuel Consumption

Science.gov (United States)

Li, Jinjian; Dridi, Mahjoub; El-Moudni, Abdellah

2016-01-01

The problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights is solved by a cooperative traffic control algorithm, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I). This resolution of the problem contains two main steps. The first step concerns the itinerary of which intersections are chosen by vehicles to arrive at their destination from their starting point. Based on the principle of minimal travel distance, each vehicle chooses its itinerary dynamically based on the traffic loads in the adjacent intersections. The second step is related to the following proposed cooperative procedures to allow vehicles to pass through each intersection rapidly and economically: on one hand, according to the real-time information sent by vehicles via V2I in the edge of the communication zone, each intersection applies Dynamic Programming (DP) to cooperatively optimize the vehicle passing sequence with minimal traffic delays so that the vehicles may rapidly pass the intersection under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search. The simulation results reveal that the proposed algorithm can significantly reduce both travel delays and fuel consumption compared with other papers under different traffic volumes. PMID:27999333

A Cooperative Traffic Control of Vehicle–Intersection (CTCVI for the Reduction of Traffic Delays and Fuel Consumption

Directory of Open Access Journals (Sweden)

Jinjian Li

2016-12-01

Full Text Available The problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights is solved by a cooperative traffic control algorithm, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I. This resolution of the problem contains two main steps. The first step concerns the itinerary of which intersections are chosen by vehicles to arrive at their destination from their starting point. Based on the principle of minimal travel distance, each vehicle chooses its itinerary dynamically based on the traffic loads in the adjacent intersections. The second step is related to the following proposed cooperative procedures to allow vehicles to pass through each intersection rapidly and economically: on one hand, according to the real-time information sent by vehicles via V2I in the edge of the communication zone, each intersection applies Dynamic Programming (DP to cooperatively optimize the vehicle passing sequence with minimal traffic delays so that the vehicles may rapidly pass the intersection under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search. The simulation results reveal that the proposed algorithm can significantly reduce both travel delays and fuel consumption compared with other papers under different traffic volumes.

Propensity scores-potential outcomes framework to incorporate severity probabilities in the highway safety manual crash prediction algorithm.

Science.gov (United States)

Sasidharan, Lekshmi; Donnell, Eric T

2014-10-01

Accurate estimation of the expected number of crashes at different severity levels for entities with and without countermeasures plays a vital role in selecting countermeasures in the framework of the safety management process. The current practice is to use the American Association of State Highway and Transportation Officials' Highway Safety Manual crash prediction algorithms, which combine safety performance functions and crash modification factors, to estimate the effects of safety countermeasures on different highway and street facility types. Many of these crash prediction algorithms are based solely on crash frequency, or assume that severity outcomes are unchanged when planning for, or implementing, safety countermeasures. Failing to account for the uncertainty associated with crash severity outcomes, and assuming crash severity distributions remain unchanged in safety performance evaluations, limits the utility of the Highway Safety Manual crash prediction algorithms in assessing the effect of safety countermeasures on crash severity. This study demonstrates the application of a propensity scores-potential outcomes framework to estimate the probability distribution for the occurrence of different crash severity levels by accounting for the uncertainties associated with them. The probability of fatal and severe injury crash occurrence at lighted and unlighted intersections is estimated in this paper using data from Minnesota. The results show that the expected probability of occurrence of fatal and severe injury crashes at a lighted intersection was 1 in 35 crashes and the estimated risk ratio indicates that the respective probabilities at an unlighted intersection was 1.14 times higher compared to lighted intersections. The results from the potential outcomes-propensity scores framework are compared to results obtained from traditional binary logit models, without application of propensity scores matching. Traditional binary logit analysis suggests that

Monitoring conical intersections in the ring opening of furan by attosecond stimulated X-ray Raman spectroscopy

Directory of Open Access Journals (Sweden)

Weijie Hua

2016-03-01

Full Text Available Attosecond X-ray pulses are short enough to capture snapshots of molecules undergoing nonadiabatic electron and nuclear dynamics at conical intersections (CoIns. We show that a stimulated Raman probe induced by a combination of an attosecond and a femtosecond pulse has a unique temporal and spectral resolution for probing the nonadiabatic dynamics and detecting the ultrafast (∼4.5 fs passage through a CoIn. This is demonstrated by a multiconfigurational self-consistent-field study of the dynamics and spectroscopy of the furan ring-opening reaction. Trajectories generated by surface hopping simulations were used to predict Attosecond Stimulated X-ray Raman Spectroscopy signals at reactant and product structures as well as representative snapshots along the conical intersection seam. The signals are highly sensitive to the changes in nonadiabatically coupled electronic structure and geometry.

ISR Intersection 1

CERN Multimedia

CERN PhotoLab

1974-01-01

The experimental apparatus used at intersection 1 by the CERN-Bologna Collaboration (experiment R105). It consists of two almost identical magnetic spectrometers centered at 90 degrees on opposite sides of the intersection region. In each spectrometer one can see magnetostrictive wire spark chambers, a magnet, more chambers and various hodoscopes of scintillation counters. Gas Cerenkov counters (almost invisible in the picture) are located in the gap of each magnet. On the left hand side, a matrix of 119 lead glass Cerenkov counters is located behind some concrete and iron shielding.

Roadside versus in-car speed support for green wave : Driving simulator study

NARCIS (Netherlands)

Duivenvoorden, K.; Schaap, N.; Horst, A.R.A. van der; Feenstra, P.; Arem, B. van

2008-01-01

A green wave on a road enables a driver to negotiate a sequence of signalized intersections without hitting red. This is accomplished by the coupling of a series of signalized intersections. This is an advantage for driver comfort, for flow and safety on the road network, and for the environment.

Roadside versus in-car speed support for a green wave: a driving simulator study

NARCIS (Netherlands)

Duivenvoorden, K.; Schaap, Nina; ter Horst, A.; Feenstra, P.; van Arem, Bart

2008-01-01

A green wave on a road enables a driver to negotiate a sequence of signalized intersections without hitting red. This is accomplished by the coupling of a series of signalized intersections. This is an advantage for driver comfort, for flow and safety on the road network, and for the environment.

Molecular dynamics simulation of dislocation intersections in aluminum

International Nuclear Information System (INIS)

Li, M.; Chu, W.Y.; Qian, C.F.; Gao, K.W.; Qiao, L.J.

2003-01-01

The molecular dynamics method is used to simulate dislocation intersection in aluminum containing 1.6x10 6 atoms using embedded atom method (EAM) potential. The results show that after intersection between two right-hand screw dislocations of opposite sign there are an extended jog corresponding to a row of 1/3 vacancies in the intersected dislocation, and a trail of vacancies behind the moving dislocation. After intersection between screw dislocations of same sign, there are an extended jog corresponding to a row of 1/3 interstitials in the intersected dislocation, and a trail of interstitials behind the moving dislocation. After intersection between screw and edge dislocations with different Burgers vector, there are a constriction corresponding to one 1/3 vacancy in the edge dislocation, and no point-defects behind the screw dislocation. When a moving screw dislocation intersects an edge dislocation with the same Burgers vector, the point of intersection will split into two constrictions corresponding to one 1/3 vacancy and 1/3 interstitial, respectively. The moving screw dislocation can pass the edge dislocation only after the two constrictions, which can move along the line of intersection of the two slip planes, meet and annihilate

The influence of traffic signal solutions on self-reported road-crossing behavior.

Science.gov (United States)

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.

Intersectional embodiment and power

DEFF Research Database (Denmark)

Elg, Camilla; Jensen, Sune Qvotrup

Through almost two decades the term ‘intersectionality' has gained influence in post colonial studies, gender studies, feminist theory and other research fields occupied with how social differences are distributed and how individuals are socially constructed  in stratified societies. The ‘interse......Through almost two decades the term ‘intersectionality' has gained influence in post colonial studies, gender studies, feminist theory and other research fields occupied with how social differences are distributed and how individuals are socially constructed  in stratified societies...... not seem to gain much attention in social stratification research in general. In our paper we will present our work on an embodied approach to intersectionality, which is inspired by Pierre Bourdieu and other thinkers of embodiment. We will argue for the importance of a focus on the embodiment of social...

Cache-Oblivious Red-Blue Line Segment Intersection

DEFF Research Database (Denmark)

Arge, Lars; Mølhave, Thomas; Zeh, Norbert

2008-01-01

We present an optimal cache-oblivious algorithm for finding all intersections between a set of non-intersecting red segments and a set of non-intersecting blue segments in the plane. Our algorithm uses $O(\\frac{N}{B}\\log_{M/B}\\frac{N}{B}+T/B)$ memory transfers, where N is the total number...... of segments, M and B are the memory and block transfer sizes of any two consecutive levels of any multilevel memory hierarchy, and T is the number of intersections....

Evaluation of Intersection Traffic Control Measures through Simulation

Science.gov (United States)

Asaithambi, Gowri; Sivanandan, R.

2015-12-01

Modeling traffic flow is stochastic in nature due to randomness in variables such as vehicle arrivals and speeds. Due to this and due to complex vehicular interactions and their manoeuvres, it is extremely difficult to model the traffic flow through analytical methods. To study this type of complex traffic system and vehicle interactions, simulation is considered as an effective tool. Application of homogeneous traffic models to heterogeneous traffic may not be able to capture the complex manoeuvres and interactions in such flows. Hence, a microscopic simulation model for heterogeneous traffic is developed using object oriented concepts. This simulation model acts as a tool for evaluating various control measures at signalized intersections. The present study focuses on the evaluation of Right Turn Lane (RTL) and Channelised Left Turn Lane (CLTL). A sensitivity analysis was performed to evaluate RTL and CLTL by varying the approach volumes, turn proportions and turn lane lengths. RTL is found to be advantageous only up to certain approach volumes and right-turn proportions, beyond which it is counter-productive. CLTL is found to be advantageous for lower approach volumes for all turn proportions, signifying the benefits of CLTL. It is counter-productive for higher approach volume and lower turn proportions. This study pinpoints the break-even points for various scenarios. The developed simulation model can be used as an appropriate intersection lane control tool for enhancing the efficiency of flow at intersections. This model can also be employed for scenario analysis and can be valuable to field traffic engineers in implementing vehicle-type based and lane-based traffic control measures.

Intersectionality - an intercategorical approach

DEFF Research Database (Denmark)

Emerek, Ruth

2017-01-01

The aim of this article is to demonstrate how to empirically uncover intersectional complexity by simple methods. The article is based on three examples of intercategorical complexity. Firstly, by discussing gender mainstreaming, it is shown that a narrow focus on categories without their interse...... of a study in partial analyses may reveal intersectionality. The examples show how interaction and interwoven categories can be included in intercategorical analyses of structural relationships....

From Cellular Attractor Selection to Adaptive Signal Control for Traffic Networks.

Science.gov (United States)

Tian, Daxin; Zhou, Jianshan; Sheng, Zhengguo; Wang, Yunpeng; Ma, Jianming

2016-03-14

The management of varying traffic flows essentially depends on signal controls at intersections. However, design an optimal control that considers the dynamic nature of a traffic network and coordinates all intersections simultaneously in a centralized manner is computationally challenging. Inspired by the stable gene expressions of Escherichia coli in response to environmental changes, we explore the robustness and adaptability performance of signalized intersections by incorporating a biological mechanism in their control policies, specifically, the evolution of each intersection is induced by the dynamics governing an adaptive attractor selection in cells. We employ a mathematical model to capture such biological attractor selection and derive a generic, adaptive and distributed control algorithm which is capable of dynamically adapting signal operations for the entire dynamical traffic network. We show that the proposed scheme based on attractor selection can not only promote the balance of traffic loads on each link of the network but also allows the global network to accommodate dynamical traffic demands. Our work demonstrates the potential of bio-inspired intelligence emerging from cells and provides a deep understanding of adaptive attractor selection-based control formation that is useful to support the designs of adaptive optimization and control in other domains.

Exploring road design factors influencing tram road safety - Melbourne tram driver focus groups.

Science.gov (United States)

Naznin, Farhana; Currie, Graham; Logan, David

2018-01-01

Melbourne, Australia has the largest tram/streetcar network in the world including the largest mixed traffic tram operating environment. Therefore, Melbourne tram drivers are responsible for controlling one of the heaviest vehicles on road ranging from shared tram lanes to exclusive tram lanes. In addition to different tram lane configurations, tram drivers need to follow different traffic signal phases at intersections including tram priority signals as well as need to serve passengers at various types of closely spaced tram stops. Despite all these challenges, no research has explored tram driver perceptions of the risk factors on different tram route road design configurations. Therefore, the aim of this study is to investigate how tram drivers' safety perceptions alter along various tram route sections, signal settings and stop configurations. A tram driver focus group approach was adopted for this research involving thirty tram drivers (4 female and 26 male drivers). The tram drivers' age ranged from 29 to 63 years, with an average age of 47.6 years (standard deviation of 10.1 years), and their experience of tram driving ranged from 1.17 to 31 years, with an average experience of 12.5 years (standard deviation of 10.2 years). The participating tram drivers perceived that the raised tram tracks and tramways with raised yellow curbing beside tracks are safer lane priority features on the Melbourne tram network compared to full-time, part-time and mixed traffic tram lanes. They regarded 'hook turns' as a safe form of tram signal priority treatment at intersections and platform tram stops as the safest tram stop design for all passengers among all other tram stop designs in Melbourne. Findings of this research could enhance the understanding of crash risk factors for different tram route features and thus can offer effective planning strategies for transit agencies to improve tram road safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intersectionality and Critical Race Parenting

Science.gov (United States)

DePouw, Christin

2018-01-01

This conceptual article employs critical race theory (CRT) as a theoretical framework to explore the importance of intersectionality in critical race parenting. In particular, I focus on intersectionality to understand better how Whiteness and racial power play out in intimate relationships within the family, particularly between White parents and…

Authenticity in Leadership: Intersectionality of Identities.

Science.gov (United States)

Jones, Susan R

2016-12-01

This chapter situates leadership and the process of becoming a leader within an understanding of identity, particularly intersecting social identities and intersectionality. © 2016 Wiley Periodicals, Inc., A Wiley Company.

The effects of the non-contingent presentation of safety signals on the elimination of safety behaviors: An experimental comparison between individuals with low and high obsessive-compulsive profiles.

Science.gov (United States)

Angelakis, Ioannis; Austin, Jennifer L

2018-06-01

Safety behaviors, defined as engagement in avoidance within safe environments, are a key symptom of obsessive-compulsive and related disorders. They may interfere with daily functioning and as such their emission should be reduced. The purpose of the current study is to investigate the effects of the non-contingent presentation of safety signals (cues produced by safety behaviors) on reducing safety behaviors in participants self-reporting low and high OCD profiles. In total, 32 participants were asked to play a game to gain points and avoid their loss. After having developed avoidance behavior, evidenced by maintaining all of their earned points, they were exposed to safe environments where no point loss was programmed. In Test 1, safety cues (blue bar) were produced contingent on performing safety behaviors. In Test 2, safety cues were presented continuously without any response requirement. Findings demonstrated that high OCD group displayed higher rates of safety behaviors than low OCD group. However, exposure to the non-contingent presentation of safety signals eliminated their emission in both groups. Future studies need to evaluate the effects of different non-contingent schedules on the suppression of safety behaviors. These findings contribute to the literature by demonstrating that non-contingent introduction of safety signals eliminated safety behaviors completely, even in high OCD participants, who performed safety behavior at higher rates. Such a treatment protocol may ameliorate exposure therapy in which response prevention constitutes a key element and is generally associated with increased drop-out rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influencing Safety in Australian Agriculture and Fisheries.

Science.gov (United States)

McBain-Rigg, Kristin E; Franklin, Richard C; King, Jemma C; Lower, Tony

2017-01-01

Improving the health and safety of those working in Australian agriculture and fishery industries is a recognized priority area for preventative activities. With Australian agricultural industries being among the nation's most dangerous workplaces, there is a need for action. While there are currently known solutions, their implementation is limited. Influential agents, i.e., people who can influence others, are important for helping engender action to enact solutions into practice. This study examines agents that influence safety behavior either negatively (barriers) or positively (facilitators), in the Australian agriculture and fishery industries. Focus groups were conducted with producers and industry representatives. Thematic analysis identified barriers and facilitators to improve health and safety. These were assessed against the Socioecological Model, which considers the various, and often intersecting, human (intrapersonal, i.e. values and attitudes, peers, familial, and cultural) factors influencing safety behavior. Seven categories of human influences were identified: self, peers, family, intergenerational change, industry agents, government agents, and other. Peers (including direct managers) and family were seen to be direct influencers. Individuals signal to others that safety is valued and important. This is reinforced by experience, skill, attitudes, and behavior. Safety practice knowledge acquisition occurred via the family unit, specific training, industry, or knowledge transfer between industries. Government influence predominately focused on legislation and while the source of this influence is distant, it does influence behavior. There is a need to support comprehensive programs. These should include strengthening relationships via peer-to-peer networking, sharing information about safety initiatives, appropriate legislation, and enhancing leadership of all influencers with regard to safety.

Intention-Aware Autonomous Driving Decision-Making in an Uncontrolled Intersection

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Weilong Song

2016-01-01

Full Text Available Autonomous vehicles need to perform social accepted behaviors in complex urban scenarios including human-driven vehicles with uncertain intentions. This leads to many difficult decision-making problems, such as deciding a lane change maneuver and generating policies to pass through intersections. In this paper, we propose an intention-aware decision-making algorithm to solve this challenging problem in an uncontrolled intersection scenario. In order to consider uncertain intentions, we first develop a continuous hidden Markov model to predict both the high-level motion intention (e.g., turn right, turn left, and go straight and the low level interaction intentions (e.g., yield status for related vehicles. Then a partially observable Markov decision process (POMDP is built to model the general decision-making framework. Due to the difficulty in solving POMDP, we use proper assumptions and approximations to simplify this problem. A human-like policy generation mechanism is used to generate the possible candidates. Human-driven vehicles’ future motion model is proposed to be applied in state transition process and the intention is updated during each prediction time step. The reward function, which considers the driving safety, traffic laws, time efficiency, and so forth, is designed to calculate the optimal policy. Finally, our method is evaluated in simulation with PreScan software and a driving simulator. The experiments show that our method could lead autonomous vehicle to pass through uncontrolled intersections safely and efficiently.

Scattering Amplitudes from Intersection Theory.

Science.gov (United States)

Mizera, Sebastian

2018-04-06

We use Picard-Lefschetz theory to prove a new formula for intersection numbers of twisted cocycles associated with a given arrangement of hyperplanes. In a special case when this arrangement produces the moduli space of punctured Riemann spheres, intersection numbers become tree-level scattering amplitudes of quantum field theories in the Cachazo-He-Yuan formulation.

Operational Safety Assessment of Turbo Generators with Wavelet Rényi Entropy from Sensor-Dependent Vibration Signals

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Xiaoli Zhang

2015-04-01

Full Text Available With the rapid development of sensor technology, various professional sensors are installed on modern machinery to monitor operational processes and assure operational safety, which play an important role in industry and society. In this work a new operational safety assessment approach with wavelet Rényi entropy utilizing sensor-dependent vibration signals is proposed. On the basis of a professional sensor and the corresponding system, sensor-dependent vibration signals are acquired and analyzed by a second generation wavelet package, which reflects time-varying operational characteristic of individual machinery. Derived from the sensor-dependent signals’ wavelet energy distribution over the observed signal frequency range, wavelet Rényi entropy is defined to compute the operational uncertainty of a turbo generator, which is then associated with its operational safety degree. The proposed method is applied in a 50 MW turbo generator, whereupon it is proved to be reasonable and effective for operation and maintenance.

