WorldWideScience

Sample records for air route traffic control centers

  1. 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…

  2. MAMMI Phase1- Collaborative workspaces for en-route air traffic controllers

    OpenAIRE

    Valès, Stéphane; Chatty, Stéphane; Lemort, Alexandre; Conversy, Stéphane

    2006-01-01

    International audience En route control positions put into operation in the last few years are all based on the WIMP (Windows, Icons, Menus, and Pointers) interaction paradigm. Each controller has only one designation mean (a mouse or a trackball) and his/her own screen(s). This technology has a lot of advantages compared to older environments that often relied on paper strips. Nevertheless, this technology has not been able to improve teamwork for ATCOs, because it implies some rigidity c...

  3. 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

  4. Distributed Air Traffic Control Simulator

    Directory of Open Access Journals (Sweden)

    R. Radovanović

    2013-06-01

    Full Text Available During initial training air traffic control students acquire theoretical knowledge in various fields including air traffic management, aircraft performance, air traffic control equipment and systems, navigation and others. This paper proposes a simulator and explains its use and features that allows students to gain a practical insight into their coursework in order to complement their training. The goal of the simulator is to realistically implement all the key functionalities needed to cover the topics that were presented in class. The simulator offers a user friendly, distributed, and multi-role environment that can be deployed on regular PCs. Moreover, this paper discusses and resolves some of the main conceptual and implementational issues that were faced during simulator development.

  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. 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.

  8. 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

  9. 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.

  10. A Cognitive-System Model for En Route Air Traffic Management

    Science.gov (United States)

    Corker, Kevin M.; Pisanich, Gregory; Lebacqz, J. Victor (Technical Monitor)

    1998-01-01

    NASA Ames Research Center has been engaged in the development of advanced air traffic management technologies whose basic form is cognitive aiding systems for air traffic controller and flight deck operations. In the design and evaluation of such systems the dynamic interaction between the airborne aiding system and the ground-based aiding systems forms a critical coupling for control. The human operator is an integral control element in the system and the optimal integration of human decision and performance parameters with those of the automation aiding systems offers a significant challenge to cognitive engineering. This paper presents a study in full mission simulation and the development of a predictive computational model of human performance. We have found that this combination of methodologies provide a powerful design-aiding process. We have extended the computational model Man Machine Integrated Design and Analysis System (N13DAS) to include representation of multiple cognitive agents (both human operators and intelligent aiding systems), operating aircraft airline operations centers and air traffic control centers in the evolving airspace. The demands of this application require the representation of many intelligent agents sharing world-models, and coordinating action/intention with cooperative scheduling of goals and actions in a potentially unpredictable world of operations. The operator's activity structures have been developed to include prioritization and interruption of multiple parallel activities among multiple operators, to provide for anticipation (knowledge of the intention and action of remote operators), and to respond to failures of the system and other operators in the system in situation-specific paradigms. We have exercised this model in a multi-air traffic sector scenario with potential conflict among aircraft at and across sector boundaries. We have modeled the control situation as a multiple closed loop system. The inner and outer

  11. Air Traffic Management Technology Demostration: 1 Research and Procedural Testing of Routes

    Science.gov (United States)

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

    2015-01-01

    NASA's Air Traffic Management Technology Demonstration-1 (ATD-1) will operationally demonstrate the feasibility of efficient arrival operations combining ground-based and airborne NASA technologies. The ATD-1 integrated system consists of the Traffic Management Advisor with Terminal Metering which generates precise time-based schedules to the runway and merge points; Controller Managed Spacing decision support tools which provide controllers with speed advisories and other information needed to meet the schedule; and Flight deck-based Interval Management avionics and procedures which allow flight crews to adjust their speed to achieve precise relative spacing. Initial studies identified air-ground challenges related to the integration of these three scheduling and spacing technologies, and NASA's airborne spacing algorithm was modified to address some of these challenges. The Research and Procedural Testing of Routes human-in-the-loop experiment was then conducted to assess the performance of the new spacing algorithm. The results of this experiment indicate that the algorithm performed as designed, and the pilot participants found the airborne spacing concept, air-ground procedures, and crew interface to be acceptable. However, the researchers concluded that the data revealed issues with the frequency of speed changes and speed reversals.

  12. Effort and Collective Creation: Experience in Air Traffic Control Work

    OpenAIRE

    Alice Itani

    2015-01-01

    How can work also represent a perspective of creation? We start from the hypothesis that air traffic controllers make an effort to cope with very hard work and to develop improvement processes when carrying out the activity, which can be considered creation. Our objective is to analyze the working conditions of air traffic controllers starting from the experience of the controller. There is effort, which is above all both cognitive and physical, of an activity developed with mental representa...

  13. 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...

  14. Traffic-Adaptive Routing

    OpenAIRE

    Kammenhuber, Nils

    2011-01-01

    Despite the bursty and highly volatile traffic, routing in the Internet today is optimised only on coarse time scales, as load-adaptive routing is known to induce performance deterioration by causing massive oscillations. We describe ReplEx, an universally applicable distributed algorithm for dynamic routing/traffic engineering, which is based on game theory. We show through extensive realistic simulations that ReplEx does not oscillate, and that it achieves performance gains comparable to tr...

  15. 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.

  16. 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.

  17. A radome for air traffic control SSR radar systems

    Science.gov (United States)

    A new generation of monopulse and discrete interrogation systems has evolved for air traffic control applications that presents significant challenges to total system design and performance. Reliable operation of the antenna system is essential in today's ever increasing air traffic congestion. An important component of the total system is a radome to protect the antenna from the environment and to enable consistent, reliable electromagnetic performance. The various types of radomes that have been employed over the years to protect antennas are discussed and evaluated relative to the air traffic control radar application. The sandwich radome is selected as the best option and a detailed design analysis is presented which considers the vital characteristics of transmissivity, boresight error, and sidelobe perturbations.

  18. Using eye tracker data in air traffic control

    NARCIS (Netherlands)

    Imants, P.; Greef, T. de

    2011-01-01

    Motivation/Research approach - An exploratory study was conducted to investigate whether eye movement metrics discriminate between different air traffic control tasks. Findings/Design - The results show the three tasks elicit different eye movement, as Yarbus (1967) also showed in static pictures, a

  19. 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.

  20. Design of air traffic control tower at Brnik airport

    OpenAIRE

    Štular, David

    2007-01-01

    Design of air traffic control tower at Brnik airport according to European Standard Eurocode is presented. The structure of tower is a concrete, 106 m high core, supported by 31 m long piles. Calculation of self weight, variable actions, snow and wind load has been examined. The main part of diploma thesis is earthquake analysis. The building belongs to importance class III which determinates the building to be designed for the earthquake with a longer return period as regular ...

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. Benefits Analysis of Multi-Center Dynamic Weather Routes

    Science.gov (United States)

    Sheth, Kapil; McNally, David; Morando, Alexander; Clymer, Alexis; Lock, Jennifer; Petersen, Julien

    2014-01-01

    Dynamic weather routes are flight plan corrections that can provide airborne flights more than user-specified minutes of flying-time savings, compared to their current flight plan. These routes are computed from the aircraft's current location to a flight plan fix downstream (within a predefined limit region), while avoiding forecasted convective weather regions. The Dynamic Weather Routes automation has been continuously running with live air traffic data for a field evaluation at the American Airlines Integrated Operations Center in Fort Worth, TX since July 31, 2012, where flights within the Fort Worth Air Route Traffic Control Center are evaluated for time savings. This paper extends the methodology to all Centers in United States and presents benefits analysis of Dynamic Weather Routes automation, if it was implemented in multiple airspace Centers individually and concurrently. The current computation of dynamic weather routes requires a limit rectangle so that a downstream capture fix can be selected, preventing very large route changes spanning several Centers. In this paper, first, a method of computing a limit polygon (as opposed to a rectangle used for Fort Worth Center) is described for each of the 20 Centers in the National Airspace System. The Future ATM Concepts Evaluation Tool, a nationwide simulation and analysis tool, is used for this purpose. After a comparison of results with the Center-based Dynamic Weather Routes automation in Fort Worth Center, results are presented for 11 Centers in the contiguous United States. These Centers are generally most impacted by convective weather. A breakdown of individual Center and airline savings is presented and the results indicate an overall average savings of about 10 minutes of flying time are obtained per flight.

  6. 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.

  7. Minimizing the Disruptive Effects of Prospective Memory in Simulated Air Traffic Control

    OpenAIRE

    Loft, Shayne; Smith, Rebekah E.; Remington, Roger

    2013-01-01

    Prospective memory refers to remembering to perform an intended action in the future. Failures of prospective memory can occur in air traffic control. In two experiments, we examined the utility of external aids for facilitating air traffic management in a simulated air traffic control task with prospective memory requirements. Participants accepted and handed-off aircraft and detected aircraft conflicts. The prospective memory task involved remembering to deviate from a routine operating pro...

  8. 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

  9. Research on construction of teachers team with internationalization of air traffic control experimental teaching demonstration center%国际化视野下的空管实验教学师资队伍建设

    Institute of Scientific and Technical Information of China (English)

    白鹏; 王婕; 杨新湦; 苗宸源

    2016-01-01

    From the internationalization perspective , taking the national‐level air traffic control experimental teaching demonstration center as an example , this paper analyzes the advantages and disadvantages of the internationalization development of our teaching faculties and puts forward some suggestions and solutions in terms of international philosophy ,talents introduction ,teachers training ,and management mechanism .%基于国际化视野,以中国民航大学空管国家级实验教学示范中心为例,分析了民航空管专业师资国际化发展的需求、条件与不足,从树立国际理念、吸纳精英人才、强化语言培训、创新管理机制等4方面提出了空管师资队伍国际化建设的对策建议。

  10. Auction Mechanism to Allocate Air Traffic Control Slots

    Science.gov (United States)

    Raffarin, Marianne

    2003-01-01

    This article deals with an auction mechanism for airspace slots, as a means of solving the European airspace congestion problem. A disequilibrium, between Air Traffic Control (ATC) services supply and ATC services demand are at the origin of almost one fourth of delays in the air transport industry in Europe. In order to tackle this congestion problem, we suggest modifying both pricing and allocation of ATC services, by setting up an auction mechanism. Objects of the auction will be the right for airlines to cross a part of the airspace, and then to benefit from ATC services over a period corresponding to the necessary time for the crossing. Allocation and payment rules have to be defined according to the objectives of this auction. The auctioneer is the public authority in charge of ATC services, whose aim is to obtain an efficient allocation. Therefore, the social value will be maximized. Another objective is to internalize congestion costs. To that end, we apply the principle of Clarke-Groves mechanism auction: each winner has to pay the externalities imposed on other bidders. The complex context of ATC leads to a specific design for this auction.

  11. 5 CFR 842.405 - Air traffic controllers, firefighters, law enforcement officers, and nuclear materials couriers.

    Science.gov (United States)

    2010-01-01

    ... RETIREMENT SYSTEM-BASIC ANNUITY Computations § 842.405 Air traffic controllers, firefighters, law enforcement... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Air traffic controllers, firefighters, law enforcement officers, and nuclear materials couriers. 842.405 Section 842.405...

  12. Use of Structure as a Basis for Abstraction in Air Traffic Control

    Science.gov (United States)

    Davison, Hayley J.; Hansman, R. John

    2004-01-01

    The safety and efficiency of the air traffic control domain is highly dependent on the capabilities and limitations of its human controllers. Past research has indicated that structure provided by the airspace and procedures could aid in simplifying the controllers cognitive tasks. In this paper, observations, interviews, voice command data analyses, and radar analyses were conducted at the Boston Terminal Route Control (TRACON) facility to determine if there was evidence of controllers using structure to simplify their cognitive processes. The data suggest that controllers do use structure-based abstractions to simplify their cognitive processes, particularly the projection task. How structure simplifies the projection task and the implications of understanding the benefits structure provides to the projection task was discussed.

  13. Characterization of Visual Scanning Patterns in Air Traffic Control.

    Science.gov (United States)

    McClung, Sarah N; Kang, Ziho

    2016-01-01

    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. PMID:27239190

  14. Using Collective Intelligence to Route Internet Traffic

    OpenAIRE

    DAVID H. WOLPERT; Tumer, Kagan; Frank, Jeremy

    1999-01-01

    A COllective INtelligence (COIN) is a set of interacting reinforcement learning (RL) algorithms designed in an automated fashion so that their collective behavior optimizes a global utility function. We summarize the theory of COINs, then present experiments using that theory to design COINs to control internet traffic routing. These experiments indicate that COINs outperform all previously investigated RL-based, shortest path routing algorithms.

  15. Using Collective Intelligence to Route Internet Traffic

    Science.gov (United States)

    Wolpert, David H.; Tumer, Kagan; Frank, Jeremy

    1998-01-01

    A Collective Intelligence (COIN) is a community of interacting reinforcement learning (RL) algorithms designed so that their collective behavior maximizes a global utility function. We introduce the theory of COINs, then present experiments using that theory to design COINs to control internet traffic routing. These experiments indicate that COINs outperform previous RL-based systems for such routing that have previously been investigated.

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

    OpenAIRE

    Arbula, Sandra; Capizzi, Mariagrazia; Lombardo, Nicoletta; Vallesi, Antonino

    2016-01-01

    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 trai...

  17. 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.

  18. 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

  19. 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,...

  20. 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.

  1. 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.

  2. 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.

  3. Air Traffic Control, chess playing and chess programs : lessons to learn

    OpenAIRE

    Alliot, Jean-Marc; Bosc, Jean-François

    1996-01-01

    International audience Air traffic control and chess playing are human cognitive activities that share a large number of characteristics. In this paper, we first discuss similarities of these two activitie; then, using the experience gained in the field of games (and chess) programming, which has encountered numerous excellent results, we try to draw some conclusions on how systems could be designed to improve performance of Air Traffic Control.

  4. 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.

  5. Analysis of Alternative Institutional Arrangements for Reform of U.S. Air Traffic Control

    OpenAIRE

    Lewis, Ira

    2004-01-01

    A considerable amount of New Public Management-oriented research investigates alternative institutional arrangements for provision of services to the public. Some of this work argues in support of service delivery through an increase in outsourcing or by privatization of existing government functions. Air traffic control is provided to aircraft operators using airports and airspace all over the world. This article studies institutional arrangements of provision of air traffic c...

  6. 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,...

  7. Discrete events simulation of a route with traffic lights through automated control in real time

    Directory of Open Access Journals (Sweden)

    Rodrigo César Teixeira Baptista

    2013-03-01

    Full Text Available This paper presents the integration and communication in real-time of a discrete event simulation model with an automatic control system. The simulation model of an intersection with roads having traffic lights was built in the Arena environment. The integration and communication have been made via network, and the control system was operated by a programmable logic controller. Scenarios were simulated for the free, regular and congested traffic situations. The results showed the average number of vehicles that entered in the system and that were retained and also the total average time of the crossing of the vehicles on the road. In general, the model allowed evaluating the behavior of the traffic in each of the ways and the commands from the controller to activation and deactivation of the traffic lights.

  8. Air Traffic Controller Performance and Acceptability of Multiple UAS in a Simulated NAS Environment

    Science.gov (United States)

    Vu, Kim-Phuong L.; Strybel, Thomas; Chiappe, Dan; Morales, Greg; Battiste, Vernol; Shively, Robert Jay

    2014-01-01

    Previously, we showed that air traffic controllers (ATCos) rated UAS pilot verbal response latencies as acceptable when a 1.5 s delay was added to the UAS pilot responses, but a 5 s delay was rated as mostly unacceptable. In the present study we determined whether a 1.5 s added delay in the UAS pilots' verbal communications would affect ATCos interactions with UAS and other conventional aircraft when the number and speed of the UAS were manipulated. Eight radar-certified ATCos participated in this simulation. The ATCos managed a medium altitude sector containing arrival aircraft, en route aircraft, and one to four UAS. The UAS were conducting a surveillance mission and flew at either a "slow" or "fast" speed. We measured both UAS and conventional pilots' verbal communication latencies, and obtained ATCos' acceptability ratings for these latencies. Although the UAS pilot response latencies were longer than those of conventional pilots, the ATCos rated UAS pilot verbal communication latencies to be as acceptable as those of conventional pilots. Because the overall traffic load within the sector was held constant, ATCos only performed slightly worse when multiple UAS were in their sector compared to when only one UAS was in the sector. Implications of these findings for UAS integration in the NAS are discussed.

  9. The Challenges of Field Testing the Traffic Management Advisor (TMA) in an Operational Air Traffic Control Facility

    Science.gov (United States)

    Hoang, Ty; Swenson, Harry N.

    1997-01-01

    The Traffic Management Advisor (TMA), the sequence and schedule tool of the Center/TRACON Automation System (CTAS), was evaluated at the Fort Worth Center (ZFW) in the summer of 1996. This paper describes the challenges encountered during the various phases of the TMA field evaluation, which included system (hardware and software) installation, personnel training, and data collection. Operational procedures were developed and applied to the evaluation process that would ensure air safety. The five weeks of field evaluation imposed minimal impact on the hosting facility and provided valuable engineering and human factors data. The collection of data was very much an opportunistic affair, due to dynamic traffic conditions. One measure of the success of the TMA evaluation is that, rather than remove TMA after the evaluation until it could be fully implemented, the prototype TMA is in continual use at ZFW as the fully operational version is readied for implementation.

  10. 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...

  11. 77 FR 30437 - Proposed Amendment of Air Traffic Service Routes; Southwestern United States

    Science.gov (United States)

    2012-05-23

    ...; Southwestern United States as published in the Federal Register of April 23, 2010 (77 FR 24156) FR Doc. 2012... (77 FR 24156). The description of V-16 in the NPRM did not reflect a previous amendment of the route that was published on September 19, 2011 (76 FR 57902). The incorrect part of the V-16 description...

  12. 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.

  13. 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.

  14. Traffic Route Modelling and Assignment with Intelligent Transport System

    OpenAIRE

    Kunicina Nadezhda; Galkina Alina; Zabasta Anatolijs; Patlins Antons; Kondratjevs Kaspars

    2014-01-01

    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 ad...

  15. 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.

  16. Analysis of a tool ergonomic working in air traffic control: perceptions of operators and contributions to workload

    Directory of Open Access Journals (Sweden)

    Arlete Ana Motter

    2012-11-01

    Full Text Available The aim of this study was to evaluate the perception of the operators and the role of the strips in the workload of air traffic controllers in light of the ergonomic analysis of work. It was developed during the data collection for the doctoral thesis defended in 2007 at the Post-graduate in Production Engineering at UFSC. Submitted to and approved by the Ethics Committee  in Research of the  Tuiuti University of Paraná. A number of 35 military operators of both sexes (80% male and 20% female participated, all belonging to the Brazilian Air Force, which carried out their functions in the Second Integrated Center of Air Defense and Air Traffic Control (CINDACTA II, located in Curitiba-PR. It was used the methodology of analysis of work ergonomics. The results made it possible to know the content of the prescribed electronic strip and the complexity of work in real activity, such as the manual entry of the strip and the AFIL flight plan. It was verified that the operators build operational strategies in terms of organization of the strips in order to facilitate their work. The conclusion is that in the work of air traffic controller there are several interacting variables, and when the content of the work required is different from what is established, the workload increases, which may endanger the health of workers as well as aircraft safety.

  17. Continental Land Mass Air Traffic Control (COLM ATC). [using three artificial satellite configurations

    Science.gov (United States)

    Pecar, J. A.; Henrich, J. E.

    1973-01-01

    The application of various satellite systems and techniques relative to providing air traffic control services for the continental United States was studied. Three satellite configurations were reviewed. The characteristics and capabilities of the satellites are described. The study includes consideration for the various ranging waveforms, multiple access alternatives, and the power and bandwidth required as a function of the number of users.

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

    International Nuclear Information System (INIS)

    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.

  19. 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.

  20. 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.

  1. 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

  2. A passive brain-computer interface application for the mental workload assessment on professional air traffic controllers during realistic air traffic control tasks.

    Science.gov (United States)

    Aricò, P; Borghini, G; Di Flumeri, G; Colosimo, A; Pozzi, S; Babiloni, F

    2016-01-01

    In the last decades, it has been a fast-growing concept in the neuroscience field. The passive brain-computer interface (p-BCI) systems allow to improve the human-machine interaction (HMI) in operational environments, by using the covert brain activity (eg, mental workload) of the operator. However, p-BCI technology could suffer from some practical issues when used outside the laboratories. In particular, one of the most important limitations is the necessity to recalibrate the p-BCI system each time before its use, to avoid a significant reduction of its reliability in the detection of the considered mental states. The objective of the proposed study was to provide an example of p-BCIs used to evaluate the users' mental workload in a real operational environment. For this purpose, through the facilities provided by the École Nationale de l'Aviation Civile of Toulouse (France), the cerebral activity of 12 professional air traffic control officers (ATCOs) has been recorded while performing high realistic air traffic management scenarios. By the analysis of the ATCOs' brain activity (electroencephalographic signal-EEG) and the subjective workload perception (instantaneous self-assessment) provided by both the examined ATCOs and external air traffic control experts, it has been possible to estimate and evaluate the variation of the mental workload under which the controllers were operating. The results showed (i) a high significant correlation between the neurophysiological and the subjective workload assessment, and (ii) a high reliability over time (up to a month) of the proposed algorithm that was also able to maintain high discrimination accuracies by using a low number of EEG electrodes (~3 EEG channels). In conclusion, the proposed methodology demonstrated the suitability of p-BCI systems in operational environments and the advantages of the neurophysiological measures with respect to the subjective ones. PMID:27590973

  3. An Integrated Tool Suite for En Route Radar Controllers in NextGen

    Science.gov (United States)

    Mercer, Joey; Prevot, Thomas; Brasil, Connie; Mainini, Matthew; Kupfer, Michael; Smtih, Nancy

    2010-01-01

    This paper describes recent human-in-the-loop research in the Airspace Operations Laboratory at the NASA Ames Research Center focusing on en route air traffic management with advanced trajectory planning tools and increased levels of human-automation cooperation. The decision support tools were exercised in a simulation of seven contiguous high-altitude sectors. Preliminary data suggests the controllers were able to manage higher amounts of traffic as compared to today, while maintaining acceptable levels of workload.

