Sample records for abnormal dns traffic

  1. Mining IP to Domain Name Interactions to Detect DNS Flood Attacks on Recursive DNS Servers.

    PubMed

    Alonso, Roberto; Monroy, Raúl; Trejo, Luis A

    2016-08-17

    The Domain Name System (DNS) is a critical infrastructure of any network, and, not surprisingly a common target of cybercrime. There are numerous works that analyse higher level DNS traffic to detect anomalies in the DNS or any other network service. By contrast, few efforts have been made to study and protect the recursive DNS level. In this paper, we introduce a novel abstraction of the recursive DNS traffic to detect a flooding attack, a kind of Distributed Denial of Service (DDoS). The crux of our abstraction lies on a simple observation: Recursive DNS queries, from IP addresses to domain names, form social groups; hence, a DDoS attack should result in drastic changes on DNS social structure. We have built an anomaly-based detection mechanism, which, given a time window of DNS usage, makes use of features that attempt to capture the DNS social structure, including a heuristic that estimates group composition. Our detection mechanism has been successfully validated (in a simulated and controlled setting) and with it the suitability of our abstraction to detect flooding attacks. To the best of our knowledge, this is the first time that work is successful in using this abstraction to detect these kinds of attacks at the recursive level. Before concluding the paper, we motivate further research directions considering this new abstraction, so we have designed and tested two additional experiments which exhibit promising results to detect other types of anomalies in recursive DNS servers.

  2. Mining IP to Domain Name Interactions to Detect DNS Flood Attacks on Recursive DNS Servers

    PubMed Central

    Alonso, Roberto; Monroy, Raúl; Trejo, Luis A.

    2016-01-01

    The Domain Name System (DNS) is a critical infrastructure of any network, and, not surprisingly a common target of cybercrime. There are numerous works that analyse higher level DNS traffic to detect anomalies in the DNS or any other network service. By contrast, few efforts have been made to study and protect the recursive DNS level. In this paper, we introduce a novel abstraction of the recursive DNS traffic to detect a flooding attack, a kind of Distributed Denial of Service (DDoS). The crux of our abstraction lies on a simple observation: Recursive DNS queries, from IP addresses to domain names, form social groups; hence, a DDoS attack should result in drastic changes on DNS social structure. We have built an anomaly-based detection mechanism, which, given a time window of DNS usage, makes use of features that attempt to capture the DNS social structure, including a heuristic that estimates group composition. Our detection mechanism has been successfully validated (in a simulated and controlled setting) and with it the suitability of our abstraction to detect flooding attacks. To the best of our knowledge, this is the first time that work is successful in using this abstraction to detect these kinds of attacks at the recursive level. Before concluding the paper, we motivate further research directions considering this new abstraction, so we have designed and tested two additional experiments which exhibit promising results to detect other types of anomalies in recursive DNS servers. PMID:27548169

  3. Methods and systems for detecting abnormal digital traffic

    DOEpatents

    Goranson, Craig A [Kennewick, WA; Burnette, John R [Kennewick, WA

    2011-03-22

    Aspects of the present invention encompass methods and systems for detecting abnormal digital traffic by assigning characterizations of network behaviors according to knowledge nodes and calculating a confidence value based on the characterizations from at least one knowledge node and on weighting factors associated with the knowledge nodes. The knowledge nodes include a characterization model based on prior network information. At least one of the knowledge nodes should not be based on fixed thresholds or signatures. The confidence value includes a quantification of the degree of confidence that the network behaviors constitute abnormal network traffic.

  4. Video Traffic Analysis for Abnormal Event Detection

    DOT National Transportation Integrated Search

    2010-01-01

    We propose the use of video imaging sensors for the detection and classification of abnormal events to be used primarily for mitigation of traffic congestion. Successful detection of such events will allow for new road guidelines; for rapid deploymen...

  5. Video traffic analysis for abnormal event detection.

    DOT National Transportation Integrated Search

    2010-01-01

    We propose the use of video imaging sensors for the detection and classification of abnormal events to : be used primarily for mitigation of traffic congestion. Successful detection of such events will allow for : new road guidelines; for rapid deplo...

  6. DNS and Embedded DNS as Tools for Investigating Unsteady Heat Transfer Phenomena in Turbines

    NASA Technical Reports Server (NTRS)

    vonTerzi, Dominic; Bauer, H.-J.

    2010-01-01

    DNS is a powerful tool with high potential for investigating unsteady heat transfer and fluid flow phenomena, in particular for cases involving transition to turbulence and/or large coherent structures. - DNS of idealized configurations related to turbomachinery components is already possible. - For more realistic configurations and the inclusion of more effects, reduction of computational cost is key issue (e.g., hybrid methods). - Approach pursued here: Embedded DNS ( segregated coupling of DNS with LES and/or RANS). - Embedded DNS is an enabling technology for many studies. - Pre-transitional heat transfer and trailing-edge cutback film-cooling are good candidates for (embedded) DNS studies.

  7. Mixed Pattern Matching-Based Traffic Abnormal Behavior Recognition

    PubMed Central

    Cui, Zhiming; Zhao, Pengpeng

    2014-01-01

    A motion trajectory is an intuitive representation form in time-space domain for a micromotion behavior of moving target. Trajectory analysis is an important approach to recognize abnormal behaviors of moving targets. Against the complexity of vehicle trajectories, this paper first proposed a trajectory pattern learning method based on dynamic time warping (DTW) and spectral clustering. It introduced the DTW distance to measure the distances between vehicle trajectories and determined the number of clusters automatically by a spectral clustering algorithm based on the distance matrix. Then, it clusters sample data points into different clusters. After the spatial patterns and direction patterns learned from the clusters, a recognition method for detecting vehicle abnormal behaviors based on mixed pattern matching was proposed. The experimental results show that the proposed technical scheme can recognize main types of traffic abnormal behaviors effectively and has good robustness. The real-world application verified its feasibility and the validity. PMID:24605045

  8. LES versus DNS: A comparative study

    NASA Technical Reports Server (NTRS)

    Shtilman, L.; Chasnov, J. R.

    1992-01-01

    We have performed Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of forced isotropic turbulence at moderate Reynolds numbers. The subgrid scale model used in the LES is based on an eddy viscosity which adjusts instantaneously the energy spectrum of the LES to that of the DNS. The statistics of the large scales of the DNS (filtered DNS field or fDNS) are compared to that of the LES. We present results for the transfer spectra, the skewness and flatness factors of the velocity components, the PDF's of the angle between the vorticity and the eigenvectors of the rate of strain, and that between the vorticity and the vorticity stretching tensor. The above LES statistics are found to be in good agreement with those measured in the fDNS field. We further observe that in all the numerical measurements, the trend was for the LES field to be more gaussian than the fDNS field. Future research on this point is planned.

  9. A quantification method for numerical dissipation in quasi-DNS and under-resolved DNS, and effects of numerical dissipation in quasi-DNS and under-resolved DNS of turbulent channel flows

    NASA Astrophysics Data System (ADS)

    Komen, E. M. J.; Camilo, L. H.; Shams, A.; Geurts, B. J.; Koren, B.

    2017-09-01

    LES for industrial applications with complex geometries is mostly characterised by: a) a finite volume CFD method using a non-staggered arrangement of the flow variables and second order accurate spatial and temporal discretisation schemes, b) an implicit top-hat filter, where the filter length is equal to the local computational cell size, and c) eddy-viscosity type LES models. LES based on these three main characteristics is indicated as industrial LES in this paper. It becomes increasingly clear that the numerical dissipation in CFD codes typically used in industrial applications with complex geometries may inhibit the predictive capabilities of explicit LES. Therefore, there is a need to quantify the numerical dissipation rate in such CFD codes. In this paper, we quantify the numerical dissipation rate in physical space based on an analysis of the transport equation for the mean turbulent kinetic energy. Using this method, we quantify the numerical dissipation rate in a quasi-Direct Numerical Simulation (DNS) and in under-resolved DNS of, as a basic demonstration case, fully-developed turbulent channel flow. With quasi-DNS, we indicate a DNS performed using a second order accurate finite volume method typically used in industrial applications. Furthermore, we determine and explain the trends in the performance of industrial LES for fully-developed turbulent channel flow for four different Reynolds numbers for three different LES mesh resolutions. The presented explanation of the mechanisms behind the observed trends is based on an analysis of the turbulent kinetic energy budgets. The presented quantitative analyses demonstrate that the numerical errors in the industrial LES computations of the considered turbulent channel flows result in a net numerical dissipation rate which is larger than the subgrid-scale dissipation rate. No new computational methods are presented in this paper. Instead, the main new elements in this paper are our detailed quantification

  10. Analysis of DNS Cache Effects on Query Distribution

    PubMed Central

    2013-01-01

    This paper studies the DNS cache effects that occur on query distribution at the CN top-level domain (TLD) server. We first filter out the malformed DNS queries to purify the log data pollution according to six categories. A model for DNS resolution, more specifically DNS caching, is presented. We demonstrate the presence and magnitude of DNS cache effects and the cache sharing effects on the request distribution through analytic model and simulation. CN TLD log data results are provided and analyzed based on the cache model. The approximate TTL distribution for domain name is inferred quantificationally. PMID:24396313

  11. Analysis of DNS cache effects on query distribution.

    PubMed

    Wang, Zheng

    2013-01-01

    This paper studies the DNS cache effects that occur on query distribution at the CN top-level domain (TLD) server. We first filter out the malformed DNS queries to purify the log data pollution according to six categories. A model for DNS resolution, more specifically DNS caching, is presented. We demonstrate the presence and magnitude of DNS cache effects and the cache sharing effects on the request distribution through analytic model and simulation. CN TLD log data results are provided and analyzed based on the cache model. The approximate TTL distribution for domain name is inferred quantificationally.

  12. Hydroacoustic forcing function modeling using DNS database

    NASA Technical Reports Server (NTRS)

    Zawadzki, I.; Gershfield, J. L.; Na, Y.; Wang, M.

    1996-01-01

    A wall pressure frequency spectrum model (Blake 1971 ) has been evaluated using databases from Direct Numerical Simulations (DNS) of a turbulent boundary layer (Na & Moin 1996). Good agreement is found for moderate to strong adverse pressure gradient flows in the absence of separation. In the separated flow region, the model underpredicts the directly calculated spectra by an order of magnitude. The discrepancy is attributed to the violation of the model assumptions in that part of the flow domain. DNS computed coherence length scales and the normalized wall pressure cross-spectra are compared with experimental data. The DNS results are consistent with experimental observations.

  13. DNS Rebinding Attacks

    DTIC Science & Technology

    2009-09-01

    active scripting, file downloads, installation of desktop items, signed and unsigned ActiveX controls, Java permissions, launching applications and...files in an IFRAME, running ActiveX controls and plug-ins, and scripting of Java applets [49]. This security measure is very effective against DNS

  14. [Traffic accidents associated with emotional stress after divorce].

    PubMed

    Cui, Li-Juan; Yi, Xu-Fu; Chen, Xiao-Gang

    2009-04-01

    In recent years, the traffic accidents increased gradually, especially those caused by the drivers daily emotional abnormality and in which the drivers were liable. This article reviewed the traffic accidents caused by divorced driver's emotional abnormality, illustrated the features of those accidents from the gender, age, occupation and mileage of drivers. It was considered that the major cause of those accidents was excessive drinking due to drivers' emotional stress. Suggestions about preventing the traffic accidents caused by emotional abnormality were put forward so as to make the corresponding rules and finally decrease the emotional abnormality traffic accidents.

  15. Touring DNS Open Houses for Trends and Configurations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kalafut, Prof. Andrew; Shue, Craig A; Gupta, Prof. Minaxi

    2011-01-01

    DNS is a critical component of the Internet. It maps domain names to IP addresses and serves as a distributed database for various other applications, including mail, Web, and spam filtering. This paper examines DNS zones in the Internet for diversity, adoption rates of new technologies, and prevalence of configuration issues. To gather data, we sweep 60% of the Internet's domains in June - August 2007 for zone transfers. 6.6% of them allow us to transfer their complete information. Surprisingly, this includes a large fraction of the domains deploying DNSSEC. We find that DNS zones vary significantly in size andmore » some span many ASes. Also, while anti-spam technologies appear to be getting deployed, the adoption rates of DNSSEC and IPv6 continue to be low. Finally, we also find that carelessness in handing DNS records can lead to reduced availability of name servers, email, and Web servers. This also undermines anti-spam efforts and the efforts to shut down phishing sites or to contain malware infections.« less

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

    PubMed

    Malakis, Stathis; Kontogiannis, Tom; Kirwan, Barry

    2010-07-01

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

  17. Numerical Investigation of Transition in Supersonic Boundary Layers Using DNS and LES

    DTIC Science & Technology

    2008-03-31

    stream values of velocity, temperature, density, and specific heat ( Uro , Tio, Pe and C2, respectively). For investigations of flows over cones, free...field is simulated without those assumptions for the current investigations. For 2,5 2 UI.l UL u* lO Pn 2BL - - Tl" TU o DNS ’. DNS PDNS T DNS T DNS 025...Because primary amplitude levels impact the resonance behavior, the resonance lo - cation moved upstream to R., = 1, 800 and the nonlinear amplification

  18. DNS load balancing in the CERN cloud

    NASA Astrophysics Data System (ADS)

    Reguero Naredo, Ignacio; Lobato Pardavila, Lorena

    2017-10-01

    Load Balancing is one of the technologies enabling deployment of large-scale applications on cloud resources. A DNS Load Balancer Daemon (LBD) has been developed at CERN as a cost-effective way to balance applications accepting DNS timing dynamics and not requiring persistence. It currently serves over 450 load-balanced aliases with two small VMs acting as master and slave. The aliases are mapped to DNS subdomains. These subdomains are managed with DDNS according to a load metric, which is collected from the alias member nodes with SNMP. During the last years, several improvements were brought to the software, for instance: support for IPv6, parallelization of the status requests, implementing the client in Python to allow for multiple aliases with differentiated states on the same machine or support for application state. The configuration of the Load Balancer is currently managed by a Puppet type. It discovers the alias member nodes and gets the alias definitions from the Ermis REST service. The Aiermis self-service GUI for the management of the LB aliases has been produced and is based on the Ermis service above that implements a form of Load Balancing as a Service (LBaaS). The Ermis REST API has authorisation based in Foreman hostgroups. The CERN DNS LBD is Open Software with Apache 2 license.

  19. Towards Petascale DNS of High Reynolds-Number Turbulent Boundary Layer

    NASA Astrophysics Data System (ADS)

    Webster, Keegan R.

    In flight vehicles, a large portion of fuel consumption is due to skin-friction drag. Reduction of this drag will significantly reduce the fuel consumption of flight vehicles and help our nation to reduce CO 2 emissions. In order to reduce skin-friction drag, an increased understanding of wall-turbulence is needed. Direct numerical simulation (DNS) of spatially developing turbulent boundary layers (SDTBL) can provide the fundamental understanding of wall-turbulence in order to produce models for Reynolds averaged Navier-Stokes (RANS) and large-eddy simulations (LES). DNS of SDTBL over a flat plate at Retheta = 1430 - 2900 were performed. Improvements were made to the DNS code allowing for higher Reynolds number simulations towards petascale DNS of turbulent boundary layers. Mesh refinement and improvements to the inflow and outflow boundary conditions have resulted in turbulence statistics that match more closely to experimental results. The Reynolds stresses and the terms of their evolution equations are reported.

  20. The Use of DNS in Turbulence Modeling

    NASA Technical Reports Server (NTRS)

    Mansour, Nagi N.; Merriam, Marshal (Technical Monitor)

    1997-01-01

    The use of Direct numerical simulations (DNS) data in developing and testing turbulence models is reviewed. The data is used to test turbulence models at all levels: algebraic, one-equation, two-equation and full Reynolds stress models were tested. Particular examples on the development of models for the dissipation rate equation are presented. Homogeneous flows are used to test new scaling arguments for the various terms in the dissipation rate equation. The channel flow data is used to develop modifications to the equation model that take into account near-wall effects. DNS of compressible flows under mean compression are used in testing new compressible modifications to the two-equation models.

  1. Detailed characteristics of drop-laden mixing layers: LES predictions compared to DNS

    NASA Technical Reports Server (NTRS)

    Okong'o, N.; Leboissetier, A.; Bellan, J.

    2004-01-01

    Results have been compared from Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) of a temporal mixing layer laden with evaporating drops, to assess the ability of LES to reproduce detailed characteristics of DNS.

  2. Abnormal responses to the carcinogen 4-nitroquinoline 1-oxide of cultured fibroblasts from patients with dysplastic nevus syndrome and hereditary cutaneous malignant melanoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith, P.J.; Greene, M.H.; Adams, D.

    The dysplastic nevus syndrome (DNS) is a preneoplastic melanocyte abnormality which occurs in families affected by hereditary cutaneous malignant melanoma (HCMM). A putative role of host-environmental interactions in the etiology of hereditary melanoma has been strengthened by the recent finding that fibroblasts derived from HCMM/DNS patients demonstrated enhanced sensitivity to u.v.-irradiation in vitro. An extension of these studies is reported in which we have examined the invitro responses to a model environmental carcinogen, 4-nitroquinoline 1-oxide (4NQO), of six non-tumor skin fibroblast strains from HCMM/DNS patients representing five families. Three of the six HCMM/DNS strains showed enhanced cell killing with sensitivitiesmore » greater than that of a xeroderma pigmentosum (XP) variant strain but less than those of ataxia telangiectasia and XP Group D cell strains. The inhibition and recovery of de novo DNA synthesis, together with the expression of repair synthesis, following 4NQO exposure appeared to be normal in HCMM/DNS strains, irrespective of their subsequent clonogenic potential. The data point to a metabolic anomaly which may contribute to the carcinogenic risk of the melanoma prone preneoplastic state presented by some DNS patients.« less

  3. 75 FR 11939 - DNS Electronics, Chandler, AZ; Notice of Termination of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,654] DNS Electronics, Chandler, AZ; Notice of Termination of Investigation Pursuant to Section 223 of the Trade Act of 1974, as... on behalf of workers of DNS Electronics, Chandler, Arizona. The petitioning group of workers is...

  4. Leveraging Client-Side DNS Failure Patterns to Identify Malicious Behaviors

    DTIC Science & Technology

    2015-09-28

    malicious behavior found in our dataset and (ii) to create ground truth to evaluate the system proposed in Section V. We begin by removing those cases that...2011. [10] S. Hao, N. Feamster, and R. Pandrangi, “Monitoring the Initial DNS Behavior of Malicious Domains,” in ACM IMC , 2011. [11] R. Perdisci et...distribution is unlimited. Leveraging Client-Side DNS Failure Patterns to Identify Malicious Behaviors The views, opinions and/or findings contained in

  5. Evaluation of a vortex-based subgrid stress model using DNS databases

    NASA Technical Reports Server (NTRS)

    Misra, Ashish; Lund, Thomas S.

    1996-01-01

    The performance of a SubGrid Stress (SGS) model for Large-Eddy Simulation (LES) developed by Misra k Pullin (1996) is studied for forced and decaying isotropic turbulence on a 32(exp 3) grid. The physical viability of the model assumptions are tested using DNS databases. The results from LES of forced turbulence at Taylor Reynolds number R(sub (lambda)) approximately equals 90 are compared with filtered DNS fields. Probability density functions (pdfs) of the subgrid energy transfer, total dissipation, and the stretch of the subgrid vorticity by the resolved velocity-gradient tensor show reasonable agreement with the DNS data. The model is also tested in LES of decaying isotropic turbulence where it correctly predicts the decay rate and energy spectra measured by Comte-Bellot & Corrsin (1971).

  6. Discussion of DNS: Past, Present, and Future

    NASA Technical Reports Server (NTRS)

    Joslin, Ronald D.

    1997-01-01

    This paper covers the review, status, and projected future of direct numerical simulation (DNS) methodology relative to the state-of-the-art in computer technology, numerical methods, and the trends in fundamental research programs.

  7. An a priori DNS study of the shadow-position mixing model

    DOE PAGES

    Zhao, Xin -Yu; Bhagatwala, Ankit; Chen, Jacqueline H.; ...

    2016-01-15

    In this study, the modeling of mixing by molecular diffusion is a central aspect for transported probability density function (tPDF) methods. In this paper, the newly-proposed shadow position mixing model (SPMM) is examined, using a DNS database for a temporally evolving di-methyl ether slot jet flame. Two methods that invoke different levels of approximation are proposed to extract the shadow displacement (equivalent to shadow position) from the DNS database. An approach for a priori analysis of the mixing-model performance is developed. The shadow displacement is highly correlated with both mixture fraction and velocity, and the peak correlation coefficient of themore » shadow displacement and mixture fraction is higher than that of the shadow displacement and velocity. This suggests that the composition-space localness is reasonably well enforced by the model, with appropriate choices of model constants. The conditional diffusion of mixture fraction and major species from DNS and from SPMM are then compared, using mixing rates that are derived by matching the mixture fraction scalar dissipation rates. Good qualitative agreement is found, for the prediction of the locations of zero and maximum/minimum conditional diffusion locations for mixture fraction and individual species. Similar comparisons are performed for DNS and the IECM (interaction by exchange with the conditional mean) model. The agreement between SPMM and DNS is better than that between IECM and DNS, in terms of conditional diffusion iso-contour similarities and global normalized residual levels. It is found that a suitable value for the model constant c that controls the mixing frequency can be derived using the local normalized scalar variance, and that the model constant a controls the localness of the model. A higher-Reynolds-number test case is anticipated to be more appropriate to evaluate the mixing models, and stand-alone transported PDF simulations are required to more fully enforce

  8. One-dimensional turbulence modeling of a turbulent counterflow flame with comparison to DNS

    DOE PAGES

    Jozefik, Zoltan; Kerstein, Alan R.; Schmidt, Heiko; ...

    2015-06-01

    The one-dimensional turbulence (ODT) model is applied to a reactant-to-product counterflow configuration and results are compared with DNS data. The model employed herein solves conservation equations for momentum, energy, and species on a one dimensional (1D) domain corresponding to the line spanning the domain between nozzle orifice centers. The effects of turbulent mixing are modeled via a stochastic process, while the Kolmogorov and reactive length and time scales are explicitly resolved and a detailed chemical kinetic mechanism is used. Comparisons between model and DNS results for spatial mean and root-mean-square (RMS) velocity, temperature, and major and minor species profiles aremore » shown. The ODT approach shows qualitatively and quantitatively reasonable agreement with the DNS data. Scatter plots and statistics conditioned on temperature are also compared for heat release rate and all species. ODT is able to capture the range of results depicted by DNS. As a result, conditional statistics show signs of underignition.« less

  9. The validity of multiphase DNS initialized on the basis of single--point statistics

    NASA Astrophysics Data System (ADS)

    Subramaniam, Shankar

    1999-11-01

    A study of the point--process statistical representation of a spray reveals that single--point statistical information contained in the droplet distribution function (ddf) is related to a sequence of single surrogate--droplet pdf's, which are in general different from the physical single--droplet pdf's. The results of this study have important consequences for the initialization and evolution of direct numerical simulations (DNS) of multiphase flows, which are usually initialized on the basis of single--point statistics such as the average number density in physical space. If multiphase DNS are initialized in this way, this implies that even the initial representation contains certain implicit assumptions concerning the complete ensemble of realizations, which are invalid for general multiphase flows. Also the evolution of a DNS initialized in this manner is shown to be valid only if an as yet unproven commutation hypothesis holds true. Therefore, it is questionable to what extent DNS that are initialized in this manner constitute a direct simulation of the physical droplets.

  10. (DNS)C: a fluorescent, environmentally sensitive cytidine derivative for the direct detection of GGG triad sequences.

    PubMed

    Kim, Ki Tae; Kim, Hyun Woo; Moon, Dohyun; Rhee, Young Min; Kim, Byeang Hyean

    2013-09-14

    With the goal of developing a fluorescent nucleoside sensitive to its environment, in this study we synthesized (DNS)C, a novel modified 2'-deoxycytidine bearing a 5-(dimethylamino)naphthalene-1-sulfonyl (dansyl) moiety at the N4 position, and tested its properties in monomeric and oligomeric states. (DNS)C undergoes intramolecular photoinduced electron transfer between its dansyl and cytosine units, resulting in remarkable changes in fluorescence that depend on the choice of solvent. In addition, the fluorescence behavior and thermal stability of oligonucleotides containing (DNS)C are dependent on the nature of the flanking and neighboring bases. Notably, (DNS)C exhibits fluorescence enhancement only in fully matched duplex DNA containing a GGG triad sequence. The environmental sensitivity of (DNS)C can be exploited as a fluorescence tool for monitoring the interactions of DNA with other biomolecules, including DNA, RNA, and proteins.

  11. High speed turbulent reacting flows: DNS and LES

    NASA Technical Reports Server (NTRS)

    Givi, Peyman

    1990-01-01

    Work on understanding the mechanisms of mixing and reaction in high speed turbulent reacting flows was continued. Efforts, in particular, were concentrated on taking advantage of modern computational methods to simulate high speed turbulent flows. In doing so, two methodologies were used: large eddy simulations (LES) and direct numerical simulations (DNS). In the work related with LES the objective is to study the behavior of the probability density functions (pdfs) of scalar properties within the subgrid in reacting turbulent flows. The data base obtained by DNS for a detailed study of the pdf characteristics within the subgrid was used. Simulations are performed for flows under various initializations to include the effects of compressibility on mixing and chemical reactions. In the work related with DNS, a two-dimensional temporally developing high speed mixing layer under the influence of a second-order non-equilibrium chemical reaction of the type A + B yields products + heat was considered. Simulations were performed with different magnitudes of the convective Mach numbers and with different chemical kinetic parameters for the purpose of examining the isolated effects of the compressibility and the heat released by the chemical reactions on the structure of the layer. A full compressible code was developed and utilized, so that the coupling between mixing and chemical reactions is captured in a realistic manner.

  12. Addressing the Confusion Related to DNS, DNSc, and DSN Degrees, With Lessons for the Nursing Profession.

    PubMed

    Reid Ponte, Patricia; Nicholas, Patrice K

    2015-07-01

    This article examines the evolution of Doctor of Nursing Science (DNS or DNSc) and Doctor of Science in Nursing (DSN) degrees, including their emergence as research-intensive doctoral degrees in the 1960s, efforts to distinguish the degrees from the Doctor of Philosophy (PhD) and Doctor of Nursing Practice (DNP) degrees, the recent decline in program numbers, and implications for degree holders. The article reviews the U.S. history of doctoral education in nursing, research examining similarities and differences between the PhD and DNS, DNSc, or DSN degrees, and how the DNS, DNSc, or DSN degree differs from DNP programs. The article also examines the confusion regarding the focus of the DNS, DNSc, or DSN degree among nurses, patients, and potential funders; and describes actions taken by universities to address the confusion, with examples provided by academic deans, nurse leaders, and nurse researchers. Longstanding confusion about the research merits of the DNS, DNSc, or DSN degree, and the growing prominence of the similarly-titled DNP degree, has created confusion about the focus of DNS, DNSc, or DSN programs and the capabilities of degree holders. Many universities have addressed this confusion by converting their DNS, DNSc, and DSN programs to a PhD or retroactively converting degrees to a PhD. Other universities have chosen not to pursue this route. The DNS, DNSc, or DSN experience highlights the importance of clarifying and standardizing the purpose and goals of nursing education programs and the repercussions for degree holders when such clarity is lacking. The international academic nursing communities have consistently pursued one doctoral-level nursing degree and therefore have not shared this challenging landscape in nursing education. Findings and recommendations presented in this article have implications for schools of nursing and professional groups that oversee the development of educational programs and pathways for nurses. © 2015 Sigma Theta

  13. Mechanism of multinucleon transfer reaction based on the GRAZING model and DNS model

    NASA Astrophysics Data System (ADS)

    Wen, Pei-wei; Li, Cheng; Zhu, Long; Lin, Cheng-jian; Zhang, Feng-shou

    2017-11-01

    Multinucleon transfer (MNT) reactions have been studied by either the GRAZING model or dinuclear system (DNS) model before. MNT reactions in the grazing regime have been described quite well by the GRAZING model. The DNS model is able to deal with MNT reactions, which happen in the closer overlapped regime after contact of two colliding nuclei. Since MNT reactions can happen in both areas and cannot be distinguished in view of experimental work, it is beneficial to compare these two models to clarify mechanism of MNT reactions. In this study, the mechanism of the MNT reaction has been studied by comparing the GRAZING model and DNS model for the first time. Reaction systems 136Xe+208Pb at {E}{{c}.{{m}}.}=450 MeV and 64Ni+238U at {E}{{c}.{{m}}.}=307 MeV are taken as examples in this paper. It is found that the gradients of transfer cross sections with respect to the impact parameter of the GRAZING model and DNS model are mainly concentrated on two different areas, which represents two kinds of transfer mechanisms. The theoretical framework of these two models are exclusive according to whether capture happens, which guarantees that the theoretical results calculated by these two models have no overlap and can be added up. Results indicate that the description of experimental MNT reaction cross sections can be significantly improved if calculations of the GRAZING model and DNS model are both considered.

  14. Prediction of dynamic and mixing characteristics of drop-laden mixing layers using DNS and LES

    NASA Technical Reports Server (NTRS)

    Okong'o, N.; Leboissetier, A.; Bellan, J.

    2004-01-01

    Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) have been conducted of a temporal mixing layer laden with evaporating drops, in order to assess the ability of LES to reproduce dynamic and mixing aspects of the DNS which affect combustion, independently of combustion models.

  15. Validation of an LES Model for Soot Evolution against DNS Data in Turbulent Jet Flames

    NASA Astrophysics Data System (ADS)

    Mueller, Michael

    2012-11-01

    An integrated modeling approach for soot evolution in turbulent reacting flows is validated against three-dimensional Direct Numerical Simulation (DNS) data in a set of n-heptane nonpremixed temporal jet flames. As in the DNS study, the evolution of the soot population is described statistically with the Hybrid Method of Moments (HMOM). The oxidation of the fuel and formation of soot precursors are described with the Radiation Flamelet/Progress Variable (RFPV) model that includes an additional transport equation for Polycyclic Aromatic Hydrocarbons (PAH) to account for the slow chemistry governing these species. In addition, the small-scale interactions between soot, chemistry, and turbulence are described with a presumed subfilter PDF approach that accounts for the very large spatial intermittency characterizing soot in turbulent reacting flows. The DNS dataset includes flames at three different Damköhler numbers to study the influence of global mixing rates on the evolution of PAH and soot. In this work, the ability of the model to capture these trends quantitatively as Damköhler number varies is investigated. In order to reliably assess the LES approach, the LES is initialized from the filtered DNS data after an initial transitional period in an effort to minimize the hydrodynamic differences between the DNS and the LES.

  16. Examination of the effect of differential molecular diffusion in DNS of turbulent non-premixed flames

    DOE PAGES

    Han, Chao; Lignell, David O.; Hawkes, Evatt R.; ...

    2017-02-09

    Here, the effect of differential molecular diffusion (DMD) in turbulent non-premixed flames is studied by examining two previously reported DNS of temporally evolving planar jet flames, one with CO/H 2 as the fuel and the other with C 2H 4 as the fuel. The effect of DMD in the CO/H 2 DNS flames in which H 2 is part of fuel is found to behave similar to laminar flamelet, while in the C 2H 4 DNS flames in which H 2 is not present in the fuel it is similar to laminar flamelet in early stages but becomes different frommore » laminar flamelet later. The scaling of the effect of DMD with respect to the Reynolds number Re is investigated in the CO/H 2 DNS flames, and an evident power law scaling (~Re –a with a a positive constant) is observed. The scaling of the effect of DMD with respect to the Damkohler number Da is explored in both laminar counter-flow jet C 2H 4 diffusion flames and the C 2H 4 DNS flames. A power law scaling (~ Daa with a a positive constant) is clearly demonstrated for C 2H 4 nonpremixed flames.« less

  17. Anticonvulsant activity of DNS II fraction in the acute seizure models.

    PubMed

    Raza, Muhammad Liaquat; Zeeshan, Mohammad; Ahmad, Manzoor; Shaheen, Farzana; Simjee, Shabana U

    2010-04-21

    Delphinium nordhagenii belongs to family Ranunculaceae, it is widely found in tropical areas of Pakistan. Other species of Delphinium are reported as anticonvulsant and are traditionally used in the treatment of epilepsy. Delphinium nordhagenii is used by local healer in Pakistan but never used for scientific investigation as anticonvulsant. Thus, Delphinium nordhagenii was subjected to bioassay-guided fractionation and the most active fraction, i.e. DNS II acetone was chosen for further testing in the acute seizure models of epilepsy to study the antiepileptic potential in male mice. Different doses (60, 65 and 70mg/kg, i.p.) of DNS II acetone fraction of Delphinium nordhagenii was administered 30min prior the chemoconvulsant's injection in the male mice. Convulsive doses of chemoconvulsants (pentylenetetrazole 90mg/kg, s.c. and picrotoxin 3.15mg/kg, s.c.) were used. The mice were observed 45-90min for the presence of seizures. Moreover, four different doses of DNS II (60, 65, 70 and 100mg/kg, i.p.) were tested in the MES test. The DNS II acetone fraction of Delphinium nordhagenii has exhibited the anticonvulsant actions by preventing the seizures against PTZ- and picrotoxin-induced seizure as well as 100% seizure protection in MES test. The results are comparable with standard AEDs (diazepam 7.5mg/kg, i.p. and phenytoin 20mg/kg, i.p.). These findings suggest that the Delphinium nordhagenii possesses the anticonvulsant activity. Further analysis is needed to confirm the structure and target the extended activity profile. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  18. PDF turbulence modeling and DNS

    NASA Technical Reports Server (NTRS)

    Hsu, A. T.

    1992-01-01

    The problem of time discontinuity (or jump condition) in the coalescence/dispersion (C/D) mixing model is addressed in probability density function (pdf). A C/D mixing model continuous in time is introduced. With the continuous mixing model, the process of chemical reaction can be fully coupled with mixing. In the case of homogeneous turbulence decay, the new model predicts a pdf very close to a Gaussian distribution, with finite higher moments also close to that of a Gaussian distribution. Results from the continuous mixing model are compared with both experimental data and numerical results from conventional C/D models. The effect of Coriolis forces on compressible homogeneous turbulence is studied using direct numerical simulation (DNS). The numerical method used in this study is an eight order compact difference scheme. Contrary to the conclusions reached by previous DNS studies on incompressible isotropic turbulence, the present results show that the Coriolis force increases the dissipation rate of turbulent kinetic energy, and that anisotropy develops as the Coriolis force increases. The Taylor-Proudman theory does apply since the derivatives in the direction of the rotation axis vanishes rapidly. A closer analysis reveals that the dissipation rate of the incompressible component of the turbulent kinetic energy indeed decreases with a higher rotation rate, consistent with incompressible flow simulations (Bardina), while the dissipation rate of the compressible part increases; the net gain is positive. Inertial waves are observed in the simulation results.

  19. Abnormal/Emergency Situations. Impact of Unmanned Aircraft Systems Emergency and Abnormal Events on the National Airspace System

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Access 5 analyzed the differences between UAS and manned aircraft operations under five categories of abnormal or emergency situations: Link Failure, Lost Communications, Onboard System Failures, Control Station Failures and Abnormal Weather. These analyses were made from the vantage point of the impact that these operations have on the US air traffic control system, with recommendations for new policies and procedures included where appropriate.

  20. Verification of bubble tracking method and DNS examinations of single- and two-phase turbulent channel flows

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tryggvason, Gretar; Bolotnov, Igor; Fang, Jun

    2017-03-30

    Direct numerical simulation (DNS) has been regarded as a reliable data source for the development and validation of turbulence models along with experiments. The realization of DNS usually involves a very fine mesh that should be able to resolve all relevant turbulence scales down to Kolmogorov scale [1]. As the most computationally expensive approach compared to other CFD techniques, DNS applications used to be limited to flow studies at very low Reynolds numbers. Thanks to the tremendous growth of computing power over the past decades, the simulation capability of DNS has now started overlapping with some of the most challengingmore » engineering problems. One of those examples in nuclear engineering is the turbulent coolant flow inside reactor cores. Coupled with interface tracking methods (ITM), the simulation capability of DNS can be extended to more complicated two-phase flow regimes. Departure from nucleate boiling (DNB) is the limiting critical heat flux phenomena for the majority of accidents that are postulated to occur in pressurized water reactors (PWR) [2]. As one of the major modeling and simulation (M&S) challenges pursued by CASL, the prediction capability is being developed for the onset of DNB utilizing multiphase-CFD (M-CFD) approach. DNS (coupled with ITM) can be employed to provide closure law information for the multiphase flow modeling at CFD scale. In the presented work, research groups at NCSU and UND will focus on applying different ITM to different geometries. Higher void fraction flow analysis at reactor prototypical conditions will be performed, and novel analysis methods will be developed, implemented and verified for the challenging flow conditions.« less

  1. DNS and LES of a Shear-Free Mixing Layer

    NASA Technical Reports Server (NTRS)

    Knaepen, B.; Debliquy, O.; Carati, D.

    2003-01-01

    The purpose of this work is twofold. First, given the computational resources available today, it is possible to reach, using DNS, higher Reynolds numbers than in Briggs et al.. In the present study, the microscale Reynolds numbers reached in the low- and high-energy homogeneous regions are, respectively, 32 and 69. The results reported earlier can thus be complemented and their robustness in the presence of increased turbulence studied. The second aim of this work is to perform a detailed and documented LES of the shear-free mixing layer. In that respect, the creation of a DNS database at higher Reynolds number is necessary in order to make meaningful LES assessments. From the point of view of LES, the shear-free mixing-layer is interesting since it allows one to test how traditional LES models perform in the presence of an inhomogeneity without having to deal with difficult numerical issues. Indeed, as argued in Briggs et al., it is possible to use a spectral code to study the shear-free mixing layer and one can thus focus on the accuracy of the modelling while avoiding contamination of the results by commutation errors etc. This paper is organized as follows. First we detail the initialization procedure used in the simulation. Since the flow is not statistically stationary, this initialization procedure has a fairly strong influence on the evolution. Although we will focus here on the shear-free mixing layer, the method proposed in the present work can easily be used for other flows with one inhomogeneous direction. The next section of the article is devoted to the description of the DNS. All the relevant parameters are listed and comparison with the Veeravalli & Warhaft experiment is performed. The section on the LES of the shear-free mixing layer follows. A detailed comparison between the filtered DNS data and the LES predictions is presented. It is shown that simple eddy viscosity models perform very well for the present test case, most probably because the

  2. DNS/LES Simulations of Separated Flows at High Reynolds Numbers

    NASA Technical Reports Server (NTRS)

    Balakumar, P.

    2015-01-01

    Direct numerical simulations (DNS) and large-eddy simulations (LES) simulations of flow through a periodic channel with a constriction are performed using the dynamic Smagorinsky model at two Reynolds numbers of 2800 and 10595. The LES equations are solved using higher order compact schemes. DNS are performed for the lower Reynolds number case using a fine grid and the data are used to validate the LES results obtained with a coarse and a medium size grid. LES simulations are also performed for the higher Reynolds number case using a coarse and a medium size grid. The results are compared with an existing reference data set. The DNS and LES results agreed well with the reference data. Reynolds stresses, sub-grid eddy viscosity, and the budgets for the turbulent kinetic energy are also presented. It is found that the turbulent fluctuations in the normal and spanwise directions have the same magnitude. The turbulent kinetic energy budget shows that the production peaks near the separation point region and the production to dissipation ratio is very high on the order of five in this region. It is also observed that the production is balanced by the advection, diffusion, and dissipation in the shear layer region. The dominant term is the turbulent diffusion that is about two times the molecular dissipation.

  3. Analysis of AS112 Traffic

    DTIC Science & Technology

    2007-06-01

    UPDATEs • TCP UPDATEs 9© 2007 Carnegie Mellon University A queries • Clients asking blackhole -1 and blackhole -2 for prisoner • Results are not cached...Clients requesting the DNS name of an RFC1918 address • Simple queries sent to blackhole -1 and blackhole -2 • Uniformity makes trending very easy...dns.qry.type == 0x000c • Clients requesting the DNS name of an RFC1918 address • Simple queries sent to blackhole -1 and blackhole -2 • Uniformity makes

  4. DNS of incompressible turbulence in a periodic box with up to 4096^3 grid points

    NASA Astrophysics Data System (ADS)

    Kaneda, Yukio

    2007-11-01

    Turbulence of incompressible fluid obeying the Navier-Stokes (NS) equations under periodic boundary conditions is one of the simplest dynamical systems keeping the essence of turbulence dynamics, and suitable for the study of high Reynolds number (Re) turbulence by direct numerical simulation (DNS). This talk presents a review on DNS of such a system with the number N^3 of the grid points up to 4096^3, performed on the Earth Simulator (ES). The ES consists of 640 processor nodes (=5120 arithmetic processors) with 10TB of main memory and the peak performance of 40 Tflops. The DNSs are based on a spectral method free from alias error. The convolution sums in the wave vector space were evaluated by radix-4 Fast Fourier Transforms with double precision arithmetic. Sustained performance of 16.4 Tflops was achieved on the 2048^3 DNS by using 512 processor nodes of the ES. The DNSs consist of two series; one is with kmax η1 (Series 1) and the other with kmax η2 (Series 2), where kmax is the highest wavenumber in each simulation, and η is the Kolmogorov length scale. In the 4096^3 DNS, the Taylor-scale Reynolds number Rλ1130 (675) and the ratio L/η of the integral length scale L to η is approximately 2133(1040), in Series 1 (Series 2). Such DNS data are expected to shed some light on the basic questions in turbulence research, including those on (i) the normalized mean rate of energy dissipation in the high Re limit, (ii) the universality of energy spectrum at small scale, (iii) scale- and Re- dependences of the statistics, and (iv) intermittency. We have constructed a database consisting of (a) animations and figures of turbulent fields (b) statistics including those associated with (i)-(iv) noted above, (c) snapshot data of the velocity fields. The data size of (c) can be very large for large N. For example, one snapshot of single precision data of the velocity vector field of the 4096^3 DNS requires approximately 0.8 TB.