Urban Traffic Signal System Control Structural Optimization Based on Network Analysis

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Li Wang

2013-01-01

Full Text Available Advanced urban traffic signal control systems such as SCOOT and SCATS normally coordinate traffic network using multilevel hierarchical control mechanism. In this mechanism, several key intersections will be selected from traffic signal network and the network will be divided into different control subareas. Traditionally, key intersection selection and control subareas division are executed according to dynamic traffic counts and link length between intersections, which largely rely on traffic engineers’ experience. However, it omits important inherent characteristics of traffic network topology. In this paper, we will apply network analysis approach into these two aspects for traffic system control structure optimization. Firstly, the modified C-means clustering algorithm will be proposed to assess the importance of intersections in traffic network and furthermore determine the key intersections based on three indexes instead of merely on traffic counts in traditional methods. Secondly, the improved network community discovery method will be used to give more reasonable evidence in traffic control subarea division. Finally, to test the effectiveness of network analysis approach, a hardware-in-loop simulation environment composed of regional traffic control system, microsimulation software and signal controller hardware, will be built. Both traditional method and proposed approach will be implemented on simulation test bed to evaluate traffic operation performance indexes, for example, travel time, stop times, delay and average vehicle speed. Simulation results show that the proposed network analysis approach can improve the traffic control system operation performance effectively.

Tracer Flux Balance at an Urban Canyon Intersection

Science.gov (United States)

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.

Using Intersectionality in Student Affairs Research

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Strayhorn, Terrell L.

2017-01-01

This chapter presents intersectionality as a useful heuristic for conducting research in higher education and student affairs contexts. Much more than just another theory, intersectionality can powerfully shape student affairs research in both obvious and tacit ways.

Optimization Method of Intersection Signal Coordinated Control Based on Vehicle Actuated Model

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Chen Zhao-Meng

2015-01-01

Full Text Available Traditional timing green wave control with predetermined cycle, split, and offset cannot adapt for dynamic real-time traffic flow. This paper proposes a coordinated control method for variable cycle time green wave bandwidth optimization integrated with traffic-actuated control. In the coordinated control, green split is optimized in real time by the measured presence of arriving and/or standing vehicles in each intersection and simultaneously green waves along arterials are guaranteed. Specifically, the dynamic bound of green wave is firstly determined, and then green early-start and green late-start algorithms are presented respectively to accommodate the fluctuations in vehicle arrival rates in each phase. Numerical examples show that the proposed method improves green time, expands green wave bandwidth, and reduces queuing.

Improving Walkability Through Control Strategies at Signalized Intersections

Science.gov (United States)

2017-01-01

As cities and communities nationwide seek to develop Complete Streets that foster livability and accommodate all modes, signal timing control strategies that include pedestrians in the operational decision process are gaining importance. This researc...

Danger zone: Men, masculinity and occupational health and safety in high risk occupations.

Science.gov (United States)

Stergiou-Kita, Mary; Mansfield, Elizabeth; Bezo, Randy; Colantonio, Angela; Garritano, Enzo; Lafrance, Marc; Lewko, John; Mantis, Steve; Moody, Joel; Power, Nicole; Theberge, Nancy; Westwood, Eleanor; Travers, Krista

2015-12-01

The workplace is a key setting where gender issues and organizational structures may influence occupational health and safety practices. The enactment of dominant norms of masculinity in high risk occupations can be particularly problematic, as it exposes men to significant risks for injuries and fatalities. To encourage multi-disciplinary collaborations and advance knowledge in the intersecting areas of gender studies, men's health, work and workplace health and safety, a national network of thirteen researchers and health and safety stakeholders completed a critical literature review examining the intersection between masculinities and men's workplace health and safety in order to: (i) account for research previously undertaken in this area; (ii) identify themes that may inform our understanding of masculinity and workplace health and safety and; (iii) identify research and practice gaps in relation to men's workplace health and safety. In this paper we present key themes from this review. Recommendations are made regarding: (i) how to define gender; (ii) how to attend to and identify how masculinities may influence workers' identities, perceptions of occupational risks and how institutionalized practices can reinforce norms of masculinity; (iii) the importance of considering how masculinities may intersect with other variables (e.g. historical context, age, class, race, geographical location) and; (iv) the added significance of present-day labour market forces on men's occupational health and safety.

SOFTWARE MODULE FOR CONSTRUCTING THE INTERSECTION OF TRIANGULATED SURFACES

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Vladimir V. Kurgansky

2018-03-01

Full Text Available The effective algorithm is proposed for implementing Boolean operations over triangulated surfaces, namely, disjunction, conjunction and Boolean difference, and its software implementation. The idea consists in as follow. The first step is to determine pairs of intersecting triangles: localizing the intersection of the two surfaces using the bounding volume of the parallelepipeds and the future of their intersection. The second step is constructing an intersection line for each pair of triangles: a pair of intersecting triangles is selected, and the segment along which they intersect is constructed. Further, thanks to the entered data structure, "adjacent" triangles are selected, among which are selected those that form the intersecting pair. The process described above continues as long as such triangles can be detected. After that the triangles involved in the intersection are retriangulated. For each triangle, all the edges are known on which it intersects with triangles from another surface. These edges are structural edges in the triangulation problem with constraints for a given triangle. The third step is to combine all surfaces into one surface. Further, subsurfaces are constructed along the loops of intersection limited by the found loops. Since the intersection line of the surfaces was constructed in sequence, it is possible to specify the direction of each edge. Any edge from the intersection line is selected. The triangle is added to the subsurface under construction, which includes this edge and its orientation is the same as the direction of the edge. The edge which was selected previously is deleted from intersection line, but two new edges are added is the remaining edges of added triangle. The third step is to combine all surfaces into one surface. Further, subsurfaces are constructed along the cycles of intersection limited by the found cycles. Since the intersection line of the surfaces was constructed in sequence, it is

Road crossing behavior under traffic light conflict: Modulating effects of green light duration and signal congruency.

Science.gov (United States)

Lange, Florian; Haiduk, Michael; Boos, Moritz; Tinschert, Peter; Schwarze, Anke; Eggert, Frank

2016-10-01

A large number of pedestrians and cyclists regularly ignore the traffic lights to cross the road illegally. In a recent analysis, illegal road crossing behavior has been shown to be enhanced in the presence of incongruent stimulus configurations. Pedestrians and cyclists are more likely to cross against a red light when exposed to an irrelevant conflicting green light. Here, we present experimental and observational data on the factors moderating the risk associated with incongruent traffic lights. In an observational study, we demonstrated that the conflict-related increase in illegal crossing rates is reduced when pedestrian and cyclist green light periods are long. In a laboratory experiment, we manipulated the color of the irrelevant signals to expose participants to different degrees of incongruency. Results revealed that individuals' performance gradually varied as a function of incongruency, suggesting that the negative impact of a conflicting green light can be reduced by slightly adjusting its color. Our findings highlight that the observation of real-world behavior at intersections and the experimental analysis of psychological processes under controlled laboratory conditions can complement each other in identifying risk factors of risky road crossing behavior. Based on this combination, our study elaborates on promising measures to improve safety at signalized intersections. Copyright © 2016 Elsevier Ltd. All rights reserved.

Watching Electrons at Conical Intersections and Funnels

Science.gov (United States)

Jonas, David M.; Smith, Eric R.; Peters, William K.; Kitney, Katherine A.

2009-06-01

The electronic motion at conical intersections and funnels is probed after polarized excitation of aligned electronic wavepackets. The pulses have bandwidth sufficient to observe vibrations mainly through their effect on the electrons. Vibrational symmetry can be identified by the polarization anisotropy of vibrational quantum beats. The polarized transients show signatures of electronic wavepacket motion (due to the energy gaps) and of electron transfer between orbitals (due to the couplings) driven by the conical intersection. For a conical intersection in a four-fold symmetric symmetry silicon naphthalocyanine molecule, electronic motions on a 100 fs timescale are driven by couplings of 1 meV. In the lower symmetry free-base naphthalocyanine, the conical intersection may be missed or missing (conical funnel), and the motions are nearly as rapid, but electronic equilibration is incomplete for red-edge excitation. These experiments probe non-adiabatic electronic dynamics with near-zero nuclear momentum - the electronic motions are determined by the principal slopes of the conical intersection and the width of the vibrational wavepacket.

Framing Gender Intersections in the European Union

DEFF Research Database (Denmark)

Lombardo, Emanuela; Agustin, Lise Rolandsen

2012-01-01

are increasingly present but they are treated implicitly and from a separate perspective, and the inclusion of a wide range of inequalities often implies a degendering of the policy content. We assess the implications of the identified intersectionality trends for the quality of intersectionality in gender...... equality policies, and we suggest the practice of an “intersectionality impact assessment” as a way to improve the quality of EU policy-making....

Coordination of IVI and transit signal priority on transit evacuations.

Science.gov (United States)

2011-02-01

During an emergency evacuation, execution time is always critical to the evacuees who are : transit dependent. Transit Signal Priority (TSP) can speed up the transit services by prioritizing : the approaching bus at a signalized intersection. With th...

The intersection of the extrinsic hedgehog and WNT/wingless signals with the intrinsic Hox code underpins branching pattern and tube shape diversity in the drosophila airways.

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Ryo Matsuda

2015-01-01

Full Text Available The tubular networks of the Drosophila respiratory system and our vasculature show distinct branching patterns and tube shapes in different body regions. These local variations are crucial for organ function and organismal fitness. Organotypic patterns and tube geometries in branched networks are typically controlled by variations of extrinsic signaling but the impact of intrinsic factors on branch patterns and shapes is not well explored. Here, we show that the intersection of extrinsic hedgehog(hh and WNT/wingless (wg signaling with the tube-intrinsic Hox code of distinct segments specifies the tube pattern and shape of the Drosophila airways. In the cephalic part of the airways, hh signaling induces expression of the transcription factor (TF knirps (kni in the anterior dorsal trunk (DTa1. kni represses the expression of another TF spalt major (salm, making DTa1 a narrow and long tube. In DTa branches of more posterior metameres, Bithorax Complex (BX-C Hox genes autonomously divert hh signaling from inducing kni, thereby allowing DTa branches to develop as salm-dependent thick and short tubes. Moreover, the differential expression of BX-C genes is partly responsible for the anterior-to-posterior gradual increase of the DT tube diameter through regulating the expression level of Salm, a transcriptional target of WNT/wg signaling. Thus, our results highlight how tube intrinsic differential competence can diversify tube morphology without changing availabilities of extrinsic factors.

Design of a rotary for an uncontrolled multi-leg intersection in Chennai, India

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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.

The intersectionality framework and identity intersections in the Journal of Counseling Psychology and The Counseling Psychologist: A content analysis.

Science.gov (United States)

Shin, Richard Q; Welch, Jamie C; Kaya, Aylin E; Yeung, Jeffrey G; Obana, Chynna; Sharma, Rajni; Vernay, Collin N; Yee, Stephanie

2017-10-01

The framework of intersectionality is a powerful analytical tool for making sense of how interlocking systems of privilege and oppression are experienced by individuals and groups. Despite the long history of the concept, intersectionality has only recently gained attention in psychology. We conducted a content analysis to assess counseling psychology's engagement with an intersectional perspective. All articles published in the Journal of Counseling Psychology (n = 4,800) and The Counseling Psychologist (n = 1,915) from their first issues until July 2016 were reviewed to identify conceptual and empirical work focused on intersectionality. A total of 40 articles were identified and examined for themes. Limitations and future directions are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Intersection spaces, spatial homology truncation, and string theory

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Banagl, Markus

2010-01-01

Intersection cohomology assigns groups which satisfy a generalized form of Poincaré duality over the rationals to a stratified singular space. The present monograph introduces a method that assigns to certain classes of stratified spaces cell complexes, called intersection spaces, whose ordinary rational homology satisfies generalized Poincaré duality. The cornerstone of the method is a process of spatial homology truncation, whose functoriality properties are analyzed in detail. The material on truncation is autonomous and may be of independent interest to homotopy theorists. The cohomology of intersection spaces is not isomorphic to intersection cohomology and possesses algebraic features such as perversity-internal cup-products and cohomology operations that are not generally available for intersection cohomology. A mirror-symmetric interpretation, as well as applications to string theory concerning massless D-branes arising in type IIB theory during a Calabi-Yau conifold transition, are discussed.

Optimising Signalised Intersection Using Wireless Vehicle Detectors

DEFF Research Database (Denmark)

Adjin, Daniel Michael Okwabi; Torkudzor, Moses; Asare, Jack

Traffic congestion on roads wastes travel times. In this paper, we developed a vehicular traffic model to optimise a signalised intersection in Accra, using wireless vehicle detectors. Traffic volume gathered was extrapolated to cover 2011 and 2016 and were analysed to obtain the peak hour traffic...... volume causing congestion. The intersection was modelled and simulated in Synchro7 as an actuated signalised model using results from the analysed data. The model for morning peak periods gave optimal cycle lengths of 100s and 150s with corresponding intersection delay of 48.9s and 90.6s in 2011 and 2016...... respectively while that for the evening was 55s giving delay of 14.2s and 16.3s respectively. It is shown that the model will improve traffic flow at the intersection....

Fine-Grained vs. Average Reliability for V2V Communications around Intersections

OpenAIRE

Abdulla, Mouhamed; Wymeersch, Henk

2017-01-01

Intersections are critical areas of the transportation infrastructure associated with 47% of all road accidents. Vehicle-to-vehicle (V2V) communication has the potential of preventing up to 35% of such serious road collisions. In fact, under the 5G/LTE Rel.15+ standardization, V2V is a critical use-case not only for the purpose of enhancing road safety, but also for enabling traffic efficiency in modern smart cities. Under this anticipated 5G definition, high reliability of 0.99999 is expecte...

Safety, operational, and energy impacts of in-vehicle adaptive stop displays using connected vehicle technology.

Science.gov (United States)

2015-07-01

Un-signalized intersections create multiple opportunities for missed or misunderstood information. : Stop sign-controlled intersections have also been shown to be a source of delay and emissions due : to their frequent, often inappropriate use. By us...

QUING WHY paper: Framing gender intersections in the European Union: what implications for the quality of intersectionality in policies?

DEFF Research Database (Denmark)

Agustin, Lise Rolandsen; Lombardo, Emanuela

are increasingly present but they are treated implicitly and from a separate perspective, and the inclusion of a wide range of inequalities often implies a degendering of the policy content. We assess the implications of the identified intersectionality trends for the quality of intersectionality in gender...... equality policies and we suggest the practice of an ‘intersectionality impact assessment’ as a way to improve the quality of EU policy-making. In this regard, we particularly focus on the interface between the civil society and the EU institutions....

Traffic Control Models Based on Cellular Automata for At-Grade Intersections in Autonomous Vehicle Environment

OpenAIRE

Wei Wu; Yang Liu; Yue Xu; Quanlun Wei; Yi Zhang

2017-01-01

Autonomous vehicle is able to facilitate road safety and traffic efficiency and has become a promising trend of future development. With a focus on highways, existing literatures studied the feasibility of autonomous vehicle in continuous traffic flows and the controllability of cooperative driving. However, rare efforts have been made to investigate the traffic control strategies in autonomous vehicle environment on urban roads, especially in urban intersections. In autonomous vehicle enviro...

Signal Timing Optimization for Corridors with Multiple Highway-Rail Grade Crossings Using Genetic Algorithm

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Yifeng Chen

2018-01-01

Full Text Available Safety and efficiency are two critical issues at highway-rail grade crossings (HRGCs and their nearby intersections. Standard traffic signal optimization programs are not designed to work on roadway networks that contain multiple HRGCs, because their underlying assumption is that the roadway traffic is in a steady-state. During a train event, steady-state conditions do not occur. This is particularly true for corridors that experience high train traffic (e.g., over 2 trains per hour. In this situation, the non-steady-state conditions predominate. This paper develops a simulation-based methodology for optimizing traffic signal timing plan on corridors of this kind. The primary goal is to maximize safety, and the secondary goal is to minimize delay. A Genetic Algorithm (GA was used as the optimization approach in the proposed methodology. A new transition preemption strategy for dual tracks (TPS_DT and a train arrival prediction model were integrated in the proposed methodology. An urban road network with multiple HRGCs in Lincoln, NE, was used as the study network. The microsimulation model VISSIM was used for evaluation purposes and was calibrated to local traffic conditions. A sensitivity analysis with different train traffic scenarios was conducted. It was concluded that the methodology can significantly improve both the safety and efficiency of traffic corridors with HRGCs.

Charting Relations between Intersectionality Theory and the Neurodiversity Paradigm

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Lauren Rose Strand

2017-06-01

Full Text Available This essay explores central elements and applications of intersectionality theory and the neurodiversity paradigm. First, the histories and tenets of intersectionality theory and neurodiversity paradigm are provided. Then, areas are explored where each of the two approaches might further engage with the principles of the other. Finally, the essay concludes by broadly considering the efforts made by the Black Lives Matter movement and the Autistic Self Advocacy Network to bring attention to and end police violence as both networks employ and attend to elements of intersectionality and neurodiversity. The way these two networks draw on both intersectionality and neurodiversity to further their mission could be a possible site for scholars to consider in the interest of advancing dialogues between intersectionality theory and the neurodiversity paradigm. Ultimately, the essay calls for a continued exploration of the potentials for intersectionality and neurodiversity to complement and complicate one another, both in terms of theoretical development and coalition building.

Microscopic Control Delay Modeling at Signalized Arterials Using Bluetooth Technology

OpenAIRE

Rajasekhar, Lakshmi

2011-01-01

Real-time control delay estimation is an important performance measure for any intersection to improve the signal timing plans dynamically in real-time and hence improve the overall system performance. Control delay estimates helps to determine the level-of-service (LOS) characteristics of various approaches at an intersection and takes into account deceleration delay, stopped delay and acceleration delay. All kinds of traffic delay calculation especially control delay calculation has always ...

Modelling how drivers respond to a bicyclist crossing their path at an intersection: How do test track and driving simulator compare?

Science.gov (United States)

Boda, Christian-Nils; Dozza, Marco; Bohman, Katarina; Thalya, Prateek; Larsson, Annika; Lubbe, Nils

2018-02-01

Bicyclist fatalities are a great concern in the European Union. Most of them are due to crashes between motorized vehicles and bicyclists at unsignalised intersections. Different countermeasures are currently being developed and implemented in order to save lives. One type of countermeasure, active safety systems, requires a deep understanding of driver behaviour to be effective without being annoying. The current study provides new knowledge about driver behaviour which can inform assessment programmes for active safety systems such as Euro NCAP. This study investigated how drivers responded to bicyclists crossing their path at an intersection. The influences of car speed and cyclist speed on the driver response process were assessed for three different crossing configurations. The same experimental protocol was tested in a fixed-base driving simulator and on a test track. A virtual model of the test track was used in the driving simulator to keep the protocol as consistent as possible across testing environments. Results show that neither car speed nor bicycle speed directly influenced the response process. The crossing configuration did not directly influence the braking response process either, but it did influence the strategy chosen by the drivers to approach the intersection. The point in time when the bicycle became visible (which depended on the car speed, the bicycle speed, and the crossing configuration) and the crossing configuration alone had the largest effects on the driver response process. Dissimilarities between test-track and driving-simulator studies were found; however, there were also interesting similarities, especially in relation to the driver braking behaviour. Drivers followed the same strategy to initiate braking, independent of the test environment. On the other hand, the test environment affected participants' strategies for releasing the gas pedal and regulating deceleration. Finally, a mathematical model, based on both experiments

Rank 2 fusion rings are complete intersections

DEFF Research Database (Denmark)

Andersen, Troels Bak

We give a non-constructive proof that fusion rings attached to a simple complex Lie algebra of rank 2 are complete intersections.......We give a non-constructive proof that fusion rings attached to a simple complex Lie algebra of rank 2 are complete intersections....