  4. 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. PMID:25993476

  5. Aeronautical mobile satellite service: Air traffic control applications

    Science.gov (United States)

    Sim, Dave

    1990-01-01

    Canada's history both in aviation and in satellite communications development spans several decades. The introduction of aeronautical mobile satellite communications will serve our requirements for airspace management in areas not served by line-of-sight radio and radar facilities. The ensuing improvements in air safety and operating efficiency are eagerly awaited by the aviation community.

  6. 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…

  7. 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.

  8. 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...

  9. 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

  10. 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)

  11. Quality of Life, Sleep, and Health of Air Traffic Controllers With Rapid Counterclockwise Shift Rotation.

    Science.gov (United States)

    Sonati, Jaqueline Girnos; De Martino, Milva Maria Figueiredo; Vilarta, Roberto; da Silva Maciel, Érika; Sonati, Renato José Ferreira; Paduan, Paulo Cézar

    2016-08-01

    Rotating shiftwork is common for air traffic controllers and usually causes sleep deprivation, biological adaptations, and life changes for these workers. This study assessed quality of life, the sleep, and the health of 30 air traffic controllers employed at an international airport in Brazil. The objective was to identify health and quality of life concerns of these professionals. The results identified physical inactivity, overweight, excess body fat, low scores for physical and social relationships, and sleep deprivation for workers in all four workshifts. In conclusion, these workers are at risk for chronic non-transmittable diseases and compromised work performance, suggesting the need for more rest time before working nightshifts and work environments that stimulate physical activity and healthy diets. PMID:27147608

  12. Satellite system performance assessment for in-flight entertainment and air traffic control

    OpenAIRE

    Radzik, José; Pirovano, Alain; Tao, Na; Bousquet, Michel

    2007-01-01

    International audience Concurrent satellite systems have been proposed for IFE (In-Flight Entertainment) communications, thus demonstrating the capability of satellites to provide multimedia access to users in aircraft cabin. At the same time, an increasing interest in the use of satellite communications for ATC (Air Traffic Control) has been motivated by the increasing load of traditional radio links mainly in the VHF band, and uses the extended capacities the satellite may provide. Howev...

  13. 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.

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

    Science.gov (United States)

    Arbula, Sandra; Capizzi, Mariagrazia; Lombardo, Nicoletta; Vallesi, Antonino

    2016-01-01

    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. PMID:27311017

  15. 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.

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

    Science.gov (United States)

    Arbula, Sandra; Capizzi, Mariagrazia; Lombardo, Nicoletta; Vallesi, Antonino

    2016-01-01

    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. PMID:27311017

  17. 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.

  18. The Development of the Multi-Center Traffic Management Advisor (MCTMA): Traffic Flow Management Research in a Multi-Facility Environment

    Science.gov (United States)

    Lee, Katharine K.; Davis, Thomas J.; Levin, Kerry M.; Rowe, Dennis W.

    2001-01-01

    The Traffic Management Advisor (TMA) is a decision-support tool for traffic managers and air traffic controllers that provides traffic flow visualization and other flow management tools. TMA creates an efficiently sequenced and safely spaced schedule for arrival traffic that meets but does not exceed specified airspace system constraints. TMA is being deployed at selected facilities throughout the National Airspace System in the US as part of the FAA's Free Flight Phase 1 program. TMA development and testing, and its current deployment, focuses on managing the arrival capacity for single major airports within single terminal areas and single en route centers. The next phase of development for this technology is the expansion of the TMA capability to complex facilities in which a terminal area or airport is fed by multiple en route centers, thus creating a multicenter TMA functionality. The focus of the multi-center TMA (McTMA) development is on the busy facilities in the Northeast comdor of the US. This paper describes the planning and development of McTMA and the challenges associated with adapting a successful traffic flow management tool for a very complex airspace.

  19. Application of the user-centred design process according ISO 9241-210 in air traffic control.

    Science.gov (United States)

    König, Christina; Hofmann, Thomas; Bruder, Ralph

    2012-01-01

    Designing a usable human machine interface for air traffic control is challenging and should follow approved methods. The ISO 9241-210 standard promises high usability of products by integrating future users and following an iterative process. This contribution describes the proceeding and first results of the analysis and application of ISO 9241-210 to develop a planning tool for air traffic controllers. PMID:22316717

  20. 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.

  1. 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.

  2. 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...

  3. Air Traffic Management Research at NASA Ames

    Science.gov (United States)

    Davis, Thomas J.

    2012-01-01

    The Aviation Systems Division at the NASA Ames Research Center conducts leading edge research in air traffic management concepts and technologies. This overview will present concepts and simulation results for research in traffic flow management, safe and efficient airport surface operations, super density terminal area operations, separation assurance and system wide modeling and simulation. A brief review of the ongoing air traffic management technology demonstration (ATD-1) will also be presented. A panel discussion, with Mr. Davis serving as a panelist, on air traffic research will follow the briefing.

  4. Traffic Engineering With Traditional IP Routing Protocols

    OpenAIRE

    Fortz, Bernard; Rexford, Jennifer; Thorup, Mikkel

    2002-01-01

    Traffic engineering involves adapting the routing of traffic to the network conditions, with the joint goals of good user performance and efficient use of network resources. In this paper, we describe an approach to intradomain traffic engineering that works within the existing deployed base of Interior Gateway Protocols (IGPs), such as Open Shortest Path First (OSPF) and Intermediate System-Intermediate System (IS-IS). We explain how to adapt the configuration of link weights, based on a ...

  5. Work and Safety in Small to Medium-Sized Air Traffic Control Towers : A Study of Distributed Cognition and Resilience

    OpenAIRE

    Linger, Oscar

    2016-01-01

    Air Traffic Control (ATC) is a safety-critical system which places high demands on air traffic controllers’ (ATCO) multitasking abilities. Having the requisite information for well-informed decision making is central, and as new technologies such as remote towers demand an increase in capacity, efficiency, and safety there is a need for research that informs system development. Adopting a systems perspective, Distributed Cognition is an approach for investigating system functioning, and Resil...

  6. From crisis to development--analysis of air traffic control work processes.

    Science.gov (United States)

    Teperi, Anna-Maria; Leppänen, Anneli

    2011-03-01

    In this study an intervention to improve work processes in air traffic control (ATC) is evaluated. The background was the Finnish air traffic controllers' strike of 1999. The old ways of thinking and acting did not support development of ATC prompting a need for a new kind of working culture in the organisation. Several actions were started. In one of these, ATC work processes were modelled by personnel and development plans concerning work were delivered to top management. Different actors (management, trade union, stakeholders) were interviewed before (n=16) and after the project (n=7). The intervention supported systematic co-operation between different actors in the organisation. However, a follow-up revealed that only a few participants had adopted the idea of continuous work development. Mastery of human factors is crucial in a high reliability work environment such as ATC. But how is the analytical and co-operative aspect kept alive in an organisation that is run by strict international regulation and has a strong technical competence, but is not that strong in collaborative and human aspects? PMID:20883978

  7. 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.

  8. Controller recovery from equipment failures in air traffic control: A framework for the quantitative assessment of the recovery context

    International Nuclear Information System (INIS)

    Air Traffic Control (ATC) involves a complex interaction of human operators (primarily air traffic controllers), equipment and procedures. On the rare occasions when equipment malfunctions, controllers play a crucial role in the recovery process of the ATC system for continued safe operation. Research on human performance in other safety critical industries using human reliability assessment techniques has shown that the context in which recovery from failures takes place has a significant influence on the outcome of the process. This paper investigates the importance of context in which air traffic controller recovery from equipment failures takes place, defining it in terms of 20 Recovery Influencing Factors (RIFs). The RIFs are used to develop a novel approach for the quantitative assessment of the recovery context based on a metric referred to as the Recovery Context Indicator (RCI). The method is validated by a series of simulation exercises conducted at a specific ATC Centre. The proposed method is useful to assess recovery enhancement approaches within ATC centres

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

    OpenAIRE

    Mohammed, Y.; A. Uzairu; J.O. Ujoh

    2013-01-01

    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 ...

  10. Bad traffic, bad air

    OpenAIRE

    Duca, Edward

    2012-01-01

    Air pollution is one of Malta’s greatest concerns. Transportation is the principal source with over 300,000 vehicles belching out smoke, which damages our environment and health. Emissions from vehicles need to be monitored and controlled, and the information used to improve the current system and ensure an acceptable air quality. By using the pollution data set, Nicolette Formosa (supervised by Dr Kenneth Scerri) mapped the air pollution levels and major sources around Malta. http://www....

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. Cubesat Constellation Design for Air Traffic Monitoring

    Science.gov (United States)

    Nag, Sreeja; Rios, Joseph Lucio; Gerhardt, David; Pham, Camvu

    2015-01-01

    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. The ADS-B signal, emitted from the aircraft's Mode-S transponder, is currently tracked by terrestrial based receivers but not over remote oceans or sparsely populated regions such as Alaska or the Pacific Ocean. Lack of real-time aircraft time/location information in remote areas significantly hinders optimal planning and control because bigger "safety bubbles" (lateral and vertical separation) are required around the aircraft until they reach radar-controlled airspace. Moreover, it presents a search-and-rescue bottleneck. Aircraft in distress, e.g. Air France AF449 that crashed in 2009, take days to be located or cannot be located at all, e.g. Malaysia Airlines MH370 in 2014. 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 and 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 has been obtained from the Future ATM Concepts Evaluation Tool (FACET), developed at NASA Ames Research Center, simulated over the Alaskan airspace over a period of one day. The simulation is driven by MATLAB with satellites propagated and coverage calculated using AGI's Satellite ToolKit(STK10).

  17. 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.

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. Impact of Flooding on Traffic Route Choices

    Directory of Open Access Journals (Sweden)

    Othman M.H.

    2014-01-01

    Full Text Available Traffic route choice using road network modelling can play a key role in preventing and minimizing traffic problems during disasters. Using road network modelling, real road conditions during flooding are simulated in order to produce a response plan for road users to evacuate based on the roads' real risks and situation. Using a Geographical Information System (GIS we can forecast and provide road users with available alternatives when certain access roads or links need to be closed due to catastrophic hazards such as floods. This study focuses on floods as it is the most common form of natural disaster occurring in Malaysia, and due to the fact that the chance and risk of a flood occurring cannot be accurately predicted nor measured. Therefore, as a response to this problem, the outcome of this study is highly useful for the retrieval of information on flooded roads and the impacts on road users. Using GIS's capability to display both spatial and attributive information, we have provided an attractive alternative to conventional methods in order to show available traffic route choices and a transportation network plan.

  3. 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

  4. 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.

  5. Testing usability and trainability of indirect touch interaction: perspective for the next generation of air traffic control systems

    OpenAIRE

    Causse, Mickael; Alonso, Roland; Vachon, François; Parise, Robert; Orliaguet, Jean-Pierre; Tremblay, Sébastien; Terrier, Patrice

    2014-01-01

    This study aims to determine whether indirect touch device can be used to interact with graphical objects displayed on another screen in an air traffic control (ATC) context. The introduction of such a device likely requires an adaptation of the sensory-motor system. The operator has to simultaneously perform movements on the horizontal plane while assessing them on the vertical plane. Thirty-six right-handed participants performed movement training with either constant or variable practice a...

  6. 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.

  7. Enhanced Optimized Link State Routing for Multimedia Traffic using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    S. Meenakshi Sundaram

    2014-05-01

    Full Text Available The aim of this research is to modify OLSR using GA to reduce the end to end delay and to improve the network throughput. Simulation was carried out for multimedia traffic and video streamed network traffic using OPNET Simulator. Routing is a primary MANET function where each node forms routes between nodes not directly in each others range for communication. Major challenges in MANET are routing protocol design while maintaining quality of service in the network. Optimized Link State Routing (OLSR protocol is a Table driven Proactive Routing Protocol having topology information and routes which are used for routing. OLSR’s efficiency depends on Multi Point Relay (MPR selection. Many studies are conducted to decrease control traffic overheads by modifying existing OLSR routing protocol and traffic shaping based on packet priority.

  8. Contributions to trajectory prediction theory and its application to arrival management for air traffic control

    OpenAIRE

    Bronsvoort, Jesper

    2014-01-01

    La gestión del tráfico aéreo (Air Traffic Management, ATM) está experimentando un cambio de paradigma hacia las denominadas operaciones basadas trayectoria. Bajo dicho paradigma se modifica el papel de los controladores de tráfico aéreo desde una operativa basada su intervención táctica continuada hacia una labor de supervisión a más largo plazo. Esto se apoya en la creciente confianza en las soluciones aportadas por las herramientas automatizadas de soporte a la decisión más modernas. Para d...

  9. 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. PMID:27652177

  10. 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.

  11. Robust routing mechanisms for intradomain traffic engineering in dynamic networks

    OpenAIRE

    Casas Hernandez, Pedro; Larroca, Federico; Vaton, Sandrine

    2009-01-01

    Internet traffic is highly dynamic and difficult to predict in current network scenarios. This makes of traffic engineering (TE) a very challenging task for network management and resources optimization. We study the problem of intradomain routing optimization under this traffic uncertainty. Recent works have proposed robust optimization techniques to tackle the problem, conceiving the robust routing (RR) approach. RR copes with traffic uncertainty in an off-line preemptive fashion, computing...

  12. 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.

  13. 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.

  14. 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.

  15. Controlled Traffic Farming

    OpenAIRE

    Controlled Traffic Farming Europe

    2011-01-01

    Metadata only record Controlled Traffic Farming (CTF) is a farming method used to reduce soil compaction, decrease inputs, and improve soil structure when coupled with reduced-till or no-till practices. This practices utilizes permanent traffic/wheel zones to limit soil compaction to a specific area. This website provides practical information on CTF, case studies, workshops, and links to additional resources.

  16. Protection Method for Data Communication between ADS-B Sensor and Next-Generation Air Traffic Control Systems

    Directory of Open Access Journals (Sweden)

    Seoung-Hyeon Lee

    2014-12-01

    Full Text Available Communications, Navigation, Surveillance/Air Traffic Management (CNS/ATM systems utilize digital technologies, satellite systems, and various levels of automation to facilitate seamless global air traffic management. Automatic Dependent Surveillance-Broadcast (ADS-B, the core component of CNS/ATM, broadcasts important monitoring information, such as the location, altitude, and direction of aircraft, to the ground. However, ADS-B data are transmitted in an unencrypted (or unprotected communication channel between ADS-B sensors and Air Traffic Control (ATC. Consequently, these data are vulnerable to security threats, such as spoofing, eavesdropping, and data modification. In this paper, we propose a method that protects the ADS-B data transmitted between ADS-B sensors and ATC using Simple Public Key Infrastructure (SPKI certificates and symmetric cryptography. The SPKI certificates are used to grant transmission authorization to the ADS-B sensors, while symmetric cryptography is used to encrypt/decrypt the ADS-B data transmitted between the ADS-B sensors and ATC. The proposed security framework comprises an ADS-B sensor authentication module, an encrypted data processing module, and an ADS-B sensor information management module. We believe that application of the proposed security framework to CNS/ATM will enable it to effectively obviate security threats, such as ground station flood denial, ground station target ghost injection, and ADS-B data modification.

  17. 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。

  18. 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.

  19. Traffic Matrix Reloaded: Impact of Routing Changes

    OpenAIRE

    Teixeira, Renata; Duffield, Nick; Rexford, Jennifer; Roughan, Matthew

    2005-01-01

    International audience A traffic matrix represents the load from each ingress point to each egress point in an IP network. Although networks are engineered to tolerate some variation in the traffic matrix, large changes can lead to congested links and poor performance. The variations in the traffic matrix are caused by statistical fluc-tuations in the traffic entering the network and shifts in where the traffic leaves the network. For an accurate view of how the traffic matrix evolves over...

  20. 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.

  1. Air Traffic Management Research at NASA

    Science.gov (United States)

    Farley, Todd

    2012-01-01

    The U.S. air transportation system is the most productive in the world, moving far more people and goods than any other. It is also the safest system in the world, thanks in part to its venerable air traffic control system. But as demand for air travel continues to grow, the air traffic control systems aging infrastructure and labor-intensive procedures are impinging on its ability to keep pace with demand. And that impinges on the growth of our economy. Part of NASA's current mission in aeronautics research is to invent new technologies and procedures for ATC that will enable our national airspace system to accommodate the increasing demand for air transportation well into the next generation while still maintaining its excellent record for safety. It is a challenging mission, as efforts to modernize have, for decades, been hamstrung by the inability to assure safety to the satisfaction of system operators, system regulators, and/or the traveling public. In this talk, we'll provide a brief history of air traffic control, focusing on the tension between efficiency and safety assurance, and we'll highlight some new NASA technologies coming down the pike.

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. Evaluation of High Density Air Traffic Operations with Automation for Separation Assurance, Weather Avoidance and Schedule Conformance

    Science.gov (United States)

    Prevot, Thomas; Mercer, Joey S.; Martin, Lynne Hazel; Homola, Jeffrey R.; Cabrall, Christopher D.; Brasil, Connie L.

    2011-01-01

    In this paper we discuss the development and evaluation of our prototype technologies and procedures for far-term air traffic control operations with automation for separation assurance, weather avoidance and schedule conformance. Controller-in-the-loop simulations in the Airspace Operations Laboratory at the NASA Ames Research Center in 2010 have shown very promising results. We found the operations to provide high airspace throughput, excellent efficiency and schedule conformance. The simulation also highlighted areas for improvements: Short-term conflict situations sometimes resulted in separation violations, particularly for transitioning aircraft in complex traffic flows. The combination of heavy metering and growing weather resulted in an increased number of aircraft penetrating convective weather cells. To address these shortcomings technologies and procedures have been improved and the operations are being re-evaluated with the same scenarios. In this paper we will first describe the concept and technologies for automating separation assurance, weather avoidance, and schedule conformance. Second, the results from the 2010 simulation will be reviewed. We report human-systems integration aspects, safety and efficiency results as well as airspace throughput, workload, and operational acceptability. Next, improvements will be discussed that were made to address identified shortcomings. We conclude that, with further refinements, air traffic control operations with ground-based automated separation assurance can routinely provide currently unachievable levels of traffic throughput in the en route airspace.

  8. 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.

  9. 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....

  10. Prediction of Traffic Complexity and Controller Workload in Mixed Equipage NextGen Environments

    Science.gov (United States)

    Lee, Paul U.; Prevot, Thomas

    2012-01-01

    Controller workload is a key factor in limiting en route air traffic capacity. Past efforts to quantify and predict workload have resulted in identifying objective metrics that correlate well with subjective workload ratings during current air traffic control operations. Although these metrics provide a reasonable statistical fit to existing data, they do not provide a good mechanism for estimating controller workload for future air traffic concepts and environments that make different assumptions about automation, enabling technologies, and controller tasks. One such future environment is characterized by en route airspace with a mixture of aircraft equipped with and without Data Communications (Data Comm). In this environment, aircraft with Data Comm will impact controller workload less than aircraft requiring voice communication, altering the close correlation between aircraft count and controller workload that exists in current air traffic operations. This paper outlines a new trajectory-based complexity (TBX) calculation that was presented to controllers during a human-in-the-loop simulation. The results showed that TBX accurately estimated the workload in a mixed Data Comm equipage environment and the resulting complexity values were understood and readily interpreted by the controllers. The complexity was represented as a "modified aircraft account" that weighted different complexity factors and summed them in such a way that the controllers could effectively treat them as aircraft count. The factors were also relatively easy to tune without an extensive data set. The results showed that the TBX approach is well suited for presenting traffic complexity in future air traffic environments.

  11. 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).

  12. Multitree-multiobjective multicast routing for traffic engineering

    OpenAIRE

    Prieto, Joel; Barán, Benjamín; Crichigno, Jorge

    2006-01-01

    This paper presents a new traffic engineering multitreemultiobjective multicast routing algorithm (M-MMA) that solves for the first time the GMM model for Dynamic Multicast Groups. Multitree traffic engineering uses several trees to transmit a multicast demand from a source to a set of destinations in order to balance traffic load, improving network resource utilization. Experimental results obtained by simulations using eight real network topologies show that this new approach gets trade off...

  13. 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 Bureau of CAAC. It is the first magazine about ATM field in CAAC. The chairman of Editorial Board of ATM is Mr. Bao Peide, Vice Minister of CAAC. Mr. Chen Ziye, Vice President of the 1st Research Institute of CAAC and Chen Xuhua, General Director of Air Traffic Management Bureau are vice chairmen of the editorial board, and six general directors of local air traffic management bureau and some professors and experts are members of the editorial board.

  14. Organic traffic control

    OpenAIRE

    Prothmann, Holger

    2011-01-01

    Modern cities cannot be imagined without traffic lights controlling the road network. To handle the network's changing demands efficiently, the signal plan specification needs to be shifted from the design time to the run-time of a signal system. The generic observer/controller architecture proposed for Organic Computing facilitates this shift. A two-levelled learning mechanism optimises signal plans on-line while a distributed coordination mechanism establishes green waves in the road network.

