WorldWideScience

Sample records for bandwidth traffic signals

  1. Directing Traffic: Managing Internet Bandwidth Fairly

    Science.gov (United States)

    Paine, Thomas A.; Griggs, Tyler J.

    2008-01-01

    Educational institutions today face budgetary restraints and scarce resources, complicating the decision of how to allot bandwidth for campus network users. Additionally, campus concerns over peer-to-peer networking (specifically outbound Internet traffic) have increased because of bandwidth and copyright issues. In this article, the authors…

  2. Bandwidth sharing networks with multiscale traffic

    Directory of Open Access Journals (Sweden)

    Mathieu Feuillet

    2015-03-01

    Full Text Available In multi-class communication networks, traffic surges due to one class of users can significantly degrade the performance for other classes. During these transient periods, it is thus of crucial importance to implement priority mechanisms that conserve the quality of service experienced by the affected classes, while ensuring that the temporarily unstable class is not entirely neglected. In this paper, we examine the complex interaction occurring between several classes of traffic when classes obtain bandwidth proportionally to their incoming traffic. We characterize the evolution of the performance measures of the network from the moment the initial surge takes place until the system reaches its equilibrium. Using a time-space-transition-scaling, we show that the trajectories of the temporarily unstable class can be described by a differential equation, while those of the stable classes retain their stochastic nature. In particular, we show that the temporarily unstable class evolves at a time-scale which is much slower than that of the stable classes. Although the time-scales decouple, the dynamics of the temporarily unstable and the stable classes continue to influence one another. We further proceed to characterize the obtained differential equations for several simple network examples. In particular, the macroscopic asymptotic behavior of the unstable class allows us to gain important qualitative insights on how the bandwidth allocation affects performance. We illustrate these results on several toy examples and we finally build a penalization rule using these results for a network integrating streaming and surging elastic traffic.

  3. Bandwidth Optimization in Centralized WLANs for Different Traffic Types

    Directory of Open Access Journals (Sweden)

    R. J. Haines

    2007-03-01

    Full Text Available Allocating bandwidth between different forms of coexisting traffic (such as web-browsing, streaming, and telephony within a wireless LAN is a challenging and interesting problem. Centralized coordination functions in wireless LANs offer several advantages over distributed approaches, having the benefit of a system overview at the controller, but obtaining a stable configuration of bandwidth allocation for the system is nontrivial. We present, review, and compare different mechanisms to achieve this end, and a number of different means of obtaining the configurations themselves. We describe an analytical model of the system under consideration and present two mathematical approaches to derive solutions for any system configuration and deployment, along with an adaptive feedback-based solution. We also describe a comprehensive simulation-based model for the problem, and a prototype that allows comparison of these approaches. Our investigations demonstrate that a self-adaptive dynamic approach far outperforms any static scheme, and that using a mathematical model to produce the configurations themselves confers several advantages.

  4. Bandwidth Optimization in Centralized WLANs for Different Traffic Types

    Directory of Open Access Journals (Sweden)

    Haines RJ

    2007-01-01

    Full Text Available Allocating bandwidth between different forms of coexisting traffic (such as web-browsing, streaming, and telephony within a wireless LAN is a challenging and interesting problem. Centralized coordination functions in wireless LANs offer several advantages over distributed approaches, having the benefit of a system overview at the controller, but obtaining a stable configuration of bandwidth allocation for the system is nontrivial. We present, review, and compare different mechanisms to achieve this end, and a number of different means of obtaining the configurations themselves. We describe an analytical model of the system under consideration and present two mathematical approaches to derive solutions for any system configuration and deployment, along with an adaptive feedback-based solution. We also describe a comprehensive simulation-based model for the problem, and a prototype that allows comparison of these approaches. Our investigations demonstrate that a self-adaptive dynamic approach far outperforms any static scheme, and that using a mathematical model to produce the configurations themselves confers several advantages.

  5. Bandwidth allocation strategy for traffic systems of scale-free network

    International Nuclear Information System (INIS)

    In this Letter, the bandwidth resource allocation strategy is considered for traffic systems of complex networks. With a finite resource of bandwidth, an allocation strategy with preference parameter α is proposed considering the links importance. The performance of bandwidth allocation strategy is studied for the local routing protocol and the shortest path protocol. When important links are slightly favored in the bandwidth allocation, the system can achieve the optimal traffic performance for the two routing protocols. For the shortest path protocol, we also give a method to estimate the network traffic capacity theoretically.

  6. Dual use of LED traffic signal system

    OpenAIRE

    Cheung, SW; Yang, ES; Tam, YY; Man, CW; D. Yang

    1999-01-01

    The dual use, signaling and communication, of LED traffic signal system is described and analyzed. The primary function of a traffic light system is to give traffic and pedestrian signals. A prototype of LED traffic signal head is developed to perform a secondary function: communication. A wireless communication link is set up using the LED traffic signal head as the transmitter. The LEDs are modulated to transmit information-carrying light. The receiver uses a silicon photodiode to detect th...

  7. Bandwidth Impacts of Localizing Peer-to-Peer IP Video Traffic in Access and Aggregation Networks

    Directory of Open Access Journals (Sweden)

    Kerpez Kenneth

    2008-01-01

    Full Text Available Abstract This paper examines the burgeoning impact of peer-to-peer (P2P traffic IP video traffic. High-quality IPTV or Internet TV has high-bandwidth requirements, and P2P IP video could severely strain broadband networks. A model for the popularity of video titles is given, showing that some titles are very popular and will often be available locally; making localized P2P attractive for video titles. The bandwidth impacts of localizing P2P video to try and keep traffic within a broadband access network area or within a broadband access aggregation network area are examined. Results indicate that such highly localized P2P video can greatly lower core bandwidth usage.

  8. Bandwidth Impacts of Localizing Peer-to-Peer IP Video Traffic in Access and Aggregation Networks

    Directory of Open Access Journals (Sweden)

    Kenneth Kerpez

    2008-10-01

    Full Text Available This paper examines the burgeoning impact of peer-to-peer (P2P traffic IP video traffic. High-quality IPTV or Internet TV has high-bandwidth requirements, and P2P IP video could severely strain broadband networks. A model for the popularity of video titles is given, showing that some titles are very popular and will often be available locally; making localized P2P attractive for video titles. The bandwidth impacts of localizing P2P video to try and keep traffic within a broadband access network area or within a broadband access aggregation network area are examined. Results indicate that such highly localized P2P video can greatly lower core bandwidth usage.

  9. Traffic Signal Using Smart Agent System

    OpenAIRE

    Cheonshik Kim; You S. Hong

    2008-01-01

    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...

  10. 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.

  11. Traffic Signals in Motorcycle Dependent Cities

    OpenAIRE

    Do, Quoc Cuong

    2009-01-01

    Traffic signal control was first invented in 1868 in Great Britain. Then, it has quickly spread across many other countries, what are now usually developed countries. Therefore, during a long history of development, traffic signals usually have been dealing with traffic in which four-wheel vehicles play an important role in motorised traffic. However, as a result of an unequal development among countries, many Motorcycle Dependent Cities (MDCs) nowadays still exist mostly in the developing co...

  12. Light signals for road traffic control.

    OpenAIRE

    Schreuder, D.A.

    1981-01-01

    Signals for road traffic control are a major constituent of the modern traffic scene, particularly in built-up areas. A vast amount of research has been executed in the last two decennia, resulting in a fairly generally accepted view on what the requirements for effective traffic lights are. For the French translation see B 19780

  13. An improved scheduled traffic model utilizing bandwidth splitting in elastic optical networks

    Science.gov (United States)

    Vyas, Upama; Prakash, Shashi

    2016-07-01

    The surge of traffic in today's networks gave birth to elastic optical networking paradigm. In this paper, first we propose to use the scheduled traffic model (STM) in elastic optical networks (EONs) to ensure guaranteed availability of resources to demands which enter into the network with a predetermined start and end times. In optical networks, such demands are referred to as scheduled lightpath demands (SLDs). To increase the amount of bandwidth accepted in network, next we introduce a time aware routing and spectrum assignment (TA-RSA) approach. We observed that provisioning of bulky SLDs has become more challenging in EONs due to enforcement of RSA constraints. To address this challenge, we improve the proposed STM and designed three heuristics for its implementation in EONs. In this work, we collectively refer to these heuristics as bandwidth segmented RSA (BSRSA). The improved STM (iSTM) allows splitting of SLDs in bandwidth dimension by utilizing the knowledge of attributes viz. demand holding time, overlapping in time and bandwidth requested by SLDs. Our numerical results show that BSRSA consistently outperformed over TA-RSA under all distinctive experimental cases that we considered and achieved fairness in serving heterogeneous bandwidth SLDs. The impact of splitting on the number and capacity of transponders at nodes is also gauged. It is observed that ingenious splitting of demands increases the number of resources (on links and nodes) used, and their utilization, leading to an increase in bandwidth accepted in the network.

  14. 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.

  15. Biometric recognition system using low bandwidth ECG signals

    OpenAIRE

    Matos, André Cigarro; Lourenço, André Ribeiro; Nascimento, José M. P.

    2013-01-01

    Biometric recognition has recently emerged as part of applications where the privacy of the information is crucial, as in the health care field. This paper presents a biometric recognition system based on the Electrocardiographic signal (ECG). The proposed system is based on a state-of-the-art recognition method which extracts information from the frequency domain. In this paper we propose a new method to increase the spectral resolution of low bandwidth ECG signals due to the limited bandwid...

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

    OpenAIRE

    Yan Ge

    2014-01-01

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

  17. Modelling of urban traffic networkof signalized intersections

    OpenAIRE

    Ocran, Abena Kwantwiwaa

    2013-01-01

    This report presents how traffic network of signalized intersection in a chosen urban area called Tema is synchronized. Using a modular approach, two different types of traffic intersection commonly found in an urban area were modelled i.e. a simple intersection and a complex intersection. A direct road, even though not an intersection, was also included in the modelling because it’s commonly found in an urban area plus it connects any two intersections. Each of these scenarios was modelled u...

  18. System and method for traffic signal timing estimation

    KAUST Repository

    Dumazert, Julien

    2015-12-30

    A method and system for estimating traffic signals. The method and system can include constructing trajectories of probe vehicles from GPS data emitted by the probe vehicles, estimating traffic signal cycles, combining the estimates, and computing the traffic signal timing by maximizing a scoring function based on the estimates. Estimating traffic signal cycles can be based on transition times of the probe vehicles starting after a traffic signal turns green.

  19. Multi-rate asynchronous sampling of bandwidth-limited signals

    CERN Document Server

    Feldster, Alfred; Horowitz, Moshe; Rosenthal, Amir; Zach, Shlomo; Singer, Lea

    2008-01-01

    We demonstrate experimentally an optical system for under-sampling several bandwidth limited signals with carrier frequencies that are not known apriori that can be located anywhere within a very broad frequency region between 0-18 GHz. The system is based on under-sampling asynchronously at three different sampling rates. The pulses required for the under-sampling are generated by a combination of an electrical comb generator and an electro-absorption modulator. To reduce loss and improve performance the implementation of the optical system is based on a wavelength division multiplexing technique. An accurate reconstruction of both the phase and the amplitude of the signals was obtained when two chirped signals generated simultaneously were sampled.

  20. Low Bandwidth Vocoding using EM Sensor and Acoustic Signal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Ng, L C; Holzrichter, J F; Larson, P E

    2001-10-25

    Low-power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference [1]. By combining these data with the corresponding acoustic signal, we've demonstrated an almost 10-fold bandwidth reduction in speech compression, compared to a standard 2.4 kbps LPC10 protocol used in the STU-III (Secure Terminal Unit, third generation) telephone. This paper describes a potential EM sensor/acoustic based vocoder implementation.

  1. Low Bandwidth Vocoding using EM Sensor and Acoustic Signal Processing

    International Nuclear Information System (INIS)

    Low-power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference [1]. By combining these data with the corresponding acoustic signal, we've demonstrated an almost 10-fold bandwidth reduction in speech compression, compared to a standard 2.4 kbps LPC10 protocol used in the STU-III (Secure Terminal Unit, third generation) telephone. This paper describes a potential EM sensor/acoustic based vocoder implementation

  2. Adaptive Traffic Signalization Model using Neuro-Fuzzy Controllers

    OpenAIRE

    Devesh Batra; Pragya Verma

    2014-01-01

    Current traffic lights are pre-programmed and use daily signal timing schedules, which contribute to traffic congestion and delay. Thus, with the increase in the number of vehicles on road, need for adaptive signal technology arises which has the potential to adjust the timing of red, yellow and green lights in order to accommodate changing traffic patterns and ease traffic congestion. In this paper, we present a model for adaptive traffic signalization, which uses fuzzy neura...

  3. Re-use of Low Bandwidth Equipment for High Bit Rate Transmission Using Signal Slicing Technique

    DEFF Research Database (Denmark)

    Wagner, Christoph; Spolitis, S.; Vegas Olmos, Juan José;

    : Massive fiber-to-the-home network deployment requires never ending equipment upgrades operating at higher bandwidth. We show effective signal slicing method, which can reuse low bandwidth opto-electronical components for optical communications at higher bit rates.......: Massive fiber-to-the-home network deployment requires never ending equipment upgrades operating at higher bandwidth. We show effective signal slicing method, which can reuse low bandwidth opto-electronical components for optical communications at higher bit rates....

  4. Modelling Signal Controlled Traffic Based on Driving Behaviors

    OpenAIRE

    Yang Wang; Yanyan Chen; Ning Chen

    2015-01-01

    In urban traffic, of particular interest the traffic breakdown which is primarily resulted from the driving behaviors is emerged to respond to the traffic signal. To investigate the influences of driving behaviors on the traffic breakdown, a cellular automaton model has been developed by incorporating a number of driving behaviors typically manifesting during the different stages when the vehicle approaching a traffic light. Numerical simulations have been performed based on a road segment co...

  5. Adaptive Traffic Signalization Model using Neuro-Fuzzy Controllers

    Directory of Open Access Journals (Sweden)

    Devesh Batra*

    2014-07-01

    Full Text Available Current traffic lights are pre-programmed and use daily signal timing schedules, which contribute to traffic congestion and delay. Thus, with the increase in the number of vehicles on road, need for adaptive signal technology arises which has the potential to adjust the timing of red, yellow and green lights in order to accommodate changing traffic patterns and ease traffic congestion. In this paper, we present a model for adaptive traffic signalization, which uses fuzzy neural network for designing traffic signal controller. The controllers use vehicle detectors in order to detect the number of incoming vehicles. Based on the number of approaching vehicles, the current signal phase is either extended or terminated. The traffic volume at one particular region in an intersection is compared with that in the competing regions of the same intersection. The decision made is thus robust and results in less congestion and delays.

  6. An Assessment Methodology for Emergency Vehicle Traffic Signal Priority Systems

    OpenAIRE

    McHale, Gene Michael

    2002-01-01

    Emergency vehicle traffic signal priority systems allow emergency vehicles such as fire and emergency medical vehicles to request and receive a green traffic signal indication when approaching an intersection. Such systems have been around for a number of years, however, there is little understanding of the costs and benefits of such systems once they are deployed. This research develops an improved method to assess the travel time impacts of emergency vehicle traffic signal priority system...

  7. Multi-rate synchronous optical undersampling of several bandwidth-limited signals.

    Science.gov (United States)

    Fleyer, M; Horowitz, M; Feldtser, A; Smulakovsky, V

    2010-08-01

    We demonstrate experimentally an optical system for undersampling several bandwidth-limited signals with carrier frequencies that are not known apriori and can be located within a broad frequency region of 0-20 GHz. The system is based on undersampling synchronously at three different rates. The optical undersampling down-converts the entire system bandwidth into a low frequency region called baseband. The synchronous sampling at several rates enables to accurately reconstruct signals even in cases in which different signals overlap in the baseband region of all sampling channels. Reconstruction of three simultaneously generated chirped signals, each with a bandwidth of about 200 MHz, was experimentally demonstrated. PMID:20721083

  8. 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.

  9. Identification and optimization of traffic bottleneck with signal timing

    OpenAIRE

    Shaoxin Yuan; Xiangmo Zhao; Yisheng An

    2014-01-01

    In urban transportation network, traffic congestion is likely to occur at traffic bottlenecks. The signal timing at intersections together with static properties of left-turn and straight-through lanes of roads are two significant factors causing traffic bottlenecks. A discrete-time model of traffic bottleneck is hence developed to analyze these two factors, and a bottleneck indicator is introduced to estimate the comprehensive bottleneck degree of individual road in regional transportation n...

  10. Traffic breakdown at a signal: classical theory versus the three-phase theory of city traffic

    International Nuclear Information System (INIS)

    Physical reasons for a crucial difference between the results of a three-phase theory developed recently (Kerner 2011 Phys. Rev. E 84 045102(R); 2013 Europhys. Lett. 102 28010; 2014 Physica A 397 76) and the classical theory are explained. Microscopic characteristics of traffic passing a traffic signal during the green signal phase and their dependence on the duration of the green phase have been found. It turns out that a moving synchronized flow pattern (MSP), which occurs in under-saturated traffic at the signal, causes ‘compression’ of traffic flow: the rate of MSP discharge can be considerably larger than the saturation flow rate of the classical traffic theory of city traffic. This leads to a considerably larger rate of traffic passing the signal in comparison with the saturation flow rate. This effect together with traffic behavior at the upstream queue front explains the metastability of under-saturated traffic with respect to a random time-delayed traffic breakdown. (paper)

  11. Traffic breakdown at a signal: classical theory versus the three-phase theory of city traffic

    Science.gov (United States)

    Kerner, Boris S.; Klenov, Sergey L.; Schreckenberg, Michael

    2014-03-01

    Physical reasons for a crucial difference between the results of a three-phase theory developed recently (Kerner 2011 Phys. Rev. E 84 045102(R); 2013 Europhys. Lett. 102 28010; 2014 Physica A 397 76) and the classical theory are explained. Microscopic characteristics of traffic passing a traffic signal during the green signal phase and their dependence on the duration of the green phase have been found. It turns out that a moving synchronized flow pattern (MSP), which occurs in under-saturated traffic at the signal, causes ‘compression’ of traffic flow: the rate of MSP discharge can be considerably larger than the saturation flow rate of the classical traffic theory of city traffic. This leads to a considerably larger rate of traffic passing the signal in comparison with the saturation flow rate. This effect together with traffic behavior at the upstream queue front explains the metastability of under-saturated traffic with respect to a random time-delayed traffic breakdown.

  12. Fuzzy Multiobjective Traffic Light Signal Optimization

    OpenAIRE

    N. Shahsavari Pour; H. Asadi; M. Pour Kheradmand

    2013-01-01

    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 ...

  13. Traffic signals - alternative method for emissions reduction; Liikennevaloillako paeaestoet alas

    Energy Technology Data Exchange (ETDEWEB)

    Niittymaeki, J. [Helsinki Univ. of Technology, Espoo (Finland)

    2001-07-01

    Traffic signalling is a process, which adapts to the prevailing traffic. The objective of traffic signalling is to direct traffic as safely as possible through a road junction. Other objectives are to maximize the road capacity, to clarify the traffic, and to effect the selection of routs. The target of design and timing of traffic signalling is to minimize the delays of the traffic. However, traffic signalling increases the emissions and fuel consumption. Traditionally the traffic adaptive control has been arranged on the basis of the extension principle, which means the extension of the green light as long as there is demand for the signal, however, only to a set maximum time. In practice the systems seeks an adequate distance in the traffic for cutting off the green light. New methods, such as mathematical optimization, fuzzy logic, neural networks and generic algorithms have been included traffic signalling. These new methods have proven to be 10-20% more efficient than the old ones. Results of the researches have shown that it is possible to achieve significant savings in social economy, including savings in fuels consumption and environmental impacts of the traffic, by development/renovation of traffic signalling. This article reviews the studies carried out in Finland on traffic signalling. A typical driving process through a signalized road junction: deceleration, idle running, acceleration and steady driving. The emissions of these phases differ from each other. Gasoline-fueled cars equipped with catalyst produces significantly more CO during idle running than in the other phases, and the HC content is highest during deceleration. On the other hand NO{sub x} formation is highest during acceleration. Formation of CO, HC and aldehydes is lowest during steady driving, and the formation of NO{sub x} during deceleration. CO and NO{sub x} emissions of diesel engines are highest during acceleration, and HC emissions during idle running. Total emissions of diesel

  14. Acousto-optics bandwidth broadening in a Bragg cell based on arbitrary synthesized signal methods.

    Science.gov (United States)

    Peled, Itay; Kaminsky, Ron; Kotler, Zvi

    2015-06-01

    In this work, we present the advantages of driving a multichannel acousto-optical deflector (AOD) with a digitally synthesized multifrequency RF signal. We demonstrate a significant bandwidth broadening of ∼40% by providing well-tuned phase control of the array transducers. Moreover, using a multifrequency, complex signal, we manage to suppress the harmonic deflections and return most of the spurious energy to the main beam. This method allows us to operate the AOD with more than an octave of bandwidth with negligible spurious energy going to the harmonic beams and a total bandwidth broadening of over 70%. PMID:26192666

  15. Signal Groups of Compatible Graph in Traffic Control Problems

    Directory of Open Access Journals (Sweden)

    Arun Kumar Baruah

    2012-07-01

    Full Text Available Signal Groups of a compatibility graph is used to solve conflict between the traffic streams and hence can be used as a solution for traffic control problem at an intersection. In this paper we have considered cliques of the compatible graph as signal groups and the set of signal groups which can simultaneously move at an intersection is taken in a phase. Phasing of traffic lights is done by splitting the cycle time among these phases so that each set of signal group is allowed to move once in the cycle.

  16. Influences of overtaking on two-lane traffic with signals

    Science.gov (United States)

    Chen, Chen; Chen, Jianqiao; Guo, Xiwei

    2010-01-01

    Based on the cellular automata method (CA method), two-lane traffic flow with the consideration of overtaking is investigated. Discrete equations are proposed to describe the traffic dynamics by using the rules of CA model. Influences of signal cycle time ( ts) and vehicular density (ρ) on the mean velocity and mean overtaking times of the traffic flow are discussed. The effects of slow vehicles and road barricades on the traffic flow are also studied. Simulation results shows that the vehicular density and the signal cycle time have significant influences on the traffic flow. The mean velocity of the traffic flow could keep a comparatively large value when ρ≤0.45. For a certain value of ρ, displays a serrated fluctuation with ts. Therefore, there may exist a certain combination of ρ and ts which optimizes the traffic flow efficiency. As compared with the results in Nagatani (2009) [7], the model proposed here and the simulation results which took into account the effects of signal cycle time, slow vehicles, and road barricades on the traffic flow with overtaking allowed, can reflect the situation of traffic flow in a more realistic way.

  17. Stimulated Brillouin scattering gain bandwidth reduction and applications in microwave photonics and optical signal processing

    Science.gov (United States)

    Preussler, Stefan; Schneider, Thomas

    2016-03-01

    Stimulated Brillouin scattering (SBS) is one of the most dominant nonlinear effects in standard single-mode fibers and its unique spectral characteristics, especially the narrow bandwidth, enable many different applications. Most of the applications would benefit from a narrower bandwidth. Different methods for the bandwidth reduction of SBS in optical fibers are presented and discussed. A bandwidth reduction down to 17% of the natural gain can be achieved by the superposition of the gain with two losses or the utilization of a multistage system. Furthermore, applications in the field of microwave photonics and optical signal processing like high-resolution spectroscopy of communication signals, the storage of optical data packets as well as the processing of frequency combs including generation of millimeter waves and ideal sinc-shaped Nyquist pulses are presented.

  18. Increasing Market Penetration of LED Traffic Signals in New York State: Review of Articles and Information on LED Traffic Signals

    OpenAIRE

    Bullough, John D; Suozzo, Margaret

    2002-01-01

    A primary purpose of this review is to identify and summarize recently published information about the use and performance of light-emitting diode (LED) traffic signals. It consists of two sections: a synopsis of experiences of municipalities using LED traffic signals in 1999 and 2000, and a discussion of technical, economic and market issues surrounding the deployment of LED signals. This review includes articles and reports published in 1999 and 2000.

  19. Integrating Traffic Signal Performance Measures into Agency Business Processes

    OpenAIRE

    Day, Christopher M.; Bullock, Darcy M; Li, Howell; Lavrenz, Steven M; Smith, W. Benjamin; Sturdevant, James R

    2016-01-01

    This report discusses uses of and requirements for performance measures in traffic signal systems facilitated by high-resolution controller event data. Uses of external travel time measurements are also discussed. The discussion is led by a high-level synthesis of the systems engineering concepts for traffic signal control, considering technical and non-technical aspects of the problem. This is followed by a presentation of the requirements for implementing data collection and processing of t...

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

    Science.gov (United States)

    Yan, Fei; Tian, Fuli; Shi, Zhongke

    2016-03-01

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

  1. Theory of self-organized traffic at light signal

    CERN Document Server

    Kerner, Boris S

    2012-01-01

    Based on numerical simulations of a three-phase traffic flow model, a probabilistic theory of traffic at the light signal is developed. We have found that very complex spatiotemporal self-organized phenomena determine features of city traffic. We have revealed that the breakdown of {\\it green wave} in a city is initiated by the emergence of a moving synchronized flow pattern (MSP) within the green wave. It turns out that a sequence of F$\\rightarrow$S$\\rightarrow$J transitions (F -- free flow, S -- synchronized flow, J -- moving queue) lead to traffic breakdown at the light signal. Both spontaneous and induced breakdowns of the green wave have been found. From a study of a variety of scenarios for arrival traffic, we have found that there are the infinite number of capacities of traffic at the light signal, which are in a capacity range between a minimum capacity and maximum capacity; each of the capacities gives a flow rate at which under-saturated traffic is in a metastable state with respect to the transiti...

  2. The Mutual Interaction effects between Array Antenna Parameters and Receiving Signals Bandwidth

    Directory of Open Access Journals (Sweden)

    Shahad D. Sateaa

    2014-03-01

    Full Text Available The presence of a single complex adaptive weight in each element channel of an adaptive array antenna is sufficient for processing of narrowband signals. The ability of an adaptive array antenna to null interference deteriorates rapidly as the interference bandwidth increases. The performance of narrowband adaptive array antenna with LMCV Beamforming algorithm is examined. The interaction effects between received signal angle of arrival and array parameters like the interelement spacing and the number of array element and the received signal bandwidth were studied. The output Signal to Interference plus Noise Ratio (SINR and Interference to Noise Ratio (INR are used as performance parameters for evaluation of these effects. It is found that the amount of degradation in the output SINR is increased significantly with the increase of array interelement spacing, number of array elements and when the angle of arrival of received signals are closet to end fire.

  3. Theory of self-organized traffic at light signal

    OpenAIRE

    Kerner, Boris S.

    2012-01-01

    Based on numerical simulations of a three-phase traffic flow model, a probabilistic theory of traffic at the light signal is developed. We have found that very complex spatiotemporal self-organized phenomena determine features of city traffic. We have revealed that the breakdown of {\\it green wave} in a city is initiated by the emergence of a moving synchronized flow pattern (MSP) within the green wave. It turns out that a sequence of F$\\rightarrow$S$\\rightarrow$J transitions (F -- free flow,...

  4. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    OpenAIRE

    Xiaojian Hu; Jian Lu; Wei Wang,; Ye Zhirui

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essen...

  5. Emergency vehicle traffic signal preemption system

    Science.gov (United States)

    Bachelder, Aaron D. (Inventor); Foster, Conrad F. (Inventor)

    2011-01-01

    An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a control module for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a priority-code (i.e. Code-3) situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a control module which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection. Real-time communications and operations software allow central and remote monitoring, logging, and command of intersections and vehicles.

  6. Acoustic Signal based Traffic Density State Estimation using SVM

    Directory of Open Access Journals (Sweden)

    Prashant Borkar

    2013-06-01

    Full Text Available Based on the information present in cumulative acoustic signal acquired from a roadside-installed single microphone, this paper considers the problem of vehicular traffic density state estimation. The occurrence and mixture weightings of traffic noise signals (Tyre, Engine, Air Turbulence, Exhaust, and Honks etc are determined by the prevalent traffic density conditions on the road segment. In this work, we extract the short-term spectral envelope features of the cumulative acoustic signals using MFCC (Mel-Frequency Cepstral Coefficients. Support Vector Machines (SVM is used as classifier is used to model the traffic density state as Low (40 Km/h and above, Medium (20-40 Km/h, and Heavy (0-20 Km/h. For the developing geographies where the traffic is non-lane driven and chaotic, other techniques (magnetic loop detectors are inapplicable. SVM classifier with different kernels are used to classify the acoustic signal segments spanning duration of 20–40 s, which results in average classification accuracy of 96.67% for Quadratic kernel function and 98.33% for polynomial kernel function, when entire frames are considered for classification.

  7. All-optical characterization of large-signal modulation bandwidth of a monolithically integrated DFB-EA

    DEFF Research Database (Denmark)

    Blaaberg, Søren; Mulvad, Hans Christian Hansen; Oxenløwe, Leif Katsuo; Chacinski, Marek; Westergren, Urban; Stoltz, Björn

    We use an all-optical method to characterize the modulation bandwidth of a DFB-EA designed for 100 Gb/s Ethernet. In a large-signal wavelength conversion set-up, we show the device has an all-optical bandwidth of 83 GHz.......We use an all-optical method to characterize the modulation bandwidth of a DFB-EA designed for 100 Gb/s Ethernet. In a large-signal wavelength conversion set-up, we show the device has an all-optical bandwidth of 83 GHz....

  8. The Use of Audible Traffic Signals in the United States.

    Science.gov (United States)

    Peck, A. F.; Uslan, M.

    1990-01-01

    This paper discusses audible traffic signals (ATS) and their use by visually impaired pedestrians in the United States and other countries. Areas of concern are noted, including the types of intersections at which ATS should be installed, the locations of poles and buttons for activating the system, and the specific type of device used.…

  9. Improving bus travel times with passive traffic signal coordination

    OpenAIRE

    Estrada Romeu, Miguel Ángel; Trapote Barreira, César; Roca Riu, Mireia; Robusté Antón, Francesc

    2009-01-01

    A simulation optimization model is outlined: traffic signal offsets in intersections are calculated to minimize the travel time of bus users in an urban network. The model considers a passive signal priority system and restricts the maximal incremental delay caused to car users. The simulation tool is able to trace discrete trajectories of both buses and cars in a network. It also evaluates potential perturbations that may cause time variations for average performance. Moreover, the optimizat...

  10. Infiuence of Bicycle Traffic on Capacity of Typical Signalized Intersection

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaoming; SHAO Chunfu; YUE Hao

    2007-01-01

    Bicycle traffic has a significant effect on the capacity of signalized intersections. This paper divides the influence of bicyclists on vehicular flow into four types with the time durations estimated based on probability, shock wave, and gap acceptance theory. Vehicular saturation flow rate is predicted for various conditions on the basis of the speed-flow curve for the capacity of typical intersections influenced by bicycle traffic.The model overcomes the limitations of the Highway Capacity Manual (HCM, 2000) method for left-turns due to data collection, and takes into account the effect of trapped bicycles on the through vehicular traffic.The numerical results show that the left-turn and through capacities predicted by the model are lower than those of the HCM method. The right-turn capacity is close to that of the HCM method at Iow bicycle volumes and higher than that of the HCM method at high bicycle volumes.

  11. TRAFFIC SIGNALS MODELLING WITH LONG DISTANCE COMMUNICATIONS USING PIC MICROCONTROLLER

    Directory of Open Access Journals (Sweden)

    Ahmet ÖZEK

    2004-04-01

    Full Text Available Today, microcontrollers are widely used in control and automation systems. For the automation of traffic signalization, the crossroads need to be controlled by microcontrollers and for the automation of more than one crossroad the communication of more than one microcontroller is required. In some special cases, the intercommunication of microcontrollers is required to change crossroad status and obtain continuous flow (green weave synchronization. In this study, a method is proposed to control the traffic flow on a hospital road with two crossroads located several km. apart from each other. For the purpose of changing the crossroads status to have a continuous flow of the traffic, the series of PIC16F877 microcontroller is used.

  12. Comparison of Two Methods of Traffic Signal Design Cycle

    Directory of Open Access Journals (Sweden)

    María Liliana Alba Menéndez

    2013-02-01

    Full Text Available To satisfy the traffic demand in intersections, with safety and efficiency it is common to use a signallike control device, such that the right of using the common space of the intersections is assignedalternatively to the currents of such traffic flow that they cross. In Cuba, for the calculation of the cyclelength and the phases of the signal the Method of Poisson is used, based on the probability ofrandom arrivals of vehicles to the access point, developed in the 50th century. Presently many countriesuse the Method developed by Webster in England during 60th century, based on empiric observationsthen and unto today has proven effective, where an optimal cycle length is calculated, that is minimumdelays and better levels of service.In this study several intersections in Havana with high levels ofcomplexity were studied, the cycle length and the intervals of green were calculated by each method,the parameters that define the quality of the operation were determined in each method. The resultwill be vital in the strategic planning as see fit the National Centre of Traffic Engineering in thedesigning of traffic lights, with efficiency in road traffic.

  13. Traffic Congestion Evaluation and Signal Control Optimization Based on Wireless Sensor Networks: Model and Algorithms

    OpenAIRE

    Wei Zhang; Guozhen Tan; Nan Ding; Guangyuan Wang

    2012-01-01

    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 ...

  14. Modeling Traffic Flow and Management at Un-signalized, Signalized and Roundabout Road Intersections

    OpenAIRE

    R. Kakooza; L. S.  Laboobi; J. Y.T.  Mugisha

    2005-01-01

    Traffic congestion continues to hinder economic and social development and also has a negative impact on the environment. A simple mathematical model is used to analyze the different types of road intersections in terms of their Performance in relation to managing traffic congestion and to establish the condition for stability of the road intersections after sufficiently longer periods of time (steady-state). In the analysis, single and double lane un-signalized, signalized and roundabout int...

  15. Calculation features of traffic light regulation regimesat the signal group control

    OpenAIRE

    Єресов, Володимир Іванович; Трушевський, Вячеслав Едуардович

    2014-01-01

    The differences between the existing technologies of traffic light control by phases and signal groups were determined in the paper. It was proved that the signal group control technology is more perfect and to a greater extent corresponds to the changing traffic conditions at intersections. Approach for compiling the traffic light regulation cycle structure based on the analysis of conflict of traffic and pedestrian flows, taking into account traffic volume, the number of road accidents in t...

  16. TRAFFIC SIGNALS MODELLING WITH LONG DISTANCE COMMUNICATIONS USING PIC MICROCONTROLLER

    OpenAIRE

    ÖZEK, Ahmet; Karal, Ömer

    2004-01-01

    Today, microcontrollers are widely used in control and automation systems. For the automation of traffic signalization, the crossroads need to be controlled by microcontrollers and for the automation of more than one crossroad the communication of more than one microcontroller is required. In some special cases, the intercommunication of microcontrollers is required to change crossroad status and obtain continuous flow (green weave) synchronization. In this study, a method is proposed to cont...

  17. Three-phase theory of city traffic: Moving synchronized flow patterns in under-saturated city traffic at signals

    Science.gov (United States)

    Kerner, Boris S.

    2014-03-01

    Three-phase traffic flow theory of city traffic has been developed. Based on simulations of a stochastic microscopic traffic flow model, features of moving synchronized flow patterns (MSP) have been studied, which are responsible for a random time-delayed breakdown of a green-wave (GW) organized in a city. A possibility of GW control leading to the prevention of GW breakdown has been demonstrated. A diagram of traffic breakdown in under-saturated traffic (transition from under- to over-saturated city traffic) at the signal has been found; the diagram presents regions of the average arrival flow rate, within which traffic breakdown can occur, in dependence of parameters of the time-function of the arrival flow rate or/and signal parameters. Physical reasons for a crucial difference between results of classical theory of city traffic and three-phase theory are explained. In particular, we have found that under-saturated traffic at the signal can exist during a long time interval, when the average arrival flow rate is larger than the capacity of the classical theory; the classical capacity is equal to a minimum capacity in three-phase theory. Within a range of the average arrival flow rate between the minimum and maximum signal capacities, under-saturated traffic is in a metastable state with respect to traffic breakdown. We have distinguished the following possible causes for the metastability of under-saturated traffic: (i) The arrival flow rate during the green phase is larger than the saturation flow rate. (ii) The length of the upstream front of a queue at the signal is a finite value. (iii) The outflow rate from a MSP (the rate of MSP discharge) is larger than the saturation flow rate.

  18. Modeling Traffic Flow and Management at Un-signalized, Signalized and Roundabout Road Intersections

    Directory of Open Access Journals (Sweden)

    R. Kakooza

    2005-01-01

    Full Text Available Traffic congestion continues to hinder economic and social development and also has a negative impact on the environment. A simple mathematical model is used to analyze the different types of road intersections in terms of their Performance in relation to managing traffic congestion and to establish the condition for stability of the road intersections after sufficiently longer periods of time (steady-state. In the analysis, single and double lane un-signalized, signalized and roundabout intersections are evaluated on the basis of their performance (expected number of vehicles and waiting time. Experimental scenarios are carefully designed to analyze the performance of the different types of intersections. It is noted that under light traffic, roundabout intersections perform better than un-signalized and signalized in terms of easing congestion. However under heavy traffic, signalized intersection perform better in terms of easing traffic congestion compared to un-signalized and roundabout intersections. It is further noted that for stability of a road intersection, the proportion of the time a road link stopping at an intersection is delayed should not exceed the utilization factor (the ratio of the arrival rate of vehicles to the product of number of service channels and service rate.

  19. Traffic

    International Nuclear Information System (INIS)

    This chapter deals with passenger and freight traffic, public and private transportation, traffic related environmental impacts, future developments, traffic indicators, regional traffic planning, health costs due to road traffic related air pollution, noise pollution, measures and regulations for traffic control and fuels for traffic. In particular energy consumption, energy efficiency, pollutant emissions ( CO2, SO2, NOx, HC, CO, N2O, NH3 and particulates) and environmental effects of the different types of traffic and different types of fuels are compared and studied. Legal regulations and measures for an effective traffic control are discussed. (a.n.)

  20. Asynchronous detection of optical code division multiple access signals using a bandwidth-efficient and wavelength-aware receiver.

    Science.gov (United States)

    Fok, Mable P; Deng, Yanhua; Prucnal, Paul R

    2010-04-01

    We experimentally demonstrate what we believe to be a novel detection scheme for interfacing asynchronous optical code division multiple access (CDMA) signals with an electronic clock and data recovery system that operates only at the baseband bandwidth. This allows using a large optical bandwidth expansion factor in which the optical chip rate is much larger than the bandwidth of the optoelectronic receiver. The received optical CDMA signal is launched into a four-wave-mixing-based wavelength-aware all-optical front end that rejects multiaccess interference, followed by an amplitude-noise suppression stage comprised of a semiconductor optical amplifier. The clean signal is then converted into a non-return-to-zero-like signal by a baseband receiver. Using the proposed detection scheme, asynchronous transmission and detection of optical CDMA signals is implemented. With the novel detection scheme, the classic CDMA near-far problem is mitigated, and error-free detection is easily obtained. PMID:20364229

  1. 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.

  2. Fuzzy urban traffic signal control - an overview: Mehko upravljanje mestne prometne signalizacije - pregled:

    OpenAIRE

    Brodnik, Andrej; Malej, Alenka

    2007-01-01

    In the last years, there have been many attempts made to improve urban traffic signal contol systems as this is one of the most cost-effective ways to improve the traffic flow through a network intersections. Besides the traditional method for traffic signal control that are usually based on a traffic flow model, the development of new system started to consider the various emerging technologies including artifical intelligence. Application of metaheuristic methods has proven to be worth of b...

  3. Measuring the frequency-dependent attenuation in lossy material using large time-bandwidth product ultrasound signals

    Science.gov (United States)

    Gordon, Grant A.

    1999-06-01

    Broadband signals are commonly used in ultrasonic spectroscopy to measure the frequency dependent attenuation characteristics of lossy solid media. Compared to narrowband signals, broadband signals are preferred since they do not require tedious frequency scanning and extensive data reduction efforts. Typically these broadband signals take the form of a pulse. Although the spectral range of a pulse is wide, the spectral resolution is limited by the duration of the signal. By employing signals with large time- bandwidth-products, the overall accuracy and resolution of ultrasonic spectroscopy can be improved. Expressions for the interaction of longitudinal waves, with large time- bandwidth-product, and isotropic materials are developed. The approach is effective for evaluating material with signals optimized for a frequency resolution and range of interest, but can also be used when thin materials (polyurethane commonly used in ultrasonic transducer fabrication.

  4. Synaptic membrane rafts: traffic lights for local neurotrophin signalling?

    Directory of Open Access Journals (Sweden)

    Liliana Minichiello

    2013-10-01

    Full Text Available Lipid rafts, cholesterol and lipid rich microdomains, are believed to play important roles as platforms for the partitioning of transmembrane and synaptic proteins involved in synaptic signalling, plasticity and maintenance. There is increasing evidence of a physical interaction between post-synaptic densities and post-synaptic lipid rafts. Localization of proteins within lipid rafts is highly regulated, and therefore lipid rafts may function as traffic lights modulating and fine-tuning neuronal signalling. The tyrosine kinase neurotrophin receptors (Trk and the low-affinity p75 neurotrophin receptor (p75NTR are enriched in neuronal lipid rafts together with the intermediates of downstream signalling pathways, suggesting a possible role of rafts in neurotrophin signalling. Moreover, neurotrophins and their receptors are involved in the regulation of cholesterol metabolism. Cholesterol is an important component of lipid rafts and its depletion leads to gradual loss of synapses, underscoring the importance of lipid rafts for proper neuronal function. Here, we review and discuss the idea that translocation of neurotrophin receptors in synaptic rafts may account for the selectivity of their transduced signals.

  5. Traffic signal synchronization in the saturated high-density grid road network.

    Science.gov (United States)

    Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN. PMID:25663835

  6. Capacity Reliability of Signalized Intersections with Mixed Traffic Conditions

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaoming; SHAO Chunfu; LI Da; DONG Chunjiao

    2009-01-01

    The reliability of capacity of signalized intersections in mixed traffic conditions involving vehicles, bicycles, and pedestrians was investigated to complete the conventional, deterministic capacity calculations. Simulations using VISSIM provided estimates of capacity distributions, and demonstrated the effects of the analysis intervals on the distributions. With the random vehicle arrivals taken into account, a capacity reli-ability assessment method was given as a function. Assessments were also performed regarding the effects of the conflicting pedestrian and bicycle volumes on capacity reliability. The simulation indicates that the pe-destrians and bicycles result in greater random fluctuations of exclusive tuming lane capacities, but have less effect on the variability of shared lane capacities. Normal distributions can be used to model the capaci-ties for intervals not less than 10 min. At higher vehicular volumes, the capacity reliability is more sensitive to the mean and standard deviation of the pedestrian and bicycle volumes.

  7. Towards 400GBASE 4-lane Solution Using Direct Detection of MultiCAP Signal in 14 GHz Bandwidth per Lane

    OpenAIRE

    Iglesias Olmedo, Miguel; Tianjian, Zuo; Jensen, Jesper Bevensee; Qiwen, Zhong; Xu, Xiaogeng; TAFUR MONROY, Idelfonso

    2013-01-01

    We report on an experimental demonstration of 102 Gbit/s transmission over a 15km single wavelength and polarization fiber link with 14GHz 3dB bandwidth. Novel multiband CAP signaling allows for a 4-lane 400GBASE long reach solution.

  8. A Proposed Model for Traffic Signal Preemption Using Global Positioning System (GPS

    Directory of Open Access Journals (Sweden)

    Nikhil Mascarenhas

    2013-07-01

    Full Text Available A Traffic Signal Preemption system is an automated system that allows normal operation of traffic lights at automated signalized intersection s to be preempted. Preemption of signals is generally done to assist emergency vehicles, such a s ambulances, so that response times are reduced and right-of-way is provided in a smooth an d controlled manner. This paper proposes an innovative and cost-effective server-centric mod el to facilitate preemption using a simple mobile phone app which uses Global Positioning Syst em (GPS and a microcontroller which controls traffic signals.

  9. Traffic signals analysis using qSDiff and qHDiff with surrogate data

    Science.gov (United States)

    Xu, Mengjia; Shang, Pengjian; Xia, Jianan

    2015-11-01

    Complexity in time series is an intriguing feature of living dynamical systems such as traffic systems, with potential use for identification of system state. Here, we introduce a method for complex system analysis, called generalized sample entropy and surrogate data analysis, to measure the complexity in traffic signals. The behavior of the weekday series is quite different from that of the weekend series. In addition, we propose and discuss a new method of multifractality based on multifractal detrended fluctuation analysis (MF-DFA) and surrogate data. MF-DFA is the most popular method to detect multifractal characteristics of nonstationary time series. This new method is further applied to binomial multifractal series and traffic signals of Beijing, China. Results show that multifractal characteristics of the artificial data are regular and distinguishing the traffic signals of different patterns is significant. Besides, we find that there is a connection of multifractal characteristics between binomial multifractal series and traffic signals.

  10. 10 CFR 431.224 - Uniform test method for the measurement of energy consumption for traffic signal modules and...

    Science.gov (United States)

    2010-01-01

    ... consumption for traffic signal modules and pedestrian modules. 431.224 Section 431.224 Energy DEPARTMENT OF... measurement of energy consumption for traffic signal modules and pedestrian modules. (a) Scope. This section... traffic signal modules and pedestrian modules. For purposes of 10 CFR part 431 and EPCA, the...

  11. Model predictive control for hybrid vehicle ecological driving using traffic signal and road slope information

    Institute of Scientific and Technical Information of China (English)

    Kaijiang YU; Junqi YANG; Daisuke YAMAGUCHI

    2015-01-01

    This paper presents development of a control system for ecological driving of a hybrid vehicle. Prediction using traffic signal and road slope information is considered to improve the fuel economy. It is assumed that the automobile receives traffic signal information from intelligent transportation systems (ITS). Model predictive control is used to calculate optimal vehicle control inputs using traffic signal and road slope information. The performance of the proposed method was analyzed through computer simulation results. Both the fuel economy and the driving profile are optimized using the proposed approach. It was observed that fuel economy was improved compared with driving of a typical human driving model.

  12. Ergonomic investigation on pedestrian crossing with traffic light signalization.

    Science.gov (United States)

    Amado, Giuseppe; de Moraes, Anamaria

    2012-01-01

    This article is about the risk behavior adopted by pedestrians at crosswalks with traffic light equipment. It was observed that many pedestrians take risk to cross the Presidente Vargas Avenue. This avenue is located in downtown in Rio de Janeiro city, Brazil, and has a heavy vehicular traffic and intense pedestrian flow. Many pedestrians cross the four lanes of avenue dangerously disobeying the traffic light indications. To conduct this research about pedestrian's behavior at crosswalks, a model known as Communication-Human Information Processing Model - C-HIP Model was used. Investigating the stages by C-HIP model perspective, using methods and techniques for each stage, enabled to identify which factors can contribute to pedestrians to disobey traffic signs and adopt a risky behavior in pedestrian crossing. PMID:22317476

  13. Positive Switched System Approach to Traffic Signal Control for Oversaturated Intersection

    OpenAIRE

    Lin Du; Yun Zhang

    2014-01-01

    The online traffic signalization for intersection is addressed. A new model for intersection called positive switched system is presented. Then, based on the dissipativity analysis results for positive switched system, an online state-feedback control strategy for traffic signal in two-phase intersection section is proposed. A numerical example is provided to illustrate the effectiveness of our theoretical findings. Finally, in order to extend to more general cases, multiphase intersection is...

