WorldWideScience

Sample records for air route traffic control centers

  1. En Route/Terminal ATC (Air Traffic Control) Operations Concept.

    Science.gov (United States)

    1983-10-28

    been provided It is recognized that for events such as catastro - controllers interface phes, hi-jackings, or sensi- with pilots and control- tive U.S...idetiie .icat " nbokcd Tig ~ l ~ C nttt V. DrONe ~iy n ieto vco Itwddr lc’ PoutionSymbls tne mpced aeadof Wet)O~te w0b9f ,i29 6 Fre tack No ~i~t pln

  2. The influence of automation support on Air Traffic Controller behaviour with a Speed And Route Advisory function

    NARCIS (Netherlands)

    Merwe, K. van de; Oprins, E.A.P.B.; Plaat, A. van der; Erikson, F.

    2009-01-01

    The aim of this paper is to describe the influence of automation support on Air Traffic Controller performance, workload and Situation Awareness (SA). Controllers handle traffic through means of tactical control involving heading, speed and altitude instructions. Future Air Traffic Management (ATM)

  3. Relationship between Air Traffic Selection and Training (AT-SAT)) Battery Test Scores and Composite Scores in the Initial en Route Air Traffic Control Qualification Training Course at the Federal Aviation Administration (FAA) Academy

    Science.gov (United States)

    Kelley, Ronald Scott

    2012-01-01

    Scope and Method of Study: This study focused on the development and use of the AT-SAT test battery and the Initial En Route Qualification training course for the selection, training, and evaluation of air traffic controller candidates. The Pearson product moment correlation coefficient was used to measure the linear relationship between the…

  4. En Route Air Traffic Control Input Devices for the Next Generation

    Science.gov (United States)

    Mainini, Matthew J.

    2010-01-01

    The purpose of this study was to investigate the usefulness of different input device configurations when trial planning new routes for aircraft in an advanced simulation of the en route workstation. The task of trial planning is one of the futuristic tools that is performed by the graphical manipulation of an aircraft's trajectory to reroute the aircraft without voice communication. In this study with two input devices, the FAA's current trackball and a basic optical computer mouse were evaluated with "pick" button in a click-and-hold state and a click-and-release state while the participant dragged the trial plan line. The trial plan was used for three different conflict types: Aircraft Conflicts, Weather Conflicts, and Aircraft + Weather Conflicts. Speed and accuracy were the primary dependent variables. Results indicate that the mouse conditions were significantly faster than the trackball conditions overall with no significant loss of accuracy. Several performance ratings and preference ratings were analyzed from post-run and post-simulation questionnaires. The release conditions were significantly more useful and likable than the hold conditions. The results suggest that the mouse in the release button state was the fastest and most well liked device configuration for trial planning in the en route workstation. Keywords-input devices, en route, controller, workstation, mouse, trackball, NextGen

  5. Situational Leadership in Air Traffic Control

    Science.gov (United States)

    Arvidsson, Marcus; Johansson, Curt R.; Ek, Asa; Akselsson, Roland

    2007-01-01

    In high-risk environments such as air traffic control, leadership on different levels plays a certain role in establishing, promoting, and maintaining a good safety culture. The current study aimed to investigate how leadership styles, leadership style adaptability, and over and under task leadership behavior differed across situations, operative conditions, leadership structures, and working tasks in an air traffic control setting. Study locations were two air traffic control centers in Sweden with different operational conditions and leadership structures, and an administrative air traffic management unit. Leadership was measured with a questionnaire based on Leader Effectiveness and Adaptability Description (LEAD; Blanchard, Zigarmi & Zigarmi, 2003; Hersey & Blanchard, 1988). The results showed that the situation had strong impact on the leadership in which the leadership behavior was more relationship oriented in Success and Group situations than in Hardship and Individual situations. The leadership adaptability was further superior in Success and Individual situations compared with Hardship and Group situations. Operational conditions, leadership structures and working tasks were, on the other hand, not associated with leadership behavior.

  6. Real-time routing control design for traffic networks with multi-route choices

    Institute of Scientific and Technical Information of China (English)

    罗莉华; 葛颖恩; 陈继红; 张方伟

    2016-01-01

    This work considers those road networks in which there are multi-route choices for bifurcation-destination (or origin-destination) pairs, and designs a real-time variable message sign (VMS)-based routing control strategy in the model predictive control (MPC) framework. The VMS route recommendation provided by the traffic management authority is directly considered as the control variable, and the routing control model is established, in which a multi-dimensional control vector is introduced to describe the influence of route recommendations on flow distribution. In the MPC framework, a system optimum routing strategy with the constraints regarding drivers’ acceptability with recommended routes is designed, which can not only meet the traffic management authority’s control requirement but also improve drivers’ satisfaction with the route guidance system. The simulation carried out shows that the proposed routing control can effectively mitigate traffic congestion, reduces followers’ time delay, and improves drivers’ satisfaction with routing control in road networks.

  7. Integration of Predictive Routing Information with Dynamic Traffic Signal Control

    Science.gov (United States)

    1994-05-01

    vehicles without the on-board guidance aid (Harris, S., Rabone , A., et.al., 1992). The simulation developed was called ROute GUidance Simulation (ROGUS...Florida. Harris, S., Rabone , A., et.al. 1992. ROGUS: A Simulation of Dynamic Route Guidance Systems. Traffic Engineering and Control(33)327-329

  8. A New Approach to an Automated Air Traffic Control

    Institute of Scientific and Technical Information of China (English)

    Patchev Dragoljub

    2014-01-01

    This paper identifies areas of improvements of the air traffic control system and proposes modification of the concept of automation by using available technologies. With the proposed modification, the current Europe wide en route network structure can be modified in order to make routes more optimal. For this new route network structure, a new concept of automation will be used to manage with the air traffic. The first identified area of improvement is implementation of automation process that will enable decentralization of the air traffic control functionality to each individual aircraft and this will be achieved through automated routing of the aircrafts and CD&R (conflict detection and resolution). The FMS (flight management system) at the aircraft will make decisions for the optimal flight route based on the sensor inputs, information on selection of the routes, next hope points and flight levels, all received by ADS-B (automatic dependant surveillance-broadcast). The second area is processing the information about the deviation from the optimal route as in flight plan due to a traffic management (vectoring, level change) and taking it into consideration when further actions are undertaken. For each action, a cost factor will be calculated from the fuel burned for that action. This factor will be used to select conflict resolution protocol. The proposed concept shall increase the capacity of the network, and enable the air traff~c more efficient and more environmentally friendly while maintaining safe separation.

  9. 14 CFR 71.13 - Classification of Air Traffic Service (ATS) routes.

    Science.gov (United States)

    2010-01-01

    ...) routes. 71.13 Section 71.13 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... ROUTES; AND REPORTING POINTS § 71.13 Classification of Air Traffic Service (ATS) routes. Unless otherwise specified, ATS routes are classified as follows: (a) In subpart A of this part: (1) Jet routes. (2)...

  10. A Mathematical Model and Algorithm for Routing Air Traffic Under Weather Uncertainty

    Science.gov (United States)

    Sadovsky, Alexander V.

    2016-01-01

    A central challenge in managing today's commercial en route air traffic is the task of routing the aircraft in the presence of adverse weather. Such weather can make regions of the airspace unusable, so all affected flights must be re-routed. Today this task is carried out by conference and negotiation between human air traffic controllers (ATC) responsible for the involved sectors of the airspace. One can argue that, in so doing, ATC try to solve an optimization problem without giving it a precise quantitative formulation. Such a formulation gives the mathematical machinery for constructing and verifying algorithms that are aimed at solving the problem. This paper contributes one such formulation and a corresponding algorithm. The algorithm addresses weather uncertainty and has closed form, which allows transparent analysis of correctness, realism, and computational costs.

  11. CATS-based Air Traffic Controller Agents

    Science.gov (United States)

    Callantine, Todd J.

    2002-01-01

    This report describes intelligent agents that function as air traffic controllers. Each agent controls traffic in a single sector in real time; agents controlling traffic in adjoining sectors can coordinate to manage an arrival flow across a given meter fix. The purpose of this research is threefold. First, it seeks to study the design of agents for controlling complex systems. In particular, it investigates agent planning and reactive control functionality in a dynamic environment in which a variety perceptual and decision making skills play a central role. It examines how heuristic rules can be applied to model planning and decision making skills, rather than attempting to apply optimization methods. Thus, the research attempts to develop intelligent agents that provide an approximation of human air traffic controller behavior that, while not based on an explicit cognitive model, does produce task performance consistent with the way human air traffic controllers operate. Second, this research sought to extend previous research on using the Crew Activity Tracking System (CATS) as the basis for intelligent agents. The agents use a high-level model of air traffic controller activities to structure the control task. To execute an activity in the CATS model, according to the current task context, the agents reference a 'skill library' and 'control rules' that in turn execute the pattern recognition, planning, and decision-making required to perform the activity. Applying the skills enables the agents to modify their representation of the current control situation (i.e., the 'flick' or 'picture'). The updated representation supports the next activity in a cycle of action that, taken as a whole, simulates air traffic controller behavior. A third, practical motivation for this research is to use intelligent agents to support evaluation of new air traffic control (ATC) methods to support new Air Traffic Management (ATM) concepts. Current approaches that use large, human

  12. Human Factors in Air Traffic Control

    Science.gov (United States)

    1982-04-01

    leaves him in a central role but provides some automated facilitiee to help him to do his 3ob. 7he concepto therefore have different emotional...which engender favourable attitudes towards them. Considering the amount of effort which goes into marketing commercial products, astonishinglXy...in air traffic control environments. Safety standards are clear and gentrally enforced, and the equipment currently marketed does not have emissions

  13. FAA Air Traffic Control Operations Concepts. Volume 2. ACF/ACCC (Area Control Facility/Area Control Computer Complex) Terminal and En Route Controllers. Change 1

    Science.gov (United States)

    1988-07-29

    i’MinimumVectorAltitude) * MVA * and {MilitarY’ Route) and (Holding_ PatterrnAirspace) and TOD @2 SLS 3.7.1.2.1.1.1.2 and Fi~nal_Approach_Course and (Navigational-Aid...and{ [Fix]) and(LMinimumVectorAltitude]) * MVA * and( [Military-Route]) and( [HoldingPatternAirspoce]) and .T13D) @ SLS 3.7.1.2.1.1.1.2 Emfphasize...Restore Conflict Alert 370 Pox ,.’Conflict Resolution Adviso, y: The cooobillity shall bc provided to optionally supressresoreo toyhe resolution

  14. Impact of bicycle route type on exposure to traffic-related air pollution.

    Science.gov (United States)

    MacNaughton, Piers; Melly, Steven; Vallarino, Jose; Adamkiewicz, Gary; Spengler, John D

    2014-08-15

    Cyclists are exposed to traffic-related air pollution (TRAP) during their commutes due to their proximity to vehicular traffic. Two of the main components of TRAP are black carbon (BC) and nitrogen dioxide (NO2), which have both been causally associated with increased mortality. To assess the impact of cyclists' exposure to TRAP, a battery-powered mobile monitoring station was designed to sample air pollutants along five bike routes in Boston, Massachusetts. The bike routes were categorized into three types: bike paths, which are separated from vehicle traffic; bike lanes, which are adjacent to traffic; and designated bike lanes, which are shared traffic lanes for buses and cyclists. Bike lanes were found to have significantly higher concentrations of BC and NO2 than bike paths in both adjusted and unadjusted generalized linear models. Higher concentrations were observed in designated bike lanes than bike paths; however, this association was only significant for NO2. After adjusting for traffic density, background concentration, and proximity to intersections, bike lanes were found to have concentrations of BC and NO2 that were approximately 33% higher than bike paths. Distance from the road, vegetation barriers, and reduced intersection density appear to influence these variations. These findings suggest that cyclists can reduce their exposure to TRAP during their commute by using bike paths preferentially over bike lanes regardless of the potential increase of traffic near these routes.

  15. 77 FR 30437 - Proposed Amendment of Air Traffic Service Routes; Southwestern United States

    Science.gov (United States)

    2012-05-23

    ... Federal Aviation Administration 14 CFR Part 71 RIN 2120-AA66 Proposed Amendment of Air Traffic Service Routes; Southwestern United States AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Administration, 800 Independence Avenue SW., Washington, DC 20591; telephone: (202) 267-8783....

  16. Validation of Air Traffic Controller Workload Models

    Science.gov (United States)

    1979-09-01

    SAR) tapes dtirinq the data reduc- tion phase of the project. Kentron International Limited provided the software support for the oroject. This included... ETABS ) or to revised traffic control procedures. The models also can be used to verify productivity benefits after new configurations have been...col- lected and processed manually. A preliminary compari- son has been made between standard NAS Stage A and ETABS operations at Miami. 1.2

  17. Air Traffic Control automation: for humans or people?

    OpenAIRE

    Brooker, Peter

    2005-01-01

    Are air traffic controllers humans or people? At first sight, this seems a very odd question, given that ‘humans’ and ‘people’ are near-synonyms in the dictionary and everyday usage. However, in research on air traffic control (ATC) automation the phrase ‘human-centred’ is used to mean particular aspects of people: for example, it does not usually address their motivations for embracing change or cover organisational behaviour issues. The objective here is to try to understa...

  18. Comprehensive Optimization of Emergency Evacuation Route and Departure Time under Traffic Control

    Directory of Open Access Journals (Sweden)

    Guo Li

    2014-01-01

    Full Text Available With the frequent occurrence of major emergencies, emergency management gets high attention from all around the world. This paper investigates the comprehensive optimization of major emergency evacuation route and departure time, in which case the evacuation propagation mechanism is considered under traffic control. Given the practical assumptions, we first establish a comprehensive optimization model based on the simulation of evacuation route and departure time. Furthermore, we explore the reasonable description method of evacuation traffic flow propagation under traffic control, including the establishment of traffic flow propagation model and the design of the simulation mudule that can simulate the evacuation traffic flow. Finally, we propose a heuristic algorithm for the optimization of this comprehensive model. In case analysis, we take some areas in Beijing as the evaluation sources to verify the reliability of our model. A series of constructive suggestions for Beijing's emergency evacuation are proposed, which can be applied to the actual situation under traffic control.

  19. Distributed Air Traffic Control : A Human Safety Perspective

    CERN Document Server

    Nikumbh, Sarvesh; Vartak, Rahul

    2011-01-01

    The issues in air traffic control have so far been addressed with the intent to improve resource utilization and achieve an optimized solution with respect to fuel comsumption of aircrafts, efficient usage of the available airspace with minimal congestion related losses under various dynamic constraints. So the focus has almost always been more on smarter management of traffic to increase profits while human safety, though achieved in the process, we believe, has remained less seriously attended. This has become all the more important given that we have overburdened and overstressed air traffic controllers managing hundreds of airports and thousands of aircrafts per day. We propose a multiagent system based distributed approach to handle air traffic ensuring complete human (passenger) safety without removing any humans (ground controllers) from the loop thereby also retaining the earlier advantages in the new solution. The detailed design of the agent system, which will be easily interfacable with the existin...

  20. Automated Air Traffic Control Operations with Weather and Time-Constraints: A First Look at (Simulated) Far-Term Control Room Operations

    Science.gov (United States)

    Prevot, Thomas; Homola, Jeffrey R.; Martin, Lynne H.; Mercer, Joey S.; Cabrall, Christopher C.

    2011-01-01

    In this paper we discuss results from a recent high fidelity simulation of air traffic control operations with automated separation assurance in the presence of weather and time-constraints. We report findings from a human-in-the-loop study conducted in the Airspace Operations Laboratory (AOL) at the NASA Ames Research Center. During four afternoons in early 2010, fifteen active and recently retired air traffic controllers and supervisors controlled high levels of traffic in a highly automated environment during three-hour long scenarios, For each scenario, twelve air traffic controllers operated eight sector positions in two air traffic control areas and were supervised by three front line managers, Controllers worked one-hour shifts, were relieved by other controllers, took a 3D-minute break, and worked another one-hour shift. On average, twice today's traffic density was simulated with more than 2200 aircraft per traffic scenario. The scenarios were designed to create peaks and valleys in traffic density, growing and decaying convective weather areas, and expose controllers to heavy and light metering conditions. This design enabled an initial look at a broad spectrum of workload, challenge, boredom, and fatigue in an otherwise uncharted territory of future operations. In this paper we report human/system integration aspects, safety and efficiency results as well as airspace throughput, workload, and operational acceptability. We conclude that, with further refinements. air traffic control operations with ground-based automated separation assurance can be an effective and acceptable means to routinely provide very high traffic throughput in the en route airspace.

  1. The Impact of Trajectory Prediction Uncertainty on Air Traffic Controller Performance and Acceptability

    Science.gov (United States)

    Mercer, Joey S.; Bienert, Nancy; Gomez, Ashley; Hunt, Sarah; Kraut, Joshua; Martin, Lynne; Morey, Susan; Green, Steven M.; Prevot, Thomas; Wu, Minghong G.

    2013-01-01

    A Human-In-The-Loop air traffic control simulation investigated the impact of uncertainties in trajectory predictions on NextGen Trajectory-Based Operations concepts, seeking to understand when the automation would become unacceptable to controllers or when performance targets could no longer be met. Retired air traffic controllers staffed two en route transition sectors, delivering arrival traffic to the northwest corner-post of Atlanta approach control under time-based metering operations. Using trajectory-based decision-support tools, the participants worked the traffic under varying levels of wind forecast error and aircraft performance model error, impacting the ground automations ability to make accurate predictions. Results suggest that the controllers were able to maintain high levels of performance, despite even the highest levels of trajectory prediction errors.

  2. TASAR Flight Trial 2: Assessment of Air Traffic Controller Acceptability of TASAR Requests

    Science.gov (United States)

    Idris, Husni; Enea, Gabriele

    2016-01-01

    In support of the Flight Trial (FT-2) of NASA's prototype of the Traffic Aware Strategic Aircrew Requests (TASAR) concept, observations were conducted at the air traffic facilities to identify and assess the main factors that affect the acceptability of pilot requests by air traffic controllers. Two observers shadowed air traffic controllers at the Atlanta (ZTL) and Jacksonville (ZJX) air traffic control centers as the test flight pilot made pre-scripted requests to invoke acceptability issues and then they interviewed the observed and other controllers voluntarily. Fifty controllers were interviewed with experience ranging from one to thirty-five years. All interviewed controllers were enthusiastic about the technology and accounting for sector boundaries in pilot requests, particularly if pilots can be made aware of high workload situations. All interviewed controllers accept more than fifty percent of pilot requests; forty percent of them reject less than ten percent of requests. The most common reason for rejecting requests is conflicting with traffic followed by violating letters of agreement (LOAs) and negatively impacting neighboring sector workload, major arrival and departure flows and flow restrictions. Thirty-six requests were made during the test, eight of which were rejected due to: the aircraft already handed off to another sector, violating LOA, opposing traffic, intruding into an active special use airspace (SUA), intruding into another center, weather, and unfamiliarity with the requested waypoint. Nine requests were accepted with delay mostly because the controller needed to locate unfamiliar waypoints or to coordinate with other controllers.

  3. Fatigue Minimization Work Shift Scheduling for Air Traffic Controllers

    Directory of Open Access Journals (Sweden)

    Ta-Chung Wang

    2013-05-01

    Full Text Available It is common for Air Traffic Controllers to control air traffic during the night and to experience fatigue. Although fatigue is not the direct cause of aviation accidents, 21 percent of accidents are fatigue-related. Therefore countries and companies have tried to regulate work hours to avoid extreme fatigue, thus decreasing human error resulting from fatigue. However, these regulations may not reflect that actual fatigue variation and fatigue levels can be decreased still more by scheduling appropriately. This paper focuses on optimal work shift scheduling to reduce air traffic controller fatigue. First, a mathematical model is established to describe fatigue levels. The objective function is to reduce the fatigue peak produced by work shifts as much as possible. Various constraints, such as holidays and manpower requirements are considered. The optimization problem is then solved using integer programming. We take a sample schedule and draw conclusions by comparing our results with the original fatigue levels.

  4. Measurement of Temporal Awareness in Air Traffic Control

    Science.gov (United States)

    Rantanen, E.M.

    2009-01-01

    Temporal awareness, or level 3 situation awareness, is critical to successful control of air traffic, yet the construct remains ill-defined and difficult to measure. This research sought evidence for air traffic controllers awareness of temporal characteristics of their tasks in data from a high-fidelity system evaluation simulation. Five teams of controllers worked on four scenarios with different traffic load. Several temporal parameters were defined for each task controllers performed during a simulation run and their actions on the tasks were timed relative to them. Controllers showed a strong tendency to prioritize tasks according to a first come, first served principle. This trend persisted as task load increased. Also evident was awareness of the urgency of tasks, as tasks with impending closing of a window of opportunity were performed before tasks that had longer time available before closing of the window.

  5. FAA Air Traffic Control Operations Concepts. Volume 6. ARTCC (Air Route Traffic Control Center)/Host En Route Controllers. Change 1

    Science.gov (United States)

    1988-07-29

    8217 and (MinimumVectorAltitude) ’ MVA ’ and Holding Pattern_Airspace and (ProminentObject) *obstruction* O Task Analysis 0-8 DOT/FAA/AP-87-O1 (VOL #6) CHG 1...0 o A 1. 4 .2 . + DETEC T A P IL O T 02 A IRCRA FT PRO 8 , 17M (E .G . .HV POX IA , × XI X X EXCEPTIN BEACON CODE) 0209 .-~-’... VL’ v Al. 4.2. 8

  6. Risk-Hedged Approach for Re-Routing Air Traffic Under Weather Uncertainty

    Science.gov (United States)

    Sadovsky, Alexander V.; Bilimoria, Karl D.

    2016-01-01

    This presentation corresponds to: our paper explores a new risk-hedged approach for re-routing air traffic around forecast convective weather. In this work, flying through a more likely weather instantiation is considered to pose a higher level of risk. Current operational practice strategically plans re-routes to avoid only the most likely (highest risk) weather instantiation, and then tactically makes any necessary adjustments as the weather evolves. The risk-hedged approach strategically plans re-routes by minimizing the risk-adjusted path length, incorporating multiple possible weather instantiations with associated likelihoods (risks). The resulting model is transparent and is readily analyzed for realism and treated with well-understood shortest-path algorithms. Risk-hedged re-routes are computed for some example weather instantiations. The main result is that in some scenarios, relative to an operational-practice proxy solution, the risk-hedged solution provides the benefits of lower risk as well as shorter path length. In other scenarios, the benefits of the risk-hedged solution are ambiguous, because the solution is characterized by a tradeoff between risk and path length. The risk-hedged solution can be executed in those scenarios where it provides a clear benefit over current operational practice.

  7. Trainer Interventions as Instructional Strategies in Air Traffic Control Training

    Science.gov (United States)

    Koskela, Inka; Palukka, Hannele

    2011-01-01

    Purpose: This paper aims to identify methods of guidance and supervision used in air traffic control training. It also aims to show how these methods facilitate trainee participation in core work activities. Design/methodology/approach: The paper applies the tools of conversation analysis and ethnomethodology to explore the ways in which trainers…

  8. Learning styles: The learning methods of air traffic control students

    Science.gov (United States)

    Jackson, Dontae L.

    In the world of aviation, air traffic controllers are an integral part in the overall level of safety that is provided. With a number of controllers reaching retirement age, the Air Traffic Collegiate Training Initiative (AT-CTI) was created to provide a stronger candidate pool. However, AT-CTI Instructors have found that a number of AT-CTI students are unable to memorize types of aircraft effectively. This study focused on the basic learning styles (auditory, visual, and kinesthetic) of students and created a teaching method to try to increase memorization in AT-CTI students. The participants were asked to take a questionnaire to determine their learning style. Upon knowing their learning styles, participants attended two classroom sessions. The participants were given a presentation in the first class, and divided into a control and experimental group for the second class. The control group was given the same presentation from the first classroom session while the experimental group had a group discussion and utilized Middle Tennessee State University's Air Traffic Control simulator to learn the aircraft types. Participants took a quiz and filled out a survey, which tested the new teaching method. An appropriate statistical analysis was applied to determine if there was a significant difference between the control and experimental groups. The results showed that even though the participants felt that the method increased their learning, there was no significant difference between the two groups.

  9. Occupational stress and stress prevention in air traffic control

    OpenAIRE

    Costa, Giovanni

    1996-01-01

    The paper indicates a number of preventive measures targeted to the elimination of the causes of stress, rather than the treatment of its effects, and how these measures can become an integral part of the necessary organizational development and eventually pay for themselves. The paper has seven chapters. 1. Introduction - What is stress? - The sources of stress in air traffic control - The consequences on health and well-being 2. How to prevent stress at work 3. Intervention on the external ...

  10. Using Historical Data to Automatically Identify Air-Traffic Control Behavior

    Science.gov (United States)

    Lauderdale, Todd A.; Wu, Yuefeng; Tretto, Celeste

    2014-01-01

    This project seeks to develop statistical-based machine learning models to characterize the types of errors present when using current systems to predict future aircraft states. These models will be data-driven - based on large quantities of historical data. Once these models are developed, they will be used to infer situations in the historical data where an air-traffic controller intervened on an aircraft's route, even when there is no direct recording of this action.

  11. The Use of the Dynamic Solution Space to Assess Air Traffic Controller Workload

    NARCIS (Netherlands)

    D'Engelbronner, J.G.; Mulder, M.; Van Paassen, M.M.; De Stigter, S.; Huisman, H.

    2010-01-01

    Air traffic capacity is mainly bound by air traffic controller workload. In order to effectively find solutions for this problem, off-line pre-experimental workload assessment methods are desirable. In order to better understand the workload associated with air traffic control, previous research int

  12. Analysis of Air Traffic Controller Workload Reduction Based on the Solution Space for the Merging Task

    NARCIS (Netherlands)

    Mercado Velasco, G.A.; Mulder, M.; Van Paassen, M.M.

    2010-01-01

    Air traffic controller workload is considered to be an important limiting factor to the growth of air traffic. The difficulty of an air traffic control task can be analyzed through examining the problem’s solution space, that is, all possible vector commands that satisfy the constraints of safety, p

  13. Cyclist route choice, traffic-related air pollution, and lung function: a scripted exposure study

    OpenAIRE

    Jarjour, Sarah; Jerrett, Michael; Westerdahl, Dane; de Nazelle, Audrey; Hanning, Cooper; Daly, Laura; Lipsitt, Jonah; Balmes,John

    2013-01-01

    Abstract Background A travel mode shift to active transportation such as bicycling would help reduce traffic volume and related air pollution emissions as well as promote increased physical activity level. Cyclists, however, are at risk for exposure to vehicle-related air pollutants due to their proximity to vehicle traffic and elevated respiratory rates. To promote safe bicycle commuting, the City of Berkeley, California, has designated a network of ...

  14. Measures related to traffic planning for air pollution control

    Energy Technology Data Exchange (ETDEWEB)

    Baumueller, J.; Reuter, U. [Office of Environmental Protection, Stuttgart (Germany). Dept. for Climatology

    1995-12-31

    The immense increase of motor traffic, in the future reinforced by the European market and the opening of boarders to the east countries, requires new efforts in traffic policy. In the city agglomerations the motor traffic is nearly collapsing. The increase of motor traffic is the reason for a considerable degradation of environment, especially by noise and air pollution. For the region of Stuttgart the problems and possibilities of counter-measures are discussed. (author)

  15. Advanced Air Traffic Management Research (Human Factors and Automation): NASA Research Initiatives in Human-Centered Automation Design in Airspace Management

    Science.gov (United States)

    Corker, Kevin M.; Condon, Gregory W. (Technical Monitor)

    1996-01-01

    NASA has initiated a significant thrust of research and development focused on providing the flight crew and air traffic managers automation aids to increase capacity in en route and terminal area operations through the use of flexible, more fuel-efficient routing, while improving the level of safety in commercial carrier operations. In that system development, definition of cognitive requirements for integrated multi-operator dynamic aiding systems is fundamental. The core processes of control and the distribution of decision making in that control are undergoing extensive analysis. From our perspective, the human operators and the procedures by which they interact are the fundamental determinants of the safe, efficient, and flexible operation of the system. In that perspective, we have begun to explore what our experience has taught will be the most challenging aspects of designing and integrating human-centered automation in the advanced system. We have performed a full mission simulation looking at the role shift to self-separation on board the aircraft with the rules of the air guiding behavior and the provision of a cockpit display of traffic information and an on-board traffic alert system that seamlessly integrates into the TCAS operations. We have performed and initial investigation of the operational impact of "Dynamic Density" metrics on controller relinquishing and reestablishing full separation authority. (We follow the assumption that responsibility at all times resides with the controller.) This presentation will describe those efforts as well as describe the process by which we will guide the development of error tolerant systems that are sensitive to shifts in operator work load levels and dynamic shifts in the operating point of air traffic management.

  16. An augmented reality binocular system (ARBS) for air traffic controllers

    Science.gov (United States)

    Fulbrook, Jim E.; Ruffner, John W.; Labbe, Roger

    2008-04-01

    The primary means by which air traffic tower controllers obtain information is through direct out-thewindow viewing, although a considerable amount of time is spent looking at electronic displays and other information sources inside the tower cab. The Air Force Research Laboratory sponsored the development of a prototype Augmented Reality Binocular System (ARBS) that enhances tower controller performance, situation awareness, and safety. The ARBS is composed of a virtual binocular (VB) that displays real-time imagery from high resolution telephoto cameras and sensors mounted on pan/tilt units (PTUs). The selected PTU tracks to the movement of the VB, which has an inertial heading and elevation sensor. Relevant airfield situation text and graphic depictions that identify airfield features are overlaid on the imagery. In addition, the display is capable of labeling and tracking vehicles on which an Automatic Dependent Surveillance - Broadcast (ADS-B) system has been installed. The ARBS provides air traffic controllers and airfield security forces with the capability to orient toward, observe, and conduct continuous airfield operations and surveillance/security missions from any number of viewing aspects in limited visibility conditions. In this paper, we describe the ARBS in detail, discuss the results of a Usability Test of the prototype ARBS, and discuss ideas for follow-on efforts to develop the ARBS to a fieldable level.

  17. Air traffic control by distributed management in a MLS environment

    Science.gov (United States)

    Kreifeldt, J. G.; Parkin, L.; Hart, S.

    1977-01-01

    The microwave landing system (MLS) is a technically feasible means for increasing runway capacity since it could support curved approaches to a short final. The shorter the final segment of the approach, the wider the variety of speed mixes possible so that theoretically, capacity would ultimately be limited by runway occupance time only. An experiment contrasted air traffic control in a MLS environment under a centralized form of management and under distributed management which was supported by a traffic situation display in each of the 3 piloted simulators. Objective flight data, verbal communication and subjective responses were recorded on 18 trial runs lasting about 20 minutes each. The results were in general agreement with previous distributed management research. In particular, distributed management permitted a smaller spread of intercrossing times and both pilots and controllers perceived distributed management as the more 'ideal' system in this task. It is concluded from this and previous research that distributed management offers a viable alternative to centralized management with definite potential for dealing with dense traffic in a safe, orderly and expeditious manner.

  18. A Survey of Modern Air Traffic Control. Volume 2

    Science.gov (United States)

    1975-07-01

    oceanic traffic would use combined hyperbolic-inertial navigation systems. System I could be implemented to meet the demanda for air traffic services...of Aviation c/o Flugrad Reykjavik ITALY Aeronautica Militare Ufficio del Delegato Nationale all’AGARD 3, Piazzale Adenauer Roma /EUR

  19. Analysis of routine communication in the air traffic control system

    Science.gov (United States)

    Clark, Herbert H.; Morrow, Daniel; Rodvoid, Michelle

    1990-01-01

    The present project has three related goals. The first is to describe the organization of routine controller-pilot communication. This includes identifying the basic units of communication and how they are organized into discourse, how controllers and pilots use language to achieve their goals, and what topics they discuss. The second goal is to identify the type and frequency of problems that interrupt routine information transfer and prompt pilots and controllers to focus on the communication itself. The authors analyze the costs of these problems in terms of communication efficiency, and the techniques used to resolve these problems. Third, the authors hope to identify factors associated with communication problems, such as deviations from conventional air traffic control procedures.

  20. Air Traffic Controller Acceptability of Unmanned Aircraft System Detect-and-Avoid Thresholds

    Science.gov (United States)

    Mueller, Eric R.; Isaacson, Douglas R.; Stevens, Derek

    2016-01-01

    A human-in-the-loop experiment was conducted with 15 retired air traffic controllers to investigate two research questions: (a) what procedures are appropriate for the use of unmanned aircraft system (UAS) detect-and-avoid systems, and (b) how long in advance of a predicted close encounter should pilots request or execute a separation maneuver. The controller participants managed a busy Oakland air route traffic control sector with mixed commercial/general aviation and manned/UAS traffic, providing separation services, miles-in-trail restrictions and issuing traffic advisories. Controllers filled out post-scenario and post-simulation questionnaires, and metrics were collected on the acceptability of procedural options and temporal thresholds. The states of aircraft were also recorded when controllers issued traffic advisories. Subjective feedback indicated a strong preference for pilots to request maneuvers to remain well clear from intruder aircraft rather than deviate from their IFR clearance. Controllers also reported that maneuvering at 120 seconds until closest point of approach (CPA) was too early; maneuvers executed with less than 90 seconds until CPA were more acceptable. The magnitudes of the requested maneuvers were frequently judged to be too large, indicating a possible discrepancy between the quantitative UAS well clear standard and the one employed subjectively by manned pilots. The ranges between pairs of aircraft and the times to CPA at which traffic advisories were issued were used to construct empirical probability distributions of those metrics. Given these distributions, we propose that UAS pilots wait until an intruder aircraft is approximately 80 seconds to CPA or 6 nmi away before requesting a maneuver, and maneuver immediately if the intruder is within 60 seconds and 4 nmi. These thresholds should make the use of UAS detect and avoid systems compatible with current airspace procedures and controller expectations.

  1. Effects of Stereoscopic 3D Digital Radar Displays on Air Traffic Controller Performance

    Science.gov (United States)

    2013-03-01

    Effects of Stereoscopic 3D Digital Radar Displays on Air Traffic Controller Performance THESIS...and is not subject to copyright protection in the United States. AFIT-ENV-13-M-24 Effects of Stereoscopic 3D Digital Radar Displays on Air... Stereoscopic 3D Digital Radar Displays on Air Traffic Controller Performance Jason G. Russi Technical Sergeant, USAF Approved

  2. A Multiple Agent Model of Human Performance in Automated Air Traffic Control and Flight Management Operations

    Science.gov (United States)

    Corker, Kevin; Pisanich, Gregory; Condon, Gregory W. (Technical Monitor)

    1995-01-01

    A predictive model of human operator performance (flight crew and air traffic control (ATC)) has been developed and applied in order to evaluate the impact of automation developments in flight management and air traffic control. The model is used to predict the performance of a two person flight crew and the ATC operators generating and responding to clearances aided by the Center TRACON Automation System (CTAS). The purpose of the modeling is to support evaluation and design of automated aids for flight management and airspace management and to predict required changes in procedure both air and ground in response to advancing automation in both domains. Additional information is contained in the original extended abstract.

  3. Trajectory Specification for Automation of Terminal Air Traffic Control

    Science.gov (United States)

    Paielli, Russell A.

    2016-01-01

    "Trajectory specification" is the explicit bounding and control of aircraft tra- jectories such that the position at each point in time is constrained to a precisely defined volume of space. The bounding space is defined by cross-track, along-track, and vertical tolerances relative to a reference trajectory that specifies position as a function of time. The tolerances are dynamic and will be based on the aircraft nav- igation capabilities and the current traffic situation. A standard language will be developed to represent these specifications and to communicate them by datalink. Assuming conformance, trajectory specification can guarantee safe separation for an arbitrary period of time even in the event of an air traffic control (ATC) sys- tem or datalink failure, hence it can help to achieve the high level of safety and reliability needed for ATC automation. As a more proactive form of ATC, it can also maximize airspace capacity and reduce the reliance on tactical backup systems during normal operation. It applies to both enroute airspace and the terminal area around airports, but this paper focuses on arrival spacing in the terminal area and presents ATC algorithms and software for achieving a specified delay of runway arrival time.

  4. Flight management concepts compatible with air traffic control

    Science.gov (United States)

    Morello, S. A.

    1986-01-01

    With the advent of airline deregulation and increased competition, the need for cost efficient airline operations is critical. This paper summarizes past research efforts and planned research thrusts toward the development of compatible flight management and air traffic control systems that promise increased operational effectiveness and efficiency. Potential capacity improvements resulting from a time-based ATC simulation (fast-time) are presented. Advanced display concepts with time guidance and velocity vector information to allow the flight crew to play an important role in the future ATC environment are discussed. Results of parametric sensitivity analyses are also presented that quantify the fuel/cost penalties for idle-thrust mismodeling and wind-modeling errors.

  5. Automation and Systems Issues in Air Traffic Control

    Directory of Open Access Journals (Sweden)

    Gabriela STROE

    2016-12-01

    Full Text Available This paper is dedicated to the study and analysis of a successfully designed control system in ATM. The aircraft's motion is affected by other factors, besides the pilot controls in the form of external disturbances, such as wind, and internal errors, due to unmodelled dynamics, tracking error and system noise. Navigation equipment tracks the exact real-time location of the aircraft in 4D space and provides feedback to both the pilot in the cockpit and ATC via ADS-B. ATM was expressed as a large, decentralized, dynamic, variable size, infinite horizon, multi-parameter, constrained, nonlinear, non-causal, non-convex, multi-objective, high-dimensionality, hybrid (continuous and combinatorial, optimal control problem. Rapidly increasing growth and demand in CNS/ATM, the advanced scheme for ATM, ADS-B system which is based on digital communication is being implemented in the field of surveillance. ADS-B is a radically new technology that is redefining the paradigm of CNS in ATM today. Automatic Dependent Surveillance-Broadcast (ADS-B is the next generation air surveillance system which supplants and complements the limitations of conventional radar, since conventional ATM radar systems will reach their limits soon due to the increases in air traffic.

  6. Control of Future Air Traffic Systems via Complexity Bound Management

    Science.gov (United States)

    Alexandrov, Natalia

    2013-01-01

    The complexity of the present system for managing air traffic has led to "discreteness" in approaches to creating new concepts: new concepts are created as point designs, based on experience, expertise, and creativity of the proposer. Discrete point designs may be highly successful but they are difficult to substantiate in the face of equally strong substantiation of competing concepts, as well as the state of the art in concept evaluation via simulations. Hybrid concepts may present a compromise - the golden middle. Yet a hybrid of sometimes in principle incompatible concepts forms another point design that faces the challenge of substantiation and validation. We are faced with the need to re-design the air transportation system ab initio. This is a daunting task, especially considering the problem of transitioning from the present system to any fundamentally new system. However, design from scratch is also an opportunity to reconsider approaches to new concept development. In this position paper we propose an approach, Optimized Parametric Functional Design, for systematic development of concepts for management and control of airspace systems, based on optimization formulations in terms of required system functions and states. This reasoning framework, realizable in the context of ab initio system design, offers an approach to deriving substantiated airspace management and control concepts. With growing computational power, we hope that the approach will also yield a methodology for actual dynamic control of airspace

  7. Analysis of learning curves in the on-the-job training of air traffic controllers

    NARCIS (Netherlands)

    Oprins, E.A.P.B.; Bruggraaff, E.; Roe, R.

    2011-01-01

    This chapter describes a competence-based assessment system, called CBAS, for air traffic control (ATC) simulator and on-the-job training (OJT), developed at Air Traffic Control The Netherlands (LVNL). In contrast with simulator training, learning processes in OJT are difficult to assess, because th

  8. Solution Space-based Approach to Assess Sector Complexity in Air Traffic Control

    NARCIS (Netherlands)

    Abdul Rahman, S.M.B.

    2014-01-01

    Various methods have been introduced in the past in efforts to optimize airspace sector design and the allocation of air traffic controllers. This is done with the aim to accommodate growth, increase productivity and most importantly to ensure safety of air traffic. To accomplish this, a more compre

  9. Impact of Operating Context on the Use of Structure in Air Traffic Controller Cognitive Processes

    Science.gov (United States)

    Davison, Hayley J.; Histon, Jonathan M.; Ragnarsdottir, Margret Dora; Major, Laura M.; Hansman, R. John

    2004-01-01

    This paper investigates the influence of structure on air traffic controllers cognitive processes in the TRACON, En Route, and Oceanic environments. Radar data and voice command analyses were conducted to support hypotheses generated through observations and interviews conducted at the various facilities. Three general types of structure-based abstractions (standard flows, groupings, and critical points) have been identified as being used in each context, though the details of their application varied in accordance with the constraints of the particular operational environment. Projection emerged as a key cognitive process aided by the structure-based abstractions, and there appears to be a significant difference between how time-based versus spatial-based projection is performed by controllers. It is recommended that consideration be given to the value provided by the structure-based abstractions to the controller as well as to maintain consistency between the type (time or spatial) of information support provided to the controller.

  10. Airborne Four-Dimensional Flight Management in a Time-based Air Traffic Control Environment

    Science.gov (United States)

    Williams, David H.; Green, Steven M.

    1991-01-01

    Advanced Air Traffic Control (ATC) systems are being developed which contain time-based (4D) trajectory predictions of aircraft. Airborne flight management systems (FMS) exist or are being developed with similar 4D trajectory generation capabilities. Differences between the ATC generated profiles and those generated by the airborne 4D FMS may introduce system problems. A simulation experiment was conducted to explore integration of a 4D equipped aircraft into a 4D ATC system. The NASA Langley Transport Systems Research Vehicle cockpit simulator was linked in real time to the NASA Ames Descent Advisor ATC simulation for this effort. Candidate procedures for handling 4D equipped aircraft were devised and traffic scenarios established which required time delays absorbed through speed control alone or in combination with path stretching. Dissimilarities in 4D speed strategies between airborne and ATC generated trajectories were tested in these scenarios. The 4D procedures and FMS operation were well received by airline pilot test subjects, who achieved an arrival accuracy at the metering fix of 2.9 seconds standard deviation time error. The amount and nature of the information transmitted during a time clearance were found to be somewhat of a problem using the voice radio communication channel. Dissimilarities between airborne and ATC-generated speed strategies were found to be a problem when the traffic remained on established routes. It was more efficient for 4D equipped aircraft to fly trajectories with similar, though less fuel efficient, speeds which conform to the ATC strategy. Heavy traffic conditions, where time delays forced off-route path stretching, were found to produce a potential operational benefit of the airborne 4D FMS.

  11. Dimensions of Air Traffic Control Tower Information Needs: From Information Requests to Display Design

    Science.gov (United States)

    Durso, Francis T.; Johnson, Brian R.; Crutchfield, Jerry M.

    2010-01-01

    In an effort to determine the information needs of tower air traffic controllers, instructors from the Federal Aviation Administration's Academy in Oklahoma City were asked to control traffic in a high-fidelity tower cab simulator. Information requests were made apparent by eliminating access to standard tower information sources. Instead,…

  12. THE REMOTE AND MOBILE AIR TRAFFIC CONTROL TOWER AND ITS POSSIBLE APPLICATION TO THE OPERATIONAL AREA

    Directory of Open Access Journals (Sweden)

    Tímea VAS

    2014-10-01

    Full Text Available The concept of remote and mobile Air Traffic Control Tower (ATC TWR and its development has started in Europe, Australia and also in the USA, in order to improve the efficiency of Air Traffic Management (ATM systems in terms of air transportation safety. These new technologies are applicable in many countries in peace time, but on mobility reasons these are promoted to achieve commitments in the operational area. This article describes the devices and range of equipment of mobile and remote tower, and their specifications, which can even serve a medium sized airport, furthermore examines, whether how can those provide the air traffic services at an operational airfield.

  13. Improving air traffic control: Proving new tools or approving the joint human-machine system?

    Science.gov (United States)

    Gaillard, Irene; Leroux, Marcel

    1994-01-01

    From the description of a field problem (i.e., designing decision aids for air traffic controllers), this paper points out how a cognitive engineering approach provides the milestones for the evaluation of future joint human-machine systems.

  14. Visual Problem Solving and Self‐regulation in Training Air Traffic Control

    NARCIS (Netherlands)

    Meeuwen van, Ludo

    2015-01-01

    Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.

  15. Visual problem solving and self-regulation in training air traffic control

    NARCIS (Netherlands)

    Van Meeuwen, Ludo

    2013-01-01

    Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.

  16. Personalised adaptive task selection in air traffic control: Effects on training efficiency and transfer.

    NARCIS (Netherlands)

    Salden, Ron; Paas, Fred; Van Merriënboer, Jeroen

    2008-01-01

    Salden, R.J.C.M., Paas, F., & Van Merriënboer, J.J.G. (2006). Personalised adaptive task selection in air traffic control: Effects on training efficiency and transfer. Learning and Instruction, 16, 350-362

  17. Multilevel Control & Optimization of Future Air Traffic Systems via Managem Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Controlling air traffic on all temporal and spatial scales – from a single aircraft to the entire airspace – can be formally stated as a dynamic,...

  18. Air traffic management evaluation tool

    Science.gov (United States)

    Sridhar, Banavar (Inventor); Sheth, Kapil S. (Inventor); Chatterji, Gano Broto (Inventor); Bilimoria, Karl D. (Inventor); Grabbe, Shon (Inventor); Schipper, John F. (Inventor)

    2012-01-01

    Methods for evaluating and implementing air traffic management tools and approaches for managing and avoiding an air traffic incident before the incident occurs. A first system receives parameters for flight plan configurations (e.g., initial fuel carried, flight route, flight route segments followed, flight altitude for a given flight route segment, aircraft velocity for each flight route segment, flight route ascent rate, flight route descent route, flight departure site, flight departure time, flight arrival time, flight destination site and/or alternate flight destination site), flight plan schedule, expected weather along each flight route segment, aircraft specifics, airspace (altitude) bounds for each flight route segment, navigational aids available. The invention provides flight plan routing and direct routing or wind optimal routing, using great circle navigation and spherical Earth geometry. The invention provides for aircraft dynamics effects, such as wind effects at each altitude, altitude changes, airspeed changes and aircraft turns to provide predictions of aircraft trajectory (and, optionally, aircraft fuel use). A second system provides several aviation applications using the first system. Several classes of potential incidents are analyzed and averted, by appropriate change en route of one or more parameters in the flight plan configuration, as provided by a conflict detection and resolution module and/or traffic flow management modules. These applications include conflict detection and resolution, miles-in trail or minutes-in-trail aircraft separation, flight arrival management, flight re-routing, weather prediction and analysis and interpolation of weather variables based upon sparse measurements. The invention combines these features to provide an aircraft monitoring system and an aircraft user system that interact and negotiate changes with each other.

  19. 78 FR 38236 - Proposed Establishment, Modification and Cancellation of Air Traffic Service (ATS) Routes...

    Science.gov (United States)

    2013-06-26

    ... the affected routes. This action would enhance the safety and efficient management of aircraft within... Airspace Docket No. 13-AEA-3) and be submitted in triplicate to the Docket Management Facility (see...: is a newly established route to become effective August 22, 2013 (78 FR 29615, May 21,...

  20. The employment of a spoken language computer applied to an air traffic control task.

    Science.gov (United States)

    Laveson, J. I.; Silver, C. A.

    1972-01-01

    Assessment of the merits of a limited spoken language (56 words) computer in a simulated air traffic control (ATC) task. An airport zone approximately 60 miles in diameter with a traffic flow simulation ranging from single-engine to commercial jet aircraft provided the workload for the controllers. This research determined that, under the circumstances of the experiments carried out, the use of a spoken-language computer would not improve the controller performance.

  1. Characterization of Visual Scanning Patterns in Air Traffic Control

    Directory of Open Access Journals (Sweden)

    Sarah N. McClung

    2016-01-01

    Full Text Available Characterization of air traffic controllers’ (ATCs’ visual scanning strategies is a challenging issue due to the dynamic movement of multiple aircraft and increasing complexity of scanpaths (order of eye fixations and saccades over time. Additionally, terminologies and methods are lacking to accurately characterize the eye tracking data into simplified visual scanning strategies linguistically expressed by ATCs. As an intermediate step to automate the characterization classification process, we (1 defined and developed new concepts to systematically filter complex visual scanpaths into simpler and more manageable forms and (2 developed procedures to map visual scanpaths with linguistic inputs to reduce the human judgement bias during interrater agreement. The developed concepts and procedures were applied to investigating the visual scanpaths of expert ATCs using scenarios with different aircraft congestion levels. Furthermore, oculomotor trends were analyzed to identify the influence of aircraft congestion on scan time and number of comparisons among aircraft. The findings show that (1 the scanpaths filtered at the highest intensity led to more consistent mapping with the ATCs’ linguistic inputs, (2 the pattern classification occurrences differed between scenarios, and (3 increasing aircraft congestion caused increased scan times and aircraft pairwise comparisons. The results provide a foundation for better characterizing complex scanpaths in a dynamic task and automating the analysis process.

  2. 78 FR 53239 - Establishment, Modification and Cancellation of Air Traffic Service (ATS) Routes; Northeast...

    Science.gov (United States)

    2013-08-29

    ... navigation guidance for portions of the affected routes. This action enhances the safe and efficient management of aircraft within the National Airspace System. DATES: Effective date 0901 UTC, October 17, 2013... northeast United States (78 FR 38236, June 26, 2013). Interested parties were invited to participate in...

  3. Pilot English Language Proficiency and the Prevalence of Communication Problems at Five U.S. Air Route Traffic Control Centers

    Science.gov (United States)

    2008-10-01

    inadequate language proficiency was involved in some aviation accidents, the International Civil Aviation Organization ( ICAO ) is requiring its contracting...paired with its readback. Each readback was scored for accuracy. The ICAO Language Proficiency Rating Scale guided encoding English language

  4. Controlling Air Traffic (Simulated) in the Presence of Automation (CATS PAu) 1995: A Study of Measurement Techniques for Situation Awareness in Air Traffic Control

    Science.gov (United States)

    French, Jennifer R.

    1995-01-01

    As automated systems proliferate in aviation systems, human operators are taking on less and less of an active role in the jobs they once performed, often reducing what should be important jobs to tasks barely more complex than monitoring machines. When operators are forced into these roles, they risk slipping into hazardous states of awareness, which can lead to reduced skills, lack of vigilance, and the inability to react quickly and competently when there is a machine failure. Using Air Traffic Control (ATC) as a model, the present study developed tools for conducting tests focusing on levels of automation as they relate to situation awareness. Subjects participated in a two-and-a-half hour experiment that consisted of a training period followed by a simulation of air traffic control similar to the system presently used by the FAA, then an additional simulation employing automated assistance. Through an iterative design process utilizing numerous revisions and three experimental sessions, several measures for situational awareness in a simulated Air Traffic Control System were developed and are prepared for use in future experiments.

  5. Risk Assessment on the Transition Program for Air Traffic Control Automation System Upgrade

    Directory of Open Access Journals (Sweden)

    Li Dong Bin

    2016-01-01

    Full Text Available We analyzed the safety risks of the transition program for Air Traffic Control (ATC automation system upgrade by using the event tree analysis method in this paper. We decomposed the occurrence progress of the three transition phase and built the event trees corresponding to the three stages, and then we determined the probability of success of each factor and calculated probability of success of the air traffic control automation system upgrade transition. In the conclusion, we illustrate the transition program safety risk according to the results.

  6. In-Trail Procedure Air Traffic Control Procedures Validation Simulation Study

    Science.gov (United States)

    Chartrand, Ryan C.; Hewitt, Katrin P.; Sweeney, Peter B.; Graff, Thomas J.; Jones, Kenneth M.

    2012-01-01

    In August 2007, Airservices Australia (Airservices) and the United States National Aeronautics and Space Administration (NASA) conducted a validation experiment of the air traffic control (ATC) procedures associated with the Automatic Dependant Surveillance-Broadcast (ADS-B) In-Trail Procedure (ITP). ITP is an Airborne Traffic Situation Awareness (ATSA) application designed for near-term use in procedural airspace in which ADS-B data are used to facilitate climb and descent maneuvers. NASA and Airservices conducted the experiment in Airservices simulator in Melbourne, Australia. Twelve current operational air traffic controllers participated in the experiment, which identified aspects of the ITP that could be improved (mainly in the communication and controller approval process). Results showed that controllers viewed the ITP as valid and acceptable. This paper describes the experiment design and results.