  15. A Life-Cycle Cost Estimating Methodology for NASA-Developed Air Traffic Control Decision Support Tools

    Science.gov (United States)

    Wang, Jianzhong Jay; Datta, Koushik; Landis, Michael R. (Technical Monitor)

    2002-01-01

    This paper describes the development of a life-cycle cost (LCC) estimating methodology for air traffic control Decision Support Tools (DSTs) under development by the National Aeronautics and Space Administration (NASA), using a combination of parametric, analogy, and expert opinion methods. There is no one standard methodology and technique that is used by NASA or by the Federal Aviation Administration (FAA) for LCC estimation of prospective Decision Support Tools. Some of the frequently used methodologies include bottom-up, analogy, top-down, parametric, expert judgement, and Parkinson's Law. The developed LCC estimating methodology can be visualized as a three-dimensional matrix where the three axes represent coverage, estimation, and timing. This paper focuses on the three characteristics of this methodology that correspond to the three axes.

  16. Application of Data Mining in Air Traffic Forecasting

    OpenAIRE

    Busquets, J. G.; Alonso, E.; Evans, A

    2015-01-01

    The main goal of the study centers on developing a model for the purpose of air traffic forecasting by using off-the-shelf data mining and machine learning techniques. Although data driven modeling has been extensively applied in the aviation sector, little research has been done in the area of air traffic forecasting. This study is inspired by previous research focused on improving the Federal Aviation Administration (FAA) Terminal Area Forecasting (TAF) methodology, which historically assum...

  17. Decentralized and Tactical Air Traffic Flow Management

    Science.gov (United States)

    Bertsimas, Dimitris; Odoni, Amedeo R.

    1997-01-01

    This project dealt with the following topics: 1. Review and description of the existing air traffic flow management system (ATFM) and identification of aspects with potential for improvement. 2. Identification and review of existing models and simulations dealing with all system segments (enroute, terminal area, ground) 3. Formulation of concepts for overall decentralization of the ATFM system, ranging from moderate decentralization to full decentralization 4. Specification of the modifications to the ATFM system required to accommodate each of the alternative concepts. 5. Identification of issues that need to be addressed with regard to: determination of the way the ATFM system would be operating; types of flow management strategies that would be used; and estimation of the effectiveness of ATFM with regard to reducing delay and re-routing costs. 6. Concept evaluation through identification of criteria and methodologies for accommodating the interests of stakeholders and of approaches to optimization of operational procedures for all segments of the ATFM system.

  18. 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.

  19. Air traffic generation for new terminal area air traffic management concepts design and evaluation

    OpenAIRE

    Besada Portas, Juan Alberto; Marquinez Prado, Iñigo; Portillo Garcia, Javier Ignacio; Miguel Vela, Gonzalo de; Bernardos Barbolla, Ana M.

    2015-01-01

    This paper describes two systems that can be used to obtain realistic random traffic samples in a terminal area: a real traffic analyser and a synthetic traffic generator. These two systems allow the air traffic management (ATM) engineer to gain insight on the traffic structure of the area under analysis, and allow obtaining realistic traffic samples enabling the evaluation of new operational concepts, the validation or system performance measurement after procedure changes, the analysis of A...

  20. 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.

  1. Border Effects in Passenger Air Traffic

    OpenAIRE

    Klodt, Henning

    2003-01-01

    National borders substantially matter in passenger air traffic. Empirical estimates based upon a new data set on domestic and international departures from German airports indicate that the German border reduces air traffic activity by a factor of four to five. This result adds a further piece of evidence to the significance of border effects in various kinds of economic activity.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Fusion Framework of Urban Traffic Control and Route Guidance Based on CPS Theory%基于CPS理论的城市交通控制与诱导融合框架

    Institute of Scientific and Technical Information of China (English)

    龚龚; 李苏剑

    2012-01-01

    To avoid the traffic congestion, improve transport efficiency, and meet the requirements of users and traffic flow equilibrium, the fusion framework of urban traffic control and route guidance was researched. The characteristics of urban traffic control and route guidance system and the cyber-physical system were analysed, and the relation of them were analysed. The technical requirements of CPS theory applied to the urban traffic control and route guidance system were discussed. According to the content of dynamic urban traffic flow guidance and urban traffic signal control system, and in the light of relevance, conflict and solution method of both systems, considered the man-machine system characteristics of cyber-physical system, a fusion framework of urban traffic control and route guidance based on cyber-physical system was proposed. The framework contains computation, communication, control and physical parts. The framework enhanced fusion degree of urban traffic flow guidance system and urban traffic signal control system. It focused on the technical analysis of the feasibility of depth fusion of both systems, and provided a theoretical basis for the implementation of urban traffic control and route guidance fusion in ITS.%以避免交通拥堵和提高交通效率为目标,同时满足交通用户要求和交通系统交通流均衡要求,对城市交通控制与诱导融合框架进行研究.分析城市交通控制与诱导系统和信息物理融合系统(CPS)的特性及两者关联.探讨CPS理论应用于城市交通控制与诱导系统的各项技术要求.根据动态城市交通流诱导系统和城市交通信号控制系统的内容,针对两者相关性、冲突性与解决方法,考虑信息物理融合系统的人机系统特点,提出一种基于信息物理融合系统理论的城市交通控制与诱导融合框架.该框架包含计算部分、通讯部分、控制部分和物理世界部分,增强了城市交通流诱导

  10. Effects of Prediction Feedback on Three-Route Intelligent Traffic Systems

    CERN Document Server

    Chuan-Fei, Dong; Bing-Hong, Wang; Xiao-Yan, Sun

    2009-01-01

    The optimal information feedback has a significant effect on many socioeconomic systems like stock market and traffic systems aiming to make full use of resources. Recently, a feedback strategy named prediction feedback strategy(Dong\\emph{et al}. 2009 Physica A {\\bf 388}, 4651) has been investigated, based on a two-route scenario. In this paper, we studied dynamics of traffic flow with real-time information provided and the influence of prediction feedback strategy on a three-route scenario in which dynamic information can be generated and displayed on the board to guide road users to make a choice. In three-route scenario, our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting prediction feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e., vehicle number and flux.

  11. 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.

  12. The neuroergonomic evaluation of human machine interface design in air traffic control using behavioral and EGG/ERP measures.

    Science.gov (United States)

    Giraudet, L; Imbert, J-P; Bérenger, M; Tremblay, S; Causse, M

    2015-11-01

    The Air Traffic Control (ATC) environment is complex and safety-critical. Whilst exchanging information with pilots, controllers must also be alert to visual notifications displayed on the radar screen (e.g., warning which indicates a loss of minimum separation between aircraft). Under the assumption that attentional resources are shared between vision and hearing, the visual interface design may also impact the ability to process these auditory stimuli. Using a simulated ATC task, we compared the behavioral and neural responses to two different visual notification designs--the operational alarm that involves blinking colored "ALRT" displayed around the label of the notified plane ("Color-Blink"), and the more salient alarm involving the same blinking text plus four moving yellow chevrons ("Box-Animation"). Participants performed a concurrent auditory task with the requirement to react to rare pitch tones. P300 from the occurrence of the tones was taken as an indicator of remaining attentional resources. Participants who were presented with the more salient visual design showed better accuracy than the group with the suboptimal operational design. On a physiological level, auditory P300 amplitude in the former group was greater than that observed in the latter group. One potential explanation is that the enhanced visual design freed up attentional resources which, in turn, improved the cerebral processing of the auditory stimuli. These results suggest that P300 amplitude can be used as a valid estimation of the efficiency of interface designs, and of cognitive load more generally. PMID:26200718

  13. 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

  14. 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.

  15. Testing usability and trainability of indirect touch interaction: perspective for the next generation of air traffic control systems.

    Science.gov (United States)

    Causse, Mickaël; Alonso, Roland; Vachon, François; Parise, Robert; Orliaguet, Jean-Pierre; Tremblay, Sébastien; Terrier, Patrice

    2014-01-01

    This study aims to determine whether indirect touch device can be used to interact with graphical objects displayed on another screen in an air traffic control (ATC) context. The introduction of such a device likely requires an adaptation of the sensory-motor system. The operator has to simultaneously perform movements on the horizontal plane while assessing them on the vertical plane. Thirty-six right-handed participants performed movement training with either constant or variable practice and with or without visual feedback of the displacement of their actions. Participants then performed a test phase without visual feedback. Performance improved in both practice conditions, but accuracy was higher with visual feedback. During the test phase, movement time was longer for those who had practiced with feedback, suggesting an element of dependency. However, this 'cost' of feedback did not extend to movement accuracy. Finally, participants who had received variable training performed better in the test phase, but accuracy was still unsatisfactory. We conclude that continuous visual feedback on the stylus position is necessary if tablets are to be introduced in ATC. PMID:25050968

  16. Reducing prospective memory error and costs in simulated air traffic control: External aids, extending practice, and removing perceived memory requirements.

    Science.gov (United States)

    Loft, Shayne; Chapman, Melissa; Smith, Rebekah E

    2016-09-01

    In air traffic control (ATC), forgetting to perform deferred actions-prospective memory (PM) errors-can have severe consequences. PM demands can also interfere with ongoing tasks (costs). We examined the extent to which PM errors and costs were reduced in simulated ATC by providing extended practice, or by providing external aids combined with extended practice, or by providing external aids combined with instructions that removed perceived memory requirements. Participants accepted/handed-off aircraft and detected conflicts. For the PM task, participants were required to substitute alternative actions for routine actions when accepting aircraft. In Experiment 1, when no aids were provided, PM errors and costs were not reduced by practice. When aids were provided, costs observed early in practice were eliminated with practice, but residual PM errors remained. Experiment 2 provided more limited practice with aids, but instructions that did not frame the PM task as a "memory" task led to high PM accuracy without costs. Attention-allocation policies that participants set based on expected PM demands were modified as individuals were increasingly exposed to reliable aids, or were given instructions that removed perceived memory requirements. These findings have implications for the design of aids for individuals who monitor multi-item dynamic displays. (PsycINFO Database Record PMID:27608067

  17. 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)...

  18. TSAFE Interface Control Document v 2.0

    Science.gov (United States)

    Paielli, Russell A.; Bach, Ralph E.

    2013-01-01

    This document specifies the data interface for TSAFE, the Tactical Separation-Assured Flight Environment. TSAFE is a research prototype of a software application program for alerting air traffic controllers to imminent conflicts in enroute airspace. It is intended for Air Route Traffic Control Centers ("Centers") in the U.S. National Airspace System. It predicts trajectories for approximately 3 minutes into the future, searches for conflicts, and sends data about predicted conflicts to the client, which uses the data to alert an air traffic controller of conflicts. TSAFE itself does not provide a graphical user interface.

  19. 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

  20. 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.

  1. 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.

  2. The development of air traffic in Sicily

    OpenAIRE

    Franca, Luigi La; Mortelliti, Daniela; Salerno, Silvia; Amoroso, Salvatore

    2004-01-01

    The aim of this work is to analyse the air traffic development that interested the airport system in Sicily, consisting of the airport of Palermo “Falcone –Borsellino”, the airport of Catania “Fontanarossa” and that one of Trapani-Birgi “Vincenzo Florio”. The analysis of the possible growth of air traffic volume and performance in Sicily was mainly suggested by the growing importance of the Mediterranean region like a new crossroad of the worldwide traffic on the East-West line. It gives a ne...

  3. 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...... of Service classes. Under the NGN context, there are plenty of proposals intending to accommodate the issues listed above. Path Computation Elements (PCE) proposed by IETF designs suitable network architecture that aiming at compute the QoS based paths for traffic transportation through intra- and inter...... (RACF) provides the platform that enables cooperation and ubiquitous integration between networks. In this paper, we investigate in the network architecture, protocols and algorithms for inter-domain QoS routing and traffic engineering. The PCE based inter-domain routing architecture is enhanced...

  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. 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,

  6. Automation for Air Traffic Control: The Rise of a New Discipline

    Science.gov (United States)

    Erzberger, Heinz; Tobias, Leonard (Technical Monitor)

    1997-01-01

    The current debate over the concept of Free Flight has renewed interest in automated conflict detection and resolution in the enroute airspace. An essential requirement for effective conflict detection is accurate prediction of trajectories. Trajectory prediction is, however, an inexact process which accumulates errors that grow in proportion to the length of the prediction time interval. Using a model of prediction errors for the trajectory predictor incorporated in the Center-TRACON Automation System (CTAS), a computationally fast algorithm for computing conflict probability has been derived. Furthermore, a method of conflict resolution has been formulated that minimizes the average cost of resolution, when cost is defined as the increment in airline operating costs incurred in flying the resolution maneuver. The method optimizes the trade off between early resolution at lower maneuver costs but higher prediction error on the one hand and late resolution with higher maneuver costs but lower prediction errors on the other. The method determines both the time to initiate the resolution maneuver as well as the characteristics of the resolution trajectory so as to minimize the cost of the resolution. Several computational examples relevant to the design of a conflict probe that can support user-preferred trajectories in the enroute airspace will be presented.

  7. A feasibility study of the use of incidents and accidents reports to evaluate effects of team resource management in air traffic control

    DEFF Research Database (Denmark)

    Andersen, V.; Bove, T.

    2000-01-01

    to the domain of Air Traffic Control under the heading of 'Team Resource Management'. In this adaptation phase, it is important to obtain knowledge concerning the effectiveness of such training programmes in relation to enhancing human factors awareness and knowledge. This requires a methodology for detecting...... training effects. For this purpose a feasibility study has been conducted concerning the use of paper cases - short written reports on real or fictitious incidents or accidents - to discriminate air traffic controllers with regard to their ability to identify 'human factors' determinants involved......Valuable improvements in performance have been obtained by 'Crew Resource Management' (CRM) courses performed in the domain of aviation related to the crew in a cockpit, and in the maritime domain related to the crew on the bridge of large ships. CRM courses are currently being adapted...

  8. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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 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...

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. Re-Examination of Mixed Media Communication: The Impact of Voice, Data Link, and Mixed Air Traffic Control Environments on the Flight Deck

    Science.gov (United States)

    Dunbar, Melisa; McGann, Alison; Mackintosh, Margaret-Anne; Lozito, Sandra; Ashford, Rose (Technical Monitor)

    2001-01-01

    A simulation in the B747-400 was conducted at NASA Ames Research Center that compared how crews handled voice and data link air traffic control (ATC) messages in a single medium versus a mixed voice and data link ATC environment The interval between ATC messages was also varied to examine the influence of time pressure in voice, data link, and mixed ATC environments. For messages sent via voice, transaction times were lengthened in the mixed media environment for closely spaced messages. The type of environment did not affect data link times. However, messages times were lengthened in both single and mixed-modality environments under time pressure. Closely spaced messages also increased the number of requests for clarification for voice messages in the mixed environment and review menu use for data link messages. Results indicated that when time pressure is introduced, the mix of voice and data link does not necessarily capitalize on the advantages of both media. These findings emphasize the need to develop procedures for managing communication in mixed voice and data link environments.

  15. Traffic Flow Analysis Model based Routing Protocol For Multi-Protocol Label Switching Network

    Directory of Open Access Journals (Sweden)

    E. R. Naganathan

    2011-01-01

    Full Text Available Problem statement: Multi-Protocol Label Switching (MPLS is a mechanism which is used in high-performance telecommunications networks that directs and carries data from one network node to the next with the help of labels. Traffic management is still an issue in MPLS network as it involves high speed internet. Approach: This study proposed a traffic flow analysis of the real time MPLS traffic and segregates the MPLS traffic as three major class based on the outcome of traffic flow analysis. Using the traffic class. This study proposed a reliable transmission methodology which provides traffic free routing in the MPLS networks. Results: The proposed traffic flow analysis based reliable routing model overcomes the network traffic and provides effective routing by offering traffic free path. Conclusion: The proposed traffic flow analysis model outperforms existing routing protocol and offers comparatively negligible packet loss.

  16. Reduction of the air traffic's contribution to climate change: A REACT4C case study

    OpenAIRE

    Grewe, V; Champougny, T.; Matthes, Sigrun; Frömming, Christine; Brinkop, Sabine; Soevde, Amund; Irvine, Emma A.; Halscheidt, Lucia

    2014-01-01

    Air traffic alters the atmospheric composition and thereby contributes to climate change. Here we investigate the trans-Atlantic air traffic for one specific winter day and analyse, which routing changes were required to achieve a reduction in the air traffic’s contribution to climate change. We have applied an atmosphere-chemistry model to calculate so-called five dimensional climate cost functions (CCF), which describe the climate effect of a locally confined emission. The five dimensions r...

  17. 14 CFR 129.21 - Control of traffic.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Control of traffic. 129.21 Section 129.21... of traffic. (a) Subject to applicable immigration laws and regulations, each foreign air carrier must... communications with its aircraft and must assist station operators in directing traffic....

  18. 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...

  19. 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.

  20. Estimation of Wireless Traffic Value for Control Center of Tianjin Subway%天律地铁控制中心无线话务量的估算

    Institute of Scientific and Technical Information of China (English)

    宋鸿昇

    2012-01-01

    Subway control center is the core of subway operation management, especially when equipment failure and unexpected events directly affect subway normal operation. Central control operator needs to manage scheduling timely and flexibly to ensure safe operation and efficient transport. Therefore, communication quality of control center plays a very important role in subway operation. According to wireless communication situation of Line 1 in Tianjin subway control center, the integration of control centers of Line 1, Line 2 and Line 3 will definitely increase the communication traffic volume. Based on this concern and estimation of future communication traffic, adding one base station will be a better solution.%地铁控制中心是地铁运营管理的核心.特别是在设备故障和突发事件直接影响地铁正常运营的情况下,控制中心调度员要及时、灵活地进行调度管理,要保障地铁安全、高效运营.所以,控制中心的通信质量在地铁运营过程中起着十分重要的作用.根据天津地铁1号线控制中心目前的无线通信现状,以及考虑1、2、3号线控制中心合设,必将增加通信话务量,为此提出了增加一套基站的解决方案.根据对将来话务量的估算,结果表明该方案是可行的.

  1. 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。

  2. 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.

  3. 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

  4. 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.

  5. 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。

  6. 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....

  7. 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 ...

  8. 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.

  9. Traffic restrictions on Routes Bloch, Maxwell and Bohr

    CERN Multimedia

    IT 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

  10. 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 mean...... during the 10 years. This increase has been analysed by a panel data model. The conclusion found by modelling is the increasing travel activity first of all is driven by increasing income and to less extent by decreasing prices. The paper is furthermore showing how the international air traffic has got...... more effective and to what extent Low Cost Carriers have taken over an important part of the travel market....

  11. 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.

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

    OpenAIRE

    Honghai Zhang; Yan Xu; Lei Yang; Hao Liu

    2014-01-01

    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 fa...

  13. 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.

  14. 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.)

  15. A Modified Efficient Traffic Scheduling Algorithm for Routing in Optical WDM Mesh Networks

    Science.gov (United States)

    Kavitha, T.; Rajamani, V.

    2013-09-01

    This paper is proposing an efficient traffic scheduling for routing in optical networks supported by Wavelength Division Multiplexing (WDM). Normally the traffic is routed through the primary path or back-up path towards the destination. In order to meet the transmission of higher data rates, the path of the WDM should be capable of carrying the traffic without any failure. Whenever the transmission through primary or backup path fails due to excessive overhead or network failure or congestion or excessive load, existing router mechanisms are not scheduling the traffic in an effective manner. This paper deals with an efficient traffic scheduling algorithm which effectively routes the traffic using multipath technique that satisfies the optical constraints. The whole procedure of routing algorithm is separated into two phases: the connection node establishment phase and multipath transmission from the connection node to destination phase. The connection node is selected on the basis of load and current traffic carrying capacity of that node. Then the traffic is routed to the destination using multiple paths. The proposed method tries to minimize the blocking probability of 70% compared to the existing Resource Efficiency Factor (REF) algorithm and also increase the throughput of 30% and better channel utilization of 23% based on data rate and 20% based on traffic time interval. Hence, the proposed algorithm is effectively routes the traffic within the network.

  16. 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.

  17. NEW POSSIBILITIES OF RAILWAY TRAFFIC CONTROL SYSTEMS

    OpenAIRE

    Lionginas LIUDVINAVIČIUS; Stasys DAILYDKA; Aleksander SŁADKOWSKI

    2016-01-01

    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.

  18. 研究和讨论空中交通管制自动化的冲突概率%Collision Probability Study and Discuss the Collision Probability of Air Traffic Control Automation

    Institute of Scientific and Technical Information of China (English)

    李欢欢

    2014-01-01

    From the air traffic control automation flight conflicts start to air traffic control automation collision probability calculation methods are discussed in detail, to provide assistance to aircraft flight safety.%从空中交通管制自动化中的飞行冲突入手,对空中交通管制自动化的冲突概率计算方法进行了详细论述,为飞机的飞行安全性提供帮助。

  19. Air traffic management in Europe - Single European Sky

    OpenAIRE

    Šyc, Petr

    2009-01-01

    Thesis analyses present status of air traffic management in European area from historical and legislative point of view. Subjects of thesis are present projects in ATM and future variants of organization of air traffic in EU. Practical part focuses on impact of ATM on air transportation.

  20. 一种改进的空管系统效能评估算法%An Improved Efficiency Evaluation Algorithm of Air Traffic Control Management System

    Institute of Scientific and Technical Information of China (English)

    霍永华; 昌汉明; 于建; 杨红伟

    2015-01-01

    Aiming at air traffic control system, an efficiency evaluation algorithm is put forward. The efficiency evaluation index system is studied,including such aspects as performance effect,fault effect,security effect,risk effect and capacity effect,each of them contains different index parameters.The fuzzy comprehensive judgement is selected for evaluation.The definition method of weight coefficient is studied.The priciple of fuzzition and consistency of evaluation indexes is realized by introducing fuzzy maths and improving analytic hierarchy process model.Finally,the efficiency evaluation on air traffic control management system is illustrated in specific application scene.%针对空管系统,提出一种效能评估算法,研究了空管系统效能评估指标体系,包括性能影响、故障影响、安全影响、风险影响和容量影响等方面,每一方面包含不同的指标参数。选择模糊综合评判法进行评估,重点研究了权重系数确定方法,通过引入模糊数学方法改进层次分析模型,体现评估指标的模糊性和一致性原则。最后通过实例说明某空管系统在特定应用场景下的效能评估。

  1. 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...