Traffic flow behavior at un-signalized intersection with crossings pedestrians

Science.gov (United States)

Khallouk, A.; Echab, H.; Ez-Zahraouy, H.; Lakouari, N.

2018-02-01

Mixed traffic flux composed of crossing pedestrians and vehicles extensively exists in cities. To study the characteristics of the interference traffic flux, we develop a pedestrian-vehicle cellular automata model to present the interaction behaviors on a simple cross road. By realizing the fundamental parameters (i.e. injecting rates α1, α2, the extracting rate β and the pedestrian arrival rate αP), simulations are carried out. The vehicular traffic flux is calculated in terms of rates. The effect of the crosswalk can be regarded as a dynamic impurity. The system phase diagrams in the (α1 ,αP) plane are built. It is found that the phase diagrams consist essentially of four phases namely Free Flow, Congested, Maximal Current and Gridlock. The value of the Maximal current phase depends on the extracting rate β, while the Gridlock phase is achieved only when the pedestrians generating rate is higher than a critical value. Furthermore, the effect of vehicles changing lane (Pch1 ,Pch2) and the location of the crosswalk XP on the dynamic characteristics of vehicles flow are investigated. It is found that traffic situation in the system is slightly enhanced if the location of the crosswalks XP is far from the intersection. However, when Pch1, Pch2 increase, the traffic becomes congested and the Gridlock phase enlarges.

Impact of Vehicular Countdown Signals on Driving Psychologies and Behaviors: Taking China as an Example

Directory of Open Access Journals (Sweden)

Fuquan Pan

2017-01-01

Full Text Available Countdown signal control is a relatively new control mode that can inform a driver in advance about the remaining time to pass through intersections or the time needed to wait for other drivers and pedestrians. At present, few countries apply vehicular countdown signals. However, in China, some cities have applied vehicular countdown signals for years, though it is unclear how and how much such signals influence driving psychologies and behaviors compared with non-countdown signal controls. The present work aims to clarify the impact of vehicular countdown signals on driving psychologies and behaviors on the cognitive level. A questionnaire survey with 32 questions about driving psychologies and behaviors was designed, and an online survey was conducted. A total of 1051 valid questionnaires were received. The survey data were analyzed, and the main results indicate that most of the surveyed drivers prefer countdown signal controls and think that such controls can improve not only traffic safety but also traffic operational efficiency. The surveyed drivers also think that countdown signal controls have an impact on driving psychologies and behaviors and the survey results have demonstrated that the driving behaviors of female drivers surveyed are not conservative under the clear conditions of green countdown signal control. Further studies and methods concerning the effects of countdown signals on driving psychologies and behaviors are discussed.

Transnational Intersectionality in Family Therapy With Resettled Refugees.

Science.gov (United States)

Gangamma, Rashmi; Shipman, Daran

2018-04-01

In this article, we discuss incorporating the transnational intersectionality framework in family therapy with resettled refugees. Transnational intersectionality is an extension of the framework of intersectionality which helps to better understand complexities of power and oppression across national contexts and their influence on refugees' lives. Adopting this framework alerts family therapists to: (a) develop critical awareness of refugee's transnational contexts; (b) understand differences in experiences of social identities across contexts; (c) acknowledge postmigration factors of oppression affecting resettlement; and (d) critically reflect upon therapist-interpreter-client intersectionalities. This shifts our conceptualization of therapy with refugees to actively consider transnational contexts which refugees uniquely occupy. We describe the framework and provide two case illustrations to highlight its usefulness. © 2017 American Association for Marriage and Family Therapy.

Urban Intersection Recognition and Construction Based on Big Trace Data

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TANG Luliang

2017-06-01

Full Text Available Intersection is an important part of the generation and renewal of urban traffic network. In this paper, a new method was proposed to detect urban intersections automatically from the spatiotemporal big trace data. Firstly, the turning point pairs were based on tracking the trace data collected by vehicles. Secondly, different types of turning point pairs were clustered by using spatial growing clustering method based on angle and distance differences, and the clustering methods of local connectivity was used to recognize the intersection. Finally, the intersection structure of multi-level road network was constructed with the range of the intersection and turning point pairs. Taking the taxi trajectory data in Wuhan city as an example, the experimental results showed that the method proposed in this paper can automatically detect and recognize the road intersection and its structure.

Power, privilege and disadvantage: Intersectionality theory and political representation

Directory of Open Access Journals (Sweden)

Eline Severs

2017-06-01

Full Text Available This article critically reviews the extant literature on social group representation and clarifies the advantages of intersectionality theory for studying political representation. It argues that the merit of intersectionality theory can be found in its ontology of power. Intersectionality theory is founded on a relational conception of political power that locates the constitution of power relations within social interactions, such as political representation. As such, intersectionality theory pushes scholarship beyond studying representation inequalities —that are linked to presumably stable societal positions— to also consider the ways in which political representation (recreates positions of privilege and disadvantage.

Beyond the Cake Model: Critical Intersectionality and the Relative Advantage of Disadvantage

Directory of Open Access Journals (Sweden)

Robert Lee Oprisko

2015-01-01

Full Text Available Intersectionality came about as a critique of traditional, uniaxial studies of oppression. The initial wave argued that the intersection(s of multiple axes of social construction create uniquely experienced forms of domination and oppression that can only be studied within the context of said intersections. Methodologically, intersectional research has been used primarily as a tool of studying dichotomous intersections of race, gender, and class. However, theoretically focused literature articulates the importance of operating in a more complex understanding of intersectional axes by adding both breadth and depth. Current intersectional studies, therefore, are locked intradeoff between precision and generalizability in any quantitative research and intersect thus far, the power of intersectionality remains unrealized. This paper argues for a large-scale expansion of the number of variables studied in order to gain the most precise understandings of social construction. This creates a tradeoff between precision and generalizability. The power of intersectionality however is not in its generalizability, but rather in its precision for the study of small-n groups. We suggest moving beyond the cake model and into acritical intersectionalitymodel that embraces the agential realism of quantum politics.

Intersectionality and Educational Leadership: A Critical Review

Science.gov (United States)

Agosto, Vonzell; Roland, Ericka

2018-01-01

In this review of research, we explore intersectionality in the literature on K-12 educational leadership. We seek to understand how researchers have used intersectionality and what their findings or arguments reveal about the work of leading to reduce inequities in education. We ask, What traditions and trends associated with intersectionality…

Developing a short range vehicle to infrastructure communication system to enhance the safety at STOP sign intersections : final report.

Science.gov (United States)

2016-05-01

Stop sign controlled unsignalized intersections raise a public safe concern. Even though various strategies, such as engineering, education, and policy, have been applied in practice, there are a number of fatal crashes occurred at unsignalized inter...

A Fully-Distributed Heuristic Algorithm for Control of Autonomous Vehicle Movements at Isolated Intersections

OpenAIRE

Abdallah A. Hassan; Hesham A. Rakha

2014-01-01

Optimizing autonomous vehicle movements through roadway intersections is a challenging problem. It has been demonstrated in the literature that traditional traffic control, such as traffic signal and stop sign control are not optimal especially for heavy traffic demand levels. Alternatively, centralized autonomous vehicle control strategies are costly and not scalable given that the ability of a central controller to track and schedule the movement of hundreds of vehicles in real-time is ques...

Appropriate Pupilness: Social Categories Intersecting in School

Science.gov (United States)

Kofoed, Jette

2008-01-01

The analytical focus in this article is on how social categories intersect in daily school life and how intersections intertwine with other empirically relevant categories such as normality, pupilness and (in)appropriatedness. The point of empirical departure is a daily ritual where teams for football are selected. The article opens up for a…

Complicating Counterspaces: Intersectionality and the Michigan Womyn's Music Festival.

Science.gov (United States)

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.

Acquisition and extinction of human avoidance behavior: Attenuating effect of safety signals and associations with anxiety vulnerabilities

Directory of Open Access Journals (Sweden)

Jony eSheynin

2014-09-01

Full Text Available While avoidance behavior is often an adaptive strategy, exaggerated avoidance can be detrimental and result in the development of psychopathologies, such as anxiety disorders. A large animal literature shows that the acquisition and extinction of avoidance behavior in rodents depends on individual differences (e.g., sex, strain and might be modulated by the presence of environmental cues. However, there is a dearth of such reports in human literature, mainly due to the lack of adequate experimental paradigms. In the current study, we employed a computer-based task, where participants control a spaceship and attempt to gain points by shooting an enemy spaceship that appears on the screen. Warning signals predict on-screen aversive events; the participants can learn a protective response to escape or avoid these events. This task has been recently used to reveal facilitated acquisition of avoidance behavior in individuals with anxiety vulnerability, due to female sex or inhibited personality. Here, we extended the task to include an extinction phase, and tested the effect of signals that appeared during safe periods. Healthy young adults (n=122 were randomly assigned to a testing condition with or without such signals. Results showed that the addition of safety signals during the acquisition phase impaired acquisition (in females and facilitated extinction of the avoidance behavior. We also replicated our recent finding of an association between female sex and longer avoidance duration and further showed that females continued to demonstrate more avoidance behavior even on extinction trials when the aversive events no longer occurred. This study is the first to show sex differences on the acquisition and extinction of human avoidance behavior and to demonstrate the role of safety signals in such behavior, highlighting the potential relevance of safety signals for cognitive therapies that focus on extinction learning to treat anxiety symptoms.

An efficient quantum scheme for Private Set Intersection

Science.gov (United States)

Shi, Run-hua; Mu, Yi; Zhong, Hong; Cui, Jie; Zhang, Shun

2016-01-01

Private Set Intersection allows a client to privately compute set intersection with the collaboration of the server, which is one of the most fundamental and key problems within the multiparty collaborative computation of protecting the privacy of the parties. In this paper, we first present a cheat-sensitive quantum scheme for Private Set Intersection. Compared with classical schemes, our scheme has lower communication complexity, which is independent of the size of the server's set. Therefore, it is very suitable for big data services in Cloud or large-scale client-server networks.

Linear Determination of a Camera's Intrinsic Parameters Using Two Intersecting Circles

Directory of Open Access Journals (Sweden)

Xu Chen

2014-03-01

Full Text Available An approach using two intersecting circles is proposed as a linear approach for determining a camera's intrinsic parameters. The two intersecting coplanar circles have four intersection points in the projective plane: two real points and two circular points. In the image plane, the diagonal triangle - on which the image of the four intersection points composes a complete quadrangle - is a self-polar triangle for the projection curves of the circles. The vertex of the self-polar triangle is the null space of the degenerate conic formed by the image of the four intersection points. By solving the three vertices of the self-polar triangle using the image coordinates of the two real intersection points, the degenerate conic can be obtained. The image of the two circular points is then computed from the intersection points of the degenerate conic. Using the image of the circular points from the three images of the same planar pattern with different directions, the intrinsic parameters can be linearly determined.

P-union and P-intersection of neutrosophic cubic sets

OpenAIRE

Florentin Smarandache; Chang Su Kim

2015-01-01

Conditions for the P-intersection and P-intersection of falsity-external (resp. indeterminacy-external and truth-external) neutrosophic cubic sets to be an falsity-external (resp. indeterminacy-external and truth- external) neutrosophic cubic set are provided. Conditions for the P-union and the P-intersection of two truth-external (resp. indeterminacy-external and falsity-external) neutrosophic cubic sets to be a truth-internal (resp. indeterminacy-internal and falsity-internal) neutrosoph...

Drug Safety Monitoring in Children: Performance of Signal Detection Algorithms and Impact of Age Stratification

NARCIS (Netherlands)

O.U. Osokogu (Osemeke); C. Dodd (Caitlin); A.C. Pacurariu (Alexandra C.); F. Kaguelidou (Florentia); D.M. Weibel (Daniel); M.C.J.M. Sturkenboom (Miriam)

2016-01-01

textabstractIntroduction: Spontaneous reports of suspected adverse drug reactions (ADRs) can be analyzed to yield additional drug safety evidence for the pediatric population. Signal detection algorithms (SDAs) are required for these analyses; however, the performance of SDAs in the pediatric

STUDY OF TRANSMISSION LINES EFFECT ON THE SYSTEM OPERATIONON OF CONTINUOUS AUTOMATIC CAB SIGNALLING

Directory of Open Access Journals (Sweden)

O. O. Hololobova

2014-10-01

Full Text Available Purpose. To conduct an effect research of the electromagnetic field of high-voltage transmission lines (HVTL (750 kV, 50 Hz on the track circuits and continuous automatic cab signalling (CACS with a signal current of 50 Hz in the areas of convergence and intersection with the transmission lines and to propose possible methods to improve noise immunity of CACS. Methodology. The measurements were performed both by means of car-laboratory and directly on rail lines. During the study the electric field strength in the range of industrial frequency directly under the transmission lines and at the distance from it to the railway lines was measured, as well as the time dependence of CACS codes with signal current frequency of 50 Hz directly under the transmission lines and at a distance from it in the absence of the train and its passing. Findings. The root causes analysis of CACS faults and failures was carried out. The effect of the electromagnetic field of high-voltage transmission lines (750 kV, 50 Hz on the track circuit and CACS with signal current of 50 Hz in the areas of convergence and intersection with the transmission line was investigated. Possible methods to improve noise immunity of CACS were considered. Originality. The effect research of transmission lines (750 kV on the operation of the automatic cab signalling on spans Prishib-Burchatsk and Privolnoye-Yelizarovo, Pridneprovsk railway in places of oblique railroads crossing and transmission lines (750 kV, 50 Hz was conducted. Electric field strength in the range of industrial frequency directly under the transmission lines and at a distance from it to the railway line, as well as the time dependences of ALSN codes with signal current frequency of 50 Hz directly under the transmission lines and at a distance from it in the absence of the train and as its passing were measured. It was found that CACS codes in track circuits under transmission lines are strongly distorted, as strength

SPATIAL UNCERTAINTY IN LINE-SURFACE INTERSECTIONS WITH APPLICATIONS TO PHOTOGRAMMETRY

Directory of Open Access Journals (Sweden)

J. Marshall

2012-07-01

Full Text Available The fields of photogrammetry and computer vision routinely use line-surface intersections to determine the point where a line intersects with a surface. The object coordinates of the intersection point can be found using standard geometric and numeric algorithms, however expressing the spatial uncertainty at the intersection point may be challenging, especially when the surface morphology is complex. This paper describes an empirical method to characterize the unknown spatial uncertainty at the intersection point by propagating random errors in the stochastic model using repeated random sampling methods. These methods accommodate complex surface morphology and nonlinearities in the functional model, however the penalty is the resulting probability density function associated with the intersection point may be non-Gaussian in nature. A formal hypothesis test is presented to show that straightforward statistical inference tools are available whether the data is Gaussian or not. The hypothesis test determines whether the computed intersection point is consistent with an externally-derived known truth point. A numerical example demonstrates the approach in a photogrammetric setting with a single frame image and a gridded terrain elevation model. The results show that uncertainties produced by the proposed empirical method are intuitive and can be assessed with conventional methods found in textbook hypothesis testing.

Political Intersectionality and Democratic Politics in the European Public Sphere

DEFF Research Database (Denmark)

Siim, Birte

2015-01-01

Public Sphere (EPS). It is inspired by results and reflections from the European Gender Project (EGP) , where intersectionality was used as an approach for analysing negotiations between gender and ethno-national diversity in selected European countries and in relation to the European Public Sphere....... The aim of the essay is to further deepen the theoretical and empirical understanding of intersectionality by reflecting on the relations between political intersectionality and democratic politics from a particular European perspective. It thus confronts theory and research findings concerning...... intersections of gender and ethnic diversity in political life at the national and transnational levels across Europe. In this context, political intersectionality refers to the framing of gender and ethnic diversity by major political actors as well as by activities of women’s and anti-racist organisations...

BLM Colorado PLSS Intersected

Data.gov (United States)

Department of the Interior — Shapefile Format –The fully intersected data is the atomic level of the PLSS that is similar to the coverage or the smallest pieces used to build the PLSS. Polygons...

Integrating intersectionality and biomedicine in health disparities research.

Science.gov (United States)

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.

Finite temperature corrections to tachyon mass in intersecting D-branes

International Nuclear Information System (INIS)

Sethi, Varun; Chowdhury, Sudipto Paul; Sarkar, Swarnendu

2017-01-01

We continue with the analysis of finite temperature corrections to the Tachyon mass in intersecting branes which was initiated in https://www.doi.org/10.1007/JHEP09(2014)063. In this paper we extend the computation to the case of intersecting D3 branes by considering a setup of two intersecting branes in flat-space background. A holographic model dual to BCS superconductor consisting of intersecting D8 branes in D4 brane background was proposed in https://www.doi.org/10.1016/j.nuclphysb.2011.07.011. The background considered here is a simplified configuration of this dual model. We compute the one-loop Tachyon amplitude in the Yang-Mills approximation and show that the result is finite. Analyzing the amplitudes further we numerically compute the transition temperature at which the Tachyon becomes massless. The analytic expressions for the one-loop amplitudes obtained here reduce to those for intersecting D1 branes obtained in https://www.doi.org/10.1007/JHEP09(2014)063 as well as those for intersecting D2 branes.

Finite temperature corrections to tachyon mass in intersecting D-branes

Energy Technology Data Exchange (ETDEWEB)

Sethi, Varun [Department of Physics and Astrophysics, University of Delhi,Delhi 110007 (India); Chowdhury, Sudipto Paul [Institute of Physics, Sachivalaya Marg,Bhubaneswar 751005 (India); Sarkar, Swarnendu [Department of Physics and Astrophysics, University of Delhi,Delhi 110007 (India)

2017-04-19

We continue with the analysis of finite temperature corrections to the Tachyon mass in intersecting branes which was initiated in https://www.doi.org/10.1007/JHEP09(2014)063. In this paper we extend the computation to the case of intersecting D3 branes by considering a setup of two intersecting branes in flat-space background. A holographic model dual to BCS superconductor consisting of intersecting D8 branes in D4 brane background was proposed in https://www.doi.org/10.1016/j.nuclphysb.2011.07.011. The background considered here is a simplified configuration of this dual model. We compute the one-loop Tachyon amplitude in the Yang-Mills approximation and show that the result is finite. Analyzing the amplitudes further we numerically compute the transition temperature at which the Tachyon becomes massless. The analytic expressions for the one-loop amplitudes obtained here reduce to those for intersecting D1 branes obtained in https://www.doi.org/10.1007/JHEP09(2014)063 as well as those for intersecting D2 branes.

Particle-nuclear intersections

International Nuclear Information System (INIS)

Anon.

