Visualizing Mobility of Public Transportation System.

PubMed

Zeng, Wei; Fu, Chi-Wing; Arisona, Stefan Müller; Erath, Alexander; Qu, Huamin

2014-12-01

Public transportation systems (PTSs) play an important role in modern cities, providing shared/massive transportation services that are essential for the general public. However, due to their increasing complexity, designing effective methods to visualize and explore PTS is highly challenging. Most existing techniques employ network visualization methods and focus on showing the network topology across stops while ignoring various mobility-related factors such as riding time, transfer time, waiting time, and round-the-clock patterns. This work aims to visualize and explore passenger mobility in a PTS with a family of analytical tasks based on inputs from transportation researchers. After exploring different design alternatives, we come up with an integrated solution with three visualization modules: isochrone map view for geographical information, isotime flow map view for effective temporal information comparison and manipulation, and OD-pair journey view for detailed visual analysis of mobility factors along routes between specific origin-destination pairs. The isotime flow map linearizes a flow map into a parallel isoline representation, maximizing the visualization of mobility information along the horizontal time axis while presenting clear and smooth pathways from origin to destinations. Moreover, we devise several interactive visual query methods for users to easily explore the dynamics of PTS mobility over space and time. Lastly, we also construct a PTS mobility model from millions of real passenger trajectories, and evaluate our visualization techniques with assorted case studies with the transportation researchers.

Protecting public health and global freight transportation systems during an influenza pandemic.

PubMed

Luke, Thomas C; Rodrigue, Jean-Paul

2008-01-01

The H5N1 influenza threat is resulting in global preparations for the next influenza pandemic. Pandemic influenza planners are prioritizing scarce vaccine, antivirals, and public health support for different segments of society. The freight, bulk goods, and energy transportation network comprise the maritime, rail, air, and trucking industries. It relies on small numbers of specialized workers who cannot be rapidly replaced if lost due to death, illness, or voluntary absenteeism. Because transportation networks link economies, provide critical infrastructures with working material, and supply citizens with necessary commodities, disrupted transportation systems can lead to cascading failures in social and economic systems. However, some pandemic influenza plans have assigned transportation workers a low priority for public health support, vaccine, and antivirals. The science of Transportation Geography demonstrates that transportation networks and workers are concentrated at, or funnel through, a small number of chokepoints and corridors. Chokepoints should be used to rapidly and efficiently vaccinate and prophylax the transportation worker cohort and to implement transmission prevention measures and thereby protect the ability to move goods. Nations, states, the transportation industry and unions, businesses, and other stakeholders must plan, resource, and exercise, and then conduct a transportation health assurance and security campaign for an influenza pandemic.

Provision of Ubiquitous Tourist Information in Public Transport Networks

PubMed Central

García, Carmelo R.; Pérez, Ricardo; Alayón, Francisco; Quesada-Arencibia, Alexis; Padrón, Gabino

2012-01-01

This paper outlines an information system for tourists using collective public transport based on mobile devices with limited computation and wireless connection capacities. In this system, the mobile device collaborates with the vehicle infrastructure in order to provide the user with multimedia (visual and audio) information about his/her trip. The information delivered, adapted to the user preferences, is synchronized with the passage of vehicles through points of interest along the route, for example: bus stops, tourist sights, public service centres, etc.

Public Transport Systems in Poland: From Bialystok to Zielona Góra by Bus and Tram Using Universal Statistics of Complex Networks

NASA Astrophysics Data System (ADS)

Sienkiewicz, J.; Holyst, J. A.

2005-05-01

We have examined a topology of 21 public transport networks in Poland. Our data exhibit several universal features in considered systems when they are analyzed from the point of view of evolving networks. Depending on the assumed definition of a network topology the degree distribution can follow a power law p(k) ˜ k-γ or can be described by an exponential function p(k) ˜ exp (-α k). In the first case one observes that mean distances between two nodes are a linear function of logarithms of their degrees product.

Mode Choice between Private and Public Transport in Klang Valley, Malaysia

PubMed Central

Karim, Mohamed Rehan; Yusoff, Sumiani

2014-01-01

In 2010, Klang Valley has only 17% trips each day were completed using public transport, with the rest of the 83% trips were made through private transport. The inclination towards private car usage will only get worse if the transport policy continues to be inefficient and ineffective. Under the National Key Economic Area, the priority aimed to stimulate the increase of modal share of public transport in the Klang Valley to 50% by 2020. In the 10th Malaysia Plan, the Klang Valley Mass Rapid Transit was proposed, equipped with 141 km of MRT system, and will integrate with the existing rail networks. Nevertheless, adding kilometers into the rail system will not help, if people do not make the shift from private into public transport. This research would like to assess the possible mode shift of travellers in the Klang Valley towards using public transport, based on the utility function of available transport modes. It intends to identify the criteria that will trigger their willingness to make changes in favour of public transport as targeted by the NKEA. PMID:24701165

Transportation Network Topologies

NASA Technical Reports Server (NTRS)

Holmes, Bruce J.; Scott, John M.

2004-01-01

A discomforting reality has materialized on the transportation scene: our existing air and ground infrastructures will not scale to meet our nation's 21st century demands and expectations for mobility, commerce, safety, and security. The consequence of inaction is diminished quality of life and economic opportunity in the 21st century. Clearly, new thinking is required for transportation that can scale to meet to the realities of a networked, knowledge-based economy in which the value of time is a new coin of the realm. This paper proposes a framework, or topology, for thinking about the problem of scalability of the system of networks that comprise the aviation system. This framework highlights the role of integrated communication-navigation-surveillance systems in enabling scalability of future air transportation networks. Scalability, in this vein, is a goal of the recently formed Joint Planning and Development Office for the Next Generation Air Transportation System. New foundations for 21PstP thinking about air transportation are underpinned by several technological developments in the traditional aircraft disciplines as well as in communication, navigation, surveillance and information systems. Complexity science and modern network theory give rise to one of the technological developments of importance. Scale-free (i.e., scalable) networks represent a promising concept space for modeling airspace system architectures, and for assessing network performance in terms of scalability, efficiency, robustness, resilience, and other metrics. The paper offers an air transportation system topology as framework for transportation system innovation. Successful outcomes of innovation in air transportation could lay the foundations for new paradigms for aircraft and their operating capabilities, air transportation system architectures, and airspace architectures and procedural concepts. The topology proposed considers air transportation as a system of networks, within

Transportation Network Topologies

NASA Technical Reports Server (NTRS)

Holmes, Bruce J.; Scott, John

2004-01-01

A discomforting reality has materialized on the transportation scene: our existing air and ground infrastructures will not scale to meet our nation's 21st century demands and expectations for mobility, commerce, safety, and security. The consequence of inaction is diminished quality of life and economic opportunity in the 21st century. Clearly, new thinking is required for transportation that can scale to meet to the realities of a networked, knowledge-based economy in which the value of time is a new coin of the realm. This paper proposes a framework, or topology, for thinking about the problem of scalability of the system of networks that comprise the aviation system. This framework highlights the role of integrated communication-navigation-surveillance systems in enabling scalability of future air transportation networks. Scalability, in this vein, is a goal of the recently formed Joint Planning and Development Office for the Next Generation Air Transportation System. New foundations for 21st thinking about air transportation are underpinned by several technological developments in the traditional aircraft disciplines as well as in communication, navigation, surveillance and information systems. Complexity science and modern network theory give rise to one of the technological developments of importance. Scale-free (i.e., scalable) networks represent a promising concept space for modeling airspace system architectures, and for assessing network performance in terms of scalability, efficiency, robustness, resilience, and other metrics. The paper offers an air transportation system topology as framework for transportation system innovation. Successful outcomes of innovation in air transportation could lay the foundations for new paradigms for aircraft and their operating capabilities, air transportation system architectures, and airspace architectures and procedural concepts. The topology proposed considers air transportation as a system of networks, within which

Transportation and public health.

PubMed

Litman, Todd

2013-01-01

This article investigates various ways that transportation policy and planning decisions affect public health and better ways to incorporate public health objectives into transport planning. Conventional planning tends to consider some public health impacts, such as crash risk and pollution emissions measured per vehicle-kilometer, but generally ignores health problems resulting from less active transport (reduced walking and cycling activity) and the additional crashes and pollution caused by increased vehicle mileage. As a result, transport agencies tend to undervalue strategies that increase transport system diversity and reduce vehicle travel. This article identifies various win-win strategies that can help improve public health and other planning objectives.

The Association between Access to Public Transportation and Self-Reported Active Commuting

PubMed Central

Djurhuus, Sune; Hansen, Henning S.; Aadahl, Mette; Glümer, Charlotte

2014-01-01

Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting. PMID:25489998

The association between access to public transportation and self-reported active commuting.

PubMed

Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette; Glümer, Charlotte

2014-12-05

Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting.

Understanding and managing disaster evacuation on a transportation network.

PubMed

Lambert, James H; Parlak, Ayse I; Zhou, Qian; Miller, John S; Fontaine, Michael D; Guterbock, Thomas M; Clements, Janet L; Thekdi, Shital A

2013-01-01

Uncertain population behaviors in a regional emergency could potentially harm the performance of the region's transportation system and subsequent evacuation effort. The integration of behavioral survey data with travel demand modeling enables an assessment of transportation system performance and the identification of operational and public health countermeasures. This paper analyzes transportation system demand and system performance for emergency management in three disaster scenarios. A two-step methodology first estimates the number of trips evacuating the region, thereby capturing behavioral aspects in a scientifically defensible manner based on survey results, and second, assigns these trips to a regional highway network, using geographic information systems software, thereby making the methodology transferable to other locations. Performance measures are generated for each scenario including maps of volume-to-capacity ratios, geographic contours of evacuation time from the center of the region, and link-specific metrics such as weighted average speed and traffic volume. The methods are demonstrated on a 600 segment transportation network in Washington, DC (USA) and are applied to three scenarios involving attacks from radiological dispersion devices (e.g., dirty bombs). The results suggests that: (1) a single detonation would degrade transportation system performance two to three times more than that which occurs during a typical weekday afternoon peak hour, (2) volume on several critical arterials within the network would exceed capacity in the represented scenarios, and (3) resulting travel times to reach intended destinations imply that un-aided evacuation is impractical. These results assist decisions made by two categories of emergency responders: (1) transportation managers who provide traveler information and who make operational adjustments to improve the network (e.g., signal retiming) and (2) public health officials who maintain shelters, food and

Development of hybrid genetic-algorithm-based neural networks using regression trees for modeling air quality inside a public transportation bus.

PubMed

Kadiyala, Akhil; Kaur, Devinder; Kumar, Ashok

2013-02-01

The present study developed a novel approach to modeling indoor air quality (IAQ) of a public transportation bus by the development of hybrid genetic-algorithm-based neural networks (also known as evolutionary neural networks) with input variables optimized from using the regression trees, referred as the GART approach. This study validated the applicability of the GART modeling approach in solving complex nonlinear systems by accurately predicting the monitored contaminants of carbon dioxide (CO2), carbon monoxide (CO), nitric oxide (NO), sulfur dioxide (SO2), 0.3-0.4 microm sized particle numbers, 0.4-0.5 microm sized particle numbers, particulate matter (PM) concentrations less than 1.0 microm (PM10), and PM concentrations less than 2.5 microm (PM2.5) inside a public transportation bus operating on 20% grade biodiesel in Toledo, OH. First, the important variables affecting each monitored in-bus contaminant were determined using regression trees. Second, the analysis of variance was used as a complimentary sensitivity analysis to the regression tree results to determine a subset of statistically significant variables affecting each monitored in-bus contaminant. Finally, the identified subsets of statistically significant variables were used as inputs to develop three artificial neural network (ANN) models. The models developed were regression tree-based back-propagation network (BPN-RT), regression tree-based radial basis function network (RBFN-RT), and GART models. Performance measures were used to validate the predictive capacity of the developed IAQ models. The results from this approach were compared with the results obtained from using a theoretical approach and a generalized practicable approach to modeling IAQ that included the consideration of additional independent variables when developing the aforementioned ANN models. The hybrid GART models were able to capture majority of the variance in the monitored in-bus contaminants. The genetic

Michigan transportation facts & figures : public transportation

DOT National Transportation Integrated Search

2002-08-16

This on-line document is part of a series, Transportation Facts & Figures, by the Michigan Department of Transportation (MDOT). The Public Transit section of Transportation Facts & Figures cover such topics as intercity bus service, intercity rail se...

Transport link scanner: simulating geographic transport network expansion through individual investments

NASA Astrophysics Data System (ADS)

Jacobs-Crisioni, C.; Koopmans, C. C.

2016-07-01

This paper introduces a GIS-based model that simulates the geographic expansion of transport networks by several decision-makers with varying objectives. The model progressively adds extensions to a growing network by choosing the most attractive investments from a limited choice set. Attractiveness is defined as a function of variables in which revenue and broader societal benefits may play a role and can be based on empirically underpinned parameters that may differ according to private or public interests. The choice set is selected from an exhaustive set of links and presumably contains those investment options that best meet private operator's objectives by balancing the revenues of additional fare against construction costs. The investment options consist of geographically plausible routes with potential detours. These routes are generated using a fine-meshed regularly latticed network and shortest path finding methods. Additionally, two indicators of the geographic accuracy of the simulated networks are introduced. A historical case study is presented to demonstrate the model's first results. These results show that the modelled networks reproduce relevant results of the historically built network with reasonable accuracy.

Transportation Network Analysis and Decomposition Methods

DOT National Transportation Integrated Search

1978-03-01

The report outlines research in transportation network analysis using decomposition techniques as a basis for problem solutions. Two transportation network problems were considered in detail: a freight network flow problem and a scheduling problem fo...

Cytoskeletal Network Morphology Regulates Intracellular Transport Dynamics.

PubMed

Ando, David; Korabel, Nickolay; Huang, Kerwyn Casey; Gopinathan, Ajay

2015-10-20

Intracellular transport is essential for maintaining proper cellular function in most eukaryotic cells, with perturbations in active transport resulting in several types of disease. Efficient delivery of critical cargos to specific locations is accomplished through a combination of passive diffusion and active transport by molecular motors that ballistically move along a network of cytoskeletal filaments. Although motor-based transport is known to be necessary to overcome cytoplasmic crowding and the limited range of diffusion within reasonable timescales, the topological features of the cytoskeletal network that regulate transport efficiency and robustness have not been established. Using a continuum diffusion model, we observed that the time required for cellular transport was minimized when the network was localized near the nucleus. In simulations that explicitly incorporated network spatial architectures, total filament mass was the primary driver of network transit times. However, filament traps that redirect cargo back to the nucleus caused large variations in network transport. Filament polarity was more important than filament orientation in reducing average transit times, and transport properties were optimized in networks with intermediate motor on and off rates. Our results provide important insights into the functional constraints on intracellular transport under which cells have evolved cytoskeletal structures, and have potential applications for enhancing reactions in biomimetic systems through rational transport network design. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Cytoskeletal Network Morphology Regulates Intracellular Transport Dynamics

PubMed Central

Ando, David; Korabel, Nickolay; Huang, Kerwyn Casey; Gopinathan, Ajay

2015-01-01

Intracellular transport is essential for maintaining proper cellular function in most eukaryotic cells, with perturbations in active transport resulting in several types of disease. Efficient delivery of critical cargos to specific locations is accomplished through a combination of passive diffusion and active transport by molecular motors that ballistically move along a network of cytoskeletal filaments. Although motor-based transport is known to be necessary to overcome cytoplasmic crowding and the limited range of diffusion within reasonable timescales, the topological features of the cytoskeletal network that regulate transport efficiency and robustness have not been established. Using a continuum diffusion model, we observed that the time required for cellular transport was minimized when the network was localized near the nucleus. In simulations that explicitly incorporated network spatial architectures, total filament mass was the primary driver of network transit times. However, filament traps that redirect cargo back to the nucleus caused large variations in network transport. Filament polarity was more important than filament orientation in reducing average transit times, and transport properties were optimized in networks with intermediate motor on and off rates. Our results provide important insights into the functional constraints on intracellular transport under which cells have evolved cytoskeletal structures, and have potential applications for enhancing reactions in biomimetic systems through rational transport network design. PMID:26488648

An Investigation of Synchrony in Transport Networks

NASA Technical Reports Server (NTRS)

Kincaid, Rex K.; Alexandrov, Natalia M.; Holroyd, Michael J.

2007-01-01

The cumulative degree distributions of transport networks, such as air transportation networks and respiratory neuronal networks, follow power laws. The significance of power laws with respect to other network performance measures, such as throughput and synchronization, remains an open question. Evolving methods for the analysis and design of air transportation networks must address network performance in the face of increasing demands and the need to contain and control local network disturbances, such as congestion. Toward this end, we investigate functional relationships that govern the performance of transport networks; for example, the links between the first nontrivial eigenvalue of a network's Laplacian matrix - a quantitative measure of network synchronizability - and other global network parameters. In particular, among networks with a fixed degree distribution and fixed network assortativity (a measure of a network's preference to attach nodes based on a similarity or difference), those with the small eigenvalue are shown to be poor synchronizers, to have much longer shortest paths and to have greater clustering in comparison to those with large. A simulation of a respiratory network adds data to our investigation. This study is a beginning step in developing metrics and design variables for the analysis and active design of air transport networks.

Charge transport network dynamics in molecular aggregates

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

Jackson, Nicholas E.; Chen, Lin X.; Ratner, Mark A.

2016-07-20

Due to the nonperiodic nature of charge transport in disordered systems, generating insight into static charge transport networks, as well as analyzing the network dynamics, can be challenging. Here, we apply time-dependent network analysis to scrutinize the charge transport networks of two representative molecular semiconductors: a rigid n-type molecule, perylenediimide, and a flexible p-type molecule, bBDT(TDPP)2. Simulations reveal the relevant timescale for local transfer integral decorrelation to be ~100 fs, which is shown to be faster than that of a crystalline morphology of the same molecule. Using a simple graph metric, global network changes are observed over timescales competitive withmore » charge carrier lifetimes. These insights demonstrate that static charge transport networks are qualitatively inadequate, whereas average networks often overestimate network connectivity. Finally, a simple methodology for tracking dynamic charge transport properties is proposed.« less

Individual Public Transportation Accessibility is Positively Associated with Self-Reported Active Commuting.

PubMed

Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette; Glümer, Charlotte

2014-01-01

Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. Twenty-eight thousand nine hundred twenty-eight commuters in The Capital Region of Denmark reported self-reported time spent either walking or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multi-modal network in a GIS. Multilevel logistic regression was used to analyze the association between accessibility, expressed as access area, and being an active commuter. Public transport accessibility area based on all stops within walking and cycling distance was positively associated with being an active commuter. Distance to work, age, and gender modified the associations. Residing within 10 km commute distance and in areas of high accessibility was associated with being an active commuter and meeting the recommendations of physical activity. For the respondents above 29 years, individual public transportation accessibility was positively associated with being an active commuter. Women having high accessibility had significantly higher odds of being an active commuter compared to having a low accessibility. For men, the associations were insignificant. This study extends the knowledge about the driving forces of using public transportation for commuting by examining the individual public transportation accessibility. Findings suggest that transportation accessibility supports active commuting and planning of improved public transit accessibility

Individual Public Transportation Accessibility is Positively Associated with Self-Reported Active Commuting

PubMed Central

Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette; Glümer, Charlotte

2014-01-01

Background: Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. Methods: Twenty-eight thousand nine hundred twenty-eight commuters in The Capital Region of Denmark reported self-reported time spent either walking or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multi-modal network in a GIS. Multilevel logistic regression was used to analyze the association between accessibility, expressed as access area, and being an active commuter. Results: Public transport accessibility area based on all stops within walking and cycling distance was positively associated with being an active commuter. Distance to work, age, and gender modified the associations. Residing within 10 km commute distance and in areas of high accessibility was associated with being an active commuter and meeting the recommendations of physical activity. For the respondents above 29 years, individual public transportation accessibility was positively associated with being an active commuter. Women having high accessibility had significantly higher odds of being an active commuter compared to having a low accessibility. For men, the associations were insignificant. Conclusion: This study extends the knowledge about the driving forces of using public transportation for commuting by examining the individual public transportation accessibility. Findings suggest that transportation accessibility supports active commuting and planning

The integration level of public transportation in Makassar City

NASA Astrophysics Data System (ADS)

Kasim, A. M. R.; Wicaksono, A. D.; Kurniawan, E. B.

2017-06-01

Multimodal transportation is transportation modes that can combine one with the other modes properly, efficiently and effectively so that people can move from one type of transportation to another modes with fast, cheap and convenient. The integration of transport services and infrastructure network is not fully realized, among others, can be seen from the public transport service between modes, one with the other modes, which makes people have to travel by other modes and is not served by public transport canal. Furthermore, intramoda displacement can not be done easily and quickly, some things that makes people tend to prefer private rather than public transport vehicles in doing movement. The main objective of this study was to determine the level of integration of modes of land transportation in the city of Makassar. By using analysis of physical alignment, non-physical, and analysis of travel time, which is then summarized into a canvas ratings to get an idea of the level of integration in general. The results showed that the level of integration of modes consist of two criteria with a very low value, 4 criteria with low and medium value, two criteria with a high value, as well as one criterion with very high value. Meanwhile, the variable of integration that influence people’s preferences in order from the highest value is the number of the fleet, the availability of routes, the number of passengers compared with the load factor, the location where the stopping points up and down, and the last is the location of the terminal with the place up and down the number of the fleet, availability of service, number of passengers, the location of the terminal to place up and down the passenger, as well as the location where the up and down passengers on the origin and destination. Some of the variables that have a low and very low value, is a variable that should receive greater attention from the municipality, so the concept of the integration of transport modes

Spatiotemporal Recurrent Convolutional Networks for Traffic Prediction in Transportation Networks

PubMed Central

Yu, Haiyang; Wu, Zhihai; Wang, Shuqin; Wang, Yunpeng; Ma, Xiaolei

2017-01-01

Predicting large-scale transportation network traffic has become an important and challenging topic in recent decades. Inspired by the domain knowledge of motion prediction, in which the future motion of an object can be predicted based on previous scenes, we propose a network grid representation method that can retain the fine-scale structure of a transportation network. Network-wide traffic speeds are converted into a series of static images and input into a novel deep architecture, namely, spatiotemporal recurrent convolutional networks (SRCNs), for traffic forecasting. The proposed SRCNs inherit the advantages of deep convolutional neural networks (DCNNs) and long short-term memory (LSTM) neural networks. The spatial dependencies of network-wide traffic can be captured by DCNNs, and the temporal dynamics can be learned by LSTMs. An experiment on a Beijing transportation network with 278 links demonstrates that SRCNs outperform other deep learning-based algorithms in both short-term and long-term traffic prediction. PMID:28672867

Spatiotemporal Recurrent Convolutional Networks for Traffic Prediction in Transportation Networks.

PubMed

Yu, Haiyang; Wu, Zhihai; Wang, Shuqin; Wang, Yunpeng; Ma, Xiaolei

2017-06-26

Predicting large-scale transportation network traffic has become an important and challenging topic in recent decades. Inspired by the domain knowledge of motion prediction, in which the future motion of an object can be predicted based on previous scenes, we propose a network grid representation method that can retain the fine-scale structure of a transportation network. Network-wide traffic speeds are converted into a series of static images and input into a novel deep architecture, namely, spatiotemporal recurrent convolutional networks (SRCNs), for traffic forecasting. The proposed SRCNs inherit the advantages of deep convolutional neural networks (DCNNs) and long short-term memory (LSTM) neural networks. The spatial dependencies of network-wide traffic can be captured by DCNNs, and the temporal dynamics can be learned by LSTMs. An experiment on a Beijing transportation network with 278 links demonstrates that SRCNs outperform other deep learning-based algorithms in both short-term and long-term traffic prediction.

A simulation study of the impact of the public-private partnership strategy on the performance of transport infrastructure.

PubMed

Huang, Zhengfeng; Zheng, Pengjun; Ma, Yanqiang; Li, Xuan; Xu, Wenjun; Zhu, Wanlu

2016-01-01

The choice of investment strategy has a great impact on the performance of transport infrastructure. Positive projects such as the "Subway plus Property" model in Hong Kong have created sustainable financial profits for the public transport projects. Owing to a series of public debt and other constraints, public-private partnership (PPP) was introduced as an innovative investment model to address this issue and help develop transport infrastructure. Yet, few studies provide a deeper understanding of relationships between PPP strategy and the performance of such transport projects (particularly the whole transport system). This paper defines the research scope as a regional network of freeway. With a popular PPP model, travel demand prediction method, and relevant parameters as input, agents in a simulation framework can simulate the choice of PPP freeway over time. The simulation framework can be used to analyze the relationship between the PPP strategy and performance of the regional freeway network. This study uses the Freeway Network of Yangtze River Delta (FN-YRD) in China as the context. The results demonstrate the value of using simulation models of complex transportation systems to help decision makers choose the right PPP projects. Such a tool is viewed as particularly important given the ongoing transformation of functions of the Chinese transportation sector, including franchise rights of transport projects, and freeway charging mechanism.

Toward Optimal Transport Networks

NASA Technical Reports Server (NTRS)

Alexandrov, Natalia; Kincaid, Rex K.; Vargo, Erik P.

2008-01-01

Strictly evolutionary approaches to improving the air transport system a highly complex network of interacting systems no longer suffice in the face of demand that is projected to double or triple in the near future. Thus evolutionary approaches should be augmented with active design methods. The ability to actively design, optimize and control a system presupposes the existence of predictive modeling and reasonably well-defined functional dependences between the controllable variables of the system and objective and constraint functions for optimization. Following recent advances in the studies of the effects of network topology structure on dynamics, we investigate the performance of dynamic processes on transport networks as a function of the first nontrivial eigenvalue of the network's Laplacian, which, in turn, is a function of the network s connectivity and modularity. The last two characteristics can be controlled and tuned via optimization. We consider design optimization problem formulations. We have developed a flexible simulation of network topology coupled with flows on the network for use as a platform for computational experiments.

Structure and formation of ant transportation networks

PubMed Central

Latty, Tanya; Ramsch, Kai; Ito, Kentaro; Nakagaki, Toshiyuki; Sumpter, David J. T.; Middendorf, Martin; Beekman, Madeleine

2011-01-01

Many biological systems use extensive networks for the transport of resources and information. Ants are no exception. How do biological systems achieve efficient transportation networks in the absence of centralized control and without global knowledge of the environment? Here, we address this question by studying the formation and properties of inter-nest transportation networks in the Argentine ant (Linepithema humile). We find that the formation of inter-nest networks depends on the number of ants involved in the construction process. When the number of ants is sufficient and networks do form, they tend to have short total length but a low level of robustness. These networks are topologically similar to either minimum spanning trees or Steiner networks. The process of network formation involves an initial construction of multiple links followed by a pruning process that reduces the number of trails. Our study thus illuminates the conditions under and the process by which minimal biological transport networks can be constructed. PMID:21288958

Transport and percolation in complex networks

NASA Astrophysics Data System (ADS)

Li, Guanliang

To design complex networks with optimal transport properties such as flow efficiency, we consider three approaches to understanding transport and percolation in complex networks. We analyze the effects of randomizing the strengths of connections, randomly adding long-range connections to regular lattices, and percolation of spatially constrained networks. Various real-world networks often have links that are differentiated in terms of their strength, intensity, or capacity. We study the distribution P(σ) of the equivalent conductance for Erdoḧs-Rényi (ER) and scale-free (SF) weighted resistor networks with N nodes, for which links are assigned with conductance σ i ≡ e-axi, where xi is a random variable with 0 < xi < 1. We find, both analytically and numerically, that P(σ) for ER networks exhibits two regimes: (i) For σ < e-apc, P(σ) is independent of N and scales as a power law P(σ) ˜ sk/a-1 . Here pc = 1/ is the critical percolation threshold of the network and is the average degree of the network. (ii) For σ > e -apc, P(σ) has strong N dependence and scales as P(σ) ˜ f(σ, apc/N1/3). Transport properties are greatly affected by the topology of networks. We investigate the transport problem in lattices with long-range connections and subject to a cost constraint, seeking design principles for optimal transport networks. Our network is built from a regular d-dimensional lattice to be improved by adding long-range connections with probability Pij ˜ r-aij , where rij is the lattice distance between site i and j. We introduce a cost constraint on the total length of the additional links and find optimal transport in the system for α = d + 1, established here for d = 1, 2 and 3 for regular lattices and df for fractals. Remarkably, this cost constraint approach remains optimal, regardless of the strategy used for transport, whether based on local or global knowledge of the network structure. To further understand the role that long

Structural Properties of the Brazilian Air Transportation Network.

PubMed

Couto, Guilherme S; da Silva, Ana Paula Couto; Ruiz, Linnyer B; Benevenuto, Fabrício

2015-09-01

The air transportation network in a country has a great impact on the local, national and global economy. In this paper, we analyze the air transportation network in Brazil with complex network features to better understand its characteristics. In our analysis, we built networks composed either by national or by international flights. We also consider the network when both types of flights are put together. Interesting conclusions emerge from our analysis. For instance, Viracopos Airport (Campinas City) is the most central and connected airport on the national flights network. Any operational problem in this airport separates the Brazilian national network into six distinct subnetworks. Moreover, the Brazilian air transportation network exhibits small world characteristics and national connections network follows a power law distribution. Therefore, our analysis sheds light on the current Brazilian air transportation infrastructure, bringing a novel understanding that may help face the recent fast growth in the usage of the Brazilian transport network.

Transport and public health in China: the road to a healthy future

PubMed Central

Jiang, Baoguo; Liang, Song; Peng, Zhong-Ren; Cong, Haozhe; Levy, Morgan; Cheng, Qu; Wang, Tianbing; Remais, Justin

2017-01-01

Transportation-related risk factors are a major source of morbidity and mortality in China, where expansion of road networks and surges in personal vehicle ownership are having profound effects on public health. Road traffic injuries and fatalities have increased alongside motorized transport in China, and accident injury risk is aggravated by inadequate emergency response systems and trauma care. National air quality standards and emission control technologies are having a positive effect, yet persistent air pollution is increasingly attributable to a growing and outdated vehicle fleet, and famously congested roads. Urban design favors motorized transport, and physical activity and its associated health benefits are hindered by poor urban infrastructure. Transport emissions of greenhouse gases contribute substantially to regional and global climate change, which compound public health risks from multiple factors. Despite these complex challenges, technological advances and innovations in planning and policy stand to make China a leader in sustainable, healthy transportation. PMID:29047445

Publications | Transportation Research | NREL

Science.gov Websites

Overview Thumbnail image of publication cover Sustainable TransportationPDF This overview fact sheet image of publication cover Alternative Fuels Data CenterPDF Thumbnail image of publication cover Clean CitiesPDF Thumbnail image of publication cover Fleet ToolsPDF Thumbnail image of publication cover Fuels

Complex Network Theory Applied to the Growth of Kuala Lumpur's Public Urban Rail Transit Network.

PubMed

Ding, Rui; Ujang, Norsidah; Hamid, Hussain Bin; Wu, Jianjun

2015-01-01

Recently, the number of studies involving complex network applications in transportation has increased steadily as scholars from various fields analyze traffic networks. Nonetheless, research on rail network growth is relatively rare. This research examines the evolution of the Public Urban Rail Transit Networks of Kuala Lumpur (PURTNoKL) based on complex network theory and covers both the topological structure of the rail system and future trends in network growth. In addition, network performance when facing different attack strategies is also assessed. Three topological network characteristics are considered: connections, clustering and centrality. In PURTNoKL, we found that the total number of nodes and edges exhibit a linear relationship and that the average degree stays within the interval [2.0488, 2.6774] with heavy-tailed distributions. The evolutionary process shows that the cumulative probability distribution (CPD) of degree and the average shortest path length show good fit with exponential distribution and normal distribution, respectively. Moreover, PURTNoKL exhibits clear cluster characteristics; most of the nodes have a 2-core value, and the CPDs of the centrality's closeness and betweenness follow a normal distribution function and an exponential distribution, respectively. Finally, we discuss four different types of network growth styles and the line extension process, which reveal that the rail network's growth is likely based on the nodes with the biggest lengths of the shortest path and that network protection should emphasize those nodes with the largest degrees and the highest betweenness values. This research may enhance the networkability of the rail system and better shape the future growth of public rail networks.

Comparative analysis of quantitative efficiency evaluation methods for transportation networks.

PubMed

He, Yuxin; Qin, Jin; Hong, Jian

2017-01-01

An effective evaluation of transportation network efficiency could offer guidance for the optimal control of urban traffic. Based on the introduction and related mathematical analysis of three quantitative evaluation methods for transportation network efficiency, this paper compares the information measured by them, including network structure, traffic demand, travel choice behavior and other factors which affect network efficiency. Accordingly, the applicability of various evaluation methods is discussed. Through analyzing different transportation network examples it is obtained that Q-H method could reflect the influence of network structure, traffic demand and user route choice behavior on transportation network efficiency well. In addition, the transportation network efficiency measured by this method and Braess's Paradox can be explained with each other, which indicates a better evaluation of the real operation condition of transportation network. Through the analysis of the network efficiency calculated by Q-H method, it can also be drawn that a specific appropriate demand is existed to a given transportation network. Meanwhile, under the fixed demand, both the critical network structure that guarantees the stability and the basic operation of the network and a specific network structure contributing to the largest value of the transportation network efficiency can be identified.

Rural Public Transportation: An Instructional Module.