  5. The extracellular nuclease Dns and its role in natural transformation of Vibrio cholerae.

    PubMed

    Blokesch, Melanie; Schoolnik, Gary K

    2008-11-01

    Free extracellular DNA is abundant in many aquatic environments. While much of this DNA will be degraded by nucleases secreted by the surrounding microbial community, some is available as transforming material that can be taken up by naturally competent bacteria. One such species is Vibrio cholerae, an autochthonous member of estuarine, riverine, and marine habitats and the causative agent of cholera, whose competence program is induced after colonization of chitin surfaces. In this study, we investigate how Vibrio cholerae's two extracellular nucleases, Xds and Dns, influence its natural transformability. We show that in the absence of Dns, transformation frequencies are significantly higher than in its presence. During growth on a chitin surface, an increase in transformation efficiency was found to correspond in time with increasing cell density and the repression of dns expression by the quorum-sensing regulator HapR. In contrast, at low cell density, the absence of HapR relieves dns repression, leading to the degradation of free DNA and to the abrogation of the transformation phenotype. Thus, as cell density increases, Vibrio cholerae undergoes a switch from nuclease-mediated degradation of extracellular DNA to the uptake of DNA by bacteria induced to a state of competence by chitin. Taken together, these results suggest the following model: nuclease production by low-density populations of V. cholerae might foster rapid growth by providing a source of nucleotides for the repletion of nucleotide pools. In contrast, the termination of nuclease production by static, high-density populations allows the uptake of intact DNA and coincides with a phase of potential genome diversification.

  6. The Extracellular Nuclease Dns and Its Role in Natural Transformation of Vibrio cholerae▿

    PubMed Central

    Blokesch, Melanie; Schoolnik, Gary K.

    2008-01-01

    Free extracellular DNA is abundant in many aquatic environments. While much of this DNA will be degraded by nucleases secreted by the surrounding microbial community, some is available as transforming material that can be taken up by naturally competent bacteria. One such species is Vibrio cholerae, an autochthonous member of estuarine, riverine, and marine habitats and the causative agent of cholera, whose competence program is induced after colonization of chitin surfaces. In this study, we investigate how Vibrio cholerae's two extracellular nucleases, Xds and Dns, influence its natural transformability. We show that in the absence of Dns, transformation frequencies are significantly higher than in its presence. During growth on a chitin surface, an increase in transformation efficiency was found to correspond in time with increasing cell density and the repression of dns expression by the quorum-sensing regulator HapR. In contrast, at low cell density, the absence of HapR relieves dns repression, leading to the degradation of free DNA and to the abrogation of the transformation phenotype. Thus, as cell density increases, Vibrio cholerae undergoes a switch from nuclease-mediated degradation of extracellular DNA to the uptake of DNA by bacteria induced to a state of competence by chitin. Taken together, these results suggest the following model: nuclease production by low-density populations of V. cholerae might foster rapid growth by providing a source of nucleotides for the repletion of nucleotide pools. In contrast, the termination of nuclease production by static, high-density populations allows the uptake of intact DNA and coincides with a phase of potential genome diversification. PMID:18757542

  7. Compressible Turbulent Channel Flows: DNS Results and Modeling

    NASA Technical Reports Server (NTRS)

    Huang, P. G.; Coleman, G. N.; Bradshaw, P.; Rai, Man Mohan (Technical Monitor)

    1994-01-01

    The present paper addresses some topical issues in modeling compressible turbulent shear flows. The work is based on direct numerical simulation of two supersonic fully developed channel flows between very cold isothermal walls. Detailed decomposition and analysis of terms appearing in the momentum and energy equations are presented. The simulation results are used to provide insights into differences between conventional time-and Favre-averaging of the mean-flow and turbulent quantities. Study of the turbulence energy budget for the two cases shows that the compressibility effects due to turbulent density and pressure fluctuations are insignificant. In particular, the dilatational dissipation and the mean product of the pressure and dilatation fluctuations are very small, contrary to the results of simulations for sheared homogeneous compressible turbulence and to recent proposals for models for general compressible turbulent flows. This provides a possible explanation of why the Van Driest density-weighted transformation is so successful in correlating compressible boundary layer data. Finally, it is found that the DNS data do not support the strong Reynolds analogy. A more general representation of the analogy is analysed and shown to match the DNS data very well.

  8. DNS of droplet motion in a turbulent flow

    NASA Astrophysics Data System (ADS)

    Rosso, Michele; Elghobashi, S.

    2013-11-01

    The objective of our research is to study the multi-way interactions between turbulence and vaporizing liquid droplets by performing direct numerical simulations (DNS). The freely-moving droplets are fully resolved in 3D space and time and all the relevant scales of the turbulent motion are simultaneously resolved down to the smallest length- and time-scales. Our DNS solve the unsteady three-dimensional Navier-Stokes and continuity equations throughout the whole computational domain, including the interior of the liquid droplets. The droplet surface motion and deformation are captured accurately by using the Level Set method. The pressure jump condition, density and viscosity discontinuities across the interface as well as surface tension are accounted for. Here, we present only the results of the first stage of our research which considers the effects of turbulence on the shape change of an initially spherical liquid droplet, at density ratio (of liquid to carrier fluid) of 1000, moving in isotropic turbulent flow. We validate our results via comparison with available expe. This research has been supported by NSF-CBET Award 0933085 and NSF PRAC (Petascale Computing Resource Allocation) Award.

  9. Turbulent flame-wall interaction: a DNS study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Jackie; Hawkes, Evatt R; Sankaran, Ramanan

    2010-01-01

    A turbulent flame-wall interaction (FWI) configuration is studied using three-dimensional direct numerical simulation (DNS) and detailed chemical kinetics. The simulations are used to investigate the effects of the wall turbulent boundary layer (i) on the structure of a hydrogen-air premixed flame, (ii) on its near-wall propagation characteristics and (iii) on the spatial and temporal patterns of the convective wall heat flux. Results show that the local flame thickness and propagation speed vary between the core flow and the boundary layer, resulting in a regime change from flamelet near the channel centreline to a thickened flame at the wall. This findingmore » has strong implications for the modelling of turbulent combustion using Reynolds-averaged Navier-Stokes or large-eddy simulation techniques. Moreover, the DNS results suggest that the near-wall coherent turbulent structures play an important role on the convective wall heat transfer by pushing the hot reactive zone towards the cold solid surface. At the wall, exothermic radical recombination reactions become important, and are responsible for approximately 70% of the overall heat release rate at the wall. Spectral analysis of the convective wall heat flux provides an unambiguous picture of its spatial and temporal patterns, previously unobserved, that is directly related to the spatial and temporal characteristic scalings of the coherent near-wall turbulent structures.« less

  10. Use of DNS Data for the Evaluation of Closure Models for Rotating Turbulent Channel Flow

    NASA Astrophysics Data System (ADS)

    Hsieh, Alan; Biringen, Sedat; Kucala, Alec

    2013-11-01

    A direct numerical simulation (DNS) of a turbulent channel flow rotating about the spanwise axis was conducted at a Reynolds number (based on the centerline velocity and channel half height) 8000, Prandtl number 0.71, and Rossby number 26. Several Reynolds-Averaged Navier-Stokes (RANS) based turbulence models for rotating flows were analyzed and tested. It was shown that the closure approximations in the pressure-strain correlation term proposed by the Speziale, Sarkar, and Gatski (SSG) RSM model were more accurate than the Girimaji EARSM model. The Reynolds stresses, primarily the shear stresses, produced by the Girimaji model were compared to the DNS data and revealed an evident discontinuity in the modeled Reynolds stress profiles; consequently, a smoothing function was generated and applied as a correction so that there is significantly better agreement between the Reynolds shear stress profiles produced by the DNS data and the modified Girimaji model.

  11. DNS of a non-equilibrium adverse pressure gradient turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Gungor, Taygun R.; Gungor, Ayse G.; Maciel, Yvan; Simens, Mark P.

    2017-11-01

    A new direct numerical simulation (DNS) dataset of a non-equilibrium adverse pressure gradient (APG) turbulent boundary layer (TBL) that evolves from a zero-pressure-gradient (ZPG) TBL to a TBL which is very close to separation at Reθ is around 8200 is presented. There are two simulations running together in the DNS computational setup. The APG TBL spans Reθ = 1476 - 8276 . Mean velocity results do not satisfy the log law as the defect in the velocity increases. The production and the Reynolds stress peak are observed around y /δ* = 1 after the flow is evolved up to a certain point. The new dataset is compared with other datasets in terms of mean values, Reynolds stresses and turbulent kinetic energy budgets and using this comparison scaling study is performed. Funded by in part by ITU-AYP and NSERC of Canada.

  12. Properties of a fluorescent bezafibrate derivative (DNS-X). A new tool to study peroxisome proliferation and fatty acid beta-oxidation.

    PubMed

    Berlot, J P; Lutz, T; Cherkaoui Malki, M; Nicolas-Frances, V; Jannin, B; Latruffe, N

    2000-12-01

    The first peroxisome proliferator-activated receptor (PPAR) was cloned in 1990 by Issemann and Green. Many studies have reported the importance of this receptor in the control of gene expression of enzymes involved in lipid metabolic pathways including mitochondrial and peroxisomal fatty acid beta-oxidation, lipoprotein structure [apolipoprotein (apo) A2, apo CIII], and fatty acid synthase. By using radiolabeled molecules, it was shown that peroxisome proliferators bind and activate PPAR. As an alternative method, we developed a fluorescent dansyl (1-dimethylaminonaphthalene-5-sulfonyl) derivative peroxisome proliferator from bezafibrate (DNS-X), a hypolipidemic agent that exhibits an in vitro peroxisome proliferative activity on rat Fao-hepatic derived cultured cells. However, until now, the effect of this new compound on the liver of animals and subcellular localization was unknown. In addition to in vivo rat studies, we present a more efficient large-scale technique of DNS-X purification. Treating rats (DNS-X in the diet at 0.3% w/w) for 6 d leads to a hepatomegaly and a marked increase in liver peroxisomal palmitoyl-CoA oxidase activity. We also developed a method to localize and quantify DNS-X in tissues or cell compartment organelles. The primarily cytosolic distribution of DNS-X was confirmed by direct visualization using fluorescence microscopy of cultured Fao cells. Finally, transfection assay demonstrated that DNS-X enhanced the PPAR alpha activity as well as other peroxisome proliferators do.

  13. Comparing DNS and Experiments of Subcritical Flow Past an Isolated Surface Roughness Element

    NASA Astrophysics Data System (ADS)

    Doolittle, Charles; Goldstein, David

    2009-11-01

    Results are presented from computational and experimental studies of subcritical roughness within a Blasius boundary layer. This work stems from discrepancies presented by Stephani and Goldstein (AIAA Paper 2009-585) where DNS results did not agree with hot-wire measurements. The near wake regions of cylindrical surface roughness elements corresponding to roughness-based Reynolds numbers Rek of about 202 are of specific concern. Laser-Doppler anemometry and flow visualization in water, as well as the same spectral DNS code used by Stephani and Goldstein are used to obtain both quantitative and qualitative comparisons with previous results. Conclusions regarding previous studies will be presented alongside discussion of current work including grid resolution studies and an examination of vorticity dynamics.

  14. DNS of flow in stenosed carotid artery

    NASA Astrophysics Data System (ADS)

    Grinberg, Leopold; Yakhot, Alexander; Karniadakis, George

    2006-11-01

    Direct numerical simulation (DNS) of a three-dimensional flow through a stenosed carotid artery has been performed. Onset of turbulence downstream of the occlusion has been observed. The developing turbulence is characterized by an alternating spatio-temporal transitional regime. The transition to turbulence occurs during the systolic phase approximately five throat-diameters downstream of the throat, while laminarization occurs during the diastolic phase. Transition in space is first enhanced and subsequently decays downstream. The wall shear stress increases in the stenosed internal carotid artery due to the vessel occlusion and as the result of turbulence.

  15. Energy Spectra of Higher Reynolds Number Turbulence by the DNS with up to 122883 Grid Points

    NASA Astrophysics Data System (ADS)

    Ishihara, Takashi; Kaneda, Yukio; Morishita, Koji; Yokokawa, Mitsuo; Uno, Atsuya

    2014-11-01

    Large-scale direct numerical simulations (DNS) of forced incompressible turbulence in a periodic box with up to 122883 grid points have been performed using K computer. The maximum Taylor-microscale Reynolds number Rλ, and the maximum Reynolds number Re based on the integral length scale are over 2000 and 105, respectively. Our previous DNS with Rλ up to 1100 showed that the energy spectrum has a slope steeper than - 5 / 3 (the Kolmogorov scaling law) by factor 0 . 1 at the wavenumber range (kη < 0 . 03). Here η is the Kolmogorov length scale. Our present DNS at higher resolutions show that the energy spectra with different Reynolds numbers (Rλ > 1000) are well normalized not by the integral length-scale but by the Kolmogorov length scale, at the wavenumber range of the steeper slope. This result indicates that the steeper slope is not inherent character in the inertial subrange, and is affected by viscosity.

  16. DNS and LES/FMDF of turbulent jet ignition and combustion

    NASA Astrophysics Data System (ADS)

    Validi, Abdoulahad; Jaberi, Farhad

    2014-11-01

    The ignition and combustion of lean fuel-air mixtures by a turbulent jet flow of hot combustion products injected into various geometries are studied by high fidelity numerical models. Turbulent jet ignition (TJI) is an efficient method for starting and controlling the combustion in complex propulsion systems and engines. The TJI and combustion of hydrogen and propane in various flow configurations are simulated with the direct numerical simulation (DNS) and the hybrid large eddy simulation/filtered mass density function (LES/FMDF) models. In the LES/FMDF model, the filtered form of the compressible Navier-Stokes equations are solved with a high-order finite difference scheme for the turbulent velocity and the FMDF transport equation is solved with a Lagrangian stochastic method to obtain the scalar field. The DNS and LES/FMDF data are used to study the physics of TJI and combustion for different turbulent jet igniter and gas mixture conditions. The results show the very complex and different behavior of the turbulence and the flame structure at different jet equivalence ratios.

  17. Dysfunctional tubular endoplasmic reticulum constitutes a pathological feature of Alzheimer's disease.

    PubMed

    Sharoar, M G; Shi, Q; Ge, Y; He, W; Hu, X; Perry, G; Zhu, X; Yan, R

    2016-09-01

    Pathological features in Alzheimer's brains include mitochondrial dysfunction and dystrophic neurites (DNs) in areas surrounding amyloid plaques. Using a mouse model that overexpresses reticulon 3 (RTN3) and spontaneously develops age-dependent hippocampal DNs, here we report that DNs contain both RTN3 and REEPs, topologically similar proteins that can shape tubular endoplasmic reticulum (ER). Importantly, ultrastructural examinations of such DNs revealed gradual accumulation of tubular ER in axonal termini, and such abnormal tubular ER inclusion is found in areas surrounding amyloid plaques in biopsy samples from Alzheimer's disease (AD) brains. Functionally, abnormally clustered tubular ER induces enhanced mitochondrial fission in the early stages of DN formation and eventual mitochondrial degeneration at later stages. Furthermore, such DNs are abrogated when RTN3 is ablated in aging and AD mouse models. Hence, abnormally clustered tubular ER can be pathogenic in brain regions: disrupting mitochondrial integrity, inducing DNs formation and impairing cognitive function in AD and aging brains.

  18. DNS, Enstrophy Balance, and the Dissipation Equation in a Separated Turbulent Channel Flow

    NASA Technical Reports Server (NTRS)

    Balakumar, Ponnampalam; Rubinstein, Robert; Rumsey, Christopher L.

    2013-01-01

    The turbulent flows through a plane channel and a channel with a constriction (2-D hill) are numerically simulated using DNS and RANS calculations. The Navier-Stokes equations in the DNS are solved using a higher order kinetic energy preserving central schemes and a fifth order accurate upwind biased WENO scheme for the space discretization. RANS calculations are performed using the NASA code CFL3D with the komega SST two-equation model and a full Reynolds stress model. Using DNS, the magnitudes of different terms that appear in the enstrophy equation are evaluated. The results show that the dissipation and the diffusion terms reach large values at the wall. All the vortex stretching terms have similar magnitudes within the buffer region. Beyond that the triple correlation among the vorticity and strain rate fluctuations becomes the important kinematic term in the enstrophy equation. This term is balanced by the viscous dissipation. In the separated flow, the triple correlation term and the viscous dissipation term peak locally and balance each other near the separated shear layer region. These findings concur with the analysis of Tennekes and Lumley, confirming that the energy transfer terms associated with the small-scale dissipation and the fluctuations of the vortex stretching essentially cancel each other, leaving an equation for the dissipation that is governed by the large-scale motion.

  19. DNS of Flows over Periodic Hills using a Discontinuous-Galerkin Spectral-Element Method

    NASA Technical Reports Server (NTRS)

    Diosady, Laslo T.; Murman, Scott M.

    2014-01-01

    Direct numerical simulation (DNS) of turbulent compressible flows is performed using a higher-order space-time discontinuous-Galerkin finite-element method. The numerical scheme is validated by performing DNS of the evolution of the Taylor-Green vortex and turbulent flow in a channel. The higher-order method is shown to provide increased accuracy relative to low-order methods at a given number of degrees of freedom. The turbulent flow over a periodic array of hills in a channel is simulated at Reynolds number 10,595 using an 8th-order scheme in space and a 4th-order scheme in time. These results are validated against previous large eddy simulation (LES) results. A preliminary analysis provides insight into how these detailed simulations can be used to improve Reynoldsaveraged Navier-Stokes (RANS) modeling

  20. Detailed Comparison of DNS to PSE for Oblique Breakdown at Mach 3

    NASA Technical Reports Server (NTRS)

    Mayer, Christian S. J.; Fasel, Hermann F.; Choudhari, Meelan; Chang, Chau-Lyan

    2010-01-01

    A pair of oblique waves at low amplitudes is introduced in a supersonic flat-plate boundary layer. Their downstream development and the concomitant process of laminar to turbulent transition is then investigated numerically using Direct Numerical Simulations (DNS) and Parabolized Stability Equations (PSE). This abstract is the last part of an extensive study of the complete transition process initiated by oblique breakdown at Mach 3. In contrast to the previous simulations, the symmetry condition in the spanwise direction is removed for the simulation presented in this abstract. By removing the symmetry condition, we are able to confirm that the flow is indeed symmetric over the entire computational domain. Asymmetric modes grow in the streamwise direction but reach only small amplitude values at the outflow. Furthermore, this abstract discusses new time-averaged data from our previous simulation CASE 3 and compares PSE data obtained from NASA's LASTRAC code to DNS results.

  1. Role of "Sural Sparing" Pattern (Absent/Abnormal Median and Ulnar with Present Sural SNAP) Compared to Absent/Abnormal Median or Ulnar with Normal Sural SNAP in Acute Inflammatory Demyelinating Polyneuropathy.

    PubMed

    Surpur, Spurthi Sunil; Govindarajan, Raghav

    2017-01-01

    Sural sparing defined as absent/abnormal median sensory nerve action potential (SNAP) amplitude or absent/abnormal ulnar SNAP amplitude with a normal sural SNAP amplitude is thought to be a marker for inflammatory demyelinating polyneuropathies. If sural sparing pattern specifically defined as absent/abnormal median and ulnar SNAP amplitude with normal sural SNAP amplitude (AMUNS) is sensitive and specific when compared with either absent/abnormal median and normal sural (AMNS) or absent/abnormal ulnar and normal sural (AUNS) for acute inflammatory demyelinating polyneuropathy (AIDP), chronic inflammatory demyelinating polyneuropathy (CIDP), select non-diabetic axonopathies (AXPs), and diabetic neuropathies (DNs). Retrospective analysis from 2001 to 2010 on all newly diagnosed AIDP, CIDP, select non-diabetic AXP, and DN. There were 20 AIDP and 23 CIDP. Twenty AXP and 50 DN patients between 2009 and 2010 were included as controls. AMUNS was seen in 65% of AIDP, 39% CIDP compared with 10% of AXP and 6% for DN with sensitivity of 51%, specificity of 92%, whereas the specificity of AMNS/AUNS was 73% and its sensitivity was 58%. If a patient has AMUNS they are >12 times more likely to have AIDP ( p  < 0.001). Sural sparing is highly specific but not sensitive when compared with either AMNS or AUNS in AIDP but does not add to sensitivity or specificity in CIDP.

  2. DNS of Laminar-Turbulent Transition in Swept-Wing Boundary Layers

    NASA Technical Reports Server (NTRS)

    Duan, L.; Choudhari, M.; Li, F.

    2014-01-01

    Direct numerical simulation (DNS) is performed to examine laminar to turbulent transition due to high-frequency secondary instability of stationary crossflow vortices in a subsonic swept-wing boundary layer for a realistic natural-laminar-flow airfoil configuration. The secondary instability is introduced via inflow forcing and the mode selected for forcing corresponds to the most amplified secondary instability mode that, in this case, derives a majority of its growth from energy production mechanisms associated with the wall-normal shear of the stationary basic state. An inlet boundary condition is carefully designed to allow for accurate injection of instability wave modes and minimize acoustic reflections at numerical boundaries. Nonlinear parabolized stability equation (PSE) predictions compare well with the DNS in terms of modal amplitudes and modal shape during the strongly nonlinear phase of the secondary instability mode. During the transition process, the skin friction coefficient rises rather rapidly and the wall-shear distribution shows a sawtooth pattern that is analogous to the previously documented surface flow visualizations of transition due to stationary crossflow instability. Fully turbulent features are observed in the downstream region of the flow.

  3. DNS of Supersonic Turbulent Flows in a DLR Scramjet Intake

    NASA Astrophysics Data System (ADS)

    Li, Xinliang; Yu, Changping

    2014-11-01

    Direct numerical simulation (DNS) of supersonic/hypersonic flow through a DLR scramjet intake GK01 is performed. The free stream Mach numbers are 3, 5 and 7, and the angle of attack is zero degree. The DNS cases are performed by using an optimized MP scheme with adaptive dissipation (OMP-AD) developed by the authors, and the blow-and-suction perturbations near the leading edge are used to trigger the transition. To stabilize the simulation, locally non-linear flittering is used in high-Mach-number case. The transition, separation, and shock-turbulent boundary layer interaction are studied by using both flow visualization and statistical analysis. A new method, OMP-AD, is also addressed in this paper. The OMP-AD scheme is developed by using joint MP method and optimized technique, and the coefficients in the scheme are flexible to show low dissipation in the smoothing region, and to show high robust (but high dissipation) in the large gradient region. Numerical tests show that the OMP-AD is more robust than the original MP schemes, and the numerical dissipation of OMP-AD is very low.

  4. Increased frequency of mitral valve prolapse in patients with deviated nasal septum.

    PubMed

    Arslan, Hasan Huseyin; Aparci, Mustafa; Arslan, Zekeriya; Ozturk, Cengiz; Isilak, Zafer; Balta, Sevket; Celik, Turgay; Iyisoy, Atila

    2015-07-01

    Any abnormality of collagen may affect the tissues with higher collagen content, e.g., joints, heart valves, and great arteries. Mitral valve prolapse (MVP) is a characteristic of generalized collagen abnormality. Nasal septum (NS) is constituted by osseous and cartilaginous septums that are highly rich in collagen. We evaluated the co-existence of deviation of NS (DNS) in patients with MVP. We retrospectively evaluated the recordings of echocardiographic and nasal examinations of subjects with MVP and DNS. We analyzed the features of MVP and anatomical classification of DNS among subjects. Totally, 74 patients with DNS and 38 subjects with normal nasal passage were enrolled to the study. Presence of MVP was significantly higher in patients with DNS compared to normal subjects (63 vs 26%, p < 0.001). Prolapse of anterior, posterior and both leaflets was higher in patients with DNS. Thickness of anterior mitral leaflet was significantly increased in patients with DNS (3.57 ± 0.68 vs 4.59 ± 1.1 mm, p < 0.001) compared to normal subjects. Type I, II, and III, IV DNS were higher in frequency in patients with MVP while type V and VI were higher in normal subjects. DNS is highly co-existent with MVP and increased thickness of mitral anterior leaflet. Generalized abnormality of collagen which is the main component of mitral valves and nasal septum may be accounted for co-existence of MVP and DNS. Also co-existence of them may exaggerate the symptoms of patients with MVP due to limited airflow through the nasal passage.

  5. 3D DNS and LES of Breaking Inertia-Gravity Waves

    NASA Astrophysics Data System (ADS)

    Remmler, S.; Fruman, M. D.; Hickel, S.; Achatz, U.

    2012-04-01

    As inertia-gravity waves we refer to gravity waves that have a sufficiently low frequency and correspondingly large horizontal wavelength to be strongly influenced by the Coriolis force. Inertia-gravity waves are very active in the middle atmosphere and their breaking is potentially an important influence on the circulation in this region. The parametrization of this process requires a good theoretical understanding, which we want to enhance with the present study. Primary linear instabilities of an inertia-gravity wave and "2.5-dimensional" nonlinear simulations (where the spatial dependence is two dimensional but the velocity and vorticity fields are three-dimensional) with the wave perturbed by its leading primary instabilities by Achatz [1] have shown that the breaking differs significantly from that of high-frequency gravity waves due to the strongly sheared component of velocity perpendicular to the plane of wave-propagation. Fruman & Achatz [2] investigated the three-dimensionalization of the breaking by computing the secondary linear instabilities of the same waves using singular vector analysis. These secondary instabilities are variations perpendicular to the direction of the primary perturbation and the wave itself, and their wavelengths are an order of magnitude shorter than both. In continuation of this work, we carried out fully three-dimensional nonlinear simulations of inertia-gravity waves perturbed by their leading primary and secondary instabilities. The direct numerical simulation (DNS) was made tractable by restricting the domain size to the dominant scales selected by the linear analyses. The study includes both convectively stable and unstable waves. To the best of our knowledge, this is the first fully three-dimensional nonlinear direct numerical simulation of inertia-gravity waves at realistic Reynolds numbers with complete resolution of the smallest turbulence scales. Previous simulations either were restricted to high frequency gravity

  6. Some Insights on Roughness Induced Transition and Control from DNS and Experiments

    NASA Astrophysics Data System (ADS)

    Suryanarayanan, Saikishan; Ibitayo, Ifeoluwa; Goldstein, David; Brown, Garry

    2016-11-01

    We study the receptivity and subsequent evolution of an initially laminar flat boundary layer on a flat plate to single and multiple discrete roughness elements (DRE) using a combination of immersed boundary DNS and water channel flow visualization experiments. We examine the transition caused by a single DRE and demonstrate the possibility of suppressing it by an appropriately designed second DRE in both DNS and experiments. The different phases of transition are identified and the roles of Reynolds numbers based on roughness height and boundary layer thickness are investigated. The underlying mechanisms in the observed transition and its control are understood by examining detailed vorticity flux balances. Connections are also made to recent developments in transient growth and streak instability. A unified picture is sought from a parametric study of different DRE dimensions and orientations. The potential applicability of the observations and understanding derived from this study to controlling transition caused by design and environmental roughness over aircraft wings is discussed. Supported by AFOSR # FA9550-15-1-0345.

  7. DNS of a turbulent lifted DME jet flame

    DOE PAGES

    Minamoto, Yuki; Chen, Jacqueline H.

    2016-05-07

    A three-dimensional direct numerical simulation (DNS) of a turbulent lifted dimethyl ether (DME) slot jet flame was performed at elevated pressure to study interactions between chemical reactions with low-temperature heat release (LTHR), negative temperature coefficient (NTC) reactions and shear generated turbulence in a jet in a heated coflow. By conditioning on mixture fraction, local reaction zones and local heat release rate, the turbulent flame is revealed to exhibit a “pentabrachial” structure that was observed for a laminar DME lifted flame [Krisman et al., (2015)]. The propagation characteristics of the stabilization and triple points are also investigated. Potential stabilization points, spatialmore » locations characterized by preferred temperature and mixture fraction conditions, exhibit autoignition characteristics with large reaction rate and negligible molecular diffusion. The actual stabilization point which coincides with the most upstream samples from the pool of potential stabilization points fovr each spanwise location shows passive flame structure with large diffusion. The propagation speed along the stoichiometric surface near the triple point is compared with the asymptotic value obtained from theory [Ruetsch et al., (1995)]. At stoichiometric conditions, the asymptotic and averaged DNS values of flame displacement speed deviate by a factor of 1.7. However, accounting for the effect of low-temperature species on the local flame speed increase, these two values become comparable. In conclusion, this suggests that the two-stage ignition influences the triple point propagation speed through enhancement of the laminar flame speed in a configuration where abundant low-temperature products from the first stage, low-temperature ignition are transported to the lifted flame by the high-velocity jet.« less

  8. DNFB-DNS hapten-induced colitis in mice should not be considered a model of inflammatory bowel disease.

    PubMed

    Bailón, Elvira; Cueto-Sola, Margarita; Utrilla, Pilar; Nieto, Ana; Garrido-Mesa, Natividad; Celada, Antonio; Zarzuelo, Antonio; Xaus, Jordi; Gálvez, Julio; Comalada, Mònica

    2011-10-01

    The dinitrofluorobenzene/dinitrosulfonic acid (DNFB/DNS) model was originally described as an experimental model of intestinal inflammation resembling human ulcerative colitis (UC). Due to the absence of acceptable UC experimental models for pharmacological preclinical assays, here we examine the immune response induced in this model. Balb/c mice were sensitized by skin application of DNFB on day 1, followed by an intrarectal challenge with DNS on day 5. We further expanded this model by administering a second DNS challenge on day 15. The features of colonic inflammation and immune response were evaluated. The changes observed in colonic tissue corresponded, in comparison to the trinitrobenzene sulfonic acid (TNBS) colitis model, to a mild mucosal effect in the colon, which spontaneously resolved in less than 5 days. Furthermore, the second hapten challenge did not exacerbate the inflammatory response. In contrast to other studies, we did not observe any clear involvement of tumor necrosis factor alpha (TNF-α) or other Th1 cytokines during the initial inflammatory response; however, we found that a more Th2-humoral response appeared to mediate the first contact with the hapten. An increased humoral response was detected during the second challenge, although an increased Th1/Th17-cytokine expression profile was also simultaneously observed. On the basis of these results, although the DNFB/DNS model can display some features found in human UC, it should be considered as a model for the study of the intestinal hypersensitivity seen, for example, during food allergy or irritable bowel syndrome but not intestinal inflammation per se. Copyright © 2010 Crohn's & Colitis Foundation of America, Inc.

  9. Relationships between traffic conflicts and accidents. Volume 2, Final technical report

    DOT National Transportation Integrated Search

    1985-07-01

    The purpose of the present research was to establish relationships between traffic conflicts and accidents, and co identify expected and abnormal conflict rates given various circumstances. The data upon which the conclusions and recommendations are ...

  10. Assessing the capability of continuum and discrete particle methods to simulate gas-solids flow using DNS predictions as a benchmark

    DOE PAGES

    Lu, Liqiang; Liu, Xiaowen; Li, Tingwen; ...

    2017-08-12

    For this study, gas–solids flow in a three-dimension periodic domain was numerically investigated by direct numerical simulation (DNS), computational fluid dynamic-discrete element method (CFD-DEM) and two-fluid model (TFM). DNS data obtained by finely resolving the flow around every particle are used as a benchmark to assess the validity of coarser DEM and TFM approaches. The CFD-DEM predicts the correct cluster size distribution and under-predicts the macro-scale slip velocity even with a grid size as small as twice the particle diameter. The TFM approach predicts larger cluster size and lower slip velocity with a homogeneous drag correlation. Although the slip velocitymore » can be matched by a simple modification to the drag model, the predicted voidage distribution is still different from DNS: Both CFD-DEM and TFM over-predict the fraction of particles in dense regions and under-predict the fraction of particles in regions of intermediate void fractions. Also, the cluster aspect ratio of DNS is smaller than CFD-DEM and TFM. Since a simple correction to the drag model can predict a correct slip velocity, it is hopeful that drag corrections based on more elaborate theories that consider voidage gradient and particle fluctuations may be able to improve the current predictions of cluster distribution.« less

  11. Assessing the capability of continuum and discrete particle methods to simulate gas-solids flow using DNS predictions as a benchmark

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lu, Liqiang; Liu, Xiaowen; Li, Tingwen

    For this study, gas–solids flow in a three-dimension periodic domain was numerically investigated by direct numerical simulation (DNS), computational fluid dynamic-discrete element method (CFD-DEM) and two-fluid model (TFM). DNS data obtained by finely resolving the flow around every particle are used as a benchmark to assess the validity of coarser DEM and TFM approaches. The CFD-DEM predicts the correct cluster size distribution and under-predicts the macro-scale slip velocity even with a grid size as small as twice the particle diameter. The TFM approach predicts larger cluster size and lower slip velocity with a homogeneous drag correlation. Although the slip velocitymore » can be matched by a simple modification to the drag model, the predicted voidage distribution is still different from DNS: Both CFD-DEM and TFM over-predict the fraction of particles in dense regions and under-predict the fraction of particles in regions of intermediate void fractions. Also, the cluster aspect ratio of DNS is smaller than CFD-DEM and TFM. Since a simple correction to the drag model can predict a correct slip velocity, it is hopeful that drag corrections based on more elaborate theories that consider voidage gradient and particle fluctuations may be able to improve the current predictions of cluster distribution.« less

  12. Traffic Behavior Recognition Using the Pachinko Allocation Model

    PubMed Central

    Huynh-The, Thien; Banos, Oresti; Le, Ba-Vui; Bui, Dinh-Mao; Yoon, Yongik; Lee, Sungyoung

    2015-01-01

    CCTV-based behavior recognition systems have gained considerable attention in recent years in the transportation surveillance domain for identifying unusual patterns, such as traffic jams, accidents, dangerous driving and other abnormal behaviors. In this paper, a novel approach for traffic behavior modeling is presented for video-based road surveillance. The proposed system combines the pachinko allocation model (PAM) and support vector machine (SVM) for a hierarchical representation and identification of traffic behavior. A background subtraction technique using Gaussian mixture models (GMMs) and an object tracking mechanism based on Kalman filters are utilized to firstly construct the object trajectories. Then, the sparse features comprising the locations and directions of the moving objects are modeled by PAM into traffic topics, namely activities and behaviors. As a key innovation, PAM captures not only the correlation among the activities, but also among the behaviors based on the arbitrary directed acyclic graph (DAG). The SVM classifier is then utilized on top to train and recognize the traffic activity and behavior. The proposed model shows more flexibility and greater expressive power than the commonly-used latent Dirichlet allocation (LDA) approach, leading to a higher recognition accuracy in the behavior classification. PMID:26151213

  13. Automatic Data Traffic Control on DSM Architecture

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Jin, Hao-Qiang; Yan, Jerry; Kwak, Dochan (Technical Monitor)

    2000-01-01

    We study data traffic on distributed shared memory machines and conclude that data placement and grouping improve performance of scientific codes. We present several methods which user can employ to improve data traffic in his code. We report on implementation of a tool which detects the code fragments causing data congestions and advises user on improvements of data routing in these fragments. The capabilities of the tool include deduction of data alignment and affinity from the source code; detection of the code constructs having abnormally high cache or TLB misses; generation of data placement constructs. We demonstrate the capabilities of the tool on experiments with NAS parallel benchmarks and with a simple computational fluid dynamics application ARC3D.

  14. Simulation and optimization of a new focusing polarizing bender for the diffuse neutrons scattering spectrometer DNS at MLZ

    NASA Astrophysics Data System (ADS)

    Nemkovski, K.; Ioffe, A.; Su, Y.; Babcock, E.; Schweika, W.; Brückel, Th

    2017-06-01

    We present the concept and the results of the simulations of a new polarizer for the diffuse neutron scattering spectrometer DNS at MLZ. The concept of the polarizer is based on the idea of a bender made from the stack of the silicon wafers with a double-side supermirror polarizing coating and absorbing spacers in between. Owing to its compact design, such a system provides more free space for the arrangement of other instrument components. To reduce activation of the polarizer in the high intensity neutron beam of the DNS spectrometer we plan to use the Fe/Si supermirrors instead of currently used FeCoV/Ti:N ones. Using the VITESS simulation package we have performed simulations for horizontally focusing polarizing benders with different geometries in the combination with the double-focusing crystal monochromator of DNS. Neutron transmission and polarization efficiency as well as the effects of the focusing for convergent conventional C-benders and S-benders have been analyzed both for wedge-like and plane-parallel convergent geometries of the channels. The results of these simulations and the advantages/disadvantages of the various configurations are discussed.

  15. DNS of High Pressure Supercritical Combustion

    NASA Astrophysics Data System (ADS)

    Chong, Shao Teng; Raman, Venkatramanan

    2016-11-01

    Supercritical flows have always been important to rocket motors, and more recently to aircraft engines and stationary gas turbines. The purpose of the present study is to understand effects of differential diffusion on reacting scalars using supercritical isotropic turbulence. Focus is on fuel and oxidant reacting in the transcritical region where density, heat capacity and transport properties are highly sensitive to variations in temperature and pressure. Reynolds and Damkohler number vary as a result and although it is common to neglect differential diffusion effects if Re is sufficiently large, this large variation in temperature with heat release can accentuate molecular transport differences. Direct numerical simulations (DNS) for one step chemistry reaction between fuel and oxidizer are used to examine the differential diffusion effects. A key issue investigated in this paper is if the flamelet progress variable approach, where the Lewis number is usually assumed to be unity and constant for all species, can be accurately applied to simulate supercritical combustion.

  16. DNS of Flow in a Low-Pressure Turbine Cascade Using a Discontinuous-Galerkin Spectral-Element Method

    NASA Technical Reports Server (NTRS)

    Garai, Anirban; Diosady, Laslo Tibor; Murman, Scott; Madavan, Nateri

    2015-01-01

    A new computational capability under development for accurate and efficient high-fidelity direct numerical simulation (DNS) and large eddy simulation (LES) of turbomachinery is described. This capability is based on an entropy-stable Discontinuous-Galerkin spectral-element approach that extends to arbitrarily high orders of spatial and temporal accuracy and is implemented in a computationally efficient manner on a modern high performance computer architecture. A validation study using this method to perform DNS of flow in a low-pressure turbine airfoil cascade are presented. Preliminary results indicate that the method captures the main features of the flow. Discrepancies between the predicted results and the experiments are likely due to the effects of freestream turbulence not being included in the simulation and will be addressed in the final paper.

  17. Detecting Abnormal Vehicular Dynamics at Intersections Based on an Unsupervised Learning Approach and a Stochastic Model

    PubMed Central

    Jiménez-Hernández, Hugo; González-Barbosa, Jose-Joel; Garcia-Ramírez, Teresa

    2010-01-01

    This investigation demonstrates an unsupervised approach for modeling traffic flow and detecting abnormal vehicle behaviors at intersections. In the first stage, the approach reveals and records the different states of the system. These states are the result of coding and grouping the historical motion of vehicles as long binary strings. In the second stage, using sequences of the recorded states, a stochastic graph model based on a Markovian approach is built. A behavior is labeled abnormal when current motion pattern cannot be recognized as any state of the system or a particular sequence of states cannot be parsed with the stochastic model. The approach is tested with several sequences of images acquired from a vehicular intersection where the traffic flow and duration used in connection with the traffic lights are continuously changed throughout the day. Finally, the low complexity and the flexibility of the approach make it reliable for use in real time systems. PMID:22163616

  18. Detecting abnormal vehicular dynamics at intersections based on an unsupervised learning approach and a stochastic model.

    PubMed

    Jiménez-Hernández, Hugo; González-Barbosa, Jose-Joel; Garcia-Ramírez, Teresa

    2010-01-01

    This investigation demonstrates an unsupervised approach for modeling traffic flow and detecting abnormal vehicle behaviors at intersections. In the first stage, the approach reveals and records the different states of the system. These states are the result of coding and grouping the historical motion of vehicles as long binary strings. In the second stage, using sequences of the recorded states, a stochastic graph model based on a Markovian approach is built. A behavior is labeled abnormal when current motion pattern cannot be recognized as any state of the system or a particular sequence of states cannot be parsed with the stochastic model. The approach is tested with several sequences of images acquired from a vehicular intersection where the traffic flow and duration used in connection with the traffic lights are continuously changed throughout the day. Finally, the low complexity and the flexibility of the approach make it reliable for use in real time systems.

  19. Assessment of diabetic neuropathy with emission tomography and magnetic resonance spectroscopy.

    PubMed

    Rao, Harshvardhan; Gaur, Neeraj; Tipre, Dnyanesh

    2017-04-01

    Diabetic neuropathies (DNs) are nerve-damaging disorders associated with diabetes. They are commonly attributed to peripheral nerves and primarily affect the limbs of the patient. They cause altered sensitivity to external stimuli along with loss in balance and reflexes of the affected patient. DNs are associated with a variety of clinical manifestations including autonomic failure and are caused by poor management of blood sugar levels. Imaging modalities provide vital information about early physiological changes in DNs. This review summarizes contributions by various teams of scientists in developing imaging methods to assess physiological changes in DNs and ongoing clinical trials where imaging modalities are applied to evaluate therapeutic intervention in DNs. Development of PET, single photon emission computed tomography, and magnetic resonance spectroscopy methods over the past 20 years are reviewed in the diagnostic assessment of DNs. Abnormal radiotracer pharmacokinetics and neurometabolite spectra in affected organs confirm physiological abnormalities in DN. With the use of the Siemens Biograph mMR and GE Signa - 60 cm (PET/MRI scanner), simultaneous acquisition of physiological and anatomical information could enhance understanding of DNs and accelerate drug development.

  20. Optimization of fermentation medium for the production of atrazine degrading strain Acinetobacter sp. DNS(32) by statistical analysis system.

