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Sample records for air taxi crash

  1. Factors associated with crashes involving taxi owners and non-owners: A case of moral hazard and adverse selection?

    Science.gov (United States)

    Tay, Richard; Choi, Jaisung

    2016-02-01

    Taxis experience a higher risk of a motor vehicle crash partly because of their much higher levels of exposure on the roads. Although several studies have been conducted to examine the factors associated with the frequency and severity of taxi collisions, little research has been conducted to examine the differences in the factors associated with owner taxis and non-owner taxis. This study finds that collisions involving non-owners are more likely to be associated with poor or risky driving behaviors than collisions involving taxi vehicle owners. This result is consistent with the economic principles of moral hazard and adverse selection. Hence, policy makers responsible for traffic safety, taxi regulation or taxi operations should consider measures to reduce these market inefficiencies and improve the safety of not only taxi drivers but all road users.

  2. Understanding taxi travel patterns

    Science.gov (United States)

    Cai, Hua; Zhan, Xiaowei; Zhu, Ji; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

    2016-09-01

    Taxis play important roles in modern urban transportation systems, especially in mega cities. While providing necessary amenities, taxis also significantly contribute to traffic congestion, urban energy consumption, and air pollution. Understanding the travel patterns of taxis is thus important for addressing many urban sustainability challenges. Previous research has primarily focused on examining the statistical properties of passenger trips, which include only taxi trips occupied with passengers. However, unoccupied trips are also important for urban sustainability issues because they represent potential opportunities to improve the efficiency of the transportation system. Therefore, we need to understand the travel patterns of taxis as an integrated system, instead of focusing only on the occupied trips. In this study we examine GPS trajectory data of 11,880 taxis in Beijing, China for a period of three weeks. Our results show that taxi travel patterns share similar traits with travel patterns of individuals but also exhibit differences. Trip displacement distribution of taxi travels is statistically greater than the exponential distribution and smaller than the truncated power-law distribution. The distribution of short trips (less than 30 miles) can be best fitted with power-law while long trips follow exponential decay. We use radius of gyration to characterize individual taxi's travel distance and find that it does not follow a truncated power-law as observed in previous studies. Spatial and temporal regularities exist in taxi travels. However, with increasing spatial coverage, taxi trips can exhibit dual high probability density centers.

  3. A Heuristic Approach to Solve Air Taxi Scheduling Problem

    OpenAIRE

    Chavan, Harish Dnyandeo

    2003-01-01

    All passengers travel at the hour most convenient to them. But it is not always possible to find a flight at the right time to fly them to their destination. In the case where service in any one time period is insufficient to meet air travel demanded, it may be expected that some unfilled demand passengers will either delay their flight or will advance it, thus adding to the effective demand of the adjoining time periods.The obvious alternate means of travel is a rental car. It takes a lot mo...

  4. A cross-sectional study with an improved methodology to assess occupational air pollution exposure and respiratory health in motorcycle taxi driving

    Energy Technology Data Exchange (ETDEWEB)

    Lawin, Herve, E-mail: hervelawin@yahoo.fr [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin); Agodokpessi, Gildas [Centre National Hospitalier et Universitaire de Pneumo-Phtisiologie, Cotonou (Benin); Ayelo, Paul [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin); Kagima, Jacqueline [Department of internal medicine, Egerton University (Kenya); Sonoukon, Rodrigue [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin); Mbatchou Ngahane, Bertrand H. [Department of Internal Medicine, Douala General Hospital, Cameroon Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala (Cameroon); Awopeju, Olayemi [Department of Medicine, Obafemi Awolowo University, Ile Ife (Nigeria); Vollmer, William M. [Center for Health Research, Kaiser Permanente Northwest, Portland (United States); Nemery, Benoit [Dept. of Public Health, Occupational and Environmental Insurance Medicine, KU Leuven, Leuven (Belgium); Burney, Peter [National Heart & Lung Institute, Imperial College, London (United Kingdom); Fayomi, Benjamin [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin)

    2016-04-15

    Introduction: Motorcycle taxi driving is common in many African cities. This study tested whether this occupation is associated with more respiratory disorders in a context of widespread urban air pollution with an improved methodology. Methods: In a cross sectional study we compared 85 male motorcycle taxi drivers in the capital city of the Republic of Benin (Cotonou) with an age and neighborhood matched control group. All participants carried a portable carbon monoxide data logger for 8 hours per day to assess exposure to air pollution. Respiratory symptoms were obtained using a standardized questionnaire and pulmonary function was assessed by spirometry. Results: The two groups did not differ significantly (p > 0.10) in their age, height, educational level, and exposures to smoke from biomass fuels and tobacco products. The taxi drivers were exposed to higher mean (SD) levels of carbon monoxide (7.6 ± 4.9 ppmvs. 5.4 ± 3.8 ppm p = 0.001). They reported more phlegm and tended to have slightly lower levels of lung function, although these differences were not statistically significant. Conclusion: In this cross sectional study of young motorcycle taxi drivers with substantial exposure to urban traffic and a matched control group, we found no evidence for respiratory impairment. A follow-up of such study population with other pollution exposure surrogate and other clinical endpoint may provide a more robust conclusion regarding the exposure response in this professional group. - Highlights: • Need of improved study method to assess air pollution effect in exposed workers • This study compared motorcycle taxi drivers and a matched control group • Personal carbon monoxide exposure and respiratory disorders were collected • No evidence of more respiratory disorders even though pollutant exposure was higher.

  5. The air pollution of automobile origin among Parisian artisans taxi drivers: perception inquiry and exposure study; La pollution atmospherique d'origine automobile chez les chauffeurs de taxi artisans parisiens: enquete de perception et etude d'exposition

    Energy Technology Data Exchange (ETDEWEB)

    Zagury, E.

    1998-02-11

    The study concerns the impact of the atmospheric pollution of automobile origin in the drivers population. It includes two parts:the first part is an inquiry to 188 Parisian artisans taxi drivers, with a questionnaire. The objective is to determine the behavior about this phenomenon and what perception they have of it. The second part is an exposure study that consists in four pollutants (carbon monoxide, fine particulates in suspension, nitrogen monoxide and nitrogen dioxide). It is in order to reveal the concentrations of these pollutants inside 29 cabs during the professional activity. The taxi drivers complain of headaches, eyes and throat irritations, respiratory difficulties. The results of exposure measurements show 3.8 p.p.m. for carbon monoxide, 168 micrograms/m{sup 3} for the fine particulates in suspension, 625 micrograms for nitrogen monoxide and 139 micrograms/m{sup 3} for nitrogen dioxide. These measures are clearly higher than these ones measured in Parisian ambient air, even higher than these ones of stations that are exposed to the maximum level to automobile effluents. (N.C.)

  6. Exposure of bus and taxi drivers to urban air pollutants as measured by DNA and protein adducts

    DEFF Research Database (Denmark)

    Hemminki, K.; Zhang, L.F.; Krüger, J.;

    1994-01-01

    Urinary 1-hydroxypyrene, lymphocyte DNA adducts, serum protein-bound PAH and hemoglobin-bound alkene adducts were analysed from 4 groups of non-smoking men: urban and suburban bus drivers, taxi drivers and suburban controls. The only differences between the groups were in DNA adducts between...... suburban bus drivers and controls, and in DNA adduct and plasma protein PAH-adducts between taxi drivers and controls....

  7. Automation of Taxiing

    Directory of Open Access Journals (Sweden)

    Jaroslav Bursík

    2017-01-01

    Full Text Available The article focuses on the possibility of automation of taxiing, which is the part of a flight, which, under adverse weather conditions, greatly reduces the operational usability of an airport, and is the only part of a flight that has not been affected by automation, yet. Taxiing is currently handled manually by the pilot, who controls the airplane based on information from visual perception. The article primarily deals with possible ways of obtaining navigational information, and its automatic transfer to the controls. Analyzed wand assessed were currently available technologies such as computer vision, Light Detection and Ranging and Global Navigation Satellite System, which are useful for navigation and their general implementation into an airplane was designed. Obstacles to the implementation were identified, too. The result is a proposed combination of systems along with their installation into airplane’s systems so that it is possible to use the automated taxiing.

  8. Analysis and Modeling of Motor Vehicle Crashes Involving Air Force Military Personnel

    Science.gov (United States)

    2009-09-01

    protection systems are safety belts and airbags for four-wheeled vehicle users, and crash helmets for two-wheeled vehicle users. Almost all of the studies...in a recall of the product if it is necessary for public safety (GAO, 03-436: 27). The owner or operator of the vehicle is accountable for...frequently are: - re-experiencing, in which it is difficult for the MVCs’ victims to forget the traumatic experience because they recall

  9. Three-wheeled scooter taxi: A safety analysis

    Indian Academy of Sciences (India)

    S Mukherjee; D Mohan; T R Gawade

    2007-08-01

    The rollover propensity of a three-wheeled scooter taxi used extensively on SE Asian roads is analysed in this report. A rigid body mathematical model was used to simulate increasing steer, NHTSA -turn, and Road Edge Recovery maneuvers. The anomaly between public perception of the rollover susceptibility and available crash data has been resolved through finite element (FE) simulation. The optimum configuration of the vehicle and seating arrangement for varying numbers of passengers was determined. The safety of occupants and pedestrians in impact events was analysed through simulation in MADYMOTM, and cost effective solutions to improve safety were identified.

  10. Taxi pooling in New York City: a network-based approach to social sharing problems

    CERN Document Server

    Santi, Paolo; Szell, Michael; Sobolevsky, Stanislav; Strogatz, Steven; Ratti, Carlo

    2013-01-01

    Taxi services are a vital part of urban transportation, and a major contributor to traffic congestion and air pollution causing substantial adverse effects on human health. Sharing taxi trips is a possible way of reducing the negative impact of taxi services on cities, but this comes at the expense of passenger discomfort in terms of a longer travel time. Due to computational challenges, taxi sharing has traditionally been approached on small scales, such as within airport perimeters, or with dynamical ad-hoc heuristics. However, a mathematical framework for the systematic understanding of the tradeoff between collective benefits of sharing and individual passenger discomfort is lacking. Here we introduce the notion of shareability network which allows us to model the collective benefits of sharing as a function of passenger inconvenience, and to efficiently compute optimal sharing strategies on massive datasets. We apply this framework to a dataset of millions of taxi trips taken in New York City, showing th...

  11. Optimum Arrangement of Taxi Drivers’ Working Hours

    OpenAIRE

    TANIZAKI, Takashi

    2014-01-01

    Part 2: Knowledge Discovery and Sharing; International audience; We propose optimum arrangement of taxi drivers’ working hours. In Japan, income of taxi vehicle is decreasing about 11 thousand yen in the past 15 years. Then some taxi companies are investing to gain more customers. But there are many small taxi companies that are difficult to invest with much money. Therefore we have been researching the other method to gain more customers by little investment for small companies. In this pape...

  12. Advanced Crash Survivable Flight Data Recorder And Accident Information Retrieval System (AIRS).

    Science.gov (United States)

    1981-08-01

    95 31 NARROW-BAND CONDUCTED EMISSIONS ON THE AIRS 24 VDC POWER RETURN (CE04 TESI ) ......................... 96 32 BROAD-BAND...three layers of vulcanized synthetic rubber containing an intumescent ceramic material and includes a wire mesh reinforcement between the outermost

  13. Advanced Techniques in Crash Impact Protection and Emergency Egress from Air Transport Aircraft

    Science.gov (United States)

    1976-06-01

    to follow relatively simple written or oral instructions. .Requires moderate recall . CO2 critical level of about 8% reached sensation of...to consider the proper- ties of an upper torso restraint, whether it be an airbag or an Air Force harness. Therefore, in devel- oping specifications...accomplished by passive restraint systems such as the airbag . The lap belt may be eliminated to yield a purely pas- sive restraint system provided

  14. Taking a Taxi IN LHASA

    Institute of Scientific and Technical Information of China (English)

    ZHOLMA; YANGZOIN

    2002-01-01

    Downtown Lhasa covers an area of 52 square km, and has a resident population of 180,000. In the early 1980s, roads were paved with dirt and the citizens relied on bicycles for intra-city travel. Two bus routes emerged in the mid-1980s, and city roads were widened and asphalted in the 1990s.With Tibet’s door opening wider to the outside world, more visitors are coming to Lhasa. Cashing in on the opportunity, a taxi service appeared in the 1980s.Nowadays, there are some 1,100 cabs plying city streets. A considerable number are the Volkswagen Santana model. Although distance meters have been installed, taxi drivers love to charge customers at the fixed rate of 10 Yuan for inner-city travel.

  15. Occupant Crash Protection in Military Air Transport (Protection Contre l’Ecrasement des Occupants des Aeronefs de Transport Militaires)

    Science.gov (United States)

    1990-08-01

    comparison of injuries received wh3le weatir.g lap belt and shoulder harness restraint versus wep ing only a lap belt restraint showed n, significant...May, 1967. Carroll, J., Crash Injury Evaluation, U.S. Army YHU-ID, Bell Iroquois Helicopter Mockup , AvCIR-16- PV-1,7, AvCIR, a Division of Flight Safety...Foundation, Inc., 2871 Sky Harbor Blvd., Phoenix, Arizona. USA, February, 1961. Carroll, J., Knowles, W. R., YHC-IB U.S. Army ’Chinook’ Mockup

  16. Efficient Air Crash Search and Rescue Methods Based on Multisource Remote Sensing Images%利用多源遥感数据的高效空难搜索定位与救援方法

    Institute of Scientific and Technical Information of China (English)

    晏泽翌; 毛志强; 孙宏峰; 张孟侠

    2016-01-01

    近年来空难接连不断,如何降低空难发生几率,及时发现失事地点和飞机残骸,提供紧急救援,保证航空飞行的安全性是目前急需解决的问题。本文对飞机的航行过程如何跟踪,空难的搜索如何准确定位进行了综合分析;并以M H370马航事件为例,使用ENVI软件,对收集到的遥感影像图进行影像数据分析,提出搜索飞机残骸的可能方法。为快速有效地寻找坠机地点,使损失降到最低提供原理方法和实践依据。%There were many air crashes in 2014 .Current urgent and critical issues in‐clude (1) to understand how to reduce the probability of air crash ,(2) to locate the accident and airplane remains ,(3) to provide rescues ,and to (4) ensure the safety of the flights .In this paper ,we investigated how to track airplanes and how to locate air crashes by using lit‐erature searching ,website searching ,and interviewing experts .In addition ,we used M H370 air crash as an example and proposed a possibility of searching the airplane remains .This was done by analyzing data from remote sensing images by ENVI software .Our research provides both theoretical and practical evidence to efficiently locate air crashes and to mini‐mize the financial loss .

  17. Motor Carrier Crash Data -

    Data.gov (United States)

    Department of Transportation — Contains data on large trucks and buses involved in Federally reportable crashes as per Title 49 U.S.C. Part 390.5 (crashes involving a commercial motor vehicle, and...

  18. Taxis and crowd-taxis: sharing as a private activity and public concern

    Directory of Open Access Journals (Sweden)

    Merethe Dotterud Leiren

    2016-06-01

    Full Text Available The sharing economy has generated interest among economists for its customer focus and potential to enhance competition. However, it has also caused uproar in industries which have felt competitive pressure, for example among the established stakeholders in the taxi industry. While regulations currently impose considerable costs on the taxi industry, they do not cover virtual transport innovations such as Uber. The lack of a level playing field between taxis and such ‘crowd-taxis’ has generated media attention and conflict. Taxi owners worry about decreasing revenues and taxi drivers about poor working conditions. Other concerns are related to poor transport preparedness, accessibility issues, quality assurance and tax evasion. Despite considerable media attention, there has so far been a lack of scholarly literature addressing the consequences of the sharing economy in the transport sector. Focusing on the Norwegian taxi market, we argue that crowd-taxis will likely produce a range of unanticipated effects, necessitating regulation. For example, crowd-taxis may contribute to a loss of transport preparedness in rural areas. The findings are based on first and secondary data and 19 interviews.

  19. Exploring Urban Taxi Drivers’ Activity Distribution Based on GPS Data

    Directory of Open Access Journals (Sweden)

    Xiaowei Hu

    2014-01-01

    Full Text Available With the rapid development of information communication technology and data mining technology, we can obtain taxi vehicle’s real time operation status through the large-scale taxi GPS trajectories data and explore the drivers’ activity distribution characteristics. Based on the 204 continuous hours of 3198 taxi vehicles’ operation data of Shenzhen, China, this paper analyzed the urban taxi driver’s activity distribution characteristics from different temporal and spatial levels. In the time level, we identified the difference with taxi daily operation pattern (weekday versus weekends, continuous time in one day, passengers in vehicle time, and taxi drivers’ operation frequency; in the space level, we explored the taxi driver’s searching pattern, including searching activity space distribution and the relationship between the pick-up locations and the drop-off locations. This research can be helpful for urban taxi drivers’ operation and behavior pattern identification, as well as the contribution to the geographical activity space analysis.

  20. Fuel cell hybrid taxi life cycle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Patricia, E-mail: patricia.baptista@ist.utl.pt [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ribau, Joao; Bravo, Joao; Silva, Carla [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Adcock, Paul; Kells, Ashley [Intelligent Energy, Charnwood Building, HolywellPark, Ashby Road, Loughborough, LE11 3GR (United Kingdom)

    2011-09-15

    A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO{sub 2} emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO{sub 2} emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: > A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. > The hydrogen powered vehicles have the lowest energy consumption and CO{sub 2} emissions results. > A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

  1. Catastrophic Equatorial Icing Caused the Air France 447 and Malaysian 370 Crashes: Risks of More Such Disasters Are Increased By Global Warming

    Science.gov (United States)

    Gibson, C. H.

    2014-12-01

    Dangerous icing conditions near the equator have been observed, and may account for the tragic crashes of Air France 447 in 2009 and Malaysian Airlines 370 in 2014, not pilot error in either case. Six cases of engine failures from icing were reported in 2013 at high altitudes for 747-8 and 787 Dreamliner planes at tropical latitudes (journalofcosmology.com volume 23). Lack of horizontal Coriolis forces accounts for the extreme intermittency of equatorial turbulence and turbulent mixing, Baker and Gibson (1987). Intermittency factors inferred from the available microstructure data sets were much larger than those at higher latitudes, reflecting the wide range of scales of the turbulence cascade from small scales to large in the horizontal direction. Lognormal statistical analysis implies mean values of dissipation rates are likely to be 30,000 times larger than mode values at the equator, compared to only 2000 times larger at midlatitudes. Modern stratified turbulence theory (journalofcosmology.com volume 21) shows turbulent mixing of heat, mass, momentum, and chemical species in natural fluids such as the ocean, atmosphere, and cosmological fluids is dominated by mixing chimneys directed perpendicular to vertical and radial layers of gravitational stratification by the inertial vortex forces that define turbulence. Rarely, thick columns of supercooled steam reach cruising altitudes of jet aircraft. After entering such a column, the plane is doomed.

  2. Global stability of prey-taxis systems

    Science.gov (United States)

    Jin, Hai-Yang; Wang, Zhi-An

    2017-02-01

    In this paper, we prove the global boundedness and stability of the predator-prey system with prey-taxis in a two-dimensional bounded domain with Neumann boundary conditions. By deriving an entropy-like equality and a boundedness criterion, we show that the intrinsic interaction between predators and preys is sufficient to prevent the population overcrowding even the prey-taxis is included and strong. Furthermore, by constructing appropriate Lyapunov functionals, we show that prey-only steady state is globally asymptotically stable if the predation is weak, and the co-existence steady state is globally asymptotically stable under some conditions (like the prey-taxis is weak or the prey diffuses fast) if the predation is strong. The convergence rates of solutions to the steady states are derived in the paper.

  3. AP statistics crash course

    CERN Document Server

    D'Alessio, Michael

    2012-01-01

    AP Statistics Crash Course - Gets You a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. AP Statistics Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know Crash Course is based on an in-depth analysis of the AP Statistics course description outline and actual Advanced Placement test questions. It covers only the information tested on the exam, so you can make the most of your valuable study time. Our easy-to-read format covers: exploring da

  4. The financial help given by the French government to LPG-fueled taxis; L'aide financiere de l'etat aux taxis GPL

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-02-01

    In the framework of its 'clean vehicle' air pollution abatement program, the French government has set up a financial help managed by the French agency of environment and energy mastery (Ademe) and devoted to taxi fleets which use LPG fuels. This brochure gives a general presentation of LPG-fueled vehicles (equipment, cost, service stations..) and explains the conditions of allocation of the help. (J.S.)

  5. Crash risk: How cycling flow can help explain crash data.

    Science.gov (United States)

    Dozza, Marco

    2016-05-12

    Crash databases are commonly queried to infer crash causation, prioritize countermeasures to prevent crashes, and evaluate safety systems. However, crash databases, which may be compiled from police and hospital records, alone cannot provide estimates of crash risk. Moreover, they fail to capture road user behavior before the crash. In Sweden, as in many other countries, crash databases are particularly sterile when it comes to bicycle crashes. In fact, not only are bicycle crashes underreported in police reports, they are also poorly documented in hospital reports. Nevertheless, these reports are irreplaceable sources of information, clearly highlighting the surprising prevalence of single-bicycle crashes and hinting at some cyclist behaviors, such as alcohol consumption, that may increase crash risk. In this study, we used exposure data from 11 roadside stations measuring cyclist flow in Gothenburg to help explain crash data and estimate risk. For instance, our results show that crash risk is greatest at night on weekends, and that this risk is larger for single-bicycle crashes than for crashes between a cyclist and another motorist. This result suggests that the population of night-cyclists on weekend nights is particularly prone to specific crash types, which may be influenced by specific contributing factors (such as alcohol), and may require specific countermeasures. Most importantly, our results demonstrate that detailed exposure data can help select, filter, aggregate, highlight, and normalize crash data to obtain a sharper view of the cycling safety problem, to achieve a more fine-tuned intervention.

  6. Crash Under Investigation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The cause of a fatal cargo plane accident in Shanghai is still unknown The flight data recorder of the Zimbabwean cargo plane that crashed on November 28 at Shanghai Pudong International Airport has been found near the crash scene,local aviation control authorities said.

  7. Road crash costs.

    NARCIS (Netherlands)

    2010-01-01

    Road crashes result in all kinds of social costs, such as medical costs, production loss, human losses, property damage, settlement costs and costs due to congestion. Studies into road crash costs and their trends are carried out quite regularly. In 2009, the costs amounted to € 12.5 billion, or 2.2

  8. Ergonomic Evaluation on Taxi Drivers Compartment

    Institute of Scientific and Technical Information of China (English)

    Jimmy; SF; Chan; YW; Chui; Reggie; Kwan; K; K; Chau

    2002-01-01

    Driving involves long hours of physical work within c onfined compartment. Taxi drivers usually work with prolonged working hours, add itional stress may likely be induced on particular body limbs. Occupational heal th may occur and working efficiency may potentially be affected resulting fr om fatigues, pains or diseases. These problems, however, could be remedied if mo re attention is paid on seating design, the workplace and driving postures adopt ed. Ergonomics design can provide better understanding...

  9. Inferring Taxi Status Using GPS Trajectories

    CERN Document Server

    Zhu, Yin; Zhang, Liuhang; Santani, Darshan; Xie, Xing; Yang, Qiang

    2012-01-01

    In this paper, we infer the statuses of a taxi, consisting of occupied, non-occupied and parked, in terms of its GPS trajectory. The status information can enable urban computing for improving a city's transportation systems and land use planning. In our solution, we first identify and extract a set of effective features incorporating the knowledge of a single trajectory, historical trajectories and geographic data like road network. Second, a parking status detection algorithm is devised to find parking places (from a given trajectory), dividing a trajectory into segments (i.e., sub-trajectories). Third, we propose a two-phase inference model to learn the status (occupied or non-occupied) of each point from a taxi segment. This model first uses the identified features to train a local probabilistic classifier and then carries out a Hidden Semi-Markov Model (HSMM) for globally considering long term travel patterns. We evaluated our method with a large-scale real-world trajectory dataset generated by 600 taxis...

  10. Crash patterns at signalized intersections

    OpenAIRE

    Polders, Evelien; Daniels, Stijn; HERMANS, Elke; Brijs, Tom; Wets, Geert

    2015-01-01

    Traffic signals are often implemented to provide for efficient movement and to improve traffic safety. Nevertheless, severe crashes still occur at signalized intersections. This study aims to improve the understanding of signalized intersection safety by identifying crash types, locations and factors associated with signalized intersections. For this purpose, 1295 police-reported crashes at 87 signalized intersections are analyzed based on detailed crash descriptions, i.e. crash data and c...

  11. Collaborative Outbound Taxi Metering for Environmental Benefits Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the concept of Collaborative Outbound Taxi Metering (COTM), which provides environmental benefits without sacrificing throughput. In current...

  12. Butler County Crash Data

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Contains locations and information about every crash incident reported to the police in Butler County from 2011 to 2015. Fields include injury severity, fatalities,...

  13. Beaver County Crash Data

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Contains locations and information about every crash incident reported to the police in Beaver County from 2011 to 2015. Fields include injury severity, fatalities,...

  14. Washington County Crash Data

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Contains locations and information about every crash incident reported to the police in Washington County from 2011 to 2015. Fields include injury severity,...

  15. Westmoreland County Crash Data

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Contains locations and information about every crash incident reported to the police in Westmoreland County from 2011 to 2015. Fields include injury severity,...

  16. Allegheny County Crash Data

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Contains locations and information about every crash incident reported to the police in Allegheny County from 2004 to 2015. Fields include injury severity,...

  17. Bubbles and market crashes

    CERN Document Server

    Youssefmir, M; Hogg, T; Youssefmir, Michael; Huberman, Bernardo; Hogg, Tad

    1994-01-01

    We present a dynamical theory of asset price bubbles that exhibits the appearance of bubbles and their subsequent crashes. We show that when speculative trends dominate over fundamental beliefs, bubbles form, leading to the growth of asset prices away from their fundamental value. This growth makes the system increasingly susceptible to any exogenous shock, thus eventually precipitating a crash. We also present computer experiments which in their aggregate behavior confirm the predictions of the theory.

  18. Critical market crashes

    Science.gov (United States)

    Sornette, D.

    2003-04-01

    This review presents a general theory of financial crashes and of stock market instabilities that his co-workers and the author have developed over the past seven years. We start by discussing the limitation of standard analyses for characterizing how crashes are special. The study of the frequency distribution of drawdowns, or runs of successive losses shows that large financial crashes are “outliers”: they form a class of their own as can be seen from their statistical signatures. If large financial crashes are “outliers”, they are special and thus require a special explanation, a specific model, a theory of their own. In addition, their special properties may perhaps be used for their prediction. The main mechanisms leading to positive feedbacks, i.e., self-reinforcement, such as imitative behavior and herding between investors are reviewed with many references provided to the relevant literature outside the narrow confine of Physics. Positive feedbacks provide the fuel for the development of speculative bubbles, preparing the instability for a major crash. We demonstrate several detailed mathematical models of speculative bubbles and crashes. A first model posits that the crash hazard drives the market price. The crash hazard may sky-rocket at some times due to the collective behavior of “noise traders”, those who act on little information, even if they think they “know”. A second version inverses the logic and posits that prices drive the crash hazard. Prices may skyrocket at some times again due to the speculative or imitative behavior of investors. According the rational expectation model, this entails automatically a corresponding increase of the probability for a crash. We also review two other models including the competition between imitation and contrarian behavior and between value investors and technical analysts. The most important message is the discovery of robust and universal signatures of the approach to crashes. These precursory

  19. Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Javad Golhosseini

    2015-06-01

    Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOC are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC.

  20. Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Javad Golhosseini*

    2015-06-01

    Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOCs are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC.

  1. Estimating likelihood of future crashes for crash-prone drivers

    Directory of Open Access Journals (Sweden)

    Subasish Das

    2015-06-01

    Full Text Available At-fault crash-prone drivers are usually considered as the high risk group for possible future incidents or crashes. In Louisiana, 34% of crashes are repeatedly committed by the at-fault crash-prone drivers who represent only 5% of the total licensed drivers in the state. This research has conducted an exploratory data analysis based on the driver faultiness and proneness. The objective of this study is to develop a crash prediction model to estimate the likelihood of future crashes for the at-fault drivers. The logistic regression method is used by employing eight years' traffic crash data (2004–2011 in Louisiana. Crash predictors such as the driver's crash involvement, crash and road characteristics, human factors, collision type, and environmental factors are considered in the model. The at-fault and not-at-fault status of the crashes are used as the response variable. The developed model has identified a few important variables, and is used to correctly classify at-fault crashes up to 62.40% with a specificity of 77.25%. This model can identify as many as 62.40% of the crash incidence of at-fault drivers in the upcoming year. Traffic agencies can use the model for monitoring the performance of an at-fault crash-prone drivers and making roadway improvements meant to reduce crash proneness. From the findings, it is recommended that crash-prone drivers should be targeted for special safety programs regularly through education and regulations.

  2. Braking news: link between crash severity and crash avoidance maneuvers

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    crash avoidance maneuvers and crash severity, with differences emerging for different critical events. Moreover, results showed two trends:(a) most drivers failed to act when facing critical events and (b) drivers rarely performed crash avoidance maneuvers that were correlated with a higher probability...... of lower crash severity. These trends suggest that efforts to understand the mechanisms of reactions to different critical events should be made to improve in-vehicle warning systems, promote responsible driving behavior, and design forgiving infrastructures....

  3. Suggestions about Taxi Service in Beijing

    Institute of Scientific and Technical Information of China (English)

    李颖

    2006-01-01

    @@ No matter what kinds1 of work we are engaged in, we usually play the role of the customers2 in life. Maybe we offer service to our clients, but at the same time, we get service from other people. So, to the society3, it is very important of the level of the service occupations4. In this essay, I want to talk about the service of the taxi in Beijing5. Because there are some problems in this service occupation, I will give three suggestions to these problems6.

  4. Road crash costs.

    OpenAIRE

    2010-01-01

    Road crashes result in all kinds of social costs, such as medical costs, production loss, human losses, property damage, settlement costs and costs due to congestion. Studies into road crash costs and their trends are carried out quite regularly. In 2009, the costs amounted to € 12.5 billion, or 2.2% of the Gross Domestic Product (GDP). Insight into these costs is used for policy preparation and evaluation, and makes it possible to compare them with costs in other areas. Another important app...

  5. Time-varying Crash Risk

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunoua, Bruno; Jeon, Yoontae

    We estimate a continuous-time model with stochastic volatility and dynamic crash probability for the S&P 500 index and find that market illiquidity dominates other factors in explaining the stock market crash risk. While the crash probability is time-varying, its dynamic depends only weakly on re...

  6. Modeling of taxi drivers’ experience for routing applications

    Institute of Scientific and Technical Information of China (English)

    SHAW; ShihLung

    2010-01-01

    Taxi drivers drive on the roads every day and become very knowledgeable of the spatiotemporal traffic patterns in a city.It therefore is reasonable to assume that the routes chosen by taxi drivers often work out better than those selected by other drivers.Since dynamic navigation assistance based on real-time traffic information faces limitations such as the spatial coverage of real-time data collection sites,performance of real-time data processing and communications,and accuracy of short-term traffic forecasts in a large urban area,experiences gained by taxi drivers can be a valuable data source for improving the quality of vehicle navigation guidance.This paper develops a vehicle navigation guidance system based on taxis drivers’ knowledge derived from floating car data collected over an extended time period.We then classify road segments based on the spatiotemporal characteristics of taxi tracking data.A case study using taxi tracking data collected in Wuhan,China is presented in this paper to demonstrate the performance of this vehicle navigation system based on taxi tracking data.

  7. Blind spot crashes.

    NARCIS (Netherlands)

    2009-01-01

    Crashes involving lorries turning right and cyclists going straight ahead usually have very serious consequences for the cyclist. The cyclist, who has right of way, is often overlooked by the lorry driver. For his part, the cyclist is often unaware that the lorry driver has not seen him or that the

  8. Advances in Crash Response

    Centers for Disease Control (CDC) Podcasts

    2009-06-29

    In this podcast, Dr. Richard C. Hunt, Director of CDC's Division of Injury Response, provides an overview on the benefits of using an Advanced Automatic Collision Notification system, or AACN, to help with emergency triage of people injured in vehicle crashes.  Created: 6/29/2009 by National Center for Injury Prevention and Control (NCIPC), Division of Injury Response (DIR).   Date Released: 6/29/2009.

  9. Reading as Wedding Crashing

    Science.gov (United States)

    Newkirk, Thomas

    2014-01-01

    Grappling with difficult texts can make readers feel as though they're crashing a party that wasn't meant for them. They don't know the occasion. They don't know the guests. They have a hard time fitting in. In this article, Thomas Newkirk suggests several reasons why students find texts difficult to understand. Students may be…

  10. [Comparative life cycle environmental assessment between electric taxi and gasoline taxi in Beijing].

    Science.gov (United States)

    Shi, Xiao-Qing; Sun, Zhao-Xin; Li, Xiao-Nuo; Li, Jin-Xiang; Yang, Jian-Xin

    2015-03-01

    Tailpipe emission of internal combustion engine vehicle (ICEV) is one of the main sources leading to atmospheric environmental problems such as haze. Substituting electric vehicles for conventional gasoline vehicles is an important solution for reducing urban air pollution. In 2011, as a pilot city of electric vehicle, Beijing launched a promotion plan of electric vehicle. In order to compare the environmental impacts between Midi electric vehicle (Midi EV) and Hyundai gasoline taxi (ICEV), this study created an inventory with local data and well-reasoned assumptions, and contributed a life cycle assessment (LCA) model with GaBi4.4 software and comparative life cycle environmental assessment by Life cycle impact analysis models of CML2001(Problem oriented) and EI99 (Damage oriented), which included the environmental impacts of full life cycle, manufacture phase, use phase and end of life. The sensitivity analysis of lifetime mileage and power structure was also provided. The results indicated that the full life cycle environmental impact of Midi EV was smaller than Hyundai ICEV, which was mainly due to the lower fossil fuel consumption. On the contrary, Midi EV exhibited the potential of increasing the environmental impacts of ecosystem quality influence and Human health influence. By CML2001 model, the results indicated that Midi EV might decrease the impact of Abiotic Depletion Potential, Global Warming Potential, Ozone Layer Depletion Potential and so on. However, in the production phase, the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Ozone Layer Depletion Potential, Marine Aquatic Ecotoxicity Potential, Terrestric Ecotoxicity Potential, Human Toxicity Potential of Midi EV were increased relative to Hyundai ICEV because of emissions impacts from its power system especially the battery production. Besides, in the use phase, electricity production was

  11. AP physics B crash course

    CERN Document Server

    Howell, Rebecca

    2012-01-01

    AP Physics B Crash Course - Get a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. Our AP Physics B Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know The Crash Course is based on an in-depth analysis of the AP Physics B course description outline and actual AP test questions. It covers only the information tested on the exam, so you can make the most of your valuable study time. Our easy-to-read format covers: mechanics, kinetic theory, t

  12. pH-Taxis of Biohybrid Microsystems

    Science.gov (United States)

    Zhuang, Jiang; Wright Carlsen, Rika; Sitti, Metin

    2015-06-01

    The last decade has seen an increasing number of studies developing bacteria and other cell-integrated biohybrid microsystems. However, the highly stochastic motion of these microsystems severely limits their potential use. Here, we present a method that exploits the pH sensing of flagellated bacteria to realize robust drift control of multi-bacteria propelled microrobots. Under three specifically configured pH gradients, we demonstrate that the microrobots exhibit both unidirectional and bidirectional pH-tactic behaviors, which are also observed in free-swimming bacteria. From trajectory analysis, we find that the swimming direction and speed biases are two major factors that contribute to their tactic drift motion. The motion analysis of microrobots also sheds light on the propulsion dynamics of the flagellated bacteria as bioactuators. It is expected that similar driving mechanisms are shared among pH-taxis, chemotaxis, and thermotaxis. By identifying the mechanism that drives the tactic behavior of bacteria-propelled microsystems, this study opens up an avenue towards improving the control of biohybrid microsystems. Furthermore, assuming that it is possible to tune the preferred pH of bioactuators by genetic engineering, these biohybrid microsystems could potentially be applied to sense the pH gradient induced by cancerous cells in stagnant fluids inside human body and realize targeted drug delivery.

  13. On Crises, Crashes and Comovements

    NARCIS (Netherlands)

    H.J.W.G. Kole (Erik)

    2006-01-01

    textabstractCrises and crashes in financial markets are investors’ worst fear. The combination of large losses, a persistent increase of price fluctuations, and a strengthening of comovements in prices causes investors great harm. While the severe consequences of crises and crashes are intuitively c

  14. Mining spatiotemporal patterns of urban dwellers from taxi trajectory data

    Science.gov (United States)

    Mao, Feng; Ji, Minhe; Liu, Ting

    2016-06-01

    With the widespread adoption of locationaware technology, obtaining long-sequence, massive and high-accuracy spatiotemporal trajectory data of individuals has become increasingly popular in various geographic studies. Trajectory data of taxis, one of the most widely used inner-city travel modes, contain rich information about both road network traffic and travel behavior of passengers. Such data can be used to study the microscopic activity patterns of individuals as well as the macro system of urban spatial structures. This paper focuses on trajectories obtained from GPS-enabled taxis and their applications for mining urban commuting patterns. A novel approach is proposed to discover spatiotemporal patterns of household travel from the taxi trajectory dataset with a large number of point locations. The approach involves three critical steps: spatial clustering of taxi origin-destination (OD) based on urban traffic grids to discover potentially meaningful places, identifying threshold values from statistics of the OD clusters to extract urban jobs-housing structures, and visualization of analytic results to understand the spatial distribution and temporal trends of the revealed urban structures and implied household commuting behavior. A case study with a taxi trajectory dataset in Shanghai, China is presented to demonstrate and evaluate the proposed method.

  15. Intelligent geocoding system to locate traffic crashes.

    Science.gov (United States)

    Qin, Xiao; Parker, Steven; Liu, Yi; Graettinger, Andrew J; Forde, Susie

    2013-01-01

    State agencies continue to face many challenges associated with new federal crash safety and highway performance monitoring requirements that use data from multiple and disparate systems across different platforms and locations. On a national level, the federal government has a long-term vision for State Departments of Transportation (DOTs) to report state route and off-state route crash data in a single network. In general, crashes occurring on state-owned or state maintained highways are a priority at the Federal and State level; therefore, state-route crashes are being geocoded by state DOTs. On the other hand, crashes occurring on off-state highway system do not always get geocoded due to limited resources and techniques. Creating and maintaining a statewide crash geographic information systems (GIS) map with state route and non-state route crashes is a complicated and expensive task. This study introduces an automatic crash mapping process, Crash-Mapping Automation Tool (C-MAT), where an algorithm translates location information from a police report crash record to a geospatial map and creates a pinpoint map for all crashes. The algorithm has approximate 83 percent mapping rate. An important application of this work is the ability to associate the mapped crash records to underlying business data, such as roadway inventory and traffic volumes. The integrated crash map is the foundation for effective and efficient crash analyzes to prevent highway crashes.

  16. On the Design of Simulation System of Intelligent City Taxi Call

    Directory of Open Access Journals (Sweden)

    Xudong Zhu

    2013-06-01

    Full Text Available The city taxi system is characterized as inconvenience information interaction with passengers and regional imbalance. With the development of wireless network technology, VANET can realize the real-time information interaction between taxi and passengers. Thus to conduct reasonable taxi scheduling and improve the efficiency of the taxi system. In order to validate the effectiveness of intelligent call system of city taxi which adopts the wireless network technology, this study provides a taxi control simulation system based on the wireless network, thus to analyze the behavior of vehicles and passengers. The results show that the real-time taxi call system and intelligent scheduling by using the wireless network technology can effectively reduce the not-taken rate and the average waiting time of passengers.

  17. Crash course in readers' advisory

    CERN Document Server

    Orr, Cynthia

    2014-01-01

    One of the key services librarians provide is helping readers find books they'll enjoy. This ""crash course"" will furnish you with the basic, practical information you need to excel at readers' advisory (RA) for adults and teens.

  18. Crash helmets for moped riders.

    NARCIS (Netherlands)

    Noordzij, P.C. & Paar, H.G.

    1975-01-01

    Research has been done into the requirements for crash helmets for moped drivers not only in relation to their comfort but also to their protection. It is stated that any helmet is better than no helmet.

  19. Seatbelt use amongst taxi drivers in Beijing, China.

    Science.gov (United States)

    Passmore, J; Ozanne-Smith, J

    2006-09-01

    Associated with explosive growth in motorization, China has the world's highest road toll with more than 100,000 deaths and 400,000 injuries annually. In response, the Chinese Government introduced the first road traffic safety law in 2003, which included mandatory use of seatbelts by drivers and front seat passengers. Noting frequent non-compliance to this seatbelt regulation by Beijing taxi drivers, the authors studied seatbelt use patterns as onboard observers in a convenience sample of 235 taxi trips. Findings indicated a low seatbelt-wearing rate among taxi drivers of 7.7%, an overt non-wearing rate of 57%, covert non-wearing of 35.3% and total non-compliance of 92.3%. As in high-income countries, adoption of proven safety strategies, including wearing safety restraints, could contribute to reducing the Chinese road toll, particularly as vehicle occupant numbers and the availability of restraints increases. Further investigation of reasons for non-compliance and pretense of wearing seatbelts is required to inform future seatbelt-wearing promotions, including attitudinal studies of taxi drivers. Seatbelt wearing rates should continue to be monitored.

  20. 77 FR 20789 - Work Group on Measuring Systems for Taxis

    Science.gov (United States)

    2012-04-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Institute of Standards and Technology Work Group on Measuring Systems for Taxis AGENCY: National... Standards and Technology (NIST) is forming a Work Group (WG) to develop proposals to revise the...

  1. Het CBb en 'Der digitale Taxi-Krieg'

    NARCIS (Netherlands)

    Westerveld, M.

    2015-01-01

    UberPOP, the taxi service company that claims to be based on the concept of shared economy, offering a positive effect on mobility, environment and usage of energy, in reality confronts us with the question whether we are able to protect 'on demand' workers against exploitation and underpayment. The

  2. The scaling of human mobility by taxis is exponential

    CERN Document Server

    Liang, Xiao; Lv, Weifeng; Zhu, Tongyu; Xu, Ke

    2011-01-01

    As a significant factor in urban planning, traffic forecasting and prediction of epidemics, modeling patterns of human mobility draws intensive attention from researchers for decades. Power-law distribution and its variations are observed from quite a few real-world human mobility datasets such as the movements of banking notes, trackings of cell phone users' locations and trajectories of vehicles. In this paper, we build models for 20 million trajectories with fine granularity collected from more than 10 thousand taxis in Beijing. In contrast to most models observed in human mobility data, the taxis' traveling displacements in urban areas tend to follow an exponential distribution instead of a power-law. Similarly, the elapsed time can also be well approximated by an exponential distribution. Worth mentioning, analysis of the interevent time indicates the bursty nature of human mobility, similar to many other human activities.

  3. Research on the Coordinated Design of Bus and Taxi Station

    Directory of Open Access Journals (Sweden)

    Jiangfeng Xi

    2015-01-01

    Full Text Available Rises in the number of transit buses, bus routes, and overall traffic volume in China’s cities, coupled with interference from other transport modes, such as taxis loading and unloading passengers nearby, have led to increasing traffic delays at bus stops, which is considered one of the factors degrading service levels and traffic operations on urban roadways. This paper studies traffic characteristics at bus stops, investigates variations in delay from different types or designs of bus stops, and analyzes the impact of it on traffic capacity, the purpose of which is to propose a solution to predicting the feasibility of an integrated design of bus stops and taxi stands with the help of mathematical models and based on the objectives of optimal traffic operations and passenger transfer.

  4. Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand

    OpenAIRE

    ISHIMARU, Tomohiro; ARPHORN, Sara; JIRAPONGSUWAN, Ann

    2016-01-01

    In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from par...

  5. Understanding traffic crash under-reporting

    DEFF Research Database (Denmark)

    Janstrup, Kira Hyldekær; Kaplan, Sigal; Hels, Tove;

    2016-01-01

    Objective: This study aligns to the body of research dedicated to estimating the underreporting of road crash injuries and adds the perspective of understanding individual and crash factors contributing to the decision to report a crash to the police, the hospital, or both. Method: This study foc...

  6. The relation between speed and crashes.

    NARCIS (Netherlands)

    2006-01-01

    The exact relation between speed and crashes depends on many factors. However, in a general sense the relation is very clear: if on a road the driven speeds become higher, the crash rate will also increase. The crash rate is also higher for an individual vehicle that drives at higher speed than the

  7. Detecting Traffic Anomalies in Urban Areas Using Taxi GPS Data

    Directory of Open Access Journals (Sweden)

    Weiming Kuang

    2015-01-01

    Full Text Available Large-scale GPS data contain hidden information and provide us with the opportunity to discover knowledge that may be useful for transportation systems using advanced data mining techniques. In major metropolitan cities, many taxicabs are equipped with GPS devices. Because taxies operate continuously for nearly 24 hours per day, they can be used as reliable sensors for the perceived traffic state. In this paper, the entire city was divided into subregions by roads, and taxi GPS data were transformed into traffic flow data to build a traffic flow matrix. In addition, a highly efficient anomaly detection method was proposed based on wavelet transform and PCA (principal component analysis for detecting anomalous traffic events in urban regions. The traffic anomaly is considered to occur in a subregion when the values of the corresponding indicators deviate significantly from the expected values. This method was evaluated using a GPS dataset that was generated by more than 15,000 taxies over a period of half a year in Harbin, China. The results show that this detection method is effective and efficient.

  8. A Mixed Integer Linear Program for Solving a Multiple Route Taxi Scheduling Problem

    Science.gov (United States)

    Montoya, Justin Vincent; Wood, Zachary Paul; Rathinam, Sivakumar; Malik, Waqar Ahmad

    2010-01-01

    Aircraft movements on taxiways at busy airports often create bottlenecks. This paper introduces a mixed integer linear program to solve a Multiple Route Aircraft Taxi Scheduling Problem. The outputs of the model are in the form of optimal taxi schedules, which include routing decisions for taxiing aircraft. The model extends an existing single route formulation to include routing decisions. An efficient comparison framework compares the multi-route formulation and the single route formulation. The multi-route model is exercised for east side airport surface traffic at Dallas/Fort Worth International Airport to determine if any arrival taxi time savings can be achieved by allowing arrivals to have two taxi routes: a route that crosses an active departure runway and a perimeter route that avoids the crossing. Results indicate that the multi-route formulation yields reduced arrival taxi times over the single route formulation only when a perimeter taxiway is used. In conditions where the departure aircraft are given an optimal and fixed takeoff sequence, accumulative arrival taxi time savings in the multi-route formulation can be as high as 3.6 hours more than the single route formulation. If the departure sequence is not optimal, the multi-route formulation results in less taxi time savings made over the single route formulation, but the average arrival taxi time is significantly decreased.

  9. Calidad del servicio de taxis del municipio Maracaibo

    Directory of Open Access Journals (Sweden)

    Joheni A. Urdaneta G.

    2011-05-01

    Full Text Available El presente trabajo tiene como objetivo describir la calidad del servicio de los taxis en el municipio Maracaibo, ya que los mismos forman parte del sistema de transporte urbano de la ciudad, y es un servicio público fundamental para la convivencia de la sociedad; para lograr este objetivo se realizó una adaptación del modelo SERVPERF, diseñando un instrumento tipo cuestionario, con 32 ítems en 6 dimensiones, adecuado a las características propias del servicio de taxi, con la finalidad de confirmar que los ítems de los instrumentos se correspondían con las dimensiones adaptadas se aplicó la técnica de análisis factorial resultando un nuevo instrumento con 24 ítems en 3 dimensiones. Se utilizó la escala de Likert con tres (3 alternativas de respuesta. La investigación es de tipo descriptiva y aplicada, bajo diseño no experimental de tipo transeccional descriptiva y de campo. La población quedó conformada por los usuarios de las líneas de taxis del municipio Maracaibo. Se aplicó muestreo aleatorio por conglomerado. La confiabilidad del instrumento se midió a través del coeficiente alfa de Cronbach resultando de 0,82 lo cual se considera aceptable. Los resultados revelan que la calidad del servicio de taxis del municipio Maracaibo es mediana por lo tanto este servicio es susceptible a mejoras, las cuales son necesarias para elevar la calidad de vida de los marabinos. Este resultado se obtuvo con el instrumento originalmente adaptado de 32 ítems y con el cuestionario resultante del análisis factorial, de 24 ítems; esto confirma lo apropiado de esta técnica, ya que se redujo el número de ítems y de las dimensiones originalmente adaptadas y no se encontraron diferencias significativas en los resultados con ambos instrumentos; de esta manera se puede medir la calidad del servicio de taxis en el municipio Maracaibo a través de las dimensiones: confiabilidad del servicio, socialización y responsabilidad.

  10. Potential Crash Location (PCL) Model

    Science.gov (United States)

    2014-02-05

    LCA ) model provides a method for calculating how large the actual lethal area at the site of impact would be. The LCA model is described in a...helicopter failures. The crash location calculations are just one portion of the TLS tool, the other portion is LCA . Although the LCA is not

  11. Technostress: Surviving a Database Crash.

    Science.gov (United States)

    Dobb, Linda S.

    1990-01-01

    Discussion of technostress in libraries focuses on a database crash at California Polytechnic State University, San Luis Obispo. Steps taken to restore the data are explained, strategies for handling technological accidents are suggested, the impact on library staff is discussed, and a 10-item annotated bibliography on technostress is provided.…

  12. Effect of Accounting for Crash Severity on the Relationship between Mass Reduction and Crash Frequency and Risk per Crash

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, Tom P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Building Technology and Urban Systems Division. Energy Technologies Area

    2016-05-20

    Previous analyses have indicated that mass reduction is associated with an increase in crash frequency (crashes per VMT), but a decrease in fatality or casualty risk once a crash has occurred, across all types of light-duty vehicles. These results are counter-intuitive: one would expect that lighter, and perhaps smaller, vehicles have better handling and shorter braking distances, and thus should be able to avoid crashes that heavier vehicles cannot. And one would expect that heavier vehicles would have lower risk once a crash has occurred than lighter vehicles. However, these trends occur under several alternative regression model specifications. This report tests whether these results continue to hold after accounting for crash severity, by excluding crashes that result in relatively minor damage to the vehicle(s) involved in the crash. Excluding non-severe crashes from the initial LBNL Phase 2 and simultaneous two-stage regression models for the most part has little effect on the unexpected relationships observed in the baseline regression models. This finding suggests that other subtle differences in vehicles and/or their drivers, or perhaps biases in the data reported in state crash databases, are causing the unexpected results from the regression models.

  13. Sleep-related crash characteristics: Implications for applying a fatigue definition to crash reports.

    Science.gov (United States)

    Filtness, A J; Armstrong, K A; Watson, A; Smith, S S

    2017-02-01

    Sleep-related (SR) crashes are an endemic problem the world over. However, police officers report difficulties in identifying sleepiness as a crash contributing factor. One approach to improving the sensitivity of SR crash identification is by applying a proxy definition post hoc to crash reports. To identify the prominent characteristics of SR crashes and highlight the influence of proxy definitions, ten years of Queensland (Australia) police reports of crashes occurring in ≥100km/h speed zones were analysed. In Queensland, two approaches are routinely taken to identifying SR crashes. First, attending police officers identify crash causal factors; one possible option is 'fatigue/fell asleep'. Second, a proxy definition is applied to all crash reports. Those meeting the definition are considered SR and added to the police-reported SR crashes. Of the 65,204 vehicle operators involved in crashes 3449 were police-reported as SR. Analyses of these data found that male drivers aged 16-24 years within the first two years of unsupervised driving were most likely to have a SR crash. Collision with a stationary object was more likely in SR than in not-SR crashes. Using the proxy definition 9739 (14.9%) crashes were classified as SR. Using the proxy definition removes the findings that SR crashes are more likely to involve males and be of high severity. Additionally, proxy defined SR crashes are no less likely at intersections than not-SR crashes. When interpreting crash data it is important to understand the implications of SR identification because strategies aimed at reducing the road toll are informed by such data. Without the correct interpretation, funding could be misdirected. Improving sleepiness identification should be a priority in terms of both improvement to police and proxy reporting.

  14. Effect of electronic stability control on automobile crash risk.

    Science.gov (United States)

    Farmer, Charles

    2004-12-01

    Per vehicle crash involvement rates were compared for otherwise identical vehicle models with and without electronic stability control (ESC) systems. ESC was found to affect single-vehicle crashes to a greater extent than multiple-vehicle crashes, and crashes with fatal injuries to a greater extent than less severe crashes. Based on all police-reported crashes in 7 states over 2 years, ESC reduced single-vehicle crash involvement risk by approximately 41 percent (95 percent confidence limits 3348) and single-vehicle injury crash involvement risk by 41 percent (2752). This translates to an estimated 7 percent reduction in overall crash involvement risk (310) and a 9 percent reduction in overall injury crash involvement risk (314). Based on all fatal crashes in the United States over 3 years, ESC was found to have reduced single-vehicle fatal crash involvement risk by 56 percent (3968). This translates to an estimated 34 percent reduction in overall fatal crash involvement risk (2145).

  15. Re-visiting crash-speed relationships: A new perspective in crash modelling.

    Science.gov (United States)

    Imprialou, Maria-Ioanna M; Quddus, Mohammed; Pitfield, David E; Lord, Dominique

    2016-01-01

    Although speed is considered to be one of the main crash contributory factors, research findings are inconsistent. Independent of the robustness of their statistical approaches, crash frequency models typically employ crash data that are aggregated using spatial criteria (e.g., crash counts by link termed as a link-based approach). In this approach, the variability in crashes between links is explained by highly aggregated average measures that may be inappropriate, especially for time-varying variables such as speed and volume. This paper re-examines crash-speed relationships by creating a new crash data aggregation approach that enables improved representation of the road conditions just before crash occurrences. Crashes are aggregated according to the similarity of their pre-crash traffic and geometric conditions, forming an alternative crash count dataset termed as a condition-based approach. Crash-speed relationships are separately developed and compared for both approaches by employing the annual crashes that occurred on the Strategic Road Network of England in 2012. The datasets are modelled by injury severity using multivariate Poisson lognormal regression, with multivariate spatial effects for the link-based model, using a full Bayesian inference approach. The results of the condition-based approach show that high speeds trigger crash frequency. The outcome of the link-based model is the opposite; suggesting that the speed-crash relationship is negative regardless of crash severity. The differences between the results imply that data aggregation is a crucial, yet so far overlooked, methodological element of crash data analyses that may have direct impact on the modelling outcomes.

  16. Nonlinear Dynamic Analysis of Air Plane Crash shell based on ANSYS/LS-DYNA%基于ANSYS/LS-DYNA的抗飞机撞击结构非线性动力分析

    Institute of Scientific and Technical Information of China (English)

    李忠诚; 黄涛

    2016-01-01

    APC shell is a important barrier of protection agaist Airplane Crash. This paper describes global nonlinear analysis on the 3D-solid APC model embedded with reinforced based on LS-DYNA program. The numerical implementation of large commercial airplane crash is conducted. Dynamic responses and elastoplastic character of APC shell structure are studied. Local effect view with large commercial airplane crash is put forward. The calculation result can provide reference for design of APC shell.%APC壳是核电站抵御飞机撞击的主要屏障,本文运用非线性有限元程序 LS-DYNA 对某核电站燃料厂房APC壳进行了分离式建模,并对大型商用飞机的撞击进行了数值计算,对APC壳的动力响应及弹塑性特性进行了研究分析,提出了大型商用飞机撞击局部效应的观点,为APC 壳的设计计算提供参考。

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

    OpenAIRE

    Yi Liu; Zongzhi Li; Jingxian Liu; Harshingar Patel

    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...

  18. Multifractal analysis of stock exchange crashes

    Science.gov (United States)

    Siokis, Fotios M.

    2013-03-01

    We analyze the complexity of rare events of the DJIA Index. We reveal that the returns of the time series exhibit strong multifractal properties meaning that temporal correlations play a substantial role. The effect of major stock market crashes can be best illustrated by the comparison of the multifractal spectra of the time series before and after the crash. Aftershock periods compared to foreshock periods exhibit richer and more complex dynamics. Compared to an average crash, calculated by taking into account the larger 5 crashes of the DJIA Index, the 1929 event exhibits significantly more increase in multifractality than the 1987 crisis.

  19. AP calculus AB & BC crash course

    CERN Document Server

    Rosebush, J

    2012-01-01

    AP Calculus AB & BC Crash Course - Gets You a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. AP Calculus AB & BC Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know Crash Course is based on an in-depth analysis of the AP Calculus AB & BC course description outline and actual AP test questions. It covers only the information tested on the exams, so you can make the most of your valuable study time. Written by experienced math teachers, our

  20. AP English language & composition crash course

    CERN Document Server

    Hogue, Dawn

    2012-01-01

    AP English Language & Composition Crash Course - Gets You a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. AP English Language & Composition Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know Crash Course is based on an in-depth analysis of the AP English Language & Composition course description outline and actual Advanced Placement test questions. It covers only the information tested on the exam, so you can make the most of your valua

  1. Modeling fault among motorcyclists involved in crashes.

    Science.gov (United States)

    Haque, Md Mazharul; Chin, Hoong Chor; Huang, Helai

    2009-03-01

    Singapore crash statistics from 2001 to 2006 show that the motorcyclist fatality and injury rates per registered vehicle are higher than those of other motor vehicles by 13 and 7 times, respectively. The crash involvement rate of motorcyclists as victims of other road users is also about 43%. The objective of this study is to identify the factors that contribute to the fault of motorcyclists involved in crashes. This is done by using the binary logit model to differentiate between at-fault and not-at-fault cases and the analysis is further categorized by the location of the crashes, i.e., at intersections, on expressways and at non-intersections. A number of explanatory variables representing roadway characteristics, environmental factors, motorcycle descriptions, and rider demographics have been evaluated. Time trend effect shows that not-at-fault crash involvement of motorcyclists has increased with time. The likelihood of night time crashes has also increased for not-at-fault crashes at intersections and expressways. The presence of surveillance cameras is effective in reducing not-at-fault crashes at intersections. Wet-road surfaces increase at-fault crash involvement at non-intersections. At intersections, not-at-fault crash involvement is more likely on single-lane roads or on median lane of multi-lane roads, while on expressways at-fault crash involvement is more likely on the median lane. Roads with higher speed limit have higher at-fault crash involvement and this is also true on expressways. Motorcycles with pillion passengers or with higher engine capacity have higher likelihood of being at-fault in crashes on expressways. Motorcyclists are more likely to be at-fault in collisions involving pedestrians and this effect is higher at night. In multi-vehicle crashes, motorcyclists are more likely to be victims than at-fault. Young and older riders are more likely to be at-fault in crashes than middle-aged group of riders. The findings of this study will help

  2. SemanticTraj: A New Approach to Interacting with Massive Taxi Trajectories.

    Science.gov (United States)

    Al-Dohuki, Shamal; Wu, Yingyu; Kamw, Farah; Yang, Jing; Li, Xin; Zhao, Ye; Ye, Xinyue; Chen, Wei; Ma, Chao; Wang, Fei

    2017-01-01

    Massive taxi trajectory data is exploited for knowledge discovery in transportation and urban planning. Existing tools typically require users to select and brush geospatial regions on a map when retrieving and exploring taxi trajectories and passenger trips. To answer seemingly simple questions such as "What were the taxi trips starting from Main Street and ending at Wall Street in the morning?" or "Where are the taxis arriving at the Art Museum at noon typically coming from?", tedious and time consuming interactions are usually needed since the numeric GPS points of trajectories are not directly linked to the keywords such as "Main Street", "Wall Street", and "Art Museum". In this paper, we present SemanticTraj, a new method for managing and visualizing taxi trajectory data in an intuitive, semantic rich, and efficient means. With SemanticTraj, domain and public users can find answers to the aforementioned questions easily through direct queries based on the terms. They can also interactively explore the retrieved data in visualizations enhanced by semantic information of the trajectories and trips. In particular, taxi trajectories are converted into taxi documents through a textualization transformation process. This process maps GPS points into a series of street/POI names and pick-up/drop-off locations. It also converts vehicle speeds into user-defined descriptive terms. Then, a corpus of taxi documents is formed and indexed to enable flexible semantic queries over a text search engine. Semantic labels and meta-summaries of the results are integrated with a set of visualizations in a SemanticTraj prototype, which helps users study taxi trajectories quickly and easily. A set of usage scenarios are presented to show the usability of the system. We also collected feedback from domain experts and conducted a preliminary user study to evaluate the visual system.