  14. Enhanced Bandwidth and Diversity in Real-Time Analog Signal Processing (R-ASP) using Nonuniform C-section Phasers

    CERN Document Server

    Taravati, Sajjad; Zhang, Qingfeng; Caloz, Christophe

    2016-01-01

    We show that a continuously nonuniform coupled line C-section phaser, as the limiting case of the step discontinuous coupled-line multisection commensurate and non-commensurate phasers, provides enhanced bandwidth and diversity in real-time analog signal processing (R-ASP). The phenomenology of the component is explained in comparison with the step-discontinuous using multiple-reflection theory and a simple synthesis procedure is provided. The bandwidth enhancement results from the suppression of spurious group delay harmonics or quasi-harmonics, while the diversity enhancement results from the greater level of freedom provided by the continuous nature of the nonuniform profile of the phaser. These statements are supported by theoretical and experimental results.

  15. GPS Tracking System Coupled With Image Processing in Traffic Signals to Enhance Life Security

    Directory of Open Access Journals (Sweden)

    Manoj Prabhakar k

    2013-08-01

    Full Text Available In modern and crowded traffic life, it becomes mandatory to save the human life by reaching the hospitalvery sooner than possible. This paper explains about the advancement in tracking the ambulance presenceamidst the traffic with the usage of GPS tracking system calculating the position of the ambulance from thetraffic signal which replaces the RF transmitter receiver circuitry. This paper also retains the use of theimage capturing technology available from the base paper (IMPACT OF IMAGE PROCESSING INSAVING THE HUMAN LIFE BY AUTOMATING TRAFFIC SIGNALS to identify the presence of theambulance, thereby changing the signalto green automatically in favour of ambulance

  16. Traffic Signals Generation with Bicolor Leds using Pic 18f Series Microcontroller.

    Directory of Open Access Journals (Sweden)

    Y.V Sripriya

    2013-10-01

    Full Text Available PIC 18F series microcontroller is used for control of signals to a specific time using port lines. In this contest we choose the Bicolor LEDs with Red and Green. The colors of the signals are illuminated by programming in the microcontroller. The aim of this paper is to generate three colors on a single traffic light instead of using three different color traffic signal lights. The purpose of this design is to reduce the manufacture cost of the signal lights and to use a minimum number of ports in a microcontroller and cable lines to transmit the signals to the light source. This paper describes a new design for the traffic signals.

  17. Electrocardiograms and heart rate signals a short distance transfer to the Android type of mobile devices, saving energy and bandwidth expenditure

    OpenAIRE

    Dalius Miežinis; Laimutis Telksnys

    2013-01-01

    Electrocardiograms and heart rate signals short distance transfer to mobile Android devices problem is examined. Energy saving and efficient use of bandwidth issues for signals transfer is discussed. Electrocardiograms and heart rate signaling proximity to mobile Android devices implementation possibilities is analyzed. Electrocardiograms and heart rate signals short distance transfer to mobile Android devices is proposed.

  18. Symmetry breaking in optimal timing of traffic signals on an idealized two-way street

    Science.gov (United States)

    Panaggio, Mark J.; Ottino-Löffler, Bertand J.; Hu, Peiguang; Abrams, Daniel M.

    2013-09-01

    Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this “green-wave” scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counterintuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive density increases.

  19. Symmetry breaking in optimal timing of traffic signals on an idealized two-way street

    CERN Document Server

    Panaggio, Mark J; Hu, Peiguang; Abrams, Daniel M

    2013-01-01

    Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this "green wave" scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counter-intuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive dens...

  20. 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.

  1. Phosphatidylinositol 3-phosphates-at the interface between cell signalling and membrane traffic.

    Science.gov (United States)

    Marat, Andrea L; Haucke, Volker

    2016-03-15

    Phosphoinositides (PIs) form a minor class of phospholipids with crucial functions in cell physiology, ranging from cell signalling and motility to a role as signposts of compartmental membrane identity. Phosphatidylinositol 3-phosphates are present at the plasma membrane and within the endolysosomal system, where they serve as key regulators of both cell signalling and of intracellular membrane traffic. Here, we provide an overview of the metabolic pathways that regulate cellular synthesis of PI 3-phosphates at distinct intracellular sites and discuss the mechanisms by which these lipids regulate cell signalling and membrane traffic. Finally, we provide a framework for how PI 3-phosphate metabolism is integrated into the cellular network. PMID:26888746

  2. GPS Tracking System Coupled With Image Processing in Traffic Signals to Enhance Life Security

    OpenAIRE

    Manoj Prabhakar k; Manoj Kumar S

    2013-01-01

    In modern and crowded traffic life, it becomes mandatory to save the human life by reaching the hospitalvery sooner than possible. This paper explains about the advancement in tracking the ambulance presenceamidst the traffic with the usage of GPS tracking system calculating the position of the ambulance from thetraffic signal which replaces the RF transmitter receiver circuitry. This paper also retains the use of theimage capturing technology available from the base paper (IMPACT OF IMAGE PR...

  3. Multiobjective Traffic Signal Control Model for Intersection Based on Dynamic Turning Movements Estimation

    Directory of Open Access Journals (Sweden)

    Pengpeng Jiao

    2014-01-01

    Full Text Available The real-time traffic signal control for intersection requires dynamic turning movements as the basic input data. It is impossible to detect dynamic turning movements directly through current traffic surveillance systems, but dynamic origin-destination (O-D estimation can obtain it. However, the combined models of dynamic O-D estimation and real-time traffic signal control are rare in the literature. A framework for the multiobjective traffic signal control model for intersection based on dynamic O-D estimation (MSC-DODE is presented. A state-space model using Kalman filtering is first formulated to estimate the dynamic turning movements; then a revised sequential Kalman filtering algorithm is designed to solve the model, and the root mean square error and mean percentage error are used to evaluate the accuracy of estimated dynamic turning proportions. Furthermore, a multiobjective traffic signal control model is put forward to achieve real-time signal control parameters and evaluation indices. Finally, based on practical survey data, the evaluation indices from MSC-DODE are compared with those from Webster method. The actual and estimated turning movements are further input into MSC-DODE, respectively, and results are also compared. Case studies show that results of MSC-DODE are better than those of Webster method and are very close to unavailable actual values.

  4. 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.

  5. Traffic analysis and signal processing in optical packet switched networks

    DEFF Research Database (Denmark)

    Fjelde, Tina

    2002-01-01

    /s optical packet switched network exploiting the best of optics and electronics, is used as a thread throughout the thesis. An overview of the DAVID network architecture is given, focussing on the MAN and WAN architecture as well as the MPLS-based network hierarchy. Subsequently, the traffic performance...... into an MI. Moreover, logic XOR is demonstrated in an MZI at 10 and 20 Gbit/s with good results. Using an MI, the excellent performance of a novel scheme for MPLS label swapping exploiting logic XOR is demonstrated at 10 Gbit/s with a negligible 0.4 dB penalty. Finally, three novel schemes are described...

  6. Vehicular motion in counter traffic flow through a series of signals controlled by a phase shift

    Science.gov (United States)

    Nagatani, Takashi; Tobita, Kazuhiro

    2012-10-01

    We study the dynamical behavior of counter traffic flow through a sequence of signals (traffic lights) controlled by a phase shift. There are two lanes for the counter traffic flow: the first lane is for east-bound vehicles and the second lane is for west-bound vehicles. The green-wave strategy is studied in the counter traffic flow where the phase shift of signals in the second lane has opposite sign to that in the first lane. A nonlinear dynamic model of the vehicular motion is presented by nonlinear maps at a low density. There is a distinct difference between the traffic flow in the first lane and that in the second lane. The counter traffic flow exhibits very complex behavior on varying the cycle time, the phase difference, and the split. Also, the fundamental diagram is derived by the use of the cellular automaton (CA) model. The dependence of east-bound and west-bound vehicles on cycle time, phase difference, and density is clarified.

  7. Heterogeneous cellular automata model for straight-through bicycle traffic at signalized intersection

    Science.gov (United States)

    Ren, Gang; Jiang, Hang; Chen, Jingxu; Huang, Zhengfeng; Lu, Lili

    2016-06-01

    This paper presents a cellular automata (CA) model to elucidate the straight-through movements of the heterogeneous bicycle traffic at signalized intersection. The CA model, via simulation, particularly exposits the dispersion phenomenon existing in the straight-through bicycle traffic. The nonlane-based cycling behavior and diverse bicycle properties are also incorporated in the CA model. A series of simulations are conducted to reveal the travel process, bicycles interaction and influence of the dispersion phenomenon. The simulation results show that the dispersion phenomenon significantly results in more bicycles interactions in terms of spilling maneuvers and overtaking maneuvers during the straight-through movements. Meanwhile, the dispersion phenomenon could contribute to the efficiency of the bicycle traffic, and straight-through bicycles need less time to depart the intersection under the circumstance of dispersion phenomenon. The simulation results are able to provide specific guideline for reasonably utilizing the dispersion phenomenon to improve the operational efficiency of straight-through bicycle traffic.

  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. Self-organization of traffic jams in cities: Effects of stochastic dynamics and signal periods

    Science.gov (United States)

    Chowdhury, Debashish; Schadschneider, Andreas

    1999-02-01

    We propose a cellular automata model for vehicular traffic in cities by combining (and appropriately modifying) ideas borrowed from the Biham-Middleton-Levine (BML) model of city traffic and the Nagel-Schreckenberg (NS) model of highway traffic. We demonstrate a phase transition from the ``free-flowing'' dynamical phase to the completely ``jammed'' phase at a vehicle density which depends on the time periods of the synchronized signals and the separation between them. The intrinsic stochasticity of the dynamics, which triggers the onset of jamming, is similar to that in the NS model, while the phenomenon of complete jamming through self-organization as well as the final jammed configurations are similar to those in the BML model. Using our model, we have made an investigation of the time dependence of the average speeds of the cars in the ``free-flowing'' phase as well as the dependence of flux and jamming on the time period of the signals.

  10. The Combined Effect of Signal Strength and Background Traffic Load on Speech Quality in IEEE 802.11 WLAN

    Directory of Open Access Journals (Sweden)

    P. Pocta

    2011-04-01

    Full Text Available This paper deals with measurements of the combined effect of signal strength and background traffic load on speech quality in IEEE 802.11 WLAN. The ITU-T G.729AB encoding scheme is deployed in this study and the Distributed Internet Traffic Generator (D-ITG is used for the purpose of background traffic generation. The speech quality and background traffic load are assessed by means of the accomplished PESQ algorithm and Wireshark network analyzer, respectively. The results show that background traffic load has a bit higher impact on speech quality than signal strength when both effects are available together. Moreover, background traffic load also partially masks the impact of signal strength. The reasons for those findings are particularly discussed. The results also suggest some implications for designers of wireless networks providing VoIP service.

  11. 基于交通噪声分析的交通流状态识别方法%Traffic Flow State Identification Based on Traffic Noise Signals

    Institute of Scientific and Technical Information of China (English)

    罗向龙

    2012-01-01

    A vehicle acoustic signal is composed of engine noise, tire noise, air turbulence noise and exhaust noise. Traffic noise signals mixture of multiple vehicles' acoustic signals is determined by the traffic state. Based on the analysis of the existing traffic state identification methods and vehicle sound characteristics, an identification method of the traffic flow state was proposed by using traffic noise signals. In accordance with the vehicle speed, traffic flow states were divided into the free flow, saturation flow and traffic jams. The spectrums of vehicle acoustic signals were analyzed for different traffic states, the normalized peak frequencies were as features, and different traffic flow states were recognized using support vector machine. The test results show that different traffic flow states can be correctly recognized with traffic noise signals with a high recognition accuracy.%车辆行驶时的声音主要由发动机噪声、轮胎噪声、空气涡流噪声、排气噪声组成,多个车辆构成的交通噪声取决于道路的交通流状态.在分析现有交通状态识别方法和车辆声音特性的基础上提出了一种利用交通噪声的交通状态识别方法.按照车速将交通流分为自由流、饱和流和交通拥堵3种状态,对不同交通流状态下的交通噪声信号进行谱分析,以归一化的峰值频率作为特征,用支持向量机对不同的交通流状态进行识别.试验结果表明,通过交通噪声能够正确识别不同的交通流状态,具有较高的识别精度.

  12. Traffic signal design and simulation for vulnerable road users safety and bus preemption

    International Nuclear Information System (INIS)

    Mostly, pedestrian car accidents occurred at a signalized interaction is because pedestrians cannot across the intersection safely within the green light. From the viewpoint of pedestrian, there might have two reasons. The first one is pedestrians cannot speed up to across the intersection, such as the elders. The other reason is pedestrians do not sense that the signal phase is going to change and their right-of-way is going to be lost. Developing signal logic to protect pedestrian, who is crossing an intersection is the first purpose of this study. In addition, to improve the reliability and reduce delay of public transportation service is the second purpose. Therefore, bus preemption is also considered in the designed signal logic. In this study, the traffic data of the intersection of Chong-Qing North Road and Min-Zu West Road, Taipei, Taiwan, is employed to calibrate and validate the signal logic by simulation. VISSIM 5.20, which is a microscopic traffic simulation software, is employed to simulate the signal logic. From the simulated results, the signal logic presented in this study can protect pedestrians crossing the intersection successfully. The design of bus preemption can reduce the average delay. However, the pedestrian safety and bus preemption signal will influence the average delay of cars largely. Thus, whether applying the pedestrian safety and bus preemption signal logic to an intersection or not should be evaluated carefully

  13. A Dynamic Traffic Signal Timing Model and its Algorithm for Junction of Urban Road

    DEFF Research Database (Denmark)

    Cai, Yanguang; Cai, Hao

    2012-01-01

    As an important part of Intelligent Transportation System, the scientific traffic signal timing of junction can improve the efficiency of urban transport. This paper presents a novel dynamic traffic signal timing model. According to the characteristics of the model, hybrid chaotic quantum......-time and dynamic signal control of junction. To obtain the optimal solution of the model by hybrid chaotic quantum evolutionary algorithm, the model is converted to an easily solvable form. To simplify calculation, we give the expression of the partial derivative and change rate of the objective function...... such that the implementation of the algorithm only involves function assignments and arithmetic operations and thus avoids complex operations such as integral and differential. Simulation results show that the algorithm has less remain vehicles than Webster method, higher convergence rate and...

  14. Multiobjective Reinforcement Learning for Traffic Signal Control Using Vehicular Ad Hoc Network

    Science.gov (United States)

    Houli, Duan; Zhiheng, Li; Yi, Zhang

    2010-12-01

    We propose a new multiobjective control algorithm based on reinforcement learning for urban traffic signal control, named multi-RL. A multiagent structure is used to describe the traffic system. A vehicular ad hoc network is used for the data exchange among agents. A reinforcement learning algorithm is applied to predict the overall value of the optimization objective given vehicles' states. The policy which minimizes the cumulative value of the optimization objective is regarded as the optimal one. In order to make the method adaptive to various traffic conditions, we also introduce a multiobjective control scheme in which the optimization objective is selected adaptively to real-time traffic states. The optimization objectives include the vehicle stops, the average waiting time, and the maximum queue length of the next intersection. In addition, we also accommodate a priority control to the buses and the emergency vehicles through our model. The simulation results indicated that our algorithm could perform more efficiently than traditional traffic light control methods.

  15. Multiobjective Reinforcement Learning for Traffic Signal Control Using Vehicular Ad Hoc Network

    Directory of Open Access Journals (Sweden)

    Houli Duan

    2010-01-01

    Full Text Available We propose a new multiobjective control algorithm based on reinforcement learning for urban traffic signal control, named multi-RL. A multiagent structure is used to describe the traffic system. A vehicular ad hoc network is used for the data exchange among agents. A reinforcement learning algorithm is applied to predict the overall value of the optimization objective given vehicles' states. The policy which minimizes the cumulative value of the optimization objective is regarded as the optimal one. In order to make the method adaptive to various traffic conditions, we also introduce a multiobjective control scheme in which the optimization objective is selected adaptively to real-time traffic states. The optimization objectives include the vehicle stops, the average waiting time, and the maximum queue length of the next intersection. In addition, we also accommodate a priority control to the buses and the emergency vehicles through our model. The simulation results indicated that our algorithm could perform more efficiently than traditional traffic light control methods.

  16. Video Traffic Prediction Using Neural Networks

    OpenAIRE

    Miloš Oravec; Miroslav Petráš; Filip Pilka

    2008-01-01

    In this paper, we consider video stream prediction for application in services likevideo-on-demand, videoconferencing, video broadcasting, etc. The aim is to predict thevideo stream for an efficient bandwidth allocation of the video signal. Efficient predictionof traffic generated by multimedia sources is an important part of traffic and congestioncontrol procedures at the network edges. As a tool for the prediction, we use neuralnetworks – multilayer perceptron (MLP), radial basis function n...

  17. Study of Truck Driver Behavior at Onset of Yellow Traffic Signal Indication for the Design of Yellow Times

    OpenAIRE

    Bryant, Craig William

    2014-01-01

    Traffic signal violations by drivers are a leading contributor to crashes at signalized intersections. The yellow indication is used to inform drivers of an upcoming change in the status of the traffic signal. Yellow-interval durations are currently calculated to provide dilemma zone protection for passenger cars. Due to differences in vehicle characteristics and driver characteristics, heavy trucks such as tractor-trailers behave differently at the onset of a yellow-indication. The resea...

  18. The influence of traffic signal solutions on self-reported road-crossing behavior.

    Science.gov (United States)

    Di Stasi, Leandro L; Megías, Alberto; Cándido, Antonio; Maldonado, Antonio; Catena, Andrés

    2014-01-01

    Injury to pedestrians is a major safety hazard in many countries. Since the beginning of the last century, modern cities have been designed around the use of motor vehicles despite the unfavourable interactions between the vehicles and pedestrians. This push towards urbanization resulted in a substantial number of crashes and fatalities involving pedestrians every day, all over the world. Thus, improving the design of urban cities and townships is a pressing issue for modern society. The study presented here provides a characterization of pedestrian safety problems, with the emphasis on signalized crosswalks (i.e. traffic signal) design solutions. We tested the impact of seven different traffic light configurations (steady [green, yellow, and red], flashing [green, yellow, and red], and light off) on pedestrian self-reported road-crossing behavior, using a 11-point scale -ranging from 0 ("I never cross in this situation") to 10 ("I always cross in this situation"). Results showed that mandatory solutions (steady green vs. steady red) are the best solutions to avoid unsafe pedestrian behaviors while crossing controlled intersections (frequency of crossing: Mgreen = 9.4 ± 1 vs. Mred = 2.6 ± 2). These findings offer important guidelines for the design of future traffic signals for encouraging a pedestrian/transit-friendly environment. PMID:26055356

  19. Algorithms and Requirements for Measuring Network Bandwidth

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Guojun

    2002-12-08

    This report unveils new algorithms for actively measuring (not estimating) available bandwidths with very low intrusion, computing cross traffic, thus estimating the physical bandwidth, provides mathematical proof that the algorithms are accurate, and addresses conditions, requirements, and limitations for new and existing algorithms for measuring network bandwidths. The paper also discusses a number of important terminologies and issues for network bandwidth measurement, and introduces a fundamental parameter -Maximum Burst Size that is critical for implementing algorithms based on multiple packets.

  20. The Preventive Signaling Maintenance Crew Scheduling Problem for European Railway Traffic Management system (ERTMS)

    DEFF Research Database (Denmark)

    Mohammad Pour, Shahrzad; Stidsen, Thomas Jacob Riis; Rasmussen, Kourosh Marjani

    A railway system is a large and complex infrastructure, which requires continuous maintenance in order to function correctly. Proper maintenance is critical but can also be costly. In this paper we consider the practical case of planning the preventive maintenance of railway signals in Jutland, the...... western part of Denmark. This case is particularly interesting, since the entire railway signalling system is currently being upgraded to the new European Railway Traffic Management System (ERTMS) standard. The new signals need continuous maintenance and in this article we plan the distribution of crew...... and also schedule their daily tasks. We formulate the problem as a multi depot vehicle routing problem with time windows and synchronization constraints, in a multi-day time schedule. We solve the problem for large realistic instances by introducing a constructive stage-wise algorithm. Experimental...

  1. Solving a signalized traffic intersection problem with an hyperbolic penalty function

    Science.gov (United States)

    Melo, Teófilo; Monteiro, M. Teresa T.; Matias, João

    2012-09-01

    Mathematical Program with Complementarity Constraints (MPCC) finds many applications in fields such as engineering design, economic equilibrium and mathematical programming theory itself. A queueing system model resulting from a single signalized intersection regulated by pre-timed control in traffic network is considered. The model is formulated as an MPCC problem. A MATLAB implementation based on an hyperbolic penalty function is used to solve this practical problem, computing the total average waiting time of the vehicles in all queues and the green split allocation. The problem was codified in AMPL.

  2. Road crossing behavior under traffic light conflict: Modulating effects of green light duration and signal congruency.

    Science.gov (United States)

    Lange, Florian; Haiduk, Michael; Boos, Moritz; Tinschert, Peter; Schwarze, Anke; Eggert, Frank

    2016-10-01

    A large number of pedestrians and cyclists regularly ignore the traffic lights to cross the road illegally. In a recent analysis, illegal road crossing behavior has been shown to be enhanced in the presence of incongruent stimulus configurations. Pedestrians and cyclists are more likely to cross against a red light when exposed to an irrelevant conflicting green light. Here, we present experimental and observational data on the factors moderating the risk associated with incongruent traffic lights. In an observational study, we demonstrated that the conflict-related increase in illegal crossing rates is reduced when pedestrian and cyclist green light periods are long. In a laboratory experiment, we manipulated the color of the irrelevant signals to expose participants to different degrees of incongruency. Results revealed that individuals' performance gradually varied as a function of incongruency, suggesting that the negative impact of a conflicting green light can be reduced by slightly adjusting its color. Our findings highlight that the observation of real-world behavior at intersections and the experimental analysis of psychological processes under controlled laboratory conditions can complement each other in identifying risk factors of risky road crossing behavior. Based on this combination, our study elaborates on promising measures to improve safety at signalized intersections. PMID:27474874

  3. A Model for Capacity Considering the Interference by Pedestrian Traffic at Signal Intersections

    Institute of Scientific and Technical Information of China (English)

    Yixin Chen; Yulong He; Xiaoduan Sun

    2016-01-01

    The capacity is impacted badly by pedestrians’ violation behavior at signal intersections. In order to quantify the impact, the time⁃headway and the vehicular speed from start⁃up to reach the stable saturation flow with and without pedestrian traffic are used as the direct measurements. Using the statistical analysis, the time⁃headway of saturation flow is mainly affected by the position of pedestrians and the degree of pedestrians ’ influence is classified into four levels. Then the speed⁃time profile for the vehicular acceleration at each level is fitted by Curve Fitting Software. Based on the effect to the time⁃headway and acceleration time, the model of capacity influenced by pedestrians is established and the influence is quantified, which enriches the fundamental theory of traffic engineering. The result shows that the vehicular capacity can be decreased by 14%at the worst case ( level I ) . The conclusions obtained in this paper are valuable for better management of the signal intersection.

  4. Prediction of CO concentrations from road traffic at signalized intersections using CAL3QHC model: the Khon Kaen case study

    OpenAIRE

    Prungchan Wongwises; Pongrid Klungboonkrong; Rudklao Pan-Aram; Atit Tippichai

    2005-01-01

    Based on the US EPA air pollution model, CAL3QHC version 2.0 was applied to predict carbon monoxide (CO) concentrations from road traffic at three signalized intersections in Khon Kaen province. Four data groups required by the model, namely site parameters, traffic parameters, meteorological parameters and emission parameters were collected at each intersection and have been used as the inputs to the model. The prediction results were compared to the measurement. The results showed that the ...

  5. Average Bandwidth Allocation Model of WFQ

    Directory of Open Access Journals (Sweden)

    Tomáš Balogh

    2012-01-01

    Full Text Available We present a new iterative method for the calculation of average bandwidth assignment to traffic flows using a WFQ scheduler in IP based NGN networks. The bandwidth assignment calculation is based on the link speed, assigned weights, arrival rate, and average packet length or input rate of the traffic flows. We prove the model outcome with examples and simulation results using NS2 simulator.

  6. Automatic Bandwidth Adjustment for Content Distribution in MPLS Networks

    Directory of Open Access Journals (Sweden)

    D. Moltchanov

    2008-04-01

    Full Text Available Aggregates of real-time traffic may experience changes in their statistical characteristics often manifesting non stationary behavior. In multi protocol label switching (MPLS networks this type of the traffic is assigned constant amount of resources. This may result in ineffective usage of resources when the load is below than expected or inappropriate performance when the load is higher. In this paper we propose new algorithm for dynamic resource adaptation to temporarily changing traffic conditions. Assuming that network nodes may reallocate resources on-demand using automatic bandwidth adjustment capability of MPLS framework, the proposed algorithm, implemented at ingress MPLS nodes, dynamically decides which amount of resources is currently sufficient to handle arriving traffic with given performance metrics. This decision is then communicated to interior MPLS nodes along the label switched path. As a basic tool of the algorithm we use change-point statistical test that signals time instants at which statistical characteristics of traffic aggregates change. The major advantage of the proposed approach is that it is fully autonomous, that is, network nodes do not need any support from hosts in terms of resource reservation requests. The proposed algorithm is well suited for traffic patterns experiencing high variability, especially, for non stationary type of the traffic.

  7. 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.

  8. 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

  9. 路口交通流不均衡饱和时的交通信号控制%Traffic Flow Equilibrium Saturation in Traffic Signal Control

    Institute of Scientific and Technical Information of China (English)

    李雪佳

    2012-01-01

    Aiming at the existing intersection queue, and different directions of traffic flow is not balanced, queue length sum minimum sum of traffic flow model are built, and 2 kinds of optimization of signal timing control strategy are presented by using the optimal control theory and algorithms.%针对交叉路口存在排队车辆,且不同方向上的交通流不均衡,建立排队长度总和达到最小的交通流模型,利用最优控制理论和算法给出两种优化的信号配时控制策略。

  10. Minireview: recent developments in the regulation of glucose transporter-4 traffic: new signals, locations, and partners.

    Science.gov (United States)

    Ishiki, Manabu; Klip, Amira

    2005-12-01

    Glucose transporter (GLUT) 4 is the major glucose transporter of muscle and adipose cells, exquisitely regulated by insulin through posttranslational events. Twenty years after the seminal observations that GLUT4 levels rapidly rise at the plasma membrane (PM) and drop in endomembranes in response to an acute insulin challenge, we are still mapping the intracellular traffic of the transporter and the regulatory events that insulin unleashes. Newly synthesized GLUT4 enters an insulin-responsive compartment aided by GGA2 (an Arf-binding protein). In cultured adipocytes and myocytes, GLUT4 concentrates in a perinuclear pole through participation of microtubules and the EHD1 Eps15 homology domain-containing protein 1. In the absence of stimuli, GLUT4 distributes between recycling endosomes and the insulin-responsive compartment. A handful of proteins that bind to GLUT4 appear to regulate its half-life (e.g. Ubc9) and tethering within endomembranes (e.g. TUG). Insulin-derived signals promote not only GLUT4 mobilization toward the PM but also its traffic between endosomal compartments and internalization from the PM. Class IA phosphatidylinositol (PI) 3-kinase plays a pivotal role at several steps of GLUT4 mobilization. The PI 3-kinase --> atypical PKC and --> Akt/PKB --> AS160 signaling cascades are major regulators of GLUT4 exocytosis aided by small GTPases. At the cell periphery, GLUT4-containing vesicles tether, dock, and fuse with the PM assisted by the exocyst complex followed by engagement of a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex [with vesicle-associated membrane protein (VAMP)2 as the vesicular (v)-SNARE and soluble NSF-attachment protein (SNAP)23 and syntaxin4 as target (t)-SNAREs] regulated by the accessory proteins Munc18c, Synip and Tomosyn. Vesicle tethering and fusion are regulated by insulin through input from class IA PI 3-kinase. PMID:16150904

  11. Performance Investigation of Virtual Private Networks with Different Bandwidth Allocations

    OpenAIRE

    Ramaswamy Muthiah; Mahalakshmi Chidambara Natarajan; Alamelu Nachiappan

    2010-01-01

    A Virtual Private Network (VPN) provides private network connections over a publicly accessible shared network. The effective allocation of bandwidth for VPNs assumes significance in the present scenario due to varied traffic. Each VPN endpoint specifies bounds on the total amount of traffic that it is likely to send or receive at any time. The network provider tailors the VPN so that there is sufficient bandwidth for any traffic matrix that is consistent with these bounds. The approach incor...

  12. Game Theory Model of Traffic Participants within Amber Time at Signalized Intersection

    OpenAIRE

    2014-01-01

    The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will g...

  13. EVALUATION OF INCOMING TRAFFIC FLOWS STABILITY IN SIGNAL CONTROL INTELLECTUAL TECHNOLOGIES

    OpenAIRE

    Yeresov, V.; Didkovskaya, L.

    2009-01-01

    A problem of using intellectual technologies for traffic regulation through estimation of incoming traffic parameters have been considered. The parameters include the level of cycle phases saturation (xi), the coefficient of intrahour irregularity (fs), the coefficient of variation (ІN), and the criterion of stability (αgop).

  14. Architectural design for a low cost FPGA-based traffic signal detection system in vehicles

    Science.gov (United States)

    López, Ignacio; Salvador, Rubén; Alarcón, Jaime; Moreno, Félix

    2007-05-01

    In this paper we propose an architecture for an embedded traffic signal detection system. Development of Advanced Driver Assistance Systems (ADAS) is one of the major trends of research in automotion nowadays. Examples of past and ongoing projects in the field are CHAMELEON ("Pre-Crash Application all around the vehicle" IST 1999-10108), PREVENT (Preventive and Active Safety Applications, FP6-507075, http://www.prevent-ip.org/) and AVRT in the US (Advanced Vision-Radar Threat Detection (AVRT): A Pre-Crash Detection and Active Safety System). It can be observed a major interest in systems for real-time analysis of complex driving scenarios, evaluating risk and anticipating collisions. The system will use a low cost CCD camera on the dashboard facing the road. The images will be processed by an Altera Cyclone family FPGA. The board does median and Sobel filtering of the incoming frames at PAL rate, and analyzes them for several categories of signals. The result is conveyed to the driver. The scarce resources provided by the hardware require an architecture developed for optimal use. The system will use a combination of neural networks and an adapted blackboard architecture. Several neural networks will be used in sequence for image analysis, by reconfiguring a single, generic hardware neural network in the FPGA. This generic network is optimized for speed, in order to admit several executions within the frame rate. The sequence will follow the execution cycle of the blackboard architecture. The global, blackboard architecture being developed and the hardware architecture for the generic, reconfigurable FPGA perceptron will be explained in this paper. The project is still at an early stage. However, some hardware implementation results are already available and will be offered in the paper.

  15. Game Theory Model of Traffic Participants within Amber Time at Signalized Intersection

    Directory of Open Access Journals (Sweden)

    Weiwei Qi

    2014-01-01

    Full Text Available The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will go against the purpose of setting amber lights if forbidding passing; on the other hand, it may lead to a mess of traffic flow running if not. And meanwhile the drivers are faced with the decision of passing the intersection or stopping during the amber light as well. So the decision-making behavior of traffic administrations and drivers can be converted into a double game model. And through quantification of their earnings in different choice conditions, the optimum decision-making plan under specific conditions could be solved via the Nash equilibrium solution concept. Thus the results will provide a basis for the formulation of the traffic management strategy.

  16. Game theory model of traffic participants within amber time at signalized intersection.

    Science.gov (United States)

    Qi, Weiwei; Wen, Huiying; Fu, Chuanyun; Song, Mo

    2014-01-01

    The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will go against the purpose of setting amber lights if forbidding passing; on the other hand, it may lead to a mess of traffic flow running if not. And meanwhile the drivers are faced with the decision of passing the intersection or stopping during the amber light as well. So the decision-making behavior of traffic administrations and drivers can be converted into a double game model. And through quantification of their earnings in different choice conditions, the optimum decision-making plan under specific conditions could be solved via the Nash equilibrium solution concept. Thus the results will provide a basis for the formulation of the traffic management strategy. PMID:25580108

  17. The Impact of a Signalized Crosswalk on Traffic Speed and Street-Crossing Behaviors of Residents in an Underserved Neighborhood.

    Science.gov (United States)

    Schultz, Courtney L; Sayers, Stephen P; Wilhelm Stanis, Sonja A; Thombs, Lori A; Thomas, Ian M; Canfield, Shannon M

    2015-10-01

    Infrastructure improvements such as pedestrian crosswalks that calm traffic and increase access to physical activity opportunities could alleviate important barriers to active living in underserved communities with outdated built environments. The purpose of this study was to explore how the built environment influences street-crossing behaviors and traffic speeds in a low-income neighborhood with barriers to active living in Columbia, Missouri. In 2013, a signalized pedestrian crosswalk and 400-ft-long median was constructed along a busy 5-lane, high-speed arterial highway linking low-income housing with a park and downtown areas. Data collection occurred prior to June 2012, and after June 2013, completion of the project at the intervention site and control site. Direct observation of street-crossing behaviors was performed at designated intersections/crosswalks or non-designated crossing points. Traffic volume and speed were captured using embedded magnetic traffic detectors. At the intervention site, designated crossings increased at the new crosswalk (p < 0.001), but not at non-designated crossings (p = 0.52) or designated crossings at intersections (p = 0.41). At the control site, there was no change in designated crossings (p = 0.94) or non-designated crossings (p = 0.79). Motor vehicles traveling above the speed limit of 35 mph decreased from 62,056 (46 %) to 46,256 (35 %) (p < 0.001) at the intervention site and increased from 57,891 (49 %) to 65,725 (59 %) (p < 0.001) at the control site. The installation of a signalized crosswalk facilitated an increase in safe street crossings and calmed traffic volume and speed in an underserved neighborhood. We believe these findings have significant public health implications that could be critical to advocacy efforts to improve infrastructure projects in similar communities. PMID:26354602

  18. Flexible Filter Bank Based on an Improved Weighted Overlap-Add Algorithm for Processing Wide Bandwidth Radio Astronomy Signals

    Science.gov (United States)

    Wang, Xianhai; Meng, Qiao; Han, J. L.; Liu, Wei; Zhang, Jianwei

    2015-12-01

    Wideband signals from a radio telescope have to be channelized for spectral observations or for dedispersion for pulsar observations. A polyphase filter bank is designed based on the improved weighted overlap-add (IWOLA) algorithm to achieve channelization. The IWOLA algorithm involves applying an equivalent Hilbert transform to the normal WOLA filter bank by shifting the center frequency of every sub-band by a half of the frequency bin, so that the IWOLA filter bank provides K independently output complex subbands instead of the usual K + 1 sub-bands, reducing the subsequent processing units by one set. Performance of the proposed IWOLA filter bank is analyzed by means of MATLAB simulations. We show how the IWOLA filter bank can be used for a two-stage, high-resolution spectrometer, with a much reduced consumption of FPGA on-chip block RAM.

  19. Delay Estimates of Mixed Traffic Flow at Signalized Intersections in China

    Institute of Scientific and Technical Information of China (English)

    SU Yuelong; WEI Zheng; CHENG Sihan; YAO Danya; ZHANG Yi; LI Li

    2009-01-01

    Two characteristics of Chinese mixed traffic invalidate the conventional queuing delay estimates for western countries. First, the driving characteristics of Chinese drivers lead to different delays even though the other conditions are the same. Second, urban traffic flow in China is often hindered by pedestrians at intersections, such that imported intelligent traffic control systems do not work appropriately. Typical delay estimates for Chinese conditions were obtained from data for over 500 vehicle queues in Beijing collected using charge coupled device (CCD) cameras. The results show that the delays mainly depend on the pro-portion and positions of heavy vehicles in the queue, as well as the start-up situations (with or without inter-ference). A simplified delay estimation model considers vehicle types and positions that compares well with the observed traffic delays.

  20. Bandwidth Resource Dynamic Allocation in Differentiated Services Model%Diffserv中带宽代理BB的实现

    Institute of Scientific and Technical Information of China (English)

    邱瑜; 朱淼良

    2003-01-01

    To employ Differentiated Services, efficient and flexible resource allocation mechanism is needed. Static bandwidth resource allocation Is not suitable for the situations in which traffic varies greatly with times. If customers bought bandwidth according to their highest traffic demands, some resource will be wasted when traffic load is light. On the other hand, the static allocated bandwidth may not satisfy the growing traffic demands. So it is necessary to allocate bandwidth resource in dynamic way. We bring up a prototype of BB, discussing the necessary components to realize the dynamic bandwidth resource allocation and further more, our BB can provides advanced reservation for bandwidth resource. Simulation tests show our design is feasible.

  1. Statistical Multiplexing of Video Traffic and Data Traffic

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper studies statistical multiplexing performance byinput of video traffic and data traffic. The inputs have different Qos requirements such as loss and delay jitter. By applying a modified FBM model, we present methods to estimate effective bandwidth of the aggregated traffic. Simulationswere paformed to evaluate effective bandwidth. The comparison between the estimation and the simulation shows that the estimations can give correct data for the effective bandwidths in terms of our interests. The analysis of gain by using priority multiplexing also addresses proper Qos configuration for the inputs in order to achieve positive gains.

  2. 雷达发射机信号谐波带宽模型分析%Analysis on harmonic wave bandwidth models of radar transmitter signals

    Institute of Scientific and Technical Information of China (English)

    何新亮; 盛松林

    2011-01-01

    It is required to analyze the law of harmonic wave bandwidth when predicting the Electromagnetic Compatibility(EMC) condition among radars. This paper analyses the laws of harmonic wave bandwidth and the causing reasons by Fourier Transform. The harmonic wave bandwidth equals to the fundamental wave bandwidth in general pulse modulation or high repeated frequency modulation; the harmonic wave bandwidth is integer times of the fundamental wave bandwidth in linear frequency modulation; while in phase-coded modulation, the uneven harmonic wave bandwidth equals to the fundamental wave bandwidth, but the even harmonic wave bandwidth is small. This result can be a reference for modeling Electromagnetic Compatibility prediction for radar transmitter.%在对雷达间电磁兼容状况进行预测时,需要对雷达的谐波带宽进行分析.从谐波的产生机理出发,运用傅里叶变换方法,深入分析了雷达谐波带宽规律及其产生原因.结果发现,常规脉冲调制、高重频的谐波带宽和基波的带宽相比是相等的,线性调频的谐波带宽呈整数倍数变化,而相位编码的奇数次谐波和基波的带宽相比是相等的,偶数次谐波带宽很小.本研究可为建立雷达发射机电磁兼容预测模型提供参考依据.

  3. The anti-motility signaling mechanism of TGFβ3 that controls cell traffic during skin wound healing.

    Science.gov (United States)

    Han, Arum; Bandyopadhyay, Balaji; Jayaprakash, Priyamvada; Lua, Ingrid; Sahu, Divya; Chen, Mei; Woodley, David T; Li, Wei

    2012-12-15

    When skin is wounded, migration of epidermal keratinocytes at the wound edge initiates within hours, whereas migration of dermal fibroblasts toward the wounded area remains undetectable until several days later. This "cell type traffic" regulation ensures proper healing of the wound, as disruptions of the regulation could either cause delay of wound healing or result in hypertrophic scars. TGFβ3 is the critical traffic controller that selectively halts migration of the dermal, but not epidermal, cells to ensure completion of wound re-epithelialization prior to wound remodeling. However, the mechanism of TGFβ3's anti-motility signaling has never been investigated. We report here that activated TβRII transmits the anti-motility signal of TGFβ3 in full to TβRI, since expression of the constitutively activated TβRI-TD mutant was sufficient to replace TGFβ3 to block PDGF-bb-induced dermal fibroblast migration. Second, the three components of R-Smad complex are all required. Individual downregulation of Smad2, Smad3 or Smad4 prevented TGFβ3 from inhibiting dermal fibroblast migration. Third, Protein Kinase Array allowed us to identify the protein kinase A (PKA) as a specific downstream effector of R-Smads in dermal fibroblasts. Activation of PKA alone blocked PDGF-bb-induced dermal fibroblast migration, just like TGFβ3. Downregulation of PKA's catalytic subunit nullified the anti-motility signaling of TGFβ3. This is the first report on anti-motility signaling mechanism by TGFβ family cytokines. Significance of this finding is not only limited to wound healing but also to other human disorders, such as heart attack and cancer, where the diseased cells have often managed to avoid the anti-motility effect of TGFβ. PMID:23259050

  4. Noncoding RNA mediated traffic of foreign mRNA into chloroplasts reveals a novel signaling mechanism in plants.

    Directory of Open Access Journals (Sweden)

    Gustavo Gómez

    Full Text Available Communication between chloroplasts and the nucleus is one of the milestones of the evolution of plants on earth. Proteins encoded by ancestral chloroplast-endogenous genes were transferred to the nucleus during the endosymbiotic evolution and originated this communication, which is mainly dependent on specific transit-peptides. However, the identification of nuclear-encoded proteins targeted to the chloroplast lacking these canonical signals suggests the existence of an alternative cellular pathway tuning this metabolic crosstalk. Non-coding RNAS (NcRNAs are increasingly recognized as regulators of gene expression as they play roles previously believed to correspond to proteins. Avsunviroidae family viroids are the only noncoding functional RNAs that have been reported to traffic inside the chloroplasts. Elucidating mechanisms used by these pathogens to enter this organelle will unearth novel transport pathways in plant cells. Here we show that a viroid-derived NcRNA acting as a 5'UTR-end mediates the functional import of Green Fluorescent Protein (GFP mRNA into chloroplast. This claim is supported by the observation at confocal microscopy of a selective accumulation of GFP in the chloroplast of the leaves expressing the chimeric vd-5'UTR/GFP and by the detection of the GFP mRNA in chloroplasts isolated from cells expressing this construct. These results support the existence of an alternative signaling mechanism in plants between the host cell and chloroplasts, where an ncRNA functions as a key regulatory molecule to control the accumulation of nuclear-encoded proteins in this organelle. In addition, our findings provide a conceptual framework to develop new biotechnological tools in systems using plant chloroplast as bioreactors. Finally, viroids of the family Avsunviroidae have probably evolved to subvert this signaling mechanism to regulate their differential traffic into the chloroplast of infected cells.

  5. Traffic Square Management System

    OpenAIRE

    Sujata V. Padole

    2013-01-01

    If the traffic is more on one side and less on other side so there all way a waste of time and fuel on the traffic signal. Which is serious problem now day so there an need to have an intelligent traffic system which can detect the amount of traffic and make the change accordingly by using sensor and tranducer. Also by using motion detection camera at the lane we can find out the vehicle owner who break the traffic rules at the signal.

  6. Coordinated control model of regional traffic signals%交通区域协调控制模型

    Institute of Scientific and Technical Information of China (English)

    刘芹; 徐建闽

    2012-01-01

    为提高交通区域通行效率,构建了适合各种交通状态的区域信号协调控制模型。以区域交叉口总排队车辆数与区域总输出车辆数为性能指标,考虑上下周期排队车辆数、各交叉口闭合相位差与有效绿灯时间,建立了模型约束条件。利用粒子群算法初始化有效绿灯时间与滞留车辆数,采用模拟退火算法求解有效绿灯时间,在不同交通状态下对某交叉口路网进行了仿真。仿真结果表明:与TRANSYT模型相比,低峰时段,采用本文模型排队车辆数降低了5.3%,区域总输出车辆数增加了5.5%;高峰时段,排队车辆数降低了17.9%,区域总输出车辆数增加了33.4%。交叉口的信号方案优化结果表明:与TRANSYT模型相比,采用本文模型时,各车道饱和度均降低,平均为1.8%,最大排队车辆数平均降低2.9%。分析结果表明:本文模型在各种交通状态下都是有效的,特别是在高峰状态下,控制效果优于TRANSYT模型。%In order to improve the traffic efficiency of traffic area, a coordinated control model of regional signals was constructed under all kinds of traffic conditions. The total queue vehicle number and the total output vehicle number of regional intersection were used as performance indexes of the model. The constraint conditions of the model were established by considering the variable relationship of the adjacent cycle queue vehicle numbers, closed phase difference of intersections and effective green time. The effective green time and waiting vehicle number were initialized by particle swarm algorithm. The effective green time was solved by simulated annealing algorithm. The road network of a certain intersection was simulated under different traffic states. Simulation result shows that the queue vehicle number reduces by 5.3% and the total output vehicle number of region increases by 5.5% in low peak period compared with the TRANSYT model. The queue vehicle number reduces by

  7. 一种新型嵌入式网络信号机研究与设计%Study and Design of Embedded Network Traffic Signal Controller

    Institute of Scientific and Technical Information of China (English)

    肖圣兵; 陈锋

    2012-01-01

    Traffic signal controller is one of the main foundations for Intelligent Traffic System. In order to meet intellectualization and network requirements, a novel embedded network signal controller is investigated. ARM and CPLD are used to design hardware structure of signal controller, and humanized user interface is developed using QT/Embedded based on touch screen. Multiple communication interfaces are supported and the communication protocol is defined by XML. The mode of two level conflict check is introduced to avoid green conflict. Single point fuzzy control module is developed to deal with dynamic traffic flow, so as to increase traffic capacity in intersection. Connecting to traffic simulation software that simulates the actual intersectiont experiments show that traffic signal controller works stably, and has excellent performance.%交通信号机是智能交通系统的基础之一,为了满足信号机的网络化和智能化的要求,研究并提出了一种新型的嵌入式网络信号机,该信号机的硬件结构采用ARM和CPLD,以触摸屏为基础采用QT/Embedded设计了人性化的人机接口,信号机支持多种通信接口,其协议采用XML予以定义;为了避免绿冲突,以两级模式进行冲突判断;单点模糊控制机制的设计能够适应动态的交通流状况,有效提高交叉口的通行能力;连接交通仿真软件,模拟实际路口,实验显示该信号机工作稳定,性能优越.