  7. Adaptive Traffic Route Control in QoS Provisioning for Cognitive Radio Technology with Heterogeneous Wireless Systems

    Science.gov (United States)

    Yamamoto, Toshiaki; Ueda, Tetsuro; Obana, Sadao

    As one of the dynamic spectrum access technologies, “cognitive radio technology,” which aims to improve the spectrum efficiency, has been studied. In cognitive radio networks, each node recognizes radio conditions, and according to them, optimizes its wireless communication routes. Cognitive radio systems integrate the heterogeneous wireless systems not only by switching over them but also aggregating and utilizing them simultaneously. The adaptive control of switchover use and concurrent use of various wireless systems will offer a stable and flexible wireless communication. In this paper, we propose the adaptive traffic route control scheme that provides high quality of service (QoS) for cognitive radio technology, and examine the performance of the proposed scheme through the field trials and computer simulations. The results of field trials show that the adaptive route control according to the radio conditions improves the user IP throughput by more than 20% and reduce the one-way delay to less than 1/6 with the concurrent use of IEEE802.16 and IEEE802.11 wireless media. Moreover, the simulation results assuming hundreds of mobile terminals reveal that the number of users receiving the required QoS of voice over IP (VoIP) service and the total network throughput of FTP users increase by more than twice at the same time with the proposed algorithm. The proposed adaptive traffic route control scheme can enhance the performances of the cognitive radio technologies by providing the appropriate communication routes for various applications to satisfy their required QoS.

  8. A generic approach to generating optimal controlled prespective route guidance in realistic traffic networks

    NARCIS (Netherlands)

    Chen, Y.; Zuurbier, F.S.; Zuylen, H.J. van; Hoogendoorn, S.P.

    2006-01-01

    This paper presents a generic methodology to generate optimal controlled dynamic prescriptive route guidance to be disseminated by means of variable message signs (VMS). The methodology is generic in the sense it can be used on any network topology and network model, with any number of VMS’s, for di

  9. A safety assessment methodology applied to CNS/ATM-based air traffic control system

    Energy Technology Data Exchange (ETDEWEB)

    Vismari, Lucio Flavio, E-mail: lucio.vismari@usp.b [Safety Analysis Group (GAS), School of Engineering at University of Sao Paulo (Poli-USP), Av. Prof. Luciano Gualberto, Trav.3, n.158, Predio da Engenharia de Eletricidade, Sala C2-32, CEP 05508-900, Sao Paulo (Brazil); Batista Camargo Junior, Joao, E-mail: joaocamargo@usp.b [Safety Analysis Group (GAS), School of Engineering at University of Sao Paulo (Poli-USP), Av. Prof. Luciano Gualberto, Trav.3, n.158, Predio da Engenharia de Eletricidade, Sala C2-32, CEP 05508-900, Sao Paulo (Brazil)

    2011-07-15

    In the last decades, the air traffic system has been changing to adapt itself to new social demands, mainly the safe growth of worldwide traffic capacity. Those changes are ruled by the Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM) paradigm , based on digital communication technologies (mainly satellites) as a way of improving communication, surveillance, navigation and air traffic management services. However, CNS/ATM poses new challenges and needs, mainly related to the safety assessment process. In face of these new challenges, and considering the main characteristics of the CNS/ATM, a methodology is proposed at this work by combining 'absolute' and 'relative' safety assessment methods adopted by the International Civil Aviation Organization (ICAO) in ICAO Doc.9689 , using Fluid Stochastic Petri Nets (FSPN) as the modeling formalism, and compares the safety metrics estimated from the simulation of both the proposed (in analysis) and the legacy system models. To demonstrate its usefulness, the proposed methodology was applied to the 'Automatic Dependent Surveillance-Broadcasting' (ADS-B) based air traffic control system. As conclusions, the proposed methodology assured to assess CNS/ATM system safety properties, in which FSPN formalism provides important modeling capabilities, and discrete event simulation allowing the estimation of the desired safety metric.

  10. Expertise differences in air traffic control: An eye-tracking study

    NARCIS (Netherlands)

    Van Meeuwen, Ludo; Jarodzka, Halszka; Brand-Gruwel, Saskia; Kirschner, Paul A.; De Bock, Jeano; Van Merriënboer, Jeroen

    2012-01-01

    Van Meeuwen, L. W., Jarodzka, H., Brand-Gruwel, S., Kirschner, P. A., De Bock, J. J. P. R., & Van Merriënboer, J. J. G. (2012, April). Expertise differences in air traffic control: An eye-tracking study. Paper presented at the American Educational Research Association Annual Meeting 2012, Vancouver,

  11. Building the Brain's "Air Traffic Control" System: How Early Experiences Shape the Development of Executive Function. Working Paper 11

    Science.gov (United States)

    National Scientific Council on the Developing Child, 2011

    2011-01-01

    Being able to focus, hold, and work with information in mind, filter distractions, and switch gears is like having an air traffic control system at a busy airport to manage the arrivals and departures of dozens of planes on multiple runways. In the brain, this air traffic control mechanism is called executive functioning, a group of skills that…

  12. Effects of Automation Types on Air Traffic Controller Situation Awareness and Performance

    Science.gov (United States)

    Sethumadhavan, A.

    2009-01-01

    The Joint Planning and Development Office has proposed the introduction of automated systems to help air traffic controllers handle the increasing volume of air traffic in the next two decades (JPDO, 2007). Because fully automated systems leave operators out of the decision-making loop (e.g., Billings, 1991), it is important to determine the right level and type of automation that will keep air traffic controllers in the loop. This study examined the differences in the situation awareness (SA) and collision detection performance of individuals when they worked with information acquisition, information analysis, decision and action selection and action implementation automation to control air traffic (Parasuraman, Sheridan, & Wickens, 2000). When the automation was unreliable, the time taken to detect an upcoming collision was significantly longer for all the automation types compared with the information acquisition automation. This poor performance following automation failure was mediated by SA, with lower SA yielding poor performance. Thus, the costs associated with automation failure are greater when automation is applied to higher order stages of information processing. Results have practical implications for automation design and development of SA training programs.

  13. Air Traffic Controllers' Control Strategies in the Terminal Area Under Off-Nominal Conditions

    Science.gov (United States)

    Martin, Lynne; Mercer, Joey; Callantine, Todd; Kupfer, Michael; Cabrall, Christopher

    2012-01-01

    A human-in-the-loop simulation investigated the robustness of a schedule-based terminal-area air traffic management concept, and its supporting controller tools, to off-nominal events - events that led to situations in which runway arrival schedules required adjustments and controllers could no longer use speed control alone to impose the necessary delays. The main research question was exploratory: to assess whether controllers could safely resolve and control the traffic during off-nominal events. A focus was the role of the supervisor - how he managed the schedules, how he assisted the controllers, what strategies he used, and which combinations of tools he used. Observations and questionnaire responses revealed supervisor strategies for resolving events followed a similar pattern: a standard approach specific to each type of event often resolved to a smooth conclusion. However, due to the range of factors influencing the event (e.g., environmental conditions, aircraft density on the schedule, etc.), sometimes the plan required revision and actions had a wide-ranging effect.

  14. Effective local dynamic routing strategy for air route networks

    Institute of Scientific and Technical Information of China (English)

    Wu Wenjun; Zhao Lingxi

    2015-01-01

    With the rapid development of air transportation, network service ability has attracted a lot of attention in academe. Aiming to improve the throughput of the air route network (ARN), we propose an effective local dynamic routing strategy in this paper. Several factors, such as the rout-ing distance, the geographical distance and the real-time local traffic, are taken into consideration. When the ARN is in the normal free-flow state, the proposed strategy can recover the shortest path routing (SPR) strategy. When the ARN undergoes congestion, the proposed strategy changes the paths of flights based on the real-time local traffic information. The throughput of the Chinese air route network (CARN) is evaluated. Results confirm that the proposed strategy can significantly improve the throughput of CARN. Meanwhile, the increase in the average flying distance and time is tiny. Results also indicate the importance of the distance related factors in a routing strategy designed for the ARN.

  15. A Human-Relatable Course of Action Planner for Air Traffic Coordinators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Traffic Managers, Supervisors and Air Traffic Control System Command Center (ATCSCC) Specialists have a critical and significant responsibility in the ATM system to...

  16. Congestion transition in air traffic networks.

    Science.gov (United States)

    Monechi, Bernardo; Servedio, Vito D P; Loreto, Vittorio

    2015-01-01

    Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios.

  17. 4D Trajectory Estimation for Air Traffic Control Automation System Based on Hybrid System Theory

    Directory of Open Access Journals (Sweden)

    Xin-Min Tang

    2012-03-01

    Full Text Available To resolve the problem of future airspace management under great traffic flow and high density condition, 4D trajectory estimation has become one of the core technologies of the next new generation air traffic control automation system. According to the flight profile and the dynamics models of different aircraft types under different flight conditions, a hybrid system model that switches the aircraft from one flight stage to another with aircraft state changing continuously in one state is constructed. Additionally, air temperature and wind speed are used to modify aircraft true airspeed as well as ground speed, and the hybrid system evolution simulation is used to estimate aircraft 4D trajectory. The case study proves that 4D trajectory estimated through hybrid system model can image the flight dynamic states of aircraft and satisfy the needs of the planned flight altitude profile.KEY WORDSair traffic management, 4D trajectory estimation, hybrid system model, aircraft dynamic model

  18. Final Environmental Assessment, Construction and Operation of Air Traffic Control Tower

    Science.gov (United States)

    2008-05-12

    Existing Control Tower Site. Complete demolition of the Control Tower building on the site would produce waste concrete, asphalt , metal, and wood...Construction & Operation of Air Traffic Control Tower 44 May 12, 2008 receptor elements. Workers would wear ear protection, as necessary, for...appear to be achieving their hazardous waste reduction goals. The major areas not meeting goals appear to be abrasive blasting and industrial

  19. Air quality on bus routes in Umea, Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Sandberg, H.; Forsberg, B. [Dept. of Environmental Health and Dept. of Public Health and Clinical Medicine, Umea University SE, Umea (Sweden)

    2000-07-01

    Bus traffic in some local streets with up to 650 buses per day has resulted in complaints about air pollution and suggestions from residents that the bus routes should be changed to other streets. We have studied nitrogen dioxide and benzene concentrations at five exposed sites and at two representative control sites without bus traffic, and found no general differences in air quality. However, the site and temperature adjusted concentrations fell significantly during a strike among bus drivers. (authors)

  20. Traffic Control Plan : DeSoto National Wildlife Refuge, DeSoto Visitor Center

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Traffic Control Plan for DeSoto NWR outlines objectives for solving the traffic problems on the Refuge by implementing a patrol schedule, restricting visitor...

  1. ROLE OF PEDAGOGY COMPETENCE OF A CONTROLLER-TRAINER IN SIMU-TRAINING OF AIR TRAFFIC CONTROLLERS

    Directory of Open Access Journals (Sweden)

    О. Петращук

    2012-04-01

    Full Text Available The article focuses on the issue of pedagogy competence of an ATCO-trainer as a constituent of hisoverall professional competency/capacity to provide quality SIMU- training of the air traffic controllers. Thecurrent University curriculum for abinitio controllers does not provide developing of the pedagogicalcompetence. But it is requested very much when an air traffic controller is employed as a controller-trainerfor SIMU-training. It is suggested to include pedagogical science as a course in the University programme

  2. Outsourcing Turns IT Leaders into the New Air Traffic Controllers

    Science.gov (United States)

    Raths, David

    2010-01-01

    Many chief information officers (CIOs) have come to accept and even embrace the role of outsourcers in their portfolio of IT services. In 2009, 47 percent of the 352 CIOs surveyed by the Center for Higher Education Chief Information Officer Studies (CHECS) said they had selectively outsourced some part of the IT function, up from 43 percent the…

  3. Landing-Time-Controlled Management Of Air Traffic

    Science.gov (United States)

    Erzberger, Heinz; Tobias, Leonard

    1988-01-01

    Conceptual system controls aircraft with old and new guidance equipment. Report begins with overview of concept, then reviews controller-interactive simulations. Describes fuel-conservative-trajectory algorithm, based on equations of motion for controlling landing time. Finally, presents results of piloted simulations.

  4. A Teamwork-Oriented Air Traffic Control Simulator

    Science.gov (United States)

    2006-06-01

    capability to train the controller and/or controller team. Neophyte controllers can be given the chance to develop without any attendant fear of the...the increasing use of the shared airspace, especially in Europe where the density of industrialized countries is high and the shared airspace is

  5. 空中交通管制员工作负荷研究%On Workload Issue of Air Traffic Controller

    Institute of Scientific and Technical Information of China (English)

    杨新湦

    2005-01-01

    This paper is focusing on workload leading to stress and fatigue,which,so far,have resulted in real or potential accidents,incidents or errors,not been explored but with impact on the controller everyday,studying workload curve on the real situations based on operational units,e.g. Zhengzhou area control center,and doing certain calculations on the number of air traffic controller needed in accordance with the air traffic to be handled. Lastly,some strategies are put forward.

  6. Human factors issues in the use of artificial intelligence in air traffic control. October 1990 Workshop

    Science.gov (United States)

    Hockaday, Stephen; Kuhlenschmidt, Sharon (Editor)

    1991-01-01

    The objective of the workshop was to explore the role of human factors in facilitating the introduction of artificial intelligence (AI) to advanced air traffic control (ATC) automation concepts. AI is an umbrella term which is continually expanding to cover a variety of techniques where machines are performing actions taken based upon dynamic, external stimuli. AI methods can be implemented using more traditional programming languages such as LISP or PROLOG, or they can be implemented using state-of-the-art techniques such as object-oriented programming, neural nets (hardware or software), and knowledge based expert systems. As this technology advances and as increasingly powerful computing platforms become available, the use of AI to enhance ATC systems can be realized. Substantial efforts along these lines are already being undertaken at the FAA Technical Center, NASA Ames Research Center, academic institutions, industry, and elsewhere. Although it is clear that the technology is ripe for bringing computer automation to ATC systems, the proper scope and role of automation are not at all apparent. The major concern is how to combine human controllers with computer technology. A wide spectrum of options exists, ranging from using automation only to provide extra tools to augment decision making by human controllers to turning over moment-by-moment control to automated systems and using humans as supervisors and system managers. Across this spectrum, it is now obvious that the difficulties that occur when tying human and automated systems together must be resolved so that automation can be introduced safely and effectively. The focus of the workshop was to further explore the role of injecting AI into ATC systems and to identify the human factors that need to be considered for successful application of the technology to present and future ATC systems.

  7. Managing emergencies and abnormal situations in air traffic control (part II): teamwork strategies.

    Science.gov (United States)

    Malakis, Stathis; Kontogiannis, Tom; Kirwan, Barry

    2010-07-01

    Team performance has been studied in many safety-critical organizations including aviation, nuclear power plant, offshore oil platforms and health organizations. This study looks into teamwork strategies that air traffic controllers employ to manage emergencies and abnormal situations. Two field studies were carried out in the form of observations of simulator training in emergency and unusual scenarios of novices and experienced controllers. Teamwork strategies covered aspects of team orientation and coordination, information exchange, change management and error handling. Several performance metrics were used to rate the efficiency of teamwork and test the construct validity of a prototype model of teamwork. This is a companion study to an earlier investigation of taskwork strategies in the same field (part I) and contributes to the development of a generic model for Taskwork and Teamwork strategies in Emergencies in Air traffic Management (T(2)EAM). Suggestions are made on how to use T(2)EAM to develop training programs, assess team performance and improve mishap investigations.

  8. A Longitudinal Study of Myers-Briggs Personality Types in Air Traffic Controllers

    Science.gov (United States)

    2004-12-01

    designed to look at the role of personality types as defined by the Myers-Briggs Type Indicator ( MBTI ). The instrument assesses personality on four...investigated the relationship between MBTI types and initial success in the Air Traffic Control Academy Screen Program, subsequent field training...outcomes, and transition to a supervisory or managerial position about 20 years later. METHOD. The 300-item MBTI was administered to 5,588 males (87

  9. A new intelligent approach for air traffic control using gravitational search algorithm

    Indian Academy of Sciences (India)

    Kazem Dastgerdi; Nasser Mehrshad; Mohsen Farshad

    2016-02-01

    Aircraft landing planning (ALP) is one of the most important challenging problems in the domain of air traffic control (ATC). Solving this NP-hard problem is a valuable aid in organizing air traffic in terminal control area (TCA), which itself leads to a decrease in aircraft fuel consumption, costs of airlines, and workload undertaken by air traffic controllers. In the present paper, the ALP problem is dealt with by applying effective rich knowledge to the optimization process (to remove obvious non-optimal solutions), and the first use of Gravitational Search Algorithm (GSA) in resolving such a case. In this regard, while the specific regulations for safe separation have been observed, the optimal landing time, the optimal runway, and the order of consecutive landings have been determined so that the main goal (minimizing total flight delays) would be best met. Results of simulations show that this approach, compared to previous ones, which are based on Genetic and Bionomic algorithms, GLS, and Scatter search method, considerably decreases total flight delays. Attaining zero in the total flight delays in three scenarios with real data shows that the suggested intelligent approach is more decisive than others in finding an optimal solution.

  10. Hematological and immunological effects of stress of air traffic controllers in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Valdenilson Ribeiro Ribas

    2011-06-01

    Full Text Available BACKGROUND: Several studies have shown that stress and emotional reactions can affect immune responses in animals and humans. OBJECTIVE: The aim of this study was to evaluate hematological and immunological effects of stress on air traffic controllers. METHODS: Thirty air traffic controllers and 15 aeronautical information service operators were evaluated. The groups were divided as information service operators with 10 years or more of experience (AIS>10 and with less than 10 years in the profession (AIS10 and with less than 10 years in the profession (ATCo10 group presented a significantly lower phagocytosis rate of monocytes at 2:00 p.m. compared to 8:00 a.m. Moreover, the ATCo>10 group presented lower hemoglobin, mean corpuscular hemoglobin concentration, platelet and leukocyte levels, and increased cortisol concentrations at 8:00 a.m. compared to the other groups. Additionally, this group had lower phagocytosis rate of monocytes, and hemoglobin, platelet, leukocyte, basophils and nitric oxide levels at 2:00 p.m. compared to the other groups. CONCLUSION: Stress seems to greatly affect immune responses of air traffic controllers with more than ten years of experience.

  11. How Life Experience Shapes Cognitive Control Strategies: The Case of Air Traffic Control Training.

    Directory of Open Access Journals (Sweden)

    Sandra Arbula

    Full Text Available Although human flexible behavior relies on cognitive control, it would be implausible to assume that there is only one, general mode of cognitive control strategy adopted by all individuals. For instance, different reliance on proactive versus reactive control strategies could explain inter-individual variability. In particular, specific life experiences, like a highly demanding training for future Air Traffic Controllers (ATCs, could modulate cognitive control functions. A group of ATC trainees and a matched group of university students were tested longitudinally on task-switching and Stroop paradigms that allowed us to measure indices of cognitive control. The results showed that the ATCs, with respect to the control group, had substantially smaller mixing costs during long cue-target intervals (CTI and a reduced Stroop interference effect. However, this advantage was present also prior to the training phase. Being more capable in managing multiple task sets and less distracted by interfering events suggests a more efficient selection and maintenance of task relevant information as an inherent characteristic of the ATC group, associated with proactive control. Critically, the training that the ATCs underwent improved their accuracy in general and reduced response time switching costs during short CTIs only. These results indicate a training-induced change in reactive control, which is described as a transient process in charge of stimulus-driven task detection and resolution. This experience-based enhancement of reactive control strategy denotes how cognitive control and executive functions in general can be shaped by real-life training and underlines the importance of experience in explaining inter-individual variability in cognitive functioning.

  12. Traffic routes and signals for the tonoplast.

    Science.gov (United States)

    Pedrazzini, Emanuela; Komarova, Nataliya Y; Rentsch, Doris; Vitale, Alessandro

    2013-06-01

    Tonoplast, the membrane delimiting plant vacuoles, regulates ion, water and nutrient movement between the cytosol and the vacuolar lumen through the activity of its membrane proteins. Correct traffic of proteins from the endoplasmic reticulum (ER) to the tonoplast requires (i) approval by the ER quality control, (ii) motifs for exit from the ER and (iii) motifs that promote sorting to the tonoplast. Recent evidence suggests that this traffic follows different pathways that are protein-specific and could also reflect vacuole specialization for lytic or storage function. The routes can be distinguished based on their sensitivity to drugs such as brefeldin A and C834 as well as using mutant plants that are defective in adaptor proteins of vesicle coats, or dominant-negative mutants of Rab GTPases.

  13. Trajectory Assessment and Modification Tools for Next Generation Air Traffic Management Operations

    Science.gov (United States)

    Brasil, Connie; Lee, Paul; Mainini, Matthew; Lee, Homola; Lee, Hwasoo; Prevot, Thomas; Smith, Nancy

    2011-01-01

    This paper reviews three Next Generation Air Transportation System (NextGen) based high fidelity air traffic control human-in-the-loop (HITL) simulations, with a focus on the expected requirement of enhanced automated trajectory assessment and modification tools to support future air traffic flow management (ATFM) planning positions. The simulations were conducted at the National Aeronautics and Space Administration (NASA) Ames Research Centers Airspace Operations Laboratory (AOL) in 2009 and 2010. The test airspace for all three simulations assumed the mid-term NextGenEn-Route high altitude environment utilizing high altitude sectors from the Kansas City and Memphis Air Route Traffic Control Centers. Trajectory assessment, modification and coordination decision support tools were developed at the AOL in order to perform future ATFM tasks. Overall tool usage results and user acceptability ratings were collected across three areas of NextGen operatoins to evaluate the tools. In addition to the usefulness and usability feedback, feasibility issues, benefits, and future requirements were also addressed. Overall, the tool sets were rated very useful and usable, and many elements of the tools received high scores and were used frequently and successfully. Tool utilization results in all three HITLs showed both user and system benefits including better airspace throughput, reduced controller workload, and highly effective communication protocols in both full Data Comm and mixed-equipage environments.

  14. UAS Air Traffic Controller Acceptability Study-2: Effects of Communications Delays and Winds in Simulation

    Science.gov (United States)

    Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2016-01-01

    This study evaluated the effects of Communications Delays and Winds on Air Traffic Controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between UAS and manned aircraft in a simulation of the Dallas-Ft. Worth East-side airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from self-separation algorithms displayed on the Multi-Aircraft Simulation System. Winds tested did not affect the acceptability ratings. Communications delays tested included 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS.

  15. 76 FR 5068 - Establishment of Low Altitude Area Navigation Routes (T-281, T-283, T-285, T-286, and T-288...

    Science.gov (United States)

    2011-01-28

    ... Routes (T-281, T- 283, T-285, T-286, and T-288); Nebraska and South Dakota AGENCY: Federal Aviation... (RNAV) routes, designated T-281, T-283, T-285, T-286, and T-288, over Nebraska and South Dakota; controlled by Denver Air Route Traffic Control Center (ARTCC) and Minneapolis ARTCC. T-routes are...

  16. FAA Air Traffic Control Operations Concepts. Volume 5. ATCT/TCCC (airport Traffic Control Tower/Tower Control Computer Complex) Tower Controllers

    Science.gov (United States)

    1988-07-29

    MANAGEMENI RESIRICTI ".NS FO-DREFF’-ECT ON~ SEQUENCE J AS NECESSARY ’T2.1.1.7 ,I ? c II PROJECT AIRCRAFT/ VEHICLE PLA,"tJD TIME/ P, SITI•lO PRLE LE...REVIEW CURRENT AND R/A TRAFFIC. WEATHER, ALL LOGICAL N/A M H PROJECTED TRAFFIC TRAFFIC MANAGEMENI DISPLAYS STATUS/ WEATHER INFORMATON T3.0.3 MANAGING...STATEMENTS OBJECTS OBJECTS T3.4.1.5 DISCUSS TRAFFIC MANAGEMENI RESTRICTION PROCEDURES NITH CONTROLLER/ PILOT TASK TYPE: VC COORD MEDIA: V FREQUENCY: MED

  17. Air Traffic Flow Management

    CERN Document Server

    Ganu, Hrishikesh V

    2008-01-01

    Air Traffic Flow Management is the regulation of air traffic in order to avoid exceeding airport or flight sector capacity in handling traffic, and to ensure that available capacity is used efficiently. We have tried to explore the logic behind the claims by Bertsimas et.al about integral solutions to the LP relaxation of the Traffic Flow Management Problem(TFMP). Polyhedral theory only indicates that the stronger TFMP formulation of Bertsimas et.al might lead to integral solutions in some cases. Our computations indicate that the encouraging results reported by Bertsimas et.al are not merely fortuitous or due to their specific data set. Indeed, we found that the TFMP had integral solutions even in case of artificial data sets generated to include severe conflicts in the flight schedules. In our limited tests with 4-5 scenarios, we obtained non-integral solutions only once. This is of significant practical importance because, the LP relaxation can be solved even on small machines with low memory and processor...

  18. En-Route Vehicular Traffic Optimization

    Directory of Open Access Journals (Sweden)

    Saravanan M

    2015-02-01

    separately for each locality from the available data set. For efficient control in mobility of vehicles an advanced dynamic digital board is introduced, which displays the speed limit set by the central node time to time. The normalized speed could be used to estimate the effective time taken between destinations precisely. By comparing normalized speed with real time values anomalies in the locality like congestion and presence of uneven roads is predicted. Accident detection model is integrated with the central node which sends a message to dynamic board indicating location of the accident along with the time taken. It even improves traffic flow around the accident occurred location. Central node together with navigation tools could provide re-routed path to the drivers during congestion or accident.

  19. Air Traffic Controllers’ Long-Term Speech-in-Noise Training Effects: A Control Group Study

    Science.gov (United States)

    Zaballos, María T.P.; Plasencia, Daniel P.; González, María L.Z.; de Miguel, Angel R.; Macías, Ángel R.

    2016-01-01

    Introduction: Speech perception in noise relies on the capacity of the auditory system to process complex sounds using sensory and cognitive skills. The possibility that these can be trained during adulthood is of special interest in auditory disorders, where speech in noise perception becomes compromised. Air traffic controllers (ATC) are constantly exposed to radio communication, a situation that seems to produce auditory learning. The objective of this study has been to quantify this effect. Subjects and Methods: 19 ATC and 19 normal hearing individuals underwent a speech in noise test with three signal to noise ratios: 5, 0 and −5 dB. Noise and speech were presented through two different loudspeakers in azimuth position. Speech tokes were presented at 65 dB SPL, while white noise files were at 60, 65 and 70 dB respectively. Results: Air traffic controllers outperform the control group in all conditions [Pcontrol group in all conditions. Thus, this study provides evidence that long-term auditory training is indeed useful in achieving better speech-in-noise understanding even in adverse conditions. PMID:27991470

  20. Traffic disruption route Einstein near building 170

    CERN Multimedia

    A Lopez - TS/CE

    2005-01-01

    The TS/CE Group informs you that, for the duration of the work at Building 170, there may be some disruption to traffic on route Einstein in the vicinity of Building 170. The work is due to take place from the 14th to 18th February. For more information, please contact 165029. A. Lopez TS/CE

  1. Traffic Performance Analysis of Manet Routing Protocol

    CERN Document Server

    Rajeswari, S; 10.5121/ijdps.2011.2306

    2011-01-01

    The primary objective of this research work is to study and investigate the performance measures of Gossip Routing protocol and Energy Efficient and Reliable Adaptive Gossip routing protocols. We use TCP and CBR based traffic models to analyze the performance of above mentioned protocols based on the parameters of Packet Delivery Ratio, Average End-to-End Delay and Throughput. We will investigate the effect of change in the simulation time and Number of nodes for the MANET routing protocols. For Simulation, we have used ns-2 simulator.

  2. Multimedia Traffic Routing in Multilayer WDM Networks

    CERN Document Server

    Amphawan, Angela; Hasan, Hassanuddin

    2012-01-01

    The advent of real-time multimedia services over the Internet has stimulated new technologies for expanding the information carrying capacity of optical network backbones. Multilayer wavelength division multiplexing (WDM) packet switching is an emerging technology for increasing the bandwidth of optical networks. Two algorithms for the routing of the multimedia traffic flows were applied: (i) Capacitated Shortest Path First (CSPF) routing, which minimizes the distance of each flow linking the given source and destination nodes and satisfying capacity constraints; and (ii) Flow Deviation Algorithm (FDA) routing, which minimizes the network?wide average packet delay.

  3. Data link air traffic control and flight deck environments: Experiment in flight crew performance

    Science.gov (United States)

    Lozito, Sandy; Mcgann, Alison; Corker, Kevin

    1993-01-01

    This report describes an experiment undertaken in a full mission simulation environment to investigate the performance impact of, and human/system response to, data-linked Air Traffic Control (ATC) and automated flight deck operations. Subjects were twenty pilots (ten crews) from a major United States air carrier. Crews flew the Advanced Concepts Flight Simulator (ACFS), a generic 'glass cockpit' simulator at NASA Ames. The method of data link used was similar to the data link implementation plans for a next-generation aircraft, and included the capability to review ATC messages and directly enter ATC clearance information into the aircraft systems. Each crew flew experimental scenarios, in which data reflecting communication timing, errors and clarifications, and procedures were collected. Results for errors and clarifications revealed an interaction between communication modality (voice v. data link) and communication type (air/ground v. intracrew). Results also revealed that voice crews initiated ATC contact significantly more than data link crews. It was also found that data link crews performed significantly more extraneous activities during the communication task than voice crews. Descriptive data from the use of the review menu indicate the pilot-not-flying accessing the review menu most often, and also suggest diffulty in accessing the target message within the review menu structure. The overall impact of communication modality upon air/ground communication and crew procedures is discussed.

  4. Improving Operational Acceptability of Dynamic Weather Routes Through Analysis of Commonly Use Routings

    Science.gov (United States)

    Evans, Antony D.; Sridhar, Banavar; McNally, David

    2016-01-01

    The Dynamic Weather Routes (DWR) tool is a ground-based trajectory automation system that continuously and automatically analyzes active in-flight aircraft in en route airspace to find simple modifications to flight plan routes that can save significant flying time, while avoiding weather and considering traffic conflicts, airspace sector congestion, special use airspace, and FAA routing restrictions. Trials of the DWR system have shown that significant delay savings are possible. However, some DWR advised routes are also rejected by dispatchers or modified before being accepted. Similarly, of those sent by dispatchers to flight crews as proposed route change requests, many are not accepted by air traffic control, or are modified before implementation as Center route amendments. Such actions suggest that the operational acceptability of DWR advised route corrections could be improved, which may reduce workload and increase delay savings. This paper analyzes the historical usage of different flight routings, varying from simple waypoint pairs to lengthy strings of waypoints incorporating jet routes, in order to improve DWR route acceptability. An approach is developed that can be incorporated into DWR, advising routings with high historical usage and savings potential similar to that of the nominal DWR advisory. It is hypothesized that modifying a nominal DWR routing to one that is commonly used, and nearby, will result in more actual savings since common routings are generally familiar and operationally acceptable to air traffic control. The approach allows routing segments with high historical usage to be concatenated to form routes that meet all DWR constraints. The relevance of a route's historical usage to its acceptance by dispatchers and air traffic control is quantified by analyzing historical DWR data. Results indicate that while historical usage may be less of a concern to flight dispatchers accepting or rejecting DWR advised route corrections, it may be

  5. Pilot and Controller Evaluations of Separation Function Allocation in Air Traffic Management

    Science.gov (United States)

    Wing, David; Prevot, Thomas; Morey, Susan; Lewis, Timothy; Martin, Lynne; Johnson, Sally; Cabrall, Christopher; Como, Sean; Homola, Jeffrey; Sheth-Chandra, Manasi; Mercer, Joey

    2013-01-01

    Two human-in-the-loop simulation experiments were conducted in coordinated fashion to investigate the allocation of separation assurance functions between ground and air and between humans and automation. The experiments modeled a mixed-operations concept in which aircraft receiving ground-based separation services shared the airspace with aircraft providing their own separation service (i.e., self-separation). Ground-based separation was provided by air traffic controllers without automation tools, with tools, or by ground-based automation with controllers in a managing role. Airborne self-separation was provided by airline pilots using self-separation automation enabled by airborne surveillance technology. The two experiments, one pilot-focused and the other controller-focused, addressed selected key issues of mixed operations, assuming the starting point of current-day operations and modeling an emergence of NextGen technologies and procedures. In the controller-focused experiment, the impact of mixed operations on controller performance was assessed at four stages of NextGen implementation. In the pilot-focused experiment, the limits to which pilots with automation tools could take full responsibility for separation from ground-controlled aircraft were tested. Results indicate that the presence of self-separating aircraft had little impact on the controllers' ability to provide separation services for ground-controlled aircraft. Overall performance was best in the most automated environment in which all aircraft were data communications equipped, ground-based separation was highly automated, and self-separating aircraft had access to trajectory intent information for all aircraft. In this environment, safe, efficient, and highly acceptable operations could be achieved for twice today's peak airspace throughput. In less automated environments, reduced trajectory intent exchange and manual air traffic control limited the safely achievable airspace throughput and

  6. Dynamic route guidance strategy in a two-route pedestrian-vehicle mixed traffic flow system

    Science.gov (United States)

    Liu, Mianfang; Xiong, Shengwu; Li, Bixiang

    2016-05-01

    With the rapid development of transportation, traffic questions have become the major issue for social, economic and environmental aspects. Especially, during serious emergencies, it is very important to alleviate road traffic congestion and improve the efficiency of evacuation to reduce casualties, and addressing these problems has been a major task for the agencies responsible in recent decades. Advanced road guidance strategies have been developed for homogeneous traffic flows, or to reduce traffic congestion and enhance the road capacity in a symmetric two-route scenario. However, feedback strategies have rarely been considered for pedestrian-vehicle mixed traffic flows with variable velocities and sizes in an asymmetric multi-route traffic system, which is a common phenomenon in many developing countries. In this study, we propose a weighted road occupancy feedback strategy (WROFS) for pedestrian-vehicle mixed traffic flows, which considers the system equilibrium to ease traffic congestion. In order to more realistic simulating the behavior of mixed traffic objects, the paper adopted a refined and dynamic cellular automaton model (RDPV_CA model) as the update mechanism for pedestrian-vehicle mixed traffic flow. Moreover, a bounded rational threshold control was introduced into the feedback strategy to avoid some negative effect of delayed information and reduce. Based on comparisons with the two previously proposed strategies, the simulation results obtained in a pedestrian-vehicle traffic flow scenario demonstrated that the proposed strategy with a bounded rational threshold was more effective and system equilibrium, system stability were reached.

  7. Computer-Aided Air-Traffic Control In The Terminal Area

    Science.gov (United States)

    Erzberger, Heinz

    1995-01-01

    Developmental computer-aided system for automated management and control of arrival traffic at large airport includes three integrated subsystems. One subsystem, called Traffic Management Advisor, another subsystem, called Descent Advisor, and third subsystem, called Final Approach Spacing Tool. Data base that includes current wind measurements and mathematical models of performances of types of aircraft contributes to effective operation of system.

  8. A Cognitive Game Theoretic Analysis of Conflict Alerts in Air Traffic Control

    Science.gov (United States)

    Erev, Ido; Gopher, Daniel; Remington, Roger

    1999-01-01

    The current research was motivated by the recommendation made by a joint Government/Industry committee to introduce a new traffic control system, referred to as the Free Flight. This system is designed to use recent new technology to facilitate efficient and safe air transportation. We addressed one of the major difficulties that arise in the design of this and similar multi-agent systems: the adaptive (and slippery) nature of human agents. To facilitate a safe and efficient design of this multi-agent system, designers have to rely on assessments of the expected behavior of the different agents under various scenarios. Whereas the behavior of the computerized agents is predictable, the behavior of the human agents (including air traffic controllers and pilots) is not. Experimental and empirical observations suggest that human agents are likely to adjust their behavior to the design of the system. To see the difficulty that the adaptive nature of human agents creates assume that a good approximation of the way operators currently behave is available. Given this information an optimal design can be performed. The problem arises as the human operator will learn to adjust their behavior to the new system. Following this adjustment process the assumptions made by the designer concerning the operators behavior will no longer be accurate and the system might reach a suboptimal state. In extreme situations these potential suboptimal states might involve unnecessary risk. That is, the fact that operators learn in an adaptive fashion does not imply that the system will become safer as they gain experience. At least in the context of Safety dilemmas, experience can lead to a pareto deficient risk taking behavior.

  9. Dynamic problem selection in air traffic control training : A comparison between performance, mental effort and mental efficiency

    NARCIS (Netherlands)

    Camp, Gino; Paas, Fred; Rikers, Remy; van Merrienboer, Jeroen

    2001-01-01

    The differential effects on training and training outcome of four methods of problem selection were investigated in a computer-based training for air traffic control. In one method, training problems were given to the participants in a fixed predetermined sequence, from simple to complex. In the oth

  10. Dynamic Resectorization and Coordination Technology: An Evaluation of Air Traffic Control Complexity

    Science.gov (United States)

    Brinton, Christopher R.

    1996-01-01

    The work described in this report is done under contract with the National Aeronautics and Space Administration (NASA) to support the Advanced Air Transportation Technology (AATR) program. The goal of this program is to contribute to and accelerate progress in Advanced Air Transportation Technologies. Wyndemere Incorporated is supporting this goal by studying the complexity of the Air Traffic Specialist's role in maintaining the safety of the Air Transportation system. It is envisioned that the implementation of Free Flight may significantly increase the complexity and difficulty of maintaining this safety. Wyndemere Incorporated is researching potential methods to reduce this complexity. This is the final report for the contract.

  11. 78 FR 78302 - Proposed Modification and Establishment of Air Traffic Service (ATS) Routes in the Vicinity of...

    Science.gov (United States)

    2013-12-26

    ... on this action must submit with those comments a self-addressed, stamped postcard on which the... Meacham Blvd., Fort Worth, TX 76137. Persons interested in being placed on a mailing list for future NPRMs... Federal airways are published in paragraph 6010(a) and low altitude RNAV routes (T) are published...

  12. Perpetual factors involved in performance of air traffic controllers using a microwave landing system

    Science.gov (United States)

    Gershzohn, G.

    1978-01-01

    The task involved the control of two simulated aircraft targets per trial, in a 37.0 -km radius terminal area, by means of conventional radar vectoring and/or speed control. The goal was to insure that the two targets crossed the Missed Approach Point (MAP) at the runway threshold exactly 60 sec apart. The effects on controller performance of the MLS configuration under wind and no-wind conditions were examined. The data for mean separation time between targets at the MAP and the range about that mean were analyzed by appropriate analyses of variance. Significant effects were found for mean separation times as a result of the configuration of the MLS and for interaction between the configuration and wind conditions. The analysis of variance for range indicated significantly poorer performance under the wind condition. These findings are believed to be a result of certain perceptual factors involved in radar air traffic control (ATC) using the MLS with separation of targets in time.

  13. Towards an agent based traffic regulation and recommendation system for the on-road air quality control

    OpenAIRE

    Sadiq, Abderrahmane; El Fazziki, Abdelaziz; Ouarzazi, Jamal; Sadgal, Mohamed

    2016-01-01

    This paper presents an integrated and adaptive problem-solving approach to control the on-road air quality by modeling the road infrastructure, managing traffic based on pollution level and generating recommendations for road users. The aim is to reduce vehicle emissions in the most polluted road segments and optimizing the pollution levels. For this we propose the use of historical and real time pollution records and contextual data to calculate the air quality index on road networks and gen...

  14. Effects of shift work in air traffic controllers: a systematic review based on the Prisma method

    Directory of Open Access Journals (Sweden)

    Alisson Vieira Marcolino

    2015-07-01

    Full Text Available Air Traffic Controllers (ATC perform very complex functions of great responsibility. Due to the necessities of the job, they are submitted to a work shift system which makes their schedule irregular. The alternation of work shifts can result in effects that cause damages to their work performance and quality of life. Objective: To explore the effects of shift work in ATCs through a systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis model (PRISMA. Methodological procedures: The systematic review was conducted based on three databases: PubMed, Science Direct and Web of Science. Results: A total of 748 articles were found, 487 from PubMed, 240 from Science Direct and 21 from Web of Science; seven articles were included in the review after the application of eligibility criteria. Conclusions: The researches showed effects that affect mainly the night shifts, caused by alteration in sleep quality, somnolence and fatigue, resulting in decreased performance and increasing the risk of air accidents.

  15. Large graph visualization of millions of connections in the CERN control system network traffic: analysis and design of routing and firewall rules with a new approach

    CERN Document Server

    Gallerani, Luigi

    2015-01-01

    Abstract The CERN Technical Network (TN) TN was intended to be a network for accelerator and infrastructure operations. However, today, more than 60 million IP packets are routed every hour between the General Purpose Network (GPN) and the TN, involving more than 6000 different hosts. In order to improve the security of the accelerator control system, it is fundamental to understand the network traffic between the two networks and to define new appropriate routing and firewall rules without impacting operations. The complexity and huge size of the infrastructure and the number of protocols and services involved, have discouraged for years any attempt to understand and control the network traffic between the GPN and the TN. In this paper, we show a new way to solve the problem graphically. Combining the network traffic analysis with the use of large graph visualization algorithms we produced usable 2D large color topology maps of the network identifying the inter-relations of the control system machines and s...

  16. [Development of New Mathematical Methodology in Air Traffic Control for the Analysis of Hybrid Systems

    Science.gov (United States)

    Hermann, Robert

    1997-01-01

    The aim of this research is to develop new mathematical methodology for the analysis of hybrid systems of the type involved in Air Traffic Control (ATC) problems. Two directions of investigation were initiated. The first used the methodology of nonlinear generalized functions, whose mathematical foundations were initiated by Colombeau and developed further by Oberguggenberger; it has been extended to apply to ordinary differential. Systems of the type encountered in control in joint work with the PI and M. Oberguggenberger. This involved a 'mixture' of 'continuous' and 'discrete' methodology. ATC clearly involves mixtures of two sorts of mathematical problems: (1) The 'continuous' dynamics of a standard control type described by ordinary differential equations (ODE) of the form: {dx/dt = f(x, u)} and (2) the discrete lattice dynamics involved of cellular automata. Most of the CA literature involves a discretization of a partial differential equation system of the type encountered in physics problems (e.g. fluid and gas problems). Both of these directions requires much thinking and new development of mathematical fundamentals before they may be utilized in the ATC work. Rather than consider CA as 'discretization' of PDE systems, I believe that the ATC applications will require a completely different and new mathematical methodology, a sort of discrete analogue of jet bundles and/or the sheaf-theoretic techniques to topologists. Here too, I have begun work on virtually 'virgin' mathematical ground (at least from an 'applied' point of view) which will require considerable preliminary work.

  17. Traffic modifications on Routes Rutherford, Democrite and Fermi

    CERN Multimedia

    2015-01-01

    The GS Department would like to inform you that until the end of December, the construction of Building 245 will result in the following traffic modifications: Traffic on Route Rutherford will be partially restricted in front of the construction site, Traffic on Route Democrite will be one-way towards Route Rutherford. Also, please note that due to construction work in front of Building 377, Route Fermi will be closed from Wednesday, 10 June until Friday, 7 August. Thank you for your understanding.

  18. Interrelation of the Problems of the Aircraft Fleet Development and the Improvement of the Air Traffic Control System

    Directory of Open Access Journals (Sweden)

    Mihail Yurevich Smurov

    2016-07-01

    Full Text Available In the article the problems of air transport have been identified. Among these problems, the congestion of airports and airspace and the need for development and modernization of the airport network are of particular importance. In this regard, the authors consider the improvement of the air traffic control system (ATC system by integrating existing ATC systems into a single global system with the use of unified international standards, rules and procedures. The article also specifies the main indicators characterizing the dynamics of the development of the air transport industry in Russia and abroad.

  19. Conflict resolution and alert zone estimation in air traffic management

    Science.gov (United States)

    Kuo, Vincent Hao-Hung

    The current air traffic control (ATC) system provides separations among all aircraft through pre-defined routes and flight procedures, and active controller participation. In particular, en route separations are achieved by choices of different flight routes, different flight levels, and speed control. During the final descent approach over an extended terminal area, aircraft separations are achieved by speed changes, altitude changes, and path stretching. Recently, a concept of free flight has been proposed for future air traffic management. In the proposed free flight environment, aircraft operators can change flight paths in real time, in order to achieve the best efficiency for the aircraft. Air traffic controllers are only supposed to intervene when situation warrants, to resolve potential conflicts among aircraft. In both cases, there is a region around each aircraft called alert zone. As soon as another aircraft touches the alert zone of own aircraft, either the own aircraft or both aircraft must initiate avoidance maneuvers to resolve a potential conflict. This thesis develops a systematic approach based on nonlinear optimal control theories to estimate alert zones in two aircraft conflict scenarios. Specifically, point-mass aircraft models are used to describe aircraft motions. Separate uses of heading, speed, and altitude control are first examined, and then the synergetic use of two control authorities are studied. Both cooperative maneuvers (in which both aircraft act) and non-cooperative maneuvers (in which the own aircraft acts alone) are considered. Optimal control problems are formulated to minimize the initial relative separation between the two aircraft for all possible initial conditions, subject to the requirement that inter-aircraft separation at any time satisfies the separation requirement. These nonlinear optimal control problems are solved numerically using a collation approach and the NPSOL software line for nonlinear programming. In

  20. UAS in the NAS Air Traffic Controller Acceptability Study-1: The Effects of Horizontal Miss Distances on Simulated UAS and Manned Aircraft Encounters

    Science.gov (United States)

    Ghatas, Rania W.; Comstock, James R., Jr.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2015-01-01

    This study examined air traffic controller acceptability ratings based on the effects of differing horizontal miss distances (HMDs) for encounters between UAS and manned aircraft. In a simulation of the Dallas/Fort Worth (DFW) East-side airspace, the CAS-1 experiment at NASA Langley Research Center enlisted fourteen recently retired DFW air traffic controllers to rate well-clear volumes based on differing HMDs that ranged from 0.5 NM to 3.0 NM. The controllers were tasked with rating these HMDs from "too small" to "too excessive" on a defined, 1-5, scale and whether these distances caused any disruptions to the controller and/or to the surrounding traffic flow. Results of the study indicated a clear favoring towards a particular HMD range. Controller workload was also measured. Data from this experiment and subsequent experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely and efficiently integrate UAS into the NAS.

  1. Suitability Screening Test for Marine Corps Air Traffic Controllers Phase 3: Non-cognitive Test Validation and Cognitive Test Prototype

    Science.gov (United States)

    2014-06-01

    Vocational Aptitude Battery (ASVAB), a test battery that assesses cognitive abilities through performance in reading, mathematics, general science...Tennessee 38055-1000  www.nprst.navy.mil NPRST-TR-14-3 June 2014 Suitability Screening Test for Marine Corps Air Traffic Controllers Phase III: Non...cognitive Test Validation and Cognitive Test Prototype Karen M. Walker, PhD Randy Brou, PhD William L. Farmer, PhD Navy Personnel Research

  2. Human activity under high pressure: A case study on fluctuation scaling of air traffic controller's communication behaviors

    Science.gov (United States)

    Wang, Yanjun; Zhang, Qiqian; Zhu, Chenping; Hu, Minghua; Duong, Vu

    2016-01-01

    Recent human dynamics research has unmasked astonishing statistical characteristics such as scaling behaviors in human daily activities. However, less is known about the general mechanism that governs the task-specific activities. In particular, whether scaling law exists in human activities under high pressure remains an open question. In air traffic management system, safety is the most important factor to be concerned by air traffic controllers who always work under high pressure, which provides a unique platform to study human activity. Here we extend fluctuation scaling method to study air traffic controller's communication activity by investigating two empirical communication datasets. Taken the number of controlled flights as the size-like parameter, we show that the relationships between the average communication activity and its standard deviation in both datasets can be well described by Taylor's power law, with scaling exponent α ≈ 0.77 ± 0.01 for the real operational data and α ≈ 0.54 ± 0.01 for the real-time training data. The difference between the exponents suggests that human dynamics under pressure is more likely dominated by the exogenous force. Our findings may lead to further understanding of human behavior.

  3. Analysis of Multi-Flight Common Routes for Traffic Flow Management

    Science.gov (United States)

    Sheth, Kapil; Clymer, Alexis; Morando, Alex; Shih, Fu-Tai

    2016-01-01

    This paper presents an approach for creating common weather avoidance reroutes for multiple flights and the associated benefits analysis, which is an extension of the single flight advisories generated using the Dynamic Weather Routes (DWR) concept. These multiple flight advisories are implemented in the National Airspace System (NAS) Constraint Evaluation and Notification Tool (NASCENT), a nation-wide simulation environment to generate time- and fuel-saving alternate routes for flights during severe weather events. These single flight advisories are clustered together in the same Center by considering parameters such as a common return capture fix. The clustering helps propose routes called, Multi-Flight Common Routes (MFCR), that avoid weather and other airspace constraints, and save time and fuel. It is expected that these routes would also provide lower workload for traffic managers and controllers since a common route is found for several flights, and presumably the route clearances would be easier and faster. This study was based on 30-days in 2014 and 2015 each, which had most delays attributed to convective weather. The results indicate that many opportunities exist where individual flight routes can be clustered to fly along a common route to save a significant amount of time and fuel, and potentially reducing the amount of coordination needed.

  4. Suppressing traffic-driven epidemic spreading by use of the efficient routing protocol

    CERN Document Server

    Yang, Han-Xin

    2015-01-01

    Despite extensive work on the interplay between traffic dynamics and epidemic spreading, the control of epidemic spreading by routing strategies has not received adequate attention. In this paper, we study the impact of efficient routing protocol on epidemic spreading. In the case of infinite node-delivery capacity, where the traffic is free of congestion, we find that that there exists optimal values of routing parameter, leading to the maximal epidemic threshold. This means that epidemic spreading can be effectively controlled by fine tuning the routing scheme. Moreover, we find that an increase in the average network connectivity and the emergence of traffic congestion can suppress the epidemic outbreak.

  5. Towards an agent based traffic regulation and recommendation system for the on-road air quality control.

    Science.gov (United States)

    Sadiq, Abderrahmane; El Fazziki, Abdelaziz; Ouarzazi, Jamal; Sadgal, Mohamed

    2016-01-01

    This paper presents an integrated and adaptive problem-solving approach to control the on-road air quality by modeling the road infrastructure, managing traffic based on pollution level and generating recommendations for road users. The aim is to reduce vehicle emissions in the most polluted road segments and optimizing the pollution levels. For this we propose the use of historical and real time pollution records and contextual data to calculate the air quality index on road networks and generate recommendations for reassigning traffic flow in order to improve the on-road air quality. The resulting air quality indexes are used in the system's traffic network generation, which the cartography is represented by a weighted graph. The weights evolve according to the pollution indexes and path properties and the graph is therefore dynamic. Furthermore, the systems use the available pollution data and meteorological records in order to predict the on-road pollutant levels by using an artificial neural network based prediction model. The proposed approach combines the benefits of multi-agent systems, Big data technology, machine learning tools and the available data sources. For the shortest path searching in the road network, we use the Dijkstra algorithm over Hadoop MapReduce framework. The use Hadoop framework in the data retrieve and analysis process has significantly improved the performance of the proposed system. Also, the agent technology allowed proposing a suitable solution in terms of robustness and agility.

  6. Traffic Route Modelling and Assignment with Intelligent Transport System

    Directory of Open Access Journals (Sweden)

    Kunicina Nadezhda

    2014-12-01

    Full Text Available The development of signal transmitting environment for multimodal traffic control will enhance the integration of emergency and specialized transport routing tools in usual traffic control paradigms - it is one of the opportunities offered by modern intelligent traffic control systems. The improvement of effective electric power use in public transport system is an advantage of Intelligent Transport System (ITS. The research is connected with the improvement of on-line traffic control and adaptation of special traffic lighting alternatives by ITS. The assignment of the nearest appropriate transport will be done by passenger request, but unlike information system, the transport planning is done on demand. The task can be solved with the help of modern technical methods and equipment, as well as by applying control paradigms of the distributed systems. The problem is solved with the help of calculations hyper-graph and scheduling theory. The goal of the research is to develop methods, which support scheduling of the emergency transport, using high performance computing.

  7. 空管系统中飞行数据处理的研究与应用%Research and application of flight data processing in air traffic control system

    Institute of Scientific and Technical Information of China (English)

    赵振宇

    2015-01-01

    In recent years,with the rapid development of China's aviation industry,China has now become a veritable aviation power,but also because of this,air traffic control is facing tremendous pressure.In view of this situation,in order to meet the demand of the healthy development of the aviation industry, China needs to construct and proficient in use of air traffic control system(hereinafter referred to as the air traffic control system),in order to effectively alleviate the pressure of air traffic control,raise the level of traffic control.This paper takes air traffic control system as the research center,and analyzes the research and application of flight data processing in air traffic control system,aiming at providing security for flight safety.%近年来,伴随着我国航空事业的迅猛发展,我国现已成为名副其实的航空大国,也正因如此,空中交通管制面临着巨大压力。鉴于此种情况,为了满足航空事业稳健发展的需求,我国亟需建设并娴熟应用空中交通管制系统(以下简称空管系统),以此有效缓解空中交通管制压力、提升交通管制工作水平。本文以空管系统为研究中心,重点探析空管系统中飞行数据处理的研究与应用,旨在为空中飞行的安全提供保障。

  8. Optimal control of systems governed by differential equations with applications in air traffic management and systems biology

    Science.gov (United States)

    Raffard, Robin L.