  3. Comparison of teen and adult driver crash scenarios in a nationally representative sample of serious crashes.

    Science.gov (United States)

    McDonald, Catherine C; Curry, Allison E; Kandadai, Venk; Sommers, Marilyn S; Winston, Flaura K

    2014-11-01

    Motor vehicle crashes are the leading cause of death and acquired disability during the first four decades of life. While teen drivers have the highest crash risk, few studies examine the similarities and differences in teen and adult driver crashes. We aimed to: (1) identify and compare the most frequent crash scenarios-integrated information on a vehicle's movement prior to crash, immediate pre-crash event, and crash configuration-for teen and adult drivers involved in serious crashes, and (2) for the most frequent scenarios, explore whether the distribution of driver critical errors differed for teens and adult drivers. We analyzed data from the National Motor Vehicle Crash Causation Survey, a nationally representative study of serious crashes conducted by the U.S. National Highway Traffic Safety Administration from 2005 to 2007. Our sample included 642 16- to 19-year-old and 1167 35- to 54-year-old crash-involved drivers (weighted n=296,482 and 439,356, respectively) who made a critical error that led to their crash's critical pre-crash event (i.e., event that made the crash inevitable). We estimated prevalence ratios (PR) and 95% confidence intervals (CI) to compare the relative frequency of crash scenarios and driver critical errors. The top five crash scenarios among teen drivers, accounting for 37.3% of their crashes, included: (1) going straight, other vehicle stopped, rear end; (2) stopped in traffic lane, turning left at intersection, turn into path of other vehicle; (3) negotiating curve, off right edge of road, right roadside departure; (4) going straight, off right edge of road, right roadside departure; and (5) stopped in lane, turning left at intersection, turn across path of other vehicle. The top five crash scenarios among adult drivers, accounting for 33.9% of their crashes, included the same scenarios as the teen drivers with the exception of scenario (3) and the addition of going straight, crossing over an intersection, and continuing on a

  4. Lt Paul R. Wolff, MC, USNR, saves crewmen during ordeal within collapsed aircraft fuselage after crash.

    Science.gov (United States)

    Leverett, S D

    1985-07-01

    Lt Paul R. Wolff, MC, USNR, is the first to receive Pride and Professionalism recognition for his heroic and professional action while responding to the crash of a Japanese Maritime Self Defense Force PS-1 aircraft. At the time of the crash, Dr. Wolff was assigned as the senior flight surgeon representing the First Marine Aircraft Wing and Naval Regional Medical Center Branch Clinic, Marine Corps Air Station, Iwakuni, Japan. On 26 April, 1983, the aircraft crashed just outside the perimeter of the Marine Corps Air Station. Lt Wolff was the first medical person to arrive at the crash site and immediately took charge of the medical aspects of the rescue. Upon learning that several air-crew members were still trapped inside the smoldering wreckage, he unhesitatingly and with complete disregard for his personal safety while fully aware of the personal dangers involved, entered the wreckage to provide medical care to the injured during a 4-hour period. Lt Wolff's bravery, superlative knowledge, exceptional skills, and outstanding leadership abilities under extremely dangerous circumstances led to saving the lives of three crewmen who were trapped. Below is a narration of the events that took place after the crash and Lt Wolff's medical response in the ensuing hours. It is given by Lt Wolff as he recounts the events.

  5. Sympathetic crashing acute pulmonary edema.

    Science.gov (United States)

    Agrawal, Naman; Kumar, Akshay; Aggarwal, Praveen; Jamshed, Nayer

    2016-12-01

    Sympathetic crashing acute pulmonary edema (SCAPE) is the extreme end of the spectrum of acute pulmonary edema. It is important to understand this disease as it is relatively common in the emergency department (ED) and has better outcomes when managed appropriately. The patients have an abrupt redistribution of fluid in the lungs, and when treated promptly and effectively, these patients will rapidly recover. Noninvasive ventilation and intravenous nitrates are the mainstay of treatment which should be started within minutes of the patient's arrival to the ED. Use of morphine and intravenous loop diuretics, although popular, has poor scientific evidence.

  6. Crash barrier research in the Netherlands.

    NARCIS (Netherlands)

    Flury, F.C. & Paar, H.G.

    1973-01-01

    Research by the SWOV has led to the development of a series of crash barriers of basically the same design but with varying degrees of resistance to lateral deflection. Requirements to which in general a crash barrier should fulfill are presented.

  7. Future of human models for crash analysis

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    In the crash safety field mathematical models can be applied in practically all area's of research and development including: reconstruction of actual accidents, design (CAD) of the crash response of vehicles, safety devices and roadside facilities and in support of human impact biomechanical studie

  8. Advances in numerical modelling of crash dummies

    NARCIS (Netherlands)

    Verhoeve, R.; Kant, R.; Margerie, L.

    2001-01-01

    Nowadays virtual testing and prototyping are generally accepted methods in crash safety research and design studies. Validated numerical crash dummy models are necessary tools in these methods. Computer models need to be robust, accurate and CPU efficient, where the balance between accuracy and effi

  9. Action plan pre-crash evaluation

    NARCIS (Netherlands)

    Bartels, O.; Langner, T.; Aparicio, A.; Lemmen, P.; Rodarius, C.

    2010-01-01

    This deliverable “Action plan pre-crash evaluation” forms the starting point of WP4 pre-crash evaluation. This document mainly is the outcome of a two days workshop held at BASt. It is strongly linked to the WP1.1 results that came up with data concerning the accident situation on European roads. WP

  10. Increasing influenza vaccination in New York City taxi drivers: A community driven approach.

    Science.gov (United States)

    Gany, Francesca; Rau-Murthy, Rohini; Mujawar, Imran

    2015-05-21

    The Healthy People 2020 influenza immunization goal is 80% for non-institutionalized adults 18-64. However, vaccination rates remain stubbornly low. Culturally tailored approaches to communities with poor vaccine uptake are necessary. Taxi drivers are at risk for influenza and its complications, could serve as vectors for influenza infection, and could be an effective vaccination target to enhance herd immunity of the urban population. To the best of our knowledge, this is the first study related to influenza vaccination among taxi drivers. The NYC Taxi Network surveyed a convenience sample of 53 taxi drivers to understand vaccination barriers. Only 17% had been vaccinated. Results informed a pilot tailored workplace intervention, which resulted in vaccinations for 44% of unvaccinated drivers. The study revealed that older drivers were more likely to be vaccinated than younger drivers, while the most common barrier to immunization was that drivers thought vaccination was 'not necessary'.

  11. Les aspects matériels de la taxis byzantine The material aspects of the Byzantine taxis

    Directory of Open Access Journals (Sweden)

    Marie‑France Auzépy

    2008-06-01

    Full Text Available La taxis grecque – correspondant exact de l’ordo latin – est un aspect essentiel de la civilisation byzantine : elle organise cette société de manière à ce que celle-ci soit un reflet aussi exact que possible de la société céleste, décrite en particulier par Denys l’Aréopagite. La taxis est donc à la fois précise et contraignante et nous a été transmise dans des livres décrivant le protocole : le De Cerimoniis au Xe siècle, le Traité du pseudo-Kodinos au XIVe siècle. Au cours de cérémonies où tous les aspects matériels – l’habit, la couronne, le trône, les acclamations à la gloire de l’empereur, l’orgue qui les accompagne, les gestes accomplis par l’empereur comme par ceux qui l’entourent – ont un sens, l’Empire byzantin affirme ainsi son équilibre et sa qualité de peuple élu. Jusqu’en 1204, les autres nations ont jalousé la qualité que s’était octroyée l’Empire romain d’Orient : celle d’image de la cour céleste, qui est figurée dans le cérémonial. Cette jalousie a pris d’autres formes après 1453, et l’on s’intéressera aux souverains européens qui, tel Louis XIV, ont voulu faire figure d’héritiers de l’empire défunt et relever ses cérémonies.The Greek taxis(order– the exact equivalent of the Latin ordo – is an essential aspect of Byzantine civilization: it organized society in such a way that it would reflect the celestial society as closely as possible, as has been described by Dionysius the Areopagite. The taxis is therefore both precise and restrictive and has been passed down to us through writings describing the protocol: the De Cerimoniis in the tenth century and the treatise of Pseudo-Kodinos in the fourteenth century. Through ceremonies in which all the material aspects have a meaning – the dress, the crown, the throne, the proclaiming of the glory of the emperor, the accompanying organ, the gestures of the emperor and of those around

  12. A Mobile, Dynamic, and Privacy-Preserving Matching System for Car and Taxi Pools

    Directory of Open Access Journals (Sweden)

    Shin-Yan Chiou

    2014-01-01

    Full Text Available Recently, rates of vehicle ownership have risen globally, exacerbating problems including air pollution, lack of parking, and traffic congestion. While many solutions to these problems have been proposed, carpooling remains one of the most effective approaches. Recently, several carpooling platforms have been built on cloud computing systems, with originators posting online list of departure/arrival points and schedules from which participants can search for rides that match their needs. However, it can be difficult to make matches quickly and the systems are subject to privacy concerns in that they may disclose private information such as names, registration data, and departure/arrival schedules. This paper proposes a dynamic matching method for car/taxi pools for use in mobile devices via ad hoc Wi-Fi networks. The proposed method also preserves user privacy including names and departure/arrival schedules. Moreover, the system does not require the user to register any personal data, so such data cannot be leaked. The system was implemented on the Android mobile platform, allowing users to immediately and securely access the system via their smart phones.

  13. Weather Conditions, Weather Information and Car Crashes

    Directory of Open Access Journals (Sweden)

    Adriaan Perrels

    2015-11-01

    Full Text Available Road traffic safety is the result of a complex interaction of factors, and causes behind road vehicle crashes require different measures to reduce their impacts. This study assesses how strongly the variation in daily winter crash rates associates with weather conditions in Finland. This is done by illustrating trends and spatiotemporal variation in the crash rates, by showing how a GIS application can evidence the association between temporary rises in regional crash rates and the occurrence of bad weather, and with a regression model on crash rate sensitivity to adverse weather conditions. The analysis indicates that a base rate of crashes depending on non-weather factors exists, and some combinations of extreme weather conditions are able to substantially push up crash rates on days with bad weather. Some spatial causation factors, such as variation of geophysical characteristics causing systematic differences in the distributions of weather variables, exist. Yet, even in winter, non-spatial factors are normally more significant. GIS data can support optimal deployment of rescue services and enhance in-depth quantitative analysis by helping to identify the most appropriate spatial and temporal resolutions. However, the supportive role of GIS should not be inferred as existence of highly significant spatial causation.

  14. Taxi Time Prediction at Charlotte Airport Using Fast-Time Simulation and Machine Learning Techniques

    Science.gov (United States)

    Lee, Hanbong

    2016-01-01

    Accurate taxi time prediction is required for enabling efficient runway scheduling that can increase runway throughput and reduce taxi times and fuel consumptions on the airport surface. Currently NASA and American Airlines are jointly developing a decision-support tool called Spot and Runway Departure Advisor (SARDA) that assists airport ramp controllers to make gate pushback decisions and improve the overall efficiency of airport surface traffic. In this presentation, we propose to use Linear Optimized Sequencing (LINOS), a discrete-event fast-time simulation tool, to predict taxi times and provide the estimates to the runway scheduler in real-time airport operations. To assess its prediction accuracy, we also introduce a data-driven analytical method using machine learning techniques. These two taxi time prediction methods are evaluated with actual taxi time data obtained from the SARDA human-in-the-loop (HITL) simulation for Charlotte Douglas International Airport (CLT) using various performance measurement metrics. Based on the taxi time prediction results, we also discuss how the prediction accuracy can be affected by the operational complexity at this airport and how we can improve the fast time simulation model before implementing it with an airport scheduling algorithm in a real-time environment.

  15. Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Liyong Niu

    2015-01-01

    Full Text Available Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly.

  16. Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization.

    Science.gov (United States)

    Niu, Liyong; Zhang, Di

    2015-01-01

    Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly.

  17. 49 CFR 238.403 - Crash energy management.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Crash energy management. 238.403 Section 238.403... Equipment § 238.403 Crash energy management. (a) Each power car and trailer car shall be designed with a crash energy management system to dissipate kinetic energy during a collision. The crash...

  18. CDC Vital Signs: Motor Vehicle Crash Injuries: Costly but Preventable

    Science.gov (United States)

    ... crashes, and how to prevent future crashes. Problem Motor vehicle crashes are a leading cause of injury in the US—harmful and expensive. What works to prevent crash injuries? Using primary enforcement seat belt laws that cover everyone in the car. A primary enforcement law means a police officer ...

  19. Forensic aspects of the highway crash.

    Science.gov (United States)

    Gikas, P W

    1983-01-01

    It can be stated that patterns of injury in highway crashes can often be related to specific design and damage features of the vehicle. The restraint systems designed to attenuate injury may also, under severe crash circumstances, produce trauma. Problems may arise as to identification of vehicular drivers. It behooves the pathologist concerned with the necropsy of crash victims and the physician responsible for treating crash victims to become familiar with the pathogenesis of injuries. Such knowledge can be utilized in the recommendation for improvement of vehicles to render them more crashworthy. Awareness of the various mechanisms of injury in vehicle crashes also enhances the diagnostic skill of the initial treating physician when he or she is confronted with a crash victim in the emergency department. Ideally, when the victim arrives at the hospital, the emergency room physician should be supplied with the details of the crash including the type of vehicle, position within the vehicle, use or nonuse of restraint systems, and the direction of the impact. When a fatality results from a car crash, ideally the autopsy pathologist should inspect the vehicle or at least view pictures of the exterior and interior of the vehicle to help establish the pathogenesis of injury in a specific collision. Unfortunately, because of time constraints, this ideal is not always achieved. Because of the considerable volume of civil and criminal litigation resulting from highway crashes, there is a need for competent medical expertise to help both the plaintiff and the defendent. The pathologist involved in forensic work and the treating physician play a particularly important role in the judicial arena.

  20. Post-crash fuel dispersal

    Energy Technology Data Exchange (ETDEWEB)

    Tieszen, S.R.

    1997-03-01

    This paper is a brief overview of work over the last several decades in understanding what occurs to jet fuel stored in aircraft fuel tanks on impact with the ground. Fuel dispersal is discussed in terms of the overall crash dynamics process and impact regimes are identified. In a generic sense, the types of flow regimes which can occur are identified and general descriptions of the processes are given. Examples of engineering level tools, both computational and experimental, which have applicability to analyzing the complex environments are presented. Finally, risk based decision is discussed as a quick means of identifying requirements for development of preventative or mitigation strategies, such as further work on the development of an anti-misting agent.

  1. Factors Contributing to Crashes among Young Drivers

    Directory of Open Access Journals (Sweden)

    Lyndel J. Bates

    2014-08-01

    Full Text Available Young drivers are the group of drivers most likely to crash. There are a number of factors that contribute to the high crash risk experienced by these drivers. While some of these factors are intrinsic to the young driver, such as their age, gender or driving skill, others relate to social factors and when and how often they drive. This article reviews the factors that affect the risk of young drivers crashing to enable a fuller understanding of why this risk is so high in order to assist in developing effective countermeasures.

  2. Factors Contributing to Crashes among Young Drivers.

    Science.gov (United States)

    Bates, Lyndel J; Davey, Jeremy; Watson, Barry; King, Mark J; Armstrong, Kerry

    2014-08-01

    Young drivers are the group of drivers most likely to crash. There are a number of factors that contribute to the high crash risk experienced by these drivers. While some of these factors are intrinsic to the young driver, such as their age, gender or driving skill, others relate to social factors and when and how often they drive. This article reviews the factors that affect the risk of young drivers crashing to enable a fuller understanding of why this risk is so high in order to assist in developing effective countermeasures.

  3. Reduced fertility after the crash of a U.S. bomber carrying nuclear weapons?

    DEFF Research Database (Denmark)

    Juel, K

    1995-01-01

    A register-based study was performed to elucidate whether workers employed on the Thule air base in the clean-up period after the crash of a U.S. B-52 bomber carrying nuclear bombs had reduced fertility, as measured by the numbers of liveborn children. The highest birth rates were among 25-34-year...

  4. Braking News: the Link between Crash Severity and Crash Avoidance Maneuvers

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    avoidance maneuvers and crash severity, with differences emerging for different critical events. Moreover, results show two trends: (i) most drivers fail to act when facing critical events, and (ii) drivers rarely perform crash avoidance maneuvers that are correlated with higher probability of lower crash...... severity. These trends suggest that effort should be posed toward understanding the reaction mechanisms to different critical events, improving in-vehicle warning systems, promoting responsible driving behavior, and designing forgiving infrastructures....

  5. A multinomial-logit ordered-probit model for jointly analyzing crash avoidance maneuvers and crash severity

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    the United States National Automotive Sampling System General Estimates System (GES) crash database for the years 2005-2009. Results show (i) the correlation between crash avoidance maneuvers and crash severity, and (ii) the link between drivers' attributes, risky driving behavior, road characteristics......Effective crash avoidance maneuvers in response to critical unexpected traffic events provide the opportunity to avoid crash occurrence and to minimize crash severity. The current study employs a joint multinomial-logit ordered-probit model (MNL-OR) for associating crash severity with drivers...

  6. Syncope and Motor Vehicle Crash Risk

    DEFF Research Database (Denmark)

    Numé, Anna-Karin; Gislason, Gunnar; Christiansen, Christine B

    2016-01-01

    IMPORTANCE: Syncope may have serious consequences for traffic safety. Current clinical guideline recommendations on driving following syncope are primarily based on expert consensus. OBJECTIVE: To identify whether there is excess risk of motor vehicle crashes among patients with syncope compared...... identified 41 039 individuals with a first-time diagnosis of syncope from emergency department or hospital. MAIN OUTCOMES AND MEASURES: Rate of motor vehicle crashes (including nonfatal and fatal crashes), based on multivariate Poisson regression models, using the total Danish population as reference....... RESULTS: The 41 039 patients with syncope had a median age of 66 years (interquartile range [IQR], 47-78 years); 51.0% were women; and 34.8% had cardiovascular disease. Through a median follow-up of 2.0 years (IQR, 0.8-3.3 years), 1791 patients with syncope (4.4%) had a motor vehicle crash, 78.1% of which...

  7. Association of Some Environmental Factors with Breath Carbon Monoxide Levels of Some Taxi Drivers in Ankara

    Directory of Open Access Journals (Sweden)

    Oguz Baran

    2010-12-01

    Full Text Available AIM: Taxi drivers are among the occupational groups with the highest smoking prevalence and exposure to carbon monoxide (CO. This study aimed to measure breath CO levels of some taxi drivers working in Ankara and to find out some associated factors (if any. METHOD: The descriptive study was carried out with 173 taxi drivers from 14 different taxi stations in the center of Ankara. Data was collected by face to face interviews with a standart questionnaire, while breath CO was measured by a Pi-CO Smokerlyser. Descriptive statistics were used to summarize data, whereas chi-square, independant samples t-test and One-Way ANOVA were used to compare groups by SPSS 15.0 statistical package programme. RESULTS: In the study, all of the taxi drivers (n=173 were male with a mean age of 39.2±9.6 years. Of the drivers, 58.4% were current smokers, whereas 75.1% were exposed to enviromental tobacco smoke. The frequency of indoor smoking in the taxi stations, taxis and drivers’ homes were 48.0%, 45.1%, and 59.0%, respectively. The mean breath CO level of the drivers was 16.9±12.8 ppm. CO level was positively associated with the current smoking status, total years of smoking, number of cigarettes smoked per day and passive exposure to tobacco smoke, whereas the association was negative with the elapsed time from the last cigarette smoked (p0.05. CONCLUSION: Results of the study provide evidence in support of the previous literature that smoking is one of the most important sources of carbonmonoxide. Interventions such as awareness raising trainings, referral of smokers willing to quit smoking to smoking cessation centers and screening programmes for smoking related diseases are needed to be implemented in collaboration with the relevant drivers’ associations. [TAF Prev Med Bull 2010; 9(6.000: 591-596

  8. Occupational and environmental exposure of garage workers and taxi drivers to airborne manganese arising from the use of methylcyclopentadienyl manganese tricarbonyl in unleaded gasoline.

    Science.gov (United States)

    Zayed, J; Gérin, M; Loranger, S; Sierra, P; Bégin, D; Kennedy, G

    1994-01-01

    Occupational and environmental exposure to airborne manganese has been measured for two groups of workers in Montreal, taxi drivers and garage mechanics. In Canada methylcyclopentadienyl manganese tricarbonyl (MMT) has replaced lead as an anti-knock agent in gasoline and represents a potentially important source of manganese contamination for the population in general and for the two chosen groups of workers in particular. Twenty workers (10 taxi drivers and 10 garage mechanics) wore a personal air sampler for five consecutive working days and two off-work periods. The amount of total Mn on each filter was determined by neutron activation analysis and then converted to atmospheric Mn concentrations. The values obtained varied from 0.004 microgram m-3 to 2.067 micrograms m-3. At work the garage mechanics were exposed to an average of 0.250 microgram m-3 and the taxi drivers to 0.024 microgram m-3. Off-work, the two groups were exposed respectively to an average of 0.007 microgram m-3 and 0.011 microgram m-3. In the garages there was twice as much Mn in the air on days when the doors were closed compared to days when they were left opened (0.314 micrograms m-3/0.152 microgram m-3). The levels found in this study remain well below the established limits for occupational and environmental airborne exposure. These results will lead to further studies to positively identify the source of Mn as MMT and to explore other pathways leading to the contamination of the general population.

  9. Collective human mobility pattern from taxi trips in urban area

    KAUST Repository

    Peng, Chengbin

    2012-04-18

    We analyze the passengers\\' traffic pattern for 1.58 million taxi trips of Shanghai, China. By employing the non-negative matrix factorization and optimization methods, we find that, people travel on workdays mainly for three purposes: commuting between home and workplace, traveling from workplace to workplace, and others such as leisure activities. Therefore, traffic flow in one area or between any pair of locations can be approximated by a linear combination of three basis flows, corresponding to the three purposes respectively. We name the coefficients in the linear combination as traffic powers, each of which indicates the strength of each basis flow. The traffic powers on different days are typically different even for the same location, due to the uncertainty of the human motion. Therefore, we provide a probability distribution function for the relative deviation of the traffic power. This distribution function is in terms of a series of functions for normalized binomial distributions. It can be well explained by statistical theories and is verified by empirical data. These findings are applicable in predicting the road traffic, tracing the traffic pattern and diagnosing the traffic related abnormal events. These results can also be used to infer land uses of urban area quite parsimoniously. 2012 Peng et al.

  10. Study the epidemiological profile of taxi drivers in the background of occupational environment, stress and personality characteristics

    Directory of Open Access Journals (Sweden)

    Mukesh Suresh Bawa

    2013-01-01

    Full Text Available Background: Work hazards have been a major cause of concern in driving industry especially in taxi drivers. This study integrates the various factors that influence physical and emotional well-being of taxi drivers into the theoretical model that shows that the work environment, stress and personality characteristics directly influence taxi drivers′ health. Objective: The aim of the following study is to study the relative and combined influence of work environment, personality characteristics and stress on the health of taxi drivers. Meterials and Methods: The present study is cross-sectional (descriptive study taxi drivers in Mumbai. They are selected using multistage random sampling method. Calculated sample size is 508. Data produced after the survey is analyzed using IBM SPSS 16.0 software. Results: Nearly 65% of taxi drivers belonged to middle-age group of 21-40 years of age. Majority (59% of taxi drivers belonged to the lower upper socio-economic class. 70% of taxi drivers worked for more than 8 h daily. 63% gave the history of one or more addictions. 52% taxi drivers had type B1 personality, only 6% had stress prone and aggressive type A1 personality. Traffic congestion (67.1% was reported as the leading stressor followed by narrow bottle neck roads (43%, too many speed breakers (41%, rude gestures and behavior by other drivers (42% and bad weather (36%. Nearly 86% taxi drivers had one or more symptoms of morbidities. Gastrointestinal symptoms predominated followed by musculoskeletal symptoms and depression. Conclusion: Socio-demographic attributes, work environment, stress and personality significantly influence physical and psychological morbidities in taxi drivers.

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

    Science.gov (United States)

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

    2016-09-01

    This article contains data on research conducted in "A double standard model for allocating limited emergency medical service vehicle resources ensuring service reliability" (Liu et al., 2016) [1]. The crash counts were sorted out from comprehensive crash records of over one thousand major signalized intersections in the city of Chicago from 2004 to 2010. For each intersection, vehicular crashes were counted by crash severity levels, including fatal, injury Types A, B, and C for major, moderate, and minor injury levels, property damage only (PDO), and unknown. The crash data was further used to rank intersections by equivalent injury crash frequency. The top 200 intersections with the highest number of crash occurrences identified based on crash frequency- and severity-based scenarios are shared in this brief. The provided data would be a valuable source for research in urban traffic safety analysis and could also be utilized to examine the effectiveness of traffic safety improvement planning and programming, intersection design enhancement, incident and emergency management, and law enforcement strategies.

  12. 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.

  13. Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand.

    Science.gov (United States)

    Ishimaru, Tomohiro; Arphorn, Sara; Jirapongsuwan, Ann

    2016-10-08

    In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from participant health check-up files. Self-administered questionnaires assessed demographics, driving mileage, working hours, and lifestyle. Statistical associations were analyzed using stepwise linear regression. Our results showed that obesity (p=0.007), daily alcohol drinking (p=0.003), and current or past smoking (p=0.016) were associated with higher HCT levels. While working hours were not directly associated with HCT levels in the current study, the effect on overworking is statistically arguable because most participants worked substantially longer hours. Our findings suggest that taxi drivers' CVD risk may be increased by their unhealthy work styles. Initiatives to improve general working conditions for taxi drivers should take into account health promotion and CVD prevention. The policy of providing periodic health check-ups is important to make workers in the informal sector aware of their health status.

  14. Gasoline prices and their relationship to drunk-driving crashes.

    Science.gov (United States)

    Chi, Guangqing; Zhou, Xuan; McClure, Timothy E; Gilbert, Paul A; Cosby, Arthur G; Zhang, Li; Robertson, Angela A; Levinson, David

    2011-01-01

    This study investigates the relationship between changing gasoline prices and drunk-driving crashes. Specifically, we examine the effects of gasoline prices on drunk-driving crashes in Mississippi by several crash types and demographic groups at the monthly level from 2004 to 2008, a period experiencing great fluctuation in gasoline prices. An exploratory visualization by graphs shows that higher gasoline prices are generally associated with fewer drunk-driving crashes. Higher gasoline prices depress drunk-driving crashes among young and adult drivers, among male and female drivers, and among white and black drivers. Results from negative binomial regression models show that when gas prices are higher, there are fewer drunk-driving crashes, particularly among property-damage-only crashes. When alcohol consumption levels are higher, there are more drunk-driving crashes, particularly fatal and injury crashes. The effects of gasoline prices and alcohol consumption are stronger on drunk-driving crashes than on all crashes. The findings do not vary much across different demographic groups. Overall, gasoline prices have greater effects on less severe crashes and alcohol consumption has greater effects on more severe crashes.

  15. Analyzing the Value of Location Information for Four Taxi Dispatching Modes

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Location-based service (LBS) is often quoted as one of the killer applications of mobile commerce. The LBS, especially the GPS dispatching system, is often adopted by taxi operators for fleet management, but there is no theoretical analysis on the real value of location information for dispatching services. This paper presents four types of dispatching modes and how location information is obtained and used to support dispatching services. Then the Pros and Cons of different taxi dispatching modes were compared. It is concluded that different mode fits different situations, no one overwhelms all situation, even if the GPS-based dispatching mode. The value of the GPS-based dispatching service then was further analyzed through the case study of DaZhong Company in Shanghai, China. The results show that the use of the up-to-date GPS technology radically changes the traditional approaches to taxi dispatching and enables companies to enhance customers'satisfaction.

  16. Revealing daily travel patterns and city structure with taxi trip data

    CERN Document Server

    Liu, Xi; Gong, Yongxi; Liu, Yu

    2013-01-01

    Detecting regional spatial structures based on spatial interactions is crucial in applications ranging from urban planning to traffic control. In the big data era, various movement trajectories are available for studying spatial structures. This research uses large scale Shanghai taxi trip data extracted from GPS-enabled taxi trajectories to reveal traffic flow patterns and urban structure of the city. Using the network science methods, 15 temporally stable regions reflecting the scope of people's daily travels are found using community detection method on the network built from short trips, which represent residents' daily intra-urban travels and exhibit a clear pattern. In each region, taxi traffic flows are dominated by a few 'hubs' and 'hubs' in suburbs impact more trips than 'hubs' in urban areas. Land use conditions in urban regions are different from those in suburban areas. Additionally, 'hubs' in urban area associate with office buildings and commercial areas more, whereas residential land use is mor...

  17. Predicting crash risk and identifying crash precursors on Korean expressways using loop detector data.

    Science.gov (United States)

    Kwak, Ho-Chan; Kho, Seungyoung

    2016-03-01

    In order to improve traffic safety on expressways, it is important to develop proactive safety management strategies with consideration for segment types and traffic flow states because crash mechanisms have some differences by each condition. The primary objective of this study is to develop real-time crash risk prediction models for different segment types and traffic flow states on expressways. The mainline of expressways is divided into basic segment and ramp vicinity, and the traffic flow states are classified into uncongested and congested conditions. Also, Korean expressways have irregular intervals between loop detector stations. Therefore, we investigated on the effect and application of the detector stations at irregular intervals for the crash risk prediction on expressways. The most significant traffic variables were selected by conditional logistic regression analysis which could control confounding factors. Based on the selected traffic variables, separate models to predict crash risk were developed using genetic programming technique. The model estimation results showed that the traffic flow characteristics leading to crashes are differed by segment type and traffic flow state. Especially, the variables related to the intervals between detector stations had a significant influence on crash risk prediction under the uncongested condition. Finally, compared with the single model for all crashes and the logistic models used in previous studies, the proposed models showed higher prediction performance. The results of this study can be applied to develop more effective proactive safety management strategies for different segment types and traffic flow states on expressways with loop detector stations at irregular intervals.

  18. A study to maximize the crash energy absorption efficiency within the limits of crash space

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bae Young; Jeong, Choong Min; Suh, Myung Won [Sungkyunkwan University, Suwon (Korea, Republic of); Kim, Si Woo [Korea Automobile Testing and Research Institute, Hwaseong (Korea, Republic of)

    2012-04-15

    The design of an engine room is important to protect the passenger from a crash impact by improving the absorption of the crash impact energy. The side member in the engine room absorbs most of the crash impact energy when the vehicle experiences a frontal crash. The side member is of two types: hat and 'U.' Analysis of the extent of energy absorption and the mechanism of the side member are necessary through a collapse mode in various load conditions. In this study, the design of experiments was used for evaluating the characteristics of the absorption of crash energy by side members through design variables. First, crash analysis was performed by experiment number extracted from the design of the experiment. Then, using the results of crash analysis, multiple regressions were conducted and sensitivity analysis performed for each design variable. Finally, the optimum design was developed for maximizing the absorption energy per unit weight considering various boundary conditions. In the present study, as a basic step for modeling the fatigue behavior of an extruded Al alloy cylinder, the fatigue crack growth data of the alloy was collected in two orientations. Microstructural analysis revealed that the material had recrystallized grains and clusters of constituent particles aligned in the direction of extrusion. Fatigue life of the samples revealed a shorter fatigue life representing a higher fatigue crack growth rate in the transverse direction.

  19. Opioids No Better Than Ibuprofen for Pain After Car Crash

    Science.gov (United States)

    ... Car Crash: Study But more patients prescribed powerful painkillers were still taking them 6 weeks later To ... persistent pain after a car crash, prescription opioid painkillers such as oxycodone (Oxycontin) are no more effective ...

  20. Adaptive Seat Energy Absorbers for Enhanced Crash Safety: Technology Demonstration

    Science.gov (United States)

    2016-08-01

    ARL-TR-7743 ● AUG 2016 US Army Research Laboratory Adaptive Seat Energy Absorbers for Enhanced Crash Safety: Technology...AUG 2016 US Army Research Laboratory Adaptive Seat Energy Absorbers for Enhanced Crash Safety: Technology Demonstration by Muthuvel...COVERED (From - To) 10 January 2012–29 February 2016 4. TITLE AND SUBTITLE Adaptive Seat Energy Absorbers for Enhanced Crash Safety: Technology

  1. Development of a speeding-related crash typology.

    NARCIS (Netherlands)

    Council, F.M. Srinivasan, R. Masten, S. Carter, C. & Reurings, M.

    2010-01-01

    The Highway Safety Information System has released a the summary of a report that examined recent crash data through the development of a speeding-related crash typology, which is designed to help define the crash, vehicle, and driver characteristics that seem to result in a higher probability of sp

  2. Simulation of an offset crash for tibia index evaluation

    NARCIS (Netherlands)

    Mugnai, A.; Burke, G.

    2000-01-01

    In 1996, the European Community released new regulations relating to frontal impact vehicle crash. One of the tests, the European offset crash, consists of crashing the car on a deformable barrier at 56 km/h with 40% of the car impacting on the barrier. The regulations require the dummy injury param

  3. 49 CFR 563.10 - Crash test performance and survivability.

    Science.gov (United States)

    2010-10-01

    ... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.10 Crash test... 49 Transportation 6 2010-10-01 2010-10-01 false Crash test performance and survivability. 563.10... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of...

  4. 14 CFR 29.952 - Fuel system crash resistance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system crash resistance. 29.952... crash resistance. Unless other means acceptable to the Administrator are employed to minimize the hazard...) Separation of fuel and ignition sources. To provide maximum crash resistance, fuel must be located as far...

  5. 14 CFR 27.952 - Fuel system crash resistance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system crash resistance. 27.952... crash resistance. Unless other means acceptable to the Administrator are employed to minimize the hazard...) Separation of fuel and ignition sources. To provide maximum crash resistance, fuel must be located as far...

  6. Research on Strategy Control of Taxi Carpooling Detour Route under Uncertain Environment

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2016-01-01

    Full Text Available For the problem of route choice in taxi carpooling detour, considering the uncertainty of traffic and the characteristic of passengers’ noncomplete rationality, an evolutionary game model of taxi carpooling detour route is built, in which prospect theory is introduced and revenue of strategy is replaced by prospect value. The model reflects more really decision-making psychology of passengers. Then the stable strategies of the model are studied, and the influences of detour distance and traffic congestion on detour carpooling success are analyzed, respectively. The results show that when at least one route of which prospect values for two passenger sides are both positive exists, carpooling route can reach an agreement. The route is stable strategy of evolutionary game, and the passengers requiring short travel time tend to select the nondetour route. With the increase of detour distance and traffic congestion rate, the possibility of reaching an agreement decreases gradually; that is, possibility of carpooling failure increases. So taxi carpooling detour is possible under the certain condition, but some measures must be carried out such as constraints of detour distance and mitigation of traffic congestion to improve carpooling success probability. These conclusions have a certain guiding significance to the formulation of taxi carpooling policy.

  7. [Association between psychosocial aspects of work and quality of life among motorcycle taxi drivers].

    Science.gov (United States)

    Teixeira, Jules Ramon Brito; Boery, Eduardo Nagib; Casotti, Cezar Augusto; Araújo, Tânia Maria de; Pereira, Rafael; Ribeiro, Ícaro José Santos; Rios, Marcela Andrade; Amorim, Camila Rego; Moreira, Ramon Missias; Boery, Rita Narriman Silva de Oliveira; Sales, Zenilda Nogueira

    2015-01-01

    This study aimed to evaluate the quality of life of motorcycle taxi drivers and the association with psychosocial characteristics of their work. This was a cross-sectional epidemiological study with a sample of 400 motorcycle taxi drivers in Jequié, Bahia State, Brazil. The study used a form containing demographic and socioeconomic data, WHO Quality of Life-Bref Questionnaire (WHOQOL-Bref), and the Job Content Questionnaire (JCQ). Motorcycle taxi drivers with greater decision-making control over their work showed better self-rated quality of life in the psychological domain; those with high psychological demands presented better self-rated quality of life in the social relations and environmental domains; those with high strain and active work showed better self-rated quality of life in the social and environmental domains. The psychosocial work environment and especially decision-making autonomy were thus important determinants of self-rated quality of life in this group of motorcycle taxi drivers.

  8. Energy Taxis Drives Campylobacter jejuni toward the Most Favorable Conditions for Growth

    DEFF Research Database (Denmark)

    Vegge, C.S.; Brondsted, L.; Li, Yiping

    2009-01-01

    Campylobacter jejuni is a serious food-borne bacterial pathogen in the developed world. Poultry is a major reservoir, and C. jejuni appears highly adapted to the gastrointestinal tract of birds. Several factors are important for chicken colonization and virulence, including a taxis mechanism...

  9. Institutional statism: an overview of the formulation of the taxi recapitalisation policy

    Directory of Open Access Journals (Sweden)

    D. van Schalkwyk

    2008-07-01

    Full Text Available This article provides an overview of the government’s formulation of the taxi recapitalisation policy which is aimed at regulating the minibus taxi industry. Coupled with a brief social and politico-historical context of the policy, the aim is to highlight the government’s statist conduct in the formulation of the recapitalisation policy. The minibus taxi industry started to fulfil a prominent role in the 1970s as a result of a loophole in the legislation of the former apartheid government. It is currently the most accessible mode of public transport and conveys 65 per cent of the country’s commuters daily. Consequently, the Industry is an imperative force to be considered by the government in its formulation of transport policies. However, the industry is characterised by numerous problems, including a high rate of minibus taxis involved in accidents, unroadworthy vehicles and violence. It is in this context that the government formulated both the original and revised versions of the recapitalisation policy. However, the formulation of the policy has been problematic. The government followed a statist approach during the formulation process when it directed the course of the process according to its interests and without adequate consultation with relevant role players.

  10. Vital Signs-Motor Vehicle Crash Injuries

    Centers for Disease Control (CDC) Podcasts

    2014-10-07

    This podcast is based on the October 2014 CDC Vital Signs report. Motor vehicle crashes are costly and preventable. Learn what can be done to help prevent motor vehicle injuries.  Created: 10/7/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/7/2014.

  11. Vehicle dynamics and crash dynamics with minicomputer.

    NARCIS (Netherlands)

    Giavotto, V. Puccinelli, L. Borri, M. Edelman, A. & Heijer, T.

    1982-01-01

    The definition and the development of the VEDYAC system is given. Following a previous large experience concerning the simulation of crashes with safety barriers, a basic philosophy has been developed and the requirements of the VEDYAC project have been fixed. The main features of the VEDYAC project

  12. Motor Vehicle Crash Injuries PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2014-10-07

    This 60 second Public Service Announcement is based on the October 2014 CDC Vital Signs report. Motor vehicle crashes are costly and preventable. Learn what can be done to help prevent motor vehicle injuries.  Created: 10/7/2014 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 10/7/2014.

  13. CRASH3: cosmological radiative transfer through metals

    CERN Document Server

    Graziani, L; Ciardi, B

    2012-01-01

    Here we introduce CRASH3, the latest release of the 3D radiative transfer code CRASH. In its current implementation CRASH3 integrates into the reference algorithm the code Cloudy to evaluate the ionisation states of metals, self-consistently with the radiative transfer through H and He. The feedback of the heavy elements on the calculation of the gas temperature is also taken into account, making of CRASH3 the first 3D code for cosmological applications which treats self-consistently the radiative transfer through an inhomogeneous distribution of metal enriched gas with an arbitrary number of point sources and/or a background radiation. The code has been tested in idealized configurations, as well as in a more realistic case of multiple sources embedded in a polluted cosmic web. Through these validation tests the new method has been proven to be numerically stable and convergent. We have studied the dependence of the results on a number of physical quantities such as the source characteristics (spectral range...

  14. Evolution of taxis responses in virtual bacteria: non-adaptive dynamics.

    Directory of Open Access Journals (Sweden)

    Richard A Goldstein

    2008-05-01

    Full Text Available Bacteria are able to sense and respond to a variety of external stimuli, with responses that vary from stimuli to stimuli and from species to species. The best-understood is chemotaxis in the model organism Escherichia coli, where the dynamics and the structure of the underlying pathway are well characterised. It is not clear, however, how well this detailed knowledge applies to mechanisms mediating responses to other stimuli or to pathways in other species. Furthermore, there is increasing experimental evidence that bacteria integrate responses from different stimuli to generate a coherent taxis response. We currently lack a full understanding of the different pathway structures and dynamics and how this integration is achieved. In order to explore different pathway structures and dynamics that can underlie taxis responses in bacteria, we perform a computational simulation of the evolution of taxis. This approach starts with a population of virtual bacteria that move in a virtual environment based on the dynamics of the simple biochemical pathways they harbour. As mutations lead to changes in pathway structure and dynamics, bacteria better able to localise with favourable conditions gain a selective advantage. We find that a certain dynamics evolves consistently under different model assumptions and environments. These dynamics, which we call non-adaptive dynamics, directly couple tumbling probability of the cell to increasing stimuli. Dynamics that are adaptive under a wide range of conditions, as seen in the chemotaxis pathway of E. coli, do not evolve in these evolutionary simulations. However, we find that stimulus scarcity and fluctuations during evolution results in complex pathway dynamics that result both in adaptive and non-adaptive dynamics depending on basal stimuli levels. Further analyses of evolved pathway structures show that effective taxis dynamics can be mediated with as few as two components. The non-adaptive dynamics

  15. Minibus taxi drivers’ sexual beliefs and practices associated with HIV infection and AIDS in KwaZulu- Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Busisiwe Ncama

    2013-01-01

    Full Text Available Risky sexual behaviours in South Africa are a major contributing factor to the spread of HIV infection and AIDS. HIV infection amongst minibus taxi drivers is a concern, because these people belong to an occupational group that exhibits risky behaviours due to the demands of their work. Given the high vulnerability of minibus taxi drivers, exploring the sexual beliefs and health-related sexual practices of this group will assist in planning targeted interventions.The objectives of this study were to assess the level of knowledge, beliefs and practices regarding HIV infection and AIDS amongst minibus taxi drivers. An exploratory descriptive study was conducted using a pre-tested questionnaire to explore and describe sexual beliefs and practices associated with HIV infection and AIDS in a convenience sample of 175 minibus taxi drivers. Permission to undertake the study was obtained from the KwaZulu-Natal Taxi Alliance and individuals who participated in the study. Data analysis were analysed using the Statistical Package for Social Sciences 13.0. The study revealed that minibus taxi drivers are one of the high- risk groups in the spread of HIV infection and AIDS; they lack necessary education and need attention in relation to control and prevention of the spread of HIV and AIDS. Multiple sexual partners are relatively common amongst the minibus taxi drivers. Violence against women and even forceful sexual intercourse in the belief that women should tolerate it to keep the family together was reported. There is a need for intervention programmes with a focus on minibus taxi drivers and similar high-risk groups. Prevention activities should incorporate the distribution of condoms amongst this group and HIV prevention educational programmes, as well as creating mechanisms for accessing circumcision by the minibus taxi drivers.

  16. How similar are two-unit bicycle and motorcycle crashes?

    Science.gov (United States)

    Haworth, Narelle; Debnath, Ashim Kumar

    2013-09-01

    This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation.

  17. Defining and screening crash surrogate events using naturalistic driving data.

    Science.gov (United States)

    Wu, Kun-Feng; Jovanis, Paul P

    2013-12-01

    Naturalistic driving studies provide an excellent opportunity to better understand crash causality and to supplement crash observations with a much larger number of near crash events. The goal of this research is the development of a set of diagnostic procedures to define, screen, and identify crash and near crash events that can be used in enhanced safety analyses. A way to better understand crash occurrence and identify potential countermeasures to improve safety is to learn from and use near crash events, particularly those near crashes that have a common etiology to crash outcomes. This paper demonstrates that a multi-stage modeling framework can be used to search through naturalistic driving data, extracting statistically similar crashes and near crashes. The procedure is tested using data from the VTTI 100-car study for road departure events. A total of 63 events are included in this application. While the sample size is limited in this empirical study, the authors believe the procedure is ready for testing in other applications.

  18. Survivors’ experiences from a train crash

    Directory of Open Access Journals (Sweden)

    Rebecca Forsberg

    2011-11-01

    Full Text Available Rarely described are people's lived experiences from severe injury events such as train crashes. The number of train crashes named disasters with ≥10 killed and/or ≥100 nonfatally injured grows globally and the trend shows that more people survive these disasters today than did so in the past. This results in an increased number of survivors needing care. The aim of the study was to explore survivors’ experiences from a train crash. Narrative interviews were performed with 14 passengers 4 years after a train crash event. Qualitative content analysis was used to analyse the interviews. Experiences were captured in three main themes: (1 Living in the mode of existential threat describes how the survivors first lost control, then were thrown into a state of unimaginable chaos as they faced death. (2 Dealing with the unthinkable described how survivors restored control, the central role of others, and the importance of reconstructing the event to move forward in their processing. (3 Having cheated death shows how some became shackled by their history, whereas others overcame the haunting of unforgettable memories. Furthermore, the result shows how all experienced a second chance in life. Experiencing a train crash meant that the passengers experienced severe vulnerability and a threat to life and interdependence turned out to play a crucial role. Focusing on helping other passengers on site was one way to regain the loss of control and kept the chaos at bay. Family, friends, and fellow passengers turned out to be extremely important during the recovery process why such closeness should be promoted and facilitated.

  19. Factors associated with crash severity on rural roadways in Wyoming

    Directory of Open Access Journals (Sweden)

    Debbie S. Shinstine

    2016-08-01

    Full Text Available The ability to identify risk factors associated with crashes is critical to determine appropriate countermeasures for improving roadway safety. Many studies have identified risk factors for urban systems and intersections, but few have addressed crashes on rural roadways, and none have analyzed crashes on Indian Reservations. This study analyzes crash severity for rural highway systems in Wyoming. These rural systems include interstates, state highways, rural county local roads, and the roadway system on the Wind River Indian Reservation (WRIR. In alignment with the Wyoming strategic highway safety goal of reducing critical crashes (fatal and serious injury, crash severity was treated as a binary response in which crashes were classified as severe or not severe. Multiple logistic regression models were developed for each of the highway systems. Five effects were prevalent on all systems including animals, driver impairment, motorcycles, mean speed, and safety equipment use. With the exception of animal crashes, all of these effects increased the probability that a crash would be severe. Based upon these results, DOTs can pursue effective policies and targeted design decisions to reduce the severity of crashes on rural highways.

  20. 手机打车软件的法律思考%Legal Reflections on Mobile Phone Taxi Software

    Institute of Scientific and Technical Information of China (English)

    孙道锐; 牛梦婧

    2014-01-01

    手机打车软件符合国家政策且合乎情理,应允予使用。为规避不具营运资格的驾驶员,应加强手机软件提供方与客运管理机构之间的合作,着力保障乘客的平等议价权,出租车驾驶员载客期间的抢客行为违反法律,应当竭力避免。%Taxi mobile phone software used in taxis conforms to state policy and its use is not illegal . To avoid unqualified taxi drivers'illegal actions , we should strengthen the cooperation between software providers and passenger transportation management institutions and safeguard passengers'equal bargaining power . The robbery conducted by taxi-drivers is illegal and should be avoided .

  1. 浅谈健康发展出租车市场之路%Healthy Development of Taxi Market

    Institute of Scientific and Technical Information of China (English)

    李艳卿

    2011-01-01

    今年来出租车客运市场迅猛发展.随着出租车数量的不断增大,各种矛盾也都不断显现出来,严重制约了出租车市场的发展.应从建立出租市场公平,公正、公开竞争的格局、改变出租公司运作方式等方面考虑健康发展出租车市场.%Taxi market has grown rapidly in recent year. With the increasing number of taxis, all kinds of contradictions have been apparent, which has seriously hampered the development of the taxi market. We should establish healthy developing taxi market from establishing a fair, just and open competitive landscape, changing the mode of operation and other aspects.

  2. The seismography of crashes in financial markets

    Science.gov (United States)

    Araújo, Tanya; Louçã, Francisco

    2008-01-01

    This Letter investigates the dynamics of stocks in the S&P500 for the last 33 years, considering the population of all companies present in the index for the whole period. Using a stochastic geometry technique and defining a robust index of the dynamics of the market structure, which is able to provide information about the intensity of the crises, the Letter proposes a seismographic classification of the crashes that occurred during the period. The index is used in order to investigate and to classify the impact of the thirteen crashes between July 1973 and March 2006 and to discuss the available evidence of change of structure after the fin de siècle.

  3. Survey of NASA research on crash dynamics

    Science.gov (United States)

    Thomson, R. G.; Carden, H. D.; Hayduk, R. J.

    1984-01-01

    Ten years of structural crash dynamics research activities conducted on general aviation aircraft by the National Aeronautics and Space Administration (NASA) are described. Thirty-two full-scale crash tests were performed at Langley Research Center, and pertinent data on airframe and seat behavior were obtained. Concurrent with the experimental program, analytical methods were developed to help predict structural behavior during impact. The effects of flight parameters at impact on cabin deceleration pulses at the seat/occupant interface, experimental and analytical correlation of data on load-limiting subfloor and seat configurations, airplane section test results for computer modeling validation, and data from emergency-locator-transmitter (ELT) investigations to determine probable cause of false alarms and nonactivations are assessed. Computer programs which provide designers with analytical methods for predicting accelerations, velocities, and displacements of collapsing structures are also discussed.

  4. Model for Incomplete Reconnection in Sawtooth Crashes

    CERN Document Server

    Beidler, Matthew T

    2011-01-01

    A model for incomplete reconnection in sawtooth crashes is presented. The reconnection inflow during the crash phase of sawteeth self-consistently convects the high pressure core toward the reconnection site, raising the pressure gradient there. Reconnection shuts off if the diamagnetic drift speed at the reconnection site exceeds a threshold, which may explain incomplete reconnection. The relaxation of magnetic shear after reconnection stops may explain the destabilization of ideal interchange instabilities reported previously. Proof-of-principle two-fluid simulations confirm this basic picture. Predictions of the model compare favorably to data from the Mega Ampere Spherical Tokamak. Applications to transport modeling of sawteeth are discussed. The results should apply across tokamaks, including ITER.

  5. Model for incomplete reconnection in sawtooth crashes.

    Science.gov (United States)

    Beidler, M T; Cassak, P A

    2011-12-16

    A model for incomplete reconnection in sawtooth crashes is presented. The reconnection inflow during the crash phase of sawteeth self-consistently convects the high pressure core toward the reconnection site, raising the pressure gradient there. Reconnection shuts off if the diamagnetic drift speed at the reconnection site exceeds a threshold, which may explain incomplete reconnection. The relaxation of magnetic shear after reconnection stops may explain the destabilization of ideal interchange instabilities reported previously. Proof-of-principle two-fluid simulations confirm this basic picture. Predictions of the model compare favorably to data from the Mega Ampere Spherical Tokamak. Applications to transport modeling of sawteeth are discussed. The results should apply across tokamaks, including ITER.

  6. Global existence of solutions and uniform persistence of a diffusive predator-prey model with prey-taxis

    Science.gov (United States)

    Wu, Sainan; Shi, Junping; Wu, Boying

    2016-04-01

    This paper proves the global existence and boundedness of solutions to a general reaction-diffusion predator-prey system with prey-taxis defined on a smooth bounded domain with no-flux boundary condition. The result holds for domains in arbitrary spatial dimension and small prey-taxis sensitivity coefficient. This paper also proves the existence of a global attractor and the uniform persistence of the system under some additional conditions. Applications to models from ecology and chemotaxis are discussed.

  7. Motor Vehicle Crash Deaths PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2016-07-06

    This 60 second public service announcement is based on the July 2016 CDC Vital Signs report. In the U.S., about 90 people die in motor vehicle crashes each day and thousands more are injured, resulting in hundreds of millions of dollars in direct medical costs each year. Learn what you can do to stay safe.  Created: 7/6/2016 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 7/6/2016.

  8. Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

    Science.gov (United States)

    Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

    2013-12-01

    Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.

  9. Video event data recording of a taxi driver used for diagnosis of epilepsy

    Directory of Open Access Journals (Sweden)

    Kotaro Sakurai

    2014-01-01

    Full Text Available A video event data recorder (VEDR in a motor vehicle records images before and after a traffic accident. This report describes a taxi driver whose seizures were recorded by VEDR, which was extremely useful for the diagnosis of epilepsy. The patient was a 63-year-old right-handed Japanese male taxi driver. He collided with a streetlight. Two years prior to this incident, he raced an engine for a long time while parked. The VEDR enabled confirmation that the accidents depended on an epileptic seizure and he was diagnosed with symptomatic localization-related epilepsy. The VEDR is useful not only for traffic accident evidence; it might also contribute to a driver's health care and road safety.

  10. Relation between workplace accidents and the levels of carboxyhemoglobin in motorcycle taxi drivers

    Directory of Open Access Journals (Sweden)

    Luiz Almeida da Silva

    2013-09-01

    Full Text Available OBJECTIVE: to investigate the relation between workplace accidents and the levels of carboxyhemoglobin found in motorcycle taxi drivers. METHOD: correlational, quantitative study involving 111 workers and data obtained in July 2012 through a questionnaire to characterize the participants and blood collection to measure carboxyhemoglobin levels. RESULT: 28.8% had suffered workplace accidents; 27.6% had fractured the lower limbs and significant symptoms of carbon monoxide exposure were verified in smokers. The carboxyhemoglobin levels were higher among smokers and victims of workplace accidents. CONCLUSION: motorcycle taxi drivers had increased levels of carboxyhemoglobin, possibly due to the exposure to carbon monoxide; these levels are also increased among smokers and victims of workplace accidents. The study provides advances in the knowledge about occupational health and environmental science, and also shows that carboxyhemoglobin can be an indicator of exposure to environmental pollutants for those working outdoors, which can be related to workplace accidents.

  11. Crash Rates of Quebec Drivers with Medical Conditions

    OpenAIRE

    Dow, Jamie; Gaudet, Michel; Turmel, Émilie

    2013-01-01

    Using a databank that combines comprehensive medical data with the driving records of 96% of the drivers in Quebec, odds ratios were calculated for crash risk involving death or serious injury according to the diagnosis of medical conditions traditionally associated with increased crash risk. Results were controlled for age, sex, residence (rural/urban), possession of a professional licence (classes 1 – 4), previous involvement in a crash with injury or death and for the presence of other med...

  12. 基于藤Copula-MCMC-SV-T模型的马航空难对六国(地)股指的风险传染研究%A Study on Risk Contagion from Malaysia Airlines Air Crashes to the Stock Indices of Six Countries(Regions)Based on the Model of Vine Copula-MCMC-SV-T

    Institute of Scientific and Technical Information of China (English)

    韩超; 严太华

    2016-01-01

    The two air crashes of MH370 and MH17 in 2014 caused people anxiety in the world. Anxiety passed from Malaysia Airlines plane crashes to the world conflict,the conflict leads to panics. Panics caused‘long-short’investing by abnormal be⁃havior in stock markets,stimulate stock market risk,the risk spill over from Kuala Lumpur and spread to the world. This paper depicts the volatility processes of six-dimensional marginal stock indices with the model of SV-T,inferred marginal model pa⁃rameters by using Gibbs sampling method of MCMC algorithm in Bayesian,and described the path diagram of risk contagion of six stock indices in the world in the structure of canonical vine copula,represented four different types of risk contagion by four common types of copula functions,used corresponding value of tau to represent the parameters of corresponding risk con⁃tagion,and finally described the risk contagion path and the risk magnitude from Kuala Lumpur to the world. This paper tried to provide a new idea or method for investors to make‘long and short’decision when facing emergencies and for various au⁃thorities to grasp the path of crisis contagion,reduce the risk of chain reaction and cut chain of risk contagion.%2014年马航MH370和MH17两次空难,引发世界人民的焦虑。焦虑从马航空难直指世界矛盾冲突,矛盾冲突导致恐慌。恐慌引起股市多空异常行为,引发股市风险,风险从吉隆坡传出,向世界蔓延。论文以SV-T模型刻画六维边缘股指波动进程,以MCMC算法的Gibbs抽样方法贝叶斯推断出边缘模型参数,以C藤Copula结构描述世界六国(地)股指风险传染路径图,以四种常见类型的Copula函数代表四种不同的风险传染类型,以相应的Copula函数Tau值表示风险传染参数,最终描绘出空难引起的危机从吉隆坡向世界蔓延的脉络和风险强度。论文尝试为投资者面对突发事件时进行多、空投资决策,以

  13. Accesibilidad en el transporte público en Valladolid ferrocarril, autobús y taxi

    OpenAIRE

    Díez Peña, Mª Begoña; Herrero Rodríguez, Sonia

    2015-01-01

    El objetivo de este trabajo es conocer la medida en la que se cumple la normativa de accesibilidad al transporte público en la ciudad de Valladolid, en concreto ferrocarril, autobús y taxi, no sólo en el sentido estricto de la normativa sino también desde el punto de vista de la autonomía de una persona con discapacidad física.

  14. The Taxi Driver Found His Long-lost Son(高一适用)

    Institute of Scientific and Technical Information of China (English)

    孙伟玲

    2002-01-01

    A taxi driver has found the son he last saw 34 years ago --as a fare in the back of his cab. The chance of reunion came when Barry Bagshaw, 61,picked up a fare at a motel near Brighton in southern England. A short panying the man in the back found the driver's identity and noticed he had the same surname as her boyfriend.

  15. Using the Crowd of Taxis to Last Mile Delivery in E-commerce: a Methodological Research

    OpenAIRE

    Chen, Chao; Pan, Shenle

    2015-01-01

    International audience; Crowdsourcing is garnering increased attention in freight transport area, mainly applied in internet-based services to city logistics. However, scientific research, especially methodology for application is still rare in the literature. This paper aims to fill this gap and to propose a methodological approach of applying crowdsourcing solution to Last Mile Delivery in E-commerce environment. The proposed solution is based on taxi fleet in city and a transport network c...

  16. Externality of risk and crash severity at roundabouts.

    Science.gov (United States)

    Daniels, Stijn; Brijs, Tom; Nuyts, Erik; Wets, Geert

    2010-11-01

    The severity of 1491 crashes on 148 roundabouts in Flanders-Belgium was examined in order to investigate which factors might explain the severity of crashes or injuries and to relate these factors to the existing knowledge about contributing factors for injury severity in traffic. Logistic regression and hierarchical binomial logistic regression techniques were used. A clear externality of risk appeared to be present in the sense that vulnerable road user groups (pedestrians, bicyclists, moped riders and motorcyclists) are more severely affected than others. Fatalities or serious injuries in multiple-vehicle crashes for drivers of four-wheel vehicles are much rarer. Injury severity increases with higher age. Crashes at night and crashes outside built-up areas are more severe. Single-vehicle crashes seem to have more severe outcomes than multiple-vehicle crashes. However, systematic differences in the reporting rate of crashes are likely to exist and may have affected the stated results. Correlations with important, but unobserved variables like the impact speeds in the crashes might exist as well and could provide an alternative explanation for some results.