1994-01-01

With the traditional distinctions between particle and nuclear physics becoming increasing blurred, the Fifth Conference on the Intersections of Particle and Nuclear Physics, held from May 31 to June 6 in St. Petersburg, Florida, brought together particle and nuclear physicists to discuss common research efforts and to define and plan a united approach

Real-time traffic signal optimization model based on average delay time per person

Directory of Open Access Journals (Sweden)

Pengpeng Jiao

2015-10-01

Full Text Available Real-time traffic signal control is very important for relieving urban traffic congestion. Many existing traffic control models were formulated using optimization approach, with the objective functions of minimizing vehicle delay time. To improve people’s trip efficiency, this article aims to minimize delay time per person. Based on the time-varying traffic flow data at intersections, the article first fits curves of accumulative arrival and departure vehicles, as well as the corresponding functions. Moreover, this article transfers vehicle delay time to personal delay time using average passenger load of cars and buses, employs such time as the objective function, and proposes a signal timing optimization model for intersections to achieve real-time signal parameters, including cycle length and green time. This research further implements a case study based on practical data collected at an intersection in Beijing, China. The average delay time per person and queue length are employed as evaluation indices to show the performances of the model. The results show that the proposed methodology is capable of improving traffic efficiency and is very effective for real-world applications.

Complex Road Intersection Modelling Based on Low-Frequency GPS Track Data

Science.gov (United States)

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.

The Priority of Intersectionality in Academic Medicine.

Science.gov (United States)

Eckstrand, Kristen L; Eliason, Jennifer; St Cloud, Tiffani; Potter, Jennifer

2016-07-01

Recent societal events highlight inequities experienced by underrepresented and marginalized communities. These inequities are the impetus for ongoing efforts in academic medicine to create inclusive educational and patient care environments for diverse stakeholders. Frequently, approaches focus on singular populations or broad macroscopic concepts and do not always elucidate the complexities that arise at the intersection between multiple identities and life experiences. Intersectionality acknowledges multidimensional aspects of identity inclusive of historical, structural, and cultural factors. Understanding how multiple identity experiences impact different individuals, from patients to trainees to providers, is critical for improving health care education and delivery. Building on existing work within academic medicine, this Commentary outlines six key recommendations to advance intersectionality in academic medicine: embrace personal and collective loci of responsibility; examine and rectify unbalanced power dynamics; celebrate visibility and intersectional innovation; engage all stakeholders in the process of change; select and analyze meaningful metrics; and sustain the commitment to achieving health equity over time. Members of the academic medical community committed to advancing health equity can use these recommendations to promote and maintain meaningful changes that recognize and respond to the multidimensional voices and expressed needs of all individuals engaged in providing and receiving health care.

An LTE implementation based on a road traffic density model

OpenAIRE

Attaullah, Muhammad

2013-01-01

The increase in vehicular traffic has created new challenges in determining the behavior of performance of data and safety measures in traffic. Hence, traffic signals on intersection used as cost effective and time saving tools for traffic management in urban areas. But on the other hand the signalized intersections in congested urban areas are the key source of high traffic density and slow traffic. High traffic density causes the slow network traffic data rate between vehicle to vehicle and...

Women's health, men's health, and gender and health: implications of intersectionality.

Science.gov (United States)

Hankivsky, Olena

2012-06-01

Although intersectionality is now recognized in the context of women's health, men's health, and gender and health, its full implications for research, policy, and practice have not yet been interrogated. This paper investigates, from an intersectionality perspective, the common struggles within each field to confront the complex interplay of factors that shape health inequities. Drawing on developments within intersectionality scholarship and various sources of research and policy evidence (including examples from the field of HIV/AIDS), the paper demonstrates the methodological feasibility of intersectionality and in particular, the wide-ranging benefits of de-centering gender through intersectional analyses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Intersectionality and the Canadian Museum for Human Rights

Science.gov (United States)

Dhamoon, Rita Kaur; Hankivsky, Olena

2015-01-01

In this commentary, the authors propose than an intersectionality perspective can transform understandings of the contentious content of the Canadian Museum for Human Rights (CMHR). The use of an intersectionality perspective starts from the position that such discourses as racialization, gendering, capitalism, and ableism are mutually…

Intersection of Three Planes Revisited--An Algebraic Approach

Science.gov (United States)

Trenkler, Götz; Trenkler, Dietrich

2017-01-01

Given three planes in space, a complete characterization of their intersection is provided. Special attention is paid to the case when the intersection set does not exist of one point only. Besides the vector cross product, the tool of generalized inverse of a matrix is used extensively.

MULTIAGENT PLANNING OF INTERSECTION PASSAGE BY AUTONOMOUS VEHICLES

Directory of Open Access Journals (Sweden)

I. A. Zikratov

2016-09-01

Full Text Available We propose a traffic management system for autonomous vehicles that are agents at the intersection. In contrast to the known solutions based on the usage of semiautonomous control systems in assembly with the control unit, this algorithm is based on the principles of decentralized multiagent control. The best travel plan for intersection passage is produced by means of optimization methods jointly by all agents belonging to a dynamic collaboration of autonomous vehicles. The order of road intersection optimal for a given criterion is determined by the agents in the process of information exchange about themselves and environment. Our experiments show that this protocol can reduce significantly the traffic density as compared to the traditional systems of traffic management. Moreover, the effectiveness of the proposed algorithm increases with increasing density of road traffic. In addition, the absence of the critical object, that is the control unit, in the control system, reduces significantly the effectiveness of possible failures and hacker attacks on the intersection control system.

Refined open intersection numbers and the Kontsevich-Penner matrix model

Energy Technology Data Exchange (ETDEWEB)

Alexandrov, Alexander [Center for Geometry and Physics, Institute for Basic Science (IBS),Pohang 37673 (Korea, Republic of); Centre de Recherches Mathématiques (CRM), Université de Montréal,Montréal (Canada); Department of Mathematics and Statistics, Concordia University,Montréal (Canada); Institute for Theoretical and Experimental Physics (ITEP),Moscow (Russian Federation); Buryak, Alexandr [Department of Mathematics, ETH Zurich, Zurich (Switzerland); Tessler, Ran J. [Institute for Theoretical Studies, ETH Zurich,Zurich (Switzerland)

2017-03-23

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.

Refined open intersection numbers and the Kontsevich-Penner matrix model

International Nuclear Information System (INIS)

Alexandrov, Alexander; Buryak, Alexandr; Tessler, Ran J.

2017-01-01

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.

A robust algorithm to solve the signal setting problem considering different traffic assignment approaches

Directory of Open Access Journals (Sweden)

Adacher Ludovica

2017-12-01

Full Text Available In this paper we extend a stochastic discrete optimization algorithm so as to tackle the signal setting problem. Signalized junctions represent critical points of an urban transportation network, and the efficiency of their traffic signal setting influences the overall network performance. Since road congestion usually takes place at or close to junction areas, an improvement in signal settings contributes to improving travel times, drivers’ comfort, fuel consumption efficiency, pollution and safety. In a traffic network, the signal control strategy affects the travel time on the roads and influences drivers’ route choice behavior. The paper presents an algorithm for signal setting optimization of signalized junctions in a congested road network. The objective function used in this work is a weighted sum of delays caused by the signalized intersections. We propose an iterative procedure to solve the problem by alternately updating signal settings based on fixed flows and traffic assignment based on fixed signal settings. To show the robustness of our method, we consider two different assignment methods: one based on user equilibrium assignment, well established in the literature as well as in practice, and the other based on a platoon simulation model with vehicular flow propagation and spill-back. Our optimization algorithm is also compared with others well known in the literature for this problem. The surrogate method (SM, particle swarm optimization (PSO and the genetic algorithm (GA are compared for a combined problem of global optimization of signal settings and traffic assignment (GOSSTA. Numerical experiments on a real test network are reported.

An Assessment Methodology for Emergency Vehicle Traffic Signal Priority Systems

OpenAIRE

McHale, Gene Michael

2002-01-01

Emergency vehicle traffic signal priority systems allow emergency vehicles such as fire and emergency medical vehicles to request and receive a green traffic signal indication when approaching an intersection. Such systems have been around for a number of years, however, there is little understanding of the costs and benefits of such systems once they are deployed. This research develops an improved method to assess the travel time impacts of emergency vehicle traffic signal priority system...

Inequalities for dual quermassintegrals of mixed intersection bodies

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

Abstract. In this paper, we first introduce a new concept of dual quermassintegral sum function of two star bodies and establish Minkowski's type inequality for dual quermassintegral sum of mixed intersection bodies, which is a general form of the. Minkowski inequality for mixed intersection bodies. Then, we give the ...

Plastic limit loads for cylindrical shell intersections under combined loading

International Nuclear Information System (INIS)

Skopinsky, V.N.; Berkov, N.A.; Vogov, R.A.

2015-01-01

In this research, applied methods of nonlinear analysis and results of determining the plastic limit loads for shell intersection configurations under combined internal pressure, in-plane moment and out-plane moment loadings are presented. The numerical analysis of shell intersections is performed using the finite element method, geometrically nonlinear shell theory in quadratic approximation and plasticity theory. For determining the load parameter of proportional combined loading, the developed maximum criterion of rate of change of relative plastic work is employed. The graphical results for model of cylindrical shell intersection under different two-parameter combined loadings (as generalized plastic limit load curves) and three-parameter combined loading (as generalized plastic limit load surface) are presented on the assumption that the internal pressure, in-plane moment and out-plane moment loads were applied in a proportional manner. - Highlights: • This paper presents nonlinear two-dimensional FE analysis for shell intersections. • Determining the plastic limit loads under combined loading is considered. • Developed maximum criterion of rate of change of relative plastic work is employed. • Plastic deformation mechanism in shell intersections is discussed. • Results for generalized plastic limit load curves of branch intersection are presented

Outlook from the intersections

International Nuclear Information System (INIS)

Haxton, W.C.

1995-01-01

I review a number of the physics themes of the Fifth Conference on the Intersections of Particle and Nuclear Physics, discussing the significance and promise of current work at the interface of these fields. copyright 1995 American Institute of Physics

The Intersection of Gender and Age: An Exploration

Science.gov (United States)

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…

Game Theory Model of Traffic Participants within Amber Time at Signalized Intersection

Directory of Open Access Journals (Sweden)

Weiwei Qi

2014-01-01

Full Text Available The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will go against the purpose of setting amber lights if forbidding passing; on the other hand, it may lead to a mess of traffic flow running if not. And meanwhile the drivers are faced with the decision of passing the intersection or stopping during the amber light as well. So the decision-making behavior of traffic administrations and drivers can be converted into a double game model. And through quantification of their earnings in different choice conditions, the optimum decision-making plan under specific conditions could be solved via the Nash equilibrium solution concept. Thus the results will provide a basis for the formulation of the traffic management strategy.

Game Theory Model of Traffic Participants within Amber Time at Signalized Intersection

Science.gov (United States)

Qi, Weiwei; Wen, Huiying; Fu, Chuanyun; Song, Mo

2014-01-01

The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will go against the purpose of setting amber lights if forbidding passing; on the other hand, it may lead to a mess of traffic flow running if not. And meanwhile the drivers are faced with the decision of passing the intersection or stopping during the amber light as well. So the decision-making behavior of traffic administrations and drivers can be converted into a double game model. And through quantification of their earnings in different choice conditions, the optimum decision-making plan under specific conditions could be solved via the Nash equilibrium solution concept. Thus the results will provide a basis for the formulation of the traffic management strategy. PMID:25580108

Buckling behaviour of imperfect ring-stiffened cone-cylinder intersections under internal pressure

International Nuclear Information System (INIS)

Zhao, Y.

2005-01-01

Cone-cylinder intersections are used commonly in pressure vessels and piping. In the case of a cone large end-to-cylinder intersection under internal pressure, the intersection is subject to a large circumferential compressive force. While both the cone and the cylinder may be locally thickened to strengthen the intersection, it is often desirable and convenient to provide an annular plate ring at the cone-to-cylinder joint to supplement local thickening or as an alternative strengthening measure, leading to a ring-stiffened cone-cylinder intersection. Only limited work has been carried out specifically on ring-stiffened cone-cylinder intersections under internal pressure. This paper presents the first experimental study on such intersections. In addition to the presentation of test results including geometric imperfections, failure behaviour and the determination of buckling mode and load based on displacement measurements, results from nonlinear bifurcation analysis using the perfect shape and nonlinear analysis using the measured imperfect shape are presented and compared with the experimental results

Intersectionality as a Framework for Inclusive Environments

Science.gov (United States)

Nunez, A. M.

2016-12-01

To create more inclusive environments for the advancement of scientific inquiry, it is critical to consider the role of intersectionality. Originating in activism and legal scholarship grounded in the realities of women of color, the concept of intersectionality emphasizes how societal power dynamics shape the differential construction of life opportunities of diverse demographic groups across a variety of social identities, contexts, and historical conditions. Importantly, intersectionality also recognizes that individuals can simultaneously hold privileged and marginalized identities. For example, while white women scientists are less represented in leadership and decision-making positions than their male counterparts, but they typically do not experience the marginalization of being mistaken for cleaning staff at their institutions, as many African American and Latina scientists report. Thus, white women are relatively privileged in this context. This case and national survey data demonstrate the critical importance of recognizing that the intersection of racial and gender identities creates complex and multi-faceted challenges for diverse women scientists in navigating the organizational culture of science. Educational research indicates that interventions seeking to create more inclusivity in science should take into account the relationships between various social identities, contexts, and broader historical conditions that affect the advancement of historically underrepresented minority groups. Therefore, this presentation will provide a conceptual framework of intersectionality to guide interventions to encourage all scientists to recognize the distinctive intellectual and social contributions of those from diverse gender, race, class, disability, sexual orientation, and other identity backgrounds. It will also address how this framework can be applied to develop programs, policies, and practices that transform organizational cultures to be more inclusive

Multilevel models for evaluating the risk of pedestrian-motor vehicle collisions at intersections and mid-blocks.

Science.gov (United States)

Quistberg, D Alex; Howard, Eric J; Ebel, Beth E; Moudon, Anne V; Saelens, Brian E; Hurvitz, Philip M; Curtin, James E; Rivara, Frederick P

2015-11-01

Walking is a popular form of physical activity associated with clear health benefits. Promoting safe walking for pedestrians requires evaluating the risk of pedestrian-motor vehicle collisions at specific roadway locations in order to identify where road improvements and other interventions may be needed. The objective of this analysis was to estimate the risk of pedestrian collisions at intersections and mid-blocks in Seattle, WA. The study used 2007-2013 pedestrian-motor vehicle collision data from police reports and detailed characteristics of the microenvironment and macroenvironment at intersection and mid-block locations. The primary outcome was the number of pedestrian-motor vehicle collisions over time at each location (incident rate ratio [IRR] and 95% confidence interval [95% CI]). Multilevel mixed effects Poisson models accounted for correlation within and between locations and census blocks over time. Analysis accounted for pedestrian and vehicle activity (e.g., residential density and road classification). In the final multivariable model, intersections with 4 segments or 5 or more segments had higher pedestrian collision rates compared to mid-blocks. Non-residential roads had significantly higher rates than residential roads, with principal arterials having the highest collision rate. The pedestrian collision rate was higher by 9% per 10 feet of street width. Locations with traffic signals had twice the collision rate of locations without a signal and those with marked crosswalks also had a higher rate. Locations with a marked crosswalk also had higher risk of collision. Locations with a one-way road or those with signs encouraging motorists to cede the right-of-way to pedestrians had fewer pedestrian collisions. Collision rates were higher in locations that encourage greater pedestrian activity (more bus use, more fast food restaurants, higher employment, residential, and population densities). Locations with higher intersection density had a lower

Multiphase flow in geometrically simple fracture intersections

Science.gov (United States)

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.

Learning-based traffic signal control algorithms with neighborhood information sharing: An application for sustainable mobility

Energy Technology Data Exchange (ETDEWEB)

Aziz, H. M. Abdul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhu, Feng [Purdue University, West Lafayette, IN (United States). Lyles School of Civil Engineering; Ukkusuri, Satish V. [Purdue University, West Lafayette, IN (United States). Lyles School of Civil Engineering

2017-10-04

Here, this research applies R-Markov Average Reward Technique based reinforcement learning (RL) algorithm, namely RMART, for vehicular signal control problem leveraging information sharing among signal controllers in connected vehicle environment. We implemented the algorithm in a network of 18 signalized intersections and compare the performance of RMART with fixed, adaptive, and variants of the RL schemes. Results show significant improvement in system performance for RMART algorithm with information sharing over both traditional fixed signal timing plans and real time adaptive control schemes. Additionally, the comparison with reinforcement learning algorithms including Q learning and SARSA indicate that RMART performs better at higher congestion levels. Further, a multi-reward structure is proposed that dynamically adjusts the reward function with varying congestion states at the intersection. Finally, the results from test networks show significant reduction in emissions (CO, CO₂, NO_x, VOC, PM₁₀) when RL algorithms are implemented compared to fixed signal timings and adaptive schemes.

Variable cycle control model for intersection based on multi-source information

Science.gov (United States)

Sun, Zhi-Yuan; Li, Yue; Qu, Wen-Cong; Chen, Yan-Yan

2018-05-01

In order to improve the efficiency of traffic control system in the era of big data, a new variable cycle control model based on multi-source information is presented for intersection in this paper. Firstly, with consideration of multi-source information, a unified framework based on cyber-physical system is proposed. Secondly, taking into account the variable length of cell, hysteresis phenomenon of traffic flow and the characteristics of lane group, a Lane group-based Cell Transmission Model is established to describe the physical properties of traffic flow under different traffic signal control schemes. Thirdly, the variable cycle control problem is abstracted into a bi-level programming model. The upper level model is put forward for cycle length optimization considering traffic capacity and delay. The lower level model is a dynamic signal control decision model based on fairness analysis. Then, a Hybrid Intelligent Optimization Algorithm is raised to solve the proposed model. Finally, a case study shows the efficiency and applicability of the proposed model and algorithm.

We Are Still Here: Re-Centring the Quintessential Subject of Intersectionality

OpenAIRE

Chantler, Khatidja; Thiara, R

2017-01-01

This paper argues that “Black woman” should remain the quintessential subject of intersectionality as we are concerned that racialization has been submerged within intersectionality debates. Drawing on research and policy related to violence against women in minoritized communities in the UK, we (re)interrogate the explanatory power and effects of intersectionality.

Switching Exciton Pulses Through Conical Intersections

Science.gov (United States)

Leonhardt, K.; Wüster, S.; Rost, J. M.

2014-11-01

Exciton pulses transport excitation and entanglement adiabatically through Rydberg aggregates, assemblies of highly excited light atoms, which are set into directed motion by resonant dipole-dipole interaction. Here, we demonstrate the coherent splitting of such pulses as well as the spatial segregation of electronic excitation and atomic motion. Both mechanisms exploit local nonadiabatic effects at a conical intersection, turning them from a decoherence source into an asset. The intersection provides a sensitive knob controlling the propagation direction and coherence properties of exciton pulses. The fundamental ideas discussed here have general implications for excitons on a dynamic network.

The potential of clustering methods to define intersection test scenarios: Assessing real-life performance of AEB.

Science.gov (United States)

Sander, Ulrich; Lubbe, Nils

2018-04-01

usage of different sets of clustering variables resulted in substantially different numbers of clusters. The stability of the resulting clusters increased with prioritization of categorical over continuous variables. For each different set of cluster variables, a strong in-cluster variance of avoided versus non-avoided accidents for the specified Intersection AEB was present. The medoids did not predict the most common Intersection AEB behavior in each cluster. Despite thorough analysis using various cluster methods and variable sets, it was impossible to reduce the diversity of intersection accidents into a set of test scenarios without compromising the ability to predict real-life performance of Intersection AEB. Although this does not imply that other methods cannot succeed, it was observed that small changes in the definition of a scenario resulted in a different avoidance outcome. Therefore, we suggest using limited physical testing to validate more extensive virtual simulations to evaluate vehicle safety. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification of black spots for traffic injury in road intersections dependence of injury definition

DEFF Research Database (Denmark)

Lund Hansen, Dennis; Lauritsen, Jens M

2010-01-01

injury information has been available for about 20 years and in the current project the aim was to investigate whether different definitions of black spots (hot spots) would point at different intersections for further scrutiny. During the years 2002 to 2007 all 29 719 patient contacts due to traffic...... defined as The upper decile of injury generating intersections. Intersections with at least one death or hospitalised patient. The intersections covering the upper decile of injuries. Results The three definitions in combination identified 295 injury burdened intersections. Only three intersections were...... identified by all three definitions. All intersections fulfilling definition three were also included in definition one. Definition two covered 103 intersections, only 22 of these were identified by definition one. Conclusion The definition of Black spot has huge implications for identification...

Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections

Directory of Open Access Journals (Sweden)

Leyre Azpilicueta

2016-07-01

Full Text Available 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.

Intersectionality and Liberal Education

Science.gov (United States)

Butler, Johnella E.

2017-01-01

Intersectionality--an integrated approach to analyzing the complex, matrix-like interconnections among patterns of discrimination based on race, gender, and other social identities, with the goal of highlighting how resulting inequalities are experienced--has many implications for exploring the relationship between knowledge and experience and for…

Considering Intersectionality in Multiculturalism

Science.gov (United States)

Clark, Madeline

2015-01-01

The intersection of feminist theory and multiculturalism is discussed. Although Frisby makes several strong points, there are several aspects of his definition of multiculturalism that are simplistic. Expansion of ideas borrowed from feminism has potential to increase the nuance and accuracy of the conceptualization of multiculturalism.

Exploring the promises of intersectionality for advancing women's health research

Directory of Open Access Journals (Sweden)

Clark Natalie

2010-02-01

Full Text Available Abstract Women's health research strives to make change. It seeks to produce knowledge that promotes action on the variety of factors that affect women's lives and their health. As part of this general movement, important strides have been made to raise awareness of the health effects of sex and gender. The resultant base of knowledge has been used to inform health research, policy, and practice. Increasingly, however, the need to pay better attention to the inequities among women that are caused by racism, colonialism, ethnocentrism, heterosexism, and able-bodism, is confronting feminist health researchers and activists. Researchers are seeking new conceptual frameworks that can transform the design of research to produce knowledge that captures how systems of discrimination or subordination overlap and "articulate" with one another. An emerging paradigm for women's health research is intersectionality. Intersectionality places an explicit focus on differences among groups and seeks to illuminate various interacting social factors that affect human lives, including social locations, health status, and quality of life. This paper will draw on recently emerging intersectionality research in the Canadian women's health context in order to explore the promises and practical challenges of the processes involved in applying an intersectionality paradigm. We begin with a brief overview of why the need for an intersectionality approach has emerged within the context of women's health research and introduce current thinking about how intersectionality can inform and transform health research more broadly. We then highlight novel Canadian research that is grappling with the challenges in addressing issues of difference and diversity. In the analysis of these examples, we focus on a largely uninvestigated aspect of intersectionality research - the challenges involved in the process of initiating and developing such projects and, in particular, the meaning

Exploring the promises of intersectionality for advancing women's health research.

Science.gov (United States)

Hankivsky, Olena; Reid, Colleen; Cormier, Renee; Varcoe, Colleen; Clark, Natalie; Benoit, Cecilia; Brotman, Shari

2010-02-11

Women's health research strives to make change. It seeks to produce knowledge that promotes action on the variety of factors that affect women's lives and their health. As part of this general movement, important strides have been made to raise awareness of the health effects of sex and gender. The resultant base of knowledge has been used to inform health research, policy, and practice. Increasingly, however, the need to pay better attention to the inequities among women that are caused by racism, colonialism, ethnocentrism, heterosexism, and able-bodism, is confronting feminist health researchers and activists. Researchers are seeking new conceptual frameworks that can transform the design of research to produce knowledge that captures how systems of discrimination or subordination overlap and "articulate" with one another. An emerging paradigm for women's health research is intersectionality. Intersectionality places an explicit focus on differences among groups and seeks to illuminate various interacting social factors that affect human lives, including social locations, health status, and quality of life. This paper will draw on recently emerging intersectionality research in the Canadian women's health context in order to explore the promises and practical challenges of the processes involved in applying an intersectionality paradigm. We begin with a brief overview of why the need for an intersectionality approach has emerged within the context of women's health research and introduce current thinking about how intersectionality can inform and transform health research more broadly. We then highlight novel Canadian research that is grappling with the challenges in addressing issues of difference and diversity. In the analysis of these examples, we focus on a largely uninvestigated aspect of intersectionality research - the challenges involved in the process of initiating and developing such projects and, in particular, the meaning and significance of social

A finite-element for the analysis of shell intersections

International Nuclear Information System (INIS)

Koves, W.J.; Nair, S.

1994-01-01

The analysis of discontinuity stresses at shell intersections is a problem of great importance in several major industries. Some of the major areas of interest are pressure-containing equipment, such as reactors and piping, in the nuclear and fossil power industry; pressure vessels and heat exchangers in the petrochemical industry; bracing in offshore oil platforms; and aerospace structures. A specialized shell-intersection finite element, which is compatible with adjoining shell elements, has been developed that has the capability of physically representing the complex three-dimensional geometry and stress state at shell intersections. The element geometry is a contoured shape that matches a wide variety of practical nozzle configurations used in ASME Code pressure vessel construction, and allows computational rigor. A closed-form theory of elasticity solution was used to compute the stress state and strain energy in the element. The concept of an energy-equivalent nodal displacement and force vector set was then developed to allow complete compatibility with adjoining shell elements and retain the analytical rigor within the element. This methodology provides a powerful and robust computation scheme that maintains the computational efficiency of shell element solutions. The shell-intersection element was then applied to the cylinder-sphere and cylinder-cylinder intersection problems

Optimizing Performance of at-grade Intersection with Bus Rapid Transit Corridor and Heterogeneous Traffic

Directory of Open Access Journals (Sweden)

Hemant Kumar Sharma

2012-06-01

Full Text Available Bus Rapid Transit (BRT has emerged as a preferred mode of public transport in various countries all over the world for its cost effectiveness in construction as well as in operation and maintenance. The rapid transit feature of BRT is seen as a solution to many traffic problems in these countries. However, in developing countries like India, the right -of-way for most of the roads is restricted and traffic is heterogeneous in nature. Provision of BRT in existing right -of-way reduces the capacity available for other motorized traffic. As the buses travel with a certain frequency on dedicated bus- ways, the dedicated corridor remains unused for most of the period when other traffic on motorized vehicle (MV lanes suffers from congestion. The problem gets severe at intersections. However, if buses are operated in mixed traffic it is no more rapid transit. Hence, a solution is required to address this problem and optimize the performance of traffic as a whole. This paper presents the effect if dedicated bus-ways end at a reasonable distance before the stop line at a busy signalized at-grade intersection, and bus lanes (beyond that are made available to all the motorized vehicular traffic (heterogeneous traffic at intersection. The performance evaluation is done in terms of average queue length, maximum queue length, average delay time per vehicle, vehicle throughput, average speed in network and emission of Carbon monoxide CO, mono-nitrogen oxides NOx and Volatile organic compounds (VOC. It is observed that availability of bus lanes to other motorized traffic for a reasonable distance before intersection considerably reduces the average queue length, maximum queue length, average delay time per vehicle and emission per vehicle, while there is an increase in vehicle throughput and average speed of all the vehicles in the network. Thus it results in reduction of congestion and performance enhancement of at-grade intersections and network. Results of

Traffic signal synchronization in the saturated high-density grid road network.

Science.gov (United States)

Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

2015-01-01

Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN.

EnviroAtlas - Portland, ME - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Woodbine, IA - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Durham, NC - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Fresno, CA - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Cleveland, OH - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Memphis, TN - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Milwaukee, WI - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Portland, OR - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Tampa, FL - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Austin, TX - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Paterson, NJ - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Phoenix, AZ - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Pittsburgh, PA - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

Teaching Intersectional and Transnational Feminisms through Fiction and Film

Science.gov (United States)

Mahrouse, Gada

2016-01-01

Author Gada Mahrouse begins this article by saying that the terms "intersectional" and "transnational" are widely misunderstood and misused by academics. She writes that the first, "intersectionality," has become a buzzword, not only in feminist courses but also in mainstream disciplines and areas of research. She…

Gender Equality, Intersectionality and Diversity in Europe

DEFF Research Database (Denmark)

Agustin, Lise Rolandsen

. Drawing on discursive policy analysis, it addresses the interaction between policies, institutions and civil society actors in relation to gender equality, diversity and intersectionality at the European level. Rolandsen Agustín successfully integrates the concepts of diversity and gender equality...... into a contextualized approach to analyzing transnational intersectionality. This unique approach focuses on processes of institutionalization and mobilization, which are addressed in relation to the institutional setup of the EU, its policies and policymaking structures, as well as transnational civil society...

Democratising intersectionality? participatory structures and equality policies in Portugal

Directory of Open Access Journals (Sweden)

Alba Alonso Alvarez

2017-06-01

Full Text Available Scholarly work on intersectionality has shown some concern on whether this policy strategy is implemented in a participatory manner. The case of Portugal has been of particular interest since the country features a long tradition of involving civil society in the making of equality policies. This article revisits the Portuguese case in order to analyse recent developments. First, the participatory and coordinated approach adopted so far to deal with inequalities is described. Second, the analysis focuses on gender-based violence policies to help capturing new advancements. These policies have been recently enlarged to tackle the situation of women at the intersections and civil society actors have been actively involved in the policy-making process. In particular, the case of policies to combat female genital mutilation illustrates how participatory structures contribute to bring an intersectional perspective. The analysis of the Portuguese case allows thus reflecting on the potential benefits of democratising intersectionality as well as its limits.

Specification and Verification of Distributed Embedded Systems: A Traffic Intersection Product Family

Directory of Open Access Journals (Sweden)

José Meseguer

2010-09-01

Full Text Available Distributed embedded systems (DESs are no longer the exception; they are the rule in many application areas such as avionics, the automotive industry, traffic systems, sensor networks, and medical devices. Formal DES specification and verification is challenging due to state space explosion and the need to support real-time features. This paper reports on an extensive industry-based case study involving a DES product family for a pedestrian and car 4-way traffic intersection in which autonomous devices communicate by asynchronous message passing without a centralized controller. All the safety requirements and a liveness requirement informally specified in the requirements document have been formally verified using Real-Time Maude and its model checking features.

Reliability of drivers in urban intersections.

Science.gov (United States)

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

Ultrafast X-Ray Spectroscopy of Conical Intersections

Science.gov (United States)

Neville, Simon P.; Chergui, Majed; Stolow, Albert; Schuurman, Michael S.

2018-06-01

Ongoing developments in ultrafast x-ray sources offer powerful new means of probing the complex nonadiabatically coupled structural and electronic dynamics of photoexcited molecules. These non-Born-Oppenheimer effects are governed by general electronic degeneracies termed conical intersections, which play a key role, analogous to that of a transition state, in the electronic-nuclear dynamics of excited molecules. Using high-level ab initio quantum dynamics simulations, we studied time-resolved x-ray absorption (TRXAS) and photoelectron spectroscopy (TRXPS) of the prototypical unsaturated organic chromophore, ethylene, following excitation to its S2(π π*) state. The TRXAS, in particular, is highly sensitive to all aspects of the ensuing dynamics. These x-ray spectroscopies provide a clear signature of the wave packet dynamics near conical intersections, related to charge localization effects driven by the nuclear dynamics. Given the ubiquity of charge localization in excited state dynamics, we believe that ultrafast x-ray spectroscopies offer a unique and powerful route to the direct observation of dynamics around conical intersections.

Teaching Guide for the Traffic Signal Light Program: Kindergarten Level.

Science.gov (United States)

Maryland State Dept. of Education, Baltimore.

This teachers' guide provides materials and suggestions for approximately 125 lessons that are designed to increase kindergarten children's traffic safety skills and knowledge. Most of the guide focuses on (1) lessons about physical structures in the pedestrian environment such as sidewalks, curbs, crosswalks, and intersections, and (2) signal…

Conformational analysis by intersection: CONAN.

Science.gov (United States)

Smellie, Andrew; Stanton, Robert; Henne, Randy; Teig, Steve

2003-01-15

As high throughput techniques in chemical synthesis and screening improve, more demands are placed on computer assisted design and virtual screening. Many of these computational methods require one or more three-dimensional conformations for molecules, creating a demand for a conformational analysis tool that can rapidly and robustly cover the low-energy conformational spaces of small molecules. A new algorithm of intersection is presented here, which quickly generates (on average heuristics are applied after intersection to generate a small representative collection of conformations that span the conformational space. In a study of approximately 97,000 randomly selected molecules from the MDDR, results are presented that explore these conformations and their ability to cover low-energy conformational space. Copyright 2002 Wiley Periodicals, Inc. J Comput Chem 24: 10-20, 2003

The OAFM magnet for ISR intersection I-8

CERN Multimedia

CERN PhotoLab

1979-01-01

The Open Axial Field Magnet (OAFM), weighing in at 300 tons, was installed in ISR intersection I-8 and brought into operation early in 1979. Fitted with a highly transparent "flat-fish" vacuum chamber, it served experiment R807 (large transverse momentum). Flat-fish vacuum chambers were originally developed for use inside the Split-Field Magnet (SFM) at intersection I-4: see 8310325 and references there.

Representing the intersection in France and America: theories of intersectionality meet social science

NARCIS (Netherlands)

Jaunait, A.; Chauvin, S.

2012-01-01

Forged in the United States in the 1980s, the notion of intersectionality sought to provide an umbrella term for the strategic and identity dilemmas faced by categories of persons suffering from combined forms of domination. This article retraces the comparative genealogy of the notion in the United

On the use of naturalistic methods to examine safety-relevant behaviours amongst children and evaluate a cycling education program.

Science.gov (United States)

Hatfield, J; Dozza, M; Patton, D A; Maharaj, P; Boufous, S; Eveston, T

2017-11-01

School-based cycling education programs aim to improve cycling safety and participation amongst children. Available research suggests that typical programs, which focus on bicycle manoeuvring skills, have limited effects on behaviour observed on a track or planned route. The current study uses theoretically more valid, naturalistic cycling data, to evaluate Safe Cycle, a program that incorporates hazard and self-awareness training. Soon after Safe Cycle was delivered at treatment schools, research bicycles instrumented with a rearward- and a forward-facing camera were loaned to six children from treatment schools and six children from (waitlist) control schools. In each group half the children were in Year 6, and half were in Year 7/8. Each child was instructed to ride the research bicycle instead of their own bicycle for the 1-2 weeks that they had a research bicycle. Video data were reduced using a purpose-designed coding scheme that identified whether participants performed specific safety-relevant behaviours in appropriate circumstances. While the participants controlled their bicycles well, gave way appropriately to traffic at intersections, and stopped at red lights, participants frequently removed one or both hands from the handlebars, and seldom signalled turns, conducted over-shoulder-checks when changing lanes, or looked in multiple directions at intersections (except when crossing a road). While aspects of design and small sample sizes limited evaluation findings, this research demonstrated the feasibility and potential of naturalistic data to support cycling education program evaluation. Further, the study substantially extended available naturalistic study of children's cycling behaviour to highlight behaviours which might be targeted by cycling safety initiatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

INTELLIGENT TRAFFIC-SAFETY MIRROR BY USING WIRELESS SENSOR NETWORK

Directory of Open Access Journals (Sweden)

Peter Danišovič

2014-03-01

Full Text Available This article is focused on the problematic of traffic safety, dealing with the problem of car intersections with blocked view crossing by a special wireless sensor network (WSN proposed for the traffic monitoring, concretely for vehicle’s detection at places, where it is necessary. Some ultra-low-power TI products were developed due to this reason: microcontroller MSP430F2232, 868MHz RF transceiver CC1101 and LDO voltage regulator TPS7033. The WSN consist of four network nodes supplied with the special safety lightings which serve the function of intelligent traffic safety mirror.

Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner.

Science.gov (United States)

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.

Intersectionality and Transnational Feminism between Constructivism, Post-Structuralism and Epistemological Performances

Directory of Open Access Journals (Sweden)

Cristina Demaria

2016-07-01

Full Text Available What does it mean today to talk about intersectionality or, better, about intersectional approaches within the vast and fragmented field of Feminist Studies? And how can intersectionality help understanding the development of transnational feminism, and viceversa? By offering a brief critical genealogy of the notion of intersectionality, from the systemic to the anti-categorial positions that have characterized the debate on this notion, the essay tries to present a reading of the main questions that stemmed from thinking the working of the many power differentials and identity markers (gender, race, class, ages, disabilities, etc. that constitute regional, national and transnational subjectivities. In adopting an anti-categorial stance, this work attempts at showing how feminism has changed thanks to different, yet complementary, perspectives on intersectional subject formations and positioning, along with the relational and transnational struggles that have been imagined in order to refine a feminist gaze at every level of social, cultural and political life, be it theoretical, methodological or epistemological.

Considering Gender and Student Leadership Through the Lens of Intersectionality.

Science.gov (United States)

Tillapaugh, Daniel; Mitchell, Donald; Soria, Krista M

2017-06-01

This chapter explores the concept of intersectionality and its applicability to student leadership development as well as recommendations on how intersectionality can provide transformative learning for students of all gender identities. © 2017 Wiley Periodicals, Inc., A Wiley Company.

Concurrent audio-visual feedback for supporting drivers at intersections: A study using two linked driving simulators.

Science.gov (United States)

Houtenbos, M; de Winter, J C F; Hale, A R; Wieringa, P A; Hagenzieker, M P

2017-04-01

A large portion of road traffic crashes occur at intersections for the reason that drivers lack necessary visual information. This research examined the effects of an audio-visual display that provides real-time sonification and visualization of the speed and direction of another car approaching the crossroads on an intersecting road. The location of red blinking lights (left vs. right on the speedometer) and the lateral input direction of beeps (left vs. right ear in headphones) corresponded to the direction from where the other car approached, and the blink and beep rates were a function of the approaching car's speed. Two driving simulators were linked so that the participant and the experimenter drove in the same virtual world. Participants (N = 25) completed four sessions (two with the audio-visual display on, two with the audio-visual display off), each session consisting of 22 intersections at which the experimenter approached from the left or right and either maintained speed or slowed down. Compared to driving with the display off, the audio-visual display resulted in enhanced traffic efficiency (i.e., greater mean speed, less coasting) while not compromising safety (i.e., the time gap between the two vehicles was equivalent). A post-experiment questionnaire showed that the beeps were regarded as more useful than the lights. It is argued that the audio-visual display is a promising means of supporting drivers until fully automated driving is technically feasible. Copyright © 2016. Published by Elsevier Ltd.

Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner

Directory of Open Access Journals (Sweden)

Jhonghyun An

2016-07-01

Full Text Available 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.

Intersections and Unions of Session Types

Directory of Open Access Journals (Sweden)

Coşku Acay

2017-02-01

Full Text Available Prior work has extended the deep, logical connection between the linear sequent calculus and session-typed message-passing concurrent computation with equi-recursive types and a natural notion of subtyping. In this paper, we extend this further by intersection and union types in order to express multiple behavioral properties of processes in a single type. We prove session fidelity and absence of deadlock and illustrate the expressive power of our system with some simple examples. We observe that we can represent internal and external choice by intersection and union, respectively, which was previously suggested by Padovani for a different language of session types motivated by operational rather than logical concerns.