    PubMed

    Zhang, Ying; Wang, Yang; Wang, Zhi-Gang; Wang, Xi; Guo, Huo-Sheng; Meng, Dong-Fang; Wong, Po-Keung

    2012-01-01

    Statistical experimental designs provided by statistical analysis system (SAS) software were applied to optimize the fermentation medium composition for the production of atrazine-degrading Acinetobacter sp. DNS(32) in shake-flask cultures. A "Plackett-Burman Design" was employed to evaluate the effects of different components in the medium. The concentrations of corn flour, soybean flour, and K(2)HPO(4) were found to significantly influence Acinetobacter sp. DNS(32) production. The steepest ascent method was employed to determine the optimal regions of these three significant factors. Then, these three factors were optimized using central composite design of "response surface methodology." The optimized fermentation medium composition was composed as follows (g/L): corn flour 39.49, soybean flour 25.64, CaCO(3) 3, K(2)HPO(4) 3.27, MgSO(4)·7H(2)O 0.2, and NaCl 0.2. The predicted and verifiable values in the medium with optimized concentration of components in shake flasks experiments were 7.079 × 10(8) CFU/mL and 7.194 × 10(8) CFU/mL, respectively. The validated model can precisely predict the growth of atrazine-degraing bacterium, Acinetobacter sp. DNS(32).

  1. Assessment of PLIF-Based Heat Release Rate Markers using DNS of Highly Turbulent Premixed Flames

    NASA Astrophysics Data System (ADS)

    Zhao, Xinyu; Zhang, Peiyu; Wabel, Timothy; Steinberg, Adam; Wang, Haiou; Hawkes, Evatt

    2017-11-01

    Planar Laser Induced Fluorescence (PLIF) remains the most common measurement tool for describing turbulent flame topologies. However, the interpretation of the images obtained from such experiments can be obscured due to various experimental constraints, such as the finite laser thickness, the application of intensifier, etc. Synthetic-PLIF images are constructed in this study to understand the effects of various experimental reality using direct numerical simulations. Two DNS databases of highly turbulent premixed methane flames are employed, to generate the synthetic PLIF images. The thickness of the laser sheet and optical blur parameters are systematically varied to study their effects on the implied reactive layer thickness, topological correspondence with heat release rates, as well as the resolved scales of the flames. It is found that the optical blur can have a significant influence on the measured layer thickness, and significant discrepancy between the DNS and the synthetic PLIF arises when the laser thickness is approximately twice the size of the reactive layers.

  2. DNS of helicity-induced stratified turbulent flow

    NASA Astrophysics Data System (ADS)

    Chandy, Abhilash J.; Rahimi, Abbas

    2013-11-01

    Helical flows undergoing density stratification have wide applications in meteorological phenomena such as dust devils, tornadoes, and hurricanes due to the complexity and disasters caused by them. Direct numerical simulations (DNS) of transition to turbulence in a stably stratified Boussinesq fluid are presented for different rotation and stratification intensities. In order to understand the effect of velocity on the energy cascade, comparisons are made between helicity initiated and non-helical flows. Results show that stratification decelerates the helicity decay and causes velocity and vorticity to align with each other. With respect to the helical and non-helical flow comparisons, the total energy in the presence of stratification decays faster with helicity. In addition, the behavior of length scales were examined by comparing temporal variations of the vertical shearing of velocities. Results showed a growing asymmetry with time in the case of helical flow, while non-helical flow stayed close to begin symmetric.

  3. Traffic safety facts 1999 : state traffic data

    DOT National Transportation Integrated Search

    2000-01-01

    This traffic safety fact sheet presents state traffic data in a figure showing 1999 Traffic Fatalities by State and Percent Change from 1998 and in 11 tables showing: (1) Traffic Fatalities and Fatality Rates, 1999; (2) Traffic Fatalities and Percent...

  4. Effects of biochars and MWNTs on biodegradation behavior of atrazine by Acinetobacter lwoffii DNS32.

    PubMed

    Yang, Fan; Jiang, Qun; Zhu, Moran; Zhao, Lulu; Zhang, Ying

    2017-01-15

    Whether the biodegradation of atrazine by Acinetobacter lwoffii DNS32 can have a difference in the presence of two representative carbon materials (CMs), namely, biochars (BCs) and carbon nanotubes (CNTs) is explored, through investigating the influence of CMs on the biodegradation rate, the viability of bacteria and the expression of atrazine genes in aqueous medium. Multi-walled carbon nanotubes (MWNTs), biochars resulted from corn straws (C-BCs) and that made from banana peels (B-BCs) were chosen as the examples. Compared to the control in the absence of C-BCs, B-BCs and MWNTs, the biodegradation efficiencies decrease from 95.3%, 101.8% and 94.8% to 82.6%, 41.8% and 31.1% as the concentrations of these materials increase from 10 to 100mg/L, indicating that BCs have relatively lower toxicity on the biodegradation of atrazine than CNTs, which are agreement with the results of bacterial viability. Transmission electron microscope (TEM) images of Acinetobacter lwoffii DNS32 cells exposure to CMs at 50mg/L show that the cell membrane can be destroyed at different levels after being exposed to various CMs, suggesting that the damage to the cell membrane induced by CMs is a substantial factor leading to the inactivation of bacteria, further decreasing the degradation rate and efficiency of bacteria. The enhanced bacterial growth and the up-regulation of degradation genes can stimulate the degradation rate to pre-adsorbed atrazine on the CMs. This study suggests that biodegradation of atrazine associated with CMs may depend on the carbon composition, structure and CM concentrations. The innovation point of this report is to compare the effects of biochars and CNTs on the degradation rate and activity of Acinetobacter lwoffii DNS32 and may help to further understand the environment effects of CMs. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. State Traffic Data: Traffic Safety Facts, 2001.

    ERIC Educational Resources Information Center

    National Center for Statistics and Analysis (NHTSA), Washington, DC.

    This brief provides statistical information on U.S. traffic accidents delineated by state. A map details the 2001 traffic fatalities by state and the percent change from 2000. Data tables include: (1) traffic fatalities and fatality rates, 2001; (2) traffic fatalities and percent change, 1975-2001; (3) alcohol involvement in fatal traffic crashes,…

  6. DNS assessment of relation between mean reaction and scalar dissipation rates in the flamelet regime of premixed turbulent combustion

    NASA Astrophysics Data System (ADS)

    Nikolaevich Lipatnikov, Andrei; Nishiki, Shinnosuke; Hasegawa, Tatsuya

    2015-05-01

    The linear relation between the mean rate of product creation and the mean scalar dissipation rate, derived in the seminal paper by K.N.C. Bray ['The interaction between turbulence and combustion', Proceedings of the Combustion Institute, Vol. 17 (1979), pp. 223-233], is the cornerstone for models of premixed turbulent combustion that deal with the dissipation rate in order to close the reaction rate. In the present work, this linear relation is straightforwardly validated by analysing data computed earlier in the 3D Direct Numerical Simulation (DNS) of three statistically stationary, 1D, planar turbulent flames associated with the flamelet regime of premixed combustion. Although the linear relation does not hold at the leading and trailing edges of the mean flame brush, such a result is expected within the framework of Bray's theory. However, the present DNS yields substantially larger (smaller) values of an input parameter cm (or K2 = 1/(2cm - 1)), involved by the studied linear relation, when compared to the commonly used value of cm = 0.7 (or K2 = 2.5). To gain further insight into the issue and into the eventual dependence of cm on mixture composition, the DNS data are combined with the results of numerical simulations of stationary, 1D, planar laminar methane-air flames with complex chemistry, with the results being reported in terms of differently defined combustion progress variables c, i.e. the normalised temperature, density, or mole fraction of CH4, O2, CO2 or H2O. Such a study indicates the dependence of cm both on the definition of c and on the equivalence ratio. Nevertheless, K2 and cm can be estimated by processing the results of simulations of counterpart laminar premixed flames. Similar conclusions were also drawn by skipping the DNS data, but invoking a presumed beta probability density function in order to evaluate cm for the differently defined c's and various equivalence ratios.

  7. Large Eddy Simulations (LES) and Direct Numerical Simulations (DNS) for the computational analyses of high speed reacting flows

    NASA Technical Reports Server (NTRS)

    Givi, Peyman; Madnia, Cyrus K.; Steinberger, C. J.; Frankel, S. H.

    1992-01-01

    The principal objective is to extend the boundaries within which large eddy simulations (LES) and direct numerical simulations (DNS) can be applied in computational analyses of high speed reacting flows. A summary of work accomplished during the last six months is presented.

  8. Analysis and Comparison with DNS of a Stochastic Model for the Relative Motion of High-Stokes-Number Particles in Isotropic Turbulence

    NASA Astrophysics Data System (ADS)

    Dhariwal, Rohit; Rani, Sarma; Koch, Donald

    2015-11-01

    In an earlier work, Rani, Dhariwal, and Koch (JFM, Vol. 756, 2014) developed an analytical closure for the diffusion current in the PDF transport equation describing the relative motion of high-Stokes-number particle pairs in isotropic turbulence. In this study, an improved closure was developed for the diffusion coefficient, such that the motion of the particle-pair center of mass is taken into account. Using the earlier and the new analytical closures, Langevin simulations of pair relative motion were performed for four particle Stokes numbers, Stη = 10 , 20 , 40 , 80 and at two Taylor micro-scale Reynolds numbers Reλ = 76 , 131 . Detailed comparisons of the analytical model predictions with those of DNS were undertaken. It is seen that the pair relative motion statistics obtained from the improved theory show excellent agreement with the DNS statistics. The radial distribution functions (RDFs), and relative velocity PDFs obtained from the improved-closure-based Langevin simulations are found to be in very good agreement with those from DNS. It was found that the RDFs and relative velocity RMS increased with Reλ for all Stη . The collision kernel also increased strongly with Reλ , since it depended on the RDF and the radial relative velocities.

  9. Traffic pollution and countermeasures of urban traffic environment

    NASA Astrophysics Data System (ADS)

    He, Yuhong; Zheng, Chaocheng

    2018-01-01

    Background: Traffic environment has become a serious social problem in China currently, therefore, urban traffic environment governance is the requirement to solve this issue because as an important place in people's social life, urban traffic environment shows a strong city's energy. Objective: Based on analysis on social function of city traffic environment and its influence of traffic on urban environment in this paper, the goal to establish a healthy urban traffic environment must be included under the aim of sustainable development eternally and feasible measures were put forward afterwards. Method, result, conclusion and possible applications.

  10. A combined volume-of-fluid method and low-Mach-number approach for DNS of evaporating droplets in turbulence

    NASA Astrophysics Data System (ADS)

    Dodd, Michael; Ferrante, Antonino

    2017-11-01

    Our objective is to perform DNS of finite-size droplets that are evaporating in isotropic turbulence. This requires fully resolving the process of momentum, heat, and mass transfer between the droplets and surrounding gas. We developed a combined volume-of-fluid (VOF) method and low-Mach-number approach to simulate this flow. The two main novelties of the method are: (i) the VOF algorithm captures the motion of the liquid gas interface in the presence of mass transfer due to evaporation and condensation without requiring a projection step for the liquid velocity, and (ii) the low-Mach-number approach allows for local volume changes caused by phase change while the total volume of the liquid-gas system is constant. The method is verified against an analytical solution for a Stefan flow problem, and the D2 law is verified for a single droplet in quiescent gas. We also demonstrate the schemes robustness when performing DNS of an evaporating droplet in forced isotropic turbulence.

  11. Traffic safety facts 1998 : state traffic data

    DOT National Transportation Integrated Search

    1999-01-01

    This publication contains a map of the United States showing 1998 traffic fatalities by state and percent change from 1997 and eleven tables containing data on the following: (1) Traffic fatalities and fatality rates, 1998; (2) Traffic fatalities and...

  12. LES, DNS and RANS for the analysis of high-speed turbulent reacting flows

    NASA Technical Reports Server (NTRS)

    Adumitroaie, V.; Colucci, P. J.; Taulbee, D. B.; Givi, P.

    1995-01-01

    The purpose of this research is to continue our efforts in advancing the state of knowledge in large eddy simulation (LES), direct numerical simulation (DNS), and Reynolds averaged Navier Stokes (RANS) methods for the computational analysis of high-speed reacting turbulent flows. In the second phase of this work, covering the period 1 Aug. 1994 - 31 Jul. 1995, we have focused our efforts on two programs: (1) developments of explicit algebraic moment closures for statistical descriptions of compressible reacting flows and (2) development of Monte Carlo numerical methods for LES of chemically reacting flows.

  13. [Bidirectional cell traffic between mother and fetus: new insights in pediatric and adult disorders].

    PubMed

    Guillemin, M; Reinert, P

    2002-02-01

    There is a heavy traffic of cells and DNA through the placenta during pregnancy. The rate of fetal cells in the maternal blood is correlated with abnormalities, such as aneuploidy and pre-eclampsia. Studying and quantifying these cells could improve antenatal diagnosis techniques, especially for Down syndrome. Maternal-fetal microchimerism is frequently observed in several auto-immune diseases in adulthood, such as systemic scleroderma. Studies suggest a rather allo-immune pathophysiology, involving maternal-fetal HLA compatibility. Microchimerism is also found in auto-immune diseases in children. Thus, the cells traffic offers new insights for antenatal diagnosis techniques and pathophysiology of auto-immune diseases.

  14. IRONSIDES: DNS With No Single Packet Denial of Service or Remote Code Execution Vulnerabilities

    DTIC Science & Technology

    2012-02-27

    Caching DNSSEC TSIG 1Pv6 Wildcard S fi.. In terface y y Y * N __ mo e ---- o •• vare y y y N NN y m progress y y y NY N Web, Y command...Proceedings of the 2007 IEEE Aerospace Conference. [6) C. Heitmeyer, M . Archer, E. Leonard and J. Mclean, "Applying formal methods to a certifiably secure...2003). [1 5] DNSSEC-The DNS Security Extensions, http:// http://www.dnssec.net/ (16] S . Conchon, E. Contcjean and J. Kanig, "Ergo : A theorem prover

  15. Air Pollution Exposure and Abnormal Glucose Tolerance during Pregnancy: The Project Viva Cohort

    PubMed Central

    Gold, Diane R.; Rifas-Shiman, Sheryl L.; Koutrakis, Petros; Schwartz, Joel D.; Kloog, Itai; Melly, Steven; Coull, Brent A.; Zanobetti, Antonella; Gillman, Matthew W.; Oken, Emily

    2014-01-01

    Background: Exposure to fine particulate matter (PM with diameter ≤ 2.5 μm; PM2.5) has been linked to type 2 diabetes mellitus, but associations with hyperglycemia in pregnancy have not been well studied. Methods: We studied Boston, Massachusetts–area pregnant women without known diabetes. We identified impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) during pregnancy from clinical glucose tolerance tests at median 28.1 weeks gestation. We used residential addresses to estimate second-trimester PM2.5 and black carbon exposure via a central monitoring site and spatiotemporal models. We estimated residential traffic density and roadway proximity as surrogates for exposure to traffic-related air pollution. We performed multinomial logistic regression analyses adjusted for sociodemographic covariates, and used multiple imputation to account for missing data. Results: Of 2,093 women, 65 (3%) had IGT and 118 (6%) had GDM. Second-trimester spatiotemporal exposures ranged from 8.5 to 15.9 μg/m3 for PM2.5 and from 0.1 to 1.7 μg/m3 for black carbon. Traffic density was 0–30,860 vehicles/day × length of road (kilometers) within 100 m; 281 (13%) women lived ≤ 200 m from a major road. The prevalence of IGT was elevated in the highest (vs. lowest) quartile of exposure to spatiotemporal PM2.5 [odds ratio (OR) = 2.63; 95% CI: 1.15, 6.01] and traffic density (OR = 2.66; 95% CI: 1.24, 5.71). IGT also was positively associated with other exposure measures, although associations were not statistically significant. No pollutant exposures were positively associated with GDM. Conclusions: Greater exposure to PM2.5 and other traffic-related pollutants during pregnancy was associated with IGT but not GDM. Air pollution may contribute to abnormal glycemia in pregnancy. Citation: Fleisch AF, Gold DR, Rifas-Shiman SL, Koutrakis P, Schwartz JD, Kloog I, Melly S, Coull BA, Zanobetti A, Gillman MW, Oken E. 2014. Air pollution exposure and abnormal glucose

  16. Traffic signal synchronization.

    PubMed

    Huang, Ding-wei; Huang, Wei-neng

    2003-05-01

    The benefits of traffic signal synchronization are examined within the cellular automata approach. The microsimulations of traffic flow are obtained with different settings of signal period T and time delay delta. Both numerical results and analytical approximations are presented. For undersaturated traffic, the green-light wave solutions can be realized. For saturated traffic, the correlation among the traffic signals has no effect on the throughput. For oversaturated traffic, the benefits of synchronization are manifest only when stochastic noise is suppressed.

  17. Vehicular Traffic Flow Theory and Tunnel Traffic Flow Measurements

    DOT National Transportation Integrated Search

    1971-06-01

    Vehicular traffic flow has been investigated theoretically and experimentally in order that peak hour collective traffic flow dynamics can be understood and that the peak hour flow through the Callahan Tunnel can be improved by means of traffic flow ...

  18. Transition Characteristic Analysis of Traffic Evolution Process for Urban Traffic Network

    PubMed Central

    Chen, Hong; Li, Yang

    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 that is appropriate for representing and analyzing the evolution progress. The methodology is illustrated by an application to data flow rate of multiple road sections from Network of Shenzhen's Nanshan District, China. Analysis and numerical results demonstrated that the methodology permits extracting many useful traffic transition characteristics including stability, preference, activity, and attractiveness. In addition, more information about the relationships between these characteristics was extracted, which should be helpful in understanding the complex behavior of the temporal evolution features of traffic patterns. PMID:24982969

  19. Enhanced peroxidase-like properties of Au@Pt DNs/NG/Cu2+ and application of sandwich-type electrochemical immunosensor for highly sensitive detection of CEA.

    PubMed

    Lv, Hui; Li, Yueyun; Zhang, Xiaobo; Gao, Zengqiang; Zhang, Chunyan; Zhang, Shuan; Dong, Yunhui

    2018-07-30

    Effective treatment of cancer depends upon the early detection of the tumor marker. Here, we report on the development of a new immunosensor for early detection of carcinoembryonic antigen (CEA). Cubic Au@Pt dendritic nanomaterials functionalized nitrogen-doped graphene loaded with copper ion (Au@Pt DNs/NG/Cu 2+ ) with enhanced peroxidase-like properties was synthesized as labels to effectively capture and immobilize secondary anti-CEA. The Au@Pt DNs with more active surface area could efficiently enhance electrocatalysis for reduction of hydrogen peroxide (H 2 O 2 ). Meanwhile, with good conductivity and large specific surface area, NG can immobilize a large amount of Au@Pt DNs. Furthermore, after adsorbed Cu 2+ can further promote the redox of H 2 O 2 and amplify the signal of the immunosensor. For the immobilization of primary antibodies, Au nanoparticles functionalized polydopamine (Au@PDA) were used as transducing materials to modify glassy carbon electrodes and enhance the electron transfer efficiently. Under optimal conditions, the immunosensor exhibited a satisfactory response to CEA with a limit detection of 0.167 pg/mL and linear detection range from 0.5 pg/mL to 50 ng/mL. Based on the high sensitivity and specificity of the immunosensor, we propose this multiple amplified biosensor for early detection of CEA. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Traffic Games: Modeling Freeway Traffic with Game Theory

    PubMed Central

    Cortés-Berrueco, Luis E.; Gershenson, Carlos; Stephens, Christopher R.

    2016-01-01

    We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers’ interactions. PMID:27855176

  1. Traffic Games: Modeling Freeway Traffic with Game Theory.

    PubMed

    Cortés-Berrueco, Luis E; Gershenson, Carlos; Stephens, Christopher R

    2016-01-01

    We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers' interactions.

  2. Area-wide traffic calming for preventing traffic related injuries.

    PubMed

    Bunn, F; Collier, T; Frost, C; Ker, K; Roberts, I; Wentz, R

    2003-01-01

    It is estimated that by 2020 road traffic crashes will have moved from ninth to third in the world disease burden ranking, as measured in disability adjusted life years, and second in developing countries. The identification of effective strategies for the prevention of traffic related injuries is of global health importance. Area-wide traffic calming schemes that discourage through traffic on residential roads is one such strategy. To evaluate the effectiveness of area-wide traffic calming in preventing traffic related crashes, injuries, and deaths. We searched the following electronic databases: Cochrane Injuries Group's Specialised Register, Cochrane Controlled Trials Register, MEDLINE, EMBASE and TRANSPORT (NTIS, TRIS, TRANSDOC). We searched the web sites of road safety organisations, handsearched conference proceedings, checked reference lists of relevant papers and contacted experts in the area. The search was not restricted by language or publication status. Randomised controlled trials, and controlled before-after studies of area-wide traffic calming schemes. Two reviewers independently extracted data on type of study, characteristics of intervention and control areas, and length of data collection periods. Before and after data were collected on the total number of road traffic crashes, all road user deaths and injuries, pedestrian-motor vehicle collisions and road user deaths. The statistical package STATA was used to calculate rate ratios for each study, which were then pooled to give an overall estimate using a random effects model. We found no randomised controlled trials, but 16 controlled before-after trials met our inclusion criteria. Seven studies were done in Germany, six in the UK, two in Australia and one in the Netherlands. There were no studies in low or middle income countries. Eight trials reported the number of road traffic crashes resulting in deaths. The pooled rate ratio was 0.63 (0.14, 2.59 95% CI). Sixteen studies reported the number

  3. Virtualized Traffic: reconstructing traffic flows from discrete spatiotemporal data.

    PubMed

    Sewall, Jason; van den Berg, Jur; Lin, Ming C; Manocha, Dinesh

    2011-01-01

    We present a novel concept, Virtualized Traffic, to reconstruct and visualize continuous traffic flows from discrete spatiotemporal data provided by traffic sensors or generated artificially to enhance a sense of immersion in a dynamic virtual world. Given the positions of each car at two recorded locations on a highway and the corresponding time instances, our approach can reconstruct the traffic flows (i.e., the dynamic motions of multiple cars over time) between the two locations along the highway for immersive visualization of virtual cities or other environments. Our algorithm is applicable to high-density traffic on highways with an arbitrary number of lanes and takes into account the geometric, kinematic, and dynamic constraints on the cars. Our method reconstructs the car motion that automatically minimizes the number of lane changes, respects safety distance to other cars, and computes the acceleration necessary to obtain a smooth traffic flow subject to the given constraints. Furthermore, our framework can process a continuous stream of input data in real time, enabling the users to view virtualized traffic events in a virtual world as they occur. We demonstrate our reconstruction technique with both synthetic and real-world input. © 2011 IEEE Published by the IEEE Computer Society

  4. Developmental Neurotoxicity of Traffic-Related Air Pollution: Focus on Autism.

    PubMed

    Costa, Lucio G; Chang, Yu-Chi; Cole, Toby B

    2017-06-01

    Epidemiological and animal studies suggest that air pollution may negatively affect the central nervous system (CNS) and contribute to CNS diseases. Traffic-related air pollution is a major contributor to global air pollution, and diesel exhaust (DE) is its most important component. Several studies suggest that young individuals may be particularly susceptible to air pollution-induced neurotoxicity and that perinatal exposure may cause or contribute to developmental disabilities and behavioral abnormalities. In particular, a number of recent studies have found associations between exposures to traffic-related air pollution and autism spectrum disorders (ASD), which are characterized by impairment in socialization and in communication and by the presence of repetitive and unusual behaviors. The cause(s) of ASD are unknown, and while it may have a hereditary component, environmental factors are increasingly suspected as playing a pivotal role in its etiology, particularly in genetically susceptible individuals. Autistic children present higher levels of neuroinflammation and systemic inflammation, which are also hallmarks of exposure to traffic-related air pollution. Gene-environment interactions may play a relevant role in determining individual susceptibility to air pollution developmental neurotoxicity. Given the worldwide presence of elevated air pollution, studies on its effects and mechanisms on the developing brain, genetic susceptibility, role in neurodevelopmental disorders, and possible therapeutic interventions are certainly warranted.

  5. Dynamics of traffic flow with real-time traffic information

    NASA Astrophysics Data System (ADS)

    Yokoya, Yasushi

    2004-01-01

    We studied dynamics of traffic flow with real-time information provided. Provision of the real-time traffic information based on advancements in telecommunication technology is expected to facilitate the efficient utilization of available road capacity. This system has a potentiality of not only engineering for road usage but also the science of complexity series. In the system, the information plays a role of feedback connecting microscopic and macroscopic phenomena beyond the hierarchical structure of statistical physics. In this paper, we tried to clarify how the information works in a network of traffic flow from the perspective of statistical physics. The dynamical feature of the traffic flow is abstracted by a contrastive study between the nonequilibrium statistical physics and a computer simulation based on cellular automaton. We found that the information disrupts the local equilibrium of traffic flow by a characteristic dissipation process due to interaction between the information and individual vehicles. The dissipative structure was observed in the time evolution of traffic flow driven far from equilibrium as a consequence of the breakdown of the local-equilibrium hypothesis.

  6. LES, DNS and RANS for the analysis of high-speed turbulent reacting flows

    NASA Technical Reports Server (NTRS)

    Givi, Peyman

    1994-01-01

    The objective of this research is to continue our efforts in advancing the state of knowledge in Large Eddy Simulation (LES), Direct Numerical Simulation (DNS), and Reynolds Averaged Navier Stokes (RANS) methods for the analysis of high-speed reacting turbulent flows. In the first phase of this research, conducted within the past six months, focus was in three directions: RANS of turbulent reacting flows by Probability Density Function (PDF) methods, RANS of non-reacting turbulent flows by advanced turbulence closures, and LES of mixing dominated reacting flows by a dynamics subgrid closure. A summary of our efforts within the past six months of this research is provided in this semi-annual progress report.

  7. Near real-time traffic routing

    NASA Technical Reports Server (NTRS)

    Yang, Chaowei (Inventor); Xie, Jibo (Inventor); Zhou, Bin (Inventor); Cao, Ying (Inventor)

    2012-01-01

    A near real-time physical transportation network routing system comprising: a traffic simulation computing grid and a dynamic traffic routing service computing grid. The traffic simulator produces traffic network travel time predictions for a physical transportation network using a traffic simulation model and common input data. The physical transportation network is divided into a multiple sections. Each section has a primary zone and a buffer zone. The traffic simulation computing grid includes multiple of traffic simulation computing nodes. The common input data includes static network characteristics, an origin-destination data table, dynamic traffic information data and historical traffic data. The dynamic traffic routing service computing grid includes multiple dynamic traffic routing computing nodes and generates traffic route(s) using the traffic network travel time predictions.

  8. Traffic safety facts 1994 : state traffic data

    DOT National Transportation Integrated Search

    1995-01-01

    Nationwide in 1994, traffic fatalities were up 1 percent for a total of 40,676 traffic deaths. These tables provide summary data of fatal crashes for the United States and individually for the 50 states, the District of Columbia, and Puerto Rico (not...

  9. Dansylated octapeptide Dns-Glu-Asp-Asp-Ser-Asp-Glu-Glu-Asn inhibits the proliferation rate of HL-60 cells.

    PubMed

    Marsili, V; Nardicchi, V; Lupidi, G; Brozzetti, A; Gianfranceschi, G L

    1996-12-01

    Small acidic phosphorylated chromatin peptides show regulatory activity on gene expression. The peptide pyroGlu-Asp-Asp-Ser-Asp-Glu-Glu-Asn, synthesized on the basis of structural and biochemical studies, shows functional properties in vitro (phosphorylation by casein kinase II, control of DNA transcription by RNA polymerase II, inhibition of proliferation and promotion of differentiation in some cell lines) very similar to those of native chromatin peptides. In this report we show that the dansylated octapeptide Dns-Glu-Asp-Asp-Ser-Asp-Glu-Glu-Asn remarkably inhibits cell growth of the HL-60 cell line. The biological effect of the peptide seems to be considerably higher than that shown by the nondansylated peptide, and it cannot be attributed to a toxic effect of the Dns group. The measurement of uptake of 3H-labelled Glu-Asp-Asp-Ser-Asp-Glu-Glu-Asn demonstrates that it is unable to pass through the HL-60 cell membrane. It is our considered opinion that the addition of hydrophobic groups to the peptide N-terminus should increase the biological activity by improving its transport through the cellular membrane.

  10. Re-understanding the law-of-the-wall for wall-bounded turbulence based on in-depth investigation of DNS data

    NASA Astrophysics Data System (ADS)

    Cao, Bochao; Xu, Hongyi

    2018-05-01

    Based on direct numerical simulation (DNS) data of the straight ducts, namely square and rectangular annular ducts, detailed analyses were conducted for the mean streamwise velocity, relevant velocity scales, and turbulence statistics. It is concluded that turbulent boundary layers (TBL) should be broadly classified into three types (Type-A, -B, and -C) in terms of their distribution patterns of the time-averaged local wall-shear stress (τ _w ) or the mean local frictional velocity (u_τ ) . With reference to the Type-A TBL analysis by von Karman in developing the law-of-the-wall using the time-averaged local frictional velocity (u_τ ) as scale, the current study extended the approach to the Type-B TBL and obtained the analytical expressions for streamwise velocity in the inner-layer using ensemble-averaged frictional velocity (\\bar{{u}}_τ ) as scale. These analytical formulae were formed by introducing the general damping and enhancing functions. Further, the research applied a near-wall DNS-guided integration to the governing equations of Type-B TBL and quantitatively proved the correctness and accuracy of the inner-layer analytical expressions for this type.

  11. TrafficTurk evaluation.

    DOT National Transportation Integrated Search

    2014-04-01

    This report summarizes a project undertaken by the University of Illinois on behalf of the Illinois Department of : Transportation to evaluate a smartphone application called TrafficTurk for traffic safety and traffic monitoring : applications. Traff...

  12. DNS of Low-Pressure Turbine Cascade Flows with Elevated Inflow Turbulence Using a Discontinuous-Galerkin Spectral-Element Method

    NASA Technical Reports Server (NTRS)

    Garai, Anirban; Diosady, Laslo T.; Murman, Scott M.; Madavan, Nateri K.

    2016-01-01

    Recent progress towards developing a new computational capability for accurate and efficient high-fidelity direct numerical simulation (DNS) and large-eddy simulation (LES) of turbomachinery is described. This capability is based on an entropy- stable Discontinuous-Galerkin spectral-element approach that extends to arbitrarily high orders of spatial and temporal accuracy, and is implemented in a computationally efficient manner on a modern high performance computer architecture. An inflow turbulence generation procedure based on a linear forcing approach has been incorporated in this framework and DNS conducted to study the effect of inflow turbulence on the suction- side separation bubble in low-pressure turbine (LPT) cascades. The T106 series of airfoil cascades in both lightly (T106A) and highly loaded (T106C) configurations at exit isentropic Reynolds numbers of 60,000 and 80,000, respectively, are considered. The numerical simulations are performed using 8th-order accurate spatial and 4th-order accurate temporal discretization. The changes in separation bubble topology due to elevated inflow turbulence is captured by the present method and the physical mechanisms leading to the changes are explained. The present results are in good agreement with prior numerical simulations but some expected discrepancies with the experimental data for the T106C case are noted and discussed.

  13. Traffic monitoring guide

    DOT National Transportation Integrated Search

    1995-02-01

    This guide is designed to provide direction on the monitoring of traffic characteristics. It begins with a discussion of the structure of traffic characteristics monitoring and traffic counting. The next two sections cover vehicle classification and ...

  14. Traffic Monitor

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Mestech's X-15 "Eye in the Sky," a traffic monitoring system, incorporates NASA imaging and robotic vision technology. A camera or "sensor box" is mounted in a housing. The sensor detects vehicles approaching an intersection and sends the information to a computer, which controls the traffic light according to the traffic rate. Jet Propulsion Laboratory technical support packages aided in the company's development of the system. The X-15's "smart highway" can also be used to count vehicles on a highway and compute the number in each lane and their speeds, important information for freeway control engineers. Additional applications are in airport and railroad operations. The system is intended to replace loop-type traffic detectors.

  15. A Posteriori Study of a DNS Database Describing Super critical Binary-Species Mixing

    NASA Technical Reports Server (NTRS)

    Bellan, Josette; Taskinoglu, Ezgi

    2012-01-01

    Currently, the modeling of supercritical-pressure flows through Large Eddy Simulation (LES) uses models derived for atmospheric-pressure flows. Those atmospheric-pressure flows do not exhibit the particularities of high densitygradient magnitude features observed both in experiments and simulations of supercritical-pressure flows in the case of two species mixing. To assess whether the current LES modeling is appropriate and if found not appropriate to propose higher-fidelity models, a LES a posteriori study has been conducted for a mixing layer that initially contains different species in the lower and upper streams, and where the initial pressure is larger than the critical pressure of either species. An initially-imposed vorticity perturbation promotes roll-up and a double pairing of four initial span-wise vortices into an ultimate vortex that reaches a transitional state. The LES equations consist of the differential conservation equations coupled with a real-gas equation of state, and the equation set uses transport properties depending on the thermodynamic variables. Unlike all LES models to date, the differential equations contain, additional to the subgrid scale (SGS) fluxes, a new SGS term that is a pressure correction in the momentum equation. This additional term results from filtering of Direct Numerical Simulation (DNS) equations, and represents the gradient of the difference between the filtered pressure and the pressure computed from the filtered flow field. A previous a priori analysis, using a DNS database for the same configuration, found this term to be of leading order in the momentum equation, a fact traced to the existence of high-densitygradient magnitude regions that populated the entire flow; in the study, models were proposed for the SGS fluxes as well as this new term. In the present study, the previously proposed constantcoefficient SGS-flux models of the a priori investigation are tested a posteriori in LES, devoid of or including, the

  16. Layer-specific gene expression in epileptogenic type II focal cortical dysplasia: normal-looking neurons reveal the presence of a hidden laminar organization

    PubMed Central

    2014-01-01

    Background Type II focal cortical dysplasias (FCDs) are malformations of cortical development characterised by the disorganisation of the normal neocortical structure and the presence of dysmorphic neurons (DNs) and balloon cells (BCs). The pathogenesis of FCDs has not yet been clearly established, although a number of histopathological patterns and molecular findings suggest that they may be due to abnormal neuronal and glial proliferation and migration processes. In order to gain further insights into cortical layering disruption and investigate the origin of DNs and BCs, we used in situ RNA hybridisation of human surgical specimens with a neuropathologically definite diagnosis of Type IIa/b FCD and a panel of layer-specific genes (LSGs) whose expression covers all cortical layers. We also used anti-phospho-S6 ribosomal protein antibody to investigate mTOR pathway hyperactivation. Results LSGs were expressed in both normal and abnormal cells (BCs and DNs) but their distribution was different. Normal-looking neurons, which were visibly reduced in the core of the lesion, were apparently located in the appropriate cortical laminae thus indicating a partial laminar organisation. On the contrary, DNs and BCs, labelled with anti-phospho-S6 ribosomal protein antibody, were spread throughout the cortex without any apparent rule and showed a highly variable LSG expression pattern. Moreover, LSGs did not reveal any differences between Type IIa and IIb FCD. Conclusion These findings suggest the existence of hidden cortical lamination involving normal-looking neurons, which retain their ability to migrate correctly in the cortex, unlike DNs which, in addition to their morphological abnormalities and mTOR hyperactivation, show an altered migratory pattern. Taken together these data suggest that an external or environmental hit affecting selected precursor cells during the very early stages of cortical development may disrupt normal cortical development. PMID:24735483

  17. Traffic Circle Model

    DOT National Transportation Integrated Search

    1971-05-01

    The report describes a dynamic model of a traffic circle which has been implemented on a CRT display terminal. The model includes sufficient parameters to allow changes in the structure of the traffic circle, the frequency of traffic introduced to th...

  18. Modeling the heterogeneous traffic correlations in urban road systems using traffic-enhanced community detection approach

    NASA Astrophysics Data System (ADS)

    Lu, Feng; Liu, Kang; Duan, Yingying; Cheng, Shifen; Du, Fei

    2018-07-01

    A better characterization of the traffic influence among urban roads is crucial for traffic control and traffic forecasting. The existence of spatial heterogeneity imposes great influence on modeling the extent and degree of road traffic correlation, which is usually neglected by the traditional distance based method. In this paper, we propose a traffic-enhanced community detection approach to spatially reveal the traffic correlation in city road networks. First, the road network is modeled as a traffic-enhanced dual graph with the closeness between two road segments determined not only by their topological connection, but also by the traffic correlation between them. Then a flow-based community detection algorithm called Infomap is utilized to identify the road segment clusters. Evaluated by Moran's I, Calinski-Harabaz Index and the traffic interpolation application, we find that compared to the distance based method and the community based method, our proposed traffic-enhanced community based method behaves better in capturing the extent of traffic relevance as both the topological structure of the road network and the traffic correlations among urban roads are considered. It can be used in more traffic-related applications, such as traffic forecasting, traffic control and guidance.

  19. National traffic speeds survey II: 2009 : traffic tech.

    DOT National Transportation Integrated Search

    2012-08-01

    Vehicle speeds are a crucial factor in traffic safety. : NHTSA estimates that speeding is involved in approximately : 31% of fatal motor vehicle crashes, costing society : over $40 billion per year. : Since speeding is such a : pervasive traffic safe...

  20. Influence of steric hindrance on enantioseparation of Dns-amino acids and pesticides on terguride based chiral selectors in capillary electrophoresis.

    PubMed

    Honzátko, Ales; Cvak, Jan; Vaingátová, Silvie; Flieger, Miroslav

    2005-05-01

    Three urea derivatives of ergoline-based chiral selectors (CSs), differing in the size of the urea side chain, i.e. dimethyl- (CSI), diethyl- (CSII), and diisopropylurea (CSIII), were used to study the effect of steric hindrance on the enantioseparation of dansyl amino acids (Dns-AAs), pesticides, and mandelic acid under condition of capillary electrophoresis (CE) in linear polyacrylamide coated capillaries. A mixture of organic modifiers (MeOH/THF, 4:1 v/v) in a BGE consisting of 100 mM beta-alanine-acetate was used to increase the solubility of CSs up to 25 mM. The capillary was filled with CS (high UV absorption), and the inlet and outlet vials contained buffer solutions only. The best enantioseparation of Dns-AAs was achieved on CSI. Increased steric hindrance of the chiral binding site led to reduction of both enantioselectivity and resolution. The opposite pattern was observed for the separation of mandelic acid enantiomers, where the best enantioseparation and resolution was obtained with CSIII. Most of the pesticides studied reached maximum selectivity on the diethylurea ergoline derivative (CSII). Enantioseparation of fenoxaprop was found to be independent of steric hindrance.

  1. DNS of unsteady, turbulent convection in a rotating stratified fluid

    NASA Astrophysics Data System (ADS)

    Pal, Anikesh; Chalmalla, Vamsi

    2017-11-01

    Turbulent convection under the influence of intense surface cooling and earth's rotation is a common phenomenon observed in the ocean. In the present study, direct numerical simulations are performed to understand this dynamics. The effect of rotation is represented by Rossby number Ro* which is defined in terms of ocean depth H, Coriolis parameter f and surface buoyancy flux B0, as Ro* =B01// 2 Hf 3 / 2 . Cooling at the surface results in the formation of unstable density configuration where denser fluid lies on top of the lighter fluid. These unstable density configuration leads to a turbulent front. When the turbulent front reaches a transition depth zc, it experiences the effect of rotation leading to the formation of quasi- 2D vortices beneath the 3D turbulent layer. If the surface cooling is strong enough, these vortices penetrate further downwards producing vortex columns. Qualitatively, DNS results agree well with the findings of experimental study by Maxworthy & Narimousa (1993). The motivation of this study is to understand the nonlinear dynamics and turbulence scaling as the surface cooling and Coriolis parameter are varied.

  2. Traffic Flow Estimates.

    ERIC Educational Resources Information Center

    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)

  3. Developmental neurotoxicity of traffic-related air pollution: focus on autism

    PubMed Central

    Costa, Lucio G.; Chang, Yu-Chi; Cole, Toby B.

    2018-01-01

    Purpose of Review Epidemiological and animal studies suggest that air pollution may negatively affect the central nervous system (CNS) and contribute to CNS diseases. Traffic-related air pollution is a major contributor to global air pollution, and diesel exhaust (DE) is its most important component. Recent findings Several studies suggest that young individuals may be particularly susceptible to air pollution-induced neurotoxicity, and that perinatal exposure may cause or contribute to developmental disabilities and behavioral abnormalities. In particular, a number of recent studies have found associations between exposures to traffic-related air pollution and autism spectrum disorders (ASD), which are characterized by impairment in socialization and in communication, and by the presence of repetitive and unusual behaviors. The cause(s) of ASD are unknown, and while it may have a hereditary component, environmental factors are increasingly suspected as playing a pivotal role in its etiology, particularly in genetically susceptible individuals. Summary Autistic children present higher levels of neuroinflammation and systemic inflammation, which are also hallmarks of exposure to traffic-related air pollution. Gene-environment interactions may play a relevant role in determining individual susceptibility to air pollution developmental neurotoxicity. Given the worldwide presence of elevated air pollution, studies on its effects and mechanisms on the developing brain, genetic susceptibility, role in neurodevelopmental disorders, and possible therapeutic interventions, are certainly warranted. PMID:28417440

  4. Obstructive sleep apnoea syndrome as a cause of road traffic accidents.

    PubMed

    Aguiar, M; Valença, J; Felizardo, M; Caeiro, F; Moreira, S; Staats, R; Bugalho de Almeida, A A

    2009-01-01

    Several studies have demonstrated that obstructive sleep apnoea syndrome (OSAS) patients have a higher rate of road traffic accidents. Our study aimed to analyse any differences in OSAS patients between those who reported having had road traffic accidents and/or near misses and those who did not. We studied 163 patients with OSAS (apnoea- hypopnoea index (AHI)>10/h) diagnosed using nocturnal polysomnography (NPSG), all drivers, 18.4% of whom drove for a living. Patients were asked at their first clinical interview to self-report road traffic accidents and/or near misses over the past 3 years which had been caused by abnormal daytime drowsiness. This allowed patients to be divided into two groups, those who had had road traffic accidents and/or near misses and those who had not. Both were compared as to age, body mass index (BMI), Epworth Sleepiness Scale (ESS), daytime PaO2 and PaCO2, Functional Outcomes of Sleep Questionnaire (FOSQ) test and NPSG data. This latter was total sleep time (TTS), sleep efficiency, sleep stages, arousal index (ARI), AHI, minimal and average SaO2, % of time with SaO2 < 90% (T90), desaturation index (ODI), total duration of apnoea-hypopnoea (TDAH) (T test). Group I (no road traffic accidents) No=89 patients; group II (road traffic accidents) No=74 patients. Age (years) was 57.6+/-11.8 vs. 54.7+/-10.9 (ns); male gender, 75% vs. 78.4%; ESS, 12.3+/-5.4 vs. 17.6+/-4.3 (p<0.001); BMI, (Kg/m2) 36.2+/-8.1 vs. 35.6+/-6.3 (ns); PaO2 (mmHg), 76.1+/-11.4 vs. 78.5+/-12.6 (ns); PaCO2 (mmHg), 42.6+/-5.1 vs. 42.2+/-4.7 (ns); FOSQ, 15.1+/-3.1 vs. 12.9+/-3.4 (p<0.001). NPSG data revealed differences only in AHI: 45.0+/-21.6 vs. 56.2+/-29.7 (p=0.01) and in TDAH (minutes), 98.5+/-63.7 vs. 133.3+/-83.2 (p=0,005). In our experience patients who had road traffic accidents and/or near misses had a more severe OSAS, with higher AHI, excessive daytime sleepiness and lower quality of life.