  17. 非正规出租车存在下的出租车合理规模研究%Reasonable Taxi Scale Based on Existence of Unregistered Taxi

    Institute of Scientific and Technical Information of China (English)

    张丰焰

    2015-01-01

    现有的出租车合理规模是根据出租车分担率计算得出的,但分担率在调查过程中受抽样比例、调查方式等因素的影响而存在较大误差,而且现有的出租车规模计算模型均未考虑非正规出租车分担了部分客运需求的事实,导致规模计算结果普遍偏低。为减少计算偏差,采用全数调查的方法,并结合出租车计价器的原始数据,直接测定出租车的日均载客人次、运营次数及单次载客人数等指标,提出在出租车有效行驶里程计算模型中不再考虑出租车分担率指标;基于非正规出租车客观存在而引入了非正规出租车承运比例指标,建立基于供需平衡的现时出租车合理保有量计算修正模型。最后通过实证分析验证了修正后的模型是合理和实用的,有利于抑制非正规出租车非法营运和城市出租车行业的健康发展。%The existing reasonable taxi scale was calculated according to the taxi share ratio. However, the taxi share ratio typically had large deviation due to the influence of sampling rate and survey method in the survey process. In addition, the fact that the unregistered taxi took some shares of market was not considered in the existing model for calculating the taxi scale. As a result, the calculated taxi scale was lower than that it should be. To reduce the deviation, combined with the original data of taxi fare meter, a full-data survey method was adopted, to investigate the daily passenger capacity, operating frequency, and average passengers on board. An effective taxi mileage calculation model which did not need to con⁃sider the taxi share rate was proposed. Due to the existence of unregistered taxi, the share of unregistered taxi was used to establish the revised reasonable taxi scale calculation model based on the balance of supply and demand. At last, through a case study, it is demonstrated that the revised model is reasonable and applicable

  18. Coordinated Charging Strategy for Electric Taxis in Temporal and Spatial Scale

    Directory of Open Access Journals (Sweden)

    Yuqing Yang

    2015-02-01

    Full Text Available Currently, electric taxis have been deployed in many cities of China. However, the charging unbalance in both temporal and spatial scale has become a rising problem, which leads to low charging efficiency or charging congestion in different stations or time periods. This paper presents a multi-objective coordinated charging strategy for electric taxis in the temporal and spatial scale. That is, the objectives are maximizing the utilization efficiency of charging facilities, minimizing the load unbalance of the regional power system and minimizing the customers’ cost. Besides, the basic configuration of a charging station and operation rules of electric taxis would be the constraints. To tackle this multi-objective optimizing problems, a fuzzy mathematical method has been utilized to transfer the multi-objective optimization to a single optimization issue, and furthermore, the Improved Particle Swarm Optimization (IPSO Algorithm has been used to solve the optimization problem. Moreover, simulation cases are carried out, Case 1 is the original charging procedure, and Cases 2 and 3 are the temporal and spatial scale optimized separately, followed with Case 4, the combined coordinated charging. The simulation shows the significant improvement in charging facilities efficiency and users’ benefits, as well as the better dispatching of electric taxis’ charging loads.

  19. Taxi ! méthode de français : niveau 3

    CERN Document Server

    Johnson, Anne-Marie

    2004-01-01

    Taxi ! 3 est une méthode interactive, qui développe non seulement les connaissances, mais aussi les savoir-faire et les savoir-être de l'apprenant, à l'écrit comme à l'oral. La méthode est très simple à utiliser : une leçon = une double page. Taxi ! 3 couvre le niveau Bl du Cadre européen commun de référence pour l'apprentissage, l'enseignement et l'évaluation des langues. La méthode permet de se préparer aux épreuves A3 et A4 du DELF 1er degré. Une progression et des contenus fonctionnels et langagiers solides permettent à l'apprenant d'atteindre rapidement une autonomie en français dans des situations de la vie courante. Taxi ! 3 permet de mieux connaître la France d'aujourd'hui et les comportements des Français à travers une grande variété de documents authentiques (écrit et audio).

  20. Association knowledge for fatal run-off-road crashes by Multiple Correspondence Analysis

    Directory of Open Access Journals (Sweden)

    Subasish Das

    2016-03-01

    Results of the MCA method can help researchers select the most effective crash countermeasures. Further work on the degree of association between the identified crash contributing factors can help safety management systems develop the most efficient crash reduction strategies.

  1. Crash protection of stock car racing drivers--application of biomechanical analysis of Indy car crash research.

    Science.gov (United States)

    Melvin, John W; Begeman, Paul C; Faller, Ronald K; Sicking, Dean L; McClellan, Scott B; Maynard, Edwin; Donegan, Michael W; Mallott, Annette M; Gideon, Thomas W

    2006-11-01

    Biomechanical analysis of Indy car crashes using on-board impact recorders (Melvin et al. 1998, Melvin et al. 2001) indicates that Indy car driver protection in high-energy crashes can be achieved in frontal, side, and rear crashes with severities in the range of 100 to 135 G peak deceleration and velocity changes in the range of 50 to 70 mph. These crashes were predominantly single-car impacts with the rigid concrete walls of oval tracks. This impressive level of protection was found to be due to the unique combination of a very supportive and tight-fitting cockpit-seating package, a six-point belt restraint system, and effective head padding with an extremely strong chassis that defines the seat and cockpit of a modern Indy car. In 2000 and 2001, a series of fatal crashes in stock car racing created great concern for improving the crash protection for drivers in those racecars. Unlike the Indy car, the typical racing stock car features a more spacious driver cockpit due to its resemblance to the shape of a passenger car. The typical racing seat used in stock cars did not have the same configuration or support characteristics of the Indy car seat, and five-point belt restraints were used. The tubular steel space frame chassis of a stock car also differs from an Indy car's composite chassis structure in both form and mechanical behavior. This paper describes the application of results of the biomechanical analysis of the Indy car crash studies to the unique requirements of stock car racing driver crash protection. Sled test and full-scale crash test data using both Hybrid III frontal crash anthropomorphic test devices (ATDs) and BioSID side crash ATDs for the purpose of evaluating countermeasures involving restraint systems, seats and head/neck restraints has been instrumental in guiding these developments. In addition, the development of deformable walls for oval tracks (the SAFER Barrier) is described as an adjunct to improved occupant restraint through control

  2. The Effect of Working Conditions to the Health Status in Taxi and Bus Drivers in Canakkale, Turkey; Community Based Study

    Directory of Open Access Journals (Sweden)

    Aysegul Uludag

    2016-04-01

    Full Text Available Aim: The growing taxi and bus driver workforce is at risk for poor health status, obesity, hypertension, metabolic syndrome and with increased risk for cardiovascular disease. We aimed to determine the relationship between working conditions and health status in taxi and bus drivers. Material and Method: This study is a descriptive study. The population of the study was taxi and bus drivers in central of Canakkale. There were total 250 taxi and bus drivers who registered in The Chamber of Canakkale Drivers and Vehicle. We reached the 70 taxi drivers and 93 bus drivers. The participants were visited at their workplace. We performed the questionnaire that include the socio-demografic features, habits, the working conditions. We evaluated the blood pressure, waist-hip measurements and capillary blood glucose at any time. Results: Total of the 163 men drivers were enrolled the study. Nine (12.9% taxi drivers and 6 (6.5% bus drivers were hipertensive, and 1 taxi driver and 2 bus drivers with random capillary blood glucose levels higher than 200 mg. The prevalence of hypertension was 9.2%, diabetes mellitus was 1.8, obesity was 49.4%. Discussion: Drivers have many risk factors for CVD like stress and immobility. In our study, the socio-demografic and working conditions are limited for explaining the risk for hipertension, diabetes mellitus and obesity in drivers in Canakkale. These study have to be done in metropolitan cities. In this aspect, the drivers can be evaluated in their own living spaces and working conditions.

  3. Sawtooth crashes at high beta on JET

    Energy Technology Data Exchange (ETDEWEB)

    Alper, B.; Huysmans, G.T.A.; Sips, A.C.C. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Nave, M.F.F. [Universidade Tecnica, Lisbon (Portugal). Inst. Superior Tecnico

    1994-07-01

    The sawtooth crashes on JET display features which depend on beta. The main observation is a transient bulging of flux surfaces (duration inferior to 30 microsec.), which is predominantly on the low field side and extends to larger radii as beta increases. This phenomenon reaches the plasma boundary when beta{sub N} exceeds 0.5 and in these cases is followed by an ELM within 50 microsec. These sawtooth/ELM events limit plasma performance. Modelling of mode coupling shows qualitative agreement between observations of the structure of the sawtooth precursor and the calculated internal kink mode at high beta. (authors). 6 refs., 5 figs.

  4. Effects of Manufacturing Process in Crash Simulations

    Directory of Open Access Journals (Sweden)

    Šašek J.

    2010-07-01

    Full Text Available This article describes an impact of a manufacturing, which can significantly change real parts behavior. The influence of technology process is neglected in regular simulations. However, advanced finite elements solvers make possible to involve themanufacturing process in final simulations. It brings distortions and initial distribution of stress and strain into simulations. The possibilities are demonstrated on a crash simulation of a simple box-beam, where stamping and welding processes and spring-back are considered. All mentioned operations are performed in Virtual Performance Solution. The effects of manufacturing process are discussed with a respect to common simulation practice at the end of the paper.

  5. Comparison of Multivariate Poisson lognormal spatial and temporal crash models to identify hot spots of intersections based on crash types.

    Science.gov (United States)

    Cheng, Wen; Gill, Gurdiljot Singh; Dasu, Ravi; Xie, Meiquan; Jia, Xudong; Zhou, Jiao

    2017-02-01

    Most of the studies are focused on the general crashes or total crash counts with considerably less research dedicated to different crash types. This study employs the Systemic approach for detection of hotspots and comprehensively cross-validates five multivariate models of crash type-based HSID methods which incorporate spatial and temporal random effects. It is anticipated that comparison of the crash estimation results of the five models would identify the impact of varied random effects on the HSID. The data over a ten year time period (2003-2012) were selected for analysis of a total 137 intersections in the City of Corona, California. The crash types collected in this study include: Rear-end, Head-on, Side-swipe, Broad-side, Hit object, and Others. Statistically significant correlations among crash outcomes for the heterogeneity error term were observed which clearly demonstrated their multivariate nature. Additionally, the spatial random effects revealed the correlations among neighboring intersections across crash types. Five cross-validation criteria which contains, Residual Sum of Squares, Kappa, Mean Absolute Deviation, Method Consistency Test, and Total Rank Difference, were applied to assess the performance of the five HSID methods at crash estimation. In terms of accumulated results which combined all crash types, the model with spatial random effects consistently outperformed the other competing models with a significant margin. However, the inclusion of spatial random effect in temporal models fell short of attaining the expected results. The overall observation from the model fitness and validation results failed to highlight any correlation among better model fitness and superior crash estimation.

  6. Life-threatening motor vehicle crashes in bright sunlight.

    Science.gov (United States)

    Redelmeier, Donald A; Raza, Sheharyar

    2017-01-01

    Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight.This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later.The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9-24, P vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash.

  7. Traffic crash liability determination: Danger and Dodge model.

    Science.gov (United States)

    Xu, Sikui; Huang, Helai

    2016-10-01

    By proposing a systematic set of rules for traffic crash liability determination, this paper attempts to prove the feasibility and practicability of legal liability in handling traffic crashes. Two sequential elements are identified for crash occurrence, i.e., the occurrence of a dangerous situation and failure in dodging the dangerous situation. A Danger and Dodge model is subsequently established for liability determination in a traffic crash. By investigating the basic mechanism of a crash occurrence, the specific contents of causalties and the effect of the parties' acts in traffic crashes are specified. Based on the theories of social adequancy, the principle of reliance and the duty of care, the study further proposes to use the "peril" of a dangerous situation and the "possibility" of dodging the dangerous situation to appraise the effect of the parties' acts upon a crash occurrence, with the rule of the "pattern deciding effect". The proposed approach would be very helpful to the concreteness of the determination of liability in a traffic crash. Two case studies are presented for demonstration.

  8. Signal balancing by the CetABC and CetZ chemoreceptors controls energy taxis in Campylobacter jejuni.

    Directory of Open Access Journals (Sweden)

    Mark Reuter

    Full Text Available The coupling of environmental sensing to flagella-mediated directed motility allows bacteria to move to optimum environments for growth and survival, either by sensing external stimuli (chemotaxis or monitoring internal metabolic status (energy taxis. Sensing is mediated by transducer-like proteins (Tlp, either located in the membrane or in the cytoplasm, which commonly influence motility via the CheA-CheY chemotaxis pathway. In this study we have investigated the role of PAS-domain-containing intracellular Tlp-sensors in energy taxis of the food-borne pathogen Campylobacter jejuni, using plate- and tube-based assays utilising the conversion of the redox indicator dyes triphenyl tetrazolium chloride (TTC and resazurin. Inactivation of the genes encoding the Campylobacter Energy Taxis system (CetA (Tlp9 and CetB (Aer2 in C. jejuni strain NCTC 11168 resulted in reduced taxis. Inactivation of the cj1191c gene, encoding the CetB homolog CetC (Aer1, did not affect taxis per se, but the cetC gene complemented a cetB mutant in trans, indicating that CetC can form a functional signal transduction complex with CetA in the absence of CetB. Inactivation of both CetB and CetC resulted in greatly reduced taxis confirming the role of CetC in energy taxis. Inactivation of the cj1110c gene, encoding Tlp8 (CetZ, a cytoplasmic sensor with two PAS-domains, resulted in increased taxis, a phenotype opposite to that of CetAB. Inactivation of the cheA gene resulted in the same overall phenotype as the cetAB mutant in both wild-type and cetZ backgrounds, suggesting that both systems use the CheA system for signal transduction. Absence of both CetAB and CetZ resulted in the cetAB taxis phenotype, suggesting that CetZ is subordinate to CetAB. In conclusion, we present evidence that C. jejuni balances the input from two counteracting PAS-domain-containing sensory systems to position itself for optimal usage of energy resources.

  9. Commuting and communication: An investigation of taxi drivers’ experiences, attitudes and beliefs about passengers with communication disorders

    Directory of Open Access Journals (Sweden)

    Sianne Green

    2015-02-01

    Full Text Available Background: One of the most popular means of public transport within South Africa is mini-bus taxis.Objectives: As South Africa is made up of diverse cultures, religions and beliefs, the aim of this study was to explore Johannesburg based taxi drivers’ experiences of beliefs about, and attitudes towards passengers who have a communication disability.Method: Semi-structured interviews were conducted with 10 mini-bus taxi drivers.Results: Interviews revealed that almost all the taxi drivers had encountered passengers with a communication disability, and had an awareness of passengers with a hearing disability as opposed to a speech disability. Furthermore mini-bus taxi drivers generally held a positive view of their passengers with a communication disability.Conclusion: Study findings contribute to existing literature within the fields of speech pathology and audiology, advocacy groups and policy makers, particularly research studies on participation experiences of persons with communication disabilities related to transportation access. The results of the study should also provide a foundation for disability policy development initiatives with the aim of increasing levels of public awareness.[Full article text to follow.

  10. Rayleigh-Taylor instability simulations with CRASH

    Science.gov (United States)

    Chou, C.-C.; Fryxell, B.; Drake, R. P.

    2012-03-01

    CRASH is a code package developed for the predictive study of radiative shocks. It is based on the BATSRUS MHD code used extensively for space-weather research. We desire to extend the applications of this code to the study of hydrodynamically unstable systems. We report here the results of Rayleigh-Taylor instability (RTI) simulations with CRASH, as a necessary step toward the study of such systems. Our goal, motivated by the previous comparison of simulations and experiment, is to be able to simulate the magnetic RTI with self-generated magnetic fields produced by the Biermann Battery effect. Here we show results for hydrodynamic RTI, comparing the effects of different solvers and numerical parameters. We find that the early-time behavior converges to the analytical result of the linear theory. We observe that the late-time morphology is sensitive to the numerical scheme and limiter beta. At low-resolution limit, the growth of RTI is highly dependent on the setup and resolution, which we attribute to the large numerical viscosity at low resolution.

  11. Life-threatening motor vehicle crashes in bright sunlight

    Science.gov (United States)

    Redelmeier, Donald A.; Raza, Sheharyar

    2017-01-01

    Abstract Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight. This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later. The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9–24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather. Bright sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash. Level of evidence: Epidemiologic Study, level III. PMID:28072708

  12. An empirical assessment of fixed and random parameter logit models using crash- and non-crash-specific injury data.

    Science.gov (United States)

    Ch Anastasopoulos, Panagiotis; Mannering, Fred L

    2011-05-01

    Traditional crash-severity modeling uses detailed data gathered after a crash has occurred (number of vehicles involved, age of occupants, weather conditions at the time of the crash, types of vehicles involved, crash type, occupant restraint use, airbag deployment, etc.) to predict the level of occupant injury. However, for prediction purposes, the use of such detailed data makes assessing the impact of alternate safety countermeasures exceedingly difficult due to the large number of variables that need to be known. Using 5-year data from interstate highways in Indiana, this study explores fixed and random parameter statistical models using detailed crash-specific data and data that include the injury outcome of the crash but not other detailed crash-specific data (only more general data are used such as roadway geometrics, pavement condition and general weather and traffic characteristics). The analysis shows that, while models that do not use detailed crash-specific data do not perform as well as those that do, random parameter models using less detailed data still can provide a reasonable level of accuracy.

  13. CrashEd – A live immersive, learning experience embedding STEM subjects in a realistic, interactive crime scene

    Directory of Open Access Journals (Sweden)

    Marie L. Bassford

    2016-09-01

    Full Text Available Interactive experiences are rapidly becoming popular via the surge of ‘escape rooms’; part game and part theatre, the ‘escape’ experience is exploding globally, having gone from zero offered at the outset of 2010 to at least 2800 different experiences available worldwide today. CrashEd is an interactive learning experience that parallels many of the attractions of an escape room – it incorporates a staged, realistic ‘crime scene’ and invites participants to work together to gather forensic evidence and question a witness in order to solve a crime, all whilst competing against a ticking clock. An animation can enhance reality and engage with cognitive processes to help learning; in CrashEd, it is the last piece of the jigsaw that consolidates the students’ incremental acquisition of knowledge to tie together the pieces of evidence, identify a suspect and ultimately solve the crime. This article presents the background to CrashEd and an overview of how a timely placed animation at the end of an educational experience can enhance learning. The lessons learned, from delivering bespoke versions of the experience to different demographic groups, are discussed. The article will consider the successes and challenges raised by the collaborative project, future developments and potential wider implications of the development of CrashEd.

  14. Air Cushion Crash Rescue Vehicle (ACCRV) (Phase 1)

    Science.gov (United States)

    1985-11-01

    J J ) ) Ll 1 l l l ] .J ] J J J J Spray Skirt (Bag) Diameter ft <t Spray Skirt Tube I I . I r Out" Edg• of Tubo --/------- I...Water flowing through the eductor ( venturi ) draws agent into the flow which is subsequently mixed with the pump discharge water, most of which is...cab and communications 3-69 l l J 1 \\ J 1 l j J 1 J J j ] Suction Venturi System (3) Connections o 2 Supply (3) Humidifiers (3

  15. 14 CFR 298.21 - Filing for registration by air taxi operators.

    Science.gov (United States)

    2010-01-01

    ... office; (iv) The type of service the carrier will offer (scheduled passenger, 7 scheduled cargo, mail under a U.S. Postal Service contract, on-demand passenger, on-demand cargo, or other service such as...

  16. The Impact of Built Environment on Pedestrian Crashes and the Identification of Crash Clusters on an Urban University Campus

    Directory of Open Access Journals (Sweden)

    Strasser, Sheryl

    2010-08-01

    Full Text Available Objectives: Motor vehicle-pedestrian crash is a significant public health concern. The urban campus of Georgia State University poses unique challenges due to a large number of students and university employees. The objectives of this study are twofold: (1 to examine the correlation between specific features of the built environment on and around the University campus and pedestrian crashes; and (2 to identify crash clusters in the study area using network-based geospatial techniques.Methods: We obtained pedestrian crash data (n=119 from 2003 to 2007 from Georgia Department of Transportation and evaluated environmental features pertaining to the road infrastructure, pedestrian infrastructure and streetscape for each road segment and intersection. Prevalence rate of each feature with pedestrian crashes present was calculated. We used network-based Kernel Density Estimation to identify the high density road segments and intersections, then used network-based K-function to examine the clustering of pedestrian crashes.Results: Over 50% of the crosswalk signs, pedestrian signals, public transit, and location branding signs (more than three at intersections involved pedestrian crashes. More than half of wider streets (greater than 29 feet, two-way streets, and streets in good condition had pedestrian crashes present. Crashes occurred more frequently in road segments with strong street compactness and mixed land use present and were significantly (p<0.05 clustered in these high-density zones.Conclusions: Findings can be used to understand the correlation between built environment and pedestrian safety, to prioritize the high-density zones for intervention efforts, and to formulate research hypotheses for investigating pedestrian crashes. [West J Emerg Med. 2010; 11(3: 295-302.

  17. Economic Analysis on Value Chain of Taxi Fleet with Battery-Swapping Mode Using Multiobjective Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Guobao Ning

    2012-01-01

    Full Text Available This paper presents an economic analysis model on value chain of taxi fleet with battery-swapping mode in a pilot city. In the model, economic benefits of charging-swapping station group, taxi company, and taxi driver in the region have been taken into consideration. Thus, the model is a multiobjective function and multiobjective genetic algorithm is used to solve this problem. According to the real data collected from the pilot city, the multiobjective genetic algorithm is tested as an effective method to solve this problem. Furthermore, the effects of price of electricity, price of battery package, life cycle of battery package, cost of battery-swapping devices and infrastructure, and driving mileage per day on the benefits of value holders are analyzed, which provide theoretical and practical reference for the deployment of electric vehicles, for the national subsidy criteria adjusment, technological innovation instruction, commercial mode selection, and infrastructure construction.

  18. The protein interaction network of a taxis signal transduction system in a Halophilic Archaeon

    Directory of Open Access Journals (Sweden)

    Schlesner Matthias

    2012-11-01

    Full Text Available Abstract Background The taxis signaling system of the extreme halophilic archaeon Halobacterium (Hbt. salinarum differs in several aspects from its model bacterial counterparts Escherichia coli and Bacillus subtilis. We studied the protein interactions in the Hbt. salinarum taxis signaling system to gain an understanding of its structure, to gain knowledge about its known components and to search for new members. Results The interaction analysis revealed that the core signaling proteins are involved in different protein complexes and our data provide evidence for dynamic interchanges between them. Fifteen of the eighteen taxis receptors (halobacterial transducers, Htrs can be assigned to four different groups depending on their interactions with the core signaling proteins. Only one of these groups, which contains six of the eight Htrs with known signals, shows the composition expected for signaling complexes (receptor, kinase CheA, adaptor CheW, response regulator CheY. From the two Hbt. salinarum CheW proteins, only CheW1 is engaged in signaling complexes with Htrs and CheA, whereas CheW2 interacts with Htrs but not with CheA. CheY connects the core signaling structure to a subnetwork consisting of the two CheF proteins (which build a link to the flagellar apparatus, CheD (the hub of the subnetwork, two CheC complexes and the receptor methylesterase CheB. Conclusions Based on our findings, we propose two hypotheses. First, Hbt. salinarum might have the capability to dynamically adjust the impact of certain Htrs or Htr clusters depending on its current needs or environmental conditions. Secondly, we propose a hypothetical feedback loop from the response regulator to Htr methylation made from the CheC proteins, CheD and CheB, which might contribute to adaptation analogous to the CheC/CheD system of B. subtilis.

  19. An Object-oriented approach to Robotic planning using Taxi domain

    OpenAIRE

    Singh, Aasheesh

    2017-01-01

    This paper aims to implement Object-Oriented Markov Decision Process (OO-MDPs) for goal planning and navigation of robot in an indoor environment. We use the OO-MDP representation of the environment which is a natural way of modeling the environment based on objects and their interactions. The paper aims to extend the well known Taxi domain example which has been tested on grid world environment to robotics domain with larger state-spaces. For the purpose of this project we have created simul...

  20. Ridesharing or Ridestealing? Changes in Taxi Ridership and Revenue in Los Angeles 2009-2014

    OpenAIRE

    Waheed, Saba; Herrera, Lucero; Ritoper, Stefanie; Mehta, Jonaki; Romero,Hugo; Narro, Victor

    2015-01-01

    In 2015, Los Angeles increased the minimum wage to one of the highest in the country, leading the way to boost stagnating pay for workers and to ensure that workers are able to earn enough to support themselves and their families. Los Angeles needs to take the same care to ensure quality employment within the taxi industry, particularly in light of the rapid growth of transportation networking companies (TNCs) such as Uber and Lyft into Los Angeles. TNCs are on-demand ride services w...

  1. Impact of traffic states on freeway crash involvement rates.

    Science.gov (United States)

    Yeo, Hwasoo; Jang, Kitae; Skabardonis, Alexander; Kang, Seungmo

    2013-01-01

    Freeway traffic accidents are complicated events that are influenced by multiple factors including roadway geometry, drivers' behavior, traffic conditions and environmental factors. Among the various factors, crash occurrence on freeways is supposed to be strongly influenced by the traffic states representing driving situations that are changed by road geometry and cause the change of drivers' behavior. This paper proposes a methodology to investigate the relationship between traffic states and crash involvements on the freeway. First, we defined section-based traffic states: free flow (FF), back of queue (BQ), bottleneck front (BN) and congestion (CT) according to their distinctive patterns; and traffic states of each freeway section are determined based on actual measurements of traffic data from upstream and downstream ends of the section. Next, freeway crash data are integrated with the traffic states of a freeway section using upstream and downstream traffic measurements. As an illustrative study to show the applicability, we applied the proposed method on a 32-mile section of I-880 freeway. By integrating freeway crash occurrence and traffic data over a three-year period, we obtained the crash involvement rate for each traffic state. The results show that crash involvement rate in BN, BQ, and CT states are approximately 5 times higher than the one in FF. The proposed method shows promise to be used for various safety performance measurement including hot spot identification and prediction of the number of crash involvements on freeway sections.

  2. Overview of the Transport Rotorcraft Airframe Crash Testbed (TRACT) Full Scale Crash Tests

    Science.gov (United States)

    Annett, Martin; Littell, Justin

    2015-01-01

    The Transport Rotorcraft Airframe Crash Testbed (TRACT) full-scale tests were performed at NASA Langley Research Center's Landing and Impact Research Facility in 2013 and 2014. Two CH-46E airframes were impacted at 33-ft/s forward and 25-ft/s vertical combined velocities onto soft soil, which represents a severe, but potentially survivable impact scenario. TRACT 1 provided a baseline set of responses, while TRACT 2 included retrofits with composite subfloors and other crash system improvements based on TRACT 1. For TRACT 2, a total of 18 unique experiments were conducted to evaluate Anthropomorphic Test Devices (ATD) responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and activation of emergency locator transmitters and crash sensors. Combinations of Hybrid II, Hybrid III, and ES-2 ATDs were placed in forward and side facing seats and occupant results were compared against injury criteria. The structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation. The response of TRACT 2 was noticeably different in the horizontal direction due to changes in the cabin configuration and soil surface, with higher acceleration and damage occurring in the cabin. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats.

  3. A lightweight neighbor-info-based routing protocol for no-base-station taxi-call system.

    Science.gov (United States)

    Zhu, Xudong; Wang, Jinhang; Chen, Yunchao

    2014-01-01

    Since the quick topology change and short connection duration, the VANET has had unstable routing and wireless signal quality. This paper proposes a kind of lightweight routing protocol-LNIB for call system without base station, which is applicable to the urban taxis. LNIB maintains and predicts neighbor information dynamically, thus finding the reliable path between the source and the target. This paper describes the protocol in detail and evaluates the performance of this protocol by simulating under different nodes density and speed. The result of evaluation shows that the performance of LNIB is better than AODV which is a classic protocol in taxi-call scene.

  4. Projecting Fatalities in Crashes Involving Older Drivers, 2000-2025

    Energy Technology Data Exchange (ETDEWEB)

    Hu, P.S.

    2001-03-23

    As part of this research effort, we developed a new methodology for projecting elderly traffic crash fatalities. This methodology separates exposure to crashes from crash risk per se, and further divides exposure into two components, the number of miles driven and the likelihood of being a driver. This component structure permits conceptually different determinants of traffic fatalities to be projected separately and has thorough motivation in behavioral theory. It also permits finer targeting of particular aspects of projections that need improvement and closer linking of projections to possible policy instruments for influencing them.

  5. Evaluation of the First Transport Rotorcraft Airframe Crash Testbed (TRACT 1) Full-Scale Crash Test

    Science.gov (United States)

    Annett, Martin S.; Littell, Justin D.; Jackson, Karen E.; Bark, Lindley W.; DeWeese, Rick L.; McEntire, B. Joseph

    2014-01-01

    In 2012, the NASA Rotary Wing Crashworthiness Program initiated the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program by obtaining two CH-46E helicopters from the Navy CH-46E Program Office (PMA-226) at the Navy Flight Readiness Center in Cherry Point, North Carolina. Full-scale crash tests were planned to assess dynamic responses of transport-category rotorcraft under combined horizontal and vertical impact loading. The first crash test (TRACT 1) was performed at NASA Langley Research Center's Landing and Impact Research Facility (LandIR), which enables the study of critical interactions between the airframe, seat, and occupant during a controlled crash environment. The CH-46E fuselage is categorized as a medium-lift rotorcraft with fuselage dimensions comparable to a regional jet or business jet. The first TRACT test (TRACT 1) was conducted in August 2013. The primary objectives for TRACT 1 were to: (1) assess improvements to occupant loads and displacement with the use of crashworthy features such as pre-tensioning active restraints and energy absorbing seats, (2) develop novel techniques for photogrammetric data acquisition to measure occupant and airframe kinematics, and (3) provide baseline data for future comparison with a retrofitted airframe configuration. Crash test conditions for TRACT 1 were 33-ft/s forward and 25-ft/s vertical combined velocity onto soft soil, which represent a severe, but potentially survivable impact scenario. The extraordinary value of the TRACT 1 test was reflected by the breadth of meaningful experiments. A total of 8 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and photogrammetric techniques. A combination of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. Loads from ATDs in energy

  6. Linux Crash Dump的设计与实现%AN INTRODUCTION TO DESIGN AND IMPLEMENTATION OF Linux Crash Dump

    Institute of Scientific and Technical Information of China (English)

    王勇; 沈亚谦; 潘金贵

    2002-01-01

    本文介绍了Linux Crash Dump的设计与实现方法.Linux Crash Dump提供了一种保存系统在发生Crash时内存映象的能力.通过对Dump结果的分析,可以有效地帮助诊断系统出错的原因.本文介绍了如何进行Crash Dump,以及Dump的数据的组织和保存方法等.

  7. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights

    Science.gov (United States)

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes. PMID:26448333

  8. Crash Prediction and Risk Evaluation Based on Traffic Analysis Zones

    Directory of Open Access Journals (Sweden)

    Cuiping Zhang

    2014-01-01

    Full Text Available Traffic safety evaluation for traffic analysis zones (TAZs plays an important role in transportation safety planning and long-range transportation plan development. This paper aims to present a comprehensive analysis of zonal safety evaluation. First, several criteria are proposed to measure the crash risk at zonal level. Then these criteria are integrated into one measure-average hazard index (AHI, which is used to identify unsafe zones. In addition, the study develops a negative binomial regression model to statistically estimate significant factors for the unsafe zones. The model results indicate that the zonal crash frequency can be associated with several social-economic, demographic, and transportation system factors. The impact of these significant factors on zonal crash is also discussed. The finding of this study suggests that safety evaluation and estimation might benefit engineers and decision makers in identifying high crash locations for potential safety improvements.

  9. Heavy Vehicle Crash Characteristics in Oman; 2009–2011

    Directory of Open Access Journals (Sweden)

    Islam Al-Bulushi

    2015-05-01

    Full Text Available In recent years, Oman has seen a shift in the burden of diseases towards road accidents. The main objective of this paper, therefore, is to describe key characteristics of heavy vehicle crashes in Oman and identify the key driving behaviours that influence fatality risks. Crash data from January 2009 to December 2011 were examined and it was found that, of the 22,543 traffic accidents that occurred within this timeframe, 3,114 involved heavy vehicles. While the majority of these crashes were attributed to driver behaviours, a small proportion was attributed to other factors. The results of the study indicate that there is a need for a more thorough crash investigation process in Oman. Future research should explore the reporting processes used by the Royal Oman Police, cultural influences on heavy vehicle operations in Oman and improvements to the current licensing system.

  10. Where Medical Pot Is Legal, Fatal Car Crashes Often Decline

    Science.gov (United States)

    ... 162675.html Where Medical Pot Is Legal, Fatal Car Crashes Often Decline It's possible that these state ... and Human Services. More Health News on: Marijuana Motor Vehicle Safety Recent Health News Related MedlinePlus Health ...

  11. Relationship between organisational safety culture dimensions and crashes.

    Science.gov (United States)

    Varmazyar, Sakineh; Mortazavi, Seyed Bagher; Arghami, Shirazeh; Hajizadeh, Ebrahim

    2016-01-01

    Knowing about organisational safety culture in public transportation system can provide an appropriate guide to establish effective safety measures and interventions to improve safety at work. The aim of this study was investigation of association between safety culture dimensions (leadership styles and company values, usage of crashes information and prevention programmes, management commitment and safety policy, participation and control) with involved self-reported crashes. The associations were considered through Spearman correlation, Pearson chi-square test and logistic regression. The results showed an association among self-reported crashes (occurrence or non-occurrence) and factors including leadership styles and company values; management commitment and safety policy; and control. Moreover, it was found a negative correlation and an odds ratio less than one between control and self-reported crashes.

  12. Finite Element Crash Simulations and Impact-Induced Injuries

    Directory of Open Access Journals (Sweden)

    Jaroslav Mackerle

    1999-01-01

    Full Text Available This bibliography lists references to papers, conference proceedings and theses/dissertations dealing with finite element simulations of crashes, impact-induced injuries and their protection that were published in 1980–1998. 390 citations are listed.

  13. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights.

    Directory of Open Access Journals (Sweden)

    Jonathan Donier

    Full Text Available Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes.

  14. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights.

    Science.gov (United States)

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes.

  15. 民用运输飞机适坠性要求浅析%Analysis of Crash-worthiness Requirements of Civil Transport Aircraft

    Institute of Scientific and Technical Information of China (English)

    范耀宇

    2014-01-01

    全面解读了民用运输飞机适坠性要求,并对CCAR/FAR25与CS25之间差异进行剖析,总结国内外相关经验,提出适坠性后续工作方向。%The paper comprehensively states the air-worthiness requirements of crash-worthiness, analyses the difference between CCAR/FAR25 and CS25 , summarizes the experience of airplane crash-worthiness in the do-mestic and over-sea, and proposes the further research domain.

  16. Car Crash Fatalities Associated With Fire in Sweden

    OpenAIRE

    Viklund, Åsa; Björnstig, Johanna; Larsson, Magnus; Björnstig, Ulf

    2013-01-01

    Objective: To study the epidemiology and causes of death in fatal car crashes on Swedish roads in which the victim's vehicle caught fire. Methods: The data set is from the Swedish Transport Administrations in-depth studies of fatal crashes 1998-2008. Autopsies from all cases provided data on injuries, toxicological analyses, and cause of death. Results: In total, 181 people died in 133 burning cars, accounting for 5 percent of all deaths in passenger cars, sport utility vehicles, vans, and mi...

  17. The xylanase inhibitor TAXI-III counteracts the necrotic activity of a Fusarium graminearum xylanase in vitro and in durum wheat transgenic plants.

    Science.gov (United States)

    Moscetti, Ilaria; Faoro, Franco; Moro, Stefano; Sabbadin, Davide; Sella, Luca; Favaron, Francesco; D'Ovidio, Renato

    2015-08-01

    The xylanase inhibitor TAXI-III has been proven to delay Fusarium head blight (FHB) symptoms caused by Fusarium graminearum in transgenic durum wheat plants. To elucidate the molecular mechanism underlying the capacity of the TAXI-III transgenic plants to limit FHB symptoms, we treated wheat tissues with the xylanase FGSG_03624, hitherto shown to induce cell death and hydrogen peroxide accumulation. Experiments performed on lemmas of flowering wheat spikes and wheat cell suspension cultures demonstrated that pre-incubation of xylanase FGSG_03624 with TAXI-III significantly decreased cell death. Most interestingly, a reduced cell death relative to control non-transgenic plants was also obtained by treating, with the same xylanase, lemmas of TAXI-III transgenic plants. Molecular modelling studies predicted an interaction between the TAXI-III residue H395 and residues E122 and E214 belonging to the active site of xylanase FGSG_03624. These results provide, for the first time, clear indications in vitro and in planta that a xylanase inhibitor can prevent the necrotic activity of a xylanase, and suggest that the reduced FHB symptoms on transgenic TAXI-III plants may be a result not only of the direct inhibition of xylanase activity secreted by the pathogen, but also of the capacity of TAXI-III to avoid host cell death.

  18. Exploring spatial autocorrelation of traffic crashes based on severity.

    Science.gov (United States)

    Soltani, Ali; Askari, Sajad

    2017-01-19

    As a developing country, Iran has one of the highest crash-related deaths, with a typical rate of 15.6 cases in every 100 thousand people. This paper is aimed to find the potential temporal and spatial patterns of road crashes aggregated at traffic analysis zonal (TAZ) level in urban environments. Localization pattern and hotspot distribution were examined using geo-information approach to find out the impact of spatial/temporal dimensions on the emergence of such patterns. The spatial clustering of crashes and hotspots were assessed using spatial autocorrelation methods such as the Moran's I and Getis-Ord Gi* index. Comap was used for comparing clusters in three attributes: the time of occurrence, severity, and location. The analysis of the annually crash frequencies aggregated in 156 TAZ in Shiraz; from 2010 to 2014, Iran showed that both Moran's I method and Getis-Ord Gi* statistics produced significant clustering of crash patterns. While crashes emerged a clustered pattern, comparison of the spatio-temporal separations showed an accidental spread in distinct categories. The local governmental agencies can use the outcomes to adopt more effective strategies for traffic safety planning and management.

  19. Structural Integrity Assessment of Reactor Containment Subjected to Aircraft Crash

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junyong; Chang, Yoonsuk [Department of Nuclear Engineering/Kyung Hee Univ., Yongin (Korea, Republic of)

    2013-05-15

    When an accident occurs at the NPP, containment building which acts as the last barrier should be assessed and analyzed structural integrity by internal loading or external loading. On many occasions that can occur in the containment internal such as LOCA(Loss Of Coolant Accident) are already reflected to design. Likewise, there are several kinds of accidents that may occur from the outside of containment such as earthquakes, hurricanes and strong wind. However, aircraft crash that at outside of containment is not reflected yet in domestic because NPP sites have been selected based on the probabilistic method. After intentional aircraft crash such as World Trade Center and Pentagon accident in US, social awareness for safety of infrastructure like NPP was raised world widely and it is time for assessment of aircraft crash in domestic. The object of this paper is assessment of reactor containment subjected to aircraft crash by FEM(Finite Element Method). In this paper, assessment of structural integrity of containment building subjected to certain aircraft crash was carried out. Verification of structure integrity of containment by intentional severe accident. Maximum stress 61.21MPa of horizontal shell crash does not penetrate containment. Research for more realistic results needed by steel reinforced concrete model.

  20. MOTORCYCLE CRASH TEST CENTRE: A MOVEABLE BARRIER APPROACH

    Directory of Open Access Journals (Sweden)

    S.V.Wong

    2012-06-01

    Full Text Available Over recent years, researchers have used full-scale motorcycle crash tests in the field of road safety research to simulate different types of crash technique and scenario. This study focuses on the development of laboratory-based motorcycle crash tests. A moveable barrier, designated as a ‘trolley’ in this study, is designed, developed and implemented in a laboratory-based motorcycle crash test. The design of the trolley underwent several versions prior to the final election. Various design considerations and factors, such as the trolley’s flexibility in various impact conditions, were weighted. Finite element analysis and experimental tests examine and explain the details of the design. The purposeful selection of this trolley is discussed, such as how it might meet wide industrial market applications. With a laboratory-based crash test facility, various crash scenarios and motorcycle crashworthiness could be determined in-situ, coupled with a reduction in expense and time. Therefore, this research would serve to enhance yet another aspect of automotive engineering.

  1. Statistical modeling of total crash frequency at highway intersections

    Directory of Open Access Journals (Sweden)

    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.

  2. Linux Crash Dump分析工具的设计与实现%The Design and Implementation of an Analysis Tool of Linux Crash Dump

    Institute of Scientific and Technical Information of China (English)

    沈亚谦; 王勇; 潘金贵

    2002-01-01

    提出了一种利用Linux Crash Dump以及对Dump的分析来进行Linux系统调试的方法.着重描述了在目前Linux系统中添加Crash Dump功能的方法和Linux Crash Dump分析工具的具体实现方案.

  3. Using an innovative price model to leverage the business model – The case of price model innovation in the largest Swedish taxi company

    Directory of Open Access Journals (Sweden)

    Carl-Johan Petri

    2014-08-01

    Full Text Available Purpose: The purpose of the paper is to describe how the biggest Swedish taxi company (Taxi Kurir developed an innovative price model to leverage the business model. Design/methodology/approach : The empirical data in the article describe Taxi Kurir’s development of a new price model. Data about the Swedish taxi market and about Taxi Kurir has been compiled though interviews and document studies. Detailed information about the background, development and implementation of Taxi Kurir’s new price model has been captured through interviews with representatives from Taxi Kurir. Findings : Based on both the empirical example, and other investigations, we have found that a company can create substantial changes in their price model, by just changing some of its basic characteristics. A well designed price model can contribute to leveraging the intentions of the business model. Practical implications : Most academic and practical texts about business models consider pricing to be an important component. However, they typically do not refer to the specifics of the price- or revenue models. According to the literature review in this paper, and the empirical findings, the configuration of a company’s price model should be aligned with its business model. This will contribute to leveraging the business model. Originality/value: The Swedish taxi market is one of the most deregulated in the world. Differently from most other countries, any individual or company can start and operate a taxi business. This case offers a unique description on how the biggest company in the market responded to the competition by introducing a fundamentally new price model, by making a small change in one of the dimensions in their existing price model.

  4. Visual exploration of big spatio-temporal urban data: a study of New York City taxi trips.

    Science.gov (United States)

    Ferreira, Nivan; Poco, Jorge; Vo, Huy T; Freire, Juliana; Silva, Cláudio T

    2013-12-01

    As increasing volumes of urban data are captured and become available, new opportunities arise for data-driven analysis that can lead to improvements in the lives of citizens through evidence-based decision making and policies. In this paper, we focus on a particularly important urban data set: taxi trips. Taxis are valuable sensors and information associated with taxi trips can provide unprecedented insight into many different aspects of city life, from economic activity and human behavior to mobility patterns. But analyzing these data presents many challenges. The data are complex, containing geographical and temporal components in addition to multiple variables associated with each trip. Consequently, it is hard to specify exploratory queries and to perform comparative analyses (e.g., compare different regions over time). This problem is compounded due to the size of the data-there are on average 500,000 taxi trips each day in NYC. We propose a new model that allows users to visually query taxi trips. Besides standard analytics queries, the model supports origin-destination queries that enable the study of mobility across the city. We show that this model is able to express a wide range of spatio-temporal queries, and it is also flexible in that not only can queries be composed but also different aggregations and visual representations can be applied, allowing users to explore and compare results. We have built a scalable system that implements this model which supports interactive response times; makes use of an adaptive level-of-detail rendering strategy to generate clutter-free visualization for large results; and shows hidden details to the users in a summary through the use of overlay heat maps. We present a series of case studies motivated by traffic engineers and economists that show how our model and system enable domain experts to perform tasks that were previously unattainable for them.

  5. Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials

    Directory of Open Access Journals (Sweden)

    Roberts Ian

    2011-02-01

    Full Text Available Abstract Background All sectors of the economy, including the health research sector, must reduce their carbon emissions. The UK National Institute for Health Research has recently prepared guidelines on how to minimize the carbon footprint of research. We compare the carbon emissions from two international clinical trials in order to identify where emissions reductions can be made. Methods We conducted a carbon audit of two clinical trials (the CRASH-1 and CRASH-2 trials, quantifying the carbon dioxide emissions produced over a one-year audit period. Carbon emissions arising from the coordination centre, freight delivery, trial-related travel and commuting were calculated and compared. Results The total emissions in carbon dioxide equivalents during the one-year audit period were 181.3 tonnes for CRASH-1 and 108.2 tonnes for CRASH-2. In total, CRASH-1 emitted 924.6 tonnes of carbon dioxide equivalents compared with 508.5 tonnes for CRASH-2. The CRASH-1 trial recruited 10,008 patients over 5.1 years, corresponding to 92 kg of carbon dioxide per randomized patient. The CRASH-2 trial recruited 20,211 patients over 4.7 years, corresponding to 25 kg of carbon dioxide per randomized patient. The largest contributor to emissions in CRASH-1 was freight delivery of trial materials (86.0 tonnes, 48% of total emissions, whereas the largest contributor in CRASH-2 was energy use by the trial coordination centre (54.6 tonnes, 30% of total emissions. Conclusions Faster patient recruitment in the CRASH-2 trial largely accounted for its greatly increased carbon efficiency in terms of emissions per randomized patient. Lighter trial materials and web-based data entry also contributed to the overall lower carbon emissions in CRASH-2 as compared to CRASH-1. Trial Registration Numbers CRASH-1: ISRCTN74459797 CRASH-2: ISRCTN86750102

  6. Front blind spot crashes in Hong Kong.

    Science.gov (United States)

    Cheng, Yuk Ki; Wong, Koon Hung; Tao, Chi Hang; Tam, Cheok Ning; Tam, Yiu Yan; Tsang, Cheuk Nam

    2016-09-01

    In 2012-2014, our laboratory had investigated a total of 9 suspected front blind spot crashes, in which the medium and heavy goods vehicles pulled away from rest and rolled over the pedestrians, who were crossing immediately in front of the vehicles. The drivers alleged that they did not see any pedestrians through the windscreens or the front blind spot mirrors. Forensic assessment of the goods vehicles revealed the existence of front blind spot zones in 3 out of these 9 accident vehicles, which were attributed to the poor mirror adjustments or even the absence of a front blind spot mirror altogether. In view of this, a small survey was devised involving 20 randomly selected volunteers and their goods vehicles and 5 out of these vehicles had blind spots at the front. Additionally, a short questionnaire was conducted on these 20 professional lorry drivers and it was shown that most of them were not aware of the hazards of blind spots immediately in front of their vehicles, and many did not use the front blind spot mirrors properly. A simple procedure for quick measurements of the coverage of front blind spot mirrors using a coloured plastic mat with dimensional grids was also introduced and described in this paper.

  7. Flight-crash events in turbulence.

    Science.gov (United States)

    Xu, Haitao; Pumir, Alain; Falkovich, Gregory; Bodenschatz, Eberhard; Shats, Michael; Xia, Hua; Francois, Nicolas; Boffetta, Guido

    2014-05-27

    The statistical properties of turbulence differ in an essential way from those of systems in or near thermal equilibrium because of the flux of energy between vastly different scales at which energy is supplied and at which it is dissipated. We elucidate this difference by studying experimentally and numerically the fluctuations of the energy of a small fluid particle moving in a turbulent fluid. We demonstrate how the fundamental property of detailed balance is broken, so that the probabilities of forward and backward transitions are not equal for turbulence. In physical terms, we found that in a large set of flow configurations, fluid elements decelerate faster than accelerate, a feature known all too well from driving in dense traffic. The statistical signature of rare "flight-crash" events, associated with fast particle deceleration, provides a way to quantify irreversibility in a turbulent flow. Namely, we find that the third moment of the power fluctuations along a trajectory, nondimensionalized by the energy flux, displays a remarkable power law as a function of the Reynolds number, both in two and in three spatial dimensions. This establishes a relation between the irreversibility of the system and the range of active scales. We speculate that the breakdown of the detailed balance characterized here is a general feature of other systems very far from equilibrium, displaying a wide range of spatial scales.

  8. Pedal cyclists, crash helmets and risk.

    Science.gov (United States)

    McCarthy, M

    1991-07-01

    As a rate per million kilometres travelled, the 'risk' of cycling appears to be high in relation to other forms of transport. Yet, in absolute numbers, there are far fewer cyclist deaths than pedestrian or motor vehicle occupant deaths, and most deaths and serious injuries to pedal cyclists are caused by other road users--principally motor vehicles. The large majority of pedal cyclist deaths are due to head injuries after collision with a motor vehicle. It is therefore commonly proposed that cyclists should wear crash helmets for their own 'safety'. Helmets may protect against fall injuries, but current models are not designed to withstand the impact of collisions with motor vehicles. Evidence for the benefit of pedal cyclists wearing helmets is limited: the existing studies cannot exclude the possibility of different risk-taking behaviour, either by cyclists or by motor vehicle drivers, for helmet wearers compared with non-wearers. A public health policy towards reducing pedal cyclist deaths should seek prevention of accidents, rather than protection from their consequences. Cycling in greater safety would reduce the 'risk' per kilometre travelled, but more cycling might not reduce total cyclist deaths or injuries--because of greater exposure. The 'risk' of cycling--the risk of injury or death--is a complex mix of exposure, 'danger' of the environment, and the perceived risk affecting our precautionary preventive behaviour.

  9. Back to the Future: Integrated Air and Missile Defense in the Pacific

    Science.gov (United States)

    2015-02-01

    Add to those the Aegis system, ground-based air defense, and short-ranged air defense to destroy an adversary’s inbound air threats. By combining...Technology Demonstra- tion. Designed to protect critical, vulnerable assets through the most cost -effective application of hardening/ resiliency methods...ability to /( flush-launch" (rapid engine start, taxi, and takeoff) alert aircraft upon receipt of warnings of tactical inbound missiles and

  10. Correlation and assessment of structural airplane crash data with flight parameters at impact

    Science.gov (United States)

    Carden, H. D.

    1982-01-01

    Crash deceleration pulse data from a crash dynamics program on general aviation airplanes and from transport crash data were analyzed. Structural airplane crash data and flight parameters at impact were correlated. Uncoupled equations for the normal and longitudinal floor impulses in the cabin area of the airplane were derived, and analytical expressions for structural crushing during impact and horizontal slide out were also determined. Agreement was found between experimental and analytical data for general aviation and transport airplanes over a relatively wide range of impact parameter. Two possible applications of the impulse data are presented: a postcrash evaluation of crash test parameters and an assumed crash scenario.

  11. Spatial regression analysis of traffic crashes in Seoul.

    Science.gov (United States)

    Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-ihn; Ulfarsson, Gudmundur F

    2016-06-01

    Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30 km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30 km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands.

  12. RCC Arch Dam Structure on the Taxi River and Water Storage Measure During Construction

    Institute of Scientific and Technical Information of China (English)

    刘光廷; 李鹏辉; 胡昱; 张富德; 谢树南

    2002-01-01

    The new structure of roller compacted concrete (RCC) arch dams is presented for extremely cold and earthquake prone areas. The influence of construction plans and improved materials on the stresses in the Taxi River dam is also given. Earlier impoundment of water is shown to not only benefit the engineering design but also improve the stresses during construction in winter. Low cement content in the concrete and artificial short joints improved the monolithic structure and the transmitted forces. The concrete plug installed in the first cooled part of the arch dam provides excellent force transmission in the arch, which increases the monolith of the earlier arch, reduces the increasing thermal stresses that occur later, and improves the deformation flexibility of the dam.

  13. Identify sequence of events likely to result in severe crash outcomes.

    Science.gov (United States)

    Wu, Kun-Feng; Thor, Craig P; Ardiansyah, Muhammad Nashir

    2016-11-01

    The current practice of crash characterization in highway engineering reduces multiple dimensions of crash contributing factors and their relative sequential connections, crash sequences, into broad definitions, resulting in crash categories such as head-on, sideswipe, rear-end, angle, and fixed-object. As a result, crashes that are classified in the same category may contain many different crash sequences. This makes it difficult to develop effective countermeasures because these crash categorizations are based on the outcomes rather than the preceding events. Consequently, the efficacy of a countermeasure designed for a specific type of crash may not be appropriate due to different pre-crash sequences. This research seeks to explore the use of event sequence to characterize crashes. Additionally, this research seeks to identify crash sequences that are likely to result in severe crash outcomes so that researchers can develop effective countermeasures to reduce severe crashes. This study utilizes the sequence of events from roadway departure crashes in the Fatality Analysis Reporting System (FARS), and converts the information to form a new categorization called "crash sequences." The similarity distance between each pair of crash sequences were calculated using the Optimal Matching approach. Cluster analysis was applied to group crash sequences that are etiologically similar in terms of the similarity distance. A hybrid model was constructed to mitigate the potential sample selection bias of FARS data, which is biased toward more severe crashes. The major findings include: (1) in terms of a roadway departure crash, the crash sequences that are most likely to result in high crash severity include a vehicle that first crosses the median or centerline, runs-off-road on the left, and then collides with a roadside fixed-object; (2) seat-belt and airbag usage reduces the probability of dying in a roadway departure crash by 90%; and (3) occupants who are seated on the

  14. Urban sprawl as a risk factor in motor vehicle crashes

    Science.gov (United States)

    Ewing, Reid; Hamidi, Shima; Grace, James B.

    2016-01-01

    A decade ago, compactness/sprawl indices were developed for metropolitan areas and counties which have been widely used in health and other research. In this study, we first update the original county index to 2010, then develop a refined index that accounts for more relevant factors, and finally seek to test the relationship between sprawl and traffic crash rates using structural equation modelling. Controlling for covariates, we find that sprawl is associated with significantly higher direct and indirect effects on fatal crash rates. The direct effect is likely due to the higher traffic speeds in sprawling areas, and the indirect effect is due to greater vehicle miles driven in such areas. Conversely, sprawl has negative direct relationships with total crashes and non-fatal injury crashes, and these offset (and sometimes overwhelm) the positive indirect effects of sprawl on both types of crashes through the mediating effect of increased vehicle miles driven. The most likely explanation is the greater prevalence of fender benders and other minor accidents in the low speed, high conflict traffic environments of compact areas, negating the lower vehicle miles travelled per capita in such areas.

  15. Human fatigue and the crash of the airship Italia

    Directory of Open Access Journals (Sweden)

    Gregg A. Bendrick

    2016-07-01

    Full Text Available The airship Italia, commanded by General Umberto Nobile, crashed during its return flight from the North Pole in 1928. The cause of the accident was never satisfactorily explained. We present evidence that the crash may have been fatigue-related. Nobile's memoirs indicate that at the time of the crash he had been awake for at least 72 h. Sleep deprivation impairs multiple aspects of cognitive functioning necessary for exploration missions. Just prior to the crash, Nobile made three command errors, all of which are of types associated with inadequate sleep. First, he ordered a release of lift gas when he should have restarted engines (an example of incorrect data synthesis, with deterioration of divergent thinking; second, he inappropriately ordered the ship above the cloud layer (a deficiency in the assessment of relative risks; and third, he remained above the cloud layer for a prolonged period of time (examples of attention to secondary problems, and calculation problems. We argue that as a result of these three errors, which would not be expected from such an experienced commander, there was no longer enough static lift to maintain level flight when the ship went below the cloud layer. Applying Circadian Performance Simulation Software to the sleep–wake patterns described by Nobile in his memoirs, we found that the predicted performance for someone awake as long as he had been is extremely low. This supports the historical evidence that human fatigue contributed to the crash of the Italia.

  16. Enabling Radiative Transfer on AMR grids in CRASH

    Science.gov (United States)

    Hariharan, N.; Graziani, L.; Ciardi, B.; Miniati, F.; Bungartz, H.-J.

    2017-01-01

    We introduce CRASH-AMR, a new version of the cosmological Radiative Transfer (RT) code CRASH, enabled to use refined grids. This new feature allows us to attain higher resolution in our RT simulations and thus to describe more accurately ionisation and temperature patterns in high density regions. We have tested CRASH-AMR by simulating the evolution of an ionised region produced by a single source embedded in gas at constant density, as well as by a more realistic configuration of multiple sources in an inhomogeneous density field. While we find an excellent agreement with the previous version of CRASH when the AMR feature is disabled, showing that no numerical artifact has been introduced in CRASH-AMR, when additional refinement levels are used the code can simulate more accurately the physics of ionised gas in high density regions. This result has been attained at no computational loss, as RT simulations on AMR grids with maximum resolution equivalent to that of a uniform cartesian grid can be run with a gain of up to 60% in computational time.

  17. Prediction of secondary crash frequency on highway networks.

    Science.gov (United States)

    Sarker, Afrid A; Paleti, Rajesh; Mishra, Sabyasachee; Golias, Mihalis M; Freeze, Philip B

    2017-01-01

    Secondary crash (SC) occurrences are major contributors to traffic delay and reduced safety, particularly in urban areas. National, state, and local agencies are investing substantial amount of resources to identify and mitigate secondary crashes to reduce congestion, related fatalities, injuries, and property damages. Though a relatively small portion of all crashes are secondary, determining the primary contributing factors for their occurrence is crucial. The non-recurring nature of SCs makes it imperative to predict their occurrences for effective incident management. In this context, the objective of this study is to develop prediction models to better understand causal factors inducing SCs. Given the count nature of secondary crash frequency data, the authors used count modeling methods including the standard Poisson and Negative Binomial (NB) models and their generalized variants to analyze secondary crash occurrences. Specifically, Generalized Ordered Response Probit (GORP) framework that subsumes standard count models as special cases and provides additional flexibility thus improving predictive accuracy were used in this study. The models developed account for possible effects of geometric design features, traffic composition and exposure, land use and other segment related attributes on frequency of SCs on freeways. The models were estimated using data from Shelby County, TN and results show that annual average daily traffic (AADT), traffic composition, land use, number of lanes, right side shoulder width, posted speed limits and ramp indicator are among key variables that effect SC occurrences. Also, the elasticity effects of these different factors were also computed to quantify their magnitude of impact.

  18. Reduction of particle emissions from light duty vehicles and from taxies; Reduktion af partikelelemissioner fra varebiler og taxier

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Johan; Henriques, M.; Weibel, T.G. [TetraPlan A/S (Denmark)

    2006-11-03

    This project, 'Reduction of particle emissions from light duty vehicles and from taxies', analyses different strategies to reduce the particle emission, their effect for particle emissions, and the resulting cost for the society and for the companies. The project describes the EU regulation of emissions, the possibilities of reducing the emissions via special requirements in environmental zones and the Danish taxation of light duty vehicles. Further, the project includes interviews with owners of light duty vehicles and taxies and also with Danish producers of particle filters. The strategies analysed in the scenarios include: 1) Promotion of particle filters; 2) Shift from diesel to gasoline and; 3) Downsizing. The effects for particle emissions and for mortality are described. Further, the costs and benefits for the society and the cost for the companies are evaluated. The effects of the scenarios are analysed, both for initiatives implemented at a national level and for implementation in an environmental zone in the municipality of Copenhagen. The main results are that the socioeconomic benefits in the year 2012 are greater than the costs, if taxis and light duty vehicles have filters installed and if they are driving in the Copenhagen area. For light duty vehicles it is only profitable, if the prices of the filters fall to the price level that is expected in the future in the study. Further, the analysis shows that for light duty vehicles and taxies driving all over the country, the socioeconomic benefits achieved by installing particle filters are too small to cover the costs. The analysis shows that it is also profitable socio-economically to change from diesel to petrol for light duty vehicles and for taxies (except taxies driving nationally). The analysis is based on the producer prices including the general net tax level, while the specific taxes are not included. From the point of view of the companies it is not profitable to change to petrol

  19. New Idea of Government Regulation of Taxi Industry in China%我国出租车行业政府管制的新思路

    Institute of Scientific and Technical Information of China (English)

    王铎

    2016-01-01

    政府对出租车行业的管制涉及政府、出租车公司、打车软件公司、出租车司机和乘客等5个相关主体。政府可以根据资质、服务质量对出租车企业进行等级分类,出租车企业通过实行绩效工资、考察服务质量等方法严格对出租车司机的管理,打车软件与政府及出租车企业合作,实现政府、企业、司机与乘客之间的有效信息沟通。运用委托代理理论的分析和检验这一管理新思路,可以看出其具有较强的可操作性。%The government manages the taxi company industry that involves five aspects such as the government itself, taxi company, taxi soft company, the drivers and passengers. The government can make taxi classification in the light of their quality and service ranks . The taxi company can control the taxi drivers in the light of their performance and the work results. The taxi software company can cooperate the government and the taxi company to make the effective management of the enterprise .