Real-life data for the optimization of the geometric layout of an intersection

NARCIS (Netherlands)

Fleuren, S.T.G.; Lefeber, A.A.J.

2016-01-01

This document contains the data of ten real-life intersections. This data can be used for the optimization of the geometric layout of the intersection, e.g., optimizing the arrival lanes, departure lanes and lane markings at the intersection.

Using intersectionality responsibly: Toward critical epistemology, structural analysis, and social justice activism.

Science.gov (United States)

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).

Extinction of avoidance behavior by safety learning depends on endocannabinoid signaling in the hippocampus.

Science.gov (United States)

Micale, Vincenzo; Stepan, Jens; Jurik, Angela; Pamplona, Fabricio A; Marsch, Rudolph; Drago, Filippo; Eder, Matthias; Wotjak, Carsten T

2017-07-01

The development of exaggerated avoidance behavior is largely responsible for the decreased quality of life in patients suffering from anxiety disorders. Studies using animal models have contributed to the understanding of the neural mechanisms underlying the acquisition of avoidance responses. However, much less is known about its extinction. Here we provide evidence in mice that learning about the safety of an environment (i.e., safety learning) rather than repeated execution of the avoided response in absence of negative consequences (i.e., response extinction) allowed the animals to overcome their avoidance behavior in a step-down avoidance task. This process was context-dependent and could be blocked by pharmacological (3 mg/kg, s.c.; SR141716) or genetic (lack of cannabinoid CB1 receptors in neurons expressing dopamine D1 receptors) inactivation of CB1 receptors. In turn, the endocannabinoid reuptake inhibitor AM404 (3 mg/kg, i.p.) facilitated safety learning in a CB1-dependent manner and attenuated the relapse of avoidance behavior 28 days after conditioning. Safety learning crucially depended on endocannabinoid signaling at level of the hippocampus, since intrahippocampal SR141716 treatment impaired, whereas AM404 facilitated safety learning. Other than AM404, treatment with diazepam (1 mg/kg, i.p.) impaired safety learning. Drug effects on behavior were directly mirrored by drug effects on evoked activity propagation through the hippocampal trisynaptic circuit in brain slices: As revealed by voltage-sensitive dye imaging, diazepam impaired whereas AM404 facilitated activity propagation to CA1 in a CB1-dependent manner. In line with this, systemic AM404 enhanced safety learning-induced expression of Egr1 at level of CA1. Together, our data render it likely that AM404 promotes safety learning by enhancing information flow through the trisynaptic circuit to CA1. Copyright © 2017 Elsevier Ltd. All rights reserved.

Safety diagnosis: are we doing a good job?

Science.gov (United States)

Park, Peter Y; Sahaji, Rajib

2013-03-01

Collision diagnosis is the second step in the six-step road safety management process described in the AASHTO Highway Safety Manual (HSM). Diagnosis is designed to identify a dominant or abnormally high proportion of particular collision configurations (e.g., rear end, right angle, etc.) at a target location. The primary diagnosis method suggested in the HSM is descriptive data analysis. This type of analysis relies on, for example, pie charts, histograms, and/or collision diagrams. Using location specific collision data (e.g., collision frequency per collision configuration for a target location), safety engineers identify (the most) frequent collision configurations. Safety countermeasures are then likely to concentrate on preventing the selected collision configurations. Although its real-world application in engineering practice is limited, an additional collision diagnosis method, known as the beta-binomial (BB) test, is also presented as the secondary diagnosis tool in the HSM. The BB test compares the proportion of a particular collision configuration observed at one location with the proportion of the same collision configuration found at other reference locations which are similar to the target location in terms of selected traffic and roadway characteristics (e.g., traffic volume, traffic control, and number of lanes). This study compared the outcomes obtained from descriptive data analysis and the BB test, and investigates two questions: (1) Do descriptive data analysis and the BB tests produce the same results (i.e., do they select the same collision configurations at the same locations)? and (2) If the tests produce different results, which result should be adopted in engineering practice? This study's analysis was based on a sample of the most recent five years (2005-2009) of collision and roadway configuration data for 143 signalized intersections in the City of Saskatoon, Saskatchewan. The study results show that the BB test's role in diagnosing

Some Results on the Intersection Graphs of Ideals of Rings

International Nuclear Information System (INIS)

Akbari, S.; Nikandish, R.; Nikmehr, M.J.

2010-08-01

Let R be a ring with unity and I(R)* be the set of all non-trivial left ideals of R. The intersection graph of ideals of R, denoted by G(R), is a graph with the vertex set I(R)* and two distinct vertices I and J are adjacent if and only if I intersection J ≠ 0. In this paper, we study some connections between the graph-theoretic properties of this graph and some algebraic properties of rings. We characterize all rings whose intersection graphs of ideals are not connected. Also we determine all rings whose clique number of the intersection graphs of ideals are finite. Among other results, it is shown that for every ring, if the clique number of G(R) is finite, then the chromatic number is finite too and if R is a reduced ring both are equal. (author)

An Intersectional Perspective on Access to HIV-Related Healthcare for Transgender Women

Science.gov (United States)

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

Teleparallel loop quantum cosmology in a system of intersecting branes

Directory of Open Access Journals (Sweden)

Alireza Sepehri

2016-09-01

Full Text Available Recently, some authors have removed the big bang singularity in teleparallel Loop Quantum Cosmology (LQC and have shown that the universe may undergo a number of oscillations. We investigate the origin of this type of teleparallel theory in a system of intersecting branes in M-theory in which the angle between them changes with time. This system is constructed by two intersecting anti-D8-branes, one compacted D4-brane and a D3-brane. These branes are built by joining M0-branes which develop in decaying fundamental strings. The compacted D4-brane is located between two intersecting anti-D8 branes and glues to one of them. Our universe is located on the D3 brane which wraps around the D4 brane from one end and sticks to one of the anti-D8 branes from the other one. In this system, there are three types of fields, corresponding to compacted D4 branes, intersecting branes and D3-branes. These fields interact with each other and make the angle between branes oscillate. By decreasing this angle, the intersecting anti-D8 branes approach each other, the D4 brane rolls, the D3 brane wraps around the D4 brane, and the universe contracts. By separating the intersecting branes and increasing the angle, the D4 brane rolls in the opposite direction, the D3 brane separates from it and the expansion branch begins. Also, the interaction between branes in this system gives us the exact form of the relevant Lagrangian for teleparallel LQC.

Teleparallel loop quantum cosmology in a system of intersecting branes

Energy Technology Data Exchange (ETDEWEB)

Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Pradhan, Anirudh, E-mail: pradhan.anirudh@gmail.com [Department of Mathematics, Institute of Applied Sciences and Humanities, GLA University, Mathura-281 406, Uttar Pradesh (India); Beesham, Aroonkumar, E-mail: beeshama@unizulu.ac.za [Department of Mathematical Sciences, University of Zululand, Kwa-Dlangezwa 3886 (South Africa); Haro, Jaume de, E-mail: jaime.haro@upc.edu [Departament de Matemàtiques, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain)

2016-09-10

Recently, some authors have removed the big bang singularity in teleparallel Loop Quantum Cosmology (LQC) and have shown that the universe may undergo a number of oscillations. We investigate the origin of this type of teleparallel theory in a system of intersecting branes in M-theory in which the angle between them changes with time. This system is constructed by two intersecting anti-D8-branes, one compacted D4-brane and a D3-brane. These branes are built by joining M0-branes which develop in decaying fundamental strings. The compacted D4-brane is located between two intersecting anti-D8 branes and glues to one of them. Our universe is located on the D3 brane which wraps around the D4 brane from one end and sticks to one of the anti-D8 branes from the other one. In this system, there are three types of fields, corresponding to compacted D4 branes, intersecting branes and D3-branes. These fields interact with each other and make the angle between branes oscillate. By decreasing this angle, the intersecting anti-D8 branes approach each other, the D4 brane rolls, the D3 brane wraps around the D4 brane, and the universe contracts. By separating the intersecting branes and increasing the angle, the D4 brane rolls in the opposite direction, the D3 brane separates from it and the expansion branch begins. Also, the interaction between branes in this system gives us the exact form of the relevant Lagrangian for teleparallel LQC.

Traffic Feasibility Study for a Grade Separator at a Busy Intersection in Vellore

Science.gov (United States)

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.

Common intersection points in dense fluids via equations of state

International Nuclear Information System (INIS)

Parsafar, G. A.; Noorian, R.

2001-01-01

Some new of state which are derived for dense fluids in recent years, namely the linear isotherm regularity, the dense system equation of state, Ihm-Song-Mason equation of state, and a newly derived semi-empirical equation of state have used to investigate the common intersection point of isobaric expansivity (α p ) in dense fluids. We have shown that the accuracy of these equations of state in predicting such a common intersection point is reduced from the new semi-imperial equation of state, dense system equation of state, linear isotherm regularity, to Ihm-Song-Mason equation of state. respectively. Form physical point of view, the van der Waals equation of state is used to investigate such an intersection point. It is shown that the van der Waals repulsion forces and temperature dependency of the effective molecular diameter are important for existence of this common point. Finally, we have shown that the common intersection points of the isotherms of thermal pressure coefficient, the isotherms of heat capacity at constant volume, and the iso chores of internal pressure for a fluid are related to each other. Also, the common intersection points of the reduced bulk modulus and 1/(Tα p ) for isotherms of a fluid both appear at the same density

EnviroAtlas - New Bedford, MA - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Green Bay, WI - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - Des Moines, IA - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

EnviroAtlas - New York, NY - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

Large-Scale Transit Signal Priority Implementation

OpenAIRE

Lee, Kevin S.; Lozner, Bailey

2018-01-01

In 2016, the District Department of Transportation (DDOT) deployed Transit Signal Priority (TSP) at 195 intersections in highly urbanized areas of Washington, DC. In collaboration with a broader regional implementation, and in partnership with the Washington Metropolitan Area Transit Authority (WMATA), DDOT set out to apply a systems engineering–driven process to identify, design, test, and accept a large-scale TSP system. This presentation will highlight project successes and lessons learned.

Road network safety evaluation using Bayesian hierarchical joint model.

Science.gov (United States)

Wang, Jie; Huang, Helai

2016-05-01

Safety and efficiency are commonly regarded as two significant performance indicators of transportation systems. In practice, road network planning has focused on road capacity and transport efficiency whereas the safety level of a road network has received little attention in the planning stage. This study develops a Bayesian hierarchical joint model for road network safety evaluation to help planners take traffic safety into account when planning a road network. The proposed model establishes relationships between road network risk and micro-level variables related to road entities and traffic volume, as well as socioeconomic, trip generation and network density variables at macro level which are generally used for long term transportation plans. In addition, network spatial correlation between intersections and their connected road segments is also considered in the model. A road network is elaborately selected in order to compare the proposed hierarchical joint model with a previous joint model and a negative binomial model. According to the results of the model comparison, the hierarchical joint model outperforms the joint model and negative binomial model in terms of the goodness-of-fit and predictive performance, which indicates the reasonableness of considering the hierarchical data structure in crash prediction and analysis. Moreover, both random effects at the TAZ level and the spatial correlation between intersections and their adjacent segments are found to be significant, supporting the employment of the hierarchical joint model as an alternative in road-network-level safety modeling as well. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prison violence and the intersectionality of race/ethnicity and gender

Directory of Open Access Journals (Sweden)

Kerryn E. Bell

2018-03-01

Full Text Available Objective to analyze the history occurrence and development of the problem of prison violence from the viewpoint of the intersectionality of raceethnicity and gender factors. Methods dialectical approach to cognition of social phenomena allowing to analyze them in historical development and functioning in the context of the totality of objective and subjective factors predetermined the following research methods formallogical comparativelegal and sociological. Results Minority men and women are significantly impacted by mass incarceration. Mass incarceration has also resulted in a growth in prison violence and previous studies in this area have focused on individuals and not their interconnected statuses. This study specifically considers the role of intersectional criminology and the commitment of prison violence in a large western state on female inmates. Intersectional criminology is a theoretical approach that enables a critical look at the impact of individuals39 interconnected statuses in relation to crime. The authors do not hypothesize about the reasons for the dependences between raceethnicity and gender factors and the level of prison violence but state that minority females commit more violent infractions in prison than White women. Intersectionality allows coming closer to solving the problem of identifying the incarcerated females as members of criminal groups and study the potential impact of this factor on the violence level. Scientific novelty for the first time the research proves that intersectionality allows receiving more reliable statistical results when estimating the level of prison violence. It has been proved that minority females commit more violent infractions in prison than White women. Thus this study builds upon previous arguments that intersectionality should be more widely used in future research and discusses implications for the findings. Practical significance the main provisions and conclusions of the article

Data-driven drug safety signal detection methods in pharmacovigilance using electronic primary care records: A population based study

Directory of Open Access Journals (Sweden)

Shang-Ming Zhou

2017-04-01

Data-driven analytic methods are a valuable aid to signal detection of ADEs from large electronic health records for drug safety monitoring. This study finds the methods can detect known ADE and so could potentially be used to detect unknown ADE.

The Intersection Probability of Brownian Motion and SLEκ

Directory of Open Access Journals (Sweden)

Shizhong Zhou

2015-01-01

Full Text Available By using excursion measure Poisson kernel method, we obtain a second-order differential equation of the intersection probability of Brownian motion and SLEκ. Moreover, we find a transformation such that the second-order differential equation transforms into a hypergeometric differential equation. Then, by solving the hypergeometric differential equation, we obtain the explicit formula of the intersection probability for the trace of the chordal SLEκ and planar Brownian motion started from distinct points in an upper half-plane H-.

Multiple intersecting cohesive discontinuities in 3D reservoir geomechanics

OpenAIRE

Das, K. C.; Sandha, S.S.; Carol, Ignacio; Vargas, P.E.; Gonzalez, Nubia Aurora; Rodrigues, E.; Segura Segarra, José María; Lakshmikantha, Ramasesha Mookanahallipatna; Mello,, U.

2013-01-01

Reservoir Geomechanics is playing an increasingly important role in developing and producing hydrocarbon reserves. One of the main challenges in reservoir modeling is accurate and efficient simulation of arbitrary intersecting faults. In this paper, we propose a new formulation to model multiple intersecting cohesive discontinuities (faults) in reservoirs using the XFEM framework. This formulation involves construction of enrichment functions and computation of stiffness sub-matrices for bulk...

Feminist Intersectionality Research in Communications: Origins, Contributions and Tensions

OpenAIRE

Carolyn M. Byerly

2017-01-01

The text considers some of the important work in intersectionality that has been done by critical feminist and postcolonial scholars in media and other communication fields since the 1990s, focusing particularly on the kinds of problems they have examined and their contributions to feminist theory building. The discussion also explores some of the challenges and tensions that accompany scholarship conducted from a standpoint of intersectionality.

Failure at Frame-Stringer Intersections in PRSEUS Panels

Science.gov (United States)

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.

Stresses at the intersection of two cylindrical shells

International Nuclear Information System (INIS)

Xue, M.D.; Chen, W.; Hwang, K.C.

1995-01-01

The stress analysis based on the theory of a thin shell is carried out for two normally intersecting cylindrical shells with a large diameter ratio. Instead of the Donnell shallow shell equation, the modified Morley equation, which is applicable to ρ 0 (R/T) 1/2 XXXX1, is used for the analysis of the shell with cut-out. The solution in terms of displacement function for the nozzle with a non-planar end is based on the Love equation. The boundary forces and displacements at the intersection are all transformed from Gaussian coordinates (α,β) on the shell, or Gaussian coordinates (ζ,θ) on the nozzle into three-dimensional cylindrical coordinates (ρ,θ,z). Their expressions on the intersecting curve are periodic functions of θ and expanded in Fourier series. Every harmonics of Fourier coefficients of boundary forces and displacements are obtained by numerical quadrature.The results obtained are in agreement with those from the finite element method and experiments for d/D≤0.8. ((orig.))

A toy model for gauge-mediation in intersecting brane models

International Nuclear Information System (INIS)

Kumar, Jason

2009-01-01

We discuss the phenomenology of a toy intersecting brane model where supersymmetry is dynamically broken in an open-string hidden sector and gauge-mediated to the visible sector. Scalar masses ∼TeV are easily realizable, and R-symmetry is broken. These ideas are easily generalizable to other intersecting brane models.

Avoided intersections of nodal lines

International Nuclear Information System (INIS)

Monastra, Alejandro G; Smilansky, Uzy; Gnutzmann, Sven

2003-01-01

We consider real eigenfunctions of the Schroedinger operator in 2D. The nodal lines of separable systems form a regular grid, and the number of nodal crossings equals the number of nodal domains. In contrast, for wavefunctions of non-integrable systems nodal intersections are rare, and for random waves, the expected number of intersections in any finite area vanishes. However, nodal lines display characteristic avoided crossings which we study in this work. We define a measure for the avoidance range and compute its distribution for the random wave ensemble. We show that the avoidance range distribution of wavefunctions of chaotic systems follows the expected random wave distributions, whereas for wavefunctions of classically integrable but quantum non-separable systems, the distribution is quite different. Thus, the study of the avoidance distribution provides more support to the conjecture that nodal structures of chaotic systems are reproduced by the predictions of the random wave ensemble

Inter-categorical intersectionality and leisure-based physical activity in Canada.

Science.gov (United States)

Abichahine, Hayfa; Veenstra, Gerry

2017-08-01

Leisure-based physical activity is socially stratified in Canada. To date, inequalities in physical activity by race or ethnicity, gender, class or sexual orientation, in Canada and elsewhere, have largely been investigated as distinct, additive phenomena. Informed by intersectionality theory, this paper examines whether racial identity, gender, class and sexuality 'intersect' with one another to predict physical activity in data from Cycles 2.1 and 3.1 of the Canadian Community Health Survey (n= 149 574). In particular, we apply the intersectional principle of multiplicativity which suggests that people's experiences of their gender identities are raced, classed and sexualized; their racial experiences are gendered, classed and sexualized, and so forth. We find that the positive effect of income on being physically active is strong among visible minority men, of moderate strength among White men and women and weak to non-existent among visible minority women. We also find that a lesbian, gay or bisexual orientation corresponds with a higher likelihood of being physically active among women (especially among less educated women) but not among men. These multiplicative findings undermine additive approaches to investigating social inequalities in leisure-based physical activity and pave the way for future intersectional analyses of axes of inequality and their diverse, intersecting effects. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Right-­turn traffic volume adjustment in traffic signal warrant analysis : final report.

Science.gov (United States)

2016-05-06

This report was based on the research project, Right-Turn Traffic Volume Adjustment in Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) and SOLARIS. Right-turn traffic does not affect intersection performance in th...

Domestic Violence among the Black Poor: Intersectionality and Social Justice

Science.gov (United States)

Conwill, William Louis

2010-01-01

There are striking gender, race, and class variations in rates of domestic violence. Some leading family theorists called for an intersectional analysis of how gender, race and class systems interact to improve domestic violence theory. This article improves domestic violence theory by: 1) using the discourse, or language, of intersectionality; 2)…

Modeling Crossing Behavior of Drivers at Unsignalized Intersections with Consideration of Risk Perception

Directory of Open Access Journals (Sweden)

Liu Miaomiao

2016-01-01

Full Text Available Drivers’ risk perception is vital to driving behavior and traffic safety. In the dynamic interaction of a driver-vehicle-environment system, drivers’ risk perception changes dynamically. This study focused on drivers’ risk perception at unsignalized intersections in China and analyzed drivers’ crossing behavior. Based on cognitive psychology theory and an adaptive neuro-fuzzy inference system, quantitative models of drivers’ risk perception were established for the crossing processes between two straight-moving vehicles from the orthogonal direction. The acceptable risk perception levels of drivers were identified using a self-developed data analysis method. Based on game theory, the relationship among the quantitative value of drivers’ risk perception, acceptable risk perception level, and vehicle motion state was analyzed. The models of drivers’ crossing behavior were then established. Finally, the behavior models were validated using data collected from real-world vehicle movements and driver decisions. The results showed that the developed behavior models had both high accuracy and good applicability. This study would provide theoretical and algorithmic references for the microscopic simulation and active safety control system of vehicles.