  5. Properties of Traffic Risk Coefficient

    NASA Astrophysics Data System (ADS)

    Tang, Tie-Qiao; Huang, Hai-Jun; Shang, Hua-Yan; Xue, Yu

    2009-10-01

    We use the model with the consideration of the traffic interruption probability (Physica A 387(2008)6845) to study the relationship between the traffic risk coefficient and the traffic interruption probability. The analytical and numerical results show that the traffic interruption probability will reduce the traffic risk coefficient and that the reduction is related to the density, which shows that this model can improve traffic security.

  6. Analysis of vehicular traffic flow in the major areas of Kuala Lumpur utilizing open-traffic

    NASA Astrophysics Data System (ADS)

    Manogaran, Saargunawathy; Ali, Muhammad; Yusof, Kamaludin Mohamad; Suhaili, Ramdhan

    2017-09-01

    Vehicular traffic congestion occurs when a large number of drivers are overcrowded on the road and the traffic flow does not run smoothly. Traffic congestion causes chaos on the road and interruption to daily activities of users. Time consumed on road give lots of negative effects on productivity, social behavior, environmental and cost to economy. Congestion is worsens and leads to havoc during the emergency such as flood, accidents, road maintenance and etc., where behavior of traffic flow is always unpredictable and uncontrollable. Real-time and historical traffic data are critical inputs for most traffic flow analysis applications. Researcher attempt to predict traffic using simulations as there is no exact model of traffic flow exists due to its high complexity. Open Traffic is an open source platform available for traffic data analysis linked to Open Street Map (OSM). This research is aimed to study and understand the Open Traffic platform. The real-time traffic flow pattern in Kuala Lumpur area was successfully been extracted and analyzed using Open Traffic. It was observed that the congestion occurs on every major road in Kuala Lumpur and most of it owes to the offices and the economic and commercial centers during rush hours. At some roads the congestion occurs at night due to the tourism activities.

  7. TrafficGen Architecture Document

    DTIC Science & Technology

    2016-01-01

    sequence diagram ....................................................5 Fig. 5 TrafficGen traffic flows viewed in SDT3D...Scripts contain commands to have the network node listen on specific ports and flows describing the start time, stop time, and specific traffic ...arranged vertically and time presented horizontally. Individual traffic flows are represented by horizontal bars indicating the start time, stop time

  8. Modeling hurricane evacuation traffic : a mobile real-time traffic counter for monitoring hurricane evacuation traffic conditions.

    DOT National Transportation Integrated Search

    2006-04-01

    In this research report, an investigation was conducted to identify a suitable traffic monitoring device for collecting traffic data during actual emergency evacuation conditions that may result from hurricanes in Louisiana. The study reviewed thorou...

  9. LES, DNS and RANS for the analysis of high-speed turbulent reacting flows

    NASA Technical Reports Server (NTRS)

    Givi, Peyman; Taulbee, Dale B.; Adumitroaie, Virgil; Sabini, George J.; Shieh, Geoffrey S.

    1994-01-01

    The purpose of this research is to continue our efforts in advancing the state of knowledge in large eddy simulation (LES), direct numerical simulation (DNS), and Reynolds averaged Navier Stokes (RANS) methods for the computational analysis of high-speed reacting turbulent flows. In the second phase of this work, covering the period 1 Sep. 1993 - 1 Sep. 1994, we have focused our efforts on two research problems: (1) developments of 'algebraic' moment closures for statistical descriptions of nonpremixed reacting systems, and (2) assessments of the Dirichlet frequency in presumed scalar probability density function (PDF) methods in stochastic description of turbulent reacting flows. This report provides a complete description of our efforts during this past year as supported by the NASA Langley Research Center under Grant NAG1-1122.

  10. Leveraging traffic and surveillance video cameras for urban traffic.

    DOT National Transportation Integrated Search

    2014-12-01

    The objective of this project was to investigate the use of existing video resources, such as traffic : cameras, police cameras, red light cameras, and security cameras for the long-term, real-time : collection of traffic statistics. An additional ob...

  11. Assessment of honking impact on traffic noise in urban traffic environment of Nagpur, India.

    PubMed

    Vijay, Ritesh; Sharma, Asheesh; Chakrabarti, Tapan; Gupta, Rajesh

    2015-01-01

    In context of increasing traffic noise in urban India, the objective of the research study is to assess noise due to heterogeneous traffic conditions and the impact of honking on it. Traffic volume, noise levels, honking, road geometry and vehicular speed were measured on national highway, major and minor roads in Nagpur, India. Initial study showed lack of correlation between traffic volume and equivalent noise due to some factors, later identified as honking, road geometry and vehicular speed. Further, frequency analysis of traffic noise showed that honking contributed an additional 2 to 5 dB (A) noise, which is quite significant. Vehicular speed was also found to increase traffic noise. Statistical method of analysis of variance (ANOVA) confirms that frequent honking (p < 0.01) and vehicular speed (p < 0.05) have substantial impact on traffic noise apart from traffic volume and type of road. The study suggests that honking must also be a component in traffic noise assessment and to identify and monitor "No Honking" zones in urban agglomerations.

  12. Traffic Generator (TrafficGen) Version 1.4.2: Users Guide

    DTIC Science & Technology

    2016-06-01

    events, the user has to enter them manually . We will research and implement a way to better define and organize the multicast addresses so they can be...the network with Transmission Control Protocol and User Datagram Protocol Internet Protocol traffic. Each node generating network traffic in an...TrafficGen Graphical User Interface (GUI) 3 3.1 Anatomy of the User Interface 3 3.2 Scenario Configuration and MGEN Files 4 4. Working with

  13. Traffic management simulation development : summary.

    DOT National Transportation Integrated Search

    2011-01-01

    Increasingly, Florida traffic is monitored electronically by components of the Intelligent Traffic System (ITS), which send data to regional traffic management centers and assist management of traffic flows and incident response using software called...

  14. Did Chile's traffic law reform push police enforcement? Understanding Chile's traffic fatalities and injuries reduction.

    PubMed

    Nazif-Munoz, José Ignacio; Quesnel-Vallée, Amélie; van den Berg, Axel

    2015-06-01

    The objective of the current study is to determine to what extent the reduction of Chile's traffic fatalities and injuries during 2000-2012 was related to the police traffic enforcement increment registered after the introduction of its 2005 traffic law reform. A unique dataset with assembled information from public institutions and analyses based on ordinary least square and robust random effects models was carried out. Dependent variables were traffic fatality and severe injury rates per population and vehicle fleet. Independent variables were: (1) presence of new national traffic law; (2) police officers per population; (3) number of traffic tickets per police officer; and (4) interaction effect of number of traffic tickets per police officer with traffic law reform. Oil prices, alcohol consumption, proportion of male population 15-24 years old, unemployment, road infrastructure investment, years' effects and regions' effects represented control variables. Empirical estimates from instrumental variables suggest that the enactment of the traffic law reform in interaction with number of traffic tickets per police officer is significantly associated with a decrease of 8% in traffic fatalities and 7% in severe injuries. Piecewise regression model results for the 2007-2012 period suggest that police traffic enforcement reduced traffic fatalities by 59% and severe injuries by 37%. Findings suggest that traffic law reforms in order to have an effect on both traffic fatality and injury rates reduction require changes in police enforcement practices. Last, this case also illustrates how the diffusion of successful road safety practices globally promoted by WHO and World Bank can be an important influence for enhancing national road safety practices. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. Cytokinesis failure due to derailed integrin traffic induces aneuploidy and oncogenic transformation in vitro and in vivo

    PubMed Central

    Högnäs, G; Tuomi, S; Veltel, S; Mattila, E; Murumägi, A; Edgren, H; Kallioniemi, O; Ivaska, J

    2012-01-01

    Aneuploidy is frequently detected in solid tumors but the mechanisms regulating the generation of aneuploidy and their relevance in cancer initiation remain under debate and are incompletely characterized. Spatial and temporal regulation of integrin traffic is critical for cell migration and cytokinesis. Impaired integrin endocytosis, because of the loss of Rab21 small GTPase or mutations in the integrin β-subunit cytoplasmic tail, induces failure of cytokinesis in vitro. Here, we describe that repeatedly failed cytokinesis, because of impaired traffic, is sufficient to trigger the generation of aneuploid cells, which display characteristics of oncogenic transformation in vitro and are tumorigenic in vivo. Furthermore, in an in vivo mouse xenograft model, non-transformed cells with impaired integrin traffic formed tumors with a long latency. More detailed investigation of these tumors revealed that the tumor cells were aneuploid. Therefore, abnormal integrin traffic was linked with generation of aneuploidy and cell transformation also in vivo. In human prostate and ovarian cancer samples, downregulation of Rab21 correlates with increased malignancy. Loss-of-function experiments demonstrate that long-term depletion of Rab21 is sufficient to induce chromosome number aberrations in normal human epithelial cells. These data are the first to demonstrate that impaired integrin traffic is sufficient to induce conversion of non-transformed cells to tumorigenic cells in vitro and in vivo. PMID:22120710

  16. Modeling hurricane evacuation traffic : a mobile real-time traffic counter for monitoring hurricane evacuation traffic conditions.

    DOT National Transportation Integrated Search

    2006-04-01

    The objective of this part of the research study was to select and acquire a mobile traffic counter capable of providing traffic flow and average speed data in intervals of time no greater than 15 minutes and transmit the data back to a central locat...

  17. Right-­turn traffic volume adjustment in traffic signal warrant analysis : final report.

    DOT National Transportation Integrated Search

    2016-05-06

    This report was based on the research project, Right-Turn Traffic Volume Adjustment in Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) and SOLARIS. Right-turn traffic does not affect intersection performance in th...

  18. Traffic operational evaluation of traffic impact analysis (TIA) case sites.

    DOT National Transportation Integrated Search

    2010-09-22

    This report summarizes traffic operational evaluation of six select traffic impact analysis (TIA) case sites and the effectiveness of forecasting methods used in TIA studies. Six TIA case sites comprising 15 signalized intersections and 2 unsignalize...

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

    PubMed

    Pan, Long; Yao, Enjian; Yang, Yang

    2016-12-01

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

  20. A DNS study on the stabilization mechanism of a turbulent lifted ethylene jet flame in highly-heated coflow

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoo, Chun S

    2011-01-01

    Direct numerical simulation (DNS) of the near-field of a three-dimensional spatially-developing turbulent ethylene jet flame in highly-heated coflow is performed with a reduced mechanism to determine the stabilization mechanism. The DNS was performed at a jet Reynolds number of 10,000 with over 1.29 billion grid points. The results show that auto-ignition in a fuel-lean mixture at the flame base is the main source of stabilization of the lifted jet flame. The Damkoehler number and chemical explosive mode (CEM) analysis also verify that auto-ignition occurs at the flame base. In addition to auto-ignition, Lagrangian tracking of the flame base reveals themore » passage of large-scale flow structures and their correlation with the fluctuations of the flame base similar to a previous study (Yoo et al., J. Fluid Mech. 640 (2009) 453-481) with hydrogen/air jet flames. It is also observed that the present lifted flame base exhibits a cyclic 'saw-tooth' shaped movement marked by rapid movement upstream and slower movement downstream. This is a consequence of the lifted flame being stabilized by a balance between consecutive auto-ignition events in hot fuel-lean mixtures and convection induced by the high-speed jet and coflow velocities. This is confirmed by Lagrangian tracking of key variables including the flame-normal velocity, displacement speed, scalar dissipation rate, and mixture fraction at the stabilization point.« less

  1. A DNS study on the stabilization mechanism of a turbulent lifted ethylene jet flame in highly-heated coflow

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoo, C. S.; Richardson, E.; Sankaran, R.

    2011-01-01

    Direct numerical simulation (DNS) of the near-field of a three-dimensional spatially-developing turbulent ethylene jet flame in highly-heated coflow is performed with a reduced mechanism to determine the stabilization mechanism. The DNS was performed at a jet Reynolds number of 10,000 with over 1.29 billion grid points. The results show that auto-ignition in a fuel-lean mixture at the flame base is the main source of stabilization of the lifted jet flame. The Damköhler number and chemical explosive mode (CEM) analysis also verify that auto-ignition occurs at the flame base. In addition to auto-ignition, Lagrangian tracking of the flame base reveals themore » passage of large-scale flow structures and their correlation with the fluctuations of the flame base similar to a previous study (Yoo et al., J. Fluid Mech. 640 (2009) 453–481) with hydrogen/air jet flames. It is also observed that the present lifted flame base exhibits a cyclic ‘saw-tooth’ shaped movement marked by rapid movement upstream and slower movement downstream. This is a consequence of the lifted flame being stabilized by a balance between consecutive auto-ignition events in hot fuel-lean mixtures and convection induced by the high-speed jet and coflow velocities. This is confirmed by Lagrangian tracking of key variables including the flame-normal velocity, displacement speed, scalar dissipation rate, and mixture fraction at the stabilization point.« less

  2. The impact of traffic sign deficit on road traffic accidents in Nigeria.

    PubMed

    Ezeibe, Christian; Ilo, Chukwudi; Oguonu, Chika; Ali, Alphonsus; Abada, Ifeanyi; Ezeibe, Ezinwanne; Oguonu, Chukwunonso; Abada, Felicia; Izueke, Edwin; Agbo, Humphrey

    2018-04-04

    This study assesses the impact of traffic sign deficit on road traffic accidents in Nigeria. The participants were 720 commercial vehicle drivers. While simple random sampling was used to select 6 out of 137 federal highways, stratified random sampling was used to select six categories of commercial vehicle drivers. The study used qual-dominant mixed methods approach comprising key informant interviews; group interviews; field observation; policy appraisal and secondary literature on traffic signs. Result shows that the failure of government to provide and maintain traffic signs in order to guide road users through the numerous accident black spots on the highways is the major cause of road accidents in Nigeria. The study argues that provision and maintenance of traffic signs present opportunity to promoting safety on the highways and achieving the sustainable development goals.

  3. Integrating intersection traffic signal data into a traffic monitoring program.

    DOT National Transportation Integrated Search

    2014-09-01

    The objective of this study was to provide the Georgia Department of Transportation with : an evaluation of the feasibility of integrating intersection traffic signal data into a traffic : monitoring program. Some of the pertinent conclusions from th...

  4. DNS study on bursting and intermittency in late boundary layer transition

    NASA Astrophysics Data System (ADS)

    Wang, YiQian; Liu, ChaoQun

    2017-11-01

    Experimental and numerical investigations have suggested the existence of a strong correlation between the passage of coherent structures and events of bursting and intermittency. However, a detailed cause-and-effect study on the subject is rarely found in the literature due to the complexity and the nonlinear multiscale nature of turbulent flows. The primary goal of this research is to explore the motion and evolution of coherent structures during late transition, whose structure is much more ordered than that of fully developed turbulence, and their relationship with events of bursting and intermittency based on a verified high-order direct numerical simulation (DNS). The computation was carried out on a flat plate at Reynolds number 1000 (based on the inflow displacement thickness) with an inflow Mach number 0.5. It is concluded that bursting and intermittency detected by stationary sensors in a transitional boundary layer actually result from the passage and development of vortical structures, and it would be more rational to design transitional turbulence models based on modelling the moving vortical structures rather than the statistical features and experimental experiences.

  5. Weather-responsive traffic management : real solutions for serious traffic problems.

    DOT National Transportation Integrated Search

    2009-04-01

    This flyer describes how weather responsive traffic management (WRTM) can prevent or mitigate the effects of weather on traffic operations and reduce congestion. The three types of WRTM described in the flyer include 1) Advisory strategies that provi...

  6. Visualization of Traffic Accidents

    NASA Technical Reports Server (NTRS)

    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.

  7. Right-\\0xADturn traffic volume adjustment in traffic signal warrant analysis : final report.

    DOT National Transportation Integrated Search

    2016-05-06

    This report was based on the research project, Right-Turn Traffic Volume Adjustment in : Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) : and SOLARIS. Right-turn traffic does not affect intersection performance i...

  8. Will higher traffic flow lead to more traffic conflicts? A crash surrogate metric based analysis

    PubMed Central

    Kuang, Yan; Yan, Yadan

    2017-01-01

    In this paper, we aim to examine the relationship between traffic flow and potential conflict risks by using crash surrogate metrics. It has been widely recognized that one traffic flow corresponds to two distinct traffic states with different speeds and densities. In view of this, instead of simply aggregating traffic conditions with the same traffic volume, we represent potential conflict risks at a traffic flow fundamental diagram. Two crash surrogate metrics, namely, Aggregated Crash Index and Time to Collision, are used in this study to represent the potential conflict risks with respect to different traffic conditions. Furthermore, Beijing North Ring III and Next Generation SIMulation Interstate 80 datasets are utilized to carry out case studies. By using the proposed procedure, both datasets generate similar trends, which demonstrate the applicability of the proposed methodology and the transferability of our conclusions. PMID:28787022

  9. Will higher traffic flow lead to more traffic conflicts? A crash surrogate metric based analysis.

    PubMed

    Kuang, Yan; Qu, Xiaobo; Yan, Yadan

    2017-01-01

    In this paper, we aim to examine the relationship between traffic flow and potential conflict risks by using crash surrogate metrics. It has been widely recognized that one traffic flow corresponds to two distinct traffic states with different speeds and densities. In view of this, instead of simply aggregating traffic conditions with the same traffic volume, we represent potential conflict risks at a traffic flow fundamental diagram. Two crash surrogate metrics, namely, Aggregated Crash Index and Time to Collision, are used in this study to represent the potential conflict risks with respect to different traffic conditions. Furthermore, Beijing North Ring III and Next Generation SIMulation Interstate 80 datasets are utilized to carry out case studies. By using the proposed procedure, both datasets generate similar trends, which demonstrate the applicability of the proposed methodology and the transferability of our conclusions.

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

    PubMed Central

    AsSadhan, Basil; Moura, José M.F.

    2013-01-01

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

  11. Synchronized flow in oversaturated city traffic.

    PubMed

    Kerner, Boris S; Klenov, Sergey L; Hermanns, Gerhard; Hemmerle, Peter; Rehborn, Hubert; Schreckenberg, Michael

    2013-11-01

    Based on numerical simulations with a stochastic three-phase traffic flow model, we reveal that moving queues (moving jams) in oversaturated city traffic dissolve at some distance upstream of the traffic signal while transforming into synchronized flow. It is found that, as in highway traffic [Kerner, Phys. Rev. E 85, 036110 (2012)], such a jam-absorption effect in city traffic is explained by a strong driver's speed adaptation: Time headways (space gaps) between vehicles increase upstream of a moving queue (moving jam), resulting in moving queue dissolution. It turns out that at given traffic signal parameters, the stronger the speed adaptation effect, the shorter the mean distance between the signal location and the road location at which moving queues dissolve fully and oversaturated traffic consists of synchronized flow only. A comparison of the synchronized flow in city traffic found in this Brief Report with synchronized flow in highway traffic is made.

  12. Synchronized flow in oversaturated city traffic

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Klenov, Sergey L.; Hermanns, Gerhard; Hemmerle, Peter; Rehborn, Hubert; Schreckenberg, Michael

    2013-11-01

    Based on numerical simulations with a stochastic three-phase traffic flow model, we reveal that moving queues (moving jams) in oversaturated city traffic dissolve at some distance upstream of the traffic signal while transforming into synchronized flow. It is found that, as in highway traffic [Kerner, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.036110 85, 036110 (2012)], such a jam-absorption effect in city traffic is explained by a strong driver's speed adaptation: Time headways (space gaps) between vehicles increase upstream of a moving queue (moving jam), resulting in moving queue dissolution. It turns out that at given traffic signal parameters, the stronger the speed adaptation effect, the shorter the mean distance between the signal location and the road location at which moving queues dissolve fully and oversaturated traffic consists of synchronized flow only. A comparison of the synchronized flow in city traffic found in this Brief Report with synchronized flow in highway traffic is made.

  13. Traffic Flow Management Wrap-Up

    NASA Technical Reports Server (NTRS)

    Grabbe, Shon

    2011-01-01

    Traffic Flow Management involves the scheduling and routing of air traffic subject to airport and airspace capacity constraints, and the efficient use of available airspace. Significant challenges in this area include: (1) weather integration and forecasting, (2) accounting for user preferences in the Traffic Flow Management decision making process, and (3) understanding and mitigating the environmental impacts of air traffic on the environment. To address these challenges, researchers in the Traffic Flow Management area are developing modeling, simulation and optimization techniques to route and schedule air traffic flights and flows while accommodating user preferences, accounting for system uncertainties and considering the environmental impacts of aviation. This presentation will highlight some of the major challenges facing researchers in this domain, while also showcasing recent innovations designed to address these challenges.

  14. Indiana freeway traffic characteristics and dynamic prediction of freeway traffic flows

    DOT National Transportation Integrated Search

    1999-12-01

    Traffic volumes on Indiana's roadways have increased significantly in the past years. During the period between 1989 and 1993, traffic volumes increased 20.2% on Indiana's urban interstate freeways and expressways, and 13.1% on rural interstates. The...

  15. Altered white matter metabolism in delayed neurologic sequelae after carbon monoxide poisoning: A proton magnetic resonance spectroscopic study.

    PubMed

    Kuroda, Hiroshi; Fujihara, Kazuo; Mugikura, Shunji; Takahashi, Shoki; Kushimoto, Shigeki; Aoki, Masashi

    2016-01-15

    Proton magnetic resonance spectroscopy ((1)H-MRS) was recently used to examine altered metabolism in the white matter (WM) of patients experiencing carbon monoxide (CO) poisoning; however, only a small number of patients with delayed neurologic sequelae (DNS) were analyzed. We aimed to detect altered metabolism in the WM of patients with DNS using (1)H-MRS; to explore its clinical relevance in the management of patients experiencing CO poisoning. Patients experiencing acute CO poisoning underwent (1)H-MRS and cerebrospinal fluid (CSF) examination within 1week and at 1month after acute poisoning. Metabolites including choline-containing compounds (Cho), creatine (Cr), N-acetylaspartate (NAA), and lactate were measured from the periventricular WM. Myelin basic protein (MBP) concentrations were measured in CSF. Fifty-two patients experiencing acute CO poisoning (15 with DNS, 37 without DNS; median age, 49years; 65% males) underwent (1)H-MRS. Within 1week, NAA/Cr ratios, reflecting neuroaxonal viability, were lower in patients with DNS than in those without DNS (P<0.05). At 1month, when 9 of 15 patients (60%) developed DNS, Cho/Cr ratios were higher, and NAA/Cr and NAA/Cho ratios lower in patients with DNS (P=0.0001, <0.0001, and <0.0001, respectively), indicating increased membrane metabolism and decreased neuroaxonal viability. (1)H-MRS parameter abnormalities correlated with the elevation of MBP in CSF. The presence of a lactate peak was a predictor for a poor long-term outcome. (1)H-MRS within 1week may be useful for predicting DNS development; (1)H-MRS at 1month may be useful for discriminating patients with DNS and predicting long-term outcomes. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Pedestrian Friendly Traffic Signal Control.

    DOT National Transportation Integrated Search

    2016-01-01

    This project continues research aimed at real-time detection and use of pedestrian : traffic flow information to enhance adaptive traffic signal control in urban areas : where pedestrian traffic is substantial and must be given appropriate attention ...

  17. The Traffic Management Advisor

    NASA Technical Reports Server (NTRS)

    Nedell, William; Erzberger, Heinz; Neuman, Frank

    1990-01-01

    The traffic management advisor (TMA) is comprised of algorithms, a graphical interface, and interactive tools for controlling the flow of air traffic into the terminal area. The primary algorithm incorporated in it is a real-time scheduler which generates efficient landing sequences and landing times for arrivals within about 200 n.m. from touchdown. A unique feature of the TMA is its graphical interface that allows the traffic manager to modify the computer-generated schedules for specific aircraft while allowing the automatic scheduler to continue generating schedules for all other aircraft. The graphical interface also provides convenient methods for monitoring the traffic flow and changing scheduling parameters during real-time operation.

  18. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... interfere with the normal flow of traffic. ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or...

  19. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... interfere with the normal flow of traffic. ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or...

  20. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... interfere with the normal flow of traffic. ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or...

  1. Pulsar population synthesis using palfa detections and pulsar search collaboratory discoveries including a wide DNS system and a nearby MSP

    NASA Astrophysics Data System (ADS)

    Swiggum, Joseph Karl

    students in the pulsar discovery process -- hands-on, cutting-edge research -- to foster their interest in pursuing Science, Technology, Engineering and Mathematics (STEM) related career paths. The PSC began in 2008; since then, over 100 teachers and 2,500 students from 18 states have participated and discovered seven pulsars. Of these seven, J1400--1431, a bright, nearby MSP shows promising characteristics for inclusion in pulsar timing arrays, which aim to detect gravitational waves by precisely timing an array of MSPs. Two others -- J1821+0155, a disrupted recycled pulsar and J1930--1852 show interesting properties due to interactions with binary companions. PSR J1930--1852 is a partially-recycled, first-to-evolve pulsar in a double neutron star (DNS) system with a high-eccentricity 45 day orbit. Its spin period and orbital period are factors of 2 and 3 higher, respectively, than any previously-known, primary DNS pulsars. We measure the relativistic advance of periastron o=0.00078(4), implying a total system mass of Mtot =2.59(4), which is consistent with other DNS systems. PSR J1930--1852's spin and orbital parameters, however, challenge current DNS evolution models, making it an important system for further investigation.

  2. Analysis of traffic growth rates

    DOT National Transportation Integrated Search

    2001-08-01

    The primary objectives of this study were to determine patterns of traffic flow and develop traffic growth rates by traffic composition and highway type for Kentucky's system of highways. Additional subtasks included the following: 1) a literature se...

  3. Traffic information computing platform for big data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duan, Zongtao, E-mail: ztduan@chd.edu.cn; Li, Ying, E-mail: ztduan@chd.edu.cn; Zheng, Xibin, E-mail: ztduan@chd.edu.cn

    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.

  4. Air Traffic Controller Working Memory: Considerations in Air Traffic Control Tactical Operations

    DTIC Science & Technology

    1993-09-01

    INFORMATION PROCESSING SYSTEM 3 2. AIR TRAFFIC CONTROLLER MEMORY 5 2.1 MEMORY CODES 6 21.1 Visual Codes 7 2.1.2 Phonetic Codes 7 2.1.3 Semantic Codes 8...raise an awareness of the memory re- quirements of ATC tactical operations by presenting information on working memory processes that are relevant to...working v memory permeates every aspect of the controller’s ability to process air traffic information and control live traffic. The

  5. Dynamic Density: An Air Traffic Management Metric

    NASA Technical Reports Server (NTRS)

    Laudeman, I. V.; Shelden, S. G.; Branstrom, R.; Brasil, C. L.

    1998-01-01

    The definition of a metric of air traffic controller workload based on air traffic characteristics is essential to the development of both air traffic management automation and air traffic procedures. Dynamic density is a proposed concept for a metric that includes both traffic density (a count of aircraft in a volume of airspace) and traffic complexity (a measure of the complexity of the air traffic in a volume of airspace). It was hypothesized that a metric that includes terms that capture air traffic complexity will be a better measure of air traffic controller workload than current measures based only on traffic density. A weighted linear dynamic density function was developed and validated operationally. The proposed dynamic density function includes a traffic density term and eight traffic complexity terms. A unit-weighted dynamic density function was able to account for an average of 22% of the variance in observed controller activity not accounted for by traffic density alone. A comparative analysis of unit weights, subjective weights, and regression weights for the terms in the dynamic density equation was conducted. The best predictor of controller activity was the dynamic density equation with regression-weighted complexity terms.

  6. Traffic safety facts 1996 : pedalcyclists

    DOT National Transportation Integrated Search

    1997-01-01

    In 1996, 761 pedalcyclists were killed and an additional 59,000 were injured in traffic crashes. Pedalcyclist deaths accounted for 2 percent of all traffic fatalities and pedalcyclists made up 2 percent of all the people injured in traffic crashes du...

  7. Traffic safety facts 1994 : pedalcyclists

    DOT National Transportation Integrated Search

    1995-01-01

    In 1994, 802 pedalcyclists were killed in traffic crashes. Pedalcyclist deaths accounted for 2 percent of all traffic fatalities during the year. Figure 1 shows trends in pedalcyclist and total traffic fatalities, 1984-1994. Of the tables, Table 1 sh...

  8. Traffic safety facts 1995 : pedalcyclists

    DOT National Transportation Integrated Search

    1996-01-01

    In 1995, 61,000 pedalcyclists were injured and 830 were killed in traffic crashes. Pedalcyclist deaths accounted for 2 percent of all traffic fatalities and pedalcyclists made up 2 percent of all the people injured in traffic crashes during the year....

  9. Traffic safety facts 1993 : pedalcyclists

    DOT National Transportation Integrated Search

    1994-01-01

    In 1993, 814 pedalcyclists were killed in traffic crashes. Pedalcyclist deaths accounted for 2 percent of all traffic fatalities during the year. Figure 1 shows trends in pedalcyclist and total traffic fatalities, 1983-1993. Of the tables, Table 1 sh...

  10. Traffic intensity monitoring using multiple object detection with traffic surveillance cameras

    NASA Astrophysics Data System (ADS)

    Hamdan, H. G. Muhammad; Khalifah, O. O.

    2017-11-01

    Object detection and tracking is a field of research that has many applications in the current generation with increasing number of cameras on the streets and lower cost for Internet of Things(IoT). In this paper, a traffic intensity monitoring system is implemented based on the Macroscopic Urban Traffic model is proposed using computer vision as its source. The input of this program is extracted from a traffic surveillance camera which has another program running a neural network classification which can identify and differentiate the vehicle type is implanted. The neural network toolbox is trained with positive and negative input to increase accuracy. The accuracy of the program is compared to other related works done and the trends of the traffic intensity from a road is also calculated. relevant articles in literature searches, great care should be taken in constructing both. Lastly the limitation and the future work is concluded.

  11. Intelligent Traffic Light Based on PLC Control

    NASA Astrophysics Data System (ADS)

    Mei, Lin; Zhang, Lijian; Wang, Lingling

    2017-11-01

    The traditional traffic light system with a fixed control mode and single control function is contradicted with the current traffic section. The traditional one has been unable to meet the functional requirements of the existing flexible traffic control system. This paper research and develop an intelligent traffic light called PLC control system. It uses PLC as control core, using a sensor module for receiving real-time information of vehicles, traffic control mode for information to select the traffic lights. Of which control mode is flexible and changeable, and it also set the countdown reminder to improve the effectiveness of traffic lights, which can realize the goal of intelligent traffic diversion, intelligent traffic diversion.

  12. Testing of RANS Turbulence Models for Stratified Flows Based on DNS Data

    NASA Technical Reports Server (NTRS)

    Venayagamoorthy, S. K.; Koseff, J. R.; Ferziger, J. H.; Shih, L. H.

    2003-01-01

    In most geophysical flows, turbulence occurs at the smallest scales and one of the two most important additional physical phenomena to account for is strati cation (the other being rotation). In this paper, the main objective is to investigate proposed changes to RANS turbulence models which include the effects of stratifi- cation more explicitly. These proposed changes were developed using a DNS database on strati ed and sheared homogenous turbulence developed by Shih et al. (2000) and are described more fully in Ferziger et al. (2003). The data generated by Shih, et al. (2000) (hereinafter referred to as SKFR) are used to study the parameters in the k- model as a function of the turbulent Froude number, Frk. A modified version of the standard k- model based on the local turbulent Froude number is proposed. The proposed model is applied to a stratified open channel flow, a test case that differs significantly from the flows from which the modified parameters were derived. The turbulence modeling and results are discussed in the next two sections followed by suggestions for future work.

  13. Safety performance of traffic phases and phase transitions in three phase traffic theory.

    PubMed

    Xu, Chengcheng; Liu, Pan; Wang, Wei; Li, Zhibin

    2015-12-01

    Crash risk prediction models were developed to link safety to various phases and phase transitions defined by the three phase traffic theory. Results of the Bayesian conditional logit analysis showed that different traffic states differed distinctly with respect to safety performance. The random-parameter logit approach was utilized to account for the heterogeneity caused by unobserved factors. The Bayesian inference approach based on the Markov Chain Monte Carlo (MCMC) method was used for the estimation of the random-parameter logit model. The proposed approach increased the prediction performance of the crash risk models as compared with the conventional logit model. The three phase traffic theory can help us better understand the mechanism of crash occurrences in various traffic states. The contributing factors to crash likelihood can be well explained by the mechanism of phase transitions. We further discovered that the free flow state can be divided into two sub-phases on the basis of safety performance, including a true free flow state in which the interactions between vehicles are minor, and a platooned traffic state in which bunched vehicles travel in successions. The results of this study suggest that a safety perspective can be added to the three phase traffic theory. The results also suggest that the heterogeneity between different traffic states should be considered when estimating the risks of crash occurrences on freeways. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Traffic analysis toolbox volume XI : weather and traffic analysis, modeling and simulation.

    DOT National Transportation Integrated Search

    2010-12-01

    This document presents a weather module for the traffic analysis tools program. It provides traffic engineers, transportation modelers and decisions makers with a guide that can incorporate weather impacts into transportation system analysis and mode...

  15. Semiautomated Management Of Arriving Air Traffic

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; Nedell, William

    1992-01-01

    System of computers, graphical workstations, and computer programs developed for semiautomated management of approach and arrival of numerous aircraft at airport. System comprises three subsystems: traffic-management advisor, used for controlling traffic into terminal area; descent advisor generates information integrated into plan-view display of traffic on monitor; and final-approach-spacing tool used to merge traffic converging on final approach path while making sure aircraft are properly spaced. Not intended to restrict decisions of air-traffic controllers.

  16. 49 CFR 1139.2 - Traffic study.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for... “base-calendar year—actual.” The study shall include a probability sampling of the actual traffic...

  17. 49 CFR 1139.2 - Traffic study.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for... “base-calendar year—actual.” The study shall include a probability sampling of the actual traffic...

  18. Turbulence-flame interactions in DNS of a laboratory high Karlovitz premixed turbulent jet flame

    NASA Astrophysics Data System (ADS)

    Wang, Haiou; Hawkes, Evatt R.; Chen, Jacqueline H.

    2016-09-01

    In the present work, direct numerical simulation (DNS) of a laboratory premixed turbulent jet flame was performed to study turbulence-flame interactions. The turbulent flame features moderate Reynolds number and high Karlovitz number (Ka). The orientations of the flame normal vector n, the vorticity vector ω and the principal strain rate eigenvectors ei are examined. The in-plane and out-of-plane angles are introduced to quantify the vector orientations, which also measure the flame geometry and the vortical structures. A general observation is that the distributions of these angles are more isotropic downstream as the flame and the flow become more developed. The out-of-plane angle of the flame normal vector, β, is a key parameter in developing the correction of 2D measurements to estimate the corresponding 3D quantities. The DNS results show that the correction factor is unity at the inlet and approaches its theoretical value of an isotropic distribution downstream. The alignment characteristics of n, ω and ei, which reflect the interactions of turbulence and flame, are also studied. Similar to a passive scalar gradient in non-reacting flows, the flame normal has a tendency to align with the most compressive strain rate, e3, in the flame, indicating that turbulence contributes to the production of scalar gradient. The vorticity dynamics are examined via the vortex stretching term, which was found to be the predominant source of vorticity generation balanced by dissipation, in the enstrophy transport equation. It is found that although the vorticity preferentially aligns with the intermediate strain rate, e2, the contribution of the most extensive strain rate, e1, to vortex stretching is comparable with that of the intermediate strain rate, e2. This is because the eigenvalue of the most extensive strain rate, λ1, is always large and positive. It is confirmed that the vorticity vector is preferentially positioned along the flame tangential plane, contributing

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

    PubMed Central

    Artuñedo, Antonio; del Toro, Raúl M.; Haber, Rodolfo E.

    2017-01-01

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks. PMID:28445398

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

    PubMed

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

    2017-04-26

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

  1. 32 CFR 634.32 - Traffic violation reports.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Traffic violation reports. 634.32 Section 634.32... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.32 Traffic violation reports. (a) Most traffic violations occurring on DOD installations (within the UNITED STATES or its...

  2. 32 CFR 634.32 - Traffic violation reports.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Traffic violation reports. 634.32 Section 634.32... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.32 Traffic violation reports. (a) Most traffic violations occurring on DOD installations (within the UNITED STATES or its...

  3. Economical Video Monitoring of Traffic

    NASA Technical Reports Server (NTRS)

    Houser, B. C.; Paine, G.; Rubenstein, L. D.; Parham, O. Bruce, Jr.; Graves, W.; Bradley, C.

    1986-01-01

    Data compression allows video signals to be transmitted economically on telephone circuits. Telephone lines transmit television signals to remote traffic-control center. Lines also carry command signals from center to TV camera and compressor at highway site. Video system with television cameras positioned at critical points on highways allows traffic controllers to determine visually, almost immediately, exact cause of traffic-flow disruption; e.g., accidents, breakdowns, or spills, almost immediately. Controllers can then dispatch appropriate emergency services and alert motorists to minimize traffic backups.

  4. Pedalcylists. Traffic Safety Facts, 2000.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on traffic accidents involving U.S. bicyclists. Data include: (1) trends in pedalcyclist and total traffic fatalities, 1990-2000; (2) non-occupant traffic fatalities, 1990-2000; (3) pedalcyclists killed and injured, and fatality and injury rates, by age and sex, 2000; and (4) pedalcyclist traffic…

  5. Traffic-Sensitive Live Migration of Virtual Machines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Deshpande, Umesh; Keahey, Kate

    2015-01-01

    In this paper we address the problem of network contention between the migration traffic and the VM application traffic for the live migration of co-located Virtual Machines (VMs). When VMs are migrated with pre-copy, they run at the source host during the migration. Therefore the VM applications with predominantly outbound traffic contend with the outgoing migration traffic at the source host. Similarly, during post-copy migration, the VMs run at the destination host. Therefore the VM applications with predominantly inbound traffic contend with the incoming migration traffic at the destination host. Such a contention increases the total migration time of themore » VMs and degrades the performance of VM application. Here, we propose traffic-sensitive live VM migration technique to reduce the contention of migration traffic with the VM application traffic. It uses a combination of pre-copy and post-copy techniques for the migration of the co-located VMs, instead of relying upon any single pre-determined technique for the migration of all the VMs. We base the selection of migration techniques on VMs' network traffic profiles so that the direction of migration traffic complements the direction of the most VM application traffic. We have implemented a prototype of traffic-sensitive migration on the KVM/QEMU platform. In the evaluation, we compare traffic-sensitive migration against the approaches that use only pre-copy or only post-copy for VM migration. We show that our approach minimizes the network contention for migration, thus reducing the total migration time and the application degradation.« less

  6. Streamlining Traffic Mitigation Fees

    DOT National Transportation Integrated Search

    1999-01-01

    The City of Lacey rewrote the ordinance governing collection of fees to mitigate : development impacts on the transportation system. Previously developers : submitted traffic generation and distribution reports prepared by qualified : traffic enginee...

  7. Perspective traffic display format and airline pilot traffic avoidance

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Mcgreevy, Michael W.; Hitchcock, Robert J.

    1987-01-01

    Part-task experiments have examined perspective projections of cockpit displays of traffic information as a means of presenting aircraft separation information to airline pilots. Ten airline pilots served as subjects in an experiment comparing the perspective projection with plan-view projections of the same air traffic situations. The pilots' task was to monitor the traffic display in order to decide if an avoidance maneuver was needed. Pilots took more time to select avoidance maneuvers with a conventional plan-view display than with an experimental perspective display. In contrast to previous results, if the pilots selected a maneuver with the perspective display, they were more likely to choose one with a vertical component. Tabulation of the outcomes of their initial avoidance decisions with both perspective and plan-view displays showed that they were more likely to achieve required separation with maneuvers chosen with the aid of perspective displays.

  8. Impacts of moving bottlenecks on traffic flow

    NASA Astrophysics Data System (ADS)

    Ou, Hui; Tang, Tie-Qiao

    2018-06-01

    Bottleneck (especially the moving bottleneck) widely exists in the urban traffic system. However, little effort has been made to study the impacts of the moving bottleneck on traffic flow (especially the evolution and propagation of traffic flow). In this article, we introduce the speed of a moving bottleneck into a traffic flow model, then propose an extended macro traffic flow with a moving bottleneck, and finally use the proposed model to study the effects of a moving bottleneck on the evolution and propagation of traffic flow under uniform flow and a small perturbation. The numerical results indicate that the moving bottleneck has prominent influences on the evolution of traffic flow under the two typical traffic situations and that the impacts are dependent on the initial density.

