WorldWideScience

Sample records for surface traffic control

  1. Surface Traffic Management Research

    Science.gov (United States)

    Jung, Yoo Chul

    2012-01-01

    This presentation discusses an overview of the surface traffic management research conducted by NASA Ames. The concept and human-in-the-loop simulation of the Spot and Runway Departure Advisor (SARDA), an integrated decision support tool for the tower controllers and airline ramp operators, is also discussed.

  2. 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.

  3. Traffic Light Controller Using Fpga

    Directory of Open Access Journals (Sweden)

    D.Bhavana

    2015-04-01

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

  4. Traffic jams: dynamics and control.

    Science.gov (United States)

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

    2010-10-13

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

  5. 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....

  6. Air Traffic Control Tools Assessment

    Directory of Open Access Journals (Sweden)

    Tomáš Noskievič

    2017-04-01

    Full Text Available Undoubtedly air transport in today’s world wouldn’t be able to exist without any air traffic control service. As the air transport has been coming through major changes and it has been expanding, it is assumed that its volume will be doubled in the next 15 years. Air traffic control uses strictly organised procedures to ensure safe course of air operations. With the skies covered with more airplanes every year, new tools must be introduced to allow the controllers to manage this rising amount of flying aircraft and to keep the air transport safe. This paper provides a comprehensive and organized material, which describes the newest tools and systems used by air traffic control officers. It proposes improvements for further research and development of ATC tools.

  7. 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.

  8. 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.

  9. Bits of Internet traffic control

    OpenAIRE

    Vojnovic, Milan; Le Boudec, Jean Yves

    2005-01-01

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

  10. Bits of Internet Traffic Control

    OpenAIRE

    Vojnovic, Milan

    2003-01-01

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

  11. 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...

  12. 30 CFR 57.9100 - Traffic control.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of self-propelled...

  13. Light signals for road traffic control.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1981-01-01

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

  14. Optimal Airport Surface Traffic Planning Using Mixed-Integer Linear Programming

    NARCIS (Netherlands)

    Roling, P.C.; Visser, H.G.

    2008-01-01

    We describe an ongoing research effort pertaining to the development of a surface traffic automation system that will help controllers to better coordinate surface traffic movements related to arrival and departure traffic. More specifically, we describe the concept for a taxi-planning support tool

  15. Optimal Airport Surface Traffic Planning Using Mixed-Integer Linear Programming

    NARCIS (Netherlands)

    Roling, P.C.; Visser, H.G.

    2008-01-01

    We describe an ongoing research effort pertaining to the development of a surface traffic automation system that will help controllers to better coordinate surface traffic movements related to arrival and departure traffic. More specifically, we describe the concept for a taxi-planning support tool

  16. 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

  17. 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

  18. 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

  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

  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. Using Automated Planning for Traffic Signals Control

    Directory of Open Access Journals (Sweden)

    Matija Gulić

    2016-08-01

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

  2. Controlling Disorder in Traffic Flow by Perturbation

    Institute of Scientific and Technical Information of China (English)

    LIKe-Ping; GAOZi-You; CHENTian-Lun

    2004-01-01

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

  3. AN AUTOMATED RAILWAY STATION TRAFFIC CONTROL SYSTEM

    African Journals Online (AJOL)

    user

    2017-01-01

    Jan 1, 2017 ... The inclusion of the automated traffic control lighting system at the level crossing gate in the system eliminates the fatigue and ... flexibility of operation. The main ..... The 6th IEEE International Symposium on High. Assurance ...

  4. 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.

  5. Traffic control: nursing practice calendar.

    Science.gov (United States)

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

    2013-01-01

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

  6. Adaptive traffic control systems for urban networks

    Directory of Open Access Journals (Sweden)

    Radivojević Danilo

    2017-01-01

    Full Text Available Adaptive traffic control systems represent complex, but powerful tool for improvement of traffic flow conditions in locations or zones where applied. Many traffic agencies, especially those that have a large number of signalized intersections with high variability of the traffic demand, choose to apply some of the adaptive traffic control systems. However, those systems are manufactured and offered by multiple vendors (companies that are competing for the market share. Due to that fact, besides the information available from the vendors themselves, or the information from different studies conducted on different continents, very limited amount of information is available about the details how those systems are operating. The reason for that is the protecting of the intellectual property from plagiarism. The primary goal of this paper is to make a brief analysis of the functionalities, characteristics, abilities and results of the most recognized, but also less known adaptive traffic control systems to the professional public and other persons with interest in this subject.

  7. 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

  8. 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.

  9. 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

  10. 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....

  11. 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...

  12. 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. ...

  13. Examining perimeter gating control of urban traffic networkswith locally adaptive traffic signals

    NARCIS (Netherlands)

    Keyvan Ekbatani, M.; Gao, X.; Gayah, V.V.; Knoop, V.L.

    2015-01-01

    Traditionally, urban traffic is controlled by traffic lights. Recent findings of the Macroscopic or Network Fundamental Diagram (MFD or NFD) have led to the development of novel traffic control strategies that can be applied at a networkwide level. One pertinent example is perimeter flow control

  14. 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, the...

  15. The design of traffic signal coordinated control

    Science.gov (United States)

    Guo, Xueting; Sun, Hongsheng; Wang, Xifu

    2017-05-01

    Traffic as the tertiary industry is an important pillar industry to support the normal development of the economy. But now China's road traffic development and economic development has shown a great imbalance and fault phenomenon, which greatly inhibited the normal development of China's economy. Now in many large and medium-sized cities in China are implementing green belt construction. The so-called green band is when the road conditions to meet the conditions for the establishment of the green band, the sections of the intersection of several planning to a traffic coordination control system, so that when the driver at a specific speed can be achieved without stopping the continuous Through the intersection. Green belt can effectively reduce the delay and queuing length of vehicle driving, the normal function of urban roads and reduce the economic losses caused by traffic congestion is a great help. In this paper, the theoretical basis of the design of the coordinated control system is described. Secondly, the green time offset is calculated by the analytic method and the green band is established. And then the VISSIM software is used to simulate the traffic system before and after the improvement. Finally, the results of the two simulations are compared.

  16. Processes mediating expertise in air traffic control

    NARCIS (Netherlands)

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

    2011-01-01

    Van Meeuwen, L. W., Jarodzka, H., Brand-Gruwel, S., Van Merriënboer, J. J. G., De Bock, J. J. P. R., & Kirschner, P. A. (2010, September). Processes mediating expertise in air traffic control. Poster presented at the European Association for Aviation Psychology Conference, Budapest.

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

    NARCIS (Netherlands)

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

    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

  18. 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.

  19. Multiple Traffic Control Using Wireless Sensor and Density Measuring Camera

    Directory of Open Access Journals (Sweden)

    Amrita RAI

    2008-07-01

    Full Text Available In the present scenario vehicular travel is increasing all over the world, especially in large urban areas. Therefore for simulating and optimizing traffic control to better accommodate this increasing demand is arises. In this paper we studied the optimization of traffic light controller in a City using wireless sensor and CCTV (Camera. We have proposed a traffic light controller and simulator that allows us to study different situation of traffic density in City and controlling the traffic of entire City by visual monitoring using CCTV. Using wireless sensor we can easily senses the density of traffic because the general architecture of wireless sensor network is an infrastructure less communication network.

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

    OpenAIRE

    2010-01-01

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

  1. Validation of Air Traffic Controller Workload Models

    Science.gov (United States)

    1979-09-01

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

  2. Chaos control in traffic flow models

    CERN Document Server

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

    1998-01-01

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

  3. Effect of Mixed Traffic Flow on Control Delay at Signalized ...

    African Journals Online (AJOL)

    Effect of Mixed Traffic Flow on Control Delay at Signalized Intersections. ... Journal of Civil Engineering Research and Practice ... There are several methods available for operational analysis including mathematical models and traffic ...

  4. 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 ...

  5. 75 FR 20935 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2010-04-22

    ... Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Maintaining Minimum...: Notice of proposed amendments (NPA). SUMMARY: The Manual on Uniform Traffic Control Devices (MUTCD) is..., and highways with narrow pavement widths and low traffic volumes. \\4\\ Carlson, Park, Andersen...

  6. 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. ...

  7. 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

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

    Directory of Open Access Journals (Sweden)

    Basil AsSadhan

    2014-07-01

    Full Text Available 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.

  9. 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.

  10. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks.

    Science.gov (United States)

    Artuñedo, Antonio; Del Toro, Raúl M; Haber, Rodolfo E

    2017-04-26

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

  11. 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.

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

    Institute of Scientific and Technical Information of China (English)

    孙智源; 陆化普; 屈闻聪

    2016-01-01

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

  13. 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.

  14. 49 CFR 236.828 - System, traffic control.

    Science.gov (United States)

    2010-10-01

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

  15. 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.

  16. Traffic process control. Automation of road- and rail traffic; Verkehrsleittechnik. Automatisierung des Strassen- und Schienenverkehrs

    Energy Technology Data Exchange (ETDEWEB)

    Schnieder, Eckehard (ed.) [TU Braunschweig (Germany). Inst. fuer Verkehrssicherheit und Automatisierungstechnik

    2007-07-01

    Traffic control aims the comprehensive guidance of complex traffic flows. The book provides a solid foundation, from design to realization with highly detailed technical systems. It presents a functionally oriented traffic process control strategy as its main topic, valuable for further technology change. Four main topics treat tasks and structures of traffic process control systems: single vehicle control and information management; traffic flow control; node control; operation and network management. The book addresses students and specialists of traffic science, who already have basic knowledge of the road- and rail sector and control engineering in relation systems theory. (GL) [German] Ziel der Verkehrsleittechnik ist die Beherrschung komplexer Verkehrsstroeme des Strassen- und Schienenverkehrs. Vom Entwurf bis zur Realisierung mit technischen Einrichtungen, die eine grosse Detailfuelle aufweisen, wird eine solide Grundlage vermittelt. Das vorliegende Buch stellt dafuer eine funktional orientierte Verkehrsleittechnik in den Mittelpunkt, die ueber den Technologiewandel hinaus gilt. Vier Abschnitte behandeln die Aufgaben und Strukturen von Verkehrsleitsystemen: Einzelfahrzeugsteuerung und -informationsmanagement; Verkehrsflusssteuerung; Knotensteuerung; Betriebs- und Netzmanagement. Das Buch richtet sich an Studierende und Fachleute des Verkehrswesens. Voraussetzungen sind Kenntnisse des Strassen- und Schienenverkehrs und der Regelungstechnik bzw. Systemtheorie. (orig.)

  17. Robust, Optimal, Predictive, and Integrated Road Traffic Control: Research proposal

    NARCIS (Netherlands)

    Van de Weg, G.S.; Hegyi, A.; Hoogendoorn, S.P.

    2014-01-01

    The development of control strategies for traffic lights, ramp metering installations, and variable speed limits to improve the throughput of road traffic networks can contribute to a more efficient use of road networks. In this project, a hierarchical controller will be developed for the improvemen

  18. 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...

  19. 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.

  20. 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.

  1. 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…

  2. Traffic noise and vehicle movement at a controlled intersection

    NARCIS (Netherlands)

    Salomons, E.M.

    2014-01-01

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

  3. 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…

  4. Air traffic control activity increases attention capacity in air traffic controllers

    Directory of Open Access Journals (Sweden)

    Valdenilson Ribeiro Ribas

    Full Text Available Abstract Air traffic controllers simultaneously develop complex and multiple tasks in the course of their activities. In this context, concern is raised over the high level of attention needed by these professionals which can ultimately be affected by stress and fatigue. Objectives: The objective of this study was to assess attention level in air traffic controllers (ATCo. Methods: 45 flight protection professionals were evaluated, comprising 30 ATCo, subdivided into ATCo with ten or more years in the profession (ATCo³10, n=15 and ATCo with less than ten years in the profession (ATCo <10, n=15 and 15 aeronautical information services operators (AIS, subdivided into AIS with ten years or more in the profession (AIS³10, n=8 and AIS with less than ten years in the profession (AIS <10, n=7, who were included as the control group. The digit symbol, d2 (the individual marks the letter d on a specific form containing 14 lines with 47 letters in each, maintaining focus on letter d followed by two dashes, forward digit span, backward digit span and PASAT (paced auditory serial addition test attention tests were used. Kruskal-Wallis was used and data expressed as Median (Minimum and Maximum with p<0.05. Results: The ATCo³10 presented greater focus of attention, sustained attention, mental manipulation and resistance to interference capacity compared to the AIS³10. Comparison of ATCo³10 to the AIS<10 showed they presented only greater resistance to interference, and when compared to the ATCo<10 presented lower focus. Conclusions: The air traffic control activity after ten years may be associated with a high level of attention.

  5. A generic solution for unwanted traffic control through trust management

    Science.gov (United States)

    Yan, Zheng; Kantola, Raimo; Shen, Yue

    2014-01-01

    The Internet has dramatically changed our daily life. But it is also bogged down by unwanted traffic, which is malicious, harmful or unexpected for its receivers. In order to control the unwanted traffic over the Internet, especially the mobile Internet, in this paper, we propose a generic unwanted traffic control (UTC) solution through trust management. It can control unwanted traffic from its source to destinations in a personalized manner according to trust evaluation at a Global Trust Operator, traffic and behavior analysis at hosts and traffic observation in the Internet. Thus, it can conduct UTC by integrating distributed and centralized functions and supporting both defensive and offensive approaches. Simulation based evaluation shows that the solution is effective with regard to accuracy and efficiency for botnet intrusion and DDoS intrusion via reflectors. It is also robust against a number of malicious system attacks, such as hide evidence attack, bad mouthing attack, on-off attack, malicious attack by an Internet Service Provider and combinations of the above, playing in conjunction with traffic intrusions. Meanwhile, the solution can provide a personalized UTC based on unwanted traffic detection behaviors.

  6. 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...

  7. 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.

  8. 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.

  9. development of an electronic vehicular traffic signal controller

    African Journals Online (AJOL)

    safety and orderly flow of traffic as well as safety of pedestrians. ... Conceptual block diagram of signal controller finite state machine .... process was repeated every other week for three months in the laboratory and for an additional two months.

  10. 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.

  11. Supplementary Computer Generated Cueing to Enhance Air Traffic Controller Efficiency

    Science.gov (United States)

    2013-03-01

    assess the complexity of air traffic control (Mogford, Guttman, Morrow, & Kopardekar, 1995; Laudeman, Shelden, Branstrom, & Brasil , 1998). Controllers...Traffic Management R&D Seminar. Santa Fe, New Mexico , USA. European Organization for the Safety of Air Navigation (2007). The Human Factors Case...Behaviorial Sciences: Volume 1: Methodological Issues Volume 2: Statistical Issues, 1, 257. Laudeman, I. V., Shelden, S. G., Branstrom, R., & Brasil

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

    OpenAIRE

    Brooker, Peter

    2005-01-01

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

  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. Task Analysis Assessment on Intrastate Bus Traffic Controllers

    Science.gov (United States)

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

    2016-11-01

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

  15. 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...

  16. Effect of Surface Traffic Count on Taxi Time at Dallas-Fort Worth (DFW) International Airport

    Science.gov (United States)

    Kistler, Matthew Stephen; Gupta, Gautam

    2008-01-01

    delay encountered. The fields investigated in this study include taxi time, the number of aircraft on the surface, the number of stop and go situations, and the time stopped for each aircraft. Taxi time is defined as spot to runway for departures, and runway to spot for arrivals. It does not include ramp area taxi time because the ramp area is controlled differently, and surface traffic schedulers do not currently incorporate them. Taxi time is found by finding the difference between take-off time (OFF) and spot crossing time for departures, and spot crossing time and landing time (ON) for arrivals. All surface data was either found directly using the Surface Operations Data Analysis and Adaptation (SODAA), a tool to analyze the Surface Management System (SMS) generated log files, or indirectly from SODAA using Matlab to derive values from SODAA data. The number of aircraft on the surface is found by looping through the ON times, OFF times, and spot times for each aircraft during a particular day. For each departure aircraft, surface counts are taken at its spot crossing and OFF time. The average of these two is used as the surface count for that aircraft. For arrivals, surface counts are taken at its ON time and its spot crossing time. The average of these two is used.

  17. Optimal Airport Surface Traffic Planning Using Mixed-Integer Linear Programming

    Directory of Open Access Journals (Sweden)

    P. C. Roling

    2008-01-01

    Full Text Available We describe an ongoing research effort pertaining to the development of a surface traffic automation system that will help controllers to better coordinate surface traffic movements related to arrival and departure traffic. More specifically, we describe the concept for a taxi-planning support tool that aims to optimize the routing and scheduling of airport surface traffic in such a way as to deconflict the taxi plans while optimizing delay, total taxi-time, or some other airport efficiency metric. Certain input parameters related to resource demand, such as the expected landing times and the expected pushback times, are rather difficult to predict accurately. Due to uncertainty in the input data driving the taxi-planning process, the taxi-planning tool is designed such that it produces solutions that are robust to uncertainty. The taxi-planning concept presented herein, which is based on mixed-integer linear programming, is designed such that it is able to adapt to perturbations in these input conditions, as well as to account for failure in the actual execution of surface trajectories. The capabilities of the tool are illustrated in a simple hypothetical airport.

  18. Collective traffic control systems on motorways; Kollektive Verkehrsbeeinflussung auf Autobahnen

    Energy Technology Data Exchange (ETDEWEB)

    Kirschfink, H. [Heusch (Dr.-Ing. H.) Boesefeldt (Dipl.-Ing. J.) Beratende Ingenieure fuer Verkehrstechnik und Datenverarbeitung GmbH, Aachen (Germany)

    2000-07-01

    The contribution describes direct and indirect traffic control measures. A general architecture of traffic control systems for motorways is outlined whose key requirement is the availability of current data. Intelligent methods of traffic flow analysis for data complementation and assessment are described. The key role of the computer center in the general architecture is stressed, and new developments in traffic jam management are outlined. [German] Schwerpunkt dieses Aufsatzes ist die Beschreibung direkter und indirekter Steuerungsmassnahmen im Rahmen kollektiver Verkehrsbeeinflussungsmassnahmen. Es wird eine generelle Architektur von Verkehrsbeeinflussungsanlagen auf Autobahnen skizziert, deren grundlegende Voraussetzung die Verfuegbarkeit aktueller Daten ist. Ausserdem werden intelligente Verkehrsflussanalyse-Verfahren zur Datenvervollstaendigung und -abschaetzung beschrieben. Es wird die tragende Rolle der Verkehrsrechnerzentrale innerhalb der Gesamtarchitektur beruecksichtigt und auf neuere Entwicklungen auf dem Gebiet des Staumanagements hingewiesen. (orig.)

  19. 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.

  20. 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.

  1. 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.

  2. A sliding mode controller for vehicular traffic flow

    Science.gov (United States)

    Li, Yongfu; Kang, Yuhao; Yang, Bin; Peeta, Srinivas; Zhang, Li; Zheng, Taixong; Li, Yinguo

    2016-11-01

    This study proposes a sliding mode controller for vehicular traffic flow based on a car-following model to enhance the smoothness and stability of traffic flow evolution. In particular, the full velocity difference (FVD) model is used to capture the characteristics of vehicular traffic flow. The proposed sliding mode controller is designed in terms of the error between the desired space headway and the actual space headway. The stability of the controller is guaranteed using the Lyapunov technique. Numerical experiments are used to compare the performance of sliding mode control (SMC) with that of feedback control. The results illustrate the effectiveness of the proposed SMC method in terms of the distribution smoothness and stability of the space headway, velocity, and acceleration profiles. They further illustrate that the SMC strategy is superior to that of the feedback control strategy, while enabling computational efficiency that can aid in practical applications.

  3. Measurement of Temporal Awareness in Air Traffic Control

    Science.gov (United States)

    Rantanen, E.M.

    2009-01-01

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

  4. Traffic jams reduce hydrolytic efficiency of cellulase on cellulose surface.

    Science.gov (United States)

    Igarashi, Kiyohiko; Uchihashi, Takayuki; Koivula, Anu; Wada, Masahisa; Kimura, Satoshi; Okamoto, Tetsuaki; Penttilä, Merja; Ando, Toshio; Samejima, Masahiro

    2011-09-02

    A deeper mechanistic understanding of the saccharification of cellulosic biomass could enhance the efficiency of biofuels development. We report here the real-time visualization of crystalline cellulose degradation by individual cellulase enzymes through use of an advanced version of high-speed atomic force microscopy. Trichoderma reesei cellobiohydrolase I (TrCel7A) molecules were observed to slide unidirectionally along the crystalline cellulose surface but at one point exhibited collective halting analogous to a traffic jam. Changing the crystalline polymorphic form of cellulose by means of an ammonia treatment increased the apparent number of accessible lanes on the crystalline surface and consequently the number of moving cellulase molecules. Treatment of this bulky crystalline cellulose simultaneously or separately with T. reesei cellobiohydrolase II (TrCel6A) resulted in a remarkable increase in the proportion of mobile enzyme molecules on the surface. Cellulose was completely degraded by the synergistic action between the two enzymes.

  5. Controlling traffic jams by time modulating the safety distance

    DEFF Research Database (Denmark)

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

    2013-01-01

    in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well......The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case....... This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance...

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

    OpenAIRE

    2015-01-01

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

  7. Traffic Adaptive Distributed Backoff Control Mechanism for Cluster-Based IEEE802.15.4 WSNs with Traffic Fluctuations

    Science.gov (United States)

    Mori, Kazuo; Naito, Katsuhiro; Kobayashi, Hideo

    The traffic adaptive 2-level active period control has been proposed as a traffic adaptation mechanism to handle temporal and spatial (geographical) traffic fluctuations in cluster-based wireless sensor networks (WSNs) employing IEEE802.15.4 medium access control (MAC). This paper proposes a traffic adaptive distributed backoff control mechanism for cluster-based WSNs with the traffic adaptive 2-level active period control to enhance the system performance, especially transmission performance. The proposed mechanism autonomously adjusts the starting time of the backoff procedure for channel accesses in the contention access period (CAP) specified by the IEEE802.15.4 MAC, and then distributes the channel access timing over a wide range within the CAP, which can mitigate channel access congestion. The results of computer simulations show that the proposed mechanism can improve the transmission delay performance while keeping the enhancement in throughput and energy consumption at the cluster-based WSNs under non-uniform traffic environments.

  8. A semi-decentralized control strategy for urban traffic

    OpenAIRE

    Farhi, Nadir; Nguyen Van Phu, Cyril; AMIR, Mouna; Haj Salem, Habib; LEBACQUE, Jean Patrick

    2015-01-01

    EWGT - Euro Working Group on Transportation, Delft, PAYS-BAS, 14-/07/2015 - 16/07/2015; We present in this article a semi-decentralized approach for urban traffic control, based on the TUC (Traffic responsive Urban Control) strategy. We assume that the control is centralized as in the TUC strategy, but we introduce a contention time window inside the cycle time, where antagonistic stages alternate a priority rule. The priority rule is set by applying green colours for given stages and yellow ...

  9. 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.

  10. 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.

  11. 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

  12. Model-Based Traffic Control for Sustainable Mobility

    NARCIS (Netherlands)

    Zegeye, S.K.

    2011-01-01

    Computationally efficient dynamic fuel consumption, emissions, and dispersion of emissions models are developed. Fast and practically feasible model-based controller is proposed. Using the developed models, the controller steers the traffic flow in such a way that a balanced trade-off between the t

  13. 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

  14. Traffic behavior of mixed traffic flow with two kinds of different self-stabilizing control vehicles

    Science.gov (United States)

    Li, Zhipeng; Li, Wenzhong; Xu, Shangzhi; Qian, Yeqing; Sun, Jian

    2015-10-01

    In this paper, we propose a heterogeneous car following model in terms of an extension to the original optimal velocity model characterizing two classes of different self-stabilizing control vehicles. Linear stability analysis method is utilized to the extended model, for purpose to explore how the varying percentages of the vehicles with short-duration self-stabilizing control influence the stability of the heterogeneous traffic flow. We obtain the neutral stability lines for different percentages of two classes of vehicles, with finding that the traffic flow trends to stable with the decrease of the percentage for short-duration self-stabilizing control vehicles. Moreover, we explore a special case that the same numbers of two different classes of vehicles with self-stabilizing control. We theoretically derive the stability condition of the special case, and conclude the effect of the average value and the standard deviation of two time gaps, on the heterogeneous traffic stability. At last, direct simulations are conducted to verify the conclusion of theoretical analysis.

  15. 78 FR 36132 - National Standards for Traffic Control Devices; Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2013-06-17

    ... books would cause unnecessary confusion because users would have to determine how to correctly apply the... experience the same fate as the Traffic Engineering Manual, which was developed to supplement the 1978...

  16. 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.

  17. 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.

  18. Development and Evaluation of a Control System for Regional Traffic Management

    Directory of Open Access Journals (Sweden)

    John L. McLin

    2011-01-01

    Full Text Available Traffic congestion is a worsening problem in metropolitan areas which will require integrated regional traffic control systems to improve traffic conditions. This paper presents a regional traffic control system which can detect incident conditions and provide integrated traffic management during nonrecurrent congestion events. The system combines advanced artificial intelligence techniques with a traffic performance model based on HCM equations. Preliminary evaluation of the control system using traffic microsimulation demonstrates that it has the potential to improve system conditions during traffic incidents. In addition, several enhancements were identified which will make the system more robust in a real traffic control setting. An assessment of the control system elements indicates that there are no substantial technical barriers in implementing this system in a large traffic network.

  19. 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.

  20. 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

  1. 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

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

    Science.gov (United States)

    1994-05-01

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

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

    Science.gov (United States)

    Koskela, Inka; Palukka, Hannele

    2011-01-01

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

  4. Automatic speed control of highway traffic

    Science.gov (United States)

    Klingman, E. E.

    1973-01-01

    Vehicle control system monitors all vehicles in its range, and automatically slows down speeding vehicles by activating governor in vehicle. System determines only maximum speed; speeds below maximum are controlled by vehicle operator. Loss of transmitted signal or activation of emergency over-ride will open fuel line and return control to operator.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Pieter Burghouwt

    2015-10-01

    Full Text Available 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 input, prior traffic from a trusted destination, or a defined set of legitimate applications, the destination is trusted and its associated traffic is classified as normal. Advantages of this approach are: the ability of zero day malicious traffic detection, low exposure to malware by passive host-external traffic monitoring, and the applicability for real-time filtering. Experimental evaluation demonstrates successful detection of diverse types of Command and Control Traffic.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Design of Air Traffic Control Operation System

    Directory of Open Access Journals (Sweden)

    Gabriela STROE

    2017-09-01

    Full Text Available This paper presents a numerical simulation for a different aircraft, based on the specific aircraft data that can be incorporated in the model and the equations of motions which can be consequently solved. The aircraft flight design involves various technical steps and requires the use of sophisticated software having modeling and simulation capabilities. Within the flight simulation model, the aerodynamic model can be regarded as the most complex and most important. With appropriate aerodynamic modeling the aerodynamic forces and moments acting on the aircraft's center of gravity can be numerically solved with accuracy. These forces and moments are further used to solve the equations of motion. The development of control and computing technology makes it possible for advanced flight control strategy. The advanced control techniques tend to make the control design and their implementation much more complicated with more control loops or channels; in this line, the autopilot of modern aircrafts includes a variety of automatic control systems that aid and support the flight navigation, flight management, and perform the enhancing and/or augmenting of the stability characteristics of the airplane. Therefore in this context it is very important to choose the dynamic that will satisfy the performance and robustness specifications.

  14. 75 FR 74128 - Manual on Uniform Traffic Control Devices (MUTCD) Compliance Dates

    Science.gov (United States)

    2010-11-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Highway Administration Manual on Uniform Traffic Control Devices (MUTCD) Compliance Dates AGENCY... control devices to comply with certain requirements established in the Manual on Uniform Traffic...

  15. 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.

  16. 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.

  17. 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.

  18. A Control Method for Congested Traffic in the Car-Following Model

    Science.gov (United States)

    Ge, Hong-Xia; Yu, Jian; Lo, Siu-Ming

    2012-05-01

    A simple control method to suppress traffic congestion is proposed for the car-following model. The stability conditions are derived by using the control method, and the feedback signals, which act on our traffic system, are extended to the car-following model. The control signals will play an effect only if the traffic is congested. The corresponding numerical simulation results agree well with our theoretical analysis, and our control method can successfully suppress traffic jams.

  19. Urban Traffic Signal System Control Structural Optimization Based on Network Analysis

    Directory of Open Access Journals (Sweden)

    Li Wang

    2013-01-01

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

  20. Controlling traffic jams by time modulating the safety distance

    Science.gov (United States)

    Gaididei, Yu. B.; Gorria, C.; Berkemer, R.; Kawamoto, A.; Shiga, T.; Christiansen, P. L.; Sørensen, M. P.; Starke, J.

    2013-10-01

    The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case. This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well separated. A link between a microscopic description and the macroscopic fundamental diagram is established.

  1. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Science.gov (United States)

    2010-10-01

    ... traffic control systems. 236.426 Section 236.426 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control systems. The rules and instructions prescribed in...

  2. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Science.gov (United States)

    2010-10-01

    ... traffic control systems. 236.476 Section 236.476 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control systems. The inspections and tests prescribed in §§ 236...

  3. 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.

  4. Fuzzy Logic in Traffic Engineering: A Review on Signal Control

    Directory of Open Access Journals (Sweden)

    Milan Koukol

    2015-01-01

    Full Text Available Since 1965 when the fuzzy logic and fuzzy algebra were introduced by Lotfi Zadeh, the fuzzy theory successfully found its applications in the wide range of subject fields. This is mainly due to its ability to process various data, including vague or uncertain data, and provide results that are suitable for the decision making. This paper aims to provide comprehensive overview of literature on fuzzy control systems used for the management of the road traffic flow at road junctions. Several theoretical approaches from basic fuzzy models from the late 1970s to most recent combinations of real-time data with fuzzy inference system and genetic algorithms are mentioned and discussed throughout the paper. In most cases, fuzzy logic controllers provide considerable improvements in the efficiency of traffic junctions’ management.

  5. Traffic Information Unit, Traffic Information System, Vehicle Management System, Vehicle, and Method of Controlling a Vehicle

    NARCIS (Netherlands)

    Papp, Z.; Doodeman, G.J.N.; Nelisse, M.W.; Sijs, J.; Theeuwes, J.A.C.; Driessen, B.J.F.

    2010-01-01

    A traffic information unit (MD1, MD2, MD3) according to the invention comprises a facility (MI) for tracking vehicle state information of individual vehicles present at a traffic infrastructure and a facility (T) for transmitting said vehicle state information to a vehicle (70B, 70E). A traffic

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

    OpenAIRE

    Chao, Kuei-Hsiang; Chen, Pi-Yun

    2014-01-01

    This study primarily focuses on the use of radio frequency identification (RFID) as a form of traffic flow detection, which transmits collected information related to traffic flow directly to a control system through an RS232 interface. At the same time, the sensor analyzes and judges the information using an extension algorithm designed to achieve the objective of controlling the flow of traffic. In addition, the traffic flow situation is also transmitted to a remote monitoring control syste...

  7. TCP/IP Communication System for Controlling a Vehicular Traffic Intersection

    Directory of Open Access Journals (Sweden)

    Pedraza-Martínez Luis Fernando

    2013-10-01

    Full Text Available This paper describes the development of a prototype of a vehicular traffic controller, whose system of communication is based on the TCP/IP protocol, in order to re- motely monitor and control the operation of traffic lights for a vehicular intersection. The results show the times of communication between the central and the traffic controller. The conclusions highlight the importance of using the TCP/IP protocol in traffic light systems.

  8. Occupational stress and stress prevention in air traffic control

    OpenAIRE

    Costa, Giovanni

    1996-01-01

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

  9. Cooperative Traffic Control based on the Artificial Bee Colony

    Directory of Open Access Journals (Sweden)

    Jinjian Li

    2016-12-01

    Full Text Available This paper studies the traffic control problem in an isolated intersection without traffic lights and phase, because the right-of-way is distributed to each vehicle individually based on connection of the Vehicle-to-Infrastructure (V2I, and the compatible streams are dynamically combined according to the arrival vehicles in each traffic flows. The control objective in the proposed algorithm is to minimize the time delay, which is defined as the difference between the travel time in real state and that in free flow state. In order to realize this target, a cooperative control structure with a two-way communications is proposed. First of all, once the vehicle enters the communication zone, it sends its information to the intersection. Then the passing sequence is optimized in the intersection with the heuristic algorithm of the Artificial Bee Colony, based on the arrival interval of the vehicles. At last, each vehicle plans its speed profile to meet the received passing sequence by V2I. The simulation results show that each vehicle can finish the entire travel trip with a near free flow speed in the proposed method.

  10. 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.

  11. Interaction Between Strategic and Local Traffic Flow Controls

    Science.gov (United States)

    Grabbe, Son; Sridhar, Banavar; Mukherjee, Avijit; Morando, Alexander

    2010-01-01

    The loosely coordinated sets of traffic flow management initiatives that are operationally implemented at the national- and local-levels have the potential to under, over, and inconsistently control flights. This study is designed to explore these interactions through fast-time simulations with an emphasis on identifying inequitable situations in which flights receive multiple uncoordinated delays. Two operationally derived scenarios were considered in which flights arriving into the Dallas/Fort Worth International Airport were first controlled at the national-level, either with a Ground Delay Program or a playbook reroute. These flights were subsequently controlled at the local level. The Traffic Management Advisor assigned them arrival scheduling delays. For the Ground Delay Program scenarios, between 51% and 53% of all arrivals experience both pre-departure delays from the Ground Delay Program and arrival scheduling delays from the Traffic Management Advisor. Of the subset of flights that received multiple delays, between 5.7% and 6.4% of the internal departures were first assigned a pre-departure delay by the Ground Delay Program, followed by a second pre-departure delay as a result of the arrival scheduling. For the playbook reroute scenario, Dallas/Fort Worth International Airport arrivals were first assigned pre-departure reroutes based on the MW_2_DALLAS playbook plan, and were subsequently assigned arrival scheduling delays by the Traffic Management Advisor. Since the airport was operating well below capacity when the playbook reroute was in effect, only 7% of the arrivals were observed to receive both rerouting and arrival scheduling delays. Findings from these initial experiments confirm field observations that Ground Delay Programs operated in conjunction with arrival scheduling can result in inequitable situations in which flights receive multiple uncoordinated delays.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

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

    Data.gov (United States)

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

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

    National Research Council Canada - National Science Library

    Tímea Vas

    2014-01-01

      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...

  17. 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.

  18. 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.

  19. 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.

  20. Automation of Data Traffic Control on DSM Architecture

    Science.gov (United States)

    Frumkin, Michael; Jin, Hao-Qiang; Yan, Jerry

    2001-01-01

    The design of distributed shared memory (DSM) computers liberates users from the duty to distribute data across processors and allows for the incremental development of parallel programs using, for example, OpenMP or Java threads. DSM architecture greatly simplifies the development of parallel programs having good performance on a few processors. However, to achieve a good program scalability on DSM computers requires that the user understand data flow in the application and use various techniques to avoid data traffic congestions. In this paper we discuss a number of such techniques, including data blocking, data placement, data transposition and page size control and evaluate their efficiency on the NAS (NASA Advanced Supercomputing) Parallel Benchmarks. We also present a tool which automates the detection of constructs causing data congestions in Fortran array oriented codes and advises the user on code transformations for improving data traffic in the application.

  1. 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...

  2. 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.

  3. Delay-feedback control strategy for reducing CO2 emission of traffic flow system

    Science.gov (United States)

    Zhang, Li-Dong; Zhu, Wen-Xing

    2015-06-01

    To study the signal control strategy for reducing traffic emission theoretically, we first presented a kind of discrete traffic flow model with relative speed term based on traditional coupled map car-following model. In the model, the relative speed difference between two successive running cars is incorporated into following vehicle's acceleration running equation. Then we analyzed its stability condition with discrete control system stability theory. Third, we designed a delay-feedback controller to suppress traffic jam and decrease traffic emission based on modern controller theory. Last, numerical simulations are made to support our theoretical results, including the comparison of models' stability analysis, the influence of model type and signal control on CO2 emissions. The results show that the temporal behavior of our model is superior to other models, and the traffic signal controller has good effect on traffic jam suppression and traffic CO2 emission, which fully supports the theoretical conclusions.