  8. Cutter Connectivity Bandwidth Study

    Science.gov (United States)

    2002-10-01

    The goal of this study was to determine how much bandwidth is required for cutters to meet emerging data transfer requirements. The Cutter Connectivity Business Solutions Team with guidance front the Commandant's 5 Innovation Council sponsored this study. Today, many Coast Guard administrative and business functions are being conducted via electronic means. Although our larger cutters can establish part-time connectivity using commercial satellite communications (SATCOM) while underway, there are numerous complaints regarding poor application performance. Additionally, smaller cutters do not have any standard means of underway connectivity. The R&D study shows the most important factor affecting web performance and enterprise applications onboard cutters was latency. Latency describes the time it takes the signal to reach the satellite and come back down through space. The latency due to use of higher orbit satellites is causing poor application performance and inefficient use of expensive SATCOM links. To improve performance, the CC must, (1) reduce latency by using alternate communications links such as low-earth orbit satellites, (2) tailor applications to the SATCOM link and/or (3) optimize protocols used for data communication to minimize time required by present applications to establish communications between the user and the host systems.

  9. Video Traffic Prediction Using Neural Networks

    Directory of Open Access Journals (Sweden)

    Miloš Oravec

    2008-10-01

    Full Text Available In this paper, we consider video stream prediction for application in services likevideo-on-demand, videoconferencing, video broadcasting, etc. The aim is to predict thevideo stream for an efficient bandwidth allocation of the video signal. Efficient predictionof traffic generated by multimedia sources is an important part of traffic and congestioncontrol procedures at the network edges. As a tool for the prediction, we use neuralnetworks – multilayer perceptron (MLP, radial basis function networks (RBF networksand backpropagation through time (BPTT neural networks. At first, we briefly introducetheoretical background of neural networks, the prediction methods and the differencebetween them. We propose also video time-series processing using moving averages.Simulation results for each type of neural network together with final comparisons arepresented. For comparison purposes, also conventional (non-neural prediction isincluded. The purpose of our work is to construct suitable neural networks for variable bitrate video prediction and evaluate them. We use video traces from [1].

  10. The anti-motility signaling mechanism of TGFβ3 that controls cell traffic during skin wound healing

    Directory of Open Access Journals (Sweden)

    Arum Han

    2012-09-01

    When skin is wounded, migration of epidermal keratinocytes at the wound edge initiates within hours, whereas migration of dermal fibroblasts toward the wounded area remains undetectable until several days later. This “cell type traffic” regulation ensures proper healing of the wound, as disruptions of the regulation could either cause delay of wound healing or result in hypertrophic scars. TGFβ3 is the critical traffic controller that selectively halts migration of the dermal, but not epidermal, cells to ensure completion of wound re-epithelialization prior to wound remodeling. However, the mechanism of TGFβ3's anti-motility signaling has never been investigated. We report here that activated TβRII transmits the anti-motility signal of TGFβ3 in full to TβRI, since expression of the constitutively activated TβRI-TD mutant was sufficient to replace TGFβ3 to block PDGF-bb-induced dermal fibroblast migration. Second, the three components of R-Smad complex are all required. Individual downregulation of Smad2, Smad3 or Smad4 prevented TGFβ3 from inhibiting dermal fibroblast migration. Third, Protein Kinase Array allowed us to identify the protein kinase A (PKA as a specific downstream effector of R-Smads in dermal fibroblasts. Activation of PKA alone blocked PDGF-bb-induced dermal fibroblast migration, just like TGFβ3. Downregulation of PKA's catalytic subunit nullified the anti-motility signaling of TGFβ3. This is the first report on anti-motility signaling mechanism by TGFβ family cytokines. Significance of this finding is not only limited to wound healing but also to other human disorders, such as heart attack and cancer, where the diseased cells have often managed to avoid the anti-motility effect of TGFβ.

  11. Signaling in Vesicle Traffic: Protein-Lipid Interface in Regulation of Plant Endomembrane Dynamics

    Czech Academy of Sciences Publication Activity Database

    Žárský, Viktor; Potocký, Martin

    Heidelberg: Springer Verlag, 2009 - (Baluska, F.; Mancuso, S.), s. 107-133 ISBN 978-3-540-89227-4 R&D Projects: GA AV ČR IAA6038410; GA AV ČR(CZ) IAA601110916; GA MŠk(CZ) LC06034; GA MŠk ME 841 Institutional research plan: CEZ:AV0Z50380511 Keywords : vesicle trafficking * secretory pathway * lipid signalling Subject RIV: EA - Cell Biology

  12. Chemical Industry Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  13. Performance Investigation of Virtual Private Networks with Different Bandwidth Allocations

    Directory of Open Access Journals (Sweden)

    Ramaswamy Muthiah

    2010-01-01

    Full Text Available A Virtual Private Network (VPN provides private network connections over a publicly accessible shared network. The effective allocation of bandwidth for VPNs assumes significance in the present scenario due to varied traffic. Each VPN endpoint specifies bounds on the total amount of traffic that it is likely to send or receive at any time. The network provider tailors the VPN so that there is sufficient bandwidth for any traffic matrix that is consistent with these bounds. The approach incorporates the use of Ad-hoc On demand Distance Vector (AODV protocol, with a view to accomplish an enhancement in the performance of the mobile networks. The NS2 based simulation results are evaluated in terms of its metrics for different bandwidth allocations, besides analyzing its performance in the event of exigencies such as link failures. The results highlight the suitability of the proposed strategy in the context of real time applications.

  14. Performance Investigation of Virtual Private Networks with Different Bandwidth Allocations

    CERN Document Server

    Natarajan, Mahalakshmi Chidambara; Nachiappan, Alamelu

    2010-01-01

    A Virtual Private Network (VPN) provides private network connections over a publicly accessible shared network. The effective allocation of bandwidth for VPNs assumes significance in the present scenario due to varied traffic. Each VPN endpoint specifies bounds on the total amount of traffic that it is likely to send or receive at any time. The network provider tailors the VPN so that there is sufficient bandwidth for any traffic matrix that is consistent with these bounds. The approach incorporates the use of Ad-hoc On demand Distance Vector (AODV) protocol, with a view to accomplish an enhancement in the performance of the mobile networks. The NS2 based simulation results are evaluated in terms of its metrics for different bandwidth allocations, besides analyzing its performance in the event of exigencies such as link failures. The results highlight the suitability of the proposed strategy in the context of real time applications.

  15. Large scale probabilistic available bandwidth estimation

    CERN Document Server

    Thouin, Frederic; Rabbat, Michael

    2010-01-01

    The common utilization-based definition of available bandwidth and many of the existing tools to estimate it suffer from several important weaknesses: i) most tools report a point estimate of average available bandwidth over a measurement interval and do not provide a confidence interval; ii) the commonly adopted models used to relate the available bandwidth metric to the measured data are invalid in almost all practical scenarios; iii) existing tools do not scale well and are not suited to the task of multi-path estimation in large-scale networks; iv) almost all tools use ad-hoc techniques to address measurement noise; and v) tools do not provide enough flexibility in terms of accuracy, overhead, latency and reliability to adapt to the requirements of various applications. In this paper we propose a new definition for available bandwidth and a novel framework that addresses these issues. We define probabilistic available bandwidth (PAB) as the largest input rate at which we can send a traffic flow along a pa...

  16. The Krüppel traffic report: Cooperative signals direct KLF8 nuclear transport

    Institute of Scientific and Technical Information of China (English)

    Estefanía Rodríguez; John A Martignetti

    2009-01-01

    @@ The Krüppel-like transcription fac-tor (KLF) family consists of 17 dis-tinct family members involved in the regulation of diverse cellular processes including differentiation, cell prolifera-tion, growth-related signal transduction, angiogenesis and apoptosis (recently reviewed in [1]). In addition to their currently known biologic roles, the discovery that at least one member of the family, KLF6, can be alternatively spliced into biologically active isoforms with antagonistic functions and a dis-tinct subcellular localization pattern [2], highlights the fact that nuclear-cytoplasmic shuttling of KLF proteins may represent an additional layer of functional regulation and the possibility of an even more diverse and completely unexplored role for KLF family mem-bers in both health and disease.

  17. Programmable bandwidth management in software-defined EPON architecture

    Science.gov (United States)

    Li, Chengjun; Guo, Wei; Wang, Wei; Hu, Weisheng; Xia, Ming

    2016-07-01

    This paper proposes a software-defined EPON architecture which replaces the hardware-implemented DBA module with reprogrammable DBA module. The DBA module allows pluggable bandwidth allocation algorithms among multiple ONUs adaptive to traffic profiles and network states. We also introduce a bandwidth management scheme executed at the controller to manage the customized DBA algorithms for all date queues of ONUs. Our performance investigation verifies the effectiveness of this new EPON architecture, and numerical results show that software-defined EPONs can achieve less traffic delay and provide better support to service differentiation in comparison with traditional EPONs.

  18. A Preliminary Evaluation of Bandwidth Allocation Model Dynamic Switching

    Directory of Open Access Journals (Sweden)

    Rafael F. Reale

    2014-06-01

    Full Text Available Bandwidth Allocation Models (BAMs are used in order to define Bandwidth Constraints (BCs in a per-class basis for MPLS/DS-TE networks and effectively define how network resources like bandwidth are obtained and shared by applications. The BAMs proposed (MAM – Maximum Allocation Model, RDM – Russian Dolls Model, G-RDM – Generic RDM and AllocTC-Sharing attempt to optimize the use of bandwidth resources on a per-link basis with different allocation and resource sharing characteristics. As such, the adoption of distinct BAMs and/or changes in network resource demands (network traffic profile may result in different network traffic allocation and operational behavior for distinct BAMs. This paper evaluates the resulting network characteristics (li nk utilization, preemption and flows blocking of using BAMs dynamically with different traffic scenarios. In brief, it is investigated the dynamics of BAM switching with distinct traffic scenarios. The paper presents initially the investigated BAMs in relation to their behavior and resource allocation characteristics. Then, distinct BAMs are compared using different traffic scenarios in order to investigate the impact of a dynamic change of the BAM configured in the network. Finally, the paper shows that the adoption of a dynamic BAM allocation strategy may result in benefits for network operation in terms of link utilization, preemption and flows blocking.

  19. Low-bandwidth authentication.

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, Patrick Joseph; McIver, Lauren; Gaines, Brian R.; Anderson, Erik; Collins, Michael Joseph; Thomas,Kurt Adam; McDaniel, Austin

    2007-09-01

    Remotely-fielded unattended sensor networks generally must operate at very low power--in the milliwatt or microwatt range--and thus have extremely limited communications bandwidth. Such sensors might be asleep most of the time to conserve power, waking only occasionally to transmit a few bits. RFID tags for tracking or material control have similarly tight bandwidth constraints, and emerging nanotechnology devices will be even more limited. Since transmitted data is subject to spoofing, and since sensors might be located in uncontrolled environments vulnerable to physical tampering, the high-consequence data generated by such systems must be protected by cryptographically sound authentication mechanisms; but such mechanisms are often lacking in current sensor networks. One reason for this undesirable situation is that standard authentication methods become impractical or impossible when bandwidth is severely constrained; if messages are small, a standard digital signature or HMAC will be many times larger than the message itself, yet it might be possible to spare only a few extra bits per message for security. Furthermore, the authentication tags themselves are only one part of cryptographic overhead, as key management functions (distributing, changing, and revoking keys) consume still more bandwidth. To address this problem, we have developed algorithms that provide secure authentication while adding very little communication overhead. Such techniques will make it possible to add strong cryptographic guarantees of data integrity to a much wider range of systems.

  20. T cell traffic signals

    OpenAIRE

    Van Epps, Heather L.

    2005-01-01

    In 1990, Charles Mackay and colleagues combined classical physiology with modern molecular biology to provide the first concrete evidence that naive and memory T cells follow distinct migratory routes out of the bloodstream— a discovery that helped invigorate the field of lymphocyte homing.

  1. Adaptive network traffic management for multi user virtual environments

    OpenAIRE

    Oliver, Iain Angus

    2011-01-01

    Multi User Virtual Environments (MUVE) are a new class of Internet application with a significant user base. This thesis adds to our understanding of how MUVE network traffic fits into the mix of Internet traffic, and how this relates to the application's needs. MUVEs differ from established Internet traffic types in their requirements from the network. They differ from traditional data traffic in that they have soft real-time constraints, from game traffic in that their bandwidth requi...

  2. Can Passive Mobile Application Traffic be Identified using Machine Learning Techniques

    OpenAIRE

    Holland, Peter

    2015-01-01

    Mobile phone applications (apps) can generate background traffic when the end-user is not actively using the app. If this background traffic could be accurately identified, network operators could de-prioritise this traffic and free up network bandwidth for priority network traffic. The background app traffic should have IP packet features that could be utilised by a machine learning algorithm to identify app-generated (passive) traffic as opposed to user-generated (active) traffic. Previous ...

  3. Application and modeling of GaN FET in 1MHz large signal bandwidth power supply for radio frequency power amplifier

    OpenAIRE

    Cucak, Dejana; Vasic, Miroslav; García Suárez, Oscar; Oliver Ramírez, Jesús Angel; Alou Cervera, Pedro; Cobos Márquez, José Antonio; Tadjer, Marko Jak; Calle Gómez, Fernando; Benkhelifa, F.; R Reiner; Waltereit, P.; Müller, S.

    2013-01-01

    In this paper, implementation and testing of non- commercial GaN HEMT in a simple buck converter for envelope amplifier in ET and EER transmission techn iques has been done. Comparing to the prototypes with commercially available EPC1014 and 1015 GaN HEMTs, experimentally demonstrated power supply provided better thermal management and increased the switching frequency up to 25MHz. 64QAM signal with 1MHz of large signal bandw idth and 10.5dB of Peak to Average Power Ratio was g...

  4. Simulation of Genetic Algorithm: Traffic Light Efficiency

    OpenAIRE

    Lienert, Eric

    2015-01-01

    Traffic is a problem in many urban areas worldwide. Traffic flow is dictated by certain devices such as traffic lights. The traffic lights signal when each lane is able to pass through the intersection. Often, static schedules interfere with ideal traffic flow. The purpose of this project was to find a way to make intersections controlled with traffic lights more efficient. This goal was accomplished through the creation of a genetic algorithm, which enhances an input algorithm through geneti...

  5. Bandwidth in bolometric interferometry

    CERN Document Server

    Charlassier, R; Hamilton, J -Ch; Kaplan, J; Malu, S

    2009-01-01

    Bolometric Interferometry is a technology currently under development that will be first dedicated to the detection of B-mode polarization fluctuations in the Cosmic Microwave Background. A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers in order to be competitive with imaging experiments. A crucial concern is that interferometers are presumed to be importantly affected by a spoiling effect known as bandwidth smearing. In this paper, we investigate how the bandwidth modifies the work principle of a bolometric interferometer and how it affects its sensitivity to the CMB angular power spectra. We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. Using an angular power spectrum estimator ...

  6. Radio Interferometers with wide bandwidths

    OpenAIRE

    Subrahmanyan, Ravi

    2003-01-01

    The Australia Telescope Compact Array and the Very Large Array are currently being upgraded to operate with wide bandwidths; interferometers dedicated to the measurement of cosmic microwave background anisotropies are being designed with large instantaneous bandwidths for high sensitivity. Interferometers with wide instantaneous bandwidths that do not operate with correlators capable of decomposing the bands into narrow channels suffer from `bandwidth smearing' effects in wide-field imaging. ...

  7. Traffic flow on realistic road networks with adaptive traffic lights

    CERN Document Server

    de Gier, Jan; Rojas, Omar

    2010-01-01

    We present a model of traffic flow on generic urban road networks based on cellular automata. We apply this model to an existing road network in the Australian city of Melbourne, using empirical data as input. For comparison, we also apply this model to a square-grid network using hypothetical input data. On both networks we compare the effects of non-adative vs adaptive traffic lights, in which instantaneous traffic state information feeds back into the traffic signal schedule. We observe that not only do adaptive traffic lights result in better averages of network observables, they also lead to significantly smaller fluctuations in these observables. We furthermore compare two different systems of adaptive traffic signals, one which is informed by the traffic state on both upstream and downstream links, and one which is informed by upstream links only. We find that, in general, the total travel time is smallest when using the joint upstream-downstream control strategy.

  8. Telecom technology based continuous wave terahertz photomixing system with 105 decibel signal-to-noise ratio and 3.5 terahertz bandwidth.

    Science.gov (United States)

    Göbel, Thorsten; Stanze, Dennis; Globisch, Björn; Dietz, Roman J B; Roehle, Helmut; Schell, Martin

    2013-10-15

    A modified photoconductive receiver significantly improves the performance of photomixing-based continuous wave (cw) THz systems driven at the optical telecommunication wavelength of 1.5 μm. The achieved signal-to-noise ratio of 105 dB at 100 GHz and 70 dB at 1 THz, both for an integration time of 200 ms, are to our knowledge the highest numbers reported in literature for any optoelectronic cw THz system, including classical setups operating at 800 nm. The developed receiver allows for combining low cost and high performance in one system for the first time to our knowledge. PMID:24321958

  9. Teleoperation over low bandwidth communication links

    International Nuclear Information System (INIS)

    Teleoperation is well established for many areas of hazardous environment working. Where such environments are well structured and contained, such as within a working plant, communications bandwidths need not be a constraining factor. However where the worksite is remote, large, poorly structured or damaged communications rapidly become a critical factor in the efficient deployment and use of teleoperation equipment. The paper justifies and describes means which we are exploring to reduce the required communications bandwidth for teleoperation whist retaining full functionality. Techniques involved include incorporation of local intelligence at the worksite, with bandwidth devoted to high-level up-link control signals and down-link feedback, and the use of highly compressed video feeding 'virtual reality type' HMDs to provide maximum system transparency for the operator. The work is drawing on previous experience with an 'anthropomorphic robot heat' for telepresence work, and proprietary algorithms capable of compressing full colour video to standard telephone modem data rates. (Author)

  10. Efficient Bandwidth Allocation for Integrated Services in Broadband Wireless ATM Networks

    DEFF Research Database (Denmark)

    Liu, Hong; Dittmann, Lars; Gliese, Ulrik Bo;

    1999-01-01

    An efficient bandwidth allocation scheme is proposed for supporting intergrated services in wireless ATM networks. These include CBR, VBR amd ABR types of traffic. The proposed scheme is based om A-PRMA for carrying ATM traffic in a dynamic TDMA type access system. It allows mobile users to adjust...

  11. QoS-aware dynamic bandwidth allocation algorithm for Gigabit-capable PONS

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; ZHAO Yang; GU Wanyi

    2007-01-01

    The Gigabit-capable passive optical network (GPON)technology is being considered as a promising solution for the next-generation broadband access network.Since the network topology of the GPON is point-to-multipoint,a media access control called dynamic bandwidth allocation(DBA)algorithm is an important factor for determining the performance of the GPON.In this paper,we propose a new DBA algorithm to effectively and fairly allocate bandwidths among end users.This DBA algorithm supports difierentiated services-a cmcial requirement for a converged broadband access network with heterogeneous traffic.In this article we first reviewed the signaling and configuration of the DBA,and then proposed a new DBA scheme that implemented QoS-based priority for this need to maximally satisfy the requirements of all optical network units(ONUs)and provide difierentiated services.Analyses and simulation results show that the new algorithm can improve the bandwidth utilization and realize the fairness for both different ONUs and services.

  12. A Study of Bandwidth Measurement Technique in Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    Ajeet Kumar Singh

    2011-09-01

    Full Text Available Wireless mesh networks (WMNs have been proposed as a key technology for next generation wireless networking to provide last-mile broadband access. H ere we have given our observation and study for end to-end bandwidth estimation in WMNs. End-to-end Ban dwidth Estimation is an important metric for network management and monitoring. It can also impr ove the effectiveness of congestion control mechanism, audio/video stream adoration and dynamic overlay. In recent years, many techniques have been developed for bandwidth estimation in the wire d as well as the last-hop wireless networks, but th ey under-perform in WMNs. We investigate attributes th at can affect the bandwidth estimation in WNMs; we found existing techniques do not consider the effec t of attributes like CSMA/CA-based contending traff ic and high interference interference that leads to th e error full estimation. In this paper, we present an active bandwidth measu rement technique called Bandwidth Probe based on th e packet dispersion principle. It measures the steady state bandwidth of the system while considering th e effects of the FIFO cross and CSMA/CA-based contend ing traffic. It is also mitigating the effect of interference. We also show how to achieve the stati onary state behaviour of the system to limit the nu mber of probe packets. On simulation, Bandwidth Probe gi ves a accurate estimation of the available bandwidt h using average convergence time and lower intrusiven ess.

  13. Traffic engineering eye diagram

    OpenAIRE

    Kowalik, Karol; Collier, Martin

    2005-01-01

    It is said that a picture is worth a thousand words - this statement also applies to networking topics. Thus, to effectively monitor network performance we need tools which present the performance metrics in a graphical way which is also clear and informative. We propose a tool for this purpose which we call the traffic engineering eye diagram (TEED). Eye diagrams are used in digital communications to analyse the quality of a digital signal; the TEED can similarly he used in the traffic engin...

  14. Scalable Network-layer Defense Against Internet Bandwidth-Flooding Attacks

    OpenAIRE

    Argyraki, Katerina; Cheriton, David R.

    2009-01-01

    In a bandwidth-flooding attack, compromised sources send high-volume traffic to the target with the purpose of causing congestion in its tail circuit and disrupting its legitimate communications. In this paper, we present Active Internet Traffic Filtering (AITF), a network-layer defense mechanism against such attacks. AITF enables a receiver to contact misbehaving sources and ask them to stop sending it traffic; each source that has been asked to stop is policed by its own Internet service pr...

  15. TRAFFIC RETIMING SYSTEM USING IMAGE PROCESSING

    OpenAIRE

    Tanmayi Jain*

    2015-01-01

    One of the main problems in cities is traffic, this paper proposed new solution to traffic control. The main design concept of this project is to control the traffic automatically. System is made more efficient with addition of intelligence in term of artificial vision, using image processing techniques to estimate actual road traffic and compute time, each time for every road before enabling the signal. This model is resemblance of traditional traffic police man who takes better ...

  16. Formation and Propagation of Local Traffic Jam

    OpenAIRE

    Hong-sheng Qi; Dian-hai Wang; Peng Chen

    2013-01-01

    Large scale traffic congestion often stems from local traffic jam in single road or intersection. In this paper, macroscopic method was used to explore the formation and propagation of local traffic jam. It is found that (1) the propagation of traffic jam can be seen as the propagation of traffic signal parameters, that is, virtual split and virtual green time; (2) for a road with endogenous flow, entrance location influences the jam propagation. With the same demand (upstream links flow and ...

  17. Gain and bandwidth in stagger-tuned gyroklystrons

    International Nuclear Information System (INIS)

    An analytical theory describing the trade-off in the bandwidth and gain in multicavity, stagger-tuned gyroklystrons (GKLs) is developed. The assumption that the cavities are short and therefore the electron ballistic bunching proceeds in long drift sections (point-gap model) allows us to develop analytically both the small-signal and large-signal theories of stagger-tuned GKLs. The results for two-, three-, and four-cavity GKLs are presented which illustrate the bandwidth increase, the gain degradation, and the increase in gain-bandwidth product due to the stagger tuning. copyright 1997 American Institute of Physics

  18. All-optical bandwidth-tailorable radar

    CERN Document Server

    Zou, Weiwen; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2015-01-01

    Radar has been widely used in military, security, and rescue. Metamaterial cloak is employed in stealth targets to evade radar detection. Hence modern radar should be reconfigurable at multi-bands for detecting stealth targets, which might be realized based on microwave photonics. Here, we demonstrate an all-optical bandwidth-tailorable radar architecture. It is a coherent system utilizing one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates wideband linearly-chirped radar signal. The working bands can be flexibly tailored with desired bandwidth at user-preferred carrier frequency. After modulated onto the pre-chirped optical pulse, radar echoes are time-stretched and frequency-compressed by several times. The digitization becomes much easier without loss of detection ability. We believe that the demonstration can innovate the radar's architecture with ultra-high range resolution.

  19. Efficient and Fair Bandwidth Allocation AQM Scheme for Wireless Networks

    Directory of Open Access Journals (Sweden)

    Rafe Alasem

    2010-05-01

    Full Text Available Heterogeneous Wireless Networks are considered nowadays as one of the potential areas in research and development. The traffic management’s schemes that have been used at the fusion points between the different wireless networks are classical and conventional. This paper is focused on developing a novel scheme to overcome the problem of traffic congestion in the fusion point router interconnected the heterogeneous wireless networks. The paper proposed an EF-AQM algorithm which provides an efficient and fair allocation of bandwidth among different established flows. Finally, the proposed scheme developed, tested and validated through a set of experiments to demonstrate the relative merits and capabilities of a proposed scheme

  20. Dynamic bandwidth Reservation in Virtual Private Network under Uncertain Traffic

    OpenAIRE

    Le Cadre, Hélène

    2006-01-01

    The aim of this paper is to analyze the dynamic evolution of a VPN, modeled as a system, controled by a manager who should take appropriate decisions. To take the best possible decisions, the operator should be able to worst behavior, in the sense of a quality of service criterion, of the system he wants to control. At first, we study the case of a simple VPN. In a second part, we propose solutions to model the various interactions that may appear in a network of multiple VPNs.

  1. Web traffic and firm performance

    DEFF Research Database (Denmark)

    Farooq, Omar; Aguenaou, Samir

    2013-01-01

    Does the traffic generated by websites of firms signal anything to stock market participants? Does higher web-traffic translate into availability of more information and therefore lower agency problems? And if answers to above questions are in affirmative, does higher web-traffic traffic translate...... into better firm performance? This paper aims to answer these questions by documenting a positive relationship between the extent of web-traffic and firm performance in the MENA region during the 2010. We argue that higher web-traffic lowers the agency problems in firms by disseminating more information...... to stock market participants. Consequently, lower agency problems translate into better performance. Furthermore, we also show that agency reducing role of web-traffic is more pronounced in regimes where information environment is already bad. For example, our results show stronger impact of web...

  2. Organic traffic control

    OpenAIRE

    Prothmann, Holger

    2011-01-01

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

  3. Physics of traffic gridlock in a city

    OpenAIRE

    Kerner, Boris S.

    2011-01-01

    Based of simulations of a stochastic three-phase traffic flow model, we reveal that at a signalized city intersection under small link inflow rates at which a vehicle queue developed during the red phase of light signal dissolves fully during the green phase, i.e., no traffic gridlock should be expected, nevertheless, traffic breakdown with the subsequent city gridlock occurs with some probability after a random time delay. This traffic breakdown is initiated by a first-order phase transition...

  4. Bandwidth of Gaussian weighted Chirp

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.

    1993-01-01

    Four major time duration and bandwidth expressions are calculated for a linearly frequency modulated sinusoid with Gaussian shaped envelope. This includes a Gaussian tone pulse. The bandwidth is found to be a nonlinear function of nominal time duration and nominal frequency excursion of the chirp...

  5. Multiple-bandwidth photoacoustic tomography

    International Nuclear Information System (INIS)

    Photoacoustic tomography, also referred to as optoacoustic tomography, employs short laser pulses to generate ultrasonic waves in biological tissues. The reconstructed images can be characterized by the convolution of the structure of samples, the laser pulse and the impulse response of the ultrasonic transducer used for detection. Although the laser-induced ultrasonic waves cover a wide spectral range, a single transducer can receive only part of the spectrum because of its limited bandwidth. To systematically analyse this problem, we constructed a photoacoustic tomographic system that uses multiple ultrasonic transducers simultaneously, each at a different central frequency. The photoacoustic images associated with the different transducers were compared and analysed. The system was tested by imaging both mouse brains and phantom samples. The vascular vessels in the brain were revealed by all of the transducers, but the image resolutions differed. The higher frequency detectors provided better image resolution while the lower frequency detectors delineated the major structural traits with a higher signal-noise ratio

  6. Intelligent Ambulance Traffic Assistance System

    Directory of Open Access Journals (Sweden)

    RONOJOY GHOSH

    2013-09-01

    Full Text Available With the increase in traffic road density, several causalities occur due to delay in taking a patient to the hospital in an ambulance. In this paper, we have developed an algorithm to find the shortest path to reach the required destination. As required the software will identify the present location of the vehicle and ask the user for the destination. Then it will show all the available paths, highlighting the shortest one or in several cases the most optimum one. Further we made the traffic signals automated for special vehicles like an ambulance or a fire-engine such that the signals will go green for the ambulance as it comes in the vicinity of the traffic signal, thus providing them with a clear path to reach its destination. The original signal is restored as soon as the ambulance goes undetected by the Bluetooth scanner of the traffic signal.

  7. Ultra-broad bandwidth parametric amplification at degeneracy.

    Science.gov (United States)

    Limpert, J; Aguergaray, C; Montant, S; Manek-Hönninger, I; Petit, S; Descamps, D; Cormier, E; Salin, F

    2005-09-19

    We report on a novel approach of ultra-broad bandwidth parametric amplification around degeneracy. A bandwidth of up to 400 nm centered around 800 nm is amplified in a BBO crystal by using chirped pump pulses with a bandwitdth as broad as 10 nm. A supercontinuum signal is generated in a microstructured fiber, having to first order a quadratic chirp, which is necessary to ensure temporal overlap of the interacting waves over this broad bandwidth. Furthermore, we discuss the potential of this approach for an octave-spanning parametric amplification. PMID:19498762

  8. Network Bandwidth Utilization Forecast Model on High Bandwidth Network

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Wucherl; Sim, Alex

    2014-07-07

    With the increasing number of geographically distributed scientific collaborations and the scale of the data size growth, it has become more challenging for users to achieve the best possible network performance on a shared network. We have developed a forecast model to predict expected bandwidth utilization for high-bandwidth wide area network. The forecast model can improve the efficiency of resource utilization and scheduling data movements on high-bandwidth network to accommodate ever increasing data volume for large-scale scientific data applications. Univariate model is developed with STL and ARIMA on SNMP path utilization data. Compared with traditional approach such as Box-Jenkins methodology, our forecast model reduces computation time by 83.2percent. It also shows resilience against abrupt network usage change. The accuracy of the forecast model is within the standard deviation of the monitored measurements.

  9. Revolutionizing Technology Prioritizing Emergency Vehicles in Traffic

    OpenAIRE

    B. Ramya Sundaram; E. Aravind; S. Harithaa; G. Karthick; Shriram K. Vasudevan

    2014-01-01

    The following study brings to the fore a technology exclusively engineered to eradicate the snags and inadequacies persisting in the existing system of traffic control and thus aims to provide a sophisticated operation and uninterrupted course for the emergency vehicles. The traffic in Indian roads has shown a tremendous rise over the years and the conventional pre-timed traffic signals and frequent traffic congestions, delaying the road commuters, have led to outrage and chaos on several occ...

  10. Multicast Traffic Engineering for Software-Defined Networks

    OpenAIRE

    Huang, Liang-Hao; Hsu, Hsiang-Chun; Shen, Shan-Hsiang; Yang, De-Nian; Chen, Wen-Tsuen

    2015-01-01

    Although Software-Defined Networking (SDN) enables flexible network resource allocations for traffic engineering, current literature mostly focuses on unicast communications. Compared to traffic engineering for multiple unicast flows, multicast traffic engineering for multiple trees is very challenging not only because minimizing the bandwidth consumption of a single multicast tree by solving the Steiner tree problem is already NP-Hard, but the Steiner tree problem does not consider the link ...

  11. Polybinary modulation for bandwidth limited optical links

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Jurado-Navas, Antonio

    2015-01-01

    Optical links using traditional modulation formats are reaching a plateau in terms of capacity, mainly due to bandwidth limitations in the devices employed at the transmitter and receivers. Advanced modulation formats, which boost the spectral efficiency, provide a smooth migration path towards...... form of partial response modulation, employs simple codification and filtering at the transmitter to drastically increase the spectral efficiency. At the receiver side, poly binary modulation requires low complexity direct detection and very little digital signal processing. This talk will review the...

  12. Self——adaptive Control Method for Traffic Signal at Single Intersection Based on Cloud Model Adaptive%基于云模型的单路口交通信号自适应控制方法研究

    Institute of Scientific and Technical Information of China (English)

    刘罗仁; 罗金玲

    2011-01-01

    为了减少车辆通过路口的延误,提出了一种基于云模型的单路口交通信号自适应控制方法;使用云模型作为信号控制的基础模型,利用云模型中的正态云发生器和前件云发生器算法分别对道路交通信息进行处理并产生自适应的控制规则,以实现单路口交通信号的自适应控制;通过仿真实验,结果表明,使用云模型作为控制方法,比较传统控制方式更具智能化,更接近于人脑思维过程的控制方法,这也是将来交通信号控制的发展方向.%In order to reduce traffic delays through the intersection, this paper presents, a single intersection based on cloud model adaptive traffic signal control. Signal control using the cloud model as the basis model, the cloud model in the normal cloud generator and the former pieces of cloud generator algorithms are processed on road traffic information and generates adaptive control rules in order to achieve a single self-intersection traffic signal adaptive control. The simulation experiment results show that the control method using the cloud model as the more traditional control method is more intelligent, more close to the brain control the process of thinking, this is the future direction of development of traffic signal control.

  13. Steel Industry Energy Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2004-10-01

    ITP conducted a study on energy use and potential savings, or "bandwidth" study, in major steelmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results based on the 2nd law of thermodynamics. The Steel Industry Energy Bandwidth Study (PDF 133 KB) also estimates steel industry energy use in the year 2010, and uses that value as a basis for comparison against the minimum requirements. This energy savings opportunity for 2010 will aid focus on longer term R&D.

  14. Mining Industry Energy Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2007-07-01

    The Industrial Technologies Program (ITP) relies on analytical studies to identify large energy reduction opportunities in energy-intensive industries and uses these results to guide its R&D portfolio. The energy bandwidth illustrates the total energy-saving opportunity that exists in the industry if the current processes are improved by implementing more energy-efficient practices and by using advanced technologies. This bandwidth analysis report was conducted to assist the ITP Mining R&D program in identifying energy-saving opportunities in coal, metals, and mineral mining. These opportunities were analyzed in key mining processes of blasting, dewatering, drilling, digging, ventilation, materials handling, crushing, grinding, and separations.

  15. Bandwidth and chirp characterisation of wavelength conversion based on electroabsorption modulators

    DEFF Research Database (Denmark)

    Xu, Lin; Oxenløwe, Leif Katsuo; Chi, Nan;

    2002-01-01

    It is demonstrated experimentally that the frequency chirp of a data modulated signal can be reduced and the modulation bandwidth increased through wavelength conversion in an electroabsorption modulator.......It is demonstrated experimentally that the frequency chirp of a data modulated signal can be reduced and the modulation bandwidth increased through wavelength conversion in an electroabsorption modulator....

  16. Self-organized control of traffic signals based on reinforcement learning and genetic algorithm%基于再励学习和遗传算法的交通信号自组织控制

    Institute of Scientific and Technical Information of China (English)

    欧海涛; 杨煜普; 张文渊; 许晓鸣

    2000-01-01

    提出一种将再励学习与遗传算法相结合的遗传再励学习方法对交通信号进行自组织控制再励学习是针对每一个道路交叉口交通流的优化,修正每个信号灯周期的绿性比;而遗传算法产生局部学习过程的全局优化标准,即是修正信号灯周期的大小这种方法克服了现有的控制方法需要大量数据传输通讯、准确的交通模型等缺陷,将局部优化和全局优化统一起来通过计算机仿真实验表明了方法的有效性%A combination algorithm of reinforcement learning and genetic algorithm is proposed in this paper to self-organized control of the traffic signals.Reinforcement learning focuses on the optimization of an intersection traffic flow which modified the split of traffic signal cycle,while the genetic algorithm are intended to introduce a global optimization criterion to each of the local learning processes which modified the cycle itself of traffic signals.This method overcome the drawbacks in existing control methods such as huge data transfer and communication,accurately traffic model and so on,and unified the local optimization and global optimization.Through the computer simulation,the effectiveness of method is demonstated.

  17. Transportation dynamic on coupled networks with limited bandwidth

    CERN Document Server

    Li, Ming; Wang, Bing-Hong

    2016-01-01

    The communication networks in real world often couple with each other to save costs, which results in any network does not have a stand-alone function and efficiency. To investigate this, in this paper we propose a transportation model on two coupled networks with bandwidth sharing. We find that the free-flow state and the congestion state can coexist in the two coupled networks, and the free-flow path and congestion path can coexist in each network. Considering three bandwidth-sharing mechanisms, random, assortative and disassortative couplings, we also find that the transportation capacity of the network only depends on the coupling mechanism, and the fraction of coupled links only affects the performance of the system in the congestion state, such as the traveling time. In addition, with assortative coupling, the traffic capacity of the system will decrease significantly. However, the disassortative coupling has little influence on the transportation capacity of the system, which provides a good strategy t...

  18. Bandwidth allocation for video under quality of service constraints

    CERN Document Server

    Anjum, Bushra

    2014-01-01

    We present queueing-based algorithms to calculate the bandwidth required for a video stream so that the three main Quality of Service constraints, i.e., end-to-end delay, jitter and packet loss, are ensured. Conversational and streaming video-based applications are becoming a major part of the everyday Internet usage. The quality of these applications (QoS), as experienced by the user, depends on three main metrics of the underlying network, namely, end-to-end delay, jitter and packet loss. These metrics are, in turn, directly related to the capacity of the links that the video traffic trave

  19. Selecting noise source and traffic representations that capture urban traffic noise dynamics

    OpenAIRE

    CAN, Arnaud; Leclercq, Ludovic; Lelong, Joël

    2009-01-01

    Considering traffic dynamics greatly improves noise estimation in urban area. This can be achieved by coupling a dynamic traffic model with both noise emission laws and sound propagation calculation. Determining the relevant noise source and traffic representations to estimate classical noise descriptors (LAeq and statistical descriptors) near traffic signals has been recently studied. This research topic is extended in this paper to more specific descriptors which are able to capture noise d...

  20. Automatic Traffic Density Estimation and Vehicle Classification for Traffic Surveillance Systems using Neural Networks

    OpenAIRE

    Ozkurt, Celil; Camci, Fatih

    2009-01-01

    It is important to know the road traffic density real time especially in mega cities for signal control and effective traffic management. In recent years, video monitoring and surveillance systems have been widely used in traffic management. Hence, traffic density estimation and vehicle classification can be achieved using video monitoring systems. In most vehicle detection methods in the literature, only the detection of vehicles in frames of the given video is emphesized. However, further a...

  1. TRAFFIC RETIMING SYSTEM USING IMAGE PROCESSING

    Directory of Open Access Journals (Sweden)

    Tanmayi Jain*

    2015-07-01

    Full Text Available One of the main problems in cities is traffic, this paper proposed new solution to traffic control. The main design concept of this project is to control the traffic automatically. System is made more efficient with addition of intelligence in term of artificial vision, using image processing techniques to estimate actual road traffic and compute time, each time for every road before enabling the signal. This model is resemblance of traditional traffic police man who takes better decision every time and soothes traffic flow. Unpredicted growth of traffic today has created serious problem in metro cities. This project has been implemented in the Matlab software and it aims to prevent heavy traffic in highways. Moreover, for implementing this project following steps must be considered: 1 image acquisition 2 RGB to gray scale transformation 3 image cropping and 4 density estimation. At first, film of highway is captured by a camera which is installed at the square that is intersection of road. Then, the camera takes pictures at regular intervals and then the captured frame is sent to the computer for further processing. After that, the number of cars in square is specified. At the end, if the number of cars is more than a threshold, a message is shown to inform the traffic status. By this message we can predict the need to reduce the size of traffic carried. Experiments show that the algorithm will work properly and also we can re-time the traffic green light and maintain the proper traffic management. Most of the city traffic is controlled by sensors and cameras shall be installed in big highways and streets. But existence of a system for detecting the size of traffic automatically will be felt. Such systems can allow extracting information from the bigger traffic issue and helps us decide to improve the traffic policy. The project aims to render automate control system for traffic on highways and street.

  2. DYNAMIC BANDWIDTH ALLOCATION ALGORITHM UTILIZING FULL BAND

    Institute of Scientific and Technical Information of China (English)

    Han Guodong; Wen Jianhua; Wu Jiangxing

    2006-01-01

    A kind of Dynamic Full Bandwidth Utilized (DFBU) allocation algorithm is introduced. This algorithm allows a single link to use bandwidth far beyond its fair share bandwidth in a multi-service packet transporting system. Three important parameters as the bound on maximum and minimum bandwidth, the maximum packet delay and the minimum band width utilization are discussed and analyzed. Results of experiments show that the DFBU-algorithm is capable of making a single link in the system to use all the spare bandwidth (up to full-bandwidth) while the performance of fairness and QoS requirement is still guaranteed.

  3. Policy Refinement for Traffic Management in Home Area Networks: Problem Statement

    OpenAIRE

    Rana, Annie Ibrahim; O Foghlu, Micheal

    2009-01-01

    Traditional home area network (HAN) equipment is usually unmanaged and network traffic is served in best effort fashion. This type of unmanaged network sometimes causes quality-of-service issues in the HAN, for example loss of quality in streamed video or audio content. Traffic management rules using policies to prioritise certain types of traffic according to user requirements and to assign bandwidth limits to other traffic types. However very little work has been done yet addressing the ...

  4. EFFICIENT MULTIPATH ROUTING AND WAVELENGTH ALLOCATION USING TRAFFIC GROOMING IN OPTICAL WAVELENGTH DIVISION MULTIPLEXING MESH NETWORKS

    OpenAIRE

    Rajamani, V.; Kavitha, T.

    2012-01-01

    In optical WDM mesh networks, traffic grooming is essential in order to utilize the bandwidth efficiently to minimize the cost and meet the user service requirement. By grooming traffic, it is possible to reduce the total cost of all Add drop multiplexer needed. Also for the high processing capability in a WDM network, the path should be capable of carrying the traffic without any failure. In this study, we use a traffic grooming algorithm to establish light paths between node pairs having th...

  5. 采用系统科学方法优化交通信号灯的控制策略%Optimization Control Strategy of Traffic Signal with System Scientific Methods

    Institute of Scientific and Technical Information of China (English)

    张世良

    2012-01-01

    In order to control vehicles easily pass in the intersection,on the basis of the introduction of system structure for traffic signal lamp,run mode and workflow,this paper analyzes different ways in system control which can use different operation patterns at different times to adaptively control vehicle pass time.Traffic induction strategies which can use different open moment according to the space between the two intersections is used to reduce waiting time for vehicle,improve pass efficiency and ensure efficient circulation in the whole traffic system,and other traffic information,such as vehicle speed,type and traffic by vehicle labels can provide basic data of traffic forecast for the road long-term planning and is signality to direct intelligent traffic control.%为了控制车辆在交叉路口顺畅通行,本文在介绍交通信号灯系统结构、运行模式及工作流程的基础上,分析了系统控制中不同策略的方法,使用在不同的时段采用不同的路口控制模式,自适应地控制车辆通行时间,并根据路口间距采用不同的开启时刻以及使用交通诱导策略,减少车辆等待时间,提高车辆通行效率,保证整个交通系统的高效流通,而且通过车载标签及时掌握的车速、车型和交通量等交通信息可以为该路段远期规划的交通预测提供基础数据,对智能交通控制具有很大的指导意义。

  6. OPTIMAL BANDWIDTH ALLOCATION WITH BANDWIDTH RESERVATION AND ADAPTATION IN WIRELESS COMMUNICATION NETWORKS

    OpenAIRE

    Ali Amiri

    2016-01-01

    Efficient management of bandwidth in wireless networks is a critical factor for a successful communication system. Special features of wireless networks such user mobility and growth of wireless applications and their high bandwidth intensity create a major challenge to utilize bandwidth resources optimally. In this research, we propose a model for an adaptable network bandwidth management method that combines bandwidth reservation and bandwidth adaptation to reduce call blocking ...

  7. Efficient Bandwidth Management for Ethernet Passive Optical Networks

    KAUST Repository

    Elrasad, Amr Elsayed M.

    2016-05-15

    The increasing bandwidth demands in access networks motivates network operators, networking devices manufacturers, and standardization institutions to search for new approaches for access networks. These approaches should support higher bandwidth, longer distance between end user and network operator, and less energy consumption. Ethernet Passive Optical Network (EPON) is a favorable choice for broadband access networks. EPONs support transmission rates up to 10 Gbps. EPONs also support distance between end users and central office up to 20 Km. Moreover, optical networks have the least energy consumption among all types of networks. In this dissertation, we focus on reducing delay and saving energy in EPONs. Reducing delay is essential for delay-sensitive traffic, while minimizing energy consumption is an environmental necessity and also reduces the network operating costs. We identify five challenges, namely excess bandwidth allocation, frame delineation, congestion resolution, large round trip time delay in long-reach EPONs (LR-EPONs), and energy saving. We provide a Dynamic Bandwidth Allocation (DBA) approach for each challenge. We also propose a novel scheme that combines the features of the proposed approaches in one highly performing scheme. Our approach is to design novel DBA protocols that can further reduce the delay and be simultaneously simple and fair. We also present a dynamic bandwidth allocation scheme for Green EPONs taking into consideration maximizing energy saving under target delay constraints. Regarding excess bandwidth allocation, we develop an effective DBA scheme called Delayed Excess Scheduling (DES). DES achieves significant delay and jitter reduction and is more suitable for industrial deployment due to its simplicity. Utilizing DES in hybrid TDM/WDM EPONs (TWDM-EPONs) is also investigated. We also study eliminating the wasted bandwidth due to frame delineation. We develop an interactive DBA scheme, Efficient Grant Sizing Interleaved

  8. Bandwidth Allocation and Session Scheduling using SIP

    Directory of Open Access Journals (Sweden)

    Jean-Marie Garcia

    2006-08-01

    Full Text Available

    Session Initiation Protocol (SIP is a new signaling protocol designed to establish multimedia sessions in telecommunication networks. In this paper, we suggest the extension of SIP functionalities to coordinate QoS mechanisms deployed in IP networks, and especially in DiffServ domain. Indeed, the interaction between small and big TCP sessions may have dramatic consequences on small TCP sessions. Hence, we use SIP to achieve QoS management on a session basis, in which the over all activity of the user during the session is considered. The suggested mechanisms deal with two issues: first, session scheduling based on session duration and/or volume, and second bandwidth allocation on a per-flow basis using equivalent bandwidth estimation techniques. The proposed mechanisms are implemented in the SIP proxy server as QoS management algorithms, and they are validated by simulations.

  9. Delays at signalised intersections with exhaustive traffic control

    OpenAIRE

    Boon, MAA Marko; Adan, IJBF Ivo; Winands, EMM Erik; Down, DG

    2014-01-01

    In this paper we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under Heavy Traffic (HT) conditions. Furthermore, we derive the Light Traffic (LT) limit of the mean delays for intersections with Poisson arrivals, and develop a heuristic adaptation of this limit to capture the LT behaviour for other in...