  9. Pedestrians. Traffic Safety Facts, 2000.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on U.S. traffic accidents involving pedestrians. Data tables include: (1) trends in pedestrian and total traffic fatalities, 1990-2000; (2) pedestrians killed and injured, by age group, 2000; (3) non-occupant traffic fatalities, 1990-2000; (4) pedestrian fatalities, by time of day and day of week,…

  10. Traffic Safety Facts, 2001: Pedalcylists.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on traffic accidents involving U.S. bicyclists. Data include: (1) trends in pedalcyclist and total traffic fatalities, 1991-2001; (2) non-occupant traffic fatalities, 1991-2001; (3) pedalcyclists killed and injured, and fatality and injury rates, by age and sex, 2000 [2001 population data by age group…

  11. Traffic Safety Facts, 2001: Pedestrians.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on U.S. traffic accidents involving pedestrians. Data tables include: (1) trends in pedestrian and total traffic fatalities, 1991-2001; (2) pedestrians killed and injured, by age group, 2001; (3) non-occupant traffic fatalities, 1991-2001; (4) pedestrian fatalities, by time of day and day of week,…

  12. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fritz, David J.; Harrison, Christopher B.; Perr, C. W.

    Choreographer is a "moving target defense system", designed to protect against attacks aimed at IP addresses without corresponding domain name system (DNS) lookups. It coordinates actions between a DNS server and a Network Address Translation (NAT) device to regularly change which publicly available IP addresses' traffic will be routed to the protected device versus routed to a honeypot. More details about how Choreographer operates can be found in Section 2: Introducing Choreographer. Operational considerations for the successful deployment of Choreographer can be found in Section 3. The Testing & Evaluation (T&E) for Choreographer involved 3 phases: Pre-testing, Code Analysis, andmore » Operational Testing. Pre-testing, described in Section 4, involved installing and configuring an instance of Choreographer and verifying it would operate as expected for a simple use case. Our findings were that it was simple and straightforward to prepare a system for a Choreographer installation as well as configure Choreographer to work in a representative environment. Code Analysis, described in Section 5, consisted of running a static code analyzer (HP Fortify) and conducting dynamic analysis tests using the Valgrind instrumentation framework. Choreographer performed well, such that only a few errors that might possibly be problematic in a given operating situation were identified. Operational Testing, described in Section 6, involved operating Choreographer in a representative environment created through Emulytics TM . Depending upon the amount of server resources dedicated to Choreographer vis-á-vis the amount of client traffic handled, Choreographer had varying degrees of operational success. In an environment with a poorly resourced Choreographer server and as few as 50-100 clients, Choreographer failed to properly route traffic over half the time. Yet, with a well-resourced server, Choreographer handled over 1000 clients without missrouting. Choreographer demonstrated

  13. Emergent traffic jams

    NASA Astrophysics Data System (ADS)

    Nagel, Kai; Paczuski, Maya

    1995-04-01

    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)~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.

  14. Simulation of traffic control signal systems

    NASA Technical Reports Server (NTRS)

    Connolly, P. J.; Concannon, P. A.; Ricci, R. C.

    1974-01-01

    In recent years there has been considerable interest in the development and testing of control strategies for networks of urban traffic signal systems by simulation. Simulation is an inexpensive and timely method for evaluating the effect of these traffic control strategies since traffic phenomena are too complex to be defined by analytical models and since a controlled experiment may be hazardous, expensive, and slow in producing meaningful results. This paper describes the application of an urban traffic corridor program, to evaluate the effectiveness of different traffic control strategies for the Massachusetts Avenue TOPICS Project.

  15. [Comics for traffic education: evaluation of a traffic safety campaign].

    PubMed

    Bonfadelli, H

    1989-01-01

    Traffic safety campaigns often are ineffective to change driving behavior because they don't reach the target group or are recognized only by people who are already interested or concerned. The evaluation of a traffic safety campaign called "Leo Lässig", addressed to young new drivers, shows that recognition and acceptance by the target group were stimulated by the age-conform means of comic-strips.

  16. Remotely Accessed Vehicle Traffic Management System

    NASA Astrophysics Data System (ADS)

    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.

  17. Traffic analysis and control using image processing

    NASA Astrophysics Data System (ADS)

    Senthilkumar, K.; Ellappan, Vijayan; Arun, A. R.

    2017-11-01

    This paper shows the work on traffic analysis and control till date. It shows an approach to regulate traffic the use of image processing and MATLAB systems. This concept uses computational images that are to be compared with original images of the street taken in order to determine the traffic level percentage and set the timing for the traffic signal accordingly which are used to reduce the traffic stoppage on traffic lights. They concept proposes to solve real life scenarios in the streets, thus enriching the traffic lights by adding image receivers like HD cameras and image processors. The input is then imported into MATLAB to be used. as a method for calculating the traffic on roads. Their results would be computed in order to adjust the traffic light timings on a particular street, and also with respect to other similar proposals but with the added value of solving a real, big instance.

  18. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... safely within traffic laws and regulations and maintain an effective and efficient flow of traffic... 32 National Defense 4 2013-07-01 2013-07-01 false Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic...

  19. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... safely within traffic laws and regulations and maintain an effective and efficient flow of traffic... 32 National Defense 4 2012-07-01 2011-07-01 true Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic...

  20. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... safely within traffic laws and regulations and maintain an effective and efficient flow of traffic... 32 National Defense 4 2014-07-01 2013-07-01 true Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic...

  1. The zebrafish mutant vps18 as a model for vesicle-traffic related hypopigmentation diseases.

    PubMed

    Maldonado, Ernesto; Hernandez, Fabiola; Lozano, Carlos; Castro, Marta E; Navarro, Rosa E

    2006-08-01

    Hypopigmentation is a characteristic of several diseases associated with vesicle traffic defects, like the Hermansky-Pudlak, Chediak-Higashi, and Griscelli syndromes. Hypopigmentation is also a characteristic of the zebrafish mutant vps18(hi2499A), which is affected in the gene vps18, a component of the homotypic fusion and protein sorting complex that is involved in tethering during vesicular traffic. Vps18, as part of this complex, participates in the formation of early endosomes, late endosomes, and lysosomes. Here, we show that Vps18 is also involved in the formation of melanosomes. In the zebrafish mutant vps18(hi2499A) the retroviral insertion located at exon 4 of vps18, leads to the formation of two abnormal splicing variants lacking the coding sequence for the clathrin repeat and the RING finger conserved domains. A deficiency of Vps18 in zebrafish larvae results in hepatomegaly and skin hypopigmentation. We also observed a drastic reduction in the number of melanosomes in the eye's retinal pigmented epithelium along with the accumulation of immature melanosomes. A significant reduction in the vps18(hi2499A) larvae visual system capacity was found using the optokinetic response assay. We propose that the insertional mutant vps18(hi2499A) can be used as a model for studying hypopigmentation diseases in which vesicle traffic problems exist.

  2. Traffic control systems handbook.

    DOT National Transportation Integrated Search

    2005-10-01

    The Traffic Control Systems Handbook updates the 1996 edition (FHWA-SA-96-032). It serves as a basic reference in planning, designing and implementing traffic control systems. : Specific chapters include introduction, summary of available and emergin...

  3. Traffic management simulation development.

    DOT National Transportation Integrated Search

    2011-01-03

    Microscopic simulation can provide significant support to traffic management center (TMC) operations. However, traffic simulation applications require data that are expensive and time-consuming to collect. Data collected by TMCs can be used as a prim...

  4. Traffic forecasting report : 2007.

    DOT National Transportation Integrated Search

    2008-05-01

    This is the sixth edition of the Traffic Forecasting Report (TFR). This edition of the TFR contains the latest (predominantly 2007) forecasting/modeling data as follows: : Functional class average traffic volume growth rates and trends : Vehi...

  5. An intelligent traffic controller

    DOT National Transportation Integrated Search

    1995-11-01

    Advances in computing sciences have not been applied to traffic control. This paper describes the development of an intelligent controller. A controller with advanced control logic can significantly improve traffic flows at intersections. In this vei...

  6. The importance of antipersistence for traffic jams

    NASA Astrophysics Data System (ADS)

    Krause, Sebastian M.; Habel, Lars; Guhr, Thomas; Schreckenberg, Michael

    2017-05-01

    Universal characteristics of road networks and traffic patterns can help to forecast and control traffic congestion. The antipersistence of traffic flow time series has been found for many data sets, but its relevance for congestion has been overseen. Based on empirical data from motorways in Germany, we study how antipersistence of traffic flow time-series impacts the duration of traffic congestion on a wide range of time scales. We find a large number of short-lasting traffic jams, which implies a large risk for rear-end collisions.

  7. Traffic signal timing manual.

    DOT National Transportation Integrated Search

    2008-06-01

    This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its : development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes ...

  8. Traffic control systems handbook

    DOT National Transportation Integrated Search

    2005-10-01

    The 2005 edition of "Traffic Control Systems Handbook" updates the 1996 edition (FHWA-SA-96-032). It serves as a basic reference in planning, designing and implementing traffic control systems. Specific chapters include introduction, summary of avail...

  9. DSL for traffic video

    DOT National Transportation Integrated Search

    1999-07-01

    Many traffic operations use twisted pair wiring, either owned by the public or leased from a local provider, to control field devices such as traffic signals or ramp meters. There are now commercially available communications technologies that ...

  10. Large Scale Traffic Simulations

    DOT National Transportation Integrated Search

    1997-01-01

    Large scale microscopic (i.e. vehicle-based) traffic simulations pose high demands on computation speed in at least two application areas: (i) real-time traffic forecasting, and (ii) long-term planning applications (where repeated "looping" between t...

  11. A computerized traffic control algorithm to determine optimal traffic signal settings. Ph.D. Thesis - Toledo Univ.

    NASA Technical Reports Server (NTRS)

    Seldner, K.

    1977-01-01

    An algorithm was developed to optimally control the traffic signals at each intersection using a discrete time traffic model applicable to heavy or peak traffic. Off line optimization procedures were applied to compute the cycle splits required to minimize the lengths of the vehicle queues and delay at each intersection. The method was applied to an extensive traffic network in Toledo, Ohio. Results obtained with the derived optimal settings are compared with the control settings presently in use.

  12. North Carolina forecasts for truck traffic

    DOT National Transportation Integrated Search

    2006-07-01

    North Carolina has experienced significant increases in truck traffic on many of its highways. Yet, current NCDOT : project-level highway traffic forecasts do not appropriately capture anticipated truck traffic growth. NCDOT : methods forecast total ...

  13. Traffic signal timing manual

    DOT National Transportation Integrated Search

    2008-06-01

    This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes th...

  14. Long-Term Exposure to Primary Traffic Pollutants and Lung Function in Children: Cross-Sectional Study and Meta-Analysis.

    PubMed

    Barone-Adesi, Francesco; Dent, Jennifer E; Dajnak, David; Beevers, Sean; Anderson, H Ross; Kelly, Frank J; Cook, Derek G; Whincup, Peter H

    2015-01-01

    There is widespread concern about the possible health effects of traffic-related air pollution. Nitrogen dioxide (NO2) is a convenient marker of primary pollution. We investigated the associations between lung function and current residential exposure to a range of air pollutants (particularly NO2, NO, NOx and particulate matter) in London children. Moreover, we placed the results for NO2 in context with a meta-analysis of published estimates of the association. Associations between primary traffic pollutants and lung function were investigated in 4884 children aged 9-10 years who participated in the Child Heart and Health Study in England (CHASE). A systematic literature search identified 13 studies eligible for inclusion in a meta-analysis. We combined results from the meta-analysis with the distribution of the values of FEV1 in CHASE to estimate the prevalence of children with abnormal lung function (FEV1<80% of predicted value) expected under different scenarios of NO2 exposure. In CHASE, there were non-significant inverse associations between all pollutants except ozone and both FEV1 and FVC. In the meta-analysis, a 10 μg/m3 increase in NO2 was associated with an 8 ml lower FEV1 (95% CI: -14 to -1 ml; p: 0.016). The observed effect was not modified by a reported asthma diagnosis. On the basis of these results, a 10 μg/m3 increase in NO2 level would translate into a 7% (95% CI: 4% to 12%) increase of the prevalence of children with abnormal lung function. Exposure to traffic pollution may cause a small overall reduction in lung function and increase the prevalence of children with clinically relevant declines in lung function.

  15. Truck Traffic Iowa : 2010

    DOT National Transportation Integrated Search

    2011-01-01

    Truck volumes represented on this map are Annual Average Daily Traffic Volumes between major traffic generators: i.e., Highway Junctions and Cities. : Truck volumes include 6-Tire and 3 Axle single unit trucks, buses and all multiple unit trucks.

  16. Traffic signal inventory project

    DOT National Transportation Integrated Search

    2001-06-01

    The purpose of this study was to determine the level of compliance with the "Manual on Uniform Traffic Control Devices" (MUTCD) and other industry standards of traffic signals on the Iowa state highway system. Signals were randomly selected in cities...

  17. 32 CFR 634.28 - Traffic accident investigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Traffic accident investigation. 634.28 Section... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.28 Traffic accident investigation. Installation law enforcement personnel must make detailed investigations of...

  18. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    ERIC Educational Resources Information Center

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  19. 36 CFR 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... flow of traffic. ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13...

  20. 36 CFR 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... flow of traffic. ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13...

  1. Compressibility effect on thermal coherent structures in spatially-developing turbulent boundary layers via DNS

    NASA Astrophysics Data System (ADS)

    Araya, Guillermo; Jansen, Kenneth

    2017-11-01

    DNS of compressible spatially-developing turbulent boundary layers is performed at a Mach number of 2.5 over an isothermal flat plate. Turbulent inflow information is generated by following the concept of the rescaling-recycling approach introduced by Lund et al. (J. Comp. Phys. 140, 233-258, 1998); although, the proposed methodology is extended to compressible flows. Furthermore, a dynamic approach is employed to connect the friction velocities at the inlet and recycle stations (i.e., there is no need of an empirical correlation as in Lund et al.). Additionally, the Morkovin's Strong Reynolds Analogy (SRA) is used in the rescaling process of the thermal fluctuations from the recycle plane. Low/high order flow statistics is compared with direct simulations of an incompressible isothermal ZPG boundary layer at similar Reynolds numbers and temperature regarded as a passive scalar. Focus is given to the effect assessment of flow compressibility on the dynamics of thermal coherent structures. AFOSR #FA9550-17-1-0051.

  2. Air Traffic Sector Configuration Change Frequency

    NASA Technical Reports Server (NTRS)

    Chatterji, Gano B.; Drew, Michael

    2010-01-01

    A Mixed Integer Linear Programming method is used for creating sectors in Fort Worth, Cleveland, and Los Angeles centers based on several days of good-weather traffic data. The performance of these sectors is studied when they are subjected to traffic data from different days. Additionally, the advantage of using different sector designs at different times of day with varying traffic loads is examined. Specifically, traffic data from 10 days are used for design, and 47 other days are played back to test if the traffic-counts stay below the design values used in creating the partitions. The primary findings of this study are as follows. Sectors created with traffic from good-weather days can be used on other good-weather days. Sector configurations created with two hours of traffic can be used for 6 to 12 hours without exceeding the peak-count requirement. Compared to using a single configuration for the entire day, most of the sector-hour reduction is achieved by using two sector configurations -one during daytime hours and one during nighttime hours.

  3. Traffic calming for the prevention of road traffic injuries: systematic review and meta-analysis.

    PubMed

    Bunn, F; Collier, T; Frost, C; Ker, K; Roberts, I; Wentz, R

    2003-09-01

    To assess whether area-wide traffic calming schemes can reduce road crash related deaths and injuries. Systematic review and meta-analysis. Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials, Medline, EMBASE, Sociological Abstracts Science (and social science) citation index, National Technical Information service, Psychlit, Transport Research Information Service, International Road Research Documentation, and Transdoc, and web sites of road safety organisation were searched; experts were contacted, conference proceedings were handsearched, and relevant reference lists were checked. Randomised controlled trials, and controlled before/after studies of area-wide traffic calming schemes designed to discourage and slow down through traffic on residential roads. Data were collected on road user deaths, injuries, and traffic crashes. For each study rate ratios were calculated, the ratio of event rates before and after intervention in the traffic calmed area divided by the corresponding ratio of event rates in the control area, which were pooled to give an overall estimate using a random effects model. Sixteen controlled before/after studies met our inclusion criteria. Eight studies reported the number of road user deaths: pooled rate ratio 0.63 (95% confidence interval (CI) 0.14 to 2.59). Sixteen studies reported the number of injuries (fatal and non-fatal): pooled rate ratio 0.89 (95% CI 0.80 to 1.00). All studies were in high income countries. Area-wide traffic calming in towns and cities has the potential to reduce road traffic injuries. However, further rigorous evaluations of this intervention are needed, especially in low and middle income countries.

  4. In vivo traffic of indium-111-oxine labeled human lymphocytes collected by automated apheresis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Read, E.J.; Keenan, A.M.; Carter, C.S.

    1990-06-01

    The in vivo traffic patterns of autologous lymphocytes were studied in five normal human volunteers using lymphocytes obtained by automated apheresis, separated on Ficoll-Hypaque gradients, and labeled ex vivo with {sup 111}In-oxine. Final lymphocyte infusions contained 1.8-3.1 X 10(9) cells and 270-390 microCi (9.99-14.43 MBq) {sup 111}In, or 11-17 microCi (0.41-0.63 MBq) per 10(8) lymphocytes. Gamma imaging showed transient lung uptake and significant retention of radioactivity in the liver and spleen. Progressive uptake of activity in normal, nonpalpable axillary and inguinal lymph nodes was seen from 24 to 96 hr. Accumulation of radioactivity also was demonstrated at the forearm skinmore » test site, as well as in its associated epitrochlear and axillary lymph nodes, in a subject who had been tested for delayed hypersensitivity with tetanus toxoid. Indium-111-oxine labeled human lymphocytes may provide a useful tool for future studies of normal and abnormal lymphocyte traffic.« less

  5. A System for Traffic Violation Detection

    PubMed Central

    Aliane, Nourdine; Fernandez, Javier; Mata, Mario; Bemposta, Sergio

    2014-01-01

    This paper describes the framework and components of an experimental platform for an advanced driver assistance system (ADAS) aimed at providing drivers with a feedback about traffic violations they have committed during their driving. The system is able to detect some specific traffic violations, record data associated to these faults in a local data-base, and also allow visualization of the spatial and temporal information of these traffic violations in a geographical map using the standard Google Earth tool. The test-bed is mainly composed of two parts: a computer vision subsystem for traffic sign detection and recognition which operates during both day and nighttime, and an event data recorder (EDR) for recording data related to some specific traffic violations. The paper covers firstly the description of the hardware architecture and then presents the policies used for handling traffic violations. PMID:25421737

  6. A system for traffic violation detection.

    PubMed

    Aliane, Nourdine; Fernandez, Javier; Mata, Mario; Bemposta, Sergio

    2014-11-24

    This paper describes the framework and components of an experimental platform for an advanced driver assistance system (ADAS) aimed at providing drivers with a feedback about traffic violations they have committed during their driving. The system is able to detect some specific traffic violations, record data associated to these faults in a local data-base, and also allow visualization of the spatial and temporal information of these traffic violations in a geographical map using the standard Google Earth tool. The test-bed is mainly composed of two parts: a computer vision subsystem for traffic sign detection and recognition which operates during both day and nighttime, and an event data recorder (EDR) for recording data related to some specific traffic violations. The paper covers firstly the description of the hardware architecture and then presents the policies used for handling traffic violations.

  7. Abnormal Uterine Bleeding

    MedlinePlus

    ... abnormal uterine bleeding? Abnormal uterine bleeding is any heavy or unusual bleeding from the uterus (through your ... one symptom of abnormal uterine bleeding. Having extremely heavy bleeding during your period can also be considered ...

  8. 2002 Alaska traffic collisions

    DOT National Transportation Integrated Search

    2004-09-01

    Traffic collisions injured 6370 and killed 89 Alaskans during 2002. There were, on average, : 36.5 crashes per day and 1.5 crashes per hour. One person died on Alaska highways every : 4.1 days. : There were 272 traffic collisions per 100 million ...

  9. The importance of spatial orientation and knowledge of traffic signs for children's traffic safety.

    PubMed

    Trifunović, Aleksandar; Pešić, Dalibor; Čičević, Svetlana; Antić, Boris

    2017-05-01

    Pre-school children, as well as children from lower grades in primary school, who although rarely, completely independently participate in traffic, represent a vulnerable population from the standpoint of traffic safety. The greatest number of children were injured or killed in road traffic crashes on their way from home to kindergarten or school. Mostly due to lack of experience, children's behavior is confusing and often reckless and hasty. Safe behavior in the traffic environment demands certain cognitive skills. Unlike adults, children have less than fully developed peripheral vision. Also, changes occur in color perception, i.e. discrimination. All this leads to the conclusion that the stage of physical and mental development of the child is very important for safe participation in traffic. So, to estimate if they are sufficiently equipped to participate safely in traffic, a sensitive test for young children that may be suitable for their level of cognitive development is required. Accordingly, road safety education should be arranged in such a way that considers the child's level of development, as has been shown to be more effective when started at younger ages. Play is the most natural and easiest way of learning because it is the lens through which children experience their world, and the world of others. Having this in mind, if we want to measure the abilities of a child, and their preparedness for safety participation in traffic, unavoidable is to use non-verbal tests. The purpose of this study is to explore primary schooler's spatial, and abilities of color perception and memorization, as well as their performances in interpreting the meaning of traffic signs. In addition, neighborhood environmental correlates (rural-urban) and possible individual differences influences on the relationship among these abilities was examined. Knowledge about these factors affecting children's safety can be applied to improve relevant intervention measures for promoting

  10. Traffic Light Detection Using Conic Section Geometry

    NASA Astrophysics Data System (ADS)

    Hosseinyalmdary, S.; Yilmaz, A.

    2016-06-01

    Traffic lights detection and their state recognition is a crucial task that autonomous vehicles must reliably fulfill. Despite scientific endeavors, it still is an open problem due to the variations of traffic lights and their perception in image form. Unlike previous studies, this paper investigates the use of inaccurate and publicly available GIS databases such as OpenStreetMap. In addition, we are the first to exploit conic section geometry to improve the shape cue of the traffic lights in images. Conic section also enables us to estimate the pose of the traffic lights with respect to the camera. Our approach can detect multiple traffic lights in the scene, it also is able to detect the traffic lights in the absence of prior knowledge, and detect the traffics lights as far as 70 meters. The proposed approach has been evaluated for different scenarios and the results show that the use of stereo cameras significantly improves the accuracy of the traffic lights detection and pose estimation.

  11. Scheduling logic for Miles-In-Trail traffic management

    NASA Technical Reports Server (NTRS)

    Synnestvedt, Robert G.; Swenson, Harry; Erzberger, Heinz

    1995-01-01

    This paper presents an algorithm which can be used for scheduling arrival air traffic in an Air Route Traffic Control Center (ARTCC or Center) entering a Terminal Radar Approach Control (TRACON) Facility . The algorithm aids a Traffic Management Coordinator (TMC) in deciding how to restrict traffic while the traffic expected to arrive in the TRACON exceeds the TRACON capacity. The restrictions employed fall under the category of Miles-in-Trail, one of two principal traffic separation techniques used in scheduling arrival traffic . The algorithm calculates aircraft separations for each stream of aircraft destined to the TRACON. The calculations depend upon TRACON characteristics, TMC preferences, and other parameters adapted to the specific needs of scheduling traffic in a Center. Some preliminary results of traffic simulations scheduled by this algorithm are presented, and conclusions are drawn as to the effectiveness of using this algorithm in different traffic scenarios.

  12. Geosynchronous platform definition study. Volume 4, Part 1: Traffic analysis and system requirements for the baseline traffic model

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The traffic analyses and system requirements data generated in the study resulted in the development of two traffic models; the baseline traffic model and the new traffic model. The baseline traffic model provides traceability between the numbers and types of geosynchronous missions considered in the study and the entire spectrum of missions foreseen in the total national space program. The information presented pertaining to the baseline traffic model includes: (1) definition of the baseline traffic model, including identification of specific geosynchronous missions and their payload delivery schedules through 1990; (2) Satellite location criteria, including the resulting distribution of the satellite population; (3) Geosynchronous orbit saturation analyses, including the effects of satellite physical proximity and potential electromagnetic interference; and (4) Platform system requirements analyses, including satellite and mission equipment descriptions, the options and limitations in grouping satellites, and on-orbit servicing criteria (both remotely controlled and man-attended).

  13. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic law enforcement principles. (a) Traffic law enforcement should motivate drivers to operate vehicles...

  14. 32 CFR 634.26 - Traffic law enforcement principles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Traffic law enforcement principles. 634.26... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.26 Traffic law enforcement principles. (a) Traffic law enforcement should motivate drivers to operate vehicles...

  15. Computers in Traffic Education.

    ERIC Educational Resources Information Center

    Alexander, O. P.

    1983-01-01

    Traffic education covers basic road skills, legal/insurance aspects, highway code, accident causation/prevention, and vehicle maintenance. Microcomputer applications to traffic education are outlined, followed by a selected example of programs currently available (focusing on drill/practice, simulation, problem-solving, data manipulation, games,…

  16. Application of the induced exposure method to compare risks of traffic crashes among different types of drivers under different environmental conditions.

    PubMed

    Redondo-Calderón, J L; de Luna-del-Castillo , J; Jiménez-Moleón, J J; García-Martín, M; Lardelli-Claret, P; Gálvez-Vargas, R

    2001-05-01

    The authors used the induced exposure method to compare risks of traffic crashes among different types of Spanish drivers under different environmental conditions. The authors analyzed traffic crashes recorded by the Spanish Dirección General de Tráfico for the years 1991 and 1992 to compare proportions of drivers in different age/sex categories who were involved in single-vehicle and multivehicle crashes under different psychological and physical conditions. Crash risk was 1.42- to 2.35-fold greater in men than in women, depending on driver category and environmental factors. Risk was also significantly higher in the 18- to 24-year-old age group (1.75- to 2.87-fold greater than in drivers aged 25-49 years) and under abnormal psychological-physical conditions (1.69- to 4.10-fold greater among drivers under the influence of alcohol). Twilight and night driving, driving in urban areas, and driving on weekends and legal holidays were also associated, though nonsignificantly, with a slightly higher traffic crash risk. These findings are consistent with earlier reports, and they support the usefulness of the induced exposure method as an easy and economical tool with which to analyze data contained in traffic crash records.

  17. Photonics approach to traffic signs

    NASA Astrophysics Data System (ADS)

    Litwin, Dariusz; Galas, Jacek; CzyŻewski, Adam; Rymsza, Barbara; Kornalewski, Leszek; Kryszczyński, Tadeusz; Mikucki, Jerzy; Wikliński, Piotr; Daszkiewicz, Marek; Malasek, Jacek

    2016-12-01

    The automotive industry has been always a driving force for all economies. Despite of its beneficial meaning to every society it brings also many issues including wide area of road safety. The latter has been enforced by the increasing number of cars and the dynamic development of the traffic as a whole. Road signs and traffic lights are crucial in context of good traffic arrangement and its fluency. Traffic designers are used to treat horizontal road signs independently of vertical signs. However, modern light sources and growing flexibility in shaping optical systems create opportunity to design more advanced and smart solutions. In this paper we present an innovative, multidisciplinary approach that consists in tight interdependence of different traffic signals. We describe new optical systems together with their influence on the perception of the road user. The analysis includes maintenance and visibility in different weather conditions. A special attention has been focused on intersections of complex geometry.

  18. Traffic calming for the prevention of road traffic injuries: systematic review and meta-analysis

    PubMed Central

    Bunn, F; Collier, T; Frost, C; Ker, K; Roberts, I; Wentz, R

    2003-01-01

    Objective: To assess whether area-wide traffic calming schemes can reduce road crash related deaths and injuries. Design: Systematic review and meta-analysis. Data sources: Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials, Medline, EMBASE, Sociological Abstracts Science (and social science) citation index, National Technical Information service, Psychlit, Transport Research Information Service, International Road Research Documentation, and Transdoc, and web sites of road safety organisation were searched; experts were contacted, conference proceedings were handsearched, and relevant reference lists were checked. Inclusion criteria: Randomised controlled trials, and controlled before/after studies of area-wide traffic calming schemes designed to discourage and slow down through traffic on residential roads. Methods: Data were collected on road user deaths, injuries, and traffic crashes. For each study rate ratios were calculated, the ratio of event rates before and after intervention in the traffic calmed area divided by the corresponding ratio of event rates in the control area, which were pooled to give an overall estimate using a random effects model. Findings: Sixteen controlled before/after studies met our inclusion criteria. Eight studies reported the number of road user deaths: pooled rate ratio 0.63 (95% confidence interval (CI) 0.14 to 2.59). Sixteen studies reported the number of injuries (fatal and non-fatal): pooled rate ratio 0.89 (95% CI 0.80 to 1.00). All studies were in high income countries. Conclusion: Area-wide traffic calming in towns and cities has the potential to reduce road traffic injuries. However, further rigorous evaluations of this intervention are needed, especially in low and middle income countries. PMID:12966005

  19. Understanding traffic dynamics at a backbone POP

    NASA Astrophysics Data System (ADS)

    Taft, Nina; Bhattacharyya, Supratik; Jetcheva, Jorjeta; Diot, Christophe

    2001-07-01

    Spatial and temporal information about traffic dynamics is central to the design of effective traffic engineering practices for IP backbones. In this paper we study backbone traffic dynamics using data collected at a major POP on a tier-1 IP backbone. We develop a methodology that combines packet-level traces from access links in the POP and BGP routing information to build components of POP-to-POP traffic matrices. Our results show that there is wide disparity in the volume of traffic headed towards different egress POPs. At the same time, we find that current routing practices in the backbone tend to constrain traffic between ingress-egress POP pairs to a small number of paths. As a result, there is a wide variation in the utilization level of links in the backbone. Frequent capacity upgrades of the heavily used links are expensive; the need for such upgrades can be reduced by designing load balancing policies that will route more traffic over less utilized links. We identify traffic aggregates based on destination address prefixes and find that this set of criteria isolates a few aggregates that account for an overwhelmingly large portion of inter-POP traffic. We also demonstrate that these aggregates exhibit stability throughout the day on per-hour time scales, and thus they form a natural basis for splitting traffic over multiple paths in order to improve load balancing.

  20. 23 CFR 772.17 - Traffic noise prediction.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Traffic noise prediction. 772.17 Section 772.17 Highways... ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.17 Traffic noise prediction. (a) Any analysis required by this subpart must use the FHWA Traffic Noise Model (FHWA TNM), which is described in...

  1. Predicting Information Flows in Network Traffic.

    ERIC Educational Resources Information Center

    Hinich, Melvin J.; Molyneux, Robert E.

    2003-01-01

    Discusses information flow in networks and predicting network traffic and describes a study that uses time series analysis on a day's worth of Internet log data. Examines nonlinearity and traffic invariants, and suggests that prediction of network traffic may not be possible with current techniques. (Author/LRW)

  2. 76 FR 54156 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-31

    ... traffic control device design, location, or operation that have made some existing devices in the field...-2010-0159] RIN 2125-AF43 National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Revision AGENCY: Federal Highway Administration (FHWA...

  3. Is vehicle automation enough to prevent crashes? Role of traffic operations in automated driving environments for traffic safety.

    PubMed

    Jeong, Eunbi; Oh, Cheol; Lee, Seolyoung

    2017-07-01

    Automated driving systems (ADSs) are expected to prevent traffic accidents caused by driver carelessness on freeways. There is no doubt regarding this safety benefit if all vehicles in the transportation system were equipped with ADSs; however, it is implausible to expect that ADSs will reach 100% market penetration rate (MPR) in the near future. Therefore, the following question arises: 'Can ADSs, which consider only situations in the vicinity of an equipped vehicle, really contribute to a significant reduction in traffic accidents?' To address this issue, the interactions between equipped and unequipped vehicles must be investigated, which is the purpose of this study. This study evaluated traffic safety at different MPRs based on a proposed index to represent the overall rear-end crash risk of the traffic stream. Two approaches were evaluated for adjusting longitudinal vehicle maneuvers: vehicle safety-based maneuvering (VSM), which considers the crash risk of an equipped vehicle and its neighboring vehicles, and traffic safety-based maneuvering (TSM), which considers the overall crash risk in the traffic stream. TSM assumes that traffic operational agencies are able to monitor all the vehicles and to intervene in vehicle maneuvering. An optimization process, which attempts to obtain vehicle maneuvering control parameters to minimize the overall crash risk, is integrated into the proposed evaluation framework. The main purpose of employing the optimization process for vehicle maneuvering in this study is to identify opportunities to improve traffic safety through effective traffic management rather than developing a vehicle control algorithm that can be implemented in practice. The microscopic traffic simulator VISSIM was used to simulate the freeway traffic stream and to conduct systematic evaluations based on the proposed methodology. Both TSM and VSM achieved significant reductions in the potential for rear-end crashes. However, TSM obtained much greater

  4. Analysis of Malicious Traffic in Modbus/TCP Communications

    NASA Astrophysics Data System (ADS)

    Kobayashi, Tiago H.; Batista, Aguinaldo B.; Medeiros, João Paulo S.; Filho, José Macedo F.; Brito, Agostinho M.; Pires, Paulo S. Motta

    This paper presents the results of our analysis about the influence of Information Technology (IT) malicious traffic on an IP-based automation environment. We utilized a traffic generator, called MACE (Malicious trAffic Composition Environment), to inject malicious traffic in a Modbus/TCP communication system and a sniffer to capture and analyze network traffic. The realized tests show that malicious traffic represents a serious risk to critical information infrastructures. We show that this kind of traffic can increase latency of Modbus/TCP communication and that, in some cases, can put Modbus/TCP devices out of communication.

  5. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of self-propelled... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE...

  6. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  7. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of self-propelled... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE...

  8. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  9. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of self-propelled...

  10. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of self-propelled...

  11. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of self-propelled...

  12. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of self-propelled...

  13. Life Times of Simulated Traffic Jams

    NASA Astrophysics Data System (ADS)

    Nagel, Kai

    We study a model for freeway traffic which includes strong noise taking into account the fluctuations of individual driving behavior. The model shows emergent traffic jams with a self-similar appearance near the throughput maximum of the traffic. The lifetime distribution of these jams shows a short scaling regime, which gets considerably longer if one reduces the fluctuations when driving at maximum speed but leaves the fluctuations for slowing down or accelerating unchanged. The outflow from a traffic jam self-organizes into this state of maximum throughput.

  14. 77 FR 28460 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ...-2010-0159] RIN 2125-AF43 National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for Streets and Highways; Revision AGENCY: Federal Highway Administration (FHWA..., approved by the FHWA, and recognized as the national standard for traffic control devices used on all...

  15. Traffic Sign Detection Based on Biologically Visual Mechanism

    NASA Astrophysics Data System (ADS)

    Hu, X.; Zhu, X.; Li, D.

    2012-07-01

    TSR (Traffic sign recognition) is an important problem in ITS (intelligent traffic system), which is being paid more and more attention for realizing drivers assisting system and unmanned vehicle etc. TSR consists of two steps: detection and recognition, and this paper describe a new traffic sign detection method. The design principle of the traffic sign is comply with the visual attention mechanism of human, so we propose a method using visual attention mechanism to detect traffic sign ,which is reasonable. In our method, the whole scene will firstly be analyzed by visual attention model to acquire the area where traffic signs might be placed. And then, these candidate areas will be analyzed according to the shape characteristics of the traffic sign to detect traffic signs. In traffic sign detection experiments, the result shows the proposed method is effectively and robust than other existing saliency detection method.

  16. 77 FR 28455 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... Options for design and applications of traffic control devices, this Manual should not be considered a... application of traffic control devices, as well as in the location and design of roads and streets that the..., while this Manual provides Standards, Guidance, and Options for design and applications of traffic...

  17. An assessment of a traffic monitoring system for a major traffic generator to improve regional planning : technical report.

    DOT National Transportation Integrated Search

    2009-09-01

    The opening of a major traffic generator in the San Antonio area provided an opportunity to develop and : implement an extensive traffic monitoring system to analyze local, area, and regional traffic impacts from the : generator. Researchers reviewed...

  18. Use of permanent traffic recorder data to develop factors for traffic and truck variations

    DOT National Transportation Integrated Search

    2002-10-01

    This project entailed the development of the following four traffic volume adjustment factors from 1995 and 1996 permanent traffic recorder data: (1) A truck (axle) adjustment factor for single pneumatic tube counters; (2) A factor for estimating Des...

  19. Next-generation smart traffic signals : RHODES with Intellidrive, the self-taught traffic control system.

    DOT National Transportation Integrated Search

    2009-01-01

    Can a self-calibrating signal control system lead to wider adoption of adaptive traffic control systems? The focus of Next Generation of Smart Traffic Signals, an Exploratory Advanced Research (EAR) Program project, is a system that-with lit...

  20. Enhancing the Quality of Service for Real Time Traffic over Optical Burst Switching (OBS) Networks with Ensuring the Fairness for Other Traffics.

    PubMed

    Al-Shargabi, Mohammed A; Shaikh, Asadullah; Ismail, Abdulsamad S

    2016-01-01

    Optical burst switching (OBS) networks have been attracting much consideration as a promising approach to build the next generation optical Internet. A solution for enhancing the Quality of Service (QoS) for high priority real time traffic over OBS with the fairness among the traffic types is absent in current OBS' QoS schemes. In this paper we present a novel Real Time Quality of Service with Fairness Ratio (RT-QoSFR) scheme that can adapt the burst assembly parameters according to the traffic QoS needs in order to enhance the real time traffic QoS requirements and to ensure the fairness for other traffic. The results show that RT-QoSFR scheme is able to fulfill the real time traffic requirements (end to end delay, and loss rate) ensuring the fairness for other traffics under various conditions such as the type of real time traffic and traffic load. RT-QoSFR can guarantee that the delay of the real time traffic packets does not exceed the maximum packets transfer delay value. Furthermore, it can reduce the real time traffic packets loss, at the same time guarantee the fairness for non real time traffic packets by determining the ratio of real time traffic inside the burst to be 50-60%, 30-40%, and 10-20% for high, normal, and low traffic loads respectively.

  1. Enhancing the Quality of Service for Real Time Traffic over Optical Burst Switching (OBS) Networks with Ensuring the Fairness for Other Traffics

    PubMed Central

    Al-Shargabi, Mohammed A.; Ismail, Abdulsamad S.

    2016-01-01

    Optical burst switching (OBS) networks have been attracting much consideration as a promising approach to build the next generation optical Internet. A solution for enhancing the Quality of Service (QoS) for high priority real time traffic over OBS with the fairness among the traffic types is absent in current OBS’ QoS schemes. In this paper we present a novel Real Time Quality of Service with Fairness Ratio (RT-QoSFR) scheme that can adapt the burst assembly parameters according to the traffic QoS needs in order to enhance the real time traffic QoS requirements and to ensure the fairness for other traffic. The results show that RT-QoSFR scheme is able to fulfill the real time traffic requirements (end to end delay, and loss rate) ensuring the fairness for other traffics under various conditions such as the type of real time traffic and traffic load. RT-QoSFR can guarantee that the delay of the real time traffic packets does not exceed the maximum packets transfer delay value. Furthermore, it can reduce the real time traffic packets loss, at the same time guarantee the fairness for non real time traffic packets by determining the ratio of real time traffic inside the burst to be 50–60%, 30–40%, and 10–20% for high, normal, and low traffic loads respectively. PMID:27583557

  2. Integrin traffic - the update.

    PubMed

    De Franceschi, Nicola; Hamidi, Hellyeh; Alanko, Jonna; Sahgal, Pranshu; Ivaska, Johanna

    2015-03-01

    Integrins are a family of transmembrane cell surface molecules that constitute the principal adhesion receptors for the extracellular matrix (ECM) and are indispensable for the existence of multicellular organisms. In vertebrates, 24 different integrin heterodimers exist with differing substrate specificity and tissue expression. Integrin-extracellular-ligand interaction provides a physical anchor for the cell and triggers a vast array of intracellular signalling events that determine cell fate. Dynamic remodelling of adhesions, through rapid endocytic and exocytic trafficking of integrin receptors, is an important mechanism employed by cells to regulate integrin-ECM interactions, and thus cellular signalling, during processes such as cell migration, invasion and cytokinesis. The initial concept of integrin traffic as a means to translocate adhesion receptors within the cell has now been expanded with the growing appreciation that traffic is intimately linked to the cell signalling apparatus. Furthermore, endosomal pathways are emerging as crucial regulators of integrin stability and expression in cells. Thus, integrin traffic is relevant in a number of pathological conditions, especially in cancer. Nearly a decade ago we wrote a Commentary in Journal of Cell Science entitled 'Integrin traffic'. With the advances in the field, we felt it would be appropriate to provide the growing number of researchers interested in integrin traffic with an update. © 2015. Published by The Company of Biologists Ltd.

  3. Fluorescent diamond nanoparticle as a probe of intracellular traffic in primary neurons in culture

    NASA Astrophysics Data System (ADS)

    Le, Xuan Loc; Lepagnol-Bestel, Aude-Marie; Adam, Marie-Pierre; Thomas, Alice; Dantelle, Géraldine; Chang, Cheng-Chun; Mohan, Nitin; Chang, Huan-Cheng; Treussart, François; Simonneau, Michel

    2012-03-01

    Neurons display dendritic spines plasticity and morphology anomalies in numerous psychiatric and neurodegenerative diseases. These changes are associated to abnormal dendritic traffic that can be evidenced by fluorescence microscopy. As a fluorescent probe we propose to use fluorescent diamond nanoparticles with size of < 50 nm. Color centers embedded inside the diamond nanoparticles are perfectly photostable emitters allowing for long-term tracking. Nanodiamond carbon surface is also well suited for biomolecule functionalization to target specific cellular compartments. We show that fluorescent nanodiamonds can be spontaneously internalized in neurons in culture and imaged by confocal and Total Internal Reflection (TIRF) microscopy with a high signal over background ratio.

  4. Traffic jams induced by fluctuation of a leading car.

    PubMed

    Nagatani, T

    2000-04-01

    We present a phase diagram of the different kinds of congested traffic triggered by fluctuation of a leading car in an open system without sources and sinks. Traffic states and density waves are investigated numerically by varying the amplitude of fluctuation using a car following model. The phase transitions among the free traffic, oscillatory congested traffic, and homogeneous congested traffic occur by fluctuation of a leading car. With increasing the amplitude of fluctuation, the transition between the free traffic and oscillatory traffic occurs at lower density and the transition between the homogeneous congested traffic and the oscillatory traffic occurs at higher density. The oscillatory congested traffic corresponds to the coexisting phase. Also, the moving localized clusters appear just above the transition lines.