  4. Commercial machine vision system for traffic monitoring and control

    Science.gov (United States)

    D Agostino, Salvatore A.

    1992-03-01

    Traffic imaging covers a range of current and potential applications. These include traffic control and analysis, license plate finding, reading and storage, violation detection and archiving, vehicle sensors, and toll collection/enforcement. Experience from commercial installations and knowledge of the system requirements have been gained over the past 10 years. Recent improvements in system component cost and performance now allow products to be applied that provide cost effective solutions to the requirements for truly intelligent vehicle/highway systems (IVHS). The United States is a country that loves to drive. The infrastructure built in the 1950s and 1960s along with the low price of gasoline created an environment where the automobiles became an accessible and intricate part of American life. The United States has spent $DLR103 billion to build 40,000 highway miles since 1956, the start of the interstate program which is nearly complete. Unfortunately, a situation has arisen where the options for dramatically improving the ability of our roadways to absorb the increasing amount of traffic is limited. This is true in other countries as well as in the United States. The number of vehicles in the world increases by over 10,000,000 each year. In the United States there are about 180 million cars, trucks, and buses and this is estimated to double in the next 30 years. Urban development, and development in general, pushes from the edge of our roadways out. This leaves little room to increase the physical amount of roadway. Americans now spend more than 1.6 billion hours a year waiting in traffic jams. It is estimated that this congestion wasted 3 billion gallons of oil or 4% of the nation's annual gas consumption. The way out of the dilemma is to increase road use efficiency as well as improve mass transportation alternatives.

  5. An Intelligent Vehicular Traffic Signal Control System with State Flow Chart Design and FPGA Prototyping

    Directory of Open Access Journals (Sweden)

    UMAIR SAEEDSOLANGI

    2017-04-01

    Full Text Available The problem of vehicular traffic congestion is a persistent constraint in the socio-economic development of Pakistan. This paper presents design and implementation of an intelligent traffic controller based on FPGA (Field Programmable Gate Array to provide an efficient traffic management by optimizing functioning of traffic lights which will result in minimizing traffic congestion at intersections. The existent Traffic Signal system in Pakistan is fixed-time based and offers only Open Loop method for Traffic Control. The Intelligent Traffic Controller presented here uses feedback sensors to read the Traffic density present at a four way intersection to provide an efficient alternative for better supervisory Control of Traffic flow. The traffic density based control logic has been developed in a State Flow Chart for improved visualization of State Machine based operation, and implemented as a Subsystem in Simulink and transferred into VHDL (Hardware Description Language code using HDL Coder for reducing development time and time to market, which are essential to capitalize Embedded Systems Market. The VHDL code is synthesized with Altera QUARTUS, simulated timing waveform is obtained to verify correctness of the algorithm for different Traffic Scenarios. For implementation purpose estimations were obtained for Cyclone-III and Stratix-III.

  6. Performance Evaluation of Road Traffic Control Using a Fuzzy Cellular Model

    CERN Document Server

    Płaczek, Bartłomiej

    2011-01-01

    In this paper a method is proposed for performance evaluation of road traffic control systems. The method is designed to be implemented in an on-line simulation environment, which enables optimisation of adaptive traffic control strategies. Performance measures are computed using a fuzzy cellular traffic model, formulated as a hybrid system combining cellular automata and fuzzy calculus. Experimental results show that the introduced method allows the performance to be evaluated using imprecise traffic measurements. Moreover, the fuzzy definitions of performance measures are convenient for uncertainty determination in traffic control decisions.

  7. Adaptive Traffic Control Systems in a medium-sized Scandinavian city

    DEFF Research Database (Denmark)

    Agerholm, Niels; Olesen, Anne Vingaard

    2017-01-01

    Adaptive Traffic Control Systems (ATCS) are aimed at reducing congestion. ATCS adapt to approaching traffic to continuously optimise the traffic flows in question. ATCS have been implemented in many locations, including the Scandinavian countries, with various effects. Due to congestion problems...

  8. Traffic Signals Control with Adaptive Fuzzy Controller in Urban Road Network

    Institute of Scientific and Technical Information of China (English)

    LI Yan; FAN Xiao-ping

    2008-01-01

    An adaptive fuzzy logic controller (AFC) is presented for the signal control of the urban traffic network.The AFC is composed of the signal control system-oriented control level and the signal controller-oriented fuzzy rules regulation level.The control level decides the signal tunings in an intersection with a fuzzy logic controller.The regulation level optimizes the fuzzy rules by the Adaptive Rule Module in AFC according to both the system performance index in current control period and the traffic flows in the last one.Consequently the system performances are improved.A weight coefficient controller (WCC) is also developed to describe the interactions of traffic flow among the adjacent intersections.So the AFC combined with the WCC can be applied in a road network for signal timings.Simulations of the AFC on a real traffic scenario have been conducted.Simulation results indicate that the adaptive controller for traffic control shows better performance than the actuated one.

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

    Science.gov (United States)

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

    1990-01-01

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

  10. Admission control with long-range dependence traffic input

    Institute of Scientific and Technical Information of China (English)

    RAO Yun-hua; ZOU Xue-cheng

    2005-01-01

    The admission control scheme is investigated for a FIFO self-similar queuing system with Quality of Service (QoS) performance guarantees. Since the self-similar queuing system performance analysis is often carried out under the condition of infinite buffer, it is difficult to deduce the upper boundary of buffer overflow probability. To overcome this shortcoming, a simple overflow condition is proposed, which defines a buffer overflow occurrence whenever the arrival rate exceeds the service rate. The analytic formula for the buffer overflow probability upper boundary is easily obtained under this condition. The required bandwidth upper boundary with long-range dependence input and determined overflow probability is then derived from this formula. Based on the above analytic formulas, the upper boundaries of the admission control regions for homogeneous and heterogeneous long-range dependence traffic sources are separately obtained. Finally, an effective admission control scheme for long-range dependence input is proposed. Simulation studies with real traffic have confirmed the validity of these results.

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

    Science.gov (United States)

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

    2008-04-01

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

  12. Cellular Automaton Models of Highway Traffic Flow Considering Lane-Control and Speed-Control

    Institute of Scientific and Technical Information of China (English)

    钱勇生; 李文俊; 曾俊伟; 王敏; 杜加伟; 广晓平

    2011-01-01

    As two kinds of management modes of highway tramc control, lane-control, and speed-control produce different effect under different conditions. In this paper, traffic flow cellular automaton models for four-lane highway system with two opposing directions under the above two modes are established considering car and truck mixed running. Through computer numerical simulating, the fundamental diagrams with different parameters are obtained, and after the analysis of density-flux diagrams, the variation discipline of flux with traffic density under different control models is gained. The results indicate that, compared with lane-control, utilization ratio of road can be further improved with speed-control when the truck number increases. The research result is of great significance for reasonable providing theoretical guidance for highway traffic control.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-12-17

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

  15. 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)

  16. 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.

  17. Traffic management and control in intelligent vehicle highway systems

    NARCIS (Netherlands)

    Baskar, L.D.

    2009-01-01

    Traffic congestion is a problem experienced daily by most of us. Among various traffic management schemes, efficient utilisation of the existing roadside infrastructure combined with in-vehicle technologies offers a promising solution to address traffic congestion and related problems. This approach

  18. Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with the TEB model

    Science.gov (United States)

    Khalifa, A.; Marchetti, M.; Bouilloud, L.; Martin, E.; Bues, M.; Chancibaut, K.

    2016-02-01

    Snowfall forecasts help winter maintenance of road networks, ensure better coordination between services, cost control, and a reduction in environmental impacts caused by an inappropriate use of de-icers. In order to determine the possible accumulation of snow on pavements, forecasting the road surface temperature (RST) is mandatory. Weather outstations are used along these networks to identify changes in pavement status, and to make forecasts by analyzing the data they provide. Physical numerical models provide such forecasts, and require an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB) numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with two approaches to evaluate traffic incidence on RST. Experiments were then conducted to measure the effect of traffic on RST increase with respect to non-circulated areas. These field data were then used for comparison with the forecast provided by this traffic-implemented TEB version.

  19. Lattice hydrodynamic model based traffic control: A transportation cyber-physical system approach

    Science.gov (United States)

    Liu, Hui; Sun, Dihua; Liu, Weining

    2016-11-01

    Lattice hydrodynamic model is a typical continuum traffic flow model, which describes the jamming transition of traffic flow properly. Previous studies in lattice hydrodynamic model have shown that the use of control method has the potential to improve traffic conditions. In this paper, a new control method is applied in lattice hydrodynamic model from a transportation cyber-physical system approach, in which only one lattice site needs to be controlled in this control scheme. The simulation verifies the feasibility and validity of this method, which can ensure the efficient and smooth operation of the traffic flow.

  20. Step-coordination Algorithm of Traffic Control Based on Multi-agent System

    Institute of Scientific and Technical Information of China (English)

    Hai-Tao Zhang; Fang Yu; Wen Li

    2009-01-01

    Aiming at the deficiency of conventional traffic control method, this paper proposes a new method based on multi-agent technology for traffic control. Different from many existing methods, this paper distinguishes traffic control on the basis of the agent technology from conventional traffic control method. The composition and structure of a multi-agent system (MAS) is first discussed. Then, the step-coordination strategies of intersection-agent, segment-agent, and area-agent are put forward. The advantages of the algorithm are demonstrated by a simulation study.

  1. Urban Traffic Control Using Adjusted Reinforcement Learning in a Multi-agent System

    Directory of Open Access Journals (Sweden)

    Mahshid Helali Moghadam

    2013-09-01

    Full Text Available Dynamism, continuous changes of states and the necessity to respond quickly are the specific characteristics of the environment in a traffic control system. Proposing an appropriate and flexible strategy to meet the existing requirements is always an important issue in traffic control. This study presents an adaptive approach to control urban traffic using multi-agent systems and a reinforcement learning augmented by an adjusting pre-learning stage. In this approach, the agent primarily uses some statistical traffic data and then uses traffic engineering theories for computing appropriate values of the traffic parameters. Having these primary values, the agents start the reinforcement learning based on the basic calculated information. The proposed approach, at first finds the approximate optimal zone for traffic parameters based on traffic engineering theories. Then using an appropriate reinforcement learning, it tries to exploit the best point according to different conditions. This approach was implemented on a network in traffic simulator software. The network was composed of six four phased intersections and 17 two lane streets. In the simulation, pedestrians were not considered in the system. The load of the network is defined in terms of Origin-Destination matrices whose entries represent the number of trips from an origin to a destination as a function of time. The simulation ran for five hours and an average traffic volume was used. According to the simulation results, the proposed approach behaved adaptively in different conditions and had better performance than the theory-based fixed-time control.

  2. An Adaptive Fuzzy-Logic Traffic Control System in Conditions of Saturated Transport Stream

    Science.gov (United States)

    Marakhimov, A. R.; Igamberdiev, H. Z.; Umarov, Sh. X.

    2016-01-01

    This paper considers the problem of building adaptive fuzzy-logic traffic control systems (AFLTCS) to deal with information fuzziness and uncertainty in case of heavy traffic streams. Methods of formal description of traffic control on the crossroads based on fuzzy sets and fuzzy logic are proposed. This paper also provides efficient algorithms for implementing AFLTCS and develops the appropriate simulation models to test the efficiency of suggested approach. PMID:27517081

  3. Flight management concepts compatible with air traffic control

    Science.gov (United States)

    Morello, S. A.

    1986-01-01

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

  4. Self-control of traffic lights and vehicle flows in urban road networks

    Science.gov (United States)

    Lämmer, Stefan; Helbing, Dirk

    2008-04-01

    Based on fluid-dynamic and many-particle (car-following) simulations of traffic flows in (urban) networks, we study the problem of coordinating incompatible traffic flows at intersections. Inspired by the observation of self-organized oscillations of pedestrian flows at bottlenecks, we propose a self-organization approach to traffic light control. The problem can be treated as a multi-agent problem with interactions between vehicles and traffic lights. Specifically, our approach assumes a priority-based control of traffic lights by the vehicle flows themselves, taking into account short-sighted anticipation of vehicle flows and platoons. The considered local interactions lead to emergent coordination patterns such as 'green waves' and achieve an efficient, decentralized traffic light control. While the proposed self-control adapts flexibly to local flow conditions and often leads to non-cyclical switching patterns with changing service sequences of different traffic flows, an almost periodic service may evolve under certain conditions and suggests the existence of a spontaneous synchronization of traffic lights despite the varying delays due to variable vehicle queues and travel times. The self-organized traffic light control is based on an optimization and a stabilization rule, each of which performs poorly at high utilizations of the road network, while their proper combination reaches a superior performance. The result is a considerable reduction not only in the average travel times, but also of their variation. Similar control approaches could be applied to the coordination of logistic and production processes.

  5. Traffic Accident Propagation Properties and Control Measures for Urban Links Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Xian-sheng Li

    2013-01-01

    Full Text Available With the rapid development of urban transport and the sharp increase in vehicle population, traffic accidents form one of the most important causes of urban traffic congestion other than the imbalance between traffic supply and demand. Traffic congestion causes severe problems, such as environment contamination and energy dissipation. Therefore, it would be useful to analyze the congestion propagation characteristics after traffic accidents. Numerical analysis and computer simulation were two of the typical methods used at present to study the traffic congestion propagation properties. The latter was more widespread as it is more consistent with the actual traffic flow and more visual than the former. In this paper, an improved cellular automata (CA model was presented to analyze traffic congestion propagation properties and to evaluate control strategies. In order to apply them to urban traffic flow simulation, the CA models have been improved and expanded on. Computer simulations were built for congestion not only extending to the upstream intersection, but also the upstream intersection and the entire road network, respectively. Congestion propagation characteristics after road traffic accidents were obtained, and controls of different severities and durations were analyzed. The results provide the theoretical foundation and practical means for the control of congestion.

  6. Mobile Phone Based RIMS for Traffic Control a Case Study of Tanzania

    Directory of Open Access Journals (Sweden)

    Angela-Aida Karugila Runyoro

    2015-04-01

    Full Text Available Vehicles saturation in transportation infrastructure causes traffic congestion, accidents, transportation delays and environment pollution. This problem can be resolved with proper management of traffic flow. Existing traffic management systems are challenged on capturing and processing real-time road data from wide area road networks. The main purpose of this study is to address the gap by implementing a mobile phone based Road Information Management System. The proposed system integrates three modules for data collection, storage and information dissemination. The modules works together to enable real-time traffic control. Disseminated information from the system, enables road users to adjust their travelling habit, also it allows the traffic lights to control the traffic in relation to the real-time situation occurring on the road. In this paper the system implementation and testing was performed. The results indicated that there is a possibility to track traffic data using Global Positioning System enabled mobile phones, and after processing the collected data, real-time traffic status was displayed on web interface. This enabled road users to know in advance the situation occurring on the roads and hence make proper travelling decision. Further research should consider adjusting the traffic lights control system to understand the disseminated real-time traffic information.

  7. The Conception Approach to the Traffic Control in Czech Cities - Examples from Prague

    Science.gov (United States)

    Tichý, Tomáš; Krajčír, Dušan

    Modern and economic development of contemporary towns is without question highly dependent upon traffic infrastructure progress. Automobile transport intensity is dramatically rising in large towns and other Czech and European cities. At the same time number of traffic congestions and accidents is increasing, standing times are becoming longer and ecological stress is also escalated. To solve this situation seems to be the most effective solution to design intelligent traffic light intersection control system, variable message signs, preference of public transportation, road line traffic control and next telematics subsystems. This control system and subsystems should improve permeability of traffic road network with a respect for all demands on recent trends of traffic development in towns and regions.

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

    Directory of Open Access Journals (Sweden)

    Guo Li

    2014-01-01

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

  9. Surface Map Traffic Intent Displays and Net-Centric Data-link Communications for NextGen

    Science.gov (United States)

    Shelton, Kevin J.; Prinzel, Lawrence J., III; Jones, Denise R.; Allamandola, Angela S.; Arthur, Jarvis J., III; Bailey, Randall E.

    2009-01-01

    By 2025, U.S. air traffic is predicted to increase three fold and may strain the current air traffic management system, which may not be able to accommodate this growth. In response to this challenge, a revolutionary new concept has been proposed for U.S. aviation operations, termed the Next Generation Air Transportation System or "NextGen". Many key capabilities are being identified to enable NextGen, including the use of data-link communications. Because NextGen represents a radically different approach to air traffic management and requires a dramatic shift in the tasks, roles, and responsibilities for the flight deck, there are numerous research issues and challenges that must be overcome to ensure a safe, sustainable air transportation system. Flight deck display and crew-vehicle interaction concepts are being developed that proactively investigate and overcome potential technology and safety barriers that might otherwise constrain the full realization of NextGen. The paper describes simulation research, conducted at National Aeronautics and Space Administration (NASA) Langley Research Center, examining data-link communications and traffic intent data during envisioned four-dimensional trajectory (4DT)-based and equivalent visual (EV) surface operations. Overall, the results suggest that controller pilot data-link communications (CPDLC) with the use of mandatory pilot read-back of all clearances significantly enhanced situation awareness for 4DT and EV surface operations. The depiction of graphical traffic state and intent information on the surface map display further enhanced off-nominal detection and pilot qualitative reports of safety and awareness.

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

    Science.gov (United States)

    2013-03-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  14. Effects of speed bottleneck on traffic flow with feedback control signal

    Science.gov (United States)

    Zhu, Kangli; Bi, Jiantao; Wu, Jianjun; Li, Shubin

    2016-09-01

    Various car-following models (CMs) have been developed to capture the complex characteristics of microscopic traffic flow, among which the coupled map CM can better reveal and reflect various phenomena of practical traffic flow. Capacity change at bottleneck contributes to high-density traffic flow upstream the bottleneck and contains very complex dynamic behavior. In this paper, we analyze the effect of speed bottleneck on the spatial-temporal evolution characteristics of traffic flow, and propose a method to reduce traffic congestion with the feedback control signal based on CM. Simulation results highlight the potential of using the feedback signal to control the stop-and-go wave and furthermore to alleviate the traffic congestion effectively.

  15. Vehicle-class Specific Control of Freeway Traffic

    NARCIS (Netherlands)

    Schreiter, T.

    2013-01-01

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

  16. Traffic control and intelligent vehicle highway systems: a survey

    NARCIS (Netherlands)

    Baskar, L.D.; Schutter, B. de; Hellendoorn, J.; Papp, Z.

    2011-01-01

    Traffic congestion in highway networks is one of the main issues to be addressed by today's traffic management schemes. Automation combined with the increasing market penetration of on-line communication, navigation and advanced driver assistance systems will ultimately result in intelligent vehicle

  17. Traffic Flow at Sags: Theory, Modeling and Control

    NARCIS (Netherlands)

    Goni-Ros, B.

    2016-01-01

    Sag vertical curves (sags) are roadway sections along which the gradient increases gradually in the direction of traffic. Empirical observations show that, on freeways, traffic congestion often occurs at sags; actually, in some countries (e.g., Japan), sags are one of the most common types of freewa

  18. EVALUATION OF A DYNAMIC SIGNAL OPTIMISATION CONTROL MODEL USING TRAFFIC SIMULATION

    Directory of Open Access Journals (Sweden)

    Suphasawas NIGARNJANAGOOL

    2005-01-01

    Full Text Available The objective of this paper is to demonstrate the feasibility of implementing a traffic signal optimisation model to improve real-time operations of traffic control systems. Advanced computer algorithms and traffic optimisation techniques can provide benefits over existing systems by reducing delays, improving travel times and reducing environmental emissions. The feasibility of the proposed approach is demonstrated by interfacing the traffic signal optimisation model to a microscopic traffic simulation tool, which enabled the evaluation of the benefits of the algorithm using computers in a controlled environment without disrupting traffic conditions. The main advantage of the proposed algorithm is its ability to detect dynamic changes in traffic flow conditions by using short-term historical demand data obtained from upstream vehicle loop detectors. The experimental results for under-saturated traffic conditions showed that the algorithm's performance was superior to optimal fixed time control. The results also confirmed that as traffic volumes reach saturated conditions, the performance of the algorithm decreased but remained better than what can be achieved by fixed time control systems.

  19. Soil, crop and emission responses to seasonal-controlled traffic in organic vegetable farming on loam soil

    NARCIS (Netherlands)

    Vermeulen, G.D.; Mosquera Losada, J.

    2009-01-01

    Some organic arable and vegetable farms in the Netherlands use cm-precise guidance of machinery to restrict wheel traffic to fixed traffic lanes and to achieve non-trafficked cropping zones with optimized soil structure in between the lanes. Contrary to controlled traffic farming (CTF) the traffic l

  20. Automation and Systems Issues in Air Traffic Control

    Directory of Open Access Journals (Sweden)

    Gabriela STROE

    2016-12-01

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

  1. 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

  2. Cognitive process modelling of controllers in en route air traffic control.

    Science.gov (United States)

    Inoue, Satoru; Furuta, Kazuo; Nakata, Keiichi; Kanno, Taro; Aoyama, Hisae; Brown, Mark

    2012-01-01

    In recent years, various efforts have been made in air traffic control (ATC) to maintain traffic safety and efficiency in the face of increasing air traffic demands. ATC is a complex process that depends to a large degree on human capabilities, and so understanding how controllers carry out their tasks is an important issue in the design and development of ATC systems. In particular, the human factor is considered to be a serious problem in ATC safety and has been identified as a causal factor in both major and minor incidents. There is, therefore, a need to analyse the mechanisms by which errors occur due to complex factors and to develop systems that can deal with these errors. From the cognitive process perspective, it is essential that system developers have an understanding of the more complex working processes that involve the cooperative work of multiple controllers. Distributed cognition is a methodological framework for analysing cognitive processes that span multiple actors mediated by technology. In this research, we attempt to analyse and model interactions that take place in en route ATC systems based on distributed cognition. We examine the functional problems in an ATC system from a human factors perspective, and conclude by identifying certain measures by which to address these problems. This research focuses on the analysis of air traffic controllers' tasks for en route ATC and modelling controllers' cognitive processes. This research focuses on an experimental study to gain a better understanding of controllers' cognitive processes in air traffic control. We conducted ethnographic observations and then analysed the data to develop a model of controllers' cognitive process. This analysis revealed that strategic routines are applicable to decision making.

  3. Pattern of traffic injuries in Shanghai: implications for control.

    Science.gov (United States)

    Yan-Hong, Li; Rahim, Yousif; Wei, Lu; Gui-Xiang, Song; Yan, Yu; De Ding, Zhou; Sheng-Nian, Zhang; Shun-Fu, Zhou; Shao-Ming, Chen; Bing-Jie, Yang

    2006-12-01

    In China, traffic-related injuries are often treated as transportation issues, called 'accidents'. The objectives of the research are to analyse traffic injury patterns, estimate costs of traffic injuries and provide evidence to develop effective prevention strategies. There were over 1 500 deaths due to traffic-related injuries annually in Shanghai from 1987 to 2003, and it is rising year by year with the rate of growth in motorization. The rates of annual increase are 3.59% in fatalities (from 7.78 to 14.18 per 100000 population) and 10.46% in non-fatalities (from 53.93 to 264.98 per 100000 population) respectively during the period. The analysis of the geographic information system showed that the geographic distribution of traffic injuries in the countryside regions of Shanghai had the highest rates. Labour force groups represented the majority of fatalities (70.97%) and serious traffic injuries (90.51%). The mortality rates were 18.40 per 100000 population and 10.02 per 100000 population in 45-65 year age group and 15-44 year age group respectively; the morbidity rates of serious traffic injuries were 121.60 per 100000 population and 70.46 per 100000 population in the same groups respectively. And females generally showed a lower incidence than males. In general, fatalities and injuries were higher for drivers, bicyclists and pedestrians. Among road traffic injury-related fatalities, 66.8% were attributed to head injuries. Of those with fatal head injuries, bicyclists accounted for 29.8% of the total; pedestrians accounted for 28.3%; motorcyclists accounted for 25.5%. Total traffic injury cost was estimated at least US $645989580 in Shanghai in 2003. Good injury intervention programmes need to be done as soon as possible to effectively reduce traffic injury burden in Shanghai, China.

  4. Theoretical Aspects of Erroneous Actions During the Process of Decision Making by Air Traffic Control

    Directory of Open Access Journals (Sweden)

    Andersone Silva

    2017-08-01

    Full Text Available The Theoretical Aspects of Erroneous Actions During the Process of Decision Making by Air Traffic Control evaluates the factors affecting the operational decision-making of a human air traffic controller, interacting in a dynamic environment with the flight crew, surrounding aircraft traffic and environmental conditions of the airspace. This article reviews the challenges of air traffic control in different conditions, ranging from normal and complex to emergency and catastrophic. Workload factors and operating conditions make an impact on air traffic controllers’ decision-making. The proposed model compares various operating conditions within an assumed air traffic control environment subsequently comparing them against a theoretically “perfect” air traffic control system. A mathematical model of flight safety assessment has been proposed for the quantitative assessment of various hazards arising during the process of Air Traffic Control. The model assumes events of various severity and probability ranging from high frequency and low severity up to less likely and catastrophic ones. Certain limitations of the model have been recognised and further improvements for effective hazard evaluation have been suggested.

  5. Design and Construction of Intelligent Traffic Light Control System Using Fuzzy Logic

    Science.gov (United States)

    Lin, Htin; Aye, Khin Muyar; Tun, Hla Myo; Theingi, Naing, Zaw Min

    2008-10-01

    Vehicular travel is increasing throughout the world, particularly in large urban areas. Therefore the need arises for simulation and optimizing traffic control algorithms to better accommodate this increasing demand. This paper presents a microcontroller simulation of intelligent traffic light controller using fuzzy logic that is used to change the traffic signal cycles adaptively at a two-way intersection. This paper is an attempt to design an intelligent traffic light control systems using microcontrollers such as PIC 16F84A and PIC 16F877A. And then traffic signal can be controlled depending upon the densities of cars behind green and red lights of the two-way intersection by using sensors and detectors circuits.

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

    Science.gov (United States)

    Idris, Husni; Enea, Gabriele

    2016-01-01

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

  7. Feedback control scheme of traffic jams based on the coupled map car-following model

    Science.gov (United States)

    Zhou, Tong; Sun, Di-Hua; Zhao, Min; Li, Hua-Min

    2013-09-01

    Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses.

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

    NARCIS (Netherlands)

    Abdul Rahman, S.M.B.

    2014-01-01

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

  9. Traffic flow impacts of adaptive cruise control deactivation and (Re)activation with cooperative driver behavior

    NARCIS (Netherlands)

    Klunder, G.; Li, M.; Minderhoud, M.

    2009-01-01

    In 2006 in the Netherlands, a field operational test was carried out to study the effect of adaptive cruise control (ACC) and lane departure warning on driver behavior and traffic flow in real traffic. To estimate the effect for larger penetration rates, simulations were needed. For a reliable

  10. Traffic flow impacts of adaptive cruise control deactivation and (Re)activation with cooperative driver behavior

    NARCIS (Netherlands)

    Klunder, G.; Li, M.; Minderhoud, M.

    2009-01-01

    In 2006 in the Netherlands, a field operational test was carried out to study the effect of adaptive cruise control (ACC) and lane departure warning on driver behavior and traffic flow in real traffic. To estimate the effect for larger penetration rates, simulations were needed. For a reliable impac

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

    Science.gov (United States)

    Erzberger, Heinz

    1995-01-01

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

  12. Potential of controlled traffic farming with automatic guidance on an organic farm in the Netherlands

    NARCIS (Netherlands)

    Vermeulen, G.D.; Mosquera, J.; Wel, van der C.; Klooster, van der A.; Steenhuizen, J.W.

    2007-01-01

    Some organic farms in the Netherlands use RTK-DGPS guidance of machinery over fixed traffic lanes to achieve non-trafficked cropping zones with optimum soil structure. These lanes are not yet used for harvesting and primary tillage. The potential of such a seasonal controlled traffic farming (SCTF)

  13. Combination of traffic-responsive and gating control in urban networks: Effective interactions

    NARCIS (Netherlands)

    Keyvan Ekbatani, M.; Gao, X.; Gayah, V.V.; Knoop, V.L.

    2016-01-01

    Recent findings regarding macroscopic relationships of urban traffic measures such as the Macroscopic or Network Fundamental Diagram (MFD or NFD) have led to the development of novel traffic control strategies that can be applied at a network-wide level. One pertinent example is perimeter flow

  14. Scheduling with conflicts, and applications to traffic signal control

    Energy Technology Data Exchange (ETDEWEB)

    Irani, S.; Leung, V. [Univ. of California, Irvine, CA (United States)

    1996-12-31

    In this paper, we consider the scheduling of jobs that may be competing for mutually exclusive resources. We model the conflicts between jobs with a conflict graph, so that all concurrently running jobs must form an independent set in the graph. We believe that this model is natural and general enough to have applications in a variety of settings; however, we are motivated by the following two specific applications: traffic intersection control and session scheduling in high speed local area networks with spatial reuse. In both of these applications, guaranteeing the best turnaround time to any job entering the system is important. Our results focus on two special classes of graphs motivated by our applications: bipartite graphs and interval graphs. Although the algorithms for bipartite and intervals graphs are quite different, the bounds they achieve are the same: we prove that for any sequence of jobs in which the maximum completion time of a job in the optimal schedule is bounded by A, the algorithm can complete every job in time O(n{sup 3} A{sup 2}). n is the number of nodes in the conflict graph. We also show that the best competitive ratio achievable by any online algorithm for the maximum completion time on interval or bipartite graphs is {Omega}(n).

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  16. Evidence of traffic-related pollutant control in soil-based sustainable urban drainage systems (SUDS).

    Science.gov (United States)

    Napier, F; Jefferies, C; Heal, K V; Fogg, P; Arcy, B J D; Clarke, R

    2009-01-01

    SUDS are being increasingly employed to control highway runoff and have the potential to protect groundwater and surface water quality by minimising the risks of both point and diffuse sources of pollution. While these systems are effective at retaining polluted solids by filtration and sedimentation processes, less is known of the detail of pollutant behaviour within SUDS structures. This paper reports on investigations carried out as part of a co-ordinated programme of controlled studies and field measurements at soft-engineered SUDS undertaken in the UK, observing the accumulation and behaviour of traffic-related heavy metals, oil and PAHs. The field data presented were collected from two extended detention basins serving the M74 motorway in the south-west of Scotland. Additional data were supplied from an experimental lysimeter soil core leaching study. Results show that basin design influences pollutant accumulation and behaviour in the basins. Management and/or control strategies are discussed for reducing the impact of traffic-related pollutants on the aqueous environment.

  17. A Traffic Forecasting Method with Function to Control Residual Error Distribution for IP Access Networks

    Science.gov (United States)

    Kitahara, Takeshi; Furuya, Hiroki; Nakamura, Hajime

    Since traffic in IP access networks is less aggregated than in backbone networks, its variance could be significant and its distribution may be long-tailed rather than Gaussian in nature. Such characteristics make it difficult to forecast traffic volume in IP access networks for appropriate capacity planning. This paper proposes a traffic forecasting method that includes a function to control residual error distribution in IP access networks. The objective of the proposed method is to grasp the statistical characteristics of peak traffic variations, while conventional methods focus on average rather than peak values. In the proposed method, a neural network model is built recursively while weighting residual errors around the peaks. This enables network operators to control the trade-off between underestimation and overestimation errors according to their planning policy. Evaluation with a total of 136 daily traffic volume data sequences measured in actual IP access networks demonstrates the performance of the proposed method.

  18. 76 FR 54156 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2011-08-31

    ... contain collection information requirements for purposes of the PRA. Executive Order 12988 (Civil Justice..., Civil Justice Reform, to minimize litigation, eliminate ambiguity, and reduce burden. Executive Order... roads, Incorporation by reference, Signs, Traffic regulations. Issued on: August 23, 2011. Victor...

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

    Science.gov (United States)

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

    1972-01-01

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

  20. TRAFFIC CONTROLLED-DEDICATED SHORT RANGE COMMUNICATION: A SECURE COMMUNICATION USING TRAFFIC CONTROLLED DEDICATED SHORT RANGE COMMUNICATION MODEL IN VEHICULAR AD HOC NETWORKS FOR SAFETY RELATED SERVICES

    Directory of Open Access Journals (Sweden)

    K. Chandramohan

    2014-01-01

    Full Text Available To increase the road safety and secure communication among the vehicles in the network environment, Dedicated Short Range Communication (DSRC is followed. Nowadays, research over DSRC is dramatically increased for enhancing the road safety applications. The main task of DSRC is to protect the vehicles by communicating the warning message regarding the vehicle changing conditions, traffic occurrence and dangers over the road in the network. So, it is necessary to maintain the accurate communication timely with high reliability by implementing the appropriate protocol. In the literature there are several methods which provided specifications defined in the physical layer and the Medium Access Control (MAC layer. In those methods, current IEEE 802.11p MAC is not able to provide predictable Quality of Service (QoS for high-priority safety services. Motivated by the fact that the existing work provided three levels of safety-related broadcast services, but did not focus on current traffic load conditions, in this study, we plan to present Traffic Controlled DSRC (TC-DSRC model to analyze and categorize the traffic patterns in the vehicular communication for safety related application. A new algorithm is presented to evaluate the process of traffic controlled DSRC model for secure communication in VANET. The dedicated short range communication broadcast of messages is sent to all the vehicles at a specific instance for defined radius on the traffic zone. Multiple traffic load conditions are categorically stated to handle the vehicular safety with quick response time. Integrating these two performance metrics (i.e., quick response time and security, by using the proposed algorithm, the traffic patterns are categorized for communication between vehicles to provide the safety measure. In addition, our proposed scheme with the categorization using traffic patterns improves the network performance by deriving a specific pattern. Compared with the recent

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

    Science.gov (United States)

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

    2013-01-01

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

  2. Seasonal controlled traffic farming im ökologischen Gemüseanbau

    DEFF Research Database (Denmark)

    Hefner, Margita; Nørremark, Michael; Kristensen, Hanne Lakkenborg

    Problems of machinery induced soil compaction are evident in organic vegetable production, resulting in stunted root growth and reduced yield. Controlled traffic farming (CTF) provides a possibility to restrict soil compaction to wheel tracks and create traffic-free vegetable beds with improved...... soil structure. A field experiment was established at a commercial organic vegetable farm in Denmark to investigate the effect of CTF on the growth of cabbage (Brassica oleracea), potato (Solanum tuberosum) and beetroot (Beta vulgaris). Random traffic farming (RTF) served as the control. Preliminary...

  3. Optimal traffic light control method for a single intersection based on hybrid systems

    Institute of Scientific and Technical Information of China (English)

    赵晓华; 陈阳舟; 崔平远

    2003-01-01

    A single intersection of two phases is selected as a model to put forward a new optimal time-planning scheme for traffic light based on the model of hybrid automata for single intersection. A method of optimization is proposed for hybrid systems, and the average queue length over all queues is used as an objective function to find an optimal switching scheme for traffic light. It is illustrated that traffic light control for single intersection is a typical hybrid system, and the optimal planning-time scheme can be obtained using the optimal hybrid systems control based on the two stages method.

  4. Adaptive Traffic Control Systems in a medium-sized Scandinavian city

    DEFF Research Database (Denmark)

    Agerholm, Niels; Olesen, Anne Vingaard

    2017-01-01

    Adaptive Traffic Control Systems (ATCS) are aimed at reducing congestion. ATCS adapt to approaching traffic to continuously optimise the traffic flows in question. ATCS have been implemented in many locations, including the Scandinavian countries, with various effects. Due to congestion problems......, ATCS were installed in the eight signalised intersections of a 1.7 km stretch of the ring road in the medium-sized Danish city of Aalborg. To measure the effect of ATCS a with/without study was carried out. GPS data from a car following the traffic, recorded transportation times for buses in service...... peak and midday off-peak. The effect on crossing and turning traffic was slight, and while reduced transportation time was found in one part of the ring road in another part transportation time was seen to increase. The benefit to the ring road was partly gained at the cost of slightly increased...

  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. 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

  7. Feedback control for car following model based on two-lane traffic flow

    Science.gov (United States)

    Ge, Hong-xia; Meng, Xiang-pei; Zhu, Hui-bing; Li, Zhi-Peng

    2014-08-01

    In the paper, two-lane traffic flow considering lane changing behaviors has been discussed based on the control theory, and the friction interference which is from the neighbor lane has been taken into account. By using the control method, the stability condition is derived. The feedback signals, which include vehicular information from both lanes, acting on the two-lane traffic system have been introduced into the Full Velocity Difference car-following model. In the end, simulations are conducted to examine the validity and reasonability of the control method. It is proven that lane changing behaviors can aggravate the traffic perturbation. The traffic flow congestion could be suppressed by using the control method and the simulation results are in good agreement with the theoretical analysis.