  10. Agent Base Network Traffic Monitoring

    Directory of Open Access Journals (Sweden)

    MONIKA JOSHI, CHIRAG GOHEL

    2013-05-01

    Full Text Available Raspberry Pi the credit-card-sized single board computer device which adopts a high performance embedded microprocessor and an embedded real-time Linux operating system, which hangs the characteristics of miniaturization, digitalization and network together well. It has virtues of low cost, small volume and flexible networking, etc, because of embedded technology adoption. Network administrators need to see what’s going on with their network. They need to know what the traffic on their network is comprised of, who's using the bandwidth, and how their infrastructure is handling the load. Fortunately, Linux runs a wide variety of free, open source network monitoring and traffic analysis applications that can give net administrator this type of insight. So this paper focuses on how to deploy network monitoring tool within this device which monitors the network traffic within LAN using the tool ntop. Ntop is a simple, free, portable traffic measurement and monitoring tool, which supports various management activities, including network optimization and to plan, and detection of network security violations.

  11. Wavelet Neural Network Based Traffic Prediction for Next Generation Network

    Institute of Scientific and Technical Information of China (English)

    Zhao Qigang; Li Qunzhan; He Zhengyou

    2005-01-01

    By using netflow traffic collecting technology, some traffic data for analysis are collected from a next generation network (NGN) operator. To build a wavelet basis neural network (NN), the Sigmoid function is replaced with the wavelet in NN. Then the wavelet multiresolution analysis method is used to decompose the traffic signal, and the decomposed component sequences are employed to train the NN. By using the methods, an NGN traffic prediction model is built to predict one day's traffic. The experimental results show that the traffic prediction method of wavelet NN is more accurate than that without using wavelet in the NGN traffic forecasting.

  12. 120 nm Bandwidth Erbium-doped Fiber Amplifier

    Institute of Scientific and Technical Information of China (English)

    姜淳; 曾庆济; 肖石林

    2002-01-01

    A new dual band erbium-doped fiber amplifier configuration that provides 120 nm of optical bandwidth is simulated. This configuration employs a split-band architecture in which optical signals are splitted using a 1550/1610 nm port filter into two independent sub-bands which then pass in parallel through separate branches of the optical amplifier. Each branch may be optimized for the sub-band that traverses it. The independent sub-bands are combined and flattened before output, resulting in a 120 nm bandwidth gain-flattened optical amplifier.

  13. Dynamic bandwidth allocation in GPON networks

    DEFF Research Database (Denmark)

    Ozimkiewiez, J.; Ruepp, Sarah Renée; Dittmann, Lars; Wessing, Henrik; Smolorz, S.

    2009-01-01

    Two Dynamic Bandwidth Allocation algorithms used for coordination of the available bandwidth between end users in a GPON network have been simulated using OPNET to determine and compare the performance, scalability and efficiency of status reporting and non status reporting dynamic bandwidth...

  14. A Bandwidth Allocation Model Provisioning Framework with Autonomic Characteristics

    Directory of Open Access Journals (Sweden)

    Rafael F. Reale

    2013-11-01

    Full Text Available The Bandwidth Allocation Models (MAM, RDM, G-RDM and AllocTC-Sharing are managementalternatives currently available which propose different resource (bandwidth allocation strategies inmultiservice networks. The BAM adoption by a network is typically a management choice andconfiguration task executed by the network operations and management system setup in a static or nearlystatic way. This paper proposes and explores the alternative ofallowing BAM definition and configurationon a more dynamic way. In effect, one of the basic motivations towards BAM dynamic allocation is the factthat multiservice networks characteristics (traffic loadmay change considerably in daily networkoperation and, as such, some dynamics in BAM allocation should be introduced in order to improveperformance. A framework is presented supporting BAM dynamicallocation. The framework adopts anOpenFlow-based software-defined networking (SDN implementation approach in order to supportscalability issues with a centralized controller and managementnetwork view. The framework architecturealso supports the implementation of some autonomic characteristics which, in brief, look for improving andfacilitating the decision-making process involved with BAM provisioning in a multiservice network. Aproof of concept is presented evaluating different BAM performance under different traffic loads in order todemonstrate the framework strategy adopted.

  15. Open-Loop Wide-Bandwidth Phase Modulation Techniques

    Directory of Open Access Journals (Sweden)

    Nitin Nidhi

    2011-01-01

    Full Text Available The ever-increasing growth in the bandwidth of wireless communication channels requires the transmitter to be wide-bandwidth and power-efficient. Polar and outphasing transmitter topologies are two promising candidates for such applications, in future. Both these architectures require a wide-bandwidth phase modulator. Open-loop phase modulation presents a viable solution for achieving wide-bandwidth operation. An overview of prior art and recent approaches for phase modulation is presented in this paper. Phase quantization noise cancellation was recently introduced to lower the out-of-band noise in a digital phase modulator. A detailed analysis on the impact of timing and quantization of the cancellation signal is presented. Noise generated by the transmitter in the receive band frequency poses another challenge for wide-bandwidth transmitter design. Addition of a noise transfer function notch, in a digital phase modulator, to reduce the noise in the receive band during phase modulation is described in this paper.

  16. Allocating Bandwidth in Datacenter Networks:A Survey

    Institute of Scientific and Technical Information of China (English)

    陈丽; 李葆春; 李波

    2014-01-01

    Datacenters have played an increasingly essential role as the underlying infrastructure in cloud computing. As implied by the essence of cloud computing, resources in these datacenters are shared by multiple competing entities, which can be either tenants that rent virtual machines (VMs) in a public cloud such as Amazon EC2, or applications that embrace data parallel frameworks like MapReduce in a private cloud maintained by Google. It has been generally observed that with traditional transport-layer protocols allocating link bandwidth in datacenters, network traffic from competing applications interferes with each other, resulting in a severe lack of predictability and fairness of application performance. Such a critical issue has drawn a substantial amount of recent research attention on bandwidth allocation in datacenter networks, with a number of new mechanisms proposed to efficiently and fairly share a datacenter network among competing entities. In this article, we present an extensive survey of existing bandwidth allocation mechanisms in the literature, covering the scenarios of both public and private clouds. We thoroughly investigate their underlying design principles, evaluate the trade-off involved in their design choices and summarize them in a unified design space, with the hope of conveying some meaningful insights for better designs in the future.

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

    OpenAIRE

    G. R. LAI; A. CHE SOH; H. MD. SARKAN; R. Z. ABDUL RAHMAN; Hassan, M. K.

    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...

  18. Bandwidth-sharing in LHCONE, an analysis of the problem

    Science.gov (United States)

    Wildish, T.

    2015-12-01

    The LHC experiments have traditionally regarded the network as an unreliable resource, one which was expected to be a major source of errors and inefficiency at the time their original computing models were derived. Now, however, the network is seen as much more capable and reliable. Data are routinely transferred with high efficiency and low latency to wherever computing or storage resources are available to use or manage them. Although there was sufficient network bandwidth for the experiments’ needs during Run-1, they cannot rely on ever-increasing bandwidth as a solution to their data-transfer needs in the future. Sooner or later they need to consider the network as a finite resource that they interact with to manage their traffic, in much the same way as they manage their use of disk and CPU resources. There are several possible ways for the experiments to integrate management of the network in their software stacks, such as the use of virtual circuits with hard bandwidth guarantees or soft real-time flow-control, with somewhat less firm guarantees. Abstractly, these can all be considered as the users (the experiments, or groups of users within the experiment) expressing a request for a given bandwidth between two points for a given duration of time. The network fabric then grants some allocation to each user, dependent on the sum of all requests and the sum of available resources, and attempts to ensure the requirements are met (either deterministically or statistically). An unresolved question at this time is how to convert the users’ requests into an allocation. Simply put, how do we decide what fraction of a network's bandwidth to allocate to each user when the sum of requests exceeds the available bandwidth? The usual problems of any resourcescheduling system arise here, namely how to ensure the resource is used efficiently and fairly, while still satisfying the needs of the users. Simply fixing quotas on network paths for each user is likely to lead

  19. Integrated Modeling of Air Traffic, Aviation Weather, and Communication Systems

    OpenAIRE

    Quan, Chuanwen

    2007-01-01

    Aviation suffers many delays due to the lack of timely air traffic flow management. These delays are also caused by the uncertainty weather information; and the lack of efficient dissemination of weather products to pilots. It is clear that better models are needed to quantify air traffic flow in three flight regions - en-route, in the terminal, and on the ground, to determine aviation weather information requirements at each region, and to quantify their bandwidth requirements. Furthermore,...

  20. Bandwidth requirements for fine resolution squinted SAR

    Energy Technology Data Exchange (ETDEWEB)

    DOERRY,ARMIN W.

    2000-03-01

    The conventional rule-of-thumb for Synthetic Aperture Radar is that an RF bandwidth of c/(2{rho}{sub r}) is required to image a scene at the desired slant-range resolution {rho}{sub r}, and perhaps a little more to account for window functions and sidelobe control. This formulation is based on the notion that the total bandwidth required is the same bandwidth that is required for a single pulse. What is neglected is that efficient processing of an entire synthetic aperture of pulses will often require different frequency content for each of the different pulses that makeup a synthetic aperture. Consequently, the total RF bandwidth required of a Synthetic Aperture Radar may then be substantially wider than the bandwidth of any single pulse. The actual RF bandwidth required depends strongly on flight geometry, owing to the desire for a radar to maintain a constant projection of the Fourier space collection surface onto the {omega}{sub y} axis. Long apertures required for fine azimuth resolution, and severe squint angles with steep depression angles may require total RF bandwidths well beyond the minimum bandwidth required of any single transmitted pulse, perhaps even by a factor of two or more. Accounting for this is crucial to designing efficient versatile high-performance imaging radars. This paper addresses how a data set conducive to efficient processing might increase the total RF bandwidth, and presents examples of how a fixed RF bandwidth might then limit SAR geometries.

  1. Marked renewal model of smoothed VBR MPEG coded traffic

    Science.gov (United States)

    Hui, Xiaoshi; Li, Jiaoyang; Liu, Xiande

    1998-08-01

    In this paper, a method of smoothing variable bit-rate (VBR) MPEG traffic is proposed. A buffer, which has capacity over the peak bandwidth of group of picture (GOP) sequence of an MPEG traffic and which output rate is controlled by the distribution of GOP sequence, is connected to a source. The degree of burst of output stream from the buffer is deceased, and the stream's autocorrelation function characterizes non-increased and non-convex property. For smoothed MPEG traffic stream, the GOP sequence is the element target source traffic using for modeling. We applied a marked renewal process to model the GOP smoothed VBR MPEG traffics. The numerical study of simulating target VBR MPEG video source with a marked renewal model shows that not only the model's bandwidth distribution can match accurately that of target source sequence, but also its leading autocorrelation can approximate the long-range dependence of a VBR MPEG traffic as well as the short-range dependence. In addition to that, the model's parameters estimation is very easy. We conclude that GOP smoothed VBR MPEG video traffic could be not only transferred more efficiently but also analyzed perfectly with a marked renewal traffic model.

  2. 城市灯控平面交叉口慢行交通时空违章特征研究%Slow Traffic Peccancy Character for Urban Signal Intersection

    Institute of Scientific and Technical Information of China (English)

    王庆; 陈学武; 周娇; 陈琳英

    2012-01-01

    在南京市内4个典型交叉口调查数据的基础上,通过对4 000多个行人样本数据和相应交叉口不同时间段的自行车违章数据的统计分析,得出了慢行交通的时空违章特征.行人个体违章在时空违章上有不同的表现形式,在不同交叉口存在很大的差异性;行人的违章行为与性别无关,与年龄有关,少年的违章比例最低.由于交叉口断面形式、信号配时、运行秩序、交通管制、周边环境等方面的因素,自行车的行驶方向平均违章率和违章性质平均违章率在不同交叉口存在很大的差异性.针对慢行交通违章者安全意识淡薄且违章成本较低、交叉口的设计不合理等原因,提出相应的预防和纠正违章的建议和措施.%It has been drawn out from statistical analysis on 4000 sample data of the peccancy of passerby at different intersection from the four model intersection in Nanjing that there is different behave forms in time and space for passby peccancy and great difference at each crossings. It relates to passerby age, but not to sex, e. G. The peccancy rate of teen-age is the lowest. There is great difference in peccancy of run way and behavior property by analysis on differ time sect bicycle date, which is related to some factors, such as road cross-section, traffic control, run order and surrounding environment. According to the main reason of slow traffic peccancy behavior, I. E. The actor's dim safety consciousness, low cost of peccany, srrationali intersecton design, corresponding suggestions and measures to prevent and correct traffic peccancy are proposed. The behavior character of slow traffic peccancy on the city s signal intersection would be a good reference for solving the urban signal intersection mixed traffic problems.

  3. Synchronization of Traffic Light Systems for Maximum Efficiency along Jalan Bukit Gambier, Penang, Malaysia

    OpenAIRE

    Ahmad Rafidi M.A.; Abdul Hamid A.H.

    2014-01-01

    The synchronization of traffic light systems is one of the best solutions in order to avoid problematic traffic jams. Traffic timing is a major concern when it comes to traffic management. One of the common causes of traffic jams is because of nonsynchronized traffic light systems. Once a light turns green, traffic begins to move, but by the time the moving traffic reaches the next light, the signal is still red. This will disrupt the continuity of the traffic flow, especially for large main ...

  4. Traffic Monitoring and Control Using RFID

    Directory of Open Access Journals (Sweden)

    Gaurav Thakur

    2013-09-01

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

  5. Wide bandwidth transimpedance amplifier for extremely high sensitivity continuous measurements

    Science.gov (United States)

    Ferrari, Giorgio; Sampietro, Marco

    2007-09-01

    This article presents a wide bandwidth transimpedance amplifier based on the series of an integrator and a differentiator stage, having an additional feedback loop to discharge the standing current from the device under test (DUT) to ensure an unlimited measuring time opportunity when compared to switched discharge configurations while maintaining a large signal amplification over the full bandwidth. The amplifier shows a flat response from 0.6Hzto1.4MHz, the capability to operate with leakage currents from the DUT as high as tens of nanoamperes, and rail-to-rail dynamic range for sinusoidal current signals independent of the DUT leakage current. Also available is a monitor output of the stationary current to track experimental slow drifts. The circuit is ideal for noise spectral and impedance measurements of nanodevices and biomolecules when in the presence of a physiological medium and in all cases where high sensitivity current measurements are requested such as in scanning probe microscopy systems.

  6. Characteristics of vehicular traffic flow at a roundabout

    Science.gov (United States)

    Ebrahim Fouladvand, M.; Sadjadi, Zeinab; Reza Shaebani, M.

    2004-10-01

    We construct a stochastic cellular automata model for the description of vehicular traffic at a roundabout designed at the intersection of two perpendicular streets. The vehicular traffic is controlled by a self-organized scheme in which traffic lights are absent. This controlling method incorporates a yield-at-entry strategy for the approaching vehicles to the circulating traffic flow in the roundabout. Vehicular dynamics is simulated and the delay experienced by the traffic at each individual street is evaluated. We discuss the impact of the geometrical properties of the roundabout on the total delay. We compare our results with traffic-light signalization schemes, and obtain the critical traffic volume over which the intersection is optimally controlled through traffic-light signalization schemes.

  7. OPTIMIZATION OF URBAN MULTI-INTERSECTION TRAFFIC FLOW VIA Q-LEARNING

    OpenAIRE

    Yit Kwong Chin; Heng Jin Tham; N.S.V. Kameswara Rao; Nurmin Bolong; Kenneth Tze Kin Teo

    2013-01-01

    Congestions of the traffic flow within the urban traffic network have been a challenging task for all the urban developers. Many approaches have been introduced into the current system to solve the traffic congestion problems. Reconfiguration of the traffic signal timing plan has been carried out through implementation of different techniques. However, dynamic characteristics of the traffic flow increase the difficulties towards the ultimate solutions. Thus, traffic congestions still remain a...

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

    OpenAIRE

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

    2014-01-01

    Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors t...

  9. Optimization of bandwidth of communication channels of corporate networks

    Directory of Open Access Journals (Sweden)

    G. I. Bondarenko

    2014-09-01

    Full Text Available Introduction. This article contains overview of the organization of communication between applications on the corporate network. It is stated that the main digital channel (channel B - 64 kbit/s and the primary digital channel (channel E1 the digital stream - 2048 kbit/s are used as the main channels in corporate networks. Problem areas of the functioning of the corporate network are identified. There are the rent of communication channels, which is growing rapidly with increasing the quality and speed of data transmission, and optimal use of bandwidth of communication channels. Setting of task. Optimal use of transmission channels bandwidth and minimizing the rent cost of channels is possible in two ways - the use of compression techniques of voice and video information and the application of variable structure of channels by using various-speed transmission channels. Differential pulse code modulation, adaptive differential pulse code modulation are the modern methods of speech signals processing. Organization of various-speed channels is performed in the structure of the BCC (for speech signals or PCR (for video. Suggestions for optimizing the structure of the channel signals. Proposed method of various-speed channels formation by using the channel intervals appropriate BCC (octets in the structure of signals E1 as envelopes containing various-speed channels. Channels can be selected for synchronization procedure CRC to simplify recognition of channels in the structure of E1. In this case, the minimal speed in the channel is 4 kbit/s. Conclusions. The proposed structure of envelopes is based on octet channel intervals of standard group signal of the primary group plesiochronous hierarchy E1 when transferring various-speed digital signals maximum allows to use the bandwidth at a fixed structure of channel interval, it makes possible to agree on the structure of the various-speed signals with the existing in communication networks.

  10. Influences of driver’s attributions on signalized intersection traffic%驾驶员属性对信号灯路口交通流的影响研究

    Institute of Scientific and Technical Information of China (English)

    梅超群

    2014-01-01

    A cellular automaton model is proposed to study the traffic at signalized intersection. The driving behaviors induced by driver’s attribution (gender, driving experience, character, etc. ) are numerically analyzed. Simulation results show that the rusty driving skills or tension driving, impatient driving and so on can lead to the transition from free flow to congestion more easily, and these behaviors are the important cause for low travel efficiency at the intersection; the signal cycle is the main factor influencing traffic flux and travel time fairness.%采用元胞自动机模型研究信号灯路口的交通流特性,系统地分析了与性别、驾驶经验、性格等驾驶员属性相关的驾驶行为对交通流的影响。数值模拟发现,技术生疏或紧张驾驶、急躁行驶等驾驶行为更易引发自由流到阻塞流的相变,是路口通行低效率及事故隐患的重要原因,信号周期是影响流量与个人通行时间公平的主要因素。

  11. Jamitons: Phantom Traffic Jams

    Science.gov (United States)

    Kowszun, Jorj

    2013-01-01

    Traffic on motorways can slow down for no apparent reason. Sudden changes in speed by one or two drivers can create a chain reaction that causes a traffic jam for the vehicles that are following. This kind of phantom traffic jam is called a "jamiton" and the article discusses some of the ways in which traffic engineers produce…

  12. Influence of Link Flow and Traffic Signal Control on the Forecast of Travel Time%流量和信号控制对运行时间预测的影响

    Institute of Scientific and Technical Information of China (English)

    徐丽群; 杨兆升; 管德永

    2001-01-01

    通过对实际交通状况的分析,说明路线运行时间不仅是路线交通流量的函数,而且是由于交叉口信号控制引起延误的函数。%The use of ATIS (Advanced Traveler Information Systems) for urban traffic management means that tripmakers can get in real time the pre-trip information and en-route information to ch oose the optimal route and reduce their travel time. Hence, reliable and frequently updated travel time information is the basis of effec tive implementation of ATIS. This paper proposes the method of foreca sting travel time at signalized network and concludes that travel time is not only the function of flow but also the function of delay caused by signal control at intersection.

  13. Scheduling, bandwidth allocation and performance evaluation of DOCSIS protocol over cable networks

    Science.gov (United States)

    Kuo, Wen-Kuang; Kumar, Sunil; Kuo, C.-C. Jay

    2002-12-01

    The Data Over Cable Service Interface Specifications (DOCSIS) of the Multimedia Cable Network System (MCNS) organization intends to support IP traffics over HFC (hybrid fiber/coax) networks with significantly higher data rates than analog modems and Integrated Service Digital Network (ISDN) links. The availability of high speed-access enables the delivery of high quality audio, video and interactive services. To support quality-of-service (QoS) for such applications, it is important for HFC networks to provide effective medium access and traffic scheduling mechanisms. In this work, a novel scheduling mechanism and a new bandwidth allocation scheme are proposed to support multimedia traffic over DOCSIS (Data Over Cable System Interface Specification)-compliant cable networks. The primary goal of our research is to improve the transmission of real-time variable bit rate (VBR) traffic in terms of throughput and delay under DOCSIS. To support integrated services, we also consider the transmission of constant bit rate (CBR) traffic and non-real-time traffic in the simulation. To demonstrate the performance, we compare the result of the proposed scheme with that of a simple multiple priority scheme. It is shown via simulation that the proposed method provides a significant amount of improvement over existing QoS scheduling services in DOCSIS. Finally, a discrete-time Markov model is used to analyze the performance of the voice traffic over DOCSIS-supported cable networks.

  14. Improving the Bandwidth Utilization by Recycling the Unused Bandwidth in IEEE 802.16 Networks

    Directory of Open Access Journals (Sweden)

    Gowri T

    2012-03-01

    Full Text Available The Physical and MAC layers have been specified in IEEE 802.16 networks. The quality of service is ensured by the bandwidth reservation. The subscriber station should reserve the bandwidth more than its demand. But the bandwidth is fully utilized by SS but not all the time. So the bandwidth has recycled by the process of recycling the unused bandwidth. The main objective of the proposed scheme is to utilize the unused bandwidth by recycling and maintain the QOS service. By recycling the throughput can be improved which maintains the QOS in the proposed scheme. During this recycling process to maintain the QOS services, the amount of reserved bandwidth is not changed. The proposed scheme can utilize the unused bandwidth up to 70% on average. Protocols and the scheduling algorithms are used to improve the utilization and throughput.

  15. Bandwidth utilization maximization of scientific RF communication systems

    Energy Technology Data Exchange (ETDEWEB)

    Rey, D. [Sandia National Lab., Albuquerque, NM (United States); Ryan, W. [New Mexico State Univ., Las Cruces, NM (United States); Ross, M.

    1997-01-01

    A method for more efficiently utilizing the frequency bandwidth allocated for data transmission is presented. Current space and range communication systems use modulation and coding schemes that transmit 0.5 to 1.0 bits per second per Hertz of radio frequency bandwidth. The goal in this LDRD project is to increase the bandwidth utilization by employing advanced digital communications techniques. This is done with little or no increase in the transmit power which is usually very limited on airborne systems. Teaming with New Mexico State University, an implementation of trellis coded modulation (TCM), a coding and modulation scheme pioneered by Ungerboeck, was developed for this application and simulated on a computer. TCM provides a means for reliably transmitting data while simultaneously increasing bandwidth efficiency. The penalty is increased receiver complexity. In particular, the trellis decoder requires high-speed, application-specific digital signal processing (DSP) chips. A system solution based on the QualComm Viterbi decoder and the Graychip DSP receiver chips is presented.

  16. Traffic Route Modelling and Assignment with Intelligent Transport System

    OpenAIRE

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

    2014-01-01

    The development of signal transmitting environment for multimodal traffic control will enhance the integration of emergency and specialized transport routing tools in usual traffic control paradigms - it is one of the opportunities offered by modern intelligent traffic control systems. The improvement of effective electric power use in public transport system is an advantage of Intelligent Transport System (ITS). The research is connected with the improvement of on-line traffic control and ad...

  17. Study on Driver Visual Physiological Characteristics in Urban Traffic

    OpenAIRE

    Fengyuan Wang; Min Li; Jieyu Fan; Fuquan Pan

    2014-01-01

    In the integrated traffic environment, human factor is always a main factor of the three elementary factors, besides the vehicle and road factor. The driver physiological and psychological characteristics have an important impact especially on traffic safety in urban road traffic conditions . Some typical traffic scenes in condition of urban road, such as light signal control at intersection, overtaking, and passing, are selected for condition analysis. An eye movement apparatus was used to o...

  18. Data Fusion in Road Traffic Engineering: An overview

    OpenAIRE

    EL-FAOUZI, NE

    2004-01-01

    The objective of this paper is to present an analysis of recent applications of data fusion (DF) in road traffic engineering. First, we report the most significant applications of data fusion techniques in road traffic engineering area: traffic monitoring, signal control, Automatic Incident Detection, traffic forecasting, Intelligent Transportation Systems ..., as well as the extent and direction of DF interest in the field. Second, a classification including applications, fusion goalsand mat...

  19. REAL TIME TRAFFIC LIGHT CONTROL USING IMAGE PROCESSING

    OpenAIRE

    PALLAVI CHOUDEKAR,; SAYANTI BANERJEE,; M.K.MUJU

    2011-01-01

    As the problem of urban traffic congestion spreads, there is a pressing need for the introduction of advanced technology and equipment to improve the state-of-the-art of traffic control. Traffic problems nowadays are increasing because of the growing number of vehicles and the limited resources provided by current nfrastructures. The simplest way for controlling a traffic light uses timer for each phase. Another way is to use electronic sensors in order to detect vehicles, and produce signal...

  20. Compression of Video Tracking and Bandwidth Balancing Routing in Wireless Multimedia Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yin Wang

    2015-12-01

    Full Text Available There has been a tremendous growth in multimedia applications over wireless networks. Wireless Multimedia Sensor Networks(WMSNs have become the premier choice in many research communities and industry. Many state-of-art applications, such as surveillance, traffic monitoring, and remote heath care are essentially video tracking and transmission in WMSNs. The transmission speed is constrained by the big file size of video data and fixed bandwidth allocation in constant routing paths. In this paper, we present a CamShift based algorithm to compress the tracking of videos. Then we propose a bandwidth balancing strategy in which each sensor node is able to dynamically select the node for the next hop with the highest potential bandwidth capacity to resume communication. Key to this strategy is that each node merely maintains two parameters that contain its historical bandwidth varying trend and then predict its near future bandwidth capacity. Then, the forwarding node selects the next hop with the highest potential bandwidth capacity. Simulations demonstrate that our approach significantly increases the data received by the sink node and decreases the delay on video transmission in Wireless Multimedia Sensor Network environments.

  1. Inferring traffic burstiness by sampling the buffer occupancy

    NARCIS (Netherlands)

    Mandjes, Michel; Meent, van de Remco

    2004-01-01

    Common practice to determine the required bandwidth capacity for a network link is to measure the 5 minute average link load and then add a safety margin to cater for traffic bursts on small time-scales. Because of the substantial measurement effort required to appropriately determine the effect of

  2. Bandwidth engineering of photonic crystal waveguide bends

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Frandsen, Lars Hagedorn; Harpøth, Anders;

    2004-01-01

    An effective design principle has been applied to photonic crystal waveguide bends fabricated in silicon-on-insulator material using deep UV lithography resulting in a large increase in the low-loss bandwidth of the bends. Furthermore, it is experimentally demonstrated that the absolute bandwidth...

  3. Energy Bandwidth for Petroleum Refining Processes

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-10-01

    The petroleum refining energy bandwidth report analyzes the most energy-intensive unit operations used in U.S. refineries: crude oil distillation, fluid catalytic cracking, catalytic hydrotreating, catalytic reforming, and alkylation. The "bandwidth" provides a snapshot of the energy losses that can potentially be recovered through best practices and technology R&D.

  4. TRANSIMS traffic flow characteristics

    OpenAIRE

    Nagel, Kai; Stretz, Paula; Pieck, Martin; Donnelly, Rick; Barrett, Christopher L.

    1997-01-01

    Knowledge of fundamental traffic flow characteristics of traffic simulation models is an essential requirement when using these models for the planning, design, and operation of transportation systems. In this paper we discuss the following: a description of how features relevant to traffic flow are currently under implementation in the TRANSIMS microsimulation, a proposition for standardized traffic flow tests for traffic simulation models, and the results of these tests for two different ve...

  5. Quantifying Data Rate and Bandwidth Requirements for Immersive 5G Experience

    OpenAIRE

    Qi, Yinan; Hunukumbure, Mythri; Nekovee, Maziar; Lorca, Javier; Sgardoni, Victoria

    2016-01-01

    The proliferation of smartphones/mobile devices that support a wide range of broadband applications and services has driven the volume of mobile data traffic to an unprecedented high level, requiring a next generation mobile communication system, i.e., the fifth generation (5G). Millimeter wave bands, due to the large available spectrum bandwidth, are considered as one of the most promising approaches to significantly boost the capacity. In this paper, we define a typical use case envisaged i...

  6. Compression of Video Tracking and Bandwidth Balancing Routing in Wireless Multimedia Sensor Networks

    OpenAIRE

    Wang, Yin; Yang, Jianjun; Shen, Ju; Guo, Juan; Hua, Kun

    2014-01-01

    There has been a tremendous growth in multimedia applications over wireless networks. Wireless Multimedia Sensor Networks(WMSNs) have become the premier choice in many research communities and industry. Many state-of-art applications, such as surveillance, traffic monitoring, and remote heath care are essentially video tracking and transmission in WMSNs. The transmission speed is constrained by big size of video data and fixed bandwidth allocation in constant routing path. In this paper, we p...

  7. Compression of Video Tracking and Bandwidth Balancing Routing in Wireless Multimedia Sensor Networks

    OpenAIRE

    Yin Wang; Jianjun Yang; Ju Shen; Bryson Payne; Juan Guo; Kun Hua

    2015-01-01

    There has been a tremendous growth in multimedia applications over wireless networks. Wireless Multimedia Sensor Networks(WMSNs) have become the premier choice in many research communities and industry. Many state-of-art applications, such as surveillance, traffic monitoring, and remote heath care are essentially video tracking and transmission in WMSNs. The transmission speed is constrained by the big file size of video data and fixed bandwidth allocation in constant routing paths. In this p...

  8. Balancing Uplink and Downlink under Asymmetric Traffic Environments Using Distributed Receive Antennas

    Science.gov (United States)

    Sohn, Illsoo; Lee, Byong Ok; Lee, Kwang Bok

    Recently, multimedia services are increasing with the widespread use of various wireless applications such as web browsers, real-time video, and interactive games, which results in traffic asymmetry between the uplink and downlink. Hence, time division duplex (TDD) systems which provide advantages in efficient bandwidth utilization under asymmetric traffic environments have become one of the most important issues in future mobile cellular systems. It is known that two types of intercell interference, referred to as crossed-slot interference, additionally arise in TDD systems; the performances of the uplink and downlink transmissions are degraded by BS-to-BS crossed-slot interference and MS-to-MS crossed-slot interference, respectively. The resulting performance unbalance between the uplink and downlink makes network deployment severely inefficient. Previous works have proposed intelligent time slot allocation algorithms to mitigate the crossed-slot interference problem. However, they require centralized control, which causes large signaling overhead in the network. In this paper, we propose to change the shape of the cellular structure itself. The conventional cellular structure is easily transformed into the proposed cellular structure with distributed receive antennas (DRAs). We set up statistical Markov chain traffic model and analyze the bit error performances of the conventional cellular structure and proposed cellular structure under asymmetric traffic environments. Numerical results show that the uplink and downlink performances of the proposed cellular structure become balanced with the proper number of DRAs and thus the proposed cellular structure is notably cost-effective in network deployment compared to the conventional cellular structure. As a result, extending the conventional cellular structure into the proposed cellular structure with DRAs is a remarkably cost-effective solution to support asymmetric traffic environments in future mobile cellular

  9. Implementation of Neural Network with a variant of Turing Machine for Traffic Flow Control

    Directory of Open Access Journals (Sweden)

    Rashmi Sehrawat

    2013-05-01

    Full Text Available The conventional method of operation of a typical traffic light is to distribute the time equally for all the directions.This method causes congestion when throughput of the signal increases and is alsoineffective in managing traffic flow. In this paper, we have proposed a new model for managing traffic intelligently.The model is based on Turing machine with the application of neural network. The modelconsiders current traffic status of its own signal along with the status of its adjacent signals to determine the ratio of time slot for each signal therefore, reducing traffic congestion to a greater extent and ensuring steady flow of traffic in a wide region.

  10. A traffic situation analysis system

    Science.gov (United States)

    Sidla, Oliver; Rosner, Marcin

    2011-01-01

    The observation and monitoring of traffic with smart visions systems for the purpose of improving traffic safety has a big potential. For example embedded vision systems built into vehicles can be used as early warning systems, or stationary camera systems can modify the switching frequency of signals at intersections. Today the automated analysis of traffic situations is still in its infancy - the patterns of vehicle motion and pedestrian flow in an urban environment are too complex to be fully understood by a vision system. We present steps towards such a traffic monitoring system which is designed to detect potentially dangerous traffic situations, especially incidents in which the interaction of pedestrians and vehicles might develop into safety critical encounters. The proposed system is field-tested at a real pedestrian crossing in the City of Vienna for the duration of one year. It consists of a cluster of 3 smart cameras, each of which is built from a very compact PC hardware system in an outdoor capable housing. Two cameras run vehicle detection software including license plate detection and recognition, one camera runs a complex pedestrian detection and tracking module based on the HOG detection principle. As a supplement, all 3 cameras use additional optical flow computation in a low-resolution video stream in order to estimate the motion path and speed of objects. This work describes the foundation for all 3 different object detection modalities (pedestrians, vehi1cles, license plates), and explains the system setup and its design.

  11. Estimated Bandwidth Distribution with Admission Control for Enhanced QoS Multicast Routing in MANETs

    Directory of Open Access Journals (Sweden)

    P.Revathi

    2009-09-01

    Full Text Available Wireless networks become more widely used to support advanced services. Traditional approaches to guarantee quality of service (QoS work well only with predictable channel and network access. The Multicast transmission is a more efficient mechanism when compared to uni-casting in supporting group communication applications and hence is an important aspect of future network developments. To enable high QoS for all admitted traffic, the Admission Control monitors the wireless channel and dynamically adapts admission control decisions to enable high network utilization while preventing congestion. Mobile Adhoc networks can provide multimedia users with mobility, if efficient QoS multicast strategies were developed. In load balancing QoS Multicast Routing QMR, constant available bandwidth for the link is assumed. A cross-layer framework to support QoS multicasting is extended for more effective than QMR. The extension reflects good packet delivery ratios associated with lower control overhead and lower packet delivery delay. If minimum real-time requirements are not met, these unusable packets waste scarce bandwidth and hinder other traffic, compounding the problem. Whereas the dynamically adapted mobility with control overhead monitors the high QoS for all admitted traffic, and the bandwidth for each node is enhanced to reflect the good packet delivery ratio associated with lower control overhead and lower packet delivery delay.

  12. System level traffic shaping in disk servers with heterogeneous protocols

    International Nuclear Information System (INIS)

    Disk access and tape migrations compete for network bandwidth in CASTORs disk servers, over various protocols: RFIO, Xroot, root and GridFTP. As there are a limited number of tape drives, it is important to keep them busy all the time, at their nominal speed. With potentially 100s of user read streams per server, the bandwidth for the tape migrations has to be guaranteed to a controlled level, and not the fair share the system gives by default. Xroot provides a prioritization mechanism, but using it implies moving exclusively to the Xroot protocol, which is not possible in short to mid-term time frame, as users are equally using all protocols. The greatest commonality of all those protocols is not more than the usage of TCP/IP. We investigated the Linux kernel traffic shaper to control TCP/ IP bandwidth. The performance and limitations of the traffic shaper have been understood in test environment, and satisfactory working point has been found for production. Notably, TCP offload engines' negative impact on traffic shaping, and the limitations of the length of the traffic shaping rules were discovered and measured. A suitable working point has been found and the traffic shaping is now successfully deployed in the CASTOR production systems at CERN. This system level approach could be transposed easily to other environments.

  13. Unmanned Aircraft System Control and ATC Communications Bandwidth Requirements

    Science.gov (United States)

    Henriksen, Steve

    2008-01-01

    There are significant activities taking place to establish the procedures and requirements for safe and routine operation of unmanned aircraft systems (UAS) in the National Airspace System (NAS). Among the barriers to overcome in achieving this goal is the lack of sufficient frequency spectrum necessary for the UAS control and air traffic control (ATC) communications links. This shortcoming is compounded by the fact that the UAS control communications links will likely be required to operate in protected frequency spectrum, just as ATC communications links are, because they relate to "safety and regularity of flight." To support future International Telecommunications Union (ITU) World Radio Conference (WRC) agenda items concerning new frequency allocations for UAS communications links, and to augment the Future Communications Study (FCS) Technology Evaluation Group efforts, NASA Glenn Research Center has sponsored a task to estimate the UAS control and ATC communications bandwidth requirements for safe, reliable, and routine operation of UAS in the NAS. This report describes the process and results of that task. The study focused on long-term bandwidth requirements for UAS approximately through 2030.

  14. Design and Development of Sensor Based Traffic Light System

    Directory of Open Access Journals (Sweden)

    A. Albagul

    2006-01-01

    Full Text Available The main object of this study was to design and implement a suitable algorithm and its simulation for an intelligent traffic signal simulator. The system developed is able to sense the presence or absence of vehicles within certain range by setting the appropriate duration for the traffic signals to react accordingly. By employing mathematical functions to calculate the appropriate timing for the green signal to illuminate, the system can help to solve the problem of traffic congestion. The simulation of the algorithm of the traffic signal system was done using MATLAB software. Hardware simulation tests were successfully performed on the algorithm implemented into a controller. The new timing scheme that was implemented promises an improvement in the current traffic light system and this system is feasible, affordable and ready to be implemented especially during peak hours. A countdown timer interfacing according to the traffic system using Lab VIEW software was also created.

  15. A Marine Traffic Flow Model

    OpenAIRE

    Tsz Leung Yip

    2013-01-01

    A model is developed for studying marine traffic flow through classical traffic flow theories, which can provide us with a better understanding of the phenomenon of traffic flow of ships. On one hand, marine traffic has its special features and is fundamentally different from highway, air and pedestrian traffic. The existing traffic models cannot be simply extended to marine traffic without addressing marine traffic features. On the other hand, existing literature on marine traffic focuses on...

  16. SELF-SIMILAR TRAFFIC GENERATOR

    OpenAIRE

    Linawati Linawati; I Made Suartika

    2009-01-01

    Network traffic generator can be produced using OPNET. OPNET generates the traffic as explicit traffic or background traffic. This paper demonstrates generating traffic in OPNET 7.0 as background traffic. The traffi generator that was simulated is self-similar traffic with different Hurst parameter. The simulation results proved that OPNET with background traffic function can be as a qualified self-similar traffic generator. These results can help in investigating and analysing network perfor...

  17. A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs

    Directory of Open Access Journals (Sweden)

    Taner Cevik

    2013-01-01

    Full Text Available One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT which is the only competent authority, each optical network unit (ONU runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand.

  18. BitTorrent Network Traffic Forecasting With ARMA

    Directory of Open Access Journals (Sweden)

    Poo KuanHoong

    2012-08-01

    Full Text Available In recent years, there are some major changes in the way content is being distributed over the network. The content distribution techniques have recently started to embrace peer-to-peer (P2P systems as an alternative to the traditional client-server architecture. P2P systemsthat are based on the BitTorrentprotocol uses end-users’ resources to provide a cost effective distribution of bandwidth intensive content to thousands of users. The BitTorrent protocol system offers a scalable mechanism for distributing a large volume of data to a set of peers over the Internet. With the growing demand for file sharing andcontent distribution, BitTorrent has become one of the most popular Internet applications and contributes to a signification fraction of the Internet traffic. With the wide usage of the BitTorrent protocol system, it has basically solved one of the major problems where data can be quickly transferred to a group of interested parties. The strength of the BitTorrent protocol lies in efficient bandwidth utilization for the downloading and uploading processes. However, the usage of BitTorrent protocol also causes latency forother applications in terms of network bandwidth which in turn has caused concerns for the Internet Service Providers, who strives for quality of service for all their customers. In this paper, we study the network traffic patterns of theBitTorrent network traffic and investigate its behavior by usingthe time series ARMA model. Our experimental results show that BitTorrent network traffic can be modeled and forecasted by using ARMA models. We compared and evaluated the forecasted network traffic with the real traffic patterns. This modeling can be utilized by the Internet Service Providers to manage their network bandwidth and also detect any abnormality in their network.

  19. OPTIMIZATION OF URBAN MULTI-INTERSECTION TRAFFIC FLOW VIA Q-LEARNING

    Directory of Open Access Journals (Sweden)

    Yit Kwong Chin

    2013-01-01

    Full Text Available Congestions of the traffic flow within the urban traffic network have been a challenging task for all the urban developers. Many approaches have been introduced into the current system to solve the traffic congestion problems. Reconfiguration of the traffic signal timing plan has been carried out through implementation of different techniques. However, dynamic characteristics of the traffic flow increase the difficulties towards the ultimate solutions. Thus, traffic congestions still remain as unsolvable problems to the current traffic control system. In this study, artificial intelligence method has been introduced in the traffic light system to alter the traffic signal timing plan to optimize the traffic flows. Q-learning algorithm in this study has enhanced the traffic light system with learning ability. The learning mechanism of Q-learning enables traffic light intersections to release itself from traffic congestions situation. Adjacent traffic light intersections will work independently and yet cooperate with each others to a common goal of ensuring the fluency of the traffic flows within the traffic network. The simulated results show that the Q-Learning algorithm is able to learn from the dynamic traffic flow and optimize the traffic flow accordingly.

  20. SPDC correlated photon source filtered for narrowed bandwidth using volume Bragg grating

    Science.gov (United States)

    Slattery, Oliver; Kuo, Paulina; Kim, Yong-Su; Ma, Lijun; Tang, Xiao

    2012-10-01

    A Volume Bragg Grating (VBG) can be used to efficiently extract a narrow bandwidth, highly collimated beam from an otherwise broad spectrum beam. We use a VBG to extract a narrow bandwidth of signal spectrum from a broadband Spontaneous Parametric Down-Conversion source to optimally match the narrow detection bandwidth of our idler upconversion detector. Improved coincidence count rates and visibility can be achieved when limiting signal-spectrum detection to the narrow signal bandwidth whose photons are correlated with a narrow idler-spectrum bandwidth that has been selected by the up-conversion detector. We compare coincidence count rate and visibility for when the entire signal spectrum is detected and when the spectrum has been filtered by the VBG. We further relax the collection techniques and show that following the VBG, the coincidence count rate improves with minimal loss in visibility compared to when the entire spectrum is detected. We introduce our initial efforts at using the VBG to further narrow the signal spectrum by placing it inside a multipass cavity. Additionally, we further adapt the single photon level up-conversion spectrometer, previously developed for idler spectrum measurement, to indirectly measure the single photon level signal spectrum. We verify its capability for several different wavelength and linewidth selections.

  1. High-Bandwidth Hybrid Sensor (HYSENS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA has demonstrated the primary innovation of combining a precision MEMS gyro (BAE SiRRS01) with a high bandwidth angular rate sensor, ATA's ARS-14 resulting in a...

  2. Traffic Flow Theory

    OpenAIRE

    Maerivoet, Sven; De Moor, Bart

    2005-01-01

    The scientific field of traffic engineering encompasses a rich set of mathematical techniques, as well as researchers with entirely different backgrounds. This paper provides an overview of what is currently the state-of-the-art with respect to traffic flow theory. Starting with a brief history, we introduce the microscopic and macroscopic characteristics of vehicular traffic flows. Moving on, we review some performance indicators that allow us to assess the quality of traffic operations. A f...

  3. Optimizing Traffic Flow

    OpenAIRE

    Huberman, Bernardo A.; Helbing, Dirk

    1998-01-01

    We present an economics-based method for deciding the optimal rates at which vehicles are allowed to enter a highway. The method exploits the naturally occuring fluctuations of traffic flow and is flexible enough to adapt in real time to the transient flow characteristics of road traffic. Simulations based on realistic parameter values show that this strategy is feasible for naturally occuring traffic, and that even far from optimality, injection policies can improve traffic flow. Our results...

  4. Traffic-flow simulation

    OpenAIRE

    OMAHEN, ANDRAŽ

    2015-01-01

    This diploma thesis presents the behavior of program, which uses the traffic light enhanced transport network to simulate the traffic flow of vehicles that behave according to the IDM model. We upgraded the program to allow, for the given network, to optimize the traffic flow. Because of the overwhelming problem of road closures or their rearrangement, we added a graphical user interface with which a user can create or modify the road network to observe changes in traffic. The objective of...

  5. Traffic Flow Estimates.

    Science.gov (United States)

    Hart, Vincent G.

    1981-01-01

    Two examples are given of ways traffic engineers estimate traffic flow. The first, Floating Car Method, involves some basic ideas and the notion of relative velocity. The second, Maximum Traffic Flow, is viewed to involve simple applications of calculus. The material provides insight into specialized applications of mathematics. (MP)

  6. Controlling Disorder in Traffic Flow by Perturbation

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  7. Intelligent traffic control system using PLC

    Science.gov (United States)

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

    2016-08-01

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

  8. Green Wave Traffic Optimization - A Survey

    DEFF Research Database (Denmark)

    Warberg, Andreas; Larsen, Jesper; Jørgensen, Rene Munk

    important conflicts, which support the notion that traffic signal optimization is a multi-objective problem, and relates this to the most common measures of effectiveness. A distinction can be made between classical systems, which operate with a common cycle time, and the more flexible, phase......-based, approach, which is shown to be more suitable for adaptive traffic control. To support this claim three adaptive systems, which use alternatives to the classical optimization procedures, are described in detail....

  9. Efficient traffic grooming with dynamic ONU grouping for multiple-OLT-based access network

    Science.gov (United States)

    Zhang, Shizong; Gu, Rentao; Ji, Yuefeng; Wang, Hongxiang

    2015-12-01

    Fast bandwidth growth urges large-scale high-density access scenarios, where the multiple Passive Optical Networking (PON) system clustered deployment can be adopted as an appropriate solution to fulfill the huge bandwidth demands, especially for a future 5G mobile network. However, the lack of interaction between different optical line terminals (OLTs) results in part of the bandwidth resources waste. To increase the bandwidth efficiency, as well as reduce bandwidth pressure at the edge of a network, we propose a centralized flexible PON architecture based on Time- and Wavelength-Division Multiplexing PON (TWDM PON). It can provide flexible affiliation for optical network units (ONUs) and different OLTs to support access network traffic localization. Specifically, a dynamic ONU grouping algorithm (DGA) is provided to obtain the minimal OLT outbound traffic. Simulation results show that DGA obtains an average 25.23% traffic gain increment under different OLT numbers within a small ONU number situation, and the traffic gain will increase dramatically with the increment of the ONU number. As the DGA can be deployed easily as an application running above the centralized control plane, the proposed architecture can be helpful to improve the network efficiency for future traffic-intensive access scenarios.

  10. Modelling the Traffic System

    Directory of Open Access Journals (Sweden)

    Važan Pavel

    2014-12-01

    Full Text Available The paper presents the simulation study results of the traffic system in the city of Hlohovec. The authors describe the process of building the model in Witness 2013c simulator. The individual entities of simulation model are explained in details, as the Witness simulator is primarily suitable for manufacture or service simulation and not for traffic system simulation. The goal of this paper is to analyse the traffic system and to suggest the changes for improving the traffic in the city of Hlohovec. All proposed measures will bring about 20% improvement of traffic when compared to the current state.

