Traffic Control Functions Research Articles

Android-based System for Intelligent Traffic Signal Control and Emergency Call Functionality

The aim of the system was to utilize technology to save lives in India by addressing the challenge of transporting patients during emergencies on congested roads. To tackle this problem, we developed two mobile apps - one for users and one for ambulance drivers. The user app requires signup and retrieves their address and location. Similarly, the ambulance driver app also retrieves their location. When the user presses the emergency button, a notification is sent to the ambulance driver via the app. The app then displays the shortest path, and traffic signals along the route are adjusted to facilitate a faster route to the hospital. Overall, our apps were created to aid accident victims in reaching the hospital promptly

A user-level traffic control function for interworking between optical access and 5G mobile networks

A user-level traffic control function for interworking between optical access and 5G mobile networks

Implementation and evaluation of the traffic control function in Pub/Sub type communication

Implementation and evaluation of the traffic control function in Pub/Sub type communication

Effects of Cognitive Loading on Pilots and Air Traffic Controller Performance: Implications for Neural Dynamics and Cognitive Flow

The digitized environment in aviation operations has seen marked growth and expansion as new technologies arrive and are implemented. The flight deck and air traffic control functions are two areas where growth is particularly robust. Previous work has identified the effects of compounded cognitive loading and SHELL interfaces in these work environments, and the potential consequences when relief or collaborative resource management is not employed effectively. This paper examines the relationship of cognitive loading in the context of cognitive flow to identify potential areas where neural metrics might aid in a better understanding of the dynamics to determine thresholds of overload. Application of the Triple-Network Model of neural regulation dynamics and Polyvagal Theory are explored for potential relationships to compromised situation awareness and working memory constraints. Conclusions indicate that when cognitive flow is disrupted, cognitive processing loads on working memory expand exponentially and rapidly reach a plateau that inhibits safe performance. Implications suggest a more focused effort in systems and training to address neural metrics and cognitive processing rates.

MATHEMATICAL MODEL OF ADAPTIVE CONTROL OF THE FUNCTIONING OF A TRAFFIC LIGHT AT THE CROSSROADS OF A URBAN TRANSPORTATION NETWORK

The subject of the research is the process of modeling the functioning of a traffic light, providing adaptive control of vehicles at the intersectionsof the city transport network. In the process of functioning of urban transport networks, such phenomena as traffic jams occur, which lead tosignificant economic losses, environmental degradation, frustration of road users and other types of negative impacts. Traffic jams often occur at thenodes of the urban transport network, which are intersections - the places of intersection, abutment or branching of roads of the urban network of thesame level. One of the causes of congestion is the ineffective management of traffic flows at intersections, which is provided by such an element of theintersection as a traffic light. Within the framework of the existing transport network, traffic lights that implement adaptive control with the help ofappropriate local controllers, and more complex system controllers created on their basis, ensuring that the situation in the external environment istaken into account, which is represented by several interconnected intersections, is currently one of the most important directions for solving theproblem of traffic jams. The traffic light flow control function is implemented using a microprocessor controller, which, according to a given algorithm, switches the traffic light colors corresponding to the phases of allowing and prohibiting the movement of the vehicle in the directions of theintersection roads.The article proposes a mathematical model for building an algorithm for the functioning of a microprocessor traffic light controller, whichprovides a prompt and adequate display of situations at intersections. The main features of the model include responsiveness to changes in situations atan intersection by changing the duration of the permissive phase of movement in each cycle of traffic light operation in proportion to the length of thequeue of vehicles in the corresponding direction of travel; adequate display of the external environment by several expressions of Poisson’s law,differing in different values of the parameter, each of which corresponds to a certain daily interval of traffic light functioning; the dynamics of changesin the traffic situation due to a decrease in the number of vehicles in the queue due to the passage of the intersection by vehicles during the green phaseof the traffic light is determined on the basis of expressions that determine the movement of bodies with uniformly accelerated and uniform movement,as well as on the basis of the differential equation of the dynamics of movement of vehicles in one row taking into account the delay caused by thereaction of drivers.

Assessment of Quality of Experience (QoE) of Web and Video Services over a Mobile Network Using a Network Emulator

This paper investigates the subjective assessment of QoE of web and video services over a mobile network. To achieve this, the authors used the network emulator (NetEm) traffic control functionality to simulate the dynamic behaviour of a mobile network. Experiments were conducted in a laboratory setting and test conditions were varied to ascertain the QoE, with a focus on QoE metrics such as delay and packet loss ratio. From the experiments conducted, it was observed that there was a negative correlation between delay and average mean opinion score (MOS), and between packet loss ratio and average MOS. The results obtained can be adopted by network operators to provide better services which would lead to improved subscriber base and profitability for the operators and better QoE for the end users.