ERIC Educational Resources Information Center

Hayden, Linda

A concept-based introduction to rural public transportation is provided in this instructional module for undergraduate and graduate transportation-related courses for disciplines such as engineering, business, sociology, and technology. Rural public transportation involves systems in rural and small urban areas with populations under 50,000…

Mobile Network Data for Public Health: Opportunities and Challenges

PubMed Central

Oliver, Nuria; Matic, Aleksandar; Frias-Martinez, Enrique

2015-01-01

The ubiquity of mobile phones worldwide is generating an unprecedented amount of human behavioral data both at an individual and aggregated levels. The study of this data as a rich source of information about human behavior emerged almost a decade ago. Since then, it has grown into a fertile area of research named computational social sciences with a wide variety of applications in different fields such as social networks, urban and transport planning, economic development, emergency relief, and, recently, public health. In this paper, we briefly describe the state of the art on using mobile phone data for public health, and present the opportunities and challenges that this kind of data presents for public health. PMID:26301211

Comparative analysis of quantitative efficiency evaluation methods for transportation networks

PubMed Central

He, Yuxin; Hong, Jian

2017-01-01

An effective evaluation of transportation network efficiency could offer guidance for the optimal control of urban traffic. Based on the introduction and related mathematical analysis of three quantitative evaluation methods for transportation network efficiency, this paper compares the information measured by them, including network structure, traffic demand, travel choice behavior and other factors which affect network efficiency. Accordingly, the applicability of various evaluation methods is discussed. Through analyzing different transportation network examples it is obtained that Q-H method could reflect the influence of network structure, traffic demand and user route choice behavior on transportation network efficiency well. In addition, the transportation network efficiency measured by this method and Braess’s Paradox can be explained with each other, which indicates a better evaluation of the real operation condition of transportation network. Through the analysis of the network efficiency calculated by Q-H method, it can also be drawn that a specific appropriate demand is existed to a given transportation network. Meanwhile, under the fixed demand, both the critical network structure that guarantees the stability and the basic operation of the network and a specific network structure contributing to the largest value of the transportation network efficiency can be identified. PMID:28399165

Individual- and area-level disparities in access to the road network, subway system and a public bicycle share program on the Island of Montreal, Canada.

PubMed

Fuller, Daniel; Gauvin, Lise; Kestens, Yan

2013-02-01

Few studies have examined potential disparities in access to transportation infrastructures, an important determinant of population health. To examine individual- and area-level disparities in access to the road network, public transportation system, and a public bicycle share program in Montreal, Canada. Examining associations between sociodemographic variables and access to the road network, public transportation system, and a public bicycle share program, 6,495 adult respondents (mean age, 48.7 years; 59.0 % female) nested in 33 areas were included in a multilevel analysis. Individuals with lower incomes lived significantly closer to public transportation and the bicycle share program. At the area level, the interaction between low-education and low-income neighborhoods showed that these areas were significantly closer to public transportation and the bicycle share program controlling for individual and urbanicity variables. More deprived areas of the Island of Montreal have better access to transportation infrastructure than less-deprived areas.

Public Participation Procedure in Integrated Transport and Green Infrastructure Planning

NASA Astrophysics Data System (ADS)

Finka, Maroš; Ondrejička, Vladimír; Jamečný, Ľubomír; Husár, Milan

2017-10-01

The dialogue among the decision makers and stakeholders is a crucial part of any decision-making processes, particularly in case of integrated transportation planning and planning of green infrastructure where a multitude of actors is present. Although the theory of public participation is well-developed after several decades of research, there is still a lack of practical guidelines due to the specificity of public participation challenges. The paper presents a model of public participation for integrated transport and green infrastructure planning for international project TRANSGREEN covering the area of five European countries - Slovakia, Czech Republic, Austria, Hungary and Romania. The challenge of the project is to coordinate the efforts of public actors and NGOs in international environment in oftentimes precarious projects of transport infrastructure building and developing of green infrastructure. The project aims at developing and environmentally-friendly and safe international transport network. The proposed public participation procedure consists of five main steps - spread of information (passive), collection of information (consultation), intermediate discussion, engagement and partnership (empowerment). The initial spread of information is a process of communicating with the stakeholders, informing and educating them and it is based on their willingness to be informed. The methods used in this stage are public displays, newsletters or press releases. The second step of consultation is based on transacting the opinions of stakeholders to the decision makers. Pools, surveys, public hearings or written responses are examples of the multitude of ways to achieve this objective and the main principle of openness of stakeholders. The third step is intermediate discussion where all sides of are invited to a dialogue using the tools such as public meetings, workshops or urban walks. The fourth step is an engagement based on humble negotiation, arbitration and

Optimizing Nutrient Uptake in Biological Transport Networks

NASA Astrophysics Data System (ADS)

Ronellenfitsch, Henrik; Katifori, Eleni

2013-03-01

Many biological systems employ complex networks of vascular tubes to facilitate transport of solute nutrients, examples include the vascular system of plants (phloem), some fungi, and the slime-mold Physarum. It is believed that such networks are optimized through evolution for carrying out their designated task. We propose a set of hydrodynamic governing equations for solute transport in a complex network, and obtain the optimal network architecture for various classes of optimizing functionals. We finally discuss the topological properties and statistical mechanics of the resulting complex networks, and examine correspondence of the obtained networks to those found in actual biological systems.

Influence of public transport in black carbon

NASA Astrophysics Data System (ADS)

Vasquez, Y.; Oyola, P.; Gramsch, E. V.; Moreno, F.; Rubio, M.

2013-05-01

. Yañez, a decrease in Alameda and no change in Departamental. The small increases in BC in some streets, and the decrease observed in an avenue dominated by public transportation, suggest that the reason of the increase in BC concentration is related to the increment in the total number of vehicles (diesel and non diesel). The lower number of buses or improved bus technology did not have an effect on BC concentrations. The three streets that increased or maintained the BC concentration had higher number of vehicles in 2007. Alameda Avenue showed a decrease in BC concentration that had to do with a lower total number of vehicles as well as improved bus technology in year 2007 than year 2005. The emissions, related exclusively to public transportation, seem to have diminished after the Transantiago implementation, considering the outcome in the observed BC in Alameda, mainly dominated by the public transport network. These results are an indication that in order to decrease pollution near a street is not enough to reduce the number of buses or improve its quality, but to reduce the total number of vehicles.

2007 public transportation fact book

DOT National Transportation Integrated Search

2007-05-01

This book includes only public transportation data and excludes taxicab, unregulated jitney, school, sightseeing, intercity, charter, : military, and services not available to the general public, or segments of the general public (e.g., governmental ...

Minimum requirements for predictive pore-network modeling of solute transport in micromodels

NASA Astrophysics Data System (ADS)

Mehmani, Yashar; Tchelepi, Hamdi A.

2017-10-01

Pore-scale models are now an integral part of analyzing fluid dynamics in porous materials (e.g., rocks, soils, fuel cells). Pore network models (PNM) are particularly attractive due to their computational efficiency. However, quantitative predictions with PNM have not always been successful. We focus on single-phase transport of a passive tracer under advection-dominated regimes and compare PNM with high-fidelity direct numerical simulations (DNS) for a range of micromodel heterogeneities. We identify the minimum requirements for predictive PNM of transport. They are: (a) flow-based network extraction, i.e., discretizing the pore space based on the underlying velocity field, (b) a Lagrangian (particle tracking) simulation framework, and (c) accurate transfer of particles from one pore throat to the next. We develop novel network extraction and particle tracking PNM methods that meet these requirements. Moreover, we show that certain established PNM practices in the literature can result in first-order errors in modeling advection-dominated transport. They include: all Eulerian PNMs, networks extracted based on geometric metrics only, and flux-based nodal transfer probabilities. Preliminary results for a 3D sphere pack are also presented. The simulation inputs for this work are made public to serve as a benchmark for the research community.

Flywheel-Based Fast Charging Station - FFCS for Electric Vehicles and Public Transportation

NASA Astrophysics Data System (ADS)

Gabbar, Hossam A.; Othman, Ahmed M.

2017-08-01

This paper demonstrates novel Flywheel-based Fast Charging Station (FFCS) for high performance and profitable charging infrastructures for public electric buses. The design criteria will be provided for fast charging stations. The station would support the private and open charging framework. Flywheel Energy storage system is utilized to offer advanced energy storage for charging stations to achieve clean public transportation, including electric buses with reducing GHG, including CO2 emission reduction. The integrated modelling and management system in the station is performed by a decision-based control platform that coordinates the power streams between the quick chargers, the flywheel storage framework, photovoltaic cells and the network association. There is a tidy exchange up between the capacity rate of flywheel framework and the power rating of the network association.”

Computer Code for Transportation Network Design and Analysis

DOT National Transportation Integrated Search

1977-01-01

This document describes the results of research into the application of the mathematical programming technique of decomposition to practical transportation network problems. A computer code called Catnap (for Control Analysis Transportation Network A...

Photo-induced Mass Transport through Polymer Networks

NASA Astrophysics Data System (ADS)

Meng, Yuan; Anthamatten, Mitchell

2014-03-01

Among adaptable materials, photo-responsive polymers are especially attractive as they allow for spatiotemporal stimuli and response. We have recently developed a macromolecular network capable of photo-induced mass transport of covalently bound species. The system comprises of crosslinked chains that form an elastic network and photosensitive fluorescent arms that become mobile upon irradiation. We form loosely crosslinked polymer networks by Michael-Addition between multifunctional thiols and small molecule containing acrylate end-groups. The arms are connected to the network by allyl sulfide, that undergoes addition-fragmentation chain transfer (AFCT) in the presence of free radicals, releasing diffusible fluorophore. The networks are loaded with photoinitiator to allow for spatial modulation of the AFCT reactions. FRAP experiments within bulk elastomers are conducted to establish correlations between the fluorophore's diffusion coefficient and experimental variables such as network architecture, temperature and UV intensity. Photo-induced mass transport between two contacted films is demonstrated, and release of fluorophore into a solvent is investigated. Spatial and temporal control of mass transport could benefit drug release, printing, and sensing applications.

Statistical analysis of passenger-crowding in bus transport network of Harbin

NASA Astrophysics Data System (ADS)

Hu, Baoyu; Feng, Shumin; Li, Jinyang; Zhao, Hu

2018-01-01

Passenger flow data is indispensable but rare in the study of public transport networks. In this study, we focus on the passenger-crowding characteristics of the bus transport network of Harbin (BTN-H) based on passenger flow investigation. The three frequency histograms for all the uplinks and downlinks in Harbin are presented, including passengers on the bus at each section, crowding coefficients, and position parameters of crowded sections. The differences in crowding position are analyzed on each route. The distributions of degree and crowding degree (in directed space L) follow an exponential law. The new finding indicates that there are many stations with few crowded sections and a few stations with many crowded sections. The distributions of path length and crowded length (in directed space P) are presented based on the minimum transfer times, and it is found that they can be fitted by a composite Gaussian function and a Gaussian function, respectively. The stations and paths can be divided into three crowd levels. We conclude that BTN-H is crowded from a network-based perspective.

Transportation Network Topologies

NASA Technical Reports Server (NTRS)

Alexandrov, Natalia (Editor)

2004-01-01

The existing U.S. hub-and-spoke air transportation system is reaching saturation. Major aspects of the current system, such as capacity, safety, mobility, customer satisfaction, security, communications, and ecological effects, require improvements. The changing dynamics - increased presence of general aviation, unmanned autonomous vehicles, military aircraft in civil airspace as part of homeland defense - contributes to growing complexity of airspace. The system has proven remarkably resistant to change. NASA Langley Research Center and the National Institute of Aerospace conducted a workshop on Transportation Network Topologies on 9-10 December 2003 in Williamsburg, Virginia. The workshop aimed to examine the feasibility of traditional methods for complex system analysis and design as well as potential novel alternatives in application to transportation systems, identify state-of-the-art models and methods, conduct gap analysis, and thus to lay a foundation for establishing a focused research program in complex systems applied to air transportation.

Spatial analysis of bus transport networks using network theory

NASA Astrophysics Data System (ADS)

Shanmukhappa, Tanuja; Ho, Ivan Wang-Hei; Tse, Chi Kong

2018-07-01

In this paper, we analyze the bus transport network (BTN) structure considering the spatial embedding of the network for three cities, namely, Hong Kong (HK), London (LD), and Bengaluru (BL). We propose a novel approach called supernode graph structuring for modeling the bus transport network. A static demand estimation procedure is proposed to assign the node weights by considering the points of interests (POIs) and the population distribution in the city over various localized zones. In addition, the end-to-end delay is proposed as a parameter to measure the topological efficiency of the bus networks instead of the shortest distance measure used in previous works. With the aid of supernode graph representation, important network parameters are analyzed for the directed, weighted and geo-referenced bus transport networks. It is observed that the supernode concept has significant advantage in analyzing the inherent topological behavior. For instance, the scale-free and small-world behavior becomes evident with supernode representation as compared to conventional or regular graph representation for the Hong Kong network. Significant improvement in clustering, reduction in path length, and increase in centrality values are observed in all the three networks with supernode representation. The correlation between topologically central nodes and the geographically central nodes reveals the interesting fact that the proposed static demand estimation method for assigning node weights aids in better identifying the geographically significant nodes in the network. The impact of these geographically significant nodes on the local traffic behavior is demonstrated by simulation using the SUMO (Simulation of Urban Mobility) tool which is also supported by real-world empirical data, and our results indicate that the traffic speed around a particular bus stop can reach a jammed state from a free flow state due to the presence of these geographically important nodes. A comparison

Energy 101: Sustainable Public Transportation

ScienceCinema

None

2018-01-16

You may already know that public transportation reduces pollution and eases congestion on the road. However, many transit fleets are switching over to cleaner, alternative fuels and technologies, making this mode of transportation even more sustainable.

Energy 101: Sustainable Public Transportation

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

None

2016-09-07

You may already know that public transportation reduces pollution and eases congestion on the road. However, many transit fleets are switching over to cleaner, alternative fuels and technologies, making this mode of transportation even more sustainable.

Public Transportation Pricing: An Instructional Module.

ERIC Educational Resources Information Center

McWha, Charley

A concept-based introduction to public transportation pricing is presented in this instructional module for undergraduate and graduate transportation-related courses for disciplines such as engineering, business administration, and technology. After an introductory section on transportation pricing planning and the history of transportation system…

2006 public transportation fact book

DOT National Transportation Integrated Search

2006-04-01

This book includes only public transportation data and excludes taxicab, unregulated jitney, school, sightseeing, intercity, charter, : military, and non-public service (e.g., governmental and corporate shuttles), and special application systems (e.g...

2004 public transportation fact book

DOT National Transportation Integrated Search

2004-03-01

This book includes only public transportation data and excludes taxicab, unregulated jitney, school, sightseeing, intercity, charter, : military, and non-public service (e.g., governmental and corporate shuttles), and special application systems (e.g...

2005 public transportation fact book

DOT National Transportation Integrated Search

2005-04-01

This book includes only public transportation data and excludes taxicab, unregulated jitney, school, sightseeing, intercity, charter, military, and non-public service (e.g., governmental and corporate shuttles), and special application systems (e.g.,...

T-SDN architecture for space and ground integrated optical transport network

NASA Astrophysics Data System (ADS)

Nie, Kunkun; Hu, Wenjing; Gao, Shenghua; Chang, Chengwu

2015-11-01

Integrated optical transport network is the development trend of the future space information backbone network. The space and ground integrated optical transport network(SGIOTN) may contain a variety of equipment and systems. Changing the network or meeting some innovation missions in the network will be an expensive implement. Software Defined Network(SDN) provides a good solution to flexibly adding process logic, timely control states and resources of the whole network, as well as shielding the differences of heterogeneous equipment and so on. According to the characteristics of SGIOTN, we propose an transport SDN architecture for it, with hierarchical control plane and data plane composed of packet networks and optical transport networks.

Community core detection in transportation networks

NASA Astrophysics Data System (ADS)

De Leo, Vincenzo; Santoboni, Giovanni; Cerina, Federica; Mureddu, Mario; Secchi, Luca; Chessa, Alessandro

2013-10-01

This work analyzes methods for the identification and the stability under perturbation of a territorial community structure with specific reference to transportation networks. We considered networks of commuters for a city and an insular region. In both cases, we have studied the distribution of commuters’ trips (i.e., home-to-work trips and vice versa). The identification and stability of the communities’ cores are linked to the land-use distribution within the zone system, and therefore their proper definition may be useful to transport planners.

Correlates of walking for transportation and use of public transportation among adults in St Louis, Missouri, 2012.

PubMed

Zwald, Marissa L; Hipp, James A; Corseuil, Marui W; Dodson, Elizabeth A

2014-07-03

Attributes of the built environment can influence active transportation, including use of public transportation. However, the relationship between perceptions of the built environment and use of public transportation deserves further attention. The objectives of this study were 1) to assess the relationship between personal characteristics and public transportation use with meeting national recommendations for moderate physical activity through walking for transportation and 2) to examine associations between personal and perceived environmental factors and frequency of public transportation use. In 2012, we administered a mail-based survey to 772 adults in St Louis, Missouri, to assess perceptions of the built environment, physical activity, and transportation behaviors. The abbreviated International Physical Activity Questionnaire was used to assess walking for transportation and use of public transportation. The Neighborhood Environment Walkability Scale was used to examine perceptions of the built environment. Associations were assessed by using multinomial logistic regression. People who used public transportation at least once in the previous week were more likely to meet moderate physical activity recommendations by walking for transportation. Age and employment were significantly associated with public transportation use. Perceptions of high traffic speed and high crime were negatively associated with public transportation use. Our results were consistent with previous research suggesting that public transportation use is related to walking for transportation. More importantly, our study suggests that perceptions of traffic speed and crime are related to frequency of public transportation use. Future interventions to encourage public transportation use should consider policy and planning decisions that reduce traffic speed and improve safety.

Correlates of Walking for Transportation and Use of Public Transportation Among Adults in St Louis, Missouri, 2012

PubMed Central

Hipp, James A.; Corseuil, Marui W.; Dodson, Elizabeth A.

2014-01-01

Introduction Attributes of the built environment can influence active transportation, including use of public transportation. However, the relationship between perceptions of the built environment and use of public transportation deserves further attention. The objectives of this study were 1) to assess the relationship between personal characteristics and public transportation use with meeting national recommendations for moderate physical activity through walking for transportation and 2) to examine associations between personal and perceived environmental factors and frequency of public transportation use. Methods In 2012, we administered a mail-based survey to 772 adults in St Louis, Missouri, to assess perceptions of the built environment, physical activity, and transportation behaviors. The abbreviated International Physical Activity Questionnaire was used to assess walking for transportation and use of public transportation. The Neighborhood Environment Walkability Scale was used to examine perceptions of the built environment. Associations were assessed by using multinomial logistic regression. Results People who used public transportation at least once in the previous week were more likely to meet moderate physical activity recommendations by walking for transportation. Age and employment were significantly associated with public transportation use. Perceptions of high traffic speed and high crime were negatively associated with public transportation use. Conclusion Our results were consistent with previous research suggesting that public transportation use is related to walking for transportation. More importantly, our study suggests that perceptions of traffic speed and crime are related to frequency of public transportation use. Future interventions to encourage public transportation use should consider policy and planning decisions that reduce traffic speed and improve safety. PMID:24995654

Performance verification of network function virtualization in software defined optical transport networks

NASA Astrophysics Data System (ADS)

Zhao, Yongli; Hu, Liyazhou; Wang, Wei; Li, Yajie; Zhang, Jie

2017-01-01

With the continuous opening of resource acquisition and application, there are a large variety of network hardware appliances deployed as the communication infrastructure. To lunch a new network application always implies to replace the obsolete devices and needs the related space and power to accommodate it, which will increase the energy and capital investment. Network function virtualization1 (NFV) aims to address these problems by consolidating many network equipment onto industry standard elements such as servers, switches and storage. Many types of IT resources have been deployed to run Virtual Network Functions (vNFs), such as virtual switches and routers. Then how to deploy NFV in optical transport networks is a of great importance problem. This paper focuses on this problem, and gives an implementation architecture of NFV-enabled optical transport networks based on Software Defined Optical Networking (SDON) with the procedure of vNFs call and return. Especially, an implementation solution of NFV-enabled optical transport node is designed, and a parallel processing method for NFV-enabled OTN nodes is proposed. To verify the performance of NFV-enabled SDON, the protocol interaction procedures of control function virtualization and node function virtualization are demonstrated on SDON testbed. Finally, the benefits and challenges of the parallel processing method for NFV-enabled OTN nodes are simulated and analyzed.

Exchanging transportation networks between two GISs via the SDTS

DOT National Transportation Integrated Search

1997-05-01

Performing meaningful network analyses is greatly dependent upon accurate and : complete transportation network models, which are digitized into a Geographic : Information System (GIS) or, more often, imported from another GIS. : Transportation netwo...

Solutions to Improve Person Transport System in the Pitesti City by Analyzing Public Transport vs. Private Transport

NASA Astrophysics Data System (ADS)

Mihaela, Istrate; Alexandru, Boroiu; Viorel, Nicolae; Ionel, Vieru

2017-10-01

One of the major problems facing the Pitesti city is the road congestion that occurs in the central area of the city during the peak hours. With all the measures taken in recent years - the widening of road arteries, increasing the number of parking spaces, the creation of overground road passages - it is obvious that the problem can only be solved by a new philosophy regarding urban mobility: it is no longer possible to continue through solutions to increase the accessibility of the central area of the city, but it is necessary, on the contrary, to promote a policy of discouraging the penetration of vehicles in the city center, coupled with a policy of improving the connection between urban public transport and county public transport. This new approach is also proposed in the new Urban Mobility Plan of Pitesti city, under development. The most convincing argument for the necessity of this new orientation in the Pitesti city mobility plan is based on the analysis of the current situation of passenger transport on the territory of Pitesti city: the analysis of “public transport versus private transport” reveals a very low occupancy rate for cars and the fact that the road surface required for a passenger (the dynamic area) is much higher in the case of private transport than in the case of public transport. Measurements of passenger flows and vehicle flows on the 6 penetration ways in the city have been made and the calculations clearly demonstrate the benefits of an urban public transport system connected by “transshipment buses” to be made at the edge of the city, to the county public transport system. In terms of inter-county transport, it will continue to be connected to the urban public transport system by existing bus Station, within the city: South Bus Station and North Bus Station. The usefulness of the paper is that it identifies the solutions for sustainable mobility in Pitesti city and proposes concrete solutions for the development of the

A Comparison of Geographic Information Systems, Complex Networks, and Other Models for Analyzing Transportation Network Topologies

NASA Technical Reports Server (NTRS)

Alexandrov, Natalia (Technical Monitor); Kuby, Michael; Tierney, Sean; Roberts, Tyler; Upchurch, Christopher

2005-01-01

This report reviews six classes of models that are used for studying transportation network topologies. The report is motivated by two main questions. First, what can the "new science" of complex networks (scale-free, small-world networks) contribute to our understanding of transport network structure, compared to more traditional methods? Second, how can geographic information systems (GIS) contribute to studying transport networks? The report defines terms that can be used to classify different kinds of models by their function, composition, mechanism, spatial and temporal dimensions, certainty, linearity, and resolution. Six broad classes of models for analyzing transport network topologies are then explored: GIS; static graph theory; complex networks; mathematical programming; simulation; and agent-based modeling. Each class of models is defined and classified according to the attributes introduced earlier. The paper identifies some typical types of research questions about network structure that have been addressed by each class of model in the literature.

Optimal Concentrations in Transport Networks

NASA Astrophysics Data System (ADS)

Jensen, Kaare; Savage, Jessica; Kim, Wonjung; Bush, John; Holbrook, N. Michele

2013-03-01

Biological and man-made systems rely on effective transport networks for distribution of material and energy. Mass flow in these networks is determined by the flow rate and the concentration of material. While the most concentrated solution offers the greatest potential for mass flow, impedance grows with concentration and thus makes it the most difficult to transport. The concentration at which mass flow is optimal depends on specific physical and physiological properties of the system. We derive a simple model which is able to predict optimal concentrations observed in blood flows, sugar transport in plants, and nectar feeding animals. Our model predicts that the viscosity at the optimal concentration μopt =2nμ0 is an integer power of two times the viscosity of the pure carrier medium μ0. We show how the observed powers 1 <= n <= 6 agree well with theory and discuss how n depends on biological constraints imposed on the transport process. The model provides a universal framework for studying flows impeded by concentration and provides hints of how to optimize engineered flow systems, such as congestion in traffic flows.

Empirical investigation of topological and weighted properties of a bus transport network from China

NASA Astrophysics Data System (ADS)

Shu-Min, Feng; Bao-Yu, Hu; Cen, Nie; Xiang-Hao, Shen; Yu-Sheng, Ci

2016-03-01

Many bus transport networks (BTNs) have evolved into directed networks. A new representation model for BTNs is proposed, called directed-space P. The bus transport network of Harbin (BTN-H) is described as a directed and weighted complex network by the proposed representation model and by giving each node weights. The topological and weighted properties are revealed in detail. In-degree and out-degree distributions, in-weight and out-weight distributions are presented as an exponential law, respectively. There is a strong relation between in-weight and in-degree (also between out-weight and out-degree), which can be fitted by a power function. Degree-degree and weight-weight correlations are investigated to reveal that BTN-H has a disassortative behavior as the nodes have relatively high degree (or weight). The disparity distributions of out-degree and in-degree follow an approximate power-law. Besides, the node degree shows a near linear increase with the number of routes that connect to the corresponding station. These properties revealed in this paper can help public transport planners to analyze the status quo of the BTN in nature. Project supported by the National High Technology Research and Development Program of China (Grant No. 2014AA110304).

Floquet-Network Theory of Nonreciprocal Transport

NASA Astrophysics Data System (ADS)

Li, Huanan; Kottos, Tsampikos; Shapiro, Boris

2018-04-01

We develop a theoretical framework that lays out the fundamental rules under which a periodic (Floquet) driving scheme can induce nonreciprocal transport. Our approach utilizes an extended Hilbert space where a Floquet network with an extra (frequency) dimension naturally arises. The properties of this network (its on-site potential and the intersite couplings) are in one-to-one correspondence with the initial driving scheme. Its proper design allows for a control of the multipath scattering processes and the associated interferences. We harness this degree of freedom to realize driving schemes with narrow-band or broadband nonreciprocal transport.

Architecture of a framework for providing information services for public transport.

PubMed

García, Carmelo R; Pérez, Ricardo; Lorenzo, Alvaro; Quesada-Arencibia, Alexis; Alayón, Francisco; Padrón, Gabino

2012-01-01

This paper presents OnRoute, a framework for developing and running ubiquitous software that provides information services to passengers of public transportation, including payment systems and on-route guidance services. To achieve a high level of interoperability, accessibility and context awareness, OnRoute uses the ubiquitous computing paradigm. To guarantee the quality of the software produced, the reliable software principles used in critical contexts, such as automotive systems, are also considered by the framework. The main components of its architecture (run-time, system services, software components and development discipline) and how they are deployed in the transportation network (stations and vehicles) are described in this paper. Finally, to illustrate the use of OnRoute, the development of a guidance service for travellers is explained.

Architecture of a Framework for Providing Information Services for Public Transport

PubMed Central

García, Carmelo R.; Pérez, Ricardo; Lorenzo, Álvaro; Quesada-Arencibia, Alexis; Alayón, Francisco; Padrón, Gabino

2012-01-01

This paper presents OnRoute, a framework for developing and running ubiquitous software that provides information services to passengers of public transportation, including payment systems and on-route guidance services. To achieve a high level of interoperability, accessibility and context awareness, OnRoute uses the ubiquitous computing paradigm. To guarantee the quality of the software produced, the reliable software principles used in critical contexts, such as automotive systems, are also considered by the framework. The main components of its architecture (run-time, system services, software components and development discipline) and how they are deployed in the transportation network (stations and vehicles) are described in this paper. Finally, to illustrate the use of OnRoute, the development of a guidance service for travellers is explained. PMID:22778585

APTS : advanced public transportation systems program : technical assistance brief

DOT National Transportation Integrated Search

1993-01-01

Advanced Public Transportation Systems, or APTS, are advanced navigation and communication technologies applied to all aspects of public transportation system operations. APTS provides the technology for transportation agencies to make timely transit...

Distance from public transportation and physical activity in Japanese older adults: The moderating role of driving status.

PubMed

Harada, Kazuhiro; Lee, Sangyoon; Lee, Sungchul; Bae, Seongryu; Anan, Yuya; Harada, Kenji; Shimada, Hiroyuki

2018-04-01

Although previous studies have shown that good access to public transportation is positively related with physical activity, the moderators of this relationship have not been explored sufficiently in older adults. It is possible that driving status could moderate this relationship. The present study examined whether the objectively measured distance between public transportation and the home was associated with physical activity levels, and whether this association was moderated by driving status among Japanese older adults. In this cross-sectional study, participants (n = 2,878) completed questionnaires and wore accelerometers for at least 7 days, to measure their average daily step counts and minutes spent engaging in moderate-to-vigorous physical activity. Road network distances between the home and the nearest bus stop or train station were measured using geographic information systems. Driving status was assessed using questionnaires. Multiple regression analyses stratified by driving status revealed that, among nondrivers, living further away from public transportation was associated with higher step counts (β = 0.08, p < .001) and moderate-to-vigorous physical activity (β = 0.06, p = .029). Among drivers, living closer to public transportation was significantly associated with higher moderate-to-vigorous physical activity levels (β = -0.05, p = .042). Despite the small effect sizes, the direction of the association between distance from public transportation and physical activity was different for current drivers and nondrivers. These findings imply that good access to public transportation does not positively relate with greater engagement in physical activity among nondriving older adults. Shorter distances to public transportation might reduce opportunities for engaging in physical activity for them. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Valuing public sector risk exposure in transportation public-private partnerships.

DOT National Transportation Integrated Search

2010-10-01

This report presents a methodological framework to evaluate public sector financial risk exposure when : delivering transportation infrastructure through public-private partnership (PPP) agreements in the United : States (U.S.). The framework is base...

Digital Networked Information Society and Public Health: Problems and Promises of Networked Health Communication of Lay Publics.

PubMed

Kim, Jeong-Nam

2018-01-01

This special issue of Health Communication compiles 10 articles to laud the promise and yet confront the problems in the digital networked information society related to public health. We present this anthology of symphony and cacophony of lay individuals' communicative actions in a digital networked information society. The collection of problems and promise of the new digital world may be a cornerstone joining two worlds-pre- and postdigital network society-and we hope this special issue will help better shape our future states of public health.

Node-node correlations and transport properties in scale-free networks

NASA Astrophysics Data System (ADS)

Obregon, Bibiana; Guzman, Lev

2011-03-01

We study some transport properties of complex networks. We focus our attention on transport properties of scale-free and small-world networks and compare two types of transport: Electric and max-flow cases. In particular, we construct scale-free networks, with a given degree sequence, to estimate the distribution of conductances for different values of assortative/dissortative mixing. For the electric case we find that the distributions of conductances are affect ed by the assortative mixing of the network whereas for the max-flow case, the distributions almost do not show changes when node-node correlations are altered. Finally, we compare local and global transport in terms of the average conductance for the small-world (Watts-Strogatz) model

28 CFR 36.310 - Transportation provided by public accommodations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Transportation provided by public... BASIS OF DISABILITY BY PUBLIC ACCOMMODATIONS AND IN COMMERCIAL FACILITIES Specific Requirements § 36.310 Transportation provided by public accommodations. (a) General. (1) A public accommodation that provides...

An assessment of public transportation markets using NHTS data.

DOT National Transportation Integrated Search

2012-03-01

In 2007, the American Public Transportation : Association (APTA) assessed public transit markets : in a national study published as A Profile of Public : Transportation Passenger Demographics and Travel : Characteristics Reported in On-Board Surveys....

Population-weighted efficiency in transportation networks

NASA Astrophysics Data System (ADS)

Dong, Lei; Li, Ruiqi; Zhang, Jiang; di, Zengru

2016-05-01

Transportation efficiency is critical for the operation of cities and is attracting great attention worldwide. Improving the transportation efficiency can not only decrease energy consumption, reduce carbon emissions, but also accelerate people’s interactions, which will become more and more important for sustainable urban living. Generally, traffic conditions in less-developed countries are not so good due to the undeveloped economy and road networks, while this issue is rarely studied before, because traditional survey data in these areas are scarce. Nowadays, with the development of ubiquitous mobile phone data, we can explore the transportation efficiency in a new way. In this paper, based on users’ call detailed records (CDRs), we propose an indicator named population-weighted efficiency (PWE) to quantitatively measure the efficiency of the transportation networks. PWE can provide insights into transportation infrastructure development, according to which we identify dozens of inefficient routes at both the intra- and inter-city levels, which are verified by several ongoing construction projects in Senegal. In addition, we compare PWE with excess commuting indices, and the fitting result of PWE is better than excess commuting index, which also proves the validity of our method.

78 FR 61251 - The National Public Transportation Safety Plan, the Public Transportation Agency Safety Plan, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-03

... Transportation Agency Safety Plan, and the Public Transportation Safety Certification Training Program; Transit... systems are in a state of good repair, and provide increased transparency into agencies' budgetary... October 2001, mail received through the U.S. Postal Service may be subject to delays. Parties submitting...

Improving Travel Projections for Public Transportation

DOT National Transportation Integrated Search

1995-08-01

Public transportation use saves energy and reduces emissions by taking people : out of single passenger automobiles and putting them into high occupancy, energy : efficient transit vehicles. Furthermore, public transit ridership and vehicular : trip ...

Freight Transportation Energy Use : Appendix. Transportation Network Model Output.

DOT National Transportation Integrated Search

1978-07-01

The overall design of the TSC Freight Energy Model is presented. A hierarchical modeling strategy is used, in which detailed modal simulators estimate the performance characteristics of transportation network elements, and the estimates are input to ...

Survey of state funding for public transportation 2010

DOT National Transportation Integrated Search

2010-07-01

The AASHTO Standing Committee on Public Transportation is pleased to release the Survey of State : Funding for Public Transportation. The survey results reflect Fiscal Year 2008 data. This annual report : provides a snapshot of state-by-state investm...