  8. 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.

  9. 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.

  10. 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,...

  11. 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.

  12. 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.

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

    Science.gov (United States)

    Gaillard, Irene; Leroux, Marcel

    1994-01-01

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

  14. Incorporating Traffic Control and Safety Hardware Performance Functions into Risk-based Highway Safety Analysis

    National Research Council Canada - National Science Library

    Zongzhi Li; Hoang Dao; Harshingar Patel; Yi Liu; Bei Zhou

    2017-01-01

    .... This study introduces a refined method for computing the Safety Index (SI) as a means of crash predictions for a highway segment that incorporates traffic control and safety hardware performance functions into the analysis...

  15. REDUCTION IN PROBABILITY OF TRAFFIC CONGESTION ON HIGH-CLASS ROAD USING RAMP ACCESS CONTROL

    Directory of Open Access Journals (Sweden)

    R. Yu. Lagerev

    2016-01-01

    Full Text Available Мerging traffic junctions on high-class roads are considered as bottlenecks in the network and quality of their operation determines a probability for formation of traffic congestions. Investigations on congestion situations in the merging zones of ramp and freeway traffic flows have demonstrated that queuing ramp traffic flow leads to formation of so called “turbulence” effect due to re-arrangement of transport facilities and reduction in their speed on main road direction. Having high queuing traffic flow on main road the “turbulence” component can result in formation of an impact blow in the main traffic flow. It has been proved that an impact of the ramp traffic flow on congestion probability is higher in comparison with main road traffic flow. The paper makes it possible to establish that some transport facilities moving along a high-way simul taneously occupy two lanes in the merging traffic zones and they reduce capacity of the used road section. It is necessary to take into account this specific feature and it is necessary to pay attention to it in the zones of “turbulence” effect formation. The paper presents main approaches, methodology, principles and stages required for access control of high-class roads which are directed on higher quality of their operation including improvement of road traffic safety. The paper proposes a methodоlogy that allows to evaluate and optimize ramp control in the context of a transport queue length minimization at adjoining ramps for the purposes of probability reduction in transport congestion.

  16. APC-MAC/TA: Adaptive Power Controlled MAC Protocol with Traffic Awareness for Wireless Sensor Networks

    Science.gov (United States)

    Woo, Seok; Kim, Kiseon

    In this paper, we propose an adaptive power controlled MAC protocol with a traffic-aware scheme specifically designed to reduce both energy and latency in wireless sensor networks. Typically, existing MAC protocols for sensor networks sacrifice latency performance for node energy efficiency. However, some sensor applications for emergencies require rather fast transmissions of sensed data, where we need to consider both energy and latency together. The proposed MAC protocol includes two novel ideas: one is a transmission power control scheme for improving latency in high traffic loads, and the other is a traffic-aware scheme to save more energy in low traffic loads. The transmission power control scheme increases channel utilization by mitigating interference between nodes, and the traffic-aware scheme allows nodes to sleep to reduce idle energy consumption when there are no traffic loads in a network. Simulation results show that the proposed protocol significantly reduces the latency as well as the energy consumption compared to the S-MAC protocol specifically for a large transmission power of nodes and low network traffic.

  17. Incorporating Traffic Control and Safety Hardware Performance Functions into Risk-based Highway Safety Analysis

    Directory of Open Access Journals (Sweden)

    Zongzhi Li

    2017-04-01

    Full Text Available Traffic control and safety hardware such as traffic signs, lighting, signals, pavement markings, guardrails, barriers, and crash cushions form an important and inseparable part of highway infrastructure affecting safety performance. Significant progress has been made in recent decades to develop safety performance functions and crash modification factors for site-specific crash predictions. However, the existing models and methods lack rigorous treatments of safety impacts of time-deteriorating conditions of traffic control and safety hardware. This study introduces a refined method for computing the Safety Index (SI as a means of crash predictions for a highway segment that incorporates traffic control and safety hardware performance functions into the analysis. The proposed method is applied in a computation experiment using five-year data on nearly two hundred rural and urban highway segments. The root-mean square error (RMSE, Chi-square, Spearman’s rank correlation, and Mann-Whitney U tests are employed for validation.

  18. Detection of randomized bot command and control traffic on an end-point host

    Directory of Open Access Journals (Sweden)

    B. Soniya

    2016-09-01

    Full Text Available Bots are malicious software entities that unobtrusively infect machines and silently engage in activities ranging from data stealing to cyber warfare. Most recent bot detection methods rely on regularity of bot command and control (C&C traffic for bot detection but state-of-the-art bots randomize traffic properties to evade regularity based detection techniques. We propose a bot detection system that aims to detect randomized bot C&C traffic and also aim at early bot detection. To this end, separate strategies are devised for bot detection: (i over a user session and (ii time periods larger than a user session. Normal HTTP traffic and bot control traffic are modeled over a user session and a Multi-Layer Perceptron Classifier is trained on the two models and later used to classify unlabeled destinations as benign or malicious. For traffic spanning time intervals larger than a user session, temporal persistence, is used to differentiate between traffic to benign and malicious destinations. Testing with multiple datasets yielded good results.

  19. 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.

  20. Controlling traffic jams on a two-lane road using delayed-feedback signals

    Institute of Scientific and Technical Information of China (English)

    Liang ZHENG; Shi-quan ZHONG; Shou-feng MA

    2012-01-01

    This paper focuses mainly on the stability analysis of two-lane traffic flow with lateral friction,which may be caused by irregular driving behavior or poorly visible road markings,and also attempts to reveal the formation mechanism of traffic jams.Firstly,a two-lane optimal velocity (OV) model without control signals is proposed and its stability condition is obtained from the viewpoint of control theory.Then delayed-feedback control signals composed of distance headway information from both lanes are added to each vehicle and a vehicular control system is designed to suppress the traffic jams.Lane change behaviors are also incorporated into the two-lane OV model and the corresponding information about distance headway and feedback signals is revised.Finally,the results of numerical experiments are shown to verify that when the stability condition is not met,the position disturbances and resulting lane change behaviors do indeed deteriorate traffic performance and cause serious traffic jams.However,once the proper delayed-feedback control signals are implemented,the traffic jams can be suppressed efficiently.

  1. 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.

  2. Predictive control strategies for energy saving of hybrid electric vehicles based on traffic light information

    Directory of Open Access Journals (Sweden)

    Kaijiang YU

    2015-10-01

    Full Text Available As the conventional control method for hybrid electric vehicle doesn’t consider the effect of known traffic light information on the vehicle energy management, this paper proposes a model predictive control intelligent optimization strategies based on traffic light information for hybrid electric vehicles. By building the simplified model of the hybrid electric vehicle and adopting the continuation/generalized minimum residual method, the model prediction problem is solved. The simulation is conducted by using MATLAB/Simulink platform. The simulation results show the effectiveness of the proposed model of the traffic light information, and that the proposed model predictive control method can improve fuel economy and the real-time control performance significantly. The research conclusions show that the proposed control strategy can achieve optimal control of the vehicle trajectory, significantly improving fuel economy of the vehicle, and meet the system requirements for the real-time optimal control.

  3. 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.

  4. Development of control strategy of variable speed limits for improving traffic operations at freeway bottlenecks

    Institute of Scientific and Technical Information of China (English)

    李志斌; 刘攀; 王炜; 徐铖铖

    2014-01-01

    A control strategy of variable speed limits (VSL) was developed to reduce the travel time at freeway recurrent bottleneck areas. The proposed control strategy particularly focused on preventing the capacity drop and increasing the discharge flow. A cell transmission model (CTM) was developed to evaluate the effects of the proposed VSL control strategy on the traffic operations. The results show that the total travel time is reduced by 25.5% and the delay is reduced by 56.1%. The average travel speed is increased by 34.3% and the queue length is reduced by 31.0%. The traffic operation is improved by the proposed VSL control strategy. The way to use the proposed VSL control strategy in different types of freeway bottlenecks was also discussed by considering different traffic flow characteristics. It is concluded that the VSL control strategy is effective for merge bottlenecks but is less effective for diverge bottlenecks.

  5. Passive monitoring for near surface void detection using traffic as a seismic source

    Science.gov (United States)

    Zhao, Y.; Kuzma, H. A.; Rector, J.; Nazari, S.

    2009-12-01

    In this poster we present preliminary results based on our several field experiments in which we study seismic detection of voids using a passive array of surface geophones. The source of seismic excitation is vehicle traffic on nearby roads, which we model as a continuous line source of seismic energy. Our passive seismic technique is based on cross-correlation of surface wave fields and studying the resulting power spectra, looking for "shadows" caused by the scattering effect of a void. High frequency noise masks this effect in the time domain, so it is difficult to see on conventional traces. Our technique does not rely on phase distortions caused by small voids because they are generally too tiny to measure. Unlike traditional impulsive seismic sources which generate highly coherent broadband signals, perfect for resolving phase but too weak for resolving amplitude, vehicle traffic affords a high power signal a frequency range which is optimal for finding shallow structures. Our technique results in clear detections of an abandoned railroad tunnel and a septic tank. The ultimate goal of this project is to develop a technology for the simultaneous imaging of shallow underground structures and traffic monitoring near these structures.

  6. New control strategy for the lattice hydrodynamic model of traffic flow

    Science.gov (United States)

    Zhu, Chenqiang; Zhong, Shiquan; Li, Guangyu; Ma, Shoufeng

    2017-02-01

    The new delayed-feedback control strategy is applied for lattice hydrodynamic model of traffic flow by considering the control signal of the variation rate of the optimal velocity. The linear stability condition is derived in the frequency-domain with control theory. Then, different feedback gains under the periodic boundary scenery and on-ramp scenery are simulated. The periodic boundary scenery provides an initial small disturbance situation on the circle road, while the on-ramp scenery reproduces the disturbance triggered by the on-ramp on the open road. Both the theoretical analysis and simulations show that this new control signal has a positive effect to suppress traffic jams.

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

    Science.gov (United States)

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

    2016-03-14

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

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

    Science.gov (United States)

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

    2016-03-01

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

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

    Science.gov (United States)

    Li, Xu; Li, Xue

    2011-10-01

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

  10. Breakdown minimization principle versus Wardrop's equilibria for dynamic traffic assignment and control in traffic and transportation networks: A critical mini-review

    Science.gov (United States)

    Kerner, Boris S.

    2017-01-01

    We review physical results of applications of the breakdown minimization (BM) principle versus applications of the classical Wardrop's equilibria (Wardrop's user equilibrium (UE) and system optimum (SO)) for dynamic traffic assignment and control in traffic and transportation networks. It is shown that depending on the total network inflow rate there are two different applications of the BM principle: (i) The network throughput maximization approach that maximizes the network throughput ensuring free flow conditions in the network. (ii) The minimization of the network breakdown probability at relatively large network inflow rates. Probabilistic features of the application of the BM principle are studied. We have found that when the application of the BM principle cannot prevent traffic breakdown in the network, nevertheless, a combination of the application of the BM principle with dynamic control of traffic breakdown at network bottlenecks can lead to the dissolution of traffic congestion. We show that applications of the classical Wardrop's equilibria for dynamic traffic assignment deteriorate basically the traffic system in networks.

  11. Improving Performance in Dense Wireless Spaces by Controlling Bulk Traffic

    Directory of Open Access Journals (Sweden)

    Marat Zhanikeev

    2017-01-01

    Full Text Available The growing number of wireless devices nowadays often results in congestion of wireless channels. In research, this topic is referred to as networking in dense wireless spaces. The literature on the topic shows that the biggest problem is the high number of concurrent sessions to a wireless access point. The obvious solution is to reduce the number of concurrent sessions. This paper proposes a simple method called Bulk-n-Pick which minimizes the number of prolonged concurrent sessions by separating bulk from sync traffic. Aiming at educational applications, under the proposed design, web applications would distribute the main bulk of content once at the beginning of a class and then rely on small messages for real time sync traffic during the class. For realistic performance analysis, this paper first performs real-life experiments with various counts of wireless devices, bulk sizes, and levels of sync intensity. Based on the experiments, this paper shows that the proposed Bulk-n-Pick method outperforms the traditional design even when only two concurrent bulk sessions are allowed. The experiment shows that up to 10 concurrent bulk sessions are feasible in practice. Based on these results, a method for online performance optimization is proposed and validated in a trace-based emulation.

  12. The Study of Reinforcement Learning for Traffic Self-Adaptive Control under Multiagent Markov Game Environment

    Directory of Open Access Journals (Sweden)

    Lun-Hui Xu

    2013-01-01

    Full Text Available Urban traffic self-adaptive control problem is dynamic and uncertain, so the states of traffic environment are hard to be observed. Efficient agent which controls a single intersection can be discovered automatically via multiagent reinforcement learning. However, in the majority of the previous works on this approach, each agent needed perfect observed information when interacting with the environment and learned individually with less efficient coordination. This study casts traffic self-adaptive control as a multiagent Markov game problem. The design employs traffic signal control agent (TSCA for each signalized intersection that coordinates with neighboring TSCAs. A mathematical model for TSCAs’ interaction is built based on nonzero-sum markov game which has been applied to let TSCAs learn how to cooperate. A multiagent Markov game reinforcement learning approach is constructed on the basis of single-agent Q-learning. This method lets each TSCA learn to update its Q-values under the joint actions and imperfect information. The convergence of the proposed algorithm is analyzed theoretically. The simulation results show that the proposed method is convergent and effective in realistic traffic self-adaptive control setting.

  13. Engineering Social Justice into Traffic Control for Self-Driving Vehicles?

    Science.gov (United States)

    Mladenovic, Milos N; McPherson, Tristram

    2016-08-01

    The convergence of computing, sensing, and communication technology will soon permit large-scale deployment of self-driving vehicles. This will in turn permit a radical transformation of traffic control technology. This paper makes a case for the importance of addressing questions of social justice in this transformation, and sketches a preliminary framework for doing so. We explain how new forms of traffic control technology have potential implications for several dimensions of social justice, including safety, sustainability, privacy, efficiency, and equal access. Our central focus is on efficiency and equal access as desiderata for traffic control design. We explain the limitations of conventional traffic control in meeting these desiderata, and sketch a preliminary vision for a next-generation traffic control tailored to address better the demands of social justice. One component of this vision is cooperative, hierarchically distributed self-organization among vehicles. Another component of this vision is a priority system enabling selection of priority levels by the user for each vehicle trip in the network, based on the supporting structure of non-monetary credits.

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

    Science.gov (United States)

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

    2012-01-01

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

  15. Facts up front versus traffic light food labels: a randomized controlled trial.

    Science.gov (United States)

    Roberto, Christina A; Bragg, Marie A; Schwartz, Marlene B; Seamans, Marissa J; Musicus, Aviva; Novak, Nicole; Brownell, Kelly D

    2012-08-01

    The U.S. food and beverage industry recently released a new front-of-package nutrition labeling system called Facts Up Front that will be used on thousands of food products. To test consumer understanding of the Facts Up Front system (Facts Up Front) compared to the Multiple Traffic Light system (Traffic Light). Facts Up Front displays grams/milligrams and percentage daily value information for various nutrients; Traffic Light uses an interpretive color-coded scheme to alert consumers to low, medium, and high levels of certain nutrients. Participants in an Internet-based study were randomized to one of five front-of-package label conditions: (1) no label; (2) Traffic Light; (3) Traffic Light plus information about protein and fiber (Traffic Light+); (4) Facts Up Front; or (5) Facts Up Front plus information about "nutrients to encourage" (Facts Up Front+). A total of 703 adults recruited through an online database in May 2011 participated in this study, and data were analyzed in June 2011. Total percentage correct quiz scores were generated reflecting participants' ability to compare two foods on nutrient levels, based on their labels, and to estimate amounts of saturated fat, sugar, sodium, fiber and protein in the foods. The front-of-package label groups outperformed the control group on nearly all of the nutrient quizzes (pFacts Up Front group on the saturated fat quiz, or from the Facts Up Front+ group on the sugars quiz. Those in the Traffic Light+ group had the best overall performance (>80% on all quizzes). Overall, those in the Traffic Light+ condition performed better than those in the Facts Up Front conditions on measures of nutrition knowledge and label perceptions. This study is registered at clinicaltrials.gov NCT01626729. Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Autonomous Traffic Control System Using Agent Based Technology

    CERN Document Server

    M, Venkatesh; V, Srinivas

    2011-01-01

    The way of analyzing, designing and building of real-time projects has been changed due to the rapid growth of internet, mobile technologies and intelligent applications. Most of these applications are intelligent, tiny and distributed components called as agent. Agent works like it takes the input from numerous real-time sources and gives back the real-time response. In this paper how these agents can be implemented in vehicle traffic management especially in large cities and identifying various challenges when there is a rapid growth of population and vehicles. In this paper our proposal gives a solution for using autonomous or agent based technology. These autonomous or intelligent agents have the capability to observe, act and learn from their past experience. This system uses the knowledge flow of precedent signal or data to identify the incoming flow of forthcoming signal. Our architecture involves the video analysis and exploration using some Intelligence learning algorithm to estimate and identify the...

  18. Road Traffic Pollution and Childhood Leukemia: A Nationwide Case-control Study in Italy.

    Science.gov (United States)

    Magnani, Corrado; Ranucci, Alessandra; Badaloni, Chiara; Cesaroni, Giulia; Ferrante, Daniela; Miligi, Lucia; Mattioli, Stefano; Rondelli, Roberto; Bisanti, Luigi; Zambon, Paola; Cannizzaro, Santina; Michelozzi, Paola; Cocco, Pierluigi; Celentano, Egidio; Assennato, Giorgio; Merlo, Domenico Franco; Mosciatti, Paola; Minelli, Liliana; Cuttini, Marina; Torregrossa, Maria Valeria; Lagorio, Susanna; Haupt, Riccardo; Forastiere, Francesco

    2016-11-01

    The association of childhood leukemia with traffic pollution was considered in a number of studies from 1989 onwards, with results not entirely consistent and little information regarding subtypes. We used the data of the Italian SETIL case-control on childhood leukemia to explore the risk by leukemia subtypes associated to exposure to vehicular traffic. We included in the analyses 648 cases of childhood leukemia (565 Acute lymphoblastic-ALL and 80 Acute non lymphoblastic-AnLL) and 980 controls. Information on traffic exposure was collected from questionnaire interviews and from the geocoding of house addresses, for all periods of life of the children. We observed an increase in risk for AnLL, and at a lower extent for ALL, with indicators of exposure to traffic pollutants. In particular, the risk was associated to the report of closeness of the house to traffic lights and to the passage of trucks (OR: 1.76; 95% CI 1.03-3.01 for ALL and 6.35; 95% CI 2.59-15.6 for AnLL). The association was shown also in the analyses limited to AML and in the stratified analyses and in respect to the house in different period of life. Results from the SETIL study provide some support to the association of traffic related exposure and risk for AnLL, but at a lesser extent for ALL. Our conclusion highlights the need for leukemia type specific analyses in future studies. Results support the need of controlling exposure from traffic pollution, even if knowledge is not complete. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  19. Estimation and Control of Networked Distributed Parameter Systems: Application to Traffic Flow

    KAUST Repository

    Canepa, Edward

    2016-11-01

    The management of large-scale transportation infrastructure is becoming a very complex task for the urban areas of this century which are covering bigger geographic spaces and facing the inclusion of connected and self-controlled vehicles. This new system paradigm can leverage many forms of sensing and interaction, including a high-scale mobile sensing approach. To obtain a high penetration sensing system on urban areas more practical and scalable platforms are needed, combined with estimation algorithms suitable to the computational capabilities of these platforms. The purpose of this work was to develop a transportation framework that is able to handle different kinds of sensing data (e.g., connected vehicles, loop detectors) and optimize the traffic state on a defined traffic network. The framework estimates the traffic on road networks modeled by a family of Lighthill-Whitham-Richards equations. Based on an equivalent formulation of the problem using a Hamilton-Jacobi equation and using a semi-analytic formula, I will show that the model constraints resulting from the Hamilton-Jacobi equation are linear, albeit with unknown integer variables. This general framework solve exactly a variety of problems arising in transportation networks: traffic estimation, traffic control (including robust control), cybersecurity and sensor fault detection, or privacy analysis of users in probe-based traffic monitoring systems. This framework is very flexible, fast, and yields exact results. The recent advances in sensors (GPS, inertial measurement units) and microprocessors enable the development low-cost dedicated devices for traffic sensing in cities, 5 which are highly scalable, providing a feasible solution to cover large urban areas. However, one of the main problems to address is the privacy of the users of the transportation system, the framework presented here is a viable option to guarantee the privacy of the users by design.

  20. Optimal Control Strategy for Traffic Driven Epidemic Spreading Based on Community Structure

    Directory of Open Access Journals (Sweden)

    Fei Shao

    2013-01-01

    Full Text Available It is shown that community structure has a great impact on traffic transportation and epidemic spreading. The density of infected nodes and the epidemic threshold have been proven to have significant relationship with the node betweenness in traffic driven epidemic spreading method. In this paper, considering the impact of community structure on traffic driven epidemic spreading, an effective and novel strategy to control epidemic spreading in scale-free networks is proposed. Theoretical analysis shows that the new control strategy will obviously increase the ratio between the first and the second moments of the node betweenness distribution in scale-free networks. It is also found that the more accurate the community is identified, the stronger community structure the network has and the more efficient the control strategy is. Simulations on both computer-generated and real-world networks have confirmed the theoretical results.

  1. IMPACT OF POLY-LINGUISTIC LOAD ON AIR TRAFFIC CONTROL AND MONITORING QUALITY

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2012-09-01

    Full Text Available  We have defined the structure and basic characteristics of the poly-linguistic audio-acoustic channel within the framework of controller – pilot communication, and set limits of poly-linguistic load impact on air traffic control.

  2. Fuzzy Neural Network Based Traffic Prediction and Congestion Control in High-Speed Networks

    Institute of Scientific and Technical Information of China (English)

    费翔; 何小燕; 罗军舟; 吴介一; 顾冠群

    2000-01-01

    Congestion control is one of the key problems in high-speed networks, such as ATM. In this paper, a kind of traffic prediction and preventive congestion control scheme is proposed using neural network approach. Traditional predictor using BP neural network has suffered from long convergence time and dissatisfying error. Fuzzy neural network developed in this paper can solve these problems satisfactorily. Simulations show the comparison among no-feedback control scheme,reactive control scheme and neural network based control scheme.

  3. P2P network traffic control mechanism based on global evaluation values

    Institute of Scientific and Technical Information of China (English)

    XU Xiao-long; WANG Ru-chuan

    2009-01-01

    Peer-to-peer (P2P) computing technology has been widely used on the Internet to exchange data. However, it occupies much network bandwidth, and thus greatly influences traditional business on the Interact. Besides, problems about free-riders and 'tragedy of the commons' in the P2P environment estrange from it P2P users who constantly contribute to the network with quality resources. This article proposes a new P2P network traffic control mechanism based on global evaluation values. It aims to help individual users to avoid peak traffic time as much as possible, ease network congestion and protect traditional business on the Interact, as well as differentiating priority grades of peers according to their contributions and stimulating them to share their valuable resources actively. This article first analyzes the current state of network traffic, and then elaborates on P2P network traffic control policies and proposes the peer's priority level differentiation mechanism based on global evaluation values. Finally,after the testing results and analysis of the proposed P2P network traffic control mechanism are discussed, conclusions are drawn.

  4. Controlled Traffic Farming – From Worldwide Research To Adoption In Europe And Its Future Prospects

    Directory of Open Access Journals (Sweden)

    Chamen Tim

    2015-09-01

    Full Text Available Controlled traffic farming is a machinery management system that confines all field vehicles to the least possible area of permanent traffic lanes. It has developed in response to research evidence of widespread soil damage from compaction due to field traffic. The history of research on soil compaction is explored and found to be a relatively new phenomenon. Controlled traffic farming as a topic for research did not appear until the 1980s although its principles and benefits were well established before then. Research expanded over the next decades but changed subtly to more reviews on the topic as well as emphasis on environmental deliverables and some economics studies. Few if any researchers attempted to develop on-farm systems using existing machinery until the mid 1990s when a small and dedicated team in Australia encouraged farmers to experiment. This quickly led to rapid expansion across the continent to its present day c. 13% of the cropped area. Despite changes to extension services in northern Europe at around the turn of the century and a move to subsidiarity, this did not alter the model of controlled traffic adoption. This followed a similar pattern to that in Australia involving individuals rather than organizations.

  5. 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.

  6. 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.

  7. AN INTELLIGENT TRAFFIC LIGHTS CONTROL ALGORITHM BASED ON TRAFFIC FLOW%基于车流量的交通灯智能控制算法

    Institute of Scientific and Technical Information of China (English)

    王鼎湘; 李茂军

    2015-01-01

    随着道路交通流量日益增加,现有交通灯使用的时间固定控制方法并不能很好地满足各种复杂交通情况。针对这一背景,在使用视频图像对车辆跟踪计数实时采集车流量的基础上,提出一种根据各方向车流量控制交通灯时间的算法。该算法根据实时的车流情况更新各方向的绿灯分配时间,自动调节各方向绿灯时间比例,并根据路口总车流量的大小智能调节绿灯时间周期大小。基于 Delphi 平台对算法进行仿真,结果表明:该算法能根据实时车流信息自适应调整各方向绿灯时长,并通过自动调节各方向绿灯时间总和来有效实现交通拥堵或畅通情况下交通灯的智能控制。%The time-fixed control method used by existing traffic lights can not well satisfy various complicated traffic conditions along with the increasingly growth of road traffic flow.Under this background and based on the acquisition of real-time traffic flow by using video images to track and count vehicles,we propose an algorithm of controlling traffic lights time according to the traffic flow from various directions.This algorithm updates the allocated time for green lights in each direction based upon real-time traffic situation and automatically adjusts the time scale of green lights in various directions.It also intelligently regulates the size of the time cycle of green lights according to the total traffic flow on intersections.The algorithm is simulated based on Delphi platform,the results show that the proposed algorithm can adaptively adjust the time length of green lights in each direction based on real-time vehicles traffic information,and effectively realises the intelligent traffic lights control in the circumstances of traffic congestion or in smooth flow by automatically adjusting the total time of green lights in different di-rections.

  8. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Science.gov (United States)

    2010-10-01

    ... TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.401 Automatic... 49 Transportation 4 2010-10-01 2010-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other...

  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. GENERAL: A control method for congested traffic in the coupled map car-following model

    Science.gov (United States)

    Shen, Fei-Ying; Ge, Hong-Xia; Zhang, Hui; Yu, Han-Mei; Lei, Li

    2009-10-01

    Based on the pioneer work of Konishi et al, a new control method is presented to suppress the traffic congestion in the coupled map (CM) car-following model under an open boundary. A control signal concluding the velocity differences of the two vehicles in front is put forward. The condition under which the traffic jam can be contained is analyzed. The results are compared with that presented by Konishi et al [Phys. Rev. 1999 E 60 4000-4007]. The simulation results show that the temporal behavior obtained by our method is better than that by the Konishi's et al. method, although both the methods could suppress the traffic jam. The simulation results are consistent with the theoretical analysis.

  11. A control method for congested traffic in the coupled map car-following model

    Institute of Scientific and Technical Information of China (English)

    Shen Fei-Ying; Ge Hong-Xia; Zhang Hui; Yu Han-Mei; Lei Li

    2009-01-01

    Based on the pioneer work of Konishi et al, a new control method is presented to suppress the traffic congestion in the coupled map (CM) car-following model under an open boundary. A control signal concluding the velocity differences of the two vehicles in front is put forward. The condition under which the traffic jam can be contained is analyzed. The results are compared with that presented by Konishi et al [Phys. Rev. 1999 E 60 4000-4007]. The simulation results show that the temporal behavior obtained by our method is better than that by the Konishi's et al. method, although both the methods could suppress the traffic jam. The simulation results are consistent with the theoretical analysis.

  12. Socioeconomic impact of widespread adoption of precision farming and controlled traffic systems in Denmark

    DEFF Research Database (Denmark)

    Jensen, Hans Grinsted; Jacobsen, Lars Bo; Pedersen, Søren Marcus;

    2012-01-01

    In this study we assess the economic profitability of implementing various precision farming (PF) technologies and controlled traffic farming (CTF) on 4 main crops in Denmark. The study provides insight into technological requirements, and identifies related costs and benefits to farmers and the ...... to politicians since it clearly facilitates aims of environmental policies currently under implementation by the Danish government.......In this study we assess the economic profitability of implementing various precision farming (PF) technologies and controlled traffic farming (CTF) on 4 main crops in Denmark. The study provides insight into technological requirements, and identifies related costs and benefits to farmers....... The obtained results reflect the long term economic effect of implementing new production methods in Denmark where soil fertility increases over time due to reduced traffic increasing yields. Over all, the Danish GDP is estimated to increase by 34 million € due to the implementation of PF and CTF on larger...

  13. Traffic flow model at fixed control signals with discrete service time distribution

    Directory of Open Access Journals (Sweden)

    Lucky I. Igbinosun

    2016-04-01

    Full Text Available Most of the models of road traffic flow at fixed-cycle controlled intersection assume stationary distributions and provide steady state results. The assumption that a constant number of vehicles can leave the system during the green phase is unrealistic in real life situations. A discrete time queuing model was developed to describe the operation of traffic flow at a road intersection with fixed-cycle signalized control and to account for the randomness in the number of vehicles that can leave the system. The results show the expected queue size in the system when the traffic is light and for a busy period, respectively. For the light period, when the traffic intensity is less than one, it takes a shorter green cycle time for vehicles to clear up than during high traffic intensity (the road junction is saturated. Increasing the number of cars that can leave the junction at the turn of the green phase reduces the number of cycle times before the queue is cleared.

  14. Characterization of Visual Scanning Patterns in Air Traffic Control

    Directory of Open Access Journals (Sweden)

    Sarah N. McClung

    2016-01-01

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

  15. Towards reducing traffic congestion using cooperative adaptive cruise control on a freeway with a ramp

    Directory of Open Access Journals (Sweden)

    Georges Arnaout

    2011-12-01

    Full Text Available Purpose: In this paper, the impact of Cooperative Adaptive Cruise Control (CACC systems on traffic performance is examined using microscopic agent-based simulation. Using a developed traffic simulation model of a freeway with an on-ramp - created to induce perturbations and to trigger stop-and-go traffic, the CACC system’s effect on the traffic performance is studied. The previously proposed traffic simulation model is extended and validated. By embedding CACC vehicles in different penetration levels, the results show significance and indicate the potential of CACC systems to improve traffic characteristics and therefore can be used to reduce traffic congestion. The study shows that the impact of CACC is positive but is highly dependent on the CACC market penetration. The flow rate of the traffic using CACC is proportional to the market penetration rate of CACC equipped vehicles and the density of the traffic.Design/methodology/approach: This paper uses microscopic simulation experiments followed by a quantitative statistical analysis. Simulation enables researchers manipulating the system variables to straightforwardly predict the outcome on the overall system, giving researchers the unique opportunity to interfere and make improvements to performance. Thus with simulation, changes to variables that might require excessive time, or be unfeasible to carry on real systems, are often completed within seconds.Findings: The findings of this paper are summarized as follow:•\tProvide and validate a platform (agent-based microscopic traffic simulator in which any CACC algorithm (current or future may be evaluated.•\tProvide detailed analysis associated with implementation of CACC vehicles on freeways.•\tInvestigate whether embedding CACC vehicles on freeways has a significant positive impact or not.Research limitations/implications: The main limitation of this research is that it has been conducted solely in a computer laboratory. Laboratory

  16. 基于车流量的交通灯控制系统设计%Traffic Light Control System Design Based on Traffic Flow

    Institute of Scientific and Technical Information of China (English)

    章伟; 张代远

    2015-01-01

    As traffic congestion rises within urban around the world,the intelligent control of traffic signals within cities is becoming in-creasingly important. Previous research for the area of intelligent traffic signal control has several shortcomings,including a reliance on historical data,fixing timing,not solving complicated and changeable situation. Propose the intelligent traffic lights control system based on traffic flow in this paper. It can get real-time traffic information with the help of video detection technology,and design the time algo-rithm that based on the information measured to adjust the control of the time of green light in all lanes,which can accurately change the time of traffic lights by achieving traffic dynamic adjustment. This solution allows signals to be updated frequently to match current traffic demand. It can alleviate traffic pressure,improve efficiency,save people's time and energy and protect the environment.%随着在世界各地交通拥堵现象日趋严重,城市内的交通信号智能控制变得越来越重要。先前研究的智能交通信号控制领域内有几个缺点,包括:依赖历史数据、固定配时、不能解决现实复杂多变的环境。文中提出的基于车流量的智能交通灯控制系统,利用视频检测技术,测得路口的实时车流信息,并依据所测得的信息设计了时间分配控制算法来调整控制各车道的绿灯时间,实时改变交通灯的时长以实现车流动态调节,该方案允许信号实时被更新以匹配当前的交通需求。运用到实际可达到缓解交通压力、提高通行效率、节省出行时间、节能减排、保护环境的目的。

  17. Surface membrane traffic in guinea pig basophils exposed to cationic ferritin.

    Science.gov (United States)

    Dvorak, A M; Dvorak, H F; Galli, S J

    1985-01-01

    Surface membrane traffic patterns can be influenced by a number of factors, including the functional state of the cell. We used transmission electron microscopy to investigate the fate of surface membrane in guinea pig basophils exposed to cationized ferritin (CF) in vitro. CF bound to the plasma membrane and was internalized on the membranes of vesicles and vacuoles, a process that was particularly prominent at the uropod of basophils exhibiting a polarized ('motile') configuration. The vesicles/vacuoles moved to the Golgi area, or, in the case of degranulating basophils, were observed in continuity with the degranulation sac, a structure formed largely by the fusion of individual cytoplasmic granule membranes. However, CF-positive vesicles were never observed to fuse directly with the membranes of intact cytoplasmic granules.

  18. Traffic Control Under Complex Weather Conditions in Suining Airport

    Institute of Scientific and Technical Information of China (English)

    吕维峰

    2014-01-01

    Complex weather conditions is meaning thunderstorm freezing turbulence wind-shear low visibility weather affect the flight safety. When confronted with complex weather conditions,the controllers should know the weather condition and trend weather,and notify the aircraft under your control zone.The controllers provide the required services to the pilots,help the pilots to avoid the complex weather.In this paper, through different complex weathers under different control command,get the different methods of control.

  19. SMART VIDEO SURVEILLANCE SYSTEM FOR VEHICLE DETECTION AND TRAFFIC FLOW CONTROL

    Directory of Open Access Journals (Sweden)

    A. A. SHAFIE

    2011-08-01

    Full Text Available Traffic signal light can be optimized using vehicle flow statistics obtained by Smart Video Surveillance Software (SVSS. This research focuses on efficient traffic control system by detecting and counting the vehicle numbers at various times and locations. At present, one of the biggest problems in the main city in any country is the traffic jam during office hour and office break hour. Sometimes it can be seen that the traffic signal green light is still ON even though there is no vehicle coming. Similarly, it is also observed that long queues of vehicles are waiting even though the road is empty due to traffic signal light selection without proper investigation on vehicle flow. This can be handled by adjusting the vehicle passing time implementing by our developed SVSS. A number of experiment results of vehicle flows are discussed in this research graphically in order to test the feasibility of the developed system. Finally, adoptive background model is proposed in SVSS in order to successfully detect target objects such as motor bike, car, bus, etc.