Assessment of Operational Risks of Electric Interlocking Systems

This article proposes a technique for assessing risks related to operational reliability levels of systems of electric interlocking of track switches and signals at railroad stations. The assessment relies on the mathematical model of such random processes as failures and recoveries of the system of electric interlocking of track switches and signals and on using this system to fulfill train traffic control functions at a given station. The risk related to the operational safety of the electric interlocking system is calculated for the railroad station in general, not for a specific scenario of events. The statistics of safety violation events is based on a small sample. The risk related to the operational reliability of the electric interlocking system is assessed using risk matrices in the form of tables, where the likelihood of occurrence and the number of train delays at the station due to failures in the electric interlocking system are used together. The train delay likelihood found from the matrix is used as the frequency of events to assess operational reliability level risks. The number of trains delayed per calculated period and the average time of train delay at the considered station are used as event aftereffects. The assessment results can be used to make valid managerial decisions.

Cleared for takeoff? A snap-shot of climate for change in a civil aviation context

High risk industries are facing increasingly volatile, uncertain, complex and ambiguous (VUCA) environments requiring continual innovation and change. And this is particularly true within the civil aviation industry where increasing focus on economic performance, increased competition, and growing safety threats, require continual adjustments. In this paper, we present the findings of a case study conducted within the Norwegian national air traffic management organization – Avinor, in preparation for a major reorganization initiative. In this study, we mapped the aggregated positioning for innovation and change in the three main Air Traffic Control Centers in Norway using a multi- method approach that was taken to assess the climate for creativity and change at each ATCC from both quantitative and qualitative perspectives, and a separate assessment of individual preferences for change to help organizational leaders better understand each unit’s positioning for change. The results suggest that participants at the different ATCCs had developed distinctly different problem-solving preferences at both the group and individual levels despite the fact that each facility was manned by Norwegian air traffic controllers having similar education and training backgrounds, performed the same high-altitude air traffic control functions, used the same type of equipment, and operated within the same air traffic control environment. Yet, each unit proved to be distinctly different from each other in their positioning and readiness for change.

Hoarseness and vocal tract discomfort and associated risk factors in air traffic controllers

IntroductionAn air traffic controller is a professional who performs air traffic control functions in air traffic control units and is responsible for controlling the various stages of a flight. ObjectiveTo compare hoarseness and vocal tract discomfort and their risk factors among air traffic controllers in the approach control of São Paulo. MethodsIn a cross-sectional survey, a voice self-evaluation adapted from to self-evaluation prepared by the Brazilian Ministry of Labor for teachers was administered to 76 air traffic controllers at approach control of São Paulo, Brazil. ResultsThe percentage of hoarseness and vocal tract discomfort was 19.7% and 38.2%, respectively. In relation to air pollution, the percentages of hoarseness and vocal tract discomfort were higher among those who consider their working environment to be intolerable than among those in a comfortable or disturbing environment. The percentage of hoarseness was higher among those who seek medical advice due to vocal complaints and among those who experience difficulty using their voice at work than among those who experience mild or no difficulty. The percentage of vocal tract discomfort was higher among those in a very tense and stressful environment than among those who consider their work environment to be mild or moderately tense and stressful. The percentage of vocal tract discomfort was higher among those who describe themselves as very tense and stressed or tense and stressed than among those who describe themselves as calm. Additionally, the percentage of vocal tract discomfort was higher among those who care about their health. ConclusionAmong air traffic controllers, the percentage of vocal tract discomfort was almost twice that of hoarseness. Both symptoms are prevalent among air traffic controllers who considered their workplace intolerable in terms of air pollution. Vocal tract discomfort was related to a tense and stressful environment, and hoarseness was related to difficulty using the voice at work.

ПОСТРОЕНИЕ СИСТЕМЫ УПРАВЛЕНИЯ БЕЗОПАСНОСТЬЮ ДВИЖЕНИЯ В ЖЕЛЕЗНОДОРОЖНОЙ КОМПАНИИ С УЧЕТОМ ЭКОНОМИЧЕСКИХ ФАКТОРОВ

aspects, as, in the time of railway industry restructuring, the competitive freight and passenger market was formed with strategic problems of railway transport, which led to building a wasteful market model. Unsolved sector-specific issues and new threats, designated in the tasks of traffic safety control, created the risks of economic security weakening of a railway company. Methods: The methods of system and system-oriented analysis, as well as Delhi method were used. Results: The issues of traffic safety control in a railway company were considered (by the example of JSC «O’zbekiston Temir Yo’llari» («OTY»)); the necessity for determining traffic security standards was shown. The company’s data analysis made it possible to identify the strategic directions of traffic safety improvement and control function. The evaluation method of economic damage from potential failure risks, depending on the investments and working expenditures, was suggested. In accordance with the method in question, several approaches to forecasting traffic security were singled out, depending on the shifts in labour productivity and changes in the volume of investments and working expenditure. A control-flow chart of traffic safety with feedback was developed. Practical importance: The introduced organizational changes make it possible to build a new structure of traffic safety control, considering the interests of both the state and JSC “OTY.” The suggested traffic safety control-flow chart makes it possible to allocate and provide the reasonable funding of the brunch, in order to provide the required security level. The forecast may be conducted both for the network in general and for all railway districts separately. Moreover, the plans for working expenditure and investments may be optimized.