Degradable transportation network with the addition of electric vehicles: Network equilibrium analysis

PubMed Central

Zhang, Rui; Yao, Enjian; Yang, Yang

2017-01-01

Introducing electric vehicles (EVs) into urban transportation network brings higher requirement on travel time reliability and charging reliability. Specifically, it is believed that travel time reliability is a key factor influencing travelers’ route choice. Meanwhile, due to the limited cruising range, EV drivers need to better learn about the required energy for the whole trip to make decisions about whether charging or not and where to charge (i.e., charging reliability). Since EV energy consumption is highly related to travel speed, network uncertainty affects travel time and charging demand estimation significantly. Considering the network uncertainty resulted from link degradation, which influences the distribution of travel demand on transportation network and the energy demand on power network, this paper aims to develop a reliability-based network equilibrium framework for accommodating degradable road conditions with the addition of EVs. First, based on the link travel time distribution, the mean and variance of route travel time and monetary expenses related to energy consumption are deduced, respectively. And the charging time distribution of EVs with charging demand is also estimated. Then, a nested structure is considered to deal with the difference of route choice behavior derived by the different uncertainty degrees between the routes with and without degradable links. Given the expected generalized travel cost and a psychological safety margin, a traffic assignment model with the addition of EVs is formulated. Subsequently, a heuristic solution algorithm is developed to solve the proposed model. Finally, the effects of travelers’ risk attitude, network degradation degree, and EV penetration rate on network performance are illustrated through an example network. The numerical results show that the difference of travelers’ risk attitudes does have impact on the route choice, and the widespread adoption of EVs can cut down the total system

Degradable transportation network with the addition of electric vehicles: Network equilibrium analysis.

PubMed

Zhang, Rui; Yao, Enjian; Yang, Yang

2017-01-01

Introducing electric vehicles (EVs) into urban transportation network brings higher requirement on travel time reliability and charging reliability. Specifically, it is believed that travel time reliability is a key factor influencing travelers' route choice. Meanwhile, due to the limited cruising range, EV drivers need to better learn about the required energy for the whole trip to make decisions about whether charging or not and where to charge (i.e., charging reliability). Since EV energy consumption is highly related to travel speed, network uncertainty affects travel time and charging demand estimation significantly. Considering the network uncertainty resulted from link degradation, which influences the distribution of travel demand on transportation network and the energy demand on power network, this paper aims to develop a reliability-based network equilibrium framework for accommodating degradable road conditions with the addition of EVs. First, based on the link travel time distribution, the mean and variance of route travel time and monetary expenses related to energy consumption are deduced, respectively. And the charging time distribution of EVs with charging demand is also estimated. Then, a nested structure is considered to deal with the difference of route choice behavior derived by the different uncertainty degrees between the routes with and without degradable links. Given the expected generalized travel cost and a psychological safety margin, a traffic assignment model with the addition of EVs is formulated. Subsequently, a heuristic solution algorithm is developed to solve the proposed model. Finally, the effects of travelers' risk attitude, network degradation degree, and EV penetration rate on network performance are illustrated through an example network. The numerical results show that the difference of travelers' risk attitudes does have impact on the route choice, and the widespread adoption of EVs can cut down the total system travel

49 CFR 37.41 - Construction of transportation facilities by public entities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... public entities. 37.41 Section 37.41 Transportation Office of the Secretary of Transportation... transportation facilities by public entities. (a) A public entity shall construct any new facility to be used in providing designated public transportation services so that the facility is readily accessible to and usable...

Acquisition management of the Global Transportation Network

DOT National Transportation Integrated Search

2001-08-02

This report discusses the acquisition management of the Global transportation Network by the U.S. Transportation Command. This report is one in a series of audit reports addressing DoD acquisition management of information technology systems. The Glo...

Public transportation's role in responding to climate change

DOT National Transportation Integrated Search

2010-01-01

This paper details the role public transportation has in responding to the challenge of climate change. It collects and analyzes data from across the country on public transportation fuel use, vehicles deployed, rides taken, and other key metrics, dr...

Migration of optical core network to next generation networks - Carrier Grade Ethernet Optical Transport Network

NASA Astrophysics Data System (ADS)

Glamočanin, D.

2017-05-01

In order to maintain the continuity of the telecom operators’ network construction, while monitoring development needs, increasing customers’ demands and application of technological improvements, it is necessary to migrate optical transport core network to the next generation networks - Carrier Grade Ethernet Optical Transport Network (OTN CE). The primary objective of OTN CE is to realize an environment that is based solely on the switching in the optical domain, i.e. the realization of transparent optical networks and optical switching to the second layer of ISO / OSI model. The realization of such a network provides opportunities for further development of existing, but also technologically more demanding, new services. It is also a prerequisite to provide higher scalability, reliability, security and quality of QoS service, as well as prerequisites for the establishment of SLA (Service Level Agreement) for existing services, especially traffic in real time. This study aims to clarify the proposed model, which has the potential to be eventually adjusted in accordance with new scientific knowledge in this field as well as market requirements.

49 CFR 37.43 - Alteration of transportation facilities by public entities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Alteration of transportation facilities by public... transportation facilities by public entities. (a)(1) When a public entity alters an existing facility or a part of an existing facility used in providing designated public transportation services in a way that...

Perceived public transport infrastructure modifies the association between public transport use and mental health: Multilevel analyses from the United Kingdom.

PubMed

Feng, Xiaoqi; Feng, Zhiqiang; Astell-Burt, Thomas

2017-01-01

Investments to promote public transport utilisation are being championed to achieve sustainable development, but the potential co-benefits for mental health are comparatively under-researched. We hypothesised that frequent users of public transport would be more likely to have better mental health (possibly due to increased levels of physical activity), but among the more frequent users, less favourable perceptions of public transport infrastructure (PPTI) could have a negative influence on mental health. Multilevel linear and logistic regressions were fitted on 30,214 participants in the UK Household Longitudinal Study with lagged PPTI and confounder measures at baseline and indicators of active travel and mental health (General Health Questionnaire (GHQ), SF-12 Mental Component Scale (MCS) and the Warwick Edinburgh Mental Well Being Scale (WEMWBS)) at follow-up. Compared to participants expressing poor PPTI, those who felt it was excellent were 1.29 (95%CI 1.15, 1.45) times more likely to be frequent users of public transport and 1.53 (95%CI 1.33, 1.76) times more likely to choose to walk or cycle journeys of less than two to three miles. Frequent use of public transport was found to be consistently associated with better mental health for GHQ caseness (OR 0.85, 95%CI 0.79, 0.91), GHQ score (coefficient -0.28, 95%CI -0.41, -0.16), MCS (coefficient 0.45, 95%CI 0.23, 0.66), and WEMWBS (coefficient 0.30, 95%CI 0.19, 0.40). Among frequent users of public transport, participants expressing poor PPTI were 1.46 (95%CI 1.11, 1.93) times more likely to report poorer mental health according to the GHQ caseness indicator, compared to frequent users that regarded PPTI as excellent. Similar results were observed for the other indicators of mental health. These findings indicate that while the provision of public transport infrastructure is a necessary pre-condition for stimulating population increases in physical activity, PPTI improvements needs to be prioritised to leverage

Perceived public transport infrastructure modifies the association between public transport use and mental health: Multilevel analyses from the United Kingdom

PubMed Central

Feng, Xiaoqi; Feng, Zhiqiang; Astell-Burt, Thomas

2017-01-01

Aims Investments to promote public transport utilisation are being championed to achieve sustainable development, but the potential co-benefits for mental health are comparatively under-researched. We hypothesised that frequent users of public transport would be more likely to have better mental health (possibly due to increased levels of physical activity), but among the more frequent users, less favourable perceptions of public transport infrastructure (PPTI) could have a negative influence on mental health. Methods Multilevel linear and logistic regressions were fitted on 30,214 participants in the UK Household Longitudinal Study with lagged PPTI and confounder measures at baseline and indicators of active travel and mental health (General Health Questionnaire (GHQ), SF-12 Mental Component Scale (MCS) and the Warwick Edinburgh Mental Well Being Scale (WEMWBS)) at follow-up. Results Compared to participants expressing poor PPTI, those who felt it was excellent were 1.29 (95%CI 1.15, 1.45) times more likely to be frequent users of public transport and 1.53 (95%CI 1.33, 1.76) times more likely to choose to walk or cycle journeys of less than two to three miles. Frequent use of public transport was found to be consistently associated with better mental health for GHQ caseness (OR 0.85, 95%CI 0.79, 0.91), GHQ score (coefficient -0.28, 95%CI -0.41, -0.16), MCS (coefficient 0.45, 95%CI 0.23, 0.66), and WEMWBS (coefficient 0.30, 95%CI 0.19, 0.40). Among frequent users of public transport, participants expressing poor PPTI were 1.46 (95%CI 1.11, 1.93) times more likely to report poorer mental health according to the GHQ caseness indicator, compared to frequent users that regarded PPTI as excellent. Similar results were observed for the other indicators of mental health. Conclusions These findings indicate that while the provision of public transport infrastructure is a necessary pre-condition for stimulating population increases in physical activity, PPTI improvements

Implications of network structure on public health collaboratives.

PubMed

Retrum, Jessica H; Chapman, Carrie L; Varda, Danielle M

2013-10-01

Interorganizational collaboration is an essential function of public health agencies. These partnerships form social networks that involve diverse types of partners and varying levels of interaction. Such collaborations are widely accepted and encouraged, yet very little comparative research exists on how public health partnerships develop and evolve, specifically in terms of how subsequent network structures are linked to outcomes. A systems science approach, that is, one that considers the interdependencies and nested features of networks, provides the appropriate methods to examine the complex nature of these networks. Applying Mays and Scutchfields's categorization of "structural signatures" (breadth, density, and centralization), this research examines how network structure influences the outcomes of public health collaboratives. Secondary data from the Program to Analyze, Record, and Track Networks to Enhance Relationships (www.partnertool.net) data set are analyzed. This data set consists of dyadic (N = 12,355), organizational (N = 2,486), and whole network (N = 99) data from public health collaborations around the United States. Network data are used to calculate structural signatures and weighted least squares regression is used to examine how network structures can predict selected intermediary outcomes (resource contributions, overall value and trust rankings, and outcomes) in public health collaboratives. Our findings suggest that network structure may have an influence on collaborative-related outcomes. The structural signature that had the most significant relationship to outcomes was density, with higher density indicating more positive outcomes. Also significant was the finding that more breadth creates new challenges such as difficulty in reaching consensus and creating ties with other members. However, assumptions that these structural components lead to improved outcomes for public health collaboratives may be slightly premature. Implications of

Development of an online tool for public health: the European Public Health Law Network.

PubMed

Basak, P

2011-09-01

The European Public Health Law Network was established in 2007 as part of the European Union (EU) co-funded Public Health Law Flu project. The aims of the website consisted of designing an interactive network of specialist information and encouraging an exchange of expertise amongst members. The website sought to appeal to academics, public health professionals and lawyers. The Public Health Law Flu project team designed and managed the website. Registered network members were recruited through publicity, advertising and word of mouth. Details of the network were sent to health organizations and universities throughout Europe. Corresponding website links attracted many new visitors. Publications, news, events and a pandemic glossary became popular features on the site. Although the website initially focused only on pandemic diseases it has grown into a multidisciplinary website covering a range of public health law topics. The network contains over 700 publications divided into 28 public health law categories. News, events, front page content, legislation and the francophone section are updated on a regular basis. Since 2007 the website has received over 15,000 views from 156 countries. Newsletter subscribers have risen to 304. There are now 723 followers on the associated Twitter site. The European Public Health Law Network has been a successful and innovative site in the area of public health law. Interest in the site continues to grow. Future funding can contribute to a bigger site with interactive features and pages in a wider variety of languages to attract a wider global audience. Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Aviation and Airports, Transportation & Public Facilities, State of Alaska

Science.gov Websites

State Employees Alaska Department of Transportation & Public Facilities header image Alaska Department of Transportation & Public Facilities / Aviation and Airports Search DOT&PF State of Stevens Anchorage International Airport Link to List of Alaska Public Airports Ketchikan International

Quantitative Assessment of Transportation Network Vulnerability with Dynamic Traffic Simulation Methods

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

Shekar, Venkateswaran; Fiondella, Lance; Chatterjee, Samrat

Transportation networks are critical to the social and economic function of nations. Given the continuing increase in the populations of cities throughout the world, the criticality of transportation infrastructure is expected to increase. Thus, it is ever more important to mitigate congestion as well as to assess the impact disruptions would have on individuals who depend on transportation for their work and livelihood. Moreover, several government organizations are responsible for ensuring transportation networks are available despite the constant threat of natural disasters and terrorist activities. Most of the previous transportation network vulnerability research has been performed in the context ofmore » static traffic models, many of which are formulated as traditional optimization problems. However, transportation networks are dynamic because their usage varies over time. Thus, more appropriate methods to characterize the vulnerability of transportation networks should consider their dynamic properties. This paper presents a quantitative approach to assess the vulnerability of a transportation network to disruptions with methods from traffic simulation. Our approach can prioritize the critical links over time and is generalizable to the case where both link and node disruptions are of concern. We illustrate the approach through a series of examples. Our results demonstrate that the approach provides quantitative insight into the time varying criticality of links. Such an approach could be used as the objective function of less traditional optimization methods that use simulation and other techniques to evaluate the relative utility of a particular network defense to reduce vulnerability and increase resilience.« less

Distributed Data Networks That Support Public Health Information Needs.

PubMed

Tabano, David C; Cole, Elizabeth; Holve, Erin; Davidson, Arthur J

Data networks, consisting of pooled electronic health data assets from health care providers serving different patient populations, promote data sharing, population and disease monitoring, and methods to assess interventions. Better understanding of data networks, and their capacity to support public health objectives, will help foster partnerships, expand resources, and grow learning health systems. We conducted semistructured interviews with 16 key informants across the United States, identified as network stakeholders based on their respective experience in advancing health information technology and network functionality. Key informants were asked about their experience with and infrastructure used to develop data networks, including each network's utility to identify and characterize populations, usage, and sustainability. Among 11 identified data networks representing hundreds of thousands of patients, key informants described aggregated health care clinical data contributing to population health measures. Key informant interview responses were thematically grouped to illustrate how networks support public health, including (1) infrastructure and information sharing; (2) population health measures; and (3) network sustainability. Collaboration between clinical data networks and public health entities presents an opportunity to leverage infrastructure investments to support public health. Data networks can provide resources to enhance population health information and infrastructure.

Learning Traffic as Images: A Deep Convolutional Neural Network for Large-Scale Transportation Network Speed Prediction.

PubMed

Ma, Xiaolei; Dai, Zhuang; He, Zhengbing; Ma, Jihui; Wang, Yong; Wang, Yunpeng

2017-04-10

This paper proposes a convolutional neural network (CNN)-based method that learns traffic as images and predicts large-scale, network-wide traffic speed with a high accuracy. Spatiotemporal traffic dynamics are converted to images describing the time and space relations of traffic flow via a two-dimensional time-space matrix. A CNN is applied to the image following two consecutive steps: abstract traffic feature extraction and network-wide traffic speed prediction. The effectiveness of the proposed method is evaluated by taking two real-world transportation networks, the second ring road and north-east transportation network in Beijing, as examples, and comparing the method with four prevailing algorithms, namely, ordinary least squares, k-nearest neighbors, artificial neural network, and random forest, and three deep learning architectures, namely, stacked autoencoder, recurrent neural network, and long-short-term memory network. The results show that the proposed method outperforms other algorithms by an average accuracy improvement of 42.91% within an acceptable execution time. The CNN can train the model in a reasonable time and, thus, is suitable for large-scale transportation networks.

Learning Traffic as Images: A Deep Convolutional Neural Network for Large-Scale Transportation Network Speed Prediction

PubMed Central

Ma, Xiaolei; Dai, Zhuang; He, Zhengbing; Ma, Jihui; Wang, Yong; Wang, Yunpeng

2017-01-01

This paper proposes a convolutional neural network (CNN)-based method that learns traffic as images and predicts large-scale, network-wide traffic speed with a high accuracy. Spatiotemporal traffic dynamics are converted to images describing the time and space relations of traffic flow via a two-dimensional time-space matrix. A CNN is applied to the image following two consecutive steps: abstract traffic feature extraction and network-wide traffic speed prediction. The effectiveness of the proposed method is evaluated by taking two real-world transportation networks, the second ring road and north-east transportation network in Beijing, as examples, and comparing the method with four prevailing algorithms, namely, ordinary least squares, k-nearest neighbors, artificial neural network, and random forest, and three deep learning architectures, namely, stacked autoencoder, recurrent neural network, and long-short-term memory network. The results show that the proposed method outperforms other algorithms by an average accuracy improvement of 42.91% within an acceptable execution time. The CNN can train the model in a reasonable time and, thus, is suitable for large-scale transportation networks. PMID:28394270

A discrete mathematical model of the dynamic evolution of a transportation network

NASA Astrophysics Data System (ADS)

Malinetskii, G. G.; Stepantsov, M. E.

2009-09-01

A dynamic model of the evolution of a transportation network is proposed. The main feature of this model is that the evolution of the transportation network is not a process of centralized transportation optimization. Rather, its dynamic behavior is a result of the system self-organization that occurs in the course of the satisfaction of needs in goods transportation and the evolution of the infrastructure of the network nodes. Nonetheless, the possibility of soft control of the network evolution direction is taken into account.

Developing public health performance measures to capture the effects of transportation facilities on multiple public health outcomes.

DOT National Transportation Integrated Search

2016-04-15

Increasingly, federal transportation and public health agencies are working together to identify : transportation investments that improve public health. Investments in transportation : infrastructure represent one method to utilize transportation to...

Single-shot secure quantum network coding on butterfly network with free public communication

NASA Astrophysics Data System (ADS)

Owari, Masaki; Kato, Go; Hayashi, Masahito

2018-01-01

Quantum network coding on the butterfly network has been studied as a typical example of quantum multiple cast network. We propose a secure quantum network code for the butterfly network with free public classical communication in the multiple unicast setting under restricted eavesdropper’s power. This protocol certainly transmits quantum states when there is no attack. We also show the secrecy with shared randomness as additional resource when the eavesdropper wiretaps one of the channels in the butterfly network and also derives the information sending through public classical communication. Our protocol does not require verification process, which ensures single-shot security.

Land Ecological on Public Transport Infrastructure Development In Indonesia

NASA Astrophysics Data System (ADS)

Sari, N.

2017-10-01

The development of public transport infrastructure in Indonesia has been growing rapidly since the last five years. The utilization of area as public transport infrastructure, for example bus depot, bus Station and terminal requires wide area and influences many elements, such as land ecological quality, water supplies, power supplies, and environmental balance. However the development of public transport infrastructure now days is less considering on environmental approach, especially for green and catchment area for water conservation (water balance).This paper aims to propose the concept of Public Transport Infrastructure using green concept. The green design concept is using GBCI (Green Building Council Indonesia) standard, which contains seven categories: land ecological enhancement, movement and connectivity, water management and conservation, solid waste and material, community wellbeing strategy, building and energy, and also innovation and future development. The result is, by using the GBCI standard for the green design of Public Transport Infrastructure, the land ecological impact could be decreased. The effective areas that required are at least 5000 m2, from which the green areas for public increase 36% and 76% of areas could be used as catchment area for water conservation.

Maximizing algebraic connectivity in air transportation networks

NASA Astrophysics Data System (ADS)

Wei, Peng

In air transportation networks the robustness of a network regarding node and link failures is a key factor for its design. An experiment based on the real air transportation network is performed to show that the algebraic connectivity is a good measure for network robustness. Three optimization problems of algebraic connectivity maximization are then formulated in order to find the most robust network design under different constraints. The algebraic connectivity maximization problem with flight routes addition or deletion is first formulated. Three methods to optimize and analyze the network algebraic connectivity are proposed. The Modified Greedy Perturbation Algorithm (MGP) provides a sub-optimal solution in a fast iterative manner. The Weighted Tabu Search (WTS) is designed to offer a near optimal solution with longer running time. The relaxed semi-definite programming (SDP) is used to set a performance upper bound and three rounding techniques are discussed to find the feasible solution. The simulation results present the trade-off among the three methods. The case study on two air transportation networks of Virgin America and Southwest Airlines show that the developed methods can be applied in real world large scale networks. The algebraic connectivity maximization problem is extended by adding the leg number constraint, which considers the traveler's tolerance for the total connecting stops. The Binary Semi-Definite Programming (BSDP) with cutting plane method provides the optimal solution. The tabu search and 2-opt search heuristics can find the optimal solution in small scale networks and the near optimal solution in large scale networks. The third algebraic connectivity maximization problem with operating cost constraint is formulated. When the total operating cost budget is given, the number of the edges to be added is not fixed. Each edge weight needs to be calculated instead of being pre-determined. It is illustrated that the edge addition and the

User requirements and understanding of public health networks in England.

PubMed

Fahey, D K; Carson, E R; Cramp, D G; Muir Gray, J A

2003-12-01

The movement of public health professionals from health authorities to primary care trusts has increased their isolation and dependence on public health networks for communication. A cross sectional survey of 60 public health professionals working in England was performed to determine their understanding of the term "public health network" and to explore the functions that they would like these networks to perform. It also assessed their attitudes towards a national network and towards individual, local, and national web sites to support these networks. The most popular functions were the support of CPD/education, the identification of expertise and maximisation of scarce resources, information sharing, and efficient information/knowledge management. The local and national networks and their web sites should provide information on current projects of the network and searches to identify people, expertise, and reports. Public health professionals have a similar but broader understanding of the term "public health network" than that of the government with greater emphasis on sharing of information. The network is more likely to be successful if its priorities are maximising scarce resources, identification of expertise, CPD/education, and knowledge management.

An assessment of public transportation markets using NHTS data : [summary].

DOT National Transportation Integrated Search

2012-01-01

In 2007, the American Public Transportation : Association (APTA) assessed public transit markets : in a national study published as A Profile of Public : Transportation Passenger Demographics and Travel : Characteristics Reported in On-Board Surveys....

2008 public transportation fact book

DOT National Transportation Integrated Search

2008-06-01

This Public Transportation Fact Book presents statistics describing the entire United States transit industry for 1995 : through 2006 with additional detail and overview presentations for 2006. Also included are definitions of reported data : items.

Advanced public transportation systems benefits

DOT National Transportation Integrated Search

1996-03-01

Benefits and cost savings for various Advanced Public Transportation Systems are outlined here. Operational efficiencies are given for Transit Management Systems in different locales, as well as compliant resolution and safety. Electronic Fare Paymen...

2010 public transportation fact book

DOT National Transportation Integrated Search

2010-04-01

The Public Transportation Fact Book, published annually, contains national aggregate statistical data covering all aspects of the transit industry in the United States and Canada. Two appendices, also available, provide additional in-depth informatio...

Accessibility of general practitioners and selected specialist physicians by car and by public transport in a rural region of Germany.

PubMed

Stentzel, Ulrike; Piegsa, Jens; Fredrich, Daniel; Hoffmann, Wolfgang; van den Berg, Neeltje

2016-10-19

The accessibility of medical care facilities in sparsely populated rural regions is relevant especially for elderly people which often represent a large segment of the population in such regions. Elderly people have higher morbidity risks and a higher demand for medical care. Although travelling with private cars is the dominating traffic mode in rural regions, accessibility by public transport is increasingly important especially because of limited mobility of elderly people. The aim of this study was to determine accessibility both by car and public transport to general practitioners (GP) and selected specialist physicians for a whole region and to detect areas with poor to no access in the county Vorpommern-Greifswald, which is a rural and sparsely populated region in the very northeast of Germany. Accessibility of medical care facilities by car was calculated on the basis of a network analysis within a geographic information system (GIS) with routable street data. Accessibility by public transport was calculated using GIS and a network analysis based on the implementation of Dijkstra's algorithm. The travelling time to general practitioners (GP) by car in the study region ranges from 0.1 to 22.9 min. This is a significant difference compared to other physician groups. Traveling times to specialist physicians are 0.4 to 42.9 min. A minority of 80 % of the inhabitants reach the specialist physicians within 20 min. The accessibility of specialist physicians by public transport is poor. The travel time (round trip) to GPs averages 99.3 min, to internists 143.0, to ophthalmologists 129.3 and to urologists 159.9 min. These differences were significant. Assumed was a one hour appointment on a Tuesday at 11 am. 8,973 inhabitants (3.8 %) have no connection to a GP by public transport. 15,455 inhabitants (6.5 %) have no connection to specialist internists. Good accessibility by public transport is not a question of distance but of transport connections. GIS

49 CFR 37.61 - Public transportation programs and activities in existing facilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Public transportation programs and activities in... TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.61 Public transportation programs and activities in existing facilities. (a) A public entity shall operate a designated...

Sailor: Maryland's Online Public Information Network. Sailor Network Assessment Final Report: Findings and Future Sailor Network Development.

ERIC Educational Resources Information Center

Bertot, John Carlo; McClure, Charles R.

This report describes the results of an assessment of Sailor, Maryland's Online Public Information Network, which provides statewide Internet connection to 100% of Maryland public libraries. The concept of a "statewide networked environment" includes information services, products, hardware and software, telecommunications…

AllAboard: Visual Exploration of Cellphone Mobility Data to Optimise Public Transport.

PubMed

Di Lorenzo, G; Sbodio, M; Calabrese, F; Berlingerio, M; Pinelli, F; Nair, R

2016-02-01

The deep penetration of mobile phones offers cities the ability to opportunistically monitor citizens' mobility and use data-driven insights to better plan and manage services. With large scale data on mobility patterns, operators can move away from the costly, mostly survey based, transportation planning processes, to a more data-centric view, that places the instrumented user at the center of development. In this framework, using mobile phone data to perform transit analysis and optimization represents a new frontier with significant societal impact, especially in developing countries. In this paper we present AllAboard, an intelligent tool that analyses cellphone data to help city authorities in visually exploring urban mobility and optimizing public transport. This is performed within a self contained tool, as opposed to the current solutions which rely on a combination of several distinct tools for analysis, reporting, optimisation and planning. An interactive user interface allows transit operators to visually explore the travel demand in both space and time, correlate it with the transit network, and evaluate the quality of service that a transit network provides to the citizens at very fine grain. Operators can visually test scenarios for transit network improvements, and compare the expected impact on the travellers' experience. The system has been tested using real telecommunication data for the city of Abidjan, Ivory Coast, and evaluated from a data mining, optimisation and user prospective.

77 FR 76597 - Limitation on Claims against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-28

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... actions announced herein for the listed public transportation project will be barred unless the claim is... issuing certain approvals for the public transportation project listed below. The actions on this project...

78 FR 65756 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... review of the FTA actions announced herein for the listed public transportation project will be barred... taken final agency actions by issuing certain approvals for the public transportation project listed...

77 FR 64586 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-22

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... actions announced herein for the listed public transportation project will be barred unless the claim is... actions by issuing certain approvals for the public transportation projects listed below. The actions on...

78 FR 45287 - Limitation on Claims against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-26

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... FTA action announced herein for the listed public transportation project will be barred unless the... final agency action by issuing a certain approval for the public transportation project listed below...

77 FR 34122 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... claim seeking judicial review of the FTA actions announced herein for the listed public transportation... given that FTA has taken final agency actions by issuing certain approvals for the public transportation...

77 FR 51106 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-23

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... claim seeking judicial review of the FTA actions announced herein for the listed public transportation... given that FTA has taken final agency actions by issuing certain approvals for the public transportation...

77 FR 14465 - Public Transportation on Indian Reservations Program; Tribal Transit Program

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-09

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Public Transportation on Indian... in funding provided by the Public Transportation on Indian Reservations Program (Tribal Transit... establishing the Public Transportation on Indian Reservations Program (Tribal Transit Program or TTP). This...

Sovereign public debt crisis in Europe. A network analysis

NASA Astrophysics Data System (ADS)

Matesanz, David; Ortega, Guillermo J.

2015-10-01

In this paper we analyse the evolving network structure of the quarterly public debt-to-GDP ratio from 2000 to 2014. By applying tools and concepts coming from complex systems we study the effects of the global financial crisis over public debt network connections and communities. Two main results arise from this analysis: firstly, countries public debts tend to synchronize their evolution, increasing global connectivity in the network and dramatically decreasing the number of communities. Secondly, a disruption in previous structure is observed at the time of the shock, emerging a more centralized and less diversify network topological organization which might be more prone to suffer contagion effects. This last fact is evidenced by an increasing tendency in countries of similar level of public debt to be connected between them, which we have quantified by the network assortativity.

Caring for Older People. Public transport.

PubMed Central

Roper, T. A.; Mulley, G. P.

1996-01-01

Most older people are mobile and able to use public transport without any problems. Those who are hard of hearing or have poor vision and those with mobility problems need not be deterred from using public transport. Though the design and provision of suitable buses, taxis, and trains is not always optimum, many now have imaginative features to help older passengers. Travel by air and sea needs extra planning for disabled elderly people, but helpful advice is available and much can be done to enable even the most disabled traveller to make long journeys confidently and in comfort. Images p415-a Fig 1 Fig 2 Fig 3 PMID:8761236

78 FR 53001 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-27

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... announced herein for the listed public transportation project will be barred unless the claim is filed on or... issuing certain approvals for the public transportation projects listed below. The actions on the projects...

49 CFR 37.41 - Construction of transportation facilities by public entities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false Construction of transportation facilities by... TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.41 Construction of transportation facilities by public entities. (a) A public entity shall construct any new facility to be used in...

75 FR 27114 - Public Transportation on Indian Reservations Program; Tribal Transit Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-13

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Public Transportation on Indian..., 2005)] amended 49 U.S.C. 5311(c) by establishing the Public Transportation on Indian Reservations... Census and may be used for public transportation capital projects, operating costs of equipment and...

Predicting the use of public transportation: a case study from Putrajaya, Malaysia.

PubMed

Borhan, Muhamad Nazri; Syamsunur, Deprizon; Akhir, Norliza Mohd; Yazid, Muhamad Razuhanafi Mat; Ismail, Amiruddin; Rahmat, Riza Atiq

2014-01-01

Putrajaya is a new federal administrative capital of Malaysia which has been set to achieve a 70% share of all travels by public transport in the city area. However, the current modal split between the public transport and private transport is 15:85. In order to understand travelers' willingness to use the public transport, a conceptual model has been developed to determine the factors that affect them to use the public transport instead of travelling in their own cars. Various variables such as service quality, environmental impact, attitude, and behavior intention were analyzed and tested using structural equation model (SEM). Results indicate that the service quality and attitude are found to have positive effects on the behavioral intention of taking the public transport. Other than this, this study also shows that the service quality and environmental impact have some positive influences on the attitude to using the public transport. However, environmental impact has no significant, positive, and direct effect on behavioral intention. The results of this study demonstrate that the model that was developed is useful in predicting the public transport and it could provide a more complete understanding of behavioral intention towards public transport use.

77 FR 71475 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-30

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... public transportation project will be barred unless the claim is filed on or before April 29, 2013. FOR... the public transportation projects listed below. The actions on the projects, as well as the laws...

77 FR 43144 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-23

... Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... public transportation project will be barred unless the claim is filed on or before January 21, 2013. FOR... the public transportation projects listed below. The actions on these projects, as well as the laws...

The Public Health Information Network (PHIN) Preparedness Initiative

PubMed Central

Loonsk, John W.; McGarvey, Sunanda R.; Conn, Laura A.; Johnson, Jennifer

2006-01-01

The Public Health Information Network (PHIN) Preparedness initiative strives to implement, on an accelerated pace, a consistent national network of information systems that will support public health in being prepared for public health emergencies. Using the principles and practices of the broader PHIN initiative, PHIN Preparedness concentrates in the short term on ensuring that all public health jurisdictions have, or have access to, systems to accomplish known preparedness functions. The PHIN Preparedness initiative defines functional requirements, technical standards and specifications, and a process to achieve consistency and interconnectedness of preparedness systems across public health. PMID:16221945

Impact of public transportation market share and other transportation and environmental policy variables on sustainable transportation.

DOT National Transportation Integrated Search

2015-01-01

Policies that encourage reduced travel, such as traveling shorter distances, and increased use of more efficient transportation modes, such as public transportation and high-occupancy private automobiles, are often considered one of several possible ...

Policy implications of transportation network companies.

DOT National Transportation Integrated Search

2016-01-01

This policy brief presents a brief introduction to transportation network companies (TNCs) and their services, a review of state-level legislation across the United States, and the municipal regulations that have been implemented in Texas in response...

Global Transport Networks and Infectious Disease Spread

PubMed Central

Tatem, A.J.; Rogers, D.J.; Hay, S.I.

2011-01-01

Air, sea and land transport networks continue to expand in reach, speed of travel and volume of passengers and goods carried. Pathogens and their vectors can now move further, faster and in greater numbers than ever before. Three important consequences of global transport network expansion are infectious disease pandemics, vector invasion events and vector-borne pathogen importation. This review briefly examines some of the important historical examples of these disease and vector movements, such as the global influenza pandemics, the devastating Anopheles gambiae invasion of Brazil and the recent increases in imported Plasmodium falciparum malaria cases. We then outline potential approaches for future studies of disease movement, focussing on vector invasion and vector-borne disease importation. Such approaches allow us to explore the potential implications of international air travel, shipping routes and other methods of transport on global pathogen and vector traffic. PMID:16647974

A link-adding strategy for transport efficiency of complex networks

NASA Astrophysics Data System (ADS)

Ma, Jinlong; Han, Weizhan; Guo, Qing; Wang, Zhenyong; Zhang, Shuai

2016-12-01

The transport efficiency is one of the critical parameters to evaluate the performance of a network. In this paper, we propose an improved efficient (IE) strategy to enhance the network transport efficiency of complex networks by adding a fraction of links to an existing network based on the node’s local degree centrality and the shortest path length. Simulation results show that the proposed strategy can bring better traffic capacity and shorter average shortest path length than the low-degree-first (LDF) strategy under the shortest path routing protocol. It is found that the proposed strategy is beneficial to the improvement of overall traffic handling and delivering ability of the network. This study can alleviate the congestion in networks, and is helpful to design and optimize realistic networks.