  20. National Motor Vehicle Crash Causation Survey (NMVCCS) - NMVCCS XML Case Viewer

    Data.gov (United States)

    Department of Transportation — The National Motor Vehicle Crash Causation Survey (NMVVCS) was a nationwide survey of crashes involving light passenger vehicles, with a focus on the factors related...

  1. Searching for preventive measures of cardiovascular events in aged Japanese taxi drivers--the daily rhythm of cardiovascular risk factors during a night duty day.

    Science.gov (United States)

    Hattori, M; Azami, Y

    2001-12-01

    Previous studies have shown that Japanese taxi drivers are exposed to more risk factors and have a higher mortality rate due to cardiovascular disease than other occupational groups. We investigated the effect of night taxi driving with a view to preventing acute events of cardiovascular disease among aged taxi drivers. Twenty-nine taxi drivers (41-67 years old) were examined for urine normetanephrine/creatinine, von Willebrand factor, anti-thrombin III, t-plasminogen activator-plasminogen activator inhibitor 1-complex, hematocrit, blood glucose and blood pressure in the morning and at midnight during a duty day and in the following morning. At the same time, the blood pressure and blood glucose of 46 taxi drivers (43-67 years old) in the morning after a night duty with little sleep and in the morning after daytime work and subsequent night sleep were compared. The results obtained indicate that the aggravation of sympathetic nervous system functions with disturbed circadian rhythms, increased blood coagulation and blood concentration, endothelial injury and the elevation of blood glucose at midnight or the next morning were induced by their night work. These conditions are supposed to favour acute vascular events in aged taxi drivers. Preventive measures considered include social support for anticoagulant food and water intake, short exercise and walking as well as taking a rest and a nap during night work.

  2. Option pricing during post-crash relaxation times

    Science.gov (United States)

    Dibeh, Ghassan; Harmanani, Haidar M.

    2007-07-01

    This paper presents a model for option pricing in markets that experience financial crashes. The stochastic differential equation (SDE) of stock price dynamics is coupled to a post-crash market index. The resultant SDE is shown to have stock price and time dependent volatility. The partial differential equation (PDE) for call prices is derived using risk-neutral pricing. European call prices are then estimated using Monte Carlo and finite difference methods. Results of the model show that call option prices after the crash are systematically less than those predicted by the Black-Scholes model. This is a result of the effect of non-constant volatility of the model that causes a volatility skew.

  3. A mixed methods investigation of bicycle exposure in crash rates.

    Science.gov (United States)

    Fournier, Nicholas; Christofa, Eleni; Knodler, Michael A

    2017-03-01

    Crash rates are an essential tool enabling researchers and practitioners to assess whether a location is truly more dangerous, or simply serves a higher volume of vehicles. Unfortunately, this simple crash rate is far more difficult to calculate for bicycles due to data challenges and the fact that they are uniquely exposed to both bicycle and automobile volumes on shared roadways. Bicycle count data, though increasingly more available, still represents a fraction of the available count data for automobiles. Further compounding on this, bicycle demand estimation methods often require more data than automobiles to account for the high variability that bicycle demand is subject to. This paper uses a combination of mixed methods to overcome these challenges and to perform an investigation of crash rates and exposure to different traffic volumes.

  4. Chain-reaction crash on a highway in high visibility

    Science.gov (United States)

    Nagatani, Takashi

    2016-05-01

    We study the chain-reaction crash (multiple-vehicle collision) in high-visibility condition on a highway. In the traffic situation, drivers control their vehicles by both gear-changing and braking. Drivers change the gears according to the headway and brake according to taillights of the forward vehicle. We investigate whether or not the first collision induces the chain-reaction crash numerically. It is shown that dynamic transitions occur from no collisions, through a single collision, to multiple collisions with decreasing the headway. Also, we find that the dynamic transition occurs from the finite chain reaction to the infinite chain reaction when the headway is less than the critical value. We compare the multiple-vehicle collisions in high-visibility with that in low-visibility. We derive the transition points and the region maps for the chain-reaction crash in high visibility.

  5. Crash Culpability Relative to Age and Sex for Injured Drivers Using Alcohol, Marijuana or Cocaine

    OpenAIRE

    Soderstrom, Carl A.; Dischinger, Patricia C; Kufera, Joseph A.; Ho, Shiu M.; Shepard, Angela

    2005-01-01

    While there is a great deal of data documenting the etiologic role alcohol use plays in crash culpability, there is a dearth of data for other drugs. The purpose of this study was to assess crash culpability for single drug use among injured drivers admitted to a regional trauma center. This study is the largest of its kind involving trauma center patients. Clinical toxicology results obtained for patient care were linked to police crash reports containing a field attributing crash culpabilit...

  6. The relative contribution of system failures and extreme behaviour in South Australian crashes.

    Science.gov (United States)

    Wundersitz, Lisa; Baldock, Matthew; Raftery, Simon

    2014-12-01

    Within the road system, there are compliant road users who may make an error that leads to a crash, resulting in a 'system failure', and there are also road users who deliberately take risks and display dangerous or 'extreme' behaviours that lead to a crash. Crashes resulting from system failures can be addressed through improvements to road system design more readily than crashes resulting from extreme behaviours. The classification of crash causation in terms of system failures or extreme behaviour is important for determining the extent to which a Safe System approach (i.e. improvements to road system design to serve compliant road users) is capable of reducing the number of crashes. This study examined the relative contribution of system failures and extreme behaviour in South Australian crashes as identified from information in Coroner's investigation files and in-depth crash investigations conducted by the Centre for Automotive Safety Research (CASR). The analysis of 189 fatal crashes, 272 non-fatal metropolitan injury crashes and 181 non-fatal rural crashes indicated that very few non-fatal crashes (3% metropolitan, 9% rural) involved extreme behaviour by road users and, even in fatal crashes, the majority (54%) were the result of system failures. Fatal crashes resulting from system failures were more likely than those resulting from extreme behaviour to occur during the day, on weekdays, in rural areas and on roads with high speed limits. Findings from the current study suggest that improvements to the road transport system (i.e. forgiving road infrastructure, appropriate speed limits, and safe vehicle design) can be expected to be much more effective in reducing crashes than concentrating on preventing extreme behaviours. Such a strategy could reduce the incidence and severity of a large proportion of crashes in South Australia.

  7. Biomechanical Response and Behavior of Users under Emergency Buffer Crash

    Directory of Open Access Journals (Sweden)

    R. Miralbes

    2013-01-01

    Full Text Available This paper aims to study the biomechanical effects on elevator users and the injuries sustained should an elevator crash happen. The analysis will focus on buffer impact, signaling that the earlier mentioned buffer is usually located at the bottom of the pit. In order to carry out this analysis, a numerical technique based on finite element method will be used, while elevator users will be simulated by means of automotive dummies. Two crash factors will be studied, namely, location of dummy and fall velocity. The analysis criteria will be damages sustained by the dummy, based on biomechanical index such as HIC, CSI, forces, and accelerations.

  8. Characteristics of Crashes with Farm Equipment that Increase Potential for Injury

    Science.gov (United States)

    Peek-Asa, Corinne; Sprince, Nancy L.; Whitten, Paul S.; Falb, Scott R.; Madsen, Murray D.; Zwerling, Craig

    2007-01-01

    Context: Crash fatality and injury rates are higher on rural roadways than other roadway types. Although slow-moving farm vehicles and equipment are risk factors on rural roads, little is known about the characteristics of crashes with farm vehicles/equipment. Purpose: To describe crashes and injuries for the drivers of farm vehicles/equipment and…

  9. A model-based, multichannel, real-time capable sawtooth crash detector

    NARCIS (Netherlands)

    van den Brand, H.; de Baar, M. R.; van Berkel, M.; Blanken, T. C.; Felici, F.; Westerhof, E.; Willensdorfer, M.; ASDEX Upgrade team,; EUROfusion MST1 Team,

    2016-01-01

    Control of the time between sawtooth crashes, necessary for ITER and DEMO, requires real-time detection of the moment of the sawtooth crash. In this paper, estimation of sawtooth crash times is demonstrated using the model-based interacting multiple model (IMM) estimator, based on simplified models

  10. 76 FR 46359 - Announcing the Nineteenth Public Meeting of the Crash Injury Research and Engineering Network...

    Science.gov (United States)

    2011-08-02

    ... review data and share expertise, which may lead to a better understanding of crash injury mechanisms and... National Highway Traffic Safety Administration Announcing the Nineteenth Public Meeting of the Crash Injury... members of the Crash Injury Research and Engineering Network. CIREN is a collaborative effort to...

  11. Characteristics of cyclist crashes in Italy using latent class analysis and association rule mining

    Science.gov (United States)

    De Angelis, Marco; Marín Puchades, Víctor; Fraboni, Federico; Pietrantoni, Luca

    2017-01-01

    The factors associated with severity of the bicycle crashes may differ across different bicycle crash patterns. Therefore, it is important to identify distinct bicycle crash patterns with homogeneous attributes. The current study aimed at identifying subgroups of bicycle crashes in Italy and analyzing separately the different bicycle crash types. The present study focused on bicycle crashes that occurred in Italy during the period between 2011 and 2013. We analyzed categorical indicators corresponding to the characteristics of infrastructure (road type, road signage, and location type), road user (i.e., opponent vehicle and cyclist’s maneuver, type of collision, age and gender of the cyclist), vehicle (type of opponent vehicle), and the environmental and time period variables (time of the day, day of the week, season, pavement condition, and weather). To identify homogenous subgroups of bicycle crashes, we used latent class analysis. Using latent class analysis, the bicycle crash data set was segmented into 19 classes, which represents 19 different bicycle crash types. Logistic regression analysis was used to identify the association between class membership and severity of the bicycle crashes. Finally, association rules were conducted for each of the latent classes to uncover the factors associated with an increased likelihood of severity. Association rules highlighted different crash characteristics associated with an increased likelihood of severity for each of the 19 bicycle crash types. PMID:28158296

  12. "Dammed Taxi Cab"--How Silent Communication in Questionnaires Can Be Understood and Used to Give Voice to Children's Experiences

    Science.gov (United States)

    Alerby, E.; Kostenius, C.

    2011-01-01

    "Dammed taxi cab"--a 12-year-old boy wrote these words in the margins of a questionnaire, and within this paper they will serve as a point of departure for the discussion of the use of questionnaires as a way to voice children's experiences. The overall aim of this paper is to enable understanding of and discuss the use of questionnaires as a way…

  13. Taxi Fleet Renewal in Cities with Improved Hybrid Powertrains: Life Cycle and Sensitivity Analysis in Lisbon Case Study

    OpenAIRE

    António P. Castel-Branco; João P. Ribau; Silva, Carla M.

    2015-01-01

    Stringent emissions regulations in cities and the high amount of daily miles driven by taxi vehicles enforce the need to renew these fleets with more efficient and cleaner technologies. Hybrid vehicles are potential candidates due to their enhanced powertrain, and slower battery depletion and fewer lifetime issues, relative to full electric vehicles. This paper proposes a methodology to analyze the best theoretical hybrid powertrain candidate with maximum in-use efficiency, minimum life cycle...

  14. A Feasibility Test on Adopting Electric Vehicles to Serve as Taxis in Daejeon Metropolitan City of South Korea

    Directory of Open Access Journals (Sweden)

    Seoin Baek

    2016-09-01

    Full Text Available For realizing sustainable development, EV (Electric Vehicle is currently considered as one of the most promising alternative due to its cleanness and inexhaustibility. However, the development and dissemination of EV has stagnated because it faces major constraints such as battery performance and an excessively long charging time. Thus, this study examined the feasibility of using EVs as taxis by analyzing real data from a pilot project in Daejeon, a metropolitan city in South Korea for proposing the effective way to adopt EV. To reflect reality and improve accuracy, we adopted scenarios and assumptions based on in-depth interviews with groups of experts. The resulting initial benefit-to-cost (B/C ratio for EV taxis is approximately 0.4, which is quite low compared to 0.7 for traditional taxis. However, after incorporating some further assumptions into the calculation, the B/C ratio shifts to approximately 0.7, which is more appropriate for EV adoption. For this improvement to be achieved, the dissemination of a charging infrastructure, improvement of the business model and policy support is strongly needed. Limitations to this work and potential areas for future study are also fully discussed.

  15. Taxi drivers' views on risky driving behavior in Tehran: a qualitative study using a social marketing approach.

    Science.gov (United States)

    Shams, Mohsen; Shojaeizadeh, Davoud; Majdzadeh, Reza; Rashidian, Arash; Montazeri, Ali

    2011-05-01

    The use of the social marketing approach for public health issues is increasing. This approach uses marketing concepts borrowed from the principles of commercial marketing to promote beneficial health behaviors. In this qualitative study, four focus groups involving 42 participants were used in consumer research to explore taxi drivers' views on the driving situation and the determinants of risky driving behaviors in Tehran, as well as to gather their ideas for developing a social marketing program to reduce risky driving behaviors among taxi drivers in Tehran, Iran. Participants were asked to respond to questions that would guide the development of a marketing mix, or four Ps (product, price, place and promotion). The discussions determined that the program product should involve avoiding risky driving behaviors through increased attention to driving. They pointed out that developing and communicating with a well-designed persuasive message meant to draw their attention to driving could affect their driving behaviors. In addition, participants identified price, place and promotion strategies. They offered suggestions for marketing nonrisky driving to the target audience. The focus group discussions generated important insights into the values and the motivations that affect consumers' decisions to adopt the product. The focus group guided the development of a social marketing program to reduce risky driving behaviors in taxi drivers in Tehran, Iran.

  16. Targeted axonal import (TAxI) peptide delivers functional proteins into spinal cord motor neurons after peripheral administration.

    Science.gov (United States)

    Sellers, Drew L; Bergen, Jamie M; Johnson, Russell N; Back, Heidi; Ravits, John M; Horner, Philip J; Pun, Suzie H

    2016-03-01

    A significant unmet need in treating neurodegenerative disease is effective methods for delivery of biologic drugs, such as peptides, proteins, or nucleic acids into the central nervous system (CNS). To date, there are no operative technologies for the delivery of macromolecular drugs to the CNS via peripheral administration routes. Using an in vivo phage-display screen, we identify a peptide, targeted axonal import (TAxI), that enriched recombinant bacteriophage accumulation and delivered protein cargo into spinal cord motor neurons after intramuscular injection. In animals with transected peripheral nerve roots, TAxI delivery into motor neurons after peripheral administration was inhibited, suggesting a retrograde axonal transport mechanism for delivery into the CNS. Notably, TAxI-Cre recombinase fusion proteins induced selective recombination and tdTomato-reporter expression in motor neurons after intramuscular injections. Furthermore, TAxI peptide was shown to label motor neurons in the human tissue. The demonstration of a nonviral-mediated delivery of functional proteins into the spinal cord establishes the clinical potential of this technology for minimally invasive administration of CNS-targeted therapeutics.

  17. Crash Survivable Flight Data Recording System Study.

    Science.gov (United States)

    1981-06-30

    fitted- position of cock- pit control 5L Airbrakes or Event Mark spoilers where I itted - position of cockpit control L6 titch Irim Full Range 1of...requirements for supplemental air car - a 25 statute mile radius of the airport uiers tn Part 121 of this chapter. of takeoff carrying persons for the except

  18. A mathematical definition of the financial bubbles and crashes

    Science.gov (United States)

    Watanabe, Kota; Takayasu, Hideki; Takayasu, Misako

    2007-09-01

    We check the validity of the mathematical method of detecting financial bubbles or crashes, which is based on a data fitting with an exponential function. We show that the period of a bubble can be determined nearly uniquely independent of the precision of data. The method is widely applicable for stock market data such as the Internet bubble.

  19. High-frequency Trading, Algorithmic Finance, and the Flash Crash

    DEFF Research Database (Denmark)

    Borch, Christian

    2016-01-01

    The Flash Crash of 6 May 2010 has an interesting status in discussions of high-frequency trading, i.e. fully automated, superfast computerized trading: it is invoked both as an important illustration of how this field of algorithmic trading operates and, more often, as an example of how fully aut...

  20. STOCK MARKET CRASH AND EXPECTATIONS OF AMERICAN HOUSEHOLDS.

    Science.gov (United States)

    Hudomiet, Péter; Kézdi, Gábor; Willis, Robert J

    2011-01-01

    This paper utilizes data on subjective probabilities to study the impact of the stock market crash of 2008 on households' expectations about the returns on the stock market index. We use data from the Health and Retirement Study that was fielded in February 2008 through February 2009. The effect of the crash is identified from the date of the interview, which is shown to be exogenous to previous stock market expectations. We estimate the effect of the crash on the population average of expected returns, the population average of the uncertainty about returns (subjective standard deviation), and the cross-sectional heterogeneity in expected returns (disagreement). We show estimates from simple reduced-form regressions on probability answers as well as from a more structural model that focuses on the parameters of interest and separates survey noise from relevant heterogeneity. We find a temporary increase in the population average of expectations and uncertainty right after the crash. The effect on cross-sectional heterogeneity is more significant and longer lasting, which implies substantial long-term increase in disagreement. The increase in disagreement is larger among the stockholders, the more informed, and those with higher cognitive capacity, and disagreement co-moves with trading volume and volatility in the market.

  1. STOCK MARKET CRASH AND EXPECTATIONS OF AMERICAN HOUSEHOLDS*

    Science.gov (United States)

    HUDOMIET, PÉTER; KÉZDI, GÁBOR; WILLIS, ROBERT J.

    2011-01-01

    SUMMARY This paper utilizes data on subjective probabilities to study the impact of the stock market crash of 2008 on households’ expectations about the returns on the stock market index. We use data from the Health and Retirement Study that was fielded in February 2008 through February 2009. The effect of the crash is identified from the date of the interview, which is shown to be exogenous to previous stock market expectations. We estimate the effect of the crash on the population average of expected returns, the population average of the uncertainty about returns (subjective standard deviation), and the cross-sectional heterogeneity in expected returns (disagreement). We show estimates from simple reduced-form regressions on probability answers as well as from a more structural model that focuses on the parameters of interest and separates survey noise from relevant heterogeneity. We find a temporary increase in the population average of expectations and uncertainty right after the crash. The effect on cross-sectional heterogeneity is more significant and longer lasting, which implies substantial long-term increase in disagreement. The increase in disagreement is larger among the stockholders, the more informed, and those with higher cognitive capacity, and disagreement co-moves with trading volume and volatility in the market. PMID:21547244

  2. Modelling Drivers' Behaviour as a Crash Risk Reduction Process

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Sadat Hoseini

    2008-05-01

    Full Text Available The evermore widespread use of microscopic traffic simulationin the analysis of road systems has refocused attention onsub models, including car-following and lane-changing models.In this research a microscopic model is developed whichcombines car-following and lane-changing models and describesdriver behaviour as a crash risk reduction process ofdrivers. This model has been simulated by a cellular automatasimulator and compared with the real data. It has been shownthat there is no reason to consider the model invalid for drivers'behaviour in the basic segments of freeways in Iran, duringnot-congested conditions. Considering that uncertainty of positionof vehicles is caused by their acceleration or deceleration, aprobability function is calibrated for calculating the presenceprobability of vehicles in their feasible cells. Multiplying thepresence probability and impact of crash, crash risk of cells iscalculated. As an application of the model, it has been shownthat when difference between vehicles brake deceleration increases,the total crash risk increases.

  3. Development of a speeding-related crash typology.

    NARCIS (Netherlands)

    Council, F.M. Reurings, M. Srinivasan, R. Masten, S. & Carter, C.

    2010-01-01

    Speeding, the driver behaviour of exceeding the posted speed limit or driving too fast for conditions, has consistently been estimated to be a contributing factor to a significant percentage of fatal and nonfatal crashes. The U.S. Department of Transportation has instituted the Speed Management Stra

  4. Nonparametric Analyses of Log-Periodic Precursors to Financial Crashes

    Science.gov (United States)

    Zhou, Wei-Xing; Sornette, Didier

    We apply two nonparametric methods to further test the hypothesis that log-periodicity characterizes the detrended price trajectory of large financial indices prior to financial crashes or strong corrections. The term "parametric" refers here to the use of the log-periodic power law formula to fit the data; in contrast, "nonparametric" refers to the use of general tools such as Fourier transform, and in the present case the Hilbert transform and the so-called (H, q)-analysis. The analysis using the (H, q)-derivative is applied to seven time series ending with the October 1987 crash, the October 1997 correction and the April 2000 crash of the Dow Jones Industrial Average (DJIA), the Standard & Poor 500 and Nasdaq indices. The Hilbert transform is applied to two detrended price time series in terms of the ln(tc-t) variable, where tc is the time of the crash. Taking all results together, we find strong evidence for a universal fundamental log-frequency f=1.02±0.05 corresponding to the scaling ratio λ=2.67±0.12. These values are in very good agreement with those obtained in earlier works with different parametric techniques. This note is extracted from a long unpublished report with 58 figures available at , which extensively describes the evidence we have accumulated on these seven time series, in particular by presenting all relevant details so that the reader can judge for himself or herself the validity and robustness of the results.

  5. Bayesian log-periodic model for financial crashes

    DEFF Research Database (Denmark)

    Rodríguez-Caballero, Carlos Vladimir; Knapik, Oskar

    2014-01-01

    This paper introduces a Bayesian approach in econophysics literature about financial bubbles in order to estimate the most probable time for a financial crash to occur. To this end, we propose using noninformative prior distributions to obtain posterior distributions. Since these distributions...

  6. Two-fractal overlap time series: Earthquakes and market crashes

    Indian Academy of Sciences (India)

    Bikas K Chakrabarti; Arnab Chatterjee; Pratip Bhattacharyya

    2008-08-01

    We find prominent similarities in the features of the time series for the (model earthquakes or) overlap of two Cantor sets when one set moves with uniform relative velocity over the other and time series of stock prices. An anticipation method for some of the crashes have been proposed here, based on these observations.

  7. Exploring older driver crash trend: New Jersey case study

    Directory of Open Access Journals (Sweden)

    Vanvi Trieu

    2014-04-01

    Full Text Available Older drivers age 65 and above are known to experience greater risk on the roadway as well as increasing the risk to other roadway users. Within the next 20 years, their population is expected to increase from 41 million in 2011 to 70 million in 2030. To address this foreseeable change, the nation's recent Moving Ahead for Progress in the 21st Century (MAP-21 act requires state and local governments to examine older drivers and pedestrian risks and implement countermeasures as appropriate. This research was conducted to assist agencies in strategising for future plans, programmes and initiatives to better address the problem presented. This was accomplished by performing a detailed engineering analysis on crash data of older drivers over a 10-year period (2003–2012 from the state of New Jersey to identify crash trends and characteristics. A major finding from this research was the increase in fatal crashes of older drivers as a function of age. Top-ranking collision types with other vehicles and non-vehicles were identified. Crashes as a function of seasonal change, climate and lighting conditions were also examined.

  8. The Impact of Driver Inattention on Near-Crash/Crash Risk: An Analysis Using the 100-Car Naturalistic Driving Study Data

    OpenAIRE

    Klauer, Sheila G.; Dingus, Thomas A.; Neale, Vicki L.; Sudweeks, Jeremy D.; Ramsey, D J

    2006-01-01

    The purpose of this report was to conduct in-depth analyses of driver inattention using the driving data collected in the 100-Car Naturalistic Driving Study. An additional database of baseline epochs was reduced from the raw data and used in conjunction with the crash and near-crash data identified as part of the original 100-Car Study to account for exposure and establish near-crash/crash risk. The analyses presented in this report are able to establish direct relationships between driving b...

  9. 78 FR 13756 - Technical Report: Effectiveness of LED Stop Lamps for Reducing Rear-End Crashes: Analyses of...

    Science.gov (United States)

    2013-02-28

    ... Reducing Rear-End Crashes: Analyses of State Crash Data AGENCY: National Highway Traffic Safety... State Crash Data. DATES: Comments must be received no later than June 28, 2013. ADDRESSES: Report: The...) using real-world crash data. Previous work on this subject included laboratory experiments that...

  10. A model-based, multichannel, real-time capable sawtooth crash detector

    Science.gov (United States)

    van den Brand, H.; de Baar, M. R.; van Berkel, M.; Blanken, T. C.; Felici, F.; Westerhof, E.; Willensdorfer, M.; The ASDEX Upgrade Team; The EUROfusion MST1 Team

    2016-07-01

    Control of the time between sawtooth crashes, necessary for ITER and DEMO, requires real-time detection of the moment of the sawtooth crash. In this paper, estimation of sawtooth crash times is demonstrated using the model-based interacting multiple model (IMM) estimator, based on simplified models for the sawtooth crash. In contrast to previous detectors, this detector uses the spatial extent of the sawtooth crash as detection characteristic. The IMM estimator is tuned and applied to multiple ECE channels at once. A model for the sawtooth crash is introduced, which is used in the IMM algorithm. The IMM algorithm is applied to seven datasets from the ASDEX Upgrade tokamak. Five crash models with different mixing radii are used. All sawtooth crashes that have been identified beforehand by visual inspection of the data, are detected by the algorithm. A few additional detections are made, which upon closer inspection are seen to be sawtooth crashes, which show a partial reconnection. A closer inspection of the detected normal crashes shows that about 42% are not well fitted by any of the full reconnection models and show some characteristics of a partial reconnection. In some case, the measurement time is during the sawtooth crashes, which also results in an incorrect estimate of the mixing radius. For data provided at a sampling rate of 1 kHz, the run time of the IMM estimator is below 1 ms, thereby fulfilling real-time requirements.

  11. Activity modes selection for project crashing through deterministic simulation

    Directory of Open Access Journals (Sweden)

    Ashok Mohanty

    2011-12-01

    Full Text Available Purpose: The time-cost trade-off problem addressed by CPM-based analytical approaches, assume unlimited resources and the existence of a continuous time-cost function. However, given the discrete nature of most resources, the activities can often be crashed only stepwise. Activity crashing for discrete time-cost function is also known as the activity modes selection problem in the project management. This problem is known to be NP-hard. Sophisticated optimization techniques such as Dynamic Programming, Integer Programming, Genetic Algorithm, Ant Colony Optimization have been used for finding efficient solution to activity modes selection problem. The paper presents a simple method that can provide efficient solution to activity modes selection problem for project crashing.Design/methodology/approach: Simulation based method implemented on electronic spreadsheet to determine activity modes for project crashing. The method is illustrated with the help of an example.Findings: The paper shows that a simple approach based on simple heuristic and deterministic simulation can give good result comparable to sophisticated optimization techniques.Research limitations/implications: The simulation based crashing method presented in this paper is developed to return satisfactory solutions but not necessarily an optimal solution.Practical implications: The use of spreadsheets for solving the Management Science and Operations Research problems make the techniques more accessible to practitioners. Spreadsheets provide a natural interface for model building, are easy to use in terms of inputs, solutions and report generation, and allow users to perform what-if analysis.Originality/value: The paper presents the application of simulation implemented on a spreadsheet to determine efficient solution to discrete time cost tradeoff problem.

  12. Seatbelt versus seatbelt and airbag injuries in a single motor vehicle crash

    Science.gov (United States)

    Afifi, Ibrahim; El-Menyar, Ayman; Al-Thani, Hassan; Peralta, Ruben

    2015-01-01

    Seatbelt restraints are important for occupant safety which substantially reduces morbidity and mortality in severe motor vehicle crashes (MVC). Though, it has been established that the air bag and seatbelt use reduce injury severity and mortality but still there is limited information on the pattern of injury by restraint type. Herein, we presented two case reports which describe the injury pattern of two patients (both were restrained but only driver had airbag) involved in a single MVC. Both of them had severe traumatic injuries, however, the restrained passenger without airbag, sustained more severe injuries of intestine, kidney and spinal cord. In addition to seatbelt, airbag provides considerable protection against severe blunt abdominal trauma. Therefore, installation of airbags especially for front seat passenger is imperative for minimizing the risk of significant traumatic injuries. PMID:25810964

  13. Seatbelt versus seatbelt and airbag injuries in a single motor vehicle crash.

    Science.gov (United States)

    Afifi, Ibrahim; El-Menyar, Ayman; Al-Thani, Hassan; Peralta, Ruben

    2015-01-01

    Seatbelt restraints are important for occupant safety which substantially reduces morbidity and mortality in severe motor vehicle crashes (MVC). Though, it has been established that the air bag and seatbelt use reduce injury severity and mortality but still there is limited information on the pattern of injury by restraint type. Herein, we presented two case reports which describe the injury pattern of two patients (both were restrained but only driver had airbag) involved in a single MVC. Both of them had severe traumatic injuries, however, the restrained passenger without airbag, sustained more severe injuries of intestine, kidney and spinal cord. In addition to seatbelt, airbag provides considerable protection against severe blunt abdominal trauma. Therefore, installation of airbags especially for front seat passenger is imperative for minimizing the risk of significant traumatic injuries.

  14. Fatal and serious road crashes involving young New Zealand drivers: a latent class clustering approach

    DEFF Research Database (Denmark)

    Weiss, Harold B.; Kaplan, Sigal; Prato, Carlo Giacomo

    2016-01-01

    classification that revealed how the identified clusters contain mostly crashes of a particular class and all the crashes of that class. The results raised three major safety concerns for young drivers that should be addressed: (1) reckless driving and traffic law violations; (2) inattention, error, and hazard......The over-representation of young drivers in road crashes remains an important concern worldwide. Cluster analysis has been applied to young driver sub-groups, but its application by analysing crash occurrence is just emerging. We present a classification analysis that advances the field through...... a holistic overview of crash patterns useful for designing youth-targeted road safety programmes. We compiled a database of 8644 New Zealand crashes from 2002 to 2011 involving at least one 15–24-year-old driver and a fatal or serious injury for at least one road user. We considered crash location...

  15. Computer simulations and experimental study on crash box of automobile in low speed collision

    Science.gov (United States)

    Liu, Yanjie; Ding, Lin; Yan, Shengyuan; Yang, Yongsheng

    2008-11-01

    Based on the problems of energy-absorbing components in the automobile low speed collision process, according to crash box frontal crash test in low speed as the example, the simulation analysis of crash box impact process was carried out by Hyper Mesh and LS-DYNA. Each parameter on the influence modeling was analyzed by mathematics analytical solution and test comparison, which guaranteed that the model was accurate. Combination of experiment and simulation result had determined the weakness part of crash box structure crashworthiness aspect, and improvement method of crash box crashworthiness was discussed. Through numerical simulation of the impact process of automobile crash box, the obtained analysis result was used to optimize the design of crash box. It was helpful to improve the vehicles structure and decrease the collision accident loss at most. And it was also provided a useful method for the further research on the automobile collision.

  16. Assessing Patient bypass Behavior Using Taxi Trip Origin–Destination (OD Data

    Directory of Open Access Journals (Sweden)

    Gege Yang

    2016-09-01

    Full Text Available Many patients prefer to use the best hospitals even if there are one or more other hospitals closer to their homes; this behavior is called “hospital bypass behavior”. Because this behavior can be problematic in urban areas, it is important that it be reduced. In this paper, the taxi GPS data of Beijing and Suzhou were used to measure hospital bypass behavior. The “bypass behavior index” (BBI represents the bypass behavior for each hospital. The results indicated that the mean hospital bypass trip distance value ranges from 5.988 km to 9.754 km in Beijing and from 4.168 km to 10.283 km in Suzhou. In general, the bypass shares of both areas show a gradually increasing trend. The following hospitals exhibited significant patient bypass behavior: the 301 Hospital, Beijing Children’s Hospital, the Second Affiliated Hospital of Soochow University and the Suzhou Hospital of Traditional Chinese Medicine. The hospitals’ reputation, transport accessibility and spatial distribution were found to be the main factors affecting patient bypass behavior. Although the hospital bypass phenomena generally appeared to be more pronounced in Beijing, the bypass trip distances between hospitals were found to be more significant in Suzhou.

  17. The Detection of Transport Land-Use Data Using Crowdsourcing Taxi Trajectory

    Science.gov (United States)

    Ai, T.; Yang, W.

    2016-06-01

    This study tries to explore the question of transport land-use change detection by large volume of vehicle trajectory data, presenting a method based on Deluanay triangulation. The whole method includes three steps. The first one is to pre-process the vehicle trajectory data including the point anomaly removing and the conversion of trajectory point to track line. Secondly, construct Deluanay triangulation within the vehicle trajectory line to detect neighborhood relation. Considering the case that some of the trajectory segments are too long, we use a interpolation measure to add more points for the improved triangulation. Thirdly, extract the transport road by cutting short triangle edge and organizing the polygon topology. We have conducted the experiment of transport land-use change discovery using the data of taxi track in Beijing City. We extract not only the transport land-use area but also the semantic information such as the transformation speed, the traffic jam distribution, the main vehicle movement direction and others. Compared with the existed transport network data, such as OpenStreet Map, our method is proved to be quick and accurate.

  18. Reactivation of latent herpes viruses in cosmonauts during a soyuz taxi mission

    Science.gov (United States)

    Mehta, Satish K.; Pierson, Duane L.

    2007-09-01

    The hypothesis tested by this project is that space flight increases the incidence and duration of herpes virus reactivation and shedding in saliva. Saliva, urine, and blood samples were collected from 3 crew members who participated in a 14-day Odessa Soyuz taxi mission. Saliva samples were collected before, during, and after the mission, and blood and urine were collected before and after the mission. The saliva and urine samples were analyzed using the polymerase chain reaction to detect the presence of 3 important herpes viruses. Epstein-Barr virus (EBV) and varicella-zoster virus (VZV) were tested in saliva, and cytomegalovirus (CMV) was measured in urine samples. Plasma antibodies levels to these viruses were determined by enzyme-linked immunosorbent assay before and after flight. EBV reactivated before, during, and after flight; CMV reactivated before and after flight; and VZV reactivated during and after flight. In other studies, greater frequencies of positive samples and greater numbers of copies of viral DNA have been found. No increases in titer of antibodies to these viruses were found, suggesting that an immune response may not be necessary for reactivation.

  19. Autonomous taxis could greatly reduce greenhouse-gas emissions of US light-duty vehicles

    Science.gov (United States)

    Greenblatt, Jeffery B.; Saxena, Samveg

    2015-09-01

    Autonomous vehicles (AVs) are conveyances to move passengers or freight without human intervention. AVs are potentially disruptive both technologically and socially, with claimed benefits including increased safety, road utilization, driver productivity and energy savings. Here we estimate 2014 and 2030 greenhouse-gas (GHG) emissions and costs of autonomous taxis (ATs), a class of fully autonomous shared AVs likely to gain rapid early market share, through three synergistic effects: (1) future decreases in electricity GHG emissions intensity, (2) smaller vehicle sizes resulting from trip-specific AT deployment, and (3) higher annual vehicle-miles travelled (VMT), increasing high-efficiency (especially battery-electric) vehicle cost-effectiveness. Combined, these factors could result in decreased US per-mile GHG emissions in 2030 per AT deployed of 87-94% below current conventionally driven vehicles (CDVs), and 63-82% below projected 2030 hybrid vehicles, without including other energy-saving benefits of AVs. With these substantial GHG savings, ATs could enable GHG reductions even if total VMT, average speed and vehicle size increased substantially. Oil consumption would also be reduced by nearly 100%.

  20. Analysis and Application of Intelligent Transportation Systems to Taxi System in Cameroon

    Institute of Scientific and Technical Information of China (English)

    Nzegge Chantale Ebude; Wang Mingyan

    2007-01-01

    Most traffic control systems available in major cities in Cameroon are still out dated,make use of theories and models which are very slow to implement,waste resources and their efficiency is very low.Thus the number of road accidents encountered on our major highways and inter urban traffic networks has been increasing despite the various efforts made by government and certain NGO to synthesize road users on certain aspects of traffic control and safety road use.Taxis are not left out in the whole show and most of the blame always falls on them.The need to use available Information and Communication Technology ICT to improve on the control of traffic in inter urban cities and major highways is imperative.ITS optimizes the use of resources,reduce pollution,contribute to environmental protection and increases the national economy.This paper starts by giving a brief situation of the transportation system in Cameroon,its drawbacks and proposes an optimized ITS based system.

  1. Crash Injury Prediction and Vehicle Damage Reporting by Paramedics: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Vaca, Federico E

    2009-05-01

    Full Text Available OBJECTIVE: The accuracy of pre-hospital crash scene details and crash victim assessment has important implications for initial trauma care assessment and management. Similarly, it is known to influence physician perception of crash victim injury severity. The goal of this feasibility study was to examine paramedic accuracy in predicting crash victim injury profile, disability outcome at hospital discharge, and reporting vehicle damage with other crash variables.METHODS: This prospective case series study was undertaken at a Southern California, Level I trauma center certified by the American College of Surgeons. Paramedics transporting crash injured motor vehicle occupants to our emergency department (ED/trauma center were surveyed. We abstracted ED and in-patient records of injured vehicle occupants. Vehicle and crash scene data were obtained from a professional crash reconstruction, which included the assessment of deformation, crash forces, change in velocity, and the source of each injury.RESULTS: We used survey, injury, and crash reconstruction data from 22 collision cases in the final analysis. The median Injury Severity Score (ISS was five (range 1-24. No enrolled patients died, and none were severely disabled at the time of discharge from the hospital. The paramedic crash injury severity predictions were sensitive for an Abbreviated Injury Scale (AIS of 2-4. Paramedics often agreed with the crash reconstruction on restraint use, ejection, and other fatalities at the scene, and had lower levels of agreement for front airbag deployment, steering wheel damage, and window/windshield impact. Paramedics had 80% accuracy in predicting any disability at the time of hospital discharge.CONCLUSION: Paramedic prediction of injury profile was sensitive, and prediction of disability outcome at discharge was accurate when compared to discharge diagnosis. Their reporting of vehicle specific crash variables was less accurate. Further study should be

  2. Crash risk analysis for Shanghai urban expressways: A Bayesian semi-parametric modeling approach.

    Science.gov (United States)

    Yu, Rongjie; Wang, Xuesong; Yang, Kui; Abdel-Aty, Mohamed

    2016-10-01

    Urban expressway systems have been developed rapidly in recent years in China; it has become one key part of the city roadway networks as carrying large traffic volume and providing high traveling speed. Along with the increase of traffic volume, traffic safety has become a major issue for Chinese urban expressways due to the frequent crash occurrence and the non-recurrent congestions caused by them. For the purpose of unveiling crash occurrence mechanisms and further developing Active Traffic Management (ATM) control strategies to improve traffic safety, this study developed disaggregate crash risk analysis models with loop detector traffic data and historical crash data. Bayesian random effects logistic regression models were utilized as it can account for the unobserved heterogeneity among crashes. However, previous crash risk analysis studies formulated random effects distributions in a parametric approach, which assigned them to follow normal distributions. Due to the limited information known about random effects distributions, subjective parametric setting may be incorrect. In order to construct more flexible and robust random effects to capture the unobserved heterogeneity, Bayesian semi-parametric inference technique was introduced to crash risk analysis in this study. Models with both inference techniques were developed for total crashes; semi-parametric models were proved to provide substantial better model goodness-of-fit, while the two models shared consistent coefficient estimations. Later on, Bayesian semi-parametric random effects logistic regression models were developed for weekday peak hour crashes, weekday non-peak hour crashes, and weekend non-peak hour crashes to investigate different crash occurrence scenarios. Significant factors that affect crash risk have been revealed and crash mechanisms have been concluded.

  3. Evaluation of rear-end crash risk at work zone using work zone traffic data.

    Science.gov (United States)

    Meng, Qiang; Weng, Jinxian

    2011-07-01

    This paper aims to evaluate the rear-end crash risk at work zone activity area and merging area, as well as analyze the impacts of contributing factors by using work zone traffic data. Here, the rear-end crash risk is referred to as the probability that a vehicle is involved in a rear-end crash accident. The deceleration rate to avoid the crash (DRAC) is used in measuring rear-end crash risk. Based on work zone traffic data in Singapore, three rear-end crash risk models are developed to examine the relationship between rear-end crash risk at activity area and its contributing factors. The fourth rear-end crash risk model is developed to examine the effects of merging behavior on crash risk at merging area. The ANOVA results show that the rear-end crash risk at work zone activity area is statistically different from lane positions. Model results indicate that rear-end crash risk at work zone activity area increases with heavy vehicle percentage and lane traffic flow rate. An interesting finding is that the lane closer to work zone is strongly associated with higher rear-end crash risk. A truck has much higher probability involving in a rear-end accident than a car. Further, the expressway work zone activity area is found to have much larger crash risk than arterial work zone activity area. The merging choice has the dominated effect on risk reduction, suggesting that encouraging vehicles to merge early may be the most effective method to reduce rear-end crash risk at work zone merging area.

  4. The effects of age, gender, and crash types on drivers' injury-related health care costs.

    Science.gov (United States)

    Shen, Sijun; Neyens, David M

    2015-04-01

    There are many studies that evaluate the effects of age, gender, and crash types on crash related injury severity. However, few studies investigate the effects of those crash factors on the crash related health care costs for drivers that are transported to hospital. The purpose of this study is to examine the relationships between drivers' age, gender, and the crash types, as well as other crash characteristics (e.g., not wearing a seatbelt, weather condition, and fatigued driving), on the crash related health care costs. The South Carolina Crash Outcome Data Evaluation System (SC CODES) from 2005 to 2007 was used to construct six separate hierarchical linear regression models based on drivers' age and gender. The results suggest that older drivers have higher health care costs than younger drivers and male drivers tend to have higher health care costs than female drivers in the same age group. Overall, single vehicle crashes had the highest health care costs for all drivers. For males older than 64-years old sideswipe crashes are as costly as single vehicle crashes. In general, not wearing a seatbelt, airbag deployment, and speeding were found to be associated with higher health care costs. Distraction-related crashes are more likely to be associated with lower health care costs in most cases. Furthermore this study highlights the value of considering drivers in subgroups, as some factors have different effects on health care costs in different driver groups. Developing an understanding of longer term outcomes of crashes and their characteristics can lead to improvements in vehicle technology, educational materials, and interventions to reduce crash-related health care costs.

  5. Spatial panel analyses of alcohol outlets and motor vehicle crashes in California: 1999-2008.

    Science.gov (United States)

    Ponicki, William R; Gruenewald, Paul J; Remer, Lillian G

    2013-06-01

    Although past research has linked alcohol outlet density to higher rates of drinking and many related social problems, there is conflicting evidence of density's association with traffic crashes. An abundance of local alcohol outlets simultaneously encourages drinking and reduces driving distances required to obtain alcohol, leading to an indeterminate expected impact on alcohol-involved crash risk. This study separately investigates the effects of outlet density on (1) the risk of injury crashes relative to population and (2) the likelihood that any given crash is alcohol-involved, as indicated by police reports and single-vehicle nighttime status of crashes. Alcohol outlet density effects are estimated using Bayesian misalignment Poisson analyses of all California ZIP codes over the years 1999-2008. These misalignment models allow panel analysis of ZIP-code data despite frequent redefinition of postal-code boundaries, while also controlling for overdispersion and the effects of spatial autocorrelation. Because models control for overall retail density, estimated alcohol-outlet associations represent the extra effect of retail establishments selling alcohol. The results indicate a number of statistically well-supported associations between retail density and crash behavior, but the implied effects on crash risks are relatively small. Alcohol-serving restaurants have a greater impact on overall crash risks than on the likelihood that those crashes involve alcohol, whereas bars primarily affect the odds that crashes are alcohol-involved. Off-premise outlet density is negatively associated with risks of both crashes and alcohol involvement, while the presence of a tribal casino in a ZIP code is linked to higher odds of police-reported drinking involvement. Alcohol outlets in a given area are found to influence crash risks both locally and in adjacent ZIP codes, and significant spatial autocorrelation also suggests important relationships across geographical units

  6. Predicting crash likelihood and severity on freeways with real-time loop detector data.

    Science.gov (United States)

    Xu, Chengcheng; Tarko, Andrew P; Wang, Wei; Liu, Pan

    2013-08-01

    Real-time crash risk prediction using traffic data collected from loop detector stations is useful in dynamic safety management systems aimed at improving traffic safety through application of proactive safety countermeasures. The major drawback of most of the existing studies is that they focus on the crash risk without consideration of crash severity. This paper presents an effort to develop a model that predicts the crash likelihood at different levels of severity with a particular focus on severe crashes. The crash data and traffic data used in this study were collected on the I-880 freeway in California, United States. This study considers three levels of crash severity: fatal/incapacitating injury crashes (KA), non-incapacitating/possible injury crashes (BC), and property-damage-only crashes (PDO). The sequential logit model was used to link the likelihood of crash occurrences at different severity levels to various traffic flow characteristics derived from detector data. The elasticity analysis was conducted to evaluate the effect of the traffic flow variables on the likelihood of crash and its severity.The results show that the traffic flow characteristics contributing to crash likelihood were quite different at different levels of severity. The PDO crashes were more likely to occur under congested traffic flow conditions with highly variable speed and frequent lane changes, while the KA and BC crashes were more likely to occur under less congested traffic flow conditions. High speed, coupled with a large speed difference between adjacent lanes under uncongested traffic conditions, was found to increase the likelihood of severe crashes (KA). This study applied the 20-fold cross-validation method to estimate the prediction performance of the developed models. The validation results show that the model's crash prediction performance at each severity level was satisfactory. The findings of this study can be used to predict the probabilities of crash at

  7. Comparison of pregnant and non-pregnant occupant crash and injury characteristics based on national crash data.

    Science.gov (United States)

    Manoogian, Sarah

    2015-01-01

    The objective of this study was to provide specific characteristics of injuries and crash characteristics for pregnant occupants from the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS) database for pregnant women as a group, broken down by trimester, and compared to non-pregnant women. Using all NASS/CDS cases collected between the years 2000 and 2012 with at least one pregnant occupant, the entire pregnant data set included 321,820 vehicles, 324,535 occupants, and 640,804 injuries. The pregnant occupant data were compared to the characteristics of NASS/CDS cases for 14,719,533 non-pregnant females 13-44 years old in vehicle crashes from 2000 to 2012. Sixty five percent of pregnant women were located in the front left seat position and roughly the same percentage of pregnant women was wearing a lap and shoulder belt. The average change in velocity was 11.6 mph for pregnant women and over 50% of crashes for pregnant women were frontal collisions. From these collisions, less than seven percent of pregnant women sustained MAIS 2+ injuries. Minor differences between the pregnant and non-pregnant occupants were identified in the body region and source of injuries sustained. However, the data indicated no large differences in injury or crash characteristics based on trimester of pregnancy. Moreover, the risk of an MAIS 2+ level injury for pregnant occupants is similar to the risk of injury for non-pregnant occupants based on the total vehicle change in velocity. Overall this study provides useful data for researchers to focus future efforts in pregnant occupant research. Additionally, this study reinforces that more detailed and complete data on pregnant crashes needs to be collected to understand the risk for pregnant occupants.

  8. Crash data quality for road safety research: Current state and future directions.

    Science.gov (United States)

    Imprialou, Marianna; Quddus, Mohammed

    2017-03-02

    Crash databases are one of the primary data sources for road safety research. Therefore, their quality is fundamental for the accuracy of crash analyses and, consequently the design of effective countermeasures. Although crash data often suffer from correctness and completeness issues, these are rarely discussed or addressed in crash analyses. Crash reports aim to answer the five "W" questions (i.e. When?, Where?, What?, Who? and Why?) of each crash by including a range of attributes. This paper reviews current literature on the state of crash data quality for each of these questions separately. The most serious data quality issues appear to be: inaccuracies in crash location and time, difficulties in data linkage (e.g. with traffic data) due to inconsistencies in databases, severity misclassification, inaccuracies and incompleteness of involved users' demographics and inaccurate identification of crash contributory factors. It is shown that the extent and the severity of data quality issues are not equal between attributes and the level of impact in road safety analyses is not yet entirely known. This paper highlights areas that require further research and provides some suggestions for the development of intelligent crash reporting systems.

  9. A Hybrid Latent Class Analysis Modeling Approach to Analyze Urban Expressway Crash Risk.

    Science.gov (United States)

    Yu, Rongjie; Wang, Xuesong; Abdel-Aty, Mohamed

    2017-02-07

    Crash risk analysis is rising as a hot research topic as it could reveal the relationships between traffic flow characteristics and crash occurrence risk, which is beneficial to understand crash mechanisms which would further refine the design of Active Traffic Management System (ATMS). However, the majority of the current crash risk analysis studies have ignored the impact of geometric characteristics on crash risk estimation while recent studies proved that crash occurrence risk was affected by the various alignment features. In this study, a hybrid Latent Class Analysis (LCA) modeling approach was proposed to account for the heterogeneous effects of geometric characteristics. Crashes were first segmented into homogenous subgroups, where the optimal number of latent classes was identified based on bootstrap likelihood ratio tests. Then, separate crash risk analysis models were developed using Bayesian random parameter logistic regression technique; data from Shanghai urban expressway system were employed to conduct the empirical study. Different crash risk contributing factors were unveiled by the hybrid LCA approach and better model goodness-of-fit was obtained while comparing to an overall total crash model. Finally, benefits of the proposed hybrid LCA approach were discussed.

  10. Investigating driver injury severity patterns in rollover crashes using support vector machine models.

    Science.gov (United States)

    Chen, Cong; Zhang, Guohui; Qian, Zhen; Tarefder, Rafiqul A; Tian, Zong

    2016-05-01

    Rollover crash is one of the major types of traffic crashes that induce fatal injuries. It is important to investigate the factors that affect rollover crashes and their influence on driver injury severity outcomes. This study employs support vector machine (SVM) models to investigate driver injury severity patterns in rollover crashes based on two-year crash data gathered in New Mexico. The impacts of various explanatory variables are examined in terms of crash and environmental information, vehicle features, and driver demographics and behavior characteristics. A classification and regression tree (CART) model is utilized to identify significant variables and SVM models with polynomial and Gaussian radius basis function (RBF) kernels are used for model performance evaluation. It is shown that the SVM models produce reasonable prediction performance and the polynomial kernel outperforms the Gaussian RBF kernel. Variable impact analysis reveals that factors including comfortable driving environment conditions, driver alcohol or drug involvement, seatbelt use, number of travel lanes, driver demographic features, maximum vehicle damages in crashes, crash time, and crash location are significantly associated with driver incapacitating injuries and fatalities. These findings provide insights for better understanding rollover crash causes and the impacts of various explanatory factors on driver injury severity patterns.

  11. Evaluation of the predictability of real-time crash risk models.

    Science.gov (United States)

    Xu, Chengcheng; Liu, Pan; Wang, Wei

    2016-09-01

    The primary objective of the present study was to investigate the predictability of crash risk models that were developed using high-resolution real-time traffic data. More specifically the present study sought answers to the following questions: (a) how to evaluate the predictability of a real-time crash risk model; and (b) how to improve the predictability of a real-time crash risk model. The predictability is defined as the crash probability given the crash precursor identified by the crash risk model. An equation was derived based on the Bayes' theorem for estimating approximately the predictability of crash risk models. The estimated predictability was then used to quantitatively evaluate the effects of the threshold of crash precursors, the matched and unmatched case-control design, and the control-to-case ratio on the predictability of crash risk models. It was found that: (a) the predictability of a crash risk model can be measured as the product of prior crash probability and the ratio between sensitivity and false alarm rate; (b) there is a trade-off between the predictability and sensitivity of a real-time crash risk model; (c) for a given level of sensitivity, the predictability of the crash risk model that is developed using the unmatched case-controlled sample is always better than that of the model developed using the matched case-controlled sample; and (d) when the control-to-case ratio is beyond 4:1, the increase in control-to-case ratio does not lead to clear improvements in predictability.

  12. Aeromedical Evacuation: Validating Civil Reserve Air Fleet

    Science.gov (United States)

    2009-02-25

    Aeromedical Evacuation: Validating Civil Reserve Air Fleet FORMAT : Civilian Research Paper DATE: 25 February 2009 WORDS: 10,172 PAGES: 56 CLASSIFICATION... Barrancas , Florida, in 1910. Unfortunately, on its first test flight, it flew only 500 yards at an altitude of 100 feet before crashing. This flight

  13. Analysis and improved design of the taxi internal facilities%出租车内部设施分析与改善设计

    Institute of Scientific and Technical Information of China (English)

    江明明; 王霞; 童一飞

    2015-01-01

    It introduces the current design of the taxi internal facilities.In order to improve the design of taxi in-ternal facilities, it presents the special requirements of such special groups as baby and the disabled.Then it de-termines the dimension in ergonomics, establishes the model of the improved taxi internal facilities based on SolidWorks.%分析了目前出租车内部设施的设计,针对婴儿和残疾人这两类特殊人群的特殊需求,运用人机工程学,确定车身和婴儿座椅的设计尺寸,对出租车的内部设施做出改善和重新设计。利用SolidWorks建立模型,得到出租车内部设施改善后的模型。

  14. Transient analysis techniques in performing impact and crash dynamic studies

    Science.gov (United States)

    Pifko, A. B.; Winter, R.

    1989-01-01

    Because of the emphasis being placed on crashworthiness as a design requirement, increasing demands are being made by various organizations to analyze a wide range of complex structures that must perform safely when subjected to severe impact loads, such as those generated in a crash event. The ultimate goal of crashworthiness design and analysis is to produce vehicles with the ability to reduce the dynamic forces experienced by the occupants to specified levels, while maintaining a survivable envelope around them during a specified crash event. DYCAST is a nonlinear structural dynamic finite element computer code that started from the plans systems of a finite element program for static nonlinear structural analysis. The essential features of DYCAST are outlined.

  15. Identifying the Bottom Line after a Stock Market Crash

    Science.gov (United States)

    Roehner, B. M.

    In this empirical paper we show that in the months following a crash there is a distinct connection between the fall of stock prices and the increase in the range of interest rates for a sample of bonds. This variable, which is often referred to as the interest rate spread variable, can be considered as a statistical measure for the disparity in lenders' opinions about the future; in other words, it provides an operational definition of the uncertainty faced by economic agents. The observation that there is a strong negative correlation between stock prices and the spread variable relies on the examination of eight major crashes in the United States between 1857 and 1987. That relationship which has remained valid for one and a half century in spite of important changes in the organization of financial markets can be of interest in the perspective of Monte Carlo simulations of stock markets.

  16. Relationship of Worldwide Rocket Launch Crashes with Geophysical Parameters

    Directory of Open Access Journals (Sweden)

    N. Romanova

    2013-01-01

    Full Text Available A statistical comparison of launch crashes at different worldwide space ports with geophysical factors has been performed. A comprehensive database has been compiled, which includes 50 years of information from the beginning of the space age in 1957 about launch crashes occurring world-wide. Special attention has been paid to statistics concerning launches at the largest space ports: Plesetsk, Baikonur, Cape Canaveral, and Vandenberg. In search of a possible influence of geophysical factors on launch failures, such parameters as the vehicle type, local time, season, sunspot number, high-energy electron fluxes, and solar proton events have been examined. Also, we have analyzed correlations with the geomagnetic indices as indirect indicators of the space weather condition. Regularities found in this study suggest that further detailed studies of space weather effects on launcher systems, especially in the high-latitude regions, should be performed.

  17. Simulations of Laboratory Astrophysics Experiments using the CRASH code

    Science.gov (United States)

    Trantham, Matthew; Kuranz, Carolyn; Fein, Jeff; Wan, Willow; Young, Rachel; Keiter, Paul; Drake, R. Paul

    2015-11-01

    Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, magnetized flows, jets, and laser-produced plasmas. This work is funded by the following grants: DEFC52-08NA28616, DE-NA0001840, and DE-NA0002032.

  18. Factors associated with HIV testing among male motorbike taxi drivers in urban Vietnam.

    Science.gov (United States)

    Huy, Nguyen Van; Khuyen, Le Thi; Ha, Pham Nguyen

    2015-01-01

    Using the Attitude-Skills-Knowledge (ASK) model, this study examined the prevalence of, and factors associated with, human immunodeficiency virus (HIV) testing among male motorbike taxi drivers (MMTDs). In a cross-sectional design, using quantitative approaches, 291 MMTDs were recruited from 135 sites across 13 districts in Hanoi, Vietnam, for a face-to-face interview. Applying the ASK model modified as a central theory, logistic regression was used to identify determinants of HIV testing. Although many MMTDs engaged in multiple risk behaviours for HIV, only 20.6% had been tested for HIV during the past 12 months. The tested model included one factor of the ASK model, HIV prevention knowledge (adjusted odds ratio [AOR] = 4.76; 95% confidence interval [CI] = 2.12-10.7) and five additional factors: being married (AOR = 3.13; 95% CI = 1.25-4.78), preferring sex with men or with both men and women (AOR = 8.72; 95% CI = 1.48-51.5), having lower number of lifetime sex partners (AOR = 0.66; 95% CI = 0.49-0.88), higher number of past year sex partners (AOR = 2.97: 95% CI = 1.21-7.31) and discussing condom use when having sex with partners (AOR = 0.08; 95% CI = 0.01-7.31). This modified ASK model provided better fit than the ASK model, as it explained more variance in HIV testing (47 vs. 29.8%). Recognising factors associated with HIV testing among MMTDs enables us to create suitable public health intervention strategies.

  19. Car Crashes and Central Disorders of Hypersomnolence: A French Study.

    Directory of Open Access Journals (Sweden)

    Fabio Pizza

    Full Text Available Drowsiness compromises driving ability by reducing alertness and attentiveness, and delayed reaction times. Sleep-related car crashes account for a considerable proportion of accident at the wheel. Narcolepsy type 1 (NT1, narcolepsy type 2 (NT2 and idiopathic hypersomnia (IH are rare central disorders of hypersomnolence, the most severe causes of sleepiness thus being potential dangerous conditions for both personal and public safety with increasing scientific, social, and political attention. Our main objective was to assess the frequency of recent car crashes in a large cohort of patients affected with well-defined central disorders of hypersomnolence versus subjects from the general population.We performed a cross-sectional study in French reference centres for rare hypersomnia diseases and included 527 patients and 781 healthy subjects. All participants included needed to have a driving license, information available on potential accident events during the last 5 years, and on potential confounders; thus analyses were performed on 282 cases (71 IH, 82 NT2, 129 NT1 and 470 healthy subjects.Patients reported more frequently than healthy subjects the occurrence of recent car crashes (in the previous five years, a risk that was confirmed in both treated and untreated subjects at study inclusion (Untreated, OR = 2.21 95%CI = [1.30-3.76], Treated OR = 2.04 95%CI = [1.26-3.30], as well as in all disease categories, and was modulated by subjective sleepiness level (Epworth scale and naps. Conversely, the risk of car accidents of patients treated for at least 5 years was not different to healthy subjects (OR = 1.23 95%CI = [0.56-2.69]. Main risk factors were analogous in patients and healthy subjects.Patients affected with central disorders of hypersomnolence had increased risk of recent car crashes compared to subjects from the general population, a finding potentially reversed by long-term treatment.

  20. 基于网格划分的城市出租车合乘研究%Study on Taxi Carpooling Based on City Gridding

    Institute of Scientific and Technical Information of China (English)

    潘国强

    2013-01-01

    A brand-new and bus-like city taxi operation mode which is based on city gridding is presented after analyzing the drawbacks of the current situation of city taxies. With reference from city bus stops, the method of setting taxi stations is suggested. The factors that may affect the implementation of city carpooling is analyzed. By developing the objective function and relevant constraint conditions, the mathematical model for maximizing the benefits of taxi drivers and clients, and minimizing the taxi route is established. It will serve as theoretical references for cities to adopt new taxi operation modes.%  根据现行出租车运营方式的不足,提出了基于城市网格划分的出租车公交化运营模式。参照城市公交站点的设置方法,提出了网格化出租车站点的设置方法。分析了影响出租车合乘的因素,通过出租车合乘运营目标函数及约束条件的建立,提出了该模式下出租车司机、乘客利益最大化以及行车路线最短的数学模型,为城市新型出租车运营模式的推行提供理论上的参考。

  1. Optimizing Scrip Systems: Efficiency, Crashes, Hoarders, and Altruists

    CERN Document Server

    Kash, Ian A; Halpern, Joseph Y

    2007-01-01

    We discuss the design of efficient scrip systems and develop tools for empirically analyzing them. For those interested in the empirical study of scrip systems, we demonstrate how characteristics of agents in a system can be inferred from the equilibrium distribution of money. From the perspective of a system designer, we examine the effect of the money supply on social welfare and show that social welfare is maximized by increasing the money supply up to the point that the system experiences a ``monetary crash,'' where money is sufficiently devalued that no agent is willing to perform a service. We also examine the implications of the presence of altruists and hoarders on the performance of the system. While a small number of altruists may improve social welfare, too many can also cause the system to experience a monetary crash, which may be bad for social welfare. Hoarders generally decrease social welfare but, surprisingly, they also promote system stability by helping prevent monetary crashes. In addition...