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

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.

Bandwidth Control Using Adaptive Packet Policer Management for Packet Transport Network Based on Service Layer Request

SUMMARYAs the mobile service, the cloud service, and machine‐to‐machine service are becoming more and more popular, network traffic increases drastically and the requirements for network services are diversifying. In this paper, we propose the transport network architecture using packet transport technology, which attains the integration of expanding traffic fairly and effectively. We propose the implementation of network traffic control functionalities, which can attain the variety of requirements for traffic control from many kinds of network services.

サービス要求と連携した適応型パケットポリサ制御によるパケットトランスポート網帯域制御方式

As the mobile service, the cloud service and M2M (Machine to Machine) service are becoming more and more popular, network traffic increases drastically and the requirements for network services are diversifying. In this paper we propose the transport network architecture using packet transport technology, which attains the integration of expanding traffic fairly, and effectively. We propose the implementation of network traffic control functionalities, which can attain the variety of requirements for traffic control from many kinds of network services.

A New Approach to an Automated Air Traffic Control

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 traffic more efficient and more environmentally friendly while maintaining safe separation. Language: en

Do High‐Reliability Systems Have Lower Error Rates? Evidence from Commercial Aircraft Accidents

High‐reliability advocates claim that highly reliable organizations (HROs), such as the Federal Aviation Administration's (FAA) air traffic control system, routinely demonstrate the ability to safely and reliably perform large‐scale technical operations. High levels of productivity with low levels of error are achieved even though complex technologies are used to accomplish mission goals. A recent study asserted that the FAA’s air traffic control function developed HRO characteristics over a long period of time as part of a larger high‐reliability system. In that study, identifiable and measurable attributes and characteristics associated with high reliability were constructed, and their emergence was tracked over time. In this article, time‐series analysis was used to measure the relationship between characteristics associated with high reliability and commercial aviation accident reduction. A small but statistically significant effect was identified linking the adoption of HRO characteristics over time with a reduction in commercial aviation accident rates.

P2P IPTV 서비스를 위한 세션 제어 메카니즘

본 논문은 P2P(Peer to Peer) IPTV(Internet Protocol Television) 서비스를 위한 세션 제어 모델을 제시하고, 제시된 모델에 근거한 IPTV 세션 제어 절차에 대해 논한다. 별도의 전용망에 의해 관련 트래픽이 처리되는 공중 IPTV(Public IPTV)와 달리 P2P IPTV 트래픽은 인터넷 접속 트래픽의 일부로 망에 의해 처리되어야 한다. 따라서 P2P IPTV 세션 제어는 IPTV를 구성하는 TPS(Triple Play Service) 트래픽을 기존 인터넷 트래픽과 분리하여 적절하게 제어할 수 있어야 하고, 분리된 TPS 트래픽을 차별화하여 처리하는 QoS(Quality of Service) 제어 기능을 포함해야 한다. 뿐만 아니라 P2P IPTV 세션 제어는 불특정 다수에 의한 비디오 전송을 효과적으로 지원하기 위한 적절한 멀티캐스트 제어 기능을 반드시 포함해야 한다. 본 논문의 P2P IPTV 세션 제어 모델은 상호 연동성(Inter-operability)이 보장되는 P2P IPTV 플랫폼의 조기 구축에 기여할 수 있도록 표준 SIP(Session Initiation Protocol), IGMP(Internet Group Management Protocol), 그리고 COPS(Common Open Policy Service) 프로토콜에 근거하여 설계되었다. This paper proposes a session control model for the P2P(Peer to Peer) IPTV(Internet Protocol Television) services and presents the IPTV session control procedures based on the proposed model. Since, while public IPTV traffic is usually processed via a separate network, P2P IPTV traffic is processed together with the conventional Internet access traffic, the P2P IPTV control mechanism needs to provide multi-stream processing for the constituent TPS(Triple Play Service) traffic and corresponding QoS(Quality of Service) control functions. Besides, P2P IPTV session control mechanism should provide appropriate multicast control functions in order to support effective transmission of video traffic generated by personal IPTV broadcasters. The P2P IPTV session control model proposed in this paper is designed to be based on the standard SIP(Session Initiation Protocol), IGMP(Internet Group Management Protocol), and COPS(Common Open Policy Service) protocol so that it can contribute to the easy and prompt deployment of inter-operable P2P IPTV platform.