Predicting the Use of Public Transportation: A Case Study from Putrajaya, Malaysia

PubMed Central

Borhan, Muhamad Nazri; Mohd Akhir, Norliza; Mat Yazid, Muhamad Razuhanafi; Ismail, Amiruddin; Rahmat, Riza Atiq

2014-01-01

Putrajaya is a new federal administrative capital of Malaysia which has been set to achieve a 70% share of all travels by public transport in the city area. However, the current modal split between the public transport and private transport is 15 : 85. In order to understand travelers' willingness to use the public transport, a conceptual model has been developed to determine the factors that affect them to use the public transport instead of travelling in their own cars. Various variables such as service quality, environmental impact, attitude, and behavior intention were analyzed and tested using structural equation model (SEM). Results indicate that the service quality and attitude are found to have positive effects on the behavioral intention of taking the public transport. Other than this, this study also shows that the service quality and environmental impact have some positive influences on the attitude to using the public transport. However, environmental impact has no significant, positive, and direct effect on behavioral intention. The results of this study demonstrate that the model that was developed is useful in predicting the public transport and it could provide a more complete understanding of behavioral intention towards public transport use. PMID:25110744

Determinants of public cooperation in multiplex networks

NASA Astrophysics Data System (ADS)

Battiston, Federico; Perc, Matjaž; Latora, Vito

2017-07-01

Synergies between evolutionary game theory and statistical physics have significantly improved our understanding of public cooperation in structured populations. Multiplex networks, in particular, provide the theoretical framework within network science that allows us to mathematically describe the rich structure of interactions characterizing human societies. While research has shown that multiplex networks may enhance the resilience of cooperation, the interplay between the overlap in the structure of the layers and the control parameters of the corresponding games has not yet been investigated. With this aim, we consider here the public goods game on a multiplex network, and we unveil the role of the number of layers and the overlap of links, as well as the impact of different synergy factors in different layers, on the onset of cooperation. We show that enhanced public cooperation emerges only when a significant edge overlap is combined with at least one layer being able to sustain some cooperation by means of a sufficiently high synergy factor. In the absence of either of these conditions, the evolution of cooperation in multiplex networks is determined by the bounds of traditional network reciprocity with no enhanced resilience. These results caution against overly optimistic predictions that the presence of multiple social domains may in itself promote cooperation, and they help us better understand the complexity behind prosocial behavior in layered social systems.

Linear network representation of multistate models of transport.

PubMed Central

Sandblom, J; Ring, A; Eisenman, G

1982-01-01

By introducing external driving forces in rate-theory models of transport we show how the Eyring rate equations can be transformed into Ohm's law with potentials that obey Kirchhoff's second law. From such a formalism the state diagram of a multioccupancy multicomponent system can be directly converted into linear network with resistors connecting nodal (branch) points and with capacitances connecting each nodal point with a reference point. The external forces appear as emf or current generators in the network. This theory allows the algebraic methods of linear network theory to be used in solving the flux equations for multistate models and is particularly useful for making proper simplifying approximation in models of complex membrane structure. Some general properties of linear network representation are also deduced. It is shown, for instance, that Maxwell's reciprocity relationships of linear networks lead directly to Onsager's relationships in the near equilibrium region. Finally, as an example of the procedure, the equivalent circuit method is used to solve the equations for a few transport models. PMID:7093425

Report : public transportation in Washington State, 1984

DOT National Transportation Integrated Search

1984-10-01

This report is an update of the Public Transportation in Washington State publication, dated December 1981. In order to reflect the changes that have occurred since that time, this report contains the most current data obtainable. Chapter One of this...

Knowledge networks for global public health.

PubMed

Natividad, Maria Dulce F; Fiereck, Kirk J; Parker, Richard

2012-01-01

The challenges posed by a globalised world have made it imperative for society to search for solutions to emerging issues and to develop new ways of looking at old problems. Current discussions about global public health demand a shift in paradigms and the strategic positioning of public health within broader policy discussions that will enable it to influence political and action agendas. Critical to responding to these challenges is the generation, transmission and dissemination of new knowledge to create value. Recognising the cutting-edge role of knowledge, as a new form of capital that drives innovation and transforms society, the formation of knowledge networks is viewed as a strategy for developing a shared intellectual, conceptual and ethical infrastructure for the field of global public health. These knowledge networks are envisioned as a vehicle for sharing diverse perspectives, encouraging debate and sustaining alternative ways of thinking about and responding to the challenges that confront global public health today and in the future.

Noise annoyance is related to the presence of urban public transport.

PubMed

Paunović, Katarina; Belojević, Goran; Jakovljević, Branko

2014-05-15

The association between noise annoyance and public transport as a source of noise has not been studied previously. The aim was to study noise annoyance in an urban population due to the presence, the type and the number of public transport vehicles, in relation to other acoustical and non-acoustical parameters. The study sample comprised 5861 adults residing in 118 streets in the city center of Belgrade. The presence, the type and the number of public transport vehicles were assessed using official transport maps and matched with residential addresses. Noise annoyance was assessed by a questionnaire including a self-report five-graded scale. 'High noise annoyance' was defined by merging 'very' and 'extremely' annoyed answers. Significant predictors of high noise annoyance were the presence of public transport at daytime (yes vs. no) (odds ratio=1.47, 95% confidence interval=1.28-1.70), and at night (yes vs. no) (OR=1.39, 95% CI=1.20-1.61). Residing in the streets with more than 79 public transport vehicles per hour (3rd tercile vs. 1st tercile) predicted high noise annoyance at daytime (OR=1.64, 95% CI=1.18-2.27). Residing in the streets with buses and trams at night ('bus and tram' vs. no public transport) increased the risk of high noise annoyance (OR=2.67, 95% CI=1.78-4.09). These associations were independent from noise sensitivity, orientation of bedroom windows, floor level, and equivalent noise levels. Living in the apartment with bedroom windows facing the street was the strongest confounder for the association between noise annoyance, noise levels and public transport. The study has identified the presence of public transport at daytime and at night as a significant and independent predictor of high noise annoyance. Future intervention measures should concern the presence, the type and the number of public transport vehicles in order to reduce noise annoyance reactions in urban areas. Copyright © 2014 Elsevier B.V. All rights reserved.

Anomalous Transport in Natural Fracture Networks Induced by Tectonic Stress

NASA Astrophysics Data System (ADS)

Kang, P. K.; Lei, Q.; Lee, S.; Dentz, M.; Juanes, R.

2017-12-01

Fluid flow and transport in fractured rock controls many natural and engineered processes in the subsurface. However, characterizing flow and transport through fractured media is challenging due to the high uncertainty and large heterogeneity associated with fractured rock properties. In addition to these "static" challenges, geologic fractures are always under significant overburden stress, and changes in the stress state can lead to changes in the fracture's ability to conduct fluids. While confining stress has been shown to impact fluid flow through fractures in a fundamental way, the impact of confining stress on transportthrough fractured rock remains poorly understood. The link between anomalous (non-Fickian) transport and confining stress has been shown, only recently, at the level of a single rough fracture [1]. Here, we investigate the impact of geologic (tectonic) stress on flow and tracer transport through natural fracture networks. We model geomechanical effects in 2D fractured rock by means of a finite-discrete element method (FEMDEM) [2], which can capture the deformation of matrix blocks, reactivation of pre-existing fractures, and propagation of new cracks, upon changes in the stress field. We apply the model to a fracture network extracted from the geological map of an actual rock outcrop to obtain the aperture field at different stress conditions. We then simulate fluid flow and particle transport through the stressed fracture networks. We observe that anomalous transport emerges in response to confining stress on the fracture network, and show that the stress state is a powerful determinant of transport behavior: (1) An anisotropic stress state induces preferential flow paths through shear dilation; (2) An increase in geologic stress increases aperture heterogeneity that induces late-time tailing of particle breakthrough curves. Finally, we develop an effective transport model that captures the anomalous transport through the stressed fracture

77 FR 67439 - Fiscal Year 2013 Public Transportation on Indian Reservations Program

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-09

... Year 2013 Public Transportation on Indian Reservations Program AGENCY: Federal Transit Administration... changes in the Public Transportation on Indian Reservations program (Tribal Transit Program) in accordance... Public Meeting: FTA will provide outreach in conjunction with the National Tribal Transportation...

A Survey of Neural Network Publications.

ERIC Educational Resources Information Center

Vijayaraman, Bindiganavale S.; Osyk, Barbara

This paper is a survey of publications on artificial neural networks published in business journals for the period ending July 1996. Its purpose is to identify and analyze trends in neural network research during that period. This paper shows which topics have been heavily researched, when these topics were researched, and how that research has…

49 CFR 37.61 - Public transportation programs and activities in existing facilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... existing facilities. 37.61 Section 37.61 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.61 Public transportation programs and activities in existing facilities. (a) A public entity shall operate a designated...

Developing a new course for public transportation education.

DOT National Transportation Integrated Search

2015-06-01

Safe, efficient, and accessible public transportation is a key component of livable and sustainable : transportation systems. It is therefore critical that both undergraduate and graduate-level Civil : Engineering students have a better understanding...

47 CFR 51.325 - Notice of network changes: Public notice requirement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Notice of network changes: Public notice... § 51.325 Notice of network changes: Public notice requirement. (a) An incumbent local exchange carrier (“LEC”) must provide public notice regarding any network change that: (1) Will affect a competing...

47 CFR 51.325 - Notice of network changes: Public notice requirement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 3 2011-10-01 2011-10-01 false Notice of network changes: Public notice... § 51.325 Notice of network changes: Public notice requirement. (a) An incumbent local exchange carrier (“LEC”) must provide public notice regarding any network change that: (1) Will affect a competing...

Modelling the public opinion transmission on social networks under opinion leaders

NASA Astrophysics Data System (ADS)

Li, Zuozhi; Li, Meng; Ji, Wanwan

2017-06-01

In this paper, based on Social Network Analysis (SNA), the social network model of opinion leaders influencing the public opinion transmission is explored. The hot event, A Female Driver Was Beaten Due To Lane Change, has characteristics of individual short-term and non-government intervention, which is used to data extraction, and formed of the network structure on opinion leaders influencing the public opinion transmission. And the evolution mechanism are analyzed in the three evolutionary situations. Opinion leaders influence micro-blogging public opinion on social network evolution model shows that this type of network public opinion transmission is largely constrained by opinion leaders, so the opinion leaders behavior supervising on the spread of this public opinion is pivotal, and which has a guiding significance.

Inventory & analysis of Advanced Public Transportation Systems in Florida

DOT National Transportation Integrated Search

2001-09-01

Through its National Center for Transit Research, and under contract with the Florida Department of Transportation, the Center for Urban Transportation Research has conducted an inventory of current and planned Advanced Public Transportation Systems ...

Noise-assisted energy transport in electrical oscillator networks with off-diagonal dynamical disorder.

PubMed

León-Montiel, Roberto de J; Quiroz-Juárez, Mario A; Quintero-Torres, Rafael; Domínguez-Juárez, Jorge L; Moya-Cessa, Héctor M; Torres, Juan P; Aragón, José L

2015-11-27

Noise is generally thought as detrimental for energy transport in coupled oscillator networks. However, it has been shown that for certain coherently evolving systems, the presence of noise can enhance, somehow unexpectedly, their transport efficiency; a phenomenon called environment-assisted quantum transport (ENAQT) or dephasing-assisted transport. Here, we report on the experimental observation of such effect in a network of coupled electrical oscillators. We demonstrate that by introducing stochastic fluctuations in one of the couplings of the network, a relative enhancement in the energy transport efficiency of 22.5 ± 3.6% can be observed.

Noise-assisted energy transport in electrical oscillator networks with off-diagonal dynamical disorder

PubMed Central

León-Montiel, Roberto de J.; Quiroz-Juárez, Mario A.; Quintero-Torres, Rafael; Domínguez-Juárez, Jorge L.; Moya-Cessa, Héctor M.; Torres, Juan P.; Aragón, José L.

2015-01-01

Noise is generally thought as detrimental for energy transport in coupled oscillator networks. However, it has been shown that for certain coherently evolving systems, the presence of noise can enhance, somehow unexpectedly, their transport efficiency; a phenomenon called environment-assisted quantum transport (ENAQT) or dephasing-assisted transport. Here, we report on the experimental observation of such effect in a network of coupled electrical oscillators. We demonstrate that by introducing stochastic fluctuations in one of the couplings of the network, a relative enhancement in the energy transport efficiency of 22.5 ± 3.6% can be observed. PMID:26610864

Balancing building and maintenance costs in growing transport networks

NASA Astrophysics Data System (ADS)

Bottinelli, Arianna; Louf, Rémi; Gherardi, Marco

2017-09-01

The costs associated to the length of links impose unavoidable constraints to the growth of natural and artificial transport networks. When future network developments cannot be predicted, the costs of building and maintaining connections cannot be minimized simultaneously, requiring competing optimization mechanisms. Here, we study a one-parameter nonequilibrium model driven by an optimization functional, defined as the convex combination of building cost and maintenance cost. By varying the coefficient of the combination, the model interpolates between global and local length minimization, i.e., between minimum spanning trees and a local version known as dynamical minimum spanning trees. We show that cost balance within this ensemble of dynamical networks is a sufficient ingredient for the emergence of tradeoffs between the network's total length and transport efficiency, and of optimal strategies of construction. At the transition between two qualitatively different regimes, the dynamics builds up power-law distributed waiting times between global rearrangements, indicating a point of nonoptimality. Finally, we use our model as a framework to analyze empirical ant trail networks, showing its relevance as a null model for cost-constrained network formation.

An integrated GIS-based data model for multimodal urban public transportation analysis and management

NASA Astrophysics Data System (ADS)

Chen, Shaopei; Tan, Jianjun; Ray, C.; Claramunt, C.; Sun, Qinqin

2008-10-01

Diversity is one of the main characteristics of transportation data collected from multiple sources or formats, which can be extremely complex and disparate. Moreover, these multimodal transportation data are usually characterised by spatial and temporal properties. Multimodal transportation network data modelling involves both an engineering and research domain that has attracted the design of a number of spatio-temporal data models in the geographic information system (GIS). However, the application of these specific models to multimodal transportation network is still a challenging task. This research addresses this challenge from both integrated multimodal data organization and object-oriented modelling perspectives, that is, how a complex urban transportation network should be organized, represented and modeled appropriately when considering a multimodal point of view, and using object-oriented modelling method. We proposed an integrated GIS-based data model for multimodal urban transportation network that lays a foundation to enhance the multimodal transportation network analysis and management. This modelling method organizes and integrates multimodal transit network data, and supports multiple representations for spatio-temporal objects and relationship as both visual and graphic views. The data model is expressed by using a spatio-temporal object-oriented modelling method, i.e., the unified modelling language (UML) extended to spatial and temporal plug-in for visual languages (PVLs), which provides an essential support to the spatio-temporal data modelling for transportation GIS.

ESTABLISHING A NATIONAL ENVIRONMENTAL PUBLIC HEALTH TRACKING NETWORK

EPA Science Inventory

This paper describes the CDC's efforts to develop a National Environmental Public Health Tracking Network Tracking Network) with particular focus on air related issues and collaboration with EPA. A Tracking Network is needed in the United States to improve the health of communit...

Transportation and dynamic networks: Models, theory, and applications to supply chains, electric power, and financial networks

NASA Astrophysics Data System (ADS)

Liu, Zugang

Network systems, including transportation and logistic systems, electric power generation and distribution networks as well as financial networks, provide the critical infrastructure for the functioning of our societies and economies. The understanding of the dynamic behavior of such systems is also crucial to national security and prosperity. The identification of new connections between distinct network systems is the inspiration for the research in this dissertation. In particular, I answer two questions raised by Beckmann, McGuire, and Winsten (1956) and Copeland (1952) over half a century ago, which are, respectively, how are electric power flows related to transportation flows and does money flow like water or electricity? In addition, in this dissertation, I achieve the following: (1) I establish the relationships between transportation networks and three other classes of complex network systems: supply chain networks, electric power generation and transmission networks, and financial networks with intermediation. The establishment of such connections provides novel theoretical insights as well as new pricing mechanisms, and efficient computational methods. (2) I develop new modeling frameworks based on evolutionary variational inequality theory that capture the dynamics of such network systems in terms of the time-varying flows and incurred costs, prices, and, where applicable, profits. This dissertation studies the dynamics of such network systems by addressing both internal competition and/or cooperation, and external changes, such as varying costs and demands. (3) I focus, in depth, on electric power supply chains. By exploiting the relationships between transportation networks and electric power supply chains, I develop a large-scale network model that integrates electric power supply chains and fuel supply markets. The model captures both the economic transactions as well as the physical transmission constraints. The model is then applied to the New

Application of Decomposition to Transportation Network Analysis

DOT National Transportation Integrated Search

1976-10-01

This document reports preliminary results of five potential applications of the decomposition techniques from mathematical programming to transportation network problems. The five application areas are (1) the traffic assignment problem with fixed de...

Strengthening the Tuberculosis Specimen Referral Network in Uganda: The Role of Public-Private Partnerships.

PubMed

Joloba, Moses; Mwangi, Christina; Alexander, Heather; Nadunga, Diana; Bwanga, Freddie; Modi, Nelson; Downing, Robert; Nabasirye, Agnes; Adatu, Francis E; Shrivastava, Ritu; Gadde, Renuka; Nkengasong, John N

2016-04-15

Diagnosis of multidrug-resistant tuberculosis and prompt initiation of effective treatment rely on access to rapid and reliable drug-susceptibility testing. Efficient specimen transport systems and appropriate training on specimen referral contribute to optimal and timely access to tuberculosis diagnostic services. With support and technical assistance from a public-private partnership (PPP) between Becton Dickinson and the US President's Emergency Plan for AIDS Relief, the Uganda National TB Reference Laboratory (NTRL) and National TB and Leprosy Program redesigned the tuberculosis specimen transport network and trained healthcare workers with the goal of improving multidrug-resistant tuberculosis detection. Between 2008 and 2011, the PPP mapped 93% of health facilities and trained 724 healthcare and postal staff members covering 72% of districts. Strengthening the tuberculosis specimen referral system increased referrals from presumptive multidrug-resistant tuberculosis cases by >10-fold, with 94% of specimens reaching the NTRL within the established target transport time. This study demonstrates the potential of PPP collaborations with ministries of health to positively influence patient care by strengthening laboratory systems through increased access to drug-susceptibility testing in Uganda. Ongoing efforts to integrate specimen transport networks will maximize resources and improve patient management. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Designed a web crawler which oriented network public opinion data acquisition

NASA Astrophysics Data System (ADS)

Lu, Shan; Ma, Hui; Gao, Ying

2015-12-01

The paper describes the meaning of network public opinion and the network public opinion research of data acquisition technique. Designed and implemented a web crawler which oriented network public opinion data acquisition. Insufficient analysis of the generic web crawler, using asynchronous Socket, DNS cache, and queue downloads to improve its bottom story frame, increase the speed of collecting.

A kinetic Monte Carlo approach to study fluid transport in pore networks

NASA Astrophysics Data System (ADS)

Apostolopoulou, M.; Day, R.; Hull, R.; Stamatakis, M.; Striolo, A.

2017-10-01

The mechanism of fluid migration in porous networks continues to attract great interest. Darcy's law (phenomenological continuum theory), which is often used to describe macroscopically fluid flow through a porous material, is thought to fail in nano-channels. Transport through heterogeneous and anisotropic systems, characterized by a broad distribution of pores, occurs via a contribution of different transport mechanisms, all of which need to be accounted for. The situation is likely more complicated when immiscible fluid mixtures are present. To generalize the study of fluid transport through a porous network, we developed a stochastic kinetic Monte Carlo (KMC) model. In our lattice model, the pore network is represented as a set of connected finite volumes (voxels), and transport is simulated as a random walk of molecules, which "hop" from voxel to voxel. We simulated fluid transport along an effectively 1D pore and we compared the results to those expected by solving analytically the diffusion equation. The KMC model was then implemented to quantify the transport of methane through hydrated micropores, in which case atomistic molecular dynamic simulation results were reproduced. The model was then used to study flow through pore networks, where it was able to quantify the effect of the pore length and the effect of the network's connectivity. The results are consistent with experiments but also provide additional physical insights. Extension of the model will be useful to better understand fluid transport in shale rocks.

Public authority control strategy for opinion evolution in social networks

NASA Astrophysics Data System (ADS)

Chen, Xi; Xiong, Xi; Zhang, Minghong; Li, Wei

2016-08-01

This paper addresses the need to deal with and control public opinion and rumors. Existing strategies to control public opinion include degree, random, and adaptive bridge control strategies. In this paper, we use the HK model to present a public opinion control strategy based on public authority (PA). This means utilizing the influence of expert or high authority individuals whose opinions we control to obtain the optimum effect in the shortest time possible and thus reach a consensus of public opinion. Public authority (PA) is only influenced by individuals' attributes (age, economic status, and education level) and not their degree distribution; hence, in this paper, we assume that PA complies with two types of public authority distribution (normal and power-law). According to the proposed control strategy, our experiment is based on random, degree, and public authority control strategies in three different social networks (small-world, scale-free, and random) and we compare and analyze the strategies in terms of convergence time (T), final number of controlled agents (C), and comprehensive efficiency (E). We find that different network topologies and the distribution of the PA in the network can influence the final controlling effect. While the effect of PA strategy differs in different network topology structures, all structures achieve comprehensive efficiency with any kind of public authority distribution in any network. Our findings are consistent with several current sociological phenomena and show that in the process of public opinion/rumor control, considerable attention should be paid to high authority individuals.

Public authority control strategy for opinion evolution in social networks.

PubMed

Chen, Xi; Xiong, Xi; Zhang, Minghong; Li, Wei

2016-08-01

This paper addresses the need to deal with and control public opinion and rumors. Existing strategies to control public opinion include degree, random, and adaptive bridge control strategies. In this paper, we use the HK model to present a public opinion control strategy based on public authority (PA). This means utilizing the influence of expert or high authority individuals whose opinions we control to obtain the optimum effect in the shortest time possible and thus reach a consensus of public opinion. Public authority (PA) is only influenced by individuals' attributes (age, economic status, and education level) and not their degree distribution; hence, in this paper, we assume that PA complies with two types of public authority distribution (normal and power-law). According to the proposed control strategy, our experiment is based on random, degree, and public authority control strategies in three different social networks (small-world, scale-free, and random) and we compare and analyze the strategies in terms of convergence time (T), final number of controlled agents (C), and comprehensive efficiency (E). We find that different network topologies and the distribution of the PA in the network can influence the final controlling effect. While the effect of PA strategy differs in different network topology structures, all structures achieve comprehensive efficiency with any kind of public authority distribution in any network. Our findings are consistent with several current sociological phenomena and show that in the process of public opinion/rumor control, considerable attention should be paid to high authority individuals.

Survey of state funding for public transportation 2005

DOT National Transportation Integrated Search

2006-05-01

This report is the 25th compilation of information on State funding of public transportation. The transportation departments in all 50 States and the District of Columbia responded to the survey, which was distributed and compiled by the U.S. Departm...

Risk Evaluation of Railway Coal Transportation Network Based on Multi Level Grey Evaluation Model

NASA Astrophysics Data System (ADS)

Niu, Wei; Wang, Xifu

2018-01-01

The railway transport mode is currently the most important way of coal transportation, and now China’s railway coal transportation network has become increasingly perfect, but there is still insufficient capacity, some lines close to saturation and other issues. In this paper, the theory and method of risk assessment, analytic hierarchy process and multi-level gray evaluation model are applied to the risk evaluation of coal railway transportation network in China. Based on the example analysis of Shanxi railway coal transportation network, to improve the internal structure and the competitiveness of the market.

76 FR 17657 - Medical Device Epidemiology Network 2011: Second Annual Public Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-30

...] Medical Device Epidemiology Network 2011: Second Annual Public Workshop AGENCY: Food and Drug... public workshop entitled ``Medical Device Epidemiology Network (MDEpiNet) 2011: Second Annual Public... and solicit feedback on the establishment of a network that works with FDA experts to determine the...

Aggregation in Network Models for Transportation Planning

DOT National Transportation Integrated Search

1978-02-01

This report documents research performed on techniques of aggregation applied to network models used in transportation planning. The central objective of this research has been to identify, extend, and evaluate methods of aggregation so as to improve...

Locating inefficient links in a large-scale transportation network

NASA Astrophysics Data System (ADS)

Sun, Li; Liu, Like; Xu, Zhongzhi; Jie, Yang; Wei, Dong; Wang, Pu

2015-02-01

Based on data from geographical information system (GIS) and daily commuting origin destination (OD) matrices, we estimated the distribution of traffic flow in the San Francisco road network and studied Braess's paradox in a large-scale transportation network with realistic travel demand. We measured the variation of total travel time Δ T when a road segment is closed, and found that | Δ T | follows a power-law distribution if Δ T < 0 or Δ T > 0. This implies that most roads have a negligible effect on the efficiency of the road network, while the failure of a few crucial links would result in severe travel delays, and closure of a few inefficient links would counter-intuitively reduce travel costs considerably. Generating three theoretical networks, we discovered that the heterogeneously distributed travel demand may be the origin of the observed power-law distributions of | Δ T | . Finally, a genetic algorithm was used to pinpoint inefficient link clusters in the road network. We found that closing specific road clusters would further improve the transportation efficiency.

IAU Public Astronomical Organisations Network

NASA Astrophysics Data System (ADS)

Canas, Lina; Cheung, Sze Leung

2015-08-01

The Office for Astronomy Outreach has devoted intensive means to create and support a global network of public astronomical organisations around the world. Focused on bringing established and newly formed amateur astronomy organizations together, providing communications channels and platforms for disseminating news to the global community and the sharing of best practices and resources among these associations around the world. In establishing the importance that these organizations have for the dissemination of activities globally and acting as key participants in IAU various campaigns social media has played a key role in keeping this network engaged and connected. Here we discuss the implementation process of maintaining this extensive network, the processing and gathering of information and the interactions between local active members at a national and international level.

Quantifying the purchasing power of public transportation in Texas : technical report.

DOT National Transportation Integrated Search

2010-07-01

Investments in public transportation in Texas contribute to the state and local economy by improving : transportation options, which in turn creates benefits for individuals, businesses, and governments. Many : different agencies provide public trans...

Understanding Charge Transport in Mixed Networks of Semiconducting Carbon Nanotubes

PubMed Central

2016-01-01

The ability to select and enrich semiconducting single-walled carbon nanotubes (SWNT) with high purity has led to a fast rise of solution-processed nanotube network field-effect transistors (FETs) with high carrier mobilities and on/off current ratios. However, it remains an open question whether it is best to use a network of only one nanotube species (monochiral) or whether a mix of purely semiconducting nanotubes but with different bandgaps is sufficient for high performance FETs. For a range of different polymer-sorted semiconducting SWNT networks, we demonstrate that a very small amount of narrow bandgap nanotubes within a dense network of large bandgap nanotubes can dominate the transport and thus severely limit on-currents and effective carrier mobility. Using gate-voltage-dependent electroluminescence, we spatially and spectrally reveal preferential charge transport that does not depend on nominal network density but on the energy level distribution within the network and carrier density. On the basis of these results, we outline rational guidelines for the use of mixed SWNT networks to obtain high performance FETs while reducing the cost for purification. PMID:26867006

78 FR 26112 - Limitation on Claims Against Proposed Public Transportation Projects; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-03

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Limitation on Claims Against Proposed Public Transportation Projects; Correction AGENCY: Federal Transit Administration (FTA), DOT. ACTION... Register on April 22, 2013, concerning a limitation on claims for certain specified public transportation...

Advanced public transportation systems : evaluation guidelines

DOT National Transportation Integrated Search

1994-01-01

The Federal Transit Administration has developed the Advanced Public Transportation Systems (APTS) Program which is an integral part of the overall U.S. DOT Intelligent Vehicle Highway Systems (IVHS) effort. A major aim of the APTS Program is to prom...

An Artificial Neural Network Controller for Intelligent Transportation Systems Applications

DOT National Transportation Integrated Search

1996-01-01

An Autonomous Intelligent Cruise Control (AICC) has been designed using a feedforward artificial neural network, as an example for utilizing artificial neural networks for nonlinear control problems arising in intelligent transportation systems appli...

36 CFR 5.9 - Discrimination in furnishing public accommodations and transportation services.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Discrimination in furnishing public accommodations and transportation services. 5.9 Section 5.9 Parks, Forests, and Public Property... furnishing public accommodations and transportation services. (a) The proprietor, owner or operator and the...

76 FR 2950 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-18

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... judicial review of the FTA actions announced herein for the listed public transportation projects will be... final agency actions by issuing certain approvals for the public transportation projects listed below...

77 FR 322 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-04

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... judicial review of the FTA actions announced herein for the listed public transportation project will be... FTA has taken final agency actions by issuing certain approvals for the public transportation projects...

75 FR 13335 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-19

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... judicial review of the FTA actions announced herein for the listed public transportation projects will be... FTA has taken final agency actions by issuing certain approvals for the public transportation projects...

75 FR 71181 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-22

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... judicial review of the FTA actions announced herein for the listed public transportation projects will be... issuing certain approvals for the public transportation projects listed below. The actions on these...

76 FR 12211 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-04

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee--Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference (COMSTAC). SUMMARY: Pursuant...

77 FR 547 - Fiscal Year 2011 Public Transportation on Indian Reservations Program Project Selections

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-05

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Fiscal Year 2011 Public Transportation... 5311 (c), Public Transportation on Indian Reservations program funds in support of the Tribal Transit... for public transportation services on and around Indian reservations. FOR FURTHER INFORMATION CONTACT...

Network Aggregation in Transportation Planning : Volume I : Summary and Survey

DOT National Transportation Integrated Search

1978-04-01

Volume 1 summarizes research on network aggregation in transportation models. It includes a survey of network aggregation practices, definition of an extraction aggregation model, computational results on a heuristic implementation of the model, and ...

Mixed Transportation Network Design under a Sustainable Development Perspective

PubMed Central

Qin, Jin; Ni, Ling-lin; Shi, Feng

2013-01-01

A mixed transportation network design problem considering sustainable development was studied in this paper. Based on the discretization of continuous link-grade decision variables, a bilevel programming model was proposed to describe the problem, in which sustainability factors, including vehicle exhaust emissions, land-use scale, link load, and financial budget, are considered. The objective of the model is to minimize the total amount of resources exploited under the premise of meeting all the construction goals. A heuristic algorithm, which combined the simulated annealing and path-based gradient projection algorithm, was developed to solve the model. The numerical example shows that the transportation network optimized with the method above not only significantly alleviates the congestion on the link, but also reduces vehicle exhaust emissions within the network by up to 41.56%. PMID:23476142

Mixed transportation network design under a sustainable development perspective.

PubMed

Qin, Jin; Ni, Ling-lin; Shi, Feng

2013-01-01

A mixed transportation network design problem considering sustainable development was studied in this paper. Based on the discretization of continuous link-grade decision variables, a bilevel programming model was proposed to describe the problem, in which sustainability factors, including vehicle exhaust emissions, land-use scale, link load, and financial budget, are considered. The objective of the model is to minimize the total amount of resources exploited under the premise of meeting all the construction goals. A heuristic algorithm, which combined the simulated annealing and path-based gradient projection algorithm, was developed to solve the model. The numerical example shows that the transportation network optimized with the method above not only significantly alleviates the congestion on the link, but also reduces vehicle exhaust emissions within the network by up to 41.56%.

76 FR 67018 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-28

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee--Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

77 FR 35102 - Commercial Space Transportation Advisory Committee; Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-12

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee; Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

78 FR 53496 - Commercial Space Transportation Advisory Committee; Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-29

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee; Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

75 FR 38866 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-06

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee--Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

76 FR 4743 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-26

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee--Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

76 FR 15041 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee--Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

77 FR 48585 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-14

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee--Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

75 FR 51332 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-19

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee--Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

78 FR 14401 - Commercial Space Transportation Advisory Committee; Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-05

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee; Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section...

78 FR 53790 - Public Forum-Safety Culture: Enhancing Transportation Safety

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-30

... NATIONAL TRANSPORTATION SAFETY BOARD Public Forum--Safety Culture: Enhancing Transportation Safety On Tuesday and Wednesday, September 10-11, 2013, the National Transportation Safety Board (NTSB) will convene a forum titled, ``Safety Culture: Enhancing Transportation Safety.'' The forum will begin at 9:00...

Getting to High School in Baltimore: Student Commuting and Public Transportation

ERIC Educational Resources Information Center

Stein, Marc L.; Grigg, Jeffrey; Cronister, Curt; Chavis, Celeste; Connolly, Faith

2017-01-01

This report is the first publication of a multi-year project examining the relationship between student commutes using public transportation and on-time arrival and absenteeism. This report begins to develop a basic understanding of how students commute to high school in Baltimore with a focus on those using public transportation. The report is…

Molecular transport network security using multi-wavelength optical spins.

PubMed

Tunsiri, Surachai; Thammawongsa, Nopparat; Mitatha, Somsak; Yupapin, Preecha P

2016-01-01

Multi-wavelength generation system using an optical spin within the modified add-drop optical filter known as a PANDA ring resonator for molecular transport network security is proposed. By using the dark-bright soliton pair control, the optical capsules can be constructed and applied to securely transport the trapped molecules within the network. The advantage is that the dark and bright soliton pair (components) can securely propagate for long distance without electromagnetic interference. In operation, the optical intensity from PANDA ring resonator is fed into gold nano-antenna, where the surface plasmon oscillation between soliton pair and metallic waveguide is established.

78 FR 1301 - Fiscal Year 2012 Public Transportation on Indian Reservations Program Project Selections

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-08

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Fiscal Year 2012 Public Transportation... Affairs (BIA) in the U.S. Department of the Interior for public transportation. An additional $500,000 is... Fiscal Year 2013 Public Transportation on Indian Reservations Program, which: (1) Introduces FTA's...

75 FR 52058 - Commercial Space Transportation Advisory Committee-Public Teleconference

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-24

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Commercial Space Transportation Advisory Committee-Public Teleconference AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Commercial Space Transportation Advisory Committee Teleconference. SUMMARY: Pursuant to Section 10...

77 FR 6624 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... for the listed public transportation project will be barred unless the claim is filed on or before... approvals for the public transportation projects listed below. The actions on these projects, as well as the...

76 FR 72746 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-25

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... for the listed public transportation project will be barred unless the claim is filed on or before May... approvals for the public transportation projects listed below. The actions on these projects, as well as the...