  2. A Study of Transport Airplane Crash-Resistant Fuel Systems

    Science.gov (United States)

    Jones, Lisa (Technical Monitor); Robertson, S. H.; Johnson, N. B.; Hall, D. S.; Rimson, I. J.

    2002-01-01

    This report presents the results of a study, funded by the Federal Aviation Administration (FAA), of transport airplane crash-resistant fuel system (CRFS). The report covers the historical studies related to aircraft crash fires and fuel containment concepts undertaken by the FAA, NASA, and the U.S. Army, which ultimately led to the current state of the art in CRFS technology. It describes the basic research, testing, field investigations and production efforts which have led to the highly successful military CRFS, which has saved many lives and reduced costs of accidents. Current CRFS technology used in transport category airplanes is defined and compared to the available state-of-the-art technology. The report provides information to the FAA and other government organizations which can help them plan their efforts to improve the state of crash fire protection in the transport airplane fleet. The report provides guidance to designers looking for information about CRFS design problems, analysis tools to use for product improvement, and a summary of current and proposed regulations for transport category airplane fuel systems.

  3. Numerical Simulation of Helicopter Cockpit Seat subjected to Crash Impact

    Directory of Open Access Journals (Sweden)

    M.N. Sulaiman

    2013-01-01

    Full Text Available Sikorsky S-61 or better known as “Nuri” had served the Malaysian aviation sector for the past four decades. It is mainly used for transportation, combat search and rescue purposes. However, there were Nuri helicopter crashes or accident cases reported during its operation period which involved loss of its occupants. The pilot survivability rate can be improved provided that the vertical impact loading on the helicopter is reduced during the crash accident. Utilization of an energy absorbing pilot seat or cockpit structure maybe one of the approaches to minimize the impact shock exerted to the occupants. However, the shock or maximum acceleration of the cockpit/pilot seat has to be first determined before a thorough design scheme can be undertaken. In this study, a vertical crash event of the Nuri pilot seat from 500 feet altitude was simulated and the maximum acceleration rate was determined using MSC PATRAN/LSDYNA. The pilot survivability was determined by comparing the result with human tolerance criteria data available in other published works. From the result, it was found that the maximum acceleration of the Nuri pilot seat was 584.4g at 19. 63 milliseconds, thus it can be concluded that the survivability aspect of the pilot is fatal when compared to other published works.

  4. Analysis of fatal road traffic crashes in Ghana.

    Science.gov (United States)

    Ackaah, Williams; Adonteng, David O

    2011-03-01

    The major objective of this study was to identify the risk factors associated with fatal road traffic crashes (RTCs) and to propose remedial measures to address them. Fatal RTC data for the period 2005-2007 in Ghana were analysed using the Micro-computer Accident Analysis Package (MAAP) software. Other transport-related research works were reviewed and incorporated in the article. The study showed that pedestrians accounted for 42% of all road traffic fatalities and nearly one-third (33%) of these crashes occurred during the early night-time hours. Children alone constituted almost one-third of all pedestrian fatalities. The occupants of goods vehicles accounted for 12% of all road traffic fatalities although goods vehicles constitute just about 9% of the total motor vehicle population in Ghana. Pedestrians, especially children bear a disproportionately high share of road traffic fatalities in Ghana. The risk of being killed as a pedestrian in traffic is exacerbated during night time. Excessive vehicular speeds, inappropriate use of goods vehicles for passenger transport, excessive loading and inadequate trauma care are the key contributory risk factors to the high number of road traffic fatalities. Concerted efforts spanning education, engineering, enforcement and trauma care are needed to stem the rise in fatal crashes in Ghana.

  5. The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature

    Directory of Open Access Journals (Sweden)

    Cripton Peter A

    2009-10-01

    Full Text Available Abstract Background Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists. Methods We reviewed studies of the impact of transportation infrastructure on bicyclist safety. The results were tabulated within two categories of infrastructure, namely that at intersections (e.g. roundabouts, traffic lights or between intersections on "straightaways" (e.g. bike lanes or paths. To assess safety, studies examining the following outcomes were included: injuries; injury severity; and crashes (collisions and/or falls. Results The literature to date on transportation infrastructure and cyclist safety is limited by the incomplete range of facilities studied and difficulties in controlling for exposure to risk. However, evidence from the 23 papers reviewed (eight that examined intersections and 15 that examined straightaways suggests that infrastructure influences injury and crash risk. Intersection studies focused mainly on roundabouts. They found that multi-lane roundabouts can significantly increase risk to bicyclists unless a separated cycle track is included in the design. Studies of straightaways grouped facilities into few categories, such that facilities with potentially different risks may have been classified within a single category. Results to date suggest that sidewalks and multi-use trails pose the highest risk, major roads are more hazardous than minor roads, and the presence of bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths was associated with the lowest

  6. Tearing mode formation induced by internal crash events at different β N

    Science.gov (United States)

    Igochine, V.; Classen, I.; Dunne, M.; Gude, A.; Günter, S.; Lackner, K.; McDermott, R. M.; Sertoli, M.; Vezinet, D.; Willensdorfer, M.; Yu, Q.; Zohm, H.; ASDEX Upgrade Team

    2017-03-01

    Tearing mode formation after internal crash events like sawteeth or fishbones is one of the most important MHD processes that results in a big island structure and associated confinement degradation. The process implies magnetic reconnection at the rational surface, which has been investigated in great detail in the ASDEX Upgrade tokamak. Using direct local measurements, it is found that the crash leads to the formation of an ideal kink mode with large saturated amplitude at the resonant surface immediately after the sawtooth crash. This kink mode transforms into a tearing mode on a much longer timescale than the crash itself. The ideal kink mode, formed at the resonant surface after the crash, provides the driving force for the magnetic reconnection. The conversion of the ideal kink mode into a tearing mode after the internal crash is similar for various values of plasma rotation and normalized pressure.

  7. Driver crash risk factors and prevalence evaluation using naturalistic driving data.

    Science.gov (United States)

    Dingus, Thomas A; Guo, Feng; Lee, Suzie; Antin, Jonathan F; Perez, Miguel; Buchanan-King, Mindy; Hankey, Jonathan

    2016-03-08

    The accurate evaluation of crash causal factors can provide fundamental information for effective transportation policy, vehicle design, and driver education. Naturalistic driving (ND) data collected with multiple onboard video cameras and sensors provide a unique opportunity to evaluate risk factors during the seconds leading up to a crash. This paper uses a National Academy of Sciences-sponsored ND dataset comprising 905 injurious and property damage crash events, the magnitude of which allows the first direct analysis (to our knowledge) of causal factors using crashes only. The results show that crash causation has shifted dramatically in recent years, with driver-related factors (i.e., error, impairment, fatigue, and distraction) present in almost 90% of crashes. The results also definitively show that distraction is detrimental to driver safety, with handheld electronic devices having high use rates and risk.

  8. Associating Crash Avoidance Maneuvers with Driver Attributes and Accident Characteristics: A Mixed Logit Model Approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    This study focuses on the propensity of drivers to engage in crash avoidance maneuvers in relation to driver attributes, critical events, crash characteristics, vehicles involved, road characteristics and environmental attributes. Five alternative actions involving emergency lateral and speed...... as from the key role of the ability of drivers to perform effective corrective maneuvers for the success of automated in-vehicle warning and driver assistance systems. The analysis is conducted by means of a mixed logit model that accommodates correlations across alternatives and heteroscedasticity. Data...... for the analysis are retrieved from the General Estimates System (GES) crash database for the year 2009. Results show that (i) the nature of the critical event that made the crash imminent influences the choice of crash avoidance maneuvers, (ii) women and elderly have a lower propensity to conduct crash avoidance...

  9. Investigation of dynamics of ELM crashes and their mitigation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pankin, Alexei Y. [Tech-X Corporation, Boulder, CO (United States)

    2015-08-14

    The accurate prediction of H-mode pedestal dynamics is critical for planning experiments in existing tokamaks and in the design of future tokamaks such as ITER and DEMO. The main objective of the proposed research is to advance the understanding of the physics of H-mode pedestal. Through advances in coupled kinetic-MHD simulations, a new model for H-mode pedestal and ELM crashes as well as an improved model for the bootstrap current will be developed. ELMmitigation techniques will also be investigated. The proposed research will help design efficient confinement scenarios and reduce transient heat loads on the divertor and plasma facing components. During the last two years, the principal investigator (PI) of this proposal actively participated in physics studies related to the DOE Joint Research Targets. These studies include the modeling of divertor heat load in the DIII-D, Alcator C-Mod, and NSTX tokamaks in 2010, and the modeling of H-mode pedestal structure in the DIII-D tokamak in 2011. It is proposed that this close collaboration with experimentalists from major US tokamaks continue during the next funding period. Verification and validation will be a strong component of the proposed research. During the course of the project, advances will be made in the following areas; Dynamics of the H-mode pedestal buildup and recovery after ELM crashes – The effects of neutral fueling, particle and thermal pinches will be explored; Dynamics of ELM crashes in realistic tokamak geometries – Heat loads associated with ELM crashes will be validated against experimental measurements. An improved model for ELM crashes will be developed; ELM mitigation – The effect of resonant magnetic perturbations on ELMs stability and their evolution will be investigated; Development of a new bootstrap current model – A reduced model for will be developed through careful verification of existing models for bootstrap current against first-principle kinetic neoclassical simulations

  10. Mean Reversion Expectations and the 1987 Stock Market Crash: An Empirical Investigation

    OpenAIRE

    Eric Hillebrand

    2005-01-01

    After the stock market crash of 1987, Fischer Black proposed a model in which he explained the crash by inconsistencies in the formation of expectations of mean reversion in stock returns. Following this explanation, a model that allows for mean reversion in stock returns is estimated on daily stock index data around the crash of 1987. The results strongly support Black’s hypothesis. Simulations show that on Friday Oct 16, 1987, a crash of 20 percent or more had a probability of more than s...

  11. Understanding crash mechanism on urban expressways using high-resolution traffic data.

    Science.gov (United States)

    Hossain, Moinul; Muromachi, Yasunori

    2013-08-01

    Urban expressways play a vital role in the modern mega cities by serving peak hour traffic alongside reducing travel time for moderate to long distance intra-city trips. Thus, ensuring safety on these roads holds high priority. Little knowledge has been acquired till date regarding crash mechanism on these roads. This study uses high-resolution traffic data collected from the detectors to identify factors influencing crash. It also identifies traffic patterns associated with different types of crashes and explains crash phenomena thereby. Unlike most of the previous studies on conventional expressways, the research separately investigates the basic freeway segments (BFS) and the ramp areas. The study employs random multinomial logit, a random forest of logit models, to rank the variables; expectation maximization clustering algorithm to identify crash prone traffic patterns and classification and regression trees to explain crash phenomena. As accentuated by the study outcome, crash mechanism is not generic throughout the expressway and it varies from the BFS to the ramp vicinities. The level of congestion and speed difference between upstream and downstream traffic best explains crashes and their types for the BFS, whereas, the ramp flow has the highest influence in determining the types of crashes within the ramp vicinities. The paper also discusses about the applicability of different countermeasures, such as, variable speed limits, temporary restriction on lane changing, posting warnings, etc., to attenuate different patterns of hazardous traffic conditions. The study outcome can be utilized in designing location and traffic condition specific proactive road safety management systems for urban expressways.

  12. Injury severity data for front and second row passengers in frontal crashes

    Directory of Open Access Journals (Sweden)

    Theresa Atkinson

    2016-06-01

    Full Text Available The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System – Crashworthiness Data System (NASS-CDS for the years 2008–2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief.

  13. The effects of roadway characteristics on farm equipment crashes: A GIS approach

    Science.gov (United States)

    Greenan, Mitchell Joseph

    Tractors and other self-propelled farm equipment, such as combines, sprayers, and towed grain carts, are often used on public roadways as the primary means for traveling from homestead to homestead or from homestead to a distributer. Increased roadway exposure has led to a growing concern for crashes involving farm equipment on the public roadway. A handful of studies exist examining public roadway crashes involving farm equipment using crash data, but none thus far have evaluated road segment data to identify road-specific risk factors. The objective of this study is to identify if roadway characteristics (traffic density, speed limit, road type, surface type, road width, and shoulder width) affect the risk of a crash involving farm equipment on Iowa public roadways. A retrospective cohort study of Iowa roads was conducted to identify the types of roads that are at an increased risk of having a farm-equipment crash on them. Crash data from the Iowa Department of Transportation (to identify crashes) were spatial linked to Iowa roadway data using Geographic Information Systems (GIS). Logistic regression was used to calculate ORs and 95% CL. Out of 319,705 road segments in Iowa, 0.4% segments (n=1,337) had a farm equipment crash from 2005-2011. The odds of having a farm equipment crash were significantly higher for road segments with increased traffic density and speed limit. Roads with an average daily traffic volume of at least 1,251 vehicles were at a 5.53 times greater odds of having a crash than roads with a daily traffic volume between 0-30 vehicles. (CI: 3.90-7.83). Roads with a posted speed limit between 50mph and 60mph were at a 4.88 times greater odds of having a crash than roads with a posted speed limit of 30mph or less. (CI: 3.85-6.20). Specific roadway characteristics such as roadway and shoulder width were also associated with the risk of a crash. For every 5 foot increase in road width, the odds for a crash decreased by 6 percent (CI: 0.89-0.99) and

  14. Comparative analysis of PA-31-350 Chieftain (N44LV) accident and NASA crash test data

    Science.gov (United States)

    Hayduk, R. J.

    1979-01-01

    A full scale, controlled crash test to simulate the crash of a Piper PA-31-350 Chieftain airplane is described. Comparisons were performed between the simulated crash and the actual crash in order to assess seat and floor behavior, and to estimate the acceleration levels experienced in the craft at the time of impact. Photographs, acceleration histories, and the tested airplane crash data is used to augment the accident information to better define the crash conditions. Measured impact parameters are presented along with flight path velocity and angle in relation to the impact surface.

  15. Availability, functionality, and use of seat belts in Beijing taxis prior to the 2008 Beijing Olympic Games.

    Science.gov (United States)

    Fleiter, Judy J; Gao, Liping; Qiu, Chen; Shi, Kan

    2009-03-01

    Use of driver seat belts and availability and functionality of passenger seat belts in a convenience sample of 231 Beijing taxis were examined in the months prior to the 2008 Beijing Olympic Games. Driver and front passenger seat belt use was mandated in China from 2004 to help address the growing public health crisis of road trauma. Results from observations made by in-vehicle passengers revealed that 21.2% of drivers were correctly wearing a belt, approximately half were not, and one third were using the belt in a non-functional way. Over 3/4 of this sample of taxi drivers were unrestrained while working. The percentage of functionally available belts was higher for front than rear passengers (88.3% and 22.9%, respectively). This low rate of belt availability in rear seats calls into question the preparedness of the fleet to cater for the safety needs of foreign visitors to China, particularly those from countries with high levels of restraint use. Factors influencing the use/misuse of seat belts in China remain largely unexplored. Results of this pilot study support further investigations of barriers to using injury prevention mechanisms such as seat belts in less motorised countries.

  16. 出租车计费系统设计%The design of taxi billing system

    Institute of Scientific and Technical Information of China (English)

    许洋洋; 王丽娟; 贾瑞匣

    2013-01-01

    A " taxi billing system" is developed based on SCM for a resistance furnace system.This system includes six functional modules that are keying circuit control module,clock circuit controlmodule,reset circuit control module and calculation of mileage control module,design of valuation unit module and display circuit control module.Assembly language is carried on the software design module,the instruction carries out the speed quick,save memory.The text inside describes the system hardware work principle in brief first,and attach with the system hardware design frame diagram,combine development history that introduced the single a machine microprocessor,discuss this graduate design a function for applied each hardware connecting a people the technique connects with each one a mold piece and work processes.This design can achieve the basic valuation function,at the same time,according to the weather condition to adjust the unit price.With the clock function provides the convenienc .%本文以出租车计费系统作为研究对象,开发了基于单片机的控制系统。本控制系统按功能分主要包括以下几个部分:按键控制电路模块、时钟电路控制模块、复位电路控制模块、里程及计价控制模块、显示电路控制模块组成。本系统的编程语言是以单片机的基本语言汇编语言来进行的,指令的执行速度快,节省存储空间。简单描述系统硬件工作原理,介绍了单片机微处理器的发展史,附以系统硬件设计框图,论述了所应用的各硬件接口技术和各个接口模块的功能及工作过程。本次设计能够实现基本计价功能,同时能够根据天气状况来调节单价。附有时钟功能提供方便。

  17. Driving environment in Iran increases blood pressure even in healthy taxi drivers

    Directory of Open Access Journals (Sweden)

    Soodabeh Navadeh Khodadadi

    2008-12-01

    Full Text Available

    • BACKGROUND: Nowadays, driving is an unseparated part of our new modern lifestyle; and we are exposed to this environment all the days for several hours whether as drivers or as riders. Many reports indicated that Iran is on the top rank of automobile-related morbidity and mortality among developed and even many developing countries that can be due to dangerous driving habits in Iran. We designed this study to find out if environment of driving have clinically important effects on blood pressure (BP and how strong is the effect. We also examined if there were any predictors for the BP rises in driving time.
    • METHODS: In a cross-sectional study, 31 healthy male taxi drivers were included through a multistage proportional sampling method in winter and spring 2007. They were referred to the clinic of hypertension in Shafa Hospital, Kerman. A trained nurse measured the BPs. She also did set up the Ambulatory Blood Pressure Monitor (ABPM on the drivers’ left arms for BP recording every 30 minutes during the day. Based on the diurnal recorded BPs, the subjects were allocated into normotensive and hypertensive (systolic BP > 135 or diastolic BP > 85mmHg groups. The difference among the clinic BPs and the driving BPs was examined by t-test in Stata version 8, followed by a multivariate analysis for exploring the main predictors for BP rises in driving time.
    • RESULTS: Both mean systolic and mean diastolic BPs were significantly increased from 116.85 (SE 2.28 and 74.44 (SE 2.22 mmHg in clinic to 138.64 (SE 2.77 and 95.70 (SE 2.55 mmHg during driving, respectively (P = 0.0001. Pulse pressure remained constant (P = 0.87. The difference between clinic's and driving time measurements was higher in hypertensive group. Those with higher systolic blood pressures in clinic had more frequent and higher BP rises in driving time (P = 0.02.
    • CONCLUSIONS: Driving

    • Crash protectiveness to occupant injury and vehicle damage: An investigation on major car brands.

      Science.gov (United States)

      Huang, Helai; Li, Chunyang; Zeng, Qiang

      2016-01-01

      This study sets out to investigate vehicles' crash protectiveness on occupant injury and vehicle damage, which can be deemed as an extension of the traditional crash worthiness. A Bayesian bivariate hierarchical ordered logistic (BVHOL) model is developed to estimate the occupant protectiveness (OP) and vehicle protectiveness (VP) of 23 major car brands in Florida, with considering vehicles' crash aggressivity and controlling external factors. The proposed model not only takes over the strength of the existing hierarchical ordered logistic (HOL) model, i.e. specifying the order characteristics of crash outcomes and cross-crash heterogeneities, but also accounts for the correlation between the two crash responses, driver injury and vehicle damage. A total of 7335 two-vehicle-crash records with 14,670 cars involved in Florida are used for the investigation. From the estimation results, it's found that most of the luxury cars such as Cadillac, Volvo and Lexus possess excellent OP and VP while some brands such as KIA and Saturn perform very badly in both aspects. The ranks of the estimated safety performance indices are even compared to the counterparts in Huang et al. study [Huang, H., Hu, S., Abdel-Aty, M., 2014. Indexing crash worthiness and crash aggressivity by major car brands. Safety Science 62, 339-347]. The results show that the rank of occupant protectiveness index (OPI) is relatively coherent with that of crash worthiness index, but the ranks of crash aggressivity index in both studies is more different from each other. Meanwhile, a great discrepancy between the OPI rank and that of vehicle protectiveness index is found. What's more, the results of control variables and hyper-parameters estimation as well as comparison to HOL models with separate or identical threshold errors, demonstrate the validity and advancement of the proposed model and the robustness of the estimated OP and VP.

    • Real-time wavelet detection of crashes in limit cycles of non-stationary fusion plasmas

      Energy Technology Data Exchange (ETDEWEB)

      Berkel, M. van, E-mail: m.v.berkel@tue.nl [Eindhoven University of Technology, Department of Mechanical Engineering, Control Systems Technology Group, PO Box 513, 5600 MB Eindhoven (Netherlands); FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Witvoet, G.; Baar, M.R. de [Eindhoven University of Technology, Department of Mechanical Engineering, Control Systems Technology Group, PO Box 513, 5600 MB Eindhoven (Netherlands); FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Nuij, P.W.J.M. [Eindhoven University of Technology, Department of Mechanical Engineering, Control Systems Technology Group, PO Box 513, 5600 MB Eindhoven (Netherlands); Morsche, H.G. ter [Eindhoven University of Technology, Department of Mathematics and Computer Science, PO Box 513, 5600 MB Eindhoven (Netherlands); Steinbuch, M. [Eindhoven University of Technology, Department of Mechanical Engineering, Control Systems Technology Group, PO Box 513, 5600 MB Eindhoven (Netherlands)

      2011-12-15

      Highlights: Black-Right-Pointing-Pointer We propose a new wavelet-based method for accurate and robust detection of limit cycle crashes in fusion plasmas. Black-Right-Pointing-Pointer The method is optimized for real-time applications such that it has small delay. Black-Right-Pointing-Pointer The method is implemented in a real-time algorithm and is tested on experimental data. Black-Right-Pointing-Pointer Almost all crashes are detected flawlessly including off-waveforms with high SNR. - Abstract: The high performance mode (H-mode) is one of the baseline plasma scenarios for the experimental fusion reactor ITER. This scenario features a periodic crash-like reorganization of the plasma pressure and the magnetic flux in the plasma core and plasma periphery. The core instability is often referred to as the sawtooth instability while the instability at the edge of the plasma is referred to as ELM. In this paper we present an algorithm for optimized (low latency, robust and high fidelity) real-time sensing of the crashes. The algorithm is based on time-scale wavelet theory and edge-detection. It is argued that detection of crashes has considerably less delay than the other methods. The realized accuracy of the detection algorithm is well below the uncertainty of the crash period for most crashes. Multiresolution analysis enables distinction between different sizes of sawtooth crashes due to the different sizes of wavelets (scales), resulting in an algorithm, which is robust and accurate. Although strictly speaking, the crash detection method is demonstrated for sawteeth measured with ECE only, it can be applied to any periodic crash, measured with any temporally resolved data. Note that the possibility of differentiating between crash like events of different nature depends on their individual time-scales and used measurement setup.

    • 出租汽车计价器加密传感器设计%Encrypted Sensor Design of Taxi Meter

      Institute of Scientific and Technical Information of China (English)

      王跃红

      2014-01-01

      This paper analyzes the encryption principle and several invasion methods of taxi meter encrypted sensor.%文章对出租汽车计价器加密传感器的加密原理、几种入侵方式进行分析。

  1. A Functional Thinking Approach to the Design of Future Transportation Systems: Taxis as a Proxy for Personal Rapid Transit in South Korea

    DEFF Research Database (Denmark)

    2014-01-01

    taxis can be used as an alternative embodiment of personal rapid transit and can serve as a test bed to support PRT-related design, research, and development. The paper then explores the transportation patterns and characteristics of cities in South Korea and the United States in order to determine...

  2. Fusarium graminearum produces different xylanases causing host cell death that is prevented by the xylanase inhibitors XIP-I and TAXI-III in wheat.

    Science.gov (United States)

    Tundo, Silvio; Moscetti, Ilaria; Faoro, Franco; Lafond, Mickaël; Giardina, Thierry; Favaron, Francesco; Sella, Luca; D'Ovidio, Renato

    2015-11-01

    To shed light on the role of Xylanase Inhibitors (XIs) during Fusarium graminearum infection, we first demonstrated that three out of four F. graminearum xylanases, in addition to their xylan degrading activity, have also the capacity to cause host cell death both in cell suspensions and wheat spike tissue. Subsequently, we demonstrated that TAXI-III and XIP-I prevented both the enzyme and host cell death activities of F. graminearum xylanases. In particular, we showed that the enzymatic inhibition by TAXI-III and XIP-I was competitive and only FGSG_11487 escaped inhibition. The finding that TAXI-III and XIP-I prevented cell death activity of heat inactivated xylanases and that XIP-I precluded the cell death activity of FGSG_11487 - even if XIP-I does not inhibit its enzyme activity - suggests that the catalytic and the cell death activities are separated features of these xylanases. Finally, the efficacy of TAXI-III or XIP-I to prevent host cell death caused by xylanases was confirmed in transgenic plants expressing separately these inhibitors, suggesting that the XIs could limit F. graminearum infection via direct inhibition of xylanase activity and/or by preventing host cell death.

  3. LOCATING TAXI SIGN BASED ON OPTIMISED DAUGMAN ALGORITHM%基于优化Daugman算法的出租车标志定位

    Institute of Scientific and Technical Information of China (English)

    段虎成

    2011-01-01

    When locating round target,traditional Hough transform algorithm is liable to interference and has poor effect,results in big location deviations. In light of this problem, we propose an optimised Daugman algorithm-based location method to realise the location of the taxi signs. This algorithm introduces an optimised Daugman operator and uses the experienced threshold value to improve the accuracy of taxi sign estimation and location. Experiments show that this algorithm can judge and locate the taxi sign accurately and have good robusmess. The experiment also shows that the optimised Daugman algorithm can locate the taxi sign effectively.%针对传统的Hough变换算法定位圆状目标时易受到干扰,效果不佳,导致定位出现较大偏差的问题,提出了一种基于优化的Daugman算法的定位方法来实现对于出租车标志定位.该算法引进一种优化的Daugnum算子并使用阈值经验以提高出租车标志判断与定位的精确度.实验表明,使用该算法判断与定位出租车标志准确且抗干扰性强,从而能有效地定位出租车标志.

  4. Analysis of 86 fatal motorcycle frontal crashes in

    Directory of Open Access Journals (Sweden)

    ZHAO Hui

    2012-06-01

    Full Text Available 【Abstract】Objective: To analyze the injuries of motorcyclists involved in fatal motorcycle frontal crashes. Methods: A survey group involving multi-discipline experts was built to randomly collect data on fatal motor-cycle frontal collision accidents that occurred in Chongqing during 2006-2010. The sampled information included medi-cal or autopsy reports, blood alcohol concentration (BAC level, helmet use, accident witness, field sketch as well as field photos. The motorcyclist injuries were scored accord-ing to the Abbreviated Injury Scale (AIS 2005. The involved riders with a BAC level≥20 mg/ml were attributed to alco-hol use. Data were processed statistically with nonparamet-ric test via software SPSS 11.0. Results: A total of 86 fatal motorcycle frontal crashes were sampled and further analyzed. The age of motorcy-clists enrolled in this investigation showed nominal distri-bution and the middle-aged (30-39 years occupied the high-est percentage of fatalities. There were only 14 motorcyclists (16.3% wearing helmets at the moment of collision. And 12.8% of these motorcyclist crashes were attributable to alcohol use. Impact injury was the main fatal cause, accounting for 72% of motorcyclist deaths, followed by tumbling injury (26% and run-over (2%. Respectively 84%, 22% and 19% of motorcyclists who sustained head, chest and abdominal trauma died. Extremity injury was the most frequently ob-served injury type. Conclusions: This investigation is helpful to build accident prevention programs and develop protection de-vices which may effectively mitigate injuries and prevent deaths following motorcycle frontal collision accidents. Further investigations on motorcycle collision accidents are still needed. Key words: Motorcycles; Mortality; Accidents, traffic; Wounds and injuries

  5. Road crash in China from 2003 to 2005

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ji-hong; QIU Jun; ZHAO Xin-cai; LIU Guo-dong; XIAO Kai; ZHANG Liang; JIANG Zhi-quan; WANG Zheng-guo

    2008-01-01

    Objective: To analyze characteristics and causes of road crash and injuries in China from 2003 to 2005.Methods : The data of road crash in 2003-2005 were collected to study the characteristics including total vehicle number, occurrence rates of traffic accidents and serious traffic accidents so as to discuss the causes and characteristics of road crash in China.Results: From 2003 to 2005, the numbers of traffic accidents, injuries and deaths as well as the mortality rates per 100 000 persons and per 10 000 vehicles declined in China. Until 2005, the total number of traffic accidents decreased to 450 000 and deaths to 99 000, with the mortality rate per 10 000 vehicles being 7.6 persons. While the drivers and passengers accounted for 33.2% and 26.6% of death casualties respectively in 2005. Most traffic accidents were caused by drivers, especially those with driving experience less than 3 years. Traffic accidents occurred on suburban roads accounted for 60%. The mortality rate of the traffic accidents per 100 km on the first grade road ranked the highest. The mortality rate of the traffic accidents on expressways ranked the highest, with continual increase of death and injury.Conclusions: At present, the increase trend of traffic accidents and casualties in China has been slowed down to some extent and shows a declining tendency, but the situation is far away from being optimistic. In order to cut down the number of traffic accidents and casualties, we should pay more attention to training and managing drivers with less than three driving years and those driving buses. Strict prevention measures should be laid on traffic accidents on first grade roads, expressways and suburban roads as well as the enhancement on improving first-aid system.

  6. Lower extremity finite element model for crash simulation

    Energy Technology Data Exchange (ETDEWEB)

    Schauer, D.A.; Perfect, S.A.

    1996-03-01

    A lower extremity model has been developed to study occupant injury mechanisms of the major bones and ligamentous soft tissues resulting from vehicle collisions. The model is based on anatomically correct digitized bone surfaces of the pelvis, femur, patella and the tibia. Many muscles, tendons and ligaments were incrementally added to the basic bone model. We have simulated two types of occupant loading that occur in a crash environment using a non-linear large deformation finite element code. The modeling approach assumed that the leg was passive during its response to the excitation, that is, no active muscular contraction and therefore no active change in limb stiffness. The approach recognized that the most important contributions of the muscles to the lower extremity response are their ability to define and modify the impedance of the limb. When nonlinear material behavior in a component of the leg model was deemed important to response, a nonlinear constitutive model was incorporated. The accuracy of these assumptions can be verified only through a review of analysis results and careful comparison with test data. As currently defined, the model meets the objective for which it was created. Much work remains to be done, both from modeling and analysis perspectives, before the model can be considered complete. The model implements a modeling philosophy that can accurately capture both kinematic and kinetic response of the lower limb. We have demonstrated that the lower extremity model is a valuable tool for understanding the injury processes and mechanisms. We are now in a position to extend the computer simulation to investigate the clinical fracture patterns observed in actual crashes. Additional experience with this model will enable us to make a statement on what measures are needed to significantly reduce lower extremity injuries in vehicle crashes. 6 refs.

  7. Analysis of 86 fatal motorcycle frontal crashes in Chongqing, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hui; HUANG Wei; YANG Guang-yu; CHEN Rong; LIU Sheng-xiong; YU Yong-min; YIN Zhi-yong; WANG Zheng-guo

    2012-01-01

    Objective: To analyze the injuries of motorcyclists involved in fatal motorcycle frontal crashes.Methods: A survey group involving multi-discipline experts was built to randomly collect data on fatal motorcycle frontal collision accidents that occurred in Chongqing during 2006-2010.The sampled information included medical or autopsy reports,blood alcohol concentration (BAC)level,helmet use,accident witness,field sketch as well as field photos.The motorcyclist injuries were scored according to the Abbreviated Injury Scale (AIS) 2005.The involved riders with a BAC level≥20 mg/ml were attributed to alcohol use.Data were processed statistically with nonparametric test via software SPSS 11.0.Results:A total of 86 fatal motorcycle frontal crashes were sampled and further analyzed.The age of motorcyclists enrolled in this investigation showed nominal distribution and the middle-aged (30-39 years) occupied the highest percentage of fatalities.There were only 14 motorcyclists (16.3%) wearing helmets at the moment ofcollision.And 12.8% of these motorcyclist crashes were attributable to alcohol use.Impact injury was the main fatal cause,accounting for 72% of motorcyclist deaths,followed by tumbling injury (26%) and run-over (2%).Respectively 84%,22% and 19%of motorcyclists who sustained head,chest and abdominal trauma died.Extremity injury was the most frequently observed injury type.Conclusions: This investigation is helpful to build accident prevention programs and develop protection devices which may effectively mitigate injuries and prevent deaths following motorcycle frontal collision accidents.Further investigations on motorcycle collision accidents are still needed.

  8. Epidemiology of Child Motor Vehicle Crash Injuries and Fatalities

    Science.gov (United States)

    Arbogast, Kristy B.; Durbin, Dennis R.

    Although children represent only 10-15 % of the overall traffic fatality burden in the United States, motor vehicle crashes (MVCs) remain the leading cause of death and disability for children and young adults; and, close to half of all unintentional injury deaths to children and adolescents (Centers for Disease Control and Prevention National Center for Injury Prevention and Control, Web-based Injury Statistics Query and Reporting System [CDC NCIPC WISQARS] 2010). Moreover, their exposure to motor vehicle risk is significant because they travel by motor vehicles nearly as much as adults. Prevention of the fatalities, injuries and disability associated with MVC must be a priority for ensuring our children's overall health.

  9. LESSONS IN CRISIS MISMANAGEMENT FROM THE 1929 CRASH

    Directory of Open Access Journals (Sweden)

    Janice M. Traflet

    2006-01-01

    Full Text Available Crisis management theory illuminates the New York Stock Exchanges efforts to recover organizational legitimacy after the 1929 crash and the scandals unearthed in its wake. Ineptly defusing charges of an unfair and disorderly marketplace, NYSE President Richard Whitney and his Old Guard colleagues magnified perceptions of Exchange dysfunction. Even after New Deal reform of the securities sector the NYSE remained a self-regulatory organization. How did the NYSE emerge from its crisis decade (1929—38 intact despite serious tactical mistakes by Exchange leaders?

  10. 关于出租车司机英语的课程设计--为北京2008奥运会%A Course Design of Taxi Drivers' English--for the 2008 Beijing Olympic Games

    Institute of Scientific and Technical Information of China (English)

    汪露秋

    2006-01-01

    This paper illustrates how an English for Specific Purposes (ESP) course is designed to meet the needs of a certain group of people engaging in a specific job. In accordance with the development of the taxi industry in Beijing, the paper focuses on how the ESP course enables the taxi drivers to acquire the English language for specific functions in their working environment. Besides, considering the approaching Olympic Games, the paper also explores how this course helps the taxi drivers develop the communicative competence for the Olympic Games.

  11. Bicycle fatalities : trends in crashes with and without motor vehicles in The Netherlands.

    NARCIS (Netherlands)

    Schepers, P. Stipdonk, H.L. Methorst, R. & Olivier, J.

    2017-01-01

    Boufous and Olivier (2015) recently found an increasing trend of police-reported cyclist deaths in single-vehicle crashes while a decreasing trend was found for fatal bicycle-motor vehicle crashes. This study sets out to conduct the same trend analyses for the Netherlands using causes of death stati

  12. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models.

    Science.gov (United States)

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-06-18

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling.

  13. Simulations of Pedestrian Impact Collisions with Virtual CRASH 3 and Comparisons with IPTM Staged Tests

    CERN Document Server

    Becker, Tony; Scurlock, Bob

    2015-01-01

    In this article, we present results from a series of Virtual CRASH-based pedestrian impact simulations. We compare the results of these Virtual CRASH pedestrian impact simulations to data from pedestrian impact collisions staged at the Institute of Police Technology and Management.

  14. 49 CFR 571.208 - Standard No. 208; Occupant crash protection.

    Science.gov (United States)

    2010-10-01

    .... This standard specifies performance requirements for the protection of vehicle occupants in crashes. S2... accelerations measured on anthropomorphic dummies in test crashes, and by specifying equipment requirements for... passenger car manufactured in the United States by more than one manufacturer, one of which also markets...

  15. Pre-crash performance of collision mitigation and avoidance systems: Results from the assess project

    NARCIS (Netherlands)

    Aparicio, A.; Baurès, S.; Bargalló, J.; Rodarius, C.; Vissers, J.; Bartels, O.; Seiniger, P.; Lemmen, P.; Unselt, T.; Ranovona, M.; Okawa, T.; Schaub, S.

    2013-01-01

    Integrated vehicle safety systems that combine elements from primary and secondary safety have a high potential to improve vehicle safety, due to their ability to influence crash conditions and/or to adapt to these crash conditions. So far no standard evaluation procedures have been developed and im

  16. Risk Factors Associated with Crash Severity on Low-Volume Rural Roads in Denmark

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Rasmussen, Thomas Kjær; Kaplan, Sigal

    2014-01-01

    -volume rural roads, including crash characteristics, driver attributes and behavior, vehicle type, road features, environmental conditions, distance from the nearest hospital, and zone rurality degree. The data consist of a set of crashes occurred on low-volume rural roads in Denmark between 2007 and 2011...

  17. Risk factors associated with crash severity on low-volume rural roads in Denmark

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Rasmussen, Thomas Kjær; Kaplan, Sigal

    -volume rural roads, including crash characteristics, driver attributes and behavior, vehicle type, road features, environmental conditions, distance from the nearest hospital, and zone rurality degree. The data consist of a set of crashes occurred on low-volume rural roads in Denmark between 2007 and 2011...

  18. The Thule episode epidemiological follow up after the crash of a B-52 bomber in Greenland

    DEFF Research Database (Denmark)

    Juel, K

    1992-01-01

    The aim was to explore the pattern of disease in staff associated with a bomber that crashed in 1968 when carrying nuclear bombs.......The aim was to explore the pattern of disease in staff associated with a bomber that crashed in 1968 when carrying nuclear bombs....

  19. Comparison of Test and Finite Element Analysis for Two Full-Scale Helicopter Crash Tests

    Science.gov (United States)

    Annett, Martin S.; Horta,Lucas G.

    2011-01-01

    Finite element analyses have been performed for two full-scale crash tests of an MD-500 helicopter. The first crash test was conducted to evaluate the performance of a composite deployable energy absorber under combined flight loads. In the second crash test, the energy absorber was removed to establish the baseline loads. The use of an energy absorbing device reduced the impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to analytical results. Details of the full-scale crash tests and development of the system-integrated finite element model are briefly described along with direct comparisons of acceleration magnitudes and durations for the first full-scale crash test. Because load levels were significantly different between tests, models developed for the purposes of predicting the overall system response with external energy absorbers were not adequate under more severe conditions seen in the second crash test. Relative error comparisons were inadequate to guide model calibration. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used for the second full-scale crash test. The calibrated parameter set reduced 2-norm prediction error by 51% but did not improve impact shape orthogonality.

  20. Driver injury severity outcome analysis in rural interstate highway crashes: a two-level Bayesian logistic regression interpretation.

    Science.gov (United States)

    Chen, Cong; Zhang, Guohui; Liu, Xiaoyue Cathy; Ci, Yusheng; Huang, Helai; Ma, Jianming; Chen, Yanyan; Guan, Hongzhi

    2016-12-01

    There is a high potential of severe injury outcomes in traffic crashes on rural interstate highways due to the significant amount of high speed traffic on these corridors. Hierarchical Bayesian models are capable of incorporating between-crash variance and within-crash correlations into traffic crash data analysis and are increasingly utilized in traffic crash severity analysis. This paper applies a hierarchical Bayesian logistic model to examine the significant factors at crash and vehicle/driver levels and their heterogeneous impacts on driver injury severity in rural interstate highway crashes. Analysis results indicate that the majority of the total variance is induced by the between-crash variance, showing the appropriateness of the utilized hierarchical modeling approach. Three crash-level variables and six vehicle/driver-level variables are found significant in predicting driver injury severities: road curve, maximum vehicle damage in a crash, number of vehicles in a crash, wet road surface, vehicle type, driver age, driver gender, driver seatbelt use and driver alcohol or drug involvement. Among these variables, road curve, functional and disabled vehicle damage in crash, single-vehicle crashes, female drivers, senior drivers, motorcycles and driver alcohol or drug involvement tend to increase the odds of drivers being incapably injured or killed in rural interstate crashes, while wet road surface, male drivers and driver seatbelt use are more likely to decrease the probability of severe driver injuries. The developed methodology and estimation results provide insightful understanding of the internal mechanism of rural interstate crashes and beneficial references for developing effective countermeasures for rural interstate crash prevention.

  1. Cyclist–motorist crash patterns in Denmark: A latent class clustering approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2013-01-01

    Objective: The current study aimed at uncovering patterns of cyclist–motorist crashes in Denmark and investigating their prevalence and severity. The importance of implementing clustering techniques for providing a holistic overview of vulnerable road users’ crash patterns derives from the need...... to prioritize safety issues and to devise efficient preventive measures. Method: The current study focused on cyclist–motorist crashes that occurred in Denmark during the period between 2007 and 2011. To uncover crash patterns, the current analysis applied latent class clustering, an unsupervised probabilistic...... clustering approach that relies on the statistical concept of likelihood and allows partial overlap across clusters. Results: The analysis yielded 13 distinguishable cyclist–motorist latent classes. Specific crash patterns for urban and rural areas were revealed. Prevalent features that allowed...

  2. Evaluation of vehicle damage involved in road crashes based on quantificated model

    Institute of Scientific and Technical Information of China (English)

    FAN Yan-hui; XU Hong-guo; JIANG Hua-ping

    2008-01-01

    Based on economics theory, social value loss caused by vehicle involved in crashes as well as various factors influencing on it were analyzed, the corresponding micro-econometrics model was theoretically given. Moreover, the practicability of the model,the veracity and rationality of quantification were analyzed. Based on probability theory and mathematical statistical theory, macro approach to evaluating vehicle damage in crashes was presented, and the corresponding macro-econometrics model was constructed. In addition, the macro-econometrics model was utilized to assess economic loss from statistical data of vehicle damaged in crashes, which has shown that the model can meet the demand of quantification analysis of vehicle damage, and be applied to the evaluation of economic loss caused by crashes. The results in this paper will be of practical significance for scientific, comprehensive and rational evaluating socio-economic loss caused by road crashes.

  3. Analysis of factors associated with injury severity in crashes involving young New Zealand drivers

    DEFF Research Database (Denmark)

    Weiss, Harold B.; Kaplan, Sigal; Prato, Carlo Giacomo

    2014-01-01

    fit than a binary and a generalized ordered logit. Results show that the young drivers’ behavior, the presence of passengers and the involvement of vulnerable road users were the most relevant factors associated with higher injury severity in both single-vehicle and two-vehicle crashes. Seatbelt non......-use, inexperience and alcohol use were the deadliest behavioral factors in single-vehicle crashes, while fatigue, reckless driving and seatbelt non-use were the deadliest factors in two-vehicle crashes. The presence of passengers in the young drivers’ vehicle, and in particular a combination of males and females......Young people are a risk to themselves and other road users, as motor vehicle crashes are the leading cause of their death. A thorough understanding of the most important factors associated with injury severity in crashes involving young drivers is important for designing well-targeted restrictive...

  4. Effect of crash pulse shape on seat stroke requirements for limiting loads on occupants of aircraft

    Science.gov (United States)

    Carden, Huey D.

    1992-01-01

    An analytical study was made to provide comparative information on various crash pulse shapes that potentially could be used to test seats under conditions included in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats, show the effects that crash pulse shape can have on the seat stroke requirements necessary to maintain a specified limit loading on the seat/occupant during crash pulse loadings, compare results from certain analytical model pulses with approximations of actual crash pulses, and compare analytical seat results with experimental airplace crash data. Structural and seat/occupant displacement equations in terms of the maximum deceleration, velocity change, limit seat pan load, and pulse time for five potentially useful pulse shapes were derived; from these, analytical seat stroke data were obtained for conditions as specified in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats.

  5. 78 FR 52605 - Announcing the Twenty First Public Meeting of the Crash Injury Research and Engineering Network...

    Science.gov (United States)

    2013-08-23

    .... Researchers can review data and share expertise, which may lead to a better understanding of crash injury... National Highway Traffic Safety Administration Announcing the Twenty First Public Meeting of the Crash... Meeting of members of the Crash Injury Research and Engineering Network. CIREN is a collaborative...

  6. Self-harm and risk of motor vehicle crashes among young drivers : findings from the DRIVE Study

    NARCIS (Netherlands)

    Martiniuk, Alexandra L. C.; Ivers, Rebecca Q.; Glozier, Nick; Patton, George C.; Lam, Lawrence T.; Boufous, Soufiane; Senserrick, Teresa; Williamson, Ann; Stevenson, Mark; Norton, Robyn

    2009-01-01

    Background: Some motor vehicle crashes, particularly single-vehicle crashes, may result from intentional self-harm. We conducted a prospective cohort study to assess the risk that intentional self-harm poses for motor vehicle crashes among young drivers. Methods: We prospectively linked survey data

  7. Rhabdomyolysis and unilateral renal infarction after a motor vehicle crash.

    Science.gov (United States)

    Sanai, Toru; Yokoyama, Masaaki; Murata, Akinari; Ukon, Kei; Fuchigami, Kazumi

    2007-01-01

    A 46-year-old man with no previous history of abnormal urinalysis findings or renal dysfunction was admitted to a local hospital because of a motor vehicle crash. An open laparotomy was performed to treat a perforation of the small intestine. After operation, oliguria and renal dysfunction developed, and he was admitted to our hospital because of acute renal failure after trauma. Acute renal failure was assumed to be due to rhabdomyolysis with elevated serum creatinine, blood urea nitrogen, and creatine kinase levels and myoglobinemia. Left flank pain occurred several days after admission, and the serum alkaline phosphatase level increased between days 5 and 12 following admission. Although hemodialysis was performed 9 times and the urine output was satisfactory, the creatinine clearance levels increased only to about 50 mL/min/1.73 m2 (0.84 mL/s/m2) at 6 weeks following admission. As a result, a diagnosis of renal infarction due to acute renal artery occlusion was considered. The left kidney was atrophic on an abdominal computed tomographic scan and was nonfunctioning on a renogram. This case shows the importance of not overlooking the possibility of a renal infarction associated with rhabdomyolysis after a motor vehicle crash. In particular, the changes in the serum alkaline phosphatase levels were important in making a correct diagnosis in this case.

  8. Damage assessment of nuclear containment against aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Mohd Ashraf, E-mail: iqbal_ashraf@rediffmail.com; Sadique, Md. Rehan, E-mail: rehan.sadique@gmail.com; Bhargava, Pradeep, E-mail: bhpdpfce@iitr.ac.in; Bhandari, N.M., E-mail: nmbcefce@iitr.ac.in

    2014-10-15

    Highlights: • Damage assessment of nuclear containment is studied against aircraft crash. • Four impact locations have been identified at the outer containment shell. • The mid of the total height has been found to be most vulnerable location. • The crown of dome has been found to be the strongest location. • Phantom F4 caused more localized and severe damage compared to other aircrafts. - Abstract: The behavior of nuclear containment structure has been studied against aircraft crash with an emphasis on the influence of strike location. The impact locations identified on the BWR Mark III type nuclear containment structure are mid-height, junction of dome and cylinder, crown of dome and arc of dome. The containment at each of the above locations has been impacted normally by Phantom F-4, Boeing 707-320 and Airbus A320 aircrafts. The loading of the aircraft has been assigned through the corresponding reaction-time response curve. ABAQUS/Explicit finite element code has been used to carry out the three-dimensional numerical simulations. The concrete damaged plasticity model was used to simulate the behavior of concrete while the behavior of steel reinforcement was incorporated using the Johnson–Cook elasto-viscoplastic material model. The mid-height of containment has been found to experience most severe deformation against each aircraft. Phantom F4 has been found to be most disastrous at each location. The results have been compared with those of the available studies with respect to the containment deformation.

  9. Coupled simulation of kinetic pedestal growth and MHD ELM crash

    Energy Technology Data Exchange (ETDEWEB)

    Park, G [Courant Institute of Mathematical Sciences, New York University (United States); Cummings, J [California Institute of Technology (United States); Chang, C S [Courant Institute of Mathematical Sciences, New York University (United States); Podhorszki, N [Univ. California at Davis (United States); Klasky, S [ORNL (United States); Ku, S [Courant Institute of Mathematical Sciences, New York University (United States); Pankin, A [Lehigh Univ. (United States); Samtaney, R [Princeton Plasma Physics Laboratory (United States); Shoshani, A [LBNL (United States); Snyder, P [General Atomics (United States); Strauss, H [Courant Institute of Mathematical Sciences, New York University (United States); Sugiyama, L [MIT (United States)

    2007-07-15

    Edge pedestal height and the accompanying ELM crash are critical elements of ITER physics yet to be understood and predicted through high performance computing. An entirely self-consistent first principles simulation is being pursued as a long term research goal, and the plan is planned for completion in time for ITER operation. However, a proof-of-principle work has already been established using a computational tool that employs the best first principles physics available at the present time. A kinetic edge equilibrium code XGC0, which can simulate the neoclassically dominant pedestal growth from neutral ionization (using a phenomenological residual turbulence diffusion motion superposed upon the neoclassical particle motion) is coupled to an extended MHD code M3D, which can perform the nonlinear ELM crash. The stability boundary of the pedestal is checked by an ideal MHD linear peeling-ballooning code, which has been validated against many experimental data sets for the large scale (type I) ELMs onset boundary. The coupling workflow and scientific results to be enabled by it are described.

  10. Spinal cord injuries from road traffic crashes in southeastern Iran

    Institute of Scientific and Technical Information of China (English)

    Mohammad R Rasouli; Mohsen Nouri; Vafa Rahimi-Movaghar

    2007-01-01

    Objective: To analyze the data of patients with spinal cord injury (SCI) induced by road traffic crashes in southeastern Iran for better understanding the pattern of these injuries and therefore for better designing health system planning.Methods: In this historical cohort study, the patients who had been transferred to Level I trauma center in southeastern Iran due to road traffic accidents with radiographic documented SCI were evaluated.Results: Among 64 patients with SCI, 38 patients (59.4%, 36 males and 2 females, aged 27.42 years ± 9.44 years on average) were injured by road traffic accidents.Car and motorcycle accidents were responsible for 26 cases (68.4%) and 12 cases (31.6%), respectively. And 31 patients (81. 6%) had complete SCI. Conus medularis (T12-L2) was the most affected level.Conclusions: Results are discussed in terms of preventive measures, specifically those concerning the use of restraint and helmet and driving behavior. This study should be extended nationally to gain a larger case series so that the SCI risk of particular vehicle configurations,considering other crash factors, can be more precisely quantified and the characteristics for low occurrence of SCI can be more precisely identified.

  11. Crash Simulator: Brain-and-Spine Injury Mechanics

    Science.gov (United States)

    Ivancevic, Vladimir G.; Reid, Darryn J.

    2015-11-01

    Recently, the first author has proposed a new coupled loading-rate hypothesis as a unique cause of both brain and spinal injuries, which states that they are both caused by a Euclidean jolt, an impulsive loading that strikes head and spine (or, any other part of the human body)- in several coupled degrees-of-freedom simultaneously. Injury never happens in a single direction only, nor is it ever caused by a static force. It is always an impulsive translational plus rotational force. The Euclidean jolt causes two basic forms of brain, spine and other musculo-skeletal injuries: (i) localized translational dislocations; and (ii) localized rotational disclinations. In the present Chapter, we first review this unique mechanics of a general human mechanical injury, and then describe how it can be predicted and controlled by a crash simulator toolbox. This rigorous Matlab toolbox has been developed using an existing thirdparty toolbox DiffMan, for accurately solving differential equations on smooth manifolds and mechanical Lie groups. The present crash simulator toolbox performs prediction/control of brain and spinal injuries within the framework of the Euclidean group SE(3) of rigid motions in our natural 3-dimensional space.

  12. Crash simulation of UNS electric vehicle under frontal front impact

    Science.gov (United States)

    Susilo, D. D.; Lukamana, N. I.; Budiana, E. P.; Tjahjana, D. D. D. P.

    2016-03-01

    Sebelas Maret University has been developing an Electric Vehicle namely SmarT-EV UNS. The main structure of the car are chasis and body. The chasis is made from steel and the body is made from fiberglass composite. To ensure the safety of the car, both static and dynamic tests were carried out to these structures, including their materials, like: tensile test, bending test, and impact test. Another test needed by this vehicle is crashworthiness test. To perform the test, it is needed complex equipments and it is quite expensive. Another way to obtain vehicle crashworthiness behaviour is by simulate it. The purpose of this study was to simulate the response of the Smart-EV UNS electric vehicle main structure when crashing rigid barrier from the front. The crash simulation was done in according to the NHTSA (National Highway Traffic Safety Administration) within the speed of the vehicle of 35 mph. The UNS Electric Vehicle was modelled using SolidWorks software, and the simulation process was done by finite element method using ANSYS software. The simulation result showed that the most internal impact energy was absorbed by chassis part. It absorbed 76.2% of impact energy, then the base absorbed 11.3 %, while the front body absorbed 2.5 %, and the rest was absorbed by fender, hood, and other parts.

  13. Using data mining techniques to predict the severity of bicycle crashes.

    Science.gov (United States)

    Prati, Gabriele; Pietrantoni, Luca; Fraboni, Federico

    2017-04-01

    To investigate the factors predicting severity of bicycle crashes in Italy, we used an observational study of official statistics. We applied two of the most widely used data mining techniques, CHAID decision tree technique and Bayesian network analysis. We used data provided by the Italian National Institute of Statistics on road crashes that occurred on the Italian road network during the period ranging from 2011 to 2013. In the present study, the dataset contains information about road crashes occurred on the Italian road network during the period ranging from 2011 to 2013. We extracted 49,621 road accidents where at least one cyclist was injured or killed from the original database that comprised a total of 575,093 road accidents. CHAID decision tree technique was employed to establish the relationship between severity of bicycle crashes and factors related to crash characteristics (type of collision and opponent vehicle), infrastructure characteristics (type of carriageway, road type, road signage, pavement type, and type of road segment), cyclists (gender and age), and environmental factors (time of the day, day of the week, month, pavement condition, and weather). CHAID analysis revealed that the most important predictors were, in decreasing order of importance, road type (0.30), crash type (0.24), age of cyclist (0.19), road signage (0.08), gender of cyclist (0.07), type of opponent vehicle (0.05), month (0.04), and type of road segment (0.02). These eight most important predictors of the severity of bicycle crashes were included as predictors of the target (i.e., severity of bicycle crashes) in Bayesian network analysis. Bayesian network analysis identified crash type (0.31), road type (0.19), and type of opponent vehicle (0.18) as the most important predictors of severity of bicycle crashes.

  14. Modeling the effect of operator and passenger characteristics on the fatality risk of motorcycle crashes

    Directory of Open Access Journals (Sweden)

    Ali Tavakoli Kashani

    2016-01-01

    Full Text Available BACKGROUND:In Iran more than 25% of crash fatalities belong to motorcycle operators and passengers in the recent years, from which about 20% are related to passenger fatalities. METHODS: The aim of this study was to investigate the motorcycle operator and passenger characteristics as well as other contributory factors that may affect the fatality risk of motorcyclists involved in traffic crashes. To this end, motorcycle crash data between 2009 and 2012 was extracted from Iran traffic crash database and a logistic regression analysis was performed to obtain odds ratio estimates for each of the study variables. RESULTS: The fatality risk of motorcyclists has a direct relationship with the number of pillion passengers carried. Results also indicate that the amount of increase in the likelihood of having a fatality in a motorcycles crash is considerably higher when the operator is accompanied by a male passenger of the same age. Furthermore, results showed that if the crash is occurred in the darkness, on curves, in rural areas and on highways, then the crash would be more likely to be fatal. Moreover, the head-on collisions, older operators, unlicensed operators and not using a safety helmet were found to increase the likelihood of a fatality in a motorcycle crash. CONCLUSIONS: Preventative measures such as, imposing stricter rules regarding safety helmet usage and confining the number of pillion passengers to one, might be implemented to reduce the fatality risk in motorcycle crashes. In addition, more appropriate infrastructures for penalizing offending motorcyclists could also reduce the frequency of law violations such as not wearing helmet or riding without motorcycle license, which in turn, would result into a reduction in the fatality risk of motorcycle crashes

  15. Levy-taxis: a novel search strategy for finding odor plumes in turbulent flow-dominated environments

    Energy Technology Data Exchange (ETDEWEB)

    Pasternak, Zohar; Grasso, Frank W [BioMimetic and Cognitive Robotics Laboratory, Department of Psychology, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn 11210, NY (United States); Bartumeus, Frederic [Department of Ecology and Evolutionary Biology and Princeton Environmental Institute, 106 Guyot Hall, Princeton University, Princeton 08544, NJ (United States)], E-mail: zpast@yahoo.com

    2009-10-30

    Locating chemical plumes in aquatic or terrestrial environments is important for many economic, conservation, security and health related human activities. The localization process is composed mainly of two phases: finding the chemical plume and then tracking it to its source. Plume tracking has been the subject of considerable study whereas plume finding has received little attention. We address here the latter issue, where the searching agent must find the plume in a region often many times larger than the plume and devoid of the relevant chemical cues. The probability of detecting the plume not only depends on the movements of the searching agent but also on the fluid mechanical regime, shaping plume intermittency in space and time; this is a basic, general problem when exploring for ephemeral resources (e.g. moving and/or concealing targets). Here we present a bio-inspired search strategy named Levy-taxis that, under certain conditions, located odor plumes significantly faster and with a better success rate than other search strategies such as Levy walks (LW), correlated random walks (CRW) and systematic zig-zag. These results are based on computer simulations which contain, for the first time ever, digitalized real-world water flow and chemical plume instead of their theoretical model approximations. Combining elements of LW and CRW, Levy-taxis is particularly efficient for searching in flow-dominated environments: it adaptively controls the stochastic search pattern using environmental information (i.e. flow) that is available throughout the course of the search and shows correlation with the source providing the cues. This strategy finds natural application in real-world search missions, both by humans and autonomous robots, since it accommodates the stochastic nature of chemical mixing in turbulent flows. In addition, it may prove useful in the field of behavioral ecology, explaining and predicting the movement patterns of various animals searching for food

  16. Lévy-taxis: a novel search strategy for finding odor plumes in turbulent flow-dominated environments

    Science.gov (United States)

    Pasternak, Zohar; Bartumeus, Frederic; Grasso, Frank W.