    Differential equations are arguably the most widespread formalism to model dynamical systems in sciences and engineering. In this dissertation, we strive to design a practical methodology which can be used for the optimal control of most systems modeled by differential equations. Namely, the method is applicable to ordinary differential equations (ODEs), partial differential equations (PDEs) and stochastic differential equations (SDEs) driven by deterministic control. The algorithm draws from both optimization and control theory. It solves the Pontryagin Maximum Principle conditions in an iterative fashion via a novel approximate Newton method. We also extend the method to the case in which multiple agents are involved in the optimal control problem. For this purpose, we use dual decomposition techniques which allow us to decentralize the control algorithm and to distribute the computational load among each individual agent. Most of the dissertation is devoted to promoting the applicability of the method to practical problems in air traffic management and systems biology. In air traffic management; we use the technique to optimize a new PDE-based Eulerian model of the airspace; suitable to represent and control air traffic flow at the scale of the US national airspace. We also apply the technique to aircraft coordination problems in the context of formation flight, in which aircraft dynamics are described by ODEs. In systems biology, we use the method to perform fast parameter identification in the analysis of protein networks, which allows us to gain some insights about the biological processes regulating the system. In particular we perform parameter identification for a PDE model of a spatially distributed network of proteins, playing a key role in the planar cell polarity of Drosophila wings. We also study a general representation of intra-cellular genetic networks, described as a stochastic nonlinear regulatory network, in which our control system approach

  9. General aviation air traffic pattern safety analysis

    Science.gov (United States)

    Parker, L. C.

    1973-01-01

    A concept is described for evaluating the general aviation mid-air collision hazard in uncontrolled terminal airspace. Three-dimensional traffic pattern measurements were conducted at uncontrolled and controlled airports. Computer programs for data reduction, storage retrieval and statistical analysis have been developed. Initial general aviation air traffic pattern characteristics are presented. These preliminary results indicate that patterns are highly divergent from the expected standard pattern, and that pattern procedures observed can affect the ability of pilots to see and avoid each other.

  10. UAS Air Traffic Controller Acceptability Study. 2; Evaluating Detect and Avoid Technology and Communication Delays in Simulation

    Science.gov (United States)

    Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2015-01-01

    This study evaluated the effects of communications delays and winds on air traffic controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between Unmanned Aircraft Systems (UAS) and manned aircraft in a simulation of the Dallas-Ft. Worth (DFW) airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from Detect and Avoid (DAA) self-separation algorithms (Stratway+) displayed on the Multi-Aircraft Control System. This guidance consisted of amber "bands" on the heading scale of the UAS navigation display indicating headings that would result in a loss of well clear between the UAS and nearby traffic. Winds tested were successfully handled by the DAA algorithms and did not affect the controller acceptability ratings of the HMDs. Voice communications delays for the UAS were also tested and included one-way delay times of 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS. Information from this study will also be of value to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 228 - Minimum Performance Standards for UAS.

  11. Fast 3D route-planning approach for air vehicle

    Science.gov (United States)

    Tu, Jilin; Ding, Mingyue; Zhou, Chengping; Ai, Haojun

    1997-06-01

    A fast 3-D route planning method for unmanned air vehicle is proposed which can generate physically realizable 3-D route within a reasonable time. Our method includes two steps: First, 2-D route planning generates a route which satisfies turning radius constraint(abbreviated as R-constrained below); second, 3-D route planning generates 3-D route in vertical profile of the 2-D route. To make 2-D route R-constrained, a method is proposed by supposing 2-D route of air vehicle is composed of a sequence of arc route segments and tangential points between neighboring arcs are searching nodes. 3 -D route planning is considered as optimal control problem, and its route can be determined by applying motion equations of air vehicle. The experiments show that our method can produce feasible 3-D routes within a reasonable time, and ensure the planned 3-D routes satisfy aerodynamics constraints of air vehicle.

  12. Traffic modifications on Routes Rutherford, Democrite and Fermi

    CERN Multimedia

    2015-01-01

    The GS Department would like to inform you that, until the end of December, the construction of Building 245 will result in the following traffic modifications: Traffic on Route Rutherford will be partially restricted in front of the construction site, Traffic on Route Democrite will be one-way towards Route Rutherford. Also, please note that due to construction work in front of Building 377, Route Fermi will be closed from Wednesday, 10 June until Friday, 7 August. Thank you for your understanding.

  13. BALANCE ROUTING TRAFFIC IN GENERALIZED SHUFFLE-EXCHANGE NETWORK

    Institute of Scientific and Technical Information of China (English)

    Chen Zhen; Liu Zengji; Qiu Zhiliang; Chen Peng; Tao Xiaoming

    2005-01-01

    A methodology is proposed to handle problem that under equiproble address of packet traffic at the input port, Generalized Shuffle-Exchange Network (GSEN) routes traffic unevenly because of the unbalanced routing tags. The idea is to use routing tag according to probability, which can be evaluated by using Moore-Penrose inverse in matrix analysis. An instance is used to illustrate the idea, and the simulation is done to show the improvement in performance issues.

  14. An optimization model for the US Air-Traffic System

    Science.gov (United States)

    Mulvey, J. M.

    1986-01-01

    A systematic approach for monitoring U.S. air traffic was developed in the context of system-wide planning and control. Towards this end, a network optimization model with nonlinear objectives was chosen as the central element in the planning/control system. The network representation was selected because: (1) it provides a comprehensive structure for depicting essential aspects of the air traffic system, (2) it can be solved efficiently for large scale problems, and (3) the design can be easily communicated to non-technical users through computer graphics. Briefly, the network planning models consider the flow of traffic through a graph as the basic structure. Nodes depict locations and time periods for either individual planes or for aggregated groups of airplanes. Arcs define variables as actual airplanes flying through space or as delays across time periods. As such, a special case of the network can be used to model the so called flow control problem. Due to the large number of interacting variables and the difficulty in subdividing the problem into relatively independent subproblems, an integrated model was designed which will depict the entire high level (above 29000 feet) jet route system for the 48 contiguous states in the U.S. As a first step in demonstrating the concept's feasibility a nonlinear risk/cost model was developed for the Indianapolis Airspace. The nonlinear network program --NLPNETG-- was employed in solving the resulting test cases. This optimization program uses the Truncated-Newton method (quadratic approximation) for determining the search direction at each iteration in the nonlinear algorithm. It was shown that aircraft could be re-routed in an optimal fashion whenever traffic congestion increased beyond an acceptable level, as measured by the nonlinear risk function.

  15. A Wavelet Analysis Approach for Categorizing Air Traffic Behavior

    Science.gov (United States)

    Drew, Michael; Sheth, Kapil

    2015-01-01

    In this paper two frequency domain techniques are applied to air traffic analysis. The Continuous Wavelet Transform (CWT), like the Fourier Transform, is shown to identify changes in historical traffic patterns caused by Traffic Management Initiatives (TMIs) and weather with the added benefit of detecting when in time those changes take place. Next, with the expectation that it could detect anomalies in the network and indicate the extent to which they affect traffic flows, the Spectral Graph Wavelet Transform (SGWT) is applied to a center based graph model of air traffic. When applied to simulations based on historical flight plans, it identified the traffic flows between centers that have the greatest impact on either neighboring flows, or flows between centers many centers away. Like the CWT, however, it can be difficult to interpret SGWT results and relate them to simulations where major TMIs are implemented, and more research may be warranted in this area. These frequency analysis techniques can detect off-nominal air traffic behavior, but due to the nature of air traffic time series data, so far they prove difficult to apply in a way that provides significant insight or specific identification of traffic patterns.

  16. 77 FR 39321 - Air Traffic Procedures Advisory Committee

    Science.gov (United States)

    2012-07-02

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF... Kyker, Environmental Specialist, Air Traffic Eastern Service Center, Operations Support Group, 1701...- point operations help enhance reliability and reduce delays by defining more precise terminal...

  17. FAA Air Traffic Control Operations Concepts. Volume 4. TAAS (Terminal Advanced Automation System) Terminal Controllers

    Science.gov (United States)

    1988-07-29

    entry message* Al 1.6.11 ENTER FDE NOTATIONS TASK TYPE: E COORD MEDIA: FREQUENCY: HI CRITICALITY! 1.24 A1.1.6.11.1 INITIATE EnterEFDE- Natation message...Stat-bsilndicotor. Aircraft Type. Assigned Altitude or Interim ... ( Sea SLS). 48.3.7.1.2.1.1.I-8 SI7UATIUN DISPLAY 779 󈧯.3.7.1.2.1.1.1-01 The...Ind:mctor’, Air’crc’ft Type, Assigned Altitude or, nteriri ... ( Sea 2S5). 40.3.7.1.2.1.1.1-00 SITUATION DISPLAY 7T9 40.3.7.1.2.1.1.1-01 The r’ouir .mtotý .,f

  18. Organizational climate in air traffic control Innovative preparedness for implementation of new technology and organizational development in a rule governed organization.

    Science.gov (United States)

    Arvidsson, Marcus; Johansson, Curt R; Ek, Asa; Akselsson, Roland

    2006-03-01

    A positive and innovative organizational climate is of great importance in order to manage and adapt to change. Such a climate seldom evolves in organizations closely governed by rules and regulations. Because of ongoing organizational and technical changes within the Swedish Air Navigation Services Provider, a study concerning the organizational climate for changes and innovations was conducted to investigate the organization's capacity to cope with changes. Study locations were the two Swedish main air traffic control centers and parts of the civil aviation administration headquarters. In the study 390 subjects took part and the CCQ questionnaire was used to measure the organizational climate. The results show that the organizational climate is quite positive despite the rule-governed work. The results also show that administrative personnel assess the organizational climate as more positive than operative personnel. Comparisons between management positions did not result in any differences.

  19. Effect of density feedback on the two-route traffic scenario with bottleneck

    Science.gov (United States)

    Sun, Xiao-Yan; Ding, Zhong-Jun; Huang, Guo-Hua

    2016-12-01

    In this paper, we investigate the effect of density feedback on the two-route scenario with a bottleneck. The simulation and theory analysis shows that there exist two critical vehicle entry probabilities αc1 and αc2. When vehicle entry probability α≤αc1, four different states, i.e. free flow state, transition state, maximum current state and congestion state are identified in the system, which correspond to three critical reference densities. However, in the interval αc1congestion state when α≥αc2. According to the results, traffic control center can adjust the reference density so that the system is in maximum current state. In this case, the capacity of the traffic system reaches maximum so that drivers can make full use of the roads. We hope that the study results can provide good advice for alleviating traffic jam and be useful to traffic control center for designing advanced traveller information systems.

  20. Investigating the Complexity of Transitioning Separation Assurance Tools into NextGen Air Traffic Control

    Science.gov (United States)

    Gomez, Ashley Nicole; Martin, Lynne Hazel; Homola, Jeffrey; Morey, Susan; Cabrall, Christopher; Mercer, Joey; Prevot, Thomas

    2013-01-01

    In a study, that introduced ground-based separation assurance automation through a series of envisioned transitional phases of concept maturity, it was found that subjective responses to scales of workload, situation awareness, and acceptability in a post run questionnaire revealed as-predicted results for three of the four study conditions but not for the third, Moderate condition. The trend continued for losses of separation (LOS) where the number of LOS events were far greater than expected in the Moderate condition. To offer an account of why the Moderate condition was perceived to be more difficult to manage than predicted, researchers examined the increase in amount and complexity of traffic, increase in communication load, and increased complexities as a result of the simulation's mix of aircraft equipage. Further analysis compared the tools presented through the phases, finding that controllers took advantage of the informational properties of the tools presented but shied away from using their decision support capabilities. Taking into account similar findings from other studies, it is suggested that the Moderate condition represented the first step into a "shared control" environment, which requires the controller to use the automation as a decision making partner rather than just a provider of information. Viewed in this light, the combination of tools offered in the Moderate condition was reviewed and some tradeoffs that may offset the identified complexities were suggested.

  1. Social dilemma structure hidden behind traffic flow with route selection

    Science.gov (United States)

    Tanimoto, Jun; Nakamura, Kousuke

    2016-10-01

    Several traffic flows contain social dilemma structures. Herein, we explored a route-selection problem using a cellular automaton simulation dovetailed with evolutionary game theory. In our model, two classes of driver-agents coexist: D agents (defective strategy), which refer to traffic information for route selection to move fast, and C agents (cooperative strategy), which are insensitive to information and less inclined to move fast. Although no evidence suggests that the social dilemma structure in low density causes vehicles to move freely and that in high density causes traffic jams, we found a structure that corresponds to an n-person (multiplayer) Chicken (n-Chicken) game if the provided traffic information is inappropriate. If appropriate traffic information is given to the agents, the n-Chicken game can be solved. The information delivered to vehicles is crucial for easing the social dilemma due to urban traffic congestion when developing technologies to support the intelligent transportation system (ITS).

  2. Allocation of Functions in a Far-Term Air Traffic Control Environment

    Science.gov (United States)

    Homola, Jeffrey; Martin, Lynne; Mercer, Joey; Cabrall, Christopher; Prevot, Thomas

    2011-01-01

    A human-in-the-loop exploration of a ground-based automated separation assurance concept was conducted that involved the allocation of certain functions between humans and automation. This exploration included operations that were sustained for prolonged periods of time with high levels of traffic in the presence of convective weather and scheduling constraints. An investigation into the acceptability of the defined roles and performance of tasks was conducted where it was found that the participants rated the concept and allocation of functions with a high level of acceptability. However, issues were encountered with the automation related to the detection of and response to tactical conflicts. Lower ratings were given on account of these concerns, and it was found that a key contributor to the underlying problems was transitioning aircraft and the uncertainty of their trajectories. Stemming from those results, participants responded that they would rather have direct control over aircraft transitions as well as more control over the tactical conflict resolution automation. In contrast, participants responded that they would rather have the automation place aircraft back on trajectory, and perform weather avoidance and scheduling tasks.

  3. Dynamic Air Route Open-Close Problem for Airspace Management

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Dynamic airspace management plans and assigns airspace resources to airspace users on demand to increase airspace capacity. Although many studies of air traffic flow management (ATFM) have sought to optimally allocate air traffic to get the best use of given airspace resources, few studies have focused on how to build an efficient air traffic network or how to adjust the current network in real time. This paper presents an integer program model named the dynamic air route open-close problem (DROP). DROP has a cost-based objective function which takes into account constraints such as the shortest occupancy time of routes, which are not considered in ATFM models. The aim of DROP is to determine which routes will be opened to a certain user during a given time period. Simulation results show that DROP can facilitate utilization of air routes. DROP, a simplified version of an air traffic network constructing problem, is the first step towards realizing dynamic airspace management. The combination of ATFM and DROP can facilitate decisions toward more reasonable, efficient use of limited airspace resources.

  4. A quantitative approach to the traffic air quality problem: the Traffic Air Quality index.

    Science.gov (United States)

    Soliman, Ahmed S M; Jacko, Robert B

    2008-05-01

    The Traffic Air Quality (TAQ) model is a simple tool to estimate traffic fine particulate emissions on roadways (g/km) and can be used for both real-time analysis and for localized conformity analysis ("hot-spot" analysis for nonattainment areas) as defined by 40 CFR 93.123. This paper is a follow-up to a study published earlier regarding the development of the TAQ model. This paper shows how local air quality levels can be a factor in traffic management in nonattainment areas. Similar to the industrial source quotas measured in tons per year, it is proposed that road segments are to be assigned emission quotas (or TAQ indices) measured in pollutant mass emitted per road length (g/km) above which traffic-measures have to be taken to reduce the fine-particulates emissions on such road links. The TAQ model as well as traffic-rerouting measures along with the Intelligent Transportation System (ITS) protocols can be used to have a real-time control of the traffic conditions along expressways to maintain the fine-particulates emissions below the quota assigned per road link and consequently improving the over all local air quality in nonattainment areas.

  5. Neurotoxicity of traffic-related air pollution.

    Science.gov (United States)

    Costa, Lucio G; Cole, Toby B; Coburn, Jacki; Chang, Yu-Chi; Dao, Khoi; Roqué, Pamela J

    2017-03-01

    The central nervous system is emerging as an important target for adverse health effects of air pollution, where it may contribute to neurodevelopmental and neurodegenerative disorders. Air pollution comprises several components, including particulate matter (PM) and ultrafine particulate matter (UFPM), gases, organic compounds, and metals. An important source of ambient PM and UFPM is represented by traffic-related air pollution, primarily diesel exhaust (DE). Human epidemiological studies and controlled animal studies have shown that exposure to air pollution, and to traffic-related air pollution or DE in particular, may lead to neurotoxicity. In particular, air pollution is emerging as a possible etiological factor in neurodevelopmental (e.g. autism spectrum disorders) and neurodegenerative (e.g. Alzheimer's disease) disorders. The most prominent effects caused by air pollution in both humans and animals are oxidative stress and neuro-inflammation. Studies in mice acutely exposed to DE (250-300μg/m(3) for 6h) have shown microglia activation, increased lipid peroxidation, and neuro-inflammation in various brain regions, particularly the hippocampus and the olfactory bulb. An impairment of adult neurogenesis was also found. In most cases, the effects of DE were more pronounced in male mice, possibly because of lower antioxidant abilities due to lower expression of paraoxonase 2.

  6. High-resolution wind and temperature observations from aircraft tracked by Mode-S air traffic control radar

    Science.gov (United States)

    de Haan, S.

    2011-05-01

    Wind, temperature, and humidity observations from radiosonde and aircraft are the main sources of upper air information for meteorology. For mesoscale meteorology, the horizontal coverage of radiosondes is too sparse. Aircraft observations through Aircraft Meteorological Data Relay (AMDAR) sample an atmospheric profile in the vicinity of airports. However, not all aircraft are equipped with AMDAR or have the system activated. Observations inferred from an enhanced tracking and ranging (TAR) air traffic control radar can fill this gap. These radars follows all aircraft in the airspace visible to the radar for air traffic management. The TAR radar at Schiphol airport in Netherlands has a range of 270 km. This Mode-S radar contacts each aircraft every 4 s on which the transponder in the aircraft responds with a message that contains information on flight level, direction, and speed. Combined with the ground track of an aircraft, meteorological information on temperature and wind can be inferred from this information. Because all aircraft are required to respond to the TAR radar, the data volume is extremely large, being around 1.5 million observations per day. Note that there are no extra costs for this data link. The quality of these observations is assessed by comparison to numerical weather prediction (NWP) model information, AMDAR observations, and radiosonde observations. A preprocessing step is applied to enhance the quality of wind and temperature observations, albeit with a reduced time frequency of one observation of horizontal wind vector and temperature per aircraft per minute. Nevertheless, the number of observations per day is still very large. In this paper it is shown that temperature observations from Mode-S, even after corrections, are not very good; an RMS which is twice as large as AMDAR is observed when compared to NWP. In contrast to the temperature observations, the quality found for wind after correction and calibration is good; it is comparable

  7. Traffic optimization in transport networks based on local routing

    Science.gov (United States)

    Scellato, S.; Fortuna, L.; Frasca, M.; Gómez-Gardeñes, J.; Latora, V.

    2010-01-01

    Congestion in transport networks is a topic of theoretical interest and practical importance. In this paper we study the flow of vehicles in urban street networks. In particular, we use a cellular automata model on a complex network to simulate the motion of vehicles along streets, coupled with a congestion-aware routing at street crossings. Such routing makes use of the knowledge of agents about traffic in nearby roads and allows the vehicles to dynamically update the routes towards their destinations. By implementing the model in real urban street patterns of various cities, we show that it is possible to achieve a global traffic optimization based on local agent decisions.

  8. Routing strategies in traffic network and phase transition in network traffic flow

    Indian Academy of Sciences (India)

    Bing-Hong Wang; Wen-Xu Wang

    2008-08-01

    The dynamics of information traffic over scale-free networks has been investigated systematically. A series of routing strategies of data packets have been proposed, including the local routing strategy, the next-nearest-neighbour routing strategy, and the mixed routing strategy based on local static and dynamic information. The capacity of the network can be quantified by the phase transition from free flow state to congestion state. The optimal parameter values of each model leading to the highest efficiency of scale-free networked traffic systems have been found. Moreover, we have found hysteretic loop in networked traffic systems with finite packets delivering ability. Such hysteretic loop indicates the existence of the bi-stable state in the traffic dynamics over scale-free networks.

  9. Evaluation of Air Pollution Measurements in Urban Environment Considering Traffic Intensity

    OpenAIRE

    Zariņš Atis; Smirnovs Jānis; Lācis Raitis

    2014-01-01

    This paper presents the analysis of air pollution monitoring and evaluation results in the center of Riga City. The air quality reports have pointed out that road traffic and road infrastructure are the main issues of air pollution in the center of Riga. However, none of the reports validated this assumption considering actual traffic flow data. In the present article, the air pollution data have been collected and analyzed in the context with traffic flow. The statistical analysis of both th...

  10. Can Simulator Immersion Change Cognitive Style? Results from a Cross-Sectional Study of Field-Dependence--Independence in Air Traffic Control Students

    Science.gov (United States)

    Van Eck, Richard N.; Fu, Hongxia; Drechsel, Paul V. J.

    2015-01-01

    Air traffic control (ATC) operations are critical to the U.S. aviation infrastructure, making ATC training a critical area of study. Because ATC performance is heavily dependent on visual processing, it is important to understand how to screen for or promote relevant visual processing abilities. While conventional wisdom has maintained that such…

  11. Chaotic Control of Network Traffic

    Institute of Scientific and Technical Information of China (English)

    YANG Tan; CUI Yi-Dong; JIN Yue-Hui; CHENG Shi-Duan

    2009-01-01

    A method of chaotic control on network traffic is presented.By this method,the chaotic network traffic can be controlled to a pre-assigned equilibrium point according to chaotic prediction and the largest Lyapunov exponent of the traffic on congested link is reduced,thereby the probability of traffic burst and network congestion can be reduced.Numerical examples show that this method is effective.

  12. Alternate Routing in Tandem Traffic-Groomed Optical Networks

    Directory of Open Access Journals (Sweden)

    Alicia Nicki Washington

    2007-09-01

    Full Text Available Recent advances in telecommunication networks have allowed WDM to emerge as a viable solution to the ever-increasing demands of the Internet. Because these networks carry large amounts of traffic, alternate routing methods are designed in order to allow traffic to be properly re-routed from source to destination in the event of certain events, such as link blocking or failure. In this paper, we consider a tandem traffic-groomed optical network, modeled as a multi-level overflow system, where each level represents a wavelength between adjacent nodes. The queueing network is analyzed using a combination of methods. As will be shown, the decomposition method provides a good approximate analysis of large overflow systems supporting traffic from multiple sources.

  13. Determination of Sulphur Dioxide Concentrations in Ambient Air of Some Selected Traffic Areas in Kaduna Metropolis

    Directory of Open Access Journals (Sweden)

    Y. Mohammed

    2013-09-01

    Full Text Available This research study was aimed at determining concentrations of sulphurdioxide in ambient air of some selected areas viz: industrial area (Kakuri, high vehicler traffic/commercial area (Leventis Roundabout, traveling route (Kawo overhead bridge, Low vehicler traffic area (Tafawa Balewa Roundabout, residential area (Kawo New Extension and a control site (NFA base in Kaduna metropolis Nigeria. Air sample was collected at each sampling site by passing ambient air through an impinger bottle containing hydrogen peroxide (absorbent, at a flow-rate of 10 L/min for 30 min using air vacuum pump. The concentration of SO2 in the resultant solution (absorbent was determined by titrating against 0.005 moL/dm3 NaOH solutions. The average SO2 concentrations in the six sampling stations were within the range 0.16-0.75 ppm, with the highest values of 0.75 and 0.70 ppm at highly industrialized area (Kakuri and a high traffic area (Leventis roundabout respectively. The ambient air concentrations of SO2 depict the pattern; Industrial area (Kakuri >High vehicler traffic/commercial area (Leventis roundabout >Traveling route (Kawo overhead bridge >Low traffic area (Tafawa Balewa roundabout >Residential area (Kawo New Extension >Remote area (NAF Base Mando. Except for highly industrial area (Kakuri and the high traffic area (Leventis, The ambient air SO2 concentration are within the acceptable limits of United States Environmental Protection Agency (EPA and Nigeria’s Federal Environmental Protection Agency (FEPA standard limit which is 0.5 ppm for 30 min exposure time.

  14. Research on Using the Naturally Cold Air and the Snow for Data Center Air-conditioning, and Humidity Control

    Science.gov (United States)

    Tsuda, Kunikazu; Tano, Shunichi; Ichino, Junko

    To lower power consumption has becomes a worldwide concern. It is also becoming a bigger area in Computer Systems, such as reflected by the growing use of software-as-a-service and cloud computing whose market has increased since 2000, at the same time, the number of data centers that accumulates and manages the computer has increased rapidly. Power consumption at data centers is accounts for a big share of the entire IT power usage, and is still rapidly increasing. This research focuses on the air-conditioning that occupies accounts for the biggest portion of electric power consumption by data centers, and proposes to develop a technique to lower the power consumption by applying the natural cool air and the snow for control temperature and humidity. We verify those effectiveness of this approach by the experiment. Furthermore, we also examine the extent to which energy reduction is possible when a data center is located in Hokkaido.

  15. Efficient algorithms for optimal arrival scheduling and air traffic flow management

    Science.gov (United States)

    Saraf, Aditya

    search for optimal trajectories to be flown by each aircraft so that the flows commanded by the outer control-module are achieved. The two-level control system is tested in a dynamic simulation. Furthermore, as a component of the Eulerian part of this two-level system, we present a method for deriving an aggregate airspace-model in real-time, without depending on online integration of aircraft trajectories. This method uses a baseline Eulerian airspace-model, which is derived offline using historical track-data. In real-time, parameters of this model are adapted depending on the differences between the baseline-model and the real-world. This book-keeping based model-derivation indirectly retains some trajectory information. Hence, it serves as an excellent trade-off between Eulerian and trajectory-based modeling approaches. Most importantly, as a vital improvement over previous approaches, we take into consideration the control-dependent nature of the Eulerian-model while computing optimal flow-control decisions. As a proof of concept, we derive a baseline model for the Fort-Worth center and adapt it to predict sector-counts for another set of air traffic data. We also demonstrate the use of this model in a simulation-based optimization scheme for regulating the arrival flow at the Dallas Fort-Worth airport. An application to optimal re-routing strategy computation is also presented.

  16. Stochastic Modeling of Traffic Air Pollution

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    2014-01-01

    In this paper, modeling of traffic air pollution is discussed with special reference to infrastructures. A number of subjects related to health effects of air pollution and the different types of pollutants are briefly presented. A simple model for estimating the social cost of traffic related air...... and using simple Monte Carlo techniques to obtain a stochastic estimate of the costs of traffic air pollution for infrastructures....... pollution is derived. Several authors have published papers on this very complicated subject, but no stochastic modelling procedure have obtained general acceptance. The subject is discussed basis of a deterministic model. However, it is straightforward to modify this model to include uncertain parameters...

  17. Delay Banking for Managing Air Traffic

    Science.gov (United States)

    Green, Steve

    2008-01-01

    Delay banking has been invented to enhance air-traffic management in a way that would increase the degree of fairness in assigning arrival, departure, and en-route delays and trajectory deviations to aircraft impacted by congestion in the national airspace system. In delay banking, an aircraft operator (airline, military, general aviation, etc.) would be assigned a numerical credit when any of their flights are delayed because of an air-traffic flow restriction. The operator could subsequently bid against other operators competing for access to congested airspace to utilize part or all of its accumulated credit. Operators utilize credits to obtain higher priority for the same flight, or other flights operating at the same time, or later, in the same airspace, or elsewhere. Operators could also trade delay credits, according to market rules that would be determined by stakeholders in the national airspace system. Delay banking would be administered by an independent third party who would use delay banking automation to continually monitor flights, allocate delay credits, maintain accounts of delay credits for participating airlines, mediate bidding and the consumption of credits of winning bidders, analyze potential transfers of credits within and between operators, implement accepted transfers, and ensure fair treatment of all participating operators. A flow restriction can manifest itself in the form of a delay in assigned takeoff time, a reduction in assigned airspeed, a change in the position for the aircraft in a queue of all aircraft in a common stream of traffic (e.g., similar route), a change in the planned altitude profile for an aircraft, or change in the planned route for the aircraft. Flow restrictions are typically imposed to mitigate traffic congestion at an airport or in a region of airspace, particularly congestion due to inclement weather, or the unavailability of a runway or region of airspace. A delay credit would be allocated to an operator of a

  18. Human Resource Management: A Case Study of the Air Traffic Controller Strike in 1981

    Institute of Scientific and Technical Information of China (English)

    GAI Ke-ke; PAN Jing

    2009-01-01

    The article discusses several hemispheres of human resource management based on a typical case review. The study presents the main problems of the case from both employees and organizations; the issued problems involve compensa- tions and benefits, restructuring, job design, and training. Based on the analysis of the ease, two alternative solutions state that the potential routes for the organizations to avoid serious negative results. The study intreduces a number of recommen- dations that can be used as a reference for other organizations to avoid similar risks.

  19. A Brief Introduction of Air Traffic Management

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Air Traffic Management(ATM)started publication in 1995 by Air Traffic Management Bureauof CAAC.It is the first magazine about ATM field in CAAC.The chairman of Editorial Board ofATM is Mr.Bao Peide,Vice Minister of CAAC.Mr.Chen Ziye,Vice President of the 1st ResearchInstitute of CAAC and Chen Xuhua,General Director of Air Traffic Management Bureau are vicechairmen of the editorial board,and six general directors of local air traffic management bureau andsome professors and experts are members of the editorial board.ATM includes more than 20 columns,which are communication,navigation,surveillance,air trafficmanagement,special articles(policy,planning and management of implementation of CNS/ATM

  20. Strategic Framework of Air Traffic Development

    Directory of Open Access Journals (Sweden)

    Sanja Steiner

    2008-05-01

    Full Text Available The paper elaborates the past development of air traffic inEurope from the aspect of its economic benefits and ecologicallack of sustainability of conventional technology. The mainguidelines of the strategic development are related to the implementationof the global ecological standard and actual reformationprocesses of the air traffic management system postulatedby A TM 2000+ Strategy and the "Single European Sky"standard. The paper studies the wider aspects of integrated trafficdevelopment at the regional level and the factors influencingfurther development of the European air traffic.

  1. Evolutionary air traffic flow management for large 3D-problems

    NARCIS (Netherlands)

    Kemenade, C.H.M. van; Akker, J.M. van den; Kok, J.N.

    1996-01-01

    We present an evolutionary tool to solve free-route Air Traffic Flow Management problems within a three-dimensional air space. This is the first evolutionary tool which solves free-route planning problems involving a few hundred aircraft. We observe that the importance of the recombination operator

  2. Route guidance strategies revisited: Comparison and evaluation in an asymmetric two-route traffic system

    CERN Document Server

    He, Zhengbing; Guan, Wei

    2013-01-01

    To alleviate traffic congestion, a variety of route guidance strategies has been proposed for intelligent transportation systems. A number of the strategies are proposed and investigated on a symmetric two-route traffic system over the past decade. To evaluate the strategies in a more general scenario, this paper conducts eight prevalent strategies on a asymmetric two-route traffic network with different slowdown behaviors on alternative routes. The results show that only mean velocity feedback strategy is able to equalize travel time, i.e., approximate user optimality; while the others fail due to incapability of establishing relations between the feedback parameters and travel time. The paper helps better understand these strategies, and suggests mean velocity feedback strategy if the authority intends to achieve user optimality.

  3. Experience-Based Mitigation of Age-Related Performance Declines: Evidence from Air Traffic Control

    Science.gov (United States)

    Nunes, Ashley; Kramer, Arthur F.

    2009-01-01

    Previous research has found age-related deficits in a variety of cognitive processes. However, some studies have demonstrated age-related sparing on tasks where individuals have substantial experience, often attained over many decades. Here, the authors examined whether decades of experience in a fast-paced demanding profession, air traffic…

  4. Effective bandwidth guaranteed routing schemes for MPLS traffic engineering

    Science.gov (United States)

    Wang, Bin; Jain, Nidhi

    2001-07-01

    In this work, we present online algorithms for dynamic routing bandwidth guaranteed label switched paths (LSPs) where LSP set-up requests (in terms of a pair of ingress and egress routers as well as its bandwidth requirement) arrive one by one and there is no a priori knowledge regarding future LSP set-up requests. In addition, we consider rerouting of LSPs in this work. Rerouting of LSPs has not been well studied in previous work on LSP routing. The need of LSP rerouting arises in a number of ways: occurrence of faults (link and/or node failures), re-optimization of existing LSPs' routes to accommodate traffic fluctuation, requests with higher priorities, and so on. We formulate the bandwidth guaranteed LSP routing with rerouting capability as a multi-commodity flow problem. The solution to this problem is used as the benchmark for comparing other computationally less costly algorithms studied in this paper. Furthermore, to more efficiently utilize the network resources, we propose online routing algorithms which route bandwidth demands over multiple paths at the ingress router to satisfy the customer requests while providing better service survivability. Traffic splitting and distribution over the multiple paths are carefully handled using table-based hashing schemes while the order of packets within a flow is preserved. Preliminary simulations are conducted to show the performance of different design choices and the effectiveness of the rerouting and multi-path routing algorithms in terms of LSP set-up request rejection probability and bandwidth blocking probability.

  5. Modeling Road Traffic Using Service Center

    Directory of Open Access Journals (Sweden)

    HARAGOS, I.-M.

    2012-05-01

    Full Text Available Transport systems have an essential role in modern society because they facilitate access to natural resources and they stimulate trade. Current studies aimed at improving transport networks by developing new methods for optimization. Because of the increase in the global number of cars, one of the most common problems facing the transport network is congestion. By creating traffic models and simulate them, we can avoid this problem and find appropriate solutions. In this paper we propose a new method for modeling traffic. This method considers road intersections as being service centers. A service center represents a set consisting of a queue followed by one or multiple servers. This model was used to simulate real situations in an urban traffic area. Based on this simulation, we have successfully determined the optimal functioning and we have computed the performance measures.

  6. Air Traffic Management Cost Assessment Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Robust Analytics air traffic management cost assessment tool provides the comprehensive capability to analyze the impacts of NASA Airspace Systems Program (ASP)...

  7. pH in exhaled breath condensate and nasal lavage as a biomarker of air pollution-related inflammation in street traffic-controllers and office-workers

    Directory of Open Access Journals (Sweden)

    Thamires Marques de Lima

    2013-12-01

    Full Text Available OBJECTIVE: To utilize low-cost and simple methods to assess airway and lung inflammation biomarkers related to air pollution. METHODS: A total of 87 male, non-smoking, healthy subjects working as street traffic-controllers or office-workers were examined to determine carbon monoxide in exhaled breath and to measure the pH in nasal lavage fluid and exhaled breath condensate. Air pollution exposure was measured by particulate matter concentration, and data were obtained from fixed monitoring stations (8-h work intervals per day, during the 5 consecutive days prior to the study. RESULTS: Exhaled carbon monoxide was two-fold greater in traffic-controllers than in office-workers. The mean pH values were 8.12 in exhaled breath condensate and 7.99 in nasal lavage fluid in office-workers; these values were lower in traffic-controllers (7.80 and 7.30, respectively. Both groups presented similar cytokines concentrations in both substrates, however, IL-1β and IL-8 were elevated in nasal lavage fluid compared with exhaled breath condensate. The particulate matter concentration was greater at the workplace of traffic-controllers compared with that of office-workers. CONCLUSION: The pH values of nasal lavage fluid and exhaled breath condensate are important, robust, easy to measure and reproducible biomarkers that can be used to monitor occupational exposure to air pollution. Additionally, traffic-controllers are at an increased risk of airway and lung inflammation during their occupational activities compared with office-workers.

  8. Integrated Evaluation of Air Traffic Controller Workload Based on Matter-Element Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming; HAN Song-chen

    2008-01-01

    A model for evaluating the controller workload was presented based on matter-element analysis, particularly from a man-machine-environment system engineering perspective. On the basis of a questionnaire survey, 18 kinds of indexes which influence the controller workload were determined. By establishing the classical field and node field of the controller workload, the correlation function of the controller workload grade was obtained; then the correlation degree and estimated grade of controller workload were given. A case study verifies the feasibility of the proposed evaluation method.

  9. Visual Analysis of Air Traffic Data

    Science.gov (United States)

    Albrecht, George Hans; Pang, Alex

    2012-01-01

    In this paper, we present visual analysis tools to help study the impact of policy changes on air traffic congestion. The tools support visualization of time-varying air traffic density over an area of interest using different time granularity. We use this visual analysis platform to investigate how changing the aircraft separation volume can reduce congestion while maintaining key safety requirements. The same platform can also be used as a decision aid for processing requests for unmanned aerial vehicle operations.

  10. The FAA Plans and Programs for the Future Airport and Air Traffic control System.

    Science.gov (United States)

    1980-11-13

    have been effectively resolved through minor software design changes, contrary to self-serving charges by the controllers’ union, the number of...improvements can be achieved. You will hear more later on about the computer and display replacement program. (VU-GRAPH -- ETABS ) o Other work in advanced...tabular weather uata t,’ the controllers, the Electronic Tabular Display Subsystem ( ETABS ) and the Terminal Information Display System (TIDS) will be used

  11. Impact of traffic volume and composition on the air quality and pedestrian exposure in urban street canyon

    Science.gov (United States)

    Rakowska, Agata; Wong, Ka Chun; Townsend, Thomas; Chan, Ka Lok; Westerdahl, Dane; Ng, Simon; Močnik, Griša; Drinovec, Luka; Ning, Zhi

    2014-12-01

    Vehicle emissions are identified as a major source of air pollution in metropolitan areas. Emission control programs in many cities have been implemented as part of larger scale transport policy interventions to control traffic pollutants and reduce public health risks. These interventions include provision of traffic-free and low emission zones and congestion charging. Various studies have investigated the impact of urban street configurations, such as street canyon in urban centers, on pollutants dispersion and roadside air quality. However, there are few investigations in the literature to study the impact of change of fleet composition and street canyon effects on the on-road pollutants concentrations and associated roadside pedestrian exposure to the pollutants. This study presents an experimental investigation on the traffic related gas and particle pollutants in and near major streets in one of the most developed business districts in Hong Kong, known as Central. Both street canyon and open roadway configurations were included in the study design. Mobile measurement techniques were deployed to monitor both on-road and roadside pollutants concentrations at different times of the day and on different days of a week. Multiple traffic counting points were also established to concurrently collect data on traffic volume and fleet composition on individual streets. Street canyon effects were evident with elevated on-road pollutants concentrations. Diesel vehicles were found to be associated with observed pollutant levels. Roadside black carbon concentrations were found to correlate with their on-road levels but with reduced concentrations. However, ultrafine particles showed very high concentrations in roadside environment with almost unity of roadside/on-road ratios possibly due to the accumulation of primary emissions and secondary PM formation. The results from the study provide useful information for the effective urban transport design and bus route

  12. Proactive Traffic Information Control in Emergency Evacuation Network

    Directory of Open Access Journals (Sweden)

    Zhengfeng Huang

    2015-01-01

    Full Text Available Traffic demand in emergency evacuation is usually too large to be effectively managed with reactive traffic information control methods. These methods adapt to the road traffic passively by publishing real-time information without consideration of the routing behavior feedback produced by evacuees. Other remedy measures have to be prepared in case of nonrecurring congestion under these methods. To use the network capacity fully to mitigate near-future evacuation traffic congestion, we propose proactive traffic information control (PTIC model. Based on the mechanism between information and routing behavior feedback, this model can change the route choice of evacuees in advance by dissipating strategic traffic information. Generally, the near-future traffic condition is difficult to accurately predict because it is uncertain in evacuation. Assume that the value of traffic information obeys certain distribution within a range, and then real-time traffic information may reflect the most-likely near-future traffic condition. Unlike the real-time information, the proactive traffic information is a selection within the range to achieve a desired level of the road network performance index (total system travel time. In the aspect of the solution algorithm, differential equilibrium decomposed optimization (D-EDO is proposed to compare with other heuristic methods. A field study on a road network around a large stadium is used to validate the PTIC.

  13. Impact of future time-based operations on situation awareness of air traffic controllers

    NARCIS (Netherlands)

    Oprins, E.A.P.B.; Zwaaf, D.; Eriksson, F.; Merwe, K. van de; Roe, R.

    2009-01-01

    A time-based operation, as planned in the ATM future, is assumed to affect the controllers’ Situation Awareness (SA) due to a higher priority of meeting a time objective and increasing automation. This paper provides SA requirements on the design of controller support tools in time-based operations,

  14. Assessing Prior Experience in the Selection of Air Traffic Control Specialists

    Science.gov (United States)

    2013-04-01

    Crosstabulation --------------------------B1 APPENDIX C: IFR Operations Experience • Academy Training Performance Crosstabulation ---------C1 APPENDIX...Control Specialist (ATCS) rating? (n=9,333) BQ35 – Do you have prior Instrument Flight Rules ( IFR ) operations experience? (n = 9,349) 2. Hold or...not have a prior ATCS rating. Do you have prior IFR (Instrument Flight Rules) Operations experience? Of the 9,349 respondents to this question

  15. Traffic-Related Air Pollution and Parkinson's Disease in Denmark

    DEFF Research Database (Denmark)

    Ritz, Beate; Lee, Pei-Chen; Hansen, Johnni

    2016-01-01

    air pollution and Parkinson's disease. METHODS: In a case-control study of 1,696 Parkinson's disease (PD) patients identified from Danish hospital registries and diagnosed 1996-2009 and 1,800 population controls matched by gender and year of birth we assessed long-term traffic-related air pollutant......OBJECTIVE: Very little is currently known about air pollutants' adverse effects on neurodegenerative diseases even though recent studies have linked particulate exposures to brain pathologies associated with Parkinson's and Alzheimer's disease. Here we investigate long-term exposure to traffic-related...

  16. Time Relevance of Convective Weather Forecast for Air Traffic Automation

    Science.gov (United States)

    Chan, William N.

    2006-01-01

    The Federal Aviation Administration (FAA) is handling nearly 120,000 flights a day through its Air Traffic Management (ATM) system and air traffic congestion is expected to increse substantially over the next 20 years. Weather-induced impacts to throughput and efficiency are the leading cause of flight delays accounting for 70% of all delays with convective weather accounting for 60% of all weather related delays. To support the Next Generation Air Traffic System goal of operating at 3X current capacity in the NAS, ATC decision support tools are being developed to create advisories to assist controllers in all weather constraints. Initial development of these decision support tools did not integrate information regarding weather constraints such as thunderstorms and relied on an additional system to provide that information. Future Decision Support Tools should move towards an integrated system where weather constraints are factored into the advisory of a Decision Support Tool (DST). Several groups such at NASA-Ames, Lincoln Laboratories, and MITRE are integrating convective weather data with DSTs. A survey of current convective weather forecast and observation data show they span a wide range of temporal and spatial resolutions. Short range convective observations can be obtained every 5 mins with longer range forecasts out to several days updated every 6 hrs. Today, the short range forecasts of less than 2 hours have a temporal resolution of 5 mins. Beyond 2 hours, forecasts have much lower temporal. resolution of typically 1 hour. Spatial resolutions vary from 1km for short range to 40km for longer range forecasts. Improving the accuracy of long range convective forecasts is a major challenge. A report published by the National Research Council states improvements for convective forecasts for the 2 to 6 hour time frame will only be achieved for a limited set of convective phenomena in the next 5 to 10 years. Improved longer range forecasts will be probabilistic

  17. Road Traffic Control Based on Genetic Algorithm for Reducing Traffic Congestion

    Science.gov (United States)

    Shigehiro, Yuji; Miyakawa, Takuya; Masuda, Tatsuya

    In this paper, we propose a road traffic control method for reducing traffic congestion with genetic algorithm. In the not too distant future, the system which controls the routes of all vehicles in a certain area must be realized. The system should optimize the routes of all vehicles, however the solution space of this problem is enormous. Therefore we apply the genetic algorithm to this problem, by encoding the route of all vehicles to a fixed length chromosome. To improve the search performance, a new genetic operator called “path shortening” is also designed. The effectiveness of the proposed method is shown by the experiment.

  18. Analysis of a Dynamic Multi-Track Airway Concept for Air Traffic Management

    Science.gov (United States)

    Wing, David J.; Smith, Jeremy C.; Ballin, Mark G.

    2008-01-01

    The Dynamic Multi-track Airways (DMA) Concept for Air Traffic Management (ATM) proposes a network of high-altitude airways constructed of multiple, closely spaced, parallel tracks designed to increase en-route capacity in high-demand airspace corridors. Segregated from non-airway operations, these multi-track airways establish high-priority traffic flow corridors along optimal routes between major terminal areas throughout the National Airspace System (NAS). Air traffic controllers transition aircraft equipped for DMA operations to DMA entry points, the aircraft use autonomous control of airspeed to fly the continuous-airspace airway and achieve an economic benefit, and controllers then transition the aircraft from the DMA exit to the terminal area. Aircraft authority within the DMA includes responsibility for spacing and/or separation from other DMA aircraft. The DMA controller is responsible for coordinating the entry and exit of traffic to and from the DMA and for traffic flow management (TFM), including adjusting DMA routing on a daily basis to account for predicted weather and wind patterns and re-routing DMAs in real time to accommodate unpredicted weather changes. However, the DMA controller is not responsible for monitoring the DMA for traffic separation. This report defines the mature state concept, explores its feasibility and performance, and identifies potential benefits. The report also discusses (a) an analysis of a single DMA, which was modeled within the NAS to assess capacity and determine the impact of a single DMA on regional sector loads and conflict potential; (b) a demand analysis, which was conducted to determine likely city-pair candidates for a nationwide DMA network and to determine the expected demand fraction; (c) two track configurations, which were modeled and analyzed for their operational characteristic; (d) software-prototype airborne capabilities developed for DMA operations research; (e) a feasibility analysis of key attributes in

  19. Next Generation Network Routing and Control Plane

    DEFF Research Database (Denmark)

    Fu, Rong

    proved, the dominating Border Gateway Protocol (BGP) cannot address all the issues that in inter-domain QoS routing. Thus a new protocol or network architecture has to be developed to be able to carry the inter-domain traffic with the QoS and TE consideration. Moreover, the current network control also......-domain. It is a routing component that flexibly supports path computation with different requirements, constraints and areas. It is also can be seen as part of NGN transport control plane, which integrates with the other functions. In the aspect of resource control, an NGN release Resource and Admission Control Functions...

  20. An Empirically grounded Agent Based simulator for the Air Traffic Management in the SESAR scenario

    CERN Document Server

    Gurtner, Gérald; Ducci, Marco; Miccichè, Salvatore

    2016-01-01

    In this paper we present a simulator allowing to perform policy experiments relative to the air traffic management. Different SESAR solutions can be implemented in the model to see the reaction of the different stakeholders as well as other relevant metrics (delays, safety, etc). The model describes both the strategic phase associated to the planning of the flight trajectories and the tactical modifications occurring in the en-route phase. An implementation of the model is available as open-source and freely accessible by any user. More specifically, different procedures related to business trajectories and free-routing are tested and we illustrate the capabilities of the model on airspace implementing these concepts. After performing numerical simulations with the model, we show that in a free-routing scenario the controllers perform less operations although they are dispersed over a larger portion of the airspace. This can potentially increase the complexity of conflict detection and resolution for controll...

  1. PRINCIPLES OF SAFETY MANAGEMENT OF AIR TRAFFIC FLOWS AND CAPACITY UNDER UNCERTAINTY CONDITIONS

    Directory of Open Access Journals (Sweden)

    Wang Bo

    2016-11-01

    Full Text Available Purpose: The aim of this study is to investigate the general principles of safety and capacity management in Aeronautical systems regarding air traffic flows operations under uncertainty conditions. In this work the theoretical framework assessing at the same time both the uncertainty model and flight plans model are proposed. Methods: To study features of safety of air traffic flows and capacity under uncertainty conditions were built the original probabilistic models including Bayesian Network for flight plan and air traffic control sector model based on Poisson Binomial Distribution. Results: We obtained models for safety management of air traffic flows and capacity under uncertainty conditions. We discussed appropriate approach for estimating the parameters of safety of air traffic flows and capacity under uncertainty and Markovian uncertainty model for the flight plan. Discussion: We developed the Bayesian Network for flight plan and air traffic control sector models for safety management of air traffic flows and capacity under uncertainty conditions.

  2. Traffic properties for stochastic routings on scale-free networks

    CERN Document Server

    Hayashi, Yukio

    2011-01-01

    For realistic scale-free networks, we investigate the traffic properties of stochastic routing inspired by a zero-range process known in statistical physics. By parameters $\\alpha$ and $\\delta$, this model controls degree-dependent hopping of packets and forwarding of packets with higher performance at more busy nodes. Through a theoretical analysis and numerical simulations, we derive the condition for the concentration of packets at a few hubs. In particular, we show that the optimal $\\alpha$ and $\\delta$ are involved in the trade-off between a detour path for $\\alpha 0$; In the low-performance regime at a small $\\delta$, the wandering path for $\\alpha 0$ and $\\alpha < 0$ is small, neither the wandering long path with short wait trapped at nodes ($\\alpha = -1$), nor the short hopping path with long wait trapped at hubs ($\\alpha = 1$) is advisable. A uniformly random walk ($\\alpha = 0$) yields slightly better performance. We also discuss the congestion phenomena in a more complicated situation with pack...

  3. Traffic Light Controller Using Fpga

    Directory of Open Access Journals (Sweden)

    D.Bhavana

    2015-04-01

    Full Text Available The traffic light sequence works on the specific switching of Red, Green and Yellow lights in a particular way with stipulated time form. The normal function of traffic lights requires sophisticated control and coordination to ensure that traffic moves as smoothly and safely as possible and that pedestrians are protected when they cross the roads [1] .This Traffic Light sequence is generated using a specific switching mechanism which will help to control a traffic light system on a road in a specified sequence. This paper focuses on the fact that the traffic lights can be varied in the day and night mode depending on the intensity of the traffic. It plays a vital role in supervising and running the metropolitan traffic and evade the possibilities of any unfortunate mishaps happening in and around the cities. It is a sequential machine to be scrutinized as per the requirements and programmed through a multistep development process. The methods that are used in this project are proposing the circuit, write a code, simulate, synthesis and implement on the hardware [8] . In this project, XILINX Software was chosen to devise a schematic using schematic edit, write a code using Verilog HDL (Hardware Description Language text editor and implements the circuit on Programmable Logic Device [PLD].The system has been successfully tested and implemented in hardware using Nexys 2 Digilent FPGA.

  4. Impact of air traffic on the climate

    Energy Technology Data Exchange (ETDEWEB)

    Stief, G. [Florence Univ. (Italy). Ist. di Agrometeorologia

    1997-12-31

    Though emission from world-wide air traffic may seem to be relatively small in comparison to that from all other anthropogenic sources, the deleterious effect on the climate of the gases and particles emitted by planes is disproportionately large. It is thought that air traffic, working together with pollutants that have already accumulated at critical heights, and depending on humidity and temperature, plays a decisive role in helping to cause the changes, presented below, in global radiation, sunshine duration, rainfall and maximum and minimum temperatures which are taking place. (author) 7 refs.

  5. Research on some key techniques to improve the reliability of air traffic control system%提高空管系统可靠性的若干关键技术的探究

    Institute of Scientific and Technical Information of China (English)

    卢昌鹏

    2015-01-01

    With the rapid development of the aviation industry in China,air traffic safety problem has become the focus of the people,air traffic control system becomes the important factor of air traffic safety..As the aviation disaster has occurred in recent years,it has also sounded the alarm for the safety of air traffic control in China..Therefore,we should greatly strengthen the air traffic safety management, improve the safety and reliability of the air traffic control system.The reliability of air traffic control system can prevent the occurrence of air accidents in the greatest degree..This paper mainly explores some key technologies of the reliability of air traffic control system,and hopes to provide theoretical support for aviation security in China..%随着我国航空行业的迅猛发展,空中交通安全问题也成为人们关注的焦点,空管系统成为空中交通安全问题的重要制约因素。随着近段时间各国以来航空灾难的不断发生,也为我国的空管安全敲响了警钟。因此,我国要大大加强空中交通安全管理,提升空管系统的安全性和可靠性。具有可靠性的空管系统技术可以在最大程度上预防空中安全事故的发生。本文主要对有关空管系统可靠性的若干关键技术进行了探究,希望能为我国航空安全提供理论上的支持。

  6. A knowledge-based system for controlling automobile traffic

    Science.gov (United States)

    Maravas, Alexander; Stengel, Robert F.

    1994-01-01

    Transportation network capacity variations arising from accidents, roadway maintenance activity, and special events as well as fluctuations in commuters' travel demands complicate traffic management. Artificial intelligence concepts and expert systems can be useful in framing policies for incident detection, congestion anticipation, and optimal traffic management. This paper examines the applicability of intelligent route guidance and control as decision aids for traffic management. Basic requirements for managing traffic are reviewed, concepts for studying traffic flow are introduced, and mathematical models for modeling traffic flow are examined. Measures for quantifying transportation network performance levels are chosen, and surveillance and control strategies are evaluated. It can be concluded that automated decision support holds great promise for aiding the efficient flow of automobile traffic over limited-access roadways, bridges, and tunnels.