76 FR 19522 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-07

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... herein for the listed public transportation projects will be barred unless the claim is filed on or... approvals for the public transportation projects listed below. The actions on these projects, as well as the...

76 FR 60963 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-30

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... announced herein for the listed public transportation project will be barred unless the claim is filed on or... the public transportation projects listed below. The actions on these projects, as well as the laws...

76 FR 35939 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-20

... Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... announced herein for the listed public transportation project will be barred unless the claim is filed on or... approvals for the public transportation projects listed below. The actions on these projects, as well as the...

32 CFR 705.36 - Government transportation of civilians for public affairs purposes.

Code of Federal Regulations, 2010 CFR

2010-07-01

....36 Government transportation of civilians for public affairs purposes. (a) General policy. (1... Assistant Secretary of Defense (Public Affairs), as appropriate. (8) Point to point transportation within... 32 National Defense 5 2010-07-01 2010-07-01 false Government transportation of civilians for...

Rural Public Transportation Technologies: User Needs and Applications. Executive Summary

DOT National Transportation Integrated Search

1998-07-01

The Rural Public Transportation Technologies: User Needs and Applications study was conducted as part of the U.S. Department of Transportation's (DOT) overall Rural Intelligent Transportation System (ITS) Program. The study examined the opportunities...

Rural public transportation technologies : user needs and applications : final report

DOT National Transportation Integrated Search

1998-07-01

The Rural Public Transportation Technologies: User Needs and Applications study was conducted as part of the U.S. Department of Transportations (DOT) overall Rural Intelligent Transportation System (ITS) Program. The study examined the opportuniti...

Survey of state funding for public transportation 2007 : [2008-12-01

DOT National Transportation Integrated Search

2008-12-01

The AASHTO Standing Committee on Public Transportation is pleased to release the Survey of State Funding : for Public Transportation. The survey results reflect Fiscal Year 2007 data. This annual report provides a : snapshot of state-by-state investm...

Managing the Cooperative Network: The Public Administration Model.

ERIC Educational Resources Information Center

Diener, Ronald E.

1981-01-01

Recommends that library administrators turn to public administration models in preference to business administration models for network management; this choice is predicated on the not-for-profit aspects of public service organizations. (RAA)

Why do Scale-Free Networks Emerge in Nature? From Gradient Networks to Transport Efficiency

NASA Astrophysics Data System (ADS)

Toroczkai, Zoltan

2004-03-01

It has recently been recognized [1,2,3] that a large number of complex networks are scale-free (having a power-law degree distribution). Examples include citation networks [4], the internet [5], the world-wide-web [6], cellular metabolic networks [7], protein interaction networks [8], the sex-web [9] and alliance networks in the U.S. biotechnology industry [10]. The existence of scale-free networks in such diverse systems suggests that there is a simple underlying common reason for their development. Here, we propose that scale-free networks emerge because they ensure efficient transport of some entity. We show that for flows generated by gradients of a scalar "potential'' distributed on a network, non scale-free networks, e.g., random graphs [11], will become maximally congested, while scale-free networks will ensure efficient transport in the large network size limit. [1] R. Albert and A.-L. Barabási, Rev.Mod.Phys. 74, 47 (2002). [2] M.E.J. Newman, SIAM Rev. 45, 167 (2003). [3] S.N. Dorogovtsev and J.F.F. Mendes, Evolution of Networks: From Biological Nets to the Internet and WWW, Oxford Univ. Press, Oxford, 2003. [4] S. Redner, Eur.Phys.J. B, 4, 131 (1998). [5] M. Faloutsos, P. Faloutsos and C. Faloutsos Comp.Comm.Rev. 29, 251 (1999). [6] R. Albert, H. Jeong, and A.L. Barabási, Nature 401, 130 (1999). [7] H. Jeong et.al. Nature 407, 651 (2000). [8] H. Jeong, S. Mason, A.-L. Barabási and Z. N. Oltvai, Nature 411, 41 (2001). [9] F. Liljeros et. al. Nature 411 907 (2000). [10] W. W. Powell, D. R. White, K. W. Koput and J. Owen-Smith Am.J.Soc. in press. [11] B. Bollobás, Random Graphs, Second Edition, Cambridge University Press (2001).

76 FR 25773 - Notice of Limitation on Claims Against Proposed Public Transportation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

... Proposed Public Transportation Project AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice of... announced herein for the listed public transportation project will be barred unless the claim is filed on or... approvals for the public transportation project listed below. The actions on this project, as well as the...

Intelligent Transport Systems in the Management of Road Transportation

NASA Astrophysics Data System (ADS)

Kalupová, Blanka; Hlavoň, Ivan

2016-11-01

Extension of European Union causes increase of free transfer of people and goods. At the same time they raised the problems associated with the transport, e.g. congestion and related accidents on roads, air traffic delays and more. To increase the efficiency and safety of transport, the European Commission supports the introduction of intelligent transport systems and services in all transport sectors. Implementation of intelligent transport systems and services in the road transport reduces accident frequency, increases the capacity of existing infrastructure and reduces congestions. Use of toll systems provides resources needed for the construction and operation of a new road network, improves public transport, cycling transport and walking transport, and also their multimodal integration with individual car transport.

Impacts of an advanced public transportation system : demonstration project

DOT National Transportation Integrated Search

1999-10-01

In 1997, the Ann Arbor (Michigan) Transportation Authority began deploying a set of integrated : advanced public transportation system technologies in its vehicles, stations and control center. This paper summarizes selected findings of a multidimens...

Relations between macropore network characteristics and the degree of preferential solute transport

NASA Astrophysics Data System (ADS)

Larsbo, M.; Koestel, J.; Jarvis, N.

2014-12-01

The characteristics of the soil macropore network determine the potential for fast transport of agrochemicals and contaminants through the soil. The objective of this study was to examine the relationships between macropore network characteristics, hydraulic properties and state variables and measures of preferential transport. Experiments were carried out under near-saturated conditions on undisturbed columns sampled from four agricultural topsoils of contrasting texture and structure. Macropore network characteristics were computed from 3-D X-ray tomography images of the soil pore system. Non-reactive solute transport experiments were carried out at five steady-state water flow rates from 2 to 12 mm h-1. The degree of preferential transport was evaluated by the normalised 5% solute arrival time and the apparent dispersivity calculated from the resulting breakthrough curves. Near-saturated hydraulic conductivities were measured on the same samples using a tension disc infiltrometer placed on top of the columns. Results showed that many of the macropore network characteristics were inter-correlated. For example, large macroporosities were associated with larger specific macropore surface areas and better local connectivity of the macropore network. Generally, an increased flow rate resulted in earlier solute breakthrough and a shifting of the arrival of peak concentration towards smaller drained volumes. Columns with smaller macroporosities, poorer local connectivity of the macropore network and smaller near-saturated hydraulic conductivities exhibited a greater degree of preferential transport. This can be explained by the fact that, with only two exceptions, global (i.e. sample scale) continuity of the macropore network was still preserved at low macroporosities. Thus, for any given flow rate, pores of larger diameter were actively conducting solute in soils of smaller near-saturated hydraulic conductivity. This was associated with larger local transport

78 FR 33890 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Limitation on Claims Against Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... advising the public of final agency actions subject to Section 139(l) of Title 23, United States Code (U.S...

78 FR 4191 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-18

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Limitation on Claims Against Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... advising the public of final agency actions subject to Section 139(l) of Title 23, United States Code (U.S...

78 FR 16764 - Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-18

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Limitation on Claims Against Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice. SUMMARY... advising the public of final agency actions subject to Section 139(l) of Title 23, United States Code (U.S...

Sustainable intermodal freight transportation: Applying the geospatial intermodal freight transport model

NASA Astrophysics Data System (ADS)

Comer, Bryan

To study the energy and environmental impacts of emissions associated with freight transportation, the Geospatial Intermodal Freight Transport (GIFT) model was created as a joint research collaborative between the Rochester Institute of Technology (RIT) and the University of Delaware (UD). The GIFT model is a Geographic Information Systems (GIS) based model that links the U.S. and Canadian water, rail, and road transportation networks through intermodal transfer facilities to create an intermodal network. The purpose of my thesis is to apply the GIFT model to examine potential public policies related to intermodal freight transportation in the Great Lakes region of the United States. My thesis will consist of two papers. The first paper will examine the environmental, economic, and time-of-delivery tradeoffs associated with freight transportation in the Great Lakes region and examine opportunities for marine vessels to replace a portion of heavy-duty trucks for containerized freight transport. The second paper will explore the potential benefits of using the Great Lakes as a corridor for short-sea shipping as part of a longer intermodal route. The intent of my thesis is to shed light on the current issues associated with freight transport in the Great Lakes region and present public policy alternatives to address said issues. Ideally, this thesis will better inform policymakers on the impacts and tradeoffs associated with freight transportation.

Survey of state funding for public transportation 2007 : [2008-02-26

DOT National Transportation Integrated Search

2008-01-01

The American Association of State Highway and Transportation Officials (AASHTO), in : coordination with the U.S. Department of Transportation Bureau of Transportation Statistics : (BTS), conducts an annual public transportation funding survey of the ...

Social network analysis of public health programs to measure partnership.

PubMed

Schoen, Martin W; Moreland-Russell, Sarah; Prewitt, Kim; Carothers, Bobbi J

2014-12-01

In order to prevent chronic diseases, community-based programs are encouraged to take an ecological approach to public health promotion and involve many diverse partners. Little is known about measuring partnership in implementing public health strategies. We collected data from 23 Missouri communities in early 2012 that received funding from three separate programs to prevent obesity and/or reduce tobacco use. While all of these funding programs encourage partnership, only the Social Innovation for Missouri (SIM) program included a focus on building community capacity and enhancing collaboration. Social network analysis techniques were used to understand contact and collaboration networks in community organizations. Measurements of average degree, density, degree centralization, and betweenness centralization were calculated for each network. Because of the various sizes of the networks, we conducted comparative analyses with and without adjustment for network size. SIM programs had increased measurements of average degree for partner collaboration and larger networks. When controlling for network size, SIM groups had higher measures of network density and lower measures of degree centralization and betweenness centralization. SIM collaboration networks were more dense and less centralized, indicating increased partnership. The methods described in this paper can be used to compare partnership in community networks of various sizes. Further research is necessary to define causal mechanisms of partnership development and their relationship to public health outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Three geographic decomposition approaches in transportation network analysis

DOT National Transportation Integrated Search

1980-03-01

This document describes the results of research into the application of geographic decomposition techniques to practical transportation network problems. Three approaches are described for the solution of the traffic assignment problem. One approach ...

Making connections : intermodal links in the public transportation system

DOT National Transportation Integrated Search

2007-09-01

Since at least 1991, federal transportation policy has sought to encourage intermodal connections the links that allow passengers to switch from one mode of public transportation to another. The intermodal terminal is a key building block for dev...

Kansas Public Television Network (KPTN).

ERIC Educational Resources Information Center

Lemen, Jack A.

The plans of the Kansas Public Television Board (KPTB) for development of the Kansas Television Network are detailed for the period extending from FY 1979 to FY 1983; the proposed system is designed to serve the needs of the communities by extending existing capabilities and resources, sharing common resources, and enriching the total system.…

Perfect quantum excitation energy transport via single edge perturbation in a complete network

NASA Astrophysics Data System (ADS)

Bassereh, Hassan; Salari, Vahid; Shahbazi, Farhad; Ala-Nissila, Tapio

2017-06-01

We consider quantum excitation energy transport (EET) in a network of two-state nodes in the Markovian approximation by employing the Lindblad formulation. We find that EET from an initial site, where the excitation is inserted to the sink, is generally inefficient due to the inhibition of transport by localization of the excitation wave packet in a symmetric, fully-connected network. We demonstrate that the EET efficiency can be significantly increased up to ≈100% by perturbing hopping transport between the initial node and the one connected directly to the sink, while the rate of energy transport is highest at a finite value of the hopping parameter. We also show that prohibiting hopping between the other nodes which are not directly linked to the sink does not improve the efficiency. We show that external dephasing noise in the network plays a constructive role for EET in the presence of localization in the network, while in the absence of localization it reduces the efficiency of EET. We also consider the influence of off-diagonal disorder in the hopping parameters of the network.

A review of the role of the California Transportation Commission in public transportation in California

DOT National Transportation Integrated Search

1986-08-05

Reports findings and recommendations of, and responses to,the California Transportation Commission's study to determine and document the focus of the CTC in transit, and more broadly, public transportation, activities in the State of California.

Application of sensor networks to intelligent transportation systems.

DOT National Transportation Integrated Search

2009-12-01

The objective of the research performed is the application of wireless sensor networks to intelligent transportation infrastructures, with the aim of increasing their dependability and improving the efficacy of data collection and utilization. Exampl...

Steerable sound transport in a 3D acoustic network

NASA Astrophysics Data System (ADS)

Xia, Bai-Zhan; Jiao, Jun-Rui; Dai, Hong-Qing; Yin, Sheng-Wen; Zheng, Sheng-Jie; Liu, Ting-Ting; Chen, Ning; Yu, De-Jie

2017-10-01

Quasi-lossless and asymmetric sound transports, which are exceedingly desirable in various modern physical systems, are almost always based on nonlinear or angular momentum biasing effects with extremely high power levels and complex modulation schemes. A practical route for the steerable sound transport along any arbitrary acoustic pathway, especially in a three-dimensional (3D) acoustic network, can revolutionize the sound power propagation and the sound communication. Here, we design an acoustic device containing a regular-tetrahedral cavity with four cylindrical waveguides. A smaller regular-tetrahedral solid in this cavity is eccentrically emplaced to break spatial symmetry of the acoustic device. The numerical and experimental results show that the sound power flow can unimpededly transport between two waveguides away from the eccentric solid within a wide frequency range. Based on the quasi-lossless and asymmetric transport characteristic of the single acoustic device, we construct a 3D acoustic network, in which the sound power flow can flexibly propagate along arbitrary sound pathways defined by our acoustic devices with eccentrically emplaced regular-tetrahedral solids.

Improved methods for operating public transportation services.

DOT National Transportation Integrated Search

2013-03-01

In this joint project, West Virginia University and the University of Maryland collaborated in developing improved methods for analyzing and managing public transportation services. Transit travel time data were collected using GPS tracking services ...

Transportation networks : data, analysis, methodology development and visualization.

DOT National Transportation Integrated Search

2007-12-29

This project provides data compilation, analysis methodology and visualization methodology for the current network : data assets of the Alabama Department of Transportation (ALDOT). This study finds that ALDOT is faced with a : considerable number of...

Public transport as a reservoir of methicillin-resistant staphylococci.

PubMed

Stepanović, S; Cirković, I; Djukić, S; Vuković, D; Svabić-Vlahović, M

2008-10-01

The aim of this study was to explore the occurrence of methicillin-resistant staphylococci in a large urban public transport system. Samples were taken from hand rails, which passengers hold onto when they are standing. In total, 1400 swabs taken from 55 vehicles (trolleybuses, trams and buses) were examined. As many as 30.1% samples were positive for the presence of methicillin-resistant coagulase-negative staphylococci (MRCoNS), but none for methicillin-resistant Staphylococcus aureus (MRSA). MRCoNS were isolated from all 55 vehicles. Nearly 50% of MRCoNS isolates displayed resistance not only to beta-lactams, but at least to two or more other classes of antimicrobials as well. This study demonstrated widespread occurrence of MRCoNS on hand rails in public transport vehicles. MRSA was not detected. The recovery of methicillin-resistant staphylococci from public transport system implies a potential risk for transmission of these bacteria in an out-hospital environment.

78 FR 19357 - Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-29

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Allocation of Public Transportation...) announces the allocation of $2,000,000,000 under the Public Transportation Emergency Relief Program... after an emergency or major disaster that affects public transportation systems. The Appropriations Act...

Deploying advanced public transportation systems in Birmingham

DOT National Transportation Integrated Search

2003-08-01

Advanced Public Transportation Systems (APTS) technologies have been deployed by many urban transit systems in order to improve efficiency, reduce operating costs, and improve service quality. The majority of : these deployments, however, have been i...

Analytical transport network theory to guide the design of 3-D microstructural networks in energy materials: Part 1. Flow without reactions

NASA Astrophysics Data System (ADS)

Cocco, Alex P.; Nakajo, Arata; Chiu, Wilson K. S.

2017-12-01

We present a fully analytical, heuristic model - the "Analytical Transport Network Model" - for steady-state, diffusive, potential flow through a 3-D network. Employing a combination of graph theory, linear algebra, and geometry, the model explicitly relates a microstructural network's topology and the morphology of its channels to an effective material transport coefficient (a general term meant to encompass, e.g., conductivity or diffusion coefficient). The model's transport coefficient predictions agree well with those from electrochemical fin (ECF) theory and finite element analysis (FEA), but are computed 0.5-1.5 and 5-6 orders of magnitude faster, respectively. In addition, the theory explicitly relates a number of morphological and topological parameters directly to the transport coefficient, whereby the distributions that characterize the structure are readily available for further analysis. Furthermore, ATN's explicit development provides insight into the nature of the tortuosity factor and offers the potential to apply theory from network science and to consider the optimization of a network's effective resistance in a mathematically rigorous manner. The ATN model's speed and relative ease-of-use offer the potential to aid in accelerating the design (with respect to transport), and thus reducing the cost, of energy materials.

Enhanced energy transport in genetically engineered excitonic networks.

PubMed

Park, Heechul; Heldman, Nimrod; Rebentrost, Patrick; Abbondanza, Luigi; Iagatti, Alessandro; Alessi, Andrea; Patrizi, Barbara; Salvalaggio, Mario; Bussotti, Laura; Mohseni, Masoud; Caruso, Filippo; Johnsen, Hannah C; Fusco, Roberto; Foggi, Paolo; Scudo, Petra F; Lloyd, Seth; Belcher, Angela M

2016-02-01

One of the challenges for achieving efficient exciton transport in solar energy conversion systems is precise structural control of the light-harvesting building blocks. Here, we create a tunable material consisting of a connected chromophore network on an ordered biological virus template. Using genetic engineering, we establish a link between the inter-chromophoric distances and emerging transport properties. The combination of spectroscopy measurements and dynamic modelling enables us to elucidate quantum coherent and classical incoherent energy transport at room temperature. Through genetic modifications, we obtain a significant enhancement of exciton diffusion length of about 68% in an intermediate quantum-classical regime.

The Public Telecommunications Network: A Concept in Transition.

ERIC Educational Resources Information Center

Noam, Eli M.

1987-01-01

Argues that the traditional centralized model of the public telecommunication networks is being undermined by a host of centrifugal forces, and that a new and open network concept is emerging that breaks down the dichotomy between the telecommunications sector and the rest of the economy. (JD)

Planning Tripoli Metro Network by the Use of Remote Sensing Imagery

NASA Astrophysics Data System (ADS)

Alhusain, O.; Engedy, Gy.; Milady, A.; Paulini, L.; Soos, G.

2012-08-01

Tripoli, the capital city of Libya is going through significant and integrated development process, this development is expected to continue in the next few decades. The Libyan authorities have put it as their goal to develop Tripoli to an important metropolis in North Africa. To achieve this goal, they identified goals for the city's future development in all human, economic, cultural, touristic, and nonetheless infrastructure levels. On the infrastructure development level, among other things, they have identified the development of public transportation as one of the important development priorities. At present, public transportation in Tripoli is carried out by a limited capacity bus network alongside of individual transportation. However, movement in the city is characterized mainly by individual transportation with all its disadvantages such as traffic jams, significant air pollution with both carbon monoxide and dust, and lack of parking space. The Libyan authorities wisely opted for an efficient, modern, and environment friendly solution for public transportation, this was to plan a complex Metro Network as the backbone of public transportation in the city, and to develop and integrate the bus network and other means of transportation to be in harmony with the planned Metro network. The Metro network is planned to provide convenient connections to Tripoli International Airport and to the planned Railway station. They plan to build a system of Park and Ride (P+R) facilities at suitable locations along the Metro lines. This paper will present in details the planned Metro Network, some of the applied technological solutions, the importance of applying remote sensing and GIS technologies in different planning phases, and problems and benefits associated with the use of multi-temporal-, multi-format spatial data in the whole network planning phase.

78 FR 19024 - Lithium Ion Batteries in Transportation Public Forum

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-28

... NATIONAL TRANSPORTATION SAFETY BOARD Lithium Ion Batteries in Transportation Public Forum On... forum titled, ``Lithium Ion Batteries in Transportation.'' The forum will begin at 9:00 a.m. on both... battery design, development, and use; Lithium ion battery regulations and standards; and Lithium ion...

76 FR 46357 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-02

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Notice of Limitation on Claims Against Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... that FTA has taken final agency actions by issuing certain approvals for the public transportation...

Large-scale transportation network congestion evolution prediction using deep learning theory.

PubMed

Ma, Xiaolei; Yu, Haiyang; Wang, Yunpeng; Wang, Yinhai

2015-01-01

Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS) and Internet of Things (IoT), transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS) data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU)-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation.

Large-Scale Transportation Network Congestion Evolution Prediction Using Deep Learning Theory

PubMed Central

Ma, Xiaolei; Yu, Haiyang; Wang, Yunpeng; Wang, Yinhai

2015-01-01

Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS) and Internet of Things (IoT), transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS) data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU)-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation. PMID:25780910

77 FR 26818 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-07

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Notice of Limitation on Claims Against Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... public transportation projects listed below. The actions on these projects, as well as the laws under...

Impact of Transport Zone Number in Simulation Models on Cost-Benefit Analysis Results in Transport Investments

NASA Astrophysics Data System (ADS)

Chmielewski, Jacek

2017-10-01

Nowadays, feasibility studies need to be prepared for all planned transport investments, mainly those co-financed with UE grants. One of the fundamental aspect of feasibility study is the economic justification of an investment, evaluated in an area of so called cost-benefit analysis (CBA). The main goal of CBA calculation is to prove that a transport investment is really important for the society and should be implemented as economically efficient one. It can be said that the number of hours (PH - passengers hours) in trips and travelled kilometres (PK - passengers kilometres) are the most important for CBA results. The differences between PH and PK calculated for particular investment scenarios are the base for benefits calculation. Typically, transport simulation models are the best source for such data. Transport simulation models are one of the most powerful tools for transport network planning. They make it possible to evaluate forecast traffic volume and passenger flows in a public transport system for defined scenarios of transport and area development. There are many different transport models. Their construction is often similar, and they mainly differ in the level of their accuracy. Even models for the same area may differ in this matter. Typically, such differences come from the accuracy of supply side representation: road and public transport network representation. In many cases only main roads and a public transport network are represented, while local and service roads are eliminated as a way of reality simplification. This also enables a faster and more effective calculation process. On the other hand, the description of demand part of these models based on transport zones is often stable. Difficulties with data collection, mainly data on land use, resulted in the lack of changes in the analysed land division into so called transport zones. In this paper the author presents an influence of land division on the results of traffic analyses, and hence

Networking for large-scale science: infrastructure, provisioning, transport and application mapping

NASA Astrophysics Data System (ADS)

Rao, Nageswara S.; Carter, Steven M.; Wu, Qishi; Wing, William R.; Zhu, Mengxia; Mezzacappa, Anthony; Veeraraghavan, Malathi; Blondin, John M.

2005-01-01

Large-scale science computations and experiments require unprecedented network capabilities in the form of large bandwidth and dynamically stable connections to support data transfers, interactive visualizations, and monitoring and steering operations. A number of component technologies dealing with the infrastructure, provisioning, transport and application mappings must be developed and/or optimized to achieve these capabilities. We present a brief account of the following technologies that contribute toward achieving these network capabilities: (a) DOE UltraScienceNet and NSF CHEETAH network testbeds that provide on-demand and scheduled dedicated network connections; (b) experimental results on transport protocols that achieve close to 100% utilization on dedicated 1Gbps wide-area channels; (c) a scheme for optimally mapping a visualization pipeline onto a network to minimize the end-to-end delays; and (d) interconnect configuration and protocols that provides multiple Gbps flows from Cray X1 to external hosts.

Least-cost transportation networks predict spatial interaction of invasion vectors.

PubMed

Drake, D Andrew R; Mandrak, Nicholas E

2010-12-01

Human-mediated dispersal among aquatic ecosystems often results in biotic transfer between drainage basins. Such activities may circumvent biogeographic factors, with considerable ecological, evolutionary, and economic implications. However, the efficacy of predictions concerning community changes following inter-basin movements are limited, often because the dispersal mechanism is poorly understood (e.g., quantified only partially). To date, spatial-interaction models that predict the movement of humans as vectors of biotic transfer have not incorporated patterns of human movement through transportation networks. As a necessary first step to determine the role of anglers as invasion vectors across a land-lake ecosystem, we investigate their movement potential within Ontario, Canada. To determine possible model improvements resulting from inclusion of network travel, spatial-interaction models were constructed using standard Euclidean (e.g., straight-line) distance measures and also with distances derived from least-cost routing of human transportation networks. Model comparisons determined that least-cost routing both provided the most parsimonious model and also excelled at forecasting spatial interactions, with a proportion of 0.477 total movement deviance explained. The distribution of movements was characterized by many relatively short to medium travel distances (median = 292.6 km) with fewer lengthier distances (75th percentile = 484.6 km, 95th percentile = 775.2 km); however, even the shortest movements were sufficient to overcome drainage-basin boundaries. Ranking of variables in order of their contribution within the most parsimonious model determined that distance traveled, origin outflow, lake attractiveness, and sportfish richness significantly influence movement patterns. Model improvements associated with least-cost routing of human transportation networks imply that patterns of human-mediated invasion are fundamentally linked to the spatial

76 FR 11554 - Fiscal Year 2010 Public Transportation on Indian Reservations Program Project Selections

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-02

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Fiscal Year 2010 Public Transportation... Interior for public transportation capital projects, operating costs and planning activities that are... authorized by the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users...

Florida public transportation anti-terrorism resource guide

DOT National Transportation Integrated Search

2001-10-01

The Center for Urban Transportation (CUTR) at the University of South Florida (USF) assembled this guide to provide public transit agencies in Florida with information on current resources available to assist them with improving system security and g...

Institutional and policy issues in adopting advanced public transportation systems technology

DOT National Transportation Integrated Search

1995-09-01

This project, Institutional and Policy Issues in Adopting Advanced Public Transportation Systems Technologies, aimed to study critical mass transportation issues associated with the implementation of intelligent transportation systems (ITS) in the no...

76 FR 55470 - Notice of Limitation on Claims Against Proposed Public Transportation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-07

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Notice of Limitation on Claims Against Proposed Public Transportation Project AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... announced herein for the listed public transportation project will be barred unless the claim is filed on or...

76 FR 4150 - Notice of Limitation on Claims Against Proposed Public Transportation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-24

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Notice of Limitation on Claims Against Proposed Public Transportation Projects AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice... public transportation project will be barred unless the claim is filed on or before July 25, 2011. FOR...

Socializing the policy on public transportation to the community

NASA Astrophysics Data System (ADS)

Asmawi, A.; Mariana, D.; Sjoraida, D. F.

2018-03-01

This article discusses how public policies on transportation can be communicated to the society in Sukabumi City, West Java, Indonesia. It is important for the community because the development of transportation services has a very close relationship with social welfare and economic growth of the region. This can be demonstrated with an indication that the region whose better transportation system tends to have better levels of social welfare and economic growth. The study here used a multiple case method. The cases consist of activities which were the implementation of the government’s program of socialization to the people of Sukabumi City on transportation. This regency is a door to an expansion of West Java development to the Southwest area that there are things new in government services, including in the field of transportation. Interviews, observation and document analyses were used to collect the data. Face to face interviews using a list of questions were also developed for this study. The findings of the study indicate that in addition to its own designing and implementing transportation development plan in Sukabumi City itself, there is also a transportation development involving West Java provincial government, even the national government of Indonesia in the region. All of the transportation plans could be properly communicated to the public because it used a variety of media, including the traditional, the modern, and the social.

Determining the Impact of Personal Mobility Carbon Allowance Schemes in Transportation Networks

DOE PAGES

Aziz, H. M. Abdul; Ukkusuri, Satish V.; Zhan, Xianyuan

2016-10-17

We know that personal mobility carbon allowance (PMCA) schemes are designed to reduce carbon consumption from transportation networks. PMCA schemes influence the travel decision process of users and accordingly impact the system metrics including travel time and greenhouse gas (GHG) emissions. Here, we develop a multi-user class dynamic user equilibrium model to evaluate the transportation system performance when PMCA scheme is implemented. The results using Sioux-Falls test network indicate that PMCA schemes can achieve the emissions reduction goals for transportation networks. Further, users characterized by high value of travel time are found to be less sensitive to carbon budget inmore » the context of work trips. Results also show that PMCA scheme can lead to higher emissions for a path compared with the case without PMCA because of flow redistribution. The developed network equilibrium model allows us to examine the change in system states at different carbon allocation levels and to design parameters of PMCA schemes accounting for population heterogeneity.« less

Determining the Impact of Personal Mobility Carbon Allowance Schemes in Transportation Networks

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

Aziz, H. M. Abdul; Ukkusuri, Satish V.; Zhan, Xianyuan

We know that personal mobility carbon allowance (PMCA) schemes are designed to reduce carbon consumption from transportation networks. PMCA schemes influence the travel decision process of users and accordingly impact the system metrics including travel time and greenhouse gas (GHG) emissions. Here, we develop a multi-user class dynamic user equilibrium model to evaluate the transportation system performance when PMCA scheme is implemented. The results using Sioux-Falls test network indicate that PMCA schemes can achieve the emissions reduction goals for transportation networks. Further, users characterized by high value of travel time are found to be less sensitive to carbon budget inmore » the context of work trips. Results also show that PMCA scheme can lead to higher emissions for a path compared with the case without PMCA because of flow redistribution. The developed network equilibrium model allows us to examine the change in system states at different carbon allocation levels and to design parameters of PMCA schemes accounting for population heterogeneity.« less

Public transportation and intercity rail passenger plan for Washington state 1997-2016

DOT National Transportation Integrated Search

1996-12-01

The Public Transportation and Intercity Rail Passenger Plan for Washington : State is a 20-year plan for preserving our current public transportation systems : while improving mobility for a growing population. The plan builds toward a : future in wh...

Psychosocial and Environmental Correlates of Walking, Cycling, Public Transport and Passive Transport to Various Destinations in Flemish Older Adolescents.

PubMed

Verhoeven, Hannah; Simons, Dorien; Van Dyck, Delfien; Van Cauwenberg, Jelle; Clarys, Peter; De Bourdeaudhuij, Ilse; de Geus, Bas; Vandelanotte, Corneel; Deforche, Benedicte

2016-01-01

Active transport is a convenient way to incorporate physical activity in adolescents' daily life. The present study aimed to investigate which psychosocial and environmental factors are associated with walking, cycling, public transport (train, tram, bus, metro) and passive transport (car, motorcycle, moped) over short distances (maximum eight kilometres) among older adolescents (17-18 years), to school and to other destinations. 562 older adolescents completed an online questionnaire assessing socio-demographic variables, psychosocial variables, environmental variables and transport to school/other destinations. Zero-inflated negative binomial regression models were performed. More social modelling and a higher residential density were positively associated with walking to school and walking to other destinations, respectively. Regarding cycling, higher self-efficacy and a higher social norm were positively associated with cycling to school and to other destinations. Regarding public transport, a higher social norm, more social modelling of siblings and/or friends, more social support and a higher land use mix access were positively related to public transport to school and to other destinations, whereas a greater distance to school only related positively to public transport to school. Regarding passive transport, more social support and more perceived benefits were positively associated with passive transport to school and to other destinations. Perceiving less walking and cycling facilities at school was positively related to passive transport to school only, and more social modelling was positively related to passive transport to other destinations. Overall, psychosocial variables seemed to be more important than environmental variables across the four transport modes. Social norm, social modelling and social support were the most consistent psychosocial factors which indicates that it is important to target both older adolescents and their social environment

Common mental disorders in public transportation drivers in Lima, Peru.

PubMed

Ruiz-Grosso, Paulo; Ramos, Mariana; Samalvides, Frine; Vega-Dienstmaier, Johann; Kruger, Hever

2014-01-01

Traffic related injuries are leading contributors to burden of disease worldwide. In developing countries a high proportion of them can be attributed to public transportation vehicles. Several mental disorders including alcohol and drug abuse, psychotic disorders, mental stress, productivity pressure, and low monetary income were found predictors of high rates of traffic related injuries in public transportation drivers. The goal of this study was to estimate the prevalence of common mental disorders in the population of public transportation drivers of buses and rickshaws in Lima, Peru. Cross sectional study. A sample of bus and rickshaw drivers was systematically selected from formal public transportation companies using a snowball approach. Participants completed self-administered questionnaires for assessing major depressive episode, anxiety symptoms, alcohol abuse, and burnout syndrome. Socio demographic information was also collected. The analyses consisted of descriptive measurement of outcomes taking into account both between and within cluster standard deviation (BCSD and WCSD). A total of 278 bus and 227 rickshaw drivers out of 25 companies agreed to participate in the study. BCSD for major depressive episode, anxiety symptoms and burnout syndrome was not found significant (p>0.05). The estimated prevalence of each variable was 13.7% (IC95%: 10.7-16.6%), 24.1% (IC95%: 19.4-28.8%) and 14.1% (IC95%: 10.8-17.4%) respectively. The estimated prevalence of alcohol abuse was 75.4% (IC95%: 69-81.7%, BCSD = 12.2%, WCSD = 41.9%, intra class correlation (ICC): 7.8%). Common mental disorders such as alcohol abuse, major depressive episode, anxiety symptoms and burnout syndrome presented higher rates in public transportation drivers than general population.

Attacks on public telephone networks: technologies and challenges

NASA Astrophysics Data System (ADS)

Kosloff, T.; Moore, Tyler; Keller, J.; Manes, Gavin W.; Shenoi, Sujeet

2003-09-01

Signaling System 7 (SS7) is vital to signaling and control in America's public telephone networks. This paper describes a class of attacks on SS7 networks involving the insertion of malicious signaling messages via compromised SS7 network components. Three attacks are discussed in detail: IAM flood attacks, redirection attacks and point code spoofing attacks. Depending on their scale of execution, these attacks can produce effects ranging from network congestion to service disruption. Methods for detecting these denial-of-service attacks and mitigating their effects are also presented.