  5. Analysis of Yearly Traffic Fluctuation on Latvian Highways

    NASA Astrophysics Data System (ADS)

    Freimanis, A.; Paeglı¯tis, A.

    2015-11-01

    Average annual daily traffic and average annual truck traffic are two most used metrics for road management decisions. They are calculated from data gathered by continuous counting stations embedded in road pavement, manual counting sessions or mobile counting devices. Last two usually do not last longer than a couple of weeks so the information gathered is influenced by yearly traffic fluctuations. Data containing a total of 8,186,871 vehicles or 1989 days from 4 WIM stations installed on highways in Latvia were used in this study. Each of the files was supposed to contain data from only 1 day and additional data were deleted. No other data cleaning steps were performed, which increased the number of vehicles as counting systems sometimes split vehicles into two. Weekly traffic and weekly truck traffic was normalized against respective average values. Each weekly value was then plotted against its number in a year for better visual perception. Weekly traffic amplitudes were used to assess differences between different locations and standard deviations for fluctuation comparison of truck and regular traffic at the same location. Results show that truck traffic fluctuates more than regular traffic during a year, especially around holidays. Differences between counting locations were larger for regular traffic than truck traffic. These results show that average annual daily traffic could be influenced more if short term counting results are adjusted by factors derived from unsuitable continuous counting stations, but truck traffic is more influenced by the time of year in which counting is done.

  6. Broadcast control of air traffic

    NASA Technical Reports Server (NTRS)

    Litchford, G. B.

    1972-01-01

    Applications of wide range broadcast procedures to improve air traffic control and make more airspace available are discussed. A combination of the Omega navigation system and the very high frequency omnirange (VOR) is recommended as a means for accomplishing improved air traffic control. The benefits to be derived by commercial and general aviation are described. The air/ground communications aspects of the improved air traffic control system are explained. Research and development programs for implementing the broadcast concept are recommended.

  7. Meiotic abnormalities

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

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

    PubMed Central

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

    2016-01-01

    Background Air pollution and weather are just two of many environmental factors contributing to traffic accidents (RTA). Objectives This study assessed the effects of these factors on traffic accidents and related mortalities in Ahvaz, Iran. Methods In this ecological study, data about RTA, traffic-related mortalities, air pollution (including NO, CO, NO2, NOx PM10, SO2, and O3 rates) and climate data from March 2008 until March 2015 was acquired from the Khuzestan State Police Force, the Environmental Protection Agency and the State Meteorological Department. Statistical analysis was performed with STATA 12 through both crude and adjusted negative binomial regression methods. Results There was a significant positive correlation between increase in the monthly average temperature, the number of rainy days, and the number of frost days with the number of RTA (P < 0.05). Increased monthly average relative humidity, evaporation, and number of sunny days were negatively correlated with the frequency of RTA (P < 0.05). We also observed an inverse significant correlation between monthly average relative humidity, evaporation, and wind speed with traffic accident mortality (P < 0.05). Some air pollutants were negatively associated with the incidence rate of RTA. Conclusions It appears that some weather variables were significantly associated with increased RTA. However, increased levels of air pollutants were not associated with increased rates of RTA and/or related mortalities. Additional studies are recommended to explore this topic in more detail. PMID:28180125

  9. Connecticut traffic accident facts, 2006

    DOT National Transportation Integrated Search

    2008-04-01

    This report documents facts on reported 2006 traffic accidents included in the : Department database. Sections of the report contain statistics on major categories of traffic : accidents. These categories include all reported accidents, reported alco...

  10. 2016 Traffic Safety Culture Index

    MedlinePlus

    ... for Traffic Safety. For media inquiries, contact: Tamra Johnson 202-942-2079 TRJohnson@national.aaa.com Authors ... for Traffic Safety. For media inquiries, contact: Tamra Johnson 202-942-2079 TRJohnson@national.aaa.com Authors ...

  11. The 3-amino-derivative of gamma-cyclodextrin as chiral selector of Dns-amino acids in electrokinetic chromatography.

    PubMed

    Giuffrida, A; Contino, A; Maccarrone, G; Messina, M; Cucinotta, V

    2009-04-24

    The enantioseparation of the enantiomeric pairs of 10 Dns derivatives of alpha-amino acids was successfully carried out by using for the first time the 3-amino derivative of the gamma-cyclodextrin. The effects of pH and selector concentration on the migration times and the resolutions of analytes were studied in detail. 3-Deoxy-3-amino-2(S),3(R)-gamma-cyclodextrin (GCD3AM) shows very good chiral recognition ability even at very low concentrations at all the three investigated values of pH, as shown by the very large values of selectivity and resolution towards several pairs of amino acids. The role played by the cavity, the substitution site and the protonation equilibria on the observed properties of chiral selectivity, on varying the specific amino acid involved, is discussed.

  12. Ohio traffic crash facts, 1994

    DOT National Transportation Integrated Search

    1994-01-01

    Information contained in this report represents traffic crash data and supporting information : from the Ohio Integrated Traffic Records System and various other state agency sources. : Data presented herein represents the contents of those files on ...

  13. Delaware traffic calming design manual

    DOT National Transportation Integrated Search

    2000-09-10

    The Delaware Traffic Calming Manual consists of roadway design standards that are intended to encourage closer adherence to posted speeds, discourage cut-through traffic, enhance vehicular and pedestrian safety and community aesthetics. Its purpose i...

  14. Ohio traffic crash facts, 2003

    DOT National Transportation Integrated Search

    2004-04-28

    Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2003. Data presented herein : represents the crash report forms as submitted ...

  15. Ohio traffic crash facts, 2005

    DOT National Transportation Integrated Search

    2006-04-01

    Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2005. Data presented herein : represents the crash report forms as submitted ...

  16. Ohio traffic crash facts, 2002

    DOT National Transportation Integrated Search

    2003-12-01

    Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2002. Data presented herein : represents the crash report forms as submitted ...

  17. Ohio traffic crash facts, 2004

    DOT National Transportation Integrated Search

    2005-04-14

    Information contained in this report represents traffic crash data and supporting information from the : Ohio Integrated Traffic Records System (ITRS) for the calendar year 2004. Data presented herein : represents the crash report forms as submitted ...

  18. Ohio traffic crash facts, 2006

    DOT National Transportation Integrated Search

    2007-07-01

    Information contained in this report represents traffic crash data and supporting information from the Ohio : Integrated Traffic Records System (ITRS) for the calendar year 2006. Data presented herein represents the : crash report forms as submitted ...

  19. Ohio traffic crash facts, 1997

    DOT National Transportation Integrated Search

    1998-07-01

    Information contained in this report represents traffic crash data and supporting information : from the Ohio Integrated Traffic Records System and various other state agency sources. : Data presented herein represents the contents of those files on ...

  20. Ohio traffic crash facts, 1998

    DOT National Transportation Integrated Search

    1999-01-01

    Information contained in this report represents traffic crash data and supporting information : from the Ohio Integrated Traffic Records System and various other state agency sources. : Data presented herein represents the contents of those files on ...

  1. Ohio traffic crash facts, 1999

    DOT National Transportation Integrated Search

    2000-07-01

    Information contained in this report represents traffic crash data and supporting information : from the Ohio Integrated Traffic Records System and various other state agency sources. : Data presented herein represents the contents of those files on ...

  2. Ohio traffic crash facts, 2001

    DOT National Transportation Integrated Search

    2002-06-05

    Information contained in this report represents traffic crash data and supporting information from the Ohio : Integrated Traffic Records System (ITRS) for the calendar year 2001. Data presented herein represents the : crash report forms as submitted ...

  3. In search of the severity dimension of traffic events: Extended Delta-V as a traffic conflict indicator.

    PubMed

    Laureshyn, Aliaksei; De Ceunynck, Tim; Karlsson, Christoffer; Svensson, Åse; Daniels, Stijn

    2017-01-01

    Most existing traffic conflict indicators do not sufficiently take into account the severity of the injuries resulting from a collision had it occurred. Thus far, most of the indicators that have been developed express the severity of a traffic encounter as their proximity to a collision in terms of time or space. This paper presents the theoretical framework and the first implementation of Extended Delta-V as a measure of traffic conflict severity in site-based observations. It is derived from the concept of Delta-V as it is applied in crash reconstructions, which refers to the change of velocity experienced by a road user during a crash. The concept of Delta-V is recognised as an important predictor of crash outcome severity. The paper explains how the measure is operationalised within the context of traffic conflict observations. The Extended Delta-V traffic conflict measure integrates the proximity to a crash as well as the outcome severity in the event a crash would have taken place, which are both important dimensions in defining the severity of a traffic event. The results from a case study are presented in which a number of traffic conflict indicators are calculated for interactions between left turning vehicles and vehicles driving straight through a signalised intersection. The results suggest that the Extended Delta-V indicator seems to perform well at selecting the most severe traffic events. The paper discusses how the indicator overcomes a number of limitations of traditional measures of conflict severity. While this is a promising first step towards operationalising an improved measure of traffic conflict severity, additional research is needed to further develop and validate the indicator. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  4. Traffic flow forecasting for intelligent transportation systems.

    DOT National Transportation Integrated Search

    1995-01-01

    The capability to forecast traffic volume in an operational setting has been identified as a critical need for intelligent transportation systems (ITS). In particular, traffic volume forecasts will directly support proactive traffic control and accur...

  5. DNS study of dependence of bulk consumption velocity in a constant-density reacting flow on turbulence and mixture characteristics

    NASA Astrophysics Data System (ADS)

    Yu, Rixin; Lipatnikov, Andrei N.

    2017-06-01

    3D Direct Numerical Simulation (DNS) study of propagation of a single-reaction wave in forced, statistically stationary, homogeneous, isotropic, and constant-density turbulence was performed in order to evaluate both developing UTt and fully developed UTs bulk turbulent consumption velocities by independently varying a ratio of 0.5 ≤u'/SL≤ 90 of the r.m.s. turbulent velocity to the laminar wave speed and a ratio of 0.39 ≤L11/δF≤ 12.5 of the longitudinal integral length scale of the turbulence to the laminar wave thickness. Accordingly, the Damköhler D a =(L11SL ) /(u'δF ) and Karlovitz K a =δF/(SLτη ) numbers were varied from 0.01 to 24.7 and from 0.36 to 587, respectively. Here, τη is the Kolmogorov time scale. The obtained DNS data show that, at sufficiently low Da, the fully developed ratio of UTs/u' is mainly controlled by Da and scales as √{D a }. However, such a scaling should not be extrapolated to high Da. The higher Da (or the lower Ka), the less pronounced dependence of UTs/u' on a ratio of L11/δF. Moreover, scaling laws UT∝u'αSL1 -α(L11/δF ) β are substantially different for developing UTt and fully developed UTs, i.e., the scaling exponents α and, especially, β depend on the wave-development time. Furthermore, α and, especially, β depend on a method used to evaluate the developing UTt. Such effects can contribute to significant scatter of expressions for UT or ST as a function of {u', SL, L11, δF}, obtained by parameterizing various experimental databases.

  6. Strobe Traffic Lights Warn of Approaching Emergency Vehicles

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron

    2004-01-01

    Strobe-enhanced traffic signals have been developed to aid in the preemption of road intersections for emergency vehicles. The strobe-enhanced traffic signals can be incorporated into both new and pre-existing traffic-control systems in which the traffic-signal heads are of a relatively new type based on arrays of light-emitting diodes (LEDs). The strobe-enhanced traffic signals offer a less expensive, less complex alternative to a recently developed system of LED-based warning signs placed next to traffic signals. Because of its visual complexity, the combination of traffic signals and warning signs is potentially confusing to motorists. The strobe-enhanced traffic signals present less visual clutter. In a given traffic-signal head, the strobe-enhanced traffic signal is embedded in the red LED array of the stop signal. Two strobe LED strips one horizontal and one vertical are made capable of operating separately from the rest of the red LED matrix. When no emergency vehicle is approaching, the red LED array functions as a normal stop signal: all the red LEDs are turned on and off together. When the intersection is to be preempted for an approaching emergency vehicle, only the LEDs in one of the strobe strips are lit, and are turned on in a sequence that indicates the direction of approach. For example (see figure), if an emergency vehicle approaches from the right, the strobe LEDs are lit in a sequence moving from right to left. Important to the success of strobe-enhanced traffic signals is conformance to city ordinances and close relation to pre-existing traffic standards. For instance, one key restriction is that new icons must not include arrows, so that motorists will not confuse new icons with conventional arrows that indicate allowed directions of movement. It is also critical that new displays like strobe-enhanced traffic signals be similar to displays used in traffic-control systems in large cities. For example, Charleston, South Carolina uses horizontal

  7. Traffic crash statistics report, 2005

    DOT National Transportation Integrated Search

    2006-01-01

    The information contained in this Traffic Crash Statistics booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form : crash report when investigating: : Motor vehic...

  8. 2006 Oregon traffic crash summary

    DOT National Transportation Integrated Search

    2007-06-01

    The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

  9. 2007 Oregon traffic crash summary

    DOT National Transportation Integrated Search

    2008-07-01

    The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

  10. 2005 Oregon traffic crash summary

    DOT National Transportation Integrated Search

    2006-06-01

    The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

  11. The Traffic Light Challenge

    ERIC Educational Resources Information Center

    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…

  12. Evaluation of traffic marking beads and paint.

    DOT National Transportation Integrated Search

    1972-01-01

    Traffic markings that retain high reflective properties under adverse lighting and weather conditions are clearly of utmost importance in traffic safety. It was the intent of this study to investigate optimum traffic striping procedures and materials...

  13. Stress in air traffic controllers : comparison of two air route traffic control centers on different shift rotation patterns.

    DOT National Transportation Integrated Search

    1975-01-01

    Stress in 23 air traffic controllers (ATCS) at Atlanta Air Route Traffic Control Center (ATL) on the straight 5-day shift rotation schedule was compared with stress in 23 ATCS's on the 2-2-1 shift rotation schedule at Fort Worth Air Route Traffic Con...

  14. Fixed Point Learning Based Intelligent Traffic Control System

    NASA Astrophysics Data System (ADS)

    Zongyao, Wang; Cong, Sui; Cheng, Shao

    2017-10-01

    Fixed point learning has become an important tool to analyse large scale distributed system such as urban traffic network. This paper presents a fixed point learning based intelligence traffic network control system. The system applies convergence property of fixed point theorem to optimize the traffic flow density. The intelligence traffic control system achieves maximum road resources usage by averaging traffic flow density among the traffic network. The intelligence traffic network control system is built based on decentralized structure and intelligence cooperation. No central control is needed to manage the system. The proposed system is simple, effective and feasible for practical use. The performance of the system is tested via theoretical proof and simulations. The results demonstrate that the system can effectively solve the traffic congestion problem and increase the vehicles average speed. It also proves that the system is flexible, reliable and feasible for practical use.

  15. Abnormal branching and regression of the notochord and its relationship to foregut abnormalities.

    PubMed

    Vleesch Dubois, V N; Quan Qi, B; Beasley, S W; Williams, A

    2002-04-01

    An abnormally positioned notochord has been reported in embryos that develop foregut abnormalities, vertebral defects and other abnormalities of the VATER association. This study examines the patterns of regression of the abnormal notochord in the rat model of the VATER association and investigates the relationship between developmental abnormalities of the notochord and those of the vertebra and foregut. Timed-pregnant Sprague-Dawley rats were given daily intraperitoneal injections of 1.75 mg/kg adriamycin on gestational days 6 - 9 inclusive. Rats were sacrificed between days 14 and 20 and their embryos harvested, histologically sectioned and stained and examined serially. The location and appearance of the degenerating notochord and its relationship to regional structural defects were analysed. All 26 embryos exposed to adriamycin developed foregut abnormalities and had an abnormal notochord. The notochord disappeared by a process of apoptotic degeneration that lagged behind that of the normal embryo: the notochord persisted in the abnormal embryo beyond day 17, whereas in the normal rat it had already disappeared. Similarly, formation of the nucleus pulposus was delayed. Vertebral abnormalities occurred when the notochord was ventrally-positioned. The notochord disappears during day 16 in the normal embryo whereas abnormal branches of the notochord persist until day 19 in the adriamycin-treated embryo. Degeneration of the notochord is dominated by apoptosis. An excessively ventrally-placed notochord is closely associated with abnormalities of the vertebral column, especially hemivertebrae.

  16. A knowledge-based system for controlling automobile traffic

    NASA Technical Reports Server (NTRS)

    Maravas, Alexander; Stengel, Robert F.

    1994-01-01

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

  17. 2003 Oregon traffic crash summary

    DOT National Transportation Integrated Search

    2004-10-01

    The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring on city streets, county roads and state highways. The data supports various local, county and state traffic safety programs, engineering and plan...

  18. Traffic crash statistics report, 1998

    DOT National Transportation Integrated Search

    1999-01-01

    The information contained in this Traffic Crash Facts booklet is extracted from law : enforcement agency long-form reports of traffic crashes. A law enforcement officer must submit a : long-form crash report when investigating: : Motor vehicle crashe...

  19. Traffic crash statistics report, 1995

    DOT National Transportation Integrated Search

    1996-01-01

    The information contained in this Traffic Crash Facts booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashe...

  20. Traffic crash statistics report, 1996

    DOT National Transportation Integrated Search

    1997-11-01

    The information contained in this Traffic Crash Facts booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashe...

  1. Traffic crash statistics report, 1994

    DOT National Transportation Integrated Search

    1995-01-01

    The information contained in this Traffic Crash Data booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashes...

  2. Traffic crash statistics report, 2004

    DOT National Transportation Integrated Search

    2005-01-01

    The information contained in this Traffic Crash Data booklet is extracted from law enforcement : agency long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report : when investigating: : Motor vehicle crashes...

  3. Traffic crash statistics report, 1997

    DOT National Transportation Integrated Search

    1998-01-01

    The information contained in this Traffic Crash Facts booklet is extracted from law enforcement agency : long-form reports of traffic crashes. A law enforcement officer must submit a long-form crash report when : investigating: : Motor vehicle crashe...

  4. Planning in air traffic control

    DOT National Transportation Integrated Search

    2001-12-01

    An experiment was conducted to examine the planning activities of en route air traffic controllers. : Controllers were placed in the role of planners and verbalized a plan for controlling traffic to a tactician : (another controller) who implemented ...

  5. Congestion control strategy on complex network with privilege traffic

    NASA Astrophysics Data System (ADS)

    Li, Shi-Bao; He, Ya; Liu, Jian-Hang; Zhang, Zhi-Gang; Huang, Jun-Wei

    The congestion control of traffic is one of the most important studies in complex networks. In the previous congestion algorithms, all the network traffic is assumed to have the same priority, and the privilege of traffic is ignored. In this paper, a privilege and common traffic congestion control routing strategy (PCR) based on the different priority of traffic is proposed, which can be devised to cope with the different traffic congestion situations. We introduce the concept of privilege traffic in traffic dynamics for the first time and construct a new traffic model which taking into account requirements with different priorities. Besides, a new factor Ui is introduced by the theoretical derivation to characterize the interaction between different traffic routing selection, furthermore, Ui is related to the network throughput. Since the joint optimization among different kinds of traffic is accomplished by PCR, the maximum value of Ui can be significantly reduced and the network performance can be improved observably. The simulation results indicate that the network throughput with PCR has a better performance than the other strategies. Moreover, the network capacity is improved by 25% at least. Additionally, the network throughput is also influenced by privilege traffic number and traffic priority.

  6. Traffic safety facts 1995 : state traffic data

    DOT National Transportation Integrated Search

    1996-01-01

    Nationwide in 1993, traffic fatalities were up 2 percent. These tables provide summary data of fatal crashes for the United States and individually for the 50 states, the District of Columbia, and Puerto Rico (not included in the national totals). Th...

  7. Fast Drawing of Traffic Sign Using Mobile Mapping System

    NASA Astrophysics Data System (ADS)

    Yao, Q.; Tan, B.; Huang, Y.

    2016-06-01

    Traffic sign provides road users with the specified instruction and information to enhance traffic safety. Automatic detection of traffic sign is important for navigation, autonomous driving, transportation asset management, etc. With the advance of laser and imaging sensors, Mobile Mapping System (MMS) becomes widely used in transportation agencies to map the transportation infrastructure. Although many algorithms of traffic sign detection are developed in the literature, they are still a tradeoff between the detection speed and accuracy, especially for the large-scale mobile mapping of both the rural and urban roads. This paper is motivated to efficiently survey traffic signs while mapping the road network and the roadside landscape. Inspired by the manual delineation of traffic sign, a drawing strategy is proposed to quickly approximate the boundary of traffic sign. Both the shape and color prior of the traffic sign are simultaneously involved during the drawing process. The most common speed-limit sign circle and the statistic color model of traffic sign are studied in this paper. Anchor points of traffic sign edge are located with the local maxima of color and gradient difference. Starting with the anchor points, contour of traffic sign is drawn smartly along the most significant direction of color and intensity consistency. The drawing process is also constrained by the curvature feature of the traffic sign circle. The drawing of linear growth is discarded immediately if it fails to form an arc over some steps. The Kalman filter principle is adopted to predict the temporal context of traffic sign. Based on the estimated point,we can predict and double check the traffic sign in consecutive frames.The event probability of having a traffic sign over the consecutive observations is compared with the null hypothesis of no perceptible traffic sign. The temporally salient traffic sign is then detected statistically and automatically as the rare event of having a

  8. Fine-Tuning ADAS Algorithm Parameters for Optimizing Traffic ...

    EPA Pesticide Factsheets

    With the development of the Connected Vehicle technology that facilitates wirelessly communication among vehicles and road-side infrastructure, the Advanced Driver Assistance Systems (ADAS) can be adopted as an effective tool for accelerating traffic safety and mobility optimization at various highway facilities. To this end, the traffic management centers identify the optimal ADAS algorithm parameter set that enables the maximum improvement of the traffic safety and mobility performance, and broadcast the optimal parameter set wirelessly to individual ADAS-equipped vehicles. After adopting the optimal parameter set, the ADAS-equipped drivers become active agents in the traffic stream that work collectively and consistently to prevent traffic conflicts, lower the intensity of traffic disturbances, and suppress the development of traffic oscillations into heavy traffic jams. Successful implementation of this objective requires the analysis capability of capturing the impact of the ADAS on driving behaviors, and measuring traffic safety and mobility performance under the influence of the ADAS. To address this challenge, this research proposes a synthetic methodology that incorporates the ADAS-affected driving behavior modeling and state-of-the-art microscopic traffic flow modeling into a virtually simulated environment. Building on such an environment, the optimal ADAS algorithm parameter set is identified through an optimization programming framework to enable th

  9. Classification of Automated Search Traffic

    NASA Astrophysics Data System (ADS)

    Buehrer, Greg; Stokes, Jack W.; Chellapilla, Kumar; Platt, John C.

    As web search providers seek to improve both relevance and response times, they are challenged by the ever-increasing tax of automated search query traffic. Third party systems interact with search engines for a variety of reasons, such as monitoring a web site’s rank, augmenting online games, or possibly to maliciously alter click-through rates. In this paper, we investigate automated traffic (sometimes referred to as bot traffic) in the query stream of a large search engine provider. We define automated traffic as any search query not generated by a human in real time. We first provide examples of different categories of query logs generated by automated means. We then develop many different features that distinguish between queries generated by people searching for information, and those generated by automated processes. We categorize these features into two classes, either an interpretation of the physical model of human interactions, or as behavioral patterns of automated interactions. Using the these detection features, we next classify the query stream using multiple binary classifiers. In addition, a multiclass classifier is then developed to identify subclasses of both normal and automated traffic. An active learning algorithm is used to suggest which user sessions to label to improve the accuracy of the multiclass classifier, while also seeking to discover new classes of automated traffic. Performance analysis are then provided. Finally, the multiclass classifier is used to predict the subclass distribution for the search query stream.

  10. Large-scale measurement and modeling of backbone Internet traffic

    NASA Astrophysics Data System (ADS)

    Roughan, Matthew; Gottlieb, Joel

    2002-07-01

    There is a brewing controversy in the traffic modeling community concerning how to model backbone traffic. The fundamental work on self-similarity in data traffic appears to be contradicted by recent findings that suggest that backbone traffic is smooth. The traffic analysis work to date has focused on high-quality but limited-scope packet trace measurements; this limits its applicability to high-speed backbone traffic. This paper uses more than one year's worth of SNMP traffic data covering an entire Tier 1 ISP backbone to address the question of how backbone network traffic should be modeled. Although the limitations of SNMP measurements do not permit us to comment on the fine timescale behavior of the traffic, careful analysis of the data suggests that irrespective of the variation at fine timescales, we can construct a simple traffic model that captures key features of the observed traffic. Furthermore, the model's parameters are measurable using existing network infrastructure, making this model practical in a present-day operational network. In addition to its practicality, the model verifies basic statistical multiplexing results, and thus sheds deep insight into how smooth backbone traffic really is.

  11. Ohio traffic crash facts, 2000

    DOT National Transportation Integrated Search

    2001-08-06

    Information contained in this report represents traffic crash data and supporting information from the Ohio Integrated Traffic Records System for the calendar year of 2000. Data presented herein represents the crash report forms as submitted to the O...

  12. Texas traffic thermostat software tool.

    DOT National Transportation Integrated Search

    2013-04-01

    The traffic thermostat decision tool is built to help guide the user through a logical, step-wise, process of examining potential changes to their Manage Lane/toll facility. : **NOTE: Project Title: Application of the Traffic Thermostat Framework. Ap...

  13. Texas traffic thermostat marketing package.

    DOT National Transportation Integrated Search

    2013-04-01

    The traffic thermostat decision tool is built to help guide the user through a logical, step-wise, process of examining potential changes to their Manage Lane/toll facility. : **NOTE: Project Title: Application of the Traffic Thermostat Framework. Ap...

  14. [Distribution of and changes in Danish traffic deaths].

    PubMed

    Bjerre, Johannes; Kirkebjerg, Peer Gregersen; Larsen, Lars Binderup

    2006-05-01

    Traffic accidents were the primary cause of death for Danes aged 15 to 24 years in 1999; per million inhabitants, that figure was 62% higher than in Great Britain. Reduction to the level in Great Britain would have reduced the number killed in traffic accidents in Denmark in 2002 from 465 to 289. The data used are from StatBank Denmark, the Danish Road Directorate and the Danish Transport Research Institute. The number of traffic deaths per billion kilometers driven was 57% higher in 1994 than in 2001. Those aged 65 and over had the largest decrease, with 67% fewer traffic deaths. Per billion kilometers driven, rural roads had around twice the number of traffic deaths as city streets and motorways. The geographic distribution showed few traffic deaths in the capital, Copenhagen, while the rest of the country had up to twice the number per 100,000 inhabitants from 1997 to 2002. Car drivers were well protected by seat belts, while people who were walking or on a motorcycle had high casualty rates per billion kilometers driven. 29% of the traffic deaths in Denmark in 2002 were registered as alcohol-related, while only 1% of drivers overall were influenced by alcohol. Men had twice the risk of traffic death compared with women per kilometer driven. Men were convicted in 93% of cases involving illegal blood alcohol level and 84% of cases involving other traffic offences. The greatest potential for reduction of traffic deaths seems to be traffic behaviour; females' behaviour, with rare drunk driving and few convictions for traffic offences, seems rational. If all drivers adhered to women's traffic behaviour, the number of road deaths in 1999 could have been reduced by 169, equivalent to 30%.

  15. A successful traffic relief program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dimino, R.A.; Bezkorovainy, G.; Campbell, B.

    This article reports that in August 1986, under the direction of Mayor Raymond Flynn, the City of Boston initiated Phase I of a Traffic Relief Program (TRP). The program was an interagency effort of the Boston Transportation Department and the Boston Police Department, to provide increased enforcement of the city's traffic and parking regulations on congested roadways in downtown Boston. The TRP is a reaffirmation of the city's philosophy that major arterials' primary function is the movement of traffic during periods of heavy traffic flow. There were six objectives: to reduce vehicular travel time along travel corridors; to increase street/intersectionmore » capacity; to eliminate vehicular blockage at intersections; to eliminate double parking; to eliminate pedestrian/vehicular conflicts at intersections and thus reduce the potential number of accidents; and to provide clear regulatory and street name signage.« less

  16. A new algorithm for DNS of turbulent polymer solutions using the FENE-P model

    NASA Astrophysics Data System (ADS)

    Vaithianathan, T.; Collins, Lance; Robert, Ashish; Brasseur, James

    2004-11-01

    Direct numerical simulations (DNS) of polymer solutions based on the finite extensible nonlinear elastic model with the Peterlin closure (FENE-P) solve for a conformation tensor with properties that must be maintained by the numerical algorithm. In particular, the eigenvalues of the tensor are all positive (to maintain positive definiteness) and the sum is bounded by the maximum extension length. Loss of either of these properties will give rise to unphysical instabilities. In earlier work, Vaithianathan & Collins (2003) devised an algorithm based on an eigendecomposition that allows you to update the eigenvalues of the conformation tensor directly, making it easier to maintain the necessary conditions for a stable calculation. However, simple fixes (such as ceilings and floors) yield results that violate overall conservation. The present finite-difference algorithm is inherently designed to satisfy all of the bounds on the eigenvalues, and thus restores overall conservation. New results suggest that the earlier algorithm may have exaggerated the energy exchange at high wavenumbers. In particular, feedback of the polymer elastic energy to the isotropic turbulence is now greatly reduced.

  17. FAA Air Traffic Control Operations Concepts. Volume 7. ATCT (Airport Traffic Control Towers) Tower Controllers

    DTIC Science & Technology

    1989-04-21

    kift rIn FAA AIR TRAFFIC CONTROL OPERATIONS CONCEPTS V olum e V iI:.................... ATCT Tower Controllers AmELECTE JUL 2 11989 21 April 1989 A...01 022.3013209-87-B 11 a FAA AIR TRAFFIC CONTROL OPERATIONS CONCEPTS VOLUME VII: ATCT TOWER CONTROLLERS CDRL Bl 12, VOL. VII CONTRACT DTF-AO1-85-Y...INCORPORATED 7150 Campus Drive, Suite 100 Colorado Springs, CO 80920 (719) 590-5100 DOT/FAA/AP-87-0i (VOL#7) 21 April 1989 FAA AIR TRAFFIC CONTROL OPERATIONS

  18. 14 CFR Section 25 - Traffic and Capacity Elements

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Traffic and Capacity Elements Section 25... Traffic Reporting Requirements Section 25 Traffic and Capacity Elements General Instructions. (a) All prescribed reporting for traffic and capacity elements shall conform with the data compilation standards set...

  19. 14 CFR Section 25 - Traffic and Capacity Elements

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Traffic and Capacity Elements Section 25... Traffic Reporting Requirements Section 25 Traffic and Capacity Elements General Instructions. (a) All prescribed reporting for traffic and capacity elements shall conform with the data compilation standards set...

  20. Traffic placement policies for a multi-band network

    NASA Technical Reports Server (NTRS)

    Maly, Kurt J.; Foudriat, E. C.; Game, David; Mukkamala, R.; Overstreet, C. Michael

    1990-01-01

    Recently protocols were introduced that enable the integration of synchronous traffic (voice or video) and asynchronous traffic (data) and extend the size of local area networks without loss in speed or capacity. One of these is DRAMA, a multiband protocol based on broadband technology. It provides dynamic allocation of bandwidth among clusters of nodes in the total network. A number of traffic placement policies for such networks are proposed and evaluated. Metrics used for performance evaluation include average network access delay, degree of fairness of access among the nodes, and network throughput. The feasibility of the DRAMA protocol is established through simulation studies. DRAMA provides effective integration of synchronous and asychronous traffic due to its ability to separate traffic types. Under the suggested traffic placement policies, the DRAMA protocol is shown to handle diverse loads, mixes of traffic types, and numbers of nodes, as well as modifications to the network structure and momentary traffic overloads.

  1. Assessment of PDF Micromixing Models Using DNS Data for a Two-Step Reaction

    NASA Astrophysics Data System (ADS)

    Tsai, Kuochen; Chakrabarti, Mitali; Fox, Rodney O.; Hill, James C.

    1996-11-01

    Although the probability density function (PDF) method is known to treat the chemical reaction terms exactly, its application to turbulent reacting flows have been overshadowed by the ability to model the molecular mixing terms satisfactorily. In this study, two PDF molecular mixing models, the linear-mean-square-estimation (LMSE or IEM) model and the generalized interaction-by-exchange-with-the-mean (GIEM) model, are compared with the DNS data in decaying turbulence with a two-step parallel-consecutive reaction and two segregated initial conditions: ``slabs" and ``blobs". Since the molecular mixing model is expected to have a strong effect on the mean values of chemical species under such initial conditions, the model evaluation is intended to answer the following questions: Can the PDF models predict the mean values of chemical species correctly with completely segregated initial conditions? (2) Is a single molecular mixing timescale sufficient for the PDF models to predict the mean values with different initial conditions? (3) Will the chemical reactions change the molecular mixing timescales of the reacting species enough to affect the accuracy of the model's prediction for the mean values of chemical species?

  2. DNS study of speed of sound in two-phase flows with phase change

    NASA Astrophysics Data System (ADS)

    Fu, Kai; Deng, Xiaolong

    2017-11-01

    Heat transfer through pipe flow is important for the safety of thermal power plants. Normally it is considered incompressible. However, in some conditions compressibility effects could deteriorate the heat transfer efficiency and even result in pipe rupture, especially when there is obvious phase change, due to the much lower sound speed in liquid-gas mixture flows. Based on the stratified multiphase flow model (Chang and Liou, JCP 2007), we present a new approach to simulate the sound speed in 3-D compressible two-phase dispersed flows, in which each face is divided into gas-gas, gas-liquid, and liquid-liquid parts via reconstruction by volume fraction, and fluxes are calculated correspondingly. Applying it to well-distributed air-water bubbly flows, comparing with the experiment measurements in air water mixture (Karplus, JASA 1957), the effects of adiabaticity, viscosity, and isothermality are examined. Under viscous and isothermal condition, the simulation results match the experimental ones very well, showing the DNS study with current method is an effective way for the sound speed of complex two-phase dispersed flows. Including the two-phase Riemann solver with phase change (Fechter et al., JCP 2017), more complex problems can be numerically studied.

  3. 2009 Oregon traffic crash summary

    DOT National Transportation Integrated Search

    2010-09-01

    The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

  4. 2008 Oregon traffic crash summary

    DOT National Transportation Integrated Search

    2009-09-01

    The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

  5. 2010 Oregon traffic crash summary

    DOT National Transportation Integrated Search

    2011-08-01

    The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

  6. Wyoming Low-Volume Roads Traffic Volume Estimation

    DOT National Transportation Integrated Search

    2015-10-01

    Low-volume roads are excluded from regular traffic counts except on a need to know basis. But needs for traffic volume data on low-volume roads in road infrastructure management, safety, and air quality analysis have necessitated regular traffic volu...

  7. LED traffic signal lamp characteristics : executive summary.

    DOT National Transportation Integrated Search

    2002-05-01

    LED traffic signal lamps are being used to replace incandescent traffic signal lamps because of the long-term cost saving associated with reduced energy consumption and longer service life. The are reasons to believe that the use of LED traffic signa...

  8. LED traffic signal lamp characteristics : final report.

    DOT National Transportation Integrated Search

    2002-05-01

    LED traffic signal lamps are being used to replace incandescent traffic signal lamps because of : the long-term cost saving associated with reduced energy consumption and longer service life. The are reasons to believe that the use of LED traffic sig...

  9. Indicators of residential traffic exposure: Modelled NOX, traffic proximity, and self-reported exposure in RHINE III

    NASA Astrophysics Data System (ADS)

    Carlsen, Hanne Krage; Bäck, Erik; Eneroth, Kristina; Gislason, Thorarinn; Holm, Mathias; Janson, Christer; Jensen, Steen Solvang; Johannessen, Ane; Kaasik, Marko; Modig, Lars; Segersson, David; Sigsgaard, Torben; Forsberg, Bertil; Olsson, David; Orru, Hans

    2017-10-01

    Few studies have investigated associations between self-reported and modelled exposure to traffic pollution. The objective of this study was to examine correlations between self-reported traffic exposure and modelled (a) NOX and (b) traffic proximity in seven different northern European cities; Aarhus (Denmark), Bergen (Norway), Gothenburg, Umeå, and Uppsala (Sweden), Reykjavik (Iceland), and Tartu (Estonia). We analysed data from the RHINE III (Respiratory Health in Northern Europe, http://www.rhine.nu)

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

    PubMed

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

    2014-04-01

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

  11. 32 CFR 636.13 - Traffic accident investigation reports.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Traffic accident investigation reports. 636.13... Stewart, Georgia § 636.13 Traffic accident investigation reports. In addition to the requirements in § 634... record traffic accident investigations on DA Form 3946 (Military Police Traffic Accident Report) and DA...

  12. 2005 Wisconsin traffic crash facts

    DOT National Transportation Integrated Search

    2006-11-01

    2005 Facts and Figures : 801 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of : over two lives lost each day on Wisconsin traffic arteries. : 53,462 persons were injured in 37,515 reported injury crashes a...

  13. 2006 Wisconsin traffic crash facts

    DOT National Transportation Integrated Search

    2008-01-01

    2006 Facts and Figures : 712 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of : more than two lives lost each day on Wisconsin traffic arteries. : 50,236 persons were injured in 35,296 reported injury cras...

  14. Traffic Management for Satellite-ATM Networks

    NASA Technical Reports Server (NTRS)

    Goyal, Rohit; Jain, Raj; Fahmy, Sonia; Vandalore, Bobby; Goyal, Mukul

    1998-01-01

    Various issues associated with "Traffic Management for Satellite-ATM Networks" are presented in viewgraph form. Specific topics include: 1) Traffic management issues for TCP/IP based data services over satellite-ATM networks; 2) Design issues for TCP/IP over ATM; 3) Optimization of the performance of TCP/IP over ATM for long delay networks; and 4) Evaluation of ATM service categories for TCP/IP traffic.

  15. Traffic Flow Theory - A State-of-the-Art Report: Revised Monograph on Traffic Flow Theory

    DOT National Transportation Integrated Search

    2002-04-13

    This publication is an update and expansion of the Transportation Research Board (TRB) Special Report 165, "Traffic Flow Theory," published in 1975. This updating was undertaken on recommendation of the TRB's Committee on Traffic Flow Theory and Char...

  16. 36 CFR § 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... with the normal flow of traffic. ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Obstructing traffic. § 1004.13 Section § 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY...

  17. 47 CFR 80.325 - Control of distress traffic.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  18. Evaluation of LADOTD traffic load data for determination of traffic load equivalency factors : technical summary.

    DOT National Transportation Integrated Search

    2002-04-01

    Louisianan has established a traffic monitoring program, compliant with FHWA incentives, that is designed to collect and manage the traffic data needed for the design and management of LADOTD's network of current and future highways. In the early 198...

  19. CATS-based Air Traffic Controller Agents

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.

    2002-01-01

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

  20. Environmental pollution of lead in traffic air and blood of traffic policemen in Khartoum State, Sudan.

    PubMed

    Rahama, Salah M; Khider, Hiba E; Mohamed, Sitt Nour H; Abuelmaali, Sara A; Elaagip, Arwa H

    2010-12-01

    A cross sectional study was conducted in Khartoum State. A total of 45 males' traffic policemen were divided into two groups according to exposure to car exhaust; n = 30 taken as exposed group, n = 15 taken as controls, who were not exposed to car exhaust. The study was conducted to determine lead concentrations in traffic ambient air, to determine lead levels in blood of traffic policemen, and to evaluate the effect of exposure to car exhaust on traffic policemen during January 2009. The level of lead in ambient air was determined in 14 locations which were taken randomly at the intersections and entrances to the bridges using personal sampler "Cassella, U.K". The blood samples of all policemen were analyzed by atomic absorption Spectrophotometer to determine lead levels. A questionnaire was designed to assess the adverse health effects on the traffic policemen. The degree of environmental lead pollution in traffic ambient air was found to be 0.1937 +/- 0.1768 mg/m3 with range between 0.000-0.5166 mg/m3. In seven locations out of fourteen locations lead concentrations were 0.1940 and 0.5166 above the permissible level of 0.15 mg/m3 permitted internationally. Blood lead levels on traffic policemen (exposed and control groups) were found to be 2.4691 +/- 1.4065 microg/100 ml and 0.3944 +/- 1.2471 microg/100 ml respectively and there is no significant differences between the two groups where using SPSS program. A questionnaire findings were: average age mean of 35.9 +/- 7.7 years, 47.48% worked for periods of more than 20 years, 74.19% did not work before joining the traffic police, 51.6% of them recognized traffic air pollution as a problem of high level, 45.2% of them estimated it as medium, and 3.2% as low. As habits 38.71% were smokers, and for health complaints, 61.29% have various complaints of headache, fatigue, abdominal, hypertension and anemia. All these symptoms have a close relationship with lead poisoning. When we compared the results of age groups and

  1. Environmental pollution of lead in traffic air and blood of traffic policemen in Khartoum State, Sudan.

    PubMed

    Rahama, Salah M; Khider, Hiba E; Mohamed, Sitt Nour H; Abuelmaali, Sara A; Elaagip, Arwa H

    2011-06-01

    A cross sectional study was conducted in Khartoum State. A total of 45 males' traffic policemen were divided into two groups according to exposure to car exhaust; n=30 taken as exposed group, n=15 taken as controls, who were not exposed to car exhaust. The study was conducted to determine lead concentrations in traffic ambient air, to determine lead levels in blood of traffic policemen, and to evaluate the effect of exposure to car exhaust on traffic policemen during January 2009. The level of lead in ambient air was determined in 14 locations which were taken randomly at the intersections and entrances to the bridges using personal sampler "Cassella, U.K". The blood samples of all policemen were analyzed by atomic absorption Spectrophotometer to determine lead levels. A questionnaire was designed to assess the adverse health effects on the traffic policemen. The degree of environmental lead pollution in traffic ambient air was found to be 0.1937 +/- 0.1768 mg/m3 with range between 0.000-0.5166 mg/m3. In seven locations out of fourteen locations lead concentrations were 0.1940 and 0.5166 above the permissible level of 0.15 mg/m3 permitted internationally. Blood lead levels on traffic policemen (exposed and control groups) were found to be 2.4691 +/- 1.4065 microg/100 ml and 0.3944 +/- 1.2471 microg/100 ml respectively and there is no significant differences between the two groups where using SPSS program. A questionnaire findings were: average age mean of 35.9 +/- 7.7 years, 47.48% worked for periods of more than 20 years, 74.19% did not work before joining the traffic police, 51.6% of them recognized traffic air pollution as a problem of high level, 45.2% of them estimated it as medium, and 3.2% as low. As habits 38.71% were smokers, and for health complaints, 61.29% have various complaints of headache, fatigue, abdominal, hypertension and anemia. All these symptoms have a close relationship with lead poisoning. When we compared the results of age groups and work

  2. Minimal Traffic Model with Safe Driving Conditions

    NASA Astrophysics Data System (ADS)

    Terborg, Heinrich; Pérez, Luis A.