  7. Risk management of air traffic control based on level of unsafe events%基于不安全事件等级的空管风险管理研究

    Institute of Scientific and Technical Information of China (English)

    张晓全; 于露; 曹钧

    2012-01-01

    空中交通管制是航空安全的重要保障,为有效避免空管不安全事件的发生,找出导致不同等级空管不安全事件的风险因素并提出针对性的控制措施,根据某管制中心发生的不安全事件信息,结合其严重性等级进行风险管理研究.首先对该管制中心进行风险识别,在统计并分析其2001-2010年不安全事件的数据后,选择SHEL模型按照人员(L)、人员与人员(L-L)、人员与软件(L-S)、人员与硬件(L-H)和人员与环境(L-E)方面系统地识别出风险因素集;在此基础上,运用灰色关联分析进行定量评价,得出不同等级不安全事件风险因素评价结果;最后根据评价结果制定出不同等级不安全事件相应的风险控制措施.%Air traffic control is essential for the safety of aviation; in order to avoid the happening of unsafe events of air traffic control effectively, find the risk factors which lead to different level of unsafe events and make corresponding risk control measures, the information of unsafe events which happened in the air traffic control center was combined with the level of severity to implement risk management. Firstly risk identification was carried out to an air traffic control center. After the statistics of the unsafe events which happened from 2001 to 2010 in this air traffic control center was analyzed, the SHELL model was selected as the risk identification tool. Air traffic control risk factors was classified and analyzed in accordance with Life (L) factors/Life and Life (L-L) factors/ Life and Software (L-S) factors/ Life and Hardware (L-H) factors/ Life and Environmental factors (L-E) factors to get the muster of risk factors; then grey correlation degree was used as the tool of risk assessment to quantitatively analyze the importance of risk factors of different level of unsafe events. Finally, based on the results of risk assessment, corresponding risk control measures of different level of unsafe events

  8. Optimal Control of Fully Routed Air Traffic in the Presence of Uncertainty and Kinodynamic Constraints

    Science.gov (United States)

    2014-09-18

    IEEE, Bogota , Colombia, 2011. [10] Bertsekas, Dimitri P. “Nondifferentiable optimization via approximation”. Mathematical Programming Studies, 3:1...and Differnetial Forms. Prentice-Hall, Inc., Upper Saddle River , NJ, 1999. [40] Isaacson, Douglas and J.E. Robinson III. “A knowledge-based conflict

  9. Airborne Use of Traffic Intent Information in a Distributed Air-Ground Traffic Management Concept: Experiment Design and Preliminary Results

    Science.gov (United States)

    Wing, David J.; Adams, Richard J.; Barmore, Bryan E.; Moses, Donald

    2002-01-01

    This paper presents initial findings of a research study designed to provide insight into the issue of intent information exchange in constrained en-route air-traffic operations and its effect on pilot decision making and flight performance. The piloted simulation was conducted in the Air Traffic Operations Laboratory at the NASA Langley Research Center. Two operational modes for autonomous operations were compared under conditions of low and high operational complexity. The tactical mode was characterized primarily by the use of state information for conflict detection and resolution and an open-loop means for the pilot to meet operational constraints. The strategic mode involved the combined use of state and intent information, provided the pilot an additional level of alerting, and allowed a closed-loop approach to meeting operational constraints. Operational constraints included separation assurance, schedule adherence, airspace hazard avoidance, flight efficiency, and passenger comfort. Potential operational benefits of both modes are illustrated through several scenario case studies. Subjective pilot ratings and comments comparing the tactical and strategic modes are presented.

  10. Design Principles and Algorithms for Air Traffic Arrival Scheduling

    Science.gov (United States)

    Erzberger, Heinz; Itoh, Eri

    2014-01-01

    This report presents design principles and algorithms for building a real-time scheduler of arrival aircraft based on a first-come-first-served (FCFS) scheduling protocol. The algorithms provide the conceptual and computational foundation for the Traffic Management Advisor (TMA) of the Center/terminal radar approach control facilities (TRACON) automation system, which comprises a set of decision support tools for managing arrival traffic at major airports in the United States. The primary objective of the scheduler is to assign arrival aircraft to a favorable landing runway and schedule them to land at times that minimize delays. A further objective of the scheduler is to allocate delays between high-altitude airspace far away from the airport and low-altitude airspace near the airport. A method of delay allocation is described that minimizes the average operating cost in the presence of errors in controlling aircraft to a specified landing time. This report is a revision of an earlier paper first presented as part of an Advisory Group for Aerospace Research and Development (AGARD) lecture series in September 1995. The authors, during vigorous discussions over the details of this paper, felt it was important to the air-trafficmanagement (ATM) community to revise and extend the original 1995 paper, providing more detail and clarity and thereby allowing future researchers to understand this foundational work as the basis for the TMA's scheduling algorithms.

  11. Traffic jams: dynamics and control.

    Science.gov (United States)

    Orosz, Gábor; Wilson, R Eddie; Stépán, Gábor

    2010-10-13

    This introductory paper reviews the current state-of-the-art scientific methods used for modelling, analysing and controlling the dynamics of vehicular traffic. Possible mechanisms underlying traffic jam formation and propagation are presented from a dynamical viewpoint. Stable and unstable motions are described that may give the skeleton of traffic dynamics, and the effects of driver behaviour are emphasized in determining the emergent state in a vehicular system. At appropriate points, references are provided to the papers published in the corresponding Theme Issue.

  12. Stochastic control of traffic patterns

    DEFF Research Database (Denmark)

    Gaididei, Yuri B.; Gorria, Carlos; Berkemer, Rainer

    2013-01-01

    A stochastic modulation of the safety distance can reduce traffic jams. It is found that the effect of random modulation on congestive flow formation depends on the spatial correlation of the noise. Jam creation is suppressed for highly correlated noise. The results demonstrate the advantage...... of heterogeneous performance of the drivers in time as well as individually. This opens the possibility for the construction of technical tools to control traffic jam formation....

  13. 针对跑道侵入开展空管系统抵御%Against the runway intrusion to carry out air traffic control system to resist

    Institute of Scientific and Technical Information of China (English)

    赵阳

    2015-01-01

    Along with the prosperity and development of the social economy,air traffic was also people make full use of and global civil aviation transportation is more and more frequent,resulting in airport ground traffic becomes congested.The runway incursion is becoming increasingly serious,the slightest mistake will cause the plane crash tragedy.This paper introduces the definition and types of the intrusion runway, analyzes the reasons of the intrusion of the runway,and puts forward the technology leading of the air traffic control system to prevent runway intrusion and improve the safety operation level of airport runway..%随着社会经济的繁荣发展,空中交通也被人们充分地利用,全球民航业的运输交通也越来越频繁,造成机场的地面交通也随之拥挤不堪。跑道侵入的现象日益严重,稍有不慎就会会造成机毁人亡的悲剧。本文介绍侵入跑道的定义及种类,分析侵入跑道产生的原因,提出空管系统对预防跑道侵入的技术主导,改善机场跑道的安全运行水平。

  14. As Traffic Piles Up, So Does Air Pollution

    Science.gov (United States)

    ... 160914.html As Traffic Piles Up, So Does Air Pollution To minimize exposure, researchers recommend shutting windows and ... Doing so can reduce your exposure to toxic air pollution from a traffic jam by up to 76 ...

  15. Traffic restrictions on Routes Bloch, Maxwell and Bohr

    CERN Multimedia

    TS Department

    2008-01-01

    Excavation and pipework is being carried out in the framework of the transfer of the waste water treatment plant for the effluents from the surface treatment workshops from Building 254 to Building 676, currently under construction. This work may encroach onto Routes Bloch, Maxwell and Bohr and disrupt the flow of traffic. Users are requested to comply with the road signs that will be erected. The work is expected to last until the beginning of December 2008. Thank you for your understanding. TS/CE and TS/FM Groups Tel.7 4188 or 16 4314

  16. Network Congestion Control with Markovian Multipath Routing

    CERN Document Server

    Cominetti, Roberto

    2011-01-01

    In this paper we consider an integrated model for TCP/IP protocols with multipath routing. The model combines a Network Utility Maximization for rate control based on end-to-end queuing delays, with a Markovian Traffic Equilibrium for routing based on total expected delays. We prove the existence of a unique equilibrium state which is characterized as the solution of an unconstrained strictly convex program. A distributed algorithm for solving this optimization problem is proposed, with a brief discussion of how it can be implemented by adapting the current Internet protocols.

  17. 民航空管安全文化建设探析%Establishment of the safety culture in civil aviation air traffic control

    Institute of Scientific and Technical Information of China (English)

    张健; 宋祥波; 王万乐

    2012-01-01

    Based on the objective law of civil aviation safety development, it is necessary to establish and sustain-ably improve effective means and measures on safety culture construction in civil aviation air traffic control for ensuring the continuous safety of civil aviation in China, with consideration of synthetically requirement of carrying out continuous safety concept for ATM, the requirement of reducing human errors in air traffic control and the requirement of building ATM safety management system. In-depth exploration is launched on the safety culture construction pathways, and relevant suggestions and measures are put forwarded, such as developing cultural and entertaining activities, establishing psychological training and counseling mechanism for air traffic controllers, enhancing air traffic controllers adaptability to ATM new technology. ATM safety culture establishment is the strong backing of ATC development, and effective means and measures promoting construction will become the strong safeguard of a-viation operation safety.%根据民航空管安全发展的客观规律,在综合考虑践行空管持续安全理念、减少空管人为差错、建设空管安全管理体系的基础上,提出要实现我国民航的持续安全,就要构建并不断完善空管安全文化建设的有效手段和途径.对空管安全文化建设的途径展开了深入探索,并提出了相关建议和措施,包括开展技能竞赛等文化娱乐活动、建立管制员心理培训与辅导机制、提升管制员新技术适应能力等.空管安全文化的建设是空管发展的坚强后盾,有效手段和措施建设的推进将成为航空运行安全的有力保障.

  18. Macroscopic Model and Simulation Analysis of Air Traffic Flow in Airport Terminal Area

    Directory of Open Access Journals (Sweden)

    Honghai Zhang

    2014-01-01

    Full Text Available We focus on the spatiotemporal characteristics and their evolvement law of the air traffic flow in airport terminal area to provide scientific basis for optimizing flight control processes and alleviating severe air traffic conditions. Methods in this work combine mathematical derivation and simulation analysis. Based on cell transmission model the macroscopic models of arrival and departure air traffic flow in terminal area are established. Meanwhile, the interrelationship and influential factors of the three characteristic parameters as traffic flux, density, and velocity are presented. Then according to such models, the macro emergence of traffic flow evolution is emulated with the NetLogo simulation platform, and the correlativity of basic traffic flow parameters is deduced and verified by means of sensitivity analysis. The results suggest that there are remarkable relations among the three characteristic parameters of the air traffic flow in terminal area. Moreover, such relationships evolve distinctly with the flight procedures, control separations, and ATC strategies.

  19. Effects of Vehicle Number Feedback in Multi-Route Intelligent Traffic Systems

    Science.gov (United States)

    Dong, Chuanfei; Ma, Xu; Wang, Binghong

    We first study dynamics of traffic flow with real-time information and the influence of a new feedback strategy named Vehicle Number Feedback Strategy (VNFS) in a multi-route scenario in which dynamic information can be generated and displayed on the board (the board refers to a variable message sign where information on the routes is displayed) to guide road users to make a choice. In a multi-route scenario, our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting vehicle number feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e. Travel Time Feedback Strategy (TTFS), Mean Velocity Feedback Strategy (MVFS) and Congestion Coefficient Feedback Strategy (CCFS). We also discuss the influence of expected arrival rate (Vp) at the entrance on the average flux of each route, and we find that the flux adopting VNFS is always the largest at each Vp value among these four feedback strategies.

  20. Wind Prediction Accuracy for Air Traffic Management Decision Support Tools

    Science.gov (United States)

    Cole, Rod; Green, Steve; Jardin, Matt; Schwartz, Barry; Benjamin, Stan

    2000-01-01

    The performance of Air Traffic Management and flight deck decision support tools depends in large part on the accuracy of the supporting 4D trajectory predictions. This is particularly relevant to conflict prediction and active advisories for the resolution of conflicts and the conformance with of traffic-flow management flow-rate constraints (e.g., arrival metering / required time of arrival). Flight test results have indicated that wind prediction errors may represent the largest source of trajectory prediction error. The tests also discovered relatively large errors (e.g., greater than 20 knots), existing in pockets of space and time critical to ATM DST performance (one or more sectors, greater than 20 minutes), are inadequately represented by the classic RMS aggregate prediction-accuracy studies of the past. To facilitate the identification and reduction of DST-critical wind-prediction errors, NASA has lead a collaborative research and development activity with MIT Lincoln Laboratories and the Forecast Systems Lab of the National Oceanographic and Atmospheric Administration (NOAA). This activity, begun in 1996, has focussed on the development of key metrics for ATM DST performance, assessment of wind-prediction skill for state of the art systems, and development/validation of system enhancements to improve skill. A 13 month study was conducted for the Denver Center airspace in 1997. Two complementary wind-prediction systems were analyzed and compared to the forecast performance of the then standard 60 km Rapid Update Cycle - version 1 (RUC-1). One system, developed by NOAA, was the prototype 40-km RUC-2 that became operational at NCEP in 1999. RUC-2 introduced a faster cycle (1 hr vs. 3 hr) and improved mesoscale physics. The second system, Augmented Winds (AW), is a prototype en route wind application developed by MITLL based on the Integrated Terminal Wind System (ITWS). AW is run at a local facility (Center) level, and updates RUC predictions based on an

  1. Fine particles and NO{sub 2}. Development and validation of a method for the immission-relevant, dynamic re-routing of traffic; Feinstaub und NO{sub 2}. Entwicklung und Validierung einer Methode zur immissionsabhaengigen dynamischen Verkehrssteuerung

    Energy Technology Data Exchange (ETDEWEB)

    Ludes, G.; Siebers, B. [simuPlan, Dorsten (Germany); Kuhlbusch, T.; Quass, U.; Beyer, M. [Institut fuer Energie- und Umwelttechnik, Duisburg (Germany); Weber, F. [Stadt Hagen (Germany)

    2010-05-15

    Due to the coming into effect of the twenty-second BImSchV comprehensive investigations on the ambient air quality have been carried out in the city of Hagen in recent years by means of measurement and modelling. High concentrations of nitrogen dioxide and respirable dust have been found along the main streets and the roads belonging to the city ring road system. Main cause of the present situation is road traffic, esp. heavy duty vehicles (HDV). Therefore the concept of measures for the implementation of the air monitoring plan and the action plan set up by the project group includes a HDV-routing system and dynamic, immission-relevant re-routing of traffic. Through this research project the practicability and the effects on air quality of the dynamic, immission-relevant re-routing of HDV-traffic will especially be examined within the highly polluted area of the ''Maerkischer Ring''. By making use of the control programme simDRIVE this innovative concept allows temporary closures of the ''Maerkischer Ring'' for HDV-traffic if transgression of critical limit values is prognosticated due to traffic volume and meteorological circumstances. During these closure periods HDV-traffic will be diverted to alternative and previously determined routes by dynamic and static traffic signs in order to guarantee that intended destinations can be reached. With the help of this research project it should be demonstrated in addition (a) if and how this particular method for NO{sub 2} can also be applied on the reduction of respirable dust, (b) how this measure affects the situation of air pollution regarding respirable dust in other parts of Hagen and (c) if the transfer of methods for the use in other cities is possible. (orig.)

  2. An Agent-Based Model for Analyzing Control Policies and the Dynamic Service-Time Performance of a Capacity-Constrained Air Traffic Management Facility

    Science.gov (United States)

    Conway, Sheila R.

    2006-01-01

    Simple agent-based models may be useful for investigating air traffic control strategies as a precursory screening for more costly, higher fidelity simulation. Of concern is the ability of the models to capture the essence of the system and provide insight into system behavior in a timely manner and without breaking the bank. The method is put to the test with the development of a model to address situations where capacity is overburdened and potential for propagation of the resultant delay though later flights is possible via flight dependencies. The resultant model includes primitive representations of principal air traffic system attributes, namely system capacity, demand, airline schedules and strategy, and aircraft capability. It affords a venue to explore their interdependence in a time-dependent, dynamic system simulation. The scope of the research question and the carefully-chosen modeling fidelity did allow for the development of an agent-based model in short order. The model predicted non-linear behavior given certain initial conditions and system control strategies. Additionally, a combination of the model and dimensionless techniques borrowed from fluid systems was demonstrated that can predict the system s dynamic behavior across a wide range of parametric settings.

  3. Development in Danish international air traffic

    DEFF Research Database (Denmark)

    Christensen, Linda

    The paper is describing the development in international air traffic made by Danes and for all travellers out of Denmark in the period 2002 - 2012. Development in passengers, destination countries and prices is illustrated. The person kilometres by Danes have increased 80% or 7.2% per year in mea...... more effective and to what extent Low Cost Carriers have taken over an important part of the travel market....

  4. Expanding the Use of Time-Based Metering: Multi-Center Traffic Management Advisor

    Science.gov (United States)

    Landry, Steven J.; Farley, Todd; Hoang, Ty

    2005-01-01

    Time-based metering is an efficient air traffic management alternative to the more common practice of distance-based metering (or "miles-in-trail spacing"). Despite having demonstrated significant operational benefit to airspace users and service providers, time-based metering is used in the United States for arrivals to just nine airports and is not used at all for non-arrival traffic flows. The Multi-Center Traffic Management Advisor promises to bring time-based metering into the mainstream of air traffic management techniques. Not constrained to operate solely on arrival traffic, Multi-Center Traffic Management Advisor is flexible enough to work in highly congested or heavily partitioned airspace for any and all traffic flows in a region. This broader and more general application of time-based metering is expected to bring the operational benefits of time-based metering to a much wider pool of beneficiaries than is possible with existing technology. It also promises to facilitate more collaborative traffic management on a regional basis. This paper focuses on the operational concept of the Multi-Center Traffic Management Advisor, touching also on its system architecture, field test results, and prospects for near-term deployment to the United States National Airspace System.

  5. Exposure to traffic-related air pollution and the risk of developing breast cancer among women in eight Canadian provinces: a case-control study.

    Science.gov (United States)

    Hystad, Perry; Villeneuve, Paul J; Goldberg, Mark S; Crouse, Dan L; Johnson, Kenneth

    2015-01-01

    A few recent studies have reported positive associations between long-term exposure to traffic-related air pollution and the incidence of breast cancer. We capitalized on an existing Canadian multi-site population-based case-control study to further investigate this association. We used the National Enhanced Cancer Surveillance System, a population-based case-control study conducted in eight of 10 Canadian provinces from 1994 to 1997. A total of 1569 breast cancer cases and 1872 population controls who reported at least 90% complete self-reported addresses over the 1975-1994 exposure period were examined. Mean exposure levels to nitrogen dioxide (NO2) (an indicator of traffic-related air pollution) were estimated for this period using three different measures: (1) satellite-derived observations; (2) satellite-derived observations scaled with historical fixed-site measurements of NO2; and (3) a national land-use regression (LUR) model. Proximity to major roads was also examined. Using unconditional logistic regression, stratified by menopausal status, we estimated odds ratios (ORs) adjusted for many individual-level and contextual breast cancer risk factors. We observed positive associations between incident breast cancer and all three measures of NO2 exposure from 1975 to 1994. In fully adjusted models for premenopausal breast cancer, a 10ppb increase in NO2 exposure estimated from the satellite-derived observations, the scaled satellite-derived observations, and the national LUR model produced ORs of 1.26 (95% confidence intervals (CIs): 0.92-1.74), 1.32 (95% CI: 1.05-1.67) and 1.28 (95% CI: 0.92-1.79). For postmenopausal breast cancer, we found corresponding ORs of 1.10 (95% CI: 0.88-1.36), 1.10 (95% CI: 0.94-1.28) and 1.07 (95% CI: 0.86-1.32). Substantial heterogeneity in the ORs was observed across the eight Canadian provinces and reduced ORs were observed when models were restricted to women who had received routine mammography examinations. No associations

  6. NEW POSSIBILITIES OF RAILWAY TRAFFIC CONTROL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Lionginas LIUDVINAVIČIUS

    2016-06-01

    Full Text Available This article analyses the train traffic control systems in 1435 mm and 1520 mm gauge railways. The article analyses the aspects of train traffic control and locomotive energy saving by using the coordinates of track profile change that have been received from GPS. In the article, achievements of Lithuanian railways (LG in the area of train traffic control optimisation are presented.

  7. Analysis of the Chinese air route network as a complex network

    Institute of Scientific and Technical Information of China (English)

    Cai Kai-Quan; Zhang Jun; Du Wen-Bo; Cao Xian-Bin

    2012-01-01

    The air route network,which supports all the flight activities of the civil aviation,is the most fundamental infrastructure of air traffic management system.In this paper,we study the Chinese air route network (CARN) within the framework of complex networks. We find that CARN is a geographical network possessing exponential degree distribution,low clustering coefficient,large shortest path length and exponential spatial distance distribution that is obviously different from that of the Chinese airport network (CAN).Besides,via investigating the flight data from 2002 to 2010,we demonstrate that the topology structure of CARN is homogeneous,howbeit the distribution of flight flow on CARN is rather heterogeneous.In addition,the traffic on CARN keeps growing in an exponential form and the increasing speed of west China is remarkably larger than that of east China.Our work will be helpful to better understand Chinese air traffic systems.

  8. Bits of Internet traffic control

    OpenAIRE

    Vojnovic, Milan; Le Boudec, Jean Yves

    2005-01-01

    In this work, we consider four problems in the context of Internet traffic control. The first problem is to understand when and why a sender that implements an equation-based rate control would be TCP-friendly, or not—a sender is said to be TCP-friendly if, under the same operating conditions, its long-term average send rate does not exceed that of a TCP sender. It is an established axiom that some senders in the Internet would need to be TCP-friendly. An equation-based rate control sender pl...

  9. Bits of Internet Traffic Control

    OpenAIRE

    Vojnovic, Milan

    2003-01-01

    In this work, we consider four problems in the context of Internet traffic control. The first problem is to understand when and why a sender that implements an equation-based rate control would be TCP-friendly, or not—a sender is said to be TCP-friendly if, under the same operating conditions, its long-term average send rate does not exceed that of a TCP sender. It is an established axiom that some senders in the Internet would need to be TCP-friendly. An equation-based rate control sender pl...

  10. 30 CFR 56.9100 - Traffic control.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of...

  11. On traffic fairness in data center fabrics

    OpenAIRE

    Belabed, Dallal; Secci, Stefano; Pujolle, Guy; Medhi, Deep

    2014-01-01

    International audience; —A present challenge in data center networks (DCN) is to better understand the impact of novel flattened and modular DCN architectures on congestion control protocols, and vice-versa. One of the major concerns in congestion control being the fairness in the offered throughput, the impact of the additional path diversity and forwarding features, brought by the novel DCN architectures and protocols, on the throughput of individual endpoints (servers) and aggregation poin...

  12. Colleges and Universities Highway Traffic and Safety Centers.

    Science.gov (United States)

    Aaron, James E., Ed.; Ritzel, Dale O., Ed.

    After consideration of the organizing of university safety centers and the growth and role of such centers in the future, descriptions are presented of the activities and practices in each of 16 existing college and university highway traffic and safety centers. Information is presented regarding center objectives, programs, staff composition,…

  13. Traffic Information and Learning in Day-to-Day Route Choice

    NARCIS (Netherlands)

    Bogers, E.A.I.

    2009-01-01

    The aim of the research is to gain insight into the impact of traffic information on day-to-day route choice. The effects of both en-route information and ex-post information are studied. Special attention is given to three other important aspects in day-to-day route choice: learning from experienc

  14. Operational Evaluatioin of Dynamic Weather Routes at American Airlines

    Science.gov (United States)

    McNally, David; Sheth, Kapil; Gong, Chester; Borchers, Paul; Osborne, Jeff; Keany, Desmond; Scott, Brennan; Smith, Steve; Sahlman, Scott; Lee, Chuhan; Cheng, Jinn-Hwei

    2013-01-01

    Dynamic Weather Routes (DWR) is a search engine that continuously and automatically analyzes inflight aircraft in en route airspace and proposes simple route amendments for more efficient routes around convective weather while considering sector congestion, traffic conflicts, and active Special Use Airspace. NASA and American Airlines (AA) are conducting an operational trial of DWR at the AA System Operations Center in Fort Worth, TX. The trial includes only AA flights in Fort Worth Center airspace. Over the period from July 31, 2012 through August 31, 2012, 45% of routes proposed by DWR and evaluated by AA users - air traffic control coordinators and flight dispatchers - were rated as acceptable as proposed or with some modifications. The wind-corrected potential flying time savings for these acceptable routes totals 470 flying min, and results suggest another 1,500 min of potential savings for flights not evaluated due to staffing limitations. A sector congestion analysis shows that in only two out of 83 DWR routes rated acceptable by AA staff were the flights predicted to fly through a congested sector inside of 30 min downstream of present position. This shows that users considered sector congestion data provided by DWR automation and in nearly all cases did not accept routes through over-capacity sectors. It is estimated that 12 AA flights were given reroute clearances as a direct result of DWR for a total savings of 67 flying min.

  15. Air Traffic Management Technology Demostration Phase 1 (ATD) Interval Management for Near-Term Operations Validation of Acceptability (IM-NOVA) Experiment

    Science.gov (United States)

    Kibler, Jennifer L.; Wilson, Sara R.; Hubbs, Clay E.; Smail, James W.

    2015-01-01

    The Interval Management for Near-term Operations Validation of Acceptability (IM-NOVA) experiment was conducted at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) in support of the NASA Airspace Systems Program's Air Traffic Management Technology Demonstration-1 (ATD-1). ATD-1 is intended to showcase an integrated set of technologies that provide an efficient arrival solution for managing aircraft using Next Generation Air Transportation System (NextGen) surveillance, navigation, procedures, and automation for both airborne and ground-based systems. The goal of the IMNOVA experiment was to assess if procedures outlined by the ATD-1 Concept of Operations were acceptable to and feasible for use by flight crews in a voice communications environment when used with a minimum set of Flight Deck-based Interval Management (FIM) equipment and a prototype crew interface. To investigate an integrated arrival solution using ground-based air traffic control tools and aircraft Automatic Dependent Surveillance-Broadcast (ADS-B) tools, the LaRC FIM system and the Traffic Management Advisor with Terminal Metering and Controller Managed Spacing tools developed at the NASA Ames Research Center (ARC) were integrated into LaRC's Air Traffic Operations Laboratory (ATOL). Data were collected from 10 crews of current 757/767 pilots asked to fly a high-fidelity, fixed-based simulator during scenarios conducted within an airspace environment modeled on the Dallas-Fort Worth (DFW) Terminal Radar Approach Control area. The aircraft simulator was equipped with the Airborne Spacing for Terminal Area Routes (ASTAR) algorithm and a FIM crew interface consisting of electronic flight bags and ADS-B guidance displays. Researchers used "pseudo-pilot" stations to control 24 simulated aircraft that provided multiple air traffic flows into the DFW International Airport, and recently retired DFW air traffic controllers served as confederate Center, Feeder, Final

  16. Traffic-related air pollution - the health effects scrutinized

    OpenAIRE

    Nijland, M.E.

    2013-01-01

    Numerous studies have been published on the health effects associated with exposure to air pollution. Air pollution is acknowledged as a public health risk and air quality regulations are set for specific air pollutants to protect human health. A major pollutant, well known for its adverse health impact, is particulate matter (PM) of which road traffic is a major source. Therefore, the health effects of traffic-related air pollution have been under considerable scrutiny. We examined in vivo t...

  17. The Impact of Different Scheduling Policies on Traffic Class Dependent Routing in Intersatellite Link

    Science.gov (United States)

    Kandus, Gorazd; Svigelj, Ales; Mohorcic, Mihael

    2003-07-01

    In this paper we analyse the impact of different scheduling policies on traffic class dependent routing in intersatellite link network of a packet switched non-geostationary satellite system. We used different unfair (first come first served and priority) and fair (weighted round robin, deficit round robin and surplus round robin) scheduling mechanisms. Specifically developed software to model the ISL network was used to evaluate the performance of different combinations of scheduling and routing procedures. The analysis was done in terms of average packet delay and average data throughput for different traffic scenarios. The results imply that there is a small impact of different fair scheduling mechanisms on traffic class depending on routing.

  18. Workload-aware request routing in cloud data center using software-defined networking

    Institute of Scientific and Technical Information of China (English)

    Haitao Yuan; Jing Bi; Bohu Li

    2015-01-01

    Large latency of applications wil bring revenue loss to cloud infrastructure providers in the cloud data center. The existing control ers of software-defined networking architecture can fetch and process traffic information in the network. Therefore, the con-trol ers can only optimize the network latency of applications. How-ever, the serving latency of applications is also an important factor in delivered user-experience for arrival requests. Unintel igent re-quest routing wil cause large serving latency if arrival requests are al ocated to overloaded virtual machines. To deal with the re-quest routing problem, this paper proposes the workload-aware software-defined networking control er architecture. Then, request routing algorithms are proposed to minimize the total round trip time for every type of request by considering the congestion in the network and the workload in virtual machines (VMs). This paper final y provides the evaluation of the proposed algorithms in a sim-ulated prototype. The simulation results show that the proposed methodology is efficient compared with the existing approaches.

  19. Light signals for road traffic control.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1981-01-01

    Signals for road traffic control are a major constituent of the modern traffic scene, particularly in built-up areas. A vast amount of research has been executed in the last two decennia, resulting in a fairly generally accepted view on what the requirements for effective traffic lights are. For the

  20. Study on Safety Capability Model of Air Traffic Controllers%管制员安全能力模型研究

    Institute of Scientific and Technical Information of China (English)

    陈芳; 罗云

    2012-01-01

    In order to evaluate civil aviation air traffic controllers'safety capabilities correctly, the nature of civil aviation air traffic controllers safety capability is defined according to the competence and controller s job responsibility. Base on the meaning of controllers safety capability and job specification, a model for controller's safety capability is built, which has three structural dimensions including physical quality, professional quality and consciousness. Physical quality includes physical conditions and psychological conditions. Professional quality includes the educational background, training background, skills and experience. Consciousness includes safety consciousness and work consciousness. In order to reduce the error under the conditions that there is a big difference of attributes among the indexes and to reflect the index objectively, efficacy coefficient method is used to standardize the evaluation index. In the meantime, the subjective and objective comprehensive weight method determines the index and makes up the shortcomings of single weight method by integrating the Gl method and entropy method. Finally, the TOPSIS is employed to evaluate the level of civil aviation air traffic controller's safety capability. Theresults show that the factors influencing controllers'safety capabilities are consciousness, physical quality and the professional quality in order according to influencing power. For the influencing power on the capabilities, the psychological condition has a greater impact than the physiological condition; skills are stronger than educational background, training background and experience; safety consciousness is stronger than work consciousness.%为准确评价管制员安全能力,基于能力的定义和管制员工作职责,界定管制员安全能力的内涵;依据该内涵及其工作特性,建立由身体素质、业务素质和意识3个结构维度组成的管制员安全能力模型.其中,身体素质包括生理

  1. Michigan/Air Force Research Laboratory (AFRL) Collaborative Center in Control Science (MACCCS)

    Science.gov (United States)

    2016-09-01

    Toronto. 34. C. Orlowski, A. Girard, and W. Shyy. Four Wing Flapping Wing Micro Air Vehicles: Dragonflies or X-Wings? Proceedings of the AIAA Guidance...18th World Congress of the International Federation of Automatic Control (IFAC), Milano, Italy, 2011. 4. B. Hyun, M. Faied, P. Kabamba, A. Girard...Girard, “Classification with Synergistic Teams”, 18th World Congress of the International Federation of Automatic Control (IFAC), Milano, Italy

  2. Air pollution burden of illness from traffic in Toronto

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, D.; Campbell, M.; Bassil, K.; Morgan, C.; Lalani, M.; Macfarlane, R.; Bienefeld, M. [Toronto Public Health, ON (Canada)

    2007-11-15

    This paper examined the health impacts of air pollution from traffic in Toronto. The paper provided a review of scientific studies on the health effects of vehicle pollution as well as a quantitative assessment of the economic costs and the burden of illness attributed to traffic pollution in Toronto. The report also assessed air pollution and traffic trends in the city, and outlined initiatives being conducted to reduce vehicle-related pollution. The study used the new air quality benefits tool (AQBAT) which determines the burden of illness and the economic impacts of traffic-related air pollution. Air modelling specialists were consulted in order to determine the contribution of traffic-related pollutants to overall pollution levels using data on traffic counts and vehicle emissions factors. The air model also considered dispersion, transport and and the transformation of compounds emitted from vehicles. Results of the study showed that traffic pollution caused approximately 440 premature deaths and 1700 hospitalizations per year. Children in the city experienced more than 1200 acute bronchitis episodes per year as a result of air pollution from traffic. Mortality-related costs associated with traffic pollution in Toronto were estimated at $2.2 billion. It was concluded that the city must pursue the implementation of sustainable transportation policies and programs which foster and enable the expansion and use of public transport. 47 refs., 8 tabs., 9 figs.

  3. Road traffic noise, air pollution components and cardiovascular events

    NARCIS (Netherlands)

    Kluizenaar, Y. de; Lenthe, F.J. van; Visschedijk, A.J.H.; Zandveld, P.Y.J; Miedema, H.M.E.; Mackenbach, J.P.

    2013-01-01

    Traffic noise and air pollution have been associated with cardiovascular health effects. Until date, only a limited amount of prospective epidemiological studies is available on long-term effects of road traffic noise and combustion related air pollution. This study investigates the relationship bet

  4. Air pollution due to road traffic in Ljubljana

    OpenAIRE

    Matej Ogrin

    2007-01-01

    Air pollution is due to road traffic an inevitable outcome of internal combustion in engines of vehicles and some other processes. Air near the roads is more polluted with some pollutants, such as carbon monoxide, nitrogen oxides, ozone, particulate matter and some others. Monitoring the air quality is a key issue, when one wants to estimate environmental impacts of the road traffic. The article shows a method of passive samplers for air quality monitoring along different roads in the area of...

  5. Using memory for prior aircraft events to detect conflicts under conditions of proactive air traffic control and with concurrent task requirements.

    Science.gov (United States)

    Bowden, Vanessa K; Loft, Shayne

    2016-06-01

    In 2 experiments we examined the impact of memory for prior events on conflict detection in simulated air traffic control under conditions where individuals proactively controlled aircraft and completed concurrent tasks. Individuals were faster to detect conflicts that had repeatedly been presented during training (positive transfer). Bayesian statistics indicated strong evidence for the null hypothesis that conflict detection was not impaired for events that resembled an aircraft pair that had repeatedly come close to conflicting during training. This is likely because aircraft altitude (the feature manipulated between training and test) was attended to by participants when proactively controlling aircraft. In contrast, a minor change to the relative position of a repeated nonconflicting aircraft pair moderately impaired conflict detection (negative transfer). There was strong evidence for the null hypothesis that positive transfer was not impacted by dividing participant attention, which suggests that part of the information retrieved regarding prior aircraft events was perceptual (the new aircraft pair "looked" like a conflict based on familiarity). These findings extend the effects previously reported by Loft, Humphreys, and Neal (2004), answering the recent strong and unanimous calls across the psychological science discipline to formally establish the robustness and generality of previously published effects. (PsycINFO Database Record

  6. Rapid Protoyping Software for Developing Next-Generation Air Traffic Management Algorithms Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Research on next-generation air traffic control systems are being conducted at several laboratories. Most of this work is being carried out using custom software. In...

  7. Vehicle Routing with Traffic Congestion and Drivers' Driving and Working Rules

    NARCIS (Netherlands)

    Kok, A.L.; Hans, E.W.; Schutten, J.M.J.; Zijm, W.H.M.

    2010-01-01

    For the intensively studied vehicle routing problem (VRP), two real-life restrictions have received only minor attention in the VRP-literature: traffic congestion and driving hours regulations. Traffic congestion causes late arrivals at customers and long travel times resulting in large transport co

  8. Congestion control and routing over satellite networks

    Science.gov (United States)

    Cao, Jinhua

    Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE

  9. FAA Air Traffic Control Operations Concepts. Volume 3. ISSS (Initial Sector Suite System) En Route Controllers. Change 1

    Science.gov (United States)

    1988-07-29

    Providing valued support to the continued efforts of the SSRVT are Richard Barker (ATR- 150), Gail Garwood (ATR-150), L. Lane Speck (ATR-100), and...A1.6.13.2 R%- CLIVE PC&EEDURtS TO KC USEC TO ACCOiGDDAT. SENSOR OJIAGE i&3i TYPE: PVW

  10. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications.

    Science.gov (United States)

    Zhang, Jisheng; Jia, Limin; Niu, Shuyun; Zhang, Fan; Tong, Lu; Zhou, Xuesong

    2015-06-12

    It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs) start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs' route planning for small and medium-scale networks.

  11. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Jisheng Zhang

    2015-06-01

    Full Text Available It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs’ route planning for small and medium-scale networks.

  12. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications

    Science.gov (United States)

    Zhang, Jisheng; Jia, Limin; Niu, Shuyun; Zhang, Fan; Tong, Lu; Zhou, Xuesong

    2015-01-01

    It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs) start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs’ route planning for small and medium-scale networks. PMID:26076404

  13. Aircraft/Air Traffic Management Functional Analysis Model. Version 2.0; User's Guide

    Science.gov (United States)

    Etheridge, Melvin; Plugge, Joana; Retina, Nusrat

    1998-01-01

    The Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 (FAM 2.0), is a discrete event simulation model designed to support analysis of alternative concepts in air traffic management and control. FAM 2.0 was developed by the Logistics Management Institute (LMI) a National Aeronautics and Space Administration (NASA) contract. This document provides a guide for using the model in analysis. Those interested in making enhancements or modification to the model should consult the companion document, Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 Technical Description.

  14. FAA Air Traffic Control Tower Cab Glass Evaluation, Specification and Assessment with Respect to Optical-Visual Characteristics

    Science.gov (United States)

    2007-08-01

    glass laminated together with clear polyvinyl butyral (PVB). The outer surfaces of the two layers of glass are coated/treated with Pilkington’s... Polyvinyl Butyral QA – Quality Assurance SOW – Statement of Work US – United States USAF – United States Air Force ZGI – Zamil Glass Industries

  15. Impact of multi-criteria routing on dynamic traffic management

    NARCIS (Netherlands)

    Zhang, F.; Chen, Y.; Zhang, J.

    2014-01-01

    Traffic simulation is conventionally based on travel time as input to the cost function. We include vehicle emission into cost function and try to investigate its impact on traffic management as well as network performance. As the emission is the product of vehicle movement, we use a bi-level approa

  16. Analysis of Factors for Incorporating User Preferences in Air Traffic Management: A system Perspective

    Science.gov (United States)

    Sheth, Kapil S.; Gutierrez-Nolasco, Sebastian

    2010-01-01

    This paper presents an analysis of factors that impact user flight schedules during air traffic congestion. In pre-departure flight planning, users file one route per flight, which often leads to increased delays, inefficient airspace utilization, and exclusion of user flight preferences. In this paper, first the idea of filing alternate routes and providing priorities on each of those routes is introduced. Then, the impact of varying planning interval and system imposed departure delay increment is discussed. The metrics of total delay and equity are used for analyzing the impact of these factors on increased traffic and on different users. The results are shown for four cases, with and without the optional routes and priority assignments. Results demonstrate that adding priorities to optional routes further improves system performance compared to filing one route per flight and using first-come first-served scheme. It was also observed that a two-hour planning interval with a five-minute system imposed departure delay increment results in highest delay reduction. The trend holds for a scenario with increased traffic.

  17. Identification of Information-Seeking Behaviors from Air Traffic Controllers′Eye Movements

    Institute of Scientific and Technical Information of China (English)

    Wang Yanjun; LiuYinxin; Cong Wei; Xu Xinhua; HuMinghua

    2016-01-01

    Air traffic controllers are the important parts of air traffic management system who are responsible for the safety and efficiency of the system.They make traffic management decisions based on information acquired from various sources.The understanding of their information seeking behaviors is still limited.We aim to identify controllers′behavior through the examination of the correlations between controllers′eye movements and air traf-fic.Sixteen air traffic controllers were invited to participate real-time simulation experiments,during which the da-ta of their eye ball movements and air traffic were recorded.Tweny-three air traffic complexity metrics and six eye movements metrics were calculated to examine their relationships.Two correlational methods,Pearson′s correla-tion and Spearman′s correlation,were tested between every eye-traffic pair of metrics.The results indicate that controllers′two kinds of information-seeking behaviors can be identified from their eye movements:Targets track-ing,and confliction recognition.The study on controllers′eye movements may contribute to the understanding of information-seeking mechanisms leading to the development of more intelligent automations in the future.

  18. Wavelength Routing Algorithm of All Optical Network Based on Traffic Engineering

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    General multi-protocol label switching(GMPLS) based on traffic engineering is one of the possible methods to implement all-optical network. This method implements the network with IP technique and guarantees the quality of service with traffic engineering. Based on the establishment of selecting schemes of optical path and methods of traffic calculation, the wavelength routing algorithm of all-optical network based on traffic engineering is presented by combining with prior route of shortest path and traffic engineering, the algorithm procedures are given, and the actual examples are introduced as well as the analysis on simulation calculation. This research results have certain significance for the achievement of optical switching technique of all-optical network.

  19. Traffic improvement and transportation pollution control in Xiamen

    Energy Technology Data Exchange (ETDEWEB)

    Dongxing Yuan; Zilin, Wu

    1996-12-31

    in this paper, the urban traffic improvement and transportation control in Xiamen are highlighted. Xiamen is a port city and an economical special zone of China. As the economy grows, the transportation is developing dramatically and becoming the key for further economic development. The air quality is threatened by the rapid growth of the vehicles in the city. The most urgent task in improving urban traffic is to establish a sound traffic system. The municipal government takes great effort to improve the traffic condition, as well as to reduce green house gases and protect air environment. Some management and technical measures are carried out. Those management measures are mainly as follows: (1) systematic planning of the city arrangement and city functional division, and integrated planning of the urban roads system, (2) putting great emphasis on tail gas monitoring and management, and (3) establishing optimized utilization of motor vehicles. Those included in the main technical measures are (1) making the roads clear, (2) enlarging traffic capacity, and (3) developing the public transport. The most urgent task in improving urban traffic is to establish a sound traffic system. The city municipal government and Transportation Management Bureau plan to make a series of reforms to improve the urban traffic condition, such as building high quality road around the city, reducing the number of one way roads and replacing gasoline buses with electric buses. An optimized traffic system of Xiamen, taking public transport as the main means, is the key to meet the needs of both traffic improvement and urban transportation pollution control.

  20. Time-based air traffic management using expert systems

    Science.gov (United States)

    Tobias, L.; Scoggins, J. L.

    1986-01-01

    A prototype expert system was developed for the time scheduling of aircraft into the terminal area. The three functions of the air traffic control schedule advisor are as follows: first, for each new arrival, it develops an admissible flight plan for that aircraft. Second, as the aircraft progresses through the terminal area, it monitors deviations from the flight plan and provides advisories to return the aircraft to its assigned schedule. Third, if major disruptions such as missed approaches occur, it develops a revised plan. The advisor is operational on a Symbolics 3600, and is programed in MRS (a logic programming language), Lisp, and FORTRAN.

  1. The Analysis of Rail Traffic Control Systems

    Directory of Open Access Journals (Sweden)

    Darius Gaidelis

    2011-04-01

    Full Text Available The systems used for rail traffic control are compared. Their advantages and disadvantages are analysed. The present and future development of rail traffic control systems in various countries is considered. The possibility of adapting these microprocessor-based traffic control systems to the conditions of Lithuania is analysed. For this purpose, the analysis of goods transported by Lithuanian railways is made, and the non-uniform amount of goods transported on different road sections is evaluated. The number of the delayed trains due to the failure of traffic control systems in recent years is determined, the cost of installing a new microprocessor-based traffic control system at the railway station, as well as its repay time and the demand for employees are calculated. Article in Lithuanian

  2. Road traffic and cardiovascular health effects - Road traffic noise and air pollution

    NARCIS (Netherlands)

    Kluizenaar, Y. de; Miedema, H.M.E.

    2009-01-01

    Exposure to both environmental noise and air pollution has been associated with cardiovascular health effects. Until now, few studies have considered both stressors simultaneously. Two large studies were carried out investigating the relationship between road traffic noise and several cardiovascular

  3. Traffic air pollution and oxidized LDL.

    Directory of Open Access Journals (Sweden)

    Lotte Jacobs

    Full Text Available BACKGROUND: Epidemiologic studies indirectly suggest that air pollution accelerates atherosclerosis. We hypothesized that individual exposure to particulate matter (PM derived from fossil fuel would correlate with plasma concentrations of oxidized low-density lipoprotein (LDL, taken as a marker of atherosclerosis. We tested this hypothesis in patients with diabetes, who are at high risk for atherosclerosis. METHODOLOGY/PRINCIPAL FINDINGS: In a cross-sectional study of non-smoking adult outpatients with diabetes we assessed individual chronic exposure to PM by measuring the area occupied by carbon in airway macrophages, collected by sputum induction and by determining the distance from the patient's residence to a major road, through geocoding. These exposure indices were regressed against plasma concentrations of oxidized LDL, von Willebrand factor and plasminogen activator inhibitor 1 (PAI-1. We could assess the carbon load of airway macrophages in 79 subjects (58 percent. Each doubling in the distance of residence from major roads was associated with a 0.027 µm(2 decrease (95% confidence interval (CI: -0.048 to -0.0051 in the carbon load of airway macrophages. Independently from other covariates, we found that each increase of 0.25 µm(2 [interquartile range (IQR] in carbon load was associated with an increase of 7.3 U/L (95% CI: 1.3 to 13.3 in plasma oxidized LDL. Each doubling in distance of residence from major roads was associated with a decrease of -2.9 U/L (95% CI: -5.2 to -0.72 in oxidized LDL. Neither the carbon load of macrophages nor the distance from residence to major roads, were associated with plasma von Willebrand factor or PAI-1. CONCLUSIONS: The observed positive association, in a susceptible group of the general population, between plasma oxidized LDL levels and either the carbon load of airway macrophages or the proximity of the subject's residence to busy roads suggests a proatherogenic effect of traffic air pollution.

  4. Evaluating Wireless Proactive Routing Protocols under Scalability and Traffic Constraints

    CERN Document Server

    Javaid, N; Khan, Z A; Khan, U; Djouani, K

    2012-01-01

    In this paper, we evaluate and analyze the impact of different network loads and varying no. of nodes on distance vector and link state routing algorithms. We select three well known proactive protocols; Destination Sequenced Distance Vector (DSDV) operates on distance vector routing, while Fisheye State Routing (FSR) and Optimized Link State Routing (OLSR) protocols are based on link state routing. Further, we evaluate and compare the effects on the performance of protocols by changing the routing strategies of routing algorithms. We also enhance selected protocols to achieve high performance. We take throughput, End-to-End Delay (E2ED) and Normalized Routing Load (NRL) as performance metrics for evaluation and comparison of chosen protocols both with default and enhanced versions. Based upon extensive simulations in NS-2, we compare and discuss performance trade-offs of the protocols, i.e., how a protocol achieves high packet delivery by paying some cost in the form of increased E2ED and/or routing overhead...

  5. Air Risk Information Support Center

    Energy Technology Data Exchange (ETDEWEB)

    Shoaf, C.R.; Guth, D.J. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    The Air Risk Information Support Center (Air RISC) was initiated in early 1988 by the US Environmental Protection Agency`s (EPA) Office of Health and Environmental Assessment (OHEA) and the Office of Air Quality Planning and Standards (OAQPS) as a technology transfer effort that would focus on providing information to state and local environmental agencies and to EPA Regional Offices in the areas of health, risk, and exposure assessment for toxic air pollutants. Technical information is fostered and disseminated by Air RISCs three primary activities: (1) a {open_quotes}hotline{close_quotes}, (2) quick turn-around technical assistance projects, and (3) general technical guidance projects. 1 ref., 2 figs.

  6. Defining the drivers for accepting decision making automation in air traffic management.

    Science.gov (United States)

    Bekier, Marek; Molesworth, Brett R C; Williamson, Ann

    2011-04-01

    Air Traffic Management (ATM) operators are under increasing pressure to improve the efficiency of their operation to cater for forecasted increases in air traffic movements. One solution involves increasing the utilisation of automation within the ATM system. The success of this approach is contingent on Air Traffic Control Operators' (ATCOs) willingness to accept increased levels of automation. The main aim of the present research was to examine the drivers underpinning ATCOs' willingness to accept increased utilisation of automation within their role. Two fictitious scenarios involving the application of two new automated decision-making tools were created. The results of an online survey revealed traditional predictors of automation acceptance such as age, trust and job satisfaction explain between 4 and 7% of the variance. Furthermore, these predictors varied depending on the purpose in which the automation was to be employed. These results are discussed from an applied and theoretical perspective. STATEMENT OF RELEVANCE: Efficiency improvements in ATM are required to cater for forecasted increases in air traffic movements. One solution is to increase the utilisation of automation within Air Traffic Control. The present research examines the drivers underpinning air traffic controllers' willingness to accept increased levels of automation in their role.

  7. 14 CFR 91.139 - Emergency air traffic rules.

    Science.gov (United States)

    2010-01-01

    ....139 Emergency air traffic rules. (a) This section prescribes a process for utilizing Notices to Airmen... with the authorizations, terms, and conditions prescribed in the regulation covered by the NOTAM....

  8. Investigating the Effects of Traffic on Air Pollution.

    Science.gov (United States)

    Taylor, Sharon

    2001-01-01

    Discusses the benefits of bringing scientists into the classroom to collaborate with children on environmental research projects. Describes one collaborative project that focused on the effects of traffic on air pollution. (DDR)

  9. How Formal Methods Impels Discovery: A Short History of an Air Traffic Management Project

    Science.gov (United States)

    Butler, Ricky W.; Hagen, George; Maddalon, Jeffrey M.; Munoz, Cesar A.; Narkawicz, Anthony; Dowek, Gilles

    2010-01-01

    In this paper we describe a process of algorithmic discovery that was driven by our goal of achieving complete, mechanically verified algorithms that compute conflict prevention bands for use in en route air traffic management. The algorithms were originally defined in the PVS specification language and subsequently have been implemented in Java and C++. We do not present the proofs in this paper: instead, we describe the process of discovery and the key ideas that enabled the final formal proof of correctness

  10. CubeSat constellation design for air traffic monitoring

    Science.gov (United States)

    Nag, Sreeja; Rios, Joseph L.; Gerhardt, David; Pham, Camvu

    2016-11-01

    Suitably equipped global and local air traffic can be tracked. The tracking information may then be used for control from ground-based stations by receiving the Automatic Dependent Surveillance-Broadcast (ADS-B) signal. In this paper, we describe a tool for designing a constellation of small satellites which demonstrates, through high-fidelity modeling based on simulated air traffic data, the value of space-based ADS-B monitoring. It thereby provides recommendations for cost-efficient deployment of a constellation of small satellites to increase safety and situational awareness in the currently poorly-served surveillance area of Alaska. Air traffic data were obtained from NASA's Future ATM Concepts Evaluation Tool, for the Alaskan airspace over one day. The results presented were driven by MATLAB and the satellites propagated and coverage calculated using AGI's Satellite Tool. While Ad-hoc and precession spread constellations have been quantitatively evaluated, Walker constellations show the best performance in simulation. Sixteen satellites in two perpendicular orbital planes are shown to provide more than 99% coverage over representative Alaskan airspace and the maximum time gap where any airplane in Alaska is not covered is six minutes, therefore meeting the standard set by the International Civil Aviation Organization to monitor every airplane at least once every fifteen minutes. In spite of the risk of signal collision when multiple packets arrive at the satellite receiver, the proposed constellation shows 99% cumulative probability of reception within four minutes when the airplanes are transmitting every minute, and at 100% reception probability if transmitting every second. Data downlink can be performed using any of the three ground stations of NASA Earth Network in Alaska.

  11. Air pollution and health risks due to vehicle traffic

    OpenAIRE

    Zhang, Kai; Batterman, Stuart

    2013-01-01

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and he...

  12. Techniques used for the analysis of oculometer eye-scanning data obtained from an air traffic control display

    Science.gov (United States)

    Crawford, Daniel J.; Burdette, Daniel W.; Capron, William R.