Vehicles for Education: Turkish Students' Beliefs and Views about Public Transport

ERIC Educational Resources Information Center

Kilinc, Ahmet; Seymen, Hatice; Malandrakis, George; Boyes, Edward; Stanisstreet, Martin

2013-01-01

The increasing use of private rather than public transport is impacting on the environment in a number of ways, including contributing to the major problem of global warming. It is necessary, therefore, to improve strategies to encourage greater use of public transport. The aim of this study is to explore which perceived aspects of public…

CSI Index Of Customer's Satisfaction Applied In The Area Of Public Transport

NASA Astrophysics Data System (ADS)

Poliaková, Adela

2015-06-01

In Western countries, the new visions are applied in quality control for an integrated public transport system. Public transport puts the customer at the centre of our decision making in achieving customer satisfaction with provided service. Sustainable surveys are kept among customers. A lot of companies are collecting huge databases containing over 30,000 voices of customers, which demonstrates the current satisfaction levels across the public transport service. Customer satisfaction with a provided service is a difficult task. In this service, the quality criteria are not clearly defined, and it is therefore difficult to define customer satisfaction. The paper introduces a possibility of CSI index application in conditions of the Slovak Republic transport area.

Implications of Network Structure on Public Health Collaboratives

ERIC Educational Resources Information Center

Retrum, Jessica H.; Chapman, Carrie L.; Varda, Danielle M.

2013-01-01

Interorganizational collaboration is an essential function of public health agencies. These partnerships form social networks that involve diverse types of partners and varying levels of interaction. Such collaborations are widely accepted and encouraged, yet very little comparative research exists on how public health partnerships develop and…

PONS - Mobility Assistance on Footpaths for Public Transportation.

PubMed

Koutny, Reinhard; Miesenberger, Klaus

2015-01-01

This paper presents an ongoing project targeting mobility support for users of public transportation including people with limited mobility. Existing approaches in this field mostly offer non-continuous guidance during the whole journey including multiple rides with different vehicles and footpaths in between at transfer points. Especially people with limited mobility, like people with disabilities and elderly people, or travelers who are not familiar with the specific route or transfer point, like tourists, often struggle with public transportation. They crave for a seamless approach covering all links of the mobility chain - the sequence of sections of the whole route - and providing comprehensive assistance throughout the whole journey. Previous projects and widespread experiences of project partners revealed that especially footpath sections are lacking proper support. In particular, the consortium identified three problem areas in existing approaches when dealing with footpath sections: (1) A lack of information, (2) a lack of orientation and (3) a lack of provision of services. In order to bridge (lat. PONS) these gaps in the mobility chain, new paradigms and technology concepts are developed to tackle the shortcomings on footpaths and combined in a toolkit to help developers of applications with focus on pedestrian navigation and public transport to improve their solutions with sustainable and state-of-the-art approaches.

Smart Collision Avoidance and Hazard Routing Mechanism for Intelligent Transport Network

NASA Astrophysics Data System (ADS)

Singh, Gurpreet; Gupta, Pooja; Wahab, Mohd Helmy Abd

2017-08-01

The smart vehicular ad-hoc network is the network that consists of vehicles for smooth movement and better management of the vehicular connectivity across the given network. This research paper aims to propose a set of solution for the VANETs consisting of the automatic driven vehicles, also called as the autonomous car. Such vehicular networks are always prone to collision due to the natural or un-natural reasons which must be solved before the large-scale deployment of the autonomous transport systems. The newly designed intelligent transport movement control mechanism is based upon the intelligent data propagation along with the vehicle collision and traffic jam prevention schema [8], which may help the future designs of smart cities to become more robust and less error-prone. In the proposed model, the focus is on designing a new dynamic and robust hazard routing protocol for intelligent vehicular networks for improvement of the overall performance in various aspects. It is expected to improve the overall transmission delay as well as the number of collisions or adversaries across the vehicular network zone.

Research on Some Bus Transport Networks with Random Overlapping Clique Structure

NASA Astrophysics Data System (ADS)

Yang, Xu-Hua; Wang, Bo; Wang, Wan-Liang; Sun, You-Xian

2008-11-01

On the basis of investigating the statistical data of bus transport networks of three big cities in China, we propose that each bus route is a clique (maximal complete subgraph) and a bus transport network (BTN) consists of a lot of cliques, which intensively connect and overlap with each other. We study the network properties, which include the degree distribution, multiple edges' overlapping time distribution, distribution of the overlap size between any two overlapping cliques, distribution of the number of cliques that a node belongs to. Naturally, the cliques also constitute a network, with the overlapping nodes being their multiple links. We also research its network properties such as degree distribution, clustering, average path length, and so on. We propose that a BTN has the properties of random clique increment and random overlapping clique, at the same time, a BTN is a small-world network with highly clique-clustered and highly clique-overlapped. Finally, we introduce a BTN evolution model, whose simulation results agree well with the statistical laws that emerge in real BTNs.

Public/Private Sector Interactions: The Implications for Networking. A Discussion Report Prepared by the Network Advisory Committee.

ERIC Educational Resources Information Center

Network Planning Paper, 1983

1983-01-01

At a 2-day meeting in October 1982, the Library of Congress Network Advisory Committee (NAC) members discussed the complex issues involved in public and private sector interactions and their relationship to networking activities. The report, "Public Sector/Private Sector Interaction in Providing Information Services," prepared by the…

Lattice Boltzmann simulation of CO2 reactive transport in network fractured media

NASA Astrophysics Data System (ADS)

Tian, Zhiwei; Wang, Junye

2017-08-01

Carbon dioxide (CO2) geological sequestration plays an important role in mitigating CO2 emissions for climate change. Understanding interactions of the injected CO2 with network fractures and hydrocarbons is key for optimizing and controlling CO2 geological sequestration and evaluating its risks to ground water. However, there is a well-known, difficult process in simulating the dynamic interaction of fracture-matrix, such as dynamic change of matrix porosity, unsaturated processes in rock matrix, and effect of rock mineral properties. In this paper, we develop an explicit model of the fracture-matrix interactions using multilayer bounce-back treatment as a first attempt to simulate CO2 reactive transport in network fractured media through coupling the Dardis's LBM porous model for a new interface treatment. Two kinds of typical fracture networks in porous media are simulated: straight cross network fractures and interleaving network fractures. The reaction rate and porosity distribution are illustrated and well-matched patterns are found. The species concentration distribution and evolution with time steps are also analyzed and compared with different transport properties. The results demonstrate the capability of this model to investigate the complex processes of CO2 geological injection and reactive transport in network fractured media, such as dynamic change of matrix porosity.

Critical forces for actin filament buckling and force transmission influence transport in actomyosin networks

NASA Astrophysics Data System (ADS)

Stam, Samantha; Gardel, Margaret

Viscoelastic networks of biopolymers coordinate the motion of intracellular objects during transport. These networks have nonlinear mechanical properties due to events such as filament buckling or breaking of cross-links. The influence of such nonlinear properties on the time and length scales of transport is not understood. Here, we use in vitro networks of actin and the motor protein myosin II to clarify how intracellular forces regulate active diffusion. We observe two transitions in the mean-squared displacement of cross-linked actin with increasing motor concentration. The first is a sharp transition from initially subdiffusive to diffusive-like motion that requires filament buckling but does not cause net contraction of the network. Further increase of the motor density produces a second transition to network rupture and ballistic actin transport. This corresponds with an increase in the correlation of motion and thus may be caused when forces propagate far enough for global motion. We conclude that filament buckling and overall network contraction require different amounts of force and produce distinct transport properties. These nonlinear transitions may act as mechanical switches that can be turned on to produce observed motion within cells.

Water transport, free volume, and polymer dynamics in crosslinked polymer networks

NASA Astrophysics Data System (ADS)

Frieberg, Bradley; Soles, Christopher

Many technologies rely on amorphous polymer membranes that selectively transport small molecules or ions, which has led to a significant scientific interest in elucidating the mechanisms of transport. A recurring theme among several different materials systems is that free volume and polymer chain dynamics facilitate transport. In order to understand the interplay between free volume, transport and polymer dynamics we quantify these properties for a model epoxy network. The epoxy chemistry allows for systematically varying both the structural rigidity of the network as well as the cross-link density. We performed positron annihilation lifetime spectroscopy measurements to characterize the unoccupied volume and correlated the unoccupied volume to the equilibrium moisture uptake and effective diffusion coefficient. We have recently extended this work to include polymer dynamics measured by quasi-elastic neutron scattering on the NIST High Flux Backscatter Spectrometer. These measurements reveal a strong correlation between the MSD and the transport kinetics, which was even stronger than the correlation previously observed between free volume and water diffusion. These observations challenge previous theories that suggest free volume governs transport.

Intelligent Urban Public Transportation for Accessibility Dedicated to People with Disabilities

PubMed Central

Zhou, Haiying; Hou, Kun-Mean; Zuo, Decheng; Li, Jian

2012-01-01

The traditional urban public transport system generally cannot provide an effective access service for people with disabilities, especially for disabled, wheelchair and blind (DWB) passengers. In this paper, based on advanced information & communication technologies (ICT) and green technologies (GT) concepts, a dedicated public urban transportation service access system named Mobi+ has been introduced, which facilitates the mobility of DWB passengers. The Mobi+ project consists of three subsystems: a wireless communication subsystem, which provides the data exchange and network connection services between buses and stations in the complex urban environments; the bus subsystem, which provides the DWB class detection & bus arrival notification services; and the station subsystem, which implements the urban environmental surveillance & bus auxiliary access services. The Mobi+ card that supports multi-microcontroller multi-transceiver adopts the fault-tolerant component-based hardware architecture, in which the dedicated embedded system software, i.e., operating system micro-kernel and wireless protocol, has been integrated. The dedicated Mobi+ embedded system provides the fault-tolerant resource awareness communication and scheduling mechanism to ensure the reliability in data exchange and service provision. At present, the Mobi+ system has been implemented on the buses and stations of line ‘2’ in the city of Clermont-Ferrand (France). The experiential results show that, on one hand the Mobi+ prototype system reaches the design expectations and provides an effective urban bus access service for people with disabilities; on the other hand the Mobi+ system is easily to deploy in the buses and at bus stations thanks to its low energy consumption and small form factor. PMID:23112622

Intelligent urban public transportation for accessibility dedicated to people with disabilities.

PubMed

Zhou, Haiying; Hou, Kun-Mean; Zuo, Decheng; Li, Jian

2012-01-01

The traditional urban public transport system generally cannot provide an effective access service for people with disabilities, especially for disabled, wheelchair and blind (DWB) passengers. In this paper, based on advanced information & communication technologies (ICT) and green technologies (GT) concepts, a dedicated public urban transportation service access system named Mobi+ has been introduced, which facilitates the mobility of DWB passengers. The Mobi+ project consists of three subsystems: a wireless communication subsystem, which provides the data exchange and network connection services between buses and stations in the complex urban environments; the bus subsystem, which provides the DWB class detection & bus arrival notification services; and the station subsystem, which implements the urban environmental surveillance & bus auxiliary access services. The Mobi+ card that supports multi-microcontroller multi-transceiver adopts the fault-tolerant component-based hardware architecture, in which the dedicated embedded system software, i.e., operating system micro-kernel and wireless protocol, has been integrated. The dedicated Mobi+ embedded system provides the fault-tolerant resource awareness communication and scheduling mechanism to ensure the reliability in data exchange and service provision. At present, the Mobi+ system has been implemented on the buses and stations of line '2' in the city of Clermont-Ferrand (France). The experiential results show that, on one hand the Mobi+ prototype system reaches the design expectations and provides an effective urban bus access service for people with disabilities; on the other hand the Mobi+ system is easily to deploy in the buses and at bus stations thanks to its low energy consumption and small form factor.

Measure-valued solutions to nonlocal transport equations on networks

NASA Astrophysics Data System (ADS)

Camilli, Fabio; De Maio, Raul; Tosin, Andrea

2018-06-01

Aiming to describe traffic flow on road networks with long-range driver interactions, we study a nonlinear transport equation defined on an oriented network where the velocity field depends not only on the state variable but also on the distribution of the population. We prove existence, uniqueness and continuous dependence results of the solution intended in a suitable measure-theoretic sense. We also provide a representation formula in terms of the push-forward of the initial and boundary data along the network and discuss an explicit example of nonlocal velocity field fitting our framework.

Cooperation among cancer cells as public goods games on Voronoi networks.

PubMed

Archetti, Marco

2016-05-07

Cancer cells produce growth factors that diffuse and sustain tumour proliferation, a form of cooperation that can be studied using mathematical models of public goods in the framework of evolutionary game theory. Cell populations, however, form heterogeneous networks that cannot be described by regular lattices or scale-free networks, the types of graphs generally used in the study of cooperation. To describe the dynamics of growth factor production in populations of cancer cells, I study public goods games on Voronoi networks, using a range of non-linear benefits that account for the known properties of growth factors, and different types of diffusion gradients. The results are surprisingly similar to those obtained on regular graphs and different from results on scale-free networks, revealing that network heterogeneity per se does not promote cooperation when public goods diffuse beyond one-step neighbours. The exact shape of the diffusion gradient is not crucial, however, whereas the type of non-linear benefit is an essential determinant of the dynamics. Public goods games on Voronoi networks can shed light on intra-tumour heterogeneity, the evolution of resistance to therapies that target growth factors, and new types of cell therapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Public Health Analysis Transport Optimization Model v. 1.0

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

Beyeler, Walt; Finley, Patrick; Walser, Alex

PHANTOM models logistic functions of national public health systems. The system enables public health officials to visualize and coordinate options for public health surveillance, diagnosis, response and administration in an integrated analytical environment. Users may simulate and analyze system performance applying scenarios that represent current conditions or future contingencies what-if analyses of potential systemic improvements. Public health networks are visualized as interactive maps, with graphical displays of relevant system performance metrics as calculated by the simulation modeling components.

Network Theory: A Primer and Questions for Air Transportation Systems Applications

NASA Technical Reports Server (NTRS)

Holmes, Bruce J.

2004-01-01

A new understanding (with potential applications to air transportation systems) has emerged in the past five years in the scientific field of networks. This development emerges in large part because we now have a new laboratory for developing theories about complex networks: The Internet. The premise of this new understanding is that most complex networks of interest, both of nature and of human contrivance, exhibit a fundamentally different behavior than thought for over two hundred years under classical graph theory. Classical theory held that networks exhibited random behavior, characterized by normal, (e.g., Gaussian or Poisson) degree distributions of the connectivity between nodes by links. The new understanding turns this idea on its head: networks of interest exhibit scale-free (or small world) degree distributions of connectivity, characterized by power law distributions. The implications of scale-free behavior for air transportation systems include the potential that some behaviors of complex system architectures might be analyzed through relatively simple approximations of local elements of the system. For air transportation applications, this presentation proposes a framework for constructing topologies (architectures) that represent the relationships between mobility, flight operations, aircraft requirements, and airspace capacity, and the related externalities in airspace procedures and architectures. The proposed architectures or topologies may serve as a framework for posing comparative and combinative analyses of performance, cost, security, environmental, and related metrics.

Evaluation Plan for the Cape Cod Advanced Public Transportation System

DOT National Transportation Integrated Search

2000-06-01

The Cape Cod Regional Transit Authority (CCRTA) Advanced Public Transportation System (APTS) project is an application of Intelligent Transportation Systems (ITS) to fixed route and paratransit operations in a rural transit setting. The purpose of th...

Rural Public Transportation Technologies: User Needs and Applications. Final Report

DOT National Transportation Integrated Search

1998-08-01

The Rural Public Transportation Technologies: User Needs and Applications Study was conducted as part of the U.S. DOT's overall Rural Intelligent Transportation System (ITS) Program. The study examined the opportunities and challenges of planning and...

77 FR 71430 - New Agency Information Collection Activity Under OMB Review: Public Transportation Baseline...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-30

... DEPARTMENT OF HOMELAND SECURITY Transportation Security Administration New Agency Information Collection Activity Under OMB Review: Public Transportation Baseline Assessment for Security Enhancement... voluntary site visits with security and operating officials of public transportation systems. This program...

Network public opinion space sentiment tendency analyze based on recurrent convolution neural network

NASA Astrophysics Data System (ADS)

Zhang, Gaowei; Xu, Lingyu; Wang, Lei

2018-04-01

The purpose of this chapter is to analyze the investor's psychological characteristics and investment decision-making behavior characteristics, to study the investor sentiment under the network public opinion, and then analyze from three aspects: First, investor sentiment analysis and how to spread in the online media; The influence mechanism of investor's emotion on the stock market and its effect; the third one is to measure the investor's emotion based on the degree of attention, trying hard to sort out the internal relations between the investor's sentiment and the network public opinion and the stock market, in order to lay the theoretical foundation of this article.

Transport through a network of capillaries from ultrametric diffusion equation with quadratic nonlinearity

NASA Astrophysics Data System (ADS)

Oleschko, K.; Khrennikov, A.

2017-10-01

This paper is about a novel mathematical framework to model transport (of, e.g., fluid or gas) through networks of capillaries. This framework takes into account the tree structure of the networks of capillaries. (Roughly speaking, we use the tree-like system of coordinates.) As is well known, tree-geometry can be topologically described as the geometry of an ultrametric space, i.e., a metric space in which the metric satisfies the strong triangle inequality: in each triangle, the third side is less than or equal to the maximum of two other sides. Thus transport (e.g., of oil or emulsion of oil and water in porous media, or blood and air in biological organisms) through networks of capillaries can be mathematically modelled as ultrametric diffusion. Such modelling was performed in a series of recently published papers of the authors. However, the process of transport through capillaries can be only approximately described by the linear diffusion, because the concentration of, e.g., oil droplets, in a capillary can essentially modify the dynamics. Therefore nonlinear dynamical equations provide a more adequate model of transport in a network of capillaries. We consider a nonlinear ultrametric diffusion equation with quadratic nonlinearity - to model transport in such a network. Here, as in the linear case, we apply the theory of ultrametric wavelets. The paper also contains a simple introduction to theory of ultrametric spaces and analysis on them.

Advanced Public Transportation Systems. Technical Assistance Brief 2

DOT National Transportation Integrated Search

1993-01-01

The Advanced Public Transportation Systems (APTS) Program requires evaluation : of pilot projects. This technical assistance brief discusses the guidelines set : for developing evaluation framework and methodology for local projects. 4p.

Benefits assessment of advanced public transportation systems (APTS)

DOT National Transportation Integrated Search

1996-07-01

This report documents work performed under FTA's Advance Public Transportation Systems (APTS) Program, a program structured to undertake research and development of innovative applications of advanced navigation, information, and communication techno...

A methodology for determining rural public transportation needs in Virginia.

DOT National Transportation Integrated Search

1974-01-01

The need for rural public transportation is coming into focus, although-Its magnitude is unknown because of limited data. This study was initiated to develop an efficient and economical methodology for determining the transportation needs of the rura...

Scaling and correlations in three bus-transport networks of China

NASA Astrophysics Data System (ADS)

Xu, Xinping; Hu, Junhui; Liu, Feng; Liu, Lianshou

2007-01-01

We report the statistical properties of three bus-transport networks (BTN) in three different cities of China. These networks are composed of a set of bus lines and stations serviced by these. Network properties, including the degree distribution, clustering and average path length are studied in different definitions of network topology. We explore scaling laws and correlations that may govern intrinsic features of such networks. Besides, we create a weighted network representation for BTN with lines mapped to nodes and number of common stations to weights between lines. In such a representation, the distributions of degree, strength and weight are investigated. A linear behavior between strength and degree s(k)∼k is also observed.

Scale-Free Networks and Commercial Air Carrier Transportation in the United States

NASA Technical Reports Server (NTRS)

Conway, Sheila R.

2004-01-01

Network science, or the art of describing system structure, may be useful for the analysis and control of large, complex systems. For example, networks exhibiting scale-free structure have been found to be particularly well suited to deal with environmental uncertainty and large demand growth. The National Airspace System may be, at least in part, a scalable network. In fact, the hub-and-spoke structure of the commercial segment of the NAS is an often-cited example of an existing scale-free network After reviewing the nature and attributes of scale-free networks, this assertion is put to the test: is commercial air carrier transportation in the United States well explained by this model? If so, are the positive attributes of these networks, e.g. those of efficiency, flexibility and robustness, fully realized, or could we effect substantial improvement? This paper first outlines attributes of various network types, then looks more closely at the common carrier air transportation network from perspectives of the traveler, the airlines, and Air Traffic Control (ATC). Network models are applied within each paradigm, including discussion of implied strengths and weaknesses of each model. Finally, known limitations of scalable networks are discussed. With an eye towards NAS operations, utilizing the strengths and avoiding the weaknesses of scale-free networks are addressed.

Psychosocial and Environmental Correlates of Walking, Cycling, Public Transport and Passive Transport to Various Destinations in Flemish Older Adolescents

PubMed Central

Verhoeven, Hannah; Simons, Dorien; Van Dyck, Delfien; Van Cauwenberg, Jelle; Clarys, Peter; De Bourdeaudhuij, Ilse; de Geus, Bas; Vandelanotte, Corneel; Deforche, Benedicte

2016-01-01

Background Active transport is a convenient way to incorporate physical activity in adolescents’ daily life. The present study aimed to investigate which psychosocial and environmental factors are associated with walking, cycling, public transport (train, tram, bus, metro) and passive transport (car, motorcycle, moped) over short distances (maximum eight kilometres) among older adolescents (17–18 years), to school and to other destinations. Methods 562 older adolescents completed an online questionnaire assessing socio-demographic variables, psychosocial variables, environmental variables and transport to school/other destinations. Zero-inflated negative binomial regression models were performed. Results More social modelling and a higher residential density were positively associated with walking to school and walking to other destinations, respectively. Regarding cycling, higher self-efficacy and a higher social norm were positively associated with cycling to school and to other destinations. Regarding public transport, a higher social norm, more social modelling of siblings and/or friends, more social support and a higher land use mix access were positively related to public transport to school and to other destinations, whereas a greater distance to school only related positively to public transport to school. Regarding passive transport, more social support and more perceived benefits were positively associated with passive transport to school and to other destinations. Perceiving less walking and cycling facilities at school was positively related to passive transport to school only, and more social modelling was positively related to passive transport to other destinations. Conclusions Overall, psychosocial variables seemed to be more important than environmental variables across the four transport modes. Social norm, social modelling and social support were the most consistent psychosocial factors which indicates that it is important to target both

Modeling flow and transport in fracture networks using graphs

NASA Astrophysics Data System (ADS)

Karra, S.; O'Malley, D.; Hyman, J. D.; Viswanathan, H. S.; Srinivasan, G.

2018-03-01

Fractures form the main pathways for flow in the subsurface within low-permeability rock. For this reason, accurately predicting flow and transport in fractured systems is vital for improving the performance of subsurface applications. Fracture sizes in these systems can range from millimeters to kilometers. Although modeling flow and transport using the discrete fracture network (DFN) approach is known to be more accurate due to incorporation of the detailed fracture network structure over continuum-based methods, capturing the flow and transport in such a wide range of scales is still computationally intractable. Furthermore, if one has to quantify uncertainty, hundreds of realizations of these DFN models have to be run. To reduce the computational burden, we solve flow and transport on a graph representation of a DFN. We study the accuracy of the graph approach by comparing breakthrough times and tracer particle statistical data between the graph-based and the high-fidelity DFN approaches, for fracture networks with varying number of fractures and degree of heterogeneity. Due to our recent developments in capabilities to perform DFN high-fidelity simulations on fracture networks with large number of fractures, we are in a unique position to perform such a comparison. We show that the graph approach shows a consistent bias with up to an order of magnitude slower breakthrough when compared to the DFN approach. We show that this is due to graph algorithm's underprediction of the pressure gradients across intersections on a given fracture, leading to slower tracer particle speeds between intersections and longer travel times. We present a bias correction methodology to the graph algorithm that reduces the discrepancy between the DFN and graph predictions. We show that with this bias correction, the graph algorithm predictions significantly improve and the results are very accurate. The good accuracy and the low computational cost, with O (104) times lower times than

Modeling flow and transport in fracture networks using graphs.

PubMed

Karra, S; O'Malley, D; Hyman, J D; Viswanathan, H S; Srinivasan, G

2018-03-01

Fractures form the main pathways for flow in the subsurface within low-permeability rock. For this reason, accurately predicting flow and transport in fractured systems is vital for improving the performance of subsurface applications. Fracture sizes in these systems can range from millimeters to kilometers. Although modeling flow and transport using the discrete fracture network (DFN) approach is known to be more accurate due to incorporation of the detailed fracture network structure over continuum-based methods, capturing the flow and transport in such a wide range of scales is still computationally intractable. Furthermore, if one has to quantify uncertainty, hundreds of realizations of these DFN models have to be run. To reduce the computational burden, we solve flow and transport on a graph representation of a DFN. We study the accuracy of the graph approach by comparing breakthrough times and tracer particle statistical data between the graph-based and the high-fidelity DFN approaches, for fracture networks with varying number of fractures and degree of heterogeneity. Due to our recent developments in capabilities to perform DFN high-fidelity simulations on fracture networks with large number of fractures, we are in a unique position to perform such a comparison. We show that the graph approach shows a consistent bias with up to an order of magnitude slower breakthrough when compared to the DFN approach. We show that this is due to graph algorithm's underprediction of the pressure gradients across intersections on a given fracture, leading to slower tracer particle speeds between intersections and longer travel times. We present a bias correction methodology to the graph algorithm that reduces the discrepancy between the DFN and graph predictions. We show that with this bias correction, the graph algorithm predictions significantly improve and the results are very accurate. The good accuracy and the low computational cost, with O(10^{4}) times lower times

Modeling flow and transport in fracture networks using graphs

DOE PAGES

Karra, S.; O'Malley, D.; Hyman, J. D.; ...

2018-03-09

Fractures form the main pathways for flow in the subsurface within low-permeability rock. For this reason, accurately predicting flow and transport in fractured systems is vital for improving the performance of subsurface applications. Fracture sizes in these systems can range from millimeters to kilometers. Although modeling flow and transport using the discrete fracture network (DFN) approach is known to be more accurate due to incorporation of the detailed fracture network structure over continuum-based methods, capturing the flow and transport in such a wide range of scales is still computationally intractable. Furthermore, if one has to quantify uncertainty, hundreds of realizationsmore » of these DFN models have to be run. To reduce the computational burden, we solve flow and transport on a graph representation of a DFN. We study the accuracy of the graph approach by comparing breakthrough times and tracer particle statistical data between the graph-based and the high-fidelity DFN approaches, for fracture networks with varying number of fractures and degree of heterogeneity. Due to our recent developments in capabilities to perform DFN high-fidelity simulations on fracture networks with large number of fractures, we are in a unique position to perform such a comparison. We show that the graph approach shows a consistent bias with up to an order of magnitude slower breakthrough when compared to the DFN approach. We show that this is due to graph algorithm's underprediction of the pressure gradients across intersections on a given fracture, leading to slower tracer particle speeds between intersections and longer travel times. We present a bias correction methodology to the graph algorithm that reduces the discrepancy between the DFN and graph predictions. We show that with this bias correction, the graph algorithm predictions significantly improve and the results are very accurate. In conclusion, the good accuracy and the low computational cost, with O(10 4

Modeling flow and transport in fracture networks using graphs

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

Karra, S.; O'Malley, D.; Hyman, J. D.

Fractures form the main pathways for flow in the subsurface within low-permeability rock. For this reason, accurately predicting flow and transport in fractured systems is vital for improving the performance of subsurface applications. Fracture sizes in these systems can range from millimeters to kilometers. Although modeling flow and transport using the discrete fracture network (DFN) approach is known to be more accurate due to incorporation of the detailed fracture network structure over continuum-based methods, capturing the flow and transport in such a wide range of scales is still computationally intractable. Furthermore, if one has to quantify uncertainty, hundreds of realizationsmore » of these DFN models have to be run. To reduce the computational burden, we solve flow and transport on a graph representation of a DFN. We study the accuracy of the graph approach by comparing breakthrough times and tracer particle statistical data between the graph-based and the high-fidelity DFN approaches, for fracture networks with varying number of fractures and degree of heterogeneity. Due to our recent developments in capabilities to perform DFN high-fidelity simulations on fracture networks with large number of fractures, we are in a unique position to perform such a comparison. We show that the graph approach shows a consistent bias with up to an order of magnitude slower breakthrough when compared to the DFN approach. We show that this is due to graph algorithm's underprediction of the pressure gradients across intersections on a given fracture, leading to slower tracer particle speeds between intersections and longer travel times. We present a bias correction methodology to the graph algorithm that reduces the discrepancy between the DFN and graph predictions. We show that with this bias correction, the graph algorithm predictions significantly improve and the results are very accurate. In conclusion, the good accuracy and the low computational cost, with O(10 4

76 FR 78332 - Amended Notice of Limitation on Claims Against Proposed Public Transportation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Amended Notice of Limitation on Claims Against Proposed Public Transportation Project AGENCY: Federal Transit Administration (FTA), DOT. ACTION... actions announced herein for the listed public transportation project will be barred unless the claim is...

Implementing multiple intervention strategies in Dutch public health-related policy networks.

PubMed

Harting, Janneke; Peters, Dorothee; Grêaux, Kimberly; van Assema, Patricia; Verweij, Stefan; Stronks, Karien; Klijn, Erik-Hans

2017-10-13

Improving public health requires multiple intervention strategies. Implementing such an intervention mix is supposed to require a multisectoral policy network. As evidence to support this assumption is scarce, we examined under which conditions public health-related policy networks were able to implement an intervention mix. Data were collected (2009-14) from 29 Dutch public health policy networks. Surveys were used to identify the number of policy sectors, participation of actors, level of trust, networking by the project leader, and intervention strategies implemented. Conditions sufficient for an intervention mix (≥3 of 4 non-educational strategies present) were determined in a fuzzy-set qualitative comparative analysis. A multisectoral policy network (≥7 of 14 sectors present) was neither a necessary nor a sufficient condition. In multisectoral networks, additionally required was either the active participation of network actors (≥50% actively involved) or active networking by the project leader (≥monthly contacts with network actors). In policy networks that included few sectors, a high level of trust (positive perceptions of each other's intentions) was needed-in the absence though of any of the other conditions. If the network actors were also actively involved, an extra requirement was active networking by the project leader. We conclude that the multisectoral composition of policy networks can contribute to the implementation of a variety of intervention strategies, but not without additional efforts. However, policy networks that include only few sectors are also able to implement an intervention mix. Here, trust seems to be the most important condition. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radionuclide gas transport through nuclear explosion-generated fracture networks

DOE PAGES

Jordan, Amy B.; Stauffer, Philip H.; Knight, Earl E.; ...

2015-12-17

Underground nuclear weapon testing produces radionuclide gases which may seep to the surface. Barometric pumping of gas through explosion-fractured rock is investigated using a new sequentially-coupled hydrodynamic rock damage/gas transport model. Fracture networks are produced for two rock types (granite and tuff) and three depths of burial. The fracture networks are integrated into a flow and transport numerical model driven by surface pressure signals of differing amplitude and variability. There are major differences between predictions using a realistic fracture network and prior results that used a simplified geometry. Matrix porosity and maximum fracture aperture have the greatest impact on gasmore » breakthrough time and window of opportunity for detection, with different effects between granite and tuff simulations highlighting the importance of accurately simulating the fracture network. In particular, maximum fracture aperture has an opposite effect on tuff and granite, due to different damage patterns and their effect on the barometric pumping process. From stochastic simulations using randomly generated hydrogeologic parameters, normalized detection curves are presented to show differences in optimal sampling time for granite and tuff simulations. In conclusion, seasonal and location-based effects on breakthrough, which occur due to differences in barometric forcing, are stronger where the barometric signal is highly variable.« less

Radionuclide gas transport through nuclear explosion-generated fracture networks

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

Jordan, Amy B.; Stauffer, Philip H.; Knight, Earl E.

Underground nuclear weapon testing produces radionuclide gases which may seep to the surface. Barometric pumping of gas through explosion-fractured rock is investigated using a new sequentially-coupled hydrodynamic rock damage/gas transport model. Fracture networks are produced for two rock types (granite and tuff) and three depths of burial. The fracture networks are integrated into a flow and transport numerical model driven by surface pressure signals of differing amplitude and variability. There are major differences between predictions using a realistic fracture network and prior results that used a simplified geometry. Matrix porosity and maximum fracture aperture have the greatest impact on gasmore » breakthrough time and window of opportunity for detection, with different effects between granite and tuff simulations highlighting the importance of accurately simulating the fracture network. In particular, maximum fracture aperture has an opposite effect on tuff and granite, due to different damage patterns and their effect on the barometric pumping process. From stochastic simulations using randomly generated hydrogeologic parameters, normalized detection curves are presented to show differences in optimal sampling time for granite and tuff simulations. In conclusion, seasonal and location-based effects on breakthrough, which occur due to differences in barometric forcing, are stronger where the barometric signal is highly variable.« less

Radionuclide Gas Transport through Nuclear Explosion-Generated Fracture Networks

PubMed Central

Jordan, Amy B.; Stauffer, Philip H.; Knight, Earl E.; Rougier, Esteban; Anderson, Dale N.

2015-01-01

Underground nuclear weapon testing produces radionuclide gases which may seep to the surface. Barometric pumping of gas through explosion-fractured rock is investigated using a new sequentially-coupled hydrodynamic rock damage/gas transport model. Fracture networks are produced for two rock types (granite and tuff) and three depths of burial. The fracture networks are integrated into a flow and transport numerical model driven by surface pressure signals of differing amplitude and variability. There are major differences between predictions using a realistic fracture network and prior results that used a simplified geometry. Matrix porosity and maximum fracture aperture have the greatest impact on gas breakthrough time and window of opportunity for detection, with different effects between granite and tuff simulations highlighting the importance of accurately simulating the fracture network. In particular, maximum fracture aperture has an opposite effect on tuff and granite, due to different damage patterns and their effect on the barometric pumping process. From stochastic simulations using randomly generated hydrogeologic parameters, normalized detection curves are presented to show differences in optimal sampling time for granite and tuff simulations. Seasonal and location-based effects on breakthrough, which occur due to differences in barometric forcing, are stronger where the barometric signal is highly variable. PMID:26676058

Radionuclide Gas Transport through Nuclear Explosion-Generated Fracture Networks.