    2009-10-01

    Locating chemical plumes in aquatic or terrestrial environments is important for many economic, conservation, security and health related human activities. The localization process is composed mainly of two phases: finding the chemical plume and then tracking it to its source. Plume tracking has been the subject of considerable study whereas plume finding has received little attention. We address here the latter issue, where the searching agent must find the plume in a region often many times larger than the plume and devoid of the relevant chemical cues. The probability of detecting the plume not only depends on the movements of the searching agent but also on the fluid mechanical regime, shaping plume intermittency in space and time; this is a basic, general problem when exploring for ephemeral resources (e.g. moving and/or concealing targets). Here we present a bio-inspired search strategy named Lévy-taxis that, under certain conditions, located odor plumes significantly faster and with a better success rate than other search strategies such as Lévy walks (LW), correlated random walks (CRW) and systematic zig-zag. These results are based on computer simulations which contain, for the first time ever, digitalized real-world water flow and chemical plume instead of their theoretical model approximations. Combining elements of LW and CRW, Lévy-taxis is particularly efficient for searching in flow-dominated environments: it adaptively controls the stochastic search pattern using environmental information (i.e. flow) that is available throughout the course of the search and shows correlation with the source providing the cues. This strategy finds natural application in real-world search missions, both by humans and autonomous robots, since it accomodates the stochastic nature of chemical mixing in turbulent flows. In addition, it may prove useful in the field of behavioral ecology, explaining and predicting the movement patterns of various animals searching for

  17. 上海市出租车司机饮食行为现状调查%Analysis on dietary behaviors among taxi drivers in Shanghai City

    Institute of Scientific and Technical Information of China (English)

    宋峻; 赖建强; 邹淑蓉; 段一凡; 黄翠花; 朱珍妮; 施爱珍; 姜培珍; 汪正园

    2012-01-01

    Objective To understand the dietary behaviors and practices characteristic among taxi drivers in Shanghai, and provide evidence for health policy making. Methods By using the method of random intercept, 1018 taxi drivers were randomly sampled from taxi parking in Shanghai Hongqiao Airport and a questionnaire survey was conducted. Results 98.4% of taxi drivers ate outside and 44. 6% of them had meals outside 3 times per day. 96. 6% of taxi drivers who took breakfast had inadequate breakfast nutrition. The proportion of adequate nutritional breakfast was only 0. 9%. The proportions of taxi drivers without breakfast, lunch or dinner were 3. 0% , 2. 0% and 2.4% , respectively. Dietary structure of lunch and dinner among taxi drivers were " grain + meat + vegetables" when they worked outside. The reasons for choosing eatery were sanitary and amount, few of them considered about nutrition. Only 4% of them thought over nutrition, and the proportion of urban drivers who considered about nutrition was higher than that of rural drivers. Conclusion Eating disorders, unreasonable distribution of meals and dietary structures still exist in taxi drivers. The health education on nutrition should be enhanced among taxi drivers to reduce the incidences of obesity and overweight and prevent chronic diseases like hypertension.%目的 了解出租车司机饮食行为和膳食结构的特点,为相关部门制定健康教育策略提供依据.方法 以随机拦截的方法,对上海虹桥机场蓄车池中的1018名出租车司机进行问卷调查.结果 出租车司机每日在外就餐以及1日3餐均在外就餐的比例分别为98.4%和44.6%;吃早餐的司机中96.6%的司机的早餐营养不充足,仅0.9%的司机早餐营养充足;司机中不吃早餐、午餐和晚餐的比例分别为3.0%、2.0%和2.4%;司机工作在外时,午餐和晚餐主要是“主食+荤菜+素菜”的膳食构成模式,较少选择水果;司机选择午餐和晚餐的就

  18. Flight-Deck Interface for High-Precision Taxi Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Faced with ever-increasing projections of air traffic, airport expansion plans, changes in operational requirements and introduction of advanced technologies are all...

  19. 基于模糊聚类和识别的出租车合乘算法研究%Algorithm Research of Taxi Carpooling Based on Fuzzy Clustering and Fuzzy Recognition

    Institute of Scientific and Technical Information of China (English)

    肖强; 何瑞春; 张薇; 马昌喜

    2014-01-01

    In some big cities,the effect and efficiency are both poor to the taxi carpooling. The taxi route clustering and carpooling identification of passenger and taxi are studied by fuzzy clustering and fuzzy recognition theory. Through randomly generated many groups of taxi and passengers data, it is pointed that taxi carpooling in particular conditions, taxi numbers will decided the passenger’s carpooling success rate, but it is found that unlimited increase taxi sample number will increase carpooling success rate to passengers in case of a fixed number of passengers, the taxi income will be stabilized, it will not increase with rising of taxi number. The results indicate that the algorithm is suitable for us take the carpooling problem of large numbers taxi and could be effective measurement for taxi carpooling.%针对目前部分大城市出租车合乘效果差,合乘效率低等现状,本文采用模糊聚类和模糊识别方法,研究出租车行驶路线模糊聚类,并利用行驶路线、行驶时间和合乘人数创建隶属函数,实现合乘乘客与出租车的合乘模糊识别。通过随机生成的多组出租车出行和合乘乘客样本数据,发现在假定的出租车合乘条件下,出租车样本数量决定了合乘的成功率,但同时也发现,在合乘人数固定的情况下,无限制的增加出租车样本数量会增加合乘乘客的搭载成功率,平均每辆合乘出租车的收入并不会随着样本数量的增大而增大,而是趋于稳定值。仿真结果说明,该算法适合于大样本的出租车合乘问题,是一种可以提高出租车合乘成功率的有效方法。

  20. 面向冲突避免的航空器场面滑行引导方法%Conflict Avoidance Oriented Airport Surface Aircraft Taxiing Guidance Method

    Institute of Scientific and Technical Information of China (English)

    汤新民; 安宏锋; 王翀

    2011-01-01

    为避免大型高密度机场航空器之间可能发生的冲突,提出了一种基于混杂系统结构的滑行引导方案.建立了航空器滑行连续动力学模型和航空器在滑行道直线段、交叉口运行的离散事件动态系统模型,通过场面运行观测器建立了连续状态到离散状态的映射.采用禁止状态线性不等式约束和禁止状态逻辑互斥约束,描述场面运行模型应遵循的控制规范,并给出满足控制规范的离散控制器设计方法.最后建立了运行模型中可控变迁的使能状态到场面冲突控制策略的映射.通过助航灯光沙盘控制系统的验证表明,该滑行引导方法能及时对可能冲突的航空器采取恰当的控制策略,并实时生成航空器滑行操纵指令,能有效避免航空器滑行冲突.%To avoid confliction troubles between aircrafts at high density airports, an aircraft taxiing guidance framework based on hybrid system is proposed. Firstly, an aircraft taxiing dynamic model in continuous space and discrete event dynamic system models for the taxiing operation on straightaway and intersection are built, and a surface operation observer that maps the continuous dynamic state into discrete observation is proposed. Secondly, the forbidden state avoidance-based regulations described by linear inequality constraints and logical mutex constraints are introduced to express surface traffic control rules, and the discrete controller design method are proposed. Finally, the mapping from the enabling state of controllable transition in the straightaway and intersection operation models to control strategies is built. The validation by control system of an airfield lighting sand table shows that the taxiing guidance method can issue feasible control strategies in time and generate taxi manoeuvring instructions for aircrafts to avoid potential taxiing conflicts effectively.

  1. Anger, Cognition, Ideology: What Crash Can Show Us About Emotion

    Directory of Open Access Journals (Sweden)

    Sue J. Kim

    2010-06-01

    Full Text Available

    Abstract (E: Sue J. Kim’s essay “Anger, Cognition, Ideology: What Crash Can Show Us About Emotion” argues for the relevance and importance of cognitive studies to ethnic and postcolonial literary studies, and vice versa. After surveying recent developments in the field of cognitive studies, the essay combines cultural and cognitive approaches in order to examine anger in and around the 2005 Paul Haggis film Crash.

     

    Abstract (F: Dans cet article, l’auteur fait un plaidoyer pour l’application des études cognitives aux études ethniques et postcoloniales et inversement. L’essai présente d’abord un survol des récents développements dans le domaine des études cognitives, puis combine les approches culturelles et cognitives dans une lecture détaillée du thème de la colère dans le film Crash de Paul Haggis (2005.

     

  2. Suppression of edge localized mode crashes by multi-spectral non-axisymmetric fields in KSTAR

    Science.gov (United States)

    Kim, Jayhyun; Park, Gunyoung; Bae, Cheonho; Yoon, Siwoo; Han, Hyunsun; Yoo, Min-Gu; Park, Young-Seok; Ko, Won-Ha; Juhn, June-Woo; Na, Yong Su; The KSTAR Team

    2017-02-01

    Among various edge localized mode (ELM) crash control methods, only non-axisymmetric magnetic perturbations (NAMPs) yield complete suppression of ELM crashes beyond their mitigation, and thus attract more attention than others. No other devices except KSTAR, DIII-D, and recently EAST have successfully achieved complete suppression with NAMPs. The underlying physics mechanisms of these successful ELM crash suppressions in a non-axisymmetric field environment, however, still remain uncertain. In this work, we investigate the ELM crash suppression characteristics of the KSTAR ELMy H-mode discharges in a controlled multi-spectral field environment, created by both n=2 middle reference and n=1 top/bottom proxy in-vessel control coils. Interestingly, the attempts have produced a set of contradictory findings, one expected (ELM crash suppression enhancement with the addition of n  =  1 to the n  =  2 field at relatively low heating discharges) and another unexpected (ELM crash suppression degradation at relatively high heating discharges) from the earlier findings in DIII-D. This contradiction indicates the dependence of the ELM crash suppression characteristics on the heating level and the associated kink-like plasma responses. Preliminary linear resistive MHD plasma response simulation shows the unexpected suppression performance degradation to be likely caused by the dominance of kink-like plasma responses over the island gap-filling effects.

  3. Random-parameters analysis of highway characteristics on crash frequency and injury severity

    Directory of Open Access Journals (Sweden)

    Bismark R.D.K. Agbelie

    2016-06-01

    Full Text Available Factors that affect highway-related crash frequency and injury severity vary across observations. Using a methodology that does not account nor correct for heterogeneity in observed and unobserved crash factors across highway segments may lead to biased and inconsistent estimated coefficients, thus resulting in erroneous inferences. The present paper demonstrates the use of random-parameters models to facilitate and enhance how crash factors affect crash frequency and injury severity along a highway segment. The results indicate that a unit increase in the presence of stop sign along a highway segment reduces crash frequency by 2.471 for 87.24% of the roadway segments. For the remaining 12.76% of the roadway segments, crash frequency is increased by the same margin. Using the random-parameters multinomial logit model, the result indicates that, for 90.89% of the observations, the presence of a stop sign on a highway segment increases the probability of the injury outcome. For 9.11% of the observations, the presence of a stop sign on a highway segment reduces the probability of the injury outcome, and the marginal effect value across observations is 0.0017. Vertical grades greater than 5% increase crash frequency for 58.46% of the highway segments, and decrease for 41.54% of the highway segments by 0.121 for one unit increase in vertical grades.

  4. A generalized nonlinear model-based mixed multinomial logit approach for crash data analysis.

    Science.gov (United States)

    Zeng, Ziqiang; Zhu, Wenbo; Ke, Ruimin; Ash, John; Wang, Yinhai; Xu, Jiuping; Xu, Xinxin

    2017-02-01

    The mixed multinomial logit (MNL) approach, which can account for unobserved heterogeneity, is a promising unordered model that has been employed in analyzing the effect of factors contributing to crash severity. However, its basic assumption of using a linear function to explore the relationship between the probability of crash severity and its contributing factors can be violated in reality. This paper develops a generalized nonlinear model-based mixed MNL approach which is capable of capturing non-monotonic relationships by developing nonlinear predictors for the contributing factors in the context of unobserved heterogeneity. The crash data on seven Interstate freeways in Washington between January 2011 and December 2014 are collected to develop the nonlinear predictors in the model. Thirteen contributing factors in terms of traffic characteristics, roadway geometric characteristics, and weather conditions are identified to have significant mixed (fixed or random) effects on the crash density in three crash severity levels: fatal, injury, and property damage only. The proposed model is compared with the standard mixed MNL model. The comparison results suggest a slight superiority of the new approach in terms of model fit measured by the Akaike Information Criterion (12.06 percent decrease) and Bayesian Information Criterion (9.11 percent decrease). The predicted crash densities for all three levels of crash severities of the new approach are also closer (on average) to the observations than the ones predicted by the standard mixed MNL model. Finally, the significance and impacts of the contributing factors are analyzed.

  5. Utilizing the eigenvectors of freeway loop data spatiotemporal schematic for real time crash prediction.

    Science.gov (United States)

    Fang, Shou'en; Xie, Wenjing; Wang, Junhua; Ragland, David R

    2016-09-01

    The concept of crash precursor identification is gaining more practicality due to the recent advancements in Advanced Transportation Management and Information Systems. Investigating the shortcomings of the existing models, this paper proposes a new method to model the real time crash likelihood based on loop data through schematic eigenvectors. Firstly, traffic volume, occupancy and density spatiotemporal schematics in certain duration before an accident occurrence were constructed to describe the traffic flow status. Secondly, eigenvectors and eigenvalues of the spatiotemporal schematics were extracted to represent traffic volume, occupancy and density situation before the crash occurrence. Thirdly, by setting the vectors in crash time as case and those at crash free time as control, a logistic model is constructed to identify the crash precursors. Results show that both the eigenvectors and eigenvalues can significantly impact the accident likelihood compared to the previous study, the proposed model has the advantage of avoiding multicollinearity, better reflection of the overall traffic flow status before the crash, and improving missing data problem of loop detectors.

  6. Off-Road Vehicle Crash Risk during the Six Months after a Birthday

    Science.gov (United States)

    Woodfine, Jason D.; Thiruchelvam, Deva; Redelmeier, Donald A.

    2016-01-01

    Background Off-road vehicles are popular and thrilling for youth outside urban settings, yet sometimes result in a serious crash that requires emergency medical care. The relation between birthdays and the subsequent risk of an off-road vehicle crash is unknown. Methods We conducted a population-based before-and-after longitudinal analysis of youth who received emergency medical care in Ontario, Canada, due to an off-road vehicle crash between April 1, 2002, and March 31, 2014. We identified youth injured in an off-road vehicle crash through population-based health-care databases of individuals treated for medical emergencies. We included youth aged 19 years or younger, distinguishing juniors (age ≤ 15 years) from juveniles (age ≥ 16 years). Results A total 32,777 youths accounted for 35,202 emergencies due to off-road vehicle crashes within six months of their nearest birthday. Comparing the six months following a birthday to the six months prior to a birthday, crashes increased by about 2.7 events per 1000 juniors (18.3 vs 21.0, p juveniles (19.2 vs 19.8, p = 0.61). Conclusions Off-road vehicle crashes leading to emergency medical care increase following a birthday in youth below age 16 years. An awareness of this association might inform public health messages, gift-giving practices, age-related parental permissions, and prevention by primary care physicians. PMID:27695070

  7. Calibration of Airframe and Occupant Models for Two Full-Scale Rotorcraft Crash Tests

    Science.gov (United States)

    Annett, Martin S.; Horta, Lucas G.; Polanco, Michael A.

    2012-01-01

    Two full-scale crash tests of an MD-500 helicopter were conducted in 2009 and 2010 at NASA Langley's Landing and Impact Research Facility in support of NASA s Subsonic Rotary Wing Crashworthiness Project. The first crash test was conducted to evaluate the performance of an externally mounted composite deployable energy absorber under combined impact conditions. In the second crash test, the energy absorber was removed to establish baseline loads that are regarded as severe but survivable. Accelerations and kinematic data collected from the crash tests were compared to a system integrated finite element model of the test article. Results from 19 accelerometers placed throughout the airframe were compared to finite element model responses. The model developed for the purposes of predicting acceleration responses from the first crash test was inadequate when evaluating more severe conditions seen in the second crash test. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used to calibrate model results for the second full-scale crash test. This combination of heuristic and quantitative methods was used to identify modeling deficiencies, evaluate parameter importance, and propose required model changes. It is shown that the multi-dimensional calibration techniques presented here are particularly effective in identifying model adequacy. Acceleration results for the calibrated model were compared to test results and the original model results. There was a noticeable improvement in the pilot and co-pilot region, a slight improvement in the occupant model response, and an over-stiffening effect in the passenger region. This approach should be adopted early on, in combination with the building-block approaches that are customarily used, for model development and test planning guidance. Complete crash simulations with validated finite element models can be used

  8. Assessment of methodologies for analysis of the dungeness B accidental aircraft crash risk.

    Energy Technology Data Exchange (ETDEWEB)

    LaChance, Jeffrey L.; Hansen, Clifford W.

    2010-09-01

    The Health and Safety Executive (HSE) has requested Sandia National Laboratories (SNL) to review the aircraft crash methodology for nuclear facilities that are being used in the United Kingdom (UK). The scope of the work included a review of one method utilized in the UK for assessing the potential for accidental airplane crashes into nuclear facilities (Task 1) and a comparison of the UK methodology against similar International Atomic Energy Agency (IAEA), United States (US) Department of Energy (DOE), and the US Nuclear Regulatory Commission (NRC) methods (Task 2). Based on the conclusions from Tasks 1 and 2, an additional Task 3 would provide an assessment of a site-specific crash frequency for the Dungeness B facility using one of the other methodologies. This report documents the results of Task 2. The comparison of the different methods was performed for the three primary contributors to aircraft crash risk at the Dungeness B site: airfield related crashes, crashes below airways, and background crashes. The methods and data specified in each methodology were compared for each of these risk contributors, differences in the methodologies were identified, and the importance of these differences was qualitatively and quantitatively assessed. The bases for each of the methods and the data used were considered in this assessment process. A comparison of the treatment of the consequences of the aircraft crashes was not included in this assessment because the frequency of crashes into critical structures is currently low based on the existing Dungeness B assessment. Although the comparison found substantial differences between the UK and the three alternative methodologies (IAEA, NRC, and DOE) this assessment concludes that use of any of these alternative methodologies would not change the conclusions reached for the Dungeness B site. Performance of Task 3 is thus not recommended.

  9. Prescription medicines and the risk of road traffic crashes: a French registry-based study.

    Directory of Open Access Journals (Sweden)

    Ludivine Orriols

    Full Text Available BACKGROUND: In recent decades, increased attention has been focused on the impact of disabilities and medicinal drug use on road safety. The aim of our study was to investigate the association between prescription medicines and the risk of road traffic crashes, and estimate the attributable fraction. METHODS AND FINDINGS: We extracted and matched data from three French nationwide databases: the national health care insurance database, police reports, and the national police database of injurious crashes. Drivers identified by their national health care number involved in an injurious crash in France, between July 2005 and May 2008, were included in the study. Medicines were grouped according to the four risk levels of the French classification system (from 0 [no risk] to 3 [high risk]. We included 72,685 drivers involved in injurious crashes. Users of level 2 (odds ratio [OR]  = 1.31 [1.24-1.40] and level 3 (OR  = 1.25 [1.12-1.40] prescription medicines were at higher risk of being responsible for a crash. The association remained after adjustment for the presence of a long-term chronic disease. The fraction of road traffic crashes attributable to levels 2 and 3 medications was 3.3% [2.7%-3.9%]. A within-person case-crossover analysis showed that drivers were more likely to be exposed to level 3 medications on the crash day than on a control day, 30 days earlier (OR  = 1.15 [1.05-1.27]. CONCLUSION: The use of prescription medicines is associated with a substantial number of road traffic crashes in France. In light of the results, warning messages appear to be relevant for level 2 and 3 medications and questionable for level 1 medications. A follow-up study is needed to evaluate the impact of the warning labeling system on road traffic crash prevention.

  10. What the 2008 stock market crash means for retirement security.

    Science.gov (United States)

    Butrica, Barbara A; Smith, Karen E; Toder, Eric J

    2010-10-01

    The 2008 stock market crash raises concerns about retirement security, especially since the increased prevalence of 401(k) and similar retirement saving plans means that more Americans are now stakeholders in the equity market than in the past. Using a dynamic microsimulation model, this paper explores the ability of alternate future stock market scenarios to restore retirement assets. The authors find that those near retirement could fare the worst because they have no time to recoup their losses. Mid-career workers could fare better because they have more time to rebuild their wealth. They may even gain income if they buy stocks at low prices and get above-average rates of return. High-income groups will be the most affected because they are most likely to have financial assets and to be invested in the stock market.

  11. The stability of portfolio investment in stock crashes

    Science.gov (United States)

    Li, Yun-Xian; Qian, Zhen-Wei; Li, Jiang-Cheng; Tang, Nian-Sheng; Mei, Dong-Cheng

    2016-08-01

    The stability of portfolio investment in stock market crashes with Markowitz portfolio is investigated by the method of theoretical and empirical simulation. From numerical simulation of the mean escape time (MET), we conclude that: (i) The increasing number (Np) of stocks in Markowitz portfolio induces a maximum in the curve of MET versus the initial position; (ii) A critical value of Np in the behavior of MET versus the long-run variance or amplitude of volatility fluctuations maximumlly enhances the stability of portfolio investment. When Np takes value below the critical value, the increasing Np enhances the stability of portfolio investment, but restrains it when Np takes value above the critical value. In addition, a good agreement of both the MET and probability density functions of returns is found between real data and theoretical results.

  12. Secondary fast reconnecting instability in the sawtooth crash

    CERN Document Server

    Del Sarto, Daniele

    2016-01-01

    In this work we consider magnetic reconnection in thin current sheets with both resistive and electron inertia effects. When the current sheet is produced by a primary instability of the internal kink type, the analysis of secondary instabilities indicates that reconnection proceeds on a time scale much shorter than the primary instability characteristic time. In the case of a sawtooth crash, non-collisional physics becomes important above a value of the Lundquist number which scales like S ~ (R/d_e)^{12/5}, in terms of the tokamak major radius R and of the electron skin depth d_e. This value is commonly achieved in present day devices. As collisionality is further reduced, the characteristic rate increases, approaching Alfv\\'enic values when the primary instability approaches the collisionless regime.

  13. A Perspective into Regulatory Requirements for Intentional Aircraft Crash

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Yun; Park, Jong Seuk; Chung, Yun Suk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Inn Seock [ISSA Technology, Maryland (Korea, Republic of); Choi, Eong Soo; Kim, Jong Hyun [ACT Co., Daejeon (Korea, Republic of)

    2010-10-15

    In the aftermath of the 9/11 terrorist attacks on the United States, there was heightened interest worldwide in protecting nuclear power plants against intentional aircraft attack by terrorists. This paper presents our perspective into regulatory requirements for intentional aircraft crash that were set forth in foreign countries, including the latest rulemaking by the U.S. Nuclear Regulatory Commission (NRC), i.e., 10 CFR 50.54(hh) and 10 CFR 50.150 that have been made effective in May and July of 2009, respectively. In light of these international efforts to further enhance safety of NPPs, a study is also underway at the Korea Institute of Nuclear Safety (KINS) to establish an effective and efficient regulatory approach in consideration of the state of the art in this area

  14. DEVELOPMENT OF A CRASH RISK PROBABILITY MODEL FOR FREEWAYS BASED ON HAZARD PREDICTION INDEX

    Directory of Open Access Journals (Sweden)

    Md. Mahmud Hasan

    2014-12-01

    Full Text Available This study presents a method for the identification of hazardous situations on the freeways. The hazard identification is done using a crash risk probability model. For this study, about 18 km long section of Eastern Freeway in Melbourne (Australia is selected as a test bed. Two categories of data i.e. traffic and accident record data are used for the analysis and modelling. In developing the crash risk probability model, Hazard Prediction Index is formulated in this study by the differences of traffic parameters with threshold values. Seven different prediction indices are examined and the best one is selected as crash risk probability model based on prediction error minimisation.

  15. Crash response data system for the controlled impact demonstration (CID) of a full scale transport aircraft

    Science.gov (United States)

    Calloway, Raymond S.; Knight, Vernie H., Jr.

    1986-01-01

    NASA Langley's Crash Response Data System (CRDS) which is designed to acquire aircraft structural and anthropomorphic dummy responses during the full-scale transport CID test is described. Included in the discussion are the system design approach, details on key instrumentation subsystems and operations, overall instrumentation crash performance, and data recovery results. Two autonomous high-environment digital flight instrumentation systems, DAS 1 and DAS 2, were employed to obtain research data from various strain gage, accelerometer, and tensiometric sensors installed in the B-720 test aircraft. The CRDS successfully acquired 343 out of 352 measurements of dynamic crash data.

  16. The application of the random regret minimization model to drivers’ choice of crash avoidance maneuvers

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    This study explores the plausibility of regret minimization as behavioral paradigm underlying the choice of crash avoidance maneuvers. Alternatively to previous studies that considered utility maximization, this study applies the random regret minimization (RRM) model while assuming that drivers...... seek to minimize their anticipated regret from their corrective actions. The model accounts for driver attributes and behavior, critical events that made the crash imminent, vehicle and road characteristics, and environmental conditions. Analyzed data are retrieved from the General Estimates System......-based model, suggesting that both models should serve as a basis for evaluating crash scenarios and driver warning systems....

  17. The application of the random regret minimization model to drivers’ choice of crash avoidance maneuvers

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    This study explores the plausibility of regret minimization as behavioral paradigm underlying the choice of crash avoidance maneuvers. Alternatively to previous studies that considered utility maximization, this study applies the random regret minimization (RRM) model while assuming that drivers...... seek to minimize their anticipated regret from their corrective actions. The model accounts for driver attributes and behavior, critical events that made the crash imminent, vehicle and road characteristics, and environmental conditions. Analyzed data are retrieved from the General Estimates System......-based model, suggesting that both models should serve as a basis for evaluating crash scenarios and driver warning systems....

  18. Experimental studies on the axial crash behavior of aluminum foam-filled hat sections

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-chun; FAN Zi-jie; GUI Liang-jin; WANG Zheng-hong; FU Zi-lai

    2006-01-01

    Drop hammer tests were carried out to study the axial crash behavior of aluminum foam-filled hat sections.First,the axial crash tests of the empty hat sections,aluminum foam and the aluminum foam-filled hat sections were carried out;then,based upon the test results,the axial crash behavior of the aluminum foam-filled hat sections were analyzed.It was found that aluminum foam filling can increase the energy absorption capacities of the hat sections.Compared with the non-filled structures,aluminum foamfilled structures were much more stable and needed less mass to absorb the specified energy.

  19. Numerical simulation of aircraft crash on nuclear containment structure

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in [Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Rai, S.; Sadique, M.R.; Bhargava, P. [Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer The deformation was more localised at the center of cylindrical portion. Black-Right-Pointing-Pointer The peak deflection at the junction of dome and cylinder was found to be 67 mm. Black-Right-Pointing-Pointer The peak deflection at midpoint of the cylindrical portion was found to be 88.9 mm. Black-Right-Pointing-Pointer The strain rate was found to be an important parameter to effect the deformation. Black-Right-Pointing-Pointer The model without strain rate and 290 s{sup -1} strain rate predicted very high deformations. - Abstract: Numerical simulations were carried with ABAQUS/Explicit finite element code in order to predict the response of BWR Mark III type nuclear containment against Boeing 707-320 aircraft crash. The load of the aircraft was applied using and force history curve. The damaged plasticity model was used to predict the behavior of concrete while the Johnson-Cook elasto-viscoplastic material model was used to incorporate the behavior of steel reinforcement. The crash was considered to occur at two different locations i.e., the midpoint of the cylindrical portion and the junction of dome and cylinder. The midpoint of the cylindrical portion experienced more deformation. The strain rate in the material model was varied and found to have a significant effect on the response of containment. The results of the present investigation were compared with those of the studies available in literature and a close agreement with the previous results was found in terms of maximum target deformation.

  20. Nuclear containment structure subjected to commercial and fighter aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Sadique, M.R., E-mail: rehan.sadique@gmail.com; Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in; Bhargava, P., E-mail: bhpdpfce@iitr.ernet.in

    2013-07-15

    Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment.

  1. Analysis of Casualty Risk per Police-Reported Crash for Model Year 2000 to 2004 Vehicles, using Crash Data from Five States

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, Tom

    2011-03-20

    In this report we compare two measures of driver risks: fatality risk per vehicle registration-year, and casualty (fatality plus serious injury) risk per police-reported crash. Our analysis is based on three sets of data from five states (Florida, Illinois, Maryland, Missouri, and Pennsylvania): data on all police-reported crashes involving model year 2000 to 2004 vehicles; 2005 county-level vehicle registration data by vehicle model year and make/model; and odometer readings from vehicle emission inspection and maintenance (I/M) programs conducted in urban areas of four of the five states (Florida does not have an I/M program). The two measures of risk could differ for three reasons: casualty risks are different from fatality risk; risks per vehicle registration-year are different from risks per crash; and risks estimated from national data are different from risks from the five states analyzed here. We also examined the effect of driver behavior, crash location, and general vehicle design on risk, as well as sources of potential bias in using the crash data from five states.

  2. Reducing young driver crash casualties in Great Britain - use of routine police crash data to estimate the potential benefits of graduated driver licensing.

    Science.gov (United States)

    Jones, Sarah J; Begg, Dorothy J; Palmer, Stephen R

    2013-01-01

    Crashes involving young drivers (YD) cause significant morbidity and mortality in Great Britain (GB). Graduated Driver Licensing (GDL) is used in some countries to address this. This study assessed potential casualty and cost savings of possible GDL programmes in GB. Police road crash data were analysed to identify YD crashes at night or while carrying passengers. These data were then used to estimate the potential effects of GDL. 314,561 casualties and 3469 fatalities occurred in YD crashes. 25.1% of YD crashes occurred between 9 pm and 6 am and 24.4% occurred with a 15- to 24-year old passenger in the car. A 'strict' form of GDL in GB (night time restriction 9 pm-6 am, no 15-24 year old passengers) with 50% compliance would prevent 114 deaths and 872 serious casualties each year. The estimated value of prevention is £424M pa. A 'less strict' form of GDL (night time restriction 10 pm-5 am, maximum of one 15-19 year old passenger) with 50% compliance would prevent 81 deaths and 538 serious injuries. The estimated value of prevention is £273M pa. Implementing GDL in GB could save significant numbers of lives. Public health organisations have a duty to advocate for such legislation.

  3. 出租车合乘收益趋势影响模型研究%Research on the Benefit Tendency Model of Taxi-sharing

    Institute of Scientific and Technical Information of China (English)

    肖强; 何瑞春; 俞建宁; 张薇

    2016-01-01

    In order to analyze the influence of taxi-sharing conditions on carpooling benefit,GPS trajectory data processing method is constructed and the taxi-sharing model is built by introducing variable data such as taking on & off distance and time.On the basis of the grey forecasting mod-el,the taxi-sharing benefit tendency is explored under the different influence conditions of sharing distance and spacing interval.The conclusion shows that taxi-sharing benefit is closely related to the distance of taking on point.The model is applied to Nanjing taxi GPS trajectory data.When the time interval of taking on point of the taxi-sharing is 20 minutes,the distance of the taxi-sha-ring increases to 1200 meters,the matching degree will increase quickly and the benefit will in-crease by 20.31%,and it indicates that the further the distance interval is,the more the income is.Otherwise,when the distance of taking on point of the taxi-sharing is 100 meters,the time in-terval of sharing increases to 35 minutes,the matching degree will increase slowly and the benefit will increase by 5.38%,and it indicates that the longer the time interval is,the less the income is.%为了分析出租车合乘条件对合乘收益趋势的影响,构建了 GPS 轨迹数据的处理方法,引入合乘下车点的距离、合乘上车点的距离和时间等参数,建立出租车合乘模型,并利用灰色预测模型,讨论了在合乘点距离和间隔时间不同的影响条件下,出租车的合乘收益趋势.研究结果表明:合乘的收益与合乘上车点间的距离密切相关.模型应用于南京市出租车 GPS 轨迹数据时,当合乘上车点的时间间隔固定为20 min,合乘上车点间的距离增大到1200 m 时,合乘的匹配数增加快,合乘的收益可以增加20.31%,且距离间隔越大,收益增长越快;当合乘上车间的距离固定在100 m 时,合乘上车点的时间间隔增加到35 min,合乘的匹配数增加

  4. Comparative Life Cycle Environmental Assessment Between Electric Taxi and Gasoline Taxi in Beijing%北京电动出租车与燃油出租车生命周期环境影响比较研究

    Institute of Scientific and Technical Information of China (English)

    施晓清; 孙赵鑫; 李笑诺; 李金香; 杨建新

    2015-01-01

    Tailpipe emission of internal combustion engine vehicle ( ICEV ) is one of the main sources leading to atmospheric environmental problems such as haze. Substituting electric vehicles for conventional gasoline vehicles is an important solution for reducing urban air pollution. In 2011, as a pilot city of electric vehicle, Beijing launched a promotion plan of electric vehicle. In order to compare the environmental impacts between Midi electric vehicle ( Midi EV) and Hyundai gasoline taxi ( ICEV) , this study created an inventory with local data and well-reasoned assumptions, and contributed a life cycle assessment ( LCA) model with GaBi4. 4 software and comparative life cycle environmental assessment by Life cycle impact analysis models of CML2001( Problem oriented) and EI99 ( Damage oriented) , which included the environmental impacts of full life cycle, manufacture phase, use phase and end of life. The sensitivity analysis of lifetime mileage and power structure was also provided. The results indicated that the full life cycle environmental impact of Midi EV was smaller than Hyundai ICEV, which was mainly due to the lower fossil fuel consumption. On the contrary, Midi EV exhibited the potential of increasing the environmental impacts of ecosystem quality influence and Human health influence. By CML2001 model, the results indicated that Midi EV might decrease the impact of Abiotic Depletion Potential, Global Warming Potential, Ozone Layer Depletion Potential and so on. However, in the production phase, the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Ozone Layer Depletion Potential, Marine Aquatic Ecotoxicity Potential, Terrestric Ecotoxicity Potential, Human Toxicity Potential of Midi EV were increased relative to Hyundai ICEV because of emissions impacts from its power system especially the battery production. Besides, in the use phase, electricity

  5. Poisson process-based algorithm for searching vacant taxi%基于泊松过程的寻找空驶出租车的算法

    Institute of Scientific and Technical Information of China (English)

    樊里略

    2016-01-01

    随着城市化进程的推进,城市车辆数量呈现激增的趋势.城市交通为居民的出行提供便利的同时,也带来了比如打车难问题.为了解决这个问题,首先采用对大规模的出租车GPS轨迹数据进行预处理,并生成道路特征索引;然后利用非齐次泊松过程NPP进行预测和推荐工作.用此方法与其它相关先进方法进行对比,实验结果表明,此方法在准确率和运行效率方面更具优势.%With the development of urbanization, the number of cars was proliferating fast. Urban transportation provides convenience for city resident, meanwhile, it also brings many challenges, such as causing a difficulty for taking a taxi. To solve the problem, main work was composed of two parts: first, a method was proposed to estimate the probability and waiting time for a vacant taxi at a given time and place, second, an recommendations was provided for passengers of where to wait for a taxi. In order to complete the main work, the Large-scale Taxi GPS Traces was preprocessed and the road characteristic index was generated. Then NPP ( Nonhomogeneous Poisson Process) was used to predict and recommend. Compared with other related advanced methods, the results show that the method has more advantages in accuracy and efficiency.

  6. Battery-quick-replacement Operation Mode for Electric Taxi Vehicle%纯电动出租汽车快速更换电池运营模式

    Institute of Scientific and Technical Information of China (English)

    王健; 梁桂航

    2011-01-01

    提出了纯电动出租汽车快速更换电池的运营模式:每一辆纯电动出租汽车配置2组电池,电池的所有权属于独立的电池租赁公司,每次更换电池的费用按实际用电量计算,电池租赁公司实行集中充电,分散更换.指出了快速更换电池运营模式的优点,并对该运营模式进行了经济分析.该运营模式的实施,可有效促进纯电动汽车的发展.%The battery-quick-replacement operation mode for electric taxi vehicles was proposed; Each electric taxi equipped with two groups of electric battery belongs to the independent battery leasing companies. The cost of replacing battery will be calculated according to actual consumption. The battery leasing companies will charge the replaced batteries in batches and distribute the charged batteries for new replacement. The advantage of the battery-quick-replacement operation mode was explained. The economic analysis of the battery-quick-replacement operation mode was performed. The implement of this operation mode is helpful for the development of electric taxi vehicle.

  7. Optimal Fare, Vacancy Rate, and Subsidies under Log-Linear Demand with the Consideration of Externalities for a Cruising Taxi Market

    Directory of Open Access Journals (Sweden)

    Chun-Hsiao Chu

    2017-01-01

    Full Text Available Externality is an important issue for formulating the regulation policy of a taxi market. However, this issue is rarely taken into account in the current policy-making process, and it has not been adequately explored in prior research. This study extends the model proposed by Chang and Chu in 2009 with the aim of exploring the effect of externality on the optimization of the regulation policy of a cruising taxi market. A closed-form solution for optimizing the fare, vacancy rate, and subsidy of the market is derived. The results show that when the externality of taxi trips is taken into consideration, the optimal vacancy rate should be lower and the subsidy should be higher than they are under current conditions where externality is not considered. The results of the sensitivity analysis on the occupied and vacant distance indicate that the relation of the vacant distance to the marginal external cost is more sensitive than the occupied distance. The result of the sensitivity analysis on the subsidy shows the existence of a negative relationship between the marginal external cost and the optimal subsidy.

  8. Effect of an Educational Program Based on the Health Belief Model to Reduce Cell Phone Usage During Driving in Taxi drivers

    Directory of Open Access Journals (Sweden)

    Babak Moeini

    2014-09-01

    Full Text Available Introduction: Cell phone usage during driving has become a threat to traffic safety. This study aimed to determine the effectiveness of an educational program based on the health belief model to reduce cell phone usage during driving in taxi drivers of Tuyserkan. Materials and Methods: In this quasi-experimental study, 110 taxi drivers younger than 35 years were randomly divided into two experimental and control groups in Tuyserkan, Iran. Data was collected using a questionnaire including the health belief model constructs, knowledge, behaviors of using cell phone and demographic variables. The questionnaires were self-reported. Intervention was three sessions applied in the experimental group. Both groups were followed for two months after the intervention. Finally, data analysis was performed using SPSS- 19 by Chi-square, Independent T-test, Paired T-test and McNemar. Results: The mean scores for the constructs of health belief model (perceived susceptibility, severity, barriers, perceived benefits, self-efficacy and cues to action, knowledge and desired behaviors about the use of cell phone during driving showed no significant differences between the two groups before the intervention. After the educational intervention, significant differences were observed in experimental group compared to control group. After educational intervention, cell phone usage reduced by 35.14% in the experimental group. Conclusion: An educational intervention based on the health belief model could reduce cell phone usage during driving in taxi drivers.

  9. Missing Just 1 Hour of Sleep May Double Drivers' Crash Risk

    Science.gov (United States)

    Skip navigation U.S. National Library of Medicine Menu ... Double Drivers' Crash Risk Too little shut-eye can equal alcohol in terms of impairment behind the wheel, traffic safety group warns To use ...

  10. How Common are Noise Sources on the Crash Arc of Malaysian Flight 370

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kunkle, Thomas David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stead, Richard J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-21

    Malaysian Flight 370 disappeared nearly without a trace. Besides some communication handshakes to the INMASAT satellite, the Comprehensive Test Ban Treaty monitoring system could have heard the aircraft crash into the southern Indian Ocean. One noise event from Cape Leeuwin has been suggested by Stead as the crash and occurs within the crash location suggested by Kunkle at el. We analyze the hydrophone data from Cape Leeuwin to understand how common such noise events are on the arc of possible locations where Malaysian Flight 370 might have crashed. Few other noise sources were found on the arc. The noise event found by Stead is the strongest. No noise events are seen within the Australian Transportation Safety Board (ATSB) new search location until the 10th strongest event, an event which is very close to the noise level.

  11. Light weight replacement and the optimization design of bumper beam based on crash safety

    Institute of Scientific and Technical Information of China (English)

    Zhang Jingwen; Ma Mingtu; Fan Tiqiang; Zhao Qingjiang; Li Yang

    2014-01-01

    Bumper beam is one of the key structural parts,which plays an important role in the frontal crashes of automobile. With the global trend of light-weighted automotive parts,the light weight of bumper beam at-tracts extensive attention of automobile manufacturers,and hot stamping technology with significant weight ad-vantage has become one of the main light weight measures for bumper beam. The quasi-static press,low speed crash and frontal crash simulation models of bumper beam were established according to its actual working con-ditions in the automobile crashes. The feasibility of replacing normal steel bumper beam with hot stamping bum-per beam was analyzed. Meanwhile,the stiffeners in the front face of hot stamping bumper beam were opti-mized with topography optimization in order to further improve its performances.

  12. An insight into the performance of road barriers - redistribution of barrier-relevant crashes.

    Science.gov (United States)

    Zou, Yaotian; Tarko, Andrew P

    2016-11-01

    Unlike most of traffic safety treatments that prevent crashes, road barriers reduce the severity of crash outcomes by replacing crashes with a high risk of severe injury and fatality (such as median crossover head-on collisions or collisions with high-hazard objects) with less risky events (such as collisions with barriers). This "crash conversion" is actually more complex than one-to-one replacement and it has not been studied yet. The published work estimated the reduction of selected types of crashes (typically, median crossover collisions) or the overall effect of barriers on crash severity. The objective of this study was to study the probabilities of various types of crash events possible under various road and barrier scenarios. The estimated probabilities are conditional given that at least one vehicle left the travelled way and the resulted crash had been recorded. The results are meant to deliver a useful insight onto the conversion of crashes by barriers from more to less risky to help better understand the mechanism of crash severity reduction. Such knowledge should allow engineers more accurate estimation of barriers' benefits and help researchers evaluate barriers' performance to improve the barrier's design. Seven barrier-relevant crash events possible after a vehicle departs the road could be identified based on the existing crash data and their probabilities estimated given the presence and location of three types of barriers: median concrete barriers, median and roadside W-beam steel guardrails, and high-tension median cable barriers. A multinomial logit model with variable outcomes was estimated based on 2049 barrier-relevant crashes occurred between 2003 and 2012 on 1258 unidirectional travelled ways in Indiana. The developed model allows calculating the changes in the probabilities of the barrier-relevant crash events. The results of this study indicated that road departures lead to less frequent crossings of unprotected (no barriers) medians

  13. Preliminary design data package. Appendices C1 and C3. [HYBRID 2; VSYS; and CRASH

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-25

    The computer programs, including HYBRID, VSYS, VEHIC and CRASH, used to compute the energy and fuel consumption, life-cycle costs and performance characteristics of a hybrid electric-powered vehicle are described and their use documented. (LCL)

  14. 77 FR 32712 - Technical Report: Evaluation of the Enhancing Vehicle-to-Vehicle Crash Compatibility Agreement...

    Science.gov (United States)

    2012-06-01

    ... Crash Compatibility Agreement (EVC) was established in 2003 as a voluntary measure to reduce occupant.... Overall, these results provide some evidence that the EVC has reduced fatalities but are not...

  15. An Inferential System for Determination of Candidate Crash Sites for Search and Rescue Operations Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop, test, and prove the feasibility of a methodology for an inferential system for the generation of crash site likelihood maps. These maps will...

  16. Examining the effect of speed, roadside features, and roadway geometry on crash experience along a rural corridor

    Institute of Scientific and Technical Information of China (English)

    Donald C.Watson Jr.; Ahmed Al-Kaisy; Nathan D.Anderson

    2014-01-01

    This paper presents a current investigation into crash experience along a 15.7-mile rural corridor in southwest Montana with the aim of better understanding crash causal factors along the corridor. The study utilized ten years of crash data, geometric data, and observed free-flow speed data along the corridor. A systematic approach was used where every tenth of a mile was described in term of the crash experience, speed, alignment, and roadside features. Using bivariate and multivariate statistical anal-yses, the study investigated the crash experience along the corridor as well as some of the underlying relationships which could explain some of the crash causal factors. Results show a strong association between crash rates and horizontal curvatures even for flat curves that can be negotiated at speeds above the posted speed limit, per the highway design equations. Higher crash rates were also found to be associated with the difference between the observed free-flow speeds and the speed dictated by the curve radius or sight distance as per the design equations. Further, results strongly support the safety benefits of guardrails as evidenced by the lower crash rates and severities. The presence of fixed objects and the steepness of side slopes were also found to have an effect on crash rates and severities.

  17. An Evaluation of the Euroncap Crash Test Safety Ratings in the Real World

    OpenAIRE

    2007-01-01

    We investigated whether the rating obtained in the EuroNCAP test procedures correlates with injury protection to vehicle occupants in real crashes using data in the UK Cooperative Crash Injury Study (CCIS) database from 1996 to 2005. Multivariate Poisson regression models were developed, using the Abbreviated Injury Scale (AIS) score by body region as the dependent variable and the EuroNCAP score for that particular body region, seat belt use, mass ratio and Equivalent Test Speed (ETS) as ind...

  18. Motor vehicle crashes during pregnancy and cerebral palsy during infancy: a longitudinal cohort analysis

    Science.gov (United States)

    Redelmeier, Donald A; Naqib, Faisal; Thiruchelvam, Deva; R Barrett, Jon F

    2016-01-01

    Objectives To assess the incidence of cerebral palsy among children born to mothers who had their pregnancy complicated by a motor vehicle crash. Design Retrospective longitudinal cohort analysis of children born from 1 April 2002 to 31 March 2012 in Ontario, Canada. Participants Cases defined as pregnancies complicated by a motor vehicle crash and controls as remaining pregnancies with no crash. Main outcome Subsequent diagnosis of cerebral palsy by age 3 years. Results A total of 1 325 660 newborns were analysed, of whom 7933 were involved in a motor vehicle crash during pregnancy. A total of 2328 were subsequently diagnosed with cerebral palsy, equal to an absolute risk of 1.8 per 1000 newborns. For the entire cohort, motor vehicle crashes correlated with a 29% increased risk of subsequent cerebral palsy that was not statistically significant (95% CI −16 to +110, p=0.274). The increased risk was only significant for those with preterm birth who showed an 89% increased risk of subsequent cerebral palsy associated with a motor vehicle crash (95% CI +7 to +266, p=0.037). No significant increase was apparent for those with a term delivery (95% CI −62 to +79, p=0.510). A propensity score-matched analysis of preterm births (n=4384) yielded a 138% increased relative risk of cerebral palsy associated with a motor vehicle crash (95% CI +27 to +349, p=0.007), equal to an absolute increase of about 10.9 additional cases per 1000 newborns (18.2 vs 7.3, p=0.010). Conclusions Motor vehicle crashes during pregnancy may be associated with an increased risk of cerebral palsy among the subgroup of cases with preterm birth. The increase highlights a specific role for traffic safety advice in prenatal care. PMID:27650764

  19. The analysis of epidemiological characteristics of road traffic crashes in a mountain city in western China

    Institute of Scientific and Technical Information of China (English)

    周继红; 赵新才; 王正国; 朱佩芳; 简华刚; 刘大维; 周金玲; 刘蕾

    2003-01-01

    Objective: To study the epidemiological characteristics and preventive methods of road traffic crashes in a mountain city in western China through sampling investigation of traffic crashes in different regions of Chongqing city in recent years. Methods: Two police teams of traffic management in downtown, two teams in suburb, one team in county and one freeway team were randomly selected, and road traffic crashes between 1988 and 1997 were investigated and analyzed. Results: A total of 13121 road traffic crashes with 6201 crashes with casualties were analyzed. The incidence of crashes was higher in May, June and July, and on Friday and Wednesday and at 8:00-12:00 and 14:00-18:00 within a day. Casualties were 44.0% in pedestrians and 42.5% in passengers of total casualties. The deaths and severe injuries in pedestrians were59.1% of total deaths and 56.4% of total severe injuries. The age of drivers and passengers were mainly at 18-30 years, followed by 31-40 years. People over 60 years old accounted for 24.1% of total pedestrian casualty. Head injury was the most common reason for deaths. The main reasons for these crashes were improper driving and violating traffic laws. Violating traffic laws by pedestrian was one of the main reasons for pedestrian casualty. Conclusions: The crashes are related to the characteristics of geography, climate, society activity of people, and the sense of traffic safety, the basic traffic construction and management in Chongqing. The traffic casualty of pedestrian is a big problem in Chongqing. To prevent and decrease road traffic injuries effective methods should be worked out and propaganda on traffic safety and traffic management should be strengthened according to different characteristics of different regions. To strengthen the first aid and treatment of cranium-brain injury and chest-back injury is also helpful in decreasing traffic deaths.

  20. Tiring job and work related injury road crashes in the GAZEL cohort.

    Science.gov (United States)

    Chiron, Mireille; Bernard, Marlène; Lafont, Sylviane; Lagarde, Emmanuel

    2008-05-01

    The objective was to describe at-work and commuting crashes occurring in a cohort of French employees and to investigate occupational risk factors. The subjects were employees of the French national electricity and gas companies, Electricité de France and Gaz de France (EDF-GDF), who volunteered to join a research cohort (the GAZEL cohort which included 20,625 participants in 1989). Only crashes with injuries were considered. Crashes for the periods 1989--2001 were recorded together with the type of journey (commuting, work, private), the type of road-user, self-estimated responsibility, and injuries sustained by the subject. Annual incidences for gender/age groups and socio-occupational groups were computed for each of the two types of work related crashes. Occupational risk factor analyses were conducted using a Cox proportional hazards regression model with time-dependent covariates adjusting for the main confounders. A total of 146,285 person years at work were observed. Two indicators of self-reported work fatigue were associated with the occurrence of at-work crashes: "nervously tiring work" for males (RR=1.6, 95% CI [1.1; 2.3]), sustained standing for females (RR=3.0, 95% CI [1.0; 8.4]), adjusting for health status, location of residence, type of family, transport mode and mileage. As regards crashes while commuting, a self-reported uncomfortable position at work was a risk factor among women (RR=1.9, 95% CI [1.1; 3.3]). On the other hand, these occupational factors were not linked to road crashes in private trips. Work related road crashes seem then to be a matter for a specific prevention. Preventing employees from becoming exhausted should be considered as the first way to initiate such a prevention.

  1. Estimating under-reporting of road crash injuries to police using multiple linked data collections.

    Science.gov (United States)

    Watson, Angela; Watson, Barry; Vallmuur, Kirsten

    2015-10-01

    The reliance on police data for the counting of road crash injuries can be problematic, as it is well known that not all road crash injuries are reported to police which under-estimates the overall burden of road crash injuries. The aim of this study was to use multiple linked data sources to estimate the extent of under-reporting of road crash injuries to police in the Australian state of Queensland. Data from the Queensland Road Crash Database (QRCD), the Queensland Hospital Admitted Patients Data Collection (QHAPDC), Emergency Department Information System (EDIS), and the Queensland Injury Surveillance Unit (QISU) for the year 2009 were linked. The completeness of road crash cases reported to police was examined via discordance rates between the police data (QRCD) and the hospital data collections. In addition, the potential bias of this discordance (under-reporting) was assessed based on gender, age, road user group, and regional location. Results showed that the level of under-reporting varied depending on the data set with which the police data was compared. When all hospital data collections are examined together the estimated population of road crash injuries was approximately 28,000, with around two-thirds not linking to any record in the police data. The results also showed that the under-reporting was more likely for motorcyclists, cyclists, males, young people, and injuries occurring in Remote and Inner Regional areas. These results have important implications for road safety research and policy in terms of: prioritising funding and resources; targeting road safety interventions into areas of higher risk; and estimating the burden of road crash injuries.

  2. Occupant injury in rollover crashes - Contribution of planar impacts with objects and other vehicles.

    Science.gov (United States)

    Ivarsson, Johan; Poplin, Gerald; McMurry, Tim; Crandall, Jeff; Kerrigan, Jason

    2015-12-01

    Planar impacts with objects and other vehicles may increase the risk and severity of injury in rollover crashes. The current study compares the frequency of injury measures (MAIS 2+, 3+, and 4+; fatal; AIS 2+ head and cervical spine; and AIS 3+ head and thorax) as well as vehicle type distribution (passenger car, SUV, van, and light truck), crash kinematics, and occupant demographics between single vehicle single event rollovers (SV Pure) and multiple event rollovers to determine which types of multiple event rollovers can be pooled with SV Pure to study rollover induced occupant injury. Four different types of multiple event rollovers were defined: single and multi-vehicle crashes for which the rollover is the most severe event (SV Prim and MV Prim) and single and multi-vehicle crashes for which the rollover is not the most severe event (SV Non-Prim and MV Non-Prim). Information from real world crashes was obtained from the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the period from 1995 through 2011. Belted, contained or partially ejected, adult occupants in vehicles that completed 1-16 lateral quarter turns were assigned to one of the five rollover categories. The results showed that the frequency of injury in non-primary rollovers (SV Non-Prim and MV Non-Prim) involving no more than one roof inversion is substantially greater than in SV Pure, but that this disparity diminishes for crashes involving multiple inversions. It can further be concluded that for a given number of roof inversions, the distribution of injuries and crash characteristics in SV Pure and SV Prim crashes are sufficiently similar for these categories to be considered collectively for purposes of understanding etiologies and developing strategies for prevention.

  3. Spatial panel analyses of alcohol outlets and motor vehicle crashes in California: 1999–2008

    OpenAIRE

    Ponicki, William R.; Gruenewald, Paul J.; Remer, Lillian G.

    2013-01-01

    Although past research has linked alcohol outlet density to higher rates of drinking and many related social problems, there is conflicting evidence of density’s association with traffic crashes. An abundance of local alcohol outlets simultaneously encourages drinking and reduces driving distances required to obtain alcohol, leading to an indeterminate expected impact on alcohol-involved crash risk. This study separately investigates the effects of outlet density on (1) the risk of injury cra...

  4. Correlating the extent of pulmonary contusion to vehicle crash parameters in near-side impacts.

    Science.gov (United States)

    Danelson, Kerry A; Chiles, Caroline; Thompson, Aaron B; Donadino, Katherine; Weaver, Ashley A; Stitzel, Joel D

    2011-01-01

    Pulmonary contusion (PC) is the most common injury following blunt thoracic trauma with an associated mortality of 10% to 20%. The purpose of this study is to determine how crash parameters correlate to the volume of pulmonary contusion. The Crash Injury Research Engineering and Network (CIREN) database was queried to extract data on all occupants sustaining PC in a near-side crash. The selected CIREN data included all completed cases from 2005 through 2010. Cases involving a roll-over or without a thorax CT uploaded to the database were excluded. After all cases had been examined the study had 64 occupants with varying volumes of PC. Specific crash characteristics compiled included change in velocity due to the impact, energy, occupant characteristics, side airbag deployment, and crush profile measurements. Crush metrics quantifying the area of the crush profile and the location of the crush relative to the occupant were calculated. The thoracic CT scans from these cases were downloaded and segmented to determine the percent volume of high attenuation lung and PC as compared to the total volume of the lung. The results of the general linear model analysis suggest that maximum crush was the best predictor of high attenuation lung and lung location best predicted PC. An analysis of NASS and CIREN demonstrated that crashes with PC tended to have crash parameters that indicated higher severity. These correlations can be used in the future to develop an injury criterion for PC using finite element metrics.

  5. Crash Frequency Analysis Using Hurdle Models with Random Effects Considering Short-Term Panel Data.

    Science.gov (United States)

    Chen, Feng; Ma, Xiaoxiang; Chen, Suren; Yang, Lin

    2016-10-26

    Random effect panel data hurdle models are established to research the daily crash frequency on a mountainous section of highway I-70 in Colorado. Road Weather Information System (RWIS) real-time traffic and weather and road surface conditions are merged into the models incorporating road characteristics. The random effect hurdle negative binomial (REHNB) model is developed to study the daily crash frequency along with three other competing models. The proposed model considers the serial correlation of observations, the unbalanced panel-data structure, and dominating zeroes. Based on several statistical tests, the REHNB model is identified as the most appropriate one among four candidate models for a typical mountainous highway. The results show that: (1) the presence of over-dispersion in the short-term crash frequency data is due to both excess zeros and unobserved heterogeneity in the crash data; and (2) the REHNB model is suitable for this type of data. Moreover, time-varying variables including weather conditions, road surface conditions and traffic conditions are found to play importation roles in crash frequency. Besides the methodological advancements, the proposed technology bears great potential for engineering applications to develop short-term crash frequency models by utilizing detailed data from field monitoring data such as RWIS, which is becoming more accessible around the world.

  6. Data development technical support document for the aircraft crash risk analysis methodology (ACRAM) standard

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, C.Y.; Glaser, R.E.; Mensing, R.W.; Lin, T.; Haley, T.A.; Barto, A.B.; Stutzke, M.A.

    1996-08-01

    The Aircraft Crash Risk Analysis Methodology (ACRAM) Panel has been formed by the US Department of Energy Office of Defense Programs (DOE/DP) for the purpose of developing a standard methodology for determining the risk from aircraft crashes onto DOE ground facilities. In order to accomplish this goal, the ACRAM panel has been divided into four teams, the data development team, the model evaluation team, the structural analysis team, and the consequence team. Each team, consisting of at least one member of the ACRAM plus additional DOE and DOE contractor personnel, specializes in the development of the methodology assigned to that team. This report documents the work performed by the data development team and provides the technical basis for the data used by the ACRAM Standard for determining the aircraft crash frequency. This report should be used to provide the generic data needed to calculate the aircraft crash frequency into the facility under consideration as part of the process for determining the aircraft crash risk to ground facilities as given by the DOE Standard Aircraft Crash Risk Assessment Methodology (ACRAM). Some broad guidance is presented on how to obtain the needed site-specific and facility specific data but this data is not provided by this document.

  7. The odds of wrong-way crashes and resulting fatalities: A comprehensive analysis.

    Science.gov (United States)

    Ponnaluri, Raj V

    2016-03-01

    The United States of America and other nations are grappling with the incidence of wrong-way driving (WWD). The issue is as important today (NTSB, 2012) as it was a half-century ago (Hulbert and Beers, 1966). In the absence of a comprehensive analysis, any effort to implement WWD countermeasures can be counterproductive. Hence, this effort began with the express intent to identify the factors that cause WWD crashes and fatalities. This work is sizeable in that it evaluated one million complete crash records from Florida. The methodology comprised (a) administering a survey on the perceptions about WWD; (b) developing binomial logistic models for computing the odds of WWD crashes, and of fatal crashes within the WWD space; (c) analyzing the contributing variables; and (d) comparing perceptions with crash analysis results. The study parameters included driver's age, gender, licensing state, physical defect, blood alcohol concentration, vehicle use, seatbelt compliance, day and time of crash, roadway lighting, facility type, weather conditions, road geometrics, and traffic volumes. Individual variable analysis of 23 parameters and the model development process included the determination of odds ratios and statistical tests for the predictive power and goodness-of-fit. The results of this work are generally consistent with expectation, yet surprising at times. This work concludes with decision-making inputs to the scientist, policy-maker and practitioner on the need for effectively engineering the roads, actively educating people about wrong-way driving, and strictly enforcing traffic laws, rules and regulations.

  8. 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.

  9. Driving risk assessment using near-crash database through data mining of tree-based model.

    Science.gov (United States)

    Wang, Jianqiang; Zheng, Yang; Li, Xiaofei; Yu, Chenfei; Kodaka, Kenji; Li, Keqiang

    2015-11-01

    This paper considers a comprehensive naturalistic driving experiment to collect driving data under potential threats on actual Chinese roads. Using acquired real-world naturalistic driving data, a near-crash database is built, which contains vehicle status, potential crash objects, driving environment and road types, weather condition, and driver information and actions. The aims of this study are summarized into two aspects: (1) to cluster different driving-risk levels involved in near-crashes, and (2) to unveil the factors that greatly influence the driving-risk level. A novel method to quantify the driving-risk level of a near-crash scenario is proposed by clustering the braking process characteristics, namely maximum deceleration, average deceleration, and percentage reduction in vehicle kinetic energy. A classification and regression tree (CART) is employed to unveil the relationship among driving risk, driver/vehicle characteristics, and road environment. The results indicate that the velocity when braking, triggering factors, potential object type, and potential crash type exerted the greatest influence on the driving-risk levels in near-crashes.

  10. A multivariate random-parameters Tobit model for analyzing highway crash rates by injury severity.

    Science.gov (United States)

    Zeng, Qiang; Wen, Huiying; Huang, Helai; Pei, Xin; Wong, S C

    2017-02-01

    In this study, a multivariate random-parameters Tobit model is proposed for the analysis of crash rates by injury severity. In the model, both correlation across injury severity and unobserved heterogeneity across road-segment observations are accommodated. The proposed model is compared with a multivariate (fixed-parameters) Tobit model in the Bayesian context, by using a crash dataset collected from the Traffic Information System of Hong Kong. The dataset contains crash, road geometric and traffic information on 224 directional road segments for a five-year period (2002-2006). The multivariate random-parameters Tobit model provides a much better fit than its fixed-parameters counterpart, according to the deviance information criteria and Bayesian R(2), while it reveals a higher correlation between crash rates at different severity levels. The parameter estimates show that a few risk factors (bus stop, lane changing opportunity and lane width) have heterogeneous effects on crash-injury-severity rates. For the other factors, the variances of their random parameters are insignificant at the 95% credibility level, then the random parameters are set to be fixed across observations. Nevertheless, most of these fixed coefficients are estimated with higher precisions (i.e., smaller variances) in the random-parameters model. Thus, the random-parameters Tobit model, which provides a more comprehensive understanding of the factors' effects on crash rates by injury severity, is superior to the multivariate Tobit model and should be considered a good alternative for traffic safety analysis.