    1993-01-01

    The methodology and techniques used to collect and analyze look-point position data from a real-time ATC display-format comparison experiment are documented. That study compared the delivery precision and controller workload of three final approach spacing aid display formats. Using an oculometer, controller lookpoint position data were collected, associated with gaze objects (e.g., moving aircraft) on the ATC display, and analyzed to determine eye-scan behavior. The equipment involved and algorithms for saving, synchronizing with the ATC simulation output, and filtering the data are described. Target (gaze object) and cross-check scanning identification algorithms are also presented. Data tables are provided of total dwell times, average dwell times, and cross-check scans. Flow charts, block diagrams, file record descriptors, and source code are included. The techniques and data presented are intended to benefit researchers in other studies that incorporate non-stationary gaze objects and oculometer equipment.

  13. Location Problem of Air Materials Supply Center for Air Force

    Institute of Scientific and Technical Information of China (English)

    王涛; 何亚群; 陶学禹

    2002-01-01

    Based on the analysis of three influencing factors on the air material supply center location, the location model of air material supply center was established. By solving the model, the rational supply center of air materials was also determined.

  14. Dealing with the white death: avalanche risk management for traffic routes.

    Science.gov (United States)

    Rheinberger, Christoph M; Bründl, Michael; Rhyner, Jakob

    2009-01-01

    This article discusses mitigation strategies to protect traffic routes from snow avalanches. Up to now, mitigation of snow avalanches on many roads and railways in the Alps has relied on avalanche sheds, which require large initial investments resulting in high opportunity costs. Therefore, avalanche risk managers have increasingly adopted organizational mitigation measures such as warning systems and closure policies instead. The effectiveness of these measures is, however, greatly dependent on human decisions. In this article, we present a method for optimizing avalanche mitigation for traffic routes in terms of both their risk reduction impact and their net benefit to society. First, we introduce a generic framework for assessing avalanche risk and for quantifying the impact of mitigation. This allows for sound cost-benefit comparisons between alternative mitigation strategies. Second, we illustrate the framework with a case study from Switzerland. Our findings suggest that site-specific characteristics of avalanche paths, as well as the economic importance of a traffic route, are decisive for the choice of optimal mitigation strategies. On routes endangered by few avalanche paths with frequent avalanche occurrences, structural measures are most efficient, whereas reliance on organizational mitigation is often the most appropriate strategy on routes endangered by many paths with infrequent or fuzzy avalanche risk. Finally, keeping a traffic route open may be very important for tourism or the transport industry. Hence, local economic value may promote the use of a hybrid strategy that combines organizational and structural measures to optimize the resource allocation of avalanche risk mitigation.

  15. Model Predictive Control for Integrating Traffic Control Measures

    NARCIS (Netherlands)

    Hegyi, A.

    2004-01-01

    Dynamic traffic control measures, such as ramp metering and dynamic speed limits, can be used to better utilize the available road capacity. Due to the increasing traffic volumes and the increasing number of traffic jams the interaction between the control measures has increased such that local cont

  16. Environmental Impact Statement. Disposal and Reuse of George Air Force Base, California. Volume 1

    Science.gov (United States)

    1992-03-01

    Agriculture, 1986) has mapped sols on and around George AFB. Most of the on-base soils consist of the Bryman loamy fine sand that forms on terraces and...The Bryman loamy fine sand, when Irrigated, meets the soil requirements for prime farmland; however, the area surrounding the base is not Irrigated...110, 4-185 Air Route Traffic Control Center (ARTCC), 3-32, Bryman loamy fine sand, 3-84 4-34 Bureau of Land Management (BLM), 3-50, 3-112, Air traffic

  17. Air pollution due to road traffic in Ljubljana

    Directory of Open Access Journals (Sweden)

    Matej Ogrin

    2007-01-01

    Full Text Available Air pollution is due to road traffic an inevitable outcome of internal combustion in engines ofvehicles and some other processes. Air near the roads is more polluted with some pollutants,such as carbon monoxide, nitrogen oxides, ozone, particulate matter and some others.Monitoring the air quality is a key issue, when one wants to estimate environmental impactsof the road traffic. The article shows a method of passive samplers for air quality monitoringalong different roads in the area of Ljubljana Municipality.

  18. Using Automated Planning for Traffic Signals Control

    Directory of Open Access Journals (Sweden)

    Matija Gulić

    2016-08-01

    Full Text Available Solving traffic congestions represents a high priority issue in many big cities. Traditional traffic control systems are mainly based on pre-programmed, reactive and local techniques. This paper presents an autonomic system that uses automated planning techniques instead. These techniques are easily configurable and modified, and can reason about the future implications of actions that change the default traffic lights behaviour. The proposed implemented system includes some autonomic properties, since it monitors the current traffic state, detects if the system is degrading its performance, sets up new sets of goals to be achieved by the planner, triggers the planner that generates plans with control actions, and executes the selected courses of actions. The obtained results in several artificial and real world data-based simulation scenarios show that the proposed system can efficiently solve traffic congestion.

  19. Distributed traffic signal control using fuzzy logic

    Science.gov (United States)

    Chiu, Stephen

    1992-01-01

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

  20. Discourse segmentation and the management of multiple tasks in single episodes of air traffic controller-pilot spoken radio communication

    Directory of Open Access Journals (Sweden)

    Paul A. Falzon

    2009-06-01

    Full Text Available Episodes of VHF radio-mediated pilot-controller spoken communication in which multiple tasks are conducted are engendered in and through the skilful deployment and combination, by the parties to the talk, of multiple orders of discourse segmentation. These orders of segmentation are manifest at the levels of transmission design and sequential organisation. Both of these features are analysed from a Conversation Analytic standpoint in order to track their segment by segment genesis, development and completion. From the analysis it emerges that in addition to the serial type of sequential organisations described by Schegloff (1986, there exists an alternative form of organisation that enables tasks to be managed in a quasi-parallel manner, and which affords controllers and pilots a number of practical advantages in the conduct of their radio-mediated service encounters.Cet article présente des extraits d’échanges oraux entre pilots et contrôleurs du ciel via la radio VHF. On peut y voir comment le déploiement et la combinaison habile de plusieurs ordres de segmentation discursive, engageant les deux coénonciateurs de la conversation, leur permet d’accomplir des tâches multiples. Ces ordres de segmentation se manifestent aux niveaux du plan de la transmission et de l’organisation séquentielle. Ces deux niveaux sont envisagées du point de vue de l’analyse conversationnelle dans le but d’examiner, segment après segment, comment ils se mettent en place, se développent puis prennent fin. Notre étude montre que, outre le type sériel d’organisations séquentielles décrit par Schegloff (1986, il existe une forme alternative d’organisation qui permet de gérer les tâches de manière quasi parallèle, et qui fournit aux contrôleurs aériens ainsi qu’aux pilotes de nombreux avantages pratiques dans la conduite de leurs radio.

  1. Dynamic Routing of IP Traffic Based on QOS Parameters

    Directory of Open Access Journals (Sweden)

    Martin Kriška

    2014-07-01

    Full Text Available The article looks into the current state of the art of dynamic routing protocols with respect to their possibilities to react to changes in the Quality of Service when selecting the best route towards a destination network. New options that could leverage information about the ever changing QoS parameters for data communication are analysed and a Cisco Performance Routing solution is described more in detail. The practical part of this work focuses on a design and implementation of a test bed that provides ascalable laboratory architecture to manipulate QoS parameters of different data communications flowing through it. The test bed is used in various use cases that were used to evaluate Cisco Performance Routing optimization capabilities in different scenarios.

  2. The Netherlands traffic route : street lighting in The Netherlands.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1966-01-01

    The general trends which were evident five years ago have continued, which implies that the tremendous increase in road traffic has been met by improvements in the overall quality of road lighting systems. Outside built-up areas, lighting is generally confined to junctions, roundabouts, and along st

  3. Bandwidth constrained QoS routing scheme for MPLS traffic engineering

    Institute of Scientific and Technical Information of China (English)

    李震宇; 张中兆

    2004-01-01

    Traffic engineering has been essential to optimize the utilization of network resource and to provide for QoS,QoS routing is a basic component of traffic engineering in MPLS networks. Aiming at some shortages of certain existing routing algorithms, we propose an efficient bandwidth constrained QoS routing scheme with additional traffic engineering objectives. The objectives of traffic engineering considered in our algorithm are to reduce the blocking probability of requests and to evenly distribute the traffic load. Accordingly, the algorithm avoids using critical links as far as possible by assigning large weights to them as a function of their criticality. The critical links can be specified according to max-flow reduction weight, a new link weight introduced by the algorithm. Then, a new defined additive metric, path saturation,is used to select optimal path. Extensive simulations are carried out to evaluate the performance of the proposed algorithm in terms of call blocking probability and link resource utilization. Compared to other several routing algorithms, the simulation results show the new algorithm performs well.

  4. Controlling Disorder in Traffic Flow by Perturbation

    Institute of Scientific and Technical Information of China (English)

    LIKe-Ping; GAOZi-You; CHENTian-Lun

    2004-01-01

    We propose a new technique for controlling disorder in traffic system. A kind of control signal which can be considered as a perturbation has been designated at a given site (perturbation point) of the single-lane highway. When a vehicle passes the perturbation point at a time, the velocity of the vehicle will be changed at the next time by the perturbation. This technique is tested for the deterministic NaSch traffic model. The simulation results indicate that the traffic system can be transited from the disorder states to the order states, such as fixed-point, periodic motion, etc.

  5. Traffic and Security using Randomized Dispersive Routes in Heterogeneous Sensor Network

    CERN Document Server

    Karunakaran, P

    2012-01-01

    Generally traffic and the sensor network security have many challenges in the transmission of data in the network. The existing schemes consider homogeneous sensor networks which have poor performance and scalability. Due to many-to-one traffic pattern, sensors may communicate with small portion of its neighbours. Key management is the critical process in sensor nodes to secure the data. Most existing schemes establish shared keys for all the sensors no matter whether they are communicating or not. Hence it leads to large storage overhead. Another problem in sensor network is compromised node attack and denial of service attack which occurs because of its wireless nature. Existing multi path routing algorithms are vulnerable to these attacks. So once an adversary acquires the routing algorithm, it can compute the same routes known to the source, and hence endanger all information sent over these routes. If an adversary performs node compromise attack, they can easily get the encryption/ decryption keys used b...

  6. Selection of Air Traffic Controllers,

    Science.gov (United States)

    1984-08-01

    Frequently used assessment instruments include the Manifest Anxiety Scale (Taylor, 1953) and the State-Trait Anxiety Inventory (Spielberger, Gorsuch ...effectiveness information system data base. McLean, VA: The MITRE Corporation, MTR-7655, Supplement 2, December 1977. Spielberger, C. D., Gorsuch , R

  7. Intelligent traffic control system using PLC

    Science.gov (United States)

    Barz, C.; Todea, C.; Latinovic, T.; Preradovic, D. M.; Deaconu, S.; Berdie, A.

    2016-08-01

    The paper presents the traffic control system controlled through a PLC which takes the signals from different sensors on roads. The global system developed ensures the coordination of four intersections, setting a path that respects coordination type green light, the integration of additional sensors, the implementation of probes radar to inform traffic participants about recommended speed for accessing the green state located in the intersection that will follow to cross.

  8. Impact of traffic-related air pollution on health.

    Science.gov (United States)

    Jakubiak-Lasocka, J; Lasocki, J; Siekmeier, R; Chłopek, Z

    2015-01-01

    Road transport contributes significantly to air quality problems through vehicle emissions, which have various detrimental impacts on public health and the environment. The aim of this study was to assess the impact of traffic-related air pollution on health of Warsaw citizens, following the basics of the Health Impact Assessment (HIA) method, and evaluate its social cost. PM10 was chosen as an indicator of traffic-related air pollution. Exposure-response functions between air pollution and health impacts were employed. The value of statistical life (VSL) approach was used for the estimation of the cost of mortality attributable to traffic-related air pollution. Costs of hospitalizations and restricted activity days were assessed basing on the cost of illness (COI) method. According to the calculations, about 827 Warsaw citizens die in a year as a result of traffic-related air pollution. Also, about 566 and 250 hospital admissions due to cardiovascular and respiratory diseases, respectively, and more than 128,453 restricted activity days can be attributed to the traffic emissions. From the social perspective, these losses generate the cost of 1,604 million PLN (1 EUR-approx. 4.2 PLN). This cost is very high and, therefore, more attention should be paid for the integrated environmental health policy.

  9. Dynamic Air-Route Adjustments - Model,Algorithm,and Sensitivity Analysis

    Institute of Scientific and Technical Information of China (English)

    GENG Rui; CHENG Peng; CUI Deguang

    2009-01-01

    Dynamic airspace management (DAM) is an important approach to extend limited air space resources by using them more efficiently and flexibly.This paper analyzes the use of the dynamic air-route adjustment (DARA) method as a core procedure in DAM systems.DARA method makes dynamic decisions on when and how to adjust the current air-route network with the minimum cost.This model differs from the air traffic flow management (ATFM) problem because it considers dynamic opening and closing of air-route segments instead of only arranging flights on a given air traffic network and it takes into account several new constraints,such as the shortest opening time constraint.The DARA problem is solved using a two-step heuristic algorithm.The sensitivities of important coefficients in the model are analyzed to determine proper values for these coefficients.The computational results based on practical data from the Beijing ATC region show that the two-step heuristic algorithm gives as good results as the CPLEX in less or equal time in most cases.

  10. Evolutionary Concepts for Decentralized Air Traffic Flow Management

    Science.gov (United States)

    Adams, Milton; Kolitz, Stephan; Milner, Joseph; Odoni, Amedeo

    1997-01-01

    Alternative concepts for modifying the policies and procedures under which the air traffic flow management system operates are described, and an approach to the evaluation of those concepts is discussed. Here, air traffic flow management includes all activities related to the management of the flow of aircraft and related system resources from 'block to block.' The alternative concepts represent stages in the evolution from the current system, in which air traffic management decision making is largely centralized within the FAA, to a more decentralized approach wherein the airlines and other airspace users collaborate in air traffic management decision making with the FAA. The emphasis in the discussion is on a viable medium-term partially decentralized scenario representing a phase of this evolution that is consistent with the decision-making approaches embodied in proposed Free Flight concepts for air traffic management. System-level metrics for analyzing and evaluating the various alternatives are defined, and a simulation testbed developed to generate values for those metrics is described. The fundamental issue of modeling airline behavior in decentralized environments is also raised, and an example of such a model, which deals with the preservation of flight bank integrity in hub airports, is presented.

  11. Traffic control: nursing practice calendar.

    Science.gov (United States)

    Rus, Linda; Cheesebro, Kathy; Nagra, Erica; Neff, Alaina

    2013-01-01

    Educating nurses on the multitude of new and updated best practices, changes in regulatory standards, new equipment, and enhanced technology creates an "information traffic jam." Multiple practice changes occurring simultaneously pose challenges for nurses to retain information to practice safely and effectively. An absence of coordination between various nursing and allied health teaching initiatives compounds this problem. A nursing practice calendar was developed to facilitate the prioritization, communication, and education of hospital-wide initiatives affecting nursing practice.

  12. An empirically grounded agent based model for modeling directs, conflict detection and resolution operations in Air Traffic Management

    CERN Document Server

    Bongiorno, C; Mantegna, Rosario N

    2016-01-01

    We present an agent based model of the Air Traffic Management socio-technical complex system that aims at modeling the interactions between aircrafts and air traffic controllers at a tactical level. The core of the model is given by the conflict detection and resolution module and by the directs module. Directs are flight shortcuts that are given by air controllers to speed up the passage of an aircraft within a certain airspace and therefore to facilitate airline operations. Conflicts resolution between flight trajectories can arise during the en-route phase of each flight due to both not detailed flight trajectory planning or unforeseen events that perturb the planned flight plan. Our model performs a local conflict detection and resolution procedure. Once a flight trajectory has been made conflict-free, the model searches for possible improvements of the system efficiency by issuing directs. We give an example of model calibration based on real data. We then provide an illustration of the capability of our...

  13. PERFORMANCE ANALYSIS OF ROUTING PROTOCOLS AND TCP VARIANTS UNDER HTTP AND FTP TRAFFIC IN MANETS

    Directory of Open Access Journals (Sweden)

    Ghassan A. QasMarrogy

    2014-12-01

    Full Text Available MANET stands for mobile ad-hoc network that has multi-hop and dynamic nature, where each station changes its location frequently and automatically configures itself. In this paper, four routing protocols that are OLSR, GRP, DSR, and AODV are discussed along with three TCP variants that are SACK, New Reno and Reno. The main focus of this paper is to study the impact scalability, mobility and traffic loads on routing protocols and TCP variants. The paper results shows that the proactive protocols OLSR and GRP outperform the reactive protocols AODV and DSR with the same nodes size, nodes speed, and traffic load. On the other hand, the TCP variants research reveal the superiority of the TCP SACK variant over the other two variants in case of adapting to varying network size, while the TCP Reno variant acts more robustly in varying mobility speeds and traffic loads

  14. A weighted mean velocity feedback strategy in intelligent two-route traffic systems

    Institute of Scientific and Technical Information of China (English)

    Xiang Zheng-Tao; Xiong Li

    2013-01-01

    Information feedback strategies can influence the traffic efficiency of intelligent traffic systems greatly.Based on the more practical symmetrical two-route scenario with one entrance and one exit,an improved weighted mean velocity feedback strategy (WMVFS) is proposed,which is not sensitive to the precision of global position system (GPS) devices.The applicability of WMVFS to different weight factors,aggressive probabilities,densities of dynamic vehicles,and different two-route scenarios (symmetrical scenario and asymmetrical scenario with a speed limit bottleneck) is analyzed.Results show that WMVFS achieves the best performance compared with three other information feedback strategies when considering the traffic flux and stability.

  15. The Impact of European Traffic Policy and Traffic Routes on the Development of the Ports of Rijeka and Place

    Directory of Open Access Journals (Sweden)

    Čedomir Ivaković

    2006-03-01

    Full Text Available Sea ports are the key segment of the traffic and economicdevelopment of maritime countries. Pan-European transportcorridors include the most important sea pmts and sea routes.They are an extension of the existing land corridors.The most important and the most promising crossings oftraffic corridors between the Central European, Pannonianand Adriatic areas, with the naturally shortest traffic routes directedtowards the Croatian sea ports are Corridor 58 ( Rijeka-Zagreb-Budapest and Corridor 5c (Ploce-Sarajevo-Osijek--Budapest. The primary purpose of this work is to study the importanceof the existing trading conditions and new investmentundertakings in the context of increase in competitiveness of theports of Rijeka and Place.The authors' attention is particularly directed to the constructionof new port terminals to increase the traffic potentialsof the Croatian sea ports. The formed conception with its characteristics,the methodology applied, and research results representthe quality starting points in determining a uniform portpolicy of the Republic of Croatia within the European trafficsystem.

  16. Traffic Monitoring and Control Using RFID

    Directory of Open Access Journals (Sweden)

    Gaurav Thakur

    2013-09-01

    Full Text Available Traffic congestion and tidal flow management were recognized as major problems in modern urban areas, which have caused much frustration and loss of man hours. The operation of standard traffic lights which are currently deployed in many junctions, are based on predetermined timing schemes, which are fixed during the installation and remain until further resetting. The timing is no more than a default setup to control what may be considered as normal traffic. Although every road junction by necessity requires different traffic light timing setup, many existing systems operate with a default sequence. To design an intelligent and efficient traffic control system, a number of parameters that represent the status of the road conditions must be identified and taken into consideration. Approach: In order to solve the problem an intelligent RFID traffic control has been developed. This project is based on monitoring the traffic density at the signal using RFID Reader. RFID tags which is placed (instead of number plate at each vehicle will serve as the unique number of vehicle .Reader will count the number of tags at the signal and take decision of increasing or decreasing the signal time .This reader is also use to find the violation(VIN of violator of the signal. Each passive tag will have certain number of bytes information will be different for different vehicles. Whenever any tag will approach any signal, reader will take that bytes of information and simultaneously will also increment the number of vehicles for making decision to change the signal timing. Each tag of data will be stored in main memory (database.This unique data will also help in determining the violator of the signal .Thus it will save human efforts and resources to a greater extent and reduce waiting of the people at the signal. After implementation of this project, now all people waiting at the signal will get proper time (green light according to the traffic density

  17. Traffic Flow Control In Automated Highway Systems

    OpenAIRE

    Alvarez, Luis; Horowitz, Roberto

    1997-01-01

    This report studies the problem of traffic control in the Automated Highway System (AHS) hierarchical architecture of the California PATH program. A link layer controller for the PATH AHS architecture is presented. It is shown that the proposed control laws stabilize the vehicular density and flow around predetermined profiles.

  18. Poison Control Centers

    Science.gov (United States)

    ... 1222 immediately. Name State American Association of Poison Control Centers Address AAPCC Central Office NOT A POISON ... not for emergency use. Arkansas ASPCA Animal Poison Control Center Address 1717 S. Philo Road, Suite 36 Urbana, ...

  19. Air pollution and health risks due to vehicle traffic

    Science.gov (United States)

    Zhang, Kai; Batterman, Stuart

    2014-01-01

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed–volume relationship, the California Line Source Dispersion Model, an empirical NO2–NOx relationship, estimated travel time changes during congestion, and concentration–response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, “U” shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2–NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion

  20. Air pollution and health risks due to vehicle traffic.

    Science.gov (United States)

    Zhang, Kai; Batterman, Stuart

    2013-04-15

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed-volume relationship, the California Line Source Dispersion Model, an empirical NO2-NOx relationship, estimated travel time changes during congestion, and concentration-response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, "U" shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2-NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion must

  1. Road traffic impact on urban water quality: a step towards integrated traffic, air and stormwater modelling.

    Science.gov (United States)

    Fallah Shorshani, Masoud; Bonhomme, Céline; Petrucci, Guido; André, Michel; Seigneur, Christian

    2014-04-01

    Methods for simulating air pollution due to road traffic and the associated effects on stormwater runoff quality in an urban environment are examined with particular emphasis on the integration of the various simulation models into a consistent modelling chain. To that end, the models for traffic, pollutant emissions, atmospheric dispersion and deposition, and stormwater contamination are reviewed. The present study focuses on the implementation of a modelling chain for an actual urban case study, which is the contamination of water runoff by cadmium (Cd), lead (Pb), and zinc (Zn) in the Grigny urban catchment near Paris, France. First, traffic emissions are calculated with traffic inputs using the COPERT4 methodology. Next, the atmospheric dispersion of pollutants is simulated with the Polyphemus line source model and pollutant deposition fluxes in different subcatchment areas are calculated. Finally, the SWMM water quantity and quality model is used to estimate the concentrations of pollutants in stormwater runoff. The simulation results are compared to mass flow rates and concentrations of Cd, Pb and Zn measured at the catchment outlet. The contribution of local traffic to stormwater contamination is estimated to be significant for Pb and, to a lesser extent, for Zn and Cd; however, Pb is most likely overestimated due to outdated emissions factors. The results demonstrate the importance of treating distributed traffic emissions from major roadways explicitly since the impact of these sources on concentrations in the catchment outlet is underestimated when those traffic emissions are spatially averaged over the catchment area.

  2. 36 CFR 4.12 - Traffic control devices.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Traffic control devices. 4.12... VEHICLES AND TRAFFIC SAFETY § 4.12 Traffic control devices. Failure to comply with the directions of a traffic control device is prohibited unless otherwise directed by the superintendent....

  3. 36 CFR 1004.12 - Traffic control devices.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Traffic control devices. 1004.12 Section 1004.12 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.12 Traffic control devices. Failure to comply with the directions of a traffic control device...

  4. An evolutionary outlook of air traffic flow management techniques

    Science.gov (United States)

    Kistan, Trevor; Gardi, Alessandro; Sabatini, Roberto; Ramasamy, Subramanian; Batuwangala, Eranga

    2017-01-01

    In recent years Air Traffic Flow Management (ATFM) has become pertinent even in regions without sustained overload conditions caused by dense traffic operations. Increasing traffic volumes in the face of constrained resources has created peak congestion at specific locations and times in many areas of the world. Increased environmental awareness and economic drivers have combined to create a resurgent interest in ATFM as evidenced by a spate of recent ATFM conferences and workshops mediated by official bodies such as ICAO, IATA, CANSO the FAA and Eurocontrol. Significant ATFM acquisitions in the last 5 years include South Africa, Australia and India. Singapore, Thailand and Korea are all expected to procure ATFM systems within a year while China is expected to develop a bespoke system. Asia-Pacific nations are particularly pro-active given the traffic growth projections for the region (by 2050 half of all air traffic will be to, from or within the Asia-Pacific region). National authorities now have access to recently published international standards to guide the development of national and regional operational concepts for ATFM, geared to Communications, Navigation, Surveillance/Air Traffic Management and Avionics (CNS+A) evolutions. This paper critically reviews the field to determine which ATFM research and development efforts hold the best promise for practical technological implementations, offering clear benefits both in terms of enhanced safety and efficiency in times of growing air traffic. An evolutionary approach is adopted starting from an ontology of current ATFM techniques and proceeding to identify the technological and regulatory evolutions required in the future CNS+A context, as the aviation industry moves forward with a clearer understanding of emerging operational needs, the geo-political realities of regional collaboration and the impending needs of global harmonisation.

  5. Impact analysis of traffic-related air pollution based on real-time traffic and basic meteorological information.

    Science.gov (United States)

    Pan, Long; Yao, Enjian; Yang, Yang

    2016-12-01

    With the rapid development of urbanization and motorization in China, traffic-related air pollution has become a major component of air pollution which constantly jeopardizes public health. This study proposes an integrated framework for estimating the concentration of traffic-related air pollution with real-time traffic and basic meteorological information and also for further evaluating the impact of traffic-related air pollution. First, based on the vehicle emission factor models sensitive to traffic status, traffic emissions are calculated according to the real-time link-based average traffic speed, traffic volume, and vehicular fleet composition. Then, based on differences in meteorological conditions, traffic pollution sources are divided into line sources and point sources, and the corresponding methods to determine the dynamic affecting areas are also proposed. Subsequently, with basic meteorological data, Gaussian dispersion model and puff integration model are applied respectively to estimate the concentration of traffic-related air pollution. Finally, the proposed estimating framework is applied to calculate the distribution of CO concentration in the main area of Beijing, and the population exposure is also calculated to evaluate the impact of traffic-related air pollution on public health. Results show that there is a certain correlation between traffic indicators (i.e., traffic speed and traffic intensity) of the affecting area and traffic-related CO concentration of the target grid, which indicates the methods to determine the affecting areas are reliable. Furthermore, the reliability of the proposed estimating framework is verified by comparing the predicted and the observed ambient CO concentration. In addition, results also show that the traffic-related CO concentration is higher in morning and evening peak hours, and has a heavier impact on public health within the Fourth Ring Road of Beijing due to higher population density and higher CO

  6. Statistical characterization of deviations from planned flight trajectories in air traffic management

    CERN Document Server

    Bongiorno, C; Lillo, F; Mantegna, R N; Miccichè, S

    2016-01-01

    Understanding the relation between planned and realized flight trajectories and the determinants of flight deviations is of great importance in air traffic management. In this paper we perform an in depth investigation of the statistical properties of planned and realized air traffic on the German airspace during a 28 day periods, corresponding to an AIRAC cycle. We find that realized trajectories are on average shorter than planned ones and this effect is stronger during night-time than daytime. Flights are more frequently deviated close to the departure airport and at a relatively large angle to destination. Moreover, the probability of a deviation is higher in low traffic phases. All these evidences indicate that deviations are mostly used by controllers to give directs to flights when traffic conditions allow it. Finally we introduce a new metric, termed difork, which is able to characterize navigation points according to the likelihood that a deviation occurs there. Difork allows to identify in a statist...

  7. Test Control Center (TCC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Test Control Center (TCC) provides a consolidated facility for planning, coordinating, controlling, monitoring, and analyzing distributed test events. ,The TCC...

  8. Relationship Between Air Pollution, Weather, Traffic, and Traffic-Related Mortality

    Science.gov (United States)

    Dastoorpoor, Maryam; Idani, Esmaeil; Khanjani, Narges; Goudarzi, Gholamreza; Bahrampour, Abbas

    2016-01-01

    Background Air pollution and weather are just two of many environmental factors contributing to traffic accidents (RTA). Objectives This study assessed the effects of these factors on traffic accidents and related mortalities in Ahvaz, Iran. Methods In this ecological study, data about RTA, traffic-related mortalities, air pollution (including NO, CO, NO2, NOx PM10, SO2, and O3 rates) and climate data from March 2008 until March 2015 was acquired from the Khuzestan State Police Force, the Environmental Protection Agency and the State Meteorological Department. Statistical analysis was performed with STATA 12 through both crude and adjusted negative binomial regression methods. Results There was a significant positive correlation between increase in the monthly average temperature, the number of rainy days, and the number of frost days with the number of RTA (P < 0.05). Increased monthly average relative humidity, evaporation, and number of sunny days were negatively correlated with the frequency of RTA (P < 0.05). We also observed an inverse significant correlation between monthly average relative humidity, evaporation, and wind speed with traffic accident mortality (P < 0.05). Some air pollutants were negatively associated with the incidence rate of RTA. Conclusions It appears that some weather variables were significantly associated with increased RTA. However, increased levels of air pollutants were not associated with increased rates of RTA and/or related mortalities. Additional studies are recommended to explore this topic in more detail.

  9. Development of a forecast model for global air traffic emissions

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Martin

    2012-07-01

    The thesis describes the methodology and results of a simulation model that quantifies fuel consumption and emissions of civil air traffic. Besides covering historical emissions, the model aims at forecasting emissions in the medium-term future. For this purpose, simulation models of aircraft and engine types are used in combination with a database of global flight movements and assumptions about traffic growth, fleet rollover and operational aspects. Results from an application of the model include emissions of scheduled air traffic for the years 2000 to 2010 as well as forecasted emissions until the year 2030. In a baseline scenario of the forecast, input assumptions (e.g. traffic growth rates) are in line with predictions by the aircraft industry. Considering the effects of advanced technologies of the short-term and medium-term future, the forecast focusses on fuel consumption and emissions of nitric oxides. Calculations for historical air traffic additionally cover emissions of carbon monoxide, unburned hydrocarbons and soot. Results are validated against reference data including studies by the International Civil Aviation Organization (ICAO) and simulation results from international research projects. (orig.)

  10. Traffic air pollution and mortality from cardiovascular disease and all causes

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Andersen, Zorana Jovanovic; Jensen, Steen Solvang;

    2012-01-01

    Traffic air pollution has been linked to cardiovascular mortality, which might be due to co-exposure to road traffic noise. Further, personal and lifestyle characteristics might modify any association.......Traffic air pollution has been linked to cardiovascular mortality, which might be due to co-exposure to road traffic noise. Further, personal and lifestyle characteristics might modify any association....

  11. Modeling the Environmental Impact of Air Traffic Operations

    Science.gov (United States)

    Chen, Neil

    2011-01-01

    There is increased interest to understand and mitigate the impacts of air traffic on the climate, since greenhouse gases, nitrogen oxides, and contrails generated by air traffic can have adverse impacts on the climate. The models described in this presentation are useful for quantifying these impacts and for studying alternative environmentally aware operational concepts. These models have been developed by leveraging and building upon existing simulation and optimization techniques developed for the design of efficient traffic flow management strategies. Specific enhancements to the existing simulation and optimization techniques include new models that simulate aircraft fuel flow, emissions and contrails. To ensure that these new models are beneficial to the larger climate research community, the outputs of these new models are compatible with existing global climate modeling tools like the FAA's Aviation Environmental Design Tool.

  12. Wheel traffic effect on air-filled porosity and air permeability in a soil catena across the wheel rut

    DEFF Research Database (Denmark)

    Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

    The impact of wheel traffic on soil physical properties is usually quantified by randomly collecting soil cores at specific depths below the wheeled surface. However, modeling studies as well as few measurements indicated a non-uniform stress distribution in a catena across the wheel rut, which m...... provide better resolution on information about traffic induce changes on soil physical properties. Key words: Compaction, Shear stress, Soil catena, Air permeability, Air-filled porosity...... might induce different effects on soil physical properties. The objective of this study was to investigate the impact of vehicle traffic on soil physical properties and air permeability by systematic collection of samples in a transect running from the center to the outside of the wheel rut. A field...... catena running from center of the wheel rut to un wheeled part of the field ( 0, 20, 40, 50,60 and 400 cm horizontal distance). We measured water retention and air permeability (ka) at -30, -100 and -300 hPa matric potentials. At -100 hPa, we obtained consistently lower air filled under the wheel rut...

  13. Controlled stochastic networks in heavy traffic: Convergence of value functions

    CERN Document Server

    Budhiraja, Amarjit; 10.1214/11-AAP784

    2012-01-01

    Scheduling control problems for a family of unitary networks under heavy traffic with general interarrival and service times, probabilistic routing and an infinite horizon discounted linear holding cost are studied. Diffusion control problems, that have been proposed as approximate models for the study of these critically loaded controlled stochastic networks, can be regarded as formal scaling limits of such stochastic systems. However, to date, a rigorous limit theory that justifies the use of such approximations for a general family of controlled networks has been lacking. It is shown that, under broad conditions, the value function of the suitably scaled network control problem converges to that of the associated diffusion control problem. This scaling limit result, in addition to giving a precise mathematical basis for the above approximation approach, suggests a general strategy for constructing near optimal controls for the physical stochastic networks by solving the associated diffusion control problem...

  14. Route selection for vehicle navigation and control

    OpenAIRE

    G. Pang; Chu, MH

    2007-01-01

    This paper presents an application of neural-fuzzy methodology for the problem of route selection in a typical vehicle navigation and control system. The idea of the primary attributes of a route is discussed, and a neural-fuzzy system is developed to help a user to select a route out of the many possible routes from an origin to the destination. The user may not adopt the recommendation provided by the system and choose an alternate route. One novel feature of the system is that the neural-f...

  15. Air traffic simulation in chemistry-climate model EMAC 2.41: AirTraf 1.0

    Science.gov (United States)

    Yamashita, Hiroshi; Grewe, Volker; Jöckel, Patrick; Linke, Florian; Schaefer, Martin; Sasaki, Daisuke

    2016-09-01

    Mobility is becoming more and more important to society and hence air transportation is expected to grow further over the next decades. Reducing anthropogenic climate impact from aviation emissions and building a climate-friendly air transportation system are required for a sustainable development of commercial aviation. A climate optimized routing, which avoids climate-sensitive regions by re-routing horizontally and vertically, is an important measure for climate impact reduction. The idea includes a number of different routing strategies (routing options) and shows a great potential for the reduction. To evaluate this, the impact of not only CO2 but also non-CO2 emissions must be considered. CO2 is a long-lived gas, while non-CO2 emissions are short-lived and are inhomogeneously distributed. This study introduces AirTraf (version 1.0) that performs global air traffic simulations, including effects of local weather conditions on the emissions. AirTraf was developed as a new submodel of the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model. Air traffic information comprises Eurocontrol's Base of Aircraft Data (BADA Revision 3.9) and International Civil Aviation Organization (ICAO) engine performance data. Fuel use and emissions are calculated by the total energy model based on the BADA methodology and Deutsches Zentrum für Luft- und Raumfahrt (DLR) fuel flow method. The flight trajectory optimization is performed by a genetic algorithm (GA) with respect to a selected routing option. In the model development phase, benchmark tests were performed for the great circle and flight time routing options. The first test showed that the great circle calculations were accurate to -0.004 %, compared to those calculated by the Movable Type script. The second test showed that the optimal solution found by the algorithm sufficiently converged to the theoretical true-optimal solution. The difference in flight time between the two solutions is less than 0.01 %. The dependence of

  16. Aircraft/Air Traffic Management Functional Analysis Model: Technical Description. 2.0

    Science.gov (United States)

    Etheridge, Melvin; Plugge, Joana; Retina, Nusrat

    1998-01-01

    The Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 (FAM 2.0), is a discrete event simulation model designed to support analysis of alternative concepts in air traffic management and control. FAM 2.0 was developed by the Logistics Management Institute (LMI) under a National Aeronautics and Space Administration (NASA) contract. This document provides a technical description of FAM 2.0 and its computer files to enable the modeler and programmer to make enhancements or modifications to the model. Those interested in a guide for using the model in analysis should consult the companion document, Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 Users Manual.

  17. Integrating Human Performance Metrics into the Future Air Traffic Management Concepts Evaluation Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Future Air traffic management Concepts Evaluation Tool (FACET) is a simulation tool to evaluate next generation air traffic management (ATM) systems. FACET...

  18. Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps), Version 2.0

    Science.gov (United States)

    Baxley, Brian T.; Johnson, William C.; Swenson, Harry N.; Robinson, John E.; Prevot, Tom; Callantine, Todd J.; Scardina, John; Greene, Michael

    2013-01-01

    This document is an update to the operations and procedures envisioned for NASA s Air Traffic Management (ATM) Technology Demonstration #1 (ATD-1). The ATD-1 Concept of Operations (ConOps) integrates three NASA technologies to achieve high throughput, fuel-efficient arrival operations into busy terminal airspace. They are Traffic Management Advisor with Terminal Metering (TMA-TM) for precise time-based schedules to the runway and points within the terminal area, Controller-Managed Spacing (CMS) decision support tools for terminal controllers to better manage aircraft delay using speed control, and Flight deck Interval Management (FIM) avionics and flight crew procedures to conduct airborne spacing operations. The ATD-1 concept provides de-conflicted and efficient operations of multiple arrival streams of aircraft, passing through multiple merge points, from top-of-descent (TOD) to the Final Approach Fix. These arrival streams are Optimized Profile Descents (OPDs) from en route altitude to the runway, using primarily speed control to maintain separation and schedule. The ATD-1 project is currently addressing the challenges of integrating the three technologies, and their implantation into an operational environment. The ATD-1 goals include increasing the throughput of high-density airports, reducing controller workload, increasing efficiency of arrival operations and the frequency of trajectory-based operations, and promoting aircraft ADS-B equipage.

  19. Traffic Management Coordinator Evaluation of the Dynamic Weather Routes Concept and System

    Science.gov (United States)

    Gong, Chester

    2014-01-01

    Dynamic Weather Routes (DWR) is a weather-avoidance system for airline dispatchers and FAA traffic managers that continually searches for and advises the user of more efficient routes around convective weather. NASA and American Airlines (AA) have been conducting an operational trial of DWR since July 17, 2012. The objective of this evaluation is to assess DWR from a traffic management coordinator (TMC) perspective, using recently retired TMCs and actual DWR reroutes advisories that were rated acceptable by AA during the operational trial. Results from the evaluation showed that the primary reasons for a TMC to modify or reject airline reroute requests were related to airspace configuration. Approximately 80 percent of the reroutes evaluated required some coordination before implementation. Analysis showed TMCs approved 62 percent of the requested DWR reroutes, resulting in 57 percent of the total requested DWR time savings.

  20. 75 FR 47252 - Proposed Establishment of Low Altitude Area Navigation Routes (T-281, T-283, T-285, T-286, and T...

    Science.gov (United States)

    2010-08-05

    ... Altitude Area Navigation Routes (T- 281, T-283, T-285, T-286, and T-288); Nebraska and South Dakota AGENCY... action proposes to establish five low altitude Area Navigation (RNAV) routes, designated T-281, T-283, T-285, T-286, and T- 288, over Nebraska and South Dakota; controlled by Denver Air Route Traffic...

  1. RECOVERY ACT: DYNAMIC ENERGY CONSUMPTION MANAGEMENT OF ROUTING TELECOM AND DATA CENTERS THROUGH REAL-TIME OPTIMAL CONTROL (RTOC): Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Ron Moon

    2011-06-30

    This final scientific report documents the Industrial Technology Program (ITP) Stage 2 Concept Development effort on Data Center Energy Reduction and Management Through Real-Time Optimal Control (RTOC). Society is becoming increasingly dependent on information technology systems, driving exponential growth in demand for data center processing and an insatiable appetite for energy. David Raths noted, 'A 50,000-square-foot data center uses approximately 4 megawatts of power, or the equivalent of 57 barrels of oil a day1.' The problem has become so severe that in some cases, users are giving up raw performance for a better balance between performance and energy efficiency. Historically, power systems for data centers were crudely sized to meet maximum demand. Since many servers operate at 60%-90% of maximum power while only utilizing an average of 5% to 15% of their capability, there are huge inefficiencies in the consumption and delivery of power in these data centers. The goal of the 'Recovery Act: Decreasing Data Center Energy Use through Network and Infrastructure Control' is to develop a state of the art approach for autonomously and intelligently reducing and managing data center power through real-time optimal control. Advances in microelectronics and software are enabling the opportunity to realize significant data center power savings through the implementation of autonomous power management control algorithms. The first step to realizing these savings was addressed in this study through the successful creation of a flexible and scalable mathematical model (equation) for data center behavior and the formulation of an acceptable low technical risk market introduction strategy leveraging commercial hardware and software familiar to the data center market. Follow-on Stage 3 Concept Development efforts include predictive modeling and simulation of algorithm performance, prototype demonstrations with representative data center equipment to

  2. Delay banking for air traffic management

    Science.gov (United States)

    Green, Steven M. (Inventor)

    2007-01-01

    A method and associated system for time delay banking for aircraft arrival time, aircraft departure time and/or en route flight position. The delay credit value for a given flight may decrease with passage of time and may be transferred to or traded with other flights having the same or a different user (airline owner or operator). The delay credit value for a given aircraft flight depends upon an initial delay credit value, which is determined by a central system and depends upon one or more other flight characteristics. Optionally, the delay credit value decreases with passage of time. Optionally, a transaction cost is assessed against a delay credit value that is used on behalf of another flight with the same user or is traded with a different user.

  3. [Estimation of average traffic emission factor based on synchronized incremental traffic flow and air pollutant concentration].

    Science.gov (United States)

    Li, Run-Kui; Zhao, Tong; Li, Zhi-Peng; Ding, Wen-Jun; Cui, Xiao-Yong; Xu, Qun; Song, Xian-Feng

    2014-04-01

    On-road vehicle emissions have become the main source of urban air pollution and attracted broad attentions. Vehicle emission factor is a basic parameter to reflect the status of vehicle emissions, but the measured emission factor is difficult to obtain, and the simulated emission factor is not localized in China. Based on the synchronized increments of traffic flow and concentration of air pollutants in the morning rush hour period, while meteorological condition and background air pollution concentration retain relatively stable, the relationship between the increase of traffic and the increase of air pollution concentration close to a road is established. Infinite line source Gaussian dispersion model was transformed for the inversion of average vehicle emission factors. A case study was conducted on a main road in Beijing. Traffic flow, meteorological data and carbon monoxide (CO) concentration were collected to estimate average vehicle emission factors of CO. The results were compared with simulated emission factors of COPERT4 model. Results showed that the average emission factors estimated by the proposed approach and COPERT4 in August were 2.0 g x km(-1) and 1.2 g x km(-1), respectively, and in December were 5.5 g x km(-1) and 5.2 g x km(-1), respectively. The emission factors from the proposed approach and COPERT4 showed close values and similar seasonal trends. The proposed method for average emission factor estimation eliminates the disturbance of background concentrations and potentially provides real-time access to vehicle fleet emission factors.

  4. 无人机空管领域现状分析与空管系统设计%Current Situation Analysis and Air Traffic Control System Design of Unmanned Aerial Vehicle

    Institute of Scientific and Technical Information of China (English)

    王雪峰; 胡潇; 杨明; 王伟勋

    2016-01-01

    According to the characteristics of low-altitude airspace management, the status of air traffic control system of UAV is analyzed and depending the application of self-developed Beidou navigation system, a frame for air traffic control system of UAV based on a general aviation Compass RDSS and ADS-B is designed, which provides a means of support for general aviation flight in low-altitude airspace of UAV.%本文针对我国低空空域管理特点,分析我国无人机空管系统的现状,结合我国自主研发的北斗导航系统的应用,设计一种基于北斗RDSS和ADS-B的无人机空管系统的体系结构,为低空空域无人机的安全飞行提供了一种技术保障手段。

  5. Routing and spectrum allocation in multi-ring based data center networks

    Science.gov (United States)

    Zhang, Zitian; Hu, Weisheng; Ye, Tong; Sun, Weiqiang; Zhao, Li; Zhang, Kuo

    2016-02-01

    Recently, we proposed a multi-ring based optical circuit switching (OCS) network following the principle of a Clos network. The network can provide connectivity to a large number of racks which may be distributed across a relatively large geographical space in a data center. However, property of the ring based switch in the central stage of the multi-ring based OCS network introduces a unique routing and spectrum allocation (RSA) problem which is more complex than the routing problem in a classical Clos switching network. In this paper, we extend our work to investigate the RSA problem. For a given set of inter-rack traffic requests, we consider two spectrum allocation schemes, namely fixed spectrum allocation and flexible spectrum allocation. For the fixed case, we show that the RSA problem degenerates into the traditional routing problem of the Clos network. As for the flexible case, property of spectrum division multiplexing technology and bandwidth limitation of the ring based switches should be taken into consideration during allocation of the central module, such that the system throughput can be maximized. This paper presents an integer linear program (ILP) formulation as well as a heuristic algorithm we developed to solve the flexible RSA problem. We evaluate the performance of both the two spectrum allocation schemes under different traffic patterns. Our results demonstrate that, to handle uneven inter-rack traffic pattern in general data center networks, flexible spectrum allocation can lead to an increase of about 120% in system throughput, although its computational complexity is slightly higher than that of the fixed spectrum allocation scheme.

  6. Energy Consumption and Control Response Evaluations of AODV Routing in WSANs for Building-Temperature Control

    Directory of Open Access Journals (Sweden)

    Chusak Limsakul

    2013-06-01

    Full Text Available The main objective of this paper is to investigate the effects of routing protocols on wireless sensor and actuator networks (WSANs, focusing on the control system response and the energy consumption of nodes in a network. We demonstrate that routing algorithms designed without considering the relationship between communication and control cannot be appropriately used in wireless networked control applications. For this purpose, an ad-hoc on-demand distance vector (AODV routing, an IEEE 802.15.4, and a building-temperature control system are employed for this exploration. The findings from our scenarios show that the AODV routing can select a path with a high traffic load for data transmission. It takes a long time before deciding to change a new route although it experiences the unsuccessful transmission of packets. As a result, the desirable control target cannot be achieved in time, and nodes consume more energy due to frequent packet collisions and retransmissions. Consequently, we propose a simple routing solution to alleviate these research problems by modifying the original AODV routing protocol. The delay-threshold is considered to avoid any congested connection during routing procedures. The simulation results demonstrate that our solution can be appropriately applied in WSANs. Both the energy consumption and the control system response are improved.

  7. Energy consumption and control response evaluations of AODV routing in WSANs for building-temperature control.

    Science.gov (United States)

    Booranawong, Apidet; Teerapabkajorndet, Wiklom; Limsakul, Chusak

    2013-06-27

    The main objective of this paper is to investigate the effects of routing protocols on wireless sensor and actuator networks (WSANs), focusing on the control system response and the energy consumption of nodes in a network. We demonstrate that routing algorithms designed without considering the relationship between communication and control cannot be appropriately used in wireless networked control applications. For this purpose, an ad-hoc on-demand distance vector (AODV) routing, an IEEE 802.15.4, and a building-temperature control system are employed for this exploration. The findings from our scenarios show that the AODV routing can select a path with a high traffic load for data transmission. It takes a long time before deciding to change a new route although it experiences the unsuccessful transmission of packets. As a result, the desirable control target cannot be achieved in time, and nodes consume more energy due to frequent packet collisions and retransmissions. Consequently, we propose a simple routing solution to alleviate these research problems by modifying the original AODV routing protocol. The delay-threshold is considered to avoid any congested connection during routing procedures. The simulation results demonstrate that our solution can be appropriately applied in WSANs. Both the energy consumption and the control system response are improved.

  8. Distance-Based Routing Strategy for Traffic Transport in Spatial Networks

    Directory of Open Access Journals (Sweden)

    Wei Huang

    2013-01-01

    Full Text Available It is well known that routing strategies based on global topological information is not a good choice for the enhancement of traffic throughput in large-scale networks due to the heavy communication cost. On the contrary, acquiring spatial information, such as spatial distances among nodes, is more feasible. In this paper, we propose a novel distance-based routing strategy in spatial scale-free networks, called LDistance strategy. The probability of establishing links among nodes obeys the power-law in the spatial network under study. Compared with the LDegree strategy (Wang et al., 2006 and the mixed strategy (a strategy combining both greedy routing strategy and random routing strategy, results show that our proposed LDistance strategy can further enhance traffic capacity. Besides, the LDistance strategy can also achieve a much shorter delivering time than the LDegree strategy. Analyses reveal that the superiority of our strategy is mainly due to the interdependent relationship between topological and spatial characteristics in spatial scale-free networks. Furthermore, along transporting path in the LDistance strategy, the spatial distance to destination decays more rapidly, and the degrees of routers are higher than those in the LDegree strategy.

  9. Test Control Center exhibit

    Science.gov (United States)

    2000-01-01

    Have you ever wondered how the engineers at John C. Stennis Space Center in Hancock County, Miss., test fire a Space Shuttle Main Engine? The Test Control Center exhibit at StenniSphere can answer your questions by simulating the test firing of a Space Shuttle Main Engine. A recreation of one of NASA's test control centers, the exhibit explains and portrays the 'shake, rattle and roar' that happens during a real test firing.

  10. Target-tracking and identity management algorithms for air traffic surveillance

    Science.gov (United States)

    Balakrishnan, Hamsa

    The air traffic control system of the United States is responsible for managing traffic in the National Airspace System; safety is a paramount concern. The air traffic surveillance network has the task of collecting and processing information on the positions, velocities and identities of the aircraft in the system, before presenting it to air traffic controllers to use in maintaining an orderly flow of traffic. This dissertation attempts to design techniques that provide controllers with high-fidelity information about the aircraft in their controlled airspace, using the observations of the air traffic surveillance network. We propose algorithms for the efficient tracking of aircraft, as well as for maintaining beliefs of their identities. Such methods would improve the processing of aircraft situation data, particularly in a congested airspace with general aviation. In this thesis, we propose an algorithmic framework for the simultaneous tracking and identity management of multiple maneuvering targets. We design an algorithm that efficiently tracks the positions, velocities, flight modes, and identities of multiple aircraft in cluttered environments. We tackle the challenges of data association, identity management and state estimation of aircraft trajectories by proposing a modification of the Joint Probabilistic Data Association algorithm, an algorithm based on identity-mass flow, and a state estimation algorithm for tracking hybrid systems, respectively. The identity of each aircraft, an essential feature of aircraft situation data, is often not available but needs to be inferred from radar observations, and maintained in terms of probabilities. We present an algorithm to update the probabilistic matrices that represent the belief of aircraft identities, in the presence of intermittent measurements. We demonstrate the performance of the framework using examples drawn from air traffic surveillance. We also consider the problem of identifying stochastic hybrid

  11. MATLAB Simulation of Fuzzy Traffic Controller for Multilane Isolated Intersection

    OpenAIRE

    2010-01-01

    This paper presents a MATLAB simulation of fuzzy traffic controller for controlling traffic flow at multilane isolated signalized intersection. The controller is developed based on the waiting time and vehicles queue length at current green phase, and vehicles queue lengths at the other phases. For control strategy, the controllercontrols the traffic light timings and phase sequence to ensure smooth flow of traffic with minimal waiting time, queue length and delay time. In this research, the ...

  12. Road traffic noise, air pollution components and cardiovascular events.

    Science.gov (United States)

    de Kluizenaar, Yvonne; van Lenthe, Frank J; Visschedijk, Antoon J H; Zandveld, Peter Y J; Miedema, Henk M E; Mackenbach, Johan P

    2013-01-01

    Traffic noise and air pollution have been associated with cardiovascular health effects. Until date, only a limited amount of prospective epidemiological studies is available on long-term effects of road traffic noise and combustion related air pollution. This study investigates the relationship between road traffic noise and air pollution and hospital admissions for ischemic heart disease (IHD: International Classification of Diseases (ICD9) 410-414) or cerebrovascular disease (cerebrovascular event [CVE]: ICD9 430-438). We linked baseline questionnaire data to 13 years of follow-up on hospital admissions and road traffic noise and air pollution exposure, for a large random sample (N = 18,213) of inhabitants of the Eindhoven region, Netherlands. Subjects with cardiovascular event during follow-up on average had higher road traffic noise day, evening, night level (L den) and air pollution exposure at the home. After adjustment for confounders (age, sex, body mass index, smoking, education, exercise, marital status, alcohol use, work situation, financial difficulties), increased exposure did not exert a significant increased risk of hospital admission for IHD or cerebrovascular disease. Relative risks (RRs) for a 5 (th) to 95 (th) percentile interval increase were 1.03 (0.88-1.20) for L den; 1.04 (0.90-1.21) for particulate matter (PM 10 ); 1.05 (0.91-1.20) for elemental carbon (EC); and 1.12 (096-1.32) for nitrogen dioxide (NO 2 ) in the full model. While the risk estimate seemed highest for NO 2 , for a 5 (th) to 95 (th) percentile interval increase, expressed as RRs per 1 μg/m 3 increases, hazard ratios seemed highest for EC (RR 1.04 [0.92-1.18]). In the subgroup of study participants with a history of cardiovascular disease, RR estimates seemed highest for noise exposure (1.19 [0.87-1.64] for L den); in the subgroup of elderly RR seemed highest for air pollution exposure (RR 1.24 [0.93-1.66] for NO 2 ).