  11. Effect of the traffic shaping function of the EF class in a DiffServ queue architecture

    Science.gov (United States)

    Kawabata, Akio; Sakaguchi, Takeshi; Yamamoto, Susumu; Shimizu, Shigeki; Nishikido, Jun; Komura, Hisashi

    2002-09-01

    An integrated IP (Internet Protocol) network that can handle leased-line, voice, and data traffic, offers great advantages in simplifying the networks of communication carriers and reducing network costs compared with separate service-specific networks. A key issue of such integrated IP networks will be to design a router that can efficiently handle each type of traffic strictly according to its QoS (Quality of Service). Diffserv (Differentiated Services) is a popular solution to handling multiple QoSs, so most routers tend to support it. In this paper, we propose a new DiffServ queue architecture featuring multiple EF (Expedited Forwarding) queues with traffic shaping functions. Because each EF queue has a traffic shaper, its QoS can be controlled without affecting other EF traffic. For example, when the leased line traffic is assigned to the first EF class and VoIP (Voice over IP) traffic to the second EF class, the VoIP traffic is transferred with high QoS even if the leased line traffic has bursty characteristics. This queue architecture can provide a low-latency, assured bandwidth for both leased-line and VoIP traffic. We evaluated the traffic characteristics of VoIP traffic by simulating this queue architecture using various bandwidths and voice codec types. The results indicate that this queuing mechanism can achieve lower latency and better QoS control than the usual DiffServ queue architecture without traffic shaping. The benefits of traffic shaping are more noticeable with low-bandwidth traffic.

  12. Fibre Bragg grating based accelerometer with extended bandwidth

    Science.gov (United States)

    Basumallick, Nandini; Biswas, Palas; Chakraborty, Rajib; Chakraborty, Sushanta; Dasgupta, Kamal; Bandyopadhyay, Somnath

    2016-03-01

    We have shown experimentally that the operable bandwidth of a fibre Bragg grating (FBG) based accelerometer can be extended significantly, without compromising its sensitivity, using a post-signal processing technique which involves frequency domain weighting. It has been demonstrated that using the above technique acceleration can be correctly interpreted even when the operating frequency encroaches on the region where the frequency response of the sensor is non-uniform. Two different excitation signals, which we often encounter in structural health monitoring applications, e.g. (i) a signal composed of multi-frequency components and (ii) a sinusoidal excitation with a frequency sweep, have been considered in our experiment. The results obtained have been compared with a piezo accelerometer.

  13. Bandwidth Extension of Telephone Speech Aided by Data Embedding

    Directory of Open Access Journals (Sweden)

    David Malah

    2007-01-01

    Full Text Available A system for bandwidth extension of telephone speech, aided by data embedding, is presented. The proposed system uses the transmitted analog narrowband speech signal as a carrier of the side information needed to carry out the bandwidth extension. The upper band of the wideband speech is reconstructed at the receiving end from two components: a synthetic wideband excitation signal, generated from the narrowband telephone speech and a wideband spectral envelope, parametrically represented and transmitted as embedded data in the telephone speech. We propose a novel data embedding scheme, in which the scalar Costa scheme is combined with an auditory masking model allowing high rate transparent embedding, while maintaining a low bit error rate. The signal is transformed to the frequency domain via the discrete Hartley transform (DHT and is partitioned into subbands. Data is embedded in an adaptively chosen subset of subbands by modifying the DHT coefficients. In our simulations, high quality wideband speech was obtained from speech transmitted over a telephone line (characterized by spectral magnitude distortion, dispersion, and noise, in which side information data is transparently embedded at the rate of 600 information bits/second and with a bit error rate of approximately 3⋅10−4. In a listening test, the reconstructed wideband speech was preferred (at different degrees over conventional telephone speech in 92.5% of the test utterances.

  14. Bandwidth Extension of Telephone Speech Aided by Data Embedding

    Directory of Open Access Journals (Sweden)

    Sagi Ariel

    2007-01-01

    Full Text Available A system for bandwidth extension of telephone speech, aided by data embedding, is presented. The proposed system uses the transmitted analog narrowband speech signal as a carrier of the side information needed to carry out the bandwidth extension. The upper band of the wideband speech is reconstructed at the receiving end from two components: a synthetic wideband excitation signal, generated from the narrowband telephone speech and a wideband spectral envelope, parametrically represented and transmitted as embedded data in the telephone speech. We propose a novel data embedding scheme, in which the scalar Costa scheme is combined with an auditory masking model allowing high rate transparent embedding, while maintaining a low bit error rate. The signal is transformed to the frequency domain via the discrete Hartley transform (DHT and is partitioned into subbands. Data is embedded in an adaptively chosen subset of subbands by modifying the DHT coefficients. In our simulations, high quality wideband speech was obtained from speech transmitted over a telephone line (characterized by spectral magnitude distortion, dispersion, and noise, in which side information data is transparently embedded at the rate of 600 information bits/second and with a bit error rate of approximately . In a listening test, the reconstructed wideband speech was preferred (at different degrees over conventional telephone speech in of the test utterances.

  15. Systems for measuring response statistics of gigahertz bandwidth photomultipliers

    Science.gov (United States)

    Abshire, J. B.; Rowe, H. E.

    1977-01-01

    New systems have been developed for measuring the average impulse response, the pulse-height spectrum, the transit-time statistics as a function of signal level, and the dark-count spectrum of gigahertz bandwidth photomultipliers. Measurements showed that the 0.53 microns pulse used as an optical test source had a 30 picoseconds and less than 70 ps pulse width. Calibration data showed the system resolution to be less than 20 ps for root mean square transit-time measurements. Test data for a static crossed-field photomultiplier showed 2-photoelectron resolution and less than 30-ps time jitter over the 1- to 100-photoelectron range.

  16. Bandwidth Extension Method Based on Spectral Envelope Estimation

    Directory of Open Access Journals (Sweden)

    Bo Hang

    2011-06-01

    Full Text Available In current communication system, high quality audio signal is supposed to be provided with low bit rate and low computational complexity. This paper proposed a novel audio coding bandwidth extension method, which can improve decoded audio quality with increasing only a few coding bits per frame and a little computational complexity. This method calculate high-frequency synthesis filter by using codebook mapping method, and transmit only quantified gain corrections in high-frequency part of multiplexing coding bit stream. The preliminary test show that this method can provide comparable audio quality with lower bit consumption and computational complexity compared to the high frequency regeneration of AMR-WB+.

  17. Optimization of congested traffic flow in systems with a localized periodic inhomogeneity

    OpenAIRE

    Tomer, Elad; Safonov, Leonid; Madar, Nilly; Havlin, Shlomo

    2001-01-01

    We study traffic flow on roads with a localized periodic inhomogeneity such as traffic signals, using a stochastic car-following model. We find that in cases of congestion, traffic flow can be optimized by controlling the inhomogeneity's frequency. By studying the wavelength dependence of the flux in stop-and-go traffic states, and exploring their stability, we are able to explain the optimization process. A general conclusion drawn from this study is, that the fundamental diagram of traffic ...

  18. Adaptable bandwidth planning using reinforcement learning

    Directory of Open Access Journals (Sweden)

    Dirk Hetzer

    2006-08-01

    Full Text Available In order to improve the bandwidth allocation considering feedback of operational environment, adaptable bandwidth planning based on reinforcement learning is proposed. The approach is based on new constrained scheduling algorithms controlled by reinforcement learning techniques. Different constrained scheduling algorithms,, such as "conflict free scheduling with minimum duration", "partial displacement" and "pattern oriented scheduling" are defined and implemented. The scheduling algorithms are integrated into reinforcement learning strategies. These strategies include: - Q-learning for selection of optimal planning schedule using Q-values; - Informed Q-learning for exploitation and handling of prior-knowledge (patterns of network behaviour; - Relational Q-learning for improving of bandwidth allocation policies dynamically in operational networks considering actual network performance data. Scenarios based on integration of the scheduling algorithms and reinforcement learning techniques in the experimental monitoring and bandwidth planning system called QORE (QoS and resource optimisation are given. The proposed adaptable bandwidth planning is required for more efficient usage of network resources.

  19. DETECCIÓN Y RECONOCIMIENTO DE SEÑALES DE TRÁNSITO UTILIZANDO MATCHING DE CHAMFER DETECTION AND RECOGNITION OF TRAFFIC SIGNALS USING MATCHING OF CHAMFER

    Directory of Open Access Journals (Sweden)

    Cristián Arriagada García

    2007-08-01

    available details at first sight etc, in our case a prototype is presented which allows the opportunity to help a car driver to pay attention to the traffic signs on the road, attempting to assist the driver, and at the same time to avoid traffic infractions and accidents. The prototype developed with computer vision techniques, allows the detection and recognition of signposts that are on the road and to inform its nature to the driver through an audible sign or a visual projection. The research was mainly centered on the phases of initial detection; with the objective of taking into account a quick heuristic, taking advantage of the segmentation by color, with their characteristics of invariability of system HSV (Brightness, Saturation, Value [10], and/or initial detection by borders, making use of the improved algorithm of Chamfer [1], finally to detect and recognize the symbols of the sign, using transformation of distance techniques and hierarchical matching of Chamfer[1], conditioned to this kind of application. The prototype in the phase of proof was implemented in Matlab, with the initial purpose of proving the effectiveness of the methods that were used. Once they are proved an OpenCV was used to verify its functioning in real time.

  20. Transition from Disorder to Order in Traffic Flow

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; GAO Zi-You

    2004-01-01

    We propose a new technique to investigate the dynamical transitions among the traffic phases. A type of the control signals has been designated at a given site (signal point) of the single-lane highway. Under the effect of the control signal, the velocity of the vehicle that passes the signal point will be changed periodically. Our method is tested for the deterministic NaSch traffic model. The simulation results demonstrate that the disorder states in the deterministic NaSch traffic model can be suppressed, and the different types of periodic states would occur.

  1. 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...

  2. Simulation technique for available bandwidth estimation

    CERN Document Server

    Sultanov, T G

    2010-01-01

    The paper proposes a method for measuring available bandwidth, based on testing network packets of various sizes (Variable Packet Size method, VPS). The boundaries of applicability of the model have been found, which are based on the accuracy of measurements of packet delays, also we have derived a formula of measuring the upper limit of bandwidth. The computer simulation has been performed and relationship between the measurement error of available bandwidth and the number of measurements has been found. Experimental verification with the use of RIPE Test Box measuring system has shown that the suggested method has advantages over existing measurement techniques. Pathload utility has been chosen as an alternative technique of measurement, and to ensure reliable results statistics by SNMP agent has been withdrawn directly from the router.

  3. Occupant traffic estimation through structural vibration sensing

    Science.gov (United States)

    Pan, Shijia; Mirshekari, Mostafa; Zhang, Pei; Noh, Hae Young

    2016-04-01

    The number of people passing through different indoor areas is useful in various smart structure applications, including occupancy-based building energy/space management, marketing research, security, etc. Existing approaches to estimate occupant traffic include vision-, sound-, and radio-based (mobile) sensing methods, which have placement limitations (e.g., requirement of line-of-sight, quiet environment, carrying a device all the time). Such limitations make these direct sensing approaches difficult to deploy and maintain. An indirect approach using geophones to measure floor vibration induced by footsteps can be utilized. However, the main challenge lies in distinguishing multiple simultaneous walkers by developing features that can effectively represent the number of mixed signals and characterize the selected features under different traffic conditions. This paper presents a method to monitor multiple persons. Once the vibration signals are obtained, features are extracted to describe the overlapping vibration signals induced by multiple footsteps, which are used for occupancy traffic estimation. In particular, we focus on analysis of the efficiency and limitations of the four selected key features when used for estimating various traffic conditions. We characterize these features with signals collected from controlled impulse load tests as well as from multiple people walking through a real-world sensing area. In our experiments, the system achieves the mean estimation error of +/-0.2 people for different occupant traffic conditions (from one to four) using k-nearest neighbor classifier.

  4. FPGA Based Real-time Network Traffic Analysis using Traffic Dispersion Patterns

    Energy Technology Data Exchange (ETDEWEB)

    Khan, F; Gokhale, M; Chuah, C N

    2010-03-26

    The problem of Network Traffic Classification (NTC) has attracted significant amount of interest in the research community, offering a wide range of solutions at various levels. The core challenge is in addressing high amounts of traffic diversity found in today's networks. The problem becomes more challenging if a quick detection is required as in the case of identifying malicious network behavior or new applications like peer-to-peer traffic that have potential to quickly throttle the network bandwidth or cause significant damage. Recently, Traffic Dispersion Graphs (TDGs) have been introduced as a viable candidate for NTC. The TDGs work by forming a network wide communication graphs that embed characteristic patterns of underlying network applications. However, these patterns need to be quickly evaluated for mounting real-time response against them. This paper addresses these concerns and presents a novel solution for real-time analysis of Traffic Dispersion Metrics (TDMs) in the TDGs. We evaluate the dispersion metrics of interest and present a dedicated solution on an FPGA for their analysis. We also present analytical measures and empirically evaluate operating effectiveness of our design. The mapped design on Virtex-5 device can process 7.4 million packets/second for a TDG comprising of 10k flows at very high accuracies of over 96%.

  5. 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.

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

    Science.gov (United States)

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

    2014-01-01

    Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors that can affect the traffic control model, it is difficult to find the optimal solution. The disability of traffic light controllers to learn from past experiences caused them to be unable to adaptively fit dynamic changes of traffic flow. Considering dynamic characteristics of the actual traffic environment, reinforcement learning algorithm based traffic control approach can be applied to get optimal scheduling policy. The proposed Sarsa(λ)-based real-time traffic control optimization model can maintain the traffic signal timing policy more effectively. The Sarsa(λ)-based model gains traffic cost of the vehicle, which considers delay time, the number of waiting vehicles, and the integrated saturation from its experiences to learn and determine the optimal actions. The experiment results show an inspiring improvement in traffic control, indicating the proposed model is capable of facilitating real-time dynamic traffic control. PMID:24592183

  7. Dealing Bandwidth to Mobile Clients Using Games

    Science.gov (United States)

    Sofokleous, Anastasis A.; Angelides, Marios C.

    This chapter exploits a gaming approach to bandwidth sharing in a network of non-cooperative clients whose aim is to satisfy their selfish objectives and be served in the shortest time and who share limited knowledge of one another. The chapter models this problem as a game in which players consume the bandwidth of a video streaming server. The rest of this chapter is organized in four sections: the proceeding section presents resource allocation taxonomies, following that is a section on game theory, where our approach is sourced from, and its application to resource allocation. The penultimate section presents our gaming approach to resource allocation. The final section concludes.

  8. Remotely Accessed Vehicle Traffic Management System

    Science.gov (United States)

    Al-Alawi, Raida

    2010-06-01

    The ever increasing number of vehicles in most metropolitan cities around the world and the limitation in altering the transportation infrastructure, led to serious traffic congestion and an increase in the travelling time. In this work we exploit the emergence of novel technologies such as the internet, to design an intelligent Traffic Management System (TMS) that can remotely monitor and control a network of traffic light controllers located at different sites. The system is based on utilizing Embedded Web Servers (EWS) technology to design a web-based TMS. The EWS located at each intersection uses IP technology for communicating remotely with a Central Traffic Management Unit (CTMU) located at the traffic department authority. Friendly GUI software installed at the CTMU will be able to monitor the sequence of operation of the traffic lights and the presence of traffic at each intersection as well as remotely controlling the operation of the signals. The system has been validated by constructing a prototype that resembles the real application.

  9. Energy consumption in rail traffic

    International Nuclear Information System (INIS)

    This report for the Swiss Federal Office of Energy (SFOE) presents the first results of a short study made on the energy consumption of the Swiss rail-bound systems for the transport of persons and goods. In this initial short study, data collected on the electricity and fossil fuel consumption of the Swiss Federal Railways and further railway companies in Switzerland is presented. The consumption is split into various categories such as person and goods traffic, internal traffic, building-infrastructure (stations, workshops, tunnels etc.) and equipment (signals, point-heaters, lighting, safety equipment). Data is presented in tables and in graphical form in relation to person-kilometres and tonne-kilometres. The development of consumption over a period of years is discussed and comparisons are made with figures for the German rail system

  10. 47 CFR 87.135 - Bandwidth of emission.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bandwidth of emission. 87.135 Section 87.135... Technical Requirements § 87.135 Bandwidth of emission. (a) Occupied bandwidth is the width of a frequency... equal to 0.5 percent of the total mean power of a given emission. (b) The authorized bandwidth is...

  11. Reference Chaser Bandwidth Controller for Wireless QoS Mapping under Delay Constraints

    Directory of Open Access Journals (Sweden)

    Marchese M

    2010-01-01

    Full Text Available Telecommunications networks are composed of functional layers acting in cascade. Quality of Service (QoS derives from the action of each layer that must assure a specific level of quality to the upper layer in terms of performance parameters (e.g., loss, delay, jitter of the packets. Appropriate algorithms are needed to compute the bandwidth necessary so to assure the requested QoS when information is transferred from one layer to the next one below. This paper proposes a scheme that adapts the bandwidth to be allocated to a buffer which conveys heterogeneous traffic (both concerning traffic sources and QoS requirements in a layer-in-cascade model. The proposal is focused on delay constraints. The proposed algorithm is based only on measures and does not use closed-form expressions, a priori information about traffic statistical properties, and assumptions about buffer dimension. Simulation results show the reliability of the approach in comparison with other techniques at the state of the art, thus corroborating the application of the algorithm for a large set of operative situations, including fading conditions.

  12. A traffic-depended multi-buffer node architecture and an effective access technique under symmetric and asymmetric IP traffic scenarios for unslotted ring WDM MANs

    Science.gov (United States)

    Baziana, Peristera A.

    2016-09-01

    This study aims to put forward an extensive discussion about the increasing demand for available bandwidth to serve the multiple types of traffic in modern wavelength division multiplexing (WDM) metropolitan area networks (MANs). A traffic-depended multi-buffer node architecture in conjunction with an efficient asynchronous transmission WDM access (WDMA) protocol to serve the variable size Internet packets in ring MANs is proposed. The structure of the multi-buffer node architecture is determined by the probability distribution of each packet size category in the MAN traffic, providing storage and dropping events equity among the nodes. The adopted WDMA algorithm satisfies the requirement for high performance efficiency especially under high offered load, by taking care to optimally face the bandwidth fragmentation problem and to maximize the bandwidth exploitation, while it effectively avoids both the packets collisions over the wavelengths and the destination conflicts. Numerical results prove that the proposed network model achieves throughput improvement up to 334% as compared with the relative study of Pranggono and Elmirghani (2011). An analytical framework is developed for the protocol throughput predictions under both symmetric and asymmetric IP traffic scenarios. Also, the proposed protocol performance is thoroughly investigated through simulation results based on Poisson and self-similar traffic model statistics, for both traffic scenarios.

  13. Implementation of Neural Network with a variant of Turing Machine for Traffic Flow Control

    OpenAIRE

    Rashmi Sehrawat; Honey Malviya; Vanditaa Kaul

    2013-01-01

    The conventional method of operation of a typical traffic light is to distribute the time equally for all the directions.This method causes congestion when throughput of the signal increases and is alsoineffective in managing traffic flow. In this paper, we have proposed a new model for managing traffic intelligently.The model is based on Turing machine with the application of neural network. The modelconsiders current traffic status of its own signal along with the status of its adjacent sig...

  14. Dynamic bandwidth allocation algorithm for full-band utilization

    Institute of Scientific and Technical Information of China (English)

    Han Guodong; Wang Hui; Wu Jiangxing

    2006-01-01

    To improve and optimize the bandwidth utilization for multi-service packet transporting system, a kind of Dynamic Full Bandwidth Utilized (DFBU) allocation algorithm allowing a single link to use far beyond its fair share bandwidth is presented. Three important parameters as the bound on max and minimum bandwidth, the maximum packet delay and the minimum bandwidth utilization are discussed and analyzed. Results of experiments show that the DFBU-algorithm is capable of making a single link in the system use all the spare bandwidth (up to full-bandwidth) while the performance of fairness and QoS requirement is still guaranteed.

  15. Costs of traffic injuries

    DEFF Research Database (Denmark)

    Kruse, Marie

    2015-01-01

    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...... 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...

  16. Trajectory Based Traffic Analysis

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin;

    2013-01-01

    We present the INTRA system for interactive path-based traffic analysis. The analyses are developed in collaboration with traffic researchers and provide novel insights into conditions such as congestion, travel-time, choice of route, and traffic-flow. INTRA supports interactive point-and-click a......We present the INTRA system for interactive path-based traffic analysis. The analyses are developed in collaboration with traffic researchers and provide novel insights into conditions such as congestion, travel-time, choice of route, and traffic-flow. INTRA supports interactive point......-and-click analysis, due to a novel and efficient indexing structure. With the web-site daisy.aau.dk/its/spqdemo/we will demonstrate several analyses, using a very large real-world data set consisting of 1.9 billion GPS records (1.5 million trajectories) recorded from more than 13000 vehicles, and touching most of...

  17. Internet Traffic Engineering

    OpenAIRE

    Bonaventure, Olivier; Trimintzios, Panos; Pavlou, George; Quoitin, Bruno; Azcorra, Arturo; Bagnulo, Marcelo; Fegkas, Paris; García-Martínez, Alberto; Georgatsos, Panos; Georgiadis, Leonidas; Jacquenet, Christian; Swinnen, Louis; Tandel, Sebastien; Uhlig, Steve

    2004-01-01

    Traffic engineering encompasses a set of techniques that can be used to control the flow of traffic in data networks. We discuss several of those techniques that have been developed during the last few years. Some techniques are focused on pure IP networks while others have been designed with emerging technologies for scalable Quality of Service (QoS) such as Differentiated Services and MPLS in mind. We first discuss traffic engineering techniques inside a single domain. We show that by using...

  18. Distraction in traffic.

    OpenAIRE

    2013-01-01

    Many drivers, as well as cyclists and pedestrians, are occupied with all kinds of activities that can distract their attention from traffic, like listening to music, conducting a conversation on their mobile phone, or texting. Distraction has negative effects on traffic behaviour. Most studies estimate that distraction plays a role in the occurrence of about 5-25% of the car crashes. Considering the increasing diffusion of electronic devices in traffic, portable media devices as well as advan...

  19. Traffic Congestion and Accidents

    OpenAIRE

    Schrage, Andrea

    2006-01-01

    Obstructions caused by accidents can trigger or exacerbate traffic congestion. This paper derives the efficient traffic pattern for a rush hour with congestion and accidents and the corresponding road toll. Compared to the model without accidents, where the toll equals external costs imposed on drivers using the road at the same time, a new insight arises: An optimal toll also internalizes the expected increase in future congestion costs. Since accidents affect more drivers if traffic volumes...

  20. 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.

  1. Traffic Light Options

    OpenAIRE

    Løchte, Peter

    2006-01-01

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic light solvency stress test system introduced by the Danish Financial Supervisory Authority (DFSA) in June 2001. This monitoring system requires L&P companies to submit regular reports documenting the ...

  2. Network Traffic Anomaly Detection

    OpenAIRE

    Huang, Hong; Al-Azzawi, Hussein; Brani, Hajar

    2014-01-01

    This paper presents a tutorial for network anomaly detection, focusing on non-signature-based approaches. Network traffic anomalies are unusual and significant changes in the traffic of a network. Networks play an important role in today's social and economic infrastructures. The security of the network becomes crucial, and network traffic anomaly detection constitutes an important part of network security. In this paper, we present three major approaches to non-signature-based network detect...

  3. Bandwidth Enhancement Techniques of Dielectric Resonator Antenna

    Directory of Open Access Journals (Sweden)

    ARCHANA SHARMA

    2011-07-01

    Full Text Available The paper briefly reviews the historical background of dielectric resonator antenna and its bandwidth enhancement techniques. The main focus is on a compact DRA that can offer broad band operation. It has been illustrated that dual resonance and multi resonance operation can be much effective to give wide band characteristics of DRA.

  4. Dynamic resource management using bandwidth brokers

    Institute of Scientific and Technical Information of China (English)

    Yu Chengzhi; Song Hantao; Hou Xianjun; Pan Chengsheng

    2006-01-01

    The admission control issue in the design of a centralized bandwidth broker model for dynamic control and management of QoS provisioning is studied. A two-phase differentiated flow treatment based dynamic admission control scheme under the centralized bandwidth broker model is proposed. In the proposed scheme, the flow requests are classified into two classes and get differentiated treatment according to their QoS demands. We demonstrate that this admission control scheme can not only improve the resource utilization but also guarantee the flows' QoS. Furthermore, the admission control is divided into two phases: edge admission control and interior admissio-n control. During the interior phase, the PoQ scheme is adopted, which enhances the call processing capability of the bandwidth broker. The simulation results show that the proposed scheme can result in lower flow blocking probability and higher resource utilization. And it also reduces the number of QoS state accesses/updates, thereby increasing the overall call processing capability of the bandwidth broker.

  5. Traffic Flow Management System

    Data.gov (United States)

    Department of Transportation — TFMS is a set NAS operational tools that predict demand, identify constraints, and facilitates collaboration among NAS users to support efficient traffic flow while...

  6. Subjective safety in traffic.

    OpenAIRE

    2012-01-01

    The term ‘subjective safety in traffic’ refers to people feeling unsafe in traffic or, more generally, to anxiety regarding being unsafe in traffic for oneself and/or others. Subjective safety in traffic can lead to road users limiting their mobility and social activities, which is one of the reasons it warrants policy-related attention. However, research has shown that, at most, there is a weak link between objective and subjective safety in traffic. There are even indications that some subj...

  7. Dynamic traffic grooming in survivable WDM networks

    Science.gov (United States)

    Zhu, Yonghua; Lin, Rujian

    2005-11-01

    This paper investigates the survivable traffic grooming problem for optical mesh networks employing wavelength-division multiplexing (WDM). While the transmission rate of a wavelength channel is high, the bandwidth requirement of a typical connection request can vary from the full wavelength capacity down to subwavelength. To efficiently utilize network resources, subwavelength-granularity connections can be groomed onto direct optical transmission channels, or lightpaths. Meanwhile, the failure of a network element can cause the failure of several lightpaths, thereby leading to large data and revenue loss. Fault-management schemes such as protection are essential to survive such failures. Different low-speed connections may request different bandwidth granularities as well as different protection schemes. How to efficiently groom such low-speed connections while satisfying their protection requirements is the main focus of our investigation. The paper tackles the dynamic survivable traffic grooming problems in multifiber wavelength-routed optical networks by representing the network as a layered graph model. This graph multi layers, where each layer represents a specific wavelength. Each link in the layered graph has more than one fibers and an associated cost. We use a modified Dijkstra algorithm that has a reduced complexity due to the structure of the layered graph. Heuristic algorithms for fiber selection based on a well-designed link-cost metrics are proposed. The performance of various routing algorithms is evaluated through simulation studies.

  8. An Improved QoS Multipath Routing Using Bandwidth Estimation and Rate Adaptation

    Directory of Open Access Journals (Sweden)

    S. Suganya

    2014-06-01

    Full Text Available Mobile Adhoc Networks (MANETs are composed of nodes which communicate with one another without network infrastructure. Their advantage being that they can be used in isolation or along with wired infrastructure, usually via a gateway node to ensure traffic relay for both networks. Quality of Service (QoS is harder to ensure in ad hoc networks than in other network types, as wireless bandwidth is shared by adjacent nodes with network topology changing as nodes move. Most QoS protocols are implemented for specific scenarios and consider parameters such as network topologies, bandwidth, mobility, security and so on. This work proposes a novel multipath routing protocol which is an extension of AOMDV by discovering routes based on available bandwidth and rate adaptation. The method with Hello message box is used to calculate available bandwidth for a route. Relative Fairness and Optimized Throughput is an approach for rate adaptation in this paper which is to ensure fairness and allow nodes to adapt transmission rates and contention windows to channel quality. In sequence this is determined by calculating the access probability of a channel for each node in a distributed manner approximating successful and failed transmissions.

  9. Traffic Dynamics of Computer Networks

    Science.gov (United States)

    Fekete, Attila

    2008-10-01

    Two important aspects of the Internet, namely the properties of its topology and the characteristics of its data traffic, have attracted growing attention of the physics community. My thesis has considered problems of both aspects. First I studied the stochastic behavior of TCP, the primary algorithm governing traffic in the current Internet, in an elementary network scenario consisting of a standalone infinite-sized buffer and an access link. The effect of the fast recovery and fast retransmission (FR/FR) algorithms is also considered. I showed that my model can be extended further to involve the effect of link propagation delay, characteristic of WAN. I continued my thesis with the investigation of finite-sized semi-bottleneck buffers, where packets can be dropped not only at the link, but also at the buffer. I demonstrated that the behavior of the system depends only on a certain combination of the parameters. Moreover, an analytic formula was derived that gives the ratio of packet loss rate at the buffer to the total packet loss rate. This formula makes it possible to treat buffer-losses as if they were link-losses. Finally, I studied computer networks from a structural perspective. I demonstrated through fluid simulations that the distribution of resources, specifically the link bandwidth, has a serious impact on the global performance of the network. Then I analyzed the distribution of edge betweenness in a growing scale-free tree under the condition that a local property, the in-degree of the "younger" node of an arbitrary edge, is known in order to find an optimum distribution of link capacity. The derived formula is exact even for finite-sized networks. I also calculated the conditional expectation of edge betweenness, rescaled for infinite networks.

  10. Impacts of Traffic Noise and Traffic Volume on Birds of Roadside Habitats

    Directory of Open Access Journals (Sweden)

    Angela Schneider

    2009-06-01

    Full Text Available Roadside habitats are important for a range of taxa including plants, insects, mammals, and birds, particularly in developed countries in which large expanses of native vegetation have been cleared for agriculture or urban development. Although roadside vegetation may provide suitable habitat for many species, resident animals can be exposed to high levels of traffic noise, visual disturbance from passing vehicles, and the risk of collision with cars and trucks. Traffic noise can reduce the distance over which acoustic signals such as song can be detected, an effect known as acoustic interference or masking. Studies from the northern hemisphere show that the singing behavior of birds changes in the presence of traffic noise. We investigated the impact of traffic noise and traffic volume on two species of birds, the Grey Shrike-thrush (Colluricincla harmonica and the Grey Fantail (Rhipidura fuliginosa, at 58 roadside sites on the Mornington Peninsula, southeastern Australia. The lower singing Grey Shrike-thrush sang at a higher frequency in the presence of traffic noise, with a predicted increase in dominant frequency of 5.8 Hz/dB of traffic noise, and a total effect size of 209 Hz. In contrast, the higher singing Grey Fantail did not appear to change its song in traffic noise. The probability of detecting each species on a visit to a site declined substantially with increasing traffic noise and traffic volume, with several lines of evidence supporting a larger effect of traffic noise. Traffic noise could hamper detection of song by conspecifics, making it more difficult for birds to establish and maintain territories, attract mates and maintain pair bonds, and possibly leading to reduced breeding success in noisy roadside habitats. Closing key roads during the breeding season is a potential, but untested, management strategy to protect threatened bird species from traffic noise and collision with vehicles at the time of year when they are most

  11. Traffic analysis of a medical multimedia communication network

    Science.gov (United States)

    Zoupas, Vasilios; Kotsopoulos, Stavros A.; Lymberopoulos, Dimitris C.

    1993-09-01

    Within the framework of the integration of medical information environment (MIE), special groupware multimedia services (GMS) should be developed. The application of GMSs to specially designed medical communication networks (MCN) creates an integrated user collaboration scheme for supporting and handling special medical cases. The present paper deals with the study and analysis of the traffic performance of a private multimedia ISDN MCN with a dynamic bandwidth allocation.

  12. The Traffic Light Challenge

    Science.gov (United States)

    Roman, Harry T.

    2014-01-01

    Traffic lights are an important part of the transportation infrastructure, regulating traffic flow and maintaining safety when crossing busy streets. When they go awry or become nonfunctional, a great deal of havoc and danger can be present. During power outages, the street lights go out all over the affected area. It would be good to be able to…

  13. Distraction in traffic.

    NARCIS (Netherlands)

    2013-01-01

    Many drivers, as well as cyclists and pedestrians, are occupied with all kinds of activities that can distract their attention from traffic, like listening to music, conducting a conversation on their mobile phone, or texting. Distraction has negative effects on traffic behaviour. Most studies estim

  14. Road Traffic in China

    NARCIS (Netherlands)

    Jie, L.; Van Zuylen, H.J.

    2014-01-01

    Traffic is tightly related to the social and economic development in a country. In China the development of the economy has been very fast in the past 30 years and this is still continuing. The transport infrastructure shows a similar pattern, while traffic is also rapidly growing. In urban areas th

  15. Controlled Traffic Farming

    OpenAIRE

    Controlled Traffic Farming Europe

    2011-01-01

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

  16. Visualization of Traffic Accidents

    Science.gov (United States)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  17. On Bandwidth Characteristics of Tuning Fork Micro-Gyroscope with Mechanically Coupled Sense Mode

    Directory of Open Access Journals (Sweden)

    Yunfang Ni

    2014-07-01

    Full Text Available The bandwidth characteristics of a tuning fork micro-gyroscope with mechanically coupled sense mode were investigated in this paper to provide some references for mechanical bandwidth design. The concept of sense mode mechanical coupling is introduced first. Theoretical frequency response analyses were then carried out on the mechanical part of the gyroscope. Equations representing the relationships between the differential output signal and the frequency of the input angular rate were deduced in full frequency range and further simplified in low frequency range. Based on these equations, bandwidth characteristics under ideal and non-ideal conditions are discussed. Analytical results show that under ideal conditions, the bandwidth characteristics of a tuning fork micro-gyroscope are similar to those of a single mass micro-gyroscope, but under non-ideal conditions, especially when sense mass and/or stiffness are asymmetric, the bandwidth characteristics would be quite different because the in-phase mode would participate in the anti-phase vibration response. Experimental verifications were carried out on two micro-gyroscope prototypes designed in our laboratory. The deduced equations and analytical results can be used in guiding the mechanical bandwidth design of tuning fork micro-gyroscopes with mechanically coupled sense mode.

  18. Experimental studies of bandwidth and power production in a three-cavity, 35 GHz gyroklystron amplifier

    Science.gov (United States)

    Calame, J. P.; Garven, M.; Choi, J. J.; Nguyen, K.; Wood, F.; Blank, M.; Danly, B. G.; Levush, B.

    1999-01-01

    The operating characteristics of a three-cavity, Ka-Band gyroklystron employing a large amount of stagger-tuning are reported. Particular attention is given to examining how the frequency response (peak power, bandwidth, and overall shape) is altered by changes in operating parameters. A peak power of 225 kW at 34.90 GHz, with a 2 μs pulse length, 32% efficiency, 30.3 dB saturated gain, and a 3 dB bandwidth of 0.82% (286 MHz) was obtained with a 70.2 kV, 10.0 A beam at a magnetic field of 13.07 kG. This operating point represents a compromise between the output power and the bandwidth. The operating magnetic field was found to have a dramatic influence on the power-bandwidth tradeoff; a lower field of 12.91 kG produced 245 kW with 0.63% bandwidth, while a higher field of 13.39 kG increased the bandwidth to 0.94% at a lower power of 200 kW. The results are in excellent agreement with large signal simulations.

  19. Performance Analysis for Bandwidth Allocation in IEEE 802.16 Broadband Wireless Networks using BMAP Queueing

    CERN Document Server

    Kafhali, Said El; Hanini, Mohamed; Haqiq, Abdelkrim; 10.5121/ijwmn.2012.4110

    2012-01-01

    This paper presents a performance analysis for the bandwidth allocation in IEEE 802.16 broadband wireless access (BWA) networks considering the packet-level quality-of-service (QoS) constraints. Adaptive Modulation and Coding (AMC) rate based on IEEE 802.16 standard is used to adjust the transmission rate adaptively in each frame time according to channel quality in order to obtain multiuser diversity gain. To model the arrival process and the traffic source we use the Batch Markov Arrival Process (BMAP), which enables more realistic and more accurate traffic modelling. We determine analytically different performance parameters, such as average queue length, packet dropping probability, queue throughput and average packet delay. Finally, the analytical results are validated numerically.

  20. Performance Analysis for Bandwidth Allocation in IEEE 802.16 Broadband Wireless Networks using BMAP Queueing

    Directory of Open Access Journals (Sweden)

    Said EL KAFHALI

    2012-03-01

    Full Text Available This paper presents a performance analysis for the bandwidth allocation in IEEE 802.16 broadband wireless access (BWA networks considering the packet-level quality-of-service (QoS constraints. Adaptive Modulation and Coding (AMC rate based on IEEE 802.16 standard is used to adjust the transmission rate adaptively in each frame time according to channel quality in order to obtain multiuser diversity gain. To model the arrival process and the traffic source we use the Batch Markov Arrival Process (BMAP, which enables more realistic and more accurate traffic modelling. We determine analytically different performance parameters, such as average queue length, packet dropping probability, queue throughput and average packet delay. Finally, the analytical results are validated numerically.

  1. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... light solvency stress test system introduced by the Danish Financial Supervisory Authority (DFSA) in June 2001. This monitoring system requires L&P companies to submit regular reports documenting the sensitivity of the companies' base capital to certain pre-defined market shocks - the red and yellow...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  2. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    2007-01-01

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... light solvency stress test system introduced by the Danish Financial Supervisory Authority (DFSA) in June 2001. This monitoring system requires L&P companies to submit regular reports documenting the sensitivity of the companies' base capital to certain pre-defined market shocks - the red and yellow...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  3. Synchronization of Traffic Light Systems for Maximum Efficiency along Jalan Bukit Gambier, Penang, Malaysia

    Directory of Open Access Journals (Sweden)

    Ahmad Rafidi M.A.

    2014-01-01

    Full Text Available The synchronization of traffic light systems is one of the best solutions in order to avoid problematic traffic jams. Traffic timing is a major concern when it comes to traffic management. One of the common causes of traffic jams is because of nonsynchronized traffic light systems. Once a light turns green, traffic begins to move, but by the time the moving traffic reaches the next light, the signal is still red. This will disrupt the continuity of the traffic flow, especially for large main roads. The smooth flow of traffic on main routes is important to clear dense traffic in a given time. This study examined the density of vehicles on Jalan Bukit Gambier and also the traffic timing was documented in order to plan out proper re-timing for traffic lights along the studied road. The outcomes of this study support the hypothesis that retiming traffic lights to create a synchronized traffic light system for main roads will greatly improve traffic flow.

  4. Multi-Layer Traffic Steering

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Gimenez, Lucas Chavarria; Viering, Ingo; Sartori, Cinzia; Lobinger, Andreas; Pedersen, Klaus I.

    2013-01-01

    This paper investigates the potentials of traffic steering in the Radio Resource Control (RRC) Idle state by evaluating the Absolute Priorities (AP) framework in a multilayer Long Term Evolution (LTE) macrocell scenario. Frequency priorities are broadcast on the system information and RRC Idle...... signaling. The priority adjustment is based on both the Composite Available Capacity (CAC) and the radio conditions of the candidate layers. Compared to broadcast AP, the proposed scheme achieves better load balancing performance and improves network capacity, given that the User Equipment (UE) inactivity...

  5. Abnormal traffic flow data detection based on wavelet analysis

    Directory of Open Access Journals (Sweden)

    Xiao Qian

    2016-01-01

    Full Text Available In view of the traffic flow data of non-stationary, the abnormal data detection is difficult.proposed basing on the wavelet analysis and least squares method of abnormal traffic flow data detection in this paper.First using wavelet analysis to make the traffic flow data of high frequency and low frequency component and separation, and then, combined with least square method to find abnormal points in the reconstructed signal data.Wavelet analysis and least square method, the simulation results show that using wavelet analysis of abnormal traffic flow data detection, effectively reduce the detection results of misjudgment rate and false negative rate.

  6. DBAS: A Deployable Bandwidth Aggregation System

    CERN Document Server

    Habak, Karim; Harras, Khaled A

    2012-01-01

    The explosive increase in data demand coupled with the rapid deployment of various wireless access technologies have led to the increase of number of multi-homed or multi-interface enabled devices. Fully exploiting these interfaces has motivated researchers to propose numerous solutions that aggregate their available bandwidths to increase overall throughput and satisfy the end-user's growing data demand. These solutions, however, have faced a steep deployment barrier that we attempt to overcome in this paper. We propose a Deployable Bandwidth Aggregation System (DBAS) for multi-interface enabled devices. Our system does not introduce any intermediate hardware, modify current operating systems, modify socket implementations, nor require changes to current applications or legacy servers. The DBAS architecture is designed to automatically estimate the characteristics of applications and dynamically schedule various connections or packets to different interfaces. Since our main focus is deployability, we fully i...

  7. Reconstitution of Low Bandwidth Reaction History

    International Nuclear Information System (INIS)

    The goal of the Test Readiness Program is to transition to a 24 month test readiness posture and if approved move to an 18-month posture. One of the key components of the Test Readiness Program necessary to meet this goal is the reconstitution of the important diagnostics. Since the end of nuclear testing, the ability to field diagnostics on a nuclear test has deteriorated. Reconstitution of diagnostics before those who had experience in nuclear testing either retire or leave is essential to achieving a shorter test readiness posture. Also, the data recording systems have not been used since the end of testing. This report documents the reconstitution of one vital diagnostic: the low bandwidth reaction history diagnostic for FY04. Reaction history is one of the major diagnostics that has been used on all LLNL and LANL tests since the early days of nuclear testing. Reaction history refers to measuring the time history of the gamma and neutron output from a nuclear test. This gives direct information on the nuclear reactions taking place in the device. The reaction history measurements are one of the prime measurements the nuclear weapon scientists use to validate their models of device performance. All tests currently under consideration require the reaction history diagnostic. Thus moving to a shorter test readiness posture requires the reconstitution of the ability to make reaction history measurements. Reconstitution of reaction history was planned to be in two steps. Reaction history measurements that have been used in the past can be broadly placed into two categories. The most common type of reaction history and the one that has been performed on virtually all nuclear tests is termed low bandwidth reaction history. This measurement has a time response that is limited by the bandpass of kilometer length coaxial cables. When higher bandwidth has been required for specific measurements, fiber optic techniques have been used. This is referred to as high-bandwidth

  8. Large-bandwidth planar photonic crystal waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Lavrinenko, Andrei

    defect has appropriate dispersion properties relative to the photonic crystal slab material surrounding the line defect. A three-dimensional theoretical analysis is given for large-bandwidth waveguide designs based on a silicon-air photonic crystal slab suspended in air. In one example, the leakage......A general design principle is presented for making finite-height photonic crystal waveguides that support leakage-free guidance of light over large frequency intervals. The large bandwidth waveguides are designed by introducing line defects in photonic crystal slabs, where the material in the line......-free single-mode guidance is found for a large frequency interval covering 60% of the photonic band-gap....

  9. Maximum-Bandwidth Node-Disjoint Paths

    Directory of Open Access Journals (Sweden)

    Mostafa H. Dahshan

    2012-03-01

    Full Text Available This paper presents a new method for finding the node-disjoint paths with maximum combined bandwidth in communication networks. This problem is an NP-complete problem which can be optimally solved in exponential time using integer linear programming (ILP. The presented method uses a maximum-cost variant of Dijkstra algorithm and a virtual-node representation to obtain the maximum-bandwidth node-disjoint path. Through several simulations, we compare the performance of our method to a modern heuristic technique and to the ILP solution. We show that, in a polynomial execution time, our proposed method produces results that are almost identical to ILP in a significantly lower execution time

  10. Dynamic Wavelength and Bandwidth Allocation Using Adaptive Linear Prediction in WDM/TDM Ethernet Passive Optical Networks

    Institute of Scientific and Technical Information of China (English)

    LU Yi-yi; GUO Yong; HE Chen

    2009-01-01

    Hybrid wavelength-division-multiplexing (WDM)/time-division-multiplexing (TDM) ethernet passive optical networks (EPONs) can achieve low per-subscriber cost and scalability to increase the number of subscribers. This paper discusses dynamic wavelength and bandwidth allocation (DWBA) algorithm in hybrid WDM/TDM EPONs. Based on the correlation structure of the variable bit rate (VBR) video traffic, we propose a quality-of-service (QoS) supported DWBA using adaptive linear traffic prediction. Wavelength and timeslot are allocated dynamically by optical line terminal (OLT) to all optical network units (ONUs) based on the bandwidth requests and the guaranteed service level agreements (SLA) of all ONUs. Mean square error of the predicted average arriv-ing rate of compound video traffic during waiting period is minimized through Wiener-Hopf equation. Simulation results show that the DWBA-adaptive-linear-prediction (DWBA-ALP) algorithm can significantly improve the QoS performances in terms of low delay and high bandwidth utilization.

  11. Digital demodulator for wide bandwidth SAR

    DEFF Research Database (Denmark)

    Jørgensen, Jørn Hjelm

    2000-01-01

    A novel approach to the design of efficient digital quadrature demodulators for wide bandwidth SAR systems is described. Efficiency is obtained by setting the intermediate frequency to 1/4 the ADC sampling frequency. One channel is made filter-free by synchronizing the local oscillator with the...... output decimator. The filter required by the other channel is optimized through global search using the system level performance metrics integrated sidelobe level ratio (ISLR) and peak sidelobe level ratio (PSLR)....

  12. Creating memory bandwidth contention with best intentions

    OpenAIRE

    Chiramel, George John

    2016-01-01

    Heterogeneous System Architecture (HSA) is a computing system architecture that integrates central processing unit (CPU) and graphics processing unit (GPU) with a shared off-chip main memory. On one hand, sharing the memory reduces the communication latency between CPU and GPU but on the other hand, sharing can lead to contention for shared resources. The programs which execute concurrently on the GPU and CPU cores, share the off-chip memory bandwidth. This sharing can result in contention fo...

  13. Terahertz quantum cascade laser bandwidth prediction

    OpenAIRE

    Agnew, G; Grier, A; Taimre, T; Lim, YL; Ikonic, Z.; Dean, P.; Khanna, SP; Lachab, M.; Valavanis, A.; Cooper, JD; Harrison, P.; Linfield, EH; Davies, AG; D Indjin; Rakic, AD

    2015-01-01

    Recent research shows that terahertz quantum cascade lasers are well-suited to high speed free space communication. The results of both theoretical and laboratory work indicate the devices are able to deliver bandwidths in the gigahertz to tens of gigahertz range without the burden of relaxation oscillations found in diode lasers. Using a novel rate equation model we explore the frequency response characteristics of a real device and report on the finding of a strongly peaked bias current-dep...

  14. Measuring Bandwidth for Super Computer Workloads

    OpenAIRE

    Madheswari, A. Neela; Banu, R. S. D. Wahida

    2010-01-01

    Parallel computing plays a major role in almost all the fields from research to major concern problem solving purposes. Many researches are till now focusing towards the area of parallel processing. Nowadays it extends its usage towards the end user application such as GPU as well as multi-core processor development. The bandwidth measurement is essential for resource management and for studying the various performance factors of the existing super computer systems which will be helpful for b...