  20. Jam-avoiding adaptive cruise control (ACC) and its impact on traffic dynamics

    CERN Document Server

    Kesting, A; Kranke, F; Sch"onhof, M; Treiber, M; Helbing, Dirk; Kesting, Arne; Kranke, Florian; Sch\\"onhof, Martin; Treiber, Martin

    2006-01-01

    Adaptive-Cruise Control (ACC) automatically accelerates or decelerates a vehicle to maintain a selected time gap, to reach a desired velocity, or to prevent a rear-end collision. To this end, the ACC sensors detect and track the vehicle ahead for measuring the actual distance and speed difference. Together with the own velocity, these input variables are exactly the same as in car-following models. The focus of this contribution is: What will be the impact of a spreading of ACC systems on the traffic dynamics? Do automated driving strategies have the potential to improve the capacity and stability of traffic flow or will they necessarily increase the heterogeneity and instability? How does the result depend on the ACC equipment level? We discuss microscopic modeling aspects for human and automated (ACC) driving. By means of microscopic traffic simulations, we study how a variable percentage of ACC-equipped vehicles influences the stability of traffic flow, the maximum flow under free traffic conditions until ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-15

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

  2. The Application of The Double Queue Asymmetric Gated Service Polling Control Theory in Intelligent Traffic System

    Directory of Open Access Journals (Sweden)

    Zhao Yi Fan

    2016-01-01

    Full Text Available paper presents a new use of double queues asymmetric gated service polling system in the intelligent traffic light control system.Usually there are more vehicles in main road than minor road,so there are more green light time be needed in the main road.From the computer simulation and theory analysis,we can find that the application of double queues asymmetric gated service polling theory in intelligent traffic system can balance intersections load and set suitable passing time for vehicles to assure the roads open.

  3. Video Demo: Deep Reinforcement Learning for Coordination in Traffic Light Control

    NARCIS (Netherlands)

    van der Pol, E.; Oliehoek, F.A.; Bosse, T.; Bredeweg, B.

    2016-01-01

    This video demonstration contrasts two approaches to coordination in traffic light control using reinforcement learning: earlier work, based on a deconstruction of the state space into a linear combination of vehicle states, and our own approach based on the Deep Q-learning algorithm.

  4. Self-directed learning skills in air-traffic control training; An eye-tracking approach

    NARCIS (Netherlands)

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

    2011-01-01

    Van Meeuwen, L. W., Brand-Gruwel, S., De Bock, J. J. P. R., Kirschner, P. A., & Van Merriënboer, J. J. G. (2010, September). Self-directed Learning Skills in Air-traffic Control Training; An Eye-tracking Approach. Paper presented at the European Association for Aviation Psychology, Budapest.

  5. Value sensitive design of automated workload distribution support for traffic control teams

    NARCIS (Netherlands)

    Harbers, M.; Neerincx, M.A.

    2014-01-01

    This paper studies the effects of automated support for workload distribution in traffic control teams on human values such as security, autonomy and privacy. The paper describes a workshop in which the support system's stakeholders, their values, and the effects of the support system on these value

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  7. Dynamic traffic grooming in distributed-controlled IP/WDM optical mesh networks

    Institute of Scientific and Technical Information of China (English)

    Huang Jun; Zeng Qingji; Liu Jimin; Xiao Pengcheng; Liu Hua; Xiao Shilin

    2005-01-01

    In this paper, the study was devoted to the traffic-grooming problem in a distributed-controlled WDM mesh network. We studied the optimization of the maximal number of ports configured at each node in the network. We gave the maximumnumber simulation results in different network environment, which could be taken as a reference for network design.

  8. Self-directed learning skills in air-traffic control; A cued retrospective reporting study

    NARCIS (Netherlands)

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

    2011-01-01

    Van Meeuwen, L. W., Brand-Gruwel, S., Van Merriënboer, J. J. G., Kirschner, P. A., & De Bock, J. J. P. R. (2010, May). Self-directed learning skills in air-traffic control; A cued retrospective reporting study. Presented at the Scandinavian Workshop on Applied Eye-tracking. Lund, Sweden.

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    Science.gov (United States)

    National Scientific Council on the Developing Child, 2011

    2011-01-01

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

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

    Science.gov (United States)

    National Scientific Council on the Developing Child, 2011

    2011-01-01

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

  12. Blurred controlling of crossroads traffic light%十字路口交通灯的模糊控制

    Institute of Scientific and Technical Information of China (English)

    张颖霄

    2009-01-01

    we could control the crossroads traffic light by blur,to solve the situation of crowded traffic in traditional controlling%通过对十字路口交通灯的模糊控制,解决了在传统控制中出现的交通堵塞情况.

  13. 4D Trajectory Estimation for Air Traffic Control Automation System Based on Hybrid System Theory

    Directory of Open Access Journals (Sweden)

    Xin-Min Tang

    2012-03-01

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

  14. 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.

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

    Science.gov (United States)

    2008-05-12

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

  16. A Teamwork-Oriented Air Traffic Control Simulator

    Science.gov (United States)

    2006-06-01

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

  17. Landing-Time-Controlled Management Of Air Traffic

    Science.gov (United States)

    Erzberger, Heinz; Tobias, Leonard

    1988-01-01

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

  18. A novel solution for car traffic control based on radiometric microwave devices

    Science.gov (United States)

    Soldovieri, Francesco; Denisov, Alexander; Speziale, Victor

    2014-05-01

    The significant problem of traffic in big cities, connected with huge and building up quantity of automobile cars, demands for novel strategies, based on nonconventional solutions, in order to improve system traffic control, especially at crossroads. As well known, the usual solution is based on the time relay, which requires the installation of a fixed traffic interval (signal light switching) at a crossroad; this solution is low cost, but does not account for the actual traffic conditions. Therefore, in the recent years, attention is towards to new designs, where the monitoring of the and control of traffic is carried out by using various methods including, optical, the infrared, magnetic, radar tracking, acoustical ones. In this work, we discuss the deployment of high sensitivity radiometric systems and radiometers(sensor) in the microwave range [1, 2]. In fact, the radiometer as "sensor" can provide an always updated information about the car traffic in any weather condition and in absence or low visibility conditions. In fact, the radiometric sensor detects the cars thanks to the different behavior of the car roofs which reflect the cold sky whereas the road asphalt is visible as warm object (at around outside temperature). [1] A. G. Denisov, V. P. Gorishnyak, S. E. Kuzmin et al., "Some experiments concerning resolution of 32 sensors passive 8mm wave imaging system," in Proceedings of the International Symposium on Space Terahertz Technology (ISSTT '09), Charlottesville, Va, USA, April 2009. [2] F. Soldovieri, A. Natale, V. Gorishnyak, A. Pavluchenko, A. Denisov, and L. Chen, "Radiometric Imaging for Monitoring and Surveillance Issues," International Journal of Antennas and Propagation, vol. 2013, Article ID 272561, 8 pages, 2013. doi:10.1155/2013/272561.

  19. Robust control tools for traffic monitoring in TCP/AQM networks

    CERN Document Server

    Ariba, Yassine; Rahme, Sandy; Labit, Yann

    2009-01-01

    Several studies have considered control theory tools for traffic control in communication networks, as for example the congestion control issue in IP (Internet Protocol) routers. In this paper, we propose to design a linear observer for time-delay systems to address the traffic monitoring issue in TCP/AQM (Transmission Control Protocol/Active Queue Management) networks. Due to several propagation delays and the queueing delay, the set TCP/AQM is modeled as a multiple delayed system of a particular form. Hence, appropriate robust control tools as quadratic separation are adopted to construct a delay dependent observer for TCP flows estimation. Note that, the developed mechanism enables also the anomaly detection issue for a class of DoS (Denial of Service) attacks. At last, simulations via the network simulator NS-2 and an emulation experiment validate the proposed methodology.

  20. Environmental risk factors contributing to traffic accidents in children: a case-control study.

    Science.gov (United States)

    Jamshidi, Ensiyeh; Moradi, Ali; Majdzadeh, Reza

    2017-09-01

    The aim of this study is to identify environmental risk factors related to road accidents in children of Tehran. This case-control study was performed in 2013. The cases were injured pedestrians aged 5-15 who were admitted to major hospitals supervised by Tehran University of Medical Sciences. The sample size for the cases was 273 and for the control group was 546. For the completeness of the clusters, 7 extra persons in case (total = 280) and 14 persons (total = 560) in control group were included. The interference of confounding variables assessed through forward conditional logistic regression. Result shows occurrence of traffic accidents was significantly associate with the width of the alleys or (traffic congestion (OR = 4.1, 95% CI: 2.6-6.4), traffic speed (OR = 2.1, 95% CI: 1.3-3.2) and existence of pedestrian bridges(OR = 4.2, 95% CI: 2.6-6.8). In the light of the important role of environmental factors in the occurrence of child traffic accidents, alleviating structural risk factors in addition to education and enforcement need more systematic efforts and planning by policymakers and urban planners to attain pedestrian safety goals.

  1. 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.

  2. 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.

  3. Optimal traffic control in highway transportation networks using linear programming

    KAUST Repository

    Li, Yanning

    2014-06-01

    This article presents a framework for the optimal control of boundary flows on transportation networks. The state of the system is modeled by a first order scalar conservation law (Lighthill-Whitham-Richards PDE). Based on an equivalent formulation of the Hamilton-Jacobi PDE, the problem of controlling the state of the system on a network link in a finite horizon can be posed as a Linear Program. Assuming all intersections in the network are controllable, we show that the optimization approach can be extended to an arbitrary transportation network, preserving linear constraints. Unlike previously investigated transportation network control schemes, this framework leverages the intrinsic properties of the Halmilton-Jacobi equation, and does not require any discretization or boolean variables on the link. Hence this framework is very computational efficient and provides the globally optimal solution. The feasibility of this framework is illustrated by an on-ramp metering control example.

  4. Real-time optical path control method that utilizes multiple support vector machines for traffic prediction

    Science.gov (United States)

    Kawase, Hiroshi; Mori, Yojiro; Hasegawa, Hiroshi; Sato, Ken-ichi

    2016-02-01

    An effective solution to the continuous Internet traffic expansion is to offload traffic to lower layers such as the L2 or L1 optical layers. One possible approach is to introduce dynamic optical path operations such as adaptive establishment/tear down according to traffic variation. Path operations cannot be done instantaneously; hence, traffic prediction is essential. Conventional prediction techniques need optimal parameter values to be determined in advance by averaging long-term variations from the past. However, this does not allow adaptation to the ever-changing short-term variations expected to be common in future networks. In this paper, we propose a real-time optical path control method based on a machinelearning technique involving support vector machines (SVMs). A SVM learns the most recent traffic characteristics, and so enables better adaptation to temporal traffic variations than conventional techniques. The difficulty lies in determining how to minimize the time gap between optical path operation and buffer management at the originating points of those paths. The gap makes the required learning data set enormous and the learning process costly. To resolve the problem, we propose the adoption of multiple SVMs running in parallel, trained with non-overlapping subsets of the original data set. The maximum value of the outputs of these SVMs will be the estimated number of necessary paths. Numerical experiments prove that our proposed method outperforms a conventional prediction method, the autoregressive moving average method with optimal parameter values determined by Akaike's information criterion, and reduces the packet-loss ratio by up to 98%.

  5. Numerical modelling of ground-borne noise and vibration in buildings due to surface rail traffic

    Science.gov (United States)

    Fiala, P.; Degrande, G.; Augusztinovicz, F.

    2007-04-01

    This paper deals with the numerical computation of the structural and acoustic response of a building to an incoming wave field generated by high-speed surface railway traffic. The source model consists of a moving vehicle on a longitudinally invariant track, coupled to a layered ground modelled with a boundary element formulation. The receiver model is based on a substructuring formulation and consists of a boundary element model of the soil and a finite element model of the structure. The acoustic response of the building's rooms is computed by means of a spectral finite element formulation. The paper investigates the structural and acoustic response of a multi-story portal frame office building up to a frequency of 150 Hz to the passage of a Thalys high-speed train at constant velocity. The isolation performance of three different vibration countermeasures: a floating-floor, a room-in-room, and base-isolation, are examined.

  6. Cellular metabolic and autophagic pathways: traffic control by redox signaling.

    Science.gov (United States)

    Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

    2013-10-01

    It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function.

  7. 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.

  8. Splitting of Traffic Flows to Control Congestion in Special Events

    Directory of Open Access Journals (Sweden)

    Ciro D'Apice

    2011-01-01

    minimized with respect to the same control parameter. The obtained results have been tested by simulations of urban networks. Decongestion effects are also confirmed estimating the time a car needs to cross a fixed route on the network.

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

    Science.gov (United States)

    1983-10-28

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

  10. Heart Rate Variability as a Measure of Airport Ramp-Traffic Controllers Workload

    Science.gov (United States)

    Hayashi, Miwa; Dulchinos, Victoria Lee

    2016-01-01

    Heart Rate Variability (HRV) has been reported to reflect the person's cognitive and emotional stress levels, and may offer an objective measure of human-operator's workload levels, which are recorded continuously and unobtrusively to the task performance. The present paper compares the HRV data collected during a human-in-the-loop simulation of airport ramp-traffic control operations with the controller participants' own verbal self-reporting ratings of their workload.

  11. Modelling and optimization of computer network traffic controllers

    Directory of Open Access Journals (Sweden)

    N. U. Ahmed

    2005-01-01

    operation of the controller and evaluate the benefits of using a genetic algorithm approach to speed up the optimization process. Our results show that the use of the genetic algorithm proves particularly useful in reducing the computation time required to optimize the operation of a system consisting of multiple token-bucket-regulated sources.

  12. Detection of Botnet Command and Control Traffic in Enterprise Networks

    NARCIS (Netherlands)

    Burghouwt, P.

    2015-01-01

    Botnets play an important role in modern Internet-related cybercrime. A botnet consists of a group of infected computers, referred to as bots. The bots are remotely controlled and deployed in malicious activities, such as DDoS attacks, spam, and espionage. Clever design of the botnet C&C (Command an

  13. Detection of Botnet Command and Control Traffic in Enterprise Networks

    NARCIS (Netherlands)

    Burghouwt, P.

    2015-01-01

    Botnets play an important role in modern Internet-related cybercrime. A botnet consists of a group of infected computers, referred to as bots. The bots are remotely controlled and deployed in malicious activities, such as DDoS attacks, spam, and espionage. Clever design of the botnet C&C (Command an

  14. A control method for congested traffic induced by bottlenecks in the coupled map car-following model

    Science.gov (United States)

    Zhao, Xiaomei; Gao, Ziyou

    2006-07-01

    We present a simple control method to suppress the traffic congestion in the coupled map car-following model under open boundary, based on the pioneer work of Konishi et al. [Coupled map car-following model and its delayed-feedback control, Phys. Rev. E 60 (1999) 4000-4007]. Theoretically, it is proven that the congested traffic in the traffic system could be suppressed by using the method. Comparison between our method and the method of Konishi et al. is carried out. The simulation results show the temporal behavior obtained by our method is better than that by the method of Konishi et al., although both the methods can suppress the traffic jam. The simulation results demonstrate that the traffic system can move into a homogeneous phase and the flux has great increases by the introduction of the control signal. The simulation results are in good agreement with the theoretical analysis.

  15. 校园网流量分析与控制%Traffic Analysis and Control of Campus Network

    Institute of Scientific and Technical Information of China (English)

    林锡川; 李志强

    2011-01-01

    本文提出了一套校园网流量分析系统的基本架构,并探讨了控制校园网流量的可行方法.%This papper presents a traffic analysis system of campus network,and discusses a way to control network traffic.

  16. Potential of low ground pressure for harvesting machinery in a controlled traffic farming system in organic agriculture

    NARCIS (Netherlands)

    Vermeulen, G.D.; Sukkel, W.

    2008-01-01

    Seasonal controlled traffic farming (SCTF), i.e. CTF without using the permanent traffic lanes for harvesting and primary soil tillage, leads to improved soil structure, higher crop yields, significant reduction of the emission of nitrous oxide and increased uptake of methane. Improved timeliness of

  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. Regulation of the Yersinia type III secretion system: traffic control

    Science.gov (United States)

    Dewoody, Rebecca S.; Merritt, Peter M.; Marketon, Melanie M.

    2013-01-01

    Yersinia species, as well as many other Gram-negative pathogens, use a type III secretion system (T3SS) to translocate effector proteins from the bacterial cytoplasm to the host cytosol. This T3SS resembles a molecular syringe, with a needle-like shaft connected to a basal body structure, which spans the inner and outer bacterial membranes. The basal body of the injectisome shares a high degree of homology with the bacterial flagellum. Extending from the T3SS basal body is the needle, which is a polymer of a single protein, YscF. The distal end of the needle serves as a platform for the assembly of a tip complex composed of LcrV. Though never directly observed, prevailing models assume that LcrV assists in the insertion of the pore-forming proteins YopB and YopD into the host cell membrane. This completes a bridge between the bacterium and host cell to provide a continuous channel through which effectors are delivered. Significant effort has gone into understanding how the T3SS is assembled, how its substrates are recognized and how substrate delivery is controlled. Arguably the latter topic is the least understood; however, recent advances have provided new insight, and therefore, this review will focus primarily on summarizing the current state of knowledge regarding the control of substrate delivery by the T3SS. Specifically, we will discuss the roles of YopK, as well as YopN and YopE, which have long been linked to regulation of translocation. We also propose models whereby the YopK regulator communicates with the basal body of the T3SS to control translocation. PMID:23390616

  19. Machine vision algorithms applied to dynamic traffic light control

    Directory of Open Access Journals (Sweden)

    Fabio Andrés Espinosa Valcárcel

    2013-01-01

    número de autos presentes en imágenes capturadas por un conjunto de cámaras estratégicamente ubicadas en cada intersección. Usando esta información, el sistema selecciona la secuencia de acciones que optimicen el flujo vehicular dentro de la zona de control, en un escenario simulado. Los resultados obtenidos muestran que el sistema disminuye en un 20% los tiempos de retraso para cada vehículo y que además es capaz de adaptarse rápida y eficientemente a los cambios de flujo.

  20. Using light to see and control membrane traffic.

    Science.gov (United States)

    Xu, Yingke; Melia, Thomas J; Toomre, Derek K

    2011-12-01

    Cellular compartmentalization into discrete organelles is maintained by membrane trafficking including vesiculation and tubulation. Recent advances in superresolution imaging have begun to bring these small and dynamic events into focus. Most nanoscopes exploit, and are limited by, switching dyes ON and OFF. Using ground state depletion to switch dyes into long-lived dark states can exploit specific photophysical properties of dyes, such as redox potential or pK(a), and expand the repertoire of nanoscopy probes for multicolor imaging. Seeing is not enough, and new technologies based on homodimerization, heterodimerization and selective release can manipulate membrane trafficking in pulse-chase and light-controlled ways. Herein we highlight the utility and promise of these strategies and discuss their current limitations.

  1. Traffic jam at adjustable tollgates controlled by line length

    Science.gov (United States)

    Nagatani, Takashi

    2016-01-01

    We present the stochastic model for the jam formation at the tollgates of which the number is adjusted by synchronizing with the jam's length. We study the jam formation and its fluctuation in front of the adjustable tollgates on a highway. Controlling the number of tollgates has an important effect on the jam formation. The jams are classified into three kinds: (a) localized jam, (b) synchronized jam, and (c) growing jam. The jamming transitions from the localized jam, through the synchronized jam, to the growing jam occur with increasing inflow probability. At an intermediate inflow, the jam fluctuates largely by synchronizing with the number of tollgates. When the inflow probability is higher than the sum of outflow probabilities at tollgates, the jam continues to grow and diverge with time. The dependence of the fluctuating jam on the inflow probability is clarified.

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

    Science.gov (United States)

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

    1995-01-01

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

  3. Congestion Control Protocol for Wireless Sensor Networks Handling Prioritized Heterogeneous Traffic

    CERN Document Server

    Monowar, Muhammad Mostafa; Pathan, Al-Sakib Khan; Hong, Choong Seon

    2008-01-01

    Heterogeneous applications could be assimilated within the same wireless sensor network with the aid of modern motes that have multiple sensor boards on a single radio board. Different types of data generated from such types of motes might have different transmission characteristics in terms of priority, transmission rate, required bandwidth, tolerable packet loss, delay demands etc. Considering a sensor network consisting of such multi-purpose nodes, in this paper we propose Prioritized Heterogeneous Traffic-oriented Congestion Control Protocol (PHTCCP) which ensures efficient rate control for prioritized heterogeneous traffic. Our protocol uses intra-queue and inter-queue priorities for ensuring feasible transmission rates of heterogeneous data. It also guarantees efficient link utilization by using dynamic transmission rate adjustment. Detailed analysis and simulation results are presented along with the description of our protocol to demonstrate its effectiveness in handling prioritized heterogeneous traf...

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

    Science.gov (United States)

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

    2014-01-01

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

  5. Measurement of electromagnetic fields generated by air traffic control radar systems with spectrum analysers.

    Science.gov (United States)

    Barellini, A; Bogi, L; Licitra, G; Silvi, A M; Zari, A

    2009-12-01

    Air traffic control (ATC) primary radars are 'classical' radars that use echoes of radiofrequency (RF) pulses from aircraft to determine their position. High-power RF pulses radiated from radar antennas may produce high electromagnetic field levels in the surrounding area. Measurement of electromagnetic fields produced by RF-pulsed radar by means of a swept-tuned spectrum analyser are investigated here. Measurements have been carried out both in the laboratory and in situ on signals generated by an ATC primary radar.

  6. Development of a framework for the evaluation of the environmental benefits of controlled traffic farming

    OpenAIRE

    Mouazen, Abdul; Palmqvist, Martin

    2015-01-01

    Although controlled traffic farming (CTF) is an environmentally friendly soil management system, no quantitative evaluation of environmental benefits is available. This paper aims at establishing a framework for quantitative evaluation of the environmental benefits of CTF, considering a list of environmental benefits, namely, reducing soil compaction, runoff/erosion, energy requirement and greenhouse gas emission (GHG), conserving organic matter, enhancing soil biodiversity and fertiliser use...

  7. TRAFFIC CONTROL AND IMPROVING RELATIONS DRIVERS OF VEHICLES WITH EMPLOYEES UNITS GAI CITIES OF DNIPROPETROVSK

    OpenAIRE

    Мозолевич, Г. Я.; А. В. ТРОЯН

    2013-01-01

    In this work there were suggested the arrangements for the improvement of mutual relations of drivers and employees of the State motor-car inspection of Dnipropetrovsk city by introduction of electronic account of documents and automation of processes of travelling traffic regulation and controlling a travelling situation on the motor-car ways of city. There has been worked out strategy of introduction and expected cost of project for Dni-propetrovsk city. 

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

    Science.gov (United States)

    2004-12-01

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

  9. Implications of traffic characteristics on interdomain traffic engineering

    OpenAIRE

    Uhlig, Steve

    2004-01-01

    This thesis discusses the implications of the traffic characteristics on interdomain traffic engineering with BGP. We first provide an overview of the interdomain traffic control problem. Then, we present results concerning the characteristics of the interdomain traffic, based on the analysis of real traffic traces gathered from non-transit ASes. We discuss the implications of the topological properties of the traffic on interdomain traffic engineering. Based on this knowledge of the...

  10. Implications of traffic characteristics on interdomain traffic engineering

    OpenAIRE

    Uhlig, Steve

    2004-01-01

    This thesis discusses the implications of the traffic characteristics on interdomain traffic engineering with BGP. We first provide an overview of the interdomain traffic control problem. Then, we present results concerning the characteristics of the interdomain traffic, based on the analysis of real traffic traces gathered from non-transit ASes. We discuss the implications of the topological properties of the traffic on interdomain traffic engineering. Based on this knowledge of the...

  11. A Study of Dynamic Right-Turn Signal Control Strategy at Mixed Traffic Flow Intersections

    Directory of Open Access Journals (Sweden)

    Zhizhou Wu

    2014-12-01

    Full Text Available Traffic conflicts among right-turn vehicles (RTVs, non-motorized vehicles (NMVs and pedestrians were examined for urban signalized intersections with exclusive right-turn lane. This study proposed an approach to dynamically calculate the duration of the prohibited right-turn for vehicles by using a measure called the Degree of Clustered Conflict (DCC. The process of DCC control includes: 1 quantitative calculation of DCC value in the conflict area; 2 establishing the general cost model that combines the delay and conflict indicators; and 3 applying the DCC-control time model to control RTV in real time. Based on these, the paper presented a general approach of detailed dynamic on-line signal control process of RTV. Finally, the RTV control process was programmed based on VISSIM simulation to evaluate the control effectiveness. The results showed that the general cost (weighted summation of delay and conflict of the RTV control decreases rapidly compared with non-control, fixed control and full control (drop of 58%, 35% and 42% under small flow conditions and 70%, 59% and 17% in the large flow conditions, respectively. The method not only improved the operation efficiency, but also reduced the potential safety risks among traffic participants when vehicles turn right at intersections.

  12. Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with TEB model

    Directory of Open Access Journals (Sweden)

    A. Khalifa

    2015-06-01

    Full Text Available A forecast of the snowfall helps winter coordination operating services, reducing the cost of the maintenance actions, and the environmental impacts caused by an inappropriate use of de-icing. In order to determine the possible accumulation of snow on pavement, the forecast of the road surface temperature (RST is mandatory. Physical numerical models provide such forecast, and do need an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with all the energy interactions, with two approaches to evaluate the traffic incidence on RST. Experiments were then conducted to measure the traffic effect on RST increase with respect to non circulated areas. These field data were then used for comparison with forecast provided by this traffic-implemented TEB version.

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

    Directory of Open Access Journals (Sweden)

    Valdenilson Ribeiro Ribas

    2011-06-01

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

  14. 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.

  15. Development and Validation in Air Traffic Control by Means of Real-Time Simulations

    Directory of Open Access Journals (Sweden)

    Stephan Herr

    2009-02-01

    Full Text Available The airspace in Central Europe is already one of the busiest airspaces in the world and the forecasts predict further traffic increases. The current air transport system is reaching its capacity limits, not only at airports but also in parts of the en-route area. This is mainly due to the workload constraints of air traffic controllers. In the past, many technical system functionalities were developed with the aim of reducing controller workload and thus enabling the safe handling of the predicted traffic growth. But these new functionalities alone will not provide adequate relief to air traffic controllers. Their working procedures and the airspace structure will have to be adapted accordingly. In order to obtain real operational benefits, these technical innovations must be integrated into an overall concept which – in addition to the above-mentioned factors – also takes account of ergonomic aspects and human-machine interfaces. When developing such an overall concept, additional evaluation and validation measures are indispensable to ensure that the desired operational benefits are achieved. This is why DFS has for many years used fast- and real-time simulations to assess and optimise any changes to be made to the air traffic control system. The working methods of DFS in this context are in keeping with the European Operational Concept Validation Methodology of 2007, in short E-OCVM. This paper outlines the development and validation activities of DFS using the MSP D/L project as an example. The project deals with the introduction of the new role of air traffic controllers as multi-sector planners (MSP and new system functionalities, such as air/ground data link (D/L. The project included the development of an operational concept for using the new functionalities as well as for defining working procedures and the airspace structure. This concept was subsequently evaluated by means of a fast-time simulation and two real-time simulations

  16. SIMULATION MODELS OF HEAVY TRUCKS TRAFFIC CONTROL WITH ELECTRIC DC DRIVE

    Directory of Open Access Journals (Sweden)

    N. N. Hurski

    2015-01-01

    Full Text Available A model of the straight course of movement of the mobile machine with a traction electric motor DC. Traffic management controller provides a closed classical scheme with feedback. The mathematical model of the electric DC motor with the energy dissipation in the rotor bearings. Design scheme of mobile machines include speed dial controller, traction electric motor, gearbox, transmission and progressively moving mass on the elastic­dissipative wheel. The results of the simulation of the machine in the form of temporary processes of change control signals, voltage and current in the windings of the motor and traction power developed on the wheel.

  17. Admission Control for Multiservices Traffic in Hierarchical Mobile IPv6 Networks by Using Fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Jung-Shyr Wu

    2012-01-01

    Full Text Available CAC (Call Admission Control plays a significant role in providing QoS (Quality of Service in mobile wireless networks. In addition to much research that focuses on modified Mobile IP to get better efficient handover performance, CAC should be introduced to Mobile IP-based network to guarantee the QoS for users. In this paper, we propose a CAC scheme which incorporates multiple traffic types and adjusts the admission threshold dynamically using fuzzy control logic to achieve better usage of resources. The method can provide QoS in Mobile IPv6 networks with few modifications on MAP (Mobility Anchor Point functionality and slight change in BU (Binding Update message formats. According to the simulation results, the proposed scheme presents good performance of voice and video traffic at the expenses of poor performance on data traffic. It is evident that these CAC schemes can reduce the probability of the handoff dropping and the cell overload and limit the probability of the new call blocking.

  18. The Sybtraps: control of synaptobrevin traffic by synaptophysin, α-synuclein and AP-180.

    Science.gov (United States)

    Gordon, Sarah L; Cousin, Michael A

    2014-03-01

    Synaptobrevin II (sybII) is a key fusogenic molecule on synaptic vesicles (SVs) therefore the active maintenance of both its conformation and location in sufficient numbers on this organelle is critical in both mediating and sustaining neurotransmitter release. Recently three proteins have been identified having key roles in the presentation, trafficking and retrieval of sybII during the fusion and endocytosis of SVs. The nerve terminal protein α-synuclein catalyses sybII entry into SNARE complexes, whereas the monomeric adaptor protein AP-180 is required for sybII retrieval during SV endocytosis. Overarching these events is the tetraspan SV protein synaptophysin, which is a major sybII interaction partner on the SV. This review will evaluate recent studies to propose working models for the control of sybII traffic by synaptophysin and other Sybtraps (sybII trafficking partners) and suggest how dysfunction in sybII traffic may contribute to human disease.

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

    Science.gov (United States)

    Williams, David H.; Green, Steven M.

    1991-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

  1. Localization and recognition of traffic signs for automated vehicle control systems

    Science.gov (United States)

    Zadeh, Mahmoud M.; Kasvand, T.; Suen, Ching Y.

    1998-01-01

    We present a computer vision system for detection and recognition of traffic signs. Such systems are required to assist drivers and for guidance and control of autonomous vehicles on roads and city streets. For experiments we use sequences of digitized photographs and off-line analysis. The system contains four stages. First, region segmentation based on color pixel classification called SRSM. SRSM limits the search to regions of interest in the scene. Second, we use edge tracing to find parts of outer edges of signs which are circular or straight, corresponding to the geometrical shapes of traffic signs. The third step is geometrical analysis of the outer edge and preliminary recognition of each candidate region, which may be a potential traffic sign. The final step in recognition uses color combinations within each region and model matching. This system maybe used for recognition of other types of objects, provided that the geometrical shape and color content remain reasonably constant. The method is reliable, easy to implement, and fast, This differs form the road signs recognition method in the PROMETEUS. The overall structure of the approach is sketched.

  2. Multiplicative models of analysis : a description and the use in analysing accident ratios as a function of hourly traffic volume and road-surface skidding resistance.

    NARCIS (Netherlands)

    Oppe, S.

    1977-01-01

    Accident ratios are analysed with regard to the variables road surface skidding resistance and hourly traffic volume. It is concluded that the multiplicative model describes the data better than the additive model. Moreover that there is no interaction between skidding resistance and traffic volume

  3. An RFID-based intelligent vehicle speed controller using active traffic signals.

    Science.gov (United States)

    Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C; de Pedro, Teresa

    2010-01-01

    These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver's attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

  4. An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

    Directory of Open Access Journals (Sweden)

    Joshué Pérez

    2010-06-01

    Full Text Available These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS. One prime example of ITS is vehicle Cruise Control (CC, which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

  5. An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

    Science.gov (United States)

    Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C.; de Pedro, Teresa

    2010-01-01

    These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results. PMID:22219692

  6. Traffic control based on dahlin algorithm and neural network prediction in TAM networks

    Institute of Scientific and Technical Information of China (English)

    沈伟; 冯瑞; 邵惠鹤

    2004-01-01

    The propagation delay in networks has a great adverse effect on rate-based traffic control. This paper proposes the composite control based on Dab lin algorithm feedback control and neural network feedforward predictive compensation online for ABR (available bit rate) communication in ATM (asynchronous transfer mode) networks, which can overcome the adverse effect caused by the delay on the control rapidity and stability better. The theoretical analysis and simulation research show that the scheme can make sources respond to the changes of network status rapidly, avoid the congestion effectively and utilize the bandwidth sufficiently. Compared with PID (proportional-integral-derivative) control, cell loss rate is much lower, link utilization rate is much higher, and required buffer capacity is much smaller.

  7. The transportation network rough description for an adaptive traffic control algorithms by means of video detection technique

    Directory of Open Access Journals (Sweden)

    Jan PIECHA

    2013-01-01

    Full Text Available The contribution discusses a transportation network rough description that corresponds to satisfactory level of an adaptive traffic control algorithms implementation [4], supported by video-detection system. The decision making algorithms have to provide us with not only vehicles’ approach time prediction, at the intersections but also finding possible solution for avoiding critical queues at the intersections. Majority of traditional traffic control systems are based on number of cars recorded by inductive loops, however they do not define any proper occupation states at any traffic lane. The time window indicated for passing the defined number of cars loses the distance gaps visible between the cars on the traffic lane. That is why remarkable part from the defined number of cars will not cross the intersection in the defined green light time. Procedures used for searching an optimal solution using the inductive measurements can, in the majority cases, be undoubtedly noticed as a theoretical analysis only.

  8. IMPROVING PERFORMANCE OF IEEE 802.11 BY A DYNAMIC CONTROL BACKOFF ALGORITHM UNDER UNSATURATED TRAFFIC LOADS

    Directory of Open Access Journals (Sweden)

    Hatm Alkadeki

    2015-12-01

    Full Text Available The IEEE 802.11 backoff algorithm is very important for controlling system throughput over contentionbased wireless networks. For this reason, there are many studies on wireless network performance focus on developing backoff algorithms. However, most existing models are based on saturated traffic loads, which are not a real representation of actual network conditions. In this paper, a dynamic control backoff time algorithm is proposed to enhance both delay and throughput performance of the IEEE 802.11 distributed coordination function. This algorithm considers the distinction between high and low traffic loads in order to deal with unsaturated traffic load conditions. In particular, the equilibrium point analysis model is used to represent the algorithm under various traffic load conditions. Results of extensive simulation experiments illustrate that the proposed algorithm yields better performance throughput and a better average transmission packet delay than related algorithms.

  9. Quantifying traffic exposure.

    Science.gov (United States)

    Pratt, Gregory C; Parson, Kris; Shinoda, Naomi; Lindgren, Paula; Dunlap, Sara; Yawn, Barbara; Wollan, Peter; Johnson, Jean

    2014-01-01

    Living near traffic adversely affects health outcomes. Traffic exposure metrics include distance to high-traffic roads, traffic volume on nearby roads, traffic within buffer distances, measured pollutant concentrations, land-use regression estimates of pollution concentrations, and others. We used Geographic Information System software to explore a new approach using traffic count data and a kernel density calculation to generate a traffic density surface with a resolution of 50 m. The density value in each cell reflects all the traffic on all the roads within the distance specified in the kernel density algorithm. The effect of a given roadway on the raster cell value depends on the amount of traffic on the road segment, its distance from the raster cell, and the form of the algorithm. We used a Gaussian algorithm in which traffic influence became insignificant beyond 300 m. This metric integrates the deleterious effects of traffic rather than focusing on one pollutant. The density surface can be used to impute exposure at any point, and it can be used to quantify integrated exposure along a global positioning system route. The traffic density calculation compares favorably with other metrics for assessing traffic exposure and can be used in a variety of applications.

  10. Analysing adjustment factors for using lanes at traffic-light-controlled intersections in Bogotá, Colombia.

    Directory of Open Access Journals (Sweden)

    Ricardo José Peña Lindarte

    2010-05-01

    Full Text Available This article was focused on analyzing the lane use adjustment factor (fLU forming one of the eleven adjustment factors proposed in the current calculation methodology contained in the 2000 version of the Transportation Research Board’s (TRB Highway Capacity Manual (HCM for analyzing traffic-light-controlled intersection capacity in terms of saturation intensity. A methodology was established when analyzing the fLU factor that considered operational conditions regarding traffic-light-controlled intersections in Bogota. Road traffic flows were analyzed, including characterizing road traffic based on statistical sampling, field data collection and analysis. The project proposed equations allowing reference values to be gathered for determining adjustment factors regarding lane use on roads in Bogota in relation to existing access typologies and road traffic volume for analyzing traffic-light- controlled intersections. For example, in the specific case of roads having direct double-lane access (2CCD, the basic equation was determined to be y=-3,03E-08X2+3,44E-05X+0,888988, having a 1.0 coefficient of correlation. The dependent variable y referred to the fLU factor and the independent variable X was the volume of road traffic in mixed vehicles/hour. This equation was considered to be statistically relevant. A comparative analysis of the lane use adjustment factors estimated in the project is also presented and compared to the values recommended by the US Highway Capacity Manual. The project’s conclusions and re- commendations were thus sustained, validating the recommended factors summarized by the HCM and recommending that the results obtained from the project should be used in traffic-light-controlled design and planning projects.