  13. Chaos control in traffic flow models

    CERN Document Server

    Shahverdiev, E M; Shahverdiev, Elman Mohammed; Tadaki, Shin-ichi

    1998-01-01

    Chaos control in some of the one- and two-dimensional traffic flow dynamical models in the mean field theory is studied.One dimensional model is investigated taking into account the effect of random delay. Two dimensional model takes into account the effects of overpasses, symmetric distribution of cars and blockages of cars moving in the same direction. Chaos synchronization is performed within both replica and nonreplica approaches, and using parameter perturbation method.

  14. Self-Adapting Routing Overlay Network for Frequently Changing Application Traffic in Content-Based Publish/Subscribe System

    Directory of Open Access Journals (Sweden)

    Meng Chi

    2014-01-01

    Full Text Available In the large-scale distributed simulation area, the topology of the overlay network cannot always rapidly adapt to frequently changing application traffic to reduce the overall traffic cost. In this paper, we propose a self-adapting routing strategy for frequently changing application traffic in content-based publish/subscribe system. The strategy firstly trains the traffic information and then uses this training information to predict the application traffic in the future. Finally, the strategy reconfigures the topology of the overlay network based on this predicting information to reduce the overall traffic cost. A predicting path is also introduced in this paper to reduce the reconfiguration numbers in the process of the reconfigurations. Compared to other strategies, the experimental results show that the strategy proposed in this paper could reduce the overall traffic cost of the publish/subscribe system in less reconfigurations.

  15. Wake Turbulence: An Obstacle to Increased Air Traffic Capacity

    Science.gov (United States)

    2008-01-01

    Wingtip vortices were first described by British aerodynamicist F.W. Lanchester in 1907. A product of lift on a finite-span wing, these counterrotating masses of air trail behind an aircraft, gradually diffusing while convecting downward and moving about under mutual induction and the influence of wind and stratification. Should a smaller aircraft happen to be following the first aircraft, it could be buffeted and even flipped if it flew into the vortex, with dangerous consequences. Given the amount of air traffic in 1907, the wake vortex hazard was not initially much of a concern. The demand for air transportation continues to increase, and it is estimated that demand could double or even triple by 2025. One factor in the capacity of the air transportation system is wake turbulence and the consequent separation distances that must be maintained between aircraft to ensure safety.

  16. Logistics of International Express Shipping and Air Traffic

    Directory of Open Access Journals (Sweden)

    Jasmina Pašagić Škrinjar

    2013-06-01

    Full Text Available The paper studies the relations between logistics of international express shipments and air traffic analysing the basic characteristics of international express shipments that are carried by combined transport, usually road vehicles and aircraft. The paper indicates the possibility of optimising individual technological processes in the logistic chain of express shipments distribution. It analyses the forms for the calculation of time slots in single logistic chain hubs of collecting and delivery of express shipments. It has been shown that the international distribution chains in the air express sector, related to the globalisation process, change the traditional functions of combined ground-air transport. Here, the increased investment into automation plays the crucial role in the development strategies of companies and in the operationalization of the quality policy of numerous carriers of express shipments by air.

  17. Health Center Controlled Network

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Health Center Controlled Network (HCCN) tool is a locator tool designed to make data and information concerning HCCN resources more easily available to our...

  18. A Two-Dimensional CA Traffic Model with Dynamic Route Choices Between Residence and Workplace

    CERN Document Server

    Fang, Jun; Chen, Xi-Qun; Qin, Zheng

    2015-01-01

    The Biham, Middleton and Levine (BML) model is extended to describe dynamic route choices between the residence and workplace in cities. The traffic dynamic in the city with a single workplace is studied from the velocity diagram, arrival time probability distribution, destination arrival rate and convergence time. The city with double workplaces is also investigated to compared with a single workplace within the framework of four modes of urban growth. The transitional region is found in the velocity diagrams where the system undergoes a continuous transition from a moving phase to a completely jamming phase. We perform a finite-size scaling analysis of the critical density from a statistical point of view and the order parameter of this jamming transition is estimated. It is also found that statistical properties of urban traffic are greatly influenced by the urban area, workplace area and urban layout.

  19. Test Control Center

    Science.gov (United States)

    2000-01-01

    At the test observation periscope in the Test Control Center exhibit in StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., visitors can observe a test of a Space Shuttle Main Engine exactly as test engineers might see it during a real engine test. The Test Control Center exhibit exactly simulates not only the test control environment, but also the procedure of testing a rocket engine. Designed to entertain while educating, StenniSphere includes informative dispays and exhibits from NASA's lead center for rocket propulsion and remote sensing applications. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  20. Self-Organized Control of Irregular or Perturbed Network Traffic

    CERN Document Server

    Helbing, D; Lebacque, J P; Helbing, Dirk; L\\"ammer, Stefan; Lebacque, Jean-Patrick

    2005-01-01

    We present a fluid-dynamic model for the simulation of urban traffic networks with road sections of different lengths and capacities. The model allows one to efficiently simulate the transitions between free and congested traffic, taking into account congestion-responsive traffic assignment and adaptive traffic control. We observe dynamic traffic patterns which significantly depend on the respective network topology. Synchronization is only one interesting example and implies the emergence of green waves. In this connection, we will discuss adaptive strategies of traffic light control which can considerably improve throughputs and travel times, using self-organization principles based on local interactions between vehicles and traffic lights. Similar adaptive control principles can be applied to other queueing networks such as production systems. In fact, we suggest to turn push operation of traffic systems into pull operation: By removing vehicles as fast as possible from the network, queuing effects can be ...

  1. Semantic Representation and Scale-Up of Integrated Air Traffic Management Data

    Science.gov (United States)

    Keller, Richard M.; Ranjan, Shubha; Wei, Mie; Eshow, Michelle

    2016-01-01

    Each day, the global air transportation industry generates a vast amount of heterogeneous data from air carriers, air traffic control providers, and secondary aviation entities handling baggage, ticketing, catering, fuel delivery, and other services. Generally, these data are stored in isolated data systems, separated from each other by significant political, regulatory, economic, and technological divides. These realities aside, integrating aviation data into a single, queryable, big data store could enable insights leading to major efficiency, safety, and cost advantages. In this paper, we describe an implemented system for combining heterogeneous air traffic management data using semantic integration techniques. The system transforms data from its original disparate source formats into a unified semantic representation within an ontology-based triple store. Our initial prototype stores only a small sliver of air traffic data covering one day of operations at a major airport. The paper also describes our analysis of difficulties ahead as we prepare to scale up data storage to accommodate successively larger quantities of data -- eventually covering all US commercial domestic flights over an extended multi-year timeframe. We review several approaches to mitigating scale-up related query performance concerns.

  2. Respiratory effects of air pollutants among nonsmoking traffic policemen of Patiala, India

    Directory of Open Access Journals (Sweden)

    Sharat Gupta

    2011-01-01

    Full Text Available Background: Air pollution due to road traffic is a serious health hazard and thus the persons who are continuously exposed, may be at an increased risk. Although several studies have confirmed the ill effects of air pollutants on the lung function of traffic policemen, only a few have investigated the relationship between respiratory health and duration of exposure in this category of occupationally exposed persons. Aim: The study was carried out with the aim of evaluating the extent of impairment in lung function in traffic policemen in respect to an unexposed control group having the same age group. Materials and Methods: A cross-sectional study was conducted in which the spirometric parameters of a group of 100 nonsmoking traffic policemen, aged 20-55 years, working in and around Patiala city, were compared with those obtained in an age-matched control group, consisting of 100 healthy males, serving in the Punjab Police, who have never done traffic duty and are thus not exposed to traffic pollution. Lung function was done with MEDSPIROR. The data on the overall health status of the subjects was collected using the standard Respirator Medical Evaluation Questionnaire. The statistical analysis was carried out with SPSS PC software version 13. Results: Traffic policemen recorded a significant decline in various parameters, such as forced vital capacity (FVC, forced expiratory volume in one second (FEV 1 , and peak expiratory flow rate (PEFR when compared with controls, and is probably due to exposure to vehicular pollution. It was also observed that in traffic policemen with >8 years of exposure, the values of FVC (2.7 L, FEV 1 (1.8 L, and PEFR (7.5 L/s were significantly lower than those obtained in traffic policemen with <8 years of exposure, in whom the values were 2.9 L, 2.3 L, and 7.7 L/s for FVC, FEV 1, and PEFR, respectively. Conclusion: The effect of pollution by vehicular exhausts may be responsible for these pulmonary function

  3. Effect of air pollution on FVC, FEV1 and FEV1/FVC% of the traffic policemen in Dhaka city

    Directory of Open Access Journals (Sweden)

    Shahriar Ahmed

    2016-12-01

    Full Text Available Background: Due to large number of vehicles, air pollution is increasing day by day in Dhaka city. Automobile exhaust cause acute and chronic respiratory disease in traffic policemen as they are exposed to air pollution for prolong period of time. Objective: To observe the effect of long term exposure to air pollution on FVC, FEV1 and FEV1/FVC% of traffic policemen. Methods: This cross sectional study was conducted in the Department of Physiology, Dhaka Medical College (DMC, Dhaka from July 2014 to June 2015. Fifty apparently healthy traffic policemen with the age 25 to 45 years were selected as study group. Fifty age and BMI matched healthy male subjects were selected as control. The study subjects were selected from different traffic junctions and the control from different offices of Dhaka city. FVC, FEV1 and FEV1/FVC% of all the subjects were measured by a digital spirometer. Statistical analysis was done by Independent sample ‘t’ test. Results: In this study FVC, FEV1 and FEV1/FVC were significantly (p< 0.001 lower in the traffic policemen than the control group. Conclusion: From the result of this study it can be concluded that prolonged exposure to air pollution may decrease pulmonary function of the traffic policemen in Dhaka city.

  4. Combined effects of road traffic noise and ambient air pollution in relation to risk for stroke?

    DEFF Research Database (Denmark)

    Sørensen, Mette; Lühdorf, Pernille; Ketzel, Matthias

    2014-01-01

    Exposure to road traffic noise and air pollution have both been associated with risk for stroke. The few studies including both exposures show inconsistent results. We aimed to investigate potential mutual confounding and combined effects between road traffic noise and air pollution in association...... to 2009 were identified in national registers and road traffic noise and air pollution were modeled for all addresses. Analyses were done using Cox regression. A higher mean annual exposure at time of diagnosis of 10µg/m(3) nitrogen dioxide (NO2) and 10dB road traffic noise at the residential address...... was found for combination of high noise and high NO2 (IRR=1.28; 95% CI=1.09-1.52). Fatal stroke was positively associated with air pollution and not with traffic noise. In conclusion, in mutually adjusted models road traffic noise and not air pollution was associated ischemic stroke, while only air...

  5. A Traffic Prediction Algorithm for Street Lighting Control Efficiency

    Directory of Open Access Journals (Sweden)

    POPA Valentin

    2013-01-01

    Full Text Available This paper presents the development of a traffic prediction algorithm that can be integrated in a street lighting monitoring and control system. The prediction algorithm must enable the reduction of energy costs and improve energy efficiency by decreasing the light intensity depending on the traffic level. The algorithm analyses and processes the information received at the command center based on the traffic level at different moments. The data is collected by means of the Doppler vehicle detection sensors integrated within the system. Thus, two methods are used for the implementation of the algorithm: a neural network and a k-NN (k-Nearest Neighbor prediction algorithm. For 500 training cycles, the mean square error of the neural network is 9.766 and for 500.000 training cycles the error amounts to 0.877. In case of the k-NN algorithm the error increases from 8.24 for k=5 to 12.27 for a number of 50 neighbors. In terms of a root means square error parameter, the use of a neural network ensures the highest performance level and can be integrated in a street lighting control system.

  6. Vehicle-class Specific Control of Freeway Traffic

    NARCIS (Netherlands)

    Schreiter, T.

    2013-01-01

    The increase of mobility of the past decades has led to substantial congestion on the freeways. Traffic jams emerge both on a daily basis at the same location, as well as during accidents when a part of the freeways is temporarily blocked. In those cases, traffic management centers intervene into tr

  7. MATLAB Simulation of Fuzzy Traffic Controller for Multilane Isolated Intersection

    Directory of Open Access Journals (Sweden)

    Azura Che Soh/Lai Guan Rhung

    2010-07-01

    Full Text Available This paper presents a MATLAB simulation of fuzzy traffic controller for controlling traffic flow at multilane isolated signalized intersection. The controller is developed based on the waiting time and vehicles queue length at current green phase, and vehicles queue lengths at the other phases. For control strategy, the controllercontrols the traffic light timings and phase sequence to ensure smooth flow of traffic with minimal waiting time, queue length and delay time. In this research, the isolated intersection model used consists of two lanes in each approach. Each approach has two different values of vehicles queue length and waiting time, respectively, at the intersection. The maximum values of vehicles queue length and waiting times are selected as the inputs to controller for optimized control of traffic flows at the intersection. A traffic model and fuzzy traffic controller are developed to evaluate the performance of traffic controllers underdifferent conditions. In the end, by comparing the experimental result obtained by the vehicle-actuated controller (VAC and fuzzy traffic controller (FTC which improves significant performance for intersections, we confirmed the efficiency of our intelligent controller based fuzzy inference system.

  8. Eulerian Air Traffic Flow Management Agent for the ACES Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of an Eulerian model based en route traffic flow management agent for the ACES software is proposed. The proposed research will use a...

  9. Distributed Scheduling Architecture for Multi-Center Time-Based Metering

    Science.gov (United States)

    Landry, Steven; Farley, Todd; Foster, John; Green, Steve; Hoang, Ty; Wong, Gregory L.

    2003-01-01

    The Traffic Management Advisor (TMA) is an air traffic control automation system currently in use in seven Air Route Traffic Control Centers (ARTCCs) to enable time based metering to busy airports within their airspace. However, this system is limited to operation within a single ARTCC, within about a 200 nautical mile radius of the airport, and on relatively simple streams of traffic. The need for coordinated metering within a greater (300+ nautical mile) radius of an airport, on streams of traffic with significant branching, and across ARTCC boundaries, has been identified. Early tests revealed that TMA could not simply be scaled up to handle such a problem. Instead, a loosely coupled hierarchy of schedules, in which constraints from downstream schedules are passed upstream, is required. Such an architecture reduces the reliance on distant projections of arrival times, making schedules robust to changes in sequence and to additions of aircraft (such as aircraft departing inside the system s scheduling horizon). This architecture is also scaleable, easily reconfigurable, and can be networked together. As such, it can be adapted for use in any size or configuration of airspace and with any number of airports delivering restrictions. An implementation of this distributed scheduling architecture is currently undergoing testing in the TMA-Multi Center system. This paper describes the architecture and its motivation.

  10. Urban scale air quality modelling using detailed traffic emissions estimates

    Science.gov (United States)

    Borrego, C.; Amorim, J. H.; Tchepel, O.; Dias, D.; Rafael, S.; Sá, E.; Pimentel, C.; Fontes, T.; Fernandes, P.; Pereira, S. R.; Bandeira, J. M.; Coelho, M. C.

    2016-04-01

    The atmospheric dispersion of NOx and PM10 was simulated with a second generation Gaussian model over a medium-size south-European city. Microscopic traffic models calibrated with GPS data were used to derive typical driving cycles for each road link, while instantaneous emissions were estimated applying a combined Vehicle Specific Power/Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (VSP/EMEP) methodology. Site-specific background concentrations were estimated using time series analysis and a low-pass filter applied to local observations. Air quality modelling results are compared against measurements at two locations for a 1 week period. 78% of the results are within a factor of two of the observations for 1-h average concentrations, increasing to 94% for daily averages. Correlation significantly improves when background is added, with an average of 0.89 for the 24 h record. The results highlight the potential of detailed traffic and instantaneous exhaust emissions estimates, together with filtered urban background, to provide accurate input data to Gaussian models applied at the urban scale.

  11. Traffic-related air pollution and risk for leukaemia of an adult population.

    Science.gov (United States)

    Raaschou-Nielsen, Ole; Ketzel, Matthias; Harbo Poulsen, Aslak; Sørensen, Mette

    2016-03-01

    Air pollution causes lung cancer, but associations with other cancers have not been established. We investigated whether long-term exposure to traffic-related air pollution is associated with the risk of the general population for leukaemia. We identified 1,967 people in whom leukaemia was diagnosed in 1992-2010 from a nation-wide cancer registry and selected 3,381 control people at random, matched on sex and year of birth, from the entire Danish population. Residential addresses since 1971 were traced in a population registry, and outdoor concentrations of NOx and NO2 , as indicators of traffic-related air pollution, were calculated at each address in a dispersion model. We used conditional logistic regression to estimate the risk for leukaemia after adjustment for income, educational level, cohabitation status and co-morbidity. In linear analyses, we found odds ratios for acute myeloid leukaemia of 1.20 (95% confidence interval: 1.04-1.38) per 20 µg/m(3) increase in NOx and 1.31 (1.02-1.68) per 10 µg/m(3) increase in NO2 , calculated as time-weighted average exposure at all addresses since 1971. We found no association with chronic myeloid or lymphocytic leukaemia. This study indicates an association between long-term exposure to traffic-related air pollution and acute myeloid leukaemia in the general population, but not for other subtypes of leukaemia.

  12. Temporal distribution of air quality related to meteorology and road traffic in Madrid.

    Science.gov (United States)

    Perez-Martinez, Pedro J; Miranda, Regina M

    2015-04-01

    The impact of climatology--air temperature, precipitation and wind speed--and road traffic--volume, vehicle speed and percentage of heavy-duty vehicles (HDVs)--on air quality in Madrid was studied by estimating the effect for each explanatory variable using generalized linear regression models controlling for monthly variations, days of week and parameter levels. Every 1 m/s increase in wind speed produced a decrease in PM10 concentrations by 10.3% (95% CI 12.6-8.6) for all weekdays and by 12.4% (95% CI 14.9-9.8) for working days (up to the cut-off of 2.4 m/s). Increases of PM10 concentrations due to air temperature (7.2% (95% CI 6.2-8.3)) and traffic volume (3.3% (95% CI 2.9-3.8)) were observed at every 10 °C and 1 million vehicle-km increases for all weekdays; oppositely, slight decreases of PM10 concentrations due to percentage of HDVs (3.2% (95% CI 2.7-3.7)) and vehicle speed (0.7% (95% CI 0.6-0.8)) were observed at every 1% and 1 km/h increases. Stronger effects of climatology on air quality than traffic parameters were found.

  13. Pilot and Controller Workload and Situation Awareness with Three Traffic Management Concept

    Science.gov (United States)

    Vu, Kim-Phuong L.; Strybel, Thomas Z.; Kraut, Joshua; Bacon, Paige; Minakata, Katsumi; Battiste, Vernol; Johnson, Walter

    2010-01-01

    This paper reports on workload and situation awareness of pilots and controllers participating in a human-in-the-loop simulation using three different distributed air-ground traffic management concepts. Eight experimental pilots started the scenario in an en-route phase of flight and were asked to avoid convective weather while performing spacing and merging tasks along with a continuous descent approach (CDA) into Louisville Standiford Airport (SDF). Two controllers managed the sectors through which the pilots flew, with one managing a sector that included the Top of Descent, and the other managing a sector that included the merge point for arrival into SDF. At 3-minute intervals in the scenario, pilots and controllers were probed on their workload or situation awareness. We employed one of three concepts of operation that distributed separation responsibility across human controllers, pilots, and automation to measure changes in operator situation awareness and workload. We found that when pilots were responsible for separation, they had higher levels of awareness, but not necessarily higher levels of workload. When controllers are responsible and actively engaged, they showed higher workload levels compared to pilots and changes in awareness that were dependent on sector characteristics.

  14. Analysis of Air Traffic Track Data with the AutoBayes Synthesis System

    Science.gov (United States)

    Schumann, Johann Martin Philip; Cate, Karen; Lee, Alan G.

    2010-01-01

    The Next Generation Air Traffic System (NGATS) is aiming to provide substantial computer support for the air traffic controllers. Algorithms for the accurate prediction of aircraft movements are of central importance for such software systems but trajectory prediction has to work reliably in the presence of unknown parameters and uncertainties. We are using the AutoBayes program synthesis system to generate customized data analysis algorithms that process large sets of aircraft radar track data in order to estimate parameters and uncertainties. In this paper, we present, how the tasks of finding structure in track data, estimation of important parameters in climb trajectories, and the detection of continuous descent approaches can be accomplished with compact task-specific AutoBayes specifications. We present an overview of the AutoBayes architecture and describe, how its schema-based approach generates customized analysis algorithms, documented C/C++ code, and detailed mathematical derivations. Results of experiments with actual air traffic control data are discussed.

  15. Tri-level programming model for combined urban traffic signal control and traffic flow guidance

    Institute of Scientific and Technical Information of China (English)

    孙智源; 陆化普; 屈闻聪

    2016-01-01

    In order to balance the temporal-spatial distribution of urban traffic flow, a model is established for combined urban traffic signal control and traffic flow guidance. With consideration of the wide use of fixed signal control at intersections, traffic assignment under traffic flow guidance, and dynamic characteristics of urban traffic management, a tri-level programming model is presented. To reflect the impact of intersection delay on traffic assignment, the lower level model is set as a modified user equilibrium model. The middle level model, which contains several definitional constraints for different phase modes, is built for the traffic signal control optimization. To solve the problem of tide lane management, the upper level model is built up based on nonlinear 0-1 integer programming. A heuristic iterative optimization algorithm (HIOA) is set up to solve the tri-level programming model. The lower level model is solved by method of successive averages (MSA), the middle level model is solved by non-dominated sorting genetic algorithm II (NSGA II), and the upper level model is solved by genetic algorithm (GA). A case study is raised to show the efficiency and applicability of the proposed modelling and computing method.

  16. Voice Traffic over Mobile Ad Hoc Networks: A Performance Analysis of the Optimized Link State Routing Protocol

    Science.gov (United States)

    2009-03-26

    Investigating MANETs in a VoIP Context. Prior research has inves- tigated the performance of MANETS carrying VoIP traffic. Thibodeau et al. studied whether...number of hops contained in the repaired route is observed. Thibodeau et al. concludes that node mobility and node density have limited influence on...testbeds. Most studies account for mobile nodes and study the routing protocols AODV and OLSR. For example, Thibodeau et al. study the effects of AODV

  17. 49 CFR 236.828 - System, traffic control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false System, traffic control. 236.828 Section 236.828..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.828 System, traffic control. A block signal system under which train movements are authorized by...

  18. Respiratory hospitalizations of children and residential exposure to traffic air pollution in Jerusalem.

    Science.gov (United States)

    Nirel, Ronit; Schiff, Michal; Paltiel, Ora

    2015-01-01

    Although exposure to traffic-related air pollution has been reported to be associated with respiratory morbidity in children, this association has not been examined in Israel. Jerusalem is ranked among the leading Israeli cities in transport-related air pollution. This case-control study examined whether pediatric hospitalization for respiratory diseases in Jerusalem is related to residential exposure to traffic-related air pollution. Cases (n=4844) were Jerusalem residents aged 0-14 years hospitalized for respiratory illnesses between 2000 and 2006. These were compared to children admitted electively (n=2161) or urgently (n=3085) for non-respiratory conditions. Individual measures of exposure included distance from residence to nearest main road, the total length of main roads, traffic volume, and bus load within buffers of 50, 150, and 300m around each address. Cases were more likely to have any diesel buses passing within 50m of their home (adjusted odds ratios=1.16 and 1.10, 95% confidence intervals 1.04-1.30 and 1.01-1.20 for elective and emergency controls, respectively). Our findings indicated that older girls (5-14) and younger boys (0-4) had increased risks of respiratory hospitalization, albeit with generally widened confidence intervals due to small sample sizes. Our results add to the limited body of evidence regarding associations between diesel exhaust particles and respiratory morbidity. The findings also point to possible differential associations between traffic-related air pollution and pediatric hospitalization among boys and girls in different age groups.

  19. LOTIR: A Routing Protocol for Multi-hop V-to-I Communication Using Local Traffic Information

    Directory of Open Access Journals (Sweden)

    Kun-chan Lan

    2012-08-01

    Full Text Available Vehicular Ad Hoc Network (VANET is an emerging technology that can be applied to safety, transport efficiency, or infotainment applications for roads and highways. However, due to its unique features, such as dynamic mobility patterns and uneven distributions of vehicles, VANET faces many challenging research issues for robust data dissemination in the network. Many routing protocols have been proposed for VANET in the past few years, and the idea of utilizing a navigation system to assist the routing protocol for selecting the next best forwarder has become increasingly popular. However, it might not be realistic to assume that every vehicle is equipped with a navigation system. In addition, due to privacy concerns, drivers might not want to reveal their planned routes to other cars. In this work, we propose a new routing protocol, called LOTIR (LOcal Traffic Information Routing, that relies on only local traffic information and does not require the assistance of a navigation system. LOTIR is a DTN-based routing protocol that utilizes the car-following theory and traffic light information to decide the next carrier to forward the data to. We implement LOTIR in NS-2, and our results show that it can achieve similar performance as prior work which depends on the availability of global network topology information.

  20. Research on an Urban Traffic Control System Based on DGPS

    Institute of Scientific and Technical Information of China (English)

    张锦; 张姝慧; 曹继红

    2002-01-01

    The basic principles of GPS (Global Positioning System) and DGPS (Differential GPS) are described. The principle and structure of vehicle navigation systems, and its application to the urban traffic flow guidance are analyzed. Then, an area-coordinated adaptive control system based on DGPS and a traffic flow guidance information system based on DGPS are put forward, and their working principles and functions are researched. This is to provides a new way for the development of urban road traffic control systems.

  1. A Multi-Operator Simulation for Investigation of Distributed Air Traffic Management Concepts

    Science.gov (United States)

    Peters, Mark E.; Ballin, Mark G.; Sakosky, John S.

    2002-01-01

    This paper discusses the current development of an air traffic operations simulation that supports feasibility research for advanced air traffic management concepts. The Air Traffic Operations Simulation (ATOS) supports the research of future concepts that provide a much greater role for the flight crew in traffic management decision-making. ATOS provides representations of the future communications, navigation, and surveillance (CNS) infrastructure, a future flight deck systems architecture, and advanced crew interfaces. ATOS also provides a platform for the development of advanced flight guidance and decision support systems that may be required for autonomous operations.

  2. 民航空中交通管制员冠状动脉瘤一例并文献复习%A case of coronary artery aneurysm found in civil air traffic controller and literature review

    Institute of Scientific and Technical Information of China (English)

    董世鹏; 刘胜燕; 李琦

    2014-01-01

    Objective To investigate the aetiological agent,clinical manifestation,diagnosis,treatment and prognosis of coronary artery aneurysm (CAA) in order to improve the cognition of the disease and provide support for flight safety.Methods Clinical data and aeromedical assessment of a civil air traffic controller (ATC) with left main CAA were retrospectively analyzed.The related literatures were reviewed.Results The treadmill exercise test of the ATC showed probable positive in the annual physical examination at our center.In order to get further confirmation,his left CAA was examined by multi-slice spiral CT coronary angiography (MSCT) and coronary arteriongraphy (CAG) in other hospital.As the aneurysm located in the left main coronary artery where closed to the bifurcation of the left anterior descending artery (LAD) and left circumflex artery (I.CX) surgery was difficult and risks were great.For the ATC had stable vital signs we chose medical conservative treatment and regular MSCT follow-up.The ATC received continued drug treatment as he discharged.He was finally disqualified.Conclusions CAA is a rare disease both in clinical medicine and in aerospace medicine fields.It has the similar clinical features with coronary artery disease.At present,C∧G is the main approach of final diagnosis and C∧∧ treatments include pharmacotherapy,interventional operation and surgical treatment.Civil aviation aircrew and ATC should be given unqualified conclusion once CAA has been diagnosed because it's a great potential hazard for flight safety.%目的 探讨冠状动脉瘤的发病原因、临床表现、诊断、治疗及预后,加强对该疾病的认识,保障飞行安全. 方法 分析1例民航空中交通管制员左主干冠状动脉瘤的临床资料和航空医学鉴定,并复习相关文献资料. 结果 本例空中交通管制员在参加年度体检鉴定中,运动踏板试验示:可疑阳性.为排除冠心病,行冠状动脉CTA及冠状动脉造影后确诊:左

  3. Traffic-related air pollution and spectacles use in schoolchildren

    Science.gov (United States)

    Nieuwenhuijsen, Mark J.; Basagaña, Xavier; Alvarez-Pedrerol, Mar; Dalmau-Bueno, Albert; Cirach, Marta; Rivas, Ioar; Brunekreef, Bert; Querol, Xavier; Morgan, Ian G.; Sunyer, Jordi

    2017-01-01

    Purpose To investigate the association between exposure to traffic-related air pollution and use of spectacles (as a surrogate measure for myopia) in schoolchildren. Methods We analyzed the impact of exposure to NO2 and PM2.5 light absorbance at home (predicted by land-use regression models) and exposure to NO2 and black carbon (BC) at school (measured by monitoring campaigns) on the use of spectacles in a cohort of 2727 schoolchildren (7–10 years old) in Barcelona (2012–2015). We conducted cross-sectional analyses based on lifelong exposure to air pollution and prevalent cases of spectacles at baseline data collection campaign as well as longitudinal analyses based on incident cases of spectacles use and exposure to air pollution during the three-year period between the baseline and last data collection campaigns. Logistic regression models were developed to quantify the association between spectacles use and each of air pollutants adjusted for relevant covariates. Results An interquartile range increase in exposure to NO2 and PM2.5 absorbance at home was respectively associated with odds ratios (95% confidence intervals (CIs)) for spectacles use of 1.16 (1.03, 1.29) and 1.13 (0.99, 1.28) in cross-sectional analyses and 1.15 (1.00, 1.33) and 1.23 (1.03, 1.46) in longitudinal analyses. Similarly, odds ratio (95% CIs) of spectacles use associated with an interquartile range increase in exposures to NO2 and black carbon at school was respectively 1.32 (1.09, 1.59) and 1.13 (0.97, 1.32) in cross-sectional analyses and 1.12 (0.84, 1.50) and 1.27 (1.03, 1.56) in longitudinal analyses. These findings were robust to a range of sensitivity analyses that we conducted. Conclusion We observed increased risk of spectacles use associated with exposure to traffic-related air pollution. These findings require further confirmation by future studies applying more refined outcome measures such as quantified visual acuity and separating different types of refractive errors. PMID

  4. A Performance Analysis of the Optimized Link State Routing Protocol Using Voice Traffic Over Mobile Ad Hoc Networks

    Science.gov (United States)

    2012-03-22

    Thibodeau et al. [TYH06] simulate the effects of node density, number of data streams and route length on the performance of VoIP traffic using only the...International Conference, pp. 176-180. [TYH06] Eric Thibodeau , Mohamed Youssef, & Alain C. Houle. (2006). Investigating manet performance in a VOIP

  5. Risk based decision support for new air traffic operations with reduced aircraft separation

    NARCIS (Netherlands)

    Speijker, L.J.P.

    2007-01-01

    With the steady increase in air traffic, the aviation system is under continuous pressure to increase aircraft handling capacity. Various new Air Traffic Management systems and flight procedures are proposed to increase airport capacity while maintaining the required level of safety. Newly proposed

  6. Analysis of Driver's Route Choice Behavior in Traffic Flow%驾驶员路线选择行为分析

    Institute of Scientific and Technical Information of China (English)

    况漠

    2003-01-01

    研究驾驶员的路线选择行为有助于提高既有道路网络(特别是城市交通网络)的利用率,从而改善交通状况.本文从宏观角度分析存在实时交通信息条件下驾驶员路线选择行为的时间演化特征,认为路线选择行为具有随机不确定性,在设计交通诱导系统或交通信息系统时,必须考虑扰动因素影响,才能保证系统有效实现均衡的交通流动态分配.%This paper, from the point of macroscopic view, discusses the time evolution pattern of driver's route choice behavior with the influence of dynamic traffic information upon the pattern.The study aims to provide theoretical support for the evaluation of long-term result of traffic information system, the forecasting of driver's route choice behavior and the study of influence on route choice behavior through controlling and changing traffic information.

  7. Obtaining Traffic Information by Urban Air Quality Inspection

    CERN Document Server

    Ferrante, P; Nicolosi, S; Scaccianoce, G; Traverso, M; Rizzo, G

    2011-01-01

    The level of air quality in urban centres is affected by emission of several pollutants, mainly coming from the vehicles flowing in their road networks. This is a well known phenomenon that influences the quality of life of people. Despite the deep concern of researchers and technicians, we are far from a total understanding of this phenomenon. On the contrary, the availability of reliable forecasting models would constitute an important tool for administrators in order of assessing suitable actions concerning the transportation policies, public as well private. Referring to the situation of the running fleet and the measured pollutant concentrations concerning the Italian town of Palermo, a data-deduced traffic model is here derived, its truthfulness being justified by a fuzzyfication of the phenomenon. A first validation of the model is supplied by utilising the emissions characteristics and the pollutant concentrations referring to a two years period of time. This work could represent a first attempt in de...

  8. Air quality nearby road traffic tunnel portals: BTEX monitoring

    Institute of Scientific and Technical Information of China (English)

    Fabio Murena

    2007-01-01

    A monitoring campaign of BTEX (benzene, toluene, ethylbenzene, o- m- and p-xylene) was carried out nearby two tunnel portals in the urban area of Naples with the aim to verify air quality in this kind of urban sites. Sampling was carried out using the active adsorption technique. Sampling time was 1 h. Ambient temperature and traffic flow measurements were carried out during each sampling operation. The results indicate that average benzene concentrations at both sites exceed the limit value of 10 μg/Nm3 established by the European Community (EC) (Dir. 2000/69). Concentration levels of other BTEX are relatively high as well. A correlation between BTEX concentration and two wheeler vehicle flow was observed.

  9. Air quality nearby road traffic tunnel portals: BTEX monitoring.

    Science.gov (United States)

    Murena, Fabio

    2007-01-01

    A monitoring campaign of BTEX (benzene, toluene, ethylbenzene, o- m- and p-xylene) was carried out nearby two tunnel portals in the urban area of Naples with the aim to verify air quality in this kind of urban sites. Sampling was carried out using the active adsorption technique. Sampling time was 1 h. Ambient temperature and traffic flow measurements were carried out during each sampling operation. The results indicate that average benzene concentrations at both sites exceed the limit value of 10 microg/Nm3 established by the European Community (EC) (Dir. 2000/69). Concentration levels of other BTEX are relatively high as well. A correlation between BTEX concentration and two wheeler vehicle flow was observed.

  10. Traffic-related air pollution and brain development

    Directory of Open Access Journals (Sweden)

    Nicholas Woodward

    2015-05-01

    Full Text Available Automotive traffic-related air pollution (TRP imposes an increasing health burden with global urbanization. Gestational and early child exposure to urban TRP is associated with higher risk of autism spectrum disorders and schizophrenia, as well as low birth weight. While cardio-respiratory effects from exposure are well documented, cognitive effects are only recently becoming widely recognized. This review discusses effects of TRP on brain and cognition in human and animal studies. The mechanisms underlying these epidemiological associations are studied with rodent models of pre- and neonatal exposure to TRP, which show persisting inflammatory changes and altered adult behaviors and cognition. Some behavioral and inflammatory changes show male bias. Rodent models may identify dietary and other interventions for neuroprotection to TRP.

  11. Impact of local urban design and traffic restrictions on air quality in a medium-sized town.

    Science.gov (United States)

    Acero, J A; Simon, A; Padro, A; Santa Coloma, O

    2012-01-01

    Traffic is the major air pollution source in most urban areas. Nowadays, most of the strategies carried out to improve urban air quality are focused on reducing traffic emissions. Nevertheless, acting locally on urban design can also reduce levels of air pollutants. In this paper, both strategies are studied in several scenarios for a medium-sized town of the Basque Country (Spain). Two main actions are analysed in order to reduce traffic emissions: (1) minor extension ofa pre-existing low emission zone (LEZ); (2) substitution of 10% of passenger cars that are older than 5 years by hybrid and electric vehicles. Regarding local urban design, three alternatives for the development of one side of a street canyon are considered: (1) a park with trees; (2) an open space without obstacles; (3) a building. Two different urban traffic dispersion models are used to calculate the air quality scenarios: PROKAS (Gaussian&box) to analyse the reduction of traffic emissions in the whole urban area and WinMISKAM (CFD) to evaluate specific urban designs. The results show the effectiveness of the analysed actions. On one hand, the definition of a small LEZ, as well as the introduction in 2015 of vehicles with new technology (hybrid and electric), results in minor impacts on PM10 and NO2 ambient concentrations. On the other hand, local urban design can cause significant variation in spatial distribution ofpollutant concentrations emitted inside street canyons. Consequently, urban planners should consider all these aspects when dealing with urban air pollution control.

  12. Simulation of Controller Pilot Data Link Communications over VHF Digital Link Mode 3

    Science.gov (United States)

    Bretmersky, Steven C.; Murawski, Robert; Nguyen, Thanh C.; Raghavan, Rajesh S.

    2004-01-01

    The Federal Aviation Administration (FAA) has established an operational plan for the future Air Traffic Management (ATM) system, in which the Controller Pilot Data Link Communications (CPDLC) is envisioned to evolve into digital messaging that will take on an ever increasing role in controller to pilot communications, significantly changing the way the National Airspace System (NAS) is operating. According to FAA, CPDLC represents the first phase of the transition from the current analog voice system to an International Civil Aviation Organization (ICAO) compliant system in which digital communication becomes the alternate and perhaps primary method of routine communication. The CPDLC application is an Air Traffic Service (ATS) application in which pilots and controllers exchange messages via an addressed data link. CPDLC includes a set of clearance, information, and request message elements that correspond to existing phraseology employed by current Air Traffic Control (ATC) procedures. These message elements encompass altitude assignments, crossing constraints, lateral deviations, route changes and clearances, speed assignments, radio frequency assignments, and various requests for information. The pilot is provided with the capability to respond to messages, to request clearances and information, to report information, and to declare/rescind an emergency. A 'free text' capability is also provided to exchange information not conforming to defined formats. This paper presents simulated results of the aeronautical telecommunication application Controller Pilot Data Link Communications over VHF Digital Link Mode 3 (VDL Mode 3). The objective of this simulation study was to determine the impact of CPDLC traffic loads, in terms of timely message delivery and capacity of the VDL Mode 3 subnetwork. The traffic model is based on and is used for generating air/ground messages with different priorities. Communication is modeled for the en route domain of the Cleveland

  13. Overcoming the Pigou-Downs Paradox Using Advanced Traffic Signal Control

    Science.gov (United States)

    Fowdur, S. C.; Rughooputh, S. D. D. V.

    2013-06-01

    Expansion of a road network has often been observed to cause more congestion and has led researchers to the formulation of traffic paradoxes such as the Pigou-Downs and the Braess paradoxes. In this paper, we present an application of advanced traffic signal control (ATSC) to overcome the Pigou-Downs paradox. Port Louis, the capital city of Mauritius is used to investigate the effect of using a harbor bridge to by-pass the city center. Using traffic cellular automata (TCA) simulations it has been shown how, if traffic is only gradually deviated along the by-pass, an overall longer travel time and decreased flux would result. By making use of ATSC, which involves traffic lights that sense the number of vehicles accumulated in the queue, better travel times and fluxes are achieved.

  14. Economic Burden of Road Traffic Accidents; Report from a Single Center from South Eastern Iran

    Directory of Open Access Journals (Sweden)

    Aliyeh Sargazi

    2016-01-01

    Full Text Available Objective: To determine the economic burden of road traffic accidents (RTAs in patients admitted to a single center in south eastern Iran. Methods: This cross-sectional study was conducted in Amir-Al-Momenin hospital of Zabol affiliated with Zabol University of Medical Sciences during a 12-month period from April 2012 to April 2013. All the RTAs patients who were admitted to our emergency department were included. The direct expenses of hospital care were recorded according to their medical charts and the accountant registration information. Data are presented according to different RTAs characteristics. Results: Overall 1155 patients were included in the current study with mean age of 36.7 ± 5.14 years among whom there were 673(58.3% men and 482 (41.7% women. The annual incidence of RTAs were calculated to be 288 per 100,000 population. The RTAs economic burden in our center was 589,448.49 USD which accounted for 10.4% of total hospital expenses during the study period. The money spend on RTAs in our center was 130 times more than gross national income per capita. Cost of each patient in road traffic was 15 times more than cost of an average patient of the hospital in other sections. Conclusion: With considerable high ratio of accidents in Zabol, proper intervention is needed for controlling and preventing RTAs in order to decrease its injuries, impact and the associated economic burden.

  15. Selective data collection in vehicular networks for traffic control applications

    CERN Document Server

    Płaczek, Bartłomiej

    2011-01-01

    Vehicular sensor network (VSN) is an emerging technology, which combines wireless communication offered by vehicular ad hoc networks (VANET) with sensing devices installed in vehicles. VSN creates a huge opportunity to extend the road-side sensor infrastructure of existing traffic control systems. The efficient use of the wireless communication medium is one of the basic issues in VSN applications development. This paper introduces a novel method of selective data collection for traffic control applications, which provides a significant reduction in data amounts transmitted through VSN. The underlying idea is to detect the necessity of data transfers on the basis of uncertainty determination of the traffic control decisions. According to the proposed approach, sensor data are transmitted from vehicles to the control node only at selected time moments. Data collected in VSN are processed using on-line traffic simulation technique, which enables traffic flow prediction, performance evaluation of control strateg...

  16. Northwest passage: Trade route for large air cushion vehicles

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    A conceptual vehicle and powerplant (10,000-ton) nuclear-powered air-cushion vehicle (ACV) that could open the Northwest Passage and other Arctic passages to commercial traffic is identified. The report contains a description of the conceptual vehicle, including the powerplant and operations, an assessment of technical feasibility, estimates of capital and operating costs, and identification of eligible cargo and markets. A comparison of the nuclear ACV freighter with nuclear container ships shows that for containerized or roll-on/roll-off cargo the ACV would provide greatly reduced transit time between North Atlantic and North Pacific ports at a competitive cost.

  17. The impact of traffic volume, composition, and road geometry on personal air pollution exposures among cyclists in Montreal, Canada.

    Science.gov (United States)

    Hatzopoulou, Marianne; Weichenthal, Scott; Dugum, Hussam; Pickett, Graeme; Miranda-Moreno, Luis; Kulka, Ryan; Andersen, Ross; Goldberg, Mark

    2013-01-01

    Cyclists may experience increased exposure to traffic-related air pollution owing to increased minute ventilation and close proximity to vehicle emissions. The aims of this study were to characterize personal exposures to air pollution among urban cyclists and to identify potential determinants of exposure including the type of cycling lane (separated vs on-road), traffic counts, and meteorological factors. In total, personal air pollution exposure data were collected over 64 cycling routes during morning and evening commutes in Montreal, Canada, over 32 days during the summer of 2011. Measured pollutants included ultrafine particles (UFPs), fine particles (PM(2.5)), black carbon (BC), and carbon monoxide (CO). Counts of diesel vehicles were important predictors of personal exposures to BC, with each 10 vehicle/h increase associated with a 15.0% (95% confidence interval (CI): 5.7%, 24.0%) increase in exposure. Use of separated cycling lanes had less impact on personal exposures with a 12% (95% CI: -43%, 14%) decrease observed for BC and smaller decreases observed for UFPs (mean: -1.3%, 95% CI: -20%, 17%) and CO (mean: -5.6%, 95% CI: -17%, 4%) after adjusting for meteorological factors and traffic counts. On average, PM(2.5) exposure increased 7.8% (95% CI: -17%, 35%) with separate cycling lane use, but this estimate was imprecise and not statistically significant. In general, our findings suggest that diesel vehicle traffic is an important contributor to personal BC exposures and that separate cycling lanes may have a modest impact on personal exposure to some air pollutants. Further evaluation is required, however, as the impact of separate cycling lanes and/or traffic counts on personal exposures may vary between regions.

  18. Associations between urban air pollution and pediatric asthma control in El Paso, Texas.

    Science.gov (United States)

    Zora, Jennifer E; Sarnat, Stefanie Ebelt; Raysoni, Amit U; Johnson, Brent A; Li, Wen-Whai; Greenwald, Roby; Holguin, Fernando; Stock, Thomas H; Sarnat, Jeremy A

    2013-03-15

    Exposure to traffic-related pollutants poses a serious health threat to residents of major urban centers around the world. In El Paso, Texas, this problem is exacerbated by the region's arid weather, frequent temperature inversions, heavy border traffic, and an aged, poorly maintained vehicle fleet. The impact of exposure to traffic pollution, particularly on children with asthma, is poorly understood. Tracking the environmental health burden related to traffic pollution in El Paso is difficult, especially within school microenvironments, because of the lack of sensitive environmental health indicator data. The Asthma Control Questionnaire (ACQ) is a survey tool for the measurement of overall asthma control, yet has not previously been considered as an outcome in air pollution health effect research. We conducted a repeated measure panel study to examine weekly associations between ACQ scores and traffic- and non-traffic air pollutants among asthmatic schoolchildren in El Paso. In the main one- and two-pollutant epidemiologic models, we found non-significant, albeit suggestive, positive associations between ACQ scores and respirable particulate matter (PM10), coarse particulate matter (PM10-2.5), fine particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO2), benzene, toluene, and ozone (O3). Notably, associations were stronger and significant for some subgroups, in particular among subjects taking daily inhaled corticosteroids. This pattern may indicate heightened immune system response in more severe asthmatics, those with worse asthma "control" and higher ACQ scores at baseline. If the ACQ is appropriately used in the context of air pollution studies, it could reflect clinically measurable and biologically relevant changes in lung function and asthma symptoms that result from poor air quality and may increase our understanding of how air pollution influences asthma exacerbation.

  19. Improved EZW image coding algorithm in air traffic control system.%空管系统中运用EZW图像编码算法的优化策略

    Institute of Scientific and Technical Information of China (English)

    胡波; 杨红雨

    2011-01-01

    In order to efficiently transmit the picture data in the air traffic control system, an improved image coding algoRithm, which is based on Embedded Zero-tree Wavelet(EZW),is presented. At fist, the lowest frequency sub-band is coded without loss. Then, based on the human visual system, different sub-bands at the same level based on different perceptual weights are merged. In the end. Huffman coding is used for EZW result. The experiment result shows that this method is better than the original EZW algorithm.%为了在空管系统中高效率传输景象数据,在嵌入式零树小波图像编码算法(EZW)的基础上进行了按步骤的整体优化,对低频子带进行无损编码,对同一级的不同子带根据人眼视觉特性进行加权合并,用Huffman编码对符号流进行二次编码,实验结果表明,该方法要优于传统的EZW算法.

  20. Kalman Filtering of Radar Technology in Air Traffic Control Surveillance System%浅析卡尔曼雷达滤波技术在空管监视系统中的应用

    Institute of Scientific and Technical Information of China (English)

    周君

    2015-01-01

    [Abstract]Kalman filter for radar surveillance technology in air traffic control systems were analyzed. Discuss the corresponding Kalman filtering techniques: Related adaptive Kalman filtering, multi-model adaptive Kalman filter, adaptive Kalman filter information based on neural network adaptive Kalman filtering, fuzzy logic adaptive Kalman filtering, and their main advantages and disadvantages of the problem.%对卡尔曼雷达滤波技术在空管监视系统中的应用进行了分析,讨论了相应的卡尔曼滤波技术:相关自适应卡尔曼滤波、多模型自适应卡尔曼滤波、基于信息的自适应卡尔曼滤波、神经网络自适应卡尔曼滤波、模糊逻辑自适应卡尔曼滤波,并对它们主要解决的问题及优缺点进行了分析。

  1. Rethinking Traffic Management: Design of Optimizable Networks

    Science.gov (United States)

    2008-06-01

    traffic traverses each path in a network. On the Internet today, end hosts run congestion control to adapt sending rates, routers route traffic on...congestion control to adapt sending rates, routers route traffic on shortest paths based on link weights, and operators tune link weights to direct traffic...Chaintreau and Christophe Diot for giving me the opportunity to intern at Thomson Research Labs in Paris. Thanks to all the interns there for v making it

  2. Traffic Modelling for Moving-Block Train Control System

    Institute of Scientific and Technical Information of China (English)

    TANG Tao; LI Ke-Ping

    2007-01-01

    This paper presents a new cellular automaton (CA) model for train control system simulation.In the proposed CA model,the driver reactions to train movements are captured by some updated rules.The space-time diagram of traffic flow and the trajectory of train movement is used to obtain insight into the characteristic behavior of railway traffic flow.A number of simulation results demonstrate that the proposed CA model can be successfully used for the simulations of railway traffic.Not only the characteristic behavior of railway traffic flow can be reproduced,but also the simulation values of the minimum time headway are close to the theoretical values.

  3. Autonomous Traffic Signal Control Model with Neural Network Analogy

    CERN Document Server

    Ohira, T

    1997-01-01

    We propose here an autonomous traffic signal control model based on analogy with neural networks. In this model, the length of cycle time period of traffic lights at each signal is autonomously adapted. We find a self-organizing collective behavior of such a model through simulation on a one-dimensional lattice model road: traffic congestion is greatly diffused when traffic signals have such autonomous adaptability with suitably tuned parameters. We also find that effectiveness of the system emerges through interactions between units and shows a threshold transition as a function of proportion of adaptive signals in the model.

  4. A geographic approach to modelling human exposure to traffic air pollution using GIS. Separate appendix report

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S.

    1998-10-01

    A new exposure model has been developed that is based on a physical, single media (air) and single source (traffic) micro environmental approach that estimates traffic related exposures geographically with the postal address as exposure indicator. The micro environments: residence, workplace and street (road user exposure) may be considered. The model estimates outdoor levels for selected ambient air pollutants (benzene, CO, NO{sub 2} and O{sub 3}). The influence of outdoor air pollution on indoor levels can be estimated using average (I/O-ratios. The model has a very high spatial resolution (the address), a high temporal resolution (one hour) and may be used to predict past, present and future exposures. The model may be used for impact assessment of control measures provided that the changes to the model inputs are obtained. The exposure model takes advantage of a standard Geographic Information System (GIS) (ArcView and Avenue) for generation of inputs, for visualisation of input and output, and uses available digital maps, national administrative registers and a local traffic database, and the Danish Operational Street Pollution Model (OSPM). The exposure model presents a new approach to exposure determination by integration of digital maps, administrative registers, a street pollution model and GIS. New methods have been developed to generate the required input parameters for the OSPM model: to geocode buildings using cadastral maps and address points, to automatically generate street configuration data based on digital maps, the BBR and GIS; to predict the temporal variation in traffic and related parameters; and to provide hourly background levels for the OSPM model. (EG)

  5. A geographic approach to modelling human exposure to traffic air pollution using GIS

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S.

    1998-10-01

    A new exposure model has been developed that is based on a physical, single media (air) and single source (traffic) micro environmental approach that estimates traffic related exposures geographically with the postal address as exposure indicator. The micro environments: residence, workplace and street (road user exposure) may be considered. The model estimates outdoor levels for selected ambient air pollutants (benzene, CO, NO{sub 2} and O{sub 3}). The influence of outdoor air pollution on indoor levels can be estimated using average (I/O-ratios. The model has a very high spatial resolution (the address), a high temporal resolution (one hour) and may be used to predict past, present and future exposures. The model may be used for impact assessment of control measures provided that the changes to the model inputs are obtained. The exposure model takes advantage of a standard Geographic Information System (GIS) (ArcView and Avenue) for generation of inputs, for visualisation of input and output, and uses available digital maps, national administrative registers and a local traffic database, and the Danish Operational Street Pollution Model (OSPM). The exposure model presents a new approach to exposure determination by integration of digital maps, administrative registers, a street pollution model and GIS. New methods have been developed to generate the required input parameters for the OSPM model: to geocode buildings using cadastral maps and address points, to automatically generate street configuration data based on digital maps, the BBR and GIS; to predict the temporal variation in traffic and related parameters; and to provide hourly background levels for the OSPM model. (EG) 109 refs.

  6. Impact of Ambient Air Pollution on Public Health under Various Traffic Policies in Shanghai,China

    Institute of Scientific and Technical Information of China (English)

    CHAN-GHONG CHEN; HAI-DONG KAN; CHENG HUANG; LI LI; YUN-HUI ZHANG; REN-JIE CHEN; BING-HENG CHEN

    2009-01-01

    Objective To investigate the potential impact of ambient air pollution on public health under various traffic policies in Shanghai. Methods The exposure level of Shanghai residents to air pollution under various planned traffic scenarios was estimated,and the public health impact was assessed using concentration-response functions derived from available epidemiological studies. Results Our results showed that ambient air pollution in relation to traffic scenarios had a significant impact on the future health status of Shanghai residents.Compared with the base case scenario,implementation of various traffic scenarios could prevent 759-1574,1885-2420,and 2277-2650 PM10-related avoidable deaths (mean-value) in 2010,2015,and 2020,respectively.It could also decrease the incidence of several relevant diseases. Conclusion Our findings emphasize the need to consider air pollution-related health effects as an important impact of traffic policy in Shanghai.