  2. A Perspective on NASA Ames Air Traffic Management Research

    Science.gov (United States)

    Schroeder, Jeffery A.

    2012-01-01

    This paper describes past and present air-traffic-management research at NASA Ames Research Center. The descriptions emerge from the perspective of a technical manager who supervised the majority of this research for the last four years. Past research contributions built a foundation for calculating accurate flight trajectories to enable efficient airspace management in time. That foundation led to two predominant research activities that continue to this day - one in automatically separating aircraft and the other in optimizing traffic flows. Today s national airspace uses many of the applications resulting from research at Ames. These applications include the nationwide deployment of the Traffic Management Advisor, new procedures enabling continuous descent arrivals, cooperation with industry to permit more direct flights to downstream way-points, a surface management system in use by two cargo carriers, and software to evaluate how well flights conform to national traffic management initiatives. The paper concludes with suggestions for prioritized research in the upcoming years. These priorities include: enabling more first-look operational evaluations, improving conflict detection and resolution for climbing or descending aircraft, and focusing additional attention on the underpinning safety critical items such as a reliable datalink.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. Air pollution burden of illness from traffic in Toronto

    International Nuclear Information System (INIS)

    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

  8. 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.

  9. Testing to Learning Mode of English Learning for Air Traffic Controllers in China%中国民航管制员以考促学模式研究

    Institute of Scientific and Technical Information of China (English)

    彭立; 何均洪

    2012-01-01

    Air Traffic Controller English Test is not the ultimate purpose, while, testing to learning, and promoting the air traffic controllers' English language proficiency is the essence of the test. This article discusses two types of learning modes among air traffic controllers' English learning from the trials at the local ATC Bureaus. One of the modes is training-based, while another is based on selfdirected learning. Hopefully, these two types of mode will be helpful for promoting English learning among air traffic controllers in China.%“民航管制员英语等级测试”并不是最终目的,以考促学,全面提升中国民航管制员整体英语水平才是根本。本文通过相关空管局(站)的试验运行,总结出两种有效的管制员英语学习模式,一是集中培训,以点带面,一是构建平台,自主学习,以期对我国民航管制员英语水平的提高有所帮助。

  10. Light signals for road traffic control.

    OpenAIRE

    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 French translation see B 19780

  11. A Concept for Robust, High Density Terminal Air Traffic Operations

    Science.gov (United States)

    Isaacson, Douglas R.; Robinson, John E.; Swenson, Harry N.; Denery, Dallas G.

    2010-01-01

    This paper describes a concept for future high-density, terminal air traffic operations that has been developed by interpreting the Joint Planning and Development Office s vision for the Next Generation (NextGen) Air Transportation System and coupling it with emergent NASA and other technologies and procedures during the NextGen timeframe. The concept described in this paper includes five core capabilities: 1) Extended Terminal Area Routing, 2) Precision Scheduling Along Routes, 3) Merging and Spacing, 4) Tactical Separation, and 5) Off-Nominal Recovery. Gradual changes are introduced to the National Airspace System (NAS) by phased enhancements to the core capabilities in the form of increased levels of automation and decision support as well as targeted task delegation. NASA will be evaluating these conceptual technological enhancements in a series of human-in-the-loop simulations and will accelerate development of the most promising capabilities in cooperation with the FAA through the Efficient Flows Into Congested Airspace Research Transition Team.

  12. 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

  13. Statistical Analysis of Air Traffic in Latvian Region

    OpenAIRE

    Afanasyeva, Helen

    2013-01-01

    The goal of the research is statistical analyzes of air traffic in airport 'Riga' zone. Special statistical methods oriented to the concrete object area - airspace of Latvia are developed. Some experiments are made to discover season's and during twenty-four hours unstationarity of this process. Air traffic intensity for some stationary period for some airways is estimated.

  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. 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 PMID:27295467

  16. IMT-2000 Satellite Standards with Applications to Mobile Air Traffic Communications Networks

    Science.gov (United States)

    Shamma, Mohammed A.

    2004-01-01

    The International Mobile Telecommunications - 2000 (IMT-2000) standard and more specifically the Satellite component of it, is investigated as a potential alternative for communications to aircraft mobile users en-route and in terminal area. Its application to Air Traffic Management (ATM) communication needs is considered. A summary of the specifications of IMT-2000 satellite standards are outlined. It is shown via a system research analysis that it is possible to support most air traffic communication needs via an IMT-2000 infrastructure. This technology can compliment existing, or future digital aeronautical communications technologies such as VDL2, VDL3, Mode S, and UAT.

  17. Modelling and control of road traffic networks

    OpenAIRE

    Haut, Bertrand

    2007-01-01

    Road traffic networks offer a particularly challenging research subject to the control community. The traffic congestion around big cities is constantly increasing and is now becoming a major problem. However, the dynamics of a road network exhibit some complex behaviours such as nonlinearities, delays and saturation effects that prevent the use of some classical control algorithms. This thesis presents different models and control algorithms used for road traffic networks. The dynamics ar...

  18. 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....

  19. Design of Compact Self-propelled Air Traffic Control Radar%紧凑型机动式航管雷达结构设计

    Institute of Scientific and Technical Information of China (English)

    刘鲁军

    2011-01-01

    基于紧凑化设计理念,研究了机动式航管雷达的结构设计技术.阐述了应用Pro/E三维设计软件构建数字化样机以及采用四连杆机构原理的举升设计和分块式抛物反射面天线的结构设计方法;同时论述了用转轴式结构解决一二次雷达天线的合装设计和机动式航管雷达天馈线的快速架设解决方案;分析了凸型方舱结构设计和机柜直列设计的集成化设计方法;最后结合抗风设计的软件仿真优化设计,实现了高可靠性机动式航管雷达的紧凑化结构设计.结果证明,紧凑化结构设计理念对机动式雷达结构设计能起到促进作用.%The structure design technology of self-propelled air traffic control radar was researched based on compact design concepts. The digital prototype built with Pro/E three-dimensional design software is elaborated. Expounded The principle of four-bar linkage lift design and the block-type parabolic refLcctor antenna design arc adopted in the radar design. The corotating shaft structure design is described. The mounted design of the secondary radar antenna and the rapid erection of antenna were solved. The integrated design of convex cabin and the cabinet arrangement are analyzed The compact structure design of high-reliahility air traffic control radar is achieved in combination with simulation optimization software for wind-resistant design.

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

    OpenAIRE

    Yan Ge

    2014-01-01

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

  1. 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.

  2. AN INTERSECTION BASED TRAFFIC AWARE ROUTING WITH LOW OVERHEAD IN VANET

    Directory of Open Access Journals (Sweden)

    Lakshmi Ramachandran

    2013-01-01

    Full Text Available Vehicular Ad-hoc network is an emerging class of wireless network that provide efficient communication between vehicles and between vehicles and road side units. VANETs are gaining attention from both industrial and academic point of view due to its applications ranging from safety applications to infotainment applications. The main component for success of VANET applications is its routing. Design of an efficient routing protocol is important for smart Intelligent Transport System (ITS. In this paper, we consider how traffic lights affect the design of routing protocol in urban vehicular communication. In urban environment the roads are partitioned to several segments due to the traffic lights. The design of a routing protocol in such an environment is difficult. This paper proposes a new intersection based routing protocol which takes traffic lights in to consideration and with low overhead.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. On the safety behavior capacity model of the civil air traffic controllers%民航管制员安全行为能力模型研究

    Institute of Scientific and Technical Information of China (English)

    王永刚; 叶仕强

    2012-01-01

    This paper intends to define the safety behavior capacity of the Civil Air Traffic Controllers (ATCs) through the objective confirmation. In jointly studying the working characteristics and access mechanism of ATCs, we have studied the main factors affecting the air-traffic safety behaving capacity of the controllers in 3 aspects: the basic professional skills, the physiological and psychological features, and some non-professional qualities. And, accordingly, we have established an index system of such capacities, which comprise 3 sub-indexes (the basic professional skills, physiological and psychological features and non-technical qualities) and 17 third-rank or sub-sub-indexes (the information processing and delivery ability, etc. ) . Due to the multi-factorial and margin-blurring characteristics of ATC, we also think it is necessary to adopt an AHP to weigh all the indexes so as to develop a fussy comprehensive evaluation approach to ascertain the final membership, safety behaving evaluation model of ATCs based on AHP, which can be achieved by the qualitative evaluations of the safety behaving capacity of ATCs. The results of our study show that the basic professional skills and physiological and psychological features in the secondary index also have considerable significance and coordinating and cooperating power, flight control and emergency-dealt ability under abnormal flight condition and sensitivity of the digital information. While doing the evaluation, we have also to allocate the very ATCs to the posts or time period of high, slightly large, generic, little flow quantity and assigned until further training was provided correspondingly, such as the evaluating effects, i.e. "high", "relatively high", "general", "relatively poor" and "poor respectively. However, in this paper, our study focus should be put on the research of the safety behaving capacity of controllers and suggests that it is essential to allocate the personnel of strong operability to the

  11. 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)

  12. 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....

  13. Finnish air traffic until 2025. Four scenarios; Suomen lentoliikenne vuoteen 2025 - neljae skenaariota

    Energy Technology Data Exchange (ETDEWEB)

    Aalto, E.; Pollanen, M.; Mantynen, J.; Makela, T.; Rauhamaki, H. [Tampere Univ. of Technology (Finland). Transport Research Centre Verne

    2012-07-01

    Air traffic is a very dynamic field of business. Its operating environment features multiple factors of change, which affect air traffic and its operators both in the short and in the long run. This study charts the significant factors in Finnish air traffic and creates four distinct scenarios for the future. These scenarios were produced on the basis of the currently available facts and are attempts to provide several alternatives for the future. The study's goal has been to produce a visionary depiction that helps one to visualise and understand the whole picture. The perspective chosen for consideration of the future is the year 2025. The study describes four scenarios differing clearly from each other. In the first, entitled Globaalista maailmasta blokkeihin (From a global world to blocs), states form clusters and regional co-operation takes precedence over the current global direction of development. The second, Eurooppa omalla reitillaeaen (Europe on its own way), depicts Europe ahead of the rest of the world in terms of environmental regulation for air traffic. Uudistuksilla talouskukoistukseen (Economic boom through reforms) is based on an optimistic economic outlook. In contrast, Oeljykriisistae taloustaantumaan (From oil crisis to recession), describes a world where economic growth has been forestalled by rising oil prices due to increasing scarcity. The study investigates passenger numbers, air traffic within Finland, the international route network, and the changes these display in the various scenarios. The estimates are designed to highlight the development trends affecting air traffic in different operating environments. Since Finland is a small country and set apart from the rest of Europe in a fashion similar to island states, air traffic is of major importance and cannot be efficiently replaced by other forms of traffic. In particular, the individual scenarios stress the impact of international interaction and economic development with regard

  14. 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...

  15. 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.

  16. 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

  17. 空中交通管制安全风险预警决策模式%Early Warning Decision Model of Safety Risk in Air Traffic Control

    Institute of Scientific and Technical Information of China (English)

    罗帆; 杨智

    2013-01-01

    The existing decision problems in the early warning management were discussed using decision theory. The effectiveness of early warning and the accuracy improvement of the early warning signal output practice were investigated. From the level of preventing missing alarming and false alarming, the connotation of early warning decision was defined and warning decision model was designed. And the decision object which needs to be focused on in the warning decision model operation was analyzed. It was pointed out that the choice of decisions implement, restructure of the index system and threshold value definition were the main works of early warning decision-making model. It provided novel research field in the air traffic control in the early warning management theory.%针对空中交通管制安全风险预警管理中,如何实现有效预警,提高预警信号输出精度的实际问题,引入决策理论,探讨预警管理中存在的决策问题.从漏警、虚警防范的层面,定义预警决策的内涵,设计预警决策模式,并对预警决策模式运行中需要重点关注的决策对象进行了分析,指出指标体系再构、阈值界定,及以预警诊断方法为集合的决策器选择,是预警决策模式的主要工作导向,从而为空中交通管制预警管理理论导入新的研究内容.

  18. 空中飞机侧向间隔标准的初步研究%Study of Lateral Separation in Air Traffic Control

    Institute of Scientific and Technical Information of China (English)

    王欣; 徐肖豪

    2001-01-01

    This paper is focused on the study of lateral separation between two aircraft flying en route. First in the light of the design of airways and the use of navigational equipment in air traffic control systems it points out two significant factors that influence lateral separation greatly. Secondly by using the probability theory it makes an analysis of the position relationship between two aircraft in two circumstances parallel airways and cross airways and establishes the probability model of collision. Finally through numerical calculation the factors' effect on collision probability is computed and a method for the study of how to lay down lateral separation criteria is devised.%主要讨论了在航路飞行过程中飞机间的侧向间隔问题。首先,根据实际航路的设计方式和导航设备的使用情况,提出了两项影响侧向间隔的因素,并分析了其对侧向间隔的影响情况;然后,以概率论为工具,分平行航路和交叉航路两种情况,分析了两架飞机之间的距离关系,从而推导出两机可能相撞的概率,建立起飞机相撞的概率模型;最后,通过具体的数值计算,分析了各因素对飞机相撞概率的实际影响,从而建立起一种对侧向间隔制定进行定量研究的方法。

  19. 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

  20. 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.

  1. Traffic Light Control by Multiagent Reinforcement Learning Systems

    NARCIS (Netherlands)

    Bakker, B.; Whiteson, S.; Kester, L.J.H.M.; Groen, F.C.A.

    2010-01-01

    Traffic light control is one of the main means of controlling road traffic. Improving traffic control is important because it can lead to higher traffic throughput and reduced traffic congestion. This chapter describes multiagent reinforcement learning techniques for automatic optimization of traffi

  2. Traffic light control by multiagent reinforcement learning systems

    NARCIS (Netherlands)

    B. Bakker; S. Whiteson; L. Kester; F.C.A. Groen

    2010-01-01

    Traffic light control is one of the main means of controlling road traffic. Improving traffic control is important because it can lead to higher traffic throughput and reduced traffic congestion. This chapter describes multiagent reinforcement learning techniques for automatic optimization of traffi

  3. 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. PMID:18808393

  4. 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.

  5. 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.

  6. Medication wrong route administration: a poisons center-based study

    OpenAIRE

    Bloch-Teitelbaum, Alexandra; Lüde, Saskia; Rauber-Lüthy, Christine; Kupferschmidt, Hugo; Russmann, Stefan; Kullak-Ublick, Gerd A.; Ceschi, Alessandro

    2013-01-01

    OBJECTIVES: To describe clinical effects, circumstances of occurrence, management and outcomes of cases of inadvertent administration of medications by an incorrect parenteral route. METHODS: Retrospective single-center consecutive review of parenteral route errors of medications, reported to our center between January 2006 and June 2010. We collected demographic data and information on medications, route and time of administration, severity of symptoms/signs, treatment, and outcome. RE...

  7. 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

  8. Navigation safety caravan route towing in stationary traffic

    OpenAIRE

    Brazhny A. I.

    2015-01-01

    The questions of navigation safety of restricted sea-going object movement have been considered; the trajectory of a restricted sea-going object as part of tow caravan has been scientifically substantiated; the vector linear equation in stationary traffic has been solved

  9. Controlling Disorder in Traffic Flow by Perturbation

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; GAO Zi-You; CHEN Tian-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.

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

    OpenAIRE

    Meng Chi; Shufen Liu; Changhong Hu

    2014-01-01

    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 strat...

  11. 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.

  12. 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.

  13. Gis-Based Route Finding Using ANT Colony Optimization and Urban Traffic Data from Different Sources

    Science.gov (United States)

    Davoodi, M.; Mesgari, M. S.

    2015-12-01

    Nowadays traffic data is obtained from multiple sources including GPS, Video Vehicle Detectors (VVD), Automatic Number Plate Recognition (ANPR), Floating Car Data (FCD), VANETs, etc. All such data can be used for route finding. This paper proposes a model for finding the optimum route based on the integration of traffic data from different sources. Ant Colony Optimization is applied in this paper because the concept of this method (movement of ants in a network) is similar to urban road network and movements of cars. The results indicate that this model is capable of incorporating data from different sources, which may even be inconsistent.

  14. Bidirectional Dijkstra algorithm for best-routing of urban traffic network

    Science.gov (United States)

    Chen, Luyao; Zhou, Ji; Li, Jing; Chen, Yunhao

    2007-06-01

    Best-routing is one of the effective ways to solve the problem of traffic jam in a technical way. Based on the classic Dijkstra Algorithm, the bidirectional search algorithm is adopted to improve algorithmic efficiency in this paper. And section resistance is also adopted in best-routing model in order to indicate not only the condition of road itself, but also the information like traffic flow, which can make the road information more general and efficient. And cross linked list is adopted to reflect topological information of road net, which ensures the weight keep minimum. The feasibility and efficiency are verified by a study case of local area in Beijing.

  15. Reduction of the air traffic's contribution to climate change: A REACT4C case study

    Science.gov (United States)

    Grewe, Volker; Champougny, Thierry; Matthes, Sigrun; Frömming, Christine; Brinkop, Sabine; Søvde, Ole Amund; Irvine, Emma A.; Halscheidt, Lucia

    2014-09-01

    Air traffic alters the atmospheric composition and thereby contributes to climate change. Here we investigate the trans-Atlantic air traffic for one specific winter day and analyse, which routing changes were required to achieve a reduction in the air traffic's contribution to climate change. We have applied an atmosphere-chemistry model to calculate so-called five dimensional climate cost functions (CCF), which describe the climate effect of a locally confined emission. The five dimensions result from the emission location (3D), time (1D) and the type of emission (1D; carbon dioxide, water vapour, nitrogen oxides). In other words, carbon dioxide (CO2), water vapour (H2O) and nitrogen oxides (NOx) are emitted in amounts typical for aviation at many confined locations and times and their impacts on climate calculated with the atmosphere-chemistry model. The impact on climate results from direct effects, such as the changes in the concentration of the greenhouse gases CO2 and H2O and indirect effects such as contrail cirrus formation and chemical changes of ozone and methane by emissions of NOx. These climate cost functions are used by a flight planning tool to optimise flight routes with respect to their climate impact and economic costs of these routes. The results for this specific winter day show that large reductions in the air traffic's contribution to climate warming (up to 60%) can be achieved for westbound flights and smaller reductions for eastbound flights (around 25%). Eastbound flights take advantage of the tail winds from the jet stream and hence routings with lower climate impacts have a large fuel penalty, whenever they leave the jet stream. Maximum reduction in climate impact increases the economic costs by 10-15%, due to higher fuel consumption, caused by a longer flight distance and lower flight levels. However, with only small changes to the air traffic routings and flight altitudes, climate reductions up to 25% can be achieved by only small

  16. 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...

  17. 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.

  18. Traffic Control in ATM Networks : Engineering Impacts of Realistic Traffic Processes

    OpenAIRE

    Jena, Ajit K.; Popescu, Adrian; Pruthi, Parag; Erramilli, Ashok

    1996-01-01

    This paper reviews the current state of the art in the rapidly developing areas of ATM traffic controls and traffic modeling, and identifies future research areas to facilitate the implementation of control methods that can support a desired quality of service without sacrificing network utilizations. Two sets of issues are identified, one on the impacts of realistic traffic on the efficacy of traffic controls in supporting specific traffic management objectives, and the other dealing with th...

  19. Performance of an Automated System for Control of Traffic in Terminal Airspace

    Science.gov (United States)

    Nikoleris, Tasos; Erzberger, Heinz; Paielli, Russell A.; Chu, Yung-Cheng

    2016-01-01

    This paper examines the performance of a system that performs automated conflict resolution and arrival scheduling for aircraft in the terminal airspace around major airports. Such a system has the potential to perform separation assurance and arrival sequencing tasks that are currently handled manually by human controllers. The performance of the system is tested against several simulated traffic scenarios that are characterized by the rate at which air traffic is metered into the terminal airspace. For each traffic scenario, the levels of performance that are examined include: number of conflicts predicted to occur, types of resolution maneuver used to resolve predicted conflicts, and the amount of delay for all flights. The simulation results indicate that the percentage of arrivals that required a maneuver that changes the flight's horizontal route ranged between 11% and 15% in all traffic scenarios. That finding has certain implications if this automated system were to be implemented simply as a decision support tool. It is also found that arrival delay due to purely wake vortex separation requirements on final approach constituted only between 29% and 35% of total arrival delay, while the remaining major portion of it is mainly due to delay back propagation effects.

  20. 基于BDI模型的管制员Agent行为建模研究%Research on Behavioral Modeling of Air Traffic Controller Based on BDI Agent

    Institute of Scientific and Technical Information of China (English)

    刘岳鹏; 隋东; 林颖达

    2016-01-01

    针对空中交通仿真系统中的管制员Agent建模问题,通过分析管制操作行为特点,采用BDI结构,建立了基于决策树模型的管制规则知识库,设计了慎思型管制员Agent。基于Jadex平台,构建了管制员Agent模型,将由JADE平台建立的航空器Agent和模拟空管自动化系统Agent与Jadex平台建立的管制员Agent进行通信与协调,通过仿真系统构建仿真场景并验证管制员Agent的BDI推理过程,实现了对管制员的日常指挥行为的模拟。实验结果表明,所构建的管制员Agent模型可以顺利进行推理过程并对飞行冲突进行探测与解脱。%For ATC operational behavior modeling problems in air traffic control simulation,this paper an-alyzed the behavior characteristic of ATC operation,and adopted BDI structure of establishing the conflict detection and resolution rule library of ATC Agent based on decision tree. Finally,this paper designed the deliberative type of ATC Agent. Based on Jadex platform,the model of ATC Agent was constructed. Then this paper have assembled the ATC Agent model to communicate and coordinate with other two kinds of Agent models,namely,aircraft Agent and ATC Automation Systems Agent established on JADE platform. The simulation scenario was constructed through simulation system and the BDI reasoning process of ATC Agent was verified. The results show that: the ATC Agent model can reasoning smoothly and detect and resolute the conflict between aircraft Agents.