  15. Improvement on Diversity Gain with Filter Bandwidth Enlargement in Fractional Sampling OFDM Receiver

    Science.gov (United States)

    Shinkai, Toshiya; Nishimura, Haruki; Sanada, Yukitoshi

    A diversity scheme with Fractional Sampling (FS) in an OFDM receiver has been investigated recently. Through FS, it is possible to separate multipath components and obtain diversity gain in OFDM systems. Enlargement of the bandwidth of the total frequency response between transmit and receive baseband filters allows the FS scheme to achieve path diversity. However, the transmit filter has to be designed according to the spectrum mask of the wireless standards such as IEEE802.11a/g to avoid interference to the other communication systems and the frequency response of the composite channel including the transmit and receive filters has often been set to minimal bandwidth to eliminate adjacent channel signals. In order to achieve the maximum signal-to-noise ratio (SNR), the same filter is commonly used in the transmitter and the receiver. In this paper, the trade-off among the SNR deterioration, adjacent channel interference, and the diversity gain due to the enlargement of the bandwidth of the receive filter is investigated. Numerical results from computer simulations indicate that the BER performance with wider bandwidth in the receiver shows better performance than that with the minimal bandwidth for maximizing the SNR in certain conditions.

  16. Gaussian entanglement distribution with GHz bandwidth

    CERN Document Server

    Ast, Stefan; Mehmet, Moritz; Schnabel, Roman

    2016-01-01

    The distribution of Gaussian entanglement can be used to generate a mathematically-proven secure key for quantum cryptography. The distributed secret key rate is limited by the bandwidth of the nonlinear resonators used for entanglement generation, which is less than 100 MHz for current state-of-the-art setups. The development of an entanglement source with a higher bandwidth promises an increased measurement speed and a linear boost in the secure data rate. Here, we present the experimental realization of a continuous-variable entanglement source with a bandwidth of more than 1.25 GHz. The measured entanglement spectrum was quantified via the inseparability criterion introduced by Duan and coworkers with a critical value of 4 below which entanglement is certified. The measurements yielded an inseparability value of about 1.8 at a frequency of 300 MHz to about 2.8 at 1.2 GHz extending further to about 3.1 at 1.48 GHz. In the experiment we used two 2.6 mm long monolithic PPKTP crystal resonators to generate tw...

  17. An Arterial Signal Coordination Optimization Model for Trams Based on Modified AM-BAND

    Directory of Open Access Journals (Sweden)

    Yangfan Zhou

    2016-01-01

    Full Text Available Modern trams are developing fast because of their characteristics like medium capability and energy saving. Exclusive way is always set in practice to avoid interruption from general vehicles, while trams have to stop at intersections frequently due to signal rules in the road network. Therefore, signal optimization has great effects on operational efficiency of trams system. In this paper, an arterial signal coordination optimization model is proposed for trams progression based on the Asymmetrical Multi-BAND (AM-BAND method. The AM-BAND is modified from the following aspects. Firstly, BAM-BAND is developed by supplementing active bandwidth constraints to AM-BAND. Assisted by the IBM ILOG CPLEX Optimization Studio, two arterial signals plans with eight intersections are achieved from AM-BAND and BAM-BAND for comparison. Secondly, based on the modified BAM-BAND, a BAM-TRAMBAND model is presented, which incorporates three constraints regarding tram operations, including dwell time at stations, active signal priority, and minimum bandwidth value. The case study and VISSIM simulation results show that travel times of trams decrease with signal plan from BAM-TRAMBAND comparing with the original signal plan. Moreover, traffic performance indicators such as stops and delay are improved significantly.

  18. Distributed learning and multi-objectivity in traffic light control

    Science.gov (United States)

    Brys, Tim; Pham, Tong T.; Taylor, Matthew E.

    2014-01-01

    Traffic jams and suboptimal traffic flows are ubiquitous in modern societies, and they create enormous economic losses each year. Delays at traffic lights alone account for roughly 10% of all delays in US traffic. As most traffic light scheduling systems currently in use are static, set up by human experts rather than being adaptive, the interest in machine learning approaches to this problem has increased in recent years. Reinforcement learning (RL) approaches are often used in these studies, as they require little pre-existing knowledge about traffic flows. Distributed constraint optimisation approaches (DCOP) have also been shown to be successful, but are limited to cases where the traffic flows are known. The distributed coordination of exploration and exploitation (DCEE) framework was recently proposed to introduce learning in the DCOP framework. In this paper, we present a study of DCEE and RL techniques in a complex simulator, illustrating the particular advantages of each, comparing them against standard isolated traffic actuated signals. We analyse how learning and coordination behave under different traffic conditions, and discuss the multi-objective nature of the problem. Finally we evaluate several alternative reward signals in the best performing approach, some of these taking advantage of the correlation between the problem-inherent objectives to improve performance.

  19. Modeling of urban traffic networks with lattice Boltzmann model

    Science.gov (United States)

    Meng, Jian-ping; Qian, Yue-hong; Dai, Shi-qiang

    2008-02-01

    It is of great importance to uncover the characteristics of traffic networks. However, there have been few researches concerning kinetics models for urban traffic networks. In this work, a lattice Boltzmann model (LBM) for urban traffic networks is proposed by incorporating the ideas of the Biham-Middleton-Levine (BML) model into the LBM for road traffic. In the present model, situations at intersections with the red and green traffic signals are treated as a kind of boundary conditions varying with time. Thus, the urban traffic network could be described in the mesoscopic level. By performing numerical simulations under the periodic boundary conditions, the behavior of average velocity is investigated in detail. The numerical results agree quite well with those given by the Chowdhury-Schadschneider (ChSch) model (Chowdhury D. and Schadschneider A., Phys. Rev. E, 59 (1999) R1311). Furthermore, the statistical noise is reduced in this discrete kinetics model, thus, the present model has considerably high computational efficiency.

  20. Analysis of Dynamic Road Traffic Congestion Control (DRTCC Techniques

    Directory of Open Access Journals (Sweden)

    Pardeep Mittal

    2015-10-01

    Full Text Available : Dynamic traffic light control at intersection has become one of the most active research areas to develop the Dynamic transportation systems (ITS. Due to the consistent growth in urbanization and traffic congestion, such a system was required which can control the timings of traffic lights dynamically with accurate measurement of traffic on the road. In this paper, analysis of all the techniques that has been developed to automate the traffic lights has been done.. The efficacy of all the techniques has been evaluated, using MATLAB software. After comparison of artificial intelligent techniques , it is found that image mosaicking technique is quite effective (in terms of improving moving time and reducing waiting time for the control of the traffic signals to control congestion on the road.

  1. Characterization of P2P IPTV Traffic: Scaling Analysis

    CERN Document Server

    Silverston, Thomas; Salamatian, Kave

    2007-01-01

    P2P IPTV applications arise on the Internet and will be massively used in the future. It is expected that P2P IPTV will contribute to increase the overall Internet traffic. In this context, it is important to measure the impact of P2P IPTV on the networks and to characterize this traffic. During the 2006 FIFA World Cup, we performed an extensive measurement campaign. We measured network traffic generated by broadcasting soccer games by the most popular P2P IPTV applications, namely PPLive, PPStream, SOPCast and TVAnts. From the collected data, we characterized the P2P IPTV traffic structure at different time scales. To the best of our knowledge, this is the first work, which presents a complete multiscale analysis of the P2P IPTV traffic. Our observations show that the network traffic has not the same scale behavior whether the applications use TCP or UDP. For all the applications, the download traffic is different from the upload traffic and the signaling traffic has an impact on the download traffic.

  2. Plasticity in the vocalizations of anurans in response to traffic noise

    Science.gov (United States)

    Cunnington, Glenn M.; Fahrig, Lenore

    2010-09-01

    Many species use acoustic signals to attract mates, and such signals can be degraded by anthropogenic noise. Anuran abundance has been shown to be negatively correlated with road traffic which could be due in part to the interruption of mate attraction by traffic noise. However, this impact could be small if anurans can alter their vocalization characteristics to avoid masking of their calls by traffic noise. We predicted that: (i) anuran vocalization characteristics (dominant frequency, mean amplitude and call rate) should be different in areas with different traffic noise levels; (ii) increases in traffic noise can cause immediate changes in amphibian vocalization characteristics; (iii) these altered vocalizations are similar to those at high traffic sites. To test the first prediction we compared vocalizations of four species of anuran at breeding sites in locations with low traffic noise vs. sites with high traffic noise. For the second prediction we broadcast traffic noise at low traffic (quiet) sites, and compared the anuran vocalizations before vs. during the broadcast traffic noise. For the third prediction we compared vocalizations at high traffic sites to those produced at low traffic sites while broadcasting traffic noise. Three species of anurans found at locations with low traffic noise produced vocalizations with different characteristics than individuals of the same species found in locations with high traffic noise. Broadcast traffic noise immediately altered amphibian vocalization characteristics such that they became similar to those of the same species found in locations with high traffic noise. We conclude that plasticity in the vocalizations of anurans allows for the maintenance of acoustic communication in the presence of traffic noise.

  3. MCMC simulation of GARCH model to forecast network traffic load

    Directory of Open Access Journals (Sweden)

    Akhter Raza Syed

    2012-05-01

    Full Text Available The performance of a computer network can be enhanced by increasing number of servers, upgrading the hardware, and gaining additional bandwidth but this solution require the huge amount to invest. In contrast to increasing the bandwidth and hardware resources, network traffic modeling play a significant role in enhancing the network performance. As the emphasis of telecommunication service providers shifted towards the high-speed networks providing integrated services at a prescribed Quality of Service (QoS, the role of accurate traffic models in network design and network simulation becomes ever more crucial. We analyze a traffic volume time series of internet requests made to a workstation. This series exhibits a long-range dependence and self-similarity in large time scale and exhibits multifractal in small time scale. In this paper, for this time series, we proposed Generalized Autoregressive Conditional Heteroscedastic, (GARCH model, and practical techniques for model fitting, Markov Chain Monte Carlo simulation and forecasting issues are demonstrated. The proposed model provides us simple and accurate approach for simulating internet data traffic patterns.

  4. FPGA-Based Filterbank Implementation for Parallel Digital Signal Processing

    Science.gov (United States)

    Berner, Stephan; DeLeon, Phillip

    1999-01-01

    One approach to parallel digital signal processing decomposes a high bandwidth signal into multiple lower bandwidth (rate) signals by an analysis bank. After processing, the subband signals are recombined into a fullband output signal by a synthesis bank. This paper describes an implementation of the analysis and synthesis banks using (Field Programmable Gate Arrays) FPGAs.

  5. VBR video traffic models

    CERN Document Server

    Tanwir, Savera

    2014-01-01

    There has been a phenomenal growth in video applications over the past few years. An accurate traffic model of Variable Bit Rate (VBR) video is necessary for performance evaluation of a network design and for generating synthetic traffic that can be used for benchmarking a network. A large number of models for VBR video traffic have been proposed in the literature for different types of video in the past 20 years. Here, the authors have classified and surveyed these models and have also evaluated the models for H.264 AVC and MVC encoded video and discussed their findings.

  6. Road Traffic Injuries

    Institute of Scientific and Technical Information of China (English)

    WANG Zheng-guo

    2005-01-01

    @@ As everybody knows that automobiles have been greatly changing our life. However, everything has two sides, motor vehicles have also caused a huge number of people's deaths, injuries and property damage. Traffic crashes are perhaps the number one public health problem in developed countries [1]. In the United States, pre-retirement years of life lost in traffic crashes are more than that of the two combined leading diseases: cancer and heart disease [1]. Today road traffic crash (RTC) ranks 11th in leading cause of death and accounts for 2.1% of all deaths globally.

  7. Revisiting multifractality of TCP traffic using multifractal detrended fluctuation analysis

    International Nuclear Information System (INIS)

    Understanding the characteristics of network traffic is critical to many network design and engineering problems, such as router buffer dimensioning and delay-sensitive service provisioning in the Internet backbone. We re-analyze the multifractal features of TCP traffic collections spanning 19 years by means of multifractal detrended fluctuation analysis. Through multifractal analysis, the generalized Hurst exponents and scaling exponents are derived. These results indicate that the TCP traffic is multifractal. The widths of the singularity spectrum show that the multifractal features of TCP traffic are weakened with increasing bandwidth and statistical multiplexing, but cannot be eliminated. In particular, comparing the generalized Hurst exponent of the original TCP traffic series with the shuffled and surrogate series, we conclude that the multifractal nature of TCP traffic is due to both long-range correlation and fat-tailed probability distributions. Moreover, the results show that the multifractality due to the correlation has a greater contribution than that from a fat-tailed probability distribution. (paper)

  8. ECG feature extraction based on the bandwidth properties of variational mode decomposition.

    Science.gov (United States)

    Mert, Ahmet

    2016-04-01

    It is a difficult process to detect abnormal heart beats, known as arrhythmia, in long-term ECG recording. Thus, computer-aided diagnosis systems have become a supportive tool for helping physicians improve the diagnostic accuracy of heartbeat detection. This paper explores the bandwidth properties of the modes obtained using variational mode decomposition (VMD) to classify arrhythmia electrocardiogram (ECG) beats. VMD is an enhanced version of the empirical mode decomposition (EMD) algorithm for analyzing non-linear and non-stationary signals. It decomposes the signal into a set of band-limited oscillations called modes. ECG signals from the MIT-BIH arrhythmia database are decomposed using VMD, and the amplitude modulation bandwidth B AM, the frequency modulation bandwidth B FM and the total bandwidth B of the modes are used as feature vectors to detect heartbeats such as normal (N), premature ventricular contraction (V), left bundle branch block (L), right bundle branch block (R), paced beat (P) and atrial premature beat (A). Bandwidth estimations based on the instantaneous frequency (IF) and amplitude (IA) spectra of the modes indicate that the proposed VMD-based features have sufficient class discrimination capability regarding ECG beats. Moreover, the extracted features using the bandwidths (B AM, B FM and B) of four modes are used to evaluate the diagnostic accuracy rates of several classifiers such as the k-nearest neighbor classifier (k-NN), the decision tree (DT), the artificial neural network (ANN), the bagged decision tree (BDT), the AdaBoost decision tree (ABDT) and random sub-spaced k-NN (RSNN) for N, R, L, V, P, and A beats. The performance of the proposed VMD-based feature extraction with a BDT classifier has accuracy rates of 99.06%, 99.00%, 99.40%, 99.51%, 98.72%, 98.71%, and 99.02% for overall, N-, R-, L-, V-, P-, and A-type ECG beats, respectively. PMID:26987295

  9. Optimization of TTEthernet Networks to Support Best-Effort Traffic

    DEFF Research Database (Denmark)

    Tamas-Selicean, Domitian; Pop, Paul

    2014-01-01

    This paper focuses on the optimization of the TTEthernet communication protocol, which offers three traffic classes: time-triggered (TT), sent according to static schedules, rate-constrained (RC) that has bounded end-to-end latency, and best-effort (BE), the classic Ethernet traffic, with no timing...... guarantees. In our earlier work we have proposed an optimization approach named DOTTS that performs the routing, scheduling and packing / fragmenting of TT and RC messages, such that the TT and RC traffic is schedulable. Although backwards compatibility with classic Ethernet networks is one of TTEthernet......’s strong points, there is little research on this topic. However, in this paper, we extend our DOTTS optimization approach to optimize TTEthernet networks, such that not only the TT and RC messages are schedulable, but we also maximize the available bandwidth for BE messages. The proposed optimization has...

  10. Reducing Network Traffic of Token Protocol Using Sharing Relation Cache

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Token protocol provides a new coherence framework for shared-memory multiprocessor systems.It avoids indirections of directory protocols for common cache-to-cache transfer misses, and achieves higher interconnect bandwidth and lower interconnect latency compared with snooping protocols. However, the broadcasting increases network traffic, limiting the scalability of token protocol. This paper describes an efficient technique to reduce the token protocol network traffic, called sharing relation cache. This cache provides destination set information for cache-to-cache miss requests by caching directory information for recent shared data. This paper introduces how to implement the technique in a token protocol. Simulations using SPLASH-2 benchmarks show that in a 16-core chip multiprocessor system, the cache reduced the network traffic by 15% on average.

  11. Two dimensional mixed traffic flow considering the transit traffic

    OpenAIRE

    Lingjiang Kong; Junhui Hu; Li Yang

    2012-01-01

    Based on the two-dimension cellular automaton traffic flow model (BML model), a mixed traffic flow model for urban traffic considering the transit traffic is established in this paper by using the Don't block the box rules. We have investigated the influences of the transit traffic ratio, and found that, in most cases, the urban traffic flow exhibited jam phase. Moreover, focusing on the traffic lights cycle, it is found that the average flow has the periodic fluctuation phenomenon, and we ha...

  12. Dynamic Bandwidth Allocation Strategy for Marine VHF Communications

    OpenAIRE

    Ding Yuan-Ming; Zhang Fang

    2013-01-01

    In order to achieve the efficient management of marine VHF communications bandwidth resources under the battlefield environment and to maximize the bandwidth utilization while ensuring high-priority business access channel, the context puts forward a kind of dynamic bandwidth allocation strategy based on business priorities. When the bandwidth resources are sufficient, the system can accommodate more business, otherwise it can call the dynamic allocation st...

  13. Vehicular Traffic Flow Controlled by Traffic Light on a Street with Open Boundaries

    Science.gov (United States)

    Mhirech, Abdelaziz; Ismaili, Assia Alaoui

    2013-08-01

    The Nagel-Schreckenberg (NS) cellular automata (CA) model for describing the vehicular traffic flow in a street with open boundaries is studied. To control the traffic flow, a traffic signalization light operating for a fixed-time scheme is placed in the middle of the street. Extensive Monte Carlo simulations are carried out to calculate various model characteristics. Essentially, we investigate the formation of the cars queue behind traffic light dependence on the duration of green light Tg, injecting and extracting probabilities α and β, respectively. Two phases of average training queues were found. Besides, the dependence of car accident probability per site and per time step on Tg, α and β is computed.

  14. Self-learning traffic signal control method of isolated intersection combining Q-learning and fuzzy logic%结合Q学习和模糊逻辑的单路口交通信号自学习控制方法

    Institute of Scientific and Technical Information of China (English)

    何兆成; 佘锡伟; 杨文臣; 陈宁宁

    2011-01-01

    To address the dynamics and uncertainty in unban transportation system, this paper proposed a traffic signal control system based on reinforcement learning, which was suitable for real-time control in isolated intersection.The proposed method was capable of online learning through a combination of BP neural network and Q-learning algorithm.Furthermore, due to the multi-objective property in traffic signal control, this paper developed a reward design method for Q-learning based on fuzzy logic.Conducted simulated experiments in three traffic scenarios, using the Paramics microscopic traffic simulation software.Experimental results show that the proposed method has high control efficiency in different traffic scenarios, and is significantly better than fixed timing control method.%针对城市交通系统的动态性和不确定性,提出了基于强化学习的信号交叉口智能控制系统结构,对单交叉口动态实时控制进行了研究.将BP神经网络与Q学习算法相结合实现了路口的在线学习.同时,针对交通信号控制的多目标评价特征,采用基于模糊逻辑的Q学习奖惩信号设计方法,实施对交通信号的优化控制.最后,在三种交通场景下,应用Paramics微观交通仿真软件对典型十字路口进行仿真实验.结果表明,该方法对不同交通场景下的突变仍可保持较高的控制效率,控制效果明显优于定时控制.

  15. A large bandwidth photonic delay line using passive cascaded silicon-on-insulator microring resonators

    International Nuclear Information System (INIS)

    This paper investigated the design and the characterization of a photonic delay line based on passive cascaded silicon-on-insulator (SOI) microrings. We considered the compromise of group delay, bandwidth and insertion loss. A 3-stage double channel side-coupled integrated spaced sequence of resonator (SCISSOR) device was optimized by shifting the resonance of each microring and fabricated with electron beam lithography and dry etching. The group delay was measured to be 17 ps for non-return-to-zero signals at different bit rates and the bandwidth of 78 GHz was achieved. The experiment result agreed well with our simulation. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  16. Coherence bandwidth characterization in an urban microcell at 62.4 GHz

    DEFF Research Database (Denmark)

    Sánchez, M. G.; Hammoudeh, A. M.; Grindrod, E.;

    2000-01-01

    Results of experiments made at 62.4 GHz in an urban mobile radio environment to characterize the coherence bandwidth are presented. The correlation coefficients between signal envelopes separated in frequency are measured and expressed as functions of distance from the base station. Due to the hi...... this parameter from the frequency correlation function obtained at each position may yield incorrect results. The coherence bandwidths for correlation levels of 0.5, 0.7, and 0.9 are given. A ray-tracing tool has been used to assist in interpreting experimental results....

  17. Plastic straw: future of high-speed signaling

    Science.gov (United States)

    Song, Ha Il; Jin, Huxian; Bae, Hyeon-Min

    2015-11-01

    The ever-increasing demand for bandwidth triggered by mobile and video Internet traffic requires advanced interconnect solutions satisfying functional and economic constraints. A new interconnect called E-TUBE is proposed as a cost-and-power-effective all-electrical-domain wideband waveguide solution for high-speed high-volume short-reach communication links. The E-TUBE achieves an unprecedented level of performance in terms of bandwidth-per-carrier frequency, power, and density without requiring a precision manufacturing process unlike conventional optical/waveguide solutions. The E-TUBE exhibits a frequency-independent loss-profile of 4 dB/m and has nearly 20-GHz bandwidth over the V band. A single-sideband signal transmission enabled by the inherent frequency response of the E-TUBE renders two-times data throughput without any physical overhead compared to conventional radio frequency communication technologies. This new interconnect scheme would be attractive to parties interested in high throughput links, including but not limited to, 100/400 Gbps chip-to-chip communications.

  18. Traffic Accident Prediction Model Implementation in Traffic Safety Management

    OpenAIRE

    Wen, Keyao

    2009-01-01

    As one of the highest fatalities causes, traffic accidents and collisions always requires a large amounteffort to be reduced or prevented from occur. Traffic safety management routines therefore always needefficient and effective implementation due to the variations of traffic, especially from trafficengineering point of view apart from driver education.Traffic Accident Prediction Model, considered as one of the handy tool of traffic safety management,has become of well followed with interest...

  19. 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.

  20. Study on a self-similar traffic shaping mechanism with QoS in transport networks

    Science.gov (United States)

    Bo, Mingxia; Lee, Peiyuan; Pan, Xiaofei; Gu, Wanyi

    2005-11-01

    Due to easy realization and high bandwidth utilization, SDH/WDM technology becomes the important way to carry IP traffic over the backbone network. On the other hand, the feature of the data traffic which is much different from the voice traffic is dynamic, burst and self-similar, and many proofs show that the self-similar traffic can lead to some adverse effects on the network performance due to the property of long-range dependence (LRD). For this reason it is widely recognized that self-similarity of the traffic is a significant problem as far as network engineering is concerned. So any reduction in the degree of self-similarity will be greatly beneficial. One possible strategy for mitigating the deleterious effects of the self-similarity is to reduce the burstiness of the input traffic through traffic shaping function at the edge nodes. According to this scheme, in this paper, we present a new self-similar traffic shaping mechanism with QoS in transport networks, called double threshold algorithm (DTA). Simulation results show that the proposed mechanism can effectively reduce the degree of input self-similar traffic, and performs better in the terms of network packet-loss rate and blocking probability than the non-traffic shaping schemes. At the same time it guarantees good quality of service.

  1. Analytical Derivation of Traffic Patterns in Shared Memory Architectures from Task Graphs

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Sparsø, Jens

    2009-01-01

    by the application modelled by the task graph. In this paper, we present a method for analytically deriving the worst-case traffic pattern when a task graph is mapped to a multiprocessor system-on-chip with a shared memory architecture. We describe the additionally needed information besides the...... dependencies in the task graph in order to derive the traffic pattern. Finally, we construct a simulator that we use to find the actual traffic pattern in a system and compare this to the derived pattern. Results show that our worst-case derivation overestimates the bandwidth by 9% for systems with small...

  2. Turning Traffic Jams to Jelly

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ Beijing, known for having the worst traffic in China, is brewing up a traffic plan with the harshest ever measures to ensure smooth traffic flow as the capital's gridlock during rush hour and private car sales soar. On December 13, the Beijing Municipal Government started soliciting public opinions for a draft plan designed to relieve the city's traffic problems.

  3. Traffic-Adaptive Routing

    OpenAIRE

    Kammenhuber, Nils

    2011-01-01

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

  4. Traffic Management Systems

    OpenAIRE

    Wei Chen; David Levinson

    2004-01-01

    This study uses regression analysis to evaluate long-run traffic management system performance. Three important traffic management systems in the Twin Cities metro area - Ramp Metering, Variable Message Signs (VMS), and Freeway Service Patrol (the Highway Helper Program) were evaluated with multiple regression models to predict link speed and incident rate. We find that ramp meters increase freeway link speed and reduce incident rate. Freeway Service Patrols increase link speed when incidents...

  5. Penalties in traffic.

    OpenAIRE

    2009-01-01

    Traffic offenders are penalized in various ways: fines, (temporary) driving licence suspensions, confiscation of their vehicles, penalty points, mandatory participation in rehabilitation programmes, prison sentences or community service. The aim of penalties is to punish offenders, to protect society and to influence the behaviour of offenders and all citizens (prevention). Many studies have found that the combination of enforcement and penalties prevent the violation of traffic regulations a...

  6. Bandwidth Constrained Multi-interface Networks

    Science.gov (United States)

    D'Angelo, Gianlorenzo; di Stefano, Gabriele; Navarra, Alfredo

    In heterogeneous networks, devices can communicate by means of multiple wired or wireless interfaces. By switching among interfaces or by combining the available interfaces, each device might establish several connections. A connection is established when the devices at its endpoints share at least one active interface. Each interface is assumed to require an activation cost, and provides a communication bandwidth. In this paper, we consider the problem of activating the cheapest set of interfaces among a network G = (V,E) in order to guarantee a minimum bandwidth B of communication between two specified nodes. Nodes V represent the devices, edges E represent the connections that can be established. In practical cases, a bounded number k of different interfaces among all the devices can be considered. Despite this assumption, the problem turns out to be NP-hard even for small values of k and Δ, where Δ is the maximum degree of the network. In particular, the problem is NP-hard for any fixed k ≥ 2 and Δ ≥ 3, while it is polynomially solvable when k = 1, or Δ ≤ 2 and k = O(1). Moreover, we show that the problem is not approximable within ηlogB or Ω(loglog|V|) for any fixed k ≥ 3, Δ ≥ 3, and for a certain constant η, unless P={NP}. We then provide an approximation algorithm with ratio guarantee of b max , where b max is the maximum communication bandwidth allowed among all the available interfaces. Finally, we focus on particular cases by providing complexity results and polynomial algorithms for Δ ≤ 2.

  7. Ant traffic rules.

    Science.gov (United States)

    Fourcassié, Vincent; Dussutour, Audrey; Deneubourg, Jean-Louis

    2010-07-15

    Many animals take part in flow-like collective movements. In most species, however, the flow is unidirectional. Ants are one of the rare group of organisms in which flow-like movements are predominantly bidirectional. This adds to the difficulty of the task of maintaining a smooth, efficient movement. Yet, ants seem to fare well at this task. Do they really? And if so, how do such simple organisms succeed in maintaining a smooth traffic flow, when even humans experience trouble with this task? How does traffic in ants compare with that in human pedestrians or vehicles? The experimental study of ant traffic is only a few years old but it has already provided interesting insights into traffic organization and regulation in animals, showing in particular that an ant colony as a whole can be considered as a typical self-organized adaptive system. In this review we will show that the study of ant traffic can not only uncover basic principles of behavioral ecology and evolution in social insects but also provide new insights into the study of traffic systems in general. PMID:20581264

  8. Possible Causes & Solutions of Traffic Jam and Their Impact on the Economy of Dhaka City

    OpenAIRE

    Khaled Mahmud; Khonika Gope; Syed Mustafizur Rahman Chowdhury

    2012-01-01

    Dhaka, capital of Bangladesh, is the most densely populated city in the whole world. More than twelve million people live in Dhaka city. Day by day the number is increasing and most part of Dhaka is badly affected by huge traffic jam. Faulty traffic signaling systems, inadequate manpower, narrow road spaces and overtaking tendency of drivers create pro-longed traffic congestions. Due to traffic jam a substantial portion of working hours have to be left on streets which indirectly put adverse ...

  9. Bandwidth Efficient OFDM Transmitter Diversity Techniques

    Directory of Open Access Journals (Sweden)

    King F. Lee

    2004-09-01

    Full Text Available Space-time block-coded orthogonal frequency division multiplexing (OFDM transmitter diversity techniques have been shown to be efficient means of achieving near-optimal diversity gain in frequency-selective fading channels. However, these known techniques all require a cyclic prefix to be added to the transmitted symbols, resulting in bandwidth expansion. In this paper, iterative space-time and space-frequency block-coded OFDM transmitter diversity techniques are proposed that exploit spatial diversity to improve spectral efficiency by eliminating the need for a cyclic prefix.

  10. A Cooperative Traffic Control Strategy

    OpenAIRE

    BORG, Dora Lee; Bhouri, Neila; SCERRI, Kenneth

    2015-01-01

    With one-third of the global population living in cities by 2030 and the need for mobility fueling traffic growth all over the world, the traffic congestion problem in major cities is becoming more and more acute. Besides economic losses, traffic congestion has detrimental effects on our standard of living and on the environment. A viable solution to the traffic congestion problem is intelligent traffic control. The main aim of this work is to test a Model Predictive Control Strategy (MPC) on...

  11. Traffic violation alert and management

    OpenAIRE

    Aliane, Nourdine; Fernández Andrés, Javier; Bemposta Rosende, Sergio; Mata Ortega, Mario

    2011-01-01

    The present paper presents an in-vehicle system for traffic violation alert and management. The system hardware consists of a combination of an on-board computer vision system for traffic sign detection and recognition with a data recorder device for traffic violation alert and management. At present, traffic violations are only focused on three signs: namely speed limit, stop sign, and forbidden turning. The system is designed to warn drivers about potential traffic violations by emitting ac...

  12. Traffic Information System for Hanoi

    OpenAIRE

    Sohr, Alexander; Brockfeld, Elmar; Sauerländer-Biebl, Anke; Melde, Eric

    2016-01-01

    To improve the traffic situation in Hanoi it is necessary to have a good overview of the existing traffic situation and to monitor the development of the traffic over longer time periods. Floating Car Data (FCD) Systems can help to acquire area wide traffic information; here a FCD system based on taxis, busses and motor-cycles is described. It consists of Web and App tools and a Hotspot-Monitoring for long term traffic analysis.

  13. Lock Traffic Signal Stations - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  14. Trajectories for Novel and Detailed Traffic Information

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Torp, Kristian

    2012-01-01

    Trajectories based on GPS tracks have been studied for a number of years but only to a limited degree been used for analyzing and monitoring traffic. This paper shows how novel and important information about traffic can be computed from trajectories. Concretely the paper proposes to compute the...... central metric free-flow speed from trajectories, instead of using point-based measurements such as induction-loops. This free-flow speed is widely used to compute and monitor the congestion level. The paper argues that the actual travel-time is a more accurate metric. The paper suggests a novel approach...... to analyzing individual intersections that enables traffic analysts to compute queue lengths and estimated time to pass an intersection. Finally, the paper uses associative rule mining for evaluating green waves on road stretches. Such information can be used to verify that signalized intersections...

  15. Bandwidth reconfigurable microwave photonic filter based on stimulated Brillouin scattering

    Science.gov (United States)

    Xiao, Yongchuan; Wang, Xin; Zhang, Youdi; Dong, Wei; Zhang, Xindong; Liu, Caixia; Ruan, Shengping; Chen, Weiyou

    2015-01-01

    A bandwidth reconfigurable microwave photonic filter is proposed and numerically analyzed employing Brillouin gain spectrum narrowing and broadening. The stimulated Brillouin scattering (SBS) process is used to convert the phase modulation to intensity modulation to generate filter passband. Due to the fact that the passband is formed by mapping the Brillouin gain spectrum, bandwidth reconfiguration can be implemented by changing Brillouin gain linewidth. In this paper, both bandwidth reduction and increase are included in a single system and the details of gain spectrum narrowing and broadening are demonstrated. Theoretically, nearly 60% bandwidth reduction and hundreds times of bandwidth increase are achieved as compared to the case without gain spectrum process.

  16. Maximum Bandwidth Enhancement of Current Mirror using Series-Resistor and Dynamic Body Bias Technique

    Directory of Open Access Journals (Sweden)

    V. Niranjan

    2014-09-01

    Full Text Available This paper introduces a new approach for enhancing the bandwidth of a low voltage CMOS current mirror. The proposed approach is based on utilizing body effect in a MOS transistor by connecting its gate and bulk terminals together for signal input. This results in boosting the effective transconductance of MOS transistor along with reduction of the threshold voltage. The proposed approach does not affect the DC gain of the current mirror. We demonstrate that the proposed approach features compatibility with widely used series-resistor technique for enhancing the current mirror bandwidth and both techniques have been employed simultaneously for maximum bandwidth enhancement. An important consequence of using both techniques simultaneously is the reduction of the series-resistor value for achieving the same bandwidth. This reduction in value is very attractive because a smaller resistor results in smaller chip area and less noise. PSpice simulation results using 180 nm CMOS technology from TSMC are included to prove the unique results. The proposed current mirror operates at 1Volt consuming only 102 µW and maximum bandwidth extension ratio of 1.85 has been obtained using the proposed approach. Simulation results are in good agreement with analytical predictions.

  17. Multi-path Probabilistic Available Bandwidth Estimation through Bayesian Active Learning

    CERN Document Server

    Thouin, Frederic; Rabbat, Michael

    2010-01-01

    Knowing the largest rate at which data can be sent on an end-to-end path such that the egress rate is equal to the ingress rate with high probability can be very practical when choosing transmission rates in video streaming or selecting peers in peer-to-peer applications. We introduce probabilistic available bandwidth, which is defined in terms of ingress rates and egress rates of traffic on a path, rather than in terms of capacity and utilization of the constituent links of the path like the standard available bandwidth metric. In this paper, we describe a distributed algorithm, based on a probabilistic graphical model and Bayesian active learning, for simultaneously estimating the probabilistic available bandwidth of multiple paths through a network. Our procedure exploits the fact that each packet train provides information not only about the path it traverses, but also about any path that shares a link with the monitored path. Simulations and PlanetLab experiments indicate that this process can dramatical...

  18. Dynamic traffic grooming with Spectrum Engineering (TG-SE) in flexible grid optical networks

    Science.gov (United States)

    Yu, Xiaosong; Zhao, Yongli; Zhang, Jiawei; Wang, Jianping; Zhang, Guoying; Chen, Xue; Zhang, Jie

    2015-12-01

    Flexible grid has emerged as an evolutionary technology to satisfy the ever increasing demand for higher spectrum efficiency and operational flexibility. To optimize the spectrum resource utilization, this paper introduces the concept of Spectrum Engineering in flex-grid optical networks. The sliceable optical transponder has been proposed to offload IP traffic to the optical layer and reduce the number of IP router ports and transponders. We discuss the impact of sliceable transponder in traffic grooming and propose several traffic-grooming schemes with Spectrum Engineering (TG-SE). Our results show that there is a tradeoff among different traffic grooming policies, which should be adopted based on the network operator's objectives. The proposed traffic grooming with Spectrum Engineering schemes can reduce OPEX as well as increase spectrum efficiency by efficiently utilizing the bandwidth variability and capability of sliceable optical transponders.

  19. Bandwidth Estimation For Mobile Ad hoc Network (MANET

    Directory of Open Access Journals (Sweden)

    Rabia Ali

    2011-09-01

    Full Text Available In this paper we presents bandwidth estimation scheme for MANET, which uses some components of the two methods for the bandwidth estimation: 'Hello Bandwidth Estimation 'Listen Bandwidth Estimation. This paper also gives the advantages of the proposed method. The proposed method is based on the comparison of these two methods. Bandwidth estimation is an important issue in the Mobile Ad-hoc Network (MANET because bandwidth estimation in MANET is difficult, because each host has imprecise knowledge of the network status and links change dynamically. Therefore, an effective bandwidth estimation scheme for MANET is highly desirable. Ad hoc networks present unique advanced challenges, including the design of protocols for mobility management, effective routing, data transport, security, power management, and quality-of-service (QoS provisioning. Once these problems are solved, the practical use of MANETs will be realizable.

  20. On Movement of Emergency Services amidst Urban Traffic

    Directory of Open Access Journals (Sweden)

    Manoj Bode

    2015-12-01

    Full Text Available Managing traffic in urban areas is a complex affair. The same becomes more challenging when one needs to take into account the prioritized movement of emergency vehicles along with the normal flow of traffic. Although, mechanisms have been proposed to model intelligent traffic management systems, a concentrated effort to facilitate the movement of emergency services amongst urban traffic is yet to be formalized. This paper proposes a distributed multi-agent based mechanism to create partial green corridors for the movement of emergency service vehicles such as ambulances, fire brigade and police vans, amidst urban traffic. The proposed approach makes se of a digital network of traffic signal nodes equipped with traffic sensors and an agent framework to autonomously extend, maintain and manage partial green corridors for such emergency vehicles. The approach was emulated using Tartarus, an agent framework over a LAN. The results gathered under varying traffic conditions and also several emergency vehicles, validate the performance of this approach and its effects on the movement of normal traffic. Comparisons with the non-prioritized and full green corridor approaches indicate that the proposed partial corridor approach outperforms the rest.

  1. 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.

  2. Bandwidth and Noise in Spatiotemporally Modulated Mueller Matrix Polarimeters

    Science.gov (United States)

    Vaughn, Israel Jacob

    Polarimetric systems design has seen recent utilization of linear systems theory for system descriptions. Although noise optimal systems have been shown, bandwidth performance has not been addressed in depth generally and is particularly lacking for Mueller matrix (active) polarimetric systems. Bandwidth must be considered in a systematic way for remote sensing polarimetric systems design. The systematic approach facilitates both understanding of fundamental constraints and design of higher bandwidth polarimetric systems. Fundamental bandwidth constraints result in production of polarimetric "artifacts" due to channel crosstalk upon Mueller matrix reconstruction. This dissertation analyzes bandwidth trade-offs in spatio-temporal channeled Mueller matrix polarimetric systems. Bandwidth is directly related to the geometric positioning of channels in the Fourier (channel) space, however channel positioning for polarimetric systems is constrained both physically and by design parameters like domain separability. We present the physical channel constraints and the constraints imposed when the carriers are separable between space and time. Polarimetric systems are also constrained by noise performance, and there is a trade-off between noise performance and bandwidth. I develop cost functions which account for the trade-off between noise and bandwidth for spatio-temporal polarimetric systems. The cost functions allow a systems designer to jointly optimize systems with good bandwidth and noise performance. Optimization is implemented for a candidate spatio-temporal system design, and high temporal bandwidth systems resulting from the optimization are presented. Systematic errors which impact the bandwidth performance and mitigation strategies for these systematic errors are also presented. Finally, a portable imaging Mueller matrix system is built and analyzed based on the theoretical bandwidth analysis and system bandwidth optimization. Temporal bandwidth performance is

  3. Traffic resource allocation for complex networks

    International Nuclear Information System (INIS)

    In this paper, an optimal resource allocation strategy is proposed to enhance traffic dynamics in complex networks. The network resources are the total node packet-delivering capacity and the total link bandwidth. An analytical method is developed to estimate the overall network capacity by using the concept of efficient betweenness (ratio of algorithmic betweenness and local processing capacity). Three network structures (scale-free, small-world, and random networks) and two typical routing protocols (shortest path protocol and efficient routing protocol) are adopted to demonstrate the performance of the proposed strategy. Our results show that the network capacity is reversely proportional to the average path length for a particular routing protocol and the shortest path protocol can achieve the largest network capacity when the proposed resource allocation strategy is adopted. (interdisciplinary physics and related areas of science and technology)

  4. Dynamics of TCP traffic over ATM networks

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, S. [Lawrence Berkeley Lab., CA (United States). Information and Computing Sciences Div.; Romanow, A. [Sun Microsystems Inc., Mountain View, CA (United States)

    1994-08-01

    The authors investigate the performance of TCP (Transport Control Protocol) connections over ATM (Asynchronous Transfer Mode) networks without ATM-level congestion control, and compare it to the performance of TCP over packet-based networks. For simulations of congested networks, the effective throughput of TCP over ATM can be quite low when cells are dropped at the congested ATM switch. The low throughput is due to wasted bandwidth as the congested link transmits cells from ``corrupted`` packets, i.e., packets in which at least one cell is dropped by the switch. This fragmentation effect can be corrected and high throughput can be achieved if the switch drops whole packets prior to buffer overflow; they call this strategy Early Packet Discard. They also discuss general issues of congestion avoidance for best-effort traffic in ATM networks.

  5. A Segmented Signal Progression Model for the Modern Streetcar System

    Directory of Open Access Journals (Sweden)

    Baojie Wang

    2015-01-01

    Full Text Available This paper is on the purpose of developing a segmented signal progression model for modern streetcar system. The new method is presented with the following features: (1 the control concept is based on the assumption of only one streetcar line operating along an arterial under a constant headway and no bandwidth demand for streetcar system signal progression; (2 the control unit is defined as a coordinated intersection group associated with several streetcar stations, and the control joints must be streetcar stations; (3 the objective function is built to ensure the two-way streetcar arrival times distributing within the available time of streetcar phase; (4 the available time of streetcar phase is determined by timing schemes, intersection structures, track locations, streetcar speeds, and vehicular accelerations; (5 the streetcar running speed is constant separately whether it is in upstream or downstream route; (6 the streetcar dwell time is preset according to historical data distribution or charging demand. The proposed method is experimentally examined in Hexi New City Streetcar Project in Nanjing, China. In the experimental results, the streetcar system operation and the progression impacts are shown to affect transit and vehicular traffic. The proposed model presents promising outcomes through the design of streetcar system segmented signal progression, in terms of ensuring high streetcar system efficiency and minimizing negative impacts on transit and vehicular traffic.

  6. Durations required to distinguish noise and tone: Effects of noise bandwidth and frequency.

    Science.gov (United States)

    Taghipour, Armin; Moore, Brian C J; Edler, Bernd

    2016-05-01

    Perceptual audio coders exploit the masking properties of the human auditory system to reduce the bit rate in audio recording and transmission systems; it is intended that the quantization noise is just masked by the audio signal. The effectiveness of the audio signal as a masker depends on whether it is tone-like or noise-like. The determination of this, both physically and perceptually, depends on the duration of the stimuli. To gather information that might improve the efficiency of perceptual coders, the duration required to distinguish between a narrowband noise and a tone was measured as a function of center frequency and noise bandwidth. In experiment 1, duration thresholds were measured for isolated noise and tone bursts. In experiment 2, duration thresholds were measured for tone and noise segments embedded within longer tone pulses. In both experiments, center frequencies were 345, 754, 1456, and 2658 Hz and bandwidths were 0.25, 0.5, and 1 times the equivalent rectangular bandwidth of the auditory filter at each center frequency. The duration thresholds decreased with increasing bandwidth and with increasing center frequency up to 1456 Hz. It is argued that the duration thresholds depended mainly on the detection of amplitude fluctuations in the noise bursts. PMID:27250144

  7. Emergent traffic jams

    CERN Document Server

    Nagel, K; Nagel, Kai; Paczuski, Maya

    1995-01-01

    We study a single-lane traffic model that is based on human driving behavior. The outflow from a traffic jam self-organizes to a critical state of maximum throughput. Small perturbations of the outflow far downstream create emergent traffic jams with a power law distribution P(t) \\sim t^{-3/2} of lifetimes, t. On varying the vehicle density in a closed system, this critical state separates lamellar and jammed regimes, and exhibits 1/f noise in the power spectrum. Using random walk arguments, in conjunction with a cascade equation, we develop a phenomenological theory that predicts the critical exponents for this transition and explains the self-organizing behavior. These predictions are consistent with all of our numerical results.

  8. Bandwidth Analysis of Smart Meter Network Infrastructure

    DEFF Research Database (Denmark)

    Balachandran, Kardi; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

    2014-01-01

    Advanced Metering Infrastructure (AMI) is a net-work infrastructure in Smart Grid, which links the electricity customers to the utility company. This network enables smart services by making it possible for the utility company to get an overview of their customers power consumption and also control...... devices in their costumers household e.g. heat pumps. With these smart services, utility companies can do load balancing on the grid by shifting load using resources the customers have. The problem investigated in this paper is what bandwidth require-ments can be expected when implementing such network to...... utilize smart meters and which existing broadband network technologies can facilitate this smart meter service. Initially, scenarios for smart meter infrastructure are identified. The paper defines abstraction models which cover the AMI scenarios. When the scenario has been identified a general overview...

  9. A high-bandwidth spintronic position sensor

    International Nuclear Information System (INIS)

    Position sensing with resolution down to the scale of a single atom is of key importance in nanoscale science and engineering. However, only optical-sensing methods are currently capable of non-contact sensing at such resolution over a high bandwidth. Here, we report a new non-contact, non-optical position-sensing concept based on detecting changes in a high-gradient magnetic field of a microscale magnetic dipole by means of spintronic sensors. Experimental measurements show a sensitivity of up to 40 Ω/μm, a linear range greater than 10 μm and a noise floor of 0.5 pm/√( Hz). Also shown is the use of the sensor for position measurements for closed-loop control of a high-speed atomic force microscope with a frame rate of more than 1 frame/s. (paper)

  10. Traffic Engineering in Metro Ethernet

    Directory of Open Access Journals (Sweden)

    Padmaraj Nair

    2010-05-01

    Full Text Available Traffic engineering is one of the major issues that has to be addressed in Metro Ethernet networks for quality of service and efficient resource utilization. This paper aims at understanding the relevant issues and outlines novel algorithms for multipoint traffic engineering in Metro Ethernet. We present an algorithmic solution for traffic engineering in Metro Ethernet using optimal multiple spanning trees. This iterative approach distributes traffic across the network uniformly without overloading network resources. We also introduce a new traffic specification model for Metro Ethernet, which is a hybrid of two widely used traffic specification models, the pipe and hose models.

  11. Two dimensional mixed traffic flow considering the transit traffic

    Directory of Open Access Journals (Sweden)

    Lingjiang Kong

    2012-12-01

    Full Text Available Based on the two-dimension cellular automaton traffic flow model (BML model, a mixed traffic flow model for urban traffic considering the transit traffic is established in this paper by using the Don't block the box rules. We have investigated the influences of the transit traffic ratio, and found that, in most cases, the urban traffic flow exhibited jam phase. Moreover, focusing on the traffic lights cycle, it is found that the average flow has the periodic fluctuation phenomenon, and we have explained this periodical oscillation change under different boundary conditions. The comparison to practical measured data shows that our stimulation results are accordant with the changes of real traffic flow, which confirms the accuracy and rationality of our model.