Intersectionality in European Union policymaking

DEFF Research Database (Denmark)

Lombardo, Emanuela; Agustin, Lise Rolandsen

2016-01-01

is particularly apt to deal with equality and diversity in policymaking. By analysing a selection of European Union policy documents on gender-based violence in the period 2000–2014, we attend to the question of what intersectionality can bring to policymaking in terms of strengthening inclusiveness and address...

On the Krull intersection theorem in function algebras | Mortini ...

African Journals Online (AJOL)

A version of the Krull intersection theorem states that for Noetherian integral domains the Krull intersection ki(I) of every proper ideal I is trivial; that is. ∞. ki(I) := ∩ In = {0}. n=1. We investigate the validity of this result for various function algebras R, present ideals I of R for which ki(I) ≠ {0}, and give conditions on I so that ki(I) ...

Feminist Intersectionality Research in Communications: Origins, Contributions and Tensions

Directory of Open Access Journals (Sweden)

Carolyn M. Byerly

2017-06-01

Full Text Available The text considers some of the important work in intersectionality that has been done by critical feminist and postcolonial scholars in media and other communication fields since the 1990s, focusing particularly on the kinds of problems they have examined and their contributions to feminist theory building. The discussion also explores some of the challenges and tensions that accompany scholarship conducted from a standpoint of intersectionality.

Helping Students Understand Intersectionality: Reflections from a Dialogue Project in Residential Life

Science.gov (United States)

Claros, Sharon Chia; Garcia, Gina A.; Johnston-Guerrero, Marc P.; Mata, Christine

2017-01-01

In this chapter, the authors share insights from a dialogue project focused on intersectionality within a residential life setting and discuss additional strategies for helping students understand intersectionality.

Safety logic systems of PFBR

International Nuclear Information System (INIS)

Sambasivan, S. Ilango

2004-01-01

Full text : PFBR is provided with two independent, fast acting and diverse shutdown systems to detect any abnormalities and to initiate safety action. Each system consists of sensors, signal processing systems, logics, drive mechanisms and absorber rods. The absorber rods of the first system are Control and Safety Rods (CSR) and that of the second are called as Diverse Safety Rods (DSR). There are nine CSR and three DSR. While CSR are used for startup, control of reactor power, controlled shutdown and SCRAM, the DSR are used only for SCRAM. The respective drive mechanisms are called as CSRDM and DSRDM. Each of these two systems is capable of executing the shutdown satisfactorily with single failure criteria. Two independent safety logic systems based on diverse principles have been designed for the two shut down systems. The analog outputs of the sensors of Core Monitoring Systems comprising of reactor flux monitoring, core temperature monitoring, failed fuel detection and core flow monitoring systems are processed and converted into binary signals depending on their instantaneous values. Safety logic systems receive the binary signals from these core-monitoring systems and process them logically to protect the reactor against postulated initiating events. Neutronic and power to flow (P/Q) signals form the inputs to safety logic system-I and temperature signals are inputs to the safety logic system II. Failed fuel detection signals are processed by both the shut down systems. The two logic systems to actuate the safety rods are also based on two diverse designs and implemented with solid-state devices to meet all the requirements of safety systems. Safety logic system I that caters to neutronic and P/Q signals is designed around combinational logic and has an on-line test facility to detect struck at faults. The second logic system is based on dynamic logic and hence is inherently safe. This paper gives an overview of the two logic systems that have been

A computerized traffic control algorithm to determine optimal traffic signal settings. Ph.D. Thesis - Toledo Univ.

Science.gov (United States)

Seldner, K.

1977-01-01

An algorithm was developed to optimally control the traffic signals at each intersection using a discrete time traffic model applicable to heavy or peak traffic. Off line optimization procedures were applied to compute the cycle splits required to minimize the lengths of the vehicle queues and delay at each intersection. The method was applied to an extensive traffic network in Toledo, Ohio. Results obtained with the derived optimal settings are compared with the control settings presently in use.

CEDAW and women's intersecting identities: a pioneering new approach to intersectional discrimination

OpenAIRE

Campbell, M

2015-01-01

CEDAW is committed to eliminating all forms of discrimination and achieving gender equality so that all women can exercise and enjoy their human rights. This article argues that this implicitly includes a commitment to understanding and addressing intersectional discrimination. Women experience disadvantage and discrimination based on their sex and gender and that is inextricably linked to other identities, factors and experiences such as a race and poverty. Under CEDAW, if sex and gender is ...

Wind tunnel measurements of pollutant turbulent fluxes in urban intersections

Science.gov (United States)

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.

Discussion on sealing performance required in disposal system. Hydraulic analysis of tunnel intersections

International Nuclear Information System (INIS)

Sugita, Yutaka; Takahashi, Yoshiaki; Uragami, Manabu; Kitayama, Kazumi; Fujita, Tomoo; Kawakami, Susumu; Yui, Mikazu; Umeki, Hiroyuki; Miyamoto, Yoichi

2005-09-01

The sealing performance of a repository must be considered in the safety assessment of the geological disposal system of the high-level radioactive waste. NUMO and JNC established 'Technical Commission on Sealing Technology of Repository' based on the cooperation agreement. The objectives of this commission are to present the concept on the sealing performance required in the disposal system and to develop the direction for future R and D programme for design requirements of closure components (backfilling material, clay plug, etc.) in the presented concept. In the first phase of this commission, the current status of domestic and international sealing technologies were reviewed; and repository components and repository environments were summarized subsequently, the hydraulic analysis of tunnel intersections, where a main tunnel and a disposal tunnel in a disposal panel meet, were performed, considering components in and around the engineered barrier system (EBS). Since all tunnels are connected in the underground facility, understanding the hydraulic behaviour of tunnel intersections is an important issue to estimate migration of radionuclides from the EBS and to evaluate the required sealing performance in the disposal system. In the analytical results, it was found that the direction of hydraulic gradient, hydraulic conductivities of concrete and backfilling materials and the position of clay plug had impact on flow condition around the EBS. (author)

Intersection syndrome: MR imaging with anatomic comparison of the distal forearm

Energy Technology Data Exchange (ETDEWEB)

Lima, Jose E. de; Kim, Hyun-Jin; Albertotti, Flavio; Resnick, Donald [University of California, San Diego, VA San Diego Healthcare System, San Diego (United States)

2004-11-01

To correlate the anatomic and MR imaging characteristics of the area of intersection of the first and the second dorsal extensor tendon compartments (DETC) in the distal forearm in an attempt to improve the design of MR imaging protocols used for the evaluation of intersection syndrome. Ten forearms of nine cadavers underwent MR imaging in the axial and sagittal-oblique planes before and after tenography with direct injection of a gadolinium-containing contrast agent into the first DETC in four forearms, the second DETC in four forearms, and both compartments in the remaining two forearms. The area of intersection between the first and second DETC was identified in each case as well as its distance from Lister's tubercle. Subsequently all forearms were sectioned in the axial (8 forearms) or sagittal-oblique planes (2 remaining forearms) to parallel the imaging planes. Detailed examination of each of the anatomic slices was performed in a search for anatomic variations and for possible anatomic connections of the tendons sheaths. One forearm was dissected to identify the area of intersection. The area of intersection between the first and second DETC occurred between 3.5 cm and 4.8 cm (mean 4.18 cm) proximal to Lister's tubercle. After tenography, gadolinium solution was noted in the third DETC in two of four specimens in which the second DETC was injected and in one of two specimens in which both the first and second DETC were injected. Extension of the gadolinium solution between the first and second DETC was noted during isolated injections of either compartment, although this finding may have related to iatrogenic injection effects. The axial plane was the most valuable for assessment of the area of intersection of the first and second DETC. MR imaging is a noninvasive method that can be used for the evaluation of distal forearm and wrist pain. Standard wrist protocols do not include the area of intersection between the first and second DETC and, in

Intersection syndrome: MR imaging with anatomic comparison of the distal forearm

International Nuclear Information System (INIS)

Lima, Jose E. de; Kim, Hyun-Jin; Albertotti, Flavio; Resnick, Donald

2004-01-01

To correlate the anatomic and MR imaging characteristics of the area of intersection of the first and the second dorsal extensor tendon compartments (DETC) in the distal forearm in an attempt to improve the design of MR imaging protocols used for the evaluation of intersection syndrome. Ten forearms of nine cadavers underwent MR imaging in the axial and sagittal-oblique planes before and after tenography with direct injection of a gadolinium-containing contrast agent into the first DETC in four forearms, the second DETC in four forearms, and both compartments in the remaining two forearms. The area of intersection between the first and second DETC was identified in each case as well as its distance from Lister's tubercle. Subsequently all forearms were sectioned in the axial (8 forearms) or sagittal-oblique planes (2 remaining forearms) to parallel the imaging planes. Detailed examination of each of the anatomic slices was performed in a search for anatomic variations and for possible anatomic connections of the tendons sheaths. One forearm was dissected to identify the area of intersection. The area of intersection between the first and second DETC occurred between 3.5 cm and 4.8 cm (mean 4.18 cm) proximal to Lister's tubercle. After tenography, gadolinium solution was noted in the third DETC in two of four specimens in which the second DETC was injected and in one of two specimens in which both the first and second DETC were injected. Extension of the gadolinium solution between the first and second DETC was noted during isolated injections of either compartment, although this finding may have related to iatrogenic injection effects. The axial plane was the most valuable for assessment of the area of intersection of the first and second DETC. MR imaging is a noninvasive method that can be used for the evaluation of distal forearm and wrist pain. Standard wrist protocols do not include the area of intersection between the first and second DETC and, in those cases

Changes in crash risk following re-timing of traffic signal change intervals.

Science.gov (United States)

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.

Congestion analysis of unsignalized intersections

NARCIS (Netherlands)

Abhishek,; Mandjes, M.R.H.; Boon, M.A.A.; Nunez Queija, R.

2016-01-01

This paper considers an unsignalized intersection used by two traffic streams. A stream of cars is using a primary road, and has priority over the other, low-priority, stream. Cars belonging to the latter stream cross the primary road if the gaps between two subsequent cars on the primary road is

The effect of stimulus modality on signal detection: implications for assessing the safety of in-vehicle technology.

Science.gov (United States)

Merat, Natasha; Jamson, A Hamish

2008-02-01

This study examined the effect of two in-vehicle information systems (IVIS) on signal detection in the visual, auditory, and tactile modalities; established whether the detrimental effects of an IVIS on driving could be quantified by these detection tasks; and examined the effect of stimulus modality on signal detection. The peripheral detection task has been used widely for assessing the effects of an IVIS on driving. However, performance on this task relies on drivers' ability to see a series of LEDs, which can be problematic in field tests (e.g., on sunny days). Participants responded to one of three detection tasks during a simulated driving experiment. The effect of IVIS interaction on these detection tasks was also measured. Reduced performance in the detection tasks was assumed to indicate a decline in drivers' ability to handle sudden events in the driving task. Response time to all detection tasks increased by around 200 ms when drivers performed the IVIS tasks, as compared with baseline driving. Analyses of variance and comparison of effect sizes showed the effects of these two IVISs to be the same across the three detection tasks. These detection tasks are useful for quantifying the safety of an IVIS during driving. The absence of a difference in signal detection by modality suggests that performance on these tasks relies on general attentional resources and is not modality specific. The signal detection tasks employed here should be further investigated for their suitability in assessing the safety of in-vehicle systems.

Analysis of silicon on insulator (SOI) optical microring add-drop filter based on waveguide intersections

Science.gov (United States)

Kaźmierczak, Andrzej; Bogaerts, Wim; Van Thourhout, Dries; Drouard, Emmanuel; Rojo-Romeo, Pedro; Giannone, Domenico; Gaffiot, Frederic

2008-04-01

We present a compact passive optical add-drop filter which incorporates two microring resonators and a waveguide intersection in silicon-on-insulator (SOI) technology. Such a filter is a key element for designing simple layouts of highly integrated complex optical networks-on-chip. The filter occupies an area smaller than 10μm×10μm and exhibits relatively high quality factors (up to 4000) and efficient signal dropping capabilities. In the present work, the influence of filter parameters such as the microring-resonators radii and the coupling section shape are analyzed theoretically and experimentally

Human-Scale Sustainability Assessment of Urban Intersections Based upon Multi-Source Big Data

Directory of Open Access Journals (Sweden)

Yuhuan Zhang

2017-07-01

Full Text Available To evaluate the sustainability of an enormous number of urban intersections, a novel assessment model is proposed, along with an indicator system and corresponding methods to determine the indicators. Considering mainly the demands and feelings of the urban residents, the three aspects of safety, functionality, and image perception are taken into account in the indicator system. Based on technologies such as street view picture crawling, image segmentation, and edge detection, GIS spatial data analysis, a rapid automated assessment method, and a corresponding multi-source database are built up to determine the indicators. The improved information entropy method is applied to obtain the entropy weights of each indicator. A case study shows the efficiency and applicability of the proposed assessment model, indicator system and algorithm.

Right-\\0xADturn traffic volume adjustment in traffic signal warrant analysis : final report.

Science.gov (United States)

2016-05-06

This report was based on the research project, Right-Turn Traffic Volume Adjustment in : Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) : and SOLARIS. Right-turn traffic does not affect intersection performance i...

Outlook from the intersections

International Nuclear Information System (INIS)

Haxton, W.C.

1994-01-01

I review a number of the physics themes of the Fifth Conference on the Intersections of Particle and Nuclear Physics, discussing the significance and promise of current work at the interface of these fields. Some of thee themes are: pattern of quark and boson masses; solar neutrino problem; lepton flavor violation tests; atomic dipole moments studies; Δs=0 weak interaction between nucleons; and strongly-interacting many-body problems

Electronic theodolite intersection systems

OpenAIRE

Bingley, R. M.

1990-01-01

The development of electronic surveying instruments, such as electronic theodolites, and concurrent advances in computer technology, has revolutionised engineering surveying; one of the more recent examples being the introduction of Electronic Theodolite Intersection Systems (ETISs). An ETIS consists of two or more electronic theodolites and a computer, with peripheral hardware and suitable software. The theoretical principles on which they are based have been known for a long time, but ...

An Intersectional Analysis of Latin@ College Women's Counter-Stories in Mathematics

Science.gov (United States)

Leyva, Luis A.

2016-01-01

In this article, the author discusses the intersectionality of mathematics experiences for two Latin@ college women pursuing mathematics-intensive STEM (science, technology, engineering, and mathematics) majors at a large, predominantly White university. The author employs intersectionality and poststructural theories to explore and make meaning…

EnviroAtlas - Minneapolis/St. Paul, MN - Estimated Intersection Density of Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates the intersection density of walkable roads within a 750 meter radius of any given 10 meter pixel in the community. Intersections...

Intersectionality and the LGBT Cancer Patient.

Science.gov (United States)

Damaskos, Penny; Amaya, Beau; Gordon, RuthAnn; Walters, Chasity Burrows

2018-02-01

To present the ways in which race, ethnicity, class, gender, and sexual orientation interact in the context of cancer risk, access to care, and treatment by health care providers. Cancer risk factors, access to care, and treatment for lesbian, gay, bisexual, and transgender (LGBT) patients are discussed within the context of intersectionality and cultural humility. Peer reviewed articles, cancer organizations, and clinical practice. LGBT patients have multiple identities that intersect to create unique experiences. These experiences shape their interactions with the health care system with the potential for positive or negative consequences. More data is needed to describe the outcomes of those experiences and inform clinical practice. Oncology nurses have an obligation to acknowledge patients' multiple identities and use the practice of cultural humility to provide individualized, patient-centered care. Copyright © 2017 Elsevier Inc. All rights reserved.

Refining Lane-Based Traffic Signal Settings to Satisfy Spatial Lane Length Requirements

Directory of Open Access Journals (Sweden)

Yanping Liu

2017-01-01

Full Text Available In conventional lane-based signal optimization models, lane markings guiding road users in making turns are optimized with traffic signal settings in a unified framework to maximize the overall intersection capacity or minimize the total delay. The spatial queue requirements of road lanes should be considered to avoid overdesigns of green durations. Point queue system adopted in the conventional lane-based framework causes overflow in practice. Based on the optimization results from the original lane-based designs, a refinement is proposed to enhance the lane-based settings to ensure that spatial holding limits of the approaching traffic lanes are not exceeded. A solution heuristic is developed to modify the green start times, green durations, and cycle length by considering the vehicle queuing patterns and physical holding capacities along the approaching traffic lanes. To show the effectiveness of this traffic signal refinement, a case study of one of the busiest and most complicated intersections in Hong Kong is given for demonstration. A site survey was conducted to collect existing traffic demand patterns and existing traffic signal settings in peak periods. Results show that the proposed refinement method is effective to ensure that all vehicle queue lengths satisfy spatial lane capacity limits, including short lanes, for daily operation.

Survey about pedestrian safety and attitudes toward automated traffic enforcement in Washington, D.C.

Science.gov (United States)

Cicchino, Jessica B; Wells, Joann K; McCartt, Anne T

2014-01-01

Pedestrians represent more than one third of all traffic deaths in Washington, D.C. The District plans to expand its long-standing automated traffic enforcement program in 2013 from speed and red light cameras to cameras to enforce pedestrian right-of-way laws at crosswalks and stop sign laws. This study collected information on the opinions, behaviors, and knowledge of D.C. residents related to camera enforcement and pedestrian safety issues. A telephone survey of 801 adult D.C. residents was conducted in November 2012 with approximately equal numbers of respondents in each of D.C.'s eight wards. Quotas were used to ensure that the sample was representative of the demographic characteristics of adults in each ward. For analyses combining responses across the wards, data were weighted to correspond with the demographic characteristics of adults in the city. Most respondents believed that drivers speeding, running red lights, running stop signs, and not stopping for pedestrians are serious threats to their safety. Respondents strongly supported the speed and red light camera programs, with 76 percent of respondents favoring speed cameras and 87 percent favoring red light cameras. Support was more limited for the camera enforcement that was not yet in place at the time of the survey, with 50 percent of respondents favoring stop sign cameras and 47 percent of respondents favoring crosswalk cameras. Twenty-four percent of respondents had not driven a car in D.C. in the past month, and higher proportions of these nondrivers favored speed cameras (90%), stop sign cameras (67%), and crosswalk cameras (59%) than respondents who drove in D.C. in the past month. Respondents who supported camera enforcement cited safety as their main reason. More than 9 in 10 respondents knew that D.C. law requires drivers to stop for pedestrians crossing the street in marked crosswalks at intersections without traffic signals and midblock, but only 54 percent knew that drivers must stop for

Danger zone: Men, masculinity and occupational health and safety in high risk occupations

OpenAIRE

Stergiou-Kita, Mary; Mansfield, Elizabeth; Bezo, Randy; Colantonio, Angela; Garritano, Enzo; Lafrance, Marc; Lewko, John; Mantis, Steve; Moody, Joel; Power, Nicole; Theberge, Nancy; Westwood, Eleanor; Travers, Krista

2015-01-01

The workplace is a key setting where gender issues and organizational structures may influence occupational health and safety practices. The enactment of dominant norms of masculinity in high risk occupations can be particularly problematic, as it exposes men to significant risks for injuries and fatalities. To encourage multi-disciplinary collaborations and advance knowledge in the intersecting areas of gender studies, men’s health, work and workplace health and safety, a national network of...