  11. Multiagent Systems: Introduction and Application in Traffic Control and Simulation and Emergency Situations Simulation

    Directory of Open Access Journals (Sweden)

    BAZZAN, A. L. C.

    2010-12-01

    Full Text Available The area of multiagent systems is new and challenging. From the moment a system includes more than one agent, artificial intelligence techniques become inadequate for they do not consider interactions with other agent, need for coordination and other factors. In this text those aspects are discussed, and an introduction to the area of autonomous agents and multiagent systems is offered. Afterwards, two application of this kind of systems are described, both in the area of transportation and emergency sistuations. In the former we discuss traffic control and simulation and in the latter, we focus on the simulation tool RoboCup Rescue

  12. Risk Analysis and Setting Priorities in Air Traffic Control by Using a Matrix of Similarities

    Directory of Open Access Journals (Sweden)

    Lacane Monta

    2015-11-01

    Full Text Available This article considers how mathematical decision-making in Air Traffic Control could be done in order to minimize the risk of collisions. An example of how to prioritize airplanes which are in the vicinity of an airport according to their level of risk in respect to other airplanes is given by using a matrix of similarities and Euclidean metric. The analysis has shown that it is necessary to classify ATC specialists and ATC centers according to their ability to provide safe enough service using time methods and highly experienced team work.

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

    Science.gov (United States)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Manganese concentrations in the air of the Montreal (Canada) subway in relation to surface automobile traffic density

    Energy Technology Data Exchange (ETDEWEB)

    Boudia, Nacera; Gareau, Lise; Zayed, Joseph [GRIS Interdisciplinary Health Research Group, University of Montreal (Canada); Halley, Renee [Transport Montreal Society (Canada); Kennedy, Greg [Department of Engineering Physics, Ecole Polytechnique de Montreal, Montreal (Canada); Lambert, Jean [Department of Social and Preventive Medicine, Faculty of Medicine, University of Montreal (Canada)

    2006-07-31

    Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn), used since 1976 in Canadian gasoline as an octane enhancer. Its combustion leads to the emission of Mn particles. Several studies carried out by our research group have established a correlation between atmospheric Mn concentrations and automobile traffic density, suggesting that MMT in gasoline could play a significant role. This study aims to measure Mn concentrations in the air of the underground subway in Montreal (Canada) and to examine the relation with nearby surface automobile traffic density and, by extension, with the use of MMT in gasoline. Three subway stations were chosen for their location in different microenvironments with different traffic densities. Respirable (MnR<5 {mu}m) and total Mn (MnT) were sampled over two weeks, 5 days/week, 12 h/day. For the station located in the lower traffic density area, relatively low levels of MnR and MnT were found, with averages of 0.018 and 0.032 {mu}g/m{sup 3}, respectively. These concentrations are within the range of the background levels in Montreal. For the other two stations, the average concentrations of MnR were twice as high and exceeded the US EPA reference concentration of 0.05 {mu}g/m{sup 3}. Although there may be several sources of Mn from different components of the subway structure and vehicles, no correlation was found between subway traffic and atmospheric Mn in the subway. Since the air in the underground subway is pumped directly from outside without filtration, our findings strongly suggest that the combustion of MMT in automobiles is an important factor. (author)

  16. Optimum airspace design with air traffic controller workload-based partitioning

    Science.gov (United States)

    Yousefi, Arash

    This dissertation proposes an Air Traffic Controller (ATC) workload based methodology for optimum airspace partitioning. Initially, we define a set of airspace metrics for analytical modeling of the ATC cognitive workload and airspace complexity. We use a large-scale, fast-time simulation to model the current sectors in five Air Route Traffic Control Centers (ARTCCs) and compute the airspace metrics for each sector. These metrics are then used to calculate ATC workload and traffic complexity during various time intervals. Sectors are then ranked based on their traffic complexity and we show that the defined metrics are able to identify the complex sectors. Having a reasonable ATC workload modeling technique, we decompose the U.S. national airspace into three layers using altitude ranges based on operational levels of low, high, and ultra-high airspace. Each layer is further tiled into 2,566 hexagonal cells (hex-cells) with 24 nautical mile sides. These hex-cells are assumed to be finite elements of airspace and ATC workload is modeled for each hex-cell using various airspace metrics. We apply visualization techniques to analyze the spatial and temporal distribution of the controller workload and to identify congested periods of the U.S. National Airspace System (NAS). Having the workload values for each hex-cell during the congested periods, we develop clustering algorithms using optimization theory to cluster hex-cells and partition the airspace to ARTCCs and sectors. We first partition the airspace to ARTCCs and define the optimum boundaries for different number of ARTCCs. Then the partitioning is continued within each ARTCC to construct optimum sector boundaries. This dissertation concentrates on simulation as a means to evaluate cognitive workload for the elements of airspace regardless of current sector and ARTCC boundaries. The only apriori inputs are the location of current ARTCC facilities and airports, the demand profiles for each city pair, and the filed

  17. Traffic Adaptive Energy Efficient and Low Latency Medium Access Control for Wireless Sensor Networks

    Science.gov (United States)

    Yadav, Rajesh; Varma, Shirshu; Malaviya, N.

    2008-05-01

    Medium access control for wireless sensor networks has been a very active research area in the recent years. The traditional wireless medium access control protocol such as IEEE 802.11 is not suitable for the sensor network application because these are battery powered. The recharging of these sensor nodes is expensive and also not possible. The most of the literature in the medium access for the sensor network focuses on the energy efficiency. The proposed MAC protocol solves the energy inefficiency caused by idle listening, control packet overhead and overhearing taking nodes latency into consideration based on the network traffic. Simulation experiments have been performed to demonstrate the effectiveness of the proposed approach. The validation of the simulation results of the proposed MAC has been done by comparing it with the analytical model. This protocol has been simulated in Network Simulator ns-2.

  18. Evaluation of Early Ground Control Station Configurations for Interacting with a UAS Traffic Management (UTM) System

    Science.gov (United States)

    Dao, Arik-Quang V.; Martin, Lynne; Mohlenbrink, Christoph; Bienert, Nancy; Wolte, Cynthia; Gomez, Ashley; Claudatos, Lauren; Mercer, Joey

    2017-01-01

    The purpose of this paper is to report on a human factors evaluation of ground control station design concepts for interacting with an unmanned traffic management system. The data collected for this paper comes from recent field tests for NASA's Unmanned Traffic Management (UTM) project, and covers the following topics; workload, situation awareness, as well as flight crew communication, coordination, and procedures. The goal of this evaluation was to determine if the various software implementations for interacting with the UTM system can be described and classified into design concepts to provide guidance for the development of future UTM interfaces. We begin with a brief description of NASA's UTM project, followed by a description of the test range configuration related to a second development phase. We identified (post hoc) two classes in which the ground control stations could be grouped. This grouping was based on level of display integration. The analysis was exploratory and informal. It was conducted to compare ground stations across those two classes and against the aforementioned topics. Herein, we discuss the results.

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

    Science.gov (United States)

    Malakis, Stathis; Kontogiannis, Tom; Kirwan, Barry

    2010-07-01

    Team performance has been studied in many safety-critical organizations including aviation, nuclear power plant, offshore oil platforms and health organizations. This study looks into teamwork strategies that air traffic controllers employ to manage emergencies and abnormal situations. Two field studies were carried out in the form of observations of simulator training in emergency and unusual scenarios of novices and experienced controllers. Teamwork strategies covered aspects of team orientation and coordination, information exchange, change management and error handling. Several performance metrics were used to rate the efficiency of teamwork and test the construct validity of a prototype model of teamwork. This is a companion study to an earlier investigation of taskwork strategies in the same field (part I) and contributes to the development of a generic model for Taskwork and Teamwork strategies in Emergencies in Air traffic Management (T(2)EAM). Suggestions are made on how to use T(2)EAM to develop training programs, assess team performance and improve mishap investigations. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Investigation of postural edema in the lower extremities of traffic control workers

    Directory of Open Access Journals (Sweden)

    Ana Paula Nunes Pereira Brito

    2013-12-01

    Full Text Available OBJECTIVE: Determine the prevalence of postural edema and investigate whether working posture - sitting down or standing up - affect its frequency. METHODS: Sixteen traffic control agents were assessed by water displacement volumetry and the results were analyzed in two groups, depending on working posture. Those who worked standing up for more than 4 hours were allocated to the SU group and those who worked sitting down for more than 4 hours were allocated to the SD group. Each worker was assessed before and after their working shift for three consecutive days. Data were analyzed using ANOVA and the test of equality of two proportions. The significance level was set at p ≤ 0.05. The assessment showed that members of both groups had postural edema of the lower extremities (p ≤ 0.001. RESULTS: When the frequency of postural edema was compared across groups, a trend was observed for greater edema formation in the SU group than in the SD group, although without statistically significant difference. CONCLUSION: It was concluded that traffic control agents suffer postural edema after 4 hours working in either of the postures investigated although with a predominance of edema formation among those who work standing up.

  1. Congestion phenomenon analysis and delayed-feedback control in a modified coupled map traffic flow model containing the velocity difference

    Science.gov (United States)

    Fang, Ya-Ling; Shi, Zhong-Ke; Cao, Jin-Liang

    2015-06-01

    Based on the coupled map car-following model which was presented by Konishi et al. (1999), a modified coupled map car-following model is proposed. Specifically, the velocity difference between two successive vehicles is included in the model. The stability condition is given for the change of the speed of the preceding vehicle on the base of the control theory. We derive a condition under which the traffic jam never occurs in our model. Furthermore, in order to suppress traffic jams, we use static and dynamic version of decentralized delayed-feedback control for each vehicle, respectively, and provide a systematic procedure for designing the controller. In addition, the controller of each vehicle does not include any other vehicle information in real traffic flows.

  2. INTEGRATION OF LOW EQUIPMENT AUTOMATED SYSTEM OF CONTROL FREIGHT TRAIN THE AUTOMATED CONTROL SYSTEM OF THE PASSENGER TRAFFIC, CONNECTING IT TO A SINGLE SYSTEM SOFTWARE DOCUMENTATION

    Directory of Open Access Journals (Sweden)

    Yu. M. Ivchenko

    2009-09-01

    Full Text Available In the paper the integration of nodes of data transfer network for automated control systems of freight and passenger traffic is proposed. It allows more efficient using the network equipment and communication channels.

  3. Performance Evaluation of Adaptive Rate Control (ARC for Burst Traffic over ATM Network

    Directory of Open Access Journals (Sweden)

    V.Ramesh

    2010-01-01

    Full Text Available Many research works have already been done for congestion control and resource management in ATM networks using static and dynamic algorithms. However, no comprehensive scheme has been suggested, which can claim optimized the resource allocations fulfilling the requirements of quality of services (QoS for existing and incoming sources. The paper suggests a new approach, which would make the dynamic allocation of resources by controlling the input rate (l, output/server rate (m and buffer size (c individually or in conjunction. The newly proposed approach with dynamical allocation of resources is much more comprehensive in nature and claims a shorter convergence time than the other previously suggested schemes based on similar dynamic allocation principle. In this paper we describe an Adaptive Rate Control (ARC implemented to improve the performance of high-speed network to handle burst traffic by guaranteeing the cell loss ratio (CLR for all cell streams. First, the cases in which a Tahoe, Reno, New Reno, SACK and Plain schemes are applicable in peak-cell-rate (PCR are discussed. The ARC improves the performance by regulating the increment (up and the decrease (down of window size (flow control. Incoming traffic rate, number of cell drop, preset size of the window and estimated delay time are taken into account for this regulation. Simulations are used to investigate how Tahoe, Reno, New Reno, SACK and Plain can conduct, as congestion existed. Then we compare these results from four schemes to the “Plain” scheme (no flow control application and to the proposed ARC. By altering windows size for the mentioned six schemes, we can obtain the supportive results.

  4. Poor asthma control and exposure to traffic pollutants and obesity in older adults.

    Science.gov (United States)

    Epstein, Tolly G; Ryan, Patrick H; LeMasters, Grace K; Bernstein, Cheryl K; Levin, Linda S; Bernstein, Jonathan A; Villareal, Manuel S; Bernstein, David I

    2012-06-01

    Environmental and host predictors of asthma control in older asthmatic patients (>65 years old) are poorly understood. To examine the effects of residential exposure to traffic exhaust and other environmental and host predictors on asthma control in older adults. One hundred four asthmatic patients 65 years of age or older from allergy and pulmonary clinics in greater Cincinnati, Ohio, completed the validated Asthma Control Questionnaire (ACQ), pulmonary function testing, and skin prick testing to 10 common aeroallergens. Patients had a physician's diagnosis of asthma, had significant reversibility in forced expiratory volume in 1 second or a positive methacholine challenge test result, and did not have chronic obstructive pulmonary disease. The mean daily residential exposure to elemental carbon attributable to traffic (ECAT) was estimated using a land-use regression model. Regression models were used to evaluate associations among independent variables, ACQ scores, and the number of asthma exacerbations, defined as acute worsening of asthma symptoms requiring prednisone use, in the past year. In the adjusted model, mean daily residential exposure to ECAT greater than 0.39 μg/m(3) was significantly associated with poorer asthma control based on ACQ scores (adjusted β = 2.85; 95% confidence interval [CI], 0.58-5.12; P = .02). High ECAT levels were also significantly associated with increased risk of asthma exacerbations (adjusted odds ratio, 3.24; 95% CI, 1.01-10.37; P = .05). A significant association was found between higher body mass index and worse ACQ scores (adjusted β = 1.15; 95% CI, 0.53-1.76; P obesity, and nonatopic status are associated with poorer asthma control among older asthmatic patients. Copyright © 2012 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  5. THE DDTCI SWITCH ALGORITHM FOR ABR TRAFFIC CONTROL IN ATM NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Lu Zhaoyi; Ning Yuxin

    2005-01-01

    For the issue of flow control for Available Bit Rate (ABR) traffic in ATM network,a new improved Explicit Rate (ER) algorithm named Dynamic Double Threshold Congestion Indication (DDTCI) algorithm is presented based on the Explicit Forward Congestion Indication (EFCI) Current Cell Rate (CCR) algorithm and Relative Rate (RR) algorithm. Different from the early ER algorithm, both the high-level and the low-level threshold is dynamically changing according to the state of the bottleneck node. We determinate the congestion state with the information of the two dynamic threshold, and control the cell rate of the source by feed back mechanism. Except for the well performance in both link utilization and fairness in distribution of available bandwidth, the improved algorithm can alleviate the fluctuation of sending rate dramatically. The mechanism is modeled by a fluid model, and the useful expressions are derived.Simulation results show up our conclusion.

  6. A Simulation-Based Framework for the Cooperation of VMS Travel Guidance and Traffic Signal Control

    Directory of Open Access Journals (Sweden)

    Meng Li

    2014-01-01

    Full Text Available Nowadays, both travel guidance systems and traffic signal control systems are quite common for urban traffic management. In order to achieve collaborative effect, different models had been proposed in the last two decades. In recent years, with the development of variable message sign (VMS technology, more and more VMS panels are installed on major arterials to provide highly visible and concise graphs or text messages to drivers, especially in developing countries. To discover drivers’ responses to VMS, we establish a drivers’ en route diversion model according to a stated-preference survey. Basically, we proposed a cooperative mechanism and systematic framework of VMS travel guidance and major arterials signal operations. And then a two-stage nested optimization problem is formulated. To solve this optimization problem, a simulation-based optimization method is adopted to optimize the cooperative strategies with TRANSIMS. The proposed method is applied to the real network of Tianjin City comprising of 30 nodes and 46 links. Simulations show that this new method could well improve the network condition by 26.3%. And analysis reveals that GA with nested dynamic programming is an effective technique to solve the optimization problem.

  7. MODELING MULTI-TRAFFIC ADMISSION CONTROL IN OFDMA SYSTEM USING COLORED PETRI NET

    Institute of Scientific and Technical Information of China (English)

    Yao Yuanyuan; Lu Yanhui; Yang Shouyi

    2012-01-01

    Call Admission Control (CAC) is one of the key traffic management mechanisms that must be deployed in order to meet the strict requirements for dependability imposed on the services provided by modern wireless networks.In this paper,we develop an executable top-down hierarchical Colored Petri Net (CPN) model for multi-traffic CAC in Orthogonal Frequency Division Multiple Access (OFDMA) system.By theoretic analysis and CPN simulation,it is demonstrated that the CPN model is isomorphic to Markov Chain (MC) assuming that each data stream follows Poisson distribution and the corresponding arrival time interval is an exponential random variable,and it breaks through MC's explicit limitation,which includes MC's memoryless property and proneness to state space explosion in evaluating CAC process.Moreover,we present four CAC schemes based on CPN model taking into account call-level and packet-level Quality of Service (QoS).The simulation results show that CPN offers significant advantages over MC in modeling CAC strategies and evaluating their performance with less computational complexity in addition to its flexibility and adaptability to different scenarios.

  8. Potential To Increase Productivity And Sustainability In Argentinean Agriculture With Controlled Traffic Farming: A Short Discussion

    Directory of Open Access Journals (Sweden)

    Antille Diogenes L.

    2015-09-01

    Full Text Available Drivers for and potential barriers against adoption of controlled traffic farming (CTF systems in Argentina are reviewed. Traffic compaction is one of the main factors affecting crop productivity within Argentinean agriculture, and has significant although less quantified impacts on the whole-of-farm system. This suggests that the benefits of no-tillage (NT, which represents the dominant form of cropping in Argentina, are not fully realised. Conservative estimates indicate that crop yields could be improved by at least 15% if NT is used in conjunction with CTF. Cost-benefit analyses of available options for compaction management are required. Despite this, and based on reported evidence internationally, a shift toward increased uptake of CTF within Argentinean agriculture is likely to: (1 improve productivity and farm profitability, (2 enhance environmental performance, and (3 maintain competitiveness of the agricultural sector. Appropriate technical advice and support is a key requirement to drive adoption of CTF. Therefore, the adoption process will benefit from collaboration developed with well-established research and extension organisations in Australia and the United Kingdom, and active engagement of machinery manufacturers.

  9. 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

  10. A Novel Algorithm of Quantum Random Walk in Server Traffic Control and Task Scheduling

    Directory of Open Access Journals (Sweden)

    Dong Yumin

    2014-01-01

    Full Text Available A quantum random walk optimization model and algorithm in network cluster server traffic control and task scheduling is proposed. In order to solve the problem of server load balancing, we research and discuss the distribution theory of energy field in quantum mechanics and apply it to data clustering. We introduce the method of random walk and illuminate what the quantum random walk is. Here, we mainly research the standard model of one-dimensional quantum random walk. For the data clustering problem of high dimensional space, we can decompose one m-dimensional quantum random walk into m one-dimensional quantum random walk. In the end of the paper, we compare the quantum random walk optimization method with GA (genetic algorithm, ACO (ant colony optimization, and SAA (simulated annealing algorithm. In the same time, we prove its validity and rationality by the experiment of analog and simulation.

  11. The large Maf factor Traffic Jam controls gonad morphogenesis in Drosophila.

    Science.gov (United States)

    Li, Michelle A; Alls, Jeffrey D; Avancini, Rita M; Koo, Karen; Godt, Dorothea

    2003-11-01

    Interactions between somatic and germline cells are critical for the normal development of egg and sperm. Here we show that the gene traffic jam (tj) produces a soma-specific factor that controls gonad morphogenesis and is required for female and male fertility. tj encodes the only large Maf factor in Drosophila melanogaster, an orthologue of the atypical basic Leu zipper transcription factors c-Maf and MafB/Kreisler in vertebrates. Expression of tj occurs in somatic gonadal cells that are in direct contact with germline cells throughout development. In tj mutant gonads, somatic cells fail to inter-mingle and properly envelop germline cells, causing an early block in germ cell differentiation. In addition, tj mutant somatic cells show an increase in the level of expression for several adhesion molecules. We propose that tj is a critical modulator of the adhesive properties of somatic cells, facilitating germline-soma interactions that are essential for germ cell differentiation.

  12. Iterative Learning Control Approach for Signaling Split in Urban Traffic Networks with Macroscopic Fundamental Diagrams

    Directory of Open Access Journals (Sweden)

    Fei Yan

    2015-01-01

    Full Text Available Recent analysis of field experiments in cities revealed that a macroscopic fundamental diagram (MFD relating network outflow and network vehicle accumulation exists in the urban traffic networks. It has been further confirmed that an MFD is well defined if the network has regular network topology and homogeneous spatial distribution of vehicle accumulation. However, many real urban networks have different levels of heterogeneity in the spatial distribution of vehicle accumulation. In order to improve the mobility in heterogeneously congested networks, we propose an iterative learning control approach for signaling split, which aims at distributing the accumulation in the networks as homogeneously as possible and ensuring the networks have a larger outflow. The asymptotic convergence of the proposed approach is proved by rigorous analysis and the effectiveness is further demonstrated by extensive simulations.

  13. Optimal Control and Coordination of Connected and Automated Vehicles at Urban Traffic Intersections

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yue J. [Boston University; Malikopoulos, Andreas [ORNL; Cassandras, Christos G. [Boston University

    2016-01-01

    We address the problem of coordinating online a continuous flow of connected and automated vehicles (CAVs) crossing two adjacent intersections in an urban area. We present a decentralized optimal control framework whose solution yields for each vehicle the optimal acceleration/deceleration at any time in the sense of minimizing fuel consumption. The solu- tion, when it exists, allows the vehicles to cross the intersections without the use of traffic lights, without creating congestion on the connecting road, and under the hard safety constraint of collision avoidance. The effectiveness of the proposed solution is validated through simulation considering two intersections located in downtown Boston, and it is shown that coordination of CAVs can reduce significantly both fuel consumption and travel time.

  14. Intraframe compression of radar image sequences for ship traffic control applications

    Science.gov (United States)

    Andreadis, Alessandro; Benelli, Giuliano; Garzelli, Andrea; Susini, S.

    1996-09-01

    In this paper, an intraframe scheme for high compression of X-band radar images for ship traffic control is proposed. We used a proprietary radar simulator which generates maritime scenarios as seen by one or more radar sites. We propose a modified adaptive discrete cosine transform (MADCT) scheme which allows us to classify each 8 by 8 image block by means of a threshold criterion based on ac and dc activity. The strategy of transmission of the DCT coefficients, the recovering process of blocks incorrectly discarded, and the bit-allocation phase have been properly designed to fit with the particular application. Accurate experimental results, in terms of PSNR and compression ratio, prove the superiority of the novel scheme with respect to standard coding techniques.

  15. On orbit surfacing of thermal control surfaces

    Science.gov (United States)

    Racette, G. W.

    1984-01-01

    Substrates to be contaminated and contamination source were prepared. Additional information on paint spray method apparatus was obtained. Silver teflon second surface mirror samples and S 13 GLO paint samples were mounted, photographed under the microscope and measured to establish baseline data. Atomic oxygen cleaning and spray painting are being considered. Electrostatic powder and plasma spray coating systems appear to have serious drawbacks.

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

    Science.gov (United States)

    Erev, Ido; Gopher, Daniel; Remington, Roger

    1999-01-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  18. Human-factors engineering for smart transport: design support for car drivers and train traffic controllers.

    Science.gov (United States)

    Lenior, Dick; Janssen, Wiel; Neerincx, Mark; Schreibers, Kirsten

    2006-07-01

    The theme Smart Transport can be described as adequate human-system symbiosis to realize effective, efficient and human-friendly transport of goods and information. This paper addresses how to attune automation to human (cognitive) capacities (e.g. to take care of information uncertainty, operator trust and mutual man-machine adaptations). An introduction to smart transport is presented, including examples of best practice for engineering human factors in the vehicle ergonomics and train traffic control domain. The examples are representative of an ongoing trend in automation and they show how the human role changes from controller to supervisor. Section 2 focuses on the car driver and systems that support, or sometimes even take over, critical parts of the driving task. Due to the diversity of driver ability, driving context and dependence between driver and context factors, there is a need for personalised, adaptive and integrated support. Systematic research is needed to establish sound systems. Section 3 focuses on the train dispatcher support systems that predict train movements, detect potential conflicts and show the dispatcher the possibilities available to solve the detected problems. Via thorough analysis of both the process to be controlled and the dispatcher's tasks and cognitive needs, support functions were developed as part of an already very complex supervision and control system. The two examples, although from a different field, both show the need for further development in cognitive modelling as well as for the value of sound ergonomics task analysis in design practice.

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

    Science.gov (United States)

    Gershzohn, G.

    1978-01-01

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

  20. Development and investigation of a pollution control pit for treatment of stormwater from metal roofs and traffic areas.

    Science.gov (United States)

    Dierkes, C; Göbel, P; Lohmann, M; Coldewey, W G

    2006-01-01

    Source control by on-site retention and infiltration of stormwater is a sustainable and proven alternative to classical drainage methods. Unfortunately, sedimentary particles and pollutants from drained surfaces cause clogging and endanger soil and groundwater during long-term operation of infiltration devices. German water authorities recommend the use of infiltration devices, such as swales or swale-trench-systems. Direct infiltration by underground facilities, such as pipes, trenches or sinks, without pretreatment of runoff is generally not permitted. Problems occur with runoff from metal roofs, traffic areas and industrial sites. However, due to site limitations, underground systems are often the only feasible option. To overcome this situation, a pollution control pit was developed with a hydrodynamic separator and a multistage filter made of coated porous concrete. The system treats runoff at source and protects soil, groundwater and receiving waterways. Typically, more than 90% of the pollutants such as sedimentary particles, hydrocarbons and heavy metals can be removed. Filters have been developed to treat even higher polluted stormwater loads from metal roofs and industrial sites. The treatment process is based on sedimentation, filtration, adsorption and chemical precipitation. Sediments are trapped in a special chamber within the pit and can be removed easily. Other pollutants are captured in the concrete filter upstream of the sediment separator chamber. Filters can be easily replaced.

  1. A Service Oriented Architecture to Integrate Short Message Service (SMS Notification in Road Traffic Volume Control System

    Directory of Open Access Journals (Sweden)

    Zahi Abu Sarhan

    2013-02-01

    Full Text Available The traffic volume becomes one of the top problems in the world, the volume of traffic spends many time and much money, the traffic volume grows daily, and there is not effective and suitable solutions for grows problem. This paper will present and describe an effective approach to integrate the Service Oriented Architecture with mobile devices and services agents in Traffic Management Systems (TMS. The Traffic Volume Control System (TVCS should enable mobile short message service (SMS notifications. Unfortunately, cellular SMS notification based on services that are not aspect of the TVCS.Developing altered exterior systems and services, to be virtually aspect of TVCS, are one of the most incorporation difficulties. In this paper, a Service Oriented Architecture (SOA approach to includecellular SMS alerts in TVCS is presented. Suggested Structure includes two layers: Service layer and Interface layer. The Service layer includes all the system software. The service layer consists of three sub layers: Orchestration, Application Services, and Agents sub-layers. While the Interface layer interrelates with speed detectors and users via sites, and with exterior organization services via Web services.

  2. ADS-B and multilateration sensor fusion algorithm for air traffic control

    Science.gov (United States)

    Liang, Mengchen

    Air traffic is expected to increase rapidly in the next decade. But, the current Air Traffic Control (ATC) system does not meet the demand of the future safety and efficiency. The Next Generation Air Transportation System (NextGen) is a transformation program for the ATC system in the United States. The latest estimates by Federal Aviation Administration (FAA) show that by 2018 NextGen will reduce total delays in flight by 35 percent and provide 23 billion dollars in cumulative benefits. A satellite-based technology called the Automatic Dependent Surveillance-Broadcast (ADS-B) system is one of the most important elements in NextGen. FAA expects that ADS-B systems will be available in the National Airspace System (NAS) by 2020. However, an alternative surveillance system is needed due to vulnerabilities that exist in ADS-B systems. Multilateration has a high accuracy performance and is believed to be an ideal back-up strategy for ADS-B systems. Thus, in this study, we develop the ADS-B and multilateration sensor fusion algorithm for aircraft tracking applications in ATC. The algorithm contains a fault detection function for ADS-B information monitoring by using Trajectory Change Points reports from ADS-B and numerical vectors from a hybrid estimation algorithm. We consider two types of faults in the ADS-B measurement model to show that the algorithm is able to deal with the bad data from ADS-B systems and automatically select good data from multilateration systems. We apply fuzzy logic concepts and generate time variant parameters during the fusion process. The parameters play a role of weights for combining data from different sensors. The algorithm performance is validated through two aircraft tracking examples.

  3. TraPy-MAC: Traffic Priority Aware Medium Access Control Protocol for Wireless Body Area Network.

    Science.gov (United States)

    Ullah, Fasee; Abdullah, Abdul Hanan; Kaiwartya, Omprakash; Cao, Yue

    2017-06-01

    Recently, Wireless Body Area Network (WBAN) has witnessed significant attentions in research and product development due to the growing number of sensor-based applications in healthcare domain. Design of efficient and effective Medium Access Control (MAC) protocol is one of the fundamental research themes in WBAN. Static on-demand slot allocation to patient data is the main approach adopted in the design of MAC protocol in literature, without considering the type of patient data specifically the level of severity on patient data. This leads to the degradation of the performance of MAC protocols considering effectiveness and traffic adjustability in realistic medical environments. In this context, this paper proposes a Traffic Priority-Aware MAC (TraPy-MAC) protocol for WBAN. It classifies patient data into emergency and non-emergency categories based on the severity of patient data. The threshold value aided classification considers a number of parameters including type of sensor, body placement location, and data transmission time for allocating dedicated slots patient data. Emergency data are not required to carry out contention and slots are allocated by giving the due importance to threshold value of vital sign data. The contention for slots is made efficient in case of non-emergency data considering threshold value in slot allocation. Moreover, the slot allocation to emergency and non-emergency data are performed parallel resulting in performance gain in channel assignment. Two algorithms namely, Detection of Severity on Vital Sign data (DSVS), and ETS Slots allocation based on the Severity on Vital Sign (ETS-SVS) are developed for calculating threshold value and resolving the conflicts of channel assignment, respectively. Simulations are performed in ns2 and results are compared with the state-of-the-art MAC techniques. Analysis of results attests the benefit of TraPy-MAC in comparison with the state-of-the-art MAC in channel assignment in realistic medical

  4. A Randomised Controlled Trial to Determine the Effectiveness of an Early Psychological Intervention with Children Involved in Road Traffic Accidents

    Science.gov (United States)

    Stallard, Paul; Velleman, Richard; Salter, Emma; Howse, Imogen; Yule, William; Taylor, Gordon

    2006-01-01

    Objective: To determine whether an early intervention using a psychological debriefing format is effective in preventing psychological distress in child road traffic accident survivors. Design: Randomised controlled trial. Setting: Accident and Emergency Department, Royal United Hospital, Bath. Subjects: 158 children aged 7-18. Follow-up…

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

    NARCIS (Netherlands)

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

    2001-01-01

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

  6. Expertise development for a visual task: Eye movements, verbal reports, and spatial abilities in air traffic control

    NARCIS (Netherlands)

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

    2011-01-01

    Van Meeuwen, L. W., Jarodzka, H., Brand-Gruwel, S., Kirschner, P. A., De Bock, J. J. P. R., & Van Merriënboer, J. J. G. (2011, August). Expertise development for a visual task: Eye movements, verbal reports, and spatial abilities in air traffic control. Poster presented at the 16th European Conferen

  7. Determining treatment frequency for controlling weeds on traffic islands using chemical and non-chemical weed control

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Larsen, S.U.; Andreasen, Christian

    2013-01-01

    Many public authorities rely on the use of non-chemical weed control methods, due to stringent restrictions on herbicide use in urban areas. However, these methods usually require more repeated treatments than chemical weed management, resulting in increased costs of weed management. In order...... to investigate the efficacy of four non-chemical weed control methods and glyphosate treatment, experiments were carried out on traffic islands in the growing seasons 2005 and 2006. Three trial sites were each divided into six treatment areas, which were either treated with glyphosate, flame, steam, hot air....../flame, hot water or left untreated. The treatments were carried out at regular, predetermined intervals throughout the growing season in 2004, whereas in 2005 and 2006 how many treatments that were required to keep weed cover below a predetermined acceptance level of 2% were investigated. Percentage weed...

  8. An optimal general type-2 fuzzy controller for Urban Traffic Network

    DEFF Research Database (Denmark)

    Khooban, Mohammad Hassan; Vafamand, Navid; Liaghat, Alireza

    2017-01-01

    Urban traffic network model is illustrated by state-charts and object-diagram. However, they have limitations to show the behavioral perspective of the Traffic Information flow. Consequently, a state space model is used to calculate the half-value waiting time of vehicles. In this study...

  9. Traffic Signs Inventory System

    Directory of Open Access Journals (Sweden)

    J. Ružbarský

    2013-06-01

    Full Text Available The paper is focused on practical application of Cambridge Correlator. The goal is to propose a traffic signs inventory system by using excellent characteristics of correlator in the rapid optical correlation. The proposal of this inventory system includes obtaining of traffic signs to create the database either collecting the GPS coordinates. It is necessary to know the traffic signs position and also to document the entire surface route for later evaluation in offline mode.

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

    Science.gov (United States)

    Hermann, Robert

    1997-01-01

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

  11. 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.

  12. p53 as the main traffic controller of the cell signaling network.

    Science.gov (United States)

    Sebastian, Sinto; Azzariti, Amalia; Silvestris, Nicola; Porcelli, Letizia; Russo, Antonio; Paradiso, Angelo

    2010-06-01

    Among different pathological conditions that affect human beings, cancer has received a great deal of attention primarily because it leads to significant morbidity and mortality. This is essentially due to increasing world-wide incidence of this disease and the inability to discover the cause and molecular mechanisms by which normal human cells acquire the characteristics that define cancer cells. Since the discovery of p53 over a quarter of a century ago, it is now recognized that virtually all cell fate pathways of live cells and the decision to die are under the control of p53. Such extensive involvement indicates that p53 protein is acting as a major traffic controller in the cell signaling network. In cancer cells, many cell signaling pathways of normal human cells are rerouted towards immortalization and this is accomplished by the corruption of the main controllers of cell signaling pathways such as p53. This review highlights how p53 signaling activity is altered in cancer cells so that cells acquire the hallmarks of cancer including deregulated infinite self replicative potential.

  13. Lagrangian Multi-Class Traffic State Estimation

    OpenAIRE

    Yuan, Y.

    2013-01-01

    Road traffic is important to everybody in the world. People travel and commute everyday. For those who travel by cars (or other types of road vehicles), traffic congestion is a daily experience. One essential goal of traffic researchers is to reduce traffic congestion and to improve the whole traffic system operation and the environment. To achieve this goal, we have to first understand prevailing traffic situations, then perform pro-active traffic control and management. The estimation of tr...

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

    Science.gov (United States)

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

    2011-01-01

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

  15. Development of a Framework for the Evaluation of the Environmental Benefits of Controlled Traffic Farming

    Directory of Open Access Journals (Sweden)

    Abdul Mounem Mouazen

    2015-07-01

    Full Text Available Although controlled traffic farming (CTF is an environmentally friendly soil management system, no quantitative evaluation of environmental benefits is available. This paper aims at establishing a framework for quantitative evaluation of the environmental benefits of CTF, considering a list of environmental benefits, namely, reducing soil compaction, runoff/erosion, energy requirement and greenhouse gas emission (GHG, conserving organic matter, enhancing soil biodiversity and fertiliser use efficiency. Based on a comprehensive literature review and the European Commission Soil Framework Directive, the choice of and the weighting of the impact of each of the environmental benefits were made. The framework was validated using data from three selected farms. For Colworth farm (Unilever, UK, the framework predicted the largest overall environmental benefit of 59.3% of the theoretically maximum achievable benefits (100%, as compared to the other two farms in Scotland (52% and Australia (47.3%. This overall benefit could be broken down into: reducing soil compaction (24%, tillage energy requirement (10% and GHG emissions (3%, enhancing soil biodiversity (7% and erosion control (6%, conserving organic matter (6%, and improving fertiliser use efficiency (3%. Similar evaluation can be performed for any farm worldwide, providing that data on soil properties, topography, machinery, and weather are available.