  1. 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.

  2. 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...

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 47 CFR 2.402 - Control of distress traffic.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Control of distress traffic. 2.402 Section 2... distress traffic. The control of distress traffic is the responsibility of the mobile station in distress... distress call. These stations may, however, delegate the control of the distress traffic to another station....

  9. 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....

  10. 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...

  11. 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...

  12. Control techniques for an automated mixed traffic vehicle

    Science.gov (United States)

    Meisenholder, G. W.; Johnston, A. R.

    1977-01-01

    The paper describes an automated mixed traffic vehicle (AMTV), a driverless low-speed tram designed to operate in mixed pedestrian and vehicular traffic. The vehicle is a six-passenger electric tram equipped with sensing and control which permit it to function on existing streets in an automatic mode. The design includes established wire-following techniques for steering and near-IR headway sensors. A 7-mph cruise speed is reduced to 2 mph or a complete stop in response to sensor (or passenger) inputs. The AMTV performance is evaluated by operation on a loop route and by simulation. Some necessary improvements involving sensors, sensor pattern, use of an audible signal, and control lag are discussed. It is suggested that appropriate modifications will eliminate collision incidents.

  13. 基于复杂网络流模型的空管设备布局算法研究%Research on facilities layout of air traffic control system based on complex network flow model

    Institute of Scientific and Technical Information of China (English)

    邵荃; 吴抗抗; 韩松臣

    2012-01-01

    In order to ensure the secure and effective operation of the ATC system, the complex network theory is used in support ability analysis of air traffic control facilities. The business continuity assessment model of air traffic control facilities based on the complex dynamic network flow capacity model is proposed, the vulnerable spot and area of continuity capability in air traffic control facilities operation are analyzed and corresponding complex network -based layout planning algorithm with multiple constraints is provided. The network configuration of air traffic control facilities with multiple-coverage characteristic and the impact of emergency events on it are investigated with the method, the complex dynamic network flow capacity model alters the traditional analysis mode which studies only separated facility. Meanwhile, the complex network-based layout planning algorithm with multiple constraints alters current analysis and deployment mode relying only on human experience and lacking of theory support. The facilities layout planning of air traffic control system ensures the continuity capability of air traffic control facilities in emer-geney events.%为保障空管系统安全有效运行,将复杂网络理论用于空管设备系统应急保障能力分析.建立基于复杂动态网络流-容量模型的空管设备系统业务持续性评估模型,分析空管设备系统中运行持续性较差的薄弱环节和区域,提出基于复杂网络的多约束空管设备布局规划算法.基于复杂网络理论的空管设备布局规划算法能够有效分析空管设备多重覆盖特征的网络结构和突发事件对空管设备系统的冲击,其中空管设备系统业务持续性评估模型改变了以往仅注重单个设备可靠性的分析方式,基于复杂网络的多约束空管设备布局规划算法改变了目前主要根据经验进行分析和配置而缺乏科学理论支持的现状.该设备布局规划算法确保了空管设

  14. 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.

  15. Mobile Application for GBAS Air Traffic Status Unit

    OpenAIRE

    Zaidi, Hiba

    2014-01-01

    At present, the Air Traffic Status Unit is a windows PC based application, which receives the status of ground based augmentation system station over Ethernet and displays on the screen. The objective of this project is to convert the PC based Application into Mobile application using Android OS.

  16. 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....

  17. 47 CFR 80.325 - Control of distress traffic.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Control of distress traffic. 80.325 Section 80... Safety Procedures § 80.325 Control of distress traffic. (a) Distress traffic consists of all messages relating to the immediate assistance required by the mobile station in distress. In distress traffic,...

  18. 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

  19. 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...

  20. A Fundamental Study on Area Traffic Control System

    OpenAIRE

    HONDA, Yoshiaki

    1992-01-01

    To save traffic congestion, this report aims at the area traffic control which increasesarea. traffic capacity without expansion of traffic facilities. This method is called AREATRAFFIC CONTROL SYSTEM.Optimum solutions for the area control system are obtained by the use of operationsresearch method. But above calculation time takes too long to fit this optimumregulation to present traffic pattern.In this report, optimization is made by the approximate solution which is composedof the first op...

  1. A scalable multi-sink gradient-based routing protocol for traffic load balancing

    Directory of Open Access Journals (Sweden)

    Kim Dongkyun

    2011-01-01

    Full Text Available Abstract Wireless sensor networks have been assumed to consist of a single sink and multiple sensor nodes which do not have mobility. In these networks, sensor nodes near the sink dissipate their energy so fast due to their many-to-one traffic pattern, and finally they die early. This uneven energy depletion phenomenon known as the hot spot problem becomes more serious as the number of sensor nodes (i.e., their scale increases. Recently, multi-sink wireless sensor networks have been envisioned to solve the hot spot problem. Gradient routing protocols are known to be appropriate for the networks in that network traffic is evenly distributed to multiple sinks to prolong network lifetime and they are scalable. Each node maintains its gradient representing the direction toward a neighbor node to reach one of the sinks. In particular, existing protocols allow a sensor node to construct its gradient using the cumulative traffic load of a path for load balancing. However, they have a critical drawback that a sensor node cannot efficiently avoid using the path with the most overloaded node. Hence, this paper introduces a new Gradient routing protocol for LOad-BALancing (GLOBAL with a new gradient model to maximize network lifetime. The proposed gradient model considers both of the cumulative path load and the traffic load of the most overloaded node over the path in calculating each node's gradient value. Therefore, packets are forwarded over the least-loaded path, which avoids the most overloaded node. In addition, it is known that assigning a unique address to each sensor node causes much communication overhead. Since the overhead increases as the network scales, routing protocols using an address to indicate the receiver in forwarding a packet are not scalable. Thus, GLOBAL also includes an addressing-free data forwarding strategy. Through ns-2 simulation, we verify that GLOBAL achieves better performance than the shortest path routing and load

  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. 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.

  4. 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...

  5. 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.

  6. 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, ...

  7. [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.

  8. Multiagent Reinforcement Learning for Urban Traffic Control Using Coordination Graphs

    OpenAIRE

    Kuyer, Lior; Whiteson, Shimon; Bakker, Bram; Vlassis, Nikos

    2008-01-01

    Since traffic jams are ubiquitous in the modern world, optimizing, the behavior of traffic lights for efficient traffic flow is a critically important goal. Though most current traffic lights use simple heuristic protocols, more efficient controllers can be discovered automatically via multiagent reinforcement learning where each agent controls a single traffic light. However, in previous work on this approach, agents select only locally optimal actions without coordinating their behavior. Th...

  9. 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.

  10. Multiagent reinforcement learning for urban traffic control using coordination graphs

    NARCIS (Netherlands)

    L. Kuyer; S. Whiteson; B. Bakker; N. Vlassis

    2008-01-01

    Since traffic jams are ubiquitous in the modern world, optimizing the behavior of traffic lights for efficient traffic flow is a critically important goal. Though most current traffic lights use simple heuristic protocols, more efficient controllers can be discovered automatically via multiagent rei

  11. 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...

  12. Advanced Interactive Display Formats for Terminal Area Traffic Control

    Science.gov (United States)

    Grunwald, Arthur J.; Shaviv, G. E.

    1999-01-01

    This research project deals with an on-line dynamic method for automated viewing parameter management in perspective displays. Perspective images are optimized such that a human observer will perceive relevant spatial geometrical features with minimal errors. In order to compute the errors at which observers reconstruct spatial features from perspective images, a visual spatial-perception model was formulated. The model was employed as the basis of an optimization scheme aimed at seeking the optimal projection parameter setting. These ideas are implemented in the context of an air traffic control (ATC) application. A concept, referred to as an active display system, was developed. This system uses heuristic rules to identify relevant geometrical features of the three-dimensional air traffic situation. Agile, on-line optimization was achieved by a specially developed and custom-tailored genetic algorithm (GA), which was to deal with the multi-modal characteristics of the objective function and exploit its time-evolving nature.

  13. Diagnostic throughput factor analysis for en-route airspace and optimal aircraft trajectory generation based on capacity prediction and controller workload

    Science.gov (United States)

    Shin, Sanghyun

    Today's National Airspace System (NAS) is approaching its limit to efficiently cope with the increasing air traffic demand. Next Generation Air Transportation System (NextGen) with its ambitious goals aims to make the air travel more predictable with fewer delays, less time sitting on the ground and holding in the air to improve the performance of the NAS. However, currently the performance of the NAS is mostly measured using delay-based metrics which do not capture a whole range of important factors that determine the quality and level of utilization of the NAS. The factors affecting the performance of the NAS are themselves not well defined to begin with. To address these issues, motivated by the use of throughput-based metrics in many areas such as ground transportation, wireless communication and manufacturing, this thesis identifies the different factors which majorly affect the performance of the NAS as demand (split into flight cancellation and flight rerouting), safe separation (split into conflict and metering) and weather (studied as convective weather) through careful comparison with other applications and performing empirical sensitivity analysis. Additionally, the effects of different factors on the NAS's performance are quantitatively studied using real traffic data with the Future ATM Concepts Evaluation Tool (FACET) for various sectors and centers of the NAS on different days. In this thesis we propose a diagnostic tool which can analyze the factors that have greater responsibility for regions of poor and better performances of the NAS. Based on the throughput factor analysis for en-route airspace, it was found that weather and controller workload are the major factors that decrease the efficiency of the airspace. Also, since resources such as air traffic controllers, infrastructure and airspace are limited, it is becoming increasingly important to use the available resources efficiently. To alleviate the impact of the weather and controller

  14. Impact of Conflict Avoidance Responsibility Allocation on Pilot Workload in a Distributed Air Traffic Management System

    Science.gov (United States)

    Ligda, Sarah V.; Dao, Arik-Quang V.; Vu, Kim-Phuong; Strybel, Thomas Z.; Battiste, Vernol; Johnson, Walter W.

    2010-01-01

    Pilot workload was examined during simulated flights requiring flight deck-based merging and spacing while avoiding weather. Pilots used flight deck tools to avoid convective weather and space behind a lead aircraft during an arrival into Louisville International airport. Three conflict avoidance management concepts were studied: pilot, controller or automation primarily responsible. A modified Air Traffic Workload Input Technique (ATWIT) metric showed highest workload during the approach phase of flight and lowest during the en-route phase of flight (before deviating for weather). In general, the modified ATWIT was shown to be a valid and reliable workload measure, providing more detailed information than post-run subjective workload metrics. The trend across multiple workload metrics revealed lowest workload when pilots had both conflict alerting and responsibility of the three concepts, while all objective and subjective measures showed highest workload when pilots had no conflict alerting or responsibility. This suggests that pilot workload was not tied primarily to responsibility for resolving conflicts, but to gaining and/or maintaining situation awareness when conflict alerting is unavailable.

  15. Optimal and Robust Switching Control Strategies: Theory, and Applications in Traffic Management

    NARCIS (Netherlands)

    Hajiahmadi, M.

    2015-01-01

    Macroscopic modeling, predictive and robust control and route guidance for large-scale freeway and urban traffic networks are the main focus of this thesis. In order to increase the efficiency of our control strategies, we propose several mathematical and optimization techniques. Moreover, in the se

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

    OpenAIRE

    Helbing, Dirk; Lämmer, 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...

  17. A User Guide for Smoothing Air Traffic Radar Data

    Science.gov (United States)

    Bach, Ralph E.; Paielli, Russell A.

    2014-01-01

    Matlab software was written to provide smoothing of radar tracking data to simulate ADS-B (Automatic Dependent Surveillance-Broadcast) data in order to test a tactical conflict probe. The probe, called TSAFE (Tactical Separation-Assured Flight Environment), is designed to handle air-traffic conflicts left undetected or unresolved when loss-of-separation is predicted to occur within approximately two minutes. The data stream that is down-linked from an aircraft equipped with an ADS-B system would include accurate GPS-derived position and velocity information at sample rates of 1 Hz. Nation-wide ADS-B equipage (mandated by 2020) should improve surveillance accuracy and TSAFE performance. Currently, position data are provided by Center radar (nominal 12-sec samples) and Terminal radar (nominal 4.8-sec samples). Aircraft ground speed and ground track are estimated using real-time filtering, causing lags up to 60 sec, compromising performance of a tactical resolution tool. Offline smoothing of radar data reduces wild-point errors, provides a sample rate as high as 1 Hz, and yields more accurate and lag-free estimates of ground speed, ground track, and climb rate. Until full ADS-B implementation is available, smoothed radar data should provide reasonable track estimates for testing TSAFE in an ADS-B-like environment. An example illustrates the smoothing of radar data and shows a comparison of smoothed-radar and ADS-B tracking. This document is intended to serve as a guide for using the smoothing software.

  18. Multi-Agent Look-Ahead Traffic-Adaptive Control

    NARCIS (Netherlands)

    Van Katwijk, R.T.

    2008-01-01

    The objective of this thesis is to create a distributed, multi-agent, approach to traffic control. This PhD thesis' focus is on the control of a network instrumented by traffic signals.A thorough literature study has been performed, reviewing the current state of the art in traffic signal control.

  19. Traffic And Security Using Randomized Dispersive Routes In Heterogeneous Sensor Network

    Directory of Open Access Journals (Sweden)

    P.Karunakaran

    2012-02-01

    Full Text Available 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 attackand 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 by that node and hence they can intercept the information easily. In this paper we are proposing a key management scheme which only establishes shared keys with their communicating neighbour and a mechanism to generate randomized multipath routes for secure transmission of data to the sink. Here we are adopting heterogeneous sensor networks and we areutilizing elliptic curve cryptography for efficient key management which is more efficient, scalable, and highly secure and reduces communication overhead. The routes generated by our mechanism are highly dispersive, energy efficient and making them quite capable of bypassing the back holes at low energy cost.

  20. Valiant load-balanced robust routing algorithm for multigranularity connection requests in traffic-grooming WDM mesh networks

    Science.gov (United States)

    Zhang, Xiaoning; Li, Lemin; Wang, Sheng

    2006-09-01

    The paper considers the problem of establishing robust routes for multi-granularity connection requests in traffic-grooming WDM mesh networks and proposes a novel Valiant Load-Balanced robust routing scheme for the hose uncertain model. Our objective is to minimize the total network cost when assuring robust routing for all possible multi-granularity connection requests under the hose model. Since the optimization problem is recently shown to be NP-hard, two heuristic algorithms are proposed and compared. When implementing Valiant Load-Balanced robust routing scheme to WDM mesh networks, a novel traffic-grooming algorithm called MHF (minimal hop first) is proposed. We evaluate MHF by Valiant Load-Balanced robust routing with the traditional traffic-grooming algorithm by computer simulation.

  1. 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

    2013-01-01

    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. PMID:23807689

  2. 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.

  3. 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

  4. A geographic approach to modelling traffic air pollution exposures

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S. [National Environmental Research Inst., Dept. of Atmospheric Environment, Roskilde (Denmark)

    1999-02-01

    A new approach has been developed for estimation of human exposures to traffic air pollution. The system applies a Geographic Information System (GIS) and is based on the Danish Operational Street Pollution Model (OSPM), technical and cadastral digital maps (buildings, roads, address points, property limits) and available Danish national administrative databases on buildings, citizens and employees (BBR, CPR, CER). The model system computes air pollution levels at the postal address for human exposure estimation, and may be applied in exposure and health studies e.g. air pollution epidemiology, as well as in health risk assessment and management e.g. as a tool for decision-support in urban air quality management. (au) 16 refs.

  5. Home air-conditioning, traffic exposure, and asthma and allergic symptoms among preschool children.

    Science.gov (United States)

    Zuraimi, Mohamed Sultan; Tham, Kwok-Wai; Chew, Fook-Tim; Ooi, Peng-Lim; Koh, David

    2011-02-01

    Epidemiological data suggest that traffic exposures can influence asthma and allergic symptoms among preschool children; however, there is no information on risk reduction via home air-conditioning (AC). The aim of this study is to evaluate the associations of self-reported traffic densities with asthma and allergic symptoms among preschool children and determine whether AC is an effect modifier. A cross-sectional study adopting an expanded and modified ISAAC--International Study of Asthma and Allergies in Childhood conducted on randomly selected 2994 children living in homes without any indoor risk factors. Specific information on demographics, indoor home risk factors, and traffic variables were obtained. Adjusted prevalence ratios (PR) and 95% confidence interval (CI) were determined by Cox proportional hazard regression model with assumption of a constant risk period controlled for covariates. We found dose-response significant relationships between validated self-reported traffic densities and asthma and rhinitis symptoms. Among children sleeping in non-air-conditioned homes, there were stronger associations between asthma and rhinitis symptoms studied. PRs for heavy traffic density were 2.06 for wheeze (95% CI 0.97-4.38), 2.89 for asthma (1.14-7.32), 1.73 for rhinitis (1.00-2.99), and 3.39 for rhinoconjunctivitis (1.24-9.27). There were no associations found for children sleeping in air-conditioned homes. Our results suggest that AC in the bedroom modifies the health effects of traffic among preschool children. This finding suggests that attention should also be paid to ventilation characteristics of the homes to remediate health-related traffic pollution problems. PMID:20561230

  6. Study on the effect of lead and lead compounds as pollutants on traffic air and traffic policemen

    International Nuclear Information System (INIS)

    This study was conducted in Khartoum state to determine the magnitude of air pollution, resulting from traffic density, due to lead and lead compounds which had been used as additives for gasoline in the form of tetra-ethyl and tetra methyl lead. The level of lead in ambient air and SPM was determined in 14 samples taken randomly at the intersections and entrances to the bridges using personal sampler (Cassella. UK). The mean concentration of suspended particulate matter (SPM) was found to be 5.77+4.04 mg/m3. with range between 0.85-12.50 mg/m3 including three sites above the limit of 10 mg/m3 allowed. The samples were analyzed with Atomic Absorption Spectrophotometer for their lead content. The average concentration of lead in the sites is found to be 0.1937±0.1768 mg/m3. With range between 0.000-0.5166 mg/m3. The concentrations in seven sites were above the limit of 0.15 mg/m3 permitted internationally. The impact of lead pollution on traffic police men was measured by analyzing blood lead concentration of 30 members exposed to traffic air pollution, from the three cities and (10 samples) from non-exposed ( control). It was found to be 2.4601±1.4065μg/100 ml and 0.3944±1.2471 μg/ 100 ml respectively. The data analysis by used SPSS program. There is no significant difference between the two groups. A questionnaire was designed to find out some data about the exposed members including their knowledge of impact, range of age, duration of their service as traffic police, their previous work, and complaints from some of the health effects. The findings were: average age mean of 35.9 ±7.7 years, 47.48% worked for periods of more than 20 years, 74.19% did not work before joining the traffic police, 51.6% of them believe that there is a problem of high level of air pollution, 45.2% medium and 3.2%, pollution is low. As habits 38.71% are smokers. As for health complains, 61.29% have various complains of headaches, fatigue, abdominal, hypertension and anemia, these

  7. 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.

  8. 航管训练系统中远程控制的设计与实现%Design and Implementation of Remote Control in Air Traffic Control Simulator Training System

    Institute of Scientific and Technical Information of China (English)

    刘佳; 胡术; 莫晶; 董志强; 寇成坤

    2015-01-01

    ATC simulation training system is the main mean and standard equipment for training and improving the control skills for air traffic area and approach radar controllers,it can realistically simulate all training related objects including device and user interface,and provide a environment close to the real work to train controllers through simulating the different air traffic status. Describe a remote auto-matic control software ScriptDispatcher based on a managed thread pool in this paper,which performs configuration script commands to distribute programs and data concurrently to several hosts using Telnet and FTP. And it has completed the design and implementation of remote execution of functions. The main functions include the distribution of training data,the distribution of a new version of the pro-gram and remotely executing the running scripts. Practice has proved that the remote automatic control software ScriptDispatcher can quickly complete training preparation,running stably and reliably,reducing the burden of training personnel and improving work efficien-cy and system utilization in large ATC simulator training system.%航管模拟训练系统是用于培养和提高空中交通区域及近雷达管制人员管制技能的主要手段和标准设备,能够逼真地模拟包括设备、用户界面等所有与训练相关的对象,通过实时模拟不同空中交通状态,以提供一个接近真实的工作环境来训练管制员。文中描述了一个基于可管理线程池的远程自动控制软件ScriptDispatcher,并使用Telnet协议和FTP协议执行配置脚本命令对系统多台主机并发进行程序和数据分发以及远程执行的功能的设计与实现。主要功能包括:分发训练数据、分发新版本程序和远程执行运行脚本等。实践证明,在大型航管模拟训练系统中,远程自动控制软件ScriptDis-patcher可以快速完成训练准备,运行稳定可靠,减轻了训练人员的负担,有效提

  9. Design and Simulation of a Decentralized Railway Traffic Control System

    Directory of Open Access Journals (Sweden)

    T. Kara

    2016-04-01

    Full Text Available With the increasing use of railway transportation, various methods have been developed for the control and management of train traffic. Train traffic control systems that are currently in use are overwhelmingly centralized systems. In this study, the development of the general structure of railway traffic control techniques is examined, centralized and decentralized control systems are investigated, and an alternative train traffic control system, the Decentralized Train Traffic Management System (DTMS, is suggested. Simulation results on the possible application of the proposed method to a railway line in South-East Turkey are employed to evaluate the performance of the developed system.