  12. Traffic Light Detection

    DEFF Research Database (Denmark)

    Philipsen, Mark Philip; Jensen, Morten Bornø; Møgelmose, Andreas;

    2015-01-01

    Traffic light recognition (TLR) is an integral part of any intelligent vehicle, which must function in the existing infrastructure. Pedestrian and sign detection have recently seen great improvements due to the introduction of learning based detectors using integral channel features. A similar push...... database is collected based on footage from US roads. The database consists of both test and training data, totaling 46,418 frames and 112,971 annotated traffic lights, captured in continuous sequences under a varying light and weather conditions. The learning based detector achieves an AUC of 0.4 and 0...

  13. An Efficient Bandwidth Estimation Schemes used in Wireless Mesh Networks

    OpenAIRE

    A.Sandeep Kumar ,Second Author

    2012-01-01

    wireless mesh networks (WMNs) has been widely used for the new generation wireless network. The capability of self-organization in WMNs reduces the complexity of wireless network deployment and maintenance. So, the perfect estimation of the bandwidth available of the mesh nodes is the required to admission control mechanism which provides QOs confirmation in wireless mesh networks. The bandwidth estimation of schemes do not give clear output. Here we are proposing bandwidth scheme estimation ...

  14. Dynamic Hybrid Topology Design for Integrated Traffic Support in WDM Mesh Networks (Invited Paper

    Directory of Open Access Journals (Sweden)

    Mina Youssef

    2010-05-01

    Full Text Available The future Internet will require the transport of a wide range of services including high bandwidth one-to-many applications, with a dynamic interconnection of devices. WDM layer support realizes such services in a transparent, reliable and efficient way. Most of the recent studies have been focused on efficiently building and configuring light-paths for unicast or light-trees for multicast in isolation, and do not take existing traffic demands and configuration into consideration. In this paper we consider a dynamic design problem of integrated traffic in a realistic WDM mesh network. In such a network, new traffic demands of either multicast and/or unicast are supported dynamically in the presence of an existing mixture of traffic. The amount of bandwidth per wavelength is abundant, while the wavelengths and light splitting capabilities on WDM switches are limited. Using subwavelength sharing among traffic demands of unicast and multicast, we build a hybrid virtual topology that exploits both existing light-trees and light-paths. By optimizing WDM resources in addition to resource sharing with existing unicast and multicast demands, we truly maximize the WDM layer capability and efficiently support more traffic demands. We validate the efficiency of our approach with extensive simulations on various network topologies.

  15. Traffic Light Detection

    DEFF Research Database (Denmark)

    Philipsen, Mark Philip; Jensen, Morten Bornø; Møgelmose, Andreas; Moeslund, Thomas B.; Trivedi, Mohan M.

    database is collected based on footage from US roads. The database consists of both test and training data, totaling 46,418 frames and 112,971 annotated traffic lights, captured in continuous sequences under a varying light and weather conditions. The learning based detector achieves an AUC of 0.4 and 0...

  16. Traffic Engineering in Metro Ethernet

    OpenAIRE

    Padmaraj Nair; Suku Nair; Girish Chiruvolu

    2010-01-01

    Traffic engineering is one of the major issues that has to be addressed in Metro Ethernet networks for quality of service and efficient resource utilization. This paper aims at understanding the relevant issues and outlines novel algorithms for multipoint traffic engineering in Metro Ethernet. We present an algorithmic solution for traffic engineering in Metro Ethernet using optimal multiple spanning trees. This iterative approach distributes traffic across the network uniformly without overl...

  17. Traffic flow modeling: a Genealogy

    OpenAIRE

    Van Wageningen-Kessels, F.L.M.; Hoogendoorn, S.P.; Vuik, C.; Lint, van J. W. C.

    2014-01-01

    80 years ago, Bruce Greenshields presented the first traffic flow model at the Annual Meeting of the Highway Research Board. Since then, many models and simulation tools have been developed. We show a model tree with four families of traffic flow models, all descending from Greenshields' model. The tree shows the historical development of traffic flow modeling and the relations between models. Based on the tree we discuss the main trends and future developments in traffic flow modeling and si...

  18. Virtualized Traffic at Metropolitan Scales

    OpenAIRE

    Wilkie, David; Sewall, Jason; Li, Weizi; Lin, Ming C.

    2015-01-01

    Few phenomena are more ubiquitous than traffic in urban scenes, and few are more significant economically, socially, or environmentally. Many virtual-reality applications and systems, including virtual globes and immersive multi-player worlds that are often set in a large-scale modern or futuristic setting, feature traffic systems. Virtual-reality models can also aid in addressing the challenges of real-world traffic – the ever-present gridlock and congestion in cities worldwide: traffic engi...

  19. Road Traffic Accidents in Kazakhstan

    OpenAIRE

    Alma Aubakirova; Alibek Kossumov; Nurbek Igissinov

    2013-01-01

    Background: The article provides the analysis of death rates in road traffic accidents in Kazakhstan from 2004 to 2010 and explores the use of sanitary aviation. Methods: Data of fatalities caused by road traffic accidents were collected and analysed. Descriptive and analytical methods of epidemiology and biomedical statistics were applied. Results: Totaly 27,003 people died as a result of road traffic accidents in this period. The death rate for the total population due to road traffic accid...

  20. Coordination of traffic lights evaluation

    OpenAIRE

    Ordeig Vila, Enric

    2012-01-01

    This case study consists in the evaluation of the Kaunas city traffic speed taking into consideration that traffic lights were coordinated. Kaunas suffers from high traffic intensity and, as a consequence, traffic jams often, and happens mainly because the city can only be crossed by the center. Lithuania, as the rest of Europe experienced a big growth, from 1995 to 2005 coinciding with the crisis, that is to say that number of cars increased to highest levels as well as the ...

  1. Automated Traffic Enforcement in France

    OpenAIRE

    BRIQUET, Philippe; CANEL, A

    2002-01-01

    One of the goals of traffic safety in cities and between cities is to increase compliance with Traffic Regulations. For this purpose, the French Ministry of Transportation decided to set up an automated traffic enforcement program. This program currently focuses on several types of violations : speeding, spacing between vehicles, and traffic light and railway crossing. This article presents the main goals of the program and the expected challenges and characteristics of operations that have b...

  2. 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.

  3. PIC Simulation of Laser Plasma Interactions with Temporal Bandwidths

    Science.gov (United States)

    Tsung, Frank; Weaver, J.; Lehmberg, R.

    2015-11-01

    We are performing particle-in-cell simulations using the code OSIRIS to study the effects of laser plasma interactions in the presence of temperal bandwidths under conditions relevant to current and future shock ignition experiments on the NIKE laser. Our simulations show that, for sufficiently large bandwidth, the saturation level, and the distribution of hot electrons, can be effected by the addition of temporal bandwidths (which can be accomplished in experiments using smoothing techniques such as SSD or ISI). We will show that temporal bandwidth along play an important role in the control of LPI's in these lasers and discuss future directions. This work is conducted under the auspices of NRL.

  4. Frequency Bandwidth Optimization of Left-Handed Metamaterial

    Science.gov (United States)

    Chevalier, Christine T.; Wilson, Jeffrey D.

    2004-01-01

    Recently, left-handed metamaterials (LHM s) have been demonstrated with an effective negative index of refraction and with antiparallel group and phase velocities for microwave radiation over a narrow frequency bandwidth. In order to take advantage of these characteristics for practical applications, it will be beneficial to develop LHM s with increased frequency bandwidth response and lower losses. In this paper a commercial three-dimensional electromagnetic simulation code is used to explore the effects of geometry parameter variations on the frequency bandwidth of a LHM at microwave frequencies. Utilizing an optimizing routine in the code, a geometry was generated with a bandwidth more than twice as large as the original geometry.

  5. 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.

  6. Wideband Spectroscopy: The Design and Implementation of a 3 GHz Bandwidth, 8192 Channel, Polyphase Digital Spectrometer

    Science.gov (United States)

    Monroe, Ryan M.

    2011-01-01

    A family of state-of-the-art digital Fourier transform spectrometers has been developed, with a combination of high bandwidth and fine resolution unavailable elsewhere. Analog signals consisting of radiation emitted by constituents in planetary atmospheres or galactic sources are downconverted and subsequently digitized by a pair of interleaved Analog-to-Digital Converters, (ADC). This 6 Gsps (giga-sample per second) digital representation of the analog signal is then processed through an FPGA-based streaming Fast Fourier Transform (FFT), the key development described below. Digital spectrometers have many advantages over previously used analog spectrometers, especially in terms of accuracy and resolution, both of which are particularly important for the type of scientific questions to be addressed with next-generation radiometers. the implementation, results and underlying math for this spectrometer, as well as, potential for future extension to even higher bandwidth, resolution and channel orthogonality, needed to support proposed future advanced atmospheric science and radioastronomy, are discussed.

  7. Traffic sign detection and analysis

    DEFF Research Database (Denmark)

    Møgelmose, Andreas; Trivedi, Mohan M.; Moeslund, Thomas B.

    Traffic sign recognition (TSR) is a research field that has seen much activity in the recent decade. This paper introduces the problem and presents 4 recent papers on traffic sign detection and 4 recent papers on traffic sign classification. It attempts to extract recent trends in the field and...

  8. WSN Applications: Automated Intelligent Traffic Control System Using Sensors

    OpenAIRE

    Rashid Hussain; Sandhyasharma; Vinita Sharma; Sandhya Sharma

    2013-01-01

    In this new Era the growing Vehicle population in all developing and developed country calls for a major improvement and innovation in the existing Traffic Signaling systems. The most widely used automated system uses a simple time based system which working on a time interval basis which is now inefficient for random and non uniform Traffic. Advance automated systems in testing use image processing techniques or advance communication system with an intelligent information gathering systems i...

  9. Energy-bandwidth trade-off in all-optical photonic crystal microcavity switches

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Kristensen, Philip Trøst; Mørk, Jesper

    2011-01-01

    The performance of all-optical switches is a compromise between the achievable bandwidth of the switched signal and the energy requirement of the switching operation. In this work we consider a system consisting of a photonic crystal cavity coupled to two input and two output waveguides. As a...... dynamics of the switching operation, and the results show optimum parameter ranges that may serve as design guidelines in device fabrication. © 2011 Optical Society of America....

  10. Design of equalized ROADMs devices with flexible bandwidth based on LCoS technology

    OpenAIRE

    Carrero Mora, Mónica; Martín Minguez, Alfredo; Rodríguez Horche, Paloma

    2014-01-01

    This paper describes the theory, design, applications and performance of a new Reconfigurable Add-drop Multiplexer (ROADM) with flexible bandwidth allocation. The device can address several wavelengths at the input to four output fibers, according to the holograms stored in a SLM (Spatial Light Modulator), where all the outputs are equalized in power. All combinations of the input wavelengths are possible at the different output fibers. Each fiber has assigned all the signals with the same ba...

  11. A Synthetic Bandwidth Method for High-Resolution SAR Based on PGA in the Range Dimension

    OpenAIRE

    Jincheng Li; Jie Chen; Wei Liu; Pengbo Wang; Chunsheng Li

    2015-01-01

    The synthetic bandwidth technique is an effective method to achieve ultra-high range resolution in an SAR system. There are mainly two challenges in its implementation. The first one is the estimation and compensation of system errors, such as the timing deviation and the amplitude-phase error. Due to precision limitation of the radar instrument, construction of the sub-band signals becomes much more complicated with these errors. The second challenge lies in the combination method, that is h...

  12. Traffic Light Geography: A Fifth Grade Community Project.

    Science.gov (United States)

    Zirschky, E. Dwight

    1989-01-01

    Describes a community study project that uses history and the five fundamental themes of geography as a framework. The project involves organizing committees to study the need for a traffic signal in a small town. By studying various dimensions of the issue, the committees are able to demonstrate the need for a signal. (KO)

  13. Effects of Traffic Lights on CA Traffic Model

    Institute of Scientific and Technical Information of China (English)

    SuweiFENG; GuoqingGU

    1997-01-01

    Cellular automaton traffic models can include various factors in traffic system with simple regulations and the corresponding computations and simulations are rather convenient and effective.In this paper,the Biham-Middleton-Levine model(briefly saying the BML model)is improved by removing its limitation of synchronized change of traffic lights.In new model,the traffic light at each crossing could arbitrarily change its starting time and tempo of variation and hence the model could more realistically describe the influence of traffic lights on the performance of traffic systems.The cases of traffic light with unsynchronized starting time and different tempo of variation are simulated in this paper.

  14. Schottky Heterodyne Receivers With Full Waveguide Bandwidth

    Science.gov (United States)

    Hesler, Jeffrey; Crowe, Thomas

    2011-01-01

    Compact THz receivers with broad bandwidth and low noise have been developed for the frequency range from 100 GHz to 1 THz. These receivers meet the requirements for high-resolution spectroscopic studies of planetary atmospheres (including the Earth s) from spacecraft, as well as airborne and balloon platforms. The ongoing research is significant not only for the development of Schottky mixers, but also for the creation of a receiver system, including the LO chain. The new receivers meet the goals of high sensitivity, compact size, low total power requirement, and operation across complete waveguide bands. The exceptional performance makes these receivers ideal for the broader range of scientific and commercial applications. These include the extension of sophisticated test and measurement equipment to 1 THz and the development of low-cost imaging systems for security applications and industrial process monitoring. As a particular example, a WR-1.9SHM (400-600 GHz) has been developed (see Figure 1), with state-of-the-art noise temperature ranging from 1,000-1,800 K (DSB) over the full waveguide band. Also, a Vector Network Analyzer extender has been developed (see Figure 2) for the WR1.5 waveguide band (500 750 GHz) with 100-dB dynamic range.

  15. All-optical central-frequency-programmable and bandwidth-tailorable radar

    Science.gov (United States)

    Zou, Weiwen; Zhang, Hao; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2016-01-01

    Radar has been widely used for military, security, and rescue purposes, and modern radar should be reconfigurable at multi-bands and have programmable central frequencies and considerable bandwidth agility. Microwave photonics or photonics-assisted radio-frequency technology is a unique solution to providing such capabilities. Here, we demonstrate an all-optical central-frequency-programmable and bandwidth-tailorable radar architecture that provides a coherent system and utilizes one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates a wideband linearly chirped radar signal. The working bands can be flexibly tailored with the desired bandwidth at a user-preferred carrier frequency. Radar echoes are first modulated onto the pre-chirped optical pulse, which is also used for signal generation, and then stretched in time or compressed in frequency several fold based on the time-stretch principle. Thus, digitization is facilitated without loss of detection ability. We believe that our results demonstrate an innovative radar architecture with an ultra-high-range resolution.

  16. All-optical central-frequency-programmable and bandwidth-tailorable radar.

    Science.gov (United States)

    Zou, Weiwen; Zhang, Hao; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2016-01-01

    Radar has been widely used for military, security, and rescue purposes, and modern radar should be reconfigurable at multi-bands and have programmable central frequencies and considerable bandwidth agility. Microwave photonics or photonics-assisted radio-frequency technology is a unique solution to providing such capabilities. Here, we demonstrate an all-optical central-frequency-programmable and bandwidth-tailorable radar architecture that provides a coherent system and utilizes one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates a wideband linearly chirped radar signal. The working bands can be flexibly tailored with the desired bandwidth at a user-preferred carrier frequency. Radar echoes are first modulated onto the pre-chirped optical pulse, which is also used for signal generation, and then stretched in time or compressed in frequency several fold based on the time-stretch principle. Thus, digitization is facilitated without loss of detection ability. We believe that our results demonstrate an innovative radar architecture with an ultra-high-range resolution. PMID:26795596

  17. Urban Road Traffic Simulation Techniques

    Directory of Open Access Journals (Sweden)

    Ana Maria Nicoleta Mocofan

    2011-09-01

    Full Text Available For achieving a reliable traffic control system it is necessary to first establish a network parameter evaluation system and also a simulation system for the traffic lights plan. In 40 years of history, the computer aided traffic simulation has developed from a small research group to a large scale technology for traffic systems planning and development. In the following thesis, a presentation of the main modeling and simulation road traffic applications will be provided, along with their utility, as well as the practical application of one of the models in a case study.

  18. ICE-based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

    CERN Document Server

    Bandura, Kevin; Dobbs, Matt; Gilbert, Adam; Ittah, David; Parra, Juan Mena; Smecher, Graeme

    2016-01-01

    New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2048 digitizer inputs across 400~MHz of bandwidth. Measured in $N^2~\\times $ bandwidth, it is the largest radio correlator that has been built. Its digital back-end must exchange and reorganize the 6.6~terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256-node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. `corner-turn'). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct,...

  19. Exploiting Witness for Traffic Simulation

    Directory of Open Access Journals (Sweden)

    Azhar Ismail

    2014-03-01

    Full Text Available Traffic congestion in urban cities is an increasing problem. Not only does it lead to an increase in pollution, but the time spent waiting in traffic queues wastes valuable time in addition to causing frustration. A system that can control and manage traffic efficiently is one way that this issue can be reduced. A specific road traffic intersection in South Manchester, UK, was selected for investigation as it experiences high levels of traffic flow through it during the evening peak time. This has led to large queues and long waiting times due to the fixed timings of the traffic lights. This paper explores strategies to better control the traffic flow through it. A model of the selected traffic junction has been built using Witness simulation software. Data for this junction has been obtained partially from observations and mostly from traffic surveys enabling a simulation of the traffic flow. Analysing the results allowed two alternative scenarios to be developed and simulated. Results from one of the scenarios showed noticeable reductions in the average queue waiting times at the traffic junction.

  20. 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.

  1. Differential effects of traffic sign stimuli upon speeding in school zones following a traffic light interruption.

    Science.gov (United States)

    Gregory, Bree; Irwin, Julia D; Faulks, Ian J; Chekaluk, Eugene

    2016-01-01

    Motorists whose journey has been interrupted by signalized traffic intersections in school zones resume their journey at a faster vehicle speed than motorists who have not been required to stop. Introducing a flashing "check speed" sign 70m after the traffic intersections counteracts this interruptive effect. The present study examined which aspects of a reminder sign are responsible for reducing the speeding behavior of interrupted motorists. When a sign that combines both written text and flashing lights was introduced, interrupted motorists did not speed, traveling on average 0.82km/h below the 40km/h speed limit when measured 100m from traffic intersections. Alternatively, when only the flashing lights were visible the interrupted motorists sped 3.36km/h over the 40km/h speed limit. Similar vehicular speeds were observed when only the written text was visible and when no sign was present (7.67 and 7.49km/h over the 40km/h speed limit, respectively). This indicates that static reminder signs add little value over the absence of a school zone reminder sign; the presence of both cues is necessary to fully offset the interruptive effect. This study also highlights the benefit of using exogenous visual cues in traffic signs to capture drivers' attention. These findings have practical implications for the design and use of traffic signs to increase compliance with posted speed limits. PMID:26545011

  2. Modeling of Bandwidth Aggregation over Heterogeneous Wireless Access Networks

    DEFF Research Database (Denmark)

    Popovska Avramova, Andrijana; Dittmann, Lars

    2012-01-01

    transfer deals with the problem on how to effectively aggregate the bandwidth by simultaneous usage of heterogeneous networks that a host is attached to in order to improve the throughput. This paper deals with a simulation based analysis of bandwidth aggregation techniques and their impact on higher layer...

  3. Evaluation of dynamic bandwidth allocation algorithms in GPON networks

    DEFF Research Database (Denmark)

    Ozimkiewicz, J.; Ruepp, Sarah Renée; Dittmann, Lars;

    2010-01-01

    In this paper, two approaches for Dynamic Bandwidth Allocation in GPON networks are proposed, and validated through simulations in the OPNET modeler. One approach address a Status Reporting scheme, where the bandwidth allocation originates from the client request. The second use a centralized Non...... services....

  4. E-Readiness Assessment Model for Low Bandwidth Environment

    Directory of Open Access Journals (Sweden)

    Nazir Ahmad Suhail

    Full Text Available This paper reports on assessment of an e-readiness model for low bandwidth environment. The main focus of the model is on technological (bandwidth related critical factors that are barrier to the adoption of technology mediated learning in developing cou ...

  5. 47 CFR 101.515 - Emissions and bandwidth.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emissions and bandwidth. 101.515 Section 101... FIXED MICROWAVE SERVICES 24 GHz Service and Digital Electronic Message Service § 101.515 Emissions and bandwidth. Different types of emissions may be authorized if the applicant describes fully the...

  6. Performance Enhancement by Measuring Traffic at Edge Routers in a High Speed Networks

    Directory of Open Access Journals (Sweden)

    K.Venkateswara Rao,

    2011-06-01

    Full Text Available There is an enormous increase of traffic on the network due to usage of real-time multimedia applications, which became an indispensable part of Internet traffic in the present day world. These applications include voice over IP, streaming audio and video, Internet gaming and real-time video conferencing. Such applications are multimedia information, geographical pictures, social network applications and global sharing applications. In order to reduce this traffic, high quality of service is needed which would be possible by Adaptive mechanisms. Integrated service on the network flows offer a bounded delay packet delivery to support real time applications. To provide bounded delay service, networks must use admission control to regulate their load. It is very mandatory to allocate and manage resources for multimedia traffic and various concurrent applications flows with real-time performance, in order to provide reliable quality of service (QoS. In this paper, we develop an enhanced model and an algorithm for admission control of real-time flows; comparisons among various distinguish features of admission control algorithms. In our approach, admission decision is made for each flowat the edge routers, but it is scalable because per-flow states are not maintained and the admission algorithm is simple. In the proposed admission control scheme, an admissible bandwidth, which is defined as the maximum rate of a flow that can be accommodated additionally while satisfying the delay performance requirements for both existing and new flows, is calculated based on the available bandwidth measured by edge routers. The admissible bandwidth is a threshold for admission control, and thus, it is very important to accurately estimate the admissible bandwidth. The performance of the proposed algorithm is evaluated by taking a set of simulation experiments using bursty traffic flows and the results are found to be encouraging.

  7. Traffic Light Detection

    DEFF Research Database (Denmark)

    Philipsen, Mark Philip; Jensen, Morten Bornø; Møgelmose, Andreas; Moeslund, Thomas B.; Trivedi, Mohan M.

    Traffic light recognition (TLR) is an integral part of any intelligent vehicle, which must function in the existing infrastructure. Pedestrian and sign detection have recently seen great improvements due to the introduction of learning based detectors using integral channel features. A similar push...... database is collected based on footage from US roads. The database consists of both test and training data, totaling 46,418 frames and 112,971 annotated traffic lights, captured in continuous sequences under a varying light and weather conditions. The learning based detector achieves an AUC of 0.4 and 0...... have not yet been seen for the detection sub-problem of TLR, where detection is dominated by methods based on heuristic models. Evaluation of existing systems is currently limited primarily to small local datasets. In order to provide a common basis for comparing future TLR research an extensive public...

  8. Inaccuracy in traffic forecasts

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent; Holm, Mette K. Skamris; Buhl, Søren Ladegaard

    2006-01-01

    This paper presents results from the first statistically significant study of traffic forecasts in transportation infrastructure projects. The sample used is the largest of its kind, covering 210 projects in 14 nations worth US$58 billion. The study shows with very high statistical significance...... that forecasters generally do a poor job of estimating the demand for transportation infrastructure projects. The result is substantial downside financial and economic risk. Forecasts have not become more accurate over the 30-year period studied. If techniques and skills for arriving at accurate demand...... reference class forecasting. Highly inaccurate traffic forecasts combined with large standard deviations translate into large financial and economic risks. But such risks are typically ignored or downplayed by planners and decision-makers, to the detriment of social and economic welfare. The paper presents...

  9. Virtual queueing techniques for UBR+ service in ATM with fair access and minimum bandwidth guarantee

    Energy Technology Data Exchange (ETDEWEB)

    Siu, K.Y.; Wu, Y.; Ren, W.

    1998-11-01

    The ATM Forum is currently discussing the need for a new best-effort service called UBR+, which is an enhancement to the existing UBR service, to support data traffic. The objective of the UBR+ service is to provide each user with a minimum service rate guarantee and a fair access to any excess available bandwidth. In this paper, the authors present a new efficient scheme for supporting this service. The key advantage of the scheme is that it employs only FIFO queueing (instead of per-VC queueing) and admits simple implementation in ATM switches. The ideas involve a simple scheduling mechanism that is based on per-VC queueing and incorporate the virtual queueing technique that can efficiently emulate per-VC queueing on a shared FIFO queue. Simulation results are presented to show that the schemes can deliver almost ideal performance for supporting the new service requirements of UBR+.

  10. Physics of Traffic Flow

    Science.gov (United States)

    Davis, L. C.

    2015-03-01

    The Texas A&M Transportation Institute estimated that traffic congestion cost the United States 121 billion in 2011 (the latest data available). The cost is due to wasted time and fuel. In addition to accidents and road construction, factors contributing to congestion include large demand, instability of high-density free flow and selfish behavior of drivers, which produces self-organized traffic bottlenecks. Extensive data collected on instrumented highways in various countries have led to a better understanding of traffic dynamics. From these measurements, Boris Kerner and colleagues developed a new theory called three-phase theory. They identified three major phases of flow observed in the data: free flow, synchronous flow and wide moving jams. The intermediate phase is called synchronous because vehicles in different lanes tend to have similar velocities. This congested phase, characterized by lower velocities yet modestly high throughput, frequently occurs near on-ramps and lane reductions. At present there are only two widely used methods of congestion mitigation: ramp metering and the display of current travel-time information to drivers. To find more effective methods to reduce congestion, researchers perform large-scale simulations using models based on the new theories. An algorithm has been proposed to realize Wardrop equilibria with real-time route information. Such equilibria have equal travel time on alternative routes between a given origin and destination. An active area of current research is the dynamics of connected vehicles, which communicate wirelessly with other vehicles and the surrounding infrastructure. These systems show great promise for improving traffic flow and safety.

  11. Untieing the Traffic Knot

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Beijing is working to resolve its longtime transportation problems before the 2008 Olympics One traffic jam after another, annoying horns, endless lines of cars,impatient sighs from passengers on an overcrowded bus, the youstomped-on-my-toe quarreling in the subway train, all have led to the unsurprising result that Beijing scored at the tail end of a survey of 287 cities in the category of transport satisfaction in China’s 2006 Report on the Quality of Urban Life.

  12. Assessing road traffic expression

    OpenAIRE

    Fábio Silva; Cesar Analide; Paulo Novais

    2014-01-01

    Road traffic is a problem which is increasing in cities with large population. Unrelated to this fact the number of portable and wearable devices has also been increasing throughout the population of most countries. With this advent, the capacity to monitor and register data about people habits and locations as well as more complex data such as intensity and strength of movements has created an opportunity to contribute to the general wealth and comfort within these environments. Ambient Inte...

  13. The Physics of Traffic

    Science.gov (United States)

    Davis, L. Craig

    2006-03-01

    Congestion in freeway traffic is an example of self-organization in the language of complexity theory. Nonequilibrium, first-order phase transitions from free flow cause complex spatiotemporal patterns. Two distinct phases of congestion are observed in empirical traffic data--wide moving jams and synchronous flow. Wide moving jams are characterized by stopped or slowly moving vehicles within the jammed region, which widens and moves upstream at 15-20 km/h. Above a critical density of vehicles, a sudden decrease in the velocity of a lead vehicle can initiate a transition from metastable states to this phase. Human behaviors, especially delayed reactions, are implicated in the formation of jams. The synchronous flow phase results from a bottleneck such as an on-ramp. Thus, in contrast to a jam, the downstream front is pinned at a fixed location. The name of the phase comes from the equilibration (or synchronization) of speed and flow rate across all lanes caused by frequent vehicle lane changes. Synchronous flow occurs when the mainline flow and the rate of merging from an on-ramp are sufficiently large. Large-scale simulations using car-following models reproduce the physical phenomena occurring in traffic and suggest methods to improve flow and mediate congestion.

  14. Effects of traffic noise

    Energy Technology Data Exchange (ETDEWEB)

    Gottlob, D.

    1986-02-01

    One of the main sources of noise is road traffic. In 1984 there were over 25 million cars, 1.2 million lorries, 1.3 million motor cycles and 1.6 million mopeds using our roads. Opinion polls showed that 21% of the population felt that they were affected by traffic noise as a nuisance factor. An outline of the effects of this noise on the affected population is given, illustrated by diagrams. Details about noise emissions (drive-past level) of the different types of vehicles in city traffic are stated and the effects of noise described. The author goes into the nuisance effect (noise is not a physical factor, but a psychosocial one), changes in behaviour (ways of speaking, reduction of stress on households in proportion to rising income and higher educational levels) and the consequences for health (the reaction of the body to noise is primarily a consequence of the psychosomatic organisation of ow bodies). In conclusion, the author deals with the subjective efficiency of noise protection measures. (HWJ).

  15. Assessing Road Traffic Expression

    Directory of Open Access Journals (Sweden)

    Fábio Silva

    2014-12-01

    Full Text Available Road traffic is a problem which is increasing in cities with large population. Unrelated to this fact the number of portable and wearable devices has also been increasing throughout the population of most countries. With this advent, the capacity to monitor and register data about people habits and locations as well as more complex data such as intensity and strength of movements has created an opportunity to contribute to the general wealth and comfort within these environments. Ambient Intelligence and Intelligent Decision Making processes can benefit from the knowledge gathered by these devices to improve decisions on everyday tasks such as deciding navigation routes by car, bicycle or other means of transportation and avoiding route perils. The concept of computational sustainability may also be applied to this problem. Current applications in this area demonstrate the usefulness of real time system that inform the user of certain conditions in the surrounding area. On the other hand, the approach presented in this work aims to describe models and approaches to automatically identify current states of traffic inside cities and use methods from computer science to improve overall comfort and the sustainability of road traffic both with the user and the environment in mind. Such objective is delivered by analyzing real time contributions from those mobile ubiquitous devices to identifying problematic situations and areas under a defined criteria that have significant influence towards a sustainable use of the road transport infrastructure.

  16. Optimizing bandwidth and dynamic range of lumped Josephson parametric amplifiers

    Science.gov (United States)

    Eddins, A.; Vijay, R.; Macklin, C.; Minev, Z.; Siddiqi, I.

    2013-03-01

    Superconducting parametric amplifiers have revolutionized the field of quantum measurement by providing high gain, ultra-low noise amplification. They have been used successfully for high-fidelity qubit state measurements, probing nano-mechanical resonators, quantum feedback, and for microwave quantum optics experiments. Though several designs exist, a simple and robust architecture is the Lumped Josephson Parametric Amplifier (LJPA). This device consists of a capacitively shunted SQUID directly coupled to a transmission line to form a low quality factor (Q) nonlinear resonator. We discuss amplifiers which can be tuned over the full 4-8 GHz band with 20-25 dB of gain and 10 - 50 MHz of signal bandwidth. However, similar to other parametric amplifiers employing a resonant circuit, the LJPA suffers from low dynamic range and has a -1 dB gain compression point of order -130 dBm. We explore new designs comprised of an array of SQUIDs to improve the dynamic range. We will present the results of numerical simulations and preliminary experiments. We will also briefly discuss improvements obtained from different biasing methods and packaging. This research was supported by the Army Research Office under a QCT grant.

  17. A scanning SQUID microscope with 200 MHz bandwidth

    International Nuclear Information System (INIS)

    We developed a scanning DC SQUID microscope with novel readout electronics capable of wideband sensing of RF magnetic fields from 50 to 200 MHz and simultaneously providing closed-loop response at kHz frequencies. To overcome the 20 MHz bandwidth limitation of traditional closed-loop SQUIDs, a flux-modulated closed-loop simultaneously locks the SQUID quasi-static flux and flux-biases the SQUID for amplification of the RF flux up to Φ0/4 in amplitude. Demodulating the SQUID voltage with a double lock-in technique yields a signal representative of both the amplitude and phase of the RF flux. This provides 80 dB of a linear dynamic range with a flux noise density of 4 μΦ0 Hz−1/2 at 200 MHz for a Y Ba2Cu3O7 bi-crystal SQUID at 77 K. We describe the electronics’ performance and present images for RF magnetic field of the travelling wave in a coplanar waveguide, the standing wave in an open-circuited microstrip, and a surface mounted device antenna. (paper)

  18. Spatial frequency bandwidth used in the recognition of facial images.

    Science.gov (United States)

    Näsänen, R

    1999-11-01

    The purpose of the study was to find out what spatial frequency information human observers use in the recognition of face images. Signal-to-noise ratio thresholds for the recognition of facial images were measured as a function of the centre spatial frequency of narrow-band additive spatial noise. The relative sensitivity of recognition to different spatial frequencies was derived from these results. The maximum sensitivity was found at 8-13 c/face width and the bandwidth was just under two octaves. Qualitatively similar results were obtained with stimuli in which Fourier phase was randomised within a narrow band of different centre spatial frequencies. This resulted in a considerable increase of energy threshold around 8 c/face width and less elsewhere. Further, contrast energy thresholds were measured as a function of the centre spatial frequency of band-pass filtered face images. As a function of object spatial frequency (c/face width), energy threshold first decreased and then increased. The lowest energy thresholds found around 10 c/face width were lower than the energy threshold for unfiltered images. This is what one would expect if face recognition is narrow-band, since band-pass filtered images of optimal centre spatial frequency do not contain unused contrast energy at low and high spatial frequencies. In conclusion, the results suggest that the recognition of facial images is tuned to a relatively narrow band (object spatial frequencies. PMID:10748918

  19. Trace Analysis of Driver Behavior on Traffic Violator by Using Big Data (Traffic Program) in Korea

    OpenAIRE

    Lee, Jonghak

    2016-01-01

    This study aims to prove the effectiveness of traffic safety education program for traffic violators. Traffic violators who finished the traffic safety education programs were tracked down. In order to analyze the effectiveness of traffic safety education program, traffic violator’s data during ten-year period were used. This study analyzed how traffic violators changed their attitudes about traffic law abidance. Also predicted social benefits from traffic safety education program...

  20. Traffic Control by Traffic Wardens in Minna, Niger State, Nigeria

    Directory of Open Access Journals (Sweden)

    P. N. NDOKE

    2006-01-01

    Full Text Available Traffic control by traffic wardens on three at-grade interactions in Minna, Northern Nigeria has been analysed. During the morning peak periods, it was observed that with traffic warden control, none of the approaches of the intersections operated beyond level of service E. However, when the wardens did not control traffic, the approaches operated at level of service, F, which has been shown in studies to be unacceptable to most drivers. Taking other factors like stability of electricity supply, motorists’ behaviour and society’s acceptance of innovations into consideration, it has been concluded that for now, there is no alternative to the traffic warden in traffic control in developing cities.

  1. Broad-Bandwidth FPGA-Based Digital Polyphase Spectrometer

    Science.gov (United States)

    Jamot, Robert F.; Monroe, Ryan M.

    2012-01-01

    With present concern for ecological sustainability ever increasing, it is desirable to model the composition of Earth s upper atmosphere accurately with regards to certain helpful and harmful chemicals, such as greenhouse gases and ozone. The microwave limb sounder (MLS) is an instrument designed to map the global day-to-day concentrations of key atmospheric constituents continuously. One important component in MLS is the spectrometer, which processes the raw data provided by the receivers into frequency-domain information that cannot only be transmitted more efficiently, but also processed directly once received. The present-generation spectrometer is fully analog. The goal is to include a fully digital spectrometer in the next-generation sensor. In a digital spectrometer, incoming analog data must be converted into a digital format, processed through a Fourier transform, and finally accumulated to reduce the impact of input noise. While the final design will be placed on an application specific integrated circuit (ASIC), the building of these chips is prohibitively expensive. To that end, this design was constructed on a field-programmable gate array (FPGA). A family of state-of-the-art digital Fourier transform spectrometers has been developed, with a combination of high bandwidth and fine resolution. Analog signals consisting of radiation emitted by constituents in planetary atmospheres or galactic sources are downconverted and subsequently digitized by a pair of interleaved analog-to-digital converters (ADCs). This 6-Gsps (gigasample per second) digital representation of the analog signal is then processed through an FPGA-based streaming fast Fourier transform (FFT). Digital spectrometers have many advantages over previously used analog spectrometers, especially in terms of accuracy and resolution, both of which are particularly important for the type of scientific questions to be addressed with next-generation radiometers.

  2. Automatic Bandwidth Adjustment for Content Distribution in MPLS Networks

    OpenAIRE

    D. Moltchanov

    2008-01-01

    Aggregates of real-time traffic may experience changes in their statistical characteristics often manifesting non stationary behavior. In multi protocol label switching (MPLS) networks this type of the traffic is assigned constant amount of resources. This may result in ineffective usage of resources when the load is below than expected or inappropriate performance when the load is higher. In this paper we propose new algorithm for dynamic resource adaptation to temporarily changing traffic c...

  3. Mahanaxar: quality of service guarantees in high-bandwidth, real-time streaming data storage

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, David [Los Alamos National Laboratory; Bent, John [Los Alamos National Laboratory; Chen, Hsing-Bung [Los Alamos National Laboratory; Brandt, Scott [UCSC

    2010-04-05

    Large radio telescopes, cyber-security systems monitoring real-time network traffic, and others have specialized data storage needs: guaranteed capture of an ultra-high-bandwidth data stream, retention of the data long enough to determine what is 'interesting,' retention of interesting data indefinitely, and concurrent read/write access to determine what data is interesting, without interrupting the ongoing capture of incoming data. Mahanaxar addresses this problem. Mahanaxar guarantees streaming real-time data capture at (nearly) the full rate of the raw device, allows concurrent read and write access to the device on a best-effort basis without interrupting the data capture, and retains data as long as possible given the available storage. It has built in mechanisms for reliability and indexing, can scale to meet arbitrary bandwidth requirements, and handles both small and large data elements equally well. Results from our prototype implementation shows that Mahanaxar provides both better guarantees and better performance than traditional file systems.

  4. State space collapse and diffusion approximation for a network operating under a fair bandwidth sharing policy

    CERN Document Server

    Kang, W N; Lee, N H; Williams, R J; 10.1214/08-AAP591

    2009-01-01

    We consider a connection-level model of Internet congestion control, introduced by Massouli\\'{e} and Roberts [Telecommunication Systems 15 (2000) 185--201], that represents the randomly varying number of flows present in a network. Here, bandwidth is shared fairly among elastic document transfers according to a weighted $\\alpha$-fair bandwidth sharing policy introduced by Mo and Walrand [IEEE/ACM Transactions on Networking 8 (2000) 556--567] [$\\alpha\\in (0,\\infty)$]. Assuming Poisson arrivals and exponentially distributed document sizes, we focus on the heavy traffic regime in which the average load placed on each resource is approximately equal to its capacity. A fluid model (or functional law of large numbers approximation) for this stochastic model was derived and analyzed in a prior work [Ann. Appl. Probab. 14 (2004) 1055--1083] by two of the authors. Here, we use the long-time behavior of the solutions of the fluid model established in that paper to derive a property called multiplicative state space col...

  5. Simulation of three lanes one-way freeway in low visibility weather by possible traffic accidents

    Science.gov (United States)

    Pang, Ming-bao; Zheng, Sha-sha; Cai, Zhang-hui

    2015-09-01

    The aim of this work is to investigate the traffic impact of low visibility weather on a freeway including the fraction of real vehicle rear-end accidents and road traffic capacity. Based on symmetric two-lane Nagel-Schreckenberg (STNS) model, a cellular automaton model of three-lane freeway mainline with the real occurrence of rear-end accidents in low visibility weather, which considers delayed reaction time and deceleration restriction, was established with access to real-time traffic information of intelligent transportation system (ITS). The characteristics of traffic flow in different visibility weather were discussed via the simulation experiments. The results indicate that incoming flow control (decreasing upstream traffic volume) and inputting variable speed limits (VSL) signal are effective in accident reducing and road actual traffic volume's enhancing. According to different visibility and traffic demand the appropriate control strategies should be adopted in order to not only decrease the probability of vehicle accidents but also avoid congestion.

  6. Robust and reactive traffic engineering for dynamic traffic demands

    OpenAIRE

    Casas Hernandez, Pedro; Fillatre, Lionel; Vaton, Sandrine

    2008-01-01

    Traffic engineering (TE) has become a challenging mechanism for network management and resources optimization due to uncertain and difficult to predict traffic patterns. Recent works have proposed robust optimization techniques to cope with uncertain traffic, computing a stable routing configuration that is immune to demand variations within certain uncertainty set. However, using a single routing configuration for longtime periods can be highly inefficient. Even more, the presence of abnorma...

  7. Dividing the Traffic Matrix to Approach Optimal Traffic Engineering

    OpenAIRE

    Balon, Simon; Leduc, Guy

    2006-01-01

    In this paper we propose a new method to approach optimal Traffic Engineering routing. The method consists of dividing the traffic matrix into $N$ sub-matrices, called strata, and route each of these independently. We propose two different implementations of our method in routers. Our method can also be used to compute a very precise approximation of the optimal value of a given objective function for comparison to heuristic Traffic Engineering algorithms. For this application, our algorithm ...

  8. Traffic Data and Their Implications for Consistent Traffic Flow Modeling

    OpenAIRE

    Helbing, Dirk

    1998-01-01

    The paper analyzes traffic data of the Dutch freeway A9 with respect to certain aspects which are relevant for traffic flow modeling as well as the calibration of model parameters and functions. Apart from the dynamic velocity distribution, the density-dependence and the temporal evolution of various, partly lane-specific quantities is investigated. The results are well compatible with recent macroscopic traffic flow models which have been derived from the dynamics of driver-vehicle units. Th...

  9. Evaluation of Traffic Management Measures on Road Traffic Noise

    OpenAIRE

    Bhaskar, A.; Chung, E; Dumont, A.-G.

    2006-01-01

    Road traffic noise affects the quality of life in the areas adjoining the road. The effect of traffic noise on people is wide ranging and may include sleep disturbance and negative impact on work efficiency. To address the problem of traffic noise, it is necessary to estimate the noise level. For this, a number of noise estimation models have been developed which can estimate noise at the receptor points, based on simple configuration of buildings. Howe...

  10. Optimal traffic states in a cellular automaton for city traffic

    OpenAIRE

    Barlovic, Robert; Brockfeld, Elmar; Schreckenberg, Michael; Schadschneider, Andreas

    2003-01-01

    The impact of global traffic light control strategies for city networks is analyzed in a recently proposed cellular automaton model. The model combines basic ideas of the Biham-Middleton-Levine model for city traffic and the Nage-Schreckenberg model for highway traffic. The city network has a simple square lattice geometry. All streets and intersections are treated equally, i.e., there are no dominant streets.

  11. Camouflaging Timing Channels in Web Traffic

    OpenAIRE

    Sellke, Sarah H; Wang, Chih-Chun; Bagchi, Saurabh; Shroff, Ness B.

    2009-01-01

    Web traffic accounts for more than half of Internet traffic today. Camouflaging covert timing channels in Web traffic would be advantageous for concealment. In this paper, we investigate the possibility of disguising network covert timing channels as HTTP traffic to avoid detection. Extensive research has shown that Internet traffic, including HTTP traffic, exhibits self-similarity and long range persistence. Existing covert timing channels that mimic i.i.d. legitimate traffic cannot imitate ...

  12. Lagrangian Multi-Class Traffic State Estimation

    OpenAIRE

    Y. Yuan

    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...

  13. SiGe HBT cryogenic preamplification for higher bandwidth donor spin read-out

    Science.gov (United States)

    Curry, Matthew; Carr, Stephen; Ten-Eyck, Greg; Wendt, Joel; Pluym, Tammy; Lilly, Michael; Carroll, Malcolm

    2014-03-01

    Single-shot read-out of a donor spin can be performed using the response of a single-electron-transistor (SET). This technique can produce relatively large changes in current, on the order of 1 (nA), to distinguish between the spin states. Despite the relatively large signal, the read-out time resolution has been limited to approximately 100 (kHz) of bandwidth because of noise. Cryogenic pre-amplification has been shown to extend the response of certain detection circuits to shorter time resolution and thus higher bandwidth. We examine a SiGe HBT circuit configuration for cryogenic preamplification, which has potential advantages over commonly used HEMT configurations. Here we present 4 (K) measurements of a circuit consisting of a Silicon-SET inline with a Heterojunction-Bipolar-Transistor (HBT). We compare the measured bandwidth with and without the HBT inline and find that at higher frequencies the signal-to-noise-ratio (SNR) with the HBT inline exceeds the SNR without the HBT inline. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  14. Utility-based bandwidth allocation algorithm for heterogeneous wireless networks

    Institute of Scientific and Technical Information of China (English)

    CHAI Rong; WANG XiuJuan; CHEN QianBin; SVENSSON Tommy

    2013-01-01

    In next generation wireless network (NGWN), mobile users are capable of connecting to the core network through various heterogeneous wireless access networks, such as cellular network, wireless metropolitan area network (WMAN), wireless local area network (WLAN), and ad hoc network. NGWN is expected to provide high-bandwidth connectivity with guaranteed quality-of-service to mobile users in a seamless manner; however, this desired function demands seamless coordination of the heterogeneous radio access network (RAN) technologies. In recent years, some researches have been conducted to design radio resource management (RRM) architectures and algorithms for NGWN; however, few studies stress the problem of joint network performance optimization, which is an essential goal for a cooperative service providing scenario. Furthermore, while some authors consider the competition among the service providers, the QoS requirements of users and the resource competition within access networks are not fully considered. In this paper, we present an interworking integrated network architecture, which is responsible for monitoring the status information of different radio access technologies (RATs) and executing the resource allocation algorithm. Within this architecture, the problem of joint bandwidth allocation for heterogeneous integrated networks is formulated based on utility function theory and bankruptcy game theory. The proposed bandwidth allocation scheme comprises two successive stages, i.e., service bandwidth allocation and user bandwidth allocation. At the service bandwidth allocation stage, the optimal amount of bandwidth for different types of services in each network is allocated based on the criterion of joint utility maximization. At the user bandwidth allocation stage, the service bandwidth in each network is optimally allocated among users in the network according to bankruptcy game theory. Numerical results demonstrate the efficiency of

  15. Modeling a bus through a sequence of traffic lights

    Science.gov (United States)

    Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Penagos, Juan Felipe; Toledo, Benjamín; Valdivia, Juan Alejandro

    2015-07-01

    We propose a model of a bus traveling through a sequence of traffic lights, which is required to stop between the traffic signals to pick up passengers. A two dimensional model, of velocity and traveled time at each traffic light, is constructed, which shows non-trivial and chaotic behaviors for realistic city traffic parameters. We restrict the parameter values where these non-trivial and chaotic behaviors occur, by following analytically and numerically the fixed points and period 2 orbits. We define conditions where chaos may arise by determining regions in parameter space where the maximum Lyapunov exponent is positive. Chaos seems to occur as long as the ratio of the braking and accelerating capacities are greater than about ˜3.