  16. Performance Analysis of Prioritized Call Admission Control Schemes for Integrated Traffic in Wireless Network

    Directory of Open Access Journals (Sweden)

    Madhu Jain

    2013-01-01

    Full Text Available Wireless/mobile communication systems are becoming increasingly popular in recent years. As the wireless resources are scarce, it is important to allocate resources efficiently and carefully, in order to achieve maximum output. The call admission control schemes play a significant role in providing the desired quality of service (QoS by judiciously assigning the radio channels that are available in a micro cell. In this paper, we present two call admission control (CAC schemes for wireless mobile network, (i Prioritized call admission control (PCAC scheme (S1 and (ii Prioritized call admission control scheme with releasing function (S2. Both schemes support integrated traffic i.e. data and voice for both new and handoff attempts. Guard channel concept is used to give the priority to the handoff attempts. To admit more handoff attempts in the cellular system, buffering process is used for the handoff attempts. The concept of balking and reneging is also incorporated for both the schemes. The calls arrive in poisson fashion whereas channel holding time and cell residence times are exponentially distributed. The arrival rate of handoff attempts is computed by using iterative algorithm. Various performance metrics such as blocking probability of new call, blocking probability of handoff data/voice attempts, time out probability of handoff data/voice attempts, force termination probability of handoff data/voice attempts, waiting time of handoff data/voice attempts, carried load, etc. are determined. The sensitivity analysis has also been carried out to facilitate the insights of controllable parameters for real time systems

  17. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    CERN Document Server

    Davis, L C

    2015-01-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested stat...

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

    Science.gov (United States)

    Hockaday, Stephen; Kuhlenschmidt, Sharon (Editor)

    1991-01-01

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

  19. Costs of traffic injuries

    DEFF Research Database (Denmark)

    Kruse, Marie

    2015-01-01

    assessed using Danish national healthcare registers. Productivity costs were computed using duration analysis (Cox regression models). In a subanalysis, cost per severe traffic injury was computed for the 12 995 individuals that experienced a severe injury. RESULTS: The socioeconomic cost of a traffic......OBJECTIVE: The aim of this study was to analyse the socioeconomic costs of traffic injuries in Denmark, notably the healthcare costs and the productivity costs related to traffic injuries, in a bottom-up, register-based perspective. METHOD: Traffic injury victims were identified using national...... emergency room data and police records. Victims were matched with five controls per case by means of propensity score, nearest-neighbour matching. In the cohort, consisting of the 52 526 individuals that experienced a traffic injury in 2000 and 262 630 matched controls, attributable healthcare costs were...

  20. Application of graph theory concept for traffic light control at crossroad

    Science.gov (United States)

    Setiawan, Ekky Kurnia; Budayasa, I. Ketut

    2017-08-01

    Graph theory can be applied to solving systems of traffic lights at crossroads. By modeling the system of traffic flows into compatible graph, 2 vertices are represented as the flow connected by an edge if and only if the flow at the crossroads can be moved simultaneously without causing crashes. Influenced by the volume of traffic flows and the weights of the traffic flow, thus to be created a mathematical model in the form of the total time of all flows function by establishing required conditions, such as minimizing running time of each flow. The solution of this model is in the form of maximum total running time is not unique, since it is influenced by volume that is per hour based on the rush-hour at each crossroad.

  1. A Data-Driven Control Design Approach for Freeway Traffic Ramp Metering with Virtual Reference Feedback Tuning

    Directory of Open Access Journals (Sweden)

    Shangtai Jin

    2014-01-01

    Full Text Available ALINEA is a simple, efficient, and easily implemented ramp metering strategy. Virtual reference feedback tuning (VRFT is most suitable for many practical systems since it is a “one-shot” data-driven control design methodology. This paper presents an application of VRFT to a ramp metering problem of freeway traffic system. When there is not enough prior knowledge of the controlled system to select a proper parameter of ALINEA, the VRFT approach is used to optimize the ALINEA's parameter by only using a batch of input and output data collected from the freeway traffic system. The extensive simulations are built on both the macroscopic MATLAB platform and the microscopic PARAMICS platform to show the effectiveness and applicability of the proposed data-driven controller tuning approach.

  2. Effect of adaptive cruise control systems on mixed traffic flow near an on-ramp

    Science.gov (United States)

    Davis, L. C.

    2007-06-01

    Mixed traffic flow consisting of vehicles equipped with adaptive cruise control (ACC) and manually driven vehicles is analyzed using car-following simulations. Simulations of merging from an on-ramp onto a freeway reported in the literature have not thus far demonstrated a substantial positive impact of ACC. In this paper cooperative merging for ACC vehicles is proposed to improve throughput and increase distance traveled in a fixed time. In such a system an ACC vehicle senses not only the preceding vehicle in the same lane but also the vehicle immediately in front in the other lane. Prior to reaching the merge region, the ACC vehicle adjusts its velocity to ensure that a safe gap for merging is obtained. If on-ramp demand is moderate, cooperative merging produces significant improvement in throughput (20%) and increases up to 3.6 km in distance traveled in 600 s for 50% ACC mixed flow relative to the flow of all-manual vehicles. For large demand, it is shown that autonomous merging with cooperation in the flow of all ACC vehicles leads to throughput limited only by the downstream capacity, which is determined by speed limit and headway time.

  3. Effect of adaptive cruise control systems on mixed traffic flow near an on-ramp

    CERN Document Server

    Davis, L C

    2005-01-01

    Mixed traffic flow consisting of vehicles equipped with adaptive cruise control (ACC) and manually driven vehicles is analyzed using car-following simulations. Unlike simulations that show suppression of jams due to increased string stability, simulations of merging from an on-ramp onto a freeway have not thus far demonstrated a substantial positive impact of ACC. In this paper cooperative merging is proposed to increase throughput and increase distance traveled in a fixed time (reduce travel times). In such a system an ACC vehicle senses not only the preceding vehicle in the same lane but also the vehicle immediately in front in the opposite lane. Prior to reaching the merge region, the ACC vehicle adjusts its velocity to ensure that a safe gap for merging is obtained. If on-ramp demand is moderate, partial implementation of cooperative merging where only main line ACC vehicles react to an on-ramp vehicle is effective. Significant improvement in throughput (18%) and increases up to 3 km in distance traveled ...

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

    Science.gov (United States)

    Lozito, Sandy; Mcgann, Alison; Corker, Kevin

    1993-01-01

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

  5. 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.

  6. Design Of Interval Type-Ii Fuzzy Logic Traffic Controller For Multilane Intersections With Emergency Vehicle Priority System Using Matlab Simulation

    Directory of Open Access Journals (Sweden)

    Mohit Jha,

    2014-06-01

    Full Text Available During the past several years fuzzy logic control has swell from one of the major active and profitable areas for research in the application of fuzzy set, especially in the zone of industrial process which do not lead themselves to control conventional methods because of lack of quantitative data regarding the input-output relations. Fuzzy control is based on fuzzy logic- a logical system which is much closer in spirit to human thinking and natural language than conventional logical systems. The fuzzy logic controller based on fuzzy logic provides a means of converting a linguistic control strategy based on expert knowledge into an automatic control strategy. As in Fuzzy logic traffic controller, the need arises for simulating and optimizing traffic control algorithms to better accommodate this increasing demand. Fuzzy optimization deals with finding the values of input parameters of a complex simulated system which result in desired output. This paper presents a MATLAB simulation of fuzzy logic traffic interval type II controller for controlling flow of traffic in multilane paths. This controller is based on the waiting time and queue length of vehicles at present green phase and vehicles queue lengths at the other lanes. The controller controls the traffic light timings and phase difference to ascertain sebaceous flow of traffic with least waiting time and queue length. In this paper, the multilane model used consists of two alleyways in each approach.

  7. 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.

  8. Complaints of Poor Sleep and Risk of Traffic Accidents: A Population-Based Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Pierre Philip

    Full Text Available This study aimed to determine the sleepiness-related factors associated with road traffic accidents.A population based case-control study was conducted in 2 French agglomerations. 272 road accident cases hospitalized in emergency units and 272 control drivers matched by time of day and randomly stopped by police forces were included in the study. Odds ratios were calculated for the risk of road traffic accidents.As expected, the main predictive factor for road traffic accidents was having a sleep episode at the wheel just before the accident (OR 9.97, CI 95%: 1.57-63.50, p<0.05. The increased risk of traffic accidents was 3.35 times higher in subjects who reported very poor quality sleep during the last 3 months (CI 95%: 1.30-8.63, p<0.05, 1.69 times higher in subjects reporting sleeping 6 hours or fewer per night during the last 3 months (CI 95%: 1.00-2.85, p<0.05, 2.02 times higher in subjects reporting symptoms of anxiety or nervousness in the previous day (CI 95%: 1.03-3.97, p<0.05, and 3.29 times higher in subjects reporting taking more than 2 medications in the last 24 h (CI 95%: 1.14-9.44, p<0.05. Chronic daytime sleepiness measured by the Epworth Sleepiness Scale, expressed heavy snoring and nocturnal leg movements did not explain traffic accidents.Physicians should be attentive to complaints of poor sleep quality and quantity, symptoms of anxiety-nervousness and/or drug consumption in regular car drivers.

  9. Fastlane: Traffic flow modeling and multi-class dynamic traffic management

    NARCIS (Netherlands)

    Schreiter, T.; Van Wageningen-Kessels, F.L.M.; Yuan, Y.; Van Lint, J.W.C.; Hoogendoorn, S.P.

    2012-01-01

    Dynamic Traffic Management (DTM) aims to improve traffic conditions. DTM usually consists of two steps: first the current traffic is estimated, then appropriate control actions are determined based on that estimate. In order to estimate and control the traffic, a suitable traffic flow model that

  10. Fastlane: Traffic flow modeling and multi-class dynamic traffic management

    NARCIS (Netherlands)

    Schreiter, T.; Van Wageningen-Kessels, F.L.M.; Yuan, Y.; Van Lint, J.W.C.; Hoogendoorn, S.P.

    2012-01-01

    Dynamic Traffic Management (DTM) aims to improve traffic conditions. DTM usually consists of two steps: first the current traffic is estimated, then appropriate control actions are determined based on that estimate. In order to estimate and control the traffic, a suitable traffic flow model that rep

  11. Feeding patterns and performance of cows in controlled cow traffic in automatic milking systems.

    Science.gov (United States)

    Melin, M; Svennersten-Sjaunja, K; Wiktorsson, H

    2005-11-01

    Two groups of dairy cows monitored from 3 to 19 wk postpartum were subjected to 2 different cow traffic routines in an automatic milking system with control gates and an open waiting area. Using different time settings in the control gates, the groups of cows were separated by average milking frequency; cows in the high milking frequency routine had a minimum of 4 h between milkings (MF(4)) and were milked 3.2 +/- 0.1 times daily, whereas cows in the low milking frequency routine had at least 8 h between milkings (MF8) and were milked 2.1 +/- 0.1 times daily. Cows in the 2 groups were switched to the opposite milking frequency control for wk 18 and 19. The increased milking frequency resulted in a higher milk yield of about 9% through 16 wk of early lactation Although the higher milk yield was not significant when measured as energy-corrected milk, significant interactions of milking frequency and study period for milk yield and energy-corrected milk yield were consistent with a yield response when cows were milked more frequently. Meal criteria estimated for each individual cow were used to group feeding visits into meals. During MF4, cows fed in fewer meals per day and had longer meals than during MF8. The control gates were used efficiently, with only a few passages not resulting in actual meals. Although the voluntary meal intervals seemed to be short, the average milking frequency was far below that theoretically possible. This was explained by individual differences in milking frequency and long intervals from when a cow was redirected in a control gate until it arrived in the milking unit. A wide individual range in the voluntary interval between the first and the second meal in the milking cycle suggests that fixed time limits for control gates set on group level have no justifiable biological basis. It was also concluded that primiparous cows were well adapted to the automatic milking system after 2 wk in the barn.

  12. Alcohol, psychoactive substances and non-fatal road traffic accidents - a case-control study

    Directory of Open Access Journals (Sweden)

    Bogstrand Stig

    2012-09-01

    Full Text Available Abstract Background The prevalence of alcohol and other psychoactive substances is high in biological specimens from injured drivers, while the prevalence of these psychoactive substances in samples from drivers in normal traffic is low. The aim of this study was to compare the prevalence of alcohol and psychoactive substances in drivers admitted to hospital for treatment of injuries after road traffic accidents with that in drivers in normal traffic, and calculate risk estimates for the substances, and combinations of substances found in both groups. Methods Injured drivers were recruited in the hospital emergency department and drivers in normal conditions were taken from the hospital catchment area in roadside tests of moving traffic. Substances found in blood samples from injured drivers and oral fluid samples from drivers in moving traffic were compared using equivalent cut off concentrations, and risk estimates were calculated using logistic regression analyses. Results In 21.9% of the injured drivers, substances were found: most commonly alcohol (11.5% and stimulants eg. cocaine or amphetamines (9.4%. This compares to 3.2% of drivers in normal traffic where the most commonly found substances were z-hypnotics (0.9% and benzodiazepines (0.8%. The greatest increase in risk of being injured was for alcohol combined with any other substance (OR: 231.9, 95% CI: 33.3- 1615.4, p  Conclusion The prevalence of psychoactive substances was higher among injured drivers than drivers in normal moving traffic. The risk of accident is greatly increased among drivers who tested positive for alcohol, in particular, those who had also ingested one or more psychoactive substances. Various preventive measures should be considered to curb the prevalence of driving under the influence of psychoactive substances as these drivers constitute a significant risk for other road users as well as themselves.

  13. Perspective on traffic control: Aspects of freeway control, intersection control and the control of transit flow in the Netherlands

    NARCIS (Netherlands)

    Hakkesteegt, P.

    1988-01-01

    Paper presented at the 1988 TRB Annual Meeting, Washington D.C., USA. The first part of this paper deals with the control and signalling system for motorways, directed to a more efficient use of available road capacity and to the improvement of road safety. The second part gives some insight into th

  14. 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...

  15. 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.

  16. A control method applied to mixed traffic flow for the coupled-map car-following model

    Science.gov (United States)

    Cheng, Rong-Jun; Han, Xiang-Lin; Lo, Siu-Ming; Ge, Hong-Xia

    2014-03-01

    In light of previous work [Phys. Rev. E 60 4000 (1999)], a modified coupled-map car-following model is proposed by considering the headways of two successive vehicles in front of a considered vehicle described by the optimal velocity function. The non-jam conditions are given on the basis of control theory. Through simulation, we find that our model can exhibit a better effect as p = 0.65, which is a parameter in the optimal velocity function. The control scheme, which was proposed by Zhao and Gao, is introduced into the modified model and the feedback gain range is determined. In addition, a modified control method is applied to a mixed traffic system that consists of two types of vehicle. The range of gains is also obtained by theoretical analysis. Comparisons between our method and that of Zhao and Gao are carried out, and the corresponding numerical simulation results demonstrate that the temporal behavior of traffic flow obtained using our method is better than that proposed by Zhao and Gao in mixed traffic systems.

  17. 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.

  18. Control of ribosome traffic by position-dependent choice of synonymous codons

    DEFF Research Database (Denmark)

    Mitarai, Namiko; Pedersen, Steen

    2013-01-01

    Messenger RNA (mRNA) encodes a sequence of amino acids by using codons. For most amino acids, there are multiple synonymous codons that can encode the amino acid. The translation speed can vary from one codon to another, thus there is room for changing the ribosome speed while keeping the amino...... acid sequence and hence the resulting protein. Recently, it has been noticed that the choice of the synonymous codon, via the resulting distribution of slow- and fast-translated codons, affects not only on the average speed of one ribosome translating the mRNA but also might have an effect on nearby...... ribosomes by affecting the appearance of 'traffic jams' where multiple ribosomes collide and form queues. To test this 'context effect' further, we here investigate the effect of the sequence of synonymous codons on the ribosome traffic by using a ribosome traffic model with codon-dependent rates, estimated...

  19. Hearing loss in civilian airline and helicopter pilots compared to air traffic control personnel.

    Science.gov (United States)

    Wagstaff, Anthony S; Arva, Per

    2009-10-01

    In order to investigate possible hearing loss as a consequence of aviation noise, a comparative analysis of audiometric data from Norwegian Air Traffic Control (ATC) personnel, airline (fixed-wing) pilots, and helicopter pilots was performed. The results may be of use in giving advice regarding preventive measures. Male ATC, airline, and helicopter pilots were selected randomly from the Civil Aviation Authority (CAA) medical files. There were 182 subjects included in the study: 50, 81, and 51 subjects for ATC, helicopter, and airline pilots, respectively. Two audiograms with a 2-3-yr interval were analyzed for each individual. Age correction was performed using data from ISO 7129. Threshold changes per year for the frequencies 3, 4, and 6 kHz were examined in particular after age correction. For all three groups, mean hearing threshold levels were above (worse than) ISO 7129 predictions for most frequencies. As expected, hearing thresholds increased with age in the group as a whole. Looking at the 3-, 4-, and 6-kHz frequencies in particular, all groups had small but highly significant increases in hearing thresholds at 4 kHz between the first and second audiogram. The mean hearing thresholds for this group of aviation personnel are higher than International Standard ISO-7129 would predict according to age. Highly significant changes in hearing threshold after age correction, indicating possible noise-induced hearing loss, were found in all groups at 4 kHz. The fact that helicopter pilots had similar hearing loss to their other aviation colleagues indicates that current hearing protection for these pilots is effective in counteracting the increased noise levels in helicopters.

  20. Multi-Robot Path-Planning Problem for a Heavy Traffic Control Application: A Survey

    Directory of Open Access Journals (Sweden)

    Ebtehal Turki Saho Alotaibi

    2016-06-01

    Full Text Available This survey looked at the methods used to solve multi-autonomous vehicle path-planning for an application of heavy traffic control in cities. Formally, the problem consisted of a graph and a set of robots. Each robot has to reach its destination in the minimum time and number of movements, considering the obstacles and other robots’ paths, hence, the problem is NP-hard. The study found that decoupled centralised approaches are the most relevant approaches for an autonomous vehicle path-planning problem for three reasons: (1 a city is a large environment and coupled centralised approaches scale weakly, (2 the overhead of a coupled decentralised approach to achieve the global optimal will affect the time and memory of the other robots, which is not important in a city configuration and (3 the coupled approaches suppose that the number of robots is defined before they start to find the paths and resolve collisions, while in a city, any car can start at any time and hence, each car should work individually and resolve collisions as they arise. In addition, the study reviewed four decoupled centralised techniques to solve the problem: multi-robot path-planning rapidly exploring random tree (MRRRT, push and swap (PAS, push and rotate (PAR and the Bibox algorithm. The experiments showed that MRRRT is the best for exploring any search space and optimizing the solution. On the other hand, PAS, PAR and Bibox are better in terms of providing a complete solution for the problem and resolving collisions in significantly much less time, the analysis, however, shows that a wider class of solvable instances are excluded from PAS and PAR domain. In addition, Bibox solves a smaller class than the class solved by PAS and PAR in less time, in the worst case, and with a shorter path than PAS and PAR.

  1. Initial afferent lymphatic vessels controlling outbound leukocyte traffic from skin to lymph nodes.

    Directory of Open Access Journals (Sweden)

    Ignacio eMelero

    2013-12-01

    Full Text Available Tissue drains fluid and macromolecules through lymphatic vessels, which are lined by a specialized endothelium that expresses peculiar differentiation proteins, not found in blood vessels (i.e: LYVE-1, Podoplanin, PROX-1 and VEGFR-3. Lymphatic capillaries are characteristically devoid of a continuous basal membrane and are anchored to the ECM by elastic fibers that act as pulling ropes which open the vessel to avoid oedema if tissue volume increases, as it occurs upon inflammation. Lymphatic vessels are also crucial for the transit of T lymphocytes and antigen presenting cells from tissue to draining lymph nodes. Importantly, cell traffic control across lymphatic endothelium is differently regulated under resting and inflammatory conditions. Under steady-state non-inflammatory conditions, leukocytes enter into the lymphatic capillaries through basal membrane gaps (portals. This entrance is integrin-independent and seems to be mainly guided by CCL21 chemokine gradients acting on leukocytes expressing CCR7. In contrast, inflammatory processes in lymphatic capillaries involve a plethora of cytokines, chemokines, leukocyte integrins and other adhesion molecules. Importantly, under inflammation a role for integrins and their ligands becomes apparent and, as a consequence, the number of leukocytes entering the lymphatic capillaries multiplies several-fold. Enhancing transmigration of dendritic cells en route to lymph nodes is conceivably useful for vaccination and cancer immunotherapy, whereas interference with such key mechanisms may ameliorate autoimmunity or excessive inflammation. Recent findings illustrate how, transient cell-to-cell interactions between lymphatic endothelial cells and leukocytes contribute to shape the subsequent behaviour of leukocytes and condition the lymphatic vessel for subsequent trans-migratory events.

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

    Science.gov (United States)

    Bie, Yiming; Wang, Yinhai

    2017-01-01

    To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios. PMID:28531198

  3. Altered Traffic of Cardiolipin during Apoptosis: Exposure on the Cell Surface as a Trigger for “Antiphospholipid Antibodies”

    Directory of Open Access Journals (Sweden)

    Valeria Manganelli

    2015-01-01

    Full Text Available Apoptosis has been reported to induce changes in the remodelling of membrane lipids; after death receptor engagement, specific changes of lipid composition occur not only at the plasma membrane, but also in intracellular membranes. This paper focuses on one important aspect of apoptotic changes in cellular lipids, namely, the redistribution of the mitochondria-specific phospholipid, cardiolipin (CL. CL predominantly resides in the inner mitochondrial membrane, even if the rapid remodelling of its acyl chains and the subsequent degradation occur in other membrane organelles. After death receptor stimulation, CL appears to concentrate into mitochondrial “raft-like” microdomains at contact sites between inner and outer mitochondrial membranes, leading to local oligomerization of proapoptotic proteins, including Bid. Clustering of Bid in CL-enriched contacts sites is interconnected with pathways of CL remodelling that intersect membrane traffic routes dependent upon actin. In addition, CL association with cytoskeleton protein vimentin was observed. Such novel association also indicated that CL molecules may be expressed at the cell surface following apoptotic stimuli. This observation adds a novel implication of biomedical relevance. The association of CL with vimentin at the cell surface may represent a “new” target antigen in the context of the apoptotic origin of anti-vimentin/CL autoantibodies in Antiphospholipid Syndrome.

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

    Science.gov (United States)

    Raffard, Robin L.

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

  5. Surface gradients under electrochemical control

    NARCIS (Netherlands)

    Krabbenborg, Sven Olle

    2014-01-01

    Gradients are systems in which the physicochemical properties of a solution and/or surface change gradually in space and/or time. They are used for a myriad of technological and biological applications, for example for high-throughput screening, or for the investigation of biological systems. The de

  6. An ultra low-power and traffic-adaptive medium access control protocol for wireless body area network.

    Science.gov (United States)

    Ullah, Sana; Kwak, Kyung Sup

    2012-06-01

    Wireless Body Area Network (WBAN) consists of low-power, miniaturized, and autonomous wireless sensor nodes that enable physicians to remotely monitor vital signs of patients and provide real-time feedback with medical diagnosis and consultations. It is the most reliable and cheaper way to take care of patients suffering from chronic diseases such as asthma, diabetes and cardiovascular diseases. Some of the most important attributes of WBAN is low-power consumption and delay. This can be achieved by introducing flexible duty cycling techniques on the energy constraint sensor nodes. Stated otherwise, low duty cycle nodes should not receive frequent synchronization and control packets if they have no data to send/receive. In this paper, we introduce a Traffic-adaptive MAC protocol (TaMAC) by taking into account the traffic information of the sensor nodes. The protocol dynamically adjusts the duty cycle of the sensor nodes according to their traffic-patterns, thus solving the idle listening and overhearing problems. The traffic-patterns of all sensor nodes are organized and maintained by the coordinator. The TaMAC protocol is supported by a wakeup radio that is used to accommodate emergency and on-demand events in a reliable manner. The wakeup radio uses a separate control channel along with the data channel and therefore it has considerably low power consumption requirements. Analytical expressions are derived to analyze and compare the performance of the TaMAC protocol with the well-known beacon-enabled IEEE 802.15.4 MAC, WiseMAC, and SMAC protocols. The analytical derivations are further validated by simulation results. It is shown that the TaMAC protocol outperforms all other protocols in terms of power consumption and delay.

  7. Analysis of Traffic Behavior Control Object and Its Characteristics%交通行为控制的对象及其特性分析

    Institute of Scientific and Technical Information of China (English)

    石建军; 李晓莉

    2011-01-01

    本文引入了交通行为控制的概念,明确其控制对象是交通中的人,以同交通系统控制区分开来.首先,借鉴行为科学、管理学和经济学中对人的研究方法,本文提出了以"交通人"的概念来承载交通行为控制对象的共性,明确了"交通人"的内涵与外延及其承载的有关人的性质的假设,并简单阐述了各项假设的意义;其次,通过探讨"交通人"与出行者的区别和联系,明确了"交通人"存在的时空范围;最后详细阐述了"交通人"存在的三个阶段:出行准备、出行中、交通行为回报阶段,提出交通行为意识、交通行为规范和交通行为回报对出行中的交通行为倾向性有重大的影响作用.%In order to differentiate from traffic system control, a concept of traffic behavior control , whose controlling object is person, was introduced in this paper. First,human research method in behavioral science, management and economics were used for reference, and the concept of “traffic man” was proposed to carry the common characteristics of the objects of traffic behavior control, and the “traffic man”possessed connotation , extension, and several assumptions of the human natures and also their implications were raised. Second, the spatial and temporal existence sphere of the “traffic man” was explained through discussion on the assumption distinctions and similarities between the “traffic man” and trip maker. Finally, three stages of the “traffic man” were elaborated: preparations for trip, in trip, traffic behavior return.It suggested that the traffic behavior consciousness, traffic behavior norms and traffic behavior return influenced the tendency of traffic behavior greatly

  8. Effects of emotions on optimism bias and illusion of control in traffic.

    NARCIS (Netherlands)

    Mesken, J. Hagenzieker, M.P. & Rothengatter, T.

    2005-01-01

    Anger is related to aggression in traffic, which in turn may lead to risky driving (e.g. Lajunen, Parker & Stradling, 1998; Deffenbacher, Huff, Lynch, Oetting & Salvatore, 2000; Parker, Lajunen & Summa!a, 2002; Deffenbacher, Lynch, Filetti, Dahlen & Oetting, 2003). Anger may also lead directly to

  9. Vehicle-class Specific Route-guidance of Freeway Traffic by Model-predictive Control

    NARCIS (Netherlands)

    Schreiter, T.; Landman, R.L.; Van Lint, J.W.C.; Hegyi, A.; Hoogendoorn, S.P.

    2012-01-01

    Few Active Traffic Management measures proposed in the past consider the distinction of different vehicle classes. Examples of vehicle-class specific measures are truck lanes and high-occupancy/toll (HOT) lanes. We propose that the distinction of different vehicle classes, with different flow

  10. Study on Control Algorithm of Traffic Signals at Intersections Based on Optimizing Sub-area Traffic Flows%基于子区域交通流优化的交叉口信号控制研究

    Institute of Scientific and Technical Information of China (English)

    臧利林; 朱文兴

    2012-01-01

    In order to reduce average delay time of passing vehicles and improve urban area traffic efficiency, considering actual geographical characteristics of intersections and sub-area traffic data, a control model for traffic signals at intersections was built based on optimizing sub-area traffic flows, and genetic algorithm was used to find out the optimal solution of the model. With traffic signals coordination of neighboring intersections considered, vehicle minimal delay time was chosen as the optimization object in the model. HCM2000 was adopted to calculate vehicle delay time and Robertson model was embedded in the optimization procedure, which ensured the proposed model to be feasible and effective. VC+ 3- 6. 0 software was applied to programm and calculate an optimal control plan for traffic signals at intersections. Finally, simulation by CORSIM was implemented to verifythe validity of the control plan. The results show that the proposed model can obtain better traffic efficiency than the coordination control method based on existing common cycle, and provides a new signal control idea at intersections for urban traffic.%为了减少车辆平均延误时间,提高城市区域交通通行效率,结合实际交叉口地理特征和区域交通流数据,建立了一种基于子区域交通流优化的交叉口信号控制模型,并应用遗传算法获得模型的最优解。在模型中,考虑相邻交叉口信号之间的协调,以车辆平均延误时间最小为优化目标,采用HCM2000延误计算方法,并在优化过程中嵌入Robertson车队离散模型,保证提出模型的可行性和有效性。在VC++6.0中编写程序,获得交叉口信号最优控制方案,最后通过CORSIM仿真证明该控制方案的优劣。结果表明:与现有基于共同周期的协调控制方法相比,所提出的模型能够获得更优的交通效益,为区域交通信号控制提供了一种新的思路。

  11. Increased risk of traffic accidents in subjects with latent toxoplasmosis: a retrospective case-control study

    Directory of Open Access Journals (Sweden)

    Malý Marek

    2002-07-01

    Full Text Available Abstract Background The parasite Toxoplasma gondii infects 30–60% of humans worldwide. Latent toxoplasmosis, i.e., the life-long presence of Toxoplasma cysts in neural and muscular tissues, leads to prolongation of reaction times in infected subjects. It is not known, however, whether the changes observed in the laboratory influence the performance of subjects in real-life situations. Methods The seroprevalence of latent toxoplasmosis in subjects involved in traffic accidents (N = 146 and in the general population living in the same area (N = 446 was compared by a Mantel-Haenszel test for age-stratified data. Correlation between relative risk of traffic accidents and level of anti-Toxoplasma antibody titre was evaluated with the Cochran-Armitage test for trends. Results A higher seroprevalence was found in the traffic accident set than in the general population (Chi2MH = 21.45, p 95= 1.76–4.01 times higher risk of an accident than the toxoplasmosis-negative subjects. The OR significantly increased with level of anti-Toxoplasma antibody titre (p 95 = 1.14–3.03 for the 99 subjects with low antibody titres (8 and 16, higher (OR = 4.78, C.I.95 = 2.39–9.59 for the 37 subjects with moderate titres (32 and 64, and very high (OR = 16.03, C.I.95 = 1.89–135.66 for the 6 subjects with titres higher than 64. Conclusion The subjects with latent toxoplasmosis have significantly increased risk of traffic accidents than the noninfected subjects. Relative risk of traffic accidents decreases with the duration of infection. These results suggest that 'asymptomatic' acquired toxoplasmosis might in fact represent a serious and highly underestimated public health problem, as well as an economic problem.

  12. Admission Control of Integrated Voice and Data CDMA/TDD System Considering Asymmetric Traffic and Power Limit

    Institute of Scientific and Technical Information of China (English)

    CAOYanbo; ZHOUBin; LIChengshu

    2004-01-01

    In this paper, we research an admission control scheme of integrated voice and data CDMA/TDD (Code division multiple access/Time division duplex) system considering asymmetric traffic and power limit. A new user can access the system only if the outage probabilities it experiences on the uplink and downlink time slots are below a threshold value. Based on the power limit the results show the voice and data blocking probabilities under different cell coverage~ arrival rates and various uplink/downlink time slot allocation patterns. Furthermore, multicode and multislot schemes are also evaluated under the presented admission control scheme.

  13. Stochastic modeling of the dynamics of incident-induced lane traffic states for incident-responsive local ramp control

    Science.gov (United States)

    Sheu, Jiuh-Biing

    2007-12-01

    Incident-induced traffic congestion has been recognized as a critical issue to solve in the development of advanced freeway incident management systems. This paper investigates the applicability of a stochastic optimal control approach to real-time incident-responsive local ramp control on freeways. The architecture of the proposed ramp control system embeds two primary functions including (1) real-time estimation of incident-induced lane traffic states and (2) dynamic prediction of ramp-metering rates in response to the changes of incident impacts. To accomplish the above two goals, a discrete-time nonlinear stochastic optimal control model is proposed, followed by the development of a recursive prediction algorithm. Based on the simulation data, the numerical results of model tests indicate that the proposed method permits relieving incident impacts particularly under low-volume and medium-volume conditions, relative to high-volume lane-blocking conditions. Particularly, the incident-induced queue lengths can be improved by 50.1% and 67.9%, compared to the existing ramp control and control-free strategies, respectively.

  14. 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.

  15. 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.

  16. Evaluation Of Onion Production On Sandy Soils By Use Of Reduced Tillage And Controlled Traffic Farming With Wide Span Tractors

    Directory of Open Access Journals (Sweden)

    Pedersen Hans Henrik

    2015-09-01

    Full Text Available Growing of vegetables is often characterised by intensive field traffic and use of heavy machines. By implementing controlled traffic farming (CTF, compaction of the growth zone can be avoided. An experiment was established in an onion field on a coarse sandy loam. Treatments were applied in the field that for five years had been managed by seasonal CTF (SCTF, where harvest is performed by random traffic due to lack of suitable harvest machines. The main treatment was compaction with a fully loaded potato harvester. The split treatment in the crossed split plot design was mechanical loosening. Bulk density, macroporosity, penetration resistance, water retention characteristics and yield were measured. Mechanical loosening caused improvements in the physical soil measurements and more roots were found in the upper soil layers. The highest yield was however found in the CTF simulation plots (19% higher than in the SCTF simulated plots. Using wide span tractors as a harvest platform will enable CTF in vegetable production. Avoidance of compaction will enable reduced tillage intensity and productivity can be improved both through higher yield of the area that is cropped and by a larger percentage of fields can be cropped area as less area will be needed for tracks.

  17. 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…

  18. Traffic flow models and impact of combined lane change and speed limit control on environment in case of high truck traffic volumes. A Research Report from the National Center for Sustainable Transportation.

    NARCIS (Netherlands)

    Ioannou, P. Zhang, Y. & Zhao, Y.

    2017-01-01

    This report presents the work performed in collaboration with University of California, Riverside (UCR) as part of a project to University of California, Davis funded by the California Energy Commission (CEC). The aim of the project is to research intelligent traffic control strategies, which will

  19. Traffic Network Computer Analysis Method Under trffic Management and Control%一种交通网络的计算机表示方法

    Institute of Scientific and Technical Information of China (English)

    彭培培; 黄卫; 陆建

    2001-01-01

    In this paper,densed chart is used to analyze traffic network anda method is developed to automatically identify the direction of flow in traffic network by compute.Then,traffic management and control can be well handled,for example sole-direction traffic.Consequently, a traffic network computer analysis method under traffic management and control is developed, and it can increase the accuracy of traffic planning.%文章采用密集表方法来表示交通管制措施条件下的交通网络,并且使用一种自动辨识网络中的交通流的流向方法,然后对主要的交通管制措施进行表示,如单向交通等,从而初步形成一种交通管制条件下的网络计算机分析方法,这种分析方法可以提高交通规划的精确性。

  20. Speed and path control for conflict-free flight in high air traffic demand in terminal airspace

    Science.gov (United States)

    Rezaei, Ali

    To accommodate the growing air traffic demand, flights will need to be planned and navigated with a much higher level of precision than today's aircraft flight path. The Next Generation Air Transportation System (NextGen) stands to benefit significantly in safety and efficiency from such movement of aircraft along precisely defined paths. Air Traffic Operations (ATO) relying on such precision--the Precision Air Traffic Operations or PATO--are the foundation of high throughput capacity envisioned for the future airports. In PATO, the preferred method is to manage the air traffic by assigning a speed profile to each aircraft in a given fleet in a given airspace (in practice known as (speed control). In this research, an algorithm has been developed, set in the context of a Hybrid Control System (HCS) model, that determines whether a speed control solution exists for a given fleet of aircraft in a given airspace and if so, computes this solution as a collective speed profile that assures separation if executed without deviation. Uncertainties such as weather are not considered but the algorithm can be modified to include uncertainties. The algorithm first computes all feasible sequences (i.e., all sequences that allow the given fleet of aircraft to reach destinations without violating the FAA's separation requirement) by looking at all pairs of aircraft. Then, the most likely sequence is determined and the speed control solution is constructed by a backward trajectory generation, starting with the aircraft last out and proceeds to the first out. This computation can be done for different sequences in parallel which helps to reduce the computation time. If such a solution does not exist, then the algorithm calculates a minimal path modification (known as path control) that will allow separation-compliance speed control. We will also prove that the algorithm will modify the path without creating a new separation violation. The new path will be generated by adding new

  1. Use of FBG sensors for bridge structural monitoring and traffic control

    Science.gov (United States)

    Caponero, Michele A.; Colonna, Danilo; Gruppi, Marco; Pallotta, Massimo; Salvadori, Robert

    2004-06-01

    This paper describes an application of Fiber Bragg Grating sensors devoted to both health monitoring of road bridge structures and traffic load monitoring. The ultimate aim of the application is the remote continuous monitoring of the structures, with real time acquisition of the dynamic and quasi-static deformations inferred by both the road traffic and the daily and seasonal thermal variations. A Fiber Bragg Grating network composed of 24 sensors has been installed on the bridge on the Po river of the 'A21 Torino Brescia' Italian Highway. The bridge is a concrete structure, and sensors are applied on various rebar components. The sensors were installed directly on the rebars, adopting a special technique specifically developed for permanent concrete embedding. An extensive data acquisition program is in progress with the aim of both health monitoring and in transit lorry weighing. Results are discussed and planned future work is presented.