  10. 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.

  11. Highway route controlled quantity shipment routing reports - An overview

    International Nuclear Information System (INIS)

    US Department of Transportation (DOT) regulations require a postnotification report from the shipper for all shipments of radioactive materials categorized as a Highway Route Controlled Quantity. These postnotification reports, filed in compliance with 49 CFR 172.203(d), have been compiled by the DOT in a database known as the Radioactive Materials Routing Report (RAMRT) since 1982. The data were sorted by each of its elements to establish historical records and trends of Highway Route Controlled Quantity shipments from 1982 through 1987. Approximately 1520 records in the RAMRT database were compiled for this analysis. Approximately half of the shipments reported for the study period were from the US Department of Energy (DOE) and its contractors, with the others being commercial movements. Two DOE installations, EG and G Idaho and Oak Ridge, accounted for nearly half of the DOE activities. Similarly, almost half of the commercial movements were reported by two vendors, Nuclear Assurance Corporation and Transnuclear, Incorporated. Spent fuel from power and research reactors accounted for approximately half of all shipments

  12. 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.

  13. 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 ...

  14. Ising model for packet routing control

    International Nuclear Information System (INIS)

    For packet routing control in computer networks, we propose an Ising model which is defined in order to express competition among a queue length and a distance from a node with a packet to its destination node. By introducing a dynamics for a mean-field value of an Ising spin, we show by computer simulations that effective control of packet routing through priority links is possible

  15. [Scientific and methodologic basis of a program for occupational control of ambient air quality within a totally sanitary protective zone at an industrial center borderline (Permsky area experience)].

    Science.gov (United States)

    Maĭ, I V; Balashov, S Iu

    2013-01-01

    The authors suggested and tested an algorithm to select optimal placement of stationary and mobile points for controlling ambient air quality on borderline of united sanitary protective zone of industrial center. The method involves claster analysis to outline sites even in levels and lists of parameters, on borderline of united sanitary protective zone of industrial center. Informative value of the occupational control parameters is evaluated through conjugated analysis of general level of surface concentration of admixtures and enterprise's contribution into pollution. For each enterprise, separate control program is provided. Tests of the method demonstrated that it is effective and conclusive in formation of minimally sufficient programs for occupational control in complicated conditions of industrial centers with single-field enterprises, when industrial releases are close in composition and in created pollution level. PMID:24640091

  16. An Experimental Study of the Effect of Shared Information on Pilot/Controller Re-Route Negotiation

    Science.gov (United States)

    Farley, Todd C.; Hansman, R. John

    1999-01-01

    Air-ground data link systems are being developed to enable pilots and air traffic controllers to share information more fully. The sharing of information is generally expected to enhance their shared situation awareness and foster more collaborative decision making. An exploratory, part-task simulator experiment is described which evaluates the extent to which shared information may lead pilots and controllers to cooperate or compete when negotiating route amendments. The results indicate an improvement in situation awareness for pilots and controllers and a willingness to work cooperatively. Independent of data link considerations, the experiment also demonstrates the value of providing controllers with a good-quality weather representation on their plan view displays. Observed improvements in situation awareness and separation assurance are discussed. It is argued that deployment of this relatively simple, low-risk addition to the plan view displays be accelerated.

  17. Aeronautical Communications Research and Development Needs for Future Air Traffic Management Applications

    Science.gov (United States)

    Kerczewski, Robert J.

    2002-01-01

    Continuing growth in regional and global air travel has resulted in increasing traffic congestion in the air and on the ground. In spite of occasional temporary downturns due to economic recessions and catastrophic events, average growth rates of air travel have remained high since the 1960s. The resulting congestion, which constrains expansion of the air transportation industry, inflicts schedule delays and decreases overall system efficiency, creating a pressing need to develop more efficient methods of air traffic management (ATM). New ATM techniques, procedures, air space automation methods, and decision support tools are being researched and developed for deployment in time frames stretching from the next few years to the year 2020 and beyond. As these methods become more advanced and increase in complexity, the requirements for information generation, sharing and transfer among the relevant entities in the ATM system increase dramatically. However, current aeronautical communications systems will be inadequate to meet the future information transfer demands created by these advanced ATM systems. Therefore, the NASA Glenn Research Center is undertaking research programs to develop communication, methods and key technologies that can meet these future requirements. As part of this process, studies, workshops, testing and experimentation, and research and analysis have established a number of research and technology development needs. The purpose of this paper is to outline the critical research and technology needs that have been identified in these activities, and explain how these needs have been determined.

  18. 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.

  19. 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

  20. Efficient routing and spectrum assignment in elastic optical networks with time scheduled traffic

    Science.gov (United States)

    Qiu, Yang; Fan, Zheyu; Chan, Chun-Kit

    2016-07-01

    Elastic optical networks (EONs) employ dynamic routing and spectrum assignment (RSA) algorithms to support diverse services and heterogeneous requests. However, these RSA algorithms may possibly induce spectrum fragments when allocating spectrum to accommodate different service requests. Therefore, such induced spectrum fragments should also be regarded as spectrum consumption besides the allocated spectrum by RSA algorithms. In this paper, by additionally considering the holding times of lightpaths and service connections, we first introduce a comprehensive spectrum consumption model to simultaneously investigate both the allocated and the fragmented spectrum consumptions. Then we solve this model in both static and dynamic traffic scenarios, by either formulating the RSA problem with time-scheduled traffic or introducing a time-aware spectrum-efficient heuristics algorithm. Since no defragmentation is executed in spectrum allocation, the proposed RSA algorithm requires no traffic disruption and can be realized more easily in reality. Simulation results show that the proposed algorithm reduces the comprehensive spectrum consumption and has lower bandwidth blocking probability than the typical first-fit RSA algorithm.

  1. 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.

  2. 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...

  3. An efficient method to detect periodic behavior in botnet traffic by analyzing control plane traffic

    Science.gov (United States)

    AsSadhan, Basil; Moura, José M.F.

    2013-01-01

    Botnets are large networks of bots (compromised machines) that are under the control of a small number of bot masters. They pose a significant threat to Internet’s communications and applications. A botnet relies on command and control (C2) communications channels traffic between its members for its attack execution. C2 traffic occurs prior to any attack; hence, the detection of botnet’s C2 traffic enables the detection of members of the botnet before any real harm happens. We analyze C2 traffic and find that it exhibits a periodic behavior. This is due to the pre-programmed behavior of bots that check for updates to download them every T seconds. We exploit this periodic behavior to detect C2 traffic. The detection involves evaluating the periodogram of the monitored traffic. Then applying Walker’s large sample test to the periodogram’s maximum ordinate in order to determine if it is due to a periodic component or not. If the periodogram of the monitored traffic contains a periodic component, then it is highly likely that it is due to a bot’s C2 traffic. The test looks only at aggregate control plane traffic behavior, which makes it more scalable than techniques that involve deep packet inspection (DPI) or tracking the communication flows of different hosts. We apply the test to two types of botnet, tinyP2P and IRC that are generated by SLINGbot. We verify the periodic behavior of their C2 traffic and compare it to the results we get on real traffic that is obtained from a secured enterprise network. We further study the characteristics of the test in the presence of injected HTTP background traffic and the effect of the duty cycle on the periodic behavior. PMID:25685512

  4. 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.

  5. 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...

  6. 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.

  7. 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. PMID:26415047

  8. Past and present measurement and control of radioactive emissions with the exhaust air of the Karlsruhe Research Center

    International Nuclear Information System (INIS)

    Radioactive releases with the exhaust air of almost 30 emitters of the Karlsruhe Research Center are monitored and measured. The maximum permissible releases of each emitter are laid down in the so-called 'gaseous effluent plan'. Thus, compliance with the dose limits pursuant to Sec. 45 of the Radiation Protection Ordinance is guaranteed for the whole site. In the course of the development of the Karlsruhe Research Center the gaseous effluent plan as well as the monitoring and measurement systems have been adopted to the individual requirements of each installation. Based on the measured data and the recorded weather statistics, the potential radiation exposure in the environment is calculated annually. Although activity discharges have decreased significantly because of nuclear installations having been decommissioned and dismantled, the effort for emission monitoring and measurement is still high. The calculated doses to the population decreased from almost 10 μSv/a in the early eighties to now less than 1 μSv/a. (orig.)

  9. 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.

  10. Sumatera Air Asia Training Center (Arsitektur Metafora)

    OpenAIRE

    Susanto, William

    2015-01-01

    Sumatera Air Asia Training Center as Air Asia training facility’s construction have a propose to train the Air Asia air craft crew who will be the employee of the Air Asia Airlines.Beside the main function;training facility for the Air Asia Crew; the other airline’s crew can be train by a cooperation with Air Asia.The aircraft crew that can be train in this facility is pilot initial, pilot type-rating, pilot recurrent, ATPL, Flight attendant initial and recurrent..This facility ha...

  11. 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.

  12. Hazards in air-, rail-, and road traffic arising from laserpointers

    International Nuclear Information System (INIS)

    Visible laser radiation with sufficient irradiance or radiant exposure might result in permanent damage of the eyes especially in the retina. In order to prevent this exposure limit values have been established based on current scientific knowledge. In addition visible laser radiation might result in effects like temporary blinding at even much lower exposure values. In this case irritations, flash-blindness and afterimages appear whose extent might exceed the respective damage level while vision is temporarily compromised in critical visual tasks more or less. The easy accessibility of hand-held laser products (laser pointers) with relatively high power might result in a modification of the security situation especially in air traffic via thoughtless and careless use of such products or in terroristic acts. In addition an increasing number of incidents in rail and road traffic where not only temporary blinding might be anticipated but permanent damage of the eyes as a result of overexposure due to laser pointer irradiation cannot be excluded any longer. Using laser pointers, which are available on the market in the power range up to 1 watt and at different wavelengths new hazard scenarios and threats with serious consequences are possible. Here the radiation protection is in great demand. (orig.)

  13. 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...... pollution affected risk for fatal strokes. There were indications of combined effects....... 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...

  14. 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.

  15. 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...

  16. 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.

  17. Association of Traffic-Related Air Pollution with Children’s Neurobehavioral Functions in Quanzhou, China

    OpenAIRE

    Wang, Shunqin; Zhang, Jinliang; Zeng, Xiaodong; Zeng, Yimin; Wang, Shengchun; Chen, Shuyun

    2009-01-01

    Background With the increase of motor vehicles, ambient air pollution related to traffic exhaust has become an important environmental issue in China. Because of their fast growth and development, children are more susceptible to ambient air pollution exposure. Many chemicals from traffic exhaust, such as carbon monoxide, nitrogen dioxide, and lead, have been reported to show adverse effects on neurobehavioral functions. Several studies in China have suggested that traffic exhaust might affec...

  18. Investigations on the distribution of air transport traffic and CO2 emissions within the European Union

    OpenAIRE

    Alonso Rodrigo, Gustavo; Benito, A; Lonza, L.; Kousoulidou, M.

    2014-01-01

    This study analyses the structure of air traffic and its distribution among the different countries in the European Union, as well as traffic with an origin or destination in non-EU countries. Data sources are Eurostat statistics and actual flight information from EUROCONTROL. Relevant variables such as the number of flights, passengers or cargo tonnes and production indicators (RPKs) are used together with fuel consumption and CO2 emissions data. The segmentation of air traffic in terms of d...

  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. 14 CFR 93.177 - Operations in the Special Air Traffic Rule Area.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Operations in the Special Air Traffic Rule Area. 93.177 Section 93.177 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... in the Vicinity of Luke AFB, AZ § 93.177 Operations in the Special Air Traffic Rule Area. (a)...

  1. 77 FR 52107 - Air Traffic Data in the Possession of Government Contractors

    Science.gov (United States)

    2012-08-28

    ... Federal Aviation Administration Air Traffic Data in the Possession of Government Contractors AGENCY... FAA's possession and the data will facilitate the individual's ability to participate in a proceeding related to an FAA investigation. Some ``air traffic data'' are in the possession of government...

  2. 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.

  3. 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...

  4. Traffic engineering in ambient networks: challenges and approaches

    OpenAIRE

    Abrahamsson, Henrik; Gunnar, Anders

    2004-01-01

    The focus of this paper is on traffic engineering in ambient networks. We describe and categorize different alternatives for making the routing more adaptive to the current traffic situation and discuss the challenges that ambient networks pose on traffic engineering methods. One of the main objectives of traffic engineering is to avoid congestion by controlling and optimising the routing function, or in short, to put the traffic where the capacity is. The main challenge for traffic engin...

  5. 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.

  6. 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.

  7. 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。

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. Traffic Modelling for Moving-Block Train Control System

    International Nuclear Information System (INIS)

    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.

  13. 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.

  14. 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.

  15. 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.

  16. An extended signal control strategy for urban network traffic flow

    Science.gov (United States)

    Yan, Fei; Tian, Fuli; Shi, Zhongke

    2016-03-01

    Traffic flow patterns are in general repeated on a daily or weekly basis. To improve the traffic conditions by using the inherent repeatability of traffic flow, a novel signal control strategy for urban networks was developed via iterative learning control (ILC) approach. Rigorous analysis shows that the proposed learning control method can guarantee the asymptotic convergence. The impacts of the ILC-based signal control strategy on the macroscopic fundamental diagram (MFD) were analyzed by simulations on a test road network. The results show that the proposed ILC strategy can evenly distribute the accumulation in the network and improve the network mobility.

  17. 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.

  18. 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…

  19. 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.

  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. Traffic-Related Air Toxics and Term Low Birth Weight in Los Angeles County, California

    OpenAIRE

    Wilhelm, Michelle; Ghosh, Jo Kay; Su, Jason; Cockburn, Myles; Jerrett, Michael; Ritz, Beate

    2011-01-01

    Background: Numerous studies have linked criteria air pollutants with adverse birth outcomes, but there is less information on the importance of specific emission sources, such as traffic, and air toxics. Objectives: We used three exposure data sources to examine odds of term low birth weight (LBW) in Los Angeles, California, women when exposed to high levels of traffic-related air pollutants during pregnancy. Methods: We identified term births during 1 June 2004 to 30 March 2006 to women res...

  2. 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...

  3. 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....

  4. 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.

  5. 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

  6. 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 ...

  7. Forecasting Air Traffic and corresponding Jet-Fuel Demand until 2025

    International Nuclear Information System (INIS)

    This paper provides i) air traffic and ii) Jet-Fuel demand projections at the worldwide level and for eight geographical zones until 2025. The general methodology may be summarized in two steps. First, air traffic forecasts are estimated using econometric methods. The modeling is performed for eight geographical zones, by using dynamic panel-data econometrics. Once estimated from historical data, the model is then used to generate air traffic forecasts. Second, the conversion of air traffic projections into quantities of Jet-Fuel is accomplished using the 'Traffic Efficiency' method developed previously by UK DTI to support the IPCC (IPCC (1999)). One of our major contribution consists in proposing an alternative methodology to obtain Energy Efficiency coefficients and energy efficiency improvements estimates based on modeling at the macro-level. These estimates are obtained by directly comparing the evolution of both Jet-Fuel consumption and air traffic time series from 1983 to 2006. According to our 'Business As Usual' scenario, air traffic should increase by about 100% between 2008 and 2025 at the world level, corresponding to a yearly average growth rate of about 4.7%. World Jet-Fuel demand is expected to increase by about 38% during the same period, corresponding to a yearly average growth rate of about 1, 9% per year. Air traffic energy efficiency improvements yield effectively to reduce the effect of air traffic rise on the Jet-Fuel demand increase, but do not annihilate it. Thus, Jet- Fuel demand is unlikely to diminish unless there is a radical technological shift, or air travel demand is restricted. (authors)

  8. 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.

  9. 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...

  10. 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.

  11. Air quality of Prague: traffic as a main pollution source.

    Science.gov (United States)

    Branis, Martin

    2009-09-01

    Political and economical transition in the Central and Eastern Europe at the end of eighties significantly influenced all aspects of life as well as technological infrastructure. Collapse of outdated energy demanding industry and adoption of environmental legislation resulted in seeming improvements of urban environmental quality. Hand in hand with modernization the newly adopted regulations also helped to phase out low quality coal frequently used for domestic heating. However, at the same time, the number of vehicles registered in the city increased. The two processes interestingly acted as parallel but antagonistic forces. To interpret the trends in urban air quality of Prague, Czech capital, monthly averages of PM(10), SO(2), NO(2), NO, O(3) and CO concentrations from the national network of automated monitoring stations were analyzed together with long term trends in fuel consumption and number of vehicles registered in Prague within a period of 1992-2005. The results showed that concentrations of SO(2) (a pollutant strongly related to fossil fuel burning) dropped significantly during the period of concern. Similarly NO(X) and PM(10) concentrations decreased significantly in the first half of the nineties (as a result of solid fuel use drop), but remained rather stable or increased after 2000, presumably reflecting rapid increase of traffic density. In conclusion, infrastructural changes in early nineties had a strong positive effect on Prague air quality namely in the first half of the period studied, nevertheless, the current trend in concentrations of automotive exhaust related pollutants (such as PM(10), NO(X)) needs adoption of stricter measures. PMID:18709434

  12. Real-time operational planning for the U.S. air traffic system

    Science.gov (United States)

    Mulvey, John M.; Zenios, Stavros A.

    1987-01-01

    This paper describes an integrated planning model for the U.S. air traffic system. The approach incorporates the dual objectives of monitoring collision risk while minimizing transportation costs. Specialized solution algorithms exploit the underlying structure of the model - especially for large-scale examples. The proposed formulation is tested with real-world data for the Indianapolis control sector. Additional experiments with a CRAY X-MP/24 supercomputer show that a full-scale model can be solved under real time conditions. Despite these advances, additional work is required in developing a practical system. Suggestions are made for combining advances in computer graphics and mathematical modeling.

  13. 77 FR 28460 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2012-05-14

    ..., 2010, request for comments on traffic control compliance dates published at 75 FR 74128. As a result... dates. \\1\\ 75 FR 74128, November 30, 2010. After reviewing and considering the nearly 600 letters... representatives, traffic engineering consultants, and private citizens, on August 31, 2011, the FHWA published...

  14. 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...

  15. Do Traffic Controllers Dream of Electric Cars?

    Directory of Open Access Journals (Sweden)

    Nicholas Taylor

    2015-03-01

    Full Text Available Traffic congestion is not a modern phenomenon, but the growth of motor traffic driven by the supply of petroleum is. This coincides with concern about climate change caused by carbon emissions to which transport makes a substantial and increasing contribution. It seems that private cars in particular cannot be useful without coming to dominate human activity and even whole economies, creating dependence, congestion and severance which paradoxically negate many of the benefits of mobility. Electrification may reduce carbon emissions, but is unlikely to support the same weight of motor traffic, and will not reduce its other effects. It is doubtful that sustainability, however defined, is compatible with current high and increasing levels of motorised movement, so a culture change will be needed.

  16. 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.

  17. 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.

  18. 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.

  19. Prenatal exposure to traffic-related air pollution and risk of early childhood cancers.

    Science.gov (United States)

    Ghosh, Jo Kay C; Heck, Julia E; Cockburn, Myles; Su, Jason; Jerrett, Michael; Ritz, Beate

    2013-10-15

    Exposure to air pollution during pregnancy has been linked to the risk of childhood cancer, but the evidence remains inconclusive. In the present study, we used land use regression modeling to estimate prenatal exposures to traffic exhaust and evaluate the associations with cancer risk in very young children. Participants in the Air Pollution and Childhood Cancers Study who were 5 years of age or younger and diagnosed with cancer between 1988 and 2008 were had their records linked to California birth certificates, and controls were selected from birth certificates. Land use regression-based estimates of exposures to nitric oxide, nitrogen dioxide, and nitrogen oxides were assigned based on birthplace residence and temporally adjusted using routine monitoring station data to evaluate air pollution exposures during specific pregnancy periods. Logistic regression models were adjusted for maternal age, race/ethnicity, educational level, parity, insurance type, and Census-based socioeconomic status, as well as child's sex and birth year. The odds of acute lymphoblastic leukemia increased by 9%, 23%, and 8% for each 25-ppb increase in average nitric oxide, nitrogen dioxide, and nitrogen oxide levels, respectively, over the entire pregnancy. Second- and third-trimester exposures increased the odds of bilateral retinoblastoma. No associations were found for annual average exposures without temporal components or for any other cancer type. These results lend support to a link between prenatal exposure to traffic exhaust and the risk of acute lymphoblastic leukemia and bilateral retinoblastoma. PMID:23989198

  20. Improving Experience-Based Admission Control through Traffic Type Awareness

    OpenAIRE

    Jens Milbrandt; Michael Menth; Jan Junker

    2007-01-01

    Experience-based admission control (EBAC) is a hybrid approach combining the classical parameter-based and measurement-based admission control. EBAC calculates an appropriate overbooking factor used to overbook link capacities with resource reservations in packet-switched networks. This overbooking factor correlates with the average peak-to-mean rate ratio of all admitted traffic flows on the link. So far, a single overbooking factor is calculated for the entire traffic aggregate. In this pap...

  1. 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.

  2. 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...

  3. 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.

  4. 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.

  5. 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

  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

    was calculated by dispersion models, and the time-weighted average concentration for all addresses was calculated for each person. We used Cox models to estimate incidence rate ratios after adjustment for smoking (status, duration, and intensity), educational level, body mass index, and alcohol consumption...... 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....