  16. Microwave photonic bandstop filter with wide tunability and adjustable bandwidth.

    Science.gov (United States)

    Li, Wei; Yang, Chengwu; Wang, Ling; Yuan, Zhilin; Liu, Jianguo; Li, Ming; Zhu, Ninghua

    2015-12-28

    A microwave photonic bandstop filter is proposed and experimentally demonstrated in this work. The filter exhibits promising performance combination of reconfigurability, frequency tunability, and bandwidth adjustment. The phase modulation on two orthogonal polarization states produces a bandpass and a lowpass MPF, respectively. The key concept of destructive interference between the bandpass and lowpass MPF enables the reconfiguration of MPF from bandpass to bandstop. By adjusting the wavelength of two orthogonally polarized optical carriers and the bandwidth of an optical bandpass filter, the bandstop filter is tunable in terms of center frequency and bandwidth. PMID:26832021

  17. 3600 digital phase detector with 100-kHz bandwidth

    International Nuclear Information System (INIS)

    The general availability of digital circuit components with propagation delay times of a few nanoseconds makes a digital phase detector with good bandwidth feasible. Such a circuit has a distinct advantage over its analog counterpart because of its linearity over wide range of phase shift. A phase detector that is being built at Los Alamos National Laboratory for the Fusion Materials Irradiation Test (FMIT) project is described. The specifications are 100-kHz bandwidth, linearity of +- 10 over +- 1800 of phase shift, and 0.660 resolution. To date, the circuit has achieved the bandwidth and resolution. The linearity is approximately +- 30 over +- 1800 phase shift

  18. Impact of local traffic exclusion on near-road air quality: Findings from the New York City 'Summer Streets' campaign

    International Nuclear Information System (INIS)

    We monitored curbside airborne particulate matter (PM) concentrations and its proinflammatory capacity during 3 weekends when vehicle traffic was excluded from Park. Ave., New York City. Fine PM concentration peaked in the morning regardless of traffic while ultrafine PM was 58% lower during mornings without traffic. Ultrafine PM concentration varied linearly with traffic flow, while fine PM spiked sharply in response to random traffic events that were weakly correlated with the traffic signal cycle. Ultrafine PM concentrations decayed exponentially with distance from a cross street with unrestricted traffic flow, reaching background levels within 100 m of the source. IL-6 induction was typically highest on Friday afternoons but showed no clear relationship to the presence of traffic. The coarse fraction (>2.5 μm) had the greatest intrinsic inflammatory capacity, suggesting that coarse PM still warrants attention even as the research focus is shifting to nano-particles. - Highlights: → During a period of traffic exclusion morning PM2.5 concentration remained high. → Ultrafine concentrations were lower during mornings without traffic. → While ultrafine PM varied linearly with traffic flow, fine PM was unrelated to flow. → Ultrafine PM decayed exponentially with distance from a cross street with traffic. → The coarse fraction (>2.5 mm) had the greatest intrinsic inflammatory capacity. - Traffic exclusion had variable effects on local particle concentrations and biomarker induction that were inconsistent with the simple expectation that air would be cleaner without traffic.

  19. Interdomain traffic engineering with BGP

    OpenAIRE

    Quoitin, Bruno; Uhlig, Steve; Pelsser, Cristel; Swinnen, Louis; Bonaventure, Olivier

    2003-01-01

    Traffic engineering is performed by means of a set of techniques that can be used to better control the flow of packets inside an IP network We discuss the utilization of these techniques across interdomain boundaries in the global Internet. We first analyze the characteristics of interdomain traffic on the basis of measurements from three different Internet service providers and show that a small number of sources are responsible for a large fraction of the traffic. Across interdomain bounda...

  20. MPC in Urban Traffic Management

    OpenAIRE

    Tettamanti, Tamás; Varga, Istvan; Peni, Tamas

    2010-01-01

    This chapter introduced the aspects of MPC applied in urban traffic management. As the urban traffic is a complex system having special attributes the appropriate traffic model had to be discussed in details as well. At the same time MPC technology is suitable to control such complex system optimally and real-time. The main control aim was the optimal and coordinated control which can be satisfied. The applicability was demonstrated by several simulations. Furthermore a distributed technology...

  1. Traffic noise and cardiovascular disease

    OpenAIRE

    Selander, Jenny

    2010-01-01

    Traffic noise is an increasing problem in urban areas worldwide, but health effects in relation to traffic noise exposure are not well understood. Several studies show that noise may give rise to acute stress reactions, possibly leading to cardiovascular effects, but the evidence is limited on cardiovascular risks associated with traffic noise exposure. Cardiovascular effects have been indicated for other environmental stressors such as occupational noise exposure and job ...

  2. Single-shot rotational Raman thermometry for turbulent flames using a low-resolution bandwidth technique

    International Nuclear Information System (INIS)

    An alternative optical thermometry technique that utilizes the low-resolution (order 101 cm−1) pure-rotational spontaneous Raman scattering of air is developed to aid single-shot multiscalar measurements in turbulent combustion studies. Temperature measurements are realized by correlating the measured envelope bandwidth of the pure-rotational manifold of the N2/O2 spectrum with a theoretical prediction of a species-weighted bandwidth. By coupling this thermometry technique with conventional vibrational Raman scattering for species determination, we demonstrate quantitative spatially resolved, single-shot measurements of the temperature and fuel/oxidizer concentrations in a high-pressure turbulent CH4–air flame. Our technique provides not only an effective means of validating other temperature measurement methods, but also serves as a secondary thermometry technique in cases where the anti-Stokes vibrational N2 Raman signals are too low for a conventional vibrational temperature analysis

  3. Single-Shot Rotational Raman Thermometry for Turbulent Flames Using a Low-Resolution Bandwidth Technique

    Science.gov (United States)

    Kojima, Jun; Nguyen, Quang-Viet

    2007-01-01

    An alternative optical thermometry technique that utilizes the low-resolution (order 10(exp 1)/cm) pure-rotational spontaneous Raman scattering of air is developed to aid single-shot multiscalar measurements in turbulent combustion studies. Temperature measurements are realized by correlating the measured envelope bandwidth of the pure-rotational manifold of the N2/O2 spectrum with a theoretical prediction of a species-weighted bandwidth. By coupling this thermometry technique with conventional vibrational Raman scattering for species determination, we demonstrate quantitative spatially resolved, single-shot measurements of the temperature and fuel/oxidizer concentrations in a high-pressure turbulent Cf4-air flame. Our technique provides not only an effective means of validating other temperature measurement methods, but also serves as a secondary thermometry technique in cases where the anti-Stokes vibrational N2 Raman signals are too low for a conventional vibrational temperature analysis.

  4. Enhancing the Bandwidth of Gravitational-Wave Detectors with Unstable Optomechanical Filters

    Science.gov (United States)

    Miao, Haixing; Ma, Yiqiu; Zhao, Chunnong; Chen, Yanbei

    2015-11-01

    Advanced interferometric gravitational-wave detectors use optical cavities to resonantly enhance their shot-noise-limited sensitivity. Because of positive dispersion of these cavities—signals at different frequencies pick up different phases, there is a tradeoff between the detector bandwidth and peak sensitivity, which is a universal feature for quantum measurement devices having resonant cavities. We consider embedding an active unstable filter inside the interferometer to compensate the phase, and using feedback control to stabilize the entire system. We show that this scheme in principle can enhance the bandwidth without sacrificing the peak sensitivity. However, the unstable filter under our current consideration is a cavity-assisted optomechanical device operating in the instability regime, and the thermal fluctuation of the mechanical oscillator puts a very stringent requirement on the environmental temperature and the mechanical quality factor.

  5. Enhancing the bandwidth of gravitational-wave detectors with unstable optomechanical filters

    CERN Document Server

    Miao, Haixing; Zhao, Chunnong; Chen, Yanbei

    2015-01-01

    For gravitational-wave interferometric detectors, there is a tradeoff between the detector bandwidth and peak sensitivity when focusing on the shot noise level. This has to do with the frequency-dependent propagation phase lag (positive dispersion) of the signal. We consider embedding an active unstable filter---a cavity-assisted optomechanical device operating in the instability regime---inside the interferometer to compensate the phase, and using feedback control to stabilize the entire system. We show that this scheme in principle can enhance the bandwidth without sacrificing the peak sensitivity. However, there is one practical difficulty for implementing it due to the thermal fluctuation of the mechanical oscillator in the optomechanical filter, which puts a very stringent requirement on the environmental temperature and the mechanical quality factor.

  6. Common Traffic Violations of Bus Drivers in Urban China: An Observational Study

    OpenAIRE

    Qiqi Wang; , Wei Zhang; Rendong Yang; Yuanxiu Huang; Lin Zhang; Peishan Ning; Xunjie Cheng; Schwebel, David C; Guoqing Hu; Hongyan Yao

    2015-01-01

    Objective To report common traffic violations in bus drivers and the factors that influence those violations in urban China. Methods We conducted an observational study to record three types of traffic violations among bus drivers in Changsha City, China: illegal stopping at bus stations, violating traffic light signals, and distracted driving. The behaviors of bus drivers on 32 routes (20% of bus routes in the city) were observed. A two-level Poisson regression examined factors that predicte...

  7. Matlab Traffic Toolbox

    Czech Academy of Sciences Publication Activity Database

    Dohnal, Pavel

    Bratislava : Slovak University of technology, 2007 - (Mikleš, J.; Fikar, M.; Kvasnica, M.), s. 1-6 ISBN 978-80-227-2677-1. [16th International Conference on Process Control. Štrbské pleso - Vysoké Tatry (SK), 11.06.2007-14.06.2007] R&D Projects: GA MŠk 1M0572; GA AV ČR 1ET100750401; GA ČR(CZ) GA102/05/0271 Institutional research plan: CEZ:AV0Z10750506 Keywords : Matlab * Traffic * Toolbox * Aimsun Subject RIV: BC - Control Systems Theory

  8. Matlab Traffic Toolbox

    Czech Academy of Sciences Publication Activity Database

    Dohnal, Pavel

    Bratislava : Slovak University of technology, 2007 - (Mikleš, J.; Fikar, M.; Kvasnica, M.) ISBN 978-80-227-2677-1. [16th International Conference on Process Control. 11.06.2007-14.06.2007, Štrbské pleso - Vysoké Tatry] R&D Projects: GA MŠk 1M0572; GA AV ČR 1ET100750401; GA ČR(CZ) GA102/05/0271 Institutional research plan: CEZ:AV0Z10750506 Keywords : Matlab * Toolbox * Aimsun * Traffic Subject RIV: BC - Control Systems Theory

  9. Trace Analysis of Driver Behavior on Traffic Violator by Using Big Data (Traffic Program in Korea

    Directory of Open Access Journals (Sweden)

    Lee, Jonghak

    2016-01-01

    Full Text Available This study aims to prove the effectiveness of traffic safety education program for traffic violators. Traffic violators who finished the traffic safety education programs were tracked down. In order to analyze the effectiveness of traffic safety education program, traffic violator’s data during ten-year period were used. This study analyzed how traffic violators changed their attitudes about traffic law abidance. Also predicted social benefits from traffic safety education program for traffic violators. Effectiveness of traffic accident prevention through traffic safety education program is approximately 93%. In terms of social benefits, it shows more than $12 billion Even though the effectiveness of traffic safety education program represents remarkable results, but this program is made for traffic violators who have already committed traffic offenses in the past. So in order to prevent traffic violations in advance, specific education program for potentially risky drivers is necessary.

  10. Large scale traffic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, K.; Barrett, C.L. [Los Alamos National Lab., NM (United States)]|[Santa Fe Institute, NM (United States); Rickert, M. [Los Alamos National Lab., NM (United States)]|[Universitaet zu Koeln (Germany)

    1997-04-01

    Large scale microscopic (i.e. vehicle-based) traffic simulations pose high demands on computational speed in at least two application areas: (i) real-time traffic forecasting, and (ii) long-term planning applications (where repeated {open_quotes}looping{close_quotes} between the microsimulation and the simulated planning of individual person`s behavior is necessary). As a rough number, a real-time simulation of an area such as Los Angeles (ca. 1 million travellers) will need a computational speed of much higher than 1 million {open_quotes}particle{close_quotes} (= vehicle) updates per second. This paper reviews how this problem is approached in different projects and how these approaches are dependent both on the specific questions and on the prospective user community. The approaches reach from highly parallel and vectorizable, single-bit implementations on parallel supercomputers for Statistical Physics questions, via more realistic implementations on coupled workstations, to more complicated driving dynamics implemented again on parallel supercomputers. 45 refs., 9 figs., 1 tab.

  11. MULTILAYER MICROSTRIP ANTENNA QUALITY FACTOR OPTIMIZATION FOR BANDWIDTH ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    M.C. SRIVASTAVA

    2012-12-01

    Full Text Available The impedance bandwidth, one of the important characteristics of microstrip patch antennas, can be significantly improved by using a multilayer dielectric configuration. In this paper the focus is on bandwidth enhancement technique of a multilayer patch antenna for X-band applications. In order to enhance the bandwidth, antenna losses are contained by controlling those quality factors which can have a significant impact on the bandwidth for a given permittivity and thickness of the substrate. This has been achieved by conformal transformation of the multidielectric microstrip antenna. For the ease of analysis Wheelers transformation is used to map the complex permittivity of a multilayer substrate to a single layer. Method of Moments and Finite Difference Time Domain approaches are used for the computation of results.

  12. Bandwidth allocation and pricing problem for a duopoly market

    Directory of Open Access Journals (Sweden)

    You Peng-Sheng

    2011-01-01

    Full Text Available This research discusses the Internet service provider (ISP bandwidth allocation and pricing problems for a duopoly bandwidth market with two competitive ISPs. According to the contracts between Internet subscribers and ISPs, Internet subscribers can enjoy their services up to their contracted bandwidth limits. However, in reality, many subscribers may experience the facts that their on-line requests are denied or their connection speeds are far below their contracted speed limits. One of the reasons is that ISPs accept too many subscribers as their subscribers. To avoid this problem, ISPs can set limits for their subscribers to enhance their service qualities. This paper develops constrained nonlinear programming to deal with this problem for two competitive ISPs. The condition for reaching the equilibrium between the two competitive firms is derived. The market equilibrium price and bandwidth resource allocations are derived as closed form solutions.

  13. Available Bandwidth Estimation Strategy Based on the Network Allocation Vector

    Directory of Open Access Journals (Sweden)

    Hongtao Liu

    2012-12-01

    Full Text Available Available bandwidth is of great importance to network Quality of Service assurance, network load balancing, streaming media rate control, routing, and congestion control, etc.. In this paper, the available bandwidth estimation strategy based on the Network Allocation Vector for Wireless Sensor Networks is proposed. According to the size of the average contention window, network nodes predict the probability of collision in process of frame transmission, and then estimate the number of retransmission. Through the collection of Hello packets periodically sent by neighbors, nodes obtain their Network Allocation Vector, and then estimate the available bandwidth. The simulation results show that the strategy is simple and effective, can accurately estimate the collision of data frames as well as the available bandwidth of Wireless Sensor Networks.

  14. An Improved Dynamic Bandwidth Allocation Algorithm for Ethernet PON

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper proposes an improved Dynamic Bandwidth Allocation (DBA) algorithm for EPON, which combines static and traditional dynamic allocation schemes. Simulation result shows that the proposed algorithm may effectively improve the performance of packet delay.

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

    OpenAIRE

    Schreiter, T.; Van Wageningen-Kessels, F.L.M.; Yuan, Y; Lint, van 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 reproduces the properties of traffic well must be used. One of the most important properties is that traffic is composed of multiple vehicle classes. While many traffic flow models have been proposed ...

  16. A Bandwidth Allocation Model Provisioning Framework with Autonomic Characteristics

    OpenAIRE

    Rafael F. Reale; Romildo M. da S. Bezerra; Martins, Joberto S. B.

    2013-01-01

    The Bandwidth Allocation Models (MAM, RDM, G-RDM and AllocTC-Sharing) are managementalternatives currently available which propose different resource (bandwidth) allocation strategies inmultiservice networks. The BAM adoption by a network is typically a management choice andconfiguration task executed by the network operations and management system setup in a static or nearlystatic way. This paper proposes and explores the alternative ofallowing BAM definition and configurationon a more dynam...

  17. Available Bandwidth Estimation Strategy Based on the Network Allocation Vector

    OpenAIRE

    Hongtao Liu; Lianglun Cheng

    2012-01-01

    Available bandwidth is of great importance to network Quality of Service assurance, network load balancing, streaming media rate control, routing, and congestion control, etc.. In this paper, the available bandwidth estimation strategy based on the Network Allocation Vector for Wireless Sensor Networks is proposed. According to the size of the average contention window, network nodes predict the probability of collision in process of frame transmission, and then estimate the number of retrans...

  18. Limits To Certainty in QoS Pricing and Bandwidth

    OpenAIRE

    Gideon, Carolyn; Camp, L Jean

    2001-01-01

    Advanced services require more reliable bandwidth than currently provided by the Internet Protocol, even with the reliability enhancements provided by TCP. More reliable bandwidth will be provided through QoS (quality of service), as currently discussed widely. Yet QoS has some implications beyond providing ubiquitous access to advance Internet service, which are of interest from a policy perspective. In particular, what are the implications for price of Internet services? Further, how will t...

  19. Review of high bandwidth fiber optics radiation sensors

    International Nuclear Information System (INIS)

    This paper summarizes the use of fiber optics or guided optical systems for radiation sensors. It is limited a passive systems wherein electrical is not required at the sensor location. However, electrically powered light sources, receivers and/or recorders may still be required for detection and data storage in sensor system operation. This paper emphasizes sensor technologies that permit high bandwidth measurements of transient radiation levels, and will also discuss several low bandwidth applications. 60 refs

  20. Practical Ranges of Loudness Levels of Various Types of Environmental Noise, Including Traffic Noise, Aircraft Noise, and Industrial Noise

    Directory of Open Access Journals (Sweden)

    Sabine A. Janssen

    2011-05-01

    Full Text Available In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A‑weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels.

  1. Practical ranges of loudness levels of various types of environmental noise, including traffic noise, aircraft noise, and industrial noise.

    Science.gov (United States)

    Salomons, Erik M; Janssen, Sabine A

    2011-06-01

    In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A-weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels. PMID:21776205

  2. Wide bandwidth instantaneous radio frequency spectrum analyzer based on nitrogen vacancy centers in diamond

    Science.gov (United States)

    Chipaux, M.; Toraille, L.; Larat, C.; Morvan, L.; Pezzagna, S.; Meijer, J.; Debuisschert, T.

    2015-12-01

    We propose an original analog method to perform instantaneous and quantitative spectral analysis of microwave signals. An ensemble of nitrogen-vacancy (NV) centers held in a diamond plate is pumped by a 532 nm laser. Its photoluminescence is imaged through an optical microscope and monitored by a digital camera. An incoming microwave signal is converted into a microwave field in the area of the NV centers by a loop shaped antenna. The resonances induced by the magnetic component of that field are detected through a decrease of the NV centers photoluminescence. A magnetic field gradient induces a Zeeman shift of the resonances and transforms the frequency information into spatial information, which allows for the simultaneous analysis of the microwave signal in the entire frequency bandwidth of the device. The time dependent spectral analysis of an amplitude modulated microwave signal is demonstrated over a bandwidth of 600 MHz , associated to a frequency resolution of 7 MHz , and a refresh rate of 4 ms . With such integration time, a field of a few hundreds of μ W can be detected. Since the optical properties of NV centers can be maintained even in high magnetic field, we estimate that an optimized device could allow frequency analysis in a range of 30 GHz , only limited by the amplitude of the magnetic field gradient. In addition, an increase of the NV centers quantity could lead both to an increase of the microwave sensitivity and to a decrease of the minimum refresh rate down to a few μ s .

  3. The Signal Distribution System

    CERN Document Server

    Belohrad, D; CERN. Geneva. AB Department

    2005-01-01

    For the purpose of LHC signal observation and high frequency signal distribution, the Signal Distribution System (SDS) was built. The SDS can contain up to 5 switching elements, where each element allows the user to switch between one of the maximum 8 bi-directional signals. The coaxial relays are used to switch the signals. Depending of the coaxial relay type used, the transfer bandwidth can go up to 18GHz. The SDS is controllable via TCP/IP, parallel port, or locally by rotary switch.

  4. Principled negotiation and distributed optimization for advanced air traffic management

    Science.gov (United States)

    Wangermann, John Paul

    Today's aircraft/airspace system faces complex challenges. Congestion and delays are widespread as air traffic continues to grow. Airlines want to better optimize their operations, and general aviation wants easier access to the system. Additionally, the accident rate must decline just to keep the number of accidents each year constant. New technology provides an opportunity to rethink the air traffic management process. Faster computers, new sensors, and high-bandwidth communications can be used to create new operating models. The choice is no longer between "inflexible" strategic separation assurance and "flexible" tactical conflict resolution. With suitable operating procedures, it is possible to have strategic, four-dimensional separation assurance that is flexible and allows system users maximum freedom to optimize operations. This thesis describes an operating model based on principled negotiation between agents. Many multi-agent systems have agents that have different, competing interests but have a shared interest in coordinating their actions. Principled negotiation is a method of finding agreement between agents with different interests. By focusing on fundamental interests and searching for options for mutual gain, agents with different interests reach agreements that provide benefits for both sides. Using principled negotiation, distributed optimization by each agent can be coordinated leading to iterative optimization of the system. Principled negotiation is well-suited to aircraft/airspace systems. It allows aircraft and operators to propose changes to air traffic control. Air traffic managers check the proposal maintains required aircraft separation. If it does, the proposal is either accepted or passed to agents whose trajectories change as part of the proposal for approval. Aircraft and operators can use all the data at hand to develop proposals that optimize their operations, while traffic managers can focus on their primary duty of ensuring

  5. Traffic flow modeling: a Genealogy

    NARCIS (Netherlands)

    Van Wageningen-Kessels, F.L.M.; Hoogendoorn, S.P.; Vuik, C.; Van Lint, J.W.C.

    2014-01-01

    80 years ago, Bruce Greenshields presented the first traffic flow model at the Annual Meeting of the Highway Research Board. Since then, many models and simulation tools have been developed. We show a model tree with four families of traffic flow models, all descending from Greenshields' model. The

  6. Probabilistic description of traffic flow

    International Nuclear Information System (INIS)

    A stochastic description of traffic flow, called probabilistic traffic flow theory, is developed. The general master equation is applied to relatively simple models to describe the formation and dissolution of traffic congestions. Our approach is mainly based on spatially homogeneous systems like periodically closed circular rings without on- and off-ramps. We consider a stochastic one-step process of growth or shrinkage of a car cluster (jam). As generalization we discuss the coexistence of several car clusters of different sizes. The basic problem is to find a physically motivated ansatz for the transition rates of the attachment and detachment of individual cars to a car cluster consistent with the empirical observations in real traffic. The emphasis is put on the analogy with first-order phase transitions and nucleation phenomena in physical systems like supersaturated vapour. The results are summarized in the flux-density relation, the so-called fundamental diagram of traffic flow, and compared with empirical data. Different regimes of traffic flow are discussed: free flow, congested mode as stop-and-go regime, and heavy viscous traffic. The traffic breakdown is studied based on the master equation as well as the Fokker-Planck approximation to calculate mean first passage times or escape rates. Generalizations are developed to allow for on-ramp effects. The calculated flux-density relation and characteristic breakdown times coincide with empirical data measured on highways. Finally, a brief summary of the stochastic cellular automata approach is given

  7. Complexity in Air Traffic Management

    OpenAIRE

    Delahaye, Daniel; Puechmorel, Stéphane; Dougui, Nour Elhouda

    2009-01-01

    Air traffic Management Requirements : -Insure separation between aircraft. -Avoid costly manoeuvres and optionally optimize trajectories. -Insure trafic organization. Trends : -Separation delegated to aircraft. -Trajectory based air traffic management. -Introduction of decision support tools / automated conflict solvers. Workload : -Related to cognitive processes of human controllers. -Easy/Hard forecasting of conflict occurrence. -Monitoring is a non negligible part of the workload. -Relevan...

  8. Road traffic noise and stroke

    DEFF Research Database (Denmark)

    Sørensen, Mette; Hvidberg, Martin; Andersen, Zorana J;

    2011-01-01

    Epidemiological studies suggest that long-term exposure to road traffic noise increases the risk of cardiovascular disorders. The aim of this study was to investigate the relation between exposure to road traffic noise and risk for stroke, which has not been studied before....

  9. 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.

  10. Dissociative Tendencies and Traffic Incidents

    Directory of Open Access Journals (Sweden)

    Valle, Virginia

    2012-01-01

    Full Text Available This paper analyses the relationship between dissociative experiences and road traffic incidents (crashes and traffic tickets in drivers (n=295 from Mar del Plata (Argentina city. A self-report questionnaire was applied to assess traffic crash involvement and sociodemographic variables. Dissociative tendencies were assessed by a modified version of the DES scale. To examine differences in DES scores tests of the difference of means were applied. Drivers who reported to be previously involved in traffic incidents obtained higher puntuations in the dissociative experiences scale than drivers who did not report such events. This result is observed for the total scale and for the three sub-scales (absorption, amnesia and depersonalization. However, differences appeared mainly for minor damage collisions. Further studies are needed to evaluate the role of dissociative tendencies as a risk factor in road traffic safety.

  11. Basic model for traffic interweave

    Science.gov (United States)

    Huang, Ding-wei

    2015-09-01

    We propose a three-parameter traffic model. The system consists of a loop with two junctions. The three parameters control the inflow, the outflow (from the junctions,) and the interweave (in the loop.) The dynamics is deterministic. The boundary conditions are stochastic. We present preliminary results for a complete phase diagram and all possible phase transitions. We observe four distinct traffic phases: free flow, congestion, bottleneck, and gridlock. The proposed model is able to present economically a clear perspective to these four different phases. Free flow and congestion are caused by the traffic conditions in the junctions. Both bottleneck and gridlock are caused by the traffic interweave in the loop. Instead of directly related to conventional congestion, gridlock can be taken as an extreme limit of bottleneck. This model can be useful to clarify the characteristics of traffic phases. This model can also be extended for practical applications.

  12. Biases caused by the instrument bandwidth and beam width on simulated brightness temperature measurements from scanning microwave radiometers

    Directory of Open Access Journals (Sweden)

    V. Meunier

    2012-11-01

    Full Text Available More so than the traditional fixed radiometers, the scanning radiometer requires a careful design to ensure high quality measurements. Here the impact of the radiometer characteristics (e.g. antenna beam width, receiver bandwidth and atmospheric propagation (e.g. curvature of the earth and refractivity on the scanning radiometer measurements are presented. A forward radiative transfer model that includes all these effects to represent the instrument measurements is used to estimate the biases as differences between the measurement with and without these characteristics for three commonly used frequency bands: K, V and W-band. The receiver channel bandwidth errors are not so important in K-band and W-band. Thus, the use of a wider bandwidth to improve detection at low signal-to-noise conditions is acceptable. The impact of the antenna beam width is higher than the receiver bandwidth, but, for V-band where they are of similar importance. Using simple regression algorithms, the effects of the bandwidth and beam width biases in liquid water path, integrated water vapor, and temperature are also examined. The largest errors in liquid water path and integrated water vapor are associated with the beam width errors.

  13. Traffic Impact Simulation for Road Construction Project

    OpenAIRE

    Yazao Yang; Xiaoni Hao; Junshao Luo

    2012-01-01

    With the increasing traffic contradiction between supply and demand, urban traffic problems have become quite complex. Reasons for traffic congestion have become much more diverse. During the construction of urban road project, the surrounding road network will encounter a huge impact, traffic problems therefore emerged. Simulation is an important means for transport impact assessment, which has an important role for construction traffic impact analysis. Accordingly, traffic simulation i...

  14. An Open-Source Microscopic Traffic Simulator

    OpenAIRE

    Treiber, Martin; Kesting, Arne

    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 ...

  15. Traffic Matrix Reloaded: Impact of Routing Changes

    OpenAIRE

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

    2005-01-01

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

  16. An Advanced Fuzzy Logic Based Traffic Controller

    OpenAIRE

    Bilal Ahmed Khan; Nai Shyan Lai

    2014-01-01

    Traffic light plays an important role in the urban traffic management. Therefore, it is necessary to improve the traffic controller for effective traffic management and better traffic flow leading to greener environment. In this paper, an advanced and intelligent traffic light controller is proposed, utilising the fuzzy logic technology and image processing technique. A fuzzy logic control has been implemented to provide the attribute of intelligence to the system. For real-time image acquisi...

  17. Simulation Study of a Traffic Light Assistant Based on Vehicle-Infrastructure Communication

    CERN Document Server

    Treiber, Martin

    2014-01-01

    Vehicle-infrastructure communication opens up new ways to improve traffic flow efficiency at signalized intersections. In this study, we assume that equipped vehicles can obtain information about switching times of relevant traffic lights in advance, and additionally counting data from upstream detectors. By means of simulation, we investigate, how equipped vehicles can make use of this information to improve traffic flow. Criteria include cycle-averaged capacity, driving comfort, fuel consumption, travel time, and the number of stops. Depending on the overall traffic demand and the penetration rate of equipped vehicles, we generally find several percent of improvement.

  18. A dispersive nanoSQUID magnetometer for ultra-low noise, high bandwidth flux detection

    International Nuclear Information System (INIS)

    We describe a dispersive nanoSQUID (nanoscale superconducting quantum interference device) magnetometer comprised of two variable thickness aluminum weak-link Josephson junctions shunted in parallel with an on-chip capacitor. This arrangement forms a nonlinear oscillator with a tunable 4–8 GHz resonant frequency with a quality factor Q = 30 when coupled directly to a 50 Ω transmission line. In the presence of a near-resonant microwave carrier signal, a low frequency flux input generates sidebands that are readily detected using microwave reflectometry. If the carrier excitation is sufficiently strong, then the magnetometer also exhibits parametric gain, resulting in a minimum effective flux noise of 30 nΦ0 Hz−1/2 with 20 MHz of instantaneous bandwidth. If the magnetometer is followed with a near-quantum-noise-limited Josephson parametric amplifier, we can increase the bandwidth to 60 MHz without compromising sensitivity. This combination of high sensitivity and wide bandwidth with no on-chip dissipation makes this device ideal for local sensing of spin dynamics, both classical and quantum. (paper)

  19. Modern Fiber Optic Submarine Cable Telecommunication Systems Planning for Explosive Bandwidth Needs at Different Deployment Depths

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-10-01

    Full Text Available The explosive bandwidth needs, especially in the inter data center market, have pushed transmission data rates to 100 Gbit/sec and beyond. Current terrestrial fibers are inadequate for long haul, high bandwidth deployments. To solve these problems a new fiber is introduced for terrestrial high bandwidth deployments: different polymeric core fibers with enlarged effective area with a significant optical signal to noise ratio improvement over other conventional terrestrial single mode fibers. To ensure the new fiber may be deployed robustly a new coating structure was employed. A rigorous cable structure was then chosen for evaluation. Based on experimental data, both the deep ocean water temperature and pressure are tailored as functions of the water depth. As well as the product of the transmitted bit rate and the repeater spacing is processed over wide ranges of the affecting parameters. It is taken into account the estimation of the total cost of the submarine fiber cable system for transmission technique under considerations. The system capacity as well as the spectral losses, and the dispersion effects are parametrically investigated over wide range ranges of the set of affecting parameters {wavelength, ocean depth (and consequently the ocean pressure and temperature, and the chemical structure}.

  20. Traffic information computing platform for big data

    International Nuclear Information System (INIS)

    Big data environment create data conditions for improving the quality of traffic information service. The target of this article is to construct a traffic information computing platform for big data environment. Through in-depth analysis the connotation and technology characteristics of big data and traffic information service, a distributed traffic atomic information computing platform architecture is proposed. Under the big data environment, this type of traffic atomic information computing architecture helps to guarantee the traffic safety and efficient operation, more intelligent and personalized traffic information service can be used for the traffic information users

  1. Web application for traffic flow forecasting

    OpenAIRE

    Dubravac, Dragan

    2015-01-01

    Disturbances in traffic on highways usually lead to an increase in traffic flow density or even traffic jams. The main goal of the diploma thesis is to produce an application that will predict traffic flow and traffic jams on any given date and time based on traffic flow in the past. By using an estimated desired speed the traffic information gained from flow counters we can forecast the evolution of traffic jams. The application presents a graph that represents the number of vehicles on a...

  2. Traffic information computing platform for big data

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Zongtao, E-mail: ztduan@chd.edu.cn; Li, Ying, E-mail: ztduan@chd.edu.cn; Zheng, Xibin, E-mail: ztduan@chd.edu.cn; Liu, Yan, E-mail: ztduan@chd.edu.cn; Dai, Jiting, E-mail: ztduan@chd.edu.cn; Kang, Jun, E-mail: ztduan@chd.edu.cn [Chang' an University School of Information Engineering, Xi' an, China and Shaanxi Engineering and Technical Research Center for Road and Traffic Detection, Xi' an (China)

    2014-10-06

    Big data environment create data conditions for improving the quality of traffic information service. The target of this article is to construct a traffic information computing platform for big data environment. Through in-depth analysis the connotation and technology characteristics of big data and traffic information service, a distributed traffic atomic information computing platform architecture is proposed. Under the big data environment, this type of traffic atomic information computing architecture helps to guarantee the traffic safety and efficient operation, more intelligent and personalized traffic information service can be used for the traffic information users.

  3. Evaluation of Intersection Traffic Control Measures through Simulation

    Science.gov (United States)

    Asaithambi, Gowri; Sivanandan, R.

    2015-12-01

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

  4. Automated Traffic Surveillance: Evolution and Implementation

    Directory of Open Access Journals (Sweden)

    Kriti Bhandari

    2013-08-01

    Full Text Available The rampant growth in use of four-wheelers has led to an increase in road congestion at all signal points. In the light of time constraints, drivers find an easier way out by breaking signals. Presently, our defense against such practices lies at the mercy of traffic policemen stationed at various signal points in the city and monitoring of surveillance cameras. However, constant manual monitoring is not always feasible because of limited manpower. Also, while the use of CCTV cameras only aids in monitoring, fine deduction is still looked after by individual traffic authorities. This system of automated surveillance is based on wireless RF transmission and circumvents the need of expensive wired fiber optic cables. The three key elements of this system include (a infrared transmitter and sensor (b a dual state transmitting system (c a control room managing the data base. The motion of a vehicle passing the pre-established line near the signal is judged by the infrared arrangement, including the strip of sensors on the lower surface of the vehicle under consideration and the IR transmitter on the surface of the road, precisely on the above mentioned limiting line at the signal. The presence of the vehicle thus detected will be accounted for by a transmitter installed in it, thus changing its regular state of transmission and providing the unique number of the offender’s vehicle to the control room. The transmission stage works on the RF frequency. FSK modulation being a reliable and apt scheme has been used for the purpose of modulation of data. This brings us to the next stage of the project dealing with the data base matching and there after sending a plan of action to the undersigned bank of the user wherein the fine deduction process will be initiated. Thus in this paper, we focus on simplifying surveillance by introducing automated monitoring system.

  5. Framework for Traffic Congestion Management

    Directory of Open Access Journals (Sweden)

    Mahmud Hassan TALUKDAR

    2013-06-01

    Full Text Available Traffic Congestion is one of many serious global problems in all great cities resulted from rapid urbanization which always exert negative externalities upon society. The solution of traffic congestion is highly geocentric and due to its heterogeneous nature, curbing congestion is one of the hard tasks for transport planners. It is not possible to suggest unique traffic congestion management framework which could be absolutely applied for every great cities. Conversely, it is quite feasible to develop a framework which could be used with or without minor adjustment to deal with congestion problem. So, the main aim of this paper is to prepare a traffic congestion mitigation framework which will be useful for urban planners, transport planners, civil engineers, transport policy makers, congestion management researchers who are directly or indirectly involved or willing to involve in the task of traffic congestion management. Literature review is the main source of information of this study. In this paper, firstly, traffic congestion is defined on the theoretical point of view and then the causes of traffic congestion are briefly described. After describing the causes, common management measures, using world- wide, are described and framework for supply side and demand side congestion management measures are prepared.

  6. Optimization Design Parameters of Electro-optic Modulators for Low Loss Wide Bandwidth Capability of Optical Communication Systems

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-06-01

    Full Text Available The effects of temperature, and operating signal wavelength on high frequency radio frequency transmission characteristics are deeply investigated against various materials based electro optic modulator devices such as lithium Niobate (LiNbO3, polymer, and semiconductor materials. On the other hand, we have developed the optimization of the electro optic modulator parameters where the effective index plays an essential role in the evaluation of the bandwidth structure. The effects of design parameters on the modulating voltage and optical bandwidth are also investigated for different materials based electro optic modulators by using rigorous transmission modeling techniques. The low loss wide bandwidth capability of optoelectronic systems makes them attractive for the transmission and processing of microwave signals, while the development of high capacity optical communication systems has required the use of modulation techniques in optical transmitters and receivers. This paper has presented the low loss wide bandwidth for different electrooptic modulators based on design of optimization parameters for high speed transmission performance.

  7. Traffic Light Detection at Night

    DEFF Research Database (Denmark)

    Jensen, Morten Bornø; Philipsen, Mark Philip; Bahnsen, Chris;

    2015-01-01

    Traffic light recognition (TLR) is an integral part of any in- telligent vehicle, it must function both at day and at night. However, the majority of TLR research is focused on day-time scenarios. In this paper we will focus on detection of traffic lights at night and evalu- ate the performance...... of three detectors based on heuristic models and one learning-based detector. Evaluation is done on night-time data from the public LISA Traffic Light Dataset. The learning-based detector out- performs the model-based detectors in both precision and recall. The learning-based detector achieves an average...

  8. Linearized Theory of Traffic Flow

    CERN Document Server

    Cohan, Tal

    2014-01-01

    The equation of motion of a general class of macroscopic traffic flow models is linearized around a steady uniform flow. A closed-form solution of a boundary-initial value problem is obtained, and it is used to describe several phenomena. Specifically, the scenarios examined involve a smooth velocity field in stop-and-go traffic, a discontinuous velocity field with shock waves in a traffic light problem, and discontinuous displacement fields in a problem where a single platoon of vehicles splits into two, and later merges back into one.

  9. Stress and Auditory Responses of the Otophysan Fish, Cyprinella venusta, to Road Traffic Noise.

    Directory of Open Access Journals (Sweden)

    Jenna A Crovo

    Full Text Available Noise pollution from anthropogenic sources is an increasingly problematic challenge faced by many taxa, including fishes. Recent studies demonstrate that road traffic noise propagates effectively from bridge crossings into surrounding freshwater ecosystems; yet, its effect on the stress response and auditory function of freshwater stream fishes is unexamined. The blacktail shiner (Cyprinella venusta was used as a model to investigate the degree to which traffic noise impacts stress and hearing in exposed fishes. Fish were exposed to an underwater recording of traffic noise played at approximately 140 dB re 1 μPa. Waterborne cortisol samples were collected and quantified using enzyme immunoassay (EIA. Auditory thresholds were assessed in control and traffic exposed groups by measuring auditory evoked potentials (AEPs. After acute exposure to traffic noise, fish exhibited a significant elevation in cortisol levels. Individuals exposed to 2 hours of traffic noise playback had elevated hearing thresholds at 300 and 400 Hz, corresponding to the most sensitive bandwidth for this species.

  10. Real-Time Corrected Traffic Correlation Model for Traffic Flow Forecasting

    OpenAIRE

    Lu, Hua-pu; Sun, Zhi-yuan; Qu, Wen-cong; Wang, Ling

    2015-01-01

    This paper focuses on the problems of short-term traffic flow forecasting. The main goal is to put forward traffic correlation model and real-time correction algorithm for traffic flow forecasting. Traffic correlation model is established based on the temporal-spatial-historical correlation characteristic of traffic big data. In order to simplify the traffic correlation model, this paper presents correction coefficients optimization algorithm. Considering multistate characteristic of traffic ...

  11. Spatiotemporal traffic-flow dependency and short-term traffic forecasting

    OpenAIRE

    Yang Yue; Anthony Gar-On Yeh

    2008-01-01

    Short-term traffic forecasting is playing an increasing role in modern transport management. Although many short-term traffic forecasting methods have been explored, the spatiotemporal dependency of traffic flow, an important characteristic of traffic dynamics that can benefit the forecasting of traffic changes, is often neglected in short-term traffic forecasting. This paper first investigates the spatiotemporal dependency of traffic flow using cross-correlation analysis and then discusses i...

  12. Transition Characteristic Analysis of Traffic Evolution Process for Urban Traffic Network

    OpenAIRE

    Longfei Wang; Hong Chen; Yang Li

    2014-01-01

    The characterization of the dynamics of traffic states remains fundamental to seeking for the solutions of diverse traffic problems. To gain more insights into traffic dynamics in the temporal domain, this paper explored temporal characteristics and distinct regularity in the traffic evolution process of urban traffic network. We defined traffic state pattern through clustering multidimensional traffic time series using self-organizing maps and construct a pattern transition network model tha...

  13. Cubesat Constellation Design for Air Traffic Monitoring

    Science.gov (United States)

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

    2015-01-01

    Suitably equipped global and local air traffic can be tracked. The tracking information may then be used for control from ground-based stations by receiving the Automatic Dependent Surveillance-Broadcast (ADS-B) signal. The ADS-B signal, emitted from the aircraft's Mode-S transponder, is currently tracked by terrestrial based receivers but not over remote oceans or sparsely populated regions such as Alaska or the Pacific Ocean. Lack of real-time aircraft time/location information in remote areas significantly hinders optimal planning and control because bigger "safety bubbles" (lateral and vertical separation) are required around the aircraft until they reach radar-controlled airspace. Moreover, it presents a search-and-rescue bottleneck. Aircraft in distress, e.g. Air France AF449 that crashed in 2009, take days to be located or cannot be located at all, e.g. Malaysia Airlines MH370 in 2014. In this paper, we describe a tool for designing a constellation of small satellites which demonstrates, through high-fidelity modeling based on simulated air traffic data, the value of space-based ADS-B monitoring and provides recommendations for cost-efficient deployment of a constellation of small satellites to increase safety and situational awareness in the currently poorly-served surveillance area of Alaska. Air traffic data has been obtained from the Future ATM Concepts Evaluation Tool (FACET), developed at NASA Ames Research Center, simulated over the Alaskan airspace over a period of one day. The simulation is driven by MATLAB with satellites propagated and coverage calculated using AGI's Satellite ToolKit(STK10).

  14. Traffic visualization - applying information visualization techniques to enhance traffic planning

    OpenAIRE

    Picozzi, Matteo; Verdezoto, Nervo; Pouke, Matti; Vatjus-Anttila, Jarkko; Quigley, Aaron John

    2013-01-01

    In this paper, we present a space-time visualization to provide city’s decision-makers the ability to analyse and uncover important “city events” in an understandable manner for city planning activities. An interactive Web mashup visualization is presented that integrates several visualization techniques to give a rapid overview of traffic data. We illustrate our approach as a case study for traffic visualization systems, using datasets from the city of Oulu that can be extended to other city...

  15. Effects of turning and through lane sharing on traffic performance at intersections

    Science.gov (United States)

    Li, Xiang; Sun, Jian-Qiao

    2016-02-01

    Turning vehicles strongly influence traffic flows at intersections. Effective regulation of turning vehicles is important to achieve better traffic performance. This paper studies the impact of lane sharing and turning signals on traffic performance at intersections by using cellular automata. Both right-turn and left-turn lane sharing are studied. Interactions between vehicles and pedestrians are considered. The transportation efficiency, road safety and energy economy are the traffic performance metrics. Extensive simulations are carried out to study the traffic performance indices. It is observed that shared turning lanes and permissive left-turn signal improve the transportation efficiency and reduce the fuel consumption in most cases, but the safety is usually sacrificed. It is not always beneficial for the through vehicles when they are allowed to be in the turning lanes.

  16. 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.

  17. Benefits of Bandwidth Feedback in Learning a Complex Gymnastic Skill

    Science.gov (United States)

    Sadowski, Jerzy; Mastalerz, Andrzej; Niznikowski, Tomasz

    The aim of this study was to examine the effects of two different frequencies of feedback during the process of learning a complex gymnastic skill, the round-off salto backward tucked. Thirty male acrobats participated in the study. They were randomly assigned to two groups: B - bandwidth feedback (n=15) or C - 100% feedback (n=15). Group B was provided with error information regarding the key elements of movement techniques only (bandwidth feedback). Our research demonstrates the advantage of augmented feedback information related to errors in the key elements. Information about errors in the key elements during learning a complex gymnastic skill prevents the gymnast from becoming overwhelmed, which promotes better motor control. These results provide support for the generalisation of bandwidth feedback principles to a complex task. Our research shows that the guidance hypothesis can also be tested in practical settings for a complex movement task. PMID:24146719

  18. The bandwidth of optimized nonlinear vibration-based energy harvesters

    International Nuclear Information System (INIS)

    In an attempt to improve the performance of vibration-based energy harvesters, many authors suggest that nonlinearities can be exploited to increase the bandwidths of linear devices. Nevertheless, the complex dependence of the response upon the input excitation has made a realistic comparison of linear harvesters with nonlinear energy harvesters challenging. In a previous work it has been demonstrated that for a given frequency of excitation, it is possible to achieve the same maximum power for a nonlinear harvester as that for a linear harvester, provided that the resistance and the linear stiffness of both are optimized. This work focuses on the bandwidths of linear and nonlinear harvesters and shows which device is more suitable for harvesting energy from vibrations. The work considers different levels of excitation as well as different frequencies of excitation. In addition, the effect of the mechanical damping of the oscillator on the power bandwidth is shown for both the linear and nonlinear cases. (paper)

  19. Analysis of bandwidth measurement methodologies over WLAN systems

    CERN Document Server

    Portoles-Comeras, Marc; Mangues-Bafalluy, Josep; Domingo-Pascual, Jordi

    2009-01-01

    WLAN devices have become a fundamental component of nowadays network deployments. However, even though traditional networking applications run mostly unchanged over wireless links, the actual interaction between these applications and the dynamics of wireless transmissions is not yet fully understood. An important example of such applications are bandwidth estimation tools. This area has become a mature research topic with well-developed results. Unfortunately recent studies have shown that the application of these results to WLAN links is not straightforward. The main reasons for this is that the assumptions taken to develop bandwidth measurements tools do not hold any longer in the presence of wireless links (e.g. non-FIFO scheduling). This paper builds from these observations and its main goal is to analyze the interaction between probe packets and WLAN transmissions in bandwidth estimation processes. The paper proposes an analytical model that better accounts for the particularities of WLAN links. The mod...

  20. INCREASING BANDWIDTH ON CELL BREATHING TECHNOLOGY USING RAT ALGORITHM

    Directory of Open Access Journals (Sweden)

    S.Manikandan*

    2015-08-01

    Full Text Available In a typical enterprise WLAN, it is difficult to identify and implement the types of network settings which cause poor performance where number of hosts may attain larger share of the available bandwidth in a access point within a limited boundary under the con cept of cell breathing technique. This approach can leads to unequal load sharing and diminished system performance. Our work can be focused on the process of regulating the bandwidth so that no user can access data more than the specified limit for a part icular access point and provide large bandwidth wherever needed. In this way the different users will get an efficient access over the network. We consider the RAT (Rate Access Technologies policy which leads to better system performance. The RAT policy h as been applied on home - grown centralized WLAN controller, ADWISER and reveals that the RAT policy definitely affords to be effective system performance