  2. 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.

  3. 基于WSN的路口交通信号控制设计%Intelligent Traffic Control Design Based on Wireless Sensors Network

    Institute of Scientific and Technical Information of China (English)

    任晓莉

    2011-01-01

    为了缓解道路交通拥堵,减少车辆延误,节约交通能源,控制车辆在交叉路口顺畅通行,提出了一种基于无线传感器网的智能交通信号控制设计.利用传感器节点收集的交通信息,结合多agent的协同方法,控制中心进行综合处理,在不同的时段采用不同的路口控制模式,调整各交叉路口的绿信比,协调干线各路口周期的确定和各路口之间的相位差,自适应地控制车辆通行时间.实现了交通信号灯的无线智能控制,从而提高车辆通行效率.实现交通信号控制的智能化、网络化.%In order to reduce traffic jam, decrease vehicle delay, economize traffic energy resources, control the vehicles to pass the crossing smoothly, the intelligent traffic signal control design based on wireless sensors network is proposed. Capturing the traffic information by the sensor nodes, combing the cooperation method of multi-agent, adopting the crossing control modes in the periods of time, the control terminal may control the vehicles' passing time adaptively. So the wireless intelligent control of the traffic signal lamp is realized, by which the vehicles' traffic efficiency is improved, and the intelligent and netting traffic control function is implemented.

  4. Hopf bifurcation and uncontrolled stochastic traffic-induced chaos in an RED-AQM congestion control system

    Science.gov (United States)

    Wang, Jun-Song; Yuan, Rui-Xi; Gao, Zhi-Wei; Wang, De-Jin

    2011-09-01

    We study the Hopf bifurcation and the chaos phenomena in a random early detection-based active queue management (RED-AQM) congestion control system with a communication delay. We prove that there is a critical value of the communication delay for the stability of the RED-AQM control system. Furthermore, we show that the system will lose its stability and Hopf bifurcations will occur when the delay exceeds the critical value. When the delay is close to its critical value, we demonstrate that typical chaos patterns may be induced by the uncontrolled stochastic traffic in the RED-AQM control system even if the system is still stable, which reveals a new route to the chaos besides the bifurcation in the network congestion control system. Numerical simulations are given to illustrate the theoretical results.

  5. Hopf bifurcation and uncontrolled stochastic traffic-induced chaos in an RED-AQM congestion control system

    Institute of Scientific and Technical Information of China (English)

    Wang Jun-Song; Yuan Rui-Xi; Gao Zhi-Wei; Wang De-Jin

    2011-01-01

    We study the Hopf bifurcation and the chaos phenomena in a random early detection-based active queue management (RED-AQM) congestion control system with a communication delay. We prove that there is a critical value of the communication delay for the stability of the RED-AQM control system. Furthermore,we show that the system will lose its stability and Hopf bifurcations will occur when the delay exceeds the critical value. When the delay is close to its critical value,we demonstrate that typical chaos patterns may be induced by the uncontrolled stochastic traffic in the RED-AQM control system even if the system is still stable,which reveals a new route to the chaos besides the bifurcation in the network congestion control system. Numerical simulations are given to illustrate the theoretical results.

  6. Dynamic Traffic Control Model Based on Traffic Environmental Capacity%基于交通环境容量的区域交通动态调控模型

    Institute of Scientific and Technical Information of China (English)

    杜怡曼; 贾宇涵; 吴建平; 许明; 杨森炎

    2015-01-01

    近年来,随着社会经济的发展,交通运输系统已经成为一个主要的空气污染源。为了保护城市空气质量,同时尽量满足居民的出行需求,应该把控制机动车排放和改善道路通行效率结合起来考虑。针对此问题,本文引入交通环境容量和宏观交通基本图,采用多目标规划模型来描述区域机动车排放和路网通行能力之间的关系,并通过动态交通调控机制降低重点区域内的交通排放总量。本文将该调控理论应用于南京某路网的管理过程中,仿真结果显示,交通环境控制效果比较显著,同时道路通行能力也得到一定程度的保证。文中相关的理论与实践,可以为城市区域交通管理和污染控制提供重要参考。%In recent years, transportation system has become an important source of air pollution. As a result, it is urgent to consider improving traffic efficiency under the condition of protecting urban air quality. Based on the traffic environmental capacity and macroscopic fundamental diagram theory, the multi-objective programming model is adopted to describe the relationship between traffic emission and traffic capacity. Then a dynamic traffic volume control method is developed for regional traffic management. As a case study, the proposed methodology is applied to a road network located in central area of Nanjing. The results show that traffic efficiency is improved significantly and the urban air quality is ensured. This paper can offer some reference for the decision-making of urban traffic management.

  7. 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.

  8. Sequential interactions with Sec23 control the direction of vesicle traffic

    OpenAIRE

    LORD, christopher; Bhandari, Deepali; Menon, Shekar; Ghassemian, Majid; Nycz, Deborah; Hay, Jesse; Ghosh, Pradipta; Ferro-Novick, Susan

    2011-01-01

    How the directionality of vesicle traffic is achieved remains an important unanswered question in cell biology. The Sec23p/Sec24p coat complex sorts the fusion machinery (SNAREs) into vesicles as they bud from the endoplasmic reticulum. Vesicle tethering to the Golgi begins when the tethering factor TRAPPI binds to Sec23p. Where the coat is released and how this event relates to membrane fusion is unknown. Here we use a yeast transport assay to demonstrate that an ER-derived vesicle retains i...

  9. Online Optimal Control of Connected Vehicles for Efficient Traffic Flow at Merging Roads

    Energy Technology Data Exchange (ETDEWEB)

    Rios-Torres, Jackeline [ORNL; Malikopoulos, Andreas [ORNL; Pisu, Pierluigi [Clemson University

    2015-01-01

    This paper addresses the problem of coordinating online connected vehicles at merging roads to achieve a smooth traffic flow without stop-and-go driving. We present a framework and a closed-form solution that optimize the acceleration profile of each vehicle in terms of fuel economy while avoiding collision with other vehicles at the merging zone. The proposed solution is validated through simulation and it is shown that coordination of connected vehicles can reduce significantly fuel consumption and travel time at merging roads.

  10. 管制员需求量预测研究%Forecast Analysis on Demand of Air Traffic Controller

    Institute of Scientific and Technical Information of China (English)

    何昕; 高浩然; 陈亚青

    2011-01-01

    A series of statistical materials were collected,analyzed,and classified. Four different kinds of forecast models,namely the gray forecast model,comprehensive index method,multiple regression approach,and combined forecast model,were selected to forecast the time sequence of the demand quantity of air traffic controllers in the next 5 years in Chinese Civil Aviation. Corresponding accuracy analysis of the demand quantity was also carried out for the validity of prediction. The obtained predictive result is of great value for reference in various aspects, such as air traffic controller education and recruitment plans for the ATC institutions and authorities.%通过收集整理和分析一系列统计资料,选择灰色预测模型、灰色-马尔可夫预测模型、多元回归法和组合预测法等4种不同的人才需求量预测模型,预测出我国民航未来5年每年持照管制员需求量的时间序列,并进行了精确度分析.所得到的结果对我国民航各级管制单位制定人才引进计划,管制员培养院校制定招生计划均具有一定的参考价值.

  11. Transient analysis of traffic generated by bursty sources, and its application to measurement-based admission control

    NARCIS (Netherlands)

    Mandjes, M.R.H.; Uitert, M.J.G. van

    2000-01-01

    The first part of the paper is devoted to a transient analysis of traffic generated by bursty sources. These sources are governed by a modulating process, whose state determines the traffic rate at which the source transmits. The class of modulating processes contains e.g. on/off traffic sources wit

  12. Sequential interactions with Sec23 control the direction of vesicle traffic.

    Science.gov (United States)

    Lord, Christopher; Bhandari, Deepali; Menon, Shekar; Ghassemian, Majid; Nycz, Deborah; Hay, Jesse; Ghosh, Pradipta; Ferro-Novick, Susan

    2011-05-12

    How the directionality of vesicle traffic is achieved remains an important unanswered question in cell biology. The Sec23p/Sec24p coat complex sorts the fusion machinery (SNAREs) into vesicles as they bud from the endoplasmic reticulum (ER). Vesicle tethering to the Golgi begins when the tethering factor TRAPPI binds to Sec23p. Where the coat is released and how this event relates to membrane fusion is unknown. Here we use a yeast transport assay to demonstrate that an ER-derived vesicle retains its coat until it reaches the Golgi. A Golgi-associated kinase, Hrr25p (CK1δ orthologue), then phosphorylates the Sec23p/Sec24p complex. Coat phosphorylation and dephosphorylation are needed for vesicle fusion and budding, respectively. Additionally, we show that Sec23p interacts in a sequential manner with different binding partners, including TRAPPI and Hrr25p, to ensure the directionality of ER-Golgi traffic and prevent the back-fusion of a COPII vesicle with the ER. These events are conserved in mammalian cells.

  13. Development of a Software Based Firewall System for Computer Network Traffic Control

    Directory of Open Access Journals (Sweden)

    Ikhajamgbe OYAKHILOME

    2009-12-01

    Full Text Available The connection of an internal network to an external network such as Internet has made it vulnerable to attacks. One class of network attack is unauthorized penetration into network due to the openness of networks. It is possible for hackers to sum access to an internal network, this pose great danger to the network and network resources. Our objective and major concern of network design was to build a secured network, based on software firewall that ensured the integrity and confidentiality of information on the network. We studied several mechanisms to achieve this; one of such mechanism is the implementation of firewall system as a network defence. Our developed firewall has the ability to determine which network traffic should be allowed in or out of the network. Part of our studied work was also channelled towards a comprehensive study of hardware firewall security system with the aim of developing this software based firewall system. Our software firewall goes a long way in protecting an internal network from external unauthorized traffic penetration. We included an anti virus software which is lacking in most firewalls.

  14. Surface-Controlled Metal Oxide Resistive Memory

    KAUST Repository

    Ke, Jr-Jian

    2015-10-28

    To explore the surface effect on resistive random-access memory (ReRAM), the impact of surface roughness on the characteristics of ZnO ReRAM were studied. The thickness-independent resistance and the higher switching probability of ZnO ReRAM with rough surfaces indicate the importance of surface oxygen chemisorption on the switching process. Furthermore, the improvements in switching probability, switching voltage and resistance distribution observed for ReRAM with rough surfaces can be attributed to the stable oxygen adatoms under various ambience conditions. The findings validate the surface-controlled stability and uniformity of ReRAM and can serve as the guideline for developing practical device applications.

  15. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    Science.gov (United States)

    Davis, L. C.

    2016-06-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested state at the bottleneck. The nature of the congested state, when it occurs, appears to be similar under a variety of conditions. Typically 80-100 vehicles are approximately equally distributed between the lanes in the 500 m region prior to the end of the terminated lane. Without the adaptive cruise control capability, connected vehicles can delay the onset of congestion but do not increase the asymptotic flow past the bottleneck. Calculations are done using the Kerner-Klenov three-phase theory, stochastic discrete-time model for manual vehicles. The dynamics of the connected vehicles is given by a conventional adaptive cruise control algorithm plus commanded deceleration. Because time in the model for manual vehicles is discrete (one-second intervals), it is assumed that the acceleration of any vehicle immediately in front of a connected vehicle is constant during the time interval, thereby preserving the computational simplicity and speed of a discrete-time model.

  16. Traffic of secondary metabolites to cell surface in the red alga Laurencia dendroidea depends on a two-step transport by the cytoskeleton.

    Directory of Open Access Journals (Sweden)

    Vanessa M Reis

    Full Text Available In Laurencia dendroidea, halogenated secondary metabolites are primarily located in the vacuole named the corps en cerise (CC. For chemical defence at the surface level, these metabolites are intracellularly mobilised through vesicle transport from the CC to the cell periphery for posterior exocytosis of these chemicals. The cell structures involved in this specific vesicle traffic as well as the cellular structures related to the positioning and anchoring of the CC within the cell are not well known. Here, we aimed to investigate the role of cytoskeletal elements in both processes. Cellular and molecular assays were conducted to i determine the ultrastructural apparatus involved in the vesicle traffic, ii localise cytoskeletal filaments, iii evaluate the role of different cytoskeletal filaments in the vesicle transport, iv identify the cytoskeletal filaments responsible for the positioning and anchoring of the CC, and v identify the transcripts related to cytoskeletal activity and vesicle transport. Our results show that microfilaments are found within the connections linking the CC to the cell periphery, playing an essential role in the vesicle traffic at these connections, which means a first step of the secondary metabolites transport to the cell surface. After that, the microtubules work in the positioning of the vesicles along the cell periphery towards specific regions where exocytosis takes place, which corresponds to the second step of the secondary metabolites transport to the cell surface. In addition, microtubules are involved in anchoring and positioning the CC to the cell periphery. Transcriptomic analysis revealed the expression of genes coding for actin filaments, microtubules, motor proteins and cytoskeletal accessory proteins. Genes related to vesicle traffic, exocytosis and membrane recycling were also identified. Our findings show, for the first time, that actin microfilaments and microtubules play an underlying cellular role

  17. Traffic of secondary metabolites to cell surface in the red alga Laurencia dendroidea depends on a two-step transport by the cytoskeleton.

    Science.gov (United States)

    Reis, Vanessa M; Oliveira, Louisi S; Passos, Raoni M F; Viana, Nathan B; Mermelstein, Cláudia; Sant'anna, Celso; Pereira, Renato C; Paradas, Wladimir C; Thompson, Fabiano L; Amado-Filho, Gilberto M; Salgado, Leonardo T

    2013-01-01

    In Laurencia dendroidea, halogenated secondary metabolites are primarily located in the vacuole named the corps en cerise (CC). For chemical defence at the surface level, these metabolites are intracellularly mobilised through vesicle transport from the CC to the cell periphery for posterior exocytosis of these chemicals. The cell structures involved in this specific vesicle traffic as well as the cellular structures related to the positioning and anchoring of the CC within the cell are not well known. Here, we aimed to investigate the role of cytoskeletal elements in both processes. Cellular and molecular assays were conducted to i) determine the ultrastructural apparatus involved in the vesicle traffic, ii) localise cytoskeletal filaments, iii) evaluate the role of different cytoskeletal filaments in the vesicle transport, iv) identify the cytoskeletal filaments responsible for the positioning and anchoring of the CC, and v) identify the transcripts related to cytoskeletal activity and vesicle transport. Our results show that microfilaments are found within the connections linking the CC to the cell periphery, playing an essential role in the vesicle traffic at these connections, which means a first step of the secondary metabolites transport to the cell surface. After that, the microtubules work in the positioning of the vesicles along the cell periphery towards specific regions where exocytosis takes place, which corresponds to the second step of the secondary metabolites transport to the cell surface. In addition, microtubules are involved in anchoring and positioning the CC to the cell periphery. Transcriptomic analysis revealed the expression of genes coding for actin filaments, microtubules, motor proteins and cytoskeletal accessory proteins. Genes related to vesicle traffic, exocytosis and membrane recycling were also identified. Our findings show, for the first time, that actin microfilaments and microtubules play an underlying cellular role in the

  18. Traffic of Secondary Metabolites to Cell Surface in the Red Alga Laurencia dendroidea Depends on a Two-Step Transport by the Cytoskeleton

    Science.gov (United States)

    Reis, Vanessa M.; Oliveira, Louisi S.; Passos, Raoni M. F.; Viana, Nathan B.; Mermelstein, Cláudia; Sant'Anna, Celso; Pereira, Renato C.; Paradas, Wladimir C.; Thompson, Fabiano L.; Amado-Filho, Gilberto M.; Salgado, Leonardo T.

    2013-01-01

    In Laurencia dendroidea, halogenated secondary metabolites are primarily located in the vacuole named the corps en cerise (CC). For chemical defence at the surface level, these metabolites are intracellularly mobilised through vesicle transport from the CC to the cell periphery for posterior exocytosis of these chemicals. The cell structures involved in this specific vesicle traffic as well as the cellular structures related to the positioning and anchoring of the CC within the cell are not well known. Here, we aimed to investigate the role of cytoskeletal elements in both processes. Cellular and molecular assays were conducted to i) determine the ultrastructural apparatus involved in the vesicle traffic, ii) localise cytoskeletal filaments, iii) evaluate the role of different cytoskeletal filaments in the vesicle transport, iv) identify the cytoskeletal filaments responsible for the positioning and anchoring of the CC, and v) identify the transcripts related to cytoskeletal activity and vesicle transport. Our results show that microfilaments are found within the connections linking the CC to the cell periphery, playing an essential role in the vesicle traffic at these connections, which means a first step of the secondary metabolites transport to the cell surface. After that, the microtubules work in the positioning of the vesicles along the cell periphery towards specific regions where exocytosis takes place, which corresponds to the second step of the secondary metabolites transport to the cell surface. In addition, microtubules are involved in anchoring and positioning the CC to the cell periphery. Transcriptomic analysis revealed the expression of genes coding for actin filaments, microtubules, motor proteins and cytoskeletal accessory proteins. Genes related to vesicle traffic, exocytosis and membrane recycling were also identified. Our findings show, for the first time, that actin microfilaments and microtubules play an underlying cellular role in the

  19. Dispersion controlled by permeable surfaces: surface properties and scaling

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Bowen; Tartakovsky, Alexandre M.; Battiato, Ilenia

    2016-07-19

    Permeable and porous surfaces are common in natural and engineered systems. Flow and transport above such surfaces are significantly affected by the surface properties, e.g. matrix porosity and permeability. However, the relationship between such properties and macroscopic solute transport is largely unknown. In this work, we focus on mass transport in a two-dimensional channel with permeable porous walls under fully developed laminar flow conditions. By means of perturbation theory and asymptotic analysis, we derive the set of upscaled equations describing mass transport in the coupled channel–porous-matrix system and an analytical expression relating the dispersion coefficient with the properties of the surface, namely porosity and permeability. Our analysis shows that their impact on the dispersion coefficient strongly depends on the magnitude of the Péclet number, i.e. on the interplay between diffusive and advective mass transport. Additionally, we demonstrate different scaling behaviours of the dispersion coefficient for thin or thick porous matrices. Our analysis shows the possibility of controlling the dispersion coefficient, i.e. transverse mixing, by either active (i.e. changing the operating conditions) or passive mechanisms (i.e. controlling matrix effective properties) for a given Péclet number. By elucidating the impact of matrix porosity and permeability on solute transport, our upscaled model lays the foundation for the improved understanding, control and design of microporous coatings with targeted macroscopic transport features.

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

    Institute of Scientific and Technical Information of China (English)

    杨新湦

    2005-01-01

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

  1. JCMT active surface control system: implementation

    Science.gov (United States)

    Smith, Ian A.

    1998-05-01

    The James Clerk Maxwell Telescope on the summit of Mauna Kea in Hawaii is a 15 meter sub-millimeter telescope which operates in the 350 microns to 2 millimeter region. The primary antenna surface consists of 276 panels, each of which is positioned by 3 stepper motors. In order to achieve the highest possible surface accuracy we are embarking upon a project to actively control the position of the panels adjuster system is based on a 6809 micro connected to the control computer by a GPIB interface. This system is slow and inflexible and it would prove difficult to build an active surface control system with it. Part of the upgrade project is to replace the existing micro with a 68060 VME micro. The poster paper will describe how the temperature of the antenna is monitored with the new system, how a Finite Element Analyses package transforms temperature changes into a series of panel adjuster moves, and how these moves are then applied to the surface. The FEA package will run on a high end Sun workstation. A series of DRAMA tasks distributed between the workstation and the Baja 68060 VxWorks Active Surface Control System micro will control the temperature monitoring, FEA and panel adjustment activities. Users can interact with the system via a Tcl/TK based GUI.

  2. Virtualized Traffic at Metropolitan Scales

    Directory of Open Access Journals (Sweden)

    David eWilkie

    2015-05-01

    Full Text Available Few phenomena are more ubiquitous than traffic, and few are more significant economically, socially, or environmentally. Any virtual reality system, including virtual globes and immersive multi-player worlds that are set in a modern or futuristic setting feature traffic systems. Virtual reality models can also aid in addressing the challenges of real-world traffic systems, the ever-present gridlock and congestion in cities worldwide: traffic engineers and planners can diagnose system instabilities and explore control strategies in virtual worlds reconstructed from available sensor data. To create these systems, road network models need to be created and represented. Traffic needs to be realistically and efficiently simulated. To analyze real-world scenarios, the traffic conditions need to be estimated and reconstructed. To create virtual scenarios, such as simulated cities, traffic needs to be intelligently and efficiently routed.

  3. Performance Analysis of Spectrum Handoff for Cognitive Radio Ad Hoc Networks without Common Control Channel under Homogeneous Primary Traffic

    CERN Document Server

    Song, Yi

    2011-01-01

    Cognitive radio (CR) technology is regarded as a promising solution to the spectrum scarcity problem. Due to the spectrum varying nature of CR networks, unlicensed users are required to perform spectrum handoffs when licensed users reuse the spectrum. In this paper, we study the performance of the spectrum handoff process in a CR ad hoc network under homogeneous primary traffic. We propose a novel three dimensional discrete-time Markov chain to characterize the process of spectrum handoffs and analyze the performance of unlicensed users. Since in real CR networks, a dedicated common control channel is not practical, in our model, we implement a network coordination scheme where no dedicated common control channel is needed. Moreover, in wireless communications, collisions among simultaneous transmissions cannot be immediately detected and the whole collided packets need to be retransmitted, which greatly affects the network performance. With this observation, we also consider the retransmissions of the collid...

  4. An Open-Source Microscopic Traffic Simulator

    CERN Document Server

    Treiber, Martin; 10.1109/MITS.2010.939208

    2010-01-01

    We present the interactive Java-based open-source traffic simulator available at www.traffic-simulation.de. In contrast to most closed-source commercial simulators, the focus is on investigating fundamental issues of traffic dynamics rather than simulating specific road networks. This includes testing theories for the spatiotemporal evolution of traffic jams, comparing and testing different microscopic traffic models, modeling the effects of driving styles and traffic rules on the efficiency and stability of traffic flow, and investigating novel ITS technologies such as adaptive cruise control, inter-vehicle and vehicle-infrastructure communication.

  5. Traffic supervisory/control system for Kobe-Awaji- Naruto expressway of Honshu-Shikoku Bridge Authority; Honshu Shikoku Renrakukyo Kodan nonyu no Kobe Awaji Naruto jidoshado kotsu kansei shisetsu seigyo system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Toshiba delivered the traffic supervisory/control system for Kobe-Awaji-Naruto expressway of Honshu-Shikoku Bridge Authority opened in May 1998. This traffic supervisory system rapidly exactly collects and services the information on the expressway of 89km including Akashi Kaikyo bridge and O-Naruto bridge. The facility control system totally efficiently maintains and controls various facilities for lighting and air circulation of tunnels on the expressway. The previous control system transmitted road information on traffic volume and traffic congestion to offices by using specific lines and terminals, while this system with a monitoring function using intranet can easily service such information by existing PCs. (translated by NEDO)

  6. Traffic supervisory/control system for Kobe-Awaji- Naruto expressway of Honshu-Shikoku Bridge Authority. Honshu Shikoku Renrakukyo Kodan nonyu no Kobe Awaji Naruto jidoshado kotsu kansei shisetsu seigyo system

    Energy Technology Data Exchange (ETDEWEB)

    1999-03-01

    Toshiba delivered the traffic supervisory/control system for Kobe-Awaji-Naruto expressway of Honshu-Shikoku Bridge Authority opened in May 1998. This traffic supervisory system rapidly exactly collects and services the information on the expressway of 89km including Akashi Kaikyo bridge and O-Naruto bridge. The facility control system totally efficiently maintains and controls various facilities for lighting and air circulation of tunnels on the expressway. The previous control system transmitted road information on traffic volume and traffic congestion to offices by using specific lines and terminals, while this system with a monitoring function using intranet can easily service such information by existing PCs. (translated by NEDO)

  7. On the System Design and Control Scheme of Traffic Lights%浅谈交通灯系统设计与控制方案

    Institute of Scientific and Technical Information of China (English)

    周庆博

    2014-01-01

    This paper introduces a system design and system control program traffic lights, this design is a traffic light control sys-tem based on single chip. The system uses MSC-51 series single-chip AT89S51-centric device designed traffic light controller. The system has a practical, simple operation, extended features and other advantages.%该文引入了交通灯的系统设计和系统控制方案,此方案设计的交通灯控制系统是基于单片机的。本系统采用MSC-51系列单片机AT89S51为中心器件来设计交通灯控制器。本系统具有实用性强、操作简单、扩展功能强等优点。

  8. 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.

  9. THE AUTOMATIC SYSTEM’S MODEL OF DECISION-MAKING SUPPORT FOR DISPATCHING CONTROL OF THE CITY PASSENGER TRAFFIC

    Directory of Open Access Journals (Sweden)

    V. A. Lakhno

    2016-04-01

    Full Text Available Purpose. This scientific work considers the further development of mathematical models and algorithms for automatic decision support for dispatching management of the city passenger traffic. Methodology. Systems of dispatching management for the city passenger transport are to provide the carrying out of the routes according schedules with minimal deviations from the planned ones through the using of appropriate control actions. The systems’ algorithm focuses on the selection of control actions that compensate the disturbances. It is proposed to use the index of the waiting time minimum for passengers of buses and taxis at stops as a criterion for evaluating of dispatching control systems work. Findings. Based on the conducted analysis of the research within the existing theory of traffic flow of vehicles, it was proposed the model for the system of dispatching management for urban passenger moving units considering the effect of the most important stochastic factors on the schedule of buses and taxis movement in large cities. The obtained system of equations that models the parameter of movement on the bus routes allows you to assess quickly the influence of disturbing effects on the service quality indicators of passengers and, if necessary, to draw up the optimal schedule. Originality. The authors propose a new model for decision support of dispatching management for the city passenger transport. They take into account the effect of the most important stochastic factors, such as the overflowing buses and taxis, their descent from the lines, delays, deviations from the speed limit on the route, etc., on indicators of service quality, as well as optimizing the schedule. Practical value. The results allow to improve approaches to building models using in the systems of dispatching management of urban bus routes, as well as to improve the selection of control actions for similar systems in large cities of Ukraine.

  10. Urban Traffic Control Under the Environmenr of Vehicle Infrastructure Integration%车路协同环境下城市交通控制研究

    Institute of Scientific and Technical Information of China (English)

    姚佼; 杨晓光

    2013-01-01

    在梳理城市交通控制随交通信息进步发展脉络的基础上,结合车路协同环境下交通信息采集的特点,综述分析单点控制、协调控制的研究现状,进一步总结了车路协同环境下城市交通控制的发展机遇和挑战.指出车路协同环境下交通流演变模型、基于实时车载数据的控制策略评价,以及面向特殊模式的控制策略是车辆协同环境下城市交通控制的突破口和发展方向.%Based on the summary of research context of synchronization development between traffic control and information technology,the urban traffic signal control at isolated intersections and arterial streets under the environment of Ⅶ (Uehicle infrastructure integration) was analysed,taking the characteristic of traffic information collection under Ⅶ into account.Moreover,the challenge and opportunity of traffic control under Ⅶ was also illustrated.It is concluded that the future research on traffic control under Ⅶ should focus on evolved traffic flow model,probe data based MOE (measurement of effectiveness) of signal control strategy in real time and specific modes oriented signal control strategy.

  11. Animation control of surface motion capture.

    Science.gov (United States)

    Tejera, Margara; Casas, Dan; Hilton, Adrian

    2013-12-01

    Surface motion capture (SurfCap) of actor performance from multiple view video provides reconstruction of the natural nonrigid deformation of skin and clothing. This paper introduces techniques for interactive animation control of SurfCap sequences which allow the flexibility in editing and interactive manipulation associated with existing tools for animation from skeletal motion capture (MoCap). Laplacian mesh editing is extended using a basis model learned from SurfCap sequences to constrain the surface shape to reproduce natural deformation. Three novel approaches for animation control of SurfCap sequences, which exploit the constrained Laplacian mesh editing, are introduced: 1) space–time editing for interactive sequence manipulation; 2) skeleton-driven animation to achieve natural nonrigid surface deformation; and 3) hybrid combination of skeletal MoCap driven and SurfCap sequence to extend the range of movement. These approaches are combined with high-level parametric control of SurfCap sequences in a hybrid surface and skeleton-driven animation control framework to achieve natural surface deformation with an extended range of movement by exploiting existing MoCap archives. Evaluation of each approach and the integrated animation framework are presented on real SurfCap sequences for actors performing multiple motions with a variety of clothing styles. Results demonstrate that these techniques enable flexible control for interactive animation with the natural nonrigid surface dynamics of the captured performance and provide a powerful tool to extend current SurfCap databases by incorporating new motions from MoCap sequences.

  12. Pedestrian road traffic injuries in urban Peruvian children and adolescents: case control analyses of personal and environmental risk factors.

    Directory of Open Access Journals (Sweden)

    Joseph Donroe

    Full Text Available BACKGROUND: Child pedestrian road traffic injuries (RTIs are an important cause of death and disability in poorer nations, however RTI prevention strategies in those countries largely draw upon studies conducted in wealthier countries. This research investigated personal and environmental risk factors for child pedestrian RTIs relevant to an urban, developing world setting. METHODS: This is a case control study of personal and environmental risk factors for child pedestrian RTIs in San Juan de Miraflores, Lima, Perú. The analysis of personal risk factors included 100 cases of serious pedestrian RTIs and 200 age and gender matched controls. Demographic, socioeconomic, and injury data were collected. The environmental risk factor study evaluated vehicle and pedestrian movement and infrastructure at the sites in which 40 of the above case RTIs occurred and 80 control sites. FINDINGS: After adjustment, factors associated with increased risk of child pedestrian RTIs included high vehicle volume (OR 7.88, 95%CI 1.97-31.52, absent lane demarcations (OR 6.59, 95% CI 1.65-26.26, high vehicle speed (OR 5.35, 95%CI 1.55-18.54, high street vendor density (OR 1.25, 95%CI 1.01-1.55, and more children living in the home (OR 1.25, 95%CI 1.00-1.56. Protective factors included more hours/day spent in school (OR 0.52, 95%CI 0.33-0.82 and years of family residence in the same home (OR 0.97, 95%CI 0.95-0.99. CONCLUSION: Reducing traffic volumes and speeds, limiting the number of street vendors on a given stretch of road, and improving lane demarcation should be evaluated as components of child pedestrian RTI interventions in poorer countries.

  13. Controlled surface chemistries and quantitative cell response

    Science.gov (United States)

    Plant, Anne L.

    2002-03-01

    Living cells experience a large number of signaling cues from their extracellular matrix. As a result of these inputs, a variety of intracellular signaling pathways are apparently initiated simultaneously. The vast array of alternative responses that result from the integration of these inputs suggests that it may be reasonable to look for cellular response not as an 'on' or 'off' condition but as a distribution of responses. A difficult challenge is to determine whether variations in responses from individual cells arise from the complexity of intracellular signals or are due to variations in the cell culture environment. By controlling surface chemistry so that every cell 'sees' the same chemical and physical environment, we can begin to assess how the distribution of cell response is affected strictly by changes in the chemistry of the cell culture surface. Using the gene for green fluorescent protein linked to the gene for the promoter of the extracellular matrix protein, tenascin, we can easily probe the end product in a signaling pathway that is purported to be linked to surface protein chemistry and to cell shape. Cell response to well-controlled, well-characterized, and highly reproducible surfaces prepared using soft lithography techniques are compared with more conventional ways of preparing extracellular matrix proteins for cell culture. Using fluorescence microscopy and image analysis of populations of cells on these surfaces, we probe quantitatively the relationship between surface chemistry, cell shape and variations in gene expression endpoint.

  14. Real time traffic models, decision support for traffic management

    OpenAIRE

    Wismans, L.; De Romph, E.; Friso, K.; Zantema, K.

    2014-01-01

    Reliable and accurate short-term traffic state prediction can improve the performance of real-time traffic management systems significantly. Using this short-time prediction based on current measurements delivered by advanced surveillance systems will support decision-making processes on various control strategies and enhance the performance of the overall network. By taking proactive action deploying traffic management measures, congestion may be prevented or its effects limited. An approach...

  15. Plasma surface interactions in controlled fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Ghendrih, Ph.; Becoulet, M.; Costanzo, L. [and others

    2000-07-01

    This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak.

  16. Tunneling Horizontal IEC 61850 Traffic through Audio Video Bridging Streams for Flexible Microgrid Control and Protection

    Directory of Open Access Journals (Sweden)

    Michael Short

    2016-03-01

    Full Text Available In this paper, it is argued that some low-level aspects of the usual IEC 61850 mapping to Ethernet are not well suited to microgrids due to their dynamic nature and geographical distribution as compared to substations. It is proposed that the integration of IEEE time-sensitive networking (TSN concepts (which are currently implemented as audio video bridging (AVB technologies within an IEC 61850 / Manufacturing Message Specification framework provides a flexible and reconfigurable platform capable of overcoming such issues. A prototype test platform and bump-in-the-wire device for tunneling horizontal traffic through AVB are described. Experimental results are presented for sending IEC 61850 GOOSE (generic object oriented substation events and SV (sampled values messages through AVB tunnels. The obtained results verify that IEC 61850 event and sampled data may be reliably transported within the proposed framework with very low latency, even over a congested network. It is argued that since AVB streams can be flexibly configured from one or more central locations, and bandwidth reserved for their data ensuring predictability of delivery, this gives a solution which seems significantly more reliable than a pure MMS-based solution.

  17. Influence of deficiencies in traffic control devices in crashes on two-lane rural roads.

    Science.gov (United States)

    López, Griselda; de Oña, Juan; Garach, Laura; Baena, Leticia

    2016-11-01

    One of the main objectives of all public administrations is reducing traffic crashes. To this end, Road Safety Inspections (RSI) stand out as a key measure. Signaling roads is one of the foremost tasks of RSI. A road that is improperly or poorly signaled can lead to incorrect placement or maneuvers of vehicles and ambiguous situations that can increase the risk of crashes. This paper analyses the relationship between road crashes in two-lane rural highways and certain deficiencies in signaling. The results show that deficiencies such as "incomplete removal of road works markings" or "no guide sign or in incorrect position" are the ones associated with a higher probability of crashes in two-lane rural highways. In view of these results, governmental agencies should verify that the original conditions of a highway are re-established after any construction work is completed. They should also continuously follow up on the signaling of this type of highway in order to maintain optimal conditions.

  18. Highway Traffic Noise Analysis and Control%公路交通噪声分析与防治

    Institute of Scientific and Technical Information of China (English)

    田华

    2012-01-01

      The Jianchang County portion of highway traffic noise monitoring, Points out the harm of traffic noise, Put forward several measures to reduce traffic noise.%  对建昌县部分交通干线的交通噪声进行监测,指出交通噪声的危害,提出降低交通噪声的几种措施

  19. Fuzzy Multiobjective Traffic Light Signal Optimization

    Directory of Open Access Journals (Sweden)

    N. Shahsavari Pour

    2013-01-01

    Full Text Available Traffic congestion is a major concern for many cities throughout the world. In a general traffic light controller, the traffic lights change at a constant cycle time. Hence it does not provide an optimal solution. Many traffic light controllers in current use are based on the “time-of-the-day” scheme, which use a limited number of predetermined traffic light patterns and implement these patterns depending upon the time of the day. These automated systems do not provide an optimal control for fluctuating traffic volumes. In this paper, the fuzzy traffic light controller is used to optimize the control of fluctuating traffic volumes such as oversaturated or unusual load conditions. The problem is solved by genetic algorithm, and a new defuzzification method is introduced. The performance of the new defuzzification method (NDM is compared with the centroid point defuzzification method (CPDM by using ANOVA. Finally, an illustrative example is presented to show the competency of proposed algorithm.