  7. Self-management in Future Internet Wireless Networks: Dynamic Resource Allocation and Traffic Routing for Multi-service Provisioning

    Science.gov (United States)

    Chochliouros, Ioannis P.; Alonistioti, Nancy; Spiliopoulou, Anastasia S.; Agapiou, George; Mihailovic, Andrej; Belesioti, Maria

    Evolution towards the Future (Internet) networks necessitates inclusion of self-management capabilities in modern network infrastructures, for a satisfactory provision of related services and for preserving network performance. We have considered a specific targeted methodology, in the form of the generic cognitive cycle model, which includes three distinct processes (i.e. Monitoring, Decision Making and Execution), known as the “MDE” model, able to support dynamic resource allocation and traffic routing schemes. For further understanding of the issue we have examined two essential use-cases of practical interest, both in the context of modern wireless infrastructures: The former was about dynamic spectrum re-allocation for efficient use of traffic, while the latter has examined intelligent dynamic traffic management for handling network overloads, to avoid congestion.

  8. Traffic Flow Analysis Model based Routing Protocol For Multi-Protocol Label Switching Network

    OpenAIRE

    E.R. Naganathan; Rajagopalan, S.; P. H. Raj

    2011-01-01

    Problem statement: Multi-Protocol Label Switching (MPLS) is a mechanism which is used in high-performance telecommunications networks that directs and carries data from one network node to the next with the help of labels. Traffic management is still an issue in MPLS network as it involves high speed internet. Approach: This study proposed a traffic flow analysis of the real time MPLS traffic and segregates the MPLS traffic as three major class based on the outcome of traffic flow analysis. U...

  9. An intermodal traffic control strategy for private vehicle and public transport

    OpenAIRE

    BHOURI, N; LOTITO, P

    2005-01-01

    This paper proposes a traffic-responsive urban traffic control strategy allowing a real time passive public transport priority. The proposed strategy is based on a store and forward modeling of both of the private vehicle and Public transport traffic. The regulator is designed using the linear quadratic, which allows a traffic responsive co-ordinated control for wide-area networks. The objective of this strategy is to control the junctions traffic lights in order to improve the traffic perfor...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Evaluation of Intersection Traffic Control Measures through Simulation

    Science.gov (United States)

    Asaithambi, Gowri; Sivanandan, R.

    2015-12-01

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

  16. Proposed safety criteria for traffic control on motorways.

    NARCIS (Netherlands)

    Heijer, T. Wiersma, E. & Polak, P.H.

    1997-01-01

    The increasing traffic demand on Dutch motorways calls for more rigorous control than is currently available. In order to develop control systems that can cope with these conditions and can meanwhile maintain an acceptable level of safety we need controlling criteria that provide more detailed infor

  17. Long-term effects of traffic-related air pollution on mortality in a Dutch cohort (NLCS-AIR study)

    NARCIS (Netherlands)

    Beelen, R.; Hoek, G.; Brandt, P.A. van den; Goldbohm, R.A.; Fischer, P.; Schouten, L.J.; Jerrett, M.; Hughes, E.; Armstrong, B.; Brunekreef, B.

    2008-01-01

    Background: Several studies have found an effect on mortality of between-city contrasts in long-term exposure to air pollution. The effect of within-city contrasts is still poorly understood. Objectives: We studied the association between long-term exposure to traffic-related air pollution and morta

  18. 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 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.

  19. Controlling traffic jams by time modulating the safety distance

    DEFF Research Database (Denmark)

    Gaididei, Yu B.; Gorria, C.; Berkemer, R.;

    2013-01-01

    . 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......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...

  20. 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.

  1. Intellectual Green Wave Cloud for Traffic Control: Challenges and Proposed Solutions

    Directory of Open Access Journals (Sweden)

    Vladimir Hahanov

    2014-12-01

    Full Text Available A cloud service “Green Wave” for an intelligent road infrastructure is proposed to monitor and control traffic in real-time through the use of traffic controllers, RFID-tagged cars, and cloud based services. The proposed infrastructure aims to improve the quality and safety of vehicle movement as well as to minimize the time and costs when vehicles are moved at specified routes. In this paper, we propose a set of innovative scientific and technological solutions for solving social, human, economic and environmental problems associated with creation and use of a cloud for monitoring and management. All of these solutions are integrated into the model of real-time interaction between monitoring and management clouds, vehicles and road infrastructure. In this paper we describe in details of the model.

  2. 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...... and childhood leukemia. Methods: We included 985 cases of childhood leukemia and 1,969 control children. We used validated models to calculate residential radon and street NOx concentrations for each home. Conditional logistic regression analyses were used to analyze the effect of radon on childhood leukemia...... 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...

  3. 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

    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...... included 985 cases of childhood leukemia and 1,969 control children. We used validated models to calculate residential radon and street NOx concentrations for each home. Conditional logistic regression analyses were used to analyze the effect of radon on childhood leukemia risk within different strata...... 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...

  4. 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.……

  5. 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.

  6. Traffic Optimization to Control Epidemic Outbreaks in Metapopulation Models

    CERN Document Server

    Preciado, Victor M

    2013-01-01

    We propose a novel framework to study viral spreading processes in metapopulation models. Large subpopulations (i.e., cities) are connected via metalinks (i.e., roads) according to a metagraph structure (i.e., the traffic infrastructure). The problem of containing the propagation of an epidemic outbreak in a metapopulation model by controlling the traffic between subpopulations is considered. Controlling the spread of an epidemic outbreak can be written as a spectral condition involving the eigenvalues of a matrix that depends on the network structure and the parameters of the model. Based on this spectral condition, we propose a convex optimization framework to find cost-optimal approaches to traffic control in epidemic outbreaks.

  7. 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.

  8. 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.

  9. Reverse Stackelberg Games: Theory and Applications in Traffic Control

    NARCIS (Netherlands)

    Groot, N.B.

    2013-01-01

    One of the major challenges in optimization-based control of large-scale intelligent infrastructural networks such as traffic networks is to find efficient multilevel optimization schemes through which decisions can be made by agents or controllers of different interacting layers. The hierarchical

  10. 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

  11. 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

  12. 基于复杂网络理论的多元混合空管技术保障系统网络特征分析∗%Analysis on network prop erties of multivariate mixed air traffic management technical supp ort system based on complex network theory

    Institute of Scientific and Technical Information of China (English)

    武喜萍; 杨红雨; 韩松臣

    2016-01-01

    Air traffic management technical support system provides communication, navigation and surveillance service for air traffic management system and air traffic controller. The failures of some facilities may lead to large delay, even affect air transportation safety. In order to improve the ability of air traffic management technical support system to respond to emergencies, a network model of air traffic management technical support system is presented. The network model of air traffic management technical support system is established according to the effective coverage of communication, navigation and surveillance facilities, the position of air traffic management technical support system and air route network. Flexibility, robustness and efficiency are used to measure the network. The measure index of air traffic management technical support system network includes degree, degree distribution, strength, clustering coefficient, network performance, betweenness centrality, average shortest path and diameter. For Beijing, Shanghai, Guangzhou, Kunming, Shenyang and Lanzhou flight information regions, the air traffic management technical support networks are built by using the data of air traffic support facilities, air route, air traffic flow, etc. The average degrees, degree distributions, degree-degree correlations, clustering coefficients, average shortest paths and diameters of these netwoks are comparatively analyzed. The results show that the degrees of most nodes are between two and four. The network has a power law distribution, which is the same as that of air transportation network. The degree-degree correlation of air traffic management technical support system network is not assortative nor disassortative mixing, which has random network characteristics. The clustering coefficients of several air traffic management technical support system networks are between 0.25 and 0.39. The clustering value is lower than that of air transportation network. The

  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. "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

  15. 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.

  16. 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.

  17. Fuzzy Controlled Routing in a Swarm Robotic Network

    Directory of Open Access Journals (Sweden)

    Navya Manoj

    2014-05-01

    Full Text Available Swarm Robotics originated in the research inspired by biology. It is the usual sense of the multi-robot systems which have been given the emerging attributes of swarm intelligence. In nature, ants, termites, wasps, bees and other social insects have inspired surprisingly inspiration of human. These groups of organisms show how to interact with a large number of simple individuals and generate the collective intelligence of systems to cope with complicated tasks. Swarm Robotics is a special robot system which is composed of a group of indiscriminate robots and so it is a typical distributed system. If a task is for only one robot and the robot will be very complex and expensive inefficiently. But if it is for the swarm robotics, the complex task can be done by many more simple robots efficiently. For the Routing problem, the quality of a potential route is determined by the length of the route (i.e. number of links and the congestion along the route. It is desired to balance the traffic load among links in the network so it is desirable to select routes with a low obstacle rate. In addition, shorter routes are preferred over longer routes because they use fewer network resources

  18. A Sarsa(λ)-Based Control Model for Real-Time Traffic Light Coordination

    OpenAIRE

    Xiaoke Zhou; Fei Zhu; Quan Liu; Yuchen Fu; Wei Huang

    2014-01-01

    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 t...

  19. Air pollution in relation to homocysteine serum level and nitric oxide indicators among traffic policemen in Egypt

    Directory of Open Access Journals (Sweden)

    Mansour N

    2011-01-01

    Full Text Available Background: Environmental pollutants are known to be harmful to health. Traffic policemen are placed at particular risk due to nature of their job. The present study examined the effect of air pollution on vascular inflammatory reactions in traffic policemen of Egypt.Methods: Twenty eight policemen who has worked in Shubra El-Khaima and a matched control from Ashmoon, El-Menoufia (n=20 were recruited. Total homocysteine (tHcy and nitric acid indicators (nitrite and nitrate in serum was determined. Each participant was subjected to personal, occupational and medical history, and clinical examination. Particulate matter (PM2.5, sulphur dioxide (SO2 and nitric oxide (NO2 was recorded at various sites.Results: Significant increase in Hcy plasma level was found in the exposed group compared to control. This elevation in tHcy is associated with significant reduction in nitrite and nitrate serum levels. Conclusion: In traffic policemen, exposure to air pollution was associated with increase in tHcy plasma level and reduction in nitric oxide indicators. This raise the attention to the importance of periodic medical assessment of policemen beside the control measures of air pollution.

  20. 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.

  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. Improving Experience-Based Admission Control through Traffic Type Awareness

    Directory of Open Access Journals (Sweden)

    Jens Milbrandt

    2007-04-01

    Full Text Available Experience-based admission control (EBAC is a hybrid approach combining the classical parameter-based and measurement-based admission control. EBAC calculates an appropriate overbooking factor used to overbook link capacities with resource reservations in packet-switched networks. This overbooking factor correlates with the average peak-to-mean rate ratio of all admitted traffic flows on the link. So far, a single overbooking factor is calculated for the entire traffic aggregate. In this paper, we propose typespecific EBAC which provides a compound overbooking factor considering different types of traffic that subsume flows with similar peak-to-mean rate ratios. The concept can be well implemented since it does not require measurements of type-specific traffic aggregates. We give a proof of concept for this extension and compare it with the conventional EBAC approach. We show that EBAC with type-specific overbooking leads to better resource utilization under normal conditions and to faster response times for changing traffic mixes.

  3. Traffic-Related Air Pollution and Incident Type 2 Diabetes: Results from the SALIA Cohort Study

    OpenAIRE

    Krämer, Ursula; Herder, Christian; Sugiri, Dorothea; Strassburger, Klaus; Schikowski, Tamara; Ranft, Ulrich; Rathmann, Wolfgang

    2010-01-01

    Background Cross-sectional and ecological studies indicate that air pollution may be a risk factor for type 2 diabetes, but prospective data are lacking. Objective We examined the association between traffic-related air pollution and incident type 2 diabetes. Design Between 1985 and 1994, cross-sectional surveys were performed in the highly industrialized Ruhr district (West Germany); a follow-up investigation was conducted in 2006 using data from the Study on the Influence of Air Pollution o...

  4. 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.

  5. A Sarsa(λ)-based control model for real-time traffic light coordination.

    Science.gov (United States)

    Zhou, Xiaoke; Zhu, Fei; Liu, Quan; Fu, Yuchen; Huang, Wei

    2014-01-01

    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. PMID:24592183

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

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

    DEFF Research Database (Denmark)

    Nielsen, T.

    1996-01-01

    The presence of particulate PAH and other air pollutants (soot, CO, NO, gas NOy, SO2, particulate metals, sulfate) in the air in a street (60,000 vehicles each day) in Central Copenhagen and in a park area adjacent to the street was investigated. The diurnal variation of PAH was determined. The PAH...... 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...

  14. Priority Based Congestion Control Routing in Wireless Mesh Network

    Directory of Open Access Journals (Sweden)

    Muhammad Sharif

    2011-11-01

    Full Text Available Wireless mesh network (WMN is a wireless networking model which currently attracts research and industry. In WMN every node passes information to the nearest node and there may be number of hops from one node to the other. In WMN the information is forward using the best possible route to any destination. The best path can be determined using the routing protocol. The congestion problem arises when every time routing protocol determines the same best path due to which traffic load occurs on that path while other path seldom used. Due to the abrupt use of single path the packets may drop causes the greater effect on the network’s performance. In this paper a technique is used to overcome such congestion problem that faced by the network. In the technique priority based selection mechanism for the paths is adopted which can ensure the performance of the network.

  15. 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

  16. The Evaluation of Traffic Control in Changsha City

    NARCIS (Netherlands)

    Lu, S.; Li, J.; Van Zuylen, H.

    2012-01-01

    Different aspects of the traffic control system in the CBD of Changsha have been evaluated. A general issue is the safety conditions, which are evaluated qualitatively. The second issue is the low saturation flow observed on the intersections, that appear to be 20 to 30% lower than the ones in compa

  17. 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

  18. 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

  19. Long-Term Exposure to Traffic-Related Air Pollution and Risk of Incident Atrial Fibrillation

    DEFF Research Database (Denmark)

    Monrad, Maria; Sajadieh, Ahmad; Christensen, Jeppe Schultz;

    2016-01-01

    of first-ever hospital admission for atrial fibrillation from enrolment to end of follow-up in 2011. For all cohort members, exposure to traffic-related air pollution assessed as nitrogen dioxide (NO2) and nitrogen oxides (NOx) was estimated at all present and historical residential addresses from 1984....... OBJECTIVES: The aim of this study was to evaluate the long-term impact of traffic-related air pollution on incidence of atrial fibrillation in the general population. METHODS: In the Danish Diet, Cancer, and Health cohort of 57,053 people aged 50-64 years at enrolment in 1993-1997, we identified 2,700 cases...

  20. 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.

  1. 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.

  2. Detection of Botnet Command and Control Traffic by the Multistage Trust Evaluation of Destination Identifiers

    OpenAIRE

    Pieter Burghouwt; Marcel E.M. Spruit; Sips, Henk J.

    2015-01-01

    Network-based detection of botnet Command and Control communication is a difficult task if the traffic has a relatively low volume and if popular protocols, such as HTTP, are used to resemble normal traffic. We present a new network-based detection approach that is capable of detecting this type of Command and Control traffic in an enterprise network by estimating the trustworthiness of the traffic destinations. If the destination identifier of a traffic flow origins directly from: human inpu...

  3. 32 CFR 245.21 - ESCAT air traffic priority list.

    Science.gov (United States)

    2010-07-01

    ... homeland security. (e) Priority Five. (1) Air transport of military commanders, their representatives, DoD...-3). (3) Military retaliatory aircraft, including direct tanker support aircraft, executing strategic.... military offensive and defensive operations including the use of activated Civil Reserve Air Fleet...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Towards understanding work-as-done in air traffic management safety assessment and design

    International Nuclear Information System (INIS)

    This paper describes the approach taken and the results to develop guidance, to include Resilience Engineering principles in methodology for safety assessment of functional changes, in Air Traffic Management (ATM). It summarizes the process of deriving resilience principles for ATM, originating from Resilience Engineering concepts and transposed into ATM operations. These principles are the foundation for guidance material incorporating Resilience Engineering (RE) concepts into safety assessment methodology. The guidance material provides a method using workshops generating qualitative descriptions of RE principles applied to ATM services of everyday work, as done currently and as envisioned after introduction of a new technology or way of working. The guidance material has been proposed as part of the safety assessment methodology of SESAR (Single European Sky ATM Research), and as stand-alone guidance for ATM design processes. The methodology was validated via a test case on the i4D/CTA (Controlled Time of Arrival) concept. Operational examples from the application of the developed guidance to the i4D/CTA concept are provided. Initial evaluation of the guidance suggests that the methodology (1) provides a narrative, vocabulary and documentation means of project discussions on resilience; (2) brings the discussions of safety and resilience closer to operational practice; (3) facilitates a broader systemic and integrative perspective on operational, management, business, safety, environmental, and human performance aspects; and (4) can extend the vocabulary of safety assessment to include the description of emergent properties, to better support functional changes in ATM. - Highlights: • Guidance material for safety assessment based on systemic thinking is proposed. • It operationalizes Resilience Engineering principles in Air Traffic Management, including a case study. • It enables description of expected changes in work-as-done when introducing a new

  9. 77 FR 28455 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2012-05-14

    ... clarify the use of engineering judgment and studies in the application of traffic control devices. DATES... existing operating procedures. Background On August 2, 2011, at 76 FR 46213, the FHWA published an NPA... established through a final rule published in the Federal Register on December 14, 2006 at 74 FR...

  10. Quasi-dynamic Traffic Light Control for a Single Intersection

    OpenAIRE

    Geng, Yanfeng; Cassandras, Christos G.

    2013-01-01

    We address the traffic light control problem for a single intersection by viewing it as a stochastic hybrid system and developing a Stochastic Flow Model (SFM) for it. We adopt a quasi-dynamic control policy based on partial state information defined by detecting whether vehicle backlog is above or below a certain threshold, without the need to observe an exact vehicle count. The policy is parameterized by green and red cycle lengths which depend on this partial state information. Using Infin...

  11. Geo-based Mobility Control for Mobile Traffic Simulators

    OpenAIRE

    Dahlström, Patrik

    2013-01-01

    Most mobile traffic simulators of today depend on the user to supply the mobility behavior of the simulated UEs. This becomes a problem when certain wanted mobility characteristics are to be tested, since the user have to go trough a trial-and-error procedure to come up with the proper mobility behavior. This thesis presents two approaches to mobility control, where the aim is to control UE mobility based on certain mobility characteristics supplied by the end user. The first approach introdu...

  12. TO THE QUESTION OF SOLVING OF THE PROBLEM OF OPTIMIZING PARAMETERS OF TRAFFIC FLOW COORDINATED CONTROL

    OpenAIRE

    L. Abramova; Chernobaev, N.

    2007-01-01

    A short review of main methods of traffic flow control is represented, great attention is paid to methods of coordinated control and quality characteristics of traffic control. The problem of parameter optimization of traffic coordinated control on the basis of vehicle delay minimizing at highway intersections has been defined.

  13. 77 FR 18297 - Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation Environmental Design Tool...

    Science.gov (United States)

    2012-03-27

    ... Federal Aviation Administration Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation... one airport, or includes actions above 3,000 feet , noise modeling will be conducted using [the Noise... required tool for noise, fuel burn, and emissions modeling of air traffic airspace and procedure...

  14. 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...

  15. Air pollution from traffic and the development of respiratory infections and asthmatic and allergic symptoms in children

    NARCIS (Netherlands)

    Brauer, M; Hoek, G; Van Vliet, P; Meliefste, K; Fischer, PH; Wijga, A; Koopman, LP; Neijens, HJ; Gerritsen, J; Kerkhof, M; Heinrich, J; Bellander, T; Brunekreef, B

    2002-01-01

    Despite the important contribution of traffic sources to urban air quality, relatively few studies have evaluated the effects of traffic-related air pollution on health, such as its influence on the development of asthma and other childhood respiratory diseases. We examined the relationship between

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Traffic effects on bird counts on North American Breeding Bird Survey routes

    Science.gov (United States)

    Griffith, Emily H.; Sauer, John R.; Royle, J. Andrew

    2010-01-01

    The North American Breeding Bird Survey (BBS) is an annual roadside survey used to estimate population change in >420 species of birds that breed in North America. Roadside sampling has been criticized, in part because traffic noise can interfere with bird counts. Since 1997, data have been collected on the numbers of vehicles that pass during counts at each stop. We assessed the effect of traffic by modeling total vehicles as a covariate of counts in hierarchical Poisson regression models used to estimate population change. We selected species for analysis that represent birds detected at low and high abundance and birds with songs of low and high frequencies. Increases in vehicle counts were associated with decreases in bird counts in most of the species examined. The size and direction of these effects remained relatively constant between two alternative models that we analyzed. Although this analysis indicated only a small effect of incorporating traffic effects when modeling roadside counts of birds, we suggest that continued evaluation of changes in traffic at BBS stops should be a component of future BBS analyses.

  1. Proposal of Wireless Traffic Control Schemes for Wireless LANs

    Science.gov (United States)

    Hiraguri, Takefumi; Ichikawa, Takeo; Iizuka, Masataka; Kubota, Shuji

    This paper proposes two traffic control schemes to support the communication quality of multimedia streaming services such as VoIP and audio/video over IEEE 802.11 wireless LAN systems. The main features of the proposed scheme are bandwidth control for each flow of the multimedia streaming service and load balancing between access points (APs) of the wireless LAN by using information of data link, network and transport layers. The proposed schemes are implemented on a Linux machine which is called the wireless traffic controller (WTC). The WTC connects a high capacity backbone network and an access network to which the APs are attached. We evaluated the performance of the proposed WTC and confirmed that the communication quality of the multimedia streaming would be greatly improved by using this technique.

  2. 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. ...

  3. Identifying Traffic-Related Air Pollution Hotspots in the Built Environment

    OpenAIRE

    Wu, Lisa

    2014-01-01

    This study characterizes the spatial and temporal distribution of air pollution in an urban street environment given traffic and meteorological conditions. A mobile air monitoring platform was used to measure ultrafine particle (UFP) counts on a 1-second basis along a 3 mile-long transect in Downtown Los Angeles in April-July 2008 for a total of 12 runs and roughly 7,500 observations. Significantly higher UFP concentrations were found in morning compared to afternoon measurements. Spatially s...