PubMed

Jordan, Amy B; Stauffer, Philip H; Knight, Earl E; Rougier, Esteban; Anderson, Dale N

2015-12-17

Underground nuclear weapon testing produces radionuclide gases which may seep to the surface. Barometric pumping of gas through explosion-fractured rock is investigated using a new sequentially-coupled hydrodynamic rock damage/gas transport model. Fracture networks are produced for two rock types (granite and tuff) and three depths of burial. The fracture networks are integrated into a flow and transport numerical model driven by surface pressure signals of differing amplitude and variability. There are major differences between predictions using a realistic fracture network and prior results that used a simplified geometry. Matrix porosity and maximum fracture aperture have the greatest impact on gas breakthrough time and window of opportunity for detection, with different effects between granite and tuff simulations highlighting the importance of accurately simulating the fracture network. In particular, maximum fracture aperture has an opposite effect on tuff and granite, due to different damage patterns and their effect on the barometric pumping process. From stochastic simulations using randomly generated hydrogeologic parameters, normalized detection curves are presented to show differences in optimal sampling time for granite and tuff simulations. Seasonal and location-based effects on breakthrough, which occur due to differences in barometric forcing, are stronger where the barometric signal is highly variable.

dfnWorks: A discrete fracture network framework for modeling subsurface flow and transport

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

Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia

DFNWORKS is a parallelized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using DFNGEN, which combines FRAM (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs with the LaGriT meshing toolbox to create a high-quality computational mesh representation. The representation produces a conforming Delaunay triangulation suitable for high performance computing finite volume solvers in anmore » intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code PFLOTRAN. A Lagrangian approach to simulating transport through the DFN is adopted within DFNTRANS to determine pathlines and solute transport through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO 2 sequestration are also included.« less

Quantifying Economic and Environmental Impacts of Transportation Network Disruptions with Dynamic Traffic Simulation

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

Shekar, Venkateswaran; Fiondella, Lance; Chatterjee, Samrat

Several transportation network vulnerability models have been proposed. However, most only consider disruptions as a static snapshot in time and the impact on total travel time. These approaches cannot consider the time-varying nature of travel demand nor other undesirable outcomes that follow from transportation network disruptions. This paper proposes an algorithmic approach to assess the vulnerability of a transportation network that considers the time-varying demand with an open source dynamic transportation simulation tool. The open source nature of the tool allows us to systematically consider many disruption scenarios and quantitatively compare their relative criticality. This is far more efficient thanmore » traditional approaches which would require days or weeks of a transportation engineers time to manually set up, run, and assess these simulations. In addition to travel time, we also collect statistics on additional fuel consumed and the corresponding carbon dioxide emissions. Our approach, thus provides a more systematic approach that is both time-varying and can consider additional negative consequences of disruptions for decision makers to evaluate.« less

dfnWorks: A discrete fracture network framework for modeling subsurface flow and transport

DOE PAGES

Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; ...

2015-11-01

DFNWORKS is a parallelized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using DFNGEN, which combines FRAM (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs with the LaGriT meshing toolbox to create a high-quality computational mesh representation. The representation produces a conforming Delaunay triangulation suitable for high performance computing finite volume solvers in anmore » intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code PFLOTRAN. A Lagrangian approach to simulating transport through the DFN is adopted within DFNTRANS to determine pathlines and solute transport through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO 2 sequestration are also included.« less

TGIS, TIG, Program Development, Transportation & Public Facilities, State

Science.gov Websites

accessible, accurate, and controlled inventory of public roadway features and linear coordinates for the Roadway Data System (RDS) network (Alaska DOT&PF's Linear Reference System or LRS) to meet Federal and

Costs and benefits of employment transportation for low-wage workers: an assessment of job access public transportation services.

PubMed

Thakuriah Vonu, Piyushimita; Persky, Joseph; Soot, Siim; Sriraj, P S

2013-04-01

This paper focuses on an evaluation of public transportation-based employment transportation (ET) services to transport low-wage workers to jobs in the US. We make an attempt to capture a more comprehensive range of intended and unintended outcomes of ET services than those traditionally considered in the case of public transportation services. Using primary data from 23 locations across the country, we present a framework to evaluate how transportation improvements, in interaction with labor markets, can affect users' short-run economic welfare, users' long-run human capital accumulation and non-users' short-run economic welfare. These services were partially funded by a specialized program - the Job Access and Reverse Commute (JARC) program - which was consolidated into larger transit funding programs by recent legislation. In the sites examined, we found that low wage users benefited from self-reported increased access to jobs, improvements in earnings potential, as well as from savings in transport cost and time. Simulations show the potential of users to accrue long-term worklife benefits. At the same time, users may have accrued changes in leisure time as a result of transitioning from unemployment to employment, and generated a range of societal impacts on three classes of non-users: the general tax-paying public, the general commuting public in the service operating area and other low-wage workers in local labor markets. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ride On! Mini-Units and Learning Activities on Public Transportation for Grades 6 through 9.

ERIC Educational Resources Information Center

Finn, Peter; And Others

One of a series of eleven curriculum manuals which cover the four transportation topics of public transportation, transportation and the environment, transportation safety, and bicycles for elementary, secondary, and adult levels, this manual covers the public transportation topic for grades 6-9. It contains forty-two learning activities grouped…

Ride On! Mini-Units and Learning Activities on Public Transportation for Grades 9 through 12.

ERIC Educational Resources Information Center

Finn, Peter; And Others

One of a series of eleven curriculum manuals which cover the four transportation topics of public transportation, transportation and the environment, transportation safety, and bicycles for elementary, secondary, and adult levels, this manual covers the public transportation topic for grades 9-12. It contains forty-nine learning activities grouped…

Active transportation and public transportation use to achieve physical activity recommendations? A combined GPS, accelerometer, and mobility survey study.

PubMed

Chaix, Basile; Kestens, Yan; Duncan, Scott; Merrien, Claire; Thierry, Benoît; Pannier, Bruno; Brondeel, Ruben; Lewin, Antoine; Karusisi, Noëlla; Perchoux, Camille; Thomas, Frédérique; Méline, Julie

2014-09-27

Accurate information is lacking on the extent of transportation as a source of physical activity, on the physical activity gains from public transportation use, and on the extent to which population shifts in the use of transportation modes could increase the percentage of people reaching official physical activity recommendations. In 2012-2013, 234 participants of the RECORD GPS Study (French Paris region, median age = 58) wore a portable GPS receiver and an accelerometer for 7 consecutive days and completed a 7-day GPS-based mobility survey (participation rate = 57.1%). Information on transportation modes and accelerometry data aggregated at the trip level [number of steps taken, energy expended, moderate to vigorous physical activity (MVPA), and sedentary time] were available for 7,644 trips. Associations between transportation modes and accelerometer-derived physical activity were estimated at the trip level with multilevel linear models. Participants spent a median of 1 h 58 min per day in transportation (8.2% of total time). Thirty-eight per-cent of steps taken, 31% of energy expended, and 33% of MVPA over 7 days were attributable to transportation. Walking and biking trips but also public transportation trips with all four transit modes examined were associated with greater steps, MVPA, and energy expenditure when compared to trips by personal motorized vehicle. Two simulated scenarios, implying a shift of approximately 14% and 33% of all motorized trips to public transportation or walking, were associated with a predicted 6 point and 13 point increase in the percentage of participants achieving the current physical activity recommendation. Collecting data with GPS receivers, accelerometers, and a GPS-based electronic mobility survey of activities and transportation modes allowed us to investigate relationships between transportation modes and physical activity at the trip level. Our findings suggest that an increase in active transportation

Robust Pricing of Transportation Networks Under Uncertainty

DOT National Transportation Integrated Search

2010-09-01

Both public and private entities are concerned with the impacts of future toll revenue, and the effects of tolled facilities on system congestion. Due to the inherent complexity of transportation systems, it is impossible to predict travel demand and...

Description of a method to support public health information management: organizational network analysis

PubMed Central

Merrill, Jacqueline; Bakken, Suzanne; Rockoff, Maxine; Gebbie, Kristine; Carley, Kathleen

2007-01-01

In this case study we describe a method that has potential to provide systematic support for public health information management. Public health agencies depend on specialized information that travels throughout an organization via communication networks among employees. Interactions that occur within these networks are poorly understood and are generally unmanaged. We applied organizational network analysis, a method for studying communication networks, to assess the method’s utility to support decision making for public health managers, and to determine what links existed between information use and agency processes. Data on communication links among a health department’s staff was obtained via survey with a 93% response rate, and analyzed using Organizational Risk Analyzer (ORA) software. The findings described the structure of information flow in the department’s communication networks. The analysis succeeded in providing insights into organizational processes which informed public health managers’ strategies to address problems and to take advantage of network strengths. PMID:17098480

A multiple case study of intersectoral public health networks: experiences and benefits of using research.

PubMed

Kothari, Anita; McPherson, Charmaine; Gore, Dana; Cohen, Benita; MacDonald, Marjorie; Sibbald, Shannon L

2016-02-11

Network partnerships between public health and third sector organisations are being used to address the complexities of population level social determinants of health and health equity. An understanding of how these networks use research and knowledge is crucial to effective network design and outcome evaluation. There is, however, a gap in the literature regarding how public health networks use research and knowledge. The purpose of this paper is to report on the qualitative findings from a larger study that explored (1) the experiences of public health networks with using research and knowledge, and (2) the perceived benefits of using research and knowledge. A multiple case study approach framed this study. Focus group data were collected from participants through a purposive sample of four public health networks. Data were analyzed using Framework Analysis and Nvivo software supported data management. Each network had the opportunity to participate in data interpretation. All networks used published research studies and other types of knowledge to accomplish their work, although in each network research and knowledge played different but complementary roles. Neither research nor other types of knowledge were privileged, and an approach that blended varied knowledge types was typically used. Network experiences with research and knowledge produced individual and collective benefits. A novel finding was that research and knowledge were both important in shaping network function. This study shifts the focus in the current literature from public health departments to the community setting where public health collaborates with a broader spectrum of actors to ameliorate health inequities. Both formal research and informal knowledge were found to be important for collaborative public health networks. Examining the benefits of research and knowledge use within public health networks may help us to better understand the relationships among process (the collaborative use

Research on assessment methods for urban public transport development in China.

PubMed

Zou, Linghong; Dai, Hongna; Yao, Enjian; Jiang, Tian; Guo, Hongwei

2014-01-01

In recent years, with the rapid increase in urban population, the urban travel demands in Chinese cities have been increasing dramatically. As a result, developing comprehensive urban transport systems becomes an inevitable choice to meet the growing urban travel demands. In urban transport systems, public transport plays the leading role to promote sustainable urban development. This paper aims to establish an assessment index system for the development level of urban public transport consisting of a target layer, a criterion layer, and an index layer. Review on existing literature shows that methods used in evaluating urban public transport structure are dominantly qualitative. To overcome this shortcoming, fuzzy mathematics method is used for describing qualitative issues quantitatively, and AHP (analytic hierarchy process) is used to quantify expert's subjective judgment. The assessment model is established based on the fuzzy AHP. The weight of each index is determined through the AHP and the degree of membership of each index through the fuzzy assessment method to obtain the fuzzy synthetic assessment matrix. Finally, a case study is conducted to verify the rationality and practicability of the assessment system and the proposed assessment method.

Research on Assessment Methods for Urban Public Transport Development in China

PubMed Central

Zou, Linghong; Guo, Hongwei

2014-01-01

In recent years, with the rapid increase in urban population, the urban travel demands in Chinese cities have been increasing dramatically. As a result, developing comprehensive urban transport systems becomes an inevitable choice to meet the growing urban travel demands. In urban transport systems, public transport plays the leading role to promote sustainable urban development. This paper aims to establish an assessment index system for the development level of urban public transport consisting of a target layer, a criterion layer, and an index layer. Review on existing literature shows that methods used in evaluating urban public transport structure are dominantly qualitative. To overcome this shortcoming, fuzzy mathematics method is used for describing qualitative issues quantitatively, and AHP (analytic hierarchy process) is used to quantify expert's subjective judgment. The assessment model is established based on the fuzzy AHP. The weight of each index is determined through the AHP and the degree of membership of each index through the fuzzy assessment method to obtain the fuzzy synthetic assessment matrix. Finally, a case study is conducted to verify the rationality and practicability of the assessment system and the proposed assessment method. PMID:25530756

Information services in social networked transportation : governance and ITS.

DOT National Transportation Integrated Search

2014-06-01

The purpose of this research seeks to understand the functions and the benefits of social : networked transportation (SNT), the processes that make SNT possible, and the institutional : innovations needed to facilitate those processes. First, this re...

[Knowledge and perception about tuberculosis among public transport workers in Lima, Peru].

PubMed

Lukac, Danitza; Garaycochea, Octavio; Taype-Rondan, Alvaro; Luque Bustamante, Laura; Mujica-Vasquez, André; Zamora, Dario

2016-11-23

To describe the level of knowledge and perception of tuberculosis among public transport workers attending Road Safety Education courses in Lima, Peru. An observational, cross-sectional, analytic study was conducted between July and August 2014 in public transport workers attending the courses of Road Safety education. In Lima, such courses are mandatory for workers in the public transport area. An anonymous and voluntary survey was applied to obtain the following variables: sociodemographic characteristics, history of tuberculosis, tuberculosis knowledge and attitudes towards the disease. The factors associated to the risk perception of Tuberculosis infection were analysed using Poisson regression. From 309 attendees, 216 surveys were analysed (69.9%). Of these, 88.4% were males, 3.2% had a history of tuberculosis. The most widely known symptom was cough with phlegm (44.4%), the most popular source of information was television (39.8%), and only 9.7% had any training about tuberculosis. A 41.2% of respondents believed that working in the public transport sector was an occupation with a high risk of tuberculosis infection. No significant association between risk perception of tuberculosis and sociodemographic characteristics was found. A considerable lack of knowledge about tuberculosis symptoms and a low perception of risk for tuberculosis exists among public transport workers in Lima. Education strategies directed to this population need to be implemented.

Suspended sediment transport trough a large fluvial-tidal channel network

USGS Publications Warehouse

Wright, Scott A.; Morgan-King, Tara L.

2015-01-01

The confluence of the Sacramento and San Joaquin Rivers, CA, forms a large network of interconnected channels, referred to as the Sacramento-San Joaquin Delta (the Delta). The Delta comprises the transition zone from the fluvial influences of the upstream rivers and tidal influences of San Francisco Bay downstream. Formerly an extensive tidal marsh, the hydrodynamics and geomorphology of Delta have been substantially modified by humans to support agriculture, navigation, and water supply. These modifications, including construction of new channels, diking and draining of tidal wetlands, dredging of navigation channels, and the operation of large pumping facilities for distribution of freshwater from the Delta to other parts of the state, have had a dramatic impact on the physical and ecological processes within the Delta. To better understand the current physical processes, and their linkages to ecological processes, the USGS maintains an extensive network of flow, sediment, and water quality gages in the Delta. Flow gaging is accomplished through use of the index-velocity method, and sediment monitoring uses turbidity as a surrogate for suspended-sediment concentration. Herein, we present analyses of the transport and dispersal of suspended sediment through the complex network of channels in the Delta. The primary source of sediment to the Delta is the Sacramento River, which delivers pulses of sediment primarily during winter and spring runoff events. Upon reaching the Delta, the sediment pulses move through the fluvial-tidal transition while also encountering numerous channel junctions as the Sacramento River branches into several distributary channels. The monitoring network allows us to track these pulses through the network and document the dominant transport pathways for suspended sediment. Further, the flow gaging allows for an assessment of the relative effects of advection (the fluvial signal) and dispersion (from the tides) on the sediment pulses as they

Privatizing transportation through public-private partnerships : definitions, models, and issues.

DOT National Transportation Integrated Search

2006-05-01

There has been greater emphasis in recent times on using public-private partnerships (PPPs or P3s) to provide and deliver transportation infrastructure and services. These public-private partnerships differ from contracting out, being applicable to a...

Transportation in the United States : highlights from 2015 transportation statistics annual report.

DOT National Transportation Integrated Search

2016-01-01

The U.S. transportation system serves nearly 319 million Americans, 7.5 : million businesses, and 75 million foreign visitors through a network of : more than 4 million miles of roads, more than 19,000 public and private : use airports, about 140,000...

Development of an Asia-Pacific regional network for public health.

PubMed

Loos, G P

1995-01-01

As public health by its very nature is multi-disciplinary, it may benefit individual programs to formulate a regional network, joining researchers and academics across programs. This approach may afford extended benefits, such as the establishment of regional health surveillance systems and collaborative funding initiatives. To explore this potential, member institutions comprising the Asia-Pacific Academic Consortium for Public Health provided data to form an aggregate profile of cross-institutional expertise and resources, which was presented to Health Specialists at the Asian Development Bank. The study provided a foundation for a planned regional network. A four-pronged approach was proffered detailing concurrent aspects of development: 1) network formation and expansion, 2) research coordination, 3) cross-institutional communication and instruction, and 4) promotion of self-sufficiency. The proposed plan affords the groundwork for an improved approach to public health research and practice that builds upon the established Consortium, and encourages new horizons. Regionalization is an increasing phenomenon world wide, and should be furthered as a concept for improved public health intervention and control.

78 FR 32296 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-29

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Second Allocation of Public... disaster that affects public transportation systems. The Disaster Relief Appropriations Act provides $10.9... projected total recovery costs for the four most severely affected public transportation systems, not...

Setting Up a Public Use Local Area Network.

ERIC Educational Resources Information Center

Flower, Eric; Thulstrup, Lisa

1988-01-01

Describes a public use microcomputer cluster at the University of Maine, Orono. Various network topologies, hardware and software options, installation problems, system management, and performance are discussed. (MES)

Public support for bicycling and transport policies in inner Sydney, Australia: a cross-sectional survey.

PubMed

Rissel, Chris; Crane, Melanie; Standen, Chris; Wen, Li Ming; Ellison, Richard; Greaves, Stephen

2018-06-01

To describe the degree of community support - and factors associated with this support - for a number of potential transport policy options among an inner-city sample of residents in Sydney, Australia. This study analysed data collected from a cross-sectional online survey: Wave 3 of the Sydney Transport and Health Study, conducted in September-October 2015 (n=418). There was a high level of overall support for policies to make public transport cheaper (85%), have more bicycle paths separated from motor vehicles (82%) and have a public bike-share program (72%), with similar levels of support across usual commute mode, age and sex. Despite a natural tendency for respondents to support transport policies that were of most relevance to themselves, it appeared that, in this sample, public support for public transport and bicycling policies remained strong across all respondents. Implications for public health: Policies that support public transport and active travel and achieve positive health outcomes would be well received by inner-Sydney residents. © 2018 The Authors.

A Robust and Energy-Efficient Transport Protocol for Cognitive Radio Sensor Networks

PubMed Central

Salim, Shelly; Moh, Sangman

2014-01-01

A cognitive radio sensor network (CRSN) is a wireless sensor network in which sensor nodes are equipped with cognitive radio. CRSNs benefit from cognitive radio capabilities such as dynamic spectrum access and transmission parameters reconfigurability; but cognitive radio also brings additional challenges and leads to higher energy consumption. Motivated to improve the energy efficiency in CRSNs, we propose a robust and energy-efficient transport protocol (RETP). The novelties of RETP are two-fold: (I) it combines distributed channel sensing and channel decision with centralized schedule-based data transmission; and (II) it differentiates the types of data transmission on the basis of data content and adopts different acknowledgment methods for different transmission types. To the best of our knowledge, no transport layer protocols have yet been designed for CRSNs. Simulation results show that the proposed protocol achieves remarkably longer network lifetime and shorter event-detection delay compared to those achieved with a conventional transport protocol, while simultaneously preserving event-detection reliability. PMID:25333288

Review of pore network modelling of porous media: Experimental characterisations, network constructions and applications to reactive transport.

PubMed

Xiong, Qingrong; Baychev, Todor G; Jivkov, Andrey P

2016-09-01

Pore network models have been applied widely for simulating a variety of different physical and chemical processes, including phase exchange, non-Newtonian displacement, non-Darcy flow, reactive transport and thermodynamically consistent oil layers. The realism of such modelling, i.e. the credibility of their predictions, depends to a large extent on the quality of the correspondence between the pore space of a given medium and the pore network constructed as its representation. The main experimental techniques for pore space characterisation, including direct imaging, mercury intrusion porosimetry and gas adsorption, are firstly summarised. A review of the main pore network construction techniques is then presented. Particular focus is given on how such constructions are adapted to the data from experimentally characterised pore systems. Current applications of pore network models are considered, with special emphasis on the effects of adsorption, dissolution and precipitation, as well as biomass growth, on transport coefficients. Pore network models are found to be a valuable tool for understanding and predicting meso-scale phenomena, linking single pore processes, where other techniques are more accurate, and the homogenised continuum porous media, used by engineering community. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

A historical perspective of the Global Transportation Network (GTN)

DOT National Transportation Integrated Search

2000-03-01

This thesis analyzes the changes within the Global Transportation Network (GTN)/In Transit Visibility (ITV) feeder systems and the subsequent ITV they provide by comparing the current position to the past and by examining future trends. Up until now,...

76 FR 10295 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... Docket 07-100; FCC 11-6] Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the... framework for the nationwide public safety broadband network. This document considers and proposes... broadband networks operating in the 700 MHz band. This document addresses public safety broadband network...

47 CFR 68.201 - Connection to the public switched telephone network.

Code of Federal Regulations, 2010 CFR

2010-10-01

... network. 68.201 Section 68.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Terminal Equipment Approval Procedures § 68.201 Connection to the public switched telephone network. Terminal equipment may...

47 CFR 68.201 - Connection to the public switched telephone network.

Code of Federal Regulations, 2011 CFR

2011-10-01

... network. 68.201 Section 68.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Terminal Equipment Approval Procedures § 68.201 Connection to the public switched telephone network. Terminal equipment may...

Montana Department of Transportation Guide to Public Involvement

DOT National Transportation Integrated Search

1996-01-01

This guide describes the various methods the Transportation Planning Division of the MDOT uses to involve the public in Division activities, and also includes a chart that provides the names of staff people responsible for various Division programs. ...

Simulation of unsteady flow and solute transport in a tidal river network

USGS Publications Warehouse

Zhan, X.

2003-01-01

A mathematical model and numerical method for water flow and solute transport in a tidal river network is presented. The tidal river network is defined as a system of open channels of rivers with junctions and cross sections. As an example, the Pearl River in China is represented by a network of 104 channels, 62 nodes, and a total of 330 cross sections with 11 boundary section for one of the applications. The simulations are performed with a supercomputer for seven scenarios of water flow and/or solute transport in the Pearl River, China, with different hydrological and weather conditions. Comparisons with available data are shown. The intention of this study is to summarize previous works and to provide a useful tool for water environmental management in a tidal river network, particularly for the Pearl River, China.

Generalisation and specialisation in hoverfly (Syrphidae) grassland pollen transport networks revealed by DNA metabarcoding.

PubMed

Lucas, Andrew; Bodger, Owen; Brosi, Berry J; Ford, Col R; Forman, Dan W; Greig, Carolyn; Hegarty, Matthew; Neyland, Penelope J; de Vere, Natasha

2018-04-16

Pollination by insects is a key ecosystem service and important to wider ecosystem function. Most species-level pollination networks studied have a generalised structure, with plants having several potential pollinators, and pollinators in turn visiting a number of different plant species. This is in apparent contrast to a plant's need for efficient conspecific pollen transfer. The aim of this study was to investigate the structure of pollen transport networks at three levels of biological hierarchy: community, species and individual. We did this using hoverflies in the genus Eristalis, a key group of non-Hymenopteran pollinators. We constructed pollen transport networks using DNA metabarcoding to identify pollen. We captured hoverflies in conservation grasslands in west Wales, UK, removed external pollen loads, sequenced the pollen DNA on the Illumina MiSeq platform using the standard plant barcode rbcL, and matched sequences using a pre-existing plant DNA barcode reference library. We found that Eristalis hoverflies transport pollen from 65 plant taxa, more than previously appreciated. Networks were generalised at the site and species level, suggesting some degree of functional redundancy, and were more generalised in late summer compared to early summer. In contrast, pollen transport at the individual level showed some degree of specialisation. Hoverflies defined as "single-plant visitors" varied from 40% of those captured in early summer to 24% in late summer. Individual hoverflies became more generalised in late summer, possibly in response to an increase in floral resources. Rubus fruticosus agg. and Succisa pratensis were key plant species for hoverflies at our sites Our results contribute to resolving the apparent paradox of how generalised pollinator networks can provide efficient pollination to plant species. Generalised hoverfly pollen transport networks may result from a varied range of short-term specialised feeding bouts by individual insects. The

Backstepping fuzzy-neural-network control design for hybrid maglev transportation system.

PubMed

Wai, Rong-Jong; Yao, Jing-Xiang; Lee, Jeng-Dao

2015-02-01

This paper focuses on the design of a backstepping fuzzy-neural-network control (BFNNC) for the online levitated balancing and propulsive positioning of a hybrid magnetic levitation (maglev) transportation system. The dynamic model of the hybrid maglev transportation system including levitated hybrid electromagnets to reduce the suspension power loss and the friction force during linear movement and a propulsive linear induction motor based on the concepts of mechanical geometry and motion dynamics is first constructed. The ultimate goal is to design an online fuzzy neural network (FNN) control methodology to cope with the problem of the complicated control transformation and the chattering control effort in backstepping control (BSC) design, and to directly ensure the stability of the controlled system without the requirement of strict constraints, detailed system information, and auxiliary compensated controllers despite the existence of uncertainties. In the proposed BFNNC scheme, an FNN control is utilized to be the major control role by imitating the BSC strategy, and adaptation laws for network parameters are derived in the sense of projection algorithm and Lyapunov stability theorem to ensure the network convergence as well as stable control performance. The effectiveness of the proposed control strategy for the hybrid maglev transportation system is verified by experimental results, and the superiority of the BFNNC scheme is indicated in comparison with the BSC strategy and the backstepping particle-swarm-optimization control system in previous research.

Harmony search optimization algorithm for a novel transportation problem in a consolidation network

NASA Astrophysics Data System (ADS)

Davod Hosseini, Seyed; Akbarpour Shirazi, Mohsen; Taghi Fatemi Ghomi, Seyed Mohammad

2014-11-01

This article presents a new harmony search optimization algorithm to solve a novel integer programming model developed for a consolidation network. In this network, a set of vehicles is used to transport goods from suppliers to their corresponding customers via two transportation systems: direct shipment and milk run logistics. The objective of this problem is to minimize the total shipping cost in the network, so it tries to reduce the number of required vehicles using an efficient vehicle routing strategy in the solution approach. Solving several numerical examples confirms that the proposed solution approach based on the harmony search algorithm performs much better than CPLEX in reducing both the shipping cost in the network and computational time requirement, especially for realistic size problem instances.

A Mathematical Study of Accessibility and Cohesion Degree in a High-Speed Rail Station Connected to an Urban Bus Transport Network

NASA Astrophysics Data System (ADS)

Mota, Carmen; López, Miguel A.; Martínez-Rodrigo, Arturo

2017-04-01

In the last twenty years, the implementation of High-Speed Rail (HSR) has been one of the major strategies for territorial structuring used by various countries. This model has enhanced the development of countries such as France, Spain, Germany and Japan. At present, the United States and China are also starting to implement this model. Nevertheless, the lack of social and economic profitability of several networks is being increasingly analysed. Many networks located in particular regions serve populations that are not large enough to recover the initial investment. For this reason, it is necessary to evaluate the population served by this transport mode, beyond the number of users. In this sense, it is essential to identify the deficiencies and potentials of implementing a network linked to other secondary networks in a specific territory which can compensate for the so-called tunnel effect. This article proposes to apply a mathematical approach based on graph theory to measure the Degree Accessibility Node (DAN) in a constrained Geographic Information System (GIS) model. Hence, it would be possible to compare regions, especially medium-sized cities, where the implementation of HSR could represent a qualitative leap due to incorporation into large transport networks. The DAN function uses static and dynamic studies to evaluate the level of connection of stations to secondary transport networks—local public transport in this case. Thus, the impact of high-speed trains could be spread to greater territorial and population ranges. Four cases have been studied, two in Germany (one of them, Fulda, is analysed in depth throughout this article) and two in Spain. These two countries were selected since HSR was implemented in the same relative period of time, in comparison with other European countries. Results show relevant differences, suggesting a review of inappropriate policies of transport integration in a city that could weaken the expansion of the positive

Integrative Analysis of the Physical Transport Network into Australia.

PubMed

Cope, Robert C; Ross, Joshua V; Wittmann, Talia A; Prowse, Thomas A A; Cassey, Phillip

2016-01-01

Effective biosecurity is necessary to protect nations and their citizens from a variety of threats, including emerging infectious diseases, agricultural or environmental pests and pathogens, and illegal wildlife trade. The physical pathways by which these threats are transported internationally, predominantly shipping and air traffic, have undergone significant growth and changes in spatial distributions in recent decades. An understanding of the specific pathways and donor-traffic hotspots created by this integrated physical transport network is vital for the development of effective biosecurity strategies into the future. In this study, we analysed the physical transport network into Australia over the period 1999-2012. Seaborne and air traffic were weighted to calculate a "weighted cumulative impact" score for each source region worldwide, each year. High risk source regions, and those source regions that underwent substantial changes in risk over the study period, were determined. An overall risk ranking was calculated by integrating across all possible weighting combinations. The source regions having greatest overall physical connectedness with Australia were Singapore, which is a global transport hub, and the North Island of New Zealand, a close regional trading partner with Australia. Both those regions with large amounts of traffic across multiple vectors (e.g., Hong Kong), and those with high levels of traffic of only one type (e.g., Bali, Indonesia with respect to passenger flights), were represented among high risk source regions. These data provide a baseline model for the transport of individuals and commodities against which the effectiveness of biosecurity controls may be assessed, and are a valuable tool in the development of future biosecurity policy.

Self-organization leads to supraoptimal performance in public transportation systems.

PubMed

Gershenson, Carlos

2011-01-01

The performance of public transportation systems affects a large part of the population. Current theory assumes that passengers are served optimally when vehicles arrive at stations with regular intervals. In this paper, it is shown that self-organization can improve the performance of public transportation systems beyond the theoretical optimum by responding adaptively to local conditions. This is possible because of a "slower-is-faster" effect, where passengers wait more time at stations but total travel times are reduced. The proposed self-organizing method uses "antipheromones" to regulate headways, which are inspired by the stigmergy (communication via environment) of some ant colonies.

Route planning with transportation network maps: an eye-tracking study.

PubMed

Grison, Elise; Gyselinck, Valérie; Burkhardt, Jean-Marie; Wiener, Jan Malte

2017-09-01

Planning routes using transportation network maps is a common task that has received little attention in the literature. Here, we present a novel eye-tracking paradigm to investigate psychological processes and mechanisms involved in such a route planning. In the experiment, participants were first presented with an origin and destination pair before we presented them with fictitious public transportation maps. Their task was to find the connecting route that required the minimum number of transfers. Based on participants' gaze behaviour, each trial was split into two phases: (1) the search for origin and destination phase, i.e., the initial phase of the trial until participants gazed at both origin and destination at least once and (2) the route planning and selection phase. Comparisons of other eye-tracking measures between these phases and the time to complete them, which depended on the complexity of the planning task, suggest that these two phases are indeed distinct and supported by different cognitive processes. For example, participants spent more time attending the centre of the map during the initial search phase, before directing their attention to connecting stations, where transitions between lines were possible. Our results provide novel insights into the psychological processes involved in route planning from maps. The findings are discussed in relation to the current theories of route planning.

[Storage and transport of isolated M. tuberculosis at public and private health institutions in Japan].

PubMed

Ohkado, Akihiro; Takahashi, Chieko; Horiba, Masahide; Murase, Yoshiro; Mitarai, Satoshi

2008-08-01

To obtain basic data about the present practices on storage and transport of isolated M. tuberculosis at public and private health institutions in Japan. Survey forms regarding the practices on storage and transport of isolated M. tuberculosis were distributed and collected by post-mail in January 2007 to 76 local public health institutions, 145 public health centres, and 150 public or private hospitals. The questionnaire was adopted from the guidelines proposed by the Ministry of Health, Labour, and Welfare in 2006 on storage and transport of isolated M. tuberculosis. The respondents of the survey were as follows: 96.1% (73/76) from local public health institutions, 93.8% (136/145) from public health centres, and 73.3% (110/150) from hospitals. In general, local public health institutions conformed well to the proposed standards, however public health centres and hospitals were not compliant to some standards. Based on the survey conducted on the practice of storage and transport of isolated M. tuberculosis, certain discrepancy was found among public health centres and hospitals.

Home vs. Public Schoolers' Relationships: Differences in Social Networks.

ERIC Educational Resources Information Center

Chatham-Carpenter, April D.

Noting the lack of basic information necessary to begin to make conclusions about a home schooled child's social contacts, a study investigated the social networks of home vs. public schooled children (with a child's "social network" defined as all of the people who interact on a regular basis with the child at least once a month). The…

Rural health network development: public policy issues and state initiatives.