  7. Traffic noise and vehicle movement at a controlled intersection

    NARCIS (Netherlands)

    Salomons, E.M.

    2014-01-01

    Traffic noise at an intersection controlled by traffic lights shows noise level variations due to the alternating green and red lights for the different trafficstreams. Noise peaks caused by automobiles pulling up or passing by at highspeed may be quite annoying for people living near the intersecti

  8. Detecting Approaching Vehicles at Streets with No Traffic Control

    Science.gov (United States)

    Emerson, Robert Wall; Sauerburger, Dona

    2008-01-01

    This study assessed the ability of people with visual impairments to reliably detect oncoming traffic at crossing situations with no traffic control. In at least one condition, the participants could not hear vehicles to afford a safe crossing time when sound levels were as quiet as possible. Significant predictors of detection accounted for a…

  9. Nonlinear relative-proportion-based route adjustment process for day-to-day traffic dynamics: modeling, equilibrium and stability analysis

    Science.gov (United States)

    Zhu, Wenlong; Ma, Shoufeng; Tian, Junfang; Li, Geng

    2016-11-01

    Travelers' route adjustment behaviors in a congested road traffic network are acknowledged as a dynamic game process between them. Existing Proportional-Switch Adjustment Process (PSAP) models have been extensively investigated to characterize travelers' route choice behaviors; PSAP has concise structure and intuitive behavior rule. Unfortunately most of which have some limitations, i.e., the flow over adjustment problem for the discrete PSAP model, the absolute cost differences route adjustment problem, etc. This paper proposes a relative-Proportion-based Route Adjustment Process (rePRAP) maintains the advantages of PSAP and overcomes these limitations. The rePRAP describes the situation that travelers on higher cost route switch to those with lower cost at the rate that is unilaterally depended on the relative cost differences between higher cost route and its alternatives. It is verified to be consistent with the principle of the rational behavior adjustment process. The equivalence among user equilibrium, stationary path flow pattern and stationary link flow pattern is established, which can be applied to judge whether a given network traffic flow has reached UE or not by detecting the stationary or non-stationary state of link flow pattern. The stability theorem is proved by the Lyapunov function approach. A simple example is tested to demonstrate the effectiveness of the rePRAP model.

  10. Impact of MD5 Authentication on Routing Traffic for the Case of: EIGRP, RIPv2 and OSPF

    Directory of Open Access Journals (Sweden)

    K. A. Al-Saud

    2008-01-01

    Full Text Available Problem Statement: With the free flow of routing data and the high availability of computer resources, possible threats to the networks can result in loss of privacy and in malicious use of information or resources that can eventually lead to large monetary losses. Approach: MD5 Authentication: Due to the major role that routing protocols play in computer network infrastructures, special cares has been given to routing protocols with built-in security constraints using authentication techniques, MD5 will be presented for this work. Results: The study evaluates the impact of the MD5 authentication on routing traffic for the case of EIGRP, RIPv2 and OSPF routing protocols in case of secured and non-secured routing traffic and measures the delay time, jitter and overhead. Conclusions: This study shows that the average delay time and jitter in the secured MD5 case can become significantly larger when compared to the unsecured case even in steady state conditions. Also, the EIGRP protocol shows the minimum overhead even when the system is extremely overloaded.

  11. A Geographic Approach to Modelling Human Exposure to Traffic Air Pollution using GIS

    DEFF Research Database (Denmark)

    Jensen, S. S.

    ), a high temporal resolution (one hour) and may be used to predict past, present and future exposures. The model may be used for impact assessment of control measures provided that the changes to the model inputs are obtained. A simple exposure index is defined that assumes that the person is present...... at the address all the time, and an exposure estimate is also defined that takes into account the time the person spends at the address assuming standardised time-profiles depending on age groups. The exposure model takes advantage of a standard Geographic Information System (GIS) (ArcView and Avenue......A new exposure model has been developed that is based on a physical, single media (air) and single source (traffic) microenvironmental approach that estimates traffic related exposures geographically with the postal address as exposure indicator. The microenvironments: residence, workplace...

  12. Vehicle Routing Algorithms for Local Delivery at Naval Supply Centers.

    Science.gov (United States)

    1981-03-01

    the purpose of selecting a vehicle routing algorithm that can be automated. This investigation led the author to a survey of " vehicle routing problem " (also...the vehicle routing problem model is described and solution techniques are sur- veyed. Additionally, computational experience that operations...researchers have had with these solution techniques is pre- sented. There are several classical and theoretical problems related to the vehicle routing problem . These

  13. An integrated user-oriented weather forecast system for air traffic using real-time observations and model data

    OpenAIRE

    Forster, Caroline; Tafferner, Arnold

    2009-01-01

    This paper presents the Weather Forecast User-oriented System Including Object Nowcasting (WxFUSION), an integrated weather forecast system for air traffic. The system is currently under development within a new project named “Weather and Flying” under the leadership of the Institute of Atmospheric Physics (IPA) at the German Aerospace Center (DLR). WxFUSION aims at combining data from various sources, as there are weather observations, remote sensing, nowcasting and numerical model forecast ...

  14. Impact of traffic-related air pollution on the expression of Platanus orientalis pollen allergens

    Science.gov (United States)

    Sedghy, Farnaz; Sankian, Mojtaba; Moghadam, Maliheh; Ghasemi, Ziba; Mahmoudi, Mahmoud; Varasteh, Abdol-Reza

    2016-06-01

    Air pollutants and their interaction with environmental allergens have been considered as an important reason for the recent increase in the prevalence of allergic diseases. The aim of this study was to investigate the traffic pollution effect, as a stressor, on Platanus orientalis pollen allergens messenger RNA (mRNA) and protein expression. P. orientalis pollen grains were collected along main streets of heavy traffic and from unpolluted sites in Mashhad city, in northeast Iran. The pollen samples were examined by scanning electron microscopy. To assess the abundance of pollen allergens (Pla or 1, Pla or 2, and Pla or 3) from polluted and unpolluted sites, immunoblotting was performed. Moreover, the sequences encoding P. orientalis allergens were amplified using real-time PCR. Scanning electron microscopy showed a number of particles of 150-550 nm on the surface of pollen from polluted sites. Also, protein and gene expression levels of Pla or 1 and Pla or 3 were considerably greater in pollen samples from highly polluted areas than in pollen from unpolluted areas (p public policies aimed at controlling traffic pollution to improve air quality and prevent the subsequent clinical outcomes and new cases of asthma.

  15. Monitoring and prediction of air polution from traffic in the urban environment

    OpenAIRE

    Reynolds, Shirley Anne

    1996-01-01

    Traffic-related air pollution is now a major concern. The Rio Earth Summit and the Government's commitment to Agenda 21 has led to Local Authorities taking responsibility to manage the growing number of vehicles and to reduce the impact of traffic on the environment. There is an urgent need to effectively monitor urban air quality at reasonable cost and to develop long and short term air pollution prediction models. The aim of the research described was to investigate relationships betw...

  16. Simulation evaluation of TIMER, a time-based, terminal air traffic, flow-management concept

    Science.gov (United States)

    Credeur, Leonard; Capron, William R.

    1989-01-01

    A description of a time-based, extended terminal area ATC concept called Traffic Intelligence for the Management of Efficient Runway scheduling (TIMER) and the results of a fast-time evaluation are presented. The TIMER concept is intended to bridge the gap between today's ATC system and a future automated time-based ATC system. The TIMER concept integrates en route metering, fuel-efficient cruise and profile descents, terminal time-based sequencing and spacing together with computer-generated controller aids, to improve delivery precision for fuller use of runway capacity. Simulation results identify and show the effects and interactions of such key variables as horizon of control location, delivery time error at both the metering fix and runway threshold, aircraft separation requirements, delay discounting, wind, aircraft heading and speed errors, and knowledge of final approach speed.

  17. Analyzing the effect of routing protocols on media access control protocols in radio networks

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C. L. (Christopher L.); Drozda, M. (Martin); Marathe, A. (Achla); Marathe, M. V. (Madhav V.)

    2002-01-01

    We study the effect of routing protocols on the performance of media access control (MAC) protocols in wireless radio networks. Three well known MAC protocols: 802.11, CSMA, and MACA are considered. Similarly three recently proposed routing protocols: AODV, DSR and LAR scheme 1 are considered. The experimental analysis was carried out using GloMoSim: a tool for simulating wireless networks. The main focus of our experiments was to study how the routing protocols affect the performance of the MAC protocols when the underlying network and traffic parameters are varied. The performance of the protocols was measured w.r.t. five important parameters: (i) number of received packets, (ii) average latency of each packet, (iii) throughput (iv) long term fairness and (v) number of control packets at the MAC layer level. Our results show that combinations of routing and MAC protocols yield varying performance under varying network topology and traffic situations. The result has an important implication; no combination of routing protocol and MAC protocol is the best over all situations. Also, the performance analysis of protocols at a given level in the protocol stack needs to be studied not locally in isolation but as a part of the complete protocol stack. A novel aspect of our work is the use of statistical technique, ANOVA (Analysis of Variance) to characterize the effect of routing protocols on MAC protocols. This technique is of independent interest and can be utilized in several other simulation and empirical studies.

  18. The traffic crisis and a tale of two cities: Traffic and air quality in Bangkok and Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Pendakur, V.S.; Badami, M.G.

    1995-12-31

    This paper focuses on congestion management techniques, traffic congestion levels and air quality. By using data from Bangkok and Mexico City, it illustrates the need for drastic changes in transportation policy tools and techniques for congestion management and for improving environmental quality. New approaches to investment and regulatory policy analysis and implementation are suggested. This requires the inclusion of all costs and benefits (economic and ecological) in the policy matrix so that investment and regulatory policies act in unison. Megacities are dominant in social, political and economic terms. 30 to 60% of national GDP is typically produced in these cities. Their human and motor vehicle populations have been doubling every 15-20 and 6-10 years respectively. They also have the most severe traffic congestion and air quality problems. They have the nation`s highest incidence of poverty and absolute poverty. Large portions of their populations endure severely unhealthy housing and sanitation conditions. Following are important characteristics of urban transportation systems in the megacities: the city centres are heavily congested with motorized traffic; traffic crawl rates vary from 2 to 10 km/hr; car and motorcycle ownership are increasing at annual rates of 10-12% and 15-20% respectively; significant air pollution with no relief in sight; TDM strategies are primarily creating new supply of road capacity; fairly high transit trips with substantial transit investments; weak air pollution monitoring and enforcement; and fairly cheap fuel and high costs of vehicles.

  19. A Network Traffic Control Enhancement Approach over Bluetooth Networks

    DEFF Research Database (Denmark)

    Son, L.T.; Schiøler, Henrik; Madsen, Ole Brun

    2003-01-01

    This paper analyzes network traffic control issues in Bluetooth data networks as convex optimization problem. We formulate the problem of maximizing of total network flows and minimizing the costs of flows. An adaptive distributed network traffic control scheme is proposed as an approximated...... solution of the stated optimization problem that satisfies quality of service requirements and topologically induced constraints in Bluetooth networks, such as link capacity and node resource limitations. The proposed scheme is decentralized and complies with frequent changes of topology as well...... as capacity limitations and flow requirements in the network. Simulation shows that the performance of Bluetooth networks could be improved by applying the adaptive distributed network traffic control scheme...

  20. Dynamic stochastic optimization models for air traffic flow management

    Science.gov (United States)

    Mukherjee, Avijit

    This dissertation presents dynamic stochastic optimization models for Air Traffic Flow Management (ATFM) that enables decisions to adapt to new information on evolving capacities of National Airspace System (NAS) resources. Uncertainty is represented by a set of capacity scenarios, each depicting a particular time-varying capacity profile of NAS resources. We use the concept of a scenario tree in which multiple scenarios are possible initially. Scenarios are eliminated as possibilities in a succession of branching points, until the specific scenario that will be realized on a particular day is known. Thus the scenario tree branching provides updated information on evolving scenarios, and allows ATFM decisions to be re-addressed and revised. First, we propose a dynamic stochastic model for a single airport ground holding problem (SAGHP) that can be used for planning Ground Delay Programs (GDPs) when there is uncertainty about future airport arrival capacities. Ground delays of non-departed flights can be revised based on updated information from scenario tree branching. The problem is formulated so that a wide range of objective functions, including non-linear delay cost functions and functions that reflect equity concerns can be optimized. Furthermore, the model improves on existing practice by ensuring efficient use of available capacity without necessarily exempting long-haul flights. Following this, we present a methodology and optimization models that can be used for decentralized decision making by individual airlines in the GDP planning process, using the solutions from the stochastic dynamic SAGHP. Airlines are allowed to perform cancellations, and re-allocate slots to remaining flights by substitutions. We also present an optimization model that can be used by the FAA, after the airlines perform cancellation and substitutions, to re-utilize vacant arrival slots that are created due to cancellations. Finally, we present three stochastic integer programming

  1. Air pollution from traffic and risk for brain tumors

    DEFF Research Database (Denmark)

    Poulsen, Aslak Harbo; Sørensen, Mette; Andersen, Zorana J

    2016-01-01

    PURPOSE: Air pollution is an established lung carcinogen, and there is increasing evidence that air pollution also negatively affects the brain. We have previously reported an association between air pollution and risk of brain tumors in a cohort study based on only 95 cases. We set out to replic......PURPOSE: Air pollution is an established lung carcinogen, and there is increasing evidence that air pollution also negatively affects the brain. We have previously reported an association between air pollution and risk of brain tumors in a cohort study based on only 95 cases. We set out...... to replicate that finding in a large nationwide case-control study. METHODS: We identified all 4,183 adult brain tumor cases in Denmark in the years 2000-2009 and 8,018 risk set sampled population controls matched on gender and year of birth. We extracted residential address histories and estimated mean...... and risk of brain tumors which was found in our previous study. The suggestion of an increased brain tumor risk at high exposures merits further attention as does the differing results according to tumor morphology....

  2. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications

    OpenAIRE

    Jisheng Zhang; Limin Jia; Shuyun Niu; Fan Zhang; Lu Tong; Xuesong Zhou

    2015-01-01

    It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs) start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and no...

  3. Operating the railway traffic control system

    Directory of Open Access Journals (Sweden)

    Anton PEPEVNIK

    2011-01-01

    Full Text Available Due to the valid traffic policy and development strategy of the Republic of Slovenia, the Slovenian Railways have to consider the developmental and strategic aims of European railways. The perspective of progress is basically determined by skimming the European system development, by taking over the European system and managing the railway traffic in the connection with the European railway system.Technology and organization of the railway traffic system present the sum of all technological and organizational elements and processes that takes part in providing aims of the system. The aims are defined as solving transport problems in railway system. The term system is defined, from the formal mathematical viewpoint, as a whole that is usually complicated or even very much complicated. Therefore, the railway system is complex as well, and that is why it has to be managed precisely. In the narrow sense of meaning, technology and work organization both comprises a variety of means and procedures to realize basic activity that can be seen as a perfect unit, and that can be the process of passengers and freight transport in a transport system.Because of the prompt development of microelectronics and computer engineering, a new generation of electronic signal-safety devices appeared.All these changes from the past few years that have been introduced into railway technology, enable railway to become attractive and competitive to other means of traffic. Therefore, the Slovenian Railways have to follow novelties in traffic technology development and gradually modernize its railway network.

  4. Associations between maternal exposure to air pollution and traffic noise and newborn's size at birth

    DEFF Research Database (Denmark)

    Hjortebjerg, Dorrit; Andersen, Anne Marie Nybo; Ketzel, Matthias

    2016-01-01

    BACKGROUND: Maternal exposure to air pollution and traffic noise has been suggested to impair fetal growth, but studies have reported inconsistent findings. Objective To investigate associations between residential air pollution and traffic noise during pregnancy and newborn's size at birth....... METHODS: From a national birth cohort we identified 75,166 live-born singletons born at term with information on the children's size at birth. Residential address history from conception until birth was collected and air pollution (NO2 and NOx) and road traffic noise was modeled at all addresses...... between air pollution and birth weight. Exposure to residential road traffic noise was weakly associated with reduced head circumference, whereas none of the other newborn's size indicators were associated with noise, neither before nor after adjustment for air pollution. CONCLUSIONS: This study indicates...

  5. Is there any interaction between domestic radon exposure and air pollution from traffic in relation to childhood leukemia risk?

    DEFF Research Database (Denmark)

    Bräuner, E.V.; Andersen, Claus Erik; Andersen, H.P.;

    2010-01-01

    Background: In a recent population-based case-control study using 2,400 cases of childhood cancer, we found a statistically significant association between residential radon and acute lymphoblastic leukemia risk. Hypothesis: Traffic exhaust in the air enhances the risk association between radon...... risk within different strata of air pollution and traffic density. Results: The relative risk for childhood leukemia in association with a 103 Bq/m3-years increase in radon was 1.77 (1.11, 2.82) among those exposed to high levels of NOx and 1.23 (0.79, 1.91) for those exposed to low levels of NOx...... pollution from traffic may enhance the effect of radon on the risk of childhood leukemia. The observed tendency may also be attributed to chance. © 2010 Springer Science+Business Media B.V....

  6. Unattended vehicle detection for automatic traffic light control

    Science.gov (United States)

    Abdel Hady, Aya Salama; Moustafa, Mohamed

    2013-12-01

    Machine vision based traffic light control depends mainly on measuring traffic statistics at cross roads. Most of the previous studies have not taken unattended vehicles into consideration when calculating either the traffic density or the traffic flow. In this paper, we propose incorporating unattended vehicles into a new metric for measuring the traffic congestion. In addition to the vehicle motion analysis, opening the driver's side door is an important indicator that this vehicle is going to be unattended. Therefore, we focus in this paper on presenting how to detect this event for stationary vehicles from a live camera or a video feed. Through a set of experiments, we have found out that a Scale Invariant Feature Transform (SIFT) feature-descriptor with a Support Vector Machines (SVM) classifier was able to successfully classify open-door vehicles from closed-door ones in 96.7% of our test dataset.

  7. Is there any interaction between domestic radon exposure and air pollution from traffic in relation to childhood leukemia risk?

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Andersen, Claus Erik; Andersen, Helle P.;

    2010-01-01

    for different morphological subtypes of leukemia and within different strata of traffic density showed a non-significant pattern of stronger associations between radon and childhood leukemia within strata of higher traffic density at the street address. Air pollution from traffic may enhance the effect of radon...... of air pollution and traffic density. The relative risk for childhood leukemia in association with a 10(3) Bq/m(3)-years increase in radon was 1.77 (1.11, 2.82) among those exposed to high levels of NOx and 1.23 (0.79, 1.91) for those exposed to low levels of NOx (p (interaction,) 0.17). Analyses......In a recent population-based case-control study using 2,400 cases of childhood cancer, we found a statistically significant association between residential radon and acute lymphoblastic leukemia risk. Traffic exhaust in the air enhances the risk association between radon and childhood leukemia. We...

  8. Empirical findings with multi-criteria routing for Dynamic Traffic Management

    NARCIS (Netherlands)

    Chen, Y.; Zhang, F.

    2013-01-01

    Traffic simulation is conventionally based on travel time as input to the cost function. The new challenge in traffic management takes into account not only travel throughput but also vehicle emission and safety. The question is then whether the network traffic performance will change if multi-crite

  9. Traffic contribution of polycyclic aromatic hydrocarbons in the center of a large city

    DEFF Research Database (Denmark)

    Nielsen, T.

    1996-01-01

    composition was also determined in the air in a street carrying only diesel buses. The concentrations of benzo(a)pyrene and benzo(e)pyrene (BeP) were 4.4 +/- 1.2 and 4.4 +/- 0.7 ng m(-3), respectively, in the street air and 1.4 +/- 0.6 and 1.3 +/- 0.3 ng m(-3), respectively, in the air in the park area....... The investigation covered the winter months, January-March. The winter was mild, with a mean temperature of 2.8 degrees C. The major PAH source in the street was the traffic. In the city park area also traffic was an important source, but not the major one. Applying BeP as PAH indicator, the traffic contribution...

  10. 空管新技术在低空空域管理中应用分析%Application and analysis of new air traffic control technology in low altitude airspace management

    Institute of Scientific and Technical Information of China (English)

    李邢超

    2015-01-01

    随着低空空域内航空器数量的不断增加,飞行科目和类型也不断呈现出多样化的趋势,这给低空空域管理带来了亲所谓有的考验。现有的低空空域管理手段中存在一系列问题,阻碍了我国航空事业的发展。除了需要进行体制方面的变革外,空管高新技术的引用是提升低空空域管理水平的重要方式,有利于实现低空空域的资源利用率达到最高,推动我国航空业的持续快速发展。%With the increasing amount of aircraft in low altitude airspace,flight course and type also shows a trend of diversification,which give low altitude airspace management brought Pro called some test.There are a series of problems in the existing low altitude airspace management,which hinders the development of aviation industry in China..In addition to the need of system change,air traffic control(ATC) high technology reference is an important way to enhance the level of low altitude airspace management, conducive to the realization of low altitude airspace resource utilization rate reached the highest,and promote the sustained and rapid development of China's aviation industry.

  11. Traffic flow collection wireless sensor network node for intersection light control

    Science.gov (United States)

    Li, Xu; Li, Xue

    2011-10-01

    Wireless sensor network (WSN) is expected to be deployed in intersection to monitor the traffic flow continuously, and the monitoring datum can be used as the foundation of traffic light control. In this paper, a WSN based on ZigBee protocol for monitoring traffic flow is proposed. Structure, hardware and work flow of WSN nodes are designed. CC2431 from Texas Instrument is chosen as the main computational and transmission unit, and CC2591 as the amplification unit. The stability experiment and the actual environment experiment are carried out in the last of the paper. The results of experiments show that WSN has the ability to collect traffic flow information quickly and transmit the datum to the processing center in real time.

  12. Task Analysis Assessment on Intrastate Bus Traffic Controllers

    Science.gov (United States)

    Yen Bin, Teo; Azlis-Sani, Jalil; Nur Annuar Mohd Yunos, Muhammad; Ismail, S. M. Sabri S. M.; Tajedi, Noor Aqilah Ahmad

    2016-11-01

    Public transportation acts as social mobility and caters the daily needs of the society for passengers to travel from one place to another. This is true for a country like Malaysia where international trade has been growing significantly over the past few decades. Task analysis assessment was conducted with the consideration of cognitive ergonomic view towards problem related to human factors. Conducting research regarding the task analysis on bus traffic controllers had allowed a better understanding regarding the nature of work and the overall monitoring activities of the bus services. This paper served to study the task analysis assessment on intrastate bus traffic controllers and the objectives of this study include to conduct task analysis assessment on the bus traffic controllers. Task analysis assessment for the bus traffic controllers was developed via Hierarchical Task Analysis (HTA). There are a total of five subsidiary tasks on level one and only two were able to be further broken down in level two. Development of HTA allowed a better understanding regarding the work and this could further ease the evaluation of the tasks conducted by the bus traffic controllers. Thus, human error could be reduced for the safety of all passengers and increase the overall efficiency of the system. Besides, it could assist in improving the operation of the bus traffic controllers by modelling or synthesizing the existing tasks if necessary.

  13. Rapid Protoyping Software for Developing Next-Generation Air Traffic Management Algorithms Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Research on next-generation air traffic management systems is being conducted at several laboratories using custom software. In order to provide a more uniform...

  14. Air-Leakage Control Manual.

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, Jim; Washington State Energy Office; United States. Bonneville Power Administration.

    1991-05-01

    This manual is for builders and designers who are interested in building energy-efficient homes. The purpose of the manual is to provide the how and why'' of controlling air leakage by means of a system called the Simple Caulk and Seal'' (SIMPLE{center dot}CS) system. This manual provides an overview of the purpose and contents of the manual; It discusses the forces that affect air leakage in homes and the benefits of controlling air leakage. Also discussed are two earlier approaches for controlling air leakage and the problems with these approaches. It describes the SIMPLE-{center dot}CS system. It outlines the standard components of the building envelope that require sealing and provides guidelines for sealing them. It outlines a step-by-step procedure for analyzing and planning the sealing effort. The procedure includes (1) identifying areas to be sealed, (2) determining the most effective and convenient stage of construction in which to do the sealing, and (3) designating the appropriate crew member or trade to be responsible for the sealing.

  15. Air-leakage control manual

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, J. [Washington State Energy Office, Olympia, WA (United States)

    1991-05-01

    This manual is for builders and designers who are interested in building energy-efficient homes. The purpose of the manual is to provide the ``how and why`` of controlling air leakage by means of a system called the ``Simple Caulk and Seal`` (SIMPLE{center_dot}CS) system. This manual provides an overview of the purpose and contents of the manual; It discusses the forces that affect air leakage in homes and the benefits of controlling air leakage. Also discussed are two earlier approaches for controlling air leakage and the problems with these approaches. It describes the SIMPLE-{center_dot}CS system. It outlines the standard components of the building envelope that require sealing and provides guidelines for sealing them. It outlines a step-by-step procedure for analyzing and planning the sealing effort. The procedure includes (1) identifying areas to be sealed, (2) determining the most effective and convenient stage of construction in which to do the sealing, and (3) designating the appropriate crew member or trade to be responsible for the sealing.

  16. Information Feedback Strategies in a Signal Controlled Network with Overlapped Routes

    Institute of Scientific and Technical Information of China (English)

    TIAN Li-Jun; HUANG Hai-Jun; LIU Tian-Liang

    2009-01-01

    We investigate the effects of four different information feedback strategies on the dynamics of traffic, travel-ers' route choice and the resultant system performance in a signal controlled network with overlapped routes.Simulation results given by the cellular automaton model show that the system purpose-based mean velocity feedback strategy and the congestion coefficient feedback strategy have more advantages in improving network utilization efficiency and reducing travelers' travel times. The travel time feedback strategy and the individual purposed-based mean velocity feedback strategy behave slightly better to ensure user equity.

  17. 基于物元分析理论的空管安全风险模糊综合评价%An Fuzzy Synthetic Evaluation Model for Safety Risk in Air Traffic Control Based on Matter Element Analysis

    Institute of Scientific and Technical Information of China (English)

    张晓燕; 韩松臣; 杨昌其

    2016-01-01

    In order to ensure aviation safety and scientifically evaluate the risks in air traffic control (ATC),a fuzzy synthetic evaluation model for risk assessment in ATC is established based on the matter element theory.The hazards in ATC are identified and classified according to Safety Management Manual issued by the International Civil Aviation Or-ganization (ICAO).An indicator system and a set of classes of effective factors and the corresponding degrees of hazards in ATC are determined.The weight of each hazard is calculated by the matter element theory,eliminating the limitation of subjectivity in experts′evaluation.Furthermore,the weight assignment is improved.After that,a multilevel fuzzy syn-thetic evaluation method is proposed to evaluate the risks in ATC.On the basis of statistics and analysis to the hazard data in ATC of a coastal sub-bureau of air traffic management (ATM)in 2012 – 2014,the risks are evaluated.The results in-dicate that the degree of impact of first-level,second-level,and third-level membership of hazards are 0.291 3,0.495 1, 0.213 6,respectively.The degree of impact in this sub-bureau lies at second-level.The results are consistent with the ac-tual operations.Thus the practicability and effectiveness of the proposed method is verified.%为保证航空安全,科学评价空管运行安全风险,提出了基于物元分析理论的空管安全风险模糊综合评价模型.依据国际民航组织的《安全管理手册》对空管危险源进行识别分级;然后确定空管危险源的指标体系和等级集合.在此基础上,运用物元分析理论,计算各空管危险源因素的权重矩阵,避免了人为评判的主观性,实现了权重客观赋值.应用多层次模糊综合评判方法,对空管安全风险进行了评估.以某沿海空管分局2012~2014年空管危险源相关数据为例进行了实际应用.结果表明,该沿海空管分局空管危险源因素对空管安全的影响级别属于Ⅰ级高风险、

  18. Programs Model the Future of Air Traffic Management

    Science.gov (United States)

    2010-01-01

    Through Small Business Innovation Research (SBIR) contracts with Ames Research Center, Intelligent Automation Inc., based in Rockville, Maryland, advanced specialized software the company had begun developing with U.S. Department of Defense funding. The agent-based infrastructure now allows NASA's Airspace Concept Evaluation System to explore ways of improving the utilization of the National Airspace System (NAS), providing flexible modeling of every part of the NAS down to individual planes, airports, control centers, and even weather. The software has been licensed to a number of aerospace and robotics customers, and has even been used to model the behavior of crowds.

  19. 7110.65H Air Traffic Control

    Science.gov (United States)

    1993-09-16

    Glossary M-4 001108 Pnlot/montroflm Glossary NAS-(See NATIONAL AIRSPACE SYSTEM). The norma service range for T, L, and H de aide is fmad in the AIM. Cr...C404 - 27/S 2,600 2,000 2 11 CHAMPION (USA-see Bellanca Aircraft). CONSTRUCCIONES AERONAUTICAS (CASA) (Spain). C-212 Aviocar

  20. HIGH LEVEL MODELLING OF REAL TIME TRAFFIC LIGHT CONTROLLER

    Directory of Open Access Journals (Sweden)

    ADITYA MANDLOI

    2012-12-01

    Full Text Available The objective of this paper is to design and implement traffic control system. The system developed is able to sense the presence of vehicles within certain range by setting the appropriate duration for the traffic signals to react accordingly. By employing logical functions to calculate the appropriate timing for the signals toilluminate, the system can help to solve the problem of traffic congestion. The use of FPGAs (Field Programmable Gate Arrays is an interesting new phenomenon in VLSI development. FPGAs offer all of thefeatures needed to implement most complex designs. Hardware simulation tests were successfully performed on the algorithm implemented into a FPGA (Field Programmable Gate Arrays. The main object of the paper is to design a Real Time Traffic Light Controller (RTTLC using VHDL and implement the RTTLC in XILINX SPARTAN - 3 FPGA.

  1. Traffic Aware Planner for Cockpit-Based Trajectory Optimization

    Science.gov (United States)

    Woods, Sharon E.; Vivona, Robert A.; Henderson, Jeffrey; Wing, David J.; Burke, Kelly A.

    2016-01-01

    The Traffic Aware Planner (TAP) software application is a cockpit-based advisory tool designed to be hosted on an Electronic Flight Bag and to enable and test the NASA concept of Traffic Aware Strategic Aircrew Requests (TASAR). The TASAR concept provides pilots with optimized route changes (including altitude) that reduce fuel burn and/or flight time, avoid interactions with known traffic, weather and restricted airspace, and may be used by the pilots to request a route and/or altitude change from Air Traffic Control. Developed using an iterative process, TAP's latest improvements include human-machine interface design upgrades and added functionality based on the results of human-in-the-loop simulation experiments and flight trials. Architectural improvements have been implemented to prepare the system for operational-use trials with partner commercial airlines. Future iterations will enhance coordination with airline dispatch and add functionality to improve the acceptability of TAP-generated route-change requests to pilots, dispatchers, and air traffic controllers.

  2. RADC/NBS (Rome Air Development Center/National Bureau of Standards) Workshop. Moisture Measurement and Control for Microelectronics (4)

    Science.gov (United States)

    Kane, Didier; Moore, Benjamin A.; Walters, E. Jane

    1987-06-01

    The fourth workshop on Moisture Measurement and Control for Microelectronics served as a forum on moisture and/or materials reliability problems and on ways to control them or measure their extent. Twenty-two presentations are included which contain detailed information on hermeticity measurement and definition; development of standard packages for mass spectrometric calibrations; moisture interaction with various materials; and techniques that can be used to measure moisture microelectronics. It was clear from several presentations in the workshop that a very systematic approach is needed when organic materials are involved; all the variables must be identified and studied one at a time. This is the key to lot-to-lot reproducibility, materials selection, and control; hence a better reliability at the design phase will decrease the need for testing; hence the cost, thus resulting in a greater satisfaction to the customer.

  3. Joint optimization traffic signal control for an urban arterial road

    Institute of Scientific and Technical Information of China (English)

    LI Yin-fei; CHEN Shu-ping

    2009-01-01

    This paper considers the optimal traffic signal setting for an urban arterial road. By introducing the concepts of synchronization rate and non-synchronization degree, a mathematical model is constructed and an optimization problem is posed. Then, a new iterative algorithm is developed to solve this optimal traffic control signal setting problem. Convergence properties for this iterative algorithm are established. Finally, a numerical example is solved to illustrate the effectiveness of the method.

  4. Optimizing urban traffic control using a rational agent

    Institute of Scientific and Technical Information of China (English)

    Salvador IBARRA-MARTÍNEZ; José A. CASTÁN-ROCHA; Julio LARIA-MENCHACA

    2014-01-01

    This paper is devoted to developing and evaluating a set of technologies with the objective of designing a method-ology for the implementation of sophisticated traffic lights by means of rational agents. These devices would be capable of op-timizing the behavior of a junction with multiple traffic signals, reaching a higher level of autonomy without losing reliability, accuracy, or efficiency in the offered services. In particular, each rational agent in a traffic signal will be able to analyze the requirements and constraints of the road, in order to know its level of demand. With such information, the rational agent will adapt its light cycles with the view of accomplishing more fluid traffic patterns and minimizing the pollutant environmental emissions produced by vehicles while they are stopped at a red light, through using a case-based reasoning (CBR) adaptation. This paper also integrates a microscopic simulator developed to run a set of tests in order to compare the presented methodology with traditional traffic control methods. Two study cases are shown to demonstrate the efficiency of the introduced approach, increasing vehicular mobility and reducing harmful activity for the environment. For instance, in the first scenario, taking into account the studied traffic volumes, our approach increases mobility by 23%and reduces emissions by 35%. When the roads are managed by sophisticated traffic lights, a better level of service and considerable environmental benefits are achieved, demon-strating the utility of the presented approach.

  5. A Computer Simulation of the System-Wide Effects of Parallel-Offset Route Maneuvers

    Science.gov (United States)

    Lauderdale, Todd A.; Santiago, Confesor; Pankok, Carl

    2010-01-01

    Most aircraft managed by air-traffic controllers in the National Airspace System are capable of flying parallel-offset routes. This paper presents the results of two related studies on the effects of increased use of offset routes as a conflict resolution maneuver. The first study analyzes offset routes in the context of all standard resolution types which air-traffic controllers currently use. This study shows that by utilizing parallel-offset route maneuvers, significant system-wide savings in delay due to conflict resolution of up to 30% are possible. It also shows that most offset resolutions replace horizontal-vectoring resolutions. The second study builds on the results of the first and directly compares offset resolutions and standard horizontal-vectoring maneuvers to determine that in-trail conflicts are often more efficiently resolved by offset maneuvers.

  6. Potential Contribution of Traffic to Air Pollution in the State of Kuwait

    Directory of Open Access Journals (Sweden)

    N. Al-Mutairi

    2009-01-01

    Full Text Available Problem statement: The reduction in ambient air pollution is a universal goal-particularly in urban areas, the lack of resources often necessitates identification and prioritization of sources of air pollutants. Efficient planning and effective management of environmental pollutants is thus important for optimum utilization of limited resources. Approach: This study examined seven years of data from three air pollution monitoring stations in the State of Kuwait. The stations-each located at a different district-were selected such that the influence of traffic source and oil refineries/power stations on ambient air pollution contaminants could be detected. A sampling plan was developed and CH4, CO, O3, SO2, NO, NOX and TS concentrations were measured both during peak-traffic hours as well as off-peak hours. Results: Analyses of the data showed that concentrations of the air pollutants had slightly increased over the seven-year study period and only those of the NOX and SO2, exceed the permitted standard levels. Traffic was the main source of air pollution in the district located adjacent to the city centre, while oil refineries contributed most to ambient air pollution in the rural district. Conclusion: The concentration levels of NO, NOX and Total Sulfate (TS were significantly less at the district located away from urban traffic and oil refineries compared to those of with heavy daily traffic congestions and those of the district in proximity to oil refineries.

  7. Controlling traffic jams by time modulating the safety distance

    DEFF Research Database (Denmark)

    Gaididei, Yu B.; Gorria, C.; Berkemer, R.

    2013-01-01

    in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well......The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case....... This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance...

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

    OpenAIRE

    2015-01-01

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

  9. Traffic-engineering-aware shortest-path routing and its application in IP-over-WDM networks [Invited

    Science.gov (United States)

    Lee, Youngseok; Mukherjee, Biswanath

    2004-03-01

    Single shortest-path routing is known to perform poorly for Internet traffic engineering (TE) where the typical optimization objective is to minimize the maximum link load. Splitting traffic uniformly over equal-cost multiple shortest paths in open shortest path first and intermediate system-intermediate system protocols does not always minimize the maximum link load when multiple paths are not carefully selected for the global traffic demand matrix. However, a TE-aware shortest path among all the equal-cost multiple shortest paths between each ingress-egress pair can be selected such that the maximum link load is significantly reduced. IP routers can use the globally optimal TE-aware shortest path without any change to existing routing protocols and without any serious configuration overhead. While calculating TE-aware shortest paths, the destination-based forwarding constraint at a node should be satisfied, because an IP router will forward a packet to the next hop toward the destination by looking up the destination prefix. We present a mathematical problem formulation for finding a set of TE-aware shortest paths for the given network as an integer linear program, and we propose a simple heuristic for solving large instances of the problem. Then we explore the usage of our proposed algorithm for the integrated TE method in IP-over-WDM networks. The proposed algorithm is evaluated through simulations in IP networks as well as in IP-over-WDM networks.

  10. Air France Offers A Second Daily Flight on Its Beijing - Paris Route

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

      Starting from 14 June 2005, Air France is adding one more daily flight on its Beijing - Paris's route. Air France customers will then have a choice of fourteen weekly flights between the two cities.……

  11. Air France Offers A Second Daily Flight on Its Beijing - Paris Route

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Starting from 14 June 2005, Air France is adding one more daily flight on its Beijing - Paris's route. Air France customers will then have a choice of fourteen weekly flights between the two cities.

  12. Impact of traffic-related air pollution on the expression of Platanus orientalis pollen allergens

    Science.gov (United States)

    Sedghy, Farnaz; Sankian, Mojtaba; Moghadam, Maliheh; Ghasemi, Ziba; Mahmoudi, Mahmoud; Varasteh, Abdol-Reza

    2017-01-01

    Air pollutants and their interaction with environmental allergens have been considered as an important reason for the recent increase in the prevalence of allergic diseases. The aim of this study was to investigate the traffic pollution effect, as a stressor, on Platanus orientalis pollen allergens messenger RNA (mRNA) and protein expression. P. orientalis pollen grains were collected along main streets of heavy traffic and from unpolluted sites in Mashhad city, in northeast Iran. The pollen samples were examined by scanning electron microscopy. To assess the abundance of pollen allergens (Pla or 1, Pla or 2, and Pla or 3) from polluted and unpolluted sites, immunoblotting was performed. Moreover, the sequences encoding P. orientalis allergens were amplified using real-time PCR. Scanning electron microscopy showed a number of particles of 150-550 nm on the surface of pollen from polluted sites. Also, protein and gene expression levels of Pla or 1 and Pla or 3 were considerably greater in pollen samples from highly polluted areas than in pollen from unpolluted areas ( p < 0.05). In contrast, no statically significant difference in Pla or 2 protein and mRNA expression level was found between samples from the two areas. We found greater expression of allergens involved in plant defense mechanisms (Pla or 1 and Pla or 3) in polluted sites than in unpolluted ones. The high expression of these proteins can lead to an increase in the prevalence of allergic diseases. These findings suggest the necessity of supporting public policies aimed at controlling traffic pollution to improve air quality and prevent the subsequent clinical outcomes and new cases of asthma.

  13. Traffic-Aware Channel Allocation and Routing in Multichannel, Multi-Radio Wireless Networks

    Science.gov (United States)

    2012-01-01

    traffic analysis by CAIDA in 2008 shows that over 55% of the packets in the internet are smaller than 100 bytes and this statistic has not changed over...comparison between internet links in 1998 and 2008,” 2009, CAIDA Research. [Online]. Available: http://www.caida. org/research/traffic-analysis/pkt size

  14. A semi-decentralized control strategy for urban traffic

    OpenAIRE

    Farhi, Nadir; Nguyen Van Phu, Cyril; AMIR, Mouna; Haj Salem, Habib; LEBACQUE, Jean Patrick

    2015-01-01

    EWGT - Euro Working Group on Transportation, Delft, PAYS-BAS, 14-/07/2015 - 16/07/2015; We present in this article a semi-decentralized approach for urban traffic control, based on the TUC (Traffic responsive Urban Control) strategy. We assume that the control is centralized as in the TUC strategy, but we introduce a contention time window inside the cycle time, where antagonistic stages alternate a priority rule. The priority rule is set by applying green colours for given stages and yellow ...

  15. Traffic Adaptive Distributed Backoff Control Mechanism for Cluster-Based IEEE802.15.4 WSNs with Traffic Fluctuations

    Science.gov (United States)

    Mori, Kazuo; Naito, Katsuhiro; Kobayashi, Hideo

    The traffic adaptive 2-level active period control has been proposed as a traffic adaptation mechanism to handle temporal and spatial (geographical) traffic fluctuations in cluster-based wireless sensor networks (WSNs) employing IEEE802.15.4 medium access control (MAC). This paper proposes a traffic adaptive distributed backoff control mechanism for cluster-based WSNs with the traffic adaptive 2-level active period control to enhance the system performance, especially transmission performance. The proposed mechanism autonomously adjusts the starting time of the backoff procedure for channel accesses in the contention access period (CAP) specified by the IEEE802.15.4 MAC, and then distributes the channel access timing over a wide range within the CAP, which can mitigate channel access congestion. The results of computer simulations show that the proposed mechanism can improve the transmission delay performance while keeping the enhancement in throughput and energy consumption at the cluster-based WSNs under non-uniform traffic environments.

  16. Comparison of MANET Routing Protocols in Different Traffic and Mobility Models

    Directory of Open Access Journals (Sweden)

    J. Baraković

    2010-06-01

    Full Text Available Routing protocol election in MANET (Mobile Ad Hoc Network is a great challenge, because of its frequent topology changes and routing overhead. This paper compares performances of three routing protocols: Destination Sequenced Distance Vector (DSDV, Ad Hoc Ondemand Distance Vector (AODV and Dynamic Source Routing (DSR, based on results analysis obtained using simulations with different load and mobility scenarios performed with Network Simulator version 2 (NS-2. In low load and low mobility scenarios routing protocols perform in a similar manner. However, with mobility and load increasing DSR outperforms AODV and DSDV protocols.

  17. "I CAMMINI DELLA REGINA" - Open Source based tools for preserving and culturally exploring historical traffic routes.

    Science.gov (United States)

    Cannata, Massimiliano; Colombo, Massimo; Antonovic, Milan; Cardoso, Mirko; Delucchi, Andrea; Gianocca, Giancarlo; Brovelli, Maria Antonia

    2015-04-01

    "I CAMMINI DELLA REGINA" (The Via Regina Paths) is an Interreg project funded within the transnational cooperation program between Italy and Switzerland 2007-2013. The aim of this project is the preservation and valorization of the cultural heritage linked to the walking historically paths crossing, connecting and serving the local territories. With the approach of leveraging the already existing tools, which generally consist of technical descriptions of the paths, the project uses the open source geospatial technologies to deploy innovative solutions which can fill some of the gaps in historical-cultural tourism offers. The Swiss part, and particularly the IST-SUPSI team, has been focusing its activities in the realization of two innovative solutions: a mobile application for the survey of historical paths and a storytelling system for immersive cultural exploration of the historical paths. The former, based on Android, allows to apply in a revised manner a consolidated and already successfully used methodology of survey focused on the conservation of the historical paths (Inventory of historical traffic routes in Switzerland). Up to now operators could rely only on hand work based on a combination of notes, pictures and GPS devices synthesized in manually drawn maps; this procedure is error prone and shows many problems both in data updating and extracting for elaborations. Thus it has been created an easy to use interface which allows to map, according to a newly developed spatially enabled data model, paths, morphological elements, and multimedia notes. When connected to the internet the application can send the data to a web service which, after applying linear referencing and further elaborating the data, makes them available using open standards. The storytelling system has been designed to provide users with cultural insights embedded in a multimedial and immersive geospatial portal. Whether the tourist is exploring physically or virtually the desired

  18. 14 CFR Sec. 19-5 - Air transport traffic and capacity elements.

    Science.gov (United States)

    2010-01-01

    ... AIR CARRIERS Operating Statistics Classifications Sec. 19-5 Air transport traffic and capacity elements. (a) Within each of the service classifications prescribed in section -19-4, data shall be... equipment. The number of days that aircraft owned or acquired through rental or lease (but not...

  19. Speed limit and ramp meter control for traffic flow networks

    Science.gov (United States)

    Goatin, Paola; Göttlich, Simone; Kolb, Oliver

    2016-07-01

    The control of traffic flow can be related to different applications. In this work, a method to manage variable speed limits combined with coordinated ramp metering within the framework of the Lighthill-Whitham-Richards (LWR) network model is introduced. Following a 'first-discretize-then-optimize' approach, the first order optimality system is derived and the switch of speeds at certain fixed points in time is explained, together with the boundary control for the ramp metering. Sequential quadratic programming methods are used to solve the control problem numerically. For application purposes, experimental setups are presented wherein variable speed limits are used as a traffic guidance system to avoid traffic jams on highway interchanges and on-ramps.

  20. Data requirements for traffic control on a macroscopic level

    NARCIS (Netherlands)

    Knoop, V.L.; Van Lint, J.W.C.; Hoogendoorn, S.P.

    2011-01-01

    With current techniques, traffic monitoring and control is a data intensive process. Network control on a higher level, using high level variables, can make this process less data demanding. The macroscopic fundamental diagram relates accumulation, i.e. the number of vehicles in an area, to the netw

  1. Deadlock-free traffic control with geometrical critical sections

    NARCIS (Netherlands)

    Schoute, Albert L.; Bouwens, Peter J.; Backer, E.

    1994-01-01

    Traffic control of vehicles on pre-planned paths may be based on critical sections where vehicles have to control their velocity mutually in order to avoid collisions. By analysing the geometry of critical sections carefully deadlock situations can be recognised and situations where vehicles may sha

  2. Model-Based Traffic Control for Sustainable Mobility

    NARCIS (Netherlands)

    Zegeye, S.K.

    2011-01-01

    Computationally efficient dynamic fuel consumption, emissions, and dispersion of emissions models are developed. Fast and practically feasible model-based controller is proposed. Using the developed models, the controller steers the traffic flow in such a way that a balanced trade-off between the t

  3. Traffic Flow Management Wrap-Up

    Science.gov (United States)

    Grabbe, Shon

    2011-01-01

    Traffic Flow Management involves the scheduling and routing of air traffic subject to airport and airspace capacity constraints, and the efficient use of available airspace. Significant challenges in this area include: (1) weather integration and forecasting, (2) accounting for user preferences in the Traffic Flow Management decision making process, and (3) understanding and mitigating the environmental impacts of air traffic on the environment. To address these challenges, researchers in the Traffic Flow Management area are developing modeling, simulation and optimization techniques to route and schedule air traffic flights and flows while accommodating user preferences, accounting for system uncertainties and considering the environmental impacts of aviation. This presentation will highlight some of the major challenges facing researchers in this domain, while also showcasing recent innovations designed to address these challenges.

  4. ACRR: Ad Hoc On-Demand Distance Vector Routing with Controlled Route Requests

    CERN Document Server

    Kataria, Jayesh; Sanyal, Sugata

    2010-01-01

    Reactive routing protocols like Ad Hoc On-Demand Distance Vector Routing (AODV) and Dynamic Source Routing (DSR)in Ad-Hoc Wireless Networks which are used in Mobile and Ad Hoc Networks (MANETs) work by flooding the network with control packets. There is generally a limit on the number of these packets that can be generated or forwarded. But a malicious node can disregard this limit and flood the network with fake control packets. These packets hog the limited bandwidth and processing power of genuine nodes in the network while being forwarded. Due to this, genuine route requests suffer and many routes either do not get a chance to materialize or they end up being longer than otherwise. In this paper we propose a non cryptographic solution to the above problem and prove its efficiency by means of simulation.

  5. Combined effects of road traffic noise and ambient air pollution in relation to risk for stroke?

    Science.gov (United States)

    Sørensen, Mette; Lühdorf, Pernille; Ketzel, Matthias; Andersen, Zorana J; Tjønneland, Anne; Overvad, Kim; Raaschou-Nielsen, Ole

    2014-08-01

    Exposure to road traffic noise and air pollution have both been associated with risk for stroke. The few studies including both exposures show inconsistent results. We aimed to investigate potential mutual confounding and combined effects between road traffic noise and air pollution in association with risk for stroke. In a population-based cohort of 57,053 people aged 50-64 years at enrollment, we identified 1999 incident stroke cases in national registries, followed by validation through medical records. Mean follow-up time was 11.2 years. Present and historical residential addresses from 1987 to 2009 were identified in national registers and road traffic noise and air pollution were modeled for all addresses. Analyses were done using Cox regression. A higher mean annual exposure at time of diagnosis of 10 µg/m(3) nitrogen dioxide (NO2) and 10 dB road traffic noise at the residential address was associated with ischemic stroke with incidence rate ratios (IRR) of 1.11 (95% CI: 1.03, 1.20) and 1.16 (95% CI: 1.07, 1.24), respectively, in single exposure models. In two-exposure models road traffic noise (IRR: 1.15) and not NO2 (IRR: 1.02) was associated with ischemic stroke. The strongest association was found for combination of high noise and high NO2 (IRR=1.28; 95% CI=1.09-1.52). Fatal stroke was positively associated with air pollution and not with traffic noise. In conclusion, in mutually adjusted models road traffic noise and not air pollution was associated ischemic stroke, while only air pollution affected risk for fatal strokes. There were indications of combined effects.

  6. Re-casting the FAC Net: People, Platforms, and Policy in Forward Air Control

    Science.gov (United States)

    2015-06-01

    supporting fighters are waiting to help. Additionally, FACs coordinate supporting aircraft by acting as airborne air traffic controllers . They must know...units and provide control as required to increase the effectiveness of close air support. FAC(A)s provided an elevated reconnaissance platform to see...case enemy fighters attacked while aircraft low on fuel dropped their ordnance quickly. TAC-As acted as air traffic controllers to accomplish this

  7. Air quality assessment based on road traffic pollutants dispersion modelling: Giurgiu – Ruse Bridge Case study

    Directory of Open Access Journals (Sweden)

    Dragos MIHAI

    2012-12-01

    Full Text Available The paper presents a case study related to air quality assessment along an important high traffic bridge (Giurgiu - Ruse, by dispersion modelling of the main pollutants. In order to estimate the level of pollution caused by bridge road traffic in the closest urban areas, Giurgiu and Ruse and based on the traffic data, four scenarios for the air quality assessment have been carried out according to different meteorological conditions. The dispersion modeling was realized on specialized environmental pollution software, which features a fully operational Gauss model in its base module. There are presented dispersion maps for the main road traffic pollutants (NOx, CO, SO2, THC, aiming to evaluate their impact on the urban areas vicinity, in four different wind directions scenarios, at a constant temperature. Conclusions are presented according to available European Legislation and future scenarios are proposed, for other different meteorological conditions.

  8. Illuminating traffic control for cell-division planes.

    Science.gov (United States)

    Robatzek, Silke

    2014-01-01

    When a plant cell divides, four related proteins control the trafficking of vesicles and ensure that cargo that is normally recycled to the plasma membrane is instead re-routed to the plane of cell division.

  9. Splitting of Traffic Flows to Control Congestion in Special Events

    Directory of Open Access Journals (Sweden)

    Ciro D'Apice

    2011-01-01

    minimized with respect to the same control parameter. The obtained results have been tested by simulations of urban networks. Decongestion effects are also confirmed estimating the time a car needs to cross a fixed route on the network.

  10. Traffic-related air pollution - the health effects scrutinized

    NARCIS (Netherlands)

    Nijland, M.E.

    2013-01-01

    Numerous studies have been published on the health effects associated with exposure to air pollution. Air pollution is acknowledged as a public health risk and air quality regulations are set for specific air pollutants to protect human health. A major pollutant, well known for its adverse health im

  11. Traffic behavior of mixed traffic flow with two kinds of different self-stabilizing control vehicles

    Science.gov (United States)

    Li, Zhipeng; Li, Wenzhong; Xu, Shangzhi; Qian, Yeqing; Sun, Jian

    2015-10-01

    In this paper, we propose a heterogeneous car following model in terms of an extension to the original optimal velocity model characterizing two classes of different self-stabilizing control vehicles. Linear stability analysis method is utilized to the extended model, for purpose to explore how the varying percentages of the vehicles with short-duration self-stabilizing control influence the stability of the heterogeneous traffic flow. We obtain the neutral stability lines for different percentages of two classes of vehicles, with finding that the traffic flow trends to stable with the decrease of the percentage for short-duration self-stabilizing control vehicles. Moreover, we explore a special case that the same numbers of two different classes of vehicles with self-stabilizing control. We theoretically derive the stability condition of the special case, and conclude the effect of the average value and the standard deviation of two time gaps, on the heterogeneous traffic stability. At last, direct simulations are conducted to verify the conclusion of theoretical analysis.

