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Dissertations / Theses on the topic 'Transportation network'
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Hunt, Gregory William. "Transportation relay network design." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/25788.
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Karim, Md Ahsanul. "Transit operations, city transportation plans and overall transportation network safety." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/33739.
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Modern transportation planning considers issues such as road congestion, pollution and mobility proactively. However, road safety is usually evaluated in a reactive manner only after the implementation of transportation plans, and when safety problems arise. Although this reactive road safety approach has been very effective, it is associated with significant costs on communities. Therefore, several researchers advocate a more proactive approach to road safety analysis. Several studies developed macro-level Collision Prediction Models (CPMs) that could assess the road safety in a proactive manner, and provide a safety planning decision support tool to community planners and engineers. However, these models have limitations as they do not target the safety evaluation of different goals of a typical city transportation plan. Therefore, the motivation for this research arises from the necessity of developing tools that could predict the safety effect of a typical city transportation plan such as changes in the transportation and transit network configurations, and ultimately could evaluate the safety estimates among alternatives of different transportation plans and policies.
The main goal of this thesis is to develop a set of macro-level collision prediction models to investigate the relationships between various transportation and sociodemographic characteristics, and the overall roadway safety. The developed models consider the Poisson variations and the heterogeneity (extra-variation) on the occurrence of collisions and the spatial effects on the distribution of collisions caused by the similarity in environment and geography of the neighbouring sites. It has been shown that the goodness of fit improved with the incorporation of spatial effect.
In this study, a set of zonal-level transit reliant and application-based collision prediction models were developed. Data from Metro Vancouver, British Columbia were used to develop models using a generalized linear modelling approach with a negative binomial error structure. Different transit-related variables were found to be statistically significant, namely bus stop density, percentage of transit-km traveled with regard to total vehicle-km traveled, percentage of commuters walking, percentage of commuters biking, and percentage of commuters using transit. The CPMs related total, severe, and property damage only collisions to the implemental aspects related to the goals of long-term transportation plans.
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Wan, Zheng. "Freight transportation planning container transportation network within China's Yangtze River /." online access from Digital Dissertation Consortium, 2008. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?1462115.
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Chiu, Yu-Yen. "An analysis of international transportation network." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33728.
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Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2005.Includes bibliographical references (leaf 70).
This thesis discusses a network design problem based on a case study with a footwear company, which intends to minimize total supply chain costs by establishing a distribution network which bypasses its primary distribution center (DC). Through the new network, called the DC bypass network, the company ships products directly from its Asian factories to a logistics hub at an entry port in the US and then on to customers, a particular group of chosen customers. We assess the project by comparing costs derived from a baseline and optimization model. A baseline model represents the company's existing logistics network while optimization models capture future supply chains with different scenarios. The models convert a real supply chain network into the relationships between nodes and links. Nodes indicate facilities while links refer to the flow of the product. In brief, this case study is about how a company evaluates its transportation network. Methods to determine a specific location or multiple locations for the DC bypass operations are discussed. Furthermore, the robustness of an optimal solution will be measured through a sensitivity analysis. Other benefits include the reduction of lead time is discussed in the further research.
by Yu-Yen Chiu.
M.Eng.in Logistics
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Wang, Chao. "Wireless Sensor Network for Safe Transportation." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209169.
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Since dangerous goods have special physical and chemical properties, they can easily produce explosion, fire, poisoning and other accident due to a traffic collision or hazardous leak under a complex transport condition. Compared with ordinary traffic accidents, accident of dangerous goods transportation has greater risks and subsequent influence. Due to the huge transportation equipment and high freight volumes, once the accident occurred, it will be difficult to deal with the danger in the first place. Faced with such a grim situation, this paper develops a system to achieve real- time monitoring of dangerous goods transportation based on wireless sensor network (WSN). Combined with different kind of sensors, wireless communication technology and data fusion technology, a real-time monitor system is developed for dangerous good transportation. In addition to real- time monitoring, the system can analyze the state parameters obtained to check whether the vehicle is in a safe condition. The system has a real-time tracking, monitoring and early warning function which has important significance in curbing accidents and lowering the accident loss as far as possible
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Hakimian, Hamed, and Zandi Mohammad Saeid. "Foliated Transportation Systems." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19609.
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First issue that this thesis tries to address is setting up a practical framework of foliated transportation network. Scope of this thesis limited to several cities in Sweden to illustrate that this organization can be set up and it can perform under corresponding regulations. Beside the possibility of performance it was of high importance to consider its positive effects on whole network factors from both social and industrial perspectives. For this purpose a comparison between network results for different truck fill rates carried out but practical use of results is completely dependent of the stakeholder who is going to utilize them.
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Kessler, Matthew L. "How Transportation Network Companies Could Replace Public Transportation in the United States." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/7045.