  11. Conversion of the dominantly ideal perturbations into a tearing mode after a sawtooth crash

    Energy Technology Data Exchange (ETDEWEB)

    Igochine, V., E-mail: valentin.igochine@ipp.mpg.de; Gude, A.; Günter, S.; Lackner, K.; Yu, Q.; Barrera Orte, L.; McDermott, R. M. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Bogomolov, A.; Classen, I. [FOM-Institute DIFFER, Dutch Institute for Fundamental Energy Research, 3430 BE Nieuwegein (Netherlands); Luhmann, N. C. [University of California at Davis, Davis, California 95616 (United States)

    2014-11-15

    Forced magnetic reconnection is a topic of common interest in astrophysics, space science, and magnetic fusion research. The tearing mode formation process after sawtooth crashes implies the existence of this type of magnetic reconnection and is investigated in great detail in the ASDEX Upgrade tokamak. The sawtooth crash provides a fast relaxation of the core plasma temperature and can trigger a tearing mode at a neighbouring resonant surface. It is demonstrated for the first time that the sawtooth crash leads to a dominantly ideal kink mode formation at the resonant surface immediately after the sawtooth crash. Local measurements show that this kink mode transforms into a tearing mode on a much longer timescale (10{sup −3}s−10{sup −2}s) than the sawtooth crash itself (10{sup −4}s). The ideal kink mode formed after the sawtooth crash provides the driving force for magnetic reconnection and its amplitude is one of the critical parameters for the length of the transition phase from a ideal into an resistive mode. Nonlinear two fluid MHD simulations confirm these observations.

  12. 基于车联网的智能打车系统%Intelligent Taxi Service System Based on Internet of Vehicle

    Institute of Scientific and Technical Information of China (English)

    于明鹭; 刘南杰; 赵海涛; 彭江琴

    2016-01-01

    由于出租车的数量管制,以及出租车行业一直没有一个有效的调配系统,导致交通拥塞、时间浪费和耗油量增加。而车联网( Internet Of Vehicle,IOV)的迅速发展,给传统出租车行业带来了新的契机。在该背景下,针对国内出租车行业出现的问题,提出基于车联网中管-云-端架构的智能打车系统。该系统采用新型车载智能终端,功能强大的云平台和实用的客户端应用。从终端信息感知、数据处理到顶层的应用展示来进行模块化功能描述和分析。该系统能显著提高用户满意度、司机积极性和整体运营性能。最后,通过将该智能打车系统应用于现实场景证明了它的价值。结果表明,该系统的服务性能优于现存的多数打车系统。%Taxi number control and inefficient dispatching system lead to many serious problems,such as traffic congestion,time wasting and increase in oil consumption. The rapid development of Internet Of Vehicle ( IOV) brings a golden opportunity to traditional taxi serv-ice systems. In this paper,aiming at the existed problems,propose an intelligent taxi service system based on Carrier-Cloud-Client frame-work of IOV for the first time. Basically,the system employs an advanced intelligent vehicle terminal,a powerful cloud platform and prac-tical client applications. Specifically,a hierarchical model is presented as an architecture to modularize the system,spanning from terminal sensing and data processing to the topmost service presentation. The proposed system can significantly improve customer satisfaction,driv-er enthusiasm and business performance. Finally,the value of the intelligent taxi service system is demonstrated by applying it to some scenarios in the real word. The result shows that this system outperforms most existing taxi service systems with respect to the service quality.

  13. Investigating Public Facility Characteristics from a Spatial Interaction Perspective: A Case Study of Beijing Hospitals Using Taxi Data

    Directory of Open Access Journals (Sweden)

    Xiaoqing Kong

    2017-02-01

    Full Text Available Services provided by public facilities are essential to people’s lives and are closely associated with human mobility. Traditionally, public facility access characteristics, such as accessibility, equity issues and service areas, are investigated mainly based on static data (census data, travel surveys and particular records, such as medical records. Currently, the advent of big data offers an unprecedented opportunity to obtain large-scale human mobility data, which can be used to study the characteristics of public facilities from the spatial interaction perspective. Intuitively, spatial interaction characteristics and service areas of different types and sizes of public facilities are different, but how different remains an open question, so we, in turn, examine this question. Based on spatial interaction, we classify public facilities and explore the differences in facilities. In the research, based on spatial interaction extracted from taxi data, we introduce an unsupervised classification method to classify 78 hospitals in 6 districts of Beijing, and the results better reflect the type of hospital. The findings are of great significance for optimizing the spatial configuration of medical facilities or other types of public facilities, allocating public resources reasonably and relieving traffic pressure.

  14. NO and NO2 emission ratios measured from in-use commercial aircraft during taxi and takeoff.

    Science.gov (United States)

    Herndon, Scott C; Shorter, Joanne H; Zahniser, Mark S; Nelson, David D; Jayne, John; Brown, Robert C; Miake-Lye, Richard C; Waitz, Ian; Silva, Phillip; Lanni, Thomas; Demerjian, Ken; Kolb, Charles E

    2004-11-15

    In August 2001, the Aerodyne Mobile Laboratory simultaneously measured NO, NO2, and CO2 within 350 m of a taxiway and 550 m of a runway at John F. Kennedy Airport. The meteorological conditions were such that taxi and takeoff plumes from individual aircraft were clearly resolved against background levels. NO and NO2 concentrations were measured with 1 s time resolution using a dual tunable infrared laser differential absorption spectroscopy instrument, utilizing an astigmatic multipass Herriott cell. The CO2 measurements were also obtained at 1 s time resolution using a commercial non-dispersive infrared absorption instrument. Plumes were measured from over 30 individual planes, ranging from turbo props to jumbo jets. NOx emission indices were determined by examining the correlation between NOx (NO + NO2) and CO2 during the plume measurements. Several aircraft tail numbers were unambiguously identified, allowing those specific airframe/engine combinations to be determined. The resulting NOx emission indices from positively identified in-service operating airplanes are compared with the published International Civil Aviation Organization engine certification test database collected on new engines in certification test cells.

  15. Effects of electro-fishing on galvano-taxis and carcass quality characteristics in sea bass (Dicentrarchus labrax

    Directory of Open Access Journals (Sweden)

    Edo D’Agaro

    2010-01-01

    Full Text Available The aim of this study was to investigate the effects of electro-fishing in sea water. We evaluated the feasibility of an electro-fishing system using numerical simulations for laboratory tanks and the open sea and performing a laboratory experiment. A non-homogeneous bi-dimensional electric-field model for marine water and fish based on discrete formulation of electro-magnetic field equations was developed using GAME (geometric approach for Maxwell equations software. Voltage gradients inside the fish and close to the body were determined. Re- sults showed that fish in the open sea and in groups had greater internal voltage differences than did fish in tanks and single fish. Sea bass (length:10 and 30 cm were exposed in laboratory tanks to pulsed direct current (PDC, 25-125 Hz and duty cycle (5-40%. We measured the electro-taxis and tetanus thresholds after electrical exposure. It is significant that these values decreased with increasing the size of fish. No differences were found after electro-fishing on overall appearance, internal and external haemorrhage, standard freshness scoring techniques and carcass quality characteristics

  16. Structure identification for compound I separated and purified from taxoids-produced endophytic fungi (Alternaria. alternata var. taxi 1011)

    Institute of Scientific and Technical Information of China (English)

    XIANG Yong; LIU Jun; LU An-guo; CUI Jing-xia

    2003-01-01

    Endophytic fungi are widely found in almost all kinds of plants. Many endophytic fungi can produce some physiological active compounds, which are same to or analog to those isolated from their hosts. Producing physiological active compounds through microbial fermentation can give a new way to resolve resource limitation and to find out alternative source. Through the methods of organic solvent extraction, thin layer chromatography (TLC) and column chromatography, compound I was isolated, purified from the liquid fermentation metabolites of the taxoids-produced endophytic fungi (Alternaria. alternata var. taxi 1011 Y. Xiang et LU An-guo) that was screened from the bark of Taxus. cuspidata Sieb.et Zucc.. Compound I was identified as one kind of taxoids type III, based on the analyzing results by using the methods of ultraviolet spectroscopy (UV), infrared spectroscopy (IR), mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). This study provides a completed method for separation and purification of the endophytic fungi as well as structure identification of its fermentation metabolite

  17. Jobs, food, taxis and journals: complexities of implementing Stepping Stones and Creating Futures in urban informal settlements in South Africa.

    Science.gov (United States)

    Gibbs, Andrew; Jewkes, Rachel; Mbatha, Nompumelelo; Washington, Laura; Willan, Samantha

    2014-01-01

    This paper seeks to refocus debates on structural interventions away from 'assessing' their effectiveness towards understanding processes around how such interventions are implemented. Implementation Science is focused on understanding potential challenges of translating interventions from highly controlled conditions into 'real life' settings. Using the case study of Stepping Stones and Creating Futures a structural and behavioural intervention to reduce intimate partner violence and HIV risk behaviours amongst young women and men in urban informal settlements, we explore the challenges of implementing such an approach. We move beyond simply describing challenges of implementing, to understand how these challenges had an impact on the safe social space the intervention seeks to create as its underlying theory of change. We identify four major challenges of implementation: taxi fares, food provided during the intervention, young people's ongoing need to work and journals provided during the intervention. We suggest that, in different ways, these factors all impinged on the emergence of a safe social space. Understanding the challenges of implementing the intervention is critical for reflecting on scaling up interventions. Central to this is the need to work with participants to help them negotiate the challenges of participating in interventions.

  18. Driving performance changes of middle-aged experienced taxi drivers due to distraction tasks during unexpected situations.

    Science.gov (United States)

    Kim, Hyung-Sik; Choi, Mi-Hyun; Choi, Jin-Seung; Kim, Hyun-Joo; Hong, Sang-Pyo; Jun, Jae-Hoon; Tack, Gye-Rae; Kim, Boseong; Min, Ung-Chan; Lim, Dae-Woon; Chung, Soon-Cheol

    2013-10-01

    This study investigated the effects of distraction taskssuch as sending a text message with a cellphone and searching navigation with car navigation system-on the driving performance of 29 highly experienced taxi drivers in their 50s. All participants were instructed to drive using a driving simulator for 2 min. while maintaining a constant distance from the vehicle in front and a constant speed. Participants drove without any distractions for the first minute. For an additional minute, they performed Driving Only or performed a task while driving (Driving + Sending Text Message or Driving + Searching Navigation). An unexpected situation, in which the participant had to stop abruptly due to a sudden stop of the preceding vehicle, occurred during this period. Driving performance during the unexpected situation was evaluated by car control variables, medial-lateral coefficient of variation and brake time, and by motion variables such as the jerk-cost function. Compared to Driving Only, jerk-cost function, medial-lateral coefficient of variation, and brake time increased during Driving + Sending Text Message or Driving + Searching Navigation.

  19. Co-Movements Of U.S. And European Stock Markets Before And After The 2008 Gloal Stock Market Crash

    Directory of Open Access Journals (Sweden)

    Meric Ilhan

    2015-08-01

    Full Text Available Empirical studies show that correlation between national stock markets increased and the benefits of global portfolio diversification decreased significantly after the global stock market crash of 1987. The 1987 and 2008 crashes are the two most important global stock market crashes since the 1929 Great depression. Although the effects of the 1987 crash on the comovements of national stock markets have been investigated extensively, the effects of the 2008 crash have not been studied sufficiently. In this paper we study this issue with a research sample that includes the U.S stock market and twenty European stock markets. We find that correlation between the twenty-one stock markets increased and the benefits of portfolio diversification decreased significantly after the 2008 stock market crash.

  20. Homogenization of vehicle fleet frontal crash pulses from 2000-2010.

    Science.gov (United States)

    Locey, Caitlin M; Garcia-Espana, J Felipe; Toh, Akira; Belwadi, Aditya; Arbogast, Kristy B; Maltese, Matthew R

    2012-01-01

    Full-scale vehicle crash tests are performed globally to assess vehicle structure and restraint system performance. The crash pulse, captured by accelerometers mounted within the occupant compartment, measures the motion of the vehicle during the impact event. From an occupant's perspective, the crash pulse is the inertial event to which the vehicle's restraint systems must respond in order to mitigate the forces and accelerations that act on a passenger, and thus reduce injury risk. The objective of this study was to quantify the characteristics of crash pulses for different vehicle types in the contemporary North American fleet, and delineate current trends in crash pulse evolution. NHTSA and Transport Canada crash test databases were queried for full-frontal rigid barrier crash tests of passenger vehicles model year 2000-2010 with impact angle equaling zero degrees. Acceleration-time histories were analyzed for all accelerometers attached to the vehicle structure within the occupant compartment. Custom software calculated the following crash pulse characteristics (CPCs): peak deceleration, time of peak deceleration, onset rate, pulse duration, and change in velocity. Vehicle body types were classified by adapting the Highway Loss Data Institute (HLDI) methodology, and vehicles were assigned a generation start year in place of model year in order to more accurately represent structural change over time. 1094 vehicle crash tests with 2795 individual occupant compartment-mounted accelerometers were analyzed. We found greater peak decelerations and and shorter pulse durations across multiple vehicle types in newer model years as compared to older. For midsize passenger cars, large passenger cars, and large SUVs in 56 km/h rigid barrier tests, maximum deceleration increased by 0.40, 0.96, and 1.57 g/year respectively, and pulse duration decreased by 0.74, 1.87, and 2.51 ms/year. We also found that the crash pulse characteristics are becoming more homogeneous in the

  1. Safety Assessment of a Metal Cask under Aircraft Engine Crash

    Directory of Open Access Journals (Sweden)

    Sanghoon Lee

    2016-04-01

    Full Text Available The structural integrity of a dual-purpose metal cask currently under development by the Korea Radioactive Waste Agency (KORAD was evaluated, through numerical simulations and a model test, under high-speed missile impact reflecting targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from literature. In the impact scenario, a missile flying horizontally hits the top side of the cask, which is freestanding on a concrete pad, with a velocity of 150 m/s. A simplified missile simulating a commercial aircraft engine was designed from an impact load–time function available in literature. In the analyses, the dynamic behavior of the metal cask and the integrity of the containment boundary were assessed. The simulation results were compared with the test results for a 1:3 scale model. Although the dynamic behavior of the cask in the model test did not match exactly with the prediction from the numerical simulation, other structural responses, such as the acceleration and strain history during the impact, showed very good agreement. Moreover, the containment function of the cask survived the missile impact as expected from the numerical simulation. Thus, the procedure and methodology adopted in the structural numerical analyses were successfully validated.

  2. Safety assessment of a metal cask under aircraft engine crash

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon [Dept. of Mechanical and Automotive Engineering, Keimyung University, Daegu (Korea, Republic of); Choi, Woo Seok; Seo, Ki Seog [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-04-15

    The structural integrity of a dual-purpose metal cask currently under development by the Korea Radioactive Waste Agency (KORAD) was evaluated, through numerical simulations and a model test, under high-speed missile impact reflecting targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from literature. In the impact scenario, a missile flying horizontally hits the top side of the cask, which is free standing on a concrete pad, with a velocity of 150 m/s. A simplified missile simulating a commercial aircraft engine was designed from an impact load-time function available in literature. In the analyses, the dynamic behavior of the metal cask and the integrity of the containment boundary were assessed. The simulation results were compared with the test results for a 1:3 scale model. Although the dynamic behavior of the cask in the model test did not match exactly with the prediction from the numerical simulation, other structural responses, such as the acceleration and strain history during the impact, showed very good agreement. Moreover, the containment function of the cask survived the missile impact as expected from the numerical simulation. Thus, the procedure and methodology adopted in the structural numerical analyses were successfully validated.

  3. [Deep sea trip of the ship crash Northern Force fleet].

    Science.gov (United States)

    Ushakov, I B; Bubeev, Iu A; Mazaĭkin, D N; Pisarev, A A

    2008-07-01

    A long-termed navy march of crash shupborn group of Northern Navy became a sign-oriented event in the life of the Armed Forces. After more then 10 years cessation this march signed recommencement of permanent Russia navy attendance in strategically important areas of the World Ocean. The authors highlight work of military-navy specialists in conditions of this march. The most important peculiarity of this march was participation of a hard aircraft carrier "Navy Admiral of the Soviet Union N.G.Kuznetsov". Activity of aircraft staff in carrying out the boardings and the deck starts requires the highest mobilization of all psycho-physiological resources. There was effectuated a complex medical-psychophysiological research of functional condition of aircraft and engineer staff of the group during the service. Also there was effectuated an operative recovery of functional condition among sailors and officers of the ship staff. Method of neuronsemantic diagnostics of psychological disadaptation and suicide risk was used during the analyze of groups of risk. The results of the analyze permitted to educe main psychotraumatizing factors, to form recommendations on psycho-correction, organization-educative measures taking into account individual peculiarities of motivation sphere and cognitive sensitivity. There were effectuated different trainings of moralities, communicativeness, strategy of negotiation and stress-managment in cooperation with the psychologist of the ship.

  4. Towards Improving Crash Data Management System in Gulf Countries

    Directory of Open Access Journals (Sweden)

    Dr. Jamal Almatawah

    2014-09-01

    Full Text Available Scientific and analytical approaches to accident data collection, storage and analysis are essential in dealing with road safety problems. Police accident records in the majority of countries form the main (and sometimes the only source of accident data. Access to the accident database is also important to identifying specific safety problems and evaluating the effectiveness of the countermeasure introduced. Accident data collection and analysis offered by technological innovation such as Electronic Data Entry (EDE, Electronic Data transfer (EDT, and Geographic Information system (GIS are implemented in developed countries. Developing countries, including the Gulf countries, should take advantage of the experience of developed countries on how the advance accident data management system works to identifying, more accurately, the main factors contributing to traffic accident. The main purpose of this research is to provide information on accident statistics process in Virginia state, starting from the time of accident occurring until it is stored in the database, with the aim of using it towards improving the process of collecting and maintaining accident data system in Gulf countries. The task is performed by reviewing the relevant international literature and interviewing police officers in charge and academic researchers in order to compare the accident data management system and also the quality of the data. Recommendations towards developing the crash data management system will be obtained based on the research results and international experience.

  5. Anti-terrorist vehicle crash impact energy absorbing barrier

    Energy Technology Data Exchange (ETDEWEB)

    Swahlan, D.J.

    1989-04-18

    An anti-terrorist vehicle crash barrier includes side support structures, crushable energy absorbing aluminum honeycomb modules, and an elongated impact-resistant beam extending between, and at its opposite ends through vertical guideways defined by, the side support structures. An actuating mechanism supports the beam at its opposite ends for movement between a lowered barrier-withdrawn position in which a traffic-supporting side of the beam is aligned with a traffic-bearing surface permitting vehicular traffic between the side support structures and over the beam, and a raised barrier-imposed position in which the beam is aligned with horizontal guideways defined in the side support structures above the traffic-bearing surface, providing an obstruction to vehicular traffic between the side support structures. The beam is movable rearwardly in the horizontal guideways with its opposite ends disposed transversely therethrough upon being impacted at its forward side by an incoming vehicle. The crushable modules are replaceably disposed in the horizontal guideways between aft ends thereof and the beam. The beam, replaceable modules, side support structures and actuating mechanism are separate and detached from one another such that the beam and replaceable modules are capable of coacting to disable and stop an incoming vehicle without causing structural damage to the side support structures and actuating mechanism. 6 figs.

  6. Anti-terrorist vehicle crash impact energy absorbing barrier

    Energy Technology Data Exchange (ETDEWEB)

    Swahlan, David J. (Albuquerque, NM)

    1989-01-01

    An anti-terrorist vehicle crash barrier includes side support structures, crushable energy absorbing aluminum honeycomb modules, and an elongated impact-resistant beam extending between, and at its opposite ends through vertical guideways defined by, the side support structures. An actuating mechanism supports the beam at its opposite ends for movement between a lowered barrier-withdrawn position in which a traffic-supporting side of the beam is aligned with a traffic-bearing surface permitting vehicular traffic between the side support structures and over the beam, and a raised barrier-imposed position in which the beam is aligned with horizontal guideways defined in the side support structures above the traffic-bearing surface, providing an obstruction to vehicular traffic between the side support structures. The beam is movable rearwardly in the horizontal guideways with its opposite ends disposed transversely therethrough upon being impacted at its forward side by an incoming vehicle. The crushable modules are replaceably disposed in the horizontal guideways between aft ends thereof and the beam. The beam, replaceable modules, side support structures and actuating mechanism are separate and detached from one another such that the beam and replaceable modules are capable of coacting to disable and stop an incoming vehicle without causing structural damage to the side support structures and actuating mechanism.

  7. A method for predicting the risk of virtual crashes in a simulated driving task using behavioural and subjective drowsiness measures.

    Science.gov (United States)

    Murata, Atsuo; Naitoh, Kensuke; Karwowski, Waldemar

    2016-08-29

    This study proposed a procedure for predicting the point in time with high risk of virtual crash using a control chart methodology for behavioural measures during a simulated driving task. Tracking error, human back pressure, sitting pressure and horizontal and vertical neck bending angles were measured during the simulated driving task. The time with a high risk of a virtual crash occurred in 9 out of 10 participants. The time interval between the successfully detected point in time with high risk of virtual crash and the point in time of virtual crash ranged from 80 to 324 s. The proposed procedure for predicting the point in time with a high risk of a crash is promising for warning drivers of the state of high risk of crash. Practitioner Summary: Many fatal crashes occur due to drowsy driving. We proposed a method to predict the point in time with high risk of virtual crash before such a virtual crash occurs. This is done using behavioural measures during a simulated driving task. The effectiveness of the method is also demonstrated.

  8. Restraints and peripheral nerve injuries in adult victims of motor vehicle crashes.

    Science.gov (United States)

    Bekelis, Kimon; Missios, Symeon; Spinner, Robert J

    2014-06-15

    The pattern of injuries in restrained victims of motor vehicle crashes (MVCs) remains an issue of debate. We investigated the association of peripheral nerve injuries with the use of protective devices (seat belt and air bag) during MVCs. We performed a retrospective cohort study of 384,539 adult MVC victims who were registered in the National Trauma Data Bank (NTDB) between 2009 and 2011. Regression techniques were used to investigate the association of restraint use with the risk of peripheral nerve injury in patients hospitalized after an MVC. Of the study patients, 271,099 were using restraints and 113,440 were not. Overall, there were a total of 3086 peripheral nerve injuries. Multivariable logistic regression analysis demonstrated an association of protective device use with decreased risk of peripheral nerve injury (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.82-0.96; absolute risk reduction, 10.68%). This corresponds to 16 patients who needed to be restrained to prevent one nerve injury. The location of the patient in the vehicle did not seem to affect the risk of peripheral nerve injury, with drivers demonstrating no association with nerve injuries (OR, 0.94; 95% CI, 0.87-1.02) in comparison with non-drivers. On the contrary, alcohol consumption was associated with increased incidence of peripheral nerve injuries (OR, 1.10; 95% CI, 1.01-1.20). In summary, restraint use was associated with decreased risk of peripheral nerve injury in MVC victims, after controlling for confounders.

  9. The use of generalized estimating equations in the analysis of motor vehicle crash data.

    Science.gov (United States)

    Hutchings, Caroline B; Knight, Stacey; Reading, James C

    2003-01-01

    The purpose of this study was to determine if it is necessary to use generalized estimating equations (GEEs) in the analysis of seat belt effectiveness in preventing injuries in motor vehicle crashes. The 1992 Utah crash dataset was used, excluding crash participants where seat belt use was not appropriate (n=93,633). The model used in the 1996 Report to Congress [Report to congress on benefits of safety belts and motorcycle helmets, based on data from the Crash Outcome Data Evaluation System (CODES). National Center for Statistics and Analysis, NHTSA, Washington, DC, February 1996] was analyzed for all occupants with logistic regression, one level of nesting (occupants within crashes), and two levels of nesting (occupants within vehicles within crashes) to compare the use of GEEs with logistic regression. When using one level of nesting compared to logistic regression, 13 of 16 variance estimates changed more than 10%, and eight of 16 parameter estimates changed more than 10%. In addition, three of the independent variables changed from significant to insignificant (alpha=0.05). With the use of two levels of nesting, two of 16 variance estimates and three of 16 parameter estimates changed more than 10% from the variance and parameter estimates in one level of nesting. One of the independent variables changed from insignificant to significant (alpha=0.05) in the two levels of nesting model; therefore, only two of the independent variables changed from significant to insignificant when the logistic regression model was compared to the two levels of nesting model. The odds ratio of seat belt effectiveness in preventing injuries was 12% lower when a one-level nested model was used. Based on these results, we stress the need to use a nested model and GEEs when analyzing motor vehicle crash data.

  10. A model to identify high crash road segments with the dynamic segmentation method.

    Science.gov (United States)

    Boroujerdian, Amin Mirza; Saffarzadeh, Mahmoud; Yousefi, Hassan; Ghassemian, Hassan

    2014-12-01

    Currently, high social and economic costs in addition to physical and mental consequences put road safety among most important issues. This paper aims at presenting a novel approach, capable of identifying the location as well as the length of high crash road segments. It focuses on the location of accidents occurred along the road and their effective regions. In other words, due to applicability and budget limitations in improving safety of road segments, it is not possible to recognize all high crash road segments. Therefore, it is of utmost importance to identify high crash road segments and their real length to be able to prioritize the safety improvement in roads. In this paper, after evaluating deficiencies of the current road segmentation models, different kinds of errors caused by these methods are addressed. One of the main deficiencies of these models is that they can not identify the length of high crash road segments. In this paper, identifying the length of high crash road segments (corresponding to the arrangement of accidents along the road) is achieved by converting accident data to the road response signal of through traffic with a dynamic model based on the wavelet theory. The significant advantage of the presented method is multi-scale segmentation. In other words, this model identifies high crash road segments with different lengths and also it can recognize small segments within long segments. Applying the presented model into a real case for identifying 10-20 percent of high crash road segment showed an improvement of 25-38 percent in relative to the existing methods.

  11. Side Impact Regulatory Trends, Crash Environment and Injury Risk in the USA.

    Science.gov (United States)

    Prasad, Priya; Dalmotas, Dainius; Chouinard, Aline

    2015-11-01

    Light duty vehicles in the US are designed to meet and exceed regulatory standards, self-imposed industry agreements and safety rating tests conducted by NHTSA and IIHS. The evolution of side impact regulation in the US from 1973 to 2015 is discussed in the paper along with two key industry agreements in 2003 affecting design of restraint systems and structures for side impact protection. A combination of all the above influences shows that vehicles in the US are being designed to more demanding and comprehensive requirements than in any other region of the world. The crash environment in the US related to side impacts was defined based on data in the nationally representative crash database NASS. Crash environment factors, including the distribution of cars, light trucks and vans (LTV's), and medium-to-heavy vehicles (MHV's) in the fleet, and the frequency of their interactions with one another in side impacts, were considered. Other factors like, crash severity in terms of closing velocity between two vehicles involved in crash, gender and age of involved drivers in two-vehicle and single vehicle crashes, were also examined. Injury risks in side impacts to drivers and passengers were determined in various circumstances such as near-side, far-side, and single vehicle crashes as a function of crash severity, in terms of estimated closing speed or lateral delta-V. Also injury risks in different pairs of striking and struck cars and LTV's, were estimated. A logistic regression model for studying injury risks in two vehicle crashes was developed. The risk factors included in the model include case and striking vehicles, consisting of cars, SUV's, vans, and pickup trucks, delta-V, damage extent, occupant proximity to the impact side, age and gender of the occupant, and belt use. Results show that car occupants make up the vast majority of serious-to-fatally injured occupants. Injury rates of car occupants in two-vehicle collision are highest when the car is struck by a

  12. Development and evaluation of a web-based software for crash data collection, processing and analysis.

    Science.gov (United States)

    Montella, Alfonso; Chiaradonna, Salvatore; Criscuolo, Giorgio; De Martino, Salvatore

    2017-02-05

    First step of the development of an effective safety management system is to create reliable crash databases since the quality of decision making in road safety depends on the quality of the data on which decisions are based. Improving crash data is a worldwide priority, as highlighted in the Global Plan for the Decade of Action for Road Safety adopted by the United Nations, which recognizes that the overall goal of the plan will be attained improving the quality of data collection at the national, regional and global levels. Crash databases provide the basic information for effective highway safety efforts at any level of government, but lack of uniformity among countries and among the different jurisdictions in the same country is observed. Several existing databases show significant drawbacks which hinder their effective use for safety analysis and improvement. Furthermore, modern technologies offer great potential for significant improvements of existing methods and procedures for crash data collection, processing and analysis. To address these issues, in this paper we present the development and evaluation of a web-based platform-independent software for crash data collection, processing and analysis. The software is designed for mobile and desktop electronic devices and enables a guided and automated drafting of the crash report, assisting police officers both on-site and in the office. The software development was based both on the detailed critical review of existing Australasian, EU, and U.S. crash databases and software as well as on the continuous consultation with the stakeholders. The evaluation was carried out comparing the completeness, timeliness, and accuracy of crash data before and after the use of the software in the city of Vico Equense, in south of Italy showing significant advantages. The amount of collected information increased from 82 variables to 268 variables, i.e., a 227% increase. The time saving was more than one hour per crash, i

  13. Crash prediction model for two-lane rural highways in the Ashanti region of Ghana

    Directory of Open Access Journals (Sweden)

    Williams Ackaah

    2011-07-01

    Full Text Available Crash Prediction Models (CPMs have been used elsewhere as a useful tool by road Engineers and Planners. There is however no study on the prediction of road traffic crashes on rural highways in Ghana. The main objective of the study was to develop a prediction model for road traffic crashes occurring on the rural sections of the highways in the Ashanti Region of Ghana. The model was developed for all injury crashes occurring on selected rural highways in the Region over the three (3 year period 2005–2007. Data was collected from 76 rural highway sections and each section varied between 0.8 km and 6.7 km. Data collected for each section comprised injury crash data, traffic flow and speed data, and roadway characteristics and road geometry data. The Generalised Linear Model (GLM with Negative Binomial (NB error structure was used to estimate the model parameters. Two types of models, the ‘core’ model which included key exposure variables only and the ‘full’ model which included a wider range of variables were developed. The results show that traffic flow, highway segment length, junction density, terrain type and presence of a village settlement within road segments were found to be statistically significant explanatory variables (p<0.05 for crash involvement. Adding one junction to a 1 km section of road segment was found to increase injury crashes by 32.0% and sections which had a village settlement within them were found to increase injury crashes by 60.3% compared with segments with no settlements. The model explained 61.2% of the systematic variation in the data. Road and Traffic Engineers and Planners can apply the crash prediction model as a tool in safety improvement works and in the design of safer roads. It is recommended that to improve safety, highways should be designed to by-pass village settlements and that the number of junctions on a highway should be limited to carefully designed ones.

  14. Robust human body model injury prediction in simulated side impact crashes.

    Science.gov (United States)

    Golman, Adam J; Danelson, Kerry A; Stitzel, Joel D

    2016-01-01

    This study developed a parametric methodology to robustly predict occupant injuries sustained in real-world crashes using a finite element (FE) human body model (HBM). One hundred and twenty near-side impact motor vehicle crashes were simulated over a range of parameters using a Toyota RAV4 (bullet vehicle), Ford Taurus (struck vehicle) FE models and a validated human body model (HBM) Total HUman Model for Safety (THUMS). Three bullet vehicle crash parameters (speed, location and angle) and two occupant parameters (seat position and age) were varied using a Latin hypercube design of Experiments. Four injury metrics (head injury criterion, half deflection, thoracic trauma index and pelvic force) were used to calculate injury risk. Rib fracture prediction and lung strain metrics were also analysed. As hypothesized, bullet speed had the greatest effect on each injury measure. Injury risk was reduced when bullet location was further from the B-pillar or when the bullet angle was more oblique. Age had strong correlation to rib fractures frequency and lung strain severity. The injuries from a real-world crash were predicted using two different methods by (1) subsampling the injury predictors from the 12 best crush profile matching simulations and (2) using regression models. Both injury prediction methods successfully predicted the case occupant's low risk for pelvic injury, high risk for thoracic injury, rib fractures and high lung strains with tight confidence intervals. This parametric methodology was successfully used to explore crash parameter interactions and to robustly predict real-world injuries.

  15. Effects of obesity on occupant responses in frontal crashes: a simulation analysis using human body models.

    Science.gov (United States)

    Shi, Xiangnan; Cao, Libo; Reed, Matthew P; Rupp, Jonathan D; Hu, Jingwen

    2015-01-01

    The objective of this study is to investigate the effects of obesity on occupant responses in frontal crashes using whole-body human finite element (FE) models representing occupants with different obesity levels. In this study, the geometry of THUMS 4 midsize male model was varied using mesh morphing techniques with target geometries defined by statistical models of external body contour and exterior ribcage geometry. Models with different body mass indices (BMIs) were calibrated against cadaver test data under high-speed abdomen loading and frontal crash conditions. A parametric analysis was performed to investigate the effects of BMI on occupant injuries in frontal crashes based on the Taguchi method while controlling for several vehicle design parameters. Simulations of obese occupants predicted significantly higher risks of injuries to the thorax and lower extremities in frontal crashes compared with non-obese occupants, which is consistent with previous field data analyses. These higher injury risks are mainly due to the increased body mass and relatively poor belt fit caused by soft tissues for obese occupants. This study demonstrated the feasibility of using a parametric human FE model to investigate the obesity effects on occupant responses in frontal crashes.

  16. Patient Litter System Response in a Full-Scale CH-46 Crash Test.

    Science.gov (United States)

    Weisenbach, Charles A; Rooks, Tyler; Bowman, Troy; Fralish, Vince; McEntire, B Joseph

    2017-03-01

    U.S. Military aeromedical patient litter systems are currently required to meet minimal static strength performance requirements at the component level. Operationally, these components must function as a system and are subjected to the dynamics of turbulent flight and potentially crash events. The first of two full-scale CH-46 crash tests was conducted at NASA's Langley Research Center and included an experiment to assess patient and litter system response during a severe but survivable crash event. A three-tiered strap and pole litter system was mounted into the airframe and occupied by three anthropomorphic test devices (ATDs). During the crash event, the litter system failed to maintain structural integrity and collapsed. Component structural failures were recorded from the litter support system and the litters. The upper ATD was displaced laterally into the cabin, while the middle ATD was displaced longitudinally into the cabin. Acceleration, force, and bending moment data from the instrumented middle ATD were analyzed using available injury criteria. Results indicated that a patient might sustain a neck injury. The current test illustrates that a litter system, with components designed and tested to static requirements only, experiences multiple component structural failures during a dynamic crash event and does not maintain restraint control of its patients. It is unknown if a modern litter system, with components tested to the same static criteria, would perform differently. A systems level dynamic performance requirement needs to be developed so that patients can be provided with protection levels equivalent to that provided to seated aircraft occupants.

  17. A comparative study on crash-influencing factors by facility types on urban expressway

    Institute of Scientific and Technical Information of China (English)

    Yong Wu; Hideki Nakamura; Miho Asano

    2013-01-01

    This study aims at identifying crash-influencing factors by facility type of Nagoya Urban Expressway, considering the interaction of geometry, traffic flow, and ambient conditions. Crash rate (CR) model is firstly developed separately at four facility types: basic, merge, and diverge segments and sharp curve. Traffic flows are thereby categorized, and based on the traffic categories, the significances of factors affecting crashes are analyzed by principal component analysis. The results reveal that, the CR at merge segment is significantly higher than those at basic and diverge segments in uncongested flow, while the value is not significantly different at the three facility types in congested flow. In both un-and congested flows, sharp curve has the worst safety performance in view of its highest CR. Regarding influencing factors, geometric design and traffic flow are most significant in un- and congested flows, respectively. As mainline flow increases, the effect of merging ratio affecting crash is on the rise at basic and merge segments as opposed to the decreasing significance of diverging ratio at diverge segment. Mean-while, longer acceleration and deceleration lanes are adverse to safety in uncongested flow, while shorter acceleration and deceleration lanes are adverse in con-gested flow. Due to its special geometric design, crashes at sharp curve are highly associated with the large centrifugal force and heavy restricted visibility.

  18. Macroscopic modeling of pedestrian and bicycle crashes: A cross-comparison of estimation methods.

    Science.gov (United States)

    Amoh-Gyimah, Richard; Saberi, Meead; Sarvi, Majid

    2016-08-01

    The paper presents a cross-comparison of different estimation methods to model pedestrian and bicycle crashes. The study contributes to macro level safety studies by providing further methodological and empirical evidence on the various factors that influence the frequency of pedestrian and bicycle crashes at the planning level. Random parameter negative binomial (RPNB) models are estimated to explore the effects of various planning factors associated with total, serious injury and minor injury crashes while accounting for unobserved heterogeneity. Results of the RPNB models were compared with the results of a non-spatial negative binomial (NB) model and a Poisson-Gamma-CAR model. Key findings are, (1) the RPNB model performed best with the lowest mean absolute deviation, mean squared predicted error and Akaiki information criterion measures and (2) signs of estimated parameters are consistent if these variables are significant in models with the same response variables. We found that vehicle kilometers traveled (VKT), population, percentage of commuters cycling or walking to work, and percentage of households without motor vehicles have a significant and positive correlation with the number of pedestrian and bicycle crashes. Mixed land use is also found to have a positive association with the number of pedestrian and bicycle crashes. Results have planning and policy implications aimed at encouraging the use of sustainable modes of transportation while ensuring the safety of pedestrians and cyclist.

  19. Refined-scale panel data crash rate analysis using random-effects tobit model.

    Science.gov (United States)

    Chen, Feng; Ma, XiaoXiang; Chen, Suren

    2014-12-01

    Random effects tobit models are developed in predicting hourly crash rates with refined-scale panel data structure in both temporal and spatial domains. The proposed models address left-censoring effects of crash rates data while accounting for unobserved heterogeneity across groups and serial correlations within group in the meantime. The utilization of panel data in both refined temporal and spatial scales (hourly record and 1-mile roadway segments on average) exhibits strong potential on capturing the nature of time-varying and spatially varying contributing variables that is usually ignored in traditional aggregated traffic accident modeling. 1-year accident data and detailed traffic, environment, road geometry and surface condition data from a segment of I-25 in Colorado are adopted to demonstrate the proposed methodology. To better understand significantly different characteristics of crashes, two separate models, one for daytime and another for nighttime, have been developed. The results show major difference in contributing factors towards crash rate between daytime and nighttime models, implying considerable needs to investigate daytime and nighttime crashes separately using refined-scale data. After the models are developed, a comprehensive review of various contributing factors is made, followed by discussions on some interesting findings.

  20. A preliminary investigation of the relationships between historical crash and naturalistic driving.

    Science.gov (United States)

    Pande, Anurag; Chand, Sai; Saxena, Neeraj; Dixit, Vinayak; Loy, James; Wolshon, Brian; Kent, Joshua D

    2017-02-16

    This paper describes a project that was undertaken using naturalistic driving data collected via Global Positioning System (GPS) devices to demonstrate a proof-of-concept for proactive safety assessments of crash-prone locations. The main hypothesis for the study is that the segments where drivers have to apply hard braking (higher jerks) more frequently might be the "unsafe" segments with more crashes over a long-term. The linear referencing methodology in ArcMap was used to link the GPS data with roadway characteristic data of US Highway 101 northbound (NB) and southbound (SB) in San Luis Obispo, California. The process used to merge GPS data with quarter-mile freeway segments for traditional crash frequency analysis is also discussed in the paper. A negative binomial regression analyses showed that proportion of high magnitude jerks while decelerating on freeway segments (from the driving data) was significantly related with the long-term crash frequency of those segments. A random parameter negative binomial model with uniformly distributed parameter for ADT and a fixed parameter for jerk provided a statistically significant estimate for quarter-mile segments. The results also indicated that roadway curvature and the presence of auxiliary lane are not significantly related with crash frequency for the highway segments under consideration. The results from this exploration are promising since the data used to derive the explanatory variable(s) can be collected using most off-the-shelf GPS devices, including many smartphones.

  1. Predicting expressway crash frequency using a random effect negative binomial model: A case study in China.

    Science.gov (United States)

    Ma, Zhuanglin; Zhang, Honglu; Chien, Steven I-Jy; Wang, Jin; Dong, Chunjiao

    2017-01-01

    To investigate the relationship between crash frequency and potential influence factors, the accident data for events occurring on a 50km long expressway in China, including 567 crash records (2006-2008), were collected and analyzed. Both the fixed-length and the homogeneous longitudinal grade methods were applied to divide the study expressway section into segments. A negative binomial (NB) model and a random effect negative binomial (RENB) model were developed to predict crash frequency. The parameters of both models were determined using the maximum likelihood (ML) method, and the mixed stepwise procedure was applied to examine the significance of explanatory variables. Three explanatory variables, including longitudinal grade, road width, and ratio of longitudinal grade and curve radius (RGR), were found as significantly affecting crash frequency. The marginal effects of significant explanatory variables to the crash frequency were analyzed. The model performance was determined by the relative prediction error and the cumulative standardized residual. The results show that the RENB model outperforms the NB model. It was also found that the model performance with the fixed-length segment method is superior to that with the homogeneous longitudinal grade segment method.

  2. Patologia da comunicação: Crash sem pentecostes

    Directory of Open Access Journals (Sweden)

    Olgária Chain Féres Matos

    2008-11-01

    Full Text Available O objetivo do ensaio é mostrar a metrópole como o sujeito histórico da contemporaneidade, por meio da análise do filme Crash. Ela é o microcosmo em que se comunicam indivíduos pela mediação do automóvel. Nela inscrevem-se as relações sociais e seus conflitos: xenofobia, racismo, particularismos legais e desregulamentações políticas. Mundo menos dominado por pessoas e mais pelo acaso, ele resulta da determinação de todas as esferas da vida pelo fator econômico e pelas derivas do mercado mundial, forma moderna do destino. Palavras-chave: crash; estado de direito; estado de exceção; fundamentalismos Abstract: The Pathology of Communication: Crash without Pentecost — The purpose of this essay is to portray the metropolis as the historical subject of contemporaneousness, based on an analysis of the movie Crash, which illustrates the microcosm in which individual communications are mediated by the automobile and which is marked by social relations and their conflicts: xenophobia, racism, legal particularities and political deregulation. A world ruled by fortuitousness rather than by human will, it is the product of the determination of all spheres of life by economic factors and by global market trends, seen as the modern depiction of fate. Keywords: Crash; rule of law; rule of exception; fundamentalism

  3. Design of lightweight magnesium car body structure under crash and vibration constraints

    Directory of Open Access Journals (Sweden)

    Morteza Kiani

    2014-06-01

    Full Text Available Car body design in view of structural performance and lightweighting is a challenging task due to all the performance targets that must be satisfied such as vehicle safety and ride quality. In this paper, material replacement along with multidisciplinary design optimization strategy is proposed to develop a lightweight car body structure that satisfies the crash and vibration criteria while minimizing weight. Through finite element simulations, full frontal, offset frontal, and side crashes of a full car model are evaluated for peak acceleration, intrusion distance, and the internal energy absorbed by the structural parts. In addition, the first three fundamental natural frequencies are combined with the crash metrics to form the design constraints. The wall thicknesses of twenty-two parts are considered as the design variables. Latin Hypercube Sampling is used to sample the design space, while Radial Basis Function methodology is used to develop surrogate models for the selected crash responses at multiple sites as well as the first three fundamental natural frequencies. A nonlinear surrogate-based optimization problem is formulated for mass minimization under crash and vibration constraints. Using Sequential Quadratic Programming, the design optimization problem is solved with the results verified by finite element simulations. The performance of the optimum design with magnesium parts shows significant weight reduction and better performance compared to the baseline design.

  4. At the Crossroads of Cyber Warfare: Signposts for the Royal Australian Air Force

    Science.gov (United States)

    2011-06-01

    M. Convertino, Lou Anne DeMattei, and Tammy M. Knierim, Flying and Fighting in Cyberspace, Maxwell Paper ; No. 40 (Maxwell Air Force Base, Ala .: Air...Communications technicians or avionic engineers with a one-month crash course on cyber will not magically become cyber warriors. It will take the training...Convertino, Sebastian M., Lou Anne DeMattei, and Tammy M. Knierim. Flying and Fighting in Cyberspace, Maxwell Paper ; No. 40. Maxwell Air Force Base, Ala

  5. Design of Taxi Sharing Billing System%出租车拼车计费系统的设计

    Institute of Scientific and Technical Information of China (English)

    彭永杰; 廖建文; 吴熹

    2014-01-01

    出租车拼车计费系统硬件设计采用单片机PK10N512VLL10为主控芯片,TPC7062KW组态触摸屏为监控操作界面,显示部分为64*16点阵;在软件上将乘车状态划分为单乘状态和拼车状态,同时根据当地物价水平设定计费方案,计算出不同乘客的车费,车内车费的显示采用实时刷新的方法;该系统样机已经成型,经测试操作简单、稳定且成本较低。%Taxi bil ing system hardware carpooling design uses a single chip PK10N512VLL10 as the main control chip, TPC7062KW touch screen as the monitoring configuration interface,the display section for 64*16 lattice.ln software,the riding state by state and carpooling divided into a single state,according to the local price level set charging scheme,calculated the different passenger fares,display the car fare by using the method of real-time refresh.The system prototype has been formed,after the test has the advantages of simple operation,stable and low cost.

  6. Final Environmental Assessment: Proposed Fire Crash Rescue Station, Hill Air Force Base, Utah

    Science.gov (United States)

    2008-10-02

    CWA), 33 USC Section 1251 et seq. • Industrial pretreatment permit number 110 issued by the North Davis Sewer District (NDSD), dated November 1, 2007...foundations; and buried utilities consisting of water, electricity, natural gas, steam lines, sanitary sewer, and storm sewer. Discussions related to...interest to them. • Occupational Safety and Health (physical and chemical hazards, radiation, explosives , bird and wildlife hazards to aircraft

  7. ON VANET-BASED ROUTING ALGORITHM FOR TAXI-CALLING SYSTEM%基于 VANET叫车系统的路由算法研究

    Institute of Scientific and Technical Information of China (English)

    李蓉; 宋飞; 张琳娟; 张宏科

    2015-01-01

    结合成熟的车载自组网技术和泛在的智能手持终端设备,提出一种去中心的动态叫车系统. 乘客可以通过该系统随时发布叫车请求,并由车载自组网完成该请求的路由及车辆的匹配. 同时,系统还提供了拼车功能,私家车也可通过该功能搭载顺路乘客. 针对信息传输特点,重点研究一种基于效用值转发的路由算法,它根据车辆匹配成功概率计算效用值,并采用基于二分法的有限副本扩散策略,有效地避免信息盲目转发、减少网络负担. 实验仿真结果表明,该系统的叫车成功率优于传统系统,基于效用的有限副本路由在网络开销、时延等方面均优于传统的传染路由和效用路由.%Combining mature VANET technology and ubiquitous smart handset terminal devices, we propose a decentralised dynamic taxi-calling system.Passengers can issue calling requests via this system at anytime, and the route and the taxi matching of the requests are accomplished by VANET.Meanwhile, the carpooling function is provided as well by the system thus the private cars are able to take the passengers on their way through the function.Aiming at the features of information transmission, we mainly focus on studying a utility forwarding-based routing algorithm.It calculates the utility value based on the probability of successful matching of taxis, and employs dichotomisation-based limited-copy diffusion strategy to effectively avoid the blind forwarding and relieve the burden of network.Results of experimental simulation show that our system can perform better than the conventional taxi-calling systems in success rates.The utility-based limited-copy routing algorithm is superior to the conventional epidemic routing and utility routing in terms of network overhead and latency.

  8. 融合出租车驾驶经验的层次路径规划方法%Hierarchical Path Planning Method Based on Taxi Driver Experiences

    Institute of Scientific and Technical Information of China (English)

    胡继华; 黄泽; 邓俊; 谢海莹

    2013-01-01

    The route choice behaviors of taxi drivers are usually representative because they are more familiar with urban road status. This makes it possible to use the taxi drivers' experience to support the path planning. To make the guidance result meet the drivers' expectations well, this study presents a hierarchical path planning method using the taxi driver experiences. The method consists of three steps; first, routes are recovered from the taxi trajectories; second, all roads are redefined and categorized according to the track data and the road network is classified into different experience grades using travel frequency for road segments; third, with the Dijkstra algorithm, a hierarchical path planning method is proposed. Finally, taking Guangzhou city as an example, this paper compares the paths generated by the proposed approach with the conventional algorithm's results. The experimental result shows that travel time of the paths planned by the proposed method has been effectively reduced.%出租车驾驶员对城市道路交通状况较为熟悉,他们选择的路径具有代表性,因此将出租车驾驶员路径选择经验融合到路径规划算法中,对提高出行效率具有重要的意义.本文提出一种融合出租车驾驶经验的层次路径规划方法,主要包括三部分:首先,从出租车GPS数据中提取出出租车载客行驶轨迹;然后,根据各路段出租车行驶频率高低对路网进行分层,构建基于出租车经验路径的分层路网;在此基础上,使用Dijkstra算法实现层次路径规划.最后,本文以广州市为研究区域,将该方法得到的规划路径与经典路径规划算法的结果进行比较.结果表明,融合出租车驾驶经验的路径规划方法所得路径在行程时间上占有一定的优势.

  9. Identification of Energy Distribution for Crash Deformational Processes of Road Vehicles

    Directory of Open Access Journals (Sweden)

    István Harmati

    2007-08-01

    Full Text Available Car body deformation modelling plays a very important role in crash accidentanalyses, as well as in safe car body design. The determination of the energy absorbed bythe deformation and the corresponding Energy Equivalent Speed can be of key importance;however their precise determination is a very difficult task. Although, using the results ofcrash tests, intelligent and soft methods offer an automatic way to model the crash processitself, as well as to determine the absorbed energy, the before-crash speed of the car, etc. Inthis paper a model is introduced which is able to describe the changing of the energydistribution during the whole deformational process and to analyze the strength of thedifferent parts without any human intervention thus significantly can contribute to theimprovement of the modelling, (automatic design, and safety of car bodies.

  10. Contributing factors and issues associated with rural ambulance crashes: literature review and annotated bibliography.

    Science.gov (United States)

    Sanddal, Nels D; Albert, Steve; Hansen, Joseph D; Kupas, Douglas F

    2008-01-01

    Ambulance crashes occur with greater frequency and severity than crashes involving vehicles of similar size and weight characteristics. Crashes in rural areas tend to be more severe in terms of injury or death to vehicle occupants. The purpose of this article was to examine the extant literature, as well as summarize and discuss the overlapping findings of that body of literature. A stepwise literature search was conducted using the following MeSH search terms ambulance; accident, traffic; emergency medical technician; occupational health; and rural in descending combination. MEDLINE was used as the primary database but was augmented by searches of Academic Search Premier, Comprehensive Index of Nursing, Allied Health Literature, and ProQuest Dissertation International. The search resulted in 32 article citations, and of these, 28 were included. An annotated bibliography is followed by a discussion and conclusion that identify opportunities for prevention activities in the areas of education, enforcement, and engineering.

  11. Multifractal analysis and instability index of prior-to-crash market situations

    CERN Document Server

    Piacquadio, M

    2009-01-01

    We take prior-to-crash market prices (NASDAQ, Dow Jones Industrial Average) as a signal, a function of time, we project these discrete values onto a vertical axis, thus obtaining a Cantordust. We study said cantordust with the tools of multifractal analysis, obtaining spectra by definition and by lagrangian coordinates. These spectra have properties that typify the prior-to-crash market situation. Any of these spectra entail elaborate processing of the raw signal data. With the unprocessed raw data we obtain an instability index, also with properties that typify the prior-to-crisis market situation. Both spectra and the instability index agree in characterizing such crashes, and in giving an early warning of them.

  12. Recession Depression: Mental Health Effects of the 2008 Stock Market Crash*

    Science.gov (United States)

    McInerney, Melissa; Mellor, Jennifer M.; Nicholas, Lauren Hersch

    2013-01-01

    Do sudden, large wealth losses affect mental health? We use exogenous variation in the interview dates of the 2008 Health and Retirement Study to assess the impact of large wealth losses on mental health among older U.S. adults. We compare cross-wave changes in wealth and mental health for respondents interviewed before and after the October 2008 stock market crash. We find that the crash reduced wealth and increased feelings of depression and use of antidepressant drugs, and that these effects were largest among respondents with high levels of stock holdings prior to the crash. These results suggest that sudden wealth losses cause immediate declines in subjective measures of mental health. However, we find no evidence that wealth losses lead to increases in clinically-validated measures of depressive symptoms or indicators of depression. PMID:24113241

  13. Recession depression: mental health effects of the 2008 stock market crash.

    Science.gov (United States)

    McInerney, Melissa; Mellor, Jennifer M; Nicholas, Lauren Hersch

    2013-12-01

    Do sudden, large wealth losses affect mental health? We use exogenous variation in the interview dates of the 2008 Health and Retirement Study to assess the impact of large wealth losses on mental health among older U.S. adults. We compare cross-wave changes in wealth and mental health for respondents interviewed before and after the October 2008 stock market crash. We find that the crash reduced wealth and increased feelings of depression and use of antidepressant drugs, and that these effects were largest among respondents with high levels of stock holdings prior to the crash. These results suggest that sudden wealth losses cause immediate declines in subjective measures of mental health. However, we find no evidence that wealth losses lead to increases in clinically-validated measures of depressive symptoms or indicators of depression.

  14. Effects of sawtooth crashes on beam ions and fusion product tritons in JET

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, F.B.; Hone, M.A.; Jarvis, O.N.; Loughlin, M.J.; Sadler, G. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Adams, J.M.; Bond, D.S.; Watkins, N. [UKAEA Harwell Lab. (United Kingdom). Energy Technology Div.; Howarth, P.J.A. [Birmingham Univ. (United Kingdom)

    1994-07-01

    The effect of a sawtooth crash on the radial distribution of the slowing down fusion product tritons and on beams ions, is examined with measurements of the 2.5 MeV and 14 MeV neutron emission line-integrals before and after sawtooth crashes. In deuterium discharges, the 14 MeV neutron production was wholly attributable to burnup of the 1 MeV fusion product tritons from d-d fusion. The local emissivity of 14 MeV neutrons, and hence of the profile of thermalizing tritons, is shown to be only weakly affected by crashes in the discharges studied. This is in contradiction with the apparent behaviour of injected beam ions as deduced from a study of the considerable changes in local emissivity of the 2.5 MeV neutrons. Nevertheless, the behaviour of the fusion product tritons is consistent with the scaling of the beam injected deuterium. 1 ref., 6 figs.

  15. 基于位置服务的出租车调度系统的研究与设计%RESEARCH AND DESIGN OF TAXI DISPATCHING SYSTEM BASED ON LOCATION SERVICE

    Institute of Scientific and Technical Information of China (English)

    蔡莉; 梁利刚; 李海

    2014-01-01

    出租车作为城市居民出行的重要辅助交通工具,目前存在空驶率高、营运效率低下、乘客打车难等一系列问题。解决这些问题的关键在于科学合理地调度出租车,有效分配出租车的运能资源。基于位置服务和 Google Maps 等技术,设计一种以乘客为中心的出租车集中式调度算法和一种新的最短路径算法,在此基础上开发相应的智能调度系统。该系统的使用能有效提高出租车行业的运营效率,改善城市环保,解决现有出租车电召业务中所存在的问题。%Taxi is an important paratransit vehicle for urban residents.At present,there are many problems existed in taxi industry,such as high no-passengers travelling rate,low operation efficiency,difficult in taxi calling and so on.The key to solve these problems depends on the scientific taxi dispatching and effective distribution of taxi transport capacity resources.Based on location service and Google Maps technology,we design a passenger-centred centralised taxi dispatching algorithm and the shortest path algorithm,and develop a corresponding smart dispatching system based on it.The application of this system can effectively improve the operation efficiency for taxi industry and improve the urban environmental protection,at the same time it solves some problems existing in phone call business of taxi services.

  16. Legislation and research in The Netherlands in the field of traffic safety regarding seat belts and crash helmets.

    NARCIS (Netherlands)

    Kampen, L.T.B. van & Edelman, A.

    1979-01-01

    Legislation on seat belts and crash helmets has been introduced since 1975. Safety belts are used by 50-75% of car drivers and passengers. Crash helmets are used by virtually all motorcyclists and moped riders. Fatalities have been reduced due to the use of seat belts by 60%, and due to the helmets

  17. A multinomial logit model-Bayesian network hybrid approach for driver injury severity analyses in rear-end crashes.

    Science.gov (United States)

    Chen, Cong; Zhang, Guohui; Tarefder, Rafiqul; Ma, Jianming; Wei, Heng; Guan, Hongzhi

    2015-07-01

    Rear-end crash is one of the most common types of traffic crashes in the U.S. A good understanding of its characteristics and contributing factors is of practical importance. Previously, both multinomial Logit models and Bayesian network methods have been used in crash modeling and analysis, respectively, although each of them has its own application restrictions and limitations. In this study, a hybrid approach is developed to combine multinomial logit models and Bayesian network methods for comprehensively analyzing driver injury severities in rear-end crashes based on state-wide crash data collected in New Mexico from 2010 to 2011. A multinomial logit model is developed to investigate and identify significant contributing factors for rear-end crash driver injury severities classified into three categories: no injury, injury, and fatality. Then, the identified significant factors are utilized to establish a Bayesian network to explicitly formulate statistical associations between injury severity outcomes and explanatory attributes, including driver behavior, demographic features, vehicle factors, geometric and environmental characteristics, etc. The test results demonstrate that the proposed hybrid approach performs reasonably well. The Bayesian network reference analyses indicate that the factors including truck-involvement, inferior lighting conditions, windy weather conditions, the number of vehicles involved, etc. could significantly increase driver injury severities in rear-end crashes. The developed methodology and estimation results provide insights for developing effective countermeasures to reduce rear-end crash injury severities and improve traffic system safety performance.

  18. Rural casualty crashes on the Kings Highway: A new approach for road safety studies.

    Science.gov (United States)

    Alian, Sahar; Baker, R G V; Wood, Stephen

    2016-10-01

    This paper will consider the contribution that changes in road geometry and driver visual information make to the incidence and distribution of road casualties in different driving environments. This relationship will be explored specifically for the Kings Highway, a major arterial road connecting Queanbeyan with coastal southern New South Wales, Australia. It introduces and suggests a new empirical approach of plotting crashes with road segmentation, calculating sinuosity indices and grades as key features of road geometry, and critical visual points as a behavioural component of road curvature, within a GIS context. It is an approach that might be used when detailed road geometry data is not available. The visualisation and segmentation approach in this research might be used for summarising crash rates and road geometry factors, and for comparing day/night and eastbound/westbound driving conditions. The results suggest some early interpretations for detailed road safety studies that might be considered at local or national levels. The rate of crashes increases according to changes in road geometry factors during the day and for eastbound travel. This is not the case for night driving where the incidence of crashes is similar on both straight and curved roads segments due to the headlight effect and limited background visual field. Crash clusters at day-time may be due to the stronger effect of road geometry (e.g. combination of curvature and vertical grade) on driver behaviour travelling eastbound. The outcomes suggest that it might be essential to consider the effect of environmental factors in any road safety and crash analysis studies.

  19. Exploring the effects of roadway characteristics on the frequency and severity of head-on crashes: case studies from Malaysian federal roads.