  4. 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 ...

  5. 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…

  6. 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.

  7. 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. PMID:26681325

  8. Agent concepts for traffic control; Agentenmodelle in der Verkehrsleittechnik

    Energy Technology Data Exchange (ETDEWEB)

    Fay, A. [ABB Forschungszentrum, Heidelberg (Germany). Abt. Automatisierungs- und Informationstechnik

    2000-07-01

    All modes of traffic reach - in their current form of operation - the limits of their respective infrastructure. Therefore, new control concepts are being investigated which allow for a more efficient usage of the existing infrastructure. In the previous issue of atp, agents have been introduced as a promising approach for decentralised control. Agents provide a means for flexible resource allocation and, thus, for achieving an optimised balance between infrastructure load and customer requirements. This paper describes how agents can be used in traffic control, taking road and rail traffic as examples. This might also give hints regarding the possible role of agents in automation and control in general. (orig.) [German] Die verschiedenen Verkehrssysteme stossen in ihrer jeweiligen bisherigen Betriebsweise an Kapazitaetsgrenzen der bestehenden Infrastruktur. Daher werden neue leittechnische Konzepte gesucht, die eine effizientere Nutzung der vorhandenen Infrastruktur ermoeglichen. Im letzten Heft wurden Agenten als dezentraler Leittechnikansatz vorgestellt. Mit Hilfe von Agenten kann ein flexibles Ressourcenmanagement betrieben werden und so ein optimaler Kompromiss zwischen Auslastung der Infrastruktur und Erfuellung der Kundenanforderungen gefunden werden. Der Beitrag beschreibt Agentenmodelle fuer die Verkehrsleittechnik am Beispiel des Schienen- und des Strassenverkehrs und gibt damit Denkanstoesse zur moeglichen Rolle von Agenten in der Leittechnik allgemein. (orig.)

  9. 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.

  10. Quantifying the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building.

    Science.gov (United States)

    Tong, Zheming; Chen, Yujiao; Malkawi, Ali; Adamkiewicz, Gary; Spengler, John D

    2016-01-01

    Improper natural ventilation practices may deteriorate indoor air quality when in close proximity to roadways, although the intention is often to reduce energy consumption. In this study, we employed a CFD-based air quality model to quantify the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building. Our study found that the building envelope restricts dispersion and dilution of particulate matter. The indoor concentration in the baseline condition located 10m away from the roadway is roughly 16-21% greater than that at the edge of the roadway. The indoor flow recirculation creates a well-mixed zone with little variation in fine particle concentration (i.e., 253nm). For ultrafine particles (air intakes are important to the indoor air quality of existing buildings adjacent to roadways.

  11. Integrated Control of Mixed Traffic Networks using Model Predictive Control

    NARCIS (Netherlands)

    Van den Berg, M.

    2010-01-01

    Motivation The growth of our road infrastructure cannot keep up with the growing mobility of people, and the corresponding increase in traffic demand. This results in daily congestion on the freeways. It is an illusion that the problem of congestion can be solved completely within a few years, but i

  12. 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.

  13. Implementation of Traffic Engineering Control System for Software Defined Networking

    OpenAIRE

    RUIZ GONZALEZ, SERGIO

    2015-01-01

    Software Defined Networking (SDN) is an emerging networking paradigm that separates the network control plane from the data forwarding plane with the promise to dramatically improve network resource utilization, simplify network management, reduce operating cost, and promote innovation and evolution. Although traffic engineering techniques have been widely exploited in the past and current data networks, such as ATM networks and IP/ MPLS networks, to optimize the performance of communication ...

  14. 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.

  15. Integration of Linear Dynamic Emission and Climate Models with Air Traffic Simulations

    Science.gov (United States)

    Sridhar, Banavar; Ng, Hok K.; Chen, Neil Y.

    2012-01-01

    Future air traffic management systems are required to balance the conflicting objectives of maximizing safety and efficiency of traffic flows while minimizing the climate impact of aviation emissions and contrails. Integrating emission and climate models together with air traffic simulations improve the understanding of the complex interaction between the physical climate system, carbon and other greenhouse gas emissions and aviation activity. This paper integrates a national-level air traffic simulation and optimization capability with simple climate models and carbon cycle models, and climate metrics to assess the impact of aviation on climate. The capability can be used to make trade-offs between extra fuel cost and reduction in global surface temperature change. The parameters in the simulation can be used to evaluate the effect of various uncertainties in emission models and contrails and the impact of different decision horizons. Alternatively, the optimization results from the simulation can be used as inputs to other tools that monetize global climate impacts like the FAA s Aviation Environmental Portfolio Management Tool for Impacts.

  16. Evaluation of the Monotonic Lagrangian Grid and Lat-Long Grid for Air Traffic Management

    Science.gov (United States)

    Kaplan, Carolyn; Dahm, Johann; Oran, Elaine; Alexandrov, Natalia; Boris, Jay

    2011-01-01

    The Air Traffic Monotonic Lagrangian Grid (ATMLG) is used to simulate a 24 hour period of air traffic flow in the National Airspace System (NAS). During this time period, there are 41,594 flights over the United States, and the flight plan information (departure and arrival airports and times, and waypoints along the way) are obtained from an Federal Aviation Administration (FAA) Enhanced Traffic Management System (ETMS) dataset. Two simulation procedures are tested and compared: one based on the Monotonic Lagrangian Grid (MLG), and the other based on the stationary Latitude-Longitude (Lat- Long) grid. Simulating one full day of air traffic over the United States required the following amounts of CPU time on a single processor of an SGI Altix: 88 s for the MLG method, and 163 s for the Lat-Long grid method. We present a discussion of the amount of CPU time required for each of the simulation processes (updating aircraft trajectories, sorting, conflict detection and resolution, etc.), and show that the main advantage of the MLG method is that it is a general sorting algorithm that can sort on multiple properties. We discuss how many MLG neighbors must be considered in the separation assurance procedure in order to ensure a five-mile separation buffer between aircraft, and we investigate the effect of removing waypoints from aircraft trajectories. When aircraft choose their own trajectory, there are more flights with shorter duration times and fewer CD&R maneuvers, resulting in significant fuel savings.

  17. Inside the Mechanics of Network Development: How Competition and Strategy Reorganize European Air Traffic

    Science.gov (United States)

    Huber, Hans

    2006-01-01

    Air transport forms complex networks that can be measured in order to understand its structural characteristics and functional properties. Recent models for network growth (i.e., preferential attachment, etc.) remain stochastic and do not seek to understand other network-specific mechanisms that may account for their development in a more microscopic way. Air traffic is made up of many constituent airlines that are either privately or publicly owned and that operate their own networks. They follow more or less similar business policies each. The way these airline networks organize among themselves into distinct traffic distributions reveals complex interaction among them, which in turn can be aggregated into larger (macro-) traffic distributions. Our approach allows for a more deterministic methodology that will assess the impact of airline strategies on the distinct distributions for air traffic, particularly inside Europe. One key question this paper is seeking to answer is whether there are distinct patterns of preferential attachment for given classes of airline networks to distinct types of European airports. Conclusions about the advancing degree of concentration in this industry and the airline operators that accelerate this process can be drawn.

  18. Air pollution from traffic and cancer incidence: a Danish cohort study

    Directory of Open Access Journals (Sweden)

    Loft Steffen

    2011-07-01

    Full Text Available Abstract Background Vehicle engine exhaust includes ultrafine particles with a large surface area and containing absorbed polycyclic aromatic hydrocarbons, transition metals and other substances. Ultrafine particles and soluble chemicals can be transported from the airways to other organs, such as the liver, kidneys, and brain. Our aim was to investigate whether air pollution from traffic is associated with risk for other cancers than lung cancer. Methods We followed up 54,304 participants in the Danish Diet Cancer and Health cohort for 20 selected cancers in the Danish Cancer Registry, from enrolment in 1993-1997 until 2006, and traced their residential addresses from 1971 onwards in the Central Population Registry. We used modeled concentration of nitrogen oxides (NOx and amount of traffic at the residence as indicators of traffic-related air pollution and used Cox models to estimate incidence rate ratios (IRRs after adjustment for potential confounders. Results NOx at the residence was significantly associated with risks for cervical cancer (IRR, 2.45; 95% confidence interval [CI], 1.01;5.93, per 100 μg/m3 NOx and brain cancer (IRR, 2.28; 95% CI, 1.25;4.19, per 100 μg/m3 NOx. Conclusions This hypothesis-generating study indicates that traffic-related air pollution might increase the risks for cervical and brain cancer, which should be tested in future studies.

  19. The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

    International Nuclear Information System (INIS)

    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.

  20. Neural Network based Vehicle Classification for Intelligent Traffic Control

    Directory of Open Access Journals (Sweden)

    Saeid Fazli

    2012-06-01

    Full Text Available Nowadays, number of vehicles has been increased and traditional systems of traffic controlling couldn’t be able to meet the needs that cause to emergence of Intelligent Traffic Controlling Systems. They improve controlling and urban management and increase confidence index in roads and highways. The goal of thisarticle is vehicles classification base on neural networks. In this research, it has been used a immovable camera which is located in nearly close height of the road surface to detect and classify the vehicles. The algorithm that used is included two general phases; at first, we are obtaining mobile vehicles in the traffic situations by using some techniques included image processing and remove background of the images and performing edge detection and morphology operations. In the second phase, vehicles near the camera areselected and the specific features are processed and extracted. These features apply to the neural networks as a vector so the outputs determine type of vehicle. This presented model is able to classify the vehicles in three classes; heavy vehicles, light vehicles and motorcycles. Results demonstrate accuracy of the algorithm and its highly functional level.

  1. Game theoretic analysis of congestion, safety and security networks, air traffic and emergency departments

    CERN Document Server

    Zhuang, Jun

    2015-01-01

    Maximizing reader insights into the roles of intelligent agents in networks, air traffic and emergency departments, this volume focuses on congestion in systems where safety and security are at stake, devoting special attention to applying game theoretic analysis of congestion to: protocols in wired and wireless networks; power generation, air transportation and emergency department overcrowding. Reviewing exhaustively the key recent research into the interactions between game theory, excessive crowding, and safety and security elements, this book establishes a new research angle by illustrating linkages between the different research approaches and serves to lay the foundations for subsequent analysis. Congestion (excessive crowding) is defined in this work as all kinds of flows; e.g., road/sea/air traffic, people, data, information, water, electricity, and organisms. Analyzing systems where congestion occurs – which may be in parallel, series, interlinked, or interdependent, with flows one way or both way...

  2. 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.

  3. An Intelligent Traffic Flow Control System Based on Radio Frequency Identification and Wireless Sensor Networks

    OpenAIRE

    Kuei-Hsiang Chao; Pi-Yun Chen

    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...

  4. Design Approach for Dynamic Traffic Control System Based on Radio Propagation Model in VANET

    OpenAIRE

    Sanjay S. Dorle; Pratima L. Patel

    2013-01-01

    In the densely populated urban area traffic control system isthe main mechanism to control the flow of vehicular traffic atthe intersection. Conventional traffic control system are notcapable of handling dynamic vehicular flow. This dynamicvehicular flow creates traffic jams , congestion at theintersection. Vehicular Ad hoc Network (VANET) is acommon part of Intelligent Transport System (ITS) which isdirectly involved in handling these problems and aims to makejourney on road comfortable. The...

  5. "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.

  6. London smog is history - traffic pollutes the air. Lontoon smog historiaa - liikenne pilaa ilmaa

    Energy Technology Data Exchange (ETDEWEB)

    Haemekoski, K.

    1992-01-01

    London is one of the most classical examples of air pollution. Sulfur dioxide and smoke concentration were very high, and during one of tne episode in 1952, 4000 excess deaths occurred due to high pollutant concentrations. Air quality has improved and currently traffic is the main source of pollution. Air quality is continuously monitored by 4 station network operated by London Scientific Services, a private company. Annual concentrations of SO{sub 2} and NO{sub 2} in 1989 were 19-62 and 47-92 {mu}g/m{sup 3}, respectively. 8-hour CO maxima reach 20 mg/m{sup 3}.

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

    Directory of Open Access Journals (Sweden)

    G. R. LAI

    2015-08-01

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

  8. Dispersion Modeling of Traffic-Related Air Pollutant Exposures and Health Effects Among Children with Asthma in Detroit, Michigan

    OpenAIRE

    Batterman, Stuart; Ganguly, Rajiv; Isakov, Vlad; Burke, Janet; Arunachalam, Saravanan; Snyder, Michelle; Robins, Thomas; Lewis, Toby

    2014-01-01

    Vehicular traffic is a major source of ambient air pollution in urban areas. Traffic-related air pollutants, including carbon monoxide, nitrogen oxides, particulate matter less than 2.5 μm in diameter, and diesel exhaust emissions, have been associated with adverse human health effects, especially in areas near major roads. In addition to emissions from vehicles, ambient concentrations of air pollutants include contributions from stationary sources and background (or regional) sources. Althou...

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

    DEFF Research Database (Denmark)

    Jensen, S. S.

    ; population data on gender and age from the Central Population Register (CPR); the number of employees from the Central Business Register (CER); standardised time-activity profiles for the different age groups in the residence and workplace microenvironments; and meteorological parameters (hourly). The......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 and......) 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 Municipality of Middelfart has been used as a case study area to develop and...

  10. Efficient Traffic Control of VoD System

    CERN Document Server

    Kanrar, Soumen

    2011-01-01

    It has been a challenging issue to provide digital quality multimedia data stream to the remote user through the distributed system. The main aspects to design the real distributed system, which reduce the cost of the network by means of reduce packet loss and enhanced over all system performance. Since the number of user increased rapidly in the network it posed heavy load to the video servers. The requested clients, servers are all distributed in nature and the data stream delivered to the user without error. In this work I have presented the performance of the video on demand server by efficient traffic control at real time with respect to incoming multirate traffic pattern . In this work, I present how the overall system performance gradually decreases when the client population sized in the clusters increase. This work indicated the load balancing required for the on demand video distributed system to provide efficient cost effective service to the local or remote clients.

  11. Modelling of material handling operations using controlled traffic

    DEFF Research Database (Denmark)

    Bochtis, Dionysis; Sørensen, Claus Aage Grøn; Jørgensen, Rasmus Nyholm;

    2009-01-01

    Controlled-traffic farming (CTF) is a management system that can eliminate soil compaction by wheels within the cropped area. According to the principles of CTF, permanent parallel wheel tracks are created within the field area. The benefits of CTF, in terms of productivity and sustainability, have...... and maintaining permanent traffic lanes within the fields. Furthermore, field efficiency is affected by CTF due to significant increases in idle time of in-field transport and the way the fields are traversed in material handling operations. During fertilisation, when tramline length and the driving...... operations, makes existing models inadequate for evaluating field efficiency. In this paper, the development of a discrete-event model for the prediction of travelled distances of a machine operating in material handling operations using the concept of CTF is presented. The model is based on the mathematical...

  12. Efficient Traffic Control of VoD System

    Directory of Open Access Journals (Sweden)

    Soumen kanrar

    2011-10-01

    Full Text Available It has been a challenging issue to provide digital quality multimedia data stream to the remote user through the distributed system. The main aspects to design the real distributed system, which reduce the cost of the network by means of reduce packet loss and enhanced over all system performance. Since thenumber of user increased rapidly in the network it posed heavy load to the video servers. The requested clients, servers are all distributed in nature and the data stream delivered to the user without error. In this work I have presented the performance of the video on demand server by efficient traffic control at real time with respect to incoming multirate traffic pattern . In this work, I present how the overall system performance gradually decreases when the client population sized in the clusters increase. Thiswork indicated the load balancing required for the on demand video distributed system to provide efficient cost effective service to the local or remote clients.

  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. 23 CFR 630.1110 - Maintenance of temporary traffic control devices.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Maintenance of temporary traffic control devices. 630.1110 Section 630.1110 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Temporary Traffic Control Devices §...

  16. Traffic, Air Pollution, Minority and Socio-Economic Status: Addressing Inequities in Exposure and Risk

    Directory of Open Access Journals (Sweden)

    Gregory C. Pratt

    2015-05-01

    Full Text Available Higher levels of nearby traffic increase exposure to air pollution and adversely affect health outcomes. Populations with lower socio-economic status (SES are particularly vulnerable to stressors like air pollution. We investigated cumulative exposures and risks from traffic and from MNRiskS-modeled air pollution in multiple source categories across demographic groups. Exposures and risks, especially from on-road sources, were higher than the mean for minorities and low SES populations and lower than the mean for white and high SES populations. Owning multiple vehicles and driving alone were linked to lower household exposures and risks. Those not owning a vehicle and walking or using transit had higher household exposures and risks. These results confirm for our study location that populations on the lower end of the socio-economic spectrum and minorities are disproportionately exposed to traffic and air pollution and at higher risk for adverse health outcomes. A major source of disparities appears to be the transportation infrastructure. Those outside the urban core had lower risks but drove more, while those living nearer the urban core tended to drive less but had higher exposures and risks from on-road sources. We suggest policy considerations for addressing these inequities.

  17. Delays in hiring Air Traffic Collegiate Training Initiative (AT-CTI) graduates and the impact on their training success rate

    Science.gov (United States)

    Jorgenson, Terra A.

    This research project identified three distinct groups of individuals the Federal Aviation Administration (FAA) utilizes when filling the employee ranks of Air Traffic Controllers (ATC). After a nationwide strike, President Reagan fired the entire ATC workforce in 1981 (Pavel, 2012). Since then the FAA has worked very diligently in filling the vacant positions. Now three decades later the impending retirements and attrition of those hired earlier is estimated at nearly 14,000 controllers over the next 10 years (FAA CWP, 2012). In response to this shortage it would be advantageous for the FAA to minimize the time lapsed in the selection, hiring and training processes. If the hiring process time was decreased, it would save the FAA money in terms of a reduction in the initial cost of training Air Traffic Controllers (GAO, 2012; IRP, 2011). Traditionally the FAA hires from three distinct groups of people. The first is those with prior ATC experience which was usually obtained through the military. Second the general public with no experience and third the Air Traffic Collegiate Training Initiative (AT-CTI) candidates. The AT-CTI program is a valued partner with the FAA that helps educate the next generation of Air Traffic Controllers; however in the past the program has had difficulty producing the total number of replacement controllers needed. Due to the delay some CTI graduates may choose other career paths rather than wait and be hired to go to the FAA Academy which will further reduce the number of candidates for the FAA to hire. To date, no public research has been done pertaining to the time delay in the hiring process of AT-CTI candidates and the impact on training success at the FAA Academy and at the CTI's first FAA facility. This study used a survey tool to gather information on how long AT-CTI graduates wait to be hired to attend the FAA Academy. Information was gathered on the factors that may affect the time lapse between graduation and the time they

  18. The impact of a forced reduction in traffic volumes on urban air pollution

    International Nuclear Information System (INIS)

    The Middle East military conflict of summer 2006 resulted in a few weeks in which the city of Haifa, Israel, and its environs experienced very profound variations in the commercial and personal activities. Large industrial plants continued almost normal operations but activities of small scale industry, shopping, and personal commuting were drastically reduced, leading to a dramatic decrease in the commercial and personal traffic volumes. This period of reduced activity serves as a real life experiment for assessment and demonstration of the impact that human activity, and mainly road traffic, may have on the air pollution levels in a bustling middle-sized city. The analysis is made especially sharp and reliable due to the abruptness of the beginning and the end of the reduced activity period, its length, and the stable summer meteorological conditions in the eastern Mediterranean region. The reduced traffic volumes resulted in lowered levels of NO2, hydrocarbons and particulate matter. The decrease in these pollutants' mean concentration was significantly larger than the reduction in the mean traffic volume. Slightly higher mean O3 concentrations were observed during the reduced traffic period. (author)

  19. The impact of traffic-flow patterns on air quality in urban street canyons.

    Science.gov (United States)

    Thaker, Prashant; Gokhale, Sharad

    2016-01-01

    We investigated the effect of different urban traffic-flow patterns on pollutant dispersion in different winds in a real asymmetric street canyon. Free-flow traffic causes more turbulence in the canyon facilitating more dispersion and a reduction in pedestrian level concentration. The comparison of with and without a vehicle-induced-turbulence revealed that when winds were perpendicular, the free-flow traffic reduced the concentration by 73% on the windward side with a minor increase of 17% on the leeward side, whereas for parallel winds, it reduced the concentration by 51% and 29%. The congested-flow traffic increased the concentrations on the leeward side by 47% when winds were perpendicular posing a higher risk to health, whereas reduced it by 17-42% for parallel winds. The urban air quality and public health can, therefore, be improved by improving the traffic-flow patterns in street canyons as vehicle-induced turbulence has been shown to contribute significantly to dispersion. PMID:26412198

  20. The impact of traffic-flow patterns on air quality in urban street canyons.

    Science.gov (United States)

    Thaker, Prashant; Gokhale, Sharad

    2016-01-01

    We investigated the effect of different urban traffic-flow patterns on pollutant dispersion in different winds in a real asymmetric street canyon. Free-flow traffic causes more turbulence in the canyon facilitating more dispersion and a reduction in pedestrian level concentration. The comparison of with and without a vehicle-induced-turbulence revealed that when winds were perpendicular, the free-flow traffic reduced the concentration by 73% on the windward side with a minor increase of 17% on the leeward side, whereas for parallel winds, it reduced the concentration by 51% and 29%. The congested-flow traffic increased the concentrations on the leeward side by 47% when winds were perpendicular posing a higher risk to health, whereas reduced it by 17-42% for parallel winds. The urban air quality and public health can, therefore, be improved by improving the traffic-flow patterns in street canyons as vehicle-induced turbulence has been shown to contribute significantly to dispersion.