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The quantity of cell phone applications or mobile apps have seen an upsurge at an exponential rate in under a decade. Many have been created for a variety of industries, including transportation. The advent and subsequent commercialized implementation of near-instant transport by a middleman-type of app is now known as a Transportation Network Company or TNC. Examples of the more renowned TNCs are Uber, Lyft and Sidecar.
In recent years, TNCs have cultivated a tremendous following, to the degree of taxicab desertion. Moreover, the massive success of TNCs led to expansion of its capacities into public transportation.
The TNC’s expeditious popularity has garnered the attention of government and transit agencies. Without fail, TNCs can complement, supplement or compete with transit. However, sparsely has there been any deep discussion about a TNC potentially supplanting transit. The aim of this paper is to show how TNCs could replace public transportation in the United States if subsidized at the same level of transit agencies. Austin, Texas was analyzed as the case study city. A comparison of subsidization between Austin’s transit agency: Cap Metro, the local TNCs, and on a national aggregate level was conducted. The evidence herein clearly shows that TNCs are highly competitive when in revenue service operating at full capacity, potentially replacing public transportation.
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Gupta, Umang 1977. "Earthquake loss estimation including transportation network damage." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/32708.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.Includes bibliographical references (leaves 145-149).
Large earthquakes have the potential of causing extensive damage and enormous economic losses. These losses are primarily attributable to the reduction in functionality of various facilities in the affected region and the rebuilding costs, and can be reduced through strategic pre- and post-earthquake decisions. This thesis describes an integrated methodology to estimate losses due to scenario earthquakes, with emphasis on the reduced functionality of the transportation infrastructure. The methodology integrates variables that were previously considered exogenous to the transportation system, through models for reduced industrial production capacity, and damage to lifelines, residential clusters and other structural components in an integrated framework. By modifying input parameters, one can evaluate the effect on the losses of various mitigating actions. The methodology is thus useful for prioritizing retrofitting efforts and in general for developing pre and post- earthquake strategies for lowering economic losses. A case study of a New Madrid scenario earthquake is presented. Future efforts needed to improve the loss estimation capability of this methodology are identified.
by Umang Gupta.
S.M.
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Lu, Yun. "Robust transportation network design under user equilibrium." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41731.
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Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2007.Includes bibliographical references (p. 59-63).
We address the problem of designing a transportation network in the presence of demand uncertainty, multiple origin-destination pairs and a budget constraint for the overall construction cost, under the behavioral assumption that travelers optimize their own travel costs (i.e., the "user-equilibrium" condition). Under deterministic demand, we propose an exact integer optimization approach that leads to a quadratic objective, linear constraints optimization problem. As a result, the problem is efficiently solvable via commercial software, when the costs are linear functions of traffic flows. We then use an iterative algorithm to address the case of nonlinear cost functions. While the problem is intractable under probabilistic assumptions on demand uncertainty, we extend the previous model and propose an iterative algorithm using a robust optimization approach that models demand uncertainty. We finally report extensive numerical results to illustrate that our approach leads to tractable solutions for large scale networks.
by Yun Lu.
S.M.
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Kim, Dong Won. "Intelligent Transportation Systems: A Multilevel Policy Network." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/28087.
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This dissertation is a descriptive study of a policy network designed for U.S. government and global cooperation to promote Intelligent Transportation Systems (ITS). It is aimed at exploring the historical and structural features of the ITS policy network, and evaluating its roles in the policy process.
Until now, the network literature has barely examined the full arrays of networks, catching just part of their full pictures. First, this study draws attention to transnational networks and their organic or systematic relationships with lower levels of networks. Second, it examines the individual properties and synergy of three core elements of the ITS policy network: public-private partnerships, professional networks, and intergovernmental networks. Third, it takes a close look at the pattern of stability change and power relations of the policy network from within the net. Finally, this study discusses what difference networks make, compared to hierarchies and markets.
This dissertation employed multiple sources of evidence: unstandardized elite interviews, government documents, and archival records. Through a networking strategy to find the best experts, face-to-face, telephone, and e-mail interviews were conducted with twenty-two public officials and ITS professionals.
It was found that the U.S. ITS policy network was a well-designed strategic governance structure at the planning level, but an experimental learning-focused one at the implementation level. It was initially designed by a new, timely, cross-sectional coalition, which brought together field leaders from both the public and the private sectors under the slogan of global competitiveness. Yet, day-to-day managers within the net often experience much more complex power relationships and internal dynamics as well as legal obstacles; also, they confront external uncertainty in political support and market.
For better results, policy networks should be designed in flexible ways that will handle their disadvantages such as ambiguous roles, exclusiveness, and increased staff time. In this respect, it is inevitable for the networks to include some components of a wide range of conventional structures, ranging from highly bureaucratic to highly entrepreneurial, on the one hand, and ranging between issue networks (grounded in American pluralism) and policy communities (based on European corporatism), on the other hand.Ph. D.
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Hammer, Kristina Marie. "Organizational network analysis in a transportation agency." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/k_hammer_120309.pdf.