  20. 交通数据质量宏观评价与控制方法%Macroscopic Evaluation and Control Method of Traffic Data Quality

    Institute of Scientific and Technical Information of China (English)

    牛世峰; 姜桂艳

    2012-01-01

    针对交通数据质量微观评价方法无法评价交通数据整体质量的问题,提出交通数据宏观评价的思想,在对非正常交通数据分类进行研究的基础上,构建了4个交通数据宏观评价指标,并设计了交通数据宏观评价流程,根据各类非正常交通数据的产生原因,设计了交通数据质量宏观控制方法,利用实测数据验证表明,所设计方法可以实现交通数据质量的宏观评价,并能给出合理的交通数据质量控制策略.%In the light of the problem which evaluate the overall quality of traffic data, the idea of macroscopic evaluation of traffic data is proposed. Four macroscopic evaluation indexes of traffic data are constructed based on the classification of non-normal traffic data, and the flow of macroscopic evaluation of traffic data quality is designed. The macroscopic control method of traffic data quality is designed based on cause analysis of non-normal data. The experimental results indicate that the proposed method can carry out the macroscopic evaluate of traffic data quality, and give a reasonable data quality improvement strategy.

  1. Traffic Signal Using Smart Agent System

    Directory of Open Access Journals (Sweden)

    Cheonshik Kim

    2008-01-01

    Full Text Available In this research, we propose an electro-sensitive traffic light using the smart agent algorithm to reduce traffic congestion and traffic accidents. The multi-agent system approach can provide a new and preferable solution. The proposed method adaptively controls the cycle of traffic signals even though the traffic volume varies. Consequently, we reduce the car waiting time and start-up delay time using fuzzy control of feedback data. In particular, we have designed and implemented a system to create optimum traffic signals in congested conditions. The effectiveness of this method was shown through simulation of multiple intersections.

  2. A method of variable speed limit control for traffic flow on freeway mainline%高速公路主线可变限速控制方法

    Institute of Scientific and Technical Information of China (English)

    马明辉; 杨庆芳; 梁士栋

    2015-01-01

    The traffic state would become congested at the bottleneck region during peak period, which increase travel time, and decrease efficiency. From time-space traffic characteristics on freeway mainline, macroscopic traffic flow model METANET is modified to describe the traffic flow with VSL control. Furthermore, based on the modified traffic flow models, establish the VSL models at bottleneck region, with the objective of improving traffic efficiency and decreasing travel time. As part of the VSL control algorithm, the proposed VSL control model is implemented at VISSIM simulation platform, the results reveal that the given VSL values according to real time traffic flow conditions can control the vehicles arriving effectively. Therefore, the implement of VSL control can improve traffic efficiency and decrease travel time effectively.%为了解决高流量状态下高速公路主线瓶颈区域交通流运行态势恶劣,导致车辆行程时间增加、道路通行效率降低等问题,从高速公路交通流运行时-空特性角度出发,对宏观交通模型METANET改进,使其能够描述可变限速控制条件下道路交通流运行状态,并以改进模型为基础,提高通行效率和缩短行程时间为目标,构建高速公路主线交通优化控制模型. 实验结果表明:高速公路主线可变限速控制方法能够根据道路交通流量的变化对安全限速值动态设置,实现对危险区车辆到达率的动态控制. 实施高速公路主线可变限速控制方法可有效提高道路通行效率,缩短车辆行程时间.

  3. Surface purity control during XMASS detector refurbishment

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Kazuyoshi, E-mail: kenkou@icrr.u-tokyo.ac.jp [Kamioka observatory, Institute for Cosmic Ray Research, the University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu, 506-1205 (Japan); Kavl Institute for the Physics and Mathematics of the Universe (WPI), the University of Tokyo, Kashiwa, Chiba, 277-8582 (Japan)

    2015-08-17

    The XMASS project aims at detecting dark matter, pp and {sup 7}Be solar neutrinos, and neutrino less double beta decay using large volume of pure liquid xenon. The first physics target of the XMASS project is to detect dark matter with 835 kg liquid xenon. After the commissioning runs, XMASS detector was refurbished to minimize the background contribution mainly from PMT sealing material and we restarted data taking in November 2013. We report how we control surface purity, especially how we prevent radon daughter accumulation on the detector copper surface, during XMASS detector refurbishment. The result and future plan of XMASS are also reported.

  4. Shape-memory-actuated compliant control surface

    Science.gov (United States)

    Maclean, Brian J.; Carpenter, Bernie F.; Draper, Jerry L.; Misra, Mohan S.

    1993-09-01

    Advanced submarine stern configurations require a variety of control surfaces to actively manage aftbody boundary layer flow, vorticity, propulsor inflow and intrapropulsor flow, as well as vehicle attitude. Two necessary attributes of advanced control surface designs include (1) integrated actuation to provide placement flexibility at remote locations with minimal structural interfacing and control interconnects, and (2) improved lift efficiency and flow using variable or adaptive camber control. To demonstrate these attributes, a shape memory alloy (SMA) actuated compliant control fin (CCF) with a planform area of 620 sq. cm was developed for evaluation as rudder and sternplane appendages on a radio control submarine model at velocities up to 5.1 m/s (Reynolds No. approximately equals 1,000,000) and up to 0.2 Hz full cycle actuation. A completely fixed root design was developed to reduce turbulence at the hull/fine interface, with compliant deformation of the foil to improve flow characteristics over the baseline full-flying and trailing-edge-flap designs.

  5. Automated Traffic Management System and Method

    Science.gov (United States)

    Glass, Brian J. (Inventor); Spirkovska, Liljana (Inventor); McDermott, William J. (Inventor); Reisman, Ronald J. (Inventor); Gibson, James (Inventor); Iverson, David L. (Inventor)

    2000-01-01

    A data management system and method that enables acquisition, integration, and management of real-time data generated at different rates, by multiple heterogeneous incompatible data sources. The system achieves this functionality by using an expert system to fuse data from a variety of airline, airport operations, ramp control, and air traffic control tower sources, to establish and update reference data values for every aircraft surface operation. The system may be configured as a real-time airport surface traffic management system (TMS) that electronically interconnects air traffic control, airline data, and airport operations data to facilitate information sharing and improve taxi queuing. In the TMS operational mode, empirical data shows substantial benefits in ramp operations for airlines, reducing departure taxi times by about one minute per aircraft in operational use, translating as $12 to $15 million per year savings to airlines at the Atlanta, Georgia airport. The data management system and method may also be used for scheduling the movement of multiple vehicles in other applications, such as marine vessels in harbors and ports, trucks or railroad cars in ports or shipping yards, and railroad cars in switching yards. Finally, the data management system and method may be used for managing containers at a shipping dock, stock on a factory floor or in a warehouse, or as a training tool for improving situational awareness of FAA tower controllers, ramp and airport operators, or commercial airline personnel in airfield surface operations.

  6. 行人横过公路交通灯PLC控制系统设计%Design of Traffic Lights PLC Control System for Pedestrians to Cross Road

    Institute of Scientific and Technical Information of China (English)

    汤文利

    2015-01-01

    This paper proposes traffic lights working principle of pedestrian crossing the road, including the hardware structure and detalled control program of PLC system, analyzes the basic idea of program design. It is of significance for practical application of traffic lights.%提出了行人横过公路交通灯动作原理,给出了用PLC实现这一动作的硬件组成及详细的控制程序并分析了程序设计的基本思路,对于交通灯的实际应用有一定指导意义。

  7. Implementation of Controlled Traffic in the Canadian Prairies: Soil and Plant Dynamics under Simulated and Field Conditions

    Science.gov (United States)

    Guenette, Kris; Hernandez-Ramirez, Guillermo

    2017-04-01

    Achieving resiliency in agroecosystems may be accomplished through the incorporation of contemporary management systems and the diversification of crop rotations with pulse crops, such as controlled traffic farming (CTF) and faba beans (Vicia faba L.). As these practices become more common in the Canadian Prairies, it is imperative to have a well-rounded understanding of how faba beans interact with the soil-plant-atmosphere continuum in conditions found in contemporary management systems. Simulated field conditions emulated soil compaction found in both the trafficked and un-trafficked areas of a CTF system, in which the presence of high water availability was shown to offset the negative results of large applications of compactive effort. Furthermore, low water availability exacerbated differences in plant responses between compaction treatments. The simulated treatment of 1.2 gcm-3 coupled with high water content yielded the most optimal results for most measured parameters, with a contrasting detrimental treatment of 1.4 gcm-3 at low water availability. The simulated field conditions were further bridged through an analysis of two commercial sites in Alberta, Canada that compared both trafficked and un-trafficked soil properties. Soil properties such as available nitrogen (AN), pH, soil total nitrogen (STN), soil organic carbon (SOC), bulk density, macroporosity, soil quality S-Index, plant available water capacity (PAWC) and unsaturated hydraulic conductivity (Km) were analysed and compared among trafficked and un-trafficked areas. The measured soil physical and hydraulic properties of bulk density, macroporosity, S-Index, PAWC and Km were shown to be heavily influenced by the CTF traffic regime, while soil nutrient properties of AN, pH, STN SOC were determined to be dependent on both management and landscape features.

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

    Science.gov (United States)

    de Haan, S.

    2011-05-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  10. АPPLICATION OF GENETIC ALGORITHM FOR IN SOLVING THE PROBLEM OF CHOICE OF OPERATING FREQUENCY FOR AIR TRAFFIC CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The problem of ensuring electromagnetic compatibility of banked radio-technical systems (RTS, i.e., ensuring a goal per- formance under the conditions of intersystem interference. Air traffic control organization suggests a continuous interaction between air-crews and air traffic controllers during the whole flight, i.e., it is necessary to consider mutual influence of RTSs situated in adjacent zones of responsibility. As the zones overlap, frequency allocation should be performed simulta- neously taking into consideration the RTSs, which determines a huge dimension of the problem. The problem of choice of operating frequency for air traffic control system radio-technical aids is formalized. It is offered to use a genetic algorithm as one of the stochastic search methods for solution of the formalized problem of the choice of operating frequencies for air traffic control system. The parameters of the genetic algorithm, and providing a better quality solution are determined. It is shown that the adaptive scheme of selection of individuals is promising for use, and it enables to receive the required solu- tion of the problem without performing additional research of the current task and the bench-mark data concerning choice of a reproduction scheme for the generalized genetic algorithm.

  11. SURFACE TEXTURE ANALYSIS FOR FUNCTIONALITY CONTROL

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Andreasen, Jan Lasson; Tosello, Guido

    This document is used in connection with three exercises of 3 hours duration as a part of the course VISION ONLINE – One week course on Precision & Nanometrology. The exercises concern surface texture analysis for functionality control, in connection with three different case stories. This docume...... contains a short description of each case story, 3-D roughness parameters analysis and relation with the product’s functionality.......This document is used in connection with three exercises of 3 hours duration as a part of the course VISION ONLINE – One week course on Precision & Nanometrology. The exercises concern surface texture analysis for functionality control, in connection with three different case stories. This document...

  12. Remote control of planetary surface vehicles.

    Science.gov (United States)

    Heer, E.

    1973-01-01

    A remotely manned system consisting of an earth-based control center and a remote rover system on the planetary surface is assumed to extend to the remote site the sensory, manipulative and certain intellectual capabilities of humans here on earth. Required system functions, including scientific payload functions, vehicle functions and ground-based human control functions are discussed and the effects of communication delay and increased remote automaticity on system performance are investigated. To accomplish the required operations for scientific exploration, the control of the remote system requires the development of techniques to deal with problems of long communication time delays so that the performance in terms of operation speed can be increased to acceptable levels. Increased operational performance can be achieved primarily by increasing the rate of useful information flow in the man-machine sensor-control loop, or by increasing the autonomous capabilities of the remote system or by both.

  13. Association between aircraft, road and railway traffic noise and depression in a large case-control study based on secondary data.

    Science.gov (United States)

    Seidler, Andreas; Hegewald, Janice; Seidler, Anna Lene; Schubert, Melanie; Wagner, Mandy; Dröge, Patrik; Haufe, Eva; Schmitt, Jochen; Swart, Enno; Zeeb, Hajo

    2017-01-01

    Few studies have examined the relationship between traffic noise and depression providing inconclusive results. This large case-control study is the first to assess and directly compare depression risks by aircraft, road traffic and railway noise. The study population included individuals aged ≥40 years that were insured by three large statutory health insurance funds and were living in the region of Frankfurt international airport. Address-specific exposure to aircraft, road and railway traffic noise in 2005 was estimated. Based on insurance claims and prescription data, 77,295 cases with a new clinical depression diagnosis between 2006 and 2010 were compared with 578,246 control subjects. For road traffic noise, a linear exposure-risk relationship was found with an odds ratio (OR) of 1.17 (95% CI=1.10-1.25) for 24-h continuous sound levels ≥70dB. For aircraft noise, the risk estimates reached a maximum OR of 1.23 (95% CI=1.19-1.28) at 50-55dB and decreased at higher exposure categories. For railway noise, risk estimates peaked at 60-65dB (OR=1.15, 95% CI=1.08-1.22). The highest OR of 1.42 (95% CI=1.33-1.52) was found for a combined exposure to noise above 50dB from all three sources. This study indicates that traffic noise exposure might lead to depression. As a potential explanation for the decreasing risks at high traffic noise levels, vulnerable people might actively cope with noise (e.g. insulate or move away). Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Aircraft, road and railway traffic noise as risk factors for heart failure and hypertensive heart disease-A case-control study based on secondary data.

    Science.gov (United States)

    Seidler, Andreas; Wagner, Mandy; Schubert, Melanie; Dröge, Patrik; Römer, Karin; Pons-Kühnemann, Jörn; Swart, Enno; Zeeb, Hajo; Hegewald, Janice

    2016-11-01

    Several studies point to an elevated risk for cardiovascular diseases induced by traffic noise. We examined the association between aircraft, road traffic and railway noise and heart failure or hypertensive heart disease (HHD) in a large case-control study. The study population consisted of individuals that were insured by three large statutory health insurance funds in the Rhine-Main area of Germany. Based on insurance claims and prescription data, 104,145 cases of heart failure or HHD diagnosed 2006-10 were identified and compared with 654,172 control subjects. Address-specific exposure to aircraft, road and railway traffic noise in 2005 was estimated. Odds Ratios were calculated using logistic regression analysis, adjusted for age, sex, local proportion of persons receiving unemployment benefits, and individual socioeconomic status (available for 39% of the individuals). A statistically significant linear exposure-risk relationship with heart failure or hypertensive heart disease was found for aircraft traffic noise (1.6% risk increase per 10dB increase in the 24-h continuous noise level; 95% CI 0.3-3.0%), road traffic noise (2.4% per 10dB; 95% CI 1.6-3.2%), and railway noise (3.1% per 10dB; 95% CI 2.2-4.1%). For individuals with 24-h continuous aircraft noise levels aircraft noise levels exceeding 50dB six or more times, a significantly increased risk was observed. In general, risks of HHD were considerably higher than the risks of heart failure. Regarding the high prevalence of traffic noise from various sources, even low risk increases for frequent diseases are relevant for the population as a whole. Copyright © 2016 Elsevier GmbH. All rights reserved.

  15. 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.

  16. Effect of short-term regional traffic restriction on urban submicron particulate pollution.

    Science.gov (United States)

    Zhao, Suping; Yu, Ye

    2017-05-01

    During the 2013 and 2015 Lanzhou International Marathon Events (LIME1 and LIME2), the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To fill the gap in information on the effect of short-period (several hours) traffic control on urban air quality, submicron particle size distributions and meteorological data were measured simultaneously during June 2013 and June 2015 in urban Lanzhou. The number and surface area concentrations of particles in the 100-200nm range declined by 67.2% and 65.0% for LIME1 due to traffic control, while they decreased by 39.2% and 37.1% for LIME2. The impact of traffic restriction on air pollution near the sampling site lagged behind the traffic control period for LIME2. In addition, the effect of traffic restriction on air pollution near the sampling site was dependent on the distance between the relative orientation of the sampling site and traffic-restricted zones, as well as meteorological conditions such as wind direction. The influence of traffic restrictions on the particle concentrations differed for different particle sizes. The size range most affected by traffic restriction was 60-200 and 60-300nm for number and surface area concentrations in the urban environment, respectively, while for the particle volume concentration it was the 100-600nm range. This study will provide a basis for implementation of future urban traffic-induced particulate pollution control measures. Copyright © 2016. Published by Elsevier B.V.

  17. Nanoscale Surface Plasmonics Sensor With Nanofluidic Control

    Science.gov (United States)

    Wei, Jianjun; Singhal, Sameer; Waldeck, David H.; Kofke, Matthew

    2013-01-01

    Conventional quantitative protein assays of bodily fluids typically involve multiple steps to obtain desired measurements. Such methods are not well suited for fast and accurate assay measurements in austere environments such as spaceflight and in the aftermath of disasters. Consequently, there is a need for a protein assay technology capable of routinely monitoring proteins in austere environments. For example, there is an immediate need for a urine protein assay to assess astronaut renal health during spaceflight. The disclosed nanoscale surface plasmonics sensor provides a core detection method that can be integrated to a lab-on-chip device that satisfies the unmet need for such a protein assay technology. Assays based upon combinations of nanoholes, nanorings, and nanoslits with transmission surface plasmon resonance (SPR) are used for assays requiring extreme sensitivity, and are capable of detecting specific analytes at concentrations as low as picomole to femtomole level in well-controlled environments. The device operates in a transmission mode configuration in which light is directed at one planar surface of the array, which functions as an optical aperture. The incident light induces surface plasmon light transmission from the opposite surface of the array. The presence of a target analyte is detected by changes in the spectrum of light transmitted by the array when a target analyte induces a change in the refractive index of the fluid within the nanochannels. This occurs, for example, when a target analyte binds to a receptor fixed to the walls of the nanochannels in the array. Independent fluid handling capability for individual nanoarrays on a nanofluidic chip containing a plurality of nanochannel arrays allows each array to be used to sense a different target analyte and/or for paired arrays to analyze control and test samples simultaneously in parallel. The present invention incorporates transmission mode nanoplasmonics and nanofluidics into a single

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

    Directory of Open Access Journals (Sweden)

    Thamires Marques de Lima

    2013-12-01

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

  19. Experimental investigation of effects of Washout control on reducing traffic jam%交通流 Washout 缓解控制方案试验分析

    Institute of Scientific and Technical Information of China (English)

    任鹏飞; 薛鹏; 李可

    2015-01-01

    Aiming at issues of traffic jams in circle,Washout out control scheme was proposed based on optimal velocity functions. Dynamic balancing control system model was established after analyzing the characteristics of cyclic traffic flows. Then indoor experi-mental platform was constructed with LEGO robot cars. Traffic flow and density were collected at a given position in 5 minutes. Compa-ring experimental results with real traffic data,the effectiveness of the model was validated. Introducing Washout controller for each ve-hicle,the data showed that the Washout control scheme can release the traffic jams and the control effect is particularly significant in the early stage of congestion.%针对环状交通流拥堵的问题,基于最优速度函数提出了 Washout 缓解控制方案。分析环状交通流的行进特点,建立系统动态平衡控制模型后,再利用乐高 NXT 模型车搭建室内试验平台。设定运行时间为5 min,定点监测车流密度和流量变化。将试验数据与实测交通数据进行对比,验证了模型的有效性。进一步为被控车流引入 Washout 控制器,试验数据显示该方案可有效缓解交通阻塞,在拥堵形成初期的控制效果尤为明显。

  20. Individual Markers of Resilience in Train Traffic Control: The Role of Operators' Goals and Strategic Mental Models and Implications for Variation, Expertise, and Performance.

    Science.gov (United States)

    Lo, Julia C; Pluyter, Kari R; Meijer, Sebastiaan A

    2016-02-01

    The aim of this study was to examine individual markers of resilience and obtain quantitative insights into the understanding and the implications of variation and expertise levels in train traffic operators' goals and strategic mental models and their impact on performance. The Dutch railways are one of the world's most heavy utilized railway networks and have been identified to be weak in system and organizational resilience. Twenty-two train traffic controllers enacted two scenarios in a human-in-the-loop simulator. Their experience, goals, strategic mental models, and performance were assessed through questionnaires and simulator logs. Goals were operationalized through performance indicators and strategic mental models through train completion strategies. A variation was found between operators for both self-reported primary performance indicators and completion strategies. Further, the primary goal of only 14% of the operators reflected the primary organizational goal (i.e., arrival punctuality). An incongruence was also found between train traffic controllers' self-reported performance indicators and objective performance in a more disrupted condition. The level of experience tends to affect performance differently. There is a gap between primary organizational goals and preferred individual goals. Further, the relative strong diversity in primary operator goals and strategic mental models indicates weak resilience at the individual level. With recent and upcoming large-scale changes throughout the sociotechnical space of the railway infrastructure organization, the findings are useful to facilitate future railway traffic control and the development of a resilient system. © 2015, Human Factors and Ergonomics Society.

  1. Adaptive Dynamic Surface Control for Generator Excitation Control System

    Directory of Open Access Journals (Sweden)

    Zhang Xiu-yu

    2014-01-01

    Full Text Available For the generator excitation control system which is equipped with static var compensator (SVC and unknown parameters, a novel adaptive dynamic surface control scheme is proposed based on neural network and tracking error transformed function with the following features: (1 the transformation of the excitation generator model to the linear systems is omitted; (2 the prespecified performance of the tracking error can be guaranteed by combining with the tracking error transformed function; (3 the computational burden is greatly reduced by estimating the norm of the weighted vector of neural network instead of the weighted vector itself; therefore, it is more suitable for the real time control; and (4 the explosion of complicity problem inherent in the backstepping control can be eliminated. It is proved that the new scheme can make the system semiglobally uniformly ultimately bounded. Simulation results show the effectiveness of this control scheme.

  2. Simulation Model of Traffic Jam at Crossroads

    Directory of Open Access Journals (Sweden)

    Mladen Kalajžić

    2002-11-01

    Full Text Available Traffic congestion is one of the major problems in most cities.It is the consequence of unavoidable motorization, butalso, in many cases, of improper solutions considering constructionof roads or organisation of traffic.This paper deals with one problematic crossroad in thetown of Zadar in which traffic jams occur due to poor organisationof traffic. Using mathematical simulation, the first partproves that traffic jams will certainly occur, and in the secondpart, crossroads signalling is considered as a possible solutionwhich, if combined with intelligent control could significantlyimprove the organisation of traffic at this crossroads.

  3. Use of a total traffic count metric to investigate the impact of roadways on asthma severity: a case-control study

    Directory of Open Access Journals (Sweden)

    deVos Annemarie JBM

    2011-06-01

    Full Text Available Abstract Background This study had two principal objectives: (i to investigate the relationship between asthma severity and proximity to major roadways in Perth, Western Australia; (ii to demonstrate a more accurate method of exposure assessment for traffic pollutants using an innovative GIS-based measure that fully integrates all traffic densities around subject residences. Methods We conducted a spatial case-control study, in which 'cases' were defined as individuals aged under 19 years of age with more severe asthma (defined here as two or more emergency department contacts with asthma in a defined 5-year period versus age- and gender-matched 'controls' with less severe asthma (defined here as one emergency department contact for asthma. Traffic exposures were measured using a GIS-based approach to determine the lengths of the roads falling within a buffer area, and then multiplying them by their respective traffic counts. Results We examined the spatial relationship between emergency department contacts for asthma at three different buffer sizes: 50 metres, 100 metres and 150 metres. No effect was noted for the 50 metre buffer (OR = 1.07; 95% CI: 0.91-1.26, but elevated odds ratios were observed with for crude (unadjusted estimates OR = 1.21 (95% CI: 1.00-1.46 for 100 metre buffers and OR = 1.25 (95% CI: 1.02-1.54 for 150 metre buffers. For adjusted risk estimates, only the 150 metre buffer yielded a statistically significant finding (OR = 1.24; 95% CI:1.00-1.52. Conclusions Our study revealed a significant 24% increase in the risk of experiencing multiple emergency department contacts for asthma for every log-unit of traffic exposure. This study provides support for the hypothesis that traffic related air pollution increases the frequency of health service contacts for asthma. This study used advanced GIS techniques to establish traffic-weighted buffer zones around the geocoded residential location of subjects to provide an accurate

  4. Methane Lunar Surface Thermal Control Test

    Science.gov (United States)

    Plachta, David W.; Sutherlin, Steven G.; Johnson, Wesley L.; Feller, Jeffrey R.; Jurns, John M.

    2012-01-01

    NASA is considering propulsion system concepts for future missions including human return to the lunar surface. Studies have identified cryogenic methane (LCH4) and oxygen (LO2) as a desirable propellant combination for the lunar surface ascent propulsion system, and they point to a surface stay requirement of 180 days. To meet this requirement, a test article was prepared with state-of-the-art insulation and tested in simulated lunar mission environments at NASA GRC. The primary goals were to validate design and models of the key thermal control technologies to store unvented methane for long durations, with a low-density high-performing Multi-layer Insulation (MLI) system to protect the propellant tanks from the environmental heat of low Earth orbit (LEO), Earth to Moon transit, lunar surface, and with the LCH4 initially densified. The data and accompanying analysis shows this storage design would have fallen well short of the unvented 180 day storage requirement, due to the MLI density being much higher than intended, its substructure collapse, and blanket separation during depressurization. Despite the performance issue, insight into analytical models and MLI construction was gained. Such modeling is important for the effective design of flight vehicle concepts, such as in-space cryogenic depots or in-space cryogenic propulsion stages.

  5. Impacts of Pedestrians on Capacity and Delay of Major Street Through Traffic at Two-Way Stop-Controlled Intersections

    Directory of Open Access Journals (Sweden)

    Zhao Yang

    2015-01-01

    Full Text Available This paper aims to estimate the impacts of pedestrians on capacity and average control delay for the major street through traffic at two-way stop-controlled (TWSC intersections. A procedure was proposed to estimate the expected delay for major street through vehicles based on the pedestrian arrival time and motorist yielding behavior. Field data were collected to calibrate the crucial parameters in the established models. The proposed models were then validated against field measured data. It was found that the calibrated models provided reasonable delay estimates. Based on the established models, sensitivity analyses were conducted to identify the effects of pedestrian arrival rate and motorist yield rate on the capacity of the major street through lanes at TWSC intersections. The results suggested that the capacity of the through movement would decrease with an increase in the pedestrian arrival rate. It was also found that, with the same pedestrian arrival rate, the capacity would decrease as the motorist yield rate became higher, and the magnitude of the capacity reduction would increase with an increase in the pedestrian arrival rate.

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

    Science.gov (United States)

    1980-11-13

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

  7. Dynamic Surface Control and Its Application to Lateral Vehicle Control

    Directory of Open Access Journals (Sweden)

    Bongsob Song

    2014-01-01

    Full Text Available This paper extends the design and analysis methodology of dynamic surface control (DSC in Song and Hedrick, 2011, for a more general class of nonlinear systems. When rotational mechanical systems such as lateral vehicle control and robot control are considered for applications, sinusoidal functions are easily included in the equation of motions. If such a sinusoidal function is used as a forcing term for DSC, the stability analysis faces the difficulty due to highly nonlinear functions resulting from the low-pass filter dynamics. With modification of input variables to the filter dynamics, the burden of mathematical analysis can be reduced and stability conditions in linear matrix inequality form to guarantee the quadratic stability via DSC are derived for the given class of nonlinear systems. Finally, the proposed design and analysis approach are applied to lateral vehicle control for forward automated driving and backward parallel parking at a low speed as well as an illustrative example.

  8. Ride control of surface effect ships using distributed control

    Directory of Open Access Journals (Sweden)

    Asgeir J. Sørensen

    1994-04-01

    Full Text Available A ride control system for active damping of heave and pitch accelerations of Surface Effect Ships (SES is presented. It is demonstrated that distributed effects that are due to a spatially varying pressure in the air cushion result in significant vertical vibrations in low and moderate sea states. In order to achieve a high quality human comfort and crew workability it is necessary to reduce these vibrations using a control system which accounts for distributed effects due to spatial pressure variations in the air cushion. A mathematical model of the process is presented, and collocated sensor and actuator pairs are used. The process stability is ensured using a controller with appropriate passivity properties. Sensor and actuator location is also discussed. The performance of the ride control system is shown by power spectra of the vertical accelerations obtained from full scale experiments with a 35 m SES.

  9. Traffic speed management

    Directory of Open Access Journals (Sweden)

    Subotić Jovana Lj.

    2014-01-01

    Full Text Available Speed, and vehicles themselves, affect the level of service and road safety, quality of life, noise from traffic, the environment, health, air pollution, emission of carbon dioxide, global warming, the economy and consumption of non-renewable energy such as oil. Therefore, the speed management of the traffic of multiple significance and that should be primarily to provide effective and economical conditions of the modern and preventive protection of human life as the greatest treasure and then the material resources. The way to accomplish this is by using various (different measures such as: appropriate planning and projecting roads and streets, speed control, the legislation, enforcement, campaigns, education, advanced technologies (ITS.

  10. Systemic Approach to Traffic Evaluation of Mostar Airport

    Directory of Open Access Journals (Sweden)

    Eldo Raguž

    2005-11-01

    Full Text Available The attempt of this work is to systematically find solutionsfor Mostar Airport development through technical and technologicalharmonization of traffic processes undertaken in twoseparate organizations - airport and air traffic control and coordinationbetween other traffic branches. The work uses theindicators of traffic flows and tourist trends in the region, andtogether with the mentioned simulations it attempts to evaluatethe traffic potentials in the region by affecting the change in thecurrent negative traffic flows at Mostar Airport.

  11. RESEARCH OF TRAFFIC PREDICTION ACCURACY INFLUENCE ON THE EFFECTIVENESS OF TRAINS BREAKING-UP ORDER CONTROL

    Directory of Open Access Journals (Sweden)

    Oleksandr BARDAS

    2017-04-01

    Full Text Available The article presents the research results of economic feasibility of trains’ breaking-up order control at marshalling yards. The article objective was to determine the area of rational use of trains’ breaking-up order model, formalized in the form of stochastic programming problem. As a effectiveness criterion of trains’ breaking-up order operating costs of marshalling yard were used, including the costs associated with cars’ and locomotives’ dwell time on the station and its approaches, as well as costs associated with additional shunting work. With the help of simulation modeling the dependence was obtained, describing the impact of trains’ arrival forecasting error and processed car volumes on reducing operating costs of the marshalling yards through the trains’ breaking-up order control. The studies enable us to establish the requirements for the accuracy of information support of operational planning tasks, which is necessary to achieve the desired economic effect of the trains’ breaking-up order control.

  12. 基于模糊PID控制的网络异常流量监控设计%Network Abnormal Traffic Monitoring Based on Fuzzy PID Control

    Institute of Scientific and Technical Information of China (English)

    王俊士

    2016-01-01

    In the large network system, because of the network congestion or the virus invasion to produce abnormal network traffic, network traffic monitoring system design and security network security and stability. BP neural network control algorithm is used in the traditional network anomaly traffic monitoring system. The BP neural network's structure is simple, and it is difficult to detect the abnormal traffic. Based on the improved fuzzy PID control system, the traffic flow model and time series analysis model is built. The quantitative recursive entropy feature is extracted. The PID neural network control method is used to design the traffic monitoring system. The simulation results show that this method can detect the abnormal spectrum characteristics accurately, and can be used to detect the abnormal traffic in time domain.%在大型网络系统中,会因为网络拥堵或者病毒入侵产生网络异常流量,通过对网络异常流量的监控系统设计保障网络的安全稳定。传统的网络异常流量监控系统采用BP神经网络控制算法,由于BP神经网络的结构单一性,对异常流量中干扰性较强的数据难以有效检测发现,提出一种基于改进的模糊PID控制的网络流量异常监控系统设计方法,在流量传输模型和时间序列分析模型构建的基础上,提取异常流量序列的定量递归熵特征,采用模糊PID神经网络控制方法进行流量监控系统设计,把监控到的异常流量通过链路信道回馈给输出层。仿真结果表明,采用该方法进行网络异常流量监控,能准确检测出异常的频谱特征,从而在时域上进行追溯定位,实现流量异常点的准确检测,对异常流量的准确检测概率比传统方法高。

  13. Two-layer hierarchical control solutions for traffic signal%面向交通信号的两层递阶控制解决方案

    Institute of Scientific and Technical Information of China (English)

    戈军; 周莲英

    2015-01-01

    针对现有交通信号控制系统的诸多不足,提出了一种用于交通信号控制的两层递阶多Agent系统解决方案。通过将交通网络进行区域划分,利用底层Agent控制各交叉口,顶层Agent控制区域,从而实现两层递阶控制。底层Agent采用经典Q学习同步学习最优策略,顶层Agent利用Tile Coding非凡的连续空间处理能力,实现Q学习的动作值函数逼近方法。仿真实验结果表明,该分层递阶控制不但提高了交通信号控制系统效率,而且也为大规模应用提供了很好的可伸缩解决方案。%In view of the existing deficiencies of traffic signal control system, this paper proposes two-layer hierarchical multi-Agent system solution for traffic signal control. Through regional division of the traffic network, it uses the bottom level Agent to control the intersection, the top level Agent to control areas, so as to achieve the two-layer hierarchical con-trol. The bottom level Agent uses the classical Q-learning to synchronize the optimal strategy, the top level Agent utilizes the special continuous space processing ability of Tile Coding to achieve Q learning of action value function approxima-tion method. The simulation test results show that, the hierarchical control not only improves the efficiency of traffic signal control system, but also provides a good scalable solution for large-scale applications.

  14. Models for Predictive Railway Traffic Management

    NARCIS (Netherlands)

    Kecman, P.

    2014-01-01

    The potential growth in transport demand in the next decade and beyond requires a change from reactive to proactive traffic control to maintain and improve the reliability of railway traffic. In order to enable an anticipative approach to traffic management, it is necessary to develop the tools for

  15. Models for Predictive Railway Traffic Management

    NARCIS (Netherlands)

    Kecman, P.

    2014-01-01

    The potential growth in transport demand in the next decade and beyond requires a change from reactive to proactive traffic control to maintain and improve the reliability of railway traffic. In order to enable an anticipative approach to traffic management, it is necessary to develop the tools for

  16. 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,

  17. 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

  18. Automatic feedback on cognitive load and emotional state of traffic controllers

    NARCIS (Netherlands)

    Neerincx, M.A.; Harbers, M.; Lim, D.; Tas, V. van der

    2014-01-01

    Workload research in command, information and process-control centers, resulted in a modular and formal Cognitive Load and Emotional State (CLES) model with transparent and easy-to-modify classification and assessment techniques. The model distinguishes three representation and analysis layers with

  19. Delivery performance of conventional aircraft by terminal-area, time-based air traffic control: A real-time simulation evaluation

    Science.gov (United States)

    Credeur, Leonard; Houck, Jacob A.; Capron, William R.; Lohr, Gary W.

    1990-01-01

    A description and results are presented of a study to measure the performance and reaction of airline flight crews, in a full workload DC-9 cockpit, flying in a real-time simulation of an air traffic control (ATC) concept called Traffic Intelligence for the Management of Efficient Runway-scheduling (TIMER). Experimental objectives were to verify earlier fast-time TIMER time-delivery precision results and obtain data for the validation or refinement of existing computer models of pilot/airborne performance. Experimental data indicated a runway threshold, interarrival-time-error standard deviation in the range of 10.4 to 14.1 seconds. Other real-time system performance parameters measured include approach speeds, response time to controller turn instructions, bank angles employed, and ATC controller message delivery-time errors.

  20. Highway traffic model-based density estimation

    OpenAIRE

    Morarescu, Irinel - Constantin; CANUDAS DE WIT, Carlos

    2011-01-01

    International audience; The travel time spent in traffic networks is one of the main concerns of the societies in developed countries. A major requirement for providing traffic control and services is the continuous prediction, for several minutes into the future. This paper focuses on an important ingredient necessary for the traffic forecasting which is the real-time traffic state estimation using only a limited amount of data. Simulation results illustrate the performances of the proposed ...