A Weibull Approach for Enabling Safety-Oriented Decision-Making for Electronic Railway Signaling Systems

Directory of Open Access Journals (Sweden)

Emanuele Pascale

2018-04-01

Full Text Available This paper presents the advantages of using Weibull distributions, within the context of railway signaling systems, for enabling safety-oriented decision-making. Failure rates are used to statistically model the basic event of fault-tree analysis, and their value sizes the maximum allowable latency of failures to fulfill the safety target for which the system has been designed. Relying on field-return failure data, Weibull parameters have been calculated for an existing electronic signaling system and a comparison with existing predictive reliability data, based on exponential distribution, is provided. Results are discussed in order to drive considerations on the respect of quantitative targets and on the impact that a wrong hypothesis might have on the choice of a given architecture. Despite the huge amount of information gathered through the after-sales logbook used to build reliability distribution, several key elements for reliable estimation of failure rate values are still missing. This might affect the uncertainty of reliability parameters and the effort required to collect all the information. We then present how to intervene when operational failure rates present higher values compared to the theoretical approach: increasing the redundancies of the system or performing preventive maintenance tasks. Possible consequences of unjustified adoption of constant failure rate are presented. Some recommendations are also shared in order to build reliability-oriented logbooks and avoid data censoring phenomena by enhancing the functions of the electronic boards composing the system.

The Use of Audible Traffic Signals in the United States.

Science.gov (United States)

Peck, A. F.; Uslan, M.

1990-01-01

This paper discusses audible traffic signals (ATS) and their use by visually impaired pedestrians in the United States and other countries. Areas of concern are noted, including the types of intersections at which ATS should be installed, the locations of poles and buttons for activating the system, and the specific type of device used.…

Exploring Driver Injury Severity at Intersection: An Ordered Probit Analysis

Directory of Open Access Journals (Sweden)

Yaping Zhang

2015-02-01

Full Text Available It is well known that intersections are the most hazardous locations; however, only little is known about driver injury severity in intersection crashes. Hence, the main goal of this study was to further examine the different factors contributing to driver injury severity involved in fatal crashes at intersections. Data used for the present analysis was from the US DOT-Fatality Analysis Reporting System (FARS crash database from the year 2011. An ordered probit model was employed to fit the fatal crash data and analyze the factors impacting each injury severity level. The analysis results displayed that driver injury severity is significantly affected by many factors. They include driver age and gender, driver ethnicity, vehicle type and age (years of use, crash type, driving drunk, speeding, violating stop sign, cognitively distracted driving, and seat belt usage. These findings from the current study are beneficial to form a solid basis for adopting corresponding measures to effectively drop injury severity suffering from intersection crash. More insights into the effects of risk factors on driver injury severity could be acquired using more advanced statistical models.

10 Best resources on… intersectionality with an emphasis on low- and middle-income countries.

Science.gov (United States)

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

The Contribution to the Procedure of Capacity Determination at Unsignalized Priority-controlled Intersections

Directory of Open Access Journals (Sweden)

Tomaž Tolazzi

2004-01-01

Full Text Available The problem of minor vehicles crossing or merging into themajor stream at unsignalized priority-controlled intersections iswell-known. Numerous solutions involve various assumptionsconcerning the major headway distributions, number of majorlanes, critical gap distributions, etc. Such cases can be dividedinto two main groups: intersections with two streams (one majorand one minor stream and intersections with more thantwo streams (more than one major stream and one minorstream. At roundabouts, also at single-lane roundabouts,there are similar problems like the ones at other unsignalizedpriority-controlled intersections. A vehicle at the roundaboutapproach can only cross the pedestrian crossing when a sufficienttime-gap between two pedestrians (or cyclists is provided.A vehicle at the roundabout entries can only merge into the majorstream when a sufficient gap between the two vehicles in themajor stream is provided. Because of that, single-lane roundaboutscan also be treated as unsignalized intersections withtwo major lanes: the first one in its circulatory roadway and thesecond one on the pedestrian crossing.

Some insights into the intersection of physical planning and governance in Zimbabwe

CSIR Research Space (South Africa)

Chakwizira, J

2008-04-01

Full Text Available This paper presents some insights into the intersection of physical planning and governance in Zimbabwe. It argues that the major theoretical, policy and practice discourses - explaining the intersection of physical planning and governance - relate...

MATHEMATICAL METHODS TO DETERMINE THE INTERSECTION CURVES OF THE CYLINDERS

Directory of Open Access Journals (Sweden)

POPA Carmen

2010-07-01

Full Text Available The aim of this paper is to establish the intersection curves between cylinders, by using the Mathematica program. This thing can be obtained by introducing the curves equations, which are inferred, in Mathematica program. This paper take into discussion three right cylinders and another inclined to 45 degrees. The intersection curves can also be obtained by using the classical methods of the descriptive geometry.

(M,N-Soft Intersection BL-Algebras and Their Congruences

Directory of Open Access Journals (Sweden)

Xueling Ma

2014-01-01

Full Text Available The purpose of this paper is to give a foundation for providing a new soft algebraic tool in considering many problems containing uncertainties. In order to provide these new soft algebraic structures, we discuss a new soft set-(M, N-soft intersection set, which is a generalization of soft intersection sets. We introduce the concepts of (M, N-SI filters of BL-algebras and establish some characterizations. Especially, (M, N-soft congruences in BL-algebras are concerned.

Semi-autonomous Intersection Collision Avoidance through Job-shop Scheduling

OpenAIRE

Ahn, Heejin; Del Vecchio, Domitilla

2016-01-01

In this paper, we design a supervisor to prevent vehicle collisions at intersections. An intersection is modeled as an area containing multiple conflict points where vehicle paths cross in the future. At every time step, the supervisor determines whether there will be more than one vehicle in the vicinity of a conflict point at the same time. If there is, then an impending collision is detected, and the supervisor overrides the drivers to avoid collision. A major challenge in the design of a ...

Requirements of a system to reduce car-to-vulnerable road user crashes in urban intersections.

Science.gov (United States)

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

Planning of Autonomous Multi-agent Intersection

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Viksnin Ilya I.

2016-01-01

Full Text Available In this paper, we propose a traffic management system with agents acting on behalf autonomous vehicle at the crossroads. Alternatively to existing solutions based on usage of semiautonomous control systems with the control unit, proposed in this paper algorithm apply the principles of decentralized multi-agent control. Agents during their collaboration generate intersection plan and determinate the optimal order of road intersection for a given criterion based on the exchange of information about them and their environment. The paper contains optimization criteria for possible routes selection and experiments that perform in order to estimate the proposed model. Experiment results show that this model can significantly reduce traffic density compared to the traditional traffic management systems. Moreover, the proposed algorithm efficiency increases with road traffic density. Furthermore, the availability of control unit in the system significantly reduces the negative impact of possible failures and hacker attacks.

(Engendering racial disparities in health trajectories: A life course and intersectional analysis

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Liana J. Richardson

2016-12-01

Full Text Available 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. Keywords: Race, Gender, Health inequalities, Intersectionality, Life course

Synthesis Study on Transitions in Signal Infrastructure and Control Algorithms for Connected and Automated Transportation

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Aziz, H. M. Abdul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Young, Stan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sperling, Joshua [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beck, John [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-06-01

Documenting existing state of practice is an initial step in developing future control infrastructure to be co-deployed for heterogeneous mix of connected and automated vehicles with human drivers while leveraging benefits to safety, congestion, and energy. With advances in information technology and extensive deployment of connected and automated vehicle technology anticipated over the coming decades, cities globally are making efforts to plan and prepare for these transitions. CAVs not only offer opportunities to improve transportation systems through enhanced safety and efficient operations of vehicles. There are also significant needs in terms of exploring how best to leverage vehicle-to-vehicle (V2V) technology, vehicle-to-infrastructure (V2I) technology and vehicle-to-everything (V2X) technology. Both Connected Vehicle (CV) and Connected and Automated Vehicle (CAV) paradigms feature bi-directional connectivity and share similar applications in terms of signal control algorithm and infrastructure implementation. The discussion in our synthesis study assumes the CAV/CV context where connectivity exists with or without automated vehicles. Our synthesis study explores the current state of signal control algorithms and infrastructure, reports the completed and newly proposed CV/CAV deployment studies regarding signal control schemes, reviews the deployment costs for CAV/AV signal infrastructure, and concludes with a discussion on the opportunities such as detector free signal control schemes and dynamic performance management for intersections, and challenges such as dependency on market adaptation and the need to build a fault-tolerant signal system deployment in a CAV/CV environment. The study will serve as an initial critical assessment of existing signal control infrastructure (devices, control instruments, and firmware) and control schemes (actuated, adaptive, and coordinated-green wave). Also, the report will help to identify the future needs for the signal

CEDAW and Women’s Intersecting Identities: A Pioneering New Approach to Intersectional Discrimination

OpenAIRE

Campbell,Meghan

2015-01-01

ABSTRACT CEDAW is committed to eliminating all forms of discrimination and achieving gender equality so that all women can exercise and enjoy their human rights. This article argues that this implicitly includes a commitment to understanding and addressing intersectional discrimination. Women experience disadvantage and discrimination based on their sex and gender and that is inextricably linked to other identities, factors and experiences such as a race and poverty. Under CEDAW, if sex and g...

Safety of mechanical devices. Safety of automation systems

International Nuclear Information System (INIS)

Pahl, G.; Schweizer, G.; Kapp, K.

1985-01-01

The paper deals with the classic procedures of safety engineering in the sectors mechanical engineering, electrical and energy engineering, construction and transport, medicine technology and process technology. Particular stress is laid on the safety of automation systems, control technology, protection of mechanical devices, reactor safety, mechanical constructions, transport systems, railway signalling devices, road traffic and protection at work in chemical plans. (DG) [de

The problem with the phrase women and minorities: intersectionality-an important theoretical framework for public health.

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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.

Teaching Domestic Violence in the New Millennium: Intersectionality as a Framework for Social Change.

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McQueeney, Krista

2016-10-01

This article describes an intersectional approach to teaching about domestic violence (DV), which aims to empower students as critical thinkers and agents of change by merging theory, service learning, self-reflection, and activism. Three intersectional strategies and techniques for teaching about DV are discussed: promoting difference-consciousness, complicating gender-only power frameworks, and organizing for change. The author argues that to empower future generations to end violence, educators should put intersectionality into action through their use of scholarship, teaching methods, and pedagogical authority. Finally, the benefits and challenges of intersectional pedagogy for social justice education are considered. © The Author(s) 2016.

47 CFR 80.1129 - Locating and homing signals.

Science.gov (United States)

2010-10-01

....1129 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating Procedures for Distress and Safety Communications § 80.1129 Locating and homing signals. (a) Locating signals are...

47 CFR 80.327 - Urgency signals and messages.

Science.gov (United States)

2010-10-01

....327 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Distress, Alarm, Urgency and Safety Procedures § 80.327 Urgency signals and messages. (a) The urgency signal indicates that the...

Macro-level safety analysis of pedestrian crashes in Shanghai, China.

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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.

The intersection of culture, disability and assistive technology.

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Ripat, Jacquie; Woodgate, Roberta

2011-01-01

Although the use of assistive technology (AT) is by an individual, it occurs within a much larger socio-cultural environment. The purpose of this article is to describe and analyse current knowledge about the intersection of culture and disability in the context of the AT user. Literature review of theoretical and empirical study papers that discuss cultural aspects related to AT use or provision. Understanding how an individual's culturally defined identity is shaped as an AT user, and the meaning the AT holds to that person and family, is essential to providing culturally appropriate AT services. AT providers also belong to a culture framed by their professional experiences; needed are ways of addressing ethnocentricity within culturally diverse practice settings. Some AT users may identify with a disability culture, a culture formed by a shared set of beliefs, values and behaviours around the construct of disability. This review reveals there is a paucity of knowledge about the intersection of AT and culture, and that this intersection requires further research. Embarking on this investigation is mandatory if we seek to meet the needs of the culturally diverse individuals who use AT.

FIJI: A Framework for the Immersion-Journalism Intersection

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Gary M. Hardee

2017-07-01

Full Text Available As journalists experiment with developing immersive journalism—first-person, interactive experiences of news events—guidelines are needed to help bridge a disconnect between the requirements of journalism and the capabilities of emerging technologies. Many journalists need to better understand the fundamental concepts of immersion and the capabilities and limitations of common immersive technologies. Similarly, developers of immersive journalism works need to know the fundamentals that define journalistic professionalism and excellence and the key requirements of various types of journalistic stories. To address these gaps, we have developed a Framework for the Immersion-Journalism Intersection (FIJI. In FIJI, we have identified four domains of knowledge that intersect to define the key requirements of immersive journalism: the fundamentals of immersion, common immersive technologies, the fundamentals of journalism, and the major types of journalistic stories. Based on these key requirements, we have formally defined four types of immersive journalism that are appropriate for public dissemination. In this article, we discuss the history of immersive journalism, present the four domains and key intersection of FIJI, and provide a number of guidelines for journalists new to creating immersive experiences.

From r-spin intersection numbers to Hodge integrals

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Ding, Xiang-Mao; Li, Yuping [Institute of Applied Mathematics, Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190, People’s Republic of (China); Meng, Lingxian [Institute of Applied Mathematics, Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190, People’s Republic of (China); College of Mathematics and Information Science, Zhengzhou University of Light Industry,Zhengzhou 450002, People’s Republic of (China)

2016-01-04

Generalized Kontsevich Matrix Model (GKMM) with a certain given potential is the partition function of r-spin intersection numbers. We represent this GKMM in terms of fermions and expand it in terms of the Schur polynomials by boson-fermion correspondence, and link it with a Hurwitz partition function and a Hodge partition by operators in a (GL)-hat (∞) group. Then, from a W{sub 1+∞} constraint of the partition function of r-spin intersection numbers, we get a W{sub 1+∞} constraint for the Hodge partition function. The W{sub 1+∞} constraint completely determines the Schur polynomials expansion of the Hodge partition function.

Compositions of professionalism in counselling work: An embodied and embedded intersectionality framework.

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Adamson, Maria; Johansson, Marjana

2016-12-01

This article explores the embodied compositions of professionalism in the context of the counselling psychology profession in Russia. Specifically, we develop an embodied intersectionality framework for theorizing compositions of professionalism, which allows us to explain how multiple embodied categories of difference intersect and are relationally co-constitutive in producing credible professionals, and, importantly, how these intersections are contingent on intercorporeal encounters that take place in localized professional settings. Our exploration of how professionalism and professional credibility are established in Russian counselling shows that, rather than assuming that a hegemonic 'ideal body' is given preference in a professional context, different embodied compositions may be deemed credible in various work settings within the same profession. An embodied intersectionality framework allows us to challenge the notion of a single professional ideal and offer a dynamic and contextually situated analysis of the lived experiences of professional privilege and disadvantage.

Geometrical Design Errors in Duhok Intersections by Driver Behavior

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Dilshad Ali Mohammed

2018-03-01

Full Text Available In many situations, drivers if certain of the absence traffic monitoring system tend to shorten their driving paths and travel time across intersections. This behavior will be encouraged if the geometrical design suffers from mistakes, or the geometrical design and road conditions make it harder for drivers to follow the correct routes. Sometimes the intersection arrangement is confusing for the driver to distinguish the right from the wrong track. In this study, two sites with large number of driving mistakes were noticed. One site is a roundabout within the university of Duhok campus. The other is the intersection just outside the University of Duhok eastern main gate. At both sites, the geometry is very confusing and encourage driving mistakes. The university roundabout which was the first site investigated, was not properly designed encouraging wrong side driving. Many traffic accidents took place at this roundabout.  Wrong side driving reaches 32 % at peak hour in one approach.  This was reduced to 6% when temporary divisional island was installed. The other approach has a 15% wrong side driving and no remedy could be done to it. At the intersection near the university gate, wrong side driving reaches 56% of the traffic emerging from the main gate at peak hour. This was reduced to 14% when drivers are guided through direction sign. This percentage was reduced further to 9% with standing policeman.

Intersectionality in Transnational Education Policy Research

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Robert, Sarah A.; Yu, Min

2018-01-01

This review assesses intersectionality as a theoretical and methodological approach to transnational education policy research. In particular, we are concerned with how the concept is translated and interpreted to interrogate globally circulating education policies and how that transformation might inform the concept within Western and Northern…

An Adaptive Traffic Signal Control in a Connected Vehicle Environment: A Systematic Review

OpenAIRE

Peng Jing; Hao Huang; Long Chen

2017-01-01

In the last few years, traffic congestion has become a growing concern due to increasing vehicle ownerships in urban areas. Intersections are one of the major bottlenecks that contribute to urban traffic congestion. Traditional traffic signal control systems cannot adjust the timing pattern depending on road traffic demand. This results in excessive delays for road users. Adaptive traffic signal control in a connected vehicle environment has shown a powerful ability to effectively alleviate u...

Understanding the micro and macro politics of health: Inequalities, intersectionality & institutions - A research agenda.

Science.gov (United States)

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.

On classical de Sitter and Minkowski solutions with intersecting branes

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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.

Effective spectral densities for system-environment dynamics at conical intersections: S{sub 2}-S{sub 1} conical intersection in pyrazine

Energy Technology Data Exchange (ETDEWEB)

Martinazzo, Rocco [Department of Physical Chemistry and Electrochemistry, University of Milan, Via Golgi 19, 20122 Milan (Italy); Hughes, Keith H. [School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW (United Kingdom); Martelli, Fausto [Department of Physical Chemistry and Electrochemistry, University of Milan, Via Golgi 19, 20122 Milan (Italy); Departement de Chimie, Ecole Normale Superieure, 24 rue Lhomond, F-75231 Paris cedex 05 (France); Burghardt, Irene, E-mail: irene.burghardt@ens.fr [Departement de Chimie, Ecole Normale Superieure, 24 rue Lhomond, F-75231 Paris cedex 05 (France)

2010-11-25

Graphical abstract: The effect of high-dimensional environments on conical intersections can be described by hierarchies of approximate spectral densities, which translate to truncated effective-mode chains in the time domain. Abstract: A recently developed effective-mode representation is employed to characterize the influence of a multi-dimensional environment on the S{sub 2}-S{sub 1} conical intersection in pyrazine, taken as a paradigm case of high-dimensional dynamics at a conical intersection. We consider a simplified model by which four modes are strongly coupled to the electronic subsystem while a number of weakly coupled tuning modes, inducing energy gap fluctuations, are sampled from a spectral density. The latter is approximated by a series of simplified spectral densities which can be cast into a continued-fraction form, as previously demonstrated in Hughes et al. (K.H. Hughes, C.D. Christ, I. Burghardt, J. Chem. Phys. 131 (2009) 124108). In the time domain, the hierarchy of spectral densities translates to truncated effective-mode chains with a Markovian or quasi-Markovian (Rubin type) closure. A sequential deconvolution procedure is employed to generate this chain representation. The implications for the ultrafast dynamics and its representation in terms of reduced-dimensional models are discussed.

Shifting Identities: Negotiating Intersections of Race and Gender in Canadian Administrative Contexts

Science.gov (United States)

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…