    We have developed a new computational traffic model in which security aspects are fundamental. In this paper we show that this model reproduces many known empirical aspects of vehicular traffic such as the three states of traffic flow and the backward speed of the downstream front of a traffic jam (C), without the aid of adjustable parameters. The model is studied for both open and closed single lane traffic systems. Also, we were able to analytically compute the value of C as 15.37 km/h from a relation that only includes the human reaction time, the mean vehicle length and the effective friction coefficient during the braking process of a vehicle as its main components.

  3. Traffic Line Manual; September,1996

    DOT National Transportation Integrated Search

    1996-09-01

    The purpose of this manual is to establish a guide for uniformity of traffic line and pavement markings throughout the state highway system. The manual is intended to be used by highway maintenance traffic line crews to assist them in their daily wor...

  4. Traffic safety facts 1998 : alcohol

    DOT National Transportation Integrated Search

    1999-01-01

    The National Highway Traffic Safety Administration (NHTSA) defines a fatal traffic crash as being alcohol-related if either a driver or a nonoccupant (e.g., pedestrian) had a blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or gre...

  5. Traffic safety facts 1995 : alcohol

    DOT National Transportation Integrated Search

    1995-01-01

    The National Highway Traffic Safety Administration (NHTSA) defines a fatal traffic crash as being alcohol-related if either a driver or a nonoccupant (e.g., pedestrian) had a blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or gre...

  6. Traffic safety facts 1993 : alcohol

    DOT National Transportation Integrated Search

    1994-01-01

    The National Highway Traffic Safety Administration (NHTSA) defines a fatal traffic crash as being alcohol-related if either a driver or a nonoccupant (e.g., pedestrian) had a blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or gre...

  7. Traffic safety facts 2000 : alcohol

    DOT National Transportation Integrated Search

    2001-01-01

    The National Highway Traffic Safety Administration (NHTSA) defines a fatal traffic crash as being alcohol-related if either a driver or a nonoccupant (e.g., pedestrian) had a blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or gre...

  8. Traffic safety facts 1994 : alcohol

    DOT National Transportation Integrated Search

    1994-01-01

    The National Highway Traffic Safety Administration (NHTSA) defines a fatal traffic crash as being alcohol-related if either a driver or a nonoccupant (e.g., pedestrian) had a blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or gre...

  9. Traffic safety facts 1999 : alcohol

    DOT National Transportation Integrated Search

    2000-01-01

    The National Highway Traffic Safety Administration (NHTSA) defines a fatal traffic crash as being alcohol-related if either a driver or a nonoccupant (e.g., pedestrian) had a blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or gre...

  10. 2007 Wisconsin traffic crash facts

    DOT National Transportation Integrated Search

    2008-12-01

    2007 Facts and Figures - 737 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of just over two lives lost each day on Wisconsin traffic arteries. - 50,676 persons were injured in 36,048 reported injury crashes and 65...

  11. Design and Operational Evaluation of the Traffic Management Advisor at the Ft. Worth Air Route Traffic Control Center

    NASA Technical Reports Server (NTRS)

    Swenson, Harry N.; Vincent, Danny; Tobias, Leonard (Technical Monitor)

    1997-01-01

    NASA and the FAA have designed and developed and an automation tool known as the Traffic Management Advisor (TMA). The system was operationally evaluated at the Ft. Worth Air Route Traffic Control Center (ARTCC). The TMA is a time-based strategic planning tool that provides Traffic Management Coordinators and En Route Air Traffic Controllers the ability to efficiently optimize the capacity of a demand impacted airport. The TMA consists of trajectory prediction, constraint-based runway scheduling, traffic flow visualization and controllers advisories. The TMA was used and operationally evaluated for forty-one rush traffic periods during a one month period in the Summer of 1996. The evaluations included all shifts of air traffic operations as well as periods of inclement weather. Performance data was collected for engineering and human factor analysis and compared with similar operations without the TMA. The engineering data indicates that the operations with the TMA show a one to two minute per aircraft delay reduction during rush periods. The human factor data indicate a perceived reduction in en route controller workload as well as an increase in job satisfaction. Upon completion of the evaluation, the TMA has become part of the normal operations at the Ft. Worth ARTCC.

  12. Observations of highway traffic noise measurements behind barriers and comparisons to FHWA's Traffic Noise Model

    DOT National Transportation Integrated Search

    2001-08-20

    In 1998, the United States Federal Highway Administration (FHWA) released a new tool for highway traffic noise prediction and noise barrier design, the Traffic Noise Model (TNM). In order to assess the accuracy and make recommendations on the use of ...

  13. Visual traffic jam analysis based on trajectory data.

    PubMed

    Wang, Zuchao; Lu, Min; Yuan, Xiaoru; Zhang, Junping; van de Wetering, Huub

    2013-12-01

    In this work, we present an interactive system for visual analysis of urban traffic congestion based on GPS trajectories. For these trajectories we develop strategies to extract and derive traffic jam information. After cleaning the trajectories, they are matched to a road network. Subsequently, traffic speed on each road segment is computed and traffic jam events are automatically detected. Spatially and temporally related events are concatenated in, so-called, traffic jam propagation graphs. These graphs form a high-level description of a traffic jam and its propagation in time and space. Our system provides multiple views for visually exploring and analyzing the traffic condition of a large city as a whole, on the level of propagation graphs, and on road segment level. Case studies with 24 days of taxi GPS trajectories collected in Beijing demonstrate the effectiveness of our system.

  14. Intelligent driving in traffic systems with partial lane discipline

    NASA Astrophysics Data System (ADS)

    Assadi, Hamid; Emmerich, Heike

    2013-04-01

    It is a most common notion in traffic theory that driving in lanes and keeping lane changes to a minimum leads to smooth and laminar traffic flow, and hence to increased traffic capacity. On the other hand, there exist persistent vehicular traffic systems that are characterised by habitual disregarding of lane markings, and partial or complete loss of laminar traffic flow. Here, we explore the stability of such systems through a microscopic traffic flow model, where the degree of lane-discipline is taken as a variable, represented by the fraction of drivers that disregard lane markings completely. The results show that lane-free traffic may win over completely ordered traffic at high densities, and that partially ordered traffic leads to the poorest overall flow, while not considering the crash probability. Partial order in a lane-free system is similar to partial disorder in a lane-disciplined system in that both lead to decreased traffic capacity. This could explain the reason why standard enforcement methods, which rely on continuous increase of order, often fail to incur order to lane-free traffic systems. The results also provide an insight into the cooperative phenomena in open systems with self-driven particles.

  15. Study of air traffic over KLFIR

    NASA Astrophysics Data System (ADS)

    Nusyirwan, I. F.; Rohani, J. Mohd

    2017-12-01

    This paper shares the overview of the work currently being conducted with the Department of Civil Aviation Malaysia related to the air traffic. The aim is to study air traffic performance over KL and KK FIR, and the area of interest in this paper is the Kuala Lumpur Flight Information Region (KLFIR). The air traffic performance parameters includes general air traffic movement such as level allocation, number of movements, sector load analysis and also more specific parameters such as airborne delays, effects of weather to the air movements as well as ground delays. To achieve this, a huge effort has been undertaken that includes live data collection algorithm development and real time statistical analysis algorithm development. The main outcome from this multi-disciplinary work is the long-term analysis on the air traffic performance in Malaysia, which will put the country at par in the aviation community, namely the International Civil Aviation Organization (ICAO).

  16. Modeling Traffic on the Web Graph

    NASA Astrophysics Data System (ADS)

    Meiss, Mark R.; Gonçalves, Bruno; Ramasco, José J.; Flammini, Alessandro; Menczer, Filippo

    Analysis of aggregate and individual Web requests shows that PageRank is a poor predictor of traffic. We use empirical data to characterize properties of Web traffic not reproduced by Markovian models, including both aggregate statistics such as page and link traffic, and individual statistics such as entropy and session size. As no current model reconciles all of these observations, we present an agent-based model that explains them through realistic browsing behaviors: (1) revisiting bookmarked pages; (2) backtracking; and (3) seeking out novel pages of topical interest. The resulting model can reproduce the behaviors we observe in empirical data, especially heterogeneous session lengths, reconciling the narrowly focused browsing patterns of individual users with the extreme variance in aggregate traffic measurements. We can thereby identify a few salient features that are necessary and sufficient to interpret Web traffic data. Beyond the descriptive and explanatory power of our model, these results may lead to improvements in Web applications such as search and crawling.

  17. Traffic evacuation time under nonhomogeneous conditions.

    PubMed

    Fazio, Joseph; Shetkar, Rohan; Mathew, Tom V

    2017-06-01

    During many manmade and natural crises such as terrorist threats, floods, hazardous chemical and gas leaks, emergency personnel need to estimate the time in which people can evacuate from the affected urban area. Knowing an estimated evacuation time for a given crisis, emergency personnel can plan and prepare accordingly with the understanding that the actual evacuation time will take longer. Given the urban area to be evacuated, street widths exiting the area's perimeter, the area's population density, average vehicle occupancy, transport mode share and crawl speed, an estimation of traffic evacuation time can be derived. Peak-hour traffic data collected at three, midblock, Mumbai sites of varying geometric features and traffic composition were used in calibrating a model that estimates peak-hour traffic flow rates. Model validation revealed a correlation coefficient of +0.98 between observed and predicted peak-hour flow rates. A methodology is developed that estimates traffic evacuation time using the model.

  18. Road traffic noise and children's inattention.

    PubMed

    Weyde, Kjell Vegard; Krog, Norun Hjertager; Oftedal, Bente; Magnus, Per; Øverland, Simon; Stansfeld, Stephen; Nieuwenhuijsen, Mark J; Vrijheid, Martine; de Castro Pascual, Montserrat; Aasvang, Gunn Marit

    2017-11-21

    An increasing number of children are exposed to road traffic noise levels that may lead to adverse effects on health and daily functioning. Childhood is a period of intense growth and brain maturation, and children may therefore be especially vulnerable to road traffic noise. The objective of the present study was to examine whether road traffic noise was associated with reported inattention symptoms in children, and whether this association was mediated by sleep duration. This study was based on the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health. Parental reports of children's inattention at age 8 were linked to modelled levels of residential road traffic noise. We investigated the association between inattention and noise exposure during pregnancy (n = 1934), noise exposure averaged over 5 years (age 3 to 8 years; n = 1384) and noise exposure at age 8 years (n = 1384), using fractional logit response models. The participants were children from Oslo, Norway. An association with inattention at age 8 years was found for road traffic noise exposure at age 8 years (coef = .0083, CI = [.0012, .0154]; 1.2% point increase in inattention score per 10 dB increase in noise level), road traffic noise exposure average for the last 5 years (coef = .0090, CI = [.0016, .0164]; 1.3% point increase/10 dB), and for pregnancy road traffic noise exposure for boys (coef = .0091, CI = [.0010, .0171]), but not girls (coef = -.0021, CI = [-.0094, .0053]). Criteria for doing mediation analyses were not fulfilled. Results indicate that road traffic noise has a negative impact on children's inattention. We found no mediation by sleep duration.

  19. Sensor Location Problem Optimization for Traffic Network with Different Spatial Distributions of Traffic Information.

    PubMed

    Bao, Xu; Li, Haijian; Qin, Lingqiao; Xu, Dongwei; Ran, Bin; Rong, Jian

    2016-10-27

    To obtain adequate traffic information, the density of traffic sensors should be sufficiently high to cover the entire transportation network. However, deploying sensors densely over the entire network may not be realistic for practical applications due to the budgetary constraints of traffic management agencies. This paper describes several possible spatial distributions of traffic information credibility and proposes corresponding different sensor information credibility functions to describe these spatial distribution properties. A maximum benefit model and its simplified model are proposed to solve the traffic sensor location problem. The relationships between the benefit and the number of sensors are formulated with different sensor information credibility functions. Next, expanding models and algorithms in analytic results are performed. For each case, the maximum benefit, the optimal number and spacing of sensors are obtained and the analytic formulations of the optimal sensor locations are derived as well. Finally, a numerical example is proposed to verify the validity and availability of the proposed models for solving a network sensor location problem. The results show that the optimal number of sensors of segments with different model parameters in an entire freeway network can be calculated. Besides, it can also be concluded that the optimal sensor spacing is independent of end restrictions but dependent on the values of model parameters that represent the physical conditions of sensors and roads.

  20. Sensor Location Problem Optimization for Traffic Network with Different Spatial Distributions of Traffic Information

    PubMed Central

    Bao, Xu; Li, Haijian; Qin, Lingqiao; Xu, Dongwei; Ran, Bin; Rong, Jian

    2016-01-01

    To obtain adequate traffic information, the density of traffic sensors should be sufficiently high to cover the entire transportation network. However, deploying sensors densely over the entire network may not be realistic for practical applications due to the budgetary constraints of traffic management agencies. This paper describes several possible spatial distributions of traffic information credibility and proposes corresponding different sensor information credibility functions to describe these spatial distribution properties. A maximum benefit model and its simplified model are proposed to solve the traffic sensor location problem. The relationships between the benefit and the number of sensors are formulated with different sensor information credibility functions. Next, expanding models and algorithms in analytic results are performed. For each case, the maximum benefit, the optimal number and spacing of sensors are obtained and the analytic formulations of the optimal sensor locations are derived as well. Finally, a numerical example is proposed to verify the validity and availability of the proposed models for solving a network sensor location problem. The results show that the optimal number of sensors of segments with different model parameters in an entire freeway network can be calculated. Besides, it can also be concluded that the optimal sensor spacing is independent of end restrictions but dependent on the values of model parameters that represent the physical conditions of sensors and roads. PMID:27801794

  1. 32 CFR 636.12 - Traffic accident investigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Traffic accident investigation. 636.12 Section... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.12 Traffic accident investigation. In addition to the requirements in § 634.28 of...

  2. Android-based E-Traffic law enforcement system in Surakarta City

    NASA Astrophysics Data System (ADS)

    Yulianto, Budi; Setiono

    2018-03-01

    The urban advancement is always overpowered by the increasing number of vehicles as the need for movement of people and goods. This can lead to traffic problems if there is no effort on the implementation of traffic management and engineering, and traffic law enforcement. In this case, the Government of Surakarta City has implemented various policies and regulations related to traffic management and engineering in order to run traffic in an orderly, safe and comfortable manner according to the applicable law. However, conditions in the field shows that traffic violations still occurred frequently due to the weakness of traffic law enforcement in terms of human resources and the system. In this connection, a tool is needed to support traffic law enforcement, especially in relation to the reporting system of traffic violations. This study aims to develop an Android-based traffic violations reporting application (E-Traffic Law Enforcement) as part of the traffic law enforcement system in Surakarta City. The Android-apps records the location and time of the traffic violations incident along with the visual evidence of the infringement. This information will be connected to the database system to detect offenders and to do the traffic law enforcement process.

  3. Traffic Safety for Special Children

    ERIC Educational Resources Information Center

    Wilson, Val; MacKenzie, R. A.

    1974-01-01

    In a 6 weeks' unit on traffic education using flannel graphs, filmstrips and models, 12 special class students (IQ 55-82) ages 7- to 11-years-old learned six basic skills including crossing a road, obeying traffic lights and walking on country roads. (CL)

  4. Traffic safety facts 1998 : pedestrians

    DOT National Transportation Integrated Search

    1999-01-01

    In 1998, 5,220 pedestrians were killed in traffic crashes in the United States - a decrease of 24 percent from the 6,870 pedestrians killed in 1988. On average, a pedestrian is killed in a traffic crash every 101 minutes. There were 69,000 pedestrian...

  5. Traffic safety facts 1999 : pedestrians

    DOT National Transportation Integrated Search

    2000-01-01

    In 1999, 4,906 pedestrians were killed in traffic crashes in the United States - a decrease of 25 percent from the 6,556 pedestrians killed in 1989. On average, a pedestrian is killed in a traffic crash every 107 minutes. There were 85,000 pedestrian...

  6. Traffic safety facts 1994 : pedestrians

    DOT National Transportation Integrated Search

    1995-01-01

    In 1994, 5,472 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1984-1994; and Figure 2, pedestrian fatalities by time of day and day of week, 1994. Of the tables, Tabl...

  7. Traffic safety facts 2000 : pedestrians

    DOT National Transportation Integrated Search

    2001-01-01

    In 2000, 4,739 pedestrians were killed in traffic crashes in the United States - a decrease of 27 percent from the 6,482 pedestrians killed in 1990. On average, a pedestrian is killed in a traffic crash every 111 minutes. There were 78,000 pedestrian...

  8. Traffic safety facts 1995 : pedestrians

    DOT National Transportation Integrated Search

    1996-01-01

    In 1995, 5,585 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1985-1995; and Figure 2, pedestrian fatalities by time of day and day of week, 1995. Of the tables, Tabl...

  9. Traffic safety facts 1996 : pedestrians

    DOT National Transportation Integrated Search

    1997-01-01

    In 1996, 5,412 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1986-1996; and Figure 2, pedestrian fatalities by time of day and day of week, 1996. Of the tables, Tabl...

  10. Traffic safety facts 1993 : pedestrians

    DOT National Transportation Integrated Search

    1994-01-01

    In 1993, 5,638 pedestrians were killed in traffic crashes in the United States. Figure 1 shows trends in pedestrian and total traffic fatalities, 1983-1993; and Figure 2, pedestrian fatalities by time of day and day of week, 1993. Of the tables, Tabl...

  11. 2009 Wisconsin traffic crash facts

    DOT National Transportation Integrated Search

    2010-10-01

    2009 Facts and Figures: 542 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of just over one life lost each day on Wisconsin traffic arteries. 41,589 persons were injured in 29,907 reported injury crashes and 488 fa...

  12. 2010 Wisconsin traffic crash facts

    DOT National Transportation Integrated Search

    2011-01-01

    562 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of just over one life lost each day on Wisconsin traffic arteries. : 40,889 persons were injured in 29,380 reported injury crashes and 517 fatal crashes. 3,845, or...

  13. Traffic safety facts 1998 : pedestrian

    DOT National Transportation Integrated Search

    1998-01-01

    In 1998, 5,220 pedestrians were killed in traffic crashes in the United States - a decrease of 24% from the 6,870 pedestrians killed in 1988. On average, a pedestrian is killed in a traffic crash every 101 minutes. There were 69,000 pedestrians injur...

  14. 2008 Wisconsin traffic crash facts

    DOT National Transportation Integrated Search

    2009-01-01

    2008 Facts and Figures 587 persons were killed in Wisconsin motor vehicle traffic crashes. This is an average of just over one life lost each day on Wisconsin traffic arteries. 46,637 persons were injured in 33,766 reported injury crashes and 542 fat...

  15. Traffic crash statistics report, 2007

    DOT National Transportation Integrated Search

    2008-01-01

    Fatalities as a result of traffic crashes on Florida roadways decreased to 3,221 in 2007 from 3,365 in 2006. For the second consecutive year in more than 10 years, traffic fatalities have decreased from the previous year; State mileage Death rate dec...

  16. Endoscopic and computed tomographic evaluation of influence of nasal septal deviation on lateral wall of nose and its relation to sinus diseases.

    PubMed

    Poorey, V K; Gupta, Neha

    2014-09-01

    To correlate symptoms of deviated nasal septum (DNS) and chronic rhinosinusitis with the findings of nasal endoscopy and computed tomographic (CT) imaging. To evaluate the influence of degree of septal angle deviation on the severity of lateral nasal wall abnormalities. A prospective study was conducted on 67 patients with clinical evidence of DNS and chronic sinusitis attending ENT OPD between January 2012 and September 2013. All these patients underwent nasal endoscopy and CT scan PNS coronal sections. Direction and degree of DNS was recorded. Range of sinus mucosal thickening on CT scan films was also recorded. Chronic sinusitis is common in the age group between 21 and 40 years (50.74 %) with male preponderance (55.22 %), chief symptoms being nasal obstruction (86.56 %), headache (73.13 %) and nasal discharge (52.23 %). Left sided DNS is more common (64.17 %). Most of the patients have moderate DNS, i.e. 6°-10° (56.7 %), followed by severe (22.4 %) and then mild (20.9 %). DNS results in compensatory structural changes in the turbinates and/or lateral nasal wall which causes ostiomeatal complex (OMC) obstruction resulting in sinusitis. Contralateral concha bullosa and ethmoid bulla prominence was noted. Maxillary sinus is most commonly affected sinus (73.13 %). Patients with increasing septal angles were associated with a higher incidence of maxillary sinus mucosal changes (p < 0.05). Present study reemphasized the concept that septal deviation causes obstruction at OMC which results in an increased incidence and severity of bilateral chronic sinus disease.

  17. PERFORMANCE OF TWO DIFFERENT CLINICAL SCORING SYSTEMS IN DIAGNOSING DISTAL SENSORY POLYNEUROPATHY IN PATIENTS WITH TYPE-2 DIABETES.

    PubMed

    Khan, Fehmeda Farrukh; Numan, Ahsan; Khawaja, Khadija Irfan; Atif, Ali; Fatima, Aziz; Masud, Faisal

    2015-01-01

    Early diagnosis of distal peripheral neuropathy (DSPN) the commonest diabetes complications, helps prevent significant morbidity. Clinical parameters are useful for detection, but subjectivity and lack of operator proficiency often results in inaccuracies. Comparative diagnostic accuracy of Diabetic Neuropathy Symptom (DNS) score and Diabetic Neuropathy Examination (DNE) score in detecting DSPN confirmed by nerve conduction studies (NCS) has not been evaluated. This study compares the performance of these scores in predicting the presence of electro physiologically proven DSPN. The objective of this, study was to compare the diagnostic accuracy of DNS and DNE scores in detecting NCS proven DSPN in type-2 diabetics, and to determine the frequency of sub-clinical DSPN among type-2 diabetics. In this cross-sectional study the DNS score and DNE score were determined in 110 diagnosed type-2 diabetic patients. NCS were carried out and amplitudes, velocities and latencies of sensory and motor nerves in lower limb were recorded. Comparison between the two clinical diagnostic modalities and NCS using Pearson's chi square test showed a significant association between NCS and DNE scores (p-value =.003, specificity 93%). The DNS score performed poorly in comparison (p-value = .068, specificity 77%). When the two scores were taken in combination the specificity in diagnosing DSPN was greater (p-value = .018, specificity 96%) than either alone. 33% of patients had subclinical neuropathy. DNE score alone and in combination with DNS score is reliable in predicting DSPN and is more specific than DNS score in evaluating DSPN. Both tests lack sensitivity. Patients without any evidence of clinical neuropathy manifest abnormalities on NCS.

  18. Use of an Accurate DNS Particulate Flow Method to Supply and Validate Boundary Conditions for the MFIX Code

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhi-Gang Feng

    2012-05-31

    The simulation of particulate flows for industrial applications often requires the use of two-fluid models, where the solid particles are considered as a separate continuous phase. One of the underlining uncertainties in the use of the two-fluid models in multiphase computations comes from the boundary condition of the solid phase. Typically, the gas or liquid fluid boundary condition at a solid wall is the so called no-slip condition, which has been widely accepted to be valid for single-phase fluid dynamics provided that the Knudsen number is low. However, the boundary condition for the solid phase is not well understood. Themore » no-slip condition at a solid boundary is not a valid assumption for the solid phase. Instead, several researchers advocate a slip condition as a more appropriate boundary condition. However, the question on the selection of an exact slip length or a slip velocity coefficient is still unanswered. Experimental or numerical simulation data are needed in order to determinate the slip boundary condition that is applicable to a two-fluid model. The goal of this project is to improve the performance and accuracy of the boundary conditions used in two-fluid models such as the MFIX code, which is frequently used in multiphase flow simulations. The specific objectives of the project are to use first principles embedded in a validated Direct Numerical Simulation particulate flow numerical program, which uses the Immersed Boundary method (DNS-IB) and the Direct Forcing scheme in order to establish, modify and validate needed energy and momentum boundary conditions for the MFIX code. To achieve these objectives, we have developed a highly efficient DNS code and conducted numerical simulations to investigate the particle-wall and particle-particle interactions in particulate flows. Most of our research findings have been reported in major conferences and archived journals, which are listed in Section 7 of this report. In this report, we will

  19. Traffic experiment reveals the nature of car-following.

    PubMed

    Jiang, Rui; Hu, Mao-Bin; Zhang, H M; Gao, Zi-You; Jia, Bin; Wu, Qing-Song; Wang, Bing; Yang, Ming

    2014-01-01

    As a typical self-driven many-particle system far from equilibrium, traffic flow exhibits diverse fascinating non-equilibrium phenomena, most of which are closely related to traffic flow stability and specifically the growth/dissipation pattern of disturbances. However, the traffic theories have been controversial due to a lack of precise traffic data. We have studied traffic flow from a new perspective by carrying out large-scale car-following experiment on an open road section, which overcomes the intrinsic deficiency of empirical observations. The experiment has shown clearly the nature of car-following, which runs against the traditional traffic flow theory. Simulations show that by removing the fundamental notion in the traditional car-following models and allowing the traffic state to span a two-dimensional region in velocity-spacing plane, the growth pattern of disturbances has changed qualitatively and becomes qualitatively or even quantitatively in consistent with that observed in the experiment.

  20. Minimal-delay traffic grooming for WDM star networks

    NASA Astrophysics Data System (ADS)

    Choi, Hongsik; Garg, Nikhil; Choi, Hyeong-Ah

    2003-10-01

    All-optical networks face the challenge of reducing slower opto-electronic conversions by managing assignment of traffic streams to wavelengths in an intelligent manner, while at the same time utilizing bandwidth resources to the maximum. This challenge becomes harder in networks closer to the end users that have insufficient data to saturate single wavelengths as well as traffic streams outnumbering the usable wavelengths, resulting in traffic grooming which requires costly traffic analysis at access nodes. We study the problem of traffic grooming that reduces the need to analyze traffic, for a class of network architecture most used by Metropolitan Area Networks; the star network. The problem being NP-complete, we provide an efficient twice-optimal-bound greedy heuristic for the same, that can be used to intelligently groom traffic at the LANs to reduce latency at the access nodes. Simulation results show that our greedy heuristic achieves a near-optimal solution.

  1. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic controller...

  2. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic controller...

  3. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic controller...

  4. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic controller...

  5. Traffic Monitor

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Intelligent Vision Systems, Inc. (InVision) needed image acquisition technology that was reliable in bad weather for its TDS-200 Traffic Detection System. InVision researchers used information from NASA Tech Briefs and assistance from Johnson Space Center to finish the system. The NASA technology used was developed for Earth-observing imaging satellites: charge coupled devices, in which silicon chips convert light directly into electronic or digital images. The TDS-200 consists of sensors mounted above traffic on poles or span wires, enabling two sensors to view an intersection; a "swing and sway" feature to compensate for movement of the sensors; a combination of electronic shutter and gain control; and sensor output to an image digital signal processor, still frame video and optionally live video.

  6. Physics of traffic gridlock in a city.

    PubMed

    Kerner, Boris S

    2011-10-01

    Based on simulations of stochastic three-phase and two-phase traffic flow models, we reveal that at a signalized city intersection under small link inflow rates at which a vehicle queue developed during the red phase of the light signal dissolves fully during the green phase, i.e., no traffic gridlock should be expected, nevertheless, spontaneous traffic breakdown with subsequent city gridlock occurs with some probability after a random time delay. In most cases, this traffic breakdown is initiated by a phase transition from free flow to a synchronized flow occurring upstream of the queue at the light signal. The probability of traffic breakdown at the light signal is an increasing function of the link inflow rate and duration of the red phase of the light signal.

  7. Abnormal Uterine Bleeding FAQ

    MedlinePlus

    ... Abnormal Uterine Bleeding • What is a normal menstrual cycle? • When is bleeding abnormal? • At what ages is ... abnormal bleeding? •Glossary What is a normal menstrual cycle? The normal length of the menstrual cycle is ...

  8. Traffic crash statistics report, 2006

    DOT National Transportation Integrated Search

    2007-01-01

    Fatalities as a result of traffic crashes on Florida roadways decreased to 3,365 in 2006 from 3,533 in 2005 **for the first time in more than 10 years traffic fatalities have decreased from the previous year; State Mileage Death Rate decreased to 1.6...

  9. 32 CFR 636.11 - Installation traffic codes

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Installation traffic codes 636.11 Section 636.11 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.11 Installation traffic codes In...

  10. Traffic Tech: National Traffic Speeds Survey III: 2015

    DOT National Transportation Integrated Search

    2018-03-01

    Vehicle speeds are an important factor in traffic safety. NHTSAs most recent data estimates that approximately 27 percent of all fatal motor vehicle crashes are speeding-related (NCSA, 2018). NHTSA estimated the economic cost of speeding-related c...

  11. Seat belt, DWI, and other traffic violations among recent immigrants in Florida and Tennessee : traffic tech.

    DOT National Transportation Integrated Search

    2013-05-01

    The rapidly changing racial and ethnic composition of the : U.S. population is important to traffic safety specialists : because involvement in fatal traffic crashes varies across : racial and ethnic groups. Some research suggests that certain : mino...

  12. Air Traffic Management Research at NASA Ames

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.

    2012-01-01

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

  13. Traffic Experiment Reveals the Nature of Car-Following

    PubMed Central

    Jiang, Rui; Hu, Mao-Bin; Zhang, H. M.; Gao, Zi-You; Jia, Bin; Wu, Qing-Song; Wang, Bing; Yang, Ming

    2014-01-01

    As a typical self-driven many-particle system far from equilibrium, traffic flow exhibits diverse fascinating non-equilibrium phenomena, most of which are closely related to traffic flow stability and specifically the growth/dissipation pattern of disturbances. However, the traffic theories have been controversial due to a lack of precise traffic data. We have studied traffic flow from a new perspective by carrying out large-scale car-following experiment on an open road section, which overcomes the intrinsic deficiency of empirical observations. The experiment has shown clearly the nature of car-following, which runs against the traditional traffic flow theory. Simulations show that by removing the fundamental notion in the traditional car-following models and allowing the traffic state to span a two-dimensional region in velocity-spacing plane, the growth pattern of disturbances has changed qualitatively and becomes qualitatively or even quantitatively in consistent with that observed in the experiment. PMID:24740284

  14. Overview of Airport Surface Traffic Control - Present and Future

    DOT National Transportation Integrated Search

    1975-09-01

    The Airport Surface Traffic Control System, an integral part of the nation's Air Traffic Control System, is specifically concerned with the safe and efficient control of airport airside surface traffic. The current status of airport surface traffic c...

  15. Urine - abnormal color

    MedlinePlus

    ... medlineplus.gov/ency/article/003139.htm Urine - abnormal color To use the sharing features on this page, please enable JavaScript. The usual color of urine is straw-yellow. Abnormally colored urine ...

  16. Comparison of electrochemical skin conductance and vibration perception threshold measurement in the detection of early diabetic neuropathy.

    PubMed

    Goel, Amit; Shivaprasad, Channabasappa; Kolly, Anish; Sarathi H A, Vijaya; Atluri, Sridevi

    2017-01-01

    The early diagnosis of diabetic peripheral neuropathy (DPN) is challenging. Sudomotor dysfunction is one of the earliest detectable abnormalities in DPN. The present study aimed to determine the diagnostic performance of the electrochemical skin conductance (ESC) test in detecting early DPN, compared with the vibration perception threshold (VPT) test and diabetic neuropathy symptom (DNS) score, using the modified neuropathy disability score (NDS) as the reference standard. Five hundred and twenty-three patients with type 2 diabetes underwent an NDS-based clinical assessment for neuropathy. Participants were classified into the DPN and non-DPN groups based on the NDS (≥ 6). Both groups were evaluated further using the DNS, and VPT and ESC testing. A receiver-operator characteristic (ROC) curve analysis was performed to compare the efficacy of ESC measurements with those of DNS and VPT testing in detecting DPN. The DPN group (n = 110, 21%) had significantly higher HbA1c levels and longer diabetes durations compared with the non-DPN group (n = 413). The sensitivity of feet ESC < 60 μS, VPT testing, and DNS in detecting DPN were 85%, 72%, and 52%, respectively. The specificity of feet ESC, VPT, and DNS in detecting DPN were 85%, 90% and 60% respectively. The areas under the curves of the ROC plots for feet ESC, VPT testing, and DNS were 0.88, 0.84, and 0.6, respectively. A significant inverse linear relationship was noted between VPT and feet ESC (r = -0.45, p = <0.0001). The odds ratios for having DPN, based on the mean feet ESC testing < 60 μS, VPT testing > 15 V, and DNS ≥ 1, were 16.4, 10.9 and 1.8, respectively. ESC measurement is an objective and sensitive technique for the early detection of DPN. Feet ESC measurement was superior to VPT testing for identifying patients with early DPN.

  17. Comparison of electrochemical skin conductance and vibration perception threshold measurement in the detection of early diabetic neuropathy

    PubMed Central

    Kolly, Anish; Sarathi H. A., Vijaya; Atluri, Sridevi

    2017-01-01

    The early diagnosis of diabetic peripheral neuropathy (DPN) is challenging. Sudomotor dysfunction is one of the earliest detectable abnormalities in DPN. The present study aimed to determine the diagnostic performance of the electrochemical skin conductance (ESC) test in detecting early DPN, compared with the vibration perception threshold (VPT) test and diabetic neuropathy symptom (DNS) score, using the modified neuropathy disability score (NDS) as the reference standard. Five hundred and twenty-three patients with type 2 diabetes underwent an NDS-based clinical assessment for neuropathy. Participants were classified into the DPN and non-DPN groups based on the NDS (≥ 6). Both groups were evaluated further using the DNS, and VPT and ESC testing. A receiver-operator characteristic (ROC) curve analysis was performed to compare the efficacy of ESC measurements with those of DNS and VPT testing in detecting DPN. The DPN group (n = 110, 21%) had significantly higher HbA1c levels and longer diabetes durations compared with the non-DPN group (n = 413). The sensitivity of feet ESC < 60 μS, VPT testing, and DNS in detecting DPN were 85%, 72%, and 52%, respectively. The specificity of feet ESC, VPT, and DNS in detecting DPN were 85%, 90% and 60% respectively. The areas under the curves of the ROC plots for feet ESC, VPT testing, and DNS were 0.88, 0.84, and 0.6, respectively. A significant inverse linear relationship was noted between VPT and feet ESC (r = -0.45, p = <0.0001). The odds ratios for having DPN, based on the mean feet ESC testing < 60 μS, VPT testing > 15 V, and DNS ≥ 1, were 16.4, 10.9 and 1.8, respectively. ESC measurement is an objective and sensitive technique for the early detection of DPN. Feet ESC measurement was superior to VPT testing for identifying patients with early DPN. PMID:28880907

  18. 33 CFR 161.55 - Vessel Traffic Service Puget Sound and the Cooperative Vessel Traffic Service for the Juan de...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Reporting Points § 161.55 Vessel Traffic Service Puget Sound and the Cooperative Vessel Traffic Service for the Juan de Fuca Region. The Vessel Traffic Service Puget Sound area consists of the navigable waters... Boundary Range C Rear Light). This area includes: Puget Sound, Hood Canal, Possession Sound, the San Juan...

  19. Road Traffic Noise Exposure and Hearing Impairment Among Traffic Policemen in Surat, Western India

    NASA Astrophysics Data System (ADS)

    Tandel, B. N.; Macwan, J. E. M.

    2017-06-01

    Among all of the sources responsible for noise pollution, traffic related sources are of great environmental concern and increasing level of discomfort in urban areas with increasing traffic concentration. It will be a larger and serious problem in the future, if effective precautions are not taken addressed and attended to. Hence, a study was undertaken to measure the levels of road traffic noise at major intersections of Surat city, located in Western India and assess the hearing impairment among the exposed group of population i.e. the traffic policemen. Manual noise measurements and vehicle counts were performed at three of the busiest traffic intersections in the city for a period of 12 h. Audiometric screening was done on 46 policemen working at these intersections to determine the occurrence of hearing impairment. At all the three intersections, Leq measured was well above the permissible levels of 65 dBA for daytime. The Lmax recorded for three intersections were 84.6 dBA (07:36 pm), 87.3 dBA (06:32 pm) and 85.6 dBA (11:41 am). Audiometric screening showed that only 10 policemen (22%) had normal hearing. Slight, moderate and severe hearing impairment was recorded among 13 (28%), 18 (39%) and 5 (11%) policemen respectively. Of the total 46 policemen, none had profound impairment (deafness, hearing loss >81 dB). Of the 36 policemen having hearing impairment, 27 had bilateral impairment.

  20. Transmit: An Advanced Traffic Management System

    DOT National Transportation Integrated Search

    1995-11-27

    TRANSCOM'S SYSTEM FOR MANAGING INCIDENTS AND TRAFFIC, KNOWN AS TRANSMIT, WAS INITIATED TO ESTABLISH THE FEASIBILITY OF USING AUTOMATIC VEHICLE IDENTIFICATION (AVI) EQUIPMENT FOR TRAFFIC MANAGEMENT AND SURVEILLANCE APPLICATIONS. AVI TECHNOLOGY SYSTEMS...

  1. Congestion and communication in confined ant traffic

    NASA Astrophysics Data System (ADS)

    Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A. D.; Goldman, Daniel I.

    2014-03-01

    Many social animals move and communicate within confined spaces. In subterranean fire ants Solenopsis invicta, mobility within crowded nest tunnels is important for resource and information transport. Within confined tunnels, communication and traffic flow are at odds: trafficking ants communicate through tactile interactions while stopped, yet ants that stop to communicate impose physical obstacles on the traffic. We monitor the bi-directional flow of fire ant workers in laboratory tunnels of varied diameter D. The persistence time of communicating ant aggregations, τ, increases approximately linearly with the number of participating ants, n. The sensitivity of traffic flow increases as D decreases and diverges at a minimum diameter, Dc. A cellular automata model incorporating minimal traffic features--excluded volume and communication duration--reproduces features of the experiment. From the model we identify a competition between information transfer and the need to maintain jam-free traffic flow. We show that by balancing information transfer and traffic flow demands, an optimum group strategy exists which maximizes information throughput. We acknowledge funding from NSF PoLS #0957659 and #PHY-1205878.

  2. Urban planning and traffic safety at night

    NASA Astrophysics Data System (ADS)

    Ispas, N.; Trusca, D.

    2016-08-01

    Urban planning including traffic signs serve vital functions, providing road users with regulatory, warning and guidance information about the roadway and surrounding environment. There are a large number of signs and even more guidelines on how these signs should be designed, installed, and maintained in concordance with on road surface traffic signs. More requirements for signs are made for night urban traffic, including appearance (size, shape, colour), placement (height, lateral, and longitudinal), maintenance (visibility, position, damage) and signs light and retroreflective. In the night, traffic signs visibility can interact by on pedestrian visibility and diminish urban traffic safety. The main aim of this paper are the scientific determination of an urban specific zone visibility for evaluate at night real conditions in case of a traffic accident in the Braşov city area. The night visibility study was made using PC-Rect version 4.2. Other goal of the paper was to modify some urban planning solution in order to increase the urban safety in Brașov.

  3. Air Traffic Sector Configuration Change Frequency

    NASA Technical Reports Server (NTRS)

    Chatterji, Gano Broto; Drew, Michael

    2009-01-01

    Several techniques for partitioning airspace have been developed in the literature. The question of whether a region of airspace created by such methods can be used with other days of traffic, and the number of times a different partition is needed during the day is examined in this paper. Both these aspects are examined for the Fort Worth Center airspace sectors. A Mixed Integer Linear Programming method is used with actual air traffic data of ten high-volume low-weather-delay days for creating sectors. Nine solutions were obtained for each two-hour period of the day by partitioning the center airspace into two through 18 sectors in steps of two sectors. Actual track-data were played back with the generated partitions for creating histograms of the traffic-counts. The best partition for each two-hour period was then identified based on the nine traffic-count distributions. Numbers of sectors in such partitions were analyzed to determine the number of times a different configuration is needed during the day. One to three partitions were selected for the 24-hour period, and traffic data from ten days were played back to test if the traffic-counts stayed below the threshold values associated with these partitions. Results show that these partitions are robust and can be used for longer durations than they were designed for

  4. Guidebook for development of traffic monitoring systems for major traffic generators in the state of Texas.

    DOT National Transportation Integrated Search

    2009-09-01

    The purpose of this guide is to aid the Texas Department of Transportation (TxDOT), Metropolitan Planning Organizations (MPO), and other state and local agencies to develop an effective traffic monitoring system for new major traffic generators in th...

  5. An assessment of traffic safety culture related to engagement efforts to improve traffic safety : research programs.

    DOT National Transportation Integrated Search

    2016-12-01

    The Center for Health and Safety Culture at Montana State University developed a survey to investigate the traffic safety culture related to engagement in traffic safety citizenship behaviors. The development of the survey was based on an augmented f...