    Science.gov (United States)

    Hosseinpour, Mehdi; Yahaya, Ahmad Shukri; Sadullah, Ahmad Farhan

    2014-01-01

    Head-on crashes are among the most severe collision types and of great concern to road safety authorities. Therefore, it justifies more efforts to reduce both the frequency and severity of this collision type. To this end, it is necessary to first identify factors associating with the crash occurrence. This can be done by developing crash prediction models that relate crash outcomes to a set of contributing factors. This study intends to identify the factors affecting both the frequency and severity of head-on crashes that occurred on 448 segments of five federal roads in Malaysia. Data on road characteristics and crash history were collected on the study segments during a 4-year period between 2007 and 2010. The frequency of head-on crashes were fitted by developing and comparing seven count-data models including Poisson, standard negative binomial (NB), random-effect negative binomial, hurdle Poisson, hurdle negative binomial, zero-inflated Poisson, and zero-inflated negative binomial models. To model crash severity, a random-effect generalized ordered probit model (REGOPM) was used given a head-on crash had occurred. With respect to the crash frequency, the random-effect negative binomial (RENB) model was found to outperform the other models according to goodness of fit measures. Based on the results of the model, the variables horizontal curvature, terrain type, heavy-vehicle traffic, and access points were found to be positively related to the frequency of head-on crashes, while posted speed limit and shoulder width decreased the crash frequency. With regard to the crash severity, the results of REGOPM showed that horizontal curvature, paved shoulder width, terrain type, and side friction were associated with more severe crashes, whereas land use, access points, and presence of median reduced the probability of severe crashes. Based on the results of this study, some potential countermeasures were proposed to minimize the risk of head-on crashes.

  20. The impact of the housing crash on the wealth of the baby boom cohorts.

    Science.gov (United States)

    Rosnick, David; Baker, Dean

    2010-04-01

    The collapse of the housing bubble and the resulting plunge in the stock market destroyed more than $10 trillion in household wealth. The impact was especially severe for the baby boom cohorts who are at or near retirement age. This paper uses data from the Federal Reserve Board's 2007 Survey of Consumer Finances to compare the wealth of the baby boomer cohorts just before the crash with projections of household wealth following the crash. These projections show that most baby boomers will be almost entirely dependent on their Social Security income after they stop working.

  1. Frontal Crash Analysis of a Fully Detailed Car Model Based on Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    Han Shan-Ling; Zhu Ping; Lin Zhong-Qin; Shi Yu-Liang

    2004-01-01

    This paper sets up a highly detailed finite element model of a car for frontal crashworthiness applications, and then explains the characteristics of it. The geometry model is preprocessed by Hypermesh software. The finite element method solver program selected for the simulation is LS-DYNA. After the crash simulation is carefully analyzed, the frontal crash experiment is aimed to validate the finite element model. The simulation results are basically in agreement with the experimental results. The validation of the finite element model is crucial for the further research in optimization of the automotive structure or lightweighting of the vehicle.

  2. Associating crash avoidance maneuvers with driver attributes and accident characteristics: a mixed logit model approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    from the key role of proactive and state-aware road users within the concept of sustainable safety systems, as well as from the key role of effective corrective maneuvers in the success of automated in-vehicle warning and driver assistance systems. Methods: The analysis is conducted by means of a mixed...... the propensity to perform crash avoidance maneuvers, and (5) visual obstruction and artificial illumination decrease the probability to carry out crash avoidance maneuvers. Conclusions: The results emphasize the need for public awareness campaigns to promote safe driving style for senior drivers and warning...

  3. 41 CFR 102-34.290 - What forms do I use to report a crash involving a domestic fleet motor vehicle?

    Science.gov (United States)

    2010-07-01

    ... report a crash involving a domestic fleet motor vehicle? 102-34.290 Section 102-34.290 Public Contracts... forms do I use to report a crash involving a domestic fleet motor vehicle? Use the following forms to report a domestic fleet crash. The forms should be carried in any domestic fleet motor vehicle....

  4. The impact of alcohol and road traffic policies on crash rates in Botswana, 2004-2011: a time-series analysis.

    Science.gov (United States)

    Sebego, Miriam; Naumann, Rebecca B; Rudd, Rose A; Voetsch, Karen; Dellinger, Ann M; Ndlovu, Christopher

    2014-09-01

    In Botswana, increased development and motorization have brought increased road traffic-related death rates. Between 1981 and 2001, the road traffic-related death rate in Botswana more than tripled. The country has taken several steps over the last several years to address the growing burden of road traffic crashes and particularly to address the burden of alcohol-related crashes. This study examines the impact of the implementation of alcohol and road safety-related policies on crash rates, including overall crash rates, fatal crash rates, and single-vehicle nighttime fatal (SVNF) crash rates, in Botswana from 2004 to 2011. The overall crash rate declined significantly in June 2009 and June 2010, such that the overall crash rate from June 2010 to December 2011 was 22% lower than the overall crash rate from January 2004 to May 2009. Additionally, there were significant declines in average fatal crash and SVNF crash rates in early 2010. Botswana's recent crash rate reductions occurred during a time when aggressive policies and other activities (e.g., education, enforcement) were implemented to reduce alcohol consumption and improve road safety. While it is unclear which of the policies or activities contributed to these declines and to what extent, these reductions are likely the result of several, combined efforts.

  5. Pyramiding PvPGIP2 and TAXI-III But Not PvPGIP2 and PMEI Enhances Resistance Against Fusarium graminearum.

    Science.gov (United States)

    Tundo, Silvio; Kalunke, Raviraj; Janni, Michela; Volpi, Chiara; Lionetti, Vincenzo; Bellincampi, Daniela; Favaron, Francesco; D'Ovidio, Renato

    2016-08-01

    Plant protein inhibitors counteract the activity of cell wall-degrading enzymes (CWDEs) secreted by pathogens to breach the plant cell-wall barrier. Transgenic plants expressing a single protein inhibitor restrict pathogen infections. However, since pathogens secrete a number of CWDEs at the onset of infection, we combined more inhibitors in a single wheat genotype to reinforce further the cell-wall barrier. We combined polygalacturonase (PG) inhibiting protein (PGIP) and pectin methyl esterase inhibitor (PMEI), both controlling the activity of PG, one of the first CWDEs secreted during infection. We also pyramided PGIP and TAXI-III, a xylanase inhibitor that controls the activity of xylanases, key factors for the degradation of xylan, a main component of cereal cell wall. We demonstrated that the pyramiding of PGIP and PMEI did not contribute to any further improvement of disease resistance. However, the presence of both pectinase inhibitors ensured a broader spectrum of disease resistance. Conversely, the PGIP and TAXI-III combination contributed to further improvement of Fusarium head blight (FHB) resistance, probably because these inhibitors target the activity of different types of CWDEs, i.e., PGs and xylanases. Worth mentioning, the reduction of FHB symptoms is accompanied by a reduction of deoxynivalenol accumulation with a foreseen great benefit to human and animal health.

  6. A Bayesian spatial random parameters Tobit model for analyzing crash rates on roadway segments.

    Science.gov (United States)

    Zeng, Qiang; Wen, Huiying; Huang, Helai; Abdel-Aty, Mohamed

    2017-03-01

    This study develops a Bayesian spatial random parameters Tobit model to analyze crash rates on road segments, in which both spatial correlation between adjacent sites and unobserved heterogeneity across observations are accounted for. The crash-rate data for a three-year period on road segments within a road network in Florida, are collected to compare the performance of the proposed model with that of a (fixed parameters) Tobit model and a spatial (fixed parameters) Tobit model in the Bayesian context. Significant spatial effect is found in both spatial models and the results of Deviance Information Criteria (DIC) show that the inclusion of spatial correlation in the Tobit regression considerably improves model fit, which indicates the reasonableness of considering cross-segment spatial correlation. The spatial random parameters Tobit regression has lower DIC value than does the spatial Tobit regression, suggesting that accommodating the unobserved heterogeneity is able to further improve model fit when the spatial correlation has been considered. Moreover, the random parameters Tobit model provides a more comprehensive understanding of the effect of speed limit on crash rates than does its fixed parameters counterpart, which suggests that it could be considered as a good alternative for crash rate analysis.

  7. Influence of deficiencies in traffic control devices in crashes on two-lane rural roads.

    Science.gov (United States)

    López, Griselda; de Oña, Juan; Garach, Laura; Baena, Leticia

    2016-11-01

    One of the main objectives of all public administrations is reducing traffic crashes. To this end, Road Safety Inspections (RSI) stand out as a key measure. Signaling roads is one of the foremost tasks of RSI. A road that is improperly or poorly signaled can lead to incorrect placement or maneuvers of vehicles and ambiguous situations that can increase the risk of crashes. This paper analyses the relationship between road crashes in two-lane rural highways and certain deficiencies in signaling. The results show that deficiencies such as "incomplete removal of road works markings" or "no guide sign or in incorrect position" are the ones associated with a higher probability of crashes in two-lane rural highways. In view of these results, governmental agencies should verify that the original conditions of a highway are re-established after any construction work is completed. They should also continuously follow up on the signaling of this type of highway in order to maintain optimal conditions.

  8. Do driver training programs reduce crashes and traffic violations? — A critical examination of the literature

    Directory of Open Access Journals (Sweden)

    Raymond C. Peck

    2011-03-01

    There is no evidence or reason to believe that merely lengthening the number of hours on the road will increase effectiveness. Programs directed toward attitude change and risk taking better address the underlying cause of the elevated crash risk of young drivers but these behaviors are notoriously resistant to modification in young people.

  9. 78 FR 53386 - Federal Motor Vehicle Safety Standards; Occupant Crash Protection

    Science.gov (United States)

    2013-08-29

    ...: Denial of petition for rulemaking. SUMMARY: This document denies a rulemaking petition submitted by BMW Group, BMW of North America, LLC, to amend the Federal motor vehicle safety standard on occupant crash... passenger cars and September 1, 1998, for light trucks and vans. II. Petition On October 23, 2012, BMW...

  10. Real-time assessment of fog-related crashes using airport weather data: a feasibility analysis.

    Science.gov (United States)

    Ahmed, Mohamed M; Abdel-Aty, Mohamed; Lee, Jaeyoung; Yu, Rongjie

    2014-11-01

    The effect of reduction of visibility on crash occurrence has recently been a major concern. Although visibility detection systems can help to mitigate the increased hazard of limited-visibility, such systems are not widely implemented and many locations with no systems are experiencing considerable number of fatal crashes due to reduction in visibility caused by fog and inclement weather. On the other hand, airports' weather stations continuously monitor all climate parameters in real-time, and the gathered data may be utilized to mitigate the increased risk for the adjacent roadways. This study aims to examine the viability of using airport weather information in real-time road crash risk assessment in locations with recurrent fog problems. Bayesian logistic regression was utilized to link six years (2005-2010) of historical crash data to real-time weather information collected from eight airports in the State of Florida, roadway characteristics and aggregate traffic parameters. The results from this research indicate that real-time weather data collected from adjacent airports are good predictors to assess increased risk on highways.

  11. Diagnostic analysis of the logistic model for pedestrian injury severity in traffic crashes.

    Science.gov (United States)

    Sze, N N; Wong, S C

    2007-11-01

    This study attempts to evaluate the injury risk of pedestrian casualties in traffic crashes and to explore the factors that contribute to mortality and severe injury, using the comprehensive historical crash record that is maintained by the Hong Kong Transport Department. The injury, demographic, crash, environmental, geometric, and traffic characteristics of 73,746 pedestrian casualties that were involved in traffic crashes from 1991 to 2004 are considered. Binary logistic regression is used to determine the associations between the probability of fatality and severe injury and all contributory factors. A consideration of the influence of implicit attributes on the trend of pedestrian injury risk, temporal confounding, and interaction effects is progressively incorporated into the predictive model. To verify the goodness-of-fit of the proposed model, the Hosmer-Lemeshow test and logistic regression diagnostics are conducted. It is revealed that there is a decreasing trend in pedestrian injury risk, controlling for the influences of demographic, road environment, and other risk factors. In addition, the influences of pedestrian behavior, traffic congestion, and junction type on pedestrian injury risk are subject to temporal variation.

  12. Spinal Injuries in an Airplane Crash : A Description of Incidence, Morphology, and Injury Mechanism

    NARCIS (Netherlands)

    Postma, I. L E; Oner, F. C.; Bijlsma, T. S.; Heetveld, M. J.; Goslings, J. C.; Bloemers, F. W.

    2015-01-01

    Study Design. Retrospective cohort. Objective. Spinal injuries of the survivors of an airplane crash are described. On the basis of injury morphology and knowledge of the conditions of the accident, injury mechanisms are described and prevention measures are discussed. Summary of Background Data. Th

  13. Conversion of the dominantly ideal perturbations into a tearing mode after a sawtooth crash

    NARCIS (Netherlands)

    Igochine, V.; Gude, A.; S. Günter,; Lackner, K.; Yu, Q.; Orte, L. B.; Bogomolov, A.; Classen, I.; McDermott, R. M.; N C Luhmann Jr.,; ASDEX Upgrade team,

    2014-01-01

    Forced magnetic reconnection is a topic of common interest in astrophysics, space science, and magnetic fusion research. The tearing mode formation process after sawtooth crashes implies the existence of this type of magnetic reconnection and is investigated in great detail in the ASDEX Upgrade toka

  14. Crash involvement during the different phases of the New Zealand Graduated Driver Licensing System (GDLS)

    NARCIS (Netherlands)

    Lewis Evans, B.

    2010-01-01

    Introduction: The New Zealand Graduated Driver Licensing System (GDLS) is designed to allow novice drivers to gain driving experience under conditions of reduced risk. Method: To examine the effectiveness of the GDLS, an analysis of how the crash involvement of novice drivers changes as drivers move

  15. Real-time wavelet detection of crashes in limit cycles of non-stationary fusion plasmas

    NARCIS (Netherlands)

    van Berkel, M.; Witvoet, G.; M.R. de Baar,; Nuij, Pwjm; Morschec, H. G. ter; Steinbuch, M.

    2011-01-01

    The high performance mode (H-mode) is one of the baseline plasma scenarios for the experimental fusion reactor ITER. This scenario features a periodic crash-like reorganization of the plasma pressure and the magnetic flux in the plasma core and plasma periphery. The core instability is often referre

  16. 75 FR 50958 - Federal Motor Vehicle Safety Standards; Motorcoach Definition; Occupant Crash Protection

    Science.gov (United States)

    2010-08-18

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK56 Federal Motor Vehicle Safety... Action Plan, NHTSA is issuing this NPRM to propose to amend the Federal motor vehicle safety standard... crash must involve a motor vehicle traveling on a traffic way customarily open to the public, and...

  17. Investigation of an alleged mechanism of finger injury in an automobile crash.

    Science.gov (United States)

    Stacey, Stephen; Kent, Richard

    2006-07-01

    This investigation centers on the case of an adult male whose finger was allegedly amputated by the steering wheel of his car during a crash. The subject claimed to have been driving with his left index finger inserted through a hole in the spoke of his steering wheel and was subsequently involved in an offset frontal collision with a tree. The finger was found to be cleanly severed at the mid-shaft of the proximal phalanx after the crash. This injury was alleged to have been caused by inertial loading from the rotation of the steering wheel during the crash. To determine whether this injury mechanism was plausible, three laboratory tests representing distinct loading scenarios were carried out with postmortem human surrogates loaded dynamically by the subject's steering wheel. It was found that the inertial loads generated in this loading scenario are insufficient to amputate the finger. Additionally, artificially constraining the finger to force an amputation to occur revealed that a separation at the proximal interphalangeal joint occurs rather than a bony fracture of the proximal phalanx. Based on these biomechanical tests, it can be concluded that the subject's injury did not occur during the automobile crash in question. Furthermore, it can be shown that the injury was self-inflicted to fraudulently claim on an insurance policy.

  18. Finite Element Simulation of Three Full-Scale Crash Tests for Cessna 172 Aircraft

    Science.gov (United States)

    Mason, Brian H.; Warren, Jerry E., Jr.

    2017-01-01

    The NASA Emergency Locator Transmitter Survivability and Reliability (ELT-SAR) project was initiated in 2013 to assess the crash performance standards for the next generation of emergency locator transmitter (ELT) systems. Three Cessna 172 aircraft were acquired to perform crash testing at NASA Langley Research Center's Landing and Impact Research Facility. Full-scale crash tests were conducted in the summer of 2015 and each test article was subjected to severe, but survivable, impact conditions including a flare-to-stall during emergency landing, and two controlled-flight-into-terrain scenarios. Full-scale finite element analyses were performed using a commercial explicit solver, ABAQUS. The first test simulated impacting a concrete surface represented analytically by a rigid plane. Tests 2 and 3 simulated impacting a dirt surface represented analytically by an Eulerian grid of brick elements using a Mohr-Coulomb material model. The objective of this paper is to summarize the test and analysis results for the three full-scale crash tests. Simulation models of the airframe which correlate well with the tests are needed for future studies of alternate ELT mounting configurations.

  19. Consequences of using the plane stress assumption for damage calculation in crash analyses

    NARCIS (Netherlands)

    Walters, C.L.

    2014-01-01

    Simulation of failure in plate materials (represented as shell elements) is critical for the correct determination of crash performance of ships and offshore structures. This need has traditionally been filled with failure loci that give the failure strain in terms of stress triaxiality. In recent y

  20. Sport cycling crashes on public roads, the influence of bunch riding and experience.

    NARCIS (Netherlands)

    Wijlhuizen, G.J. Gent, P. van & Stipdonk, H.L.

    2014-01-01

    Cycling is a popular but unsafe mode of transport in the Netherlands and the number of seriously injured bicyclists has increased significantly since 2006. A special subgroup is the population of sport cyclists who perform their sport on public roads. The number of road crashes with sport cyclists s

  1. Localization of the magnetic reconnection zone during sawtooth crashes in tokamak plasmas

    NARCIS (Netherlands)

    Munsat, T.; Park, H. K.; Classen, I.G.J.; Domier, C.W.; Donne, A. J. H.; N C Luhmann Jr.,; Mazzucato, E.; van de Pol, M.J.

    2007-01-01

    Recent 2D spatially and temporally resolved measurements of electron temperature fluctuations in the tokamak core have revealed new information on the dynamics of the sawtooth crash. Measures of poloidal localization of the reconnection zone are achieved through direct analysis of the 2D data and th

  2. A new access density definition and its correlation with crash rates by microscopic traffic simulation method.

    Science.gov (United States)

    Huang, Bing; Zhang, Yu; Lu, Linjun; Lu, Jian John

    2014-03-01

    Better access management can improve highway safety by reducing potential crashes and conflicts. To make adequate access management decisions, it is essential to understand the impact of different access types on roadway safety, usually represented by the crash rate of a roadway segment. The objective of this paper is to propose a new access density definition reflecting the impact of traffic speed variation of different access types. The traffic speed variation was obtained from a microscopic traffic simulation software package TSIS-CORSIM. A sample roadway Temple Terrace Highway was selected to perform traffic simulation. Access Weight was obtained from traffic speed variation, and access density was obtained from access weight. The proposed access density was then compared with the existing definition by analyzing their correlations with crash rates on one suburban street in Temple Terrace, Florida. The comparison demonstrates that crash rates are more highly correlated with the proposed access density than that in the previous study, which is helpful for Federal Highway Administration (FHWA), United States Department of Transportation (USDOT), and transportation consulting companies to regulate the construction, management and design of roadway segments.

  3. 北京地区出租汽车司机超重与肥胖调查分析%Investigation and Analysis on Overweight and Obesity of Taxi Drivers in Beijing Area

    Institute of Scientific and Technical Information of China (English)

    王洪瑛

    2011-01-01

    [Objective]To understand the present status of overweight and obesity among taxi drivers in Beijing area. [Methods] The physical examination was conducted in 5941 taxi drivers, and the characteristics of overweight and obesity were analyzed. [ Results] Among the 5941 taxi drivers, there were 1009 cases of overweight and obesity, which accounted for 67.48% , and the in-cidence was significantly higher than that of the general population. [ Conclusion] The incidence of overweight and obesity among taxi drivers is high. It is necessary to improve the health management, in order to prevent and control the chronic diseases.%目的 了解北京地区出租汽车司机超重与肥胖状况.方法对5941例出租汽车司机进行体格检查,分析超重、肥胖的特征.结果5941例出租汽车司机中超重、肥胖者4009例,占67.48%,明显高于一般人群.结论出租汽车司机超重、肥胖发生率高,应加大健康管理,预防控制慢性疾病发生.

  4. Seatbelt syndrome with gastric mucosal breaks and intra-gastric wall air leakage.

    Science.gov (United States)

    Mori, Hirohito; Tsushimi, Takaaki; Kobara, Hideki; Nishiyama, Noriko; Fujihara, Shintaro; Matsunaga, Tae; Ayaki, Maki; Chiyo, Taiga; Masaki, Tsutomu

    2015-01-01

    As numerous reports were published regarding the so-called seatbelt syndrome involved in car crashes, most of them were mentioned about small intestine, duodenum and colon perforations and solid organ bleeding. No reports have been published regarding multiple gastric mucosal tears with intra-gastric wall air leakage with massive bleeding. A 65-year-old woman was admitted after a motor vehicle crash. She vomited massive fresh blood. Gastric mucosal breaks, approximately 5 cm in length, were observed. Computed tomography imaging revealed multiple gastric mucosal breaks. We report a rare case wherein a traffic accident caused a serious condition associated with massive digestive bleeding.

  5. A method to account for and estimate underreporting in crash frequency research.

    Science.gov (United States)

    Wood, Jonathan S; Donnell, Eric T; Fariss, Christopher J

    2016-10-01

    Underreporting is a well-known issue in crash frequency research. However, statistical methods that can account for underreporting have received little attention in the published literature. This paper compares results from underreporting models to models that account for unobserved heterogeneity. The difference in the elasticities between the negative binomial underreporting model and random parameters negative binomial models, which accounts for unobserved heterogeneity in crash frequency models, are used as the basis for comparison. The paper also includes a comparison of the predicted number of unreported PDO crashes based on the negative binomial underreporting model with crashes that were reported to police but were not considered reportable to PennDOT to assess the ability of the underreporting models to predict non-reportable crashes. The data used in this study included 21,340 segments of two-lane rural highways that are owned and maintained by PennDOT. Reported accident frequencies over an eight year period (2005-2012) were included in the sample, producing a total of 170,468 segment-years of data. The results indicate that if a variable impacts both the true accident frequency and the probability of accidents being reported, statistical modeling methods that ignore underreporting produce biased regression coefficients. The magnitude of the bias in the present study (based on elasticities) ranged from 0.00-16.79%. If the variable affects the true accident frequency, but not the probability of accidents being reported, the results from the negative binomial underreporting models are consistent with analysis methods that do not account for underreporting.

  6. A joint econometric analysis of seat belt use and crash-related injury severity.

    Science.gov (United States)

    Eluru, Naveen; Bhat, Chandra R

    2007-09-01

    This paper formulates a comprehensive econometric structure that recognizes two important issues in crash-related injury severity analysis. First, the impact of a factor on injury severity may be moderated by various observed and unobserved variables specific to an individual or to a crash. Second, seat belt use is likely to be endogenous to injury severity. That is, it is possible that intrinsically unsafe drivers do not wear seat belts and are the ones likely to be involved in high injury severity crashes because of their unsafe driving habits. The preceding issues are considered in the current research effort through the development of a comprehensive model of seat belt use and injury severity that takes the form of a joint correlated random coefficients binary-ordered response system. To our knowledge, this is the first instance of such a model formulation and application not only in the safety analysis literature, but in the econometrics literature in general. The empirical analysis is based on the 2003 General Estimates System (GES) data base. Several types of variables are considered to explain seat belt use and injury severity levels, including driver characteristics, vehicle characteristics, roadway design attributes, environmental factors, and crash characteristics. The results, in addition to confirming the effects of various explanatory variables, also highlight the importance of (a) considering the moderating effects of unobserved individual/crash-related factors on the determinants of injury severity and (b) seat belt use endogeneity. From a policy standpoint, the results suggest that seat belt non-users, when apprehended in the act, should perhaps be subjected to both a fine (to increase the chances that they wear seat belts) as well as mandatory enrollment in a defensive driving course (to attempt to change their aggressive driving behaviors).

  7. Emergency Locator Transmitter System Performance During Three Full-Scale General Aviation Crash Tests

    Science.gov (United States)

    Littell, Justin D.; Stimson, Chad M.

    2016-01-01

    Full-scale crash tests were conducted on three Cessna 172 aircraft at NASA Langley Research Center's Landing and Impact Research facility during the summer of 2015. The purpose of the three tests was to evaluate the performance of commercially available Emergency Locator Transmitter (ELT) systems and support development of enhanced installation guidance. ELTs are used to provide location information to Search and Rescue (SAR) organizations in the event of an aviation distress situation, such as a crash. The crash tests simulated three differing severe but survivable crash conditions, in which it is expected that the onboard occupants have a reasonable chance of surviving the accident and would require assistance from SAR personnel. The first simulated an emergency landing onto a rigid surface, while the second and third simulated controlled flight into terrain. Multiple ELT systems were installed on each airplane according to federal regulations. The majority of the ELT systems performed nominally. In the systems which did not activate, post-test disassembly and inspection offered guidance for non-activation cause in some cases, while in others, no specific cause could be found. In a subset of installations purposely disregarding best practice guidelines, failure of the ELT-to-antenna cabling connections were found. Recommendations for enhanced installation guidance of ELT systems will be made to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 229 for consideration for adoption in a future release of ELT minimum operational performance specifications. These recommendations will be based on the data gathered during this test series as well as a larger series of crash simulations using computer models that will be calibrated based on these data

  8. Calibration of safety performance function for crashes on inter-city four lane highways in India

    Directory of Open Access Journals (Sweden)

    Naveen Kumar ChikkaKrishna

    2015-12-01

    Full Text Available There is a significant need to improve the highway safety during roadway planning, design and operations in developing countries like India. To receive appropriate consideration, safety needs to be dealt objectively within the transportation planning and highway design processes. Lack of available tools is a deterrent to quantify safety of a transportation facility during the planning or highway design process. The objective of this paper is to develop safety performance functions considering various elements involved in the planning, design and operation of a section on four-lane National Highway (NH-58 located in the state of Uttarakhand, India. The mixed traffic on Indian multilane highways comes with a lot of variability within, ranging from different vehicle types to different driver characteristics. This could result in variability in the effect of explanatory variables on crashes across locations. Hence, explanatory variables for highway segment safety analysis considered were geometric characteristics like curvature change rate, slope change rate, transverse slope and traffic characteristics in the form of average daily traffic, light vehicle traffic, light commercial vehicle traffic, heavy vehicle traffic, two-wheelers, non-motorised traffic volume and operating speed were analysed against dependent variable as crash count per 200 m per year. Safety performance functions involving the explanatory variables are calibrated to predict crash frequency using Poisson Weibull technique and crash types are predicted using ordered logit model. Model results suggest that increase in traffic volume leads to higher probability of crash risk and traffic safety is significantly distorted by higher curvature change rate values.

  9. 纵坑切梢小蠹虫对松节油及其不同组分的趋性1)%Taxis of Tomicus piniperda to Turpentine and Its Components

    Institute of Scientific and Technical Information of China (English)

    乔淑芬; 孙忠林; 顾地周; 宫汝淳

    2014-01-01

    The experiment was conducted to study the effect of the taxis of Tomicus piniperda to turpentine and its different com-ponents.T.pinipre da has some taxis to the α-pinene, limonene, myrcene, and camphene turpentine in turpentine, but the taxis difference is not significant compared with the control.The taxis of T.piniperda to turpentine×α-pinene andα-pi-nene×β-pinene are significantly stronger than that of the other interaction and control, but T.piniperda has weak taxis to the interaction of the other two compounds and other single compound.Therefore, one can use volatile substances in tur-pentine to control T.piniperda.%以自制昆虫嗅觉仪研究了纵坑切梢小蠹虫( Tomicus piniperda)对松节油及其不同组分的趋性效果。结果表明:纵坑切梢小蠹虫对松节油中α-派烯、苎烯、月桂烯、莰烯有一定的趋性,但趋性与对照差异不显著;对松节油×α-派烯以及α-派烯×β-派烯的趋性最强并显著高于对照;对其他单一化合物和其他化合物的交互作用趋性较弱。可以通过松节油中挥发性物质对纵坑切梢小蠹虫的引诱作用实现对其虫害的人工防治。

  10. PERFORMANCE AND DURABILITY OF THE PSA PEUGEOT CITROEN'S DPF SYSTEM ON A TAXI FLEET IN THE PARIS AREA

    Energy Technology Data Exchange (ETDEWEB)

    COROLLER, P; PLASSAT, G

    2003-08-24

    The use of Diesel engines has strongly increased during the last years and now represents 40% of the sales in Europe and up to 50% of the number of cars in circulation for some countries. This success is linked not only to the economical aspect of the use of such vehicles, but also to the recent technological improvements of these engines. The new technical solutions (high pressure direct injection, turbocharger) have indeed allowed the increase of these engine performances while decreasing their fuel consumption, pollutant emissions and noise level. From an environment point of view, Diesel engines are nevertheless penalized by their particulates and NOx emissions. The study and the treatment of the particulate, highly criticized for their potential impact on health, are the subject of numerous works of characterizations and developments. PSA Peugeot Citroen has recently (2000) launched its particulate filter technology on several types of vehicles (500,000 vehicles with DPF have been sold today). In order to evaluate the durability of this technology over a long period of time, a study program has been set-up by ADEME (French Environmental Agency), IFP Powertrain, PSA Peugeot Citroen and Taxis G7 (a Parisian taxis Company). The objective is to study the evolution of five taxis and their after-treatment system performances over 80,000km mileage--which corresponds to the recommended mileage before the first DPF maintenance--in hard urban driving conditions, as well over 120,000km, after the DPF maintenance and remanufacturing. More specifically, the following evaluations are being performed at regular intervals (around 20,000km): regulated gaseous pollutant emissions on NEDC cycle, particulate emissions and unregulated pollutant emissions. The results obtained until now have not shown any degradation of the particulate filter efficiency (more than 90%). This paper presents the methodology set-up, and the explanation of the first results obtained. Indeed, a more

  11. Thoracic Injury Risk as a Function of Crash Severity - Car-to-car Side Impact Tests with WorldSID Compared to Real-life Crashes.

    Science.gov (United States)

    Sunnevång, Cecilia; Rosén, Erik; Boström, Ola; Lechelt, Ulf

    2010-01-01

    Side airbags reduce the risk of fatal injury by approximately 30%. Due to limited real-life data the risk reducing effect for serious injury has not yet been established. Since side airbags are mainly designed and validated for crash severities used in available test procedures little is known regarding the protective effect when severity increases.The objective of this study was to understand for which crash severities AIS3+ thorax occupant protection in car-to-car nearside collisions need to and can be improved. The aim was fulfilled by means of real life data, for older cars without side airbag, and a series of car-to-car tests performed with the WorldSID 50%-ile in modern and older cars at different impact speeds.The real life data showed that the risk of AIS3+ injury was highest for the thorax followed by the pelvis and head. For both non-senior and senior occupants, most thorax injuries were sustained at lateral delta-v from 20 km/h to 40 km/h. In this severity range, senior occupants were found to have approximately four times higher risk of thoracic injury than non-senior occupants. The crash tests at lateral impact speed 55 km/h (delta-v 32 km/h) confirmed the improved performance at severities represented in current legal and rating tests. The structural integrity of the modern car impacted at 70 km/h showed a potential for improved side impact protection by interior countermeasures.

  12. Kinetics and substrate selectivity of a Triticum aestivum xylanase inhibitor (TAXI) resistant D11F/R122D variant of Bacillus subtilis XynA xylanase

    DEFF Research Database (Denmark)

    Rasmussen, Louise Enggaard; Sørensen, Jens F.; Meyer, Anne S.

    2010-01-01

    ), water-unextractable arabinoxylan (WUAX), birchwood xylan, and wheat bran. Both the BsX and the BsX(mut) catalyzed the release of xylo-oligosaccharides with higher degree of polymerization from WUAX than from WEAX. At equimolar addition levels the activity of the BsX(mut) was lower than that of the Bs......X with respect to both the initial rate and the product yields obtained after prolonged reaction on the xylan substrates. The calculated substrate selectivity factors indicated that the BsX and the BsX(mut) both had higher catalytic rate on WUAX than on WEAX. Addition of a 100:1 (TAXI:xylanase) molar ratio...

  13. Bangkok and its air pollution problem

    Energy Technology Data Exchange (ETDEWEB)

    Panich, S.

    1995-12-31

    Bangkok is the city on a former river delta and is a very flat area. The topography is unremarkable but being only a few kilometers (about 20) from the sea in the Gulf of Bangkok, the City experiences the sea breeze every afternoon and evening. The natural phenomenon is caused by the uplifting of hot air from the sun-baked ground and heat generation in the city, to be replaced by the cooler air from the sea, which is to the south. During the nighttime the sea breeze ceases to operate as the ground temperature cools down. The late night and early morning is characterized by the calm or no wind. With 2.1 million vehicles, the city has a serious problem of carbon monoxide from the gasoline vehicles stuck in the traffic on start and stop cycles, while particulate matter is the result of diesel vehicles. Hydrocarbons mainly result from two-stroke motorcycles and tuk-tuk (three-wheeled) taxis. Air pollution in Bangkok and major cities of Thailand is the result of emissions from gasoline, diesel, and LPG fueled vehicles, which contribute to the observed levels of carbon monoxide, lead, particulate matter, sulfur dioxide, nitrogen dioxide, ozone and hydrocarbons. The industrial activities contribute smaller share due to tall stacks and more efficient combusting processes and pollution control.

  14. Crash response data system for the controlled impact demonstration (CID) of a full-scale transport aircraft

    Science.gov (United States)

    Calloway, R. S.; Knight, V. H., Jr.

    1986-01-01

    A study involving the Controlled Impact Demonstration (CID) of a transport category aircraft was conducted with the objective to improve occupant safety during survivable crash scenarios. in connection with this study, the first remotely-piloted Full-Scale Transport aircraft was purposely crashed into the California desert. The program was initated to demonstrate the effectiveness of an imisting kerosene (AMK), a fuel additive emplyed to reduce postcrash fires. The unmanned CID flight carried 73 life-like flight research dummies, multiple experiments, high-speed interior cabin cameras, and the high-environment Crash Response Data System. Attention is given to the design approach, a block diagram of the Crash Response Data System, measurements, the digital data subsystem, signal conditioning, telemetry, on-board recording, the power subsystem, preflight checkout and calibration, and aspects of system qualification.

  15. Effectiveness of forward collision warning and autonomous emergency braking systems in reducing front-to-rear crash rates.

    Science.gov (United States)

    Cicchino, Jessica B

    2017-02-01

    The objective of this study was to evaluate the effectiveness of forward collision warning (FCW) alone, a low-speed autonomous emergency braking (AEB) system operational at speeds up to 19mph that does not warn the driver prior to braking, and FCW with AEB that operates at higher speeds in reducing front-to-rear crashes and injuries. Poisson regression was used to compare rates of police-reported crash involvements per insured vehicle year in 22 U.S. states during 2010-2014 between passenger vehicle models with FCW alone or with AEB and the same models where the optional systems were not purchased, controlling for other factors affecting crash risk. Similar analyses compared rates between Volvo 2011-2012 model S60 and 2010-2012 model XC60 vehicles with a standard low-speed AEB system to those of other luxury midsize cars and SUVs, respectively, without the system. FCW alone, low-speed AEB, and FCW with AEB reduced rear-end striking crash involvement rates by 27%, 43%, and 50%, respectively. Rates of rear-end striking crash involvements with injuries were reduced by 20%, 45%, and 56%, respectively, by FCW alone, low-speed AEB, and FCW with AEB, and rates of rear-end striking crash involvements with third-party injuries were reduced by 18%, 44%, and 59%, respectively. Reductions in rear-end striking crashes with third-party injuries were marginally significant for FCW alone, and all other reductions were statistically significant. FCW alone and low-speed AEB reduced rates of being rear struck in rear-end crashes by 13% and 12%, respectively, but FCW with AEB increased rates of rear-end struck crash involvements by 20%. Almost 1 million U.S. police-reported rear-end crashes in 2014 and more than 400,000 injuries in such crashes could have been prevented if all vehicles were equipped with FCW and AEB that perform similarly as systems did for study vehicles.

  16. Motor vehicle crashes in diabetic patients with tight glycemic control: a population-based case control analysis.

    Directory of Open Access Journals (Sweden)

    Donald A Redelmeier

    2009-12-01

    Full Text Available BACKGROUND: Complications from diabetes mellitus can compromise a driver's ability to safely operate a motor vehicle, yet little is known about whether euglycemia predicts normal driving risks among adults with diabetes. We studied the association between glycosylated hemoglobin (HbA1c and the risk of a motor vehicle crash using a population-based case control analysis. METHODS AND FINDINGS: We identified consecutive drivers reported to vehicle licensing authorities between January 1, 2005 to January 1, 2007 who had a diagnosis of diabetes mellitus and a HbA1c documented. The risk of a crash was calculated taking into account potential confounders including blood glucose monitoring, complications, and treatments. A total of 57 patients were involved in a crash and 738 were not involved in a crash. The mean HbA1c was lower for those in a crash than controls (7.4% versus 7.9%, unpaired t-test, p = 0.019, equal to a 26% increase in the relative risk of a crash for each 1% reduction in HbA1c (odds ratio = 1.26, 95% confidence interval 1.03-1.54. The trend was evident across the range of HbA1c values and persisted after adjustment for measured confounders (odds ratio = 1.25, 95% confidence interval 1.02-1.55. The two other significant risk factors for a crash were a history of severe hypoglycemia requiring outside assistance (odds ratio = 4.07, 95% confidence interval 2.35-7.04 and later age at diabetes diagnosis (odds ratio per decade = 1.29, 95% confidence interval 1.07-1.57. CONCLUSIONS: In this selected population, tighter glycemic control, as measured by the HbA1c, is associated with an increased risk of a motor vehicle crash.

  17. Safety impacts of platform tram stops on pedestrians in mixed traffic operation: A comparison group before-after crash study.

    Science.gov (United States)

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

    2016-01-01

    Tram stops in mixed traffic environments present a variety of safety, accessibility and transport efficiency challenges. In Melbourne, Australia the hundred year-old electric tram system is progressively being modernized to improve passenger accessibility. Platform stops, incorporating raised platforms for level entry into low floor trams, are being retro-fitted system-wide to replace older design stops. The aim of this study was to investigate the safety impacts of platform stops over older design stops (i.e. Melbourne safety zone tram stops) on pedestrians in the context of mixed traffic tram operation in Melbourne, using an advanced before-after crash analysis approach, the comparison group (CG) method. The CG method evaluates safety impacts by taking into account the general trends in safety and the unobserved factors at treatment and comparison sites that can alter the outcomes of a simple before-after analysis. The results showed that pedestrian-involved all injury crashes reduced by 43% after platform stop installation. This paper also explores a concern that the conventional CG method might underestimate safety impacts as a result of large differences in passenger stop use between treatment and comparison sites, suggesting differences in crash risk exposure. To adjust for this, a modified analysis explored crash rates (crash counts per 10,000 stop passengers) for each site. The adjusted results suggested greater reductions in pedestrian-involved crashes after platform stop installation: an 81% reduction in pedestrian-involved all injury crashes and 86% reduction in pedestrian-involved FSI crashes, both are significant at the 95% level. Overall, the results suggest that platform stops have considerable safety benefits for pedestrians. Implications for policy and areas for future research are explored.

  18. Road traffic crash circumstances and consequences among young unlicensed drivers: A Swedish cohort study on socioeconomic disparities

    Directory of Open Access Journals (Sweden)

    Laflamme Lucie

    2010-01-01

    Full Text Available Abstract Background Young car drivers run a higher risk of road traffic crash and injury not only because of their lack of experience but also because of their young age and their greater propensity for adopting unsafe driving practices. Also, low family socioeconomic position increases the risk of crash and of severe crash in particular. Whether this holds true for young unlicensed drivers as well is not known. Increasing attention is being drawn to the prevalence and practice of unlicensed driving among young people as an important contributor to road traffic fatalities. Methods This is a population-based cohort study linking Swedish national register data for a cohort of 1 616 621 individuals born between 1977 and 1991. Crash circumstances for first-time road traffic crash (RTC were compared considering licensed and unlicensed drivers. The socioeconomic distribution of injury was assessed considering household socioeconomic position, social welfare benefits, and level of urbanicity of the living area. The main outcome measure is relative risk of RTC. Results RTCs involving unlicensed drivers were over-represented among male drivers, suspected impaired drivers, severe injuries, crashes occurring in higher speed limit areas, and in fair road conditions. Unlicensed drivers from families in a lower socioeconomic position showed increased relative risks for RTC in the range of 1.75 to 3.25. Those living in rural areas had an increased relative risk for a severe RTC of 3.29 (95% CI 2.47 - 4.39 compared to those living in metropolitan areas. Conclusions At the time of the crash, young unlicensed drivers display more risky driving practices than their licensed counterparts. Just as licensed drivers, unlicensed young people from low socioeconomic positions are over-represented in the most severe injury crashes. Whether the mechanisms lying behind those similarities compare between these groups remains to be determined.

  19. 76 FR 60118 - Tesla Motors, Inc. Grant of Petition for Renewal of a Temporary Exemption From the Advanced Air...

    Science.gov (United States)

    2011-09-28

    ... National Highway Traffic Safety Administration Tesla Motors, Inc. Grant of Petition for Renewal of a... (FMVSS) No. 208, Occupant Crash Protection. SUMMARY: This notice grants the petition of Tesla Motors, Inc. (Tesla) for the renewal of a temporary exemption of its Roadster model from the advanced air...

  20. 77 FR 39564 - Group Lotus Plc, Receipt of Petition for Temporary Exemption From an Advanced Air Bag Requirement...

    Science.gov (United States)

    2012-07-03

    ... National Highway Traffic Safety Administration Group Lotus Plc, Receipt of Petition for Temporary Exemption... Crash Protection. SUMMARY: In accordance with the procedures in 49 CFR part 555, Group Lotus Plc has... went into effect, low volume manufacturers now have access to advanced air bag technology....

  1. Geospatial and machine learning techniques for wicked social science problems: analysis of crash severity on a regional highway corridor

    Science.gov (United States)

    Effati, Meysam; Thill, Jean-Claude; Shabani, Shahin

    2015-04-01

    The contention of this paper is that many social science research problems are too "wicked" to be suitably studied using conventional statistical and regression-based methods of data analysis. This paper argues that an integrated geospatial approach based on methods of machine learning is well suited to this purpose. Recognizing the intrinsic wickedness of traffic safety issues, such approach is used to unravel the complexity of traffic crash severity on highway corridors as an example of such problems. The support vector machine (SVM) and coactive neuro-fuzzy inference system (CANFIS) algorithms are tested as inferential engines to predict crash severity and uncover spatial and non-spatial factors that systematically relate to crash severity, while a sensitivity analysis is conducted to determine the relative influence of crash severity factors. Different specifications of the two methods are implemented, trained, and evaluated against crash events recorded over a 4-year period on a regional highway corridor in Northern Iran. Overall, the SVM model outperforms CANFIS by a notable margin. The combined use of spatial analysis and artificial intelligence is effective at identifying leading factors of crash severity, while explicitly accounting for spatial dependence and spatial heterogeneity effects. Thanks to the demonstrated effectiveness of a sensitivity analysis, this approach produces comprehensive results that are consistent with existing traffic safety theories and supports the prioritization of effective safety measures that are geographically targeted and behaviorally sound on regional highway corridors.

  2. Crash Simulation of Roll Formed Parts by Damage Modelling Taking Into Account Preforming Effects

    Science.gov (United States)

    Till, Edwin T.; Hackl, Benjamin; Schauer, Hermann

    2011-08-01

    Complex phase steels of strength levels up to 1200 MPa are suitable to roll forming. These may be applied in automotive structures for enhancing the crashworthiness, e. g. as stiffeners in doors. Even though the strain hardening of the material is low there is considerable bending formability. However ductility decreases with the strength level. Higher strength requires more focus to the structural integrity of the part during the process planning stage and with respect to the crash behavior. Nowadays numerical simulation is used as a process design tool for roll-forming in a production environment. The assessment of the stability of a roll forming process is quite challenging for AHSS grades. There are two objectives of the present work. First to provide a reliable assessment tool to the roll forming analyst for failure prediction. Second to establish simulation procedures in order to predict the part's behavior in crash applications taking into account damage and failure. Today adequate ductile fracture models are available which can be used in forming and crash applications. These continuum models are based on failure strain curves or surfaces which depend on the stress triaxiality (e. g. Crach or GISSMO) and may additionally include the Lode angle (extended Mohr Coulomb or extended GISSMO model). A challenging task is to obtain the respective failure strain curves. In the paper the procedure is described in detail how these failure strain curves are obtained using small scale tests within voestalpine Stahl, notch tensile-, bulge and shear tests. It is shown that capturing the surface strains is not sufficient for obtaining reliable material failure parameters. The simulation tool for roll-forming at the site of voestalpine Krems is Copra® FEA RF, which is a 3D continuum finite element solver based on MSC.Marc. The simulation environment for crash applications is LS-DYNA. Shell elements are used for this type of analyses. A major task is to provide results of

  3. An evaluation of the EuroNCAP crash test safety ratings in the real world.

    Science.gov (United States)

    Segui-Gomez, Maria; Lopez-Valdes, Francisco J; Frampton, Richard

    2007-01-01

    We investigated whether the rating obtained in the EuroNCAP test procedures correlates with injury protection to vehicle occupants in real crashes using data in the UK Cooperative Crash Injury Study (CCIS) database from 1996 to 2005. Multivariate Poisson regression models were developed, using the Abbreviated Injury Scale (AIS) score by body region as the dependent variable and the EuroNCAP score for that particular body region, seat belt use, mass ratio and Equivalent Test Speed (ETS) as independent variables. Our models identified statistically significant relationships between injury severity and safety belt use, mass ratio and ETS. We could not identify any statistically significant relationships between the EuroNCAP body region scores and real injury outcome except for the protection to pelvis-femur-knee in frontal impacts where scoring "green" is significantly better than scoring "yellow" or "red".

  4. Drugs related to motor vehicle crashes in northern European countries: A study of fatally injured drivers

    DEFF Research Database (Denmark)

    Mørland, Jørg; Steentoft, Anni; Simonsen, Kirsten Wiese

    2011-01-01

    , and psychoactive medicinal drugs were detected less frequently than in younger age groups. In 75% of single vehicle crashes, the driver was under 50 years. Thus, the majority of accidents where the drivers must be considered responsible, occurred with drivers who had recently used alcohol, or drugs, alone...... within 24 h of the accident, in the years 2001 and 2002 in the five Nordic countries (total population about 24 million inhabitants). The samples were analysed for more than 200 different drugs in addition to alcohol, using a similar analytical programme and cut-off limits in all countries. In three...... countries (Finland, Norway and Sweden) blood samples were available for more than 70% of the drivers, allowing representative prevalence data to be collected. 60% of the drivers in single vehicle crashes had alcohol and/or drug in their blood samples, compared with 30% of drivers killed in collisions...

  5. Spatiotemporal and random parameter panel data models of traffic crash fatalities in Vietnam.

    Science.gov (United States)

    Truong, Long T; Kieu, Le-Minh; Vu, Tuan A

    2016-09-01

    This paper investigates factors associated with traffic crash fatalities in 63 provinces of Vietnam during the period from 2012 to 2014. Random effect negative binomial (RENB) and random parameter negative binomial (RPNB) panel data models are adopted to consider spatial heterogeneity across provinces. In addition, a spatiotemporal model with conditional autoregressive priors (ST-CAR) is utilised to account for spatiotemporal autocorrelation in the data. The statistical comparison indicates the ST-CAR model outperforms the RENB and RPNB models. Estimation results provide several significant findings. For example, traffic crash fatalities tend to be higher in provinces with greater numbers of level crossings. Passenger distance travelled and road lengths are also positively associated with fatalities. However, hospital densities are negatively associated with fatalities. The safety impact of the national highway 1A, the main transport corridor of the country, is also highlighted.

  6. Analyzing the Relationship Between Car Generation and Severity of Motor-Vehicle Crashes in Denmark

    DEFF Research Database (Denmark)

    Rich, Jeppe; Prato, Carlo Giacomo; Hels, Tove;

    2013-01-01

    car market with remarkably high registration tax that causes potential buyers to hold longer onto old cars, the relationship between technological enhancements of vehicles and severity of crashes requires particular attention. The current study investigated the relationship between car generation (i.......e., car’s first registration year) and injury severity sustained by car drivers involved in accidents in Denmark between 2004 and 2010. A generalized ordered logit model was estimated while controlling for several characteristics of the crash, the vehicle and the persons involved, and a sensitivity...... analysis was performed to assess the effect of car generation on drivers’ injury severity. Results illustrate that newer car generations are associated to significantly lower probability of injury and fatality, and that replacing older cars with newer ones introduces significant and not to be overlooked...

  7. The log-periodic-AR(1)-GARCH(1,1) model for financial crashes

    CERN Document Server

    Gazola, L; Pizzinga, A; Riera, R

    2008-01-01

    This paper intends to meet recent claims for the attainment of more rigorous statistical methodology within the econophysics literature. To this end, we consider an econometric approach to investigate the outcomes of the log-periodic model of price movements, which has been largely used to forecast financial crashes. In order to accomplish reliable statistical inference for unknown parameters, we incorporate an autoregressive dynamic and a conditional heteroskedasticity structure in the error term of the original model, yielding the log-periodic-AR(1)-GARCH(1,1) model. Both the original and the extended models are fitted to financial indices of U. S. market, namely S&P500 and NASDAQ. Our analysis reveal two main points: (i) the log-periodic-AR(1)-GARCH(1,1) model has residuals with better statistical properties and (ii) the estimation of the parameter concerning the time of the financial crash has been improved.

  8. Air Safety Spinoffs

    Science.gov (United States)

    1977-01-01

    Weight saving-even a matter of a few pounds-is an important consideration in airplane design and . construction. Boeing saved 200 pounds simply by substituting a new type of compressed gas cylinder on their 747 commercial airliners. For quickly evacuating passengers in the event of a ground emergency the 747 escape chutes allow ' passengers to slide to safety from the two-story height of the cabin deck. The chutes pop out of exitways and are automatically inflated in seconds by compressed air stored in pressure vessels. Boeing's weight saving resulted from a recent changeover to a new type of pressure vessel built by Structural Composites Industries Inc. of Azusa, Cal. The company employs technology originally developed for rocket motor casings; the cylinders are constructed by winding fibers around an aluminum liner. This technique offers high strength for very low weight-in this case 60 percent less than the pressure vessels earlier used on the 747. Another contribution to improved air safety is an underwater locator device. Called the "Pinger," it uses sonar techniques to locate aircraft crashed in water-or, more specifically, to recover the flight recorder aboard the airplane. Its recovery provides clues as to what caused the accident and suggests measures to prevent similar future occurrences. Until recently, there was no way to recover flight recorders aboard aircraft lost in water crashes. The Pinger, now serving 95 percent of the airline industry, provides an answer. Key element of the Pinger system is a small, battery-powered transmitter, or homing beacon, included as part of the recorder package. For as long as 30 days, the transmitter sends out an acoustic signal from water depths up to 20,000 feet. The other element of the system is a receiver, used by search crews to home in on the transmitter's signal. Originating as a U.S. Navy project, this device was refined and further developed by NASA's Langley Research Center to retrieve submerged nose cones

  9. General and specific statistical properties of foreign exchange markets during a financial crash

    Science.gov (United States)

    Li, Wei-Shen; Tsai, Yun-Jie; Shen, Yu-Hsien; Liaw, Sy-Sang

    2016-06-01

    We investigate minute-by-minute foreign exchange rate (FX) data of 14 currencies with different exchange-rate regimes during a financial crash, and divide these data into several stages according to their respective tendencies: depreciation stage (stage 1), fluctuating stage (stage 2), and appreciation stage (stage 3). The tail distribution of FX rate returns satisfies a power-law structure for different types of currencies. We find the absolute value of the power-law exponent is smaller in emerging markets than in developed markets, especially during the stage 1, and is greatest in pegged currencies. We also find that the correlation properties of the FX rate return series have quite disparate results among the various types of currencies. Currencies in developed markets respectively have weak persistence and anti-persistence in short and long timescales; whereas the pegged currencies and currencies in emerging markets show different degrees of anti-persistence in various timescales. Further analyses on the data in divided stages indicate that emerging markets and pegged currencies have more prominent dual fractal structures after the depreciation stage, while the developed markets do not. Hurst exponent analyses on the sign series yield similar results to that on the original return series for most currencies. The magnitude series of the returns provide some unique results during a crash. The developed market currencies have strong persistence and exhibit a weaker correlation in the depreciation and appreciation stages. In contrast, the currencies of emerging markets as well as pegged currencies fail to show such a transformation, but rather show a constant-correlation behavior in the corresponding stages of a crash. These results indicate that external shocks exert different degrees of influence during different stages of the crash in various markets.

  10. Understanding and Reducing Off-Duty Vehicle Crashes Among Military Personnel

    Science.gov (United States)

    2010-01-01

    Scotland , based on the Theory of Planned Behavior (Fishbein and Ajzen, 1975), is an excellent example. Foolspeed targeted perceptions of normative...Roehrs, Timothy, David Beare, Frank Zorick, and Thomas Roth , “Sleepiness and Ethanol Effects on Simulated Driving,” Alcoholism: Clinical and Experimental... Roth , Jane Stutts, Pat Waller, and David Willis, Drowsy Driving and Automobile Crashes, Washington, D.C.: NCSDR/NHTSA Expert Panel on Driver

  11. Anatomy of a system accident: The crash of Avianca Flight 052

    Science.gov (United States)

    Helmreich, Robert L.

    1994-01-01

    On January 25, 1990, Avianca Flight 052 crashed after running out of fuel following a missed approach to New York's John F. Kennedy Airport. Weather was poor on the East Coast of the United States that day, and the flight had experienced several holding patterns enroute from Medellin, Colombia, to New York. The accident is analyzed in terms of Helmreich and Foushee's (1993) model of crew performance and Reason's (1990) model of latent pathogens in system operations.

  12. Aircraft-crash-protected steel reactor building roof structure for the European market

    Energy Technology Data Exchange (ETDEWEB)

    Posta, B.A.; Kadar, I. [Bechtel Corp., San Francisco, CA (United States); Rao, A.S. [General Electric Nuclear Engineering, San Jose, CA (United States)

    1996-07-01

    This paper recommends the use of all steel roof structures for the reactor building of European Boiling Water Reactor (BWR) plants. This change would make the advanced US BWR designs more compatible with European requirements. Replacement of the existing concrete roof slab with a sufficiently thick steel plate would eliminate the concrete spelling resulting from a postulated aircraft crash, potentially damaging the drywell head or the spent fuel pool.

  13. Magnetic reconnection triggering magnetohydrodynamic instabilities during a sawtooth crash in a Tokamak plasma.

    Science.gov (United States)

    Chapman, I T; Scannell, R; Cooper, W A; Graves, J P; Hastie, R J; Naylor, G; Zocco, A

    2010-12-17

    Thomson scattering measurements with subcentimeter spatial resolution have been made during a sawtooth crash in a Mega Ampere Spherical Tokamak fusion plasma. The unparalleled resolution of the temperature profile has shed new light on the mechanisms that underlie the sawtooth. As magnetic reconnection occurs, the temperature gradient at the island boundary increases. The increased local temperature gradient is sufficient to make the helical core unstable to ideal magnetohydrodynamic instabilities, thought to be responsible for the rapidity of the collapse.

  14. HESS Opinions "Crash tests for a standardized evaluation of hydrological models"

    Directory of Open Access Journals (Sweden)

    A. Valéry

    2009-10-01

    Full Text Available As all hydrological models are intrinsically limited hypotheses on the behaviour of catchments, models – which attempt to represent real-world behaviour – will always remain imperfect. To make progress on the long road towards improved models, we need demanding tests, i.e. true crash tests. Efficient testing requires large and varied data sets to develop and assess hydrological models, to ensure their generality, to diagnose their failures, and ultimately, help improving them.

  15. CDC Vital Signs–Motor Vehicle Crash Deaths

    Centers for Disease Control (CDC) Podcasts

    2016-07-06

    This podcast is based on the July 2016 CDC Vital Signs report. In the U.S., about 90 people die in motor vehicle crashes each day and thousands more are injured, resulting in hundreds of millions of dollars in direct medical costs each year. Learn what you can do to stay safe.  Created: 7/6/2016 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 7/6/2016.

  16. 'Crashing' the rugby scrum -- an avoidable cause of cervical spinal injury. Case reports.

    Science.gov (United States)

    Scher, A T

    1982-06-12

    Deliberate crashing of the opposing packs prior to a rugby scrum is an illegal but commonly practised manoeuvre which can lead to abnormal flexion forces being applied to players in the front row, with resultant cervical spine and spinal cord injury. Two cases of cervical spinal cord injury sustained in this manner are presented. The mechanism of injury, the forces involved and preventive measures are discussed.

  17. REPAIR TECHNOLOGY OF THE COMPOSITE WING OF A LIGHT PLANE DAMAGED DURING AN AIRCRAFT CRASH

    Directory of Open Access Journals (Sweden)

    Andrzej ŚWIĄTONIOWSKI

    2016-09-01

    Full Text Available The increasing use of composite structures in aircraft constructions has made it necessary to develop repair methods that will restore the component’s original design strength without compromising its structural integrity. In this paper, the complex repair technology of the composite wing of a light plane, which was damaged during an aircraft crash, is described. The applied repair scheme should meet all the original design requirements for the plane structure.

  18. Clustering, concurrency control, crash recovery, garbage collection, and security in object-oriented database management systems

    OpenAIRE

    1991-01-01

    This paper presents considerations about several topics that have a direct influence on data reliability and performance in object oriented database management systems. These topics are: physical storage management (clustering), concurrency control, crash recovery, garbage collection, and database security. Each topic is illustrated by its application to the Tactical Database as designed for the Low Cost Combat Direction System Naval Postgraduate School, Department of Computer Science, Cod...

  19. The bus crash in Sierre (Switzerland. From trauma to reprocessing: The role of schools

    Directory of Open Access Journals (Sweden)

    Erik de Soir

    2014-09-01

    Full Text Available In this article, Erik de Soir describes his involvement in the organised response to a coach crash occurred in Sierre, Switzerland, in which twenty-two Belgian and Dutch schoolchildren died, along with six adults. The author highlights the needs of the various actors, the different psychological aspects to be considered, and the complexity of the situation. He also notes the problems encountered in the management of the situation, with the goal of learning important technical lessons for the future.

  20. APP对出租车市场竞争政策的挑战与重塑%Challenges and Reconstruction of Competition Policy in Taxi Market Resulting from APP

    Institute of Scientific and Technical Information of China (English)

    李俊峰

    2016-01-01

    The majority of regulatory authorities in the world prohibit free access to taxi mar-ket and free bargaining for taxi fares between drivers and passengers .This kind of policy restric-ting competition results from the game between interests groups ,but also matches with signifi-cant information asymmetry in taxi market .APP remodels information transmission and trade competition mechanisms in taxi market ,overturns the legitimacy foundation of restricting compe-tition policy ,and makes taxi market policy pattern with global convergence fall apart .A triangle analytical framework ,so called group games-institutional environment-economic thoughts ,as the important means for studying the transition of competition policy ,can be used to reveal the gen-eral reasons for the transition of market regulation policy between competition openness and com-petition ban ,and indicates that taxi markets in different law domains will achieve competition lib-eralization asynchronously and converge constantly to regulation policy encouraging competition .%世界各地的监管当局,大多限制出租车服务市场的自由进入,限制司机与乘客自由议价。此类限制竞争政策是利益集团博弈的产物,但也与出租车市场显著的信息不对称特性相适应。APP重塑了出租车市场的信息传递机制与交易竞争机制,颠覆了限制竞争政策的正当性基础,使全球趋同的出租车市场政策格局趋于分崩离析。“集团博弈—制度环境—经济学思辨”的三维分析框架,作为竞争政策变迁研究的重要工具,能够揭示市场管制政策在“开放竞争”与“禁止竞争”两种取向之间变迁的一般动因,而且预示着各法域的出租车服务市场将不同步地实现竞争自由化,并逐渐向开放竞争的管制政策趋同。