A versatile timing unit for traffic shaping, policing and charging in packet-switched networks

Timing has a key role in several traffic control functions encountered in modern packet-switched networks. In order to be effective, a timing unit must provide fine resolution, be simple to implement and scale well with the number of controlled traffic streams. This paper addresses the design, implementation and evaluation of a timing unit that can support accurate and efficient implementations of traffic shaping, policing and charging in packet-switched networks. The timing unit is implemented in hardware and, therefore, overcomes constraints associated with software-based timers. It accommodates a pool of independently-clocked timers and counters, organised in timing blocks, and, consequently, is able to support, in parallel, traffic streams with diverse timing requirements. The design supports shaping and policing through token buckets, leaky buckets and a scheme, variation of the token bucket, that aims at providing statistical quality of service guarantees by exploiting the effective rate concept. Charging is supported by dedicated counters that measure the utilization of the effective rate. The granularity of the timing unit is adjustable in run-time to adapt to changes in the rate parameters of the shaping and policing functions. The validation of the timing unit is done through the development of a prototype board consisting of programmable hardware and embedded software blocks. The temporal resolution of the timing unit and the advantages of the hardware/software co-design are experimentally evaluated.

An optimal downsampling procedure for microscopic simulation modeling of transportation networks: a proof-of-concept study

This paper investigates and demonstrates the concept of scalability of microscopic traffic simulation systems as a means of reducing the associated computational requirements and maximizing their potential support for real-time traffic control and management functions. The primary goal of this research is to examine the feasibility of transforming the original simulation environment into a downsampled simulation environment, where fewer representative entities are simulated. This must be achieved, however, while retaining maximum fidelity to microscopic simulation properties and preserving most of the macroscopic characteristics. The methodology is presented as an optimization problem whose objective is to minimize the errors resulting from the transformation process and to seek optimal values of the behavioral parameters in the downsampled environment. In this proof-of-concept stage, experimental analysis was conducted on a homogeneous freeway segment using one of the well-known, and arguably sufficiently calibrated, car-following models developed by General Motors Laboratories (GM3). The results were promising and showed that optimal relationships between the behavioral parameters in both environments can be established to minimize the information loss associated with the transformation process.Key words: microscopic simulation, scalability, computational efficiency, downsampling, car-following models.

A QoS-aware residential gateway with bandwidth management

The residential gateway (RG) is the core device of the digital home network. The RG translates communication protocols, coordinates information sharing and serves as a gateway to external networks for integrated multimedia entertainment, on-line services, home security, home automation, information exchange and data storage. Modern home network applications especially for real-time are demanding guaranteed quality of service (QoS) for bounded network bandwidth resources. In order to initiate a DiffServ-QoS (differentiated services-QoS) bandwidth management mechanism during network congestion, this paper proposes a QRG (QoS-aware residential gateway) with both real-time traffic monitoring, DiffServ-QoS and CBQ bandwidth management. Firstly, QRG classifies traffic flow into separate types, with specialized treatment per traffic type to optimize compliance with user-specified priorities. Applications with higher priority get the right to deliver first. Additionally, QRG with built-in traffic control function adopts class based queuing (CBQ) as DiffServ-QoS bandwidth/traffic management for optimized use of bounded network resources. QRG is experimentally implemented on a Linux platform. High-end application is simulated by hosting QRG in a general-purpose PC, while minimum-cost modular application is simulated by hosting QRG in a light-weight low-power ARM920T embedded system. Results show that in both implementations, QRG successfully performs DiffServ-QoS and CBQ bandwidth management functions so that good quality of service and video performance are maintained during network congestion.

A simulation-based performance evaluation of Tahoe, Reno and Sack TCP as appropriate transport protocols for SIP

The Session Initiation Protocol currently supports the use of both the Transmission Control Protocol and the User Datagram Protocol as transport protocols. Proponents of the SIP protocol have cited this characteristic as a laudable consequence of the modular nature of SIP. However, the explicit support of an unreliable protocol such as UDP leads to, arguably, unnecessary complication in the protocol standard. The matter has been the subject of recent debate with some favouring the deprecation of explicit support for UDP. This paper seeks to compare the performance of different TCP variants, specifically the Tahoe, Reno and Selective Acknowledgement (Sack) variants in the particular context of SIP signalling. We simulate a scenario that is likely to receive the maximum benefit from TCP's end system-based traffic control functionality; we present results and draw conclusions from our evaluation.