  6. Road traffic injuries in Colombia.

    PubMed

    Rodríguez, Deysi Yasmin; Fernández, Francisco José; Acero Velásquez, Hugo

    2003-01-01

    Road traffic injuries are a leading public health problem in Colombia. Pedestrians are the most vulnerable road users, especially in the main urban centers of Bogotá, Medellin and Cali. Data analyzed in this report include official statistics from the National Police and the National Institute of Legal Medicine and Forensic Sciences for 1996-2000, and results of a study conducted at the National University of Colombia in 2000. Methods from the Highway Capacity Manual were used for determining physical and technical variables, and a Geographical Information System tool was used for the location and spatial analysis of the road traffic crashes. Pedestrians accounted for close to 32% of injuries and 40% of the deaths from road traffic crashes. The problem of road traffic crashes existed predominately in urban areas. In the main urban centers, pedestrians constituted nearly 68% of road traffic crash victims. The high level of risky road use behaviors demonstrated by pedestrians and drivers, and inadequate infrastructure for safe mobility of pedestrians in some sections of the road network were the main contributing factors. Major improvements were achieved in Bogotá following enhancements to the municipal transport system and other policies introduced since 1995. In conclusion, policies and programs for improving road safety, in particular pedestrian safety, and strengthening urban planning are top priority.

  7. 32 CFR 634.40 - General off installation traffic activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reports received from civil authorities on serious traffic violations, accidents, and intoxicated driving... 32 National Defense 4 2010-07-01 2010-07-01 true General off installation traffic activities. 634... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision...

  8. Patients' Risk of Causing Traffic Violations and Traffic Accidents while Driving.

    PubMed

    Šestan, Nevenka; Dodič Fikfak, Metoda; Balantič, Zvone

    2017-09-01

    This study examines whether drivers suffering from epilepsy, chronic alcoholism and/or hazardous drinking, psychoactive substance abuse, other diseases of the nervous system, mental and behavioural disorders, cardiovascular diseases, severe diabetes, and severe eye diseases are at a greater risk of causing traffic accidents and traffic violations than drivers that cause accidents and violations without these diagnoses. A case control study was carried out. The cases were drivers checked by a special medical committee in the period observed suffering from the diseases listed above. Matched controls were taken from the cohort of those that caused accidents and violations during the same period observed. The descriptive statistics were followed by calculation of correlations, t-tests and χ 2 , and the odds ratio. Drivers with referrals for diseases of the nervous system are five times more likely to cause a traffic accident compared to controls (OR=5.18; 95% CI=2.59-10.34); in addition, a high risk is associated with drivers with mental and behavioural disorders (OR=3.64; 95% CI=1.91-6.94), drivers with epilepsy (OR=1.99; 95% CI=1.01-3.92), and drivers addicted to alcohol (OR=1.71; 95% CI=1.01-2.89). Drivers suffering from addiction, a disease of the nervous system, or epilepsy are more likely to cause a traffic accident, which is a contribution to the inconclusive findings of previous studies. The multiple reasons for risks of patients suffering from mental and behavioural disorders need to be further investigated. Copyright© by the National Institute of Public Health, Prague 2017

  9. Analysis of Child-related Road Traffic Accidents in Vietnam

    NASA Astrophysics Data System (ADS)

    Vu, Anh Tuan; Nguyen, Dinh Vinh Man

    2018-04-01

    In recent years, the number of road traffic accidents, fatalities and injuries have been decreasing, but the figures of children road traffic accidents have been increasing in Ho Chi Minh City of Vietnam. This fact strongly calls for implementing effective solutions to improve traffic safety for children by the local government. This paper presents the trends, patterns and causes of road traffic accidents involving children based on the analysis of road traffic accident data over the period 2010-2015 and the video-based observations of road traffic law violations at 15 typical school gates and 10 typical roads. The results could be useful for the city government to formulate solutions to effectively improve traffic safety for children in Ho Chi Minh City and other cities in Vietnam.

  10. STOL Traffic environment and operational procedures

    NASA Technical Reports Server (NTRS)

    Schlundt, R. W.; Dewolf, R. W.; Ausrotas, R. A.; Curry, R. E.; Demaio, D.; Keene, D. W.; Speyer, J. L.; Weinreich, M.; Zeldin, S.

    1972-01-01

    The expected traffic environment for an intercity STOL transportation system is examined, and operational procedures are discussed in order to identify problem areas which impact STOL avionics requirements. Factors considered include: traffic densities, STOL/CTOL/VTOL traffic mix, the expect ATC environment, aircraft noise models and community noise models and community noise impact, flight paths for noise abatement, wind considerations affecting landing, approach and landing considerations, STOLport site selection, runway capacity, and STOL operations at jetports, suburban airports, and separate STOLports.

  11. Pedestrian friendly traffic signal control : final research report.

    DOT National Transportation Integrated Search

    2016-01-01

    This project continues research aimed at real-time detection and use of pedestrian : traffic flow information to enhance adaptive traffic signal control in urban areas : where pedestrian traffic is substantial and must be given appropriate attention ...

  12. 7210.56 air traffic quality assurance

    DOT National Transportation Integrated Search

    1998-02-01

    This order is the culmination of a long and thoughtful process involving the : active participation of nearly all elements of air traffic, including : headquarters, regional offices, facility managers, Air Traffic Supervisors : Committee (SUPCOM), Na...

  13. A queuing model for road traffic simulation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guerrouahane, N.; Aissani, D.; Bouallouche-Medjkoune, L.

    We present in this article a stochastic queuing model for the raod traffic. The model is based on the M/G/c/c state dependent queuing model, and is inspired from the deterministic Godunov scheme for the road traffic simulation. We first propose a variant of M/G/c/c state dependent model that works with density-flow fundamental diagrams rather than density-speed relationships. We then extend this model in order to consider upstream traffic demand as well as downstream traffic supply. Finally, we show how to model a whole raod by concatenating raod sections as in the deterministic Godunov scheme.

  14. Mobile phones in a traffic flow: a geographical perspective to evening rush hour traffic analysis using call detail records.

    PubMed

    Järv, Olle; Ahas, Rein; Saluveer, Erki; Derudder, Ben; Witlox, Frank

    2012-01-01

    Excessive land use and suburbanisation around densely populated urban areas has gone hand in hand with a growth in overall transportation and discussions about causality of traffic congestions. The objective of this paper is to gain new insight regarding the composition of traffic flows, and to reveal how and to what extent suburbanites' travelling affects rush hour traffic. We put forward an alternative methodological approach using call detail records of mobile phones to assess the composition of traffic flows during the evening rush hour in Tallinn, Estonia. We found that daily commuting and suburbanites influence transportation demand by amplifying the evening rush hour traffic, although daily commuting trips comprises only 31% of all movement at that time. The geography of the Friday evening rush hour is distinctive from other working days, presumably in connection with domestic tourism and leisure time activities. This suggests that the rise of the overall mobility of individuals due to societal changes may play a greater role in evening rush hour traffic conditions than does the impact of suburbanisation.

  15. Mobile Phones in a Traffic Flow: A Geographical Perspective to Evening Rush Hour Traffic Analysis Using Call Detail Records

    PubMed Central

    Järv, Olle; Ahas, Rein; Saluveer, Erki; Derudder, Ben; Witlox, Frank

    2012-01-01

    Excessive land use and suburbanisation around densely populated urban areas has gone hand in hand with a growth in overall transportation and discussions about causality of traffic congestions. The objective of this paper is to gain new insight regarding the composition of traffic flows, and to reveal how and to what extent suburbanites’ travelling affects rush hour traffic. We put forward an alternative methodological approach using call detail records of mobile phones to assess the composition of traffic flows during the evening rush hour in Tallinn, Estonia. We found that daily commuting and suburbanites influence transportation demand by amplifying the evening rush hour traffic, although daily commuting trips comprises only 31% of all movement at that time. The geography of the Friday evening rush hour is distinctive from other working days, presumably in connection with domestic tourism and leisure time activities. This suggests that the rise of the overall mobility of individuals due to societal changes may play a greater role in evening rush hour traffic conditions than does the impact of suburbanisation. PMID:23155461

  16. Distributed traffic signal control using fuzzy logic

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed Central

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

    2016-01-01

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

  18. Cockpit displayed traffic information and distributed management in air traffic control

    NASA Technical Reports Server (NTRS)

    Kreifeldt, J. G.

    1980-01-01

    A graphical display of information (such as surrounding aircraft and navigation routes) in the cockpit on a cathode ray tube has been proposed for improving the safety, orderliness, and expeditiousness of the air traffic control system. An investigation of this method at NASA-Ames indicated a large reduction in controller verbal work load without increasing pilot verbal load; the visual work may be increased. The cockpit displayed traffic and navigation information system reduced response delays permitting pilots to maintain their spacing more closely and precisely than when depending entirely on controller-issued radar vectors and speed command.

  19. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a park road, except as authorized by the superintendent, or in the event of an...

  20. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a park road, except as authorized by the superintendent, or in the event of an...

  1. Impact of traffic oscillations on freeway crash occurrences.

    PubMed

    Zheng, Zuduo; Ahn, Soyoung; Monsere, Christopher M

    2010-03-01

    Traffic oscillations are typical features of congested traffic flow that are characterized by recurring decelerations followed by accelerations (stop-and-go driving). The negative environmental impacts of these oscillations are widely accepted, but their impact on traffic safety has been debated. This paper describes the impact of freeway traffic oscillations on traffic safety. This study employs a matched case-control design using high-resolution traffic and crash data from a freeway segment. Traffic conditions prior to each crash were taken as cases, while traffic conditions during the same periods on days without crashes were taken as controls. These were also matched by presence of congestion, geometry and weather. A total of 82 cases and about 80,000 candidate controls were extracted from more than three years of data from 2004 to 2007. Conditional logistic regression models were developed based on the case-control samples. To verify consistency in the results, 20 different sets of controls were randomly extracted from the candidate pool for varying control-case ratios. The results reveal that the standard deviation of speed (thus, oscillations) is a significant variable, with an average odds ratio of about 1.08. This implies that the likelihood of a (rear-end) crash increases by about 8% with an additional unit increase in the standard deviation of speed. The average traffic states prior to crashes were less significant than the speed variations in congestion. Published by Elsevier Ltd.

  2. Traffic and related self-driven many-particle systems

    NASA Astrophysics Data System (ADS)

    Helbing, Dirk

    2001-10-01

    Since the subject of traffic dynamics has captured the interest of physicists, many surprising effects have been revealed and explained. Some of the questions now understood are the following: Why are vehicles sometimes stopped by ``phantom traffic jams'' even though drivers all like to drive fast? What are the mechanisms behind stop-and-go traffic? Why are there several different kinds of congestion, and how are they related? Why do most traffic jams occur considerably before the road capacity is reached? Can a temporary reduction in the volume of traffic cause a lasting traffic jam? Under which conditions can speed limits speed up traffic? Why do pedestrians moving in opposite directions normally organize into lanes, while similar systems ``freeze by heating''? All of these questions have been answered by applying and extending methods from statistical physics and nonlinear dynamics to self-driven many-particle systems. This article considers the empirical data and then reviews the main approaches to modeling pedestrian and vehicle traffic. These include microscopic (particle-based), mesoscopic (gas-kinetic), and macroscopic (fluid-dynamic) models. Attention is also paid to the formulation of a micro-macro link, to aspects of universality, and to other unifying concepts, such as a general modeling framework for self-driven many-particle systems, including spin systems. While the primary focus is upon vehicle and pedestrian traffic, applications to biological or socio-economic systems such as bacterial colonies, flocks of birds, panics, and stock market dynamics are touched upon as well.

  3. Transportation data requirements : evaluation of portable traffic recorders.

    DOT National Transportation Integrated Search

    1978-01-01

    The objective of this study was to evaluate the accuracy of the Department's portable traffic recorder models under diverse types of traffic conditions. The study was conducted by (1) reviewing the characteristics of five models of traffic recorders,...

  4. Towards a Cloud Based Smart Traffic Management Framework

    NASA Astrophysics Data System (ADS)

    Rahimi, M. M.; Hakimpour, F.

    2017-09-01

    Traffic big data has brought many opportunities for traffic management applications. However several challenges like heterogeneity, storage, management, processing and analysis of traffic big data may hinder their efficient and real-time applications. All these challenges call for well-adapted distributed framework for smart traffic management that can efficiently handle big traffic data integration, indexing, query processing, mining and analysis. In this paper, we present a novel, distributed, scalable and efficient framework for traffic management applications. The proposed cloud computing based framework can answer technical challenges for efficient and real-time storage, management, process and analyse of traffic big data. For evaluation of the framework, we have used OpenStreetMap (OSM) real trajectories and road network on a distributed environment. Our evaluation results indicate that speed of data importing to this framework exceeds 8000 records per second when the size of datasets is near to 5 million. We also evaluate performance of data retrieval in our proposed framework. The data retrieval speed exceeds 15000 records per second when the size of datasets is near to 5 million. We have also evaluated scalability and performance of our proposed framework using parallelisation of a critical pre-analysis in transportation applications. The results show that proposed framework achieves considerable performance and efficiency in traffic management applications.

  5. Traffic mortality and the role of minor roads.

    PubMed

    van Langevelde, Frank; van Dooremalen, Coby; Jaarsma, Catharinus F

    2009-01-01

    Roads have large impacts on wildlife, as they form one of the principal causes of mortality, and disturbance and fragmentation of habitat. These impacts are mainly studied and mitigated on major roads. It is, however, a widespread misconception that most animals are killed on major roads. In this paper, we argue that minor roads have a larger impact on wildlife with respect to habitat destruction, noise load and traffic mortality. We use data on traffic related deaths in badgers (Meles meles) in The Netherlands to illustrate that traffic mortality is higher on minor roads. We ask for a more extensive investigation of the environmental impacts of minor roads. Moreover, we argue that the success of mitigation on roads drastically increases when both major and minor roads are integrated in the planning of traffic flows. Therefore, we propose a strategy based on the concept of a "traffic-calmed area". Traffic-calmed areas create opportunities for wildlife by decreasing limitations for animal movement. We ask for further studies to estimate what size traffic-calmed areas should be to maintain minimum viable animal populations.

  6. Improvement of driving safety in road traffic system

    NASA Astrophysics Data System (ADS)

    Li, Ke-Ping; Gao, Zi-You

    2005-05-01

    A road traffic system is a complex system in which humans participate directly. In this system, human factors play a very important role. In this paper, a kind of control signal is designated at a given site (i.e., signal point) of the road. Under the effect of the control signal, the drivers will decrease their velocities when their vehicles pass the signal point. Our aim is to transit the traffic flow states from disorder to order and then improve the traffic safety. We have tested this technique for the two-lane traffic model that is based on the deterministic Nagel-Schreckenberg (NaSch) traffic model. The simulation results indicate that the traffic flow states can be transited from disorder to order. Different order states can be observed in the system and these states are safer.

  7. Coordinated Traffic Incident and Congestion Management (TIM-CM) : Mitigating Regional Impacts of Major Traffic Incidents in the Seattle I-5 Corridor

    DOT National Transportation Integrated Search

    2018-02-02

    Within the Seattle metropolitan area, traffic incident management (TIM) operations provide a multi-jurisdictional and coordinated strategy to detect, respond to, and clear traffic incidents so that traffic flow can be restored quickly and safely. The...

  8. Steering Kids to Traffic Safety.

    ERIC Educational Resources Information Center

    PTA Today, 1991

    1991-01-01

    Guidelines to help parents explain traffic safety to children cover the following: school bus safety (e.g., remain seated, do not shout); walking (e.g., obey traffic signals, cross at crosswalks); driving (e.g., wear seatbelts, enter and exit from the curb side); and biking (e.g., wear helmets, do not ride at night). (SM)

  9. 77 FR 39321 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... INFORMATION CONTACT: Ms. Lee Kyker, Environmental Specialist, Air Traffic Eastern Service Center, Operations... Manager, Operations Support Group, FAA, Air Traffic, Eastern Service Center. [FR Doc. 2012-16100 Filed 6...

  10. 77 FR 56698 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and practices for...

  11. 76 FR 27168 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and practices for...

  12. 75 FR 22892 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and practices for...

  13. 78 FR 2711 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and practices for...

  14. 76 FR 59481 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and practices for...

  15. 77 FR 27835 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and practices for...

  16. 77 FR 2603 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and practices for...

  17. 77 FR 67862 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-14

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... advise the public that the FAA's Air Traffic Procedures Advisory Committee (ATPAC) two year charter has... provides a venue to review air traffic control procedures and practices for standardization, revision...

  18. A Wavelet Analysis Approach for Categorizing Air Traffic Behavior

    NASA Technical Reports Server (NTRS)

    Drew, Michael; Sheth, Kapil

    2015-01-01

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

  19. Managing Student Traffic during Peak Periods.

    ERIC Educational Resources Information Center

    Raphael, Carol; Milks, Linda

    1980-01-01

    Some suggestions to help financial aid offices develop a rational system for coping with high traffic periods are offered. Creating a system to handle peak traffic periods involves three related components: planning, resource management, and evaluation. (MLW)

  20. Level of neurotic disorders among drivers causing traffic accidents.

    PubMed

    Durić, Predrag; Filipović, Danka

    2007-01-01

    Different aspects of driver personality may affect traffic safety. Extended driver reaction time causes deceleration of the reflexes, which is a major cause of traffic accidents. Cornell index was used in 30 drivers responsible for traffic accidents, with the aim to measure their level of neurotic disorder and compare them with results of controls (drivers not responsible for traffic accidents). Reaction time was maesured and compared among subjects with normal results of Cornell test and those with pathological findings. Drivers causing traffic accidents showed significantly higher Cornell index scores than drivers not responsible for traffic accidents. Drivers with pathological results of Cornell index showed a significantly longer reaction time.

  1. Abnormal pressures as hydrodynamic phenomena

    USGS Publications Warehouse

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  2. Traffic Driven Analysis of Cellular and WiFi Networks

    ERIC Educational Resources Information Center

    Paul, Utpal Kumar

    2012-01-01

    Since the days Internet traffic proliferated, measurement, monitoring and analysis of network traffic have been critical to not only the basic understanding of large networks, but also to seek improvements in resource management, traffic engineering and security. At the current times traffic in wireless local and wide area networks are facing…

  3. National traffic speeds survey I: 2007 : traffic tech.

    DOT National Transportation Integrated Search

    2012-09-01

    The speed survey reviewed in this edition of "Traffic Tech" was designed as a geographic cluster : sample of primary sampling units (PSUs), which can be : a city, county, or group of two or three counties. PSUs : were chosen to represent a range of c...

  4. Urban street structure and traffic safety.

    PubMed

    Mohan, Dinesh; Bangdiwala, Shrikant I; Villaveces, Andres

    2017-09-01

    This paper reports the influence of road type and junction density on road traffic fatality rates in U.S. cities. The Fatality Analysis Reporting System (FARS) files were used to obtain fatality rates for all cities for the years 2005-2010. A stratified random sample of 16 U.S. cities was taken, and cities with high and low road traffic fatality rates were compared on their road layout details (TIGER maps were used). Statistical analysis was done to determine the effect of junction density and road type on road traffic fatality rates. The analysis of road network and road traffic crash fatality rates in these randomly selected U.S. cities shows that, (a) higher number of junctions per road length was significantly associated with a lower motor- vehicle crash and pedestrian mortality rates, and, (b) increased number of kilometers of roads of any kind was associated with higher fatality rates, but an additional kilometer of main arterial road was associated with a significantly higher increase in total fatalities. When compared to non-arterial roads, the higher the ratio of highways and main arterial roads, there was an association with higher fatality rates. These results have important implications for road safety professionals. They suggest that once the road and street structure is put in place, that will influence whether a city has low or high traffic fatality rates. A city with higher proportion of wider roads and large city blocks will tend to have higher traffic fatality rates, and therefore in turn require much more efforts in police enforcement and other road safety measures. Urban planners need to know that smaller block size with relatively less wide roads will result in lower traffic fatality rates and this needs to be incorporated at the planning stage. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

  5. The impact of abnormal autoimmune function on reproduction: maternal and fetal consequences.

    PubMed

    Gleicher, Norbert; Weiner, Rebecca; Vietzke, Mary

    2006-11-01

    The impact of abnormal autoimmune function on reproductive success has remained a highly controversial issue. This is, at least partially, due to the relative lack of demographic data from women with established autoimmune diseases. We, therefore, investigated 163 women with proven autoimmune diseases and 73 controls in a demographic study of reproductive success and impact of abnormal autoimmunity on pregnancy and offspring. Women with autoimmune diseases experienced fewer pregnancies overall (p=0.04) and fewer pregnancy losses (p=0.05). Offspring from women with autoimmune diseases demonstrated a significantly increased prevalence of confirmed autoimmune diseases (p=0.04; OR 3.759; 95%CL 1.04-1.27), which increased further if suspected, but not yet confirmed, cases were added (p=0.001; OR 8.592; 95%CL 1.05-55.0). Women with autoimmune diseases exhibited a trend towards lower cesarean section delivery during their own birth and a significantly increased prevalence of disease in vaginally delivered offspring (p=0.014; OR 6.041; 95%CL 1.32-38.22). Autoimmune diseases impair female fecundity even before the diseases become clinically overt. Offspring are at increased risk to develop autoimmune diseases, though they may differ from those of their mothers. This risk appears to correlate with mode of delivery and may be the consequence of varying cell traffic dynamics with vaginal and cesarean section deliveries.

  6. Traffic control procedures for emergency responders.

    DOT National Transportation Integrated Search

    2006-10-01

    The objective of this study was to develop a training course and handbook to guide on-scene emergency responders responsible for controlling traffic during a roadway crash and subsequent clearance. : Traffic control is an essential component of incid...

  7. Traffic Aware Strategic Aircrew Requests (TASAR)

    NASA Technical Reports Server (NTRS)

    Ballin, Mark G.; Wing, David J.

    2012-01-01

    Under Instrument Flight Rules, pilots are not permitted to make changes to their approved trajectory without first receiving permission from Air Traffic Control (ATC). Referred to as "user requests," trajectory change requests from aircrews are often denied or deferred by controllers because they have awareness of traffic and airspace constraints not currently available to flight crews. With the introduction of Automatic Dependent Surveillance-Broadcast (ADS-B) and other information services, a rich traffic, weather, and airspace information environment is becoming available on the flight deck. Automation developed by NASA uses this information to aid flight crews in the identification and formulation of optimal conflict-free trajectory requests. The concept of Traffic Aware Strategic Aircrew Requests (TASAR) combines ADS-B and airborne automation to enable user-optimal in-flight trajectory replanning and to increase the likelihood of ATC approval for the resulting trajectory change request. TASAR may improve flight efficiency or other user-desired attributes of the flight while not impacting and potentially benefiting the air traffic controller. This paper describes the TASAR concept of operations, its enabling automation technology which is currently under development, and NASA s plans for concept assessment and maturation.

  8. 78 FR 66098 - Air Traffic Procedures Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Procedures Advisory... issuing this notice to advise the public that a meeting of the Federal Aviation Administration Air Traffic Procedures Advisory Committee (ATPAC) will be held to review present air traffic control procedures and...

  9. Traffic calming of state highways : application New England

    DOT National Transportation Integrated Search

    2002-06-19

    This study has two main objectives; to evaluate the effect on safety of traffic calming of arterials and to look at the acceptance of traffic-calming measures. We found that there are only a few truly traffic-calmed arterials worldwide, and even fewe...

  10. 23 CFR 772.11 - Analysis of traffic noise impacts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Analysis of traffic noise impacts. 772.11 Section 772.11... PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Analysis of traffic noise impacts. (a) The highway agency shall determine and analyze expected traffic noise impacts. (1) For...

  11. 23 CFR 772.11 - Analysis of traffic noise impacts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Analysis of traffic noise impacts. 772.11 Section 772.11... PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Analysis of traffic noise impacts. (a) The highway agency shall determine and analyze expected traffic noise impacts. (1) For...

  12. 23 CFR 772.11 - Analysis of traffic noise impacts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Analysis of traffic noise impacts. 772.11 Section 772.11... PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Analysis of traffic noise impacts. (a) The highway agency shall determine and analyze expected traffic noise impacts. (1) For...

  13. Mixed Traffic Information Collection System based on Pressure Sensor

    NASA Astrophysics Data System (ADS)

    Liao, Wenzhe; Liu, Mingsheng; Meng, Qingli

    The traffic information collection is the base of Intelligent Traffic.At present, there exist mixed traffic situation in urban road in China. This paper researched and implemented a system through collecting the vehicle and bicycle mixed traffic flow parameters based on pressure sensor. According to information collection requirements, we selected pressure sensor, designed the data collection, storage and other hardware circuitries and information processing software. The experiment shows that the system can meet the demand of traffic information collection in the actual.

  14. Active Traffic Capture for Network Forensics

    NASA Astrophysics Data System (ADS)

    Slaviero, Marco; Granova, Anna; Olivier, Martin

    Network traffic capture is an integral part of network forensics, but current traffic capture techniques are typically passive in nature. Under heavy loads, it is possible for a sniffer to miss packets, which affects the quality of forensic evidence.

  15. Delaware's annual traffic statistical report, 2010

    DOT National Transportation Integrated Search

    2011-01-01

    The Traffic Control Section of the Delaware State Police is the repository for all Delaware traffic crash data. This includes all crash reports regardless of the geographical areas in which they occur or the policy agency conducting the investigation...

  16. Delaware's annual traffic statistical report, 2005

    DOT National Transportation Integrated Search

    2006-04-10

    The Traffic Control Section of the Delaware State Police is the repository for all Delaware traffic crash data. This includes all crash reports regardless of the geographical areas in which they occur or the policy agency conducting the investigation...

  17. Delaware's annual traffic statistical report, 2007

    DOT National Transportation Integrated Search

    2007-01-01

    The Traffic Control Section of the Delaware State Police is the repository for all Delaware traffic crash data. This includes all crash reports regardless of the geographical areas in which they occur or the policy agency conducting the investigation...

  18. Delaware's annual traffic statistical report, 2006

    DOT National Transportation Integrated Search

    2006-01-01

    The Traffic Control Section of the Delaware State Police is the repository for all Delaware traffic crash data. This includes all crash reports regardless of the geographical areas in which they occur or the policy agency conducting the investigation...

  19. Delaware's annual traffic statistical report, 2009

    DOT National Transportation Integrated Search

    2010-04-12

    The Traffic Control Section of the Delaware State Police is the repository for all Delaware traffic crash data. This includes all crash reports regardless of the geographical areas in which they occur or the policy agency conducting the investigation...

  20. Delaware's annual traffic statistical report, 2011

    DOT National Transportation Integrated Search

    2012-01-01

    The Traffic Control Section of the Delaware State Police is the repository for all Delaware traffic crash data. This includes all crash reports regardless of the geographical areas in which they occur or the policy agency conducting the investigation...

  1. Delaware's annual traffic statistical report, 2008

    DOT National Transportation Integrated Search

    2009-04-13

    The Traffic Control Section of the Delaware State Police is the repository for all Delaware traffic crash data. This includes all crash reports regardless of the geographical areas in which they occur or the policy agency conducting the investigation...

  2. Accuracy Of LTPP Traffic Loading Estimates

    DOT National Transportation Integrated Search

    1998-07-01

    The accuracy and reliability of traffic load estimates are key to determining a pavement's life expectancy. To better understand the variability of traffic loading rates and its effect on the accuracy of the Long Term Pavement Performance (LTPP) prog...

  3. En route air traffic flow simulation.

    DOT National Transportation Integrated Search

    1971-01-01

    The report covers the conception, design, development, and initial implementation of an advanced simulation technique applied to a study of national air traffic flow and its control by En Route Air Route Traffic Control Centers (ARTCC). It is intende...

  4. Citizen Science for Traffic Planning: A Practical Example

    NASA Astrophysics Data System (ADS)

    Rieke, Matthes; Stasch, Christoph; Autermann, Christian; de Wall, Arne; Remke, Albert; Wulffius, Herwig; Jirka, Simon

    2017-04-01

    Measures affecting traffic flows in urban areas, e.g. changing the configuration of traffic lights, are often causing emotional debates by citizens who are affected by these measures. Up to now, citizens are usually not involved in traffic planning and the evaluation of the decisions that were taken. The enviroCar project provides an open platform for collecting and analyzing car sensor data with GPS position data. On the hardware side, enviroCar relies on using Android smartphones and OBD-II Bluetooth adapters. A Web server component collects and aggregates the readings from the cars, anonymizes them and publishes the data as open data which scientists, public administrations or other third parties can utilize for further analysis. In this work, we provide a general overview on the enviroCar project and present a project in a mid-size city in Germany. The city's administration utilized the enviroCar platform with the help of a traffic system consultancy for including citizens in the evaluation process of different traffic light configurations along major traffic axes. Therefore, a public campaign was started including local workshops to engage the citizens. More than 150 citizens were actively collecting more about 9.500 tracks including about 2.5 million measurements. Dedicated evaluation results for the different traffic axes were computed based on the collected data set. Because the data is publicly available as open data, others may prove and reproduce the evaluation results contributing to an objective discussion of traffic planning measures. In summary, the project illustrates how Citizen Science methods and technologies improve traffic planning and related discussions.

  5. Distributed Trajectory Flexibility Preservation for Traffic Complexity Mitigation

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Wing, David; Delahaye, Daniel

    2009-01-01

    The growing demand for air travel is increasing the need for mitigation of air traffic congestion and complexity problems, which are already at high levels. At the same time new information and automation technologies are enabling the distribution of tasks and decisions from the service providers to the users of the air traffic system, with potential capacity and cost benefits. This distribution of tasks and decisions raises the concern that independent user actions will decrease the predictability and increase the complexity of the traffic system, hence inhibiting and possibly reversing any potential benefits. In answer to this concern, the authors propose the introduction of decision-making metrics for preserving user trajectory flexibility. The hypothesis is that such metrics will make user actions naturally mitigate traffic complexity. In this paper, the impact of using these metrics on traffic complexity is investigated. The scenarios analyzed include aircraft in en route airspace with each aircraft meeting a required time of arrival in a one-hour time horizon while mitigating the risk of loss of separation with the other aircraft, thus preserving its trajectory flexibility. The experiments showed promising results in that the individual trajectory flexibility preservation induced self-separation and self-organization effects in the overall traffic situation. The effects were quantified using traffic complexity metrics based on Lyapunov exponents and traffic proximity.

  6. Analytical studies on the instabilities of heterogeneous intelligent traffic flow

    NASA Astrophysics Data System (ADS)

    Ngoduy, D.

    2013-10-01

    It has been widely reported in literature that a small perturbation in traffic flow such as a sudden deceleration of a vehicle could lead to the formation of traffic jams without a clear bottleneck. These traffic jams are usually related to instabilities in traffic flow. The applications of intelligent traffic systems are a potential solution to reduce the amplitude or to eliminate the formation of such traffic instabilities. A lot of research has been conducted to theoretically study the effect of intelligent vehicles, for example adaptive cruise control vehicles, using either computer simulation or analytical method. However, most current analytical research has only applied to single class traffic flow. To this end, the main topic of this paper is to perform a linear stability analysis to find the stability threshold of heterogeneous traffic flow using microscopic models, particularly the effect of intelligent vehicles on heterogeneous (or multi-class) traffic flow instabilities. The analytical results will show how intelligent vehicle percentages affect the stability of multi-class traffic flow.

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  8. 1997 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    1998-06-01

    This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1997. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

  9. 1995 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    1996-09-01

    This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1995. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

  10. Traffic safety facts 1996 : occupant protection

    DOT National Transportation Integrated Search

    1997-01-01

    In 1996, 32,317 occupants of passenger vehicles (cars, light trucks, vans, and utility vehicles) were killed in motor vehicle traffic crashes, 77 percent of the 41,907 traffic fatalities reported for the year. Among passenger vehicle occupants over 4...

  11. Traffic safety facts 1994 : occupant protection

    DOT National Transportation Integrated Search

    1995-01-01

    In 1994, 30,780 occupants of passenger vehicles (cars, light trucks, vans, and utility vehicles) were killed in motor vehicle traffic crashes, 76 percent of the 40,676 traffic fatalities reported for the year. Among passenger vehicle occupants over 4...

  12. Traffic safety facts 1995 : occupant protection

    DOT National Transportation Integrated Search

    1996-01-01

    In 1995, 31,897 occupants of passenger vehicles (cars, light trucks, vans, and utility vehicles) were killed in motor vehicle traffic crashes, 76 percent of the 41,798 traffic fatalities reported for the year. Among passenger vehicle occupants over 4...

  13. Traffic safety facts 1993 : occupant protection

    DOT National Transportation Integrated Search

    1994-01-01

    In 1993, 26,873 front-seat occupants of passenger vehicles (cars, light trucks, vans, and utility vehicles) were killed in motor vehicle traffic crashes, 67 percent of the 40,115 traffic fatalities reported for the year. Among front-seat passenger ve...

  14. Manual of Transit and Traffic Studies

    DOT National Transportation Integrated Search

    1947-01-01

    This first edition of the "Manual of Transit and Traffic Studies" has been designed to assist transit companies and traffic engineers in the conduct and application of studies deemed essential to a solution of present and future problems of urban tra...

  15. Traffic control concepts for incident clearance

    DOT National Transportation Integrated Search

    2009-01-01

    This document discusses various aspects of traffic control for incidents with the focus on the traffic control roles and responsibilities of the responders as well as the safety of the responders and the motoring public. It also recognizes that activ...

  16. 2000 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    2002-03-01

    This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2000. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

  17. 2005 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    2006-11-01

    This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2005. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

  18. 2001 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    2003-01-01

    This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2001. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

  19. 2008 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    2010-05-01

    This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through December, : 2008. It presents crash data in the form of graphs for those who : prefer an impressionistic view and tables for those wh...

  20. 1996 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    1997-06-01

    This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1997. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

  1. 1998 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    1999-06-01

    This edition of New Mexico Traffic Crash Information reviews : traffic crash data in New Mexico from January through : December, 1998. It presents crash data in the form of graphs : for those who prefer an impressionistic view and tables for : those ...

  2. 2002 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    2004-02-01

    This edition of New Mexico Traffic Crash Information reviews traffic : crash data in New Mexico from January through December, 2002. : It presents crash data in the form of graphs for those who prefer : an impressionistic view and tables for those wh...

  3. Evaluation of the traffic count program.

    DOT National Transportation Integrated Search

    1978-01-01

    The purpose of this study was to determine the Department's needs for traffic count data, to relate them to an evaluation of the traffic count programs and procedures, to identify problems and deficiencies with data requirements, and to seek means of...

  4. The Effect of Road Traffic Noise on Reaction Time.

    PubMed

    Alimohammadi, Iraj; Zokaei, Mojtaba; Sandrock, Stephan

    2015-01-01

    Traffic noise is one of the main important sources in urban noise pollution, which causes various physiological and psychological effects that can cause disturbs in performance, sleep disturbances, hearing loss and impact on job performance. This study was conducted to verify the impact of road traffic noise on reaction time in terms of extraversion and sex. Traffic noise was measured and recorded in 10 arterial streets in Tehran, and then the recorded noise was emitted towards participants in an acoustic room. The participants were 80 (40 cases and 40 controls) students. Personality type was determined by Eysenck Personality Inventory (EPI) questioner. Reaction time before and after exposure to traffic noise was measured. Reaction time before exposure to traffic noise did not differ (P=0.437) significantly between introverts and extraverts. However, it was increased significantly in both groups after exposure to traffic noise (P<0.01). Introvert's reaction time was more increased than that of extraverts. Traffic noise augmented reaction time of both males and females. This study also revealed that exposure to traffic noise leads to increase in reaction time.

  5. Traffic Noise Assessment at Residential Areas in Skudai, Johor

    NASA Astrophysics Data System (ADS)

    Sulaiman, F. S.; Darus, N.; Mashros, N.; Haron, Z.; Yahya, K.

    2018-03-01

    Vehicles passing by on roadways in residential areas may produce unpleasant traffic noise that affects the residents. This paper presents the traffic noise assessment of three selected residential areas located in Skudai, Johor. The objectives of this study are to evaluate traffic characteristics at selected residential areas, determine related noise indices, and assess impact of traffic noise. Traffic characteristics such as daily traffic volume and vehicle speed were evaluated using automatic traffic counter (ATC). Meanwhile, noise indices like equivalent continuous sound pressure level (LAeq), noise level exceeded 10% (L10) and 90% (L90) of measurement time were determined using sound level meter (SLM). Besides that, traffic noise index (TNI) and noise pollution level (LNP) were calculated based on the measured noise indices. The results showed an increase in noise level of 60 to 70 dBA maximum due to increase in traffic volume. There was also a significant change in noise level of more than 70 dBA even though average vehicle speed did not vary significantly. Nevertheless, LAeq, TNI, and LNP values for all sites during daytime were lower than the maximum recommended levels. Thus, residents in the three studied areas were not affected in terms of quality of life and health.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Traffic signal synchronization..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic signal synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without...

  8. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Traffic signal synchronization..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic signal synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without...

  9. 36 CFR 504.13 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... times and shall comply with the signals and directions of the guards and all posted traffic signs. (b... traffic. 504.13 Section 504.13 Parks, Forests, and Public Property SMITHSONIAN INSTITUTION RULES AND REGULATIONS GOVERNING SMITHSONIAN INSTITUTION BUILDINGS AND GROUNDS § 504.13 Vehicular and pedestrian traffic...

  10. 32 CFR 634.24 - Traffic planning and codes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and most efficient use of primary and secondary roads. Circulation planning should be a major part of... control of traffic using planned direction, including measures for special events and adverse road or... traffic directors or wardens, including trained school-crossing guards. (4) Use of traffic control signs...

  11. 32 CFR 634.24 - Traffic planning and codes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and most efficient use of primary and secondary roads. Circulation planning should be a major part of... control of traffic using planned direction, including measures for special events and adverse road or... traffic directors or wardens, including trained school-crossing guards. (4) Use of traffic control signs...

  12. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Traffic signal synchronization..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic signal synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without...

  13. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Traffic signal synchronization..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic signal synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without...

  14. Intersection Monitor for Traffic-Light-Preemption System

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron; Foster, Conrad

    2006-01-01

    The figure shows an intersection monitor that is a key subsystem of an emergency traffic-light-preemption system that could be any of the systems described in the three immediately preceding articles and in Systems Would Preempt Traffic Lights for Emergency Vehicles (NPO-30573), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 36. This unit is so named because it is installed at an intersection, where it monitors the phases (in the sense of timing) of the traffic lights. The mode of operation of this monitor is independent of the type of traffic-light-controller hardware or software in use at the intersection. Moreover, the design of the monitor is such that (1) the monitor does not, by itself, affect the operation of the traffic- light controller and (2) in the event of a failure of the monitor, the trafficlight controller continues to function normally (albeit without preemption). The monitor is installed in series with the traffic-light controller at an intersection. The control signals of interest are monitored by use of high-impedance taps on affected control lines. These taps are fully isolated and further protected by high-voltage diodes that prevent any voltages or short circuits that arise within the monitor from affecting the controller. The signals from the taps are processed digitally and cleaned up by use of high-speed logic gates, and the resulting data are passed on to other parts of the traffic-light-preemption intersection subsystem. The data are compared continuously with data from vehicles and used to calculate timing for reliable preemption of the traffic lights. The pedestrian crossing at the intersection is also monitored, and pedestrians are warned not to cross during preemption.

  15. Global collaboration on road traffic injury prevention.

    PubMed

    Peden, Margie

    2005-06-01

    Worldwide, nearly 1.2 million people are killed in road traffic crashes every year and 20 million to 50 million more are injured or disabled. These injuries account for 2.1% of global mortality and 2.6% of all disability-adjusted life years (DALYs) lost. Low- and middle-income countries account for about 85% of the deaths and 90% of the DALYs lost annually. Without appropriate action, by 2020, road traffic injuries are predicted to be the third leading contributor to the global burden of disease. The economic cost of road traffic crashes is enormous. Globally it is estimated that US$518 billion is spent on road traffic crashes with low- and middle-income countries accounting for US$65 billion--more than these countries receive in development assistance. But these costs are just the tip of the iceberg. For everyone killed, injured or disabled by a road traffic crash there are countless others deeply affected. Many families are driven into poverty by the expenses of prolonged medical care, loss of a family breadwinner or the added burden of caring for the disabled. There is an urgent need for global collaboration on road traffic injury prevention. Since 2000, WHO has stepped up its response to the road safety crisis by firstly developing a 5-year strategy for road traffic injury prevention and following this by dedicating World Health Day 2004 to road safety and launching the WHO/World Bank World Report on Road Traffic Injury Prevention at the global World Health Day event in Paris, France. This short article highlights the main messages from the World Report and the six recommendations for action on road safety at a national and international level. It goes on to briefly discuss other international achievements since World Health Day and calls for countries to take up the challenge of implementing the recommendations of the World Report.

  16. 2009 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    2011-05-01

    This edition of New Mexico Traffic Crash Information reviews traffic crash data in New Mexico from January through December, 2009. It presents crash data in the form of graphs for those who prefer an impressionistic view and tables for those who requ...

  17. 1999 New Mexico traffic crash information

    DOT National Transportation Integrated Search

    2001-03-01

    This edition of New Mexico Traffic Crash Information reviews traffic crash data in New MExico from January through Decemeber, 1999. It presents crash data in the form of graphs for those who prefer an impressionistic view and tables for those who req...

  18. 49 CFR 236.769 - Locking, traffic.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, traffic. 236.769 Section 236.769 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, traffic. Electric locking which prevents the manipulation of levers or other devices for changing...

  19. 49 CFR 384.209 - Notification of traffic violations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... relating to motor vehicle traffic control (other than a parking violation), in any type of vehicle, the... State or local law relating to motor vehicle traffic control (other than a parking violation), the... 49 Transportation 5 2010-10-01 2010-10-01 false Notification of traffic violations. 384.209...

  20. 49 CFR 384.209 - Notification of traffic violations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... State or local law relating to motor vehicle traffic control (other than parking, vehicle weight or... vehicle traffic control (other than a parking violation), the licensing entity of the State in which the... 49 Transportation 5 2011-10-01 2011-10-01 false Notification of traffic violations. 384.209...