PubMed

Casey, M M; Wellever, A; Moscovice, I

1997-02-01

Rural health networks are a potential way for rural health care systems to improve access to care, reduce costs, and enhance quality of care. Networks provide a means for rural providers to contract with managed care organizations, develop their own managed care entities, share resources, and structure practice opportunities to support recruitment and retention of rural physicians and other health care professionals. The results of early network development initiatives indicate a need for state officials and others interested in encouraging network development to agree on common rural health network definitions, to identify clearly the goals of network development programs, and to document and analyze program outcomes. Future network development efforts need to be much more comprehensive if they are to have a significant impact on rural health care. This article analyzes public policy issues related to integrated rural health network development, discusses current efforts to encourage network development in rural areas, and suggests actions that states may take if they desire to support rural health network development. These actions include adopting a formal rural health network definition, providing networks with alternatives to certain regulatory requirements, and providing incentives such as matching grants, loans, or technical assistance. Without public sector support for networks, managed care options may continue to be unavailable in many less densely populated rural areas of the country, and locally controlled rural health networks are unlikely to develop as an alternative to the dominant pattern of managed care expansion by large urban entities. Implementation of Medicare reform legislation could provide significant incentives for the development of rural health networks, depending on the reimbursement provisions, financial solvency standards, and antitrust exemptions for provider-sponsored networks in the final legislation and federal regulations.

47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Network. 90.18 Section 90.18 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... 700 MHz Nationwide Broadband Network. The 763-768/793-798 MHz band is dedicated to a broadband public..., pursuant to a Network Sharing Agreement and such other agreements as the Commission may require. The...

47 CFR 90.18 - Public Safety 700 MHz Nationwide Broadband Network.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Network. 90.18 Section 90.18 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... 700 MHz Nationwide Broadband Network. The 763-768/793-798 MHz band is dedicated to a broadband public..., pursuant to a Network Sharing Agreement and such other agreements as the Commission may require. The...

36 CFR 1005.9 - Discrimination in furnishing public accommodations and transportation services.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Discrimination in furnishing public accommodations and transportation services. 1005.9 Section 1005.9 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.9 Discrimination in furnishing public...

Extending natural hazard impacts: an assessment of landslide disruptions on a national road transportation network

NASA Astrophysics Data System (ADS)

Postance, Benjamin; Hillier, John; Dijkstra, Tom; Dixon, Neil

2017-01-01

Disruptions to transportation networks by natural hazard events cause direct losses (e.g. by physical damage) and indirect socio-economic losses via travel delays and decreased transportation efficiency. The severity and spatial distribution of these losses varies according to user travel demands and which links, nodes or infrastructure assets are physically disrupted. Increasing transport network resilience, for example by targeted mitigation strategies, requires the identification of the critical network segments which if disrupted would incur undesirable or unacceptable socio-economic impacts. Here, these impacts are assessed on a national road transportation network by coupling hazard data with a transport network model. This process is illustrated using a case study of landslide hazards on the road network of Scotland. A set of possible landslide-prone road segments is generated using landslide susceptibility data. The results indicate that at least 152 road segments are susceptible to landslides, which could cause indirect economic losses exceeding £35 k for each day of closure. In addition, previous estimates for historic landslide events might be significant underestimates. For example, the estimated losses for the 2007 A83 ‘Rest and Be Thankful’ landslide are £80 k day-1, totalling £1.2 million over a 15 day closure, and are ˜60% greater than previous estimates. The spatial distribution of impact to road users is communicated in terms of ‘extended hazard impact footprints’. These footprints reveal previously unknown exposed communities and unanticipated spatial patterns of severe disruption. Beyond cost-benefit analyses for landslide mitigation efforts, the approach implemented is applicable to other natural hazards (e.g. flooding), combinations of hazards, or even other network disruption events.

Quantitative evaluation of an air-monitoring network using atmospheric transport modeling and frequency of detection methods

DOE PAGES

Rood, Arthur S.; Sondrup, A. Jeffrey; Ritter, Paul D.

2016-04-01

A methodology to quantify the performance of an air monitoring network in terms of frequency of detection has been developed. The methodology utilizes an atmospheric transport model to predict air concentrations of radionuclides at the samplers for a given release time and duration. Frequency of detection is defined as the fraction of “events” that result in a detection at either a single sampler or network of samplers. An “event” is defined as a release of finite duration that begins on a given day and hour of the year from a facility with the potential to emit airborne radionuclides. Another metricmore » of interest is the network intensity, which is defined as the fraction of samplers in the network that have a positive detection for a given event. The frequency of detection methodology allows for evaluation of short-term releases that include effects of short-term variability in meteorological conditions. The methodology was tested using the U.S. Department of Energy Idaho National Laboratory (INL) Site ambient air monitoring network consisting of 37 low-volume air samplers in 31 different locations covering a 17,630 km 2 region. Releases from six major INL facilities distributed over an area of 1,435 km 2 were modeled and included three stack sources and eight ground-level sources. A Lagrangian Puff air dispersion model (CALPUFF) was used to model atmospheric transport. The model was validated using historical 125Sb releases and measurements. Relevant one-week release quantities from each emission source were calculated based on a dose of 1.9 × 10 –4 mSv at a public receptor (0.01 mSv assuming release persists over a year). Important radionuclides considered include 241Am, 137Cs, 238Pu, 239Pu, 90Sr, and tritium. Results show the detection frequency is over 97.5% for the entire network considering all sources and radionuclides. Network intensities ranged from 3.75% to 62.7%. Evaluation of individual samplers indicated some samplers were poorly

Quantitative evaluation of an air-monitoring network using atmospheric transport modeling and frequency of detection methods

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

Rood, Arthur S.; Sondrup, A. Jeffrey; Ritter, Paul D.

A methodology to quantify the performance of an air monitoring network in terms of frequency of detection has been developed. The methodology utilizes an atmospheric transport model to predict air concentrations of radionuclides at the samplers for a given release time and duration. Frequency of detection is defined as the fraction of “events” that result in a detection at either a single sampler or network of samplers. An “event” is defined as a release of finite duration that begins on a given day and hour of the year from a facility with the potential to emit airborne radionuclides. Another metricmore » of interest is the network intensity, which is defined as the fraction of samplers in the network that have a positive detection for a given event. The frequency of detection methodology allows for evaluation of short-term releases that include effects of short-term variability in meteorological conditions. The methodology was tested using the U.S. Department of Energy Idaho National Laboratory (INL) Site ambient air monitoring network consisting of 37 low-volume air samplers in 31 different locations covering a 17,630 km 2 region. Releases from six major INL facilities distributed over an area of 1,435 km 2 were modeled and included three stack sources and eight ground-level sources. A Lagrangian Puff air dispersion model (CALPUFF) was used to model atmospheric transport. The model was validated using historical 125Sb releases and measurements. Relevant one-week release quantities from each emission source were calculated based on a dose of 1.9 × 10 –4 mSv at a public receptor (0.01 mSv assuming release persists over a year). Important radionuclides considered include 241Am, 137Cs, 238Pu, 239Pu, 90Sr, and tritium. Results show the detection frequency is over 97.5% for the entire network considering all sources and radionuclides. Network intensities ranged from 3.75% to 62.7%. Evaluation of individual samplers indicated some samplers were poorly

Advanced public transportation system deployment in the United States

DOT National Transportation Integrated Search

1999-01-01

This report documents work performed under FTA's Advanced Public Transportation Systems (APTS) Program, a program structured to undertake research and development of innovative applications of advanced navigation, information, and communication techn...

75 FR 63534 - International Standards on the Transport of Dangerous Goods; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

...: Any person wishing to participate in the public meeting should send an e-mail to [email protected] Standards on the Transport of Dangerous Goods; Public Meeting AGENCY: Pipeline and Hazardous Materials... the 38th session of the United Nations Sub-Committee of Experts on the Transport of Dangerous Goods...

Networking for applied field epidemiology - Eastern Mediterranean Public Health Network (EMPHNET) Conference 2011.

PubMed

Al Nsour, M; Kaiser, R

2011-12-01

On the occasion of the second Eastern Mediterranean Public Health Network (EMPHNET) conference that was held from 6-9 December 2011 in Sharm Al Sheikh, Egypt, this article introduces EMPHNET and its role to link Field Epidemiology Training Programs (FETP) in the region. The paper briefly describes the changing epidemiology situation in the region to illustrate the urgent need to strengthen public health systems and to build up the epidemiologist workforce.

Optimal Micropatterns in 2D Transport Networks and Their Relation to Image Inpainting

NASA Astrophysics Data System (ADS)

Brancolini, Alessio; Rossmanith, Carolin; Wirth, Benedikt

2018-04-01

We consider two different variational models of transport networks: the so-called branched transport problem and the urban planning problem. Based on a novel relation to Mumford-Shah image inpainting and techniques developed in that field, we show for a two-dimensional situation that both highly non-convex network optimization tasks can be transformed into a convex variational problem, which may be very useful from analytical and numerical perspectives. As applications of the convex formulation, we use it to perform numerical simulations (to our knowledge this is the first numerical treatment of urban planning), and we prove a lower bound for the network cost that matches a known upper bound (in terms of how the cost scales in the model parameters) which helps better understand optimal networks and their minimal costs.

Efficient transportation for Vermont : optimal statewide transit networks.

DOT National Transportation Integrated Search

2011-01-01

"Public transit systems are receiving increased attention as viable solutions to problems with : transportation system robustness, energy-efficiency and equity. The over-reliance on a single : mode, the automobile, is a threat to system robustness. I...

How to assess extreme weather impacts - case European transport network

NASA Astrophysics Data System (ADS)

Leviäkangas, P.

2010-09-01

To assess the impacts of climate change and preparing for impacts is a process. This process we must understand and learn to apply. EWENT (Extreme Weather impacts on European Networks of Transport) will be a test bench for one prospective approach. It has the following main components: 1) identifying what is "extreme", 2) assessing the change in the probabilities, 3) constructing the causal impact models, 4) finding appropriate methods of pricing and costing, 5) finding alternative strategy option, 6) assessing the efficiency of strategy option. This process follows actually the steps of standardized risk management process. Each step is challenging, but if EWENT project succeeds to assess the extreme weather impacts on European transport networks, it is one possible benchmark how to carry out similar analyses in other regions and on country level. EWENT approach could particularly useful for weather and climate information service providers, offering tools for transport authorities and financiers to assess weather risks, and then rationally managing the risks. EWENT project is financed by the European Commission and participated by met-service organisations and transport research institutes from different parts of Europe. The presentation will explain EWENT approach in detail and bring forth the findings of the first work packages.

Characterization of attacks on public telephone networks

NASA Astrophysics Data System (ADS)

Lorenz, Gary V.; Manes, Gavin W.; Hale, John C.; Marks, Donald; Davis, Kenneth; Shenoi, Sujeet

2001-02-01

The U.S. Public Telephone Network (PTN) is a massively connected distributed information systems, much like the Internet. PTN signaling, transmission and operations functions must be protected from physical and cyber attacks to ensure the reliable delivery of telecommunications services. The increasing convergence of PTNs with wireless communications systems, computer networks and the Internet itself poses serious threats to our nation's telecommunications infrastructure. Legacy technologies and advanced services encumber well-known and as of yet undiscovered vulnerabilities that render them susceptible to cyber attacks. This paper presents a taxonomy of cyber attacks on PTNs in converged environments that synthesizes exploits in computer and communications network domains. The taxonomy provides an opportunity for the systematic exploration of mitigative and preventive strategies, as well as for the identification and classification of emerging threats.

Findings from an Organizational Network Analysis to Support Local Public Health Management

PubMed Central

Caldwell, Michael; Rockoff, Maxine L.; Gebbie, Kristine; Carley, Kathleen M.; Bakken, Suzanne

2008-01-01

We assessed the feasibility of using organizational network analysis in a local public health organization. The research setting was an urban/suburban county health department with 156 employees. The goal of the research was to study communication and information flow in the department and to assess the technique for public health management. Network data were derived from survey questionnaires. Computational analysis was performed with the Organizational Risk Analyzer. Analysis revealed centralized communication, limited interdependencies, potential knowledge loss through retirement, and possible informational silos. The findings suggested opportunities for more cross program coordination but also suggested the presences of potentially efficient communication paths and potentially beneficial social connectedness. Managers found the findings useful to support decision making. Public health organizations must be effective in an increasingly complex environment. Network analysis can help build public health capacity for complex system management. PMID:18481183

Advanced public transportation systems : the state of the art

DOT National Transportation Integrated Search

1991-03-01

This report documents one of the early initiatives of UMTA's Advanced Public Transportation Systems (APTS) Program, a program structured to undertake research and development of innovative applications of advanced navigation, information, and communi...

Integrative Analysis of the Physical Transport Network into Australia

PubMed Central

Cope, Robert C.; Ross, Joshua V.; Wittmann, Talia A.; Prowse, Thomas A. A.; Cassey, Phillip

2016-01-01

Effective biosecurity is necessary to protect nations and their citizens from a variety of threats, including emerging infectious diseases, agricultural or environmental pests and pathogens, and illegal wildlife trade. The physical pathways by which these threats are transported internationally, predominantly shipping and air traffic, have undergone significant growth and changes in spatial distributions in recent decades. An understanding of the specific pathways and donor-traffic hotspots created by this integrated physical transport network is vital for the development of effective biosecurity strategies into the future. In this study, we analysed the physical transport network into Australia over the period 1999–2012. Seaborne and air traffic were weighted to calculate a “weighted cumulative impact” score for each source region worldwide, each year. High risk source regions, and those source regions that underwent substantial changes in risk over the study period, were determined. An overall risk ranking was calculated by integrating across all possible weighting combinations. The source regions having greatest overall physical connectedness with Australia were Singapore, which is a global transport hub, and the North Island of New Zealand, a close regional trading partner with Australia. Both those regions with large amounts of traffic across multiple vectors (e.g., Hong Kong), and those with high levels of traffic of only one type (e.g., Bali, Indonesia with respect to passenger flights), were represented among high risk source regions. These data provide a baseline model for the transport of individuals and commodities against which the effectiveness of biosecurity controls may be assessed, and are a valuable tool in the development of future biosecurity policy. PMID:26881782

Nonlinear transport of soft droplets in pore networks

NASA Astrophysics Data System (ADS)

Vernerey, Franck; Benet Cerda, Eduard; Koo, Kanghyeon

A large number of biological and technological processes depend on the transport of soft colloidal particles through porous media; this includes the transport and separation of cells, viruses or drugs through tissues, membranes and microfluidic devices. In these systems, the interactions between soft particles, background fluid and the surrounding pore space yield complex, nonlinear behaviors such as non-Darcy flows, localization and jamming. We devise a computational strategy to investigate the transport of non-wetting and deformable water droplets in a microfluidic device made of a random distribution of cylindrical obstacles. We first derive scaling laws for the entry of the droplet in a single pore and discuss the role of surface tension, contact angle and size in this process. This information is then used to study the transport of multiple droplets in an obstacle network. We find that when the droplet size is close to the pore size, fluid flow and droplet trafficking strongly interact, leading to local redistributions in pressure fields, intermittent clogging and jamming. Importantly, it is found that the overall droplet and fluid transport display three different scaling regimes depending on the forcing pressure, and that these regimes can be related to droplet properties.

Achieving recommended daily physical activity levels through commuting by public transportation: unpacking individual and contextual influences.

PubMed

Wasfi, Rania A; Ross, Nancy A; El-Geneidy, Ahmed M

2013-09-01

This paper estimates the amount of daily walking associated with using public transportation in a large metropolitan area and examines individual and contextual characteristics associated with walking distances. Total walking distance to and from transit was calculated from a travel diary survey for 6913 individuals. Multilevel regression modelling was used to examine the underlying factors associated with walking to public transportation. The physical activity benefits of public transportation varied along gender and socio-economic lines. Recommended minutes of daily physical activity can be achieved for public transportation users, especially train users living in affluent suburbs. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cross-layer restoration with software defined networking based on IP over optical transport networks

NASA Astrophysics Data System (ADS)

Yang, Hui; Cheng, Lei; Deng, Junni; Zhao, Yongli; Zhang, Jie; Lee, Young

2015-10-01

The IP over optical transport network is a very promising networking architecture applied to the interconnection of geographically distributed data centers due to the performance guarantee of low delay, huge bandwidth and high reliability at a low cost. It can enable efficient resource utilization and support heterogeneous bandwidth demands in highly-available, cost-effective and energy-effective manner. In case of cross-layer link failure, to ensure a high-level quality of service (QoS) for user request after the failure becomes a research focus. In this paper, we propose a novel cross-layer restoration scheme for data center services with software defined networking based on IP over optical network. The cross-layer restoration scheme can enable joint optimization of IP network and optical network resources, and enhance the data center service restoration responsiveness to the dynamic end-to-end service demands. We quantitatively evaluate the feasibility and performances through the simulation under heavy traffic load scenario in terms of path blocking probability and path restoration latency. Numeric results show that the cross-layer restoration scheme improves the recovery success rate and minimizes the overall recovery time.

Resilience and efficiency in transportation networks

PubMed Central

Ganin, Alexander A.; Kitsak, Maksim; Marchese, Dayton; Keisler, Jeffrey M.; Seager, Thomas; Linkov, Igor

2017-01-01

Urban transportation systems are vulnerable to congestion, accidents, weather, special events, and other costly delays. Whereas typical policy responses prioritize reduction of delays under normal conditions to improve the efficiency of urban road systems, analytic support for investments that improve resilience (defined as system recovery from additional disruptions) is still scarce. In this effort, we represent paved roads as a transportation network by mapping intersections to nodes and road segments between the intersections to links. We built road networks for 40 of the urban areas defined by the U.S. Census Bureau. We developed and calibrated a model to evaluate traffic delays using link loads. The loads may be regarded as traffic-based centrality measures, estimating the number of individuals using corresponding road segments. Efficiency was estimated as the average annual delay per peak-period auto commuter, and modeled results were found to be close to observed data, with the notable exception of New York City. Resilience was estimated as the change in efficiency resulting from roadway disruptions and was found to vary between cities, with increased delays due to a 5% random loss of road linkages ranging from 9.5% in Los Angeles to 56.0% in San Francisco. The results demonstrate that many urban road systems that operate inefficiently under normal conditions are nevertheless resilient to disruption, whereas some more efficient cities are more fragile. The implication is that resilience, not just efficiency, should be considered explicitly in roadway project selection and justify investment opportunities related to disaster and other disruptions. PMID:29291243

76 FR 51271 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-18

... Docket 07-100; FCC 11-6] Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the... interoperable public safety broadband network. The establishment of a common air interface for 700 MHz public safety broadband networks will create a foundation for interoperability and provide a clear path for the...

78 FR 33467 - Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-04

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Second Allocation of Public Transportation Emergency Relief Funds in Response to Hurricane Sandy: Response, Recovery & Resiliency; Correction... allocation of $3.7 billion under the Public Transportation Emergency Relief Program to the four FTA...

Potential health impact of switching from car to public transportation when commuting to work.

PubMed

Morabia, Alfredo; Mirer, Franklin E; Amstislavski, Tashia M; Eisl, Holger M; Werbe-Fuentes, Jordan; Gorczynski, John; Goranson, Chris; Wolff, Mary S; Markowitz, Steven B

2010-12-01

We assessed humidity-corrected particulate matter (PM(2.5)) exposure and physical activity (using global positioning system monitors and diaries) among 18 people who commuted by car to Queens College, New York, New York, for 5 days, and then switched to commuting for the next 5 days via public transportation. The PM(2.5) differed little between car and public transportation commutes (1.41 μg/M(3)·min; P = .226). Commuting by public transportation rather than by car increased energy expenditure (+124 kcal/day; P < .001) equivalent to the loss of 1 pound of body fat per 6 weeks.

Potential Health Impact of Switching From Car to Public Transportation When Commuting to Work

PubMed Central

Mirer, Franklin E.; Amstislavski, Tashia M.; Eisl, Holger M.; Werbe-Fuentes, Jordan; Gorczynski, John; Goranson, Chris; Wolff, Mary S.; Markowitz, Steven B.

2010-01-01

We assessed humidity-corrected particulate matter (PM2.5) exposure and physical activity (using global positioning system monitors and diaries) among 18 people who commuted by car to Queens College, New York, New York, for 5 days, and then switched to commuting for the next 5 days via public transportation. The PM2.5 differed little between car and public transportation commutes (1.41 μg/M3·min; P = .226). Commuting by public transportation rather than by car increased energy expenditure (+124 kcal/day; P < .001) equivalent to the loss of 1 pound of body fat per 6 weeks. PMID:20966368

Heuristic urban transportation network design method, a multilayer coevolution approach

NASA Astrophysics Data System (ADS)

Ding, Rui; Ujang, Norsidah; Hamid, Hussain bin; Manan, Mohd Shahrudin Abd; Li, Rong; Wu, Jianjun

2017-08-01

The design of urban transportation networks plays a key role in the urban planning process, and the coevolution of urban networks has recently garnered significant attention in literature. However, most of these recent articles are based on networks that are essentially planar. In this research, we propose a heuristic multilayer urban network coevolution model with lower layer network and upper layer network that are associated with growth and stimulate one another. We first use the relative neighbourhood graph and the Gabriel graph to simulate the structure of rail and road networks, respectively. With simulation we find that when a specific number of nodes are added, the total travel cost ratio between an expanded network and the initial lower layer network has the lowest value. The cooperation strength Λ and the changeable parameter average operation speed ratio Θ show that transit users' route choices change dramatically through the coevolution process and that their decisions, in turn, affect the multilayer network structure. We also note that the simulated relation between the Gini coefficient of the betweenness centrality, Θ and Λ have an optimal point for network design. This research could inspire the analysis of urban network topology features and the assessment of urban growth trends.

Impact of pore size variability and network coupling on electrokinetic transport in porous media

NASA Astrophysics Data System (ADS)

Alizadeh, Shima; Bazant, Martin Z.; Mani, Ali

2016-11-01

We have developed and validated an efficient and robust computational model to study the coupled fluid and ion transport through electrokinetic porous media, which are exposed to external gradients of pressure, electric potential, and concentration. In our approach a porous media is modeled as a network of many pores through which the transport is described by the coupled Poisson-Nernst-Planck-Stokes equations. When the pore sizes are random, the interactions between various modes of transport may provoke complexities such as concentration polarization shocks and internal flow circulations. These phenomena impact mixing and transport in various systems including deionization and filtration systems, supercapacitors, and lab-on-a-chip devices. In this work, we present simulations of massive networks of pores and we demonstrate the impact of pore size variation, and pore-pore coupling on the overall electrokinetic transport in porous media.

Methicillin-resistant Staphylococcus aureus in the environment of public transport: data from the metropolitan network in Lyon, France.

PubMed

Gaymard, Alexandre; Pichon, Maxime; Degaud, Michaël; Tasse, Jason; Dupieux, Céline; Laurent, Frédéric

2016-10-01

Methicillin-resistant Staphylococcus aureus (MRSA) is involved in community-acquired and nosocomial diseases. The means of MRSA transmission and dissemination in the community remain uncertain. Studies have shown that public transport systems could be a source of MRSA and may serve as a potential source for community-acquired MRSA infections. This study aimed to investigate MRSA contamination on Lyon's metropolitan network (Métro) in France. Hand-touched surfaces were sampled with sterile swabs (Transystem(®)) during a 1-day transversal study by collecting 50 samples in seven hub stations and two trains for each of the four Métro lines. Then, during a longitudinal study, one sample was collected twice daily for 30 consecutive days in the busiest and most congested hub station. All swabs were incubated in enrichment medium for 24 h and then each suspension was plated onto a chromogenic selective medium for MRSA. After 24 h at 36 °C, all presumptive MRSA colonies were tested using VITEK(®) MS to confirm identification as S. aureus as well as by Alere™ PBP2a Culture Colony Test and mecA/mecC PCR to check methicillin resistance. Of the 110 swabs tested, 24 presumptive MRSA colonies were isolated, of which 2 were confirmed as S. aureus by VITEK(®) MS. These two isolates were tested negative using the PBP2a Culture Colony Test and PCR. Unlike other foreign cities such as Lisbon, the current data suggest a low level of MRSA contamination of hand-touched surfaces on Lyon's Métro. This should be put in perspective with the low level of MRSA colonisation in the French community. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

A Bayesian additive model for understanding public transport usage in special events.

PubMed

Rodrigues, Filipe; Borysov, Stanislav; Ribeiro, Bernardete; Pereira, Francisco

2016-12-02

Public special events, like sports games, concerts and festivals are well known to create disruptions in transportation systems, often catching the operators by surprise. Although these are usually planned well in advance, their impact is difficult to predict, even when organisers and transportation operators coordinate. The problem highly increases when several events happen concurrently. To solve these problems, costly processes, heavily reliant on manual search and personal experience, are usual practice in large cities like Singapore, London or Tokyo. This paper presents a Bayesian additive model with Gaussian process components that combines smart card records from public transport with context information about events that is continuously mined from the Web. We develop an efficient approximate inference algorithm using expectation propagation, which allows us to predict the total number of public transportation trips to the special event areas, thereby contributing to a more adaptive transportation system. Furthermore, for multiple concurrent event scenarios, the proposed algorithm is able to disaggregate gross trip counts into their most likely components related to specific events and routine behavior. Using real data from Singapore, we show that the presented model outperforms the best baseline model by up to 26% in R2 and also has explanatory power for its individual components.

Meta-analysis for explaining the variance in public transport demand elasticities in Europe

DOT National Transportation Integrated Search

1998-01-01

Results from past studies on transport demand elasticities show a large variance. This paper assesses key factors that influence the sensitivity of public transport users to transport costs in Europe, by carrying out a comparative analysis of the dif...

Modeling sediment transport after ditch network maintenance of a forested peatland

NASA Astrophysics Data System (ADS)

Haahti, K.; Marttila, H.; Warsta, L.; Kokkonen, T.; Finér, L.; Koivusalo, H.

2016-11-01

Elevated suspended sediment (SS) loads released from peatlands after drainage operations and the resulting negative effect on the ecological status of the receiving water bodies have been widely recognized. Understanding the processes controlling erosion and sediment transport within the ditch network forms a prerequisite for adequate sediment control. While numerous experimental studies have been reported in this field, model based assessments are rare. This study presents a modeling approach to investigate sediment transport in a peatland ditch network. The transport model describes bed erosion, rain-induced bank erosion, floc deposition, and consolidation of the bed. Coupled to a distributed hydrological model, sediment transport was simulated in a 5.2 ha forestry-drained peatland catchment for 2 years after ditch cleaning. Comparing simulation results to measured SS concentrations suggested that the loose peat material, produced during excavation, contributed markedly to elevated SS concentrations immediately after ditch cleaning. Both snowmelt and summer rainstorms contributed critically to annual loads. Springtime peat erosion during snowmelt was driven by ditch flow whereas during summer rainfalls, bank erosion by raindrop impact was identified as an important process. Relating modeling results to observed spatial topographic changes in the ditch network was challenging and the results were difficult to verify. Nevertheless, the model has potential to identify risk areas for erosion. The results demonstrate that modeling is effective in separating the importance of different processes and complements pure experimental approaches. Modeling results can aid planning and designing efficient sediment control measures and guide the focus of experimental studies.

Self-Learning Intelligent Agents for Dynamic Traffic Routing on Transportation Networks

NASA Astrophysics Data System (ADS)

Sadek, Add; Basha, Nagi

Intelligent Transportation Systems (ITS) are designed to take advantage of recent advances in communications, electronics, and Information Technology in improving the efficiency and safety of transportation systems. Among the several ITS applications is the notion of Dynamic Traffic Routing (DTR), which involves generating "optimal" routing recommendations to drivers with the aim of maximizing network utilizing. In this paper, we demonstrate the feasibility of using a self-learning intelligent agent to solve the DTR problem to achieve traffic user equilibrium in a transportation network. The core idea is to deploy an agent to a simulation model of a highway. The agent then learns by itself by interacting with the simulation model. Once the agent reaches a satisfactory level of performance, it can then be deployed to the real-world, where it would continue to learn how to refine its control policies over time. To test this concept in this paper, the Cell Transmission Model (CTM) developed by Carlos Daganzo of the University of California at Berkeley is used to simulate a simple highway with two main alternative routes. With the model developed, a Reinforcement Learning Agent (RLA) is developed to learn how to best dynamically route traffic, so as to maximize the utilization of existing capacity. Preliminary results obtained from our experiments are promising. RL, being an adaptive online learning technique, appears to have a great potential for controlling a stochastic dynamic systems such as a transportation system. Furthermore, the approach is highly scalable and applicable to a variety of networks and roadways.

Linking Climate Risk, Policy Networks and Adaptation Planning in Public Lands

NASA Astrophysics Data System (ADS)

Lubell, M.; Schwartz, M.; Peters, C.

2014-12-01

Federal public land management agencies in the United States have engaged a variety of planning efforts to address climate adaptation. A major goal of these efforts is to build policy networks that enable land managers to access information and expertise needed for responding to local climate risks. This paper investigates whether the perceived and modeled climate risk faced by different land managers is leading to larger networks or more participating in climate adaptation. In theory, the benefits of climate planning networks are larger when land managers are facing more potential changes. The basic hypothesis is tested with a survey of public land managers from hundreds of local and regional public lands management units in the Southwestern United States, as well as other stakeholders involved with climate adaptation planning. All survey respondents report their perceptions of climate risk along a variety of dimensions, as well as their participation in climate adaptation planning and information sharing networks. For a subset of respondents, we have spatially explicity GIS data about their location, which will be linked with downscaled climate model data. With the focus on climate change, the analysis is a subset of the overall idea of linking social and ecological systems.

Using Public Network Infrastructures for UAV Remote Sensing in Civilian Security Operations

DTIC Science & Technology

2011-03-01

leveraging public wireless communication networks for UAV-based sensor networks with respect to existing constraints and user requirements...Detection with an Autonomous Micro UAV Mesh Network . In the near future police departments, fire brigades and other homeland security ...UAV-based sensor networks with respect to existing constraints and user requirements. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

Achieving 10,000 steps: a comparison of public transport users and drivers in a university setting.

PubMed

Villanueva, Karen; Giles-Corti, Billie; McCormack, Gavin

2008-09-01

To compare pedometer steps of university students who used public transport and private motor vehicles to travel to and or from The University of Western Australia (UWA). 103 undergraduate students in 2006 recruited by e-mail and snowballing wore a pedometer for five consecutive university days, and completed a travel and physical activity diary. Compared with private motor vehicle users, public transport users performed more daily steps (11443 vs. 10242 steps/day, p=0.04) After adjusting for gender, age group and average daily minutes of self-reported leisure-time physical activity, the odds of achieving 10,000 steps/day was higher in public transport users compared with private motor vehicle users (OR 3.55; 95% CI 1.34-9.38, p=0.01). Walking associated with public transport use appeared to contribute to university students achieving higher levels of daily steps. Encouraging public transport use could help increase and maintain community physical activity levels.

77 FR 69899 - Public Conference on Geographic Information Systems (GIS) in Transportation Safety

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-21

... NATIONAL TRANSPORTATION SAFETY BOARD Public Conference on Geographic Information Systems (GIS) in... Geographic Information Systems (GIS) in transportation safety on December 4-5, 2012. GIS is a rapidly... visualization of data. The meeting will bring researchers and practitioners in transportation safety and GIS...

Multilayered complex network datasets for three supply chain network archetypes on an urban road grid.

PubMed

Viljoen, Nadia M; Joubert, Johan W

2018-02-01

This article presents the multilayered complex network formulation for three different supply chain network archetypes on an urban road grid and describes how 500 instances were randomly generated for each archetype. Both the supply chain network layer and the urban road network layer are directed unweighted networks. The shortest path set is calculated for each of the 1 500 experimental instances. The datasets are used to empirically explore the impact that the supply chain's dependence on the transport network has on its vulnerability in Viljoen and Joubert (2017) [1]. The datasets are publicly available on Mendeley (Joubert and Viljoen, 2017) [2].

77 FR 60680 - Development of the Nationwide Interoperable Public Safety Broadband Network

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-04

... public comment on the conceptual network architecture presentation made at the FirstNet Board of... business plan considerations. NTIA also seeks comment on the general concept of how to develop applications... network based on a single, nationwide network architecture called for under the Middle Class Tax Relief...

A profile of public transportation passenger demographics and travel characteristics reported in on-board surveys

DOT National Transportation Integrated Search

2007-05-01

Data from 150 on-board vehicle passenger surveys conducted by public transportation agencies from : 2000 through 2005 were compiled. This is the largest ever on-board survey study about the public : transportation industry. These surveys summarized t...

76 FR 49832 - Notice of Market Assessment and Public Meeting for Digital Transportation Exchange

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-11

... Market Assessment and Public Meeting for Digital Transportation Exchange AGENCY: Office of the Secretary...--creating a thriving marketplace for digital transportation solutions. The Digital Transportation Exchange... best digital products and services for the transportation industry--from very simple to very complex...

Climate and change: simulating flooding impacts on urban transport network

NASA Astrophysics Data System (ADS)

Pregnolato, Maria; Ford, Alistair; Dawson, Richard

2015-04-01

National-scale climate projections indicate that in the future there will be hotter and drier summers, warmer and wetter winters, together with rising sea levels. The frequency of extreme weather events is expected to increase, causing severe damage to the built environment and disruption of infrastructures (Dawson, 2007), whilst population growth and changed demographics are placing new demands on urban infrastructure. It is therefore essential to ensure infrastructure networks are robust to these changes. This research addresses these challenges by focussing on the development of probabilistic tools for managing risk by modelling urban transport networks within the context of extreme weather events. This paper presents a methodology to investigate the impacts of extreme weather events on urban environment, in particular infrastructure networks, through a combination of climate simulations and spatial representations. By overlaying spatial data on hazard thresholds from a flood model and a flood safety function, mitigated by potential adaptation strategies, different levels of disruption to commuting journeys on road networks are evaluated. The method follows the Catastrophe Modelling approach and it consists of a spatial model, combining deterministic loss models and probabilistic risk assessment techniques. It can be applied to present conditions as well as future uncertain scenarios, allowing the examination of the impacts alongside socio-economic and climate changes. The hazard is determined by simulating free surface water flooding, with the software CityCAT (Glenis et al., 2013). The outputs are overlapped to the spatial locations of a simple network model in GIS, which uses journey-to-work (JTW) observations, supplemented with speed and capacity information. To calculate the disruptive effect of flooding on transport networks, a function relating water depth to safe driving car speed has been developed by combining data from experimental reports (Morris et