  12. 78 FR 36132 - National Standards for Traffic Control Devices; Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2013-06-17

    ... books would cause unnecessary confusion because users would have to determine how to correctly apply the... experience the same fate as the Traffic Engineering Manual, which was developed to supplement the 1978...

  13. Warning Threshold Value Determination of Team Safety Behavior Risks in Air Traffic Control%空中交通管制班组安全行为风险告警阈值界定

    Institute of Scientific and Technical Information of China (English)

    杨智; 罗帆

    2012-01-01

    针对空中变通管制班组安全行为的风险类型,在实地调研的基础上选取班组行为风险指标,结合层次分析法构建指标体系,并在风险危害因子及风险抵御因子的基础上,运用加权综合评价法构建班组安全行为风险的评价模型,在以年龄、职称及学历为控制变量的情况下,通过运用有序聚类的最优分割算法界定班组安全行为风险的阈值,阈值界定过程中以班组安全行为绩效为参照序列.结果表明,空中交通管制班组安全行为风险与职称及年龄变量相关性较高,其告警阈值的划分也相对更为严格,职称及年龄组告警区间明显窄于学历控制组的阈值区间,因而在充分考虑各控制变量的基础上划设空中交通管制班组安全行为风险的阈值将更为合理,可有效避免因阈值划设过松或过严而出现的漏警及虚警的问题.%According to the types of the team safety behavior risks in air traffic control ( ATC) , team behavior risk indexes are selected through practical investigation. Then, analytic hierarchy process (AHP) is used to build an index system. A comprehensive evaluation model is developed by weighting team safety behavior risks described by the risk destruction and resistance factors. In the model, it takes the age, professional level, and education as the control variables. By using the orderly clustering of optimal partition algorithm, we take team's performance as reference sequence to define the risk threshold value of the team safety behavior. Results show that the team's safety risk behavior depends heavily on variable titles and ages in ATC. Its alarm threshold division is relatively stricter and obviously narrower than the part of diploma control- With full consideration of the total control variables by the proposed method, the risk threshold value is reasonable such that the threshold is neither too loose nor too strict, which can reduce both false positive and negative.

  14. Network Wide Service Level-Oriented Route Guidance in Road Traffic Networks: Traffic management in line with the policy objectives of the road authorities

    NARCIS (Netherlands)

    Landman, R.L.; Hegyi, A.; Hoogendoorn, S.P.

    2012-01-01

    Service level control is a promising strategy to realize policy objectives within road networks like improving network production while taking road user interests, livability and safety into account. In this contribution a service level-oriented route guidance control approach is presented that is a

  15. Backpressure-Based Packet-By-Packet Adaptive Routing For Traffic Management in Communication Networks

    Directory of Open Access Journals (Sweden)

    P. Swetha,

    2014-06-01

    Full Text Available Back pressure-based adaptive routing algorithms where each packet is routed along a possibly different pathhave been extensively studied in the literature. However, suchalgorithms typically result in poor delay performance and involvehigh implementation complexity. In this paper, we develop anew adaptive routing algorithm built upon the widely-studiedback-pressure algorithm. We decouple the routing and schedulingcomponents of the algorithm by designing a probabilistic routingtable which is used to route packets to per-destination queues.The scheduling decisions in the case of wireless networks aremade using counters called shadow queues. The results arealso extended to the case of networks which employ simpleforms of network coding. In that case, our algorithm provides alow-complexity solution to optimally exploit the routing-codingtrade-off.

  16. FL-FN-MOGA Based Traffic Signal Control

    Institute of Scientific and Technical Information of China (English)

    魏武; 张毅

    2003-01-01

    In this paper, a traffic signal control method based on fuzzy logic (FL), fuzzy-neuro (FN) and multi-objective genetic algorithms (MOGA) for an isolated four-approach intersection with through and left-turning movements is presented. This method has an adaptive signal timing ability, and can make adjustments to signal timing in response to observed changes. The "urgency degree" term, which can describe the different user's demand for green time is used in decision-making by which strategy of signal timing can be determined. Using a fuzzy logic controller, we can determine whether to extend or terminate the current signal phase and select the sequences of phases. In this paper, a method based on fuzzy-neuro can be used to predict traffic parameters used in fuzzy logic controller. The feasibility of using a multi-objective genetic algorithm (MOGA) to find a group of optimizing sets of parameters for fuzzy logic controller depending on different objects is also demonstrated. Simulation results show that the proposed methed is effecfive to adjust the signal timing in response to changing traffic conditions on a real-time basis, and the controller can produce lower vehicle delays and percentage of stopped vehicles than a traffic-actuated controller.

  17. A Sarsa(λ-Based Control Model for Real-Time Traffic Light Coordination

    Directory of Open Access Journals (Sweden)

    Xiaoke Zhou

    2014-01-01

    Full Text Available Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors that can affect the traffic control model, it is difficult to find the optimal solution. The disability of traffic light controllers to learn from past experiences caused them to be unable to adaptively fit dynamic changes of traffic flow. Considering dynamic characteristics of the actual traffic environment, reinforcement learning algorithm based traffic control approach can be applied to get optimal scheduling policy. The proposed Sarsa(λ-based real-time traffic control optimization model can maintain the traffic signal timing policy more effectively. The Sarsa(λ-based model gains traffic cost of the vehicle, which considers delay time, the number of waiting vehicles, and the integrated saturation from its experiences to learn and determine the optimal actions. The experiment results show an inspiring improvement in traffic control, indicating the proposed model is capable of facilitating real-time dynamic traffic control.

  18. Development and Evaluation of a Control System for Regional Traffic Management

    Directory of Open Access Journals (Sweden)

    John L. McLin

    2011-01-01

    Full Text Available Traffic congestion is a worsening problem in metropolitan areas which will require integrated regional traffic control systems to improve traffic conditions. This paper presents a regional traffic control system which can detect incident conditions and provide integrated traffic management during nonrecurrent congestion events. The system combines advanced artificial intelligence techniques with a traffic performance model based on HCM equations. Preliminary evaluation of the control system using traffic microsimulation demonstrates that it has the potential to improve system conditions during traffic incidents. In addition, several enhancements were identified which will make the system more robust in a real traffic control setting. An assessment of the control system elements indicates that there are no substantial technical barriers in implementing this system in a large traffic network.

  19. Analysis of the traffic running cost in a two-route system with feedback strategy

    Science.gov (United States)

    Tang, Tie-Qiao; Yu, Qiang; Liu, Kai

    2017-01-01

    In this paper, we apply the FVD (full velocity difference) model to study the influences of MVFS (mean velocity feedback strategy) and NVFS (the number of vehicles feedback strategy) on each vehicle's running cost and each route's total cost in a two-route system from the numerical perspective. The numerical results illustrate that MFVS and NVFS have significant effects on each vehicle's running cost and each route's total cost, and that the impacts, each vehicle's running cost and each route's total cost are related to the gap of each vehicle's departure time at the origin.

  20. Poison control center - emergency number

    Science.gov (United States)

    For a POISON EMERGENCY call: 1-800-222-1222 ANYWHERE IN THE UNITED STATES This national hotline number will let you ... is a free and confidential service. All local poison control centers in the United States use this ...

  1. Antennas Designed for Advanced Communications for Air Traffic Management (AC/ATM) Project

    Science.gov (United States)

    Zakrajsek, Robert J.

    2000-01-01

    The goal of the Advanced Communications for Air Traffic Management (AC/ATM) Project at the NASA Glenn Research Center at Lewis Field is to enable a communications infrastructure that provides the capacity, efficiency, and flexibility necessary to realize a mature free-flight environment. The technical thrust of the AC/ATM Project is targeted at the design, development, integration, test, and demonstration of enabling technologies for global broadband aeronautical communications. Since Ku-band facilities and equipment are readily available, one of the near-term demonstrations involves a link through a Kuband communications satellite. Two conformally mounted antennas will support the initial AC/ATM communications links. Both of these are steered electronically through monolithic microwave integrated circuit (MMIC) amplifiers and phase shifters. This link will be asymmetrical with the downlink to the aircraft (mobile vehicle) at a throughput rate of greater than 1.5 megabits per second (Mbps), whereas the throughput rate of the uplink from the aircraft will be greater than 100 kilobits per second (kbps). The data on the downlink can be narrow-band, wide-band, or a combination of both, depending on the requirements of the experiment. The AC/ATM project is purchasing a phased-array Ku-band transmitting antenna for the uplink from the test vehicle. Many Ku-band receiving antennas have been built, and one will be borrowed for a short time to perform the initial experiments at the NASA Glenn Research Center at Lewis Field. The Ku-band transmitting antenna is a 254-element MMIC phased-array antenna being built by Boeing Phantom Works. Each element can radiate 100 mW. The antenna is approximately 43-cm high by 24-cm wide by 3.3-cm thick. It can be steered beyond 60 from broadside. The beamwidth varies from 6 at broadside to 12 degrees at 60 degrees, which is typical of phased-array antennas. When the antenna is steered to 60 degrees, the beamwidth will illuminate

  2. Individual traffic-related air pollution and new onset adult asthma:A GIS-based pilot study

    DEFF Research Database (Denmark)

    Lysbeck Hansen, Carl; Jensen, Steen Solvang; Baelum, Jesper

    individual traffic-related air pollution exposure and new onset asthma and wheeze. It is recommended that the analytic methods developed in this pilot study are used in a larger prospective cohort to investigate individual traffic-related air pollutants as a risk factor for the development of new asthma......The background for the project is that traffic-related air pollution may provoke the onset of asthma. The objective of this pilot study is to investigate the relation between asthma and wheeze debut and individually estimated exposure to traffic-related air pollutants with a validated exposure...... successfully identified for all study participants (N=33). Using AirGIS traffic-related air pollutant levels from both urban background and street level were estimated for the 10 year study period on an hourly basis. Individual levels of air pollutants in the years preceding debut of asthma or wheeze were...

  3. Routing protocol of wireless sensor networks for traffic flow statistics%无线传感器网络车流量统计的路由协议

    Institute of Scientific and Technical Information of China (English)

    任秀丽; 谭振江

    2012-01-01

    提出了一种应用于交通管理中心统计道路车流量的路由协议,以便更好地进行交通管理.根据无线传感器网络能量有限的特点和具体应用的需求,在路由表中添加了车辆在检测区域内的有效时间,动态控制了中间节点是否转发信息,避免了基站接收无用信息,减少了节点的能量消耗.提出了一种节点唤醒策略,有效地提高了车流量统计应用中对目标追踪的质量.仿真实验表明:与AODV协议和TSR协议相比,延长了网络生存周期.%Routing protocol for traffic flow statistics is proposed to adapt for traffic management. Because of limited energy of wireless sensor networks and requirement of practical application, effective time of the vehicles in the detection region is added in the routing table in order to dynamicly control whether the middle node retransmits the message and to avoid the base station receiving useless information and the energy consumption of node is reduced. A wake-up strategy of nodes is proposed to improve the quality of the target tracking for traffic flow statistic. The simulation results show that the protocol prolongs the network lifetime compared with AODV and TSR protocols.

  4. Stability analysis of traffic flow with extended CACC control models

    Science.gov (United States)

    Ya-Zhou, Zheng; Rong-Jun, Cheng; Siu-Ming, Lo; Hong-Xia, Ge

    2016-06-01

    To further investigate car-following behaviors in the cooperative adaptive cruise control (CACC) strategy, a comprehensive control system which can handle three traffic conditions to guarantee driving efficiency and safety is designed by using three CACC models. In this control system, some vital comprehensive information, such as multiple preceding cars’ speed differences and headway, variable safety distance (VSD) and time-delay effect on the traffic current and the jamming transition have been investigated via analytical or numerical methods. Local and string stability criterion for the velocity control (VC) model and gap control (GC) model are derived via linear stability theory. Numerical simulations are conducted to study the performance of the simulated traffic flow. The simulation results show that the VC model and GC model can improve driving efficiency and suppress traffic congestion. Project supported by the National Natural Science Foundation of China (Grant Nos. 71571107 and 11302110). The Scientific Research Fund of Zhejiang Province, China (Grant Nos. LY15A020007, LY15E080013, and LY16G010003). The Natural Science Foundation of Ningbo City (Grant Nos. 2014A610030 and 2015A610299), the Fund from the Government of the Hong Kong Administrative Region, China (Grant No. CityU11209614), and the K C Wong Magna Fund in Ningbo University, China.

  5. Measurement of black carbon concentration as an indicator of air quality benefits of traffic restriction policies within the ecopass zone in Milan, Italy

    Science.gov (United States)

    Invernizzi, Giovanni; Ruprecht, Ario; Mazza, Roberto; De Marco, Cinzia; Močnik, Griša; Sioutas, Costantinos; Westerdahl, Dane

    2011-07-01

    Traffic restrictions are an unpopular tool to mitigate urban air pollution, and a measurable improvement in air quality is needed to demonstrate the effectiveness of this measure. Previous attempts failed to detect measurable reductions of PM mass pollution within the areas subject to traffic restriction. However black carbon, which is emitted primarily by traffic sources, could be a PM metric more suitable than PM mass to demonstrate pollutant reductions. In this study we report the results of a black carbon monitoring campaign carried out in Milan, Italy, with the aim to detect - and demonstrate more suitably than PM mass - differences in local urban air quality among three zones located very closely with different traffic intensity. The study was carried out in three different days by measuring simultaneously black carbon and PM mass concentrations with fixed monitoring stations located in three main radial roads connecting the outskirts to the city center, each with three segments: 1) an outer one, with no traffic restrictions 2) an intermediate one, subject to the congestion traffic charge called "Ecopass", where a ticket is required to enter for cars equipped with engines prior to Euro 4 standard; 3) the pedestrian zone (no cars admitted) of Duomo Square in the city center, where each of the three main roads ends. The results demonstrated a sharply declining gradient in black carbon levels from the outer zone, without traffic restrictions, to the more central areas, for all of the three radial main roads. The differences in mean black carbon levels in the same day in the different traffic scheme locations were highly significant for each comparison. In contrast to the Black carbon results, mean PM 10, PM 2.5, PM 1 concentrations did not show significant differences among the different traffic zones on the different campaign days. The ratio of black carbon to PM 10 decreased by 47% and 62% in the Ecopass zone and in the pedestrian zone, respectively, as

  6. Air pollution from traffic and risk for lung cancer in three Danish cohorts

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Bak, Helle; Sørensen, Mette;

    2010-01-01

    BACKGROUND: Air pollution is suspected to cause lung cancer. The purpose was to investigate whether the concentration of nitrogen oxides (NOx) at the residence, used as an indicator of air pollution from traffic, is associated with risk for lung cancer. METHODS: We identified 679 lung cancer case...... and the risk for lung cancer. IMPACT: This study points at traffic as a source of carcinogenic air pollution and stresses the importance of strategies for reduction of population exposure to traffic-related air pollution.......BACKGROUND: Air pollution is suspected to cause lung cancer. The purpose was to investigate whether the concentration of nitrogen oxides (NOx) at the residence, used as an indicator of air pollution from traffic, is associated with risk for lung cancer. METHODS: We identified 679 lung cancer cases...... in the Danish Cancer Registry from the members of three prospective cohorts and selected a comparison group of 3,481 persons from the same cohorts in a case-cohort design. Residential addresses from January 1, 1971, were traced in the Central Population Registry. The NOx concentration at each address...

  7. Influence of road traffic, residential heating and meteorological conditions on PM10 concentrations during air pollution critical episodes.

    Science.gov (United States)

    Gualtieri, Giovanni; Toscano, Piero; Crisci, Alfonso; Di Lonardo, Sara; Tartaglia, Mario; Vagnoli, Carolina; Zaldei, Alessandro; Gioli, Beniamino

    2015-12-01

    The importance of road traffic, residential heating and meteorological conditions as major drivers of urban PM10 concentrations during air pollution critical episodes has been assessed in the city of Florence (Italy) during the winter season. The most significant meteorological variables (wind speed and atmospheric stability) explained 80.5-85.5% of PM10 concentrations variance, while a marginal role was played by major emission sources such as residential heating (12.1%) and road traffic (5.7%). The persistence of low wind speeds and unstable atmospheric conditions was the leading factor controlling PM10 during critical episodes. A specific PM10 critical episode was analysed, following a snowstorm that caused a "natural" scenario of 2-day dramatic road traffic abatement (-43%), and a massive (up to +48%) and persistent (8 consecutive days) increase in residential heating use. Even with such a strong variability in local PM10 emissions, the role of meteorological conditions was prominent, revealing that short-term traffic restrictions are insufficient countermeasures to reduce the health impacts and risks of PM10 critical episodes, while efforts should be made to anticipate those measures by linking them with air quality and weather forecasts.

  8. Dynamic one-way traffic control in automated transportation systems

    NARCIS (Netherlands)

    Ebben, M; van der Zee, DJ

    2004-01-01

    In a project on underground freight transportation using Automated Guided Vehicles, single lanes for traffic in two directions are constructed to reduce infrastructure investment. Intelligent control rules are required to manage vehicle flows such, that collision is avoided and waiting times are min

  9. Model based monitoring for industrial and traffic noise control

    NARCIS (Netherlands)

    Eerden, F.J.M. van der; Binnerts, B.; Graafland, F.

    2015-01-01

    Noise control starts by understanding the actual noise situation. Especially for situations where the distance between industrial and traffic noise sources and a local community is in the order of one kilometer or more, it may not be clear what sources are the main contributors to annoyance. Then a

  10. Automatic speed control of highway traffic

    Science.gov (United States)

    Klingman, E. E.

    1973-01-01

    Vehicle control system monitors all vehicles in its range, and automatically slows down speeding vehicles by activating governor in vehicle. System determines only maximum speed; speeds below maximum are controlled by vehicle operator. Loss of transmitted signal or activation of emergency over-ride will open fuel line and return control to operator.

  11. Heavy traffic on a controlled motorway

    CERN Document Server

    Kelly, F P

    2010-01-01

    Unlimited access to a motorway network can, in overloaded conditions, cause a loss of capacity. Ramp metering (signals on slip roads to control access to the motorway) can help avoid this loss of capacity. The design of ramp metering strategies has several features in common with the design of access control mechanisms in communication networks. Inspired by models and rate control mechanisms developed for Internet congestion control, we propose a Brownian network model as an approximate model for a controlled motorway and consider it operating under a proportionally fair ramp metering policy.We present an analysis of the performance of this model.

  12. Constrained optimal steady-state control for isolated traffic intersections

    Institute of Scientific and Technical Information of China (English)

    Jack HADDAD; David MAHALEL; Ilya IOSLOVICH; Per-Olof GUTMAN

    2014-01-01

    The steady-state or cyclic control problem for a simplified isolated traffic intersection is considered. The optimization problem for the green-red switching sequence is formulated with the help of a discrete-event max-plus model. Two steady-state control problems are formulated: optimal steady-state with green duration constraints, and optimal steady-state control with lost time. In the case when the criterion is a strictly increasing, linear function of the queue lengths, the steady-state control problems can be solved analytically. The structure of constrained optimal steady-state traffic control is revealed, and the effect of the lost time on the optimal solution is illustrated.

  13. Urban Intersection Traffic Signal Control Based on Fuzzy Logic

    Institute of Scientific and Technical Information of China (English)

    魏武; 张毅; 张佐; 宋靖雁

    2002-01-01

    This paper presents a fuzzy logic adaptive traffic signal control method for an isolated four-approach intersection with through and left-turning movements. In the proposed method, the fuzzy logic controller can make adjustments to signal timing in response to observed changes. The "urgency degree" term that can describe different user's demands for a green light is used in the fuzzy logic decision-making. In addition, a three-level fuzzy controller model decides whether to extend or terminate the current signal phase and the sequence of phases. Simulation results show that the fuzzy controller can adjust its signal timing in response to changing traffic conditions on a real-time basis and that the proposed fuzzy logic controller leads to less vehicle delays and a lower percentage of stopped vehicles.

  14. Clean air matters: an overview of traffic-related air pollution and pregnancy

    Science.gov (United States)

    Slovic, Anne Dorothée; Diniz, Carmen Simone; Ribeiro, Helena

    2017-01-01

    ABSTRACT The right to a healthy pregnancy and to giving birth in a safe environment is source of comprehensive research. Decent birth facilities, respect, and no discrimination are already recognized as fundamental rights, but an accurate look at the outdoor environment is required. Air pollution is a dangerous factor to pregnant women and newborns, many of whom highly exposed to traffic-related atmospheric pollutants in urban areas. Such exposure can lead to low birth weight and long-lasting effects, such as respiratory diseases and premature death. Thus, this commentary, based on the analysis of literature, presents the importance of the exposome concept and of epigenetics in identifying the role of the environment for better health conditions of pregnant women and newborns. In the final considerations, this study proposes the deepening of the subject and the mobilization in this regard, with a human rights-based approach to environmental health and to the increased awareness of pregnant women on the risks of air pollution and its effects on health. PMID:28225911

  15. Intelligent Control in Automation Based on Wireless Traffic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kurt Derr; Milos Manic

    2007-08-01

    Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

  16. Intelligent Control in Automation Based on Wireless Traffic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kurt Derr; Milos Manic

    2007-09-01

    Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

  17. The relevance of commuter and work/school exposure in an epidemiological study on traffic-related air pollution.

    Science.gov (United States)

    Ragettli, Martina S; Phuleria, Harish C; Tsai, Ming-Yi; Schindler, Christian; de Nazelle, Audrey; Ducret-Stich, Regina E; Ineichen, Alex; Perez, Laura; Braun-Fahrländer, Charlotte; Probst-Hensch, Nicole; Künzli, Nino

    2015-01-01

    Exposure during transport and at non-residential locations is ignored in most epidemiological studies of traffic-related air pollution. We investigated the impact of separately estimating NO2 long-term outdoor exposures at home, work/school, and while commuting on the association between this marker of exposure and potential health outcomes. We used spatially and temporally resolved commuter route data and model-based NO2 estimates of a population sample in Basel, Switzerland, to assign individual NO2-exposure estimates of increasing complexity, namely (1) home outdoor concentration; (2) time-weighted home and work/school concentrations; and (3) time-weighted concentration incorporating home, work/school and commute. On the basis of their covariance structure, we estimated the expectable relative differences in the regression slopes between a quantitative health outcome and our measures of individual NO2 exposure using a standard measurement error model. The traditional use of home outdoor NO2 alone indicated a 12% (95% CI: 11-14%) underestimation of related health effects as compared with integrating both home and work/school outdoor concentrations. Mean contribution of commuting to total weekly exposure was small (3.2%; range 0.1-13.5%). Thus, ignoring commute in the total population may not significantly underestimate health effects as compared with the model combining home and work/school. For individuals commuting between Basel-City and Basel-Country, ignoring commute may produce, however, a significant attenuation bias of 4% (95% CI: 4-5%). Our results illustrate the importance of including work/school locations in assessments of long-term exposures to traffic-related air pollutants such as NO2. Information on individuals' commuting behavior may further improve exposure estimates, especially for subjects having lengthy commutes along major transportation routes.

  18. Short-Term Memory, Executive Control, and Children's Route Learning

    Science.gov (United States)

    Purser, Harry R. M.; Farran, Emily K.; Courbois, Yannick; Lemahieu, Axelle; Mellier, Daniel; Sockeel, Pascal; Blades, Mark

    2012-01-01

    The aim of this study was to investigate route-learning ability in 67 children aged 5 to 11 years and to relate route-learning performance to the components of Baddeley's model of working memory. Children carried out tasks that included measures of verbal and visuospatial short-term memory and executive control and also measures of verbal and…

  19. Routing and admission control in general topology networks with poisson arrivals

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, A.; Palmon, O.; Plotkin, S. [Stanford Univ., CA (United States)

    1996-12-31

    Emerging high speed networks will carry traffic for services such as video-on-demand and video teleconferencing - that require resource reservation along the path on which the traffic is sent. High bandwidth-delay product of these networks prevents circuit rerouting, i.e. once it is routed on a certain path, the bandwidth a circuit taken by this circuit remains unavailable for the duration (holding time) of this circuit. As a result, such networks will need effective routing and admission control strategies. Recently developed online routing and admission control strategies have logarithmic competitive ratios with respect to the admission ratio (the fraction of admitted circuits). Such guarantees on performance are rather weak in the most interesting case where the rejection ratio of the optimum algorithm is very small or even 0. Unfortunately, these guarantees can not be improved in the context of the considered models, making it impossible to use these models to identify algorithms that are going to perform well in practice.

  20. Traffic Congestion Evaluation and Signal Control Optimization Based on Wireless Sensor Networks: Model and Algorithms

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2012-01-01

    Full Text Available This paper presents the model and algorithms for traffic flow data monitoring and optimal traffic light control based on wireless sensor networks. Given the scenario that sensor nodes are sparsely deployed along the segments between signalized intersections, an analytical model is built using continuum traffic equation and develops the method to estimate traffic parameter with the scattered sensor data. Based on the traffic data and principle of traffic congestion formation, we introduce the congestion factor which can be used to evaluate the real-time traffic congestion status along the segment and to predict the subcritical state of traffic jams. The result is expected to support the timing phase optimization of traffic light control for the purpose of avoiding traffic congestion before its formation. We simulate the traffic monitoring based on the Mobile Century dataset and analyze the performance of traffic light control on VISSIM platform when congestion factor is introduced into the signal timing optimization model. The simulation result shows that this method can improve the spatial-temporal resolution of traffic data monitoring and evaluate traffic congestion status with high precision. It is helpful to remarkably alleviate urban traffic congestion and decrease the average traffic delays and maximum queue length.

  1. Traffic air pollution and mortality from cardiovascular disease and all causes: a Danish cohort study

    Directory of Open Access Journals (Sweden)

    Raaschou-Nielsen Ole

    2012-09-01

    Full Text Available Abstract Background Traffic air pollution has been linked to cardiovascular mortality, which might be due to co-exposure to road traffic noise. Further, personal and lifestyle characteristics might modify any association. Methods We followed up 52 061 participants in a Danish cohort for mortality in the nationwide Register of Causes of Death, from enrollment in 1993–1997 through 2009, and traced their residential addresses from 1971 onwards in the Central Population Registry. We used dispersion-modelled concentration of nitrogen dioxide (NO2 since 1971 as indicator of traffic air pollution and used Cox regression models to estimate mortality rate ratios (MRRs with adjustment for potential confounders. Results Mean levels of NO2 at the residence since 1971 were significantly associated with mortality from cardiovascular disease (MRR, 1.26; 95% confidence interval [CI], 1.06–1.51, per doubling of NO2 concentration and all causes (MRR, 1.13; 95% CI, 1.04–1.23, per doubling of NO2 concentration after adjustment for potential confounders. For participants who ate  Conclusions Traffic air pollution is associated with mortality from cardiovascular diseases and all causes, after adjustment for traffic noise. The association was strongest for people with a low fruit and vegetable intake.

  2. Location-routing Problem with Fuzzy time windows and Traffic time

    Directory of Open Access Journals (Sweden)

    Shima Teimoori

    2014-05-01

    Full Text Available The location-routing problem is a relatively new branch of logistics system. Its objective is to determine a suitable location for constructing distribution warehouses and proper transportation routing from warehouse to the customer. In this study, the location-routing problem is investigated with considering fuzzy servicing time window for each customer. Another important issue in this regard is the existence of congested times during the service time and distributing goods to the customer. This caused a delay in providing service for customer and imposed additional costs to distribution system. Thus we have provided a mathematical model for designing optimal distributing system. Since the vehicle location-routing problem is Np-hard, thus a solution method using genetic meta-heuristic algorithm was developed and the optimal sequence of servicing for the vehicle and optimal location for the warehouses were determined through an example.

  3. Simple Models for Airport Delays During Transition to a Trajectory-Based Air Traffic System

    Science.gov (United States)

    Brooker, Peter

    It is now widely recognised that a paradigm shift in air traffic control concepts is needed. This requires state-of-the-art innovative technologies, making much better use of the information in the air traffic management (ATM) system. These paradigm shifts go under the names of NextGen in the USA and SESAR in Europe, which inter alia will make dramatic changes to the nature of airport operations. A vital part of moving from an existing system to a new paradigm is the operational implications of the transition process. There would be business incentives for early aircraft fitment, it is generally safer to introduce new technologies gradually, and researchers are already proposing potential transition steps to the new system. Simple queuing theory models are used to establish rough quantitative estimates of the impact of the transition to a more efficient time-based navigational and ATM system. Such models are approximate, but they do offer insight into the broad implications of system change and its significant features. 4D-equipped aircraft in essence have a contract with the airport runway and, in return, they would get priority over any other aircraft waiting for use of the runway. The main operational feature examined here is the queuing delays affecting non-4D-equipped arrivals. These get a reasonable service if the proportion of 4D-equipped aircraft is low, but this can deteriorate markedly for high proportions, and be economically unviable. Preventative measures would be to limit the additional growth of 4D-equipped flights and/or to modify their contracts to provide sufficient space for the non-4D-equipped flights to operate without excessive delays. There is a potential for non-Poisson models, for which there is little in the literature, and for more complex models, e.g. grouping a succession of 4D-equipped aircraft as a batch.

  4. Long-term personal exposure to traffic-related air pollution among school children, a validation study.

    NARCIS (Netherlands)

    Roosbroeck, Sofie van; Wichmann, Janine; Janssen, Nicole A H; Hoek, Gerard; Wijnen, Joop H van; Lebret, Erik; Brunekreef, Bert

    2006-01-01

    Several recent studies suggest an association between long-term exposure to traffic-related air pollution and health. Most studies use indicators of exposure such as outdoor air pollution or traffic density on the street of residence. Little information is available about the validity of these measu

  5. Dispersion Modeling of Traffic-Related Air Pollutant Exposures and Health Effects among Children with Asthma in Detroit, Michigan

    Science.gov (United States)

    Vehicular traffic is a major source of ambient air pollution in urban areas, and traffic-related air pollutants, including carbon monoxide, nitrogen oxides, particulate matter under 2.5 microns in diameter (PM2.5) and diesel exhaust emissions, have been associated with...

  6. 76 FR 17473 - Twelfth Meeting: RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data...

    Science.gov (United States)

    2011-03-29

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 214: Working Group 78: Standards...: Notice of RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data Communication... Committee 214: Working Group 78: Standards for Air Traffic Data Communication Services. DATES: The...

  7. 75 FR 20423 - Tenth Meeting: RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data...

    Science.gov (United States)

    2010-04-19

    ... Federal Aviation Administration Tenth Meeting: RTCA Special Committee 214: Working Group 78: Standards for...: Notice of RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data Communication... Committee 214: Working Group 78: Standards for Air Traffic Data Communication Services. DATES: The...

  8. 75 FR 66828 - Eleventh Meeting: RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data...

    Science.gov (United States)

    2010-10-29

    ... Federal Aviation Administration Eleventh Meeting: RTCA Special Committee 214: Working Group 78: Standards...: Notice of RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data Communication... Committee 214: Working Group 78: Standards for Air Traffic Data Communication Services. DATES: The...

  9. 76 FR 58078 - Thirteenth Meeting: RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data...

    Science.gov (United States)

    2011-09-19

    ... Federal Aviation Administration Thirteenth Meeting: RTCA Special Committee 214: Working Group 78.... ACTION: Notice of RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data... Special Committee 214: Working Group 78: Standards for Air Traffic Data Communication Services. DATES:...

  10. Modeling personal exposure to traffic related air pollutants

    NARCIS (Netherlands)

    Montagne, D.R.

    2015-01-01

    The first part of this thesis is about the VE3SPA project. Land use regression (LUR) models are often used to predict the outdoor air pollution at the home address of study participants, to study long-term effects of air pollution. While several studies have documented that PM2.5 mass measured at a

  11. 75 FR 74128 - Manual on Uniform Traffic Control Devices (MUTCD) Compliance Dates

    Science.gov (United States)

    2010-11-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Highway Administration Manual on Uniform Traffic Control Devices (MUTCD) Compliance Dates AGENCY... control devices to comply with certain requirements established in the Manual on Uniform Traffic...

  12. Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode.

    Science.gov (United States)

    Zhou, Kang; He, Shiwei; Song, Rui

    2016-01-01

    Service routes optimization (SRO) of pallet service center should meet customers' demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP) and Chinese postman problem (CPP), but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling) operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case.

  13. Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode

    Directory of Open Access Journals (Sweden)

    Kang Zhou

    2016-01-01

    Full Text Available Service routes optimization (SRO of pallet service center should meet customers’ demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP and Chinese postman problem (CPP, but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case.

  14. Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode

    Science.gov (United States)

    He, Shiwei; Song, Rui

    2016-01-01

    Service routes optimization (SRO) of pallet service center should meet customers' demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP) and Chinese postman problem (CPP), but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling) operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case. PMID:27528865

  15. TAF7: traffic controller in transcription initiation.

    Science.gov (United States)

    Gegonne, Anne; Devaiah, Ballachanda N; Singer, Dinah S

    2013-01-01

    TAF7, a component of the TFIID complex, controls the first steps of transcription. It interacts with and regulates the enzymatic activities of transcription factors that regulate RNA polymerase II progression. Its diverse functions in transcription initiation are consistent with its essential role in cell proliferation.

  16. Controlled traffic and soil physical quality of an Oxisol under sugarcane cultivation

    Directory of Open Access Journals (Sweden)

    Gustavo Soares de Souza

    2015-06-01

    Full Text Available Machinery traffic in sugarcane (Saccharumsp. plantations reduces soil physical quality, and hinders both root development and crop yield. We evaluated the physical quality of an Oxisol and the development of sugarcane roots under controlled traffic. The treatments assessed were: without controlled machinery traffic (WCT, controlled traffic by adjusting the tractor and infield wagons to a 3.0 m track width with the operator guiding the machinery (CT1 and the previous treatment using real time kinematic / global positioning system (RTK / GPS precision auto steer (CT2. Soil samples were collected from the planting rows, seedbed and inter-row center to determine the least limiting water range (LLWR and soil porosity from scanned 2-D images. The root dry mass was sampled from monoliths, separated from the soil by washing through a 2-mm sieve and dried in an oven. A higher LLWR was observed in the planting row under CT1 and CT2 than under WCT. The planting row had a predominance of complex pores with a diameter > 500 µm in the 0.15-0.27 m depth layer under CT1 and CT2. In the planting rows under WCT, the root dry mass was only 44 % of that measured under CT2. Benefits regarding soil physical quality and growth roots were observed when the tractor-wagon track width was adjusted based on the sugarcane spacing using either precision auto steering or manual operation of the machinery.

  17. A Control Method for Congested Traffic in the Car-Following Model

    Science.gov (United States)

    Ge, Hong-Xia; Yu, Jian; Lo, Siu-Ming

    2012-05-01

    A simple control method to suppress traffic congestion is proposed for the car-following model. The stability conditions are derived by using the control method, and the feedback signals, which act on our traffic system, are extended to the car-following model. The control signals will play an effect only if the traffic is congested. The corresponding numerical simulation results agree well with our theoretical analysis, and our control method can successfully suppress traffic jams.

  18. "To Control Tibet, First Pacify Kham": Trade Routes and "Official Routes" (Guandao in Easternmost Kham

    Directory of Open Access Journals (Sweden)

    Patrick Booz

    2016-06-01

    Full Text Available This article focuses on the trade routes in the western Sichuan borderlands that facilitated contact and trade between Chinese counties and Eastern Tibet. In particular, the article offers a description of “official routes” (guandao—which the Chinese emperor twice proclaimed to be the vital mode of access between China and Tibet—from Chengdu, Sichuan’s provincial capital, to Khampa areas, with Lhasa as the final destination. The exchange of goods in this region followed various routes during different periods. From the tenth to sixteenth centuries, transactions occurred primarily along the borders of Amdo (Tib. A mdo, Northeastern Tibet, but for political, economic, and practical reasons, such exchanges became more limited geographically and eventually focused along the Sichuan–Kham/Ngawa border. Many routes shifted to the towns of Kangding (Tib. Dartsedo and Songpan (Tib. Zungchu, the main sites of distribution, where rich opportunities for trade and a strictly limiting transport geography made them important entrepôts that evolved into centers of prosperity. The geographic range of this article reaches to these two towns and leaves the investigation of the routes that led to western centers such as Derge, Batang, Chamdo, and Jyekundo for future research.

  19. Urban Traffic Signal System Control Structural Optimization Based on Network Analysis

    Directory of Open Access Journals (Sweden)

    Li Wang

    2013-01-01

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

  20. Cardiovascular effects of road traffic noise with adjustment for air pollution

    NARCIS (Netherlands)

    Kluizenaar, Y. de; Miedema, H.M.E.; Gansevoort, R.T.; Jong, P.E. de

    2007-01-01

    This study investigates cardiovascular effects of road traffic noise, accounting for air pollution. Noise and particulate matter (PM10) exposure was assessed for the City of Groningen sample (N = 40 856), and a selection of subjects that next visited the outpatient clinic (PREVEND cohort; N = 8 592)

  1. Effect of geocoding errors on traffic-related air pollutant exposure and concentration estimates

    Science.gov (United States)

    Exposure to traffic-related air pollutants is highest very near roads, and thus exposure estimates are sensitive to positional errors. This study evaluates positional and PM2.5 concentration errors that result from the use of automated geocoding methods and from linearized approx...

  2. INFLUENCE THE SESAR CONCEPT UPON AIR TRAFFIC SERVICES IN EUROPEAN REGION

    Directory of Open Access Journals (Sweden)

    Yuriy Chynchenko

    2011-03-01

    Full Text Available Abstract. The article deals with the analysis of the researches conducted in field of the SESAR concept.Benefits of the concept, work packages and stakeholders of SESAR joint undertake have been reviewed.Principles of implementation and impact on air traffic services system have been analysed and generalsolutions appropriable for Ukraine have been proposed.

  3. Effect of traffic air pollution on spirometeric parameters in Eastern Uttar Pradesh population, India

    OpenAIRE

    Vinay Singh; Devesh Kumar; Farhat Ali; Gaurav Kumar

    2016-01-01

    Background: In the present era of the 21st century there are lots of discussion on environmental population and its impact on life and various clinical studies done to find out the effect of air pollution on respiratory physiology, particularly pulmonary functions. Pulmonary function tests give valuable information about lung physiology in health and disease. In the present study to assess the pulmonary function test between the population groups exposed to traffic related air pollution. ...

  4. Controlling traffic jams by time modulating the safety distance

    Science.gov (United States)

    Gaididei, Yu. B.; Gorria, C.; Berkemer, R.; Kawamoto, A.; Shiga, T.; Christiansen, P. L.; Sørensen, M. P.; Starke, J.

    2013-10-01

    The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case. This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well separated. A link between a microscopic description and the macroscopic fundamental diagram is established.

  5. Vehicular Traffic Optimization in VANETs: a Proposal for Nodes Re-routing and Congestion Reduction

    Directory of Open Access Journals (Sweden)

    Mauro Tropea

    2015-01-01

    Full Text Available Recently, vehicular networking has grown up in terms of interest and transmission capability, due to the possibility of exploiting the distributed communication paradigm in a mobile scenario, where moving nodes are represented by vehicles. In this paper, we focus our attention on the optimization of traffic flowing in a vehicular environment with vehicle-roadside capability. As shown in the next sections, the proposed idea exploits the information that is gathered by road-side units with the main aim of redirecting traffic flows (in terms of vehicles to less congested roads, with an overall system optimization, also in terms of Carbon Dioxide emissions reduction. A deep campaign of simulations has been carried out to give more effectiveness to our proposal.

  6. Human resources for the control of road traffic injury.

    Science.gov (United States)

    Mock, Charles; Kobusingye, Olive; Anh, Le Vu; Afukaar, Francis; Arreola-Risa, Carlos

    2005-04-01

    The definition of the ideal numbers and distribution of human resources required for control of road traffic injury (RTI) is not as advanced as for other health problems. We can nonetheless identify functions that need to be addressed across the spectrum of injury control: surveillance; road safety (including infrastructure, vehicle design, and behaviour); and trauma care. Many low-cost strategies to improve these functions in low- or middle-income countries can be identified. For all these strategies, there is need for adequate institutional capacity, including funding, legal authority, and human resources. Several categories of human resources need to be developed: epidemiologists who can handle injury data, design surveillance systems, and undertake research; engineers and planners versed in safety aspects of road design, traffic flow, urban planning, and vehicle design; police and lawyers who understand the health impact of traffic law; clinicians who can develop cost-effective improvements in the entire system of trauma treatment; media experts to undertake effective behaviour change and social marketing; and economists to assist with cost-effectiveness evaluations. RTI control can be strengthened by enhancing such training in these disciplines, as well as encouraging retention of those who have the needed skills. Mechanisms to enhance collaboration between these different fields need to be promoted. Finally, the burden of RTI is borne disproportionately by the poor; in addition to technical issues, more profound equity issues must be addressed. This mandates that people from all professional backgrounds who work for RTI control should develop skills in advocacy and politics.

  7. Combination of vehicle routing models and dynamic traffic simulation for city logistics applications

    OpenAIRE

    Grzybwska, Hanna

    2012-01-01

    The urban network is a highly dynamic system. Thus, a modern and efficient fleet management in urban areas should account for dynamics of traffic conditions, variability in travel times, changes in demand and fleet availability. All these factors significantly affect the distribution of goods and the provision of services. As a consequence, the freight operations optimizing approaches should be based on the time-dependent travel time estimates rather than on the average static values commonly...

  8. Effects of traffic control on the soil physical quality and the cultivation of sugarcane

    Directory of Open Access Journals (Sweden)

    Gustavo Soares de Souza

    2014-02-01

    Full Text Available The cultivation of sugarcane with intensive use of machinery, especially for harvest, induces soil compaction, affecting the crop development. The control of agricultural traffic is an alternative of management in the sector, with a view to preserve the soil physical quality, resulting in increased sugarcane root growth, productivity and technological quality. The objective of this study was to evaluate the physical quality of an Oxisol with and without control traffic and the resulting effects on sugarcane root development, productivity and technological quality. The following managements were tested: no traffic control (NTC, traffic control consisting of an adjustment of the track width of the tractor and sugarcane trailer (TC1 and traffic control consisting of an adjustment of the track width of the tractor and trailer and use of an autopilot (TC2. Soil samples were collected (layers 0.00-0.10; 0.10-0.20 and 0.20-0.30 m in the plant rows, inter-row center and seedbed region, 0.30 m away from the plant row. The productivity was measured with a specific weighing scale. The technological variables of sugarcane were measured in each plot. Soil cores were collected to analyze the root system. In TC2, the soil bulk density and compaction degree were lowest and total porosity and macroporosity highest in the plant row. Soil penetration resistance in the plant row, was less than 2 MPa in TC1 and TC2. Soil aggregation and total organic carbon did not differ between the management systems. The root surface and volume were increased in TC1 and TC2, with higher productivity and sugar yield than under NTC. The sugarcane variables did not differ between the managements. The soil physical quality in the plant row was preserved under management TC1 and TC2, with an improved root development and increases of 18.72 and 20.29 % in productivity and sugar yield, respectively.

  9. Center for Intelligent Control Systems

    Science.gov (United States)

    1992-12-01

    CENTER FOR INTELLIGENT CONTROL SYSTEMS Brown Umiversity Harvard University Marsachomtta Institute of Tecnology PUBLICATIONS LIST CICS Number Authors...Equivalence of the Auction Algorithm for 11/1/92 Assignment and die e-Relaxation (Preflow- Push ) Method for Min Cost Flow 26

  10. Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter in Venice air.

    Science.gov (United States)

    Gregoris, Elena; Barbaro, Elena; Morabito, Elisa; Toscano, Giuseppa; Donateo, Antonio; Cesari, Daniela; Contini, Daniele; Gambaro, Andrea

    2016-04-01

    Harbours are important hubs for economic growth in both tourism and commercial activities. They are also an environmental burden being a source of atmospheric pollution often localized near cities and industrial complexes. The aim of this study is to quantify the relative contribution of maritime traffic and harbour activities to atmospheric pollutant concentration in the Venice lagoon. The impact of ship traffic was quantified on various pollutants that are not directly included in the current European legislation for shipping emission reduction: (i) gaseous and particulate PAHs; (ii) metals in PM10; and (iii) PM10 and PM2.5. All contributions were correlated with the tonnage of ships during the sampling periods and results were used to evaluate the impact of the European Directive 2005/33/EC on air quality in Venice comparing measurements taken before and after the application of the Directive (year 2010). The outcomes suggest that legislation on ship traffic, which focused on the issue of the emissions of sulphur oxides, could be an efficient method also to reduce the impact of shipping on primary particulate matter concentration; on the other hand, we did not observe a significant reduction in the contribution of ship traffic and harbour activities to particulate PAHs and metals. Graphical abstract Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter and evaluation of the effect of an European Directive on air quality in Venice.

  11. Fuzzy Logic in Traffic Engineering: A Review on Signal Control

    Directory of Open Access Journals (Sweden)

    Milan Koukol

    2015-01-01

    Full Text Available Since 1965 when the fuzzy logic and fuzzy algebra were introduced by Lotfi Zadeh, the fuzzy theory successfully found its applications in the wide range of subject fields. This is mainly due to its ability to process various data, including vague or uncertain data, and provide results that are suitable for the decision making. This paper aims to provide comprehensive overview of literature on fuzzy control systems used for the management of the road traffic flow at road junctions. Several theoretical approaches from basic fuzzy models from the late 1970s to most recent combinations of real-time data with fuzzy inference system and genetic algorithms are mentioned and discussed throughout the paper. In most cases, fuzzy logic controllers provide considerable improvements in the efficiency of traffic junctions’ management.

  12. Air Traffic Controller Working Memory: Considerations in Air Traffic Control Tactical Operations

    Science.gov (United States)

    1993-09-01

    largely unsubstantiated (Hellige, & Wong, 1983; Klapp, Marshburn, & Lester, 1983; Klapp & Philipoff, 1983; Roediger, Knight, & Kantowitz , 1977). A...psychology (Klapp, Marshburn, & Lester, 1983) and human factors (Adams, 1989; Kantowitz & Sorkin, 1983; Sanders & McCormick, 1987) propose a single, 24...attention and automaticity. Ir R. Parasuraman & R. Davies (Eds.), Varieties at attentioil (pp. 29-61). New York: Academic Press. Kantowitz , B. H. & Sorkin

  13. Mobile phone tracking: in support of modelling traffic-related air pollution contribution to individual exposure and its implications for public health impact assessment.

    Science.gov (United States)

    Liu, Hai-Ying; Skjetne, Erik; Kobernus, Mike

    2013-11-04

    We propose a new approach to assess the impact of traffic-related air pollution on public health by mapping personal trajectories using mobile phone tracking technology in an urban environment. Although this approach is not based on any empirical studies, we believe that this method has great potential and deserves serious attention. Mobile phone tracking technology makes it feasible to generate millions of personal trajectories and thereby cover a large fraction of an urban population. Through analysis, personal trajectories are not only associated to persons, but it can also be associated with vehicles, vehicle type, vehicle speed, vehicle emission rates, and sources of vehicle emissions. Pollution levels can be estimated by dispersion models from calculated traffic emissions. Traffic pollution exposure to individuals can be estimated based on the exposure along the individual human trajectories in the estimated pollution concentration fields by utilizing modelling tools. By data integration, one may identify trajectory patterns of particularly exposed human groups. The approach of personal trajectories may open a new paradigm in understanding urban dynamics and new perspectives in population-wide empirical public health research. This new approach can be further applied to individual commuter route planning, land use planning, urban traffic network planning, and used by authorities to formulate air pollution mitigation policies and regulations.

  14. An Intelligent Traffic Flow Control System Based on Radio Frequency Identification and Wireless Sensor Networks

    OpenAIRE

    Chao, Kuei-Hsiang; Chen, Pi-Yun

    2014-01-01

    This study primarily focuses on the use of radio frequency identification (RFID) as a form of traffic flow detection, which transmits collected information related to traffic flow directly to a control system through an RS232 interface. At the same time, the sensor analyzes and judges the information using an extension algorithm designed to achieve the objective of controlling the flow of traffic. In addition, the traffic flow situation is also transmitted to a remote monitoring control syste...

  15. TCP/IP Communication System for Controlling a Vehicular Traffic Intersection

    Directory of Open Access Journals (Sweden)

    Pedraza-Martínez Luis Fernando

    2013-10-01

    Full Text Available This paper describes the development of a prototype of a vehicular traffic controller, whose system of communication is based on the TCP/IP protocol, in order to re- motely monitor and control the operation of traffic lights for a vehicular intersection. The results show the times of communication between the central and the traffic controller. The conclusions highlight the importance of using the TCP/IP protocol in traffic light systems.

  16. Cooperative Traffic Control based on the Artificial Bee Colony

    Directory of Open Access Journals (Sweden)

    Jinjian Li

    2016-12-01

    Full Text Available This paper studies the traffic control problem in an isolated intersection without traffic lights and phase, because the right-of-way is distributed to each vehicle individually based on connection of the Vehicle-to-Infrastructure (V2I, and the compatible streams are dynamically combined according to the arrival vehicles in each traffic flows. The control objective in the proposed algorithm is to minimize the time delay, which is defined as the difference between the travel time in real state and that in free flow state. In order to realize this target, a cooperative control structure with a two-way communications is proposed. First of all, once the vehicle enters the communication zone, it sends its information to the intersection. Then the passing sequence is optimized in the intersection with the heuristic algorithm of the Artificial Bee Colony, based on the arrival interval of the vehicles. At last, each vehicle plans its speed profile to meet the received passing sequence by V2I. The simulation results show that each vehicle can finish the entire travel trip with a near free flow speed in the proposed method.

  17. The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues de Carvalho, Paulo Victor, E-mail: paulov@ien.gov.br [National Nuclear Energy Commission/Nuclear Engineering Institute, Cidade Universitaria-Ilha do Fundao, Rio de Janeiro, RJ 21945-970 (Brazil)

    2011-11-15

    The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning. - Highlights: > The Functional Resonance Analysis Model (FRAM) was used in a mid-air collision over Amazon. > The aim was to understand key resilience characteristics of the Air Traffic Management System (ATM). > The analysis showed how, under normal conditions, the system was not able to control flight functions. > The findings shed some light about the resilience of Brazilian ATM system operation.

  18. A Systems Dynamics Approach to Explore Traffic Congestion and Air Pollution Link in the City of Accra, Ghana

    Directory of Open Access Journals (Sweden)

    Alex A. N. M. Pappoe

    2010-01-01

    Full Text Available Economic development and urbanization poses myriad challenges to transportation systems in relation to negative externalities such as traffic congestion and environmental health risks. Accra, the capital of Ghana, faces mounting urban planning problems, for example traffic congestion, air pollution, traffic safety, and land use planning, among others. The paper aims to provide a system dynamics perspective of the problems. Most of the drivers and cause-effect relationships of traffic congestion and its attendant air pollution are investigated and analyzed using causal loop diagrams. The paper further suggests mechanisms by which the negative externalities associated with road transport in the city of Accra can be addressed.

  19. Airport Activity Statistics of Certificated Route Air Carriers.

    Science.gov (United States)

    1981-12-31

    CaielailIbIn1kg High Poit. Q ---. - Gronsbors/igh Point/Winston.ahig. BMVt Moolef/Brr. Hollemn AMD N. Mim -- Alfllbdo/Boliimen AID Salida Crosk. KI& -- Kaiaueaoo...Airlins, Inc. 1 Aeromech, Inc. KC 4 2 AK Altair Airlines, Inc. 2 Air California Inc. OC 2 a AL U.S. Air, ie., d&a U.S. Air 8 Air Florida, Inc. QE 2 1>4 AS...OC Air California , Inc. 36 Mid-South Aviation, Inc. VL 4 37 OZ Ozark Air Lines, Inc. 37 Midway Airlines, ic. 1L 3 38 PA Pan American World Airways

  20. Increased micronuclei and bulky DNA adducts in cord blood after maternal exposures to traffic-related air pollution

    DEFF Research Database (Denmark)

    Pedersen, M.; Wichmann, J.; Autrup, H.

    2009-01-01

    Exposure to traffic-related air pollution in urban environment is common and has been associated with adverse human health effects. In utero exposures that result in DNA damage may affect health later in life. Early effects of maternal and in utero exposures to traffic-related air pollution were...... for potential confounders and effect modifiers. For the first time increased bulky DNA adducts and MN in cord blood after maternal exposures to traffic-related air pollution are found, demonstrating that these transplacental environmental exposures induce DNA damage in newborns. Given that increased DNA damage...... umbilical cords, concurrently collected at the time of planned Caesarean section. Modeled residential traffic density, a proxy measure of traffic-related air pollution exposures, was validated by indoor levels of nitrogen dioxide and polycyclic aromatic hydrocarbons in 42 non-smoking homes. DNA adduct...