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Thesis (M.S. in civil engineering)--Washington State University, December 2009.Title from PDF title page (viewed on Jan. 15, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. [9-10]).
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Urena, Serulle Nayel. "Transportation Network Resiliency: A Fuzzy Systems Approach." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/769.
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Every day the dependence on transportation grows as local, regional, national, and international independence increases. Resilient transportation systems are needed to secure the highest possible level of service during disruptive events, including natural and man-made disasters. Because of limited resources, decision makers need guidance on how, when, and where to invest to improve resiliency of their networks. The research objective is to develop a method to assess and quantify resiliency, at pre-event conditions, using a fuzzy inference approach. This research expands previous work, refining key variable definitions, adjusting model interactions, and increasing transparency between metrics. This thesis presents the method and provides an illustrative example of the methodology using the Dominican Republic as a case study. The example explains how a transportation network responds to a disruptive event and how specific investments can increase resiliency of the network. The result of this research is a quantitative basis for decision makers to conduct cost-benefit analysis of resiliency increasing projects.
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Simhairi, Nather Zeki. "Traffic assignment and network analysis." Thesis, Royal Holloway, University of London, 1987. http://repository.royalholloway.ac.uk/items/a3377f99-4ed8-4000-91f8-0384aed4a3c6/1/.
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This thesis studies the transportation network, and is divided into three sections. Initially an algorithm is described which finds the user-equilibrium assignment for networks with linear congestion functions where the cost of travel on a link is dependent on the flow in the whole network. Secondly it investigates the sensitivity of the cost of travel and of the flow distribution in the network, to changes in the link congestion function. Combinatorial methods are used for evaluating the results of the sensitivity analysis. This is done with the aim of obtaining fast and efficient algorithms for the evaluation of cost sensitive and paradoxical links. Finally, for networks where the demand is elastic, it describes the catastrophic behaviour of the point representing the user-equilibrium flow distribution under certain cost conditions.
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Holovatch, T. "Complex transportation networks : resilience, modelling and optimisation." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/eafefd84-ff08-43cf-a544-597ee5e63237/1.
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Liang, Li. "Supply chain network for hydrogen transportation in Spain." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61892.
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Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 77-79).
Hydrogen fuel is considered one of the major emerging renewable substitutes for fossil fuel. A crucial factor as to whether hydrogen will be successful depends on its cost as a substitute. Recently, there has been a growing interest in investigating the feasibility from a supply chain point of view. This thesis intends to provide a comprehensive study of the feasibility of hydrogen as a transportation fuel from a supply chain point of view. The aim is to discover the most efficient, sustainable, and ultimately most cost-effective strategy to meet future transportation demand scenarios. This includes optimizing costs over production, compression, storage, distribution, and dispensation. Moreover, through the decision support model developed in this thesis, insights regarding strategic approaches for hydrogen supply chain infrastructure development are developed, such as the tradeoff between centralized and distributed production. A case study in Spain is presented to illustrate the supply chain. Different models are proposed to estimate electricity generation capacity, hydrogen production scheme, transportation topology, distribution methods and future demands. Six different scenarios, based on different production scheme, future demand level, are tested. Results from the case study indicate that it is more cost effective to transmit electricity from wind farms to locations close to demand sites to do centralized production. In terms of transportation, liquid gas truck is the preferred mode of transportation from production sites to local demand regions. The model can adapt be extended and adapted to consider other configurations of the supply chain network.
by Li Liang.
S.M.
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Zhang, Xu. "INCORPORATING TRAVEL TIME RELIABILITY INTO TRANSPORTATION NETWORK MODELING." UKnowledge, 2017. http://uknowledge.uky.edu/ce_etds/54.
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Travel time reliability is deemed as one of the most important factors affecting travelers’ route choice decisions. However, existing practices mostly consider average travel time only. This dissertation establishes a methodology framework to overcome such limitation.
Semi-standard deviation is first proposed as the measure of reliability to quantify the risk under uncertain conditions on the network. This measure only accounts for travel times that exceed certain pre-specified benchmark, which offers a better behavioral interpretation and theoretical foundation than some currently used measures such as standard deviation and the probability of on-time arrival.
Two path finding models are then developed by integrating both average travel time and semi-standard deviation. The single objective model tries to minimize the weighted sum of average travel time and semi-standard deviation, while the multi-objective model treats them as separate objectives and seeks to minimize them simultaneously. The multi-objective formulation is preferred to the single objective model, because it eliminates the need for prior knowledge of reliability ratios. It offers an additional benefit of providing multiple attractive paths for traveler’s further decision making.
The sampling based approach using archived travel time data is applied to derive the path semi-standard deviation. The approach provides a nice workaround to the problem that there is no exact solution to analytically derive the measure. Through this process, the correlation structure can be implicitly accounted for while simultaneously avoiding the complicated link travel time distribution fitting and convolution process.
Furthermore, the metaheuristic algorithm and stochastic dominance based approach are adapted to solve the proposed models. Both approaches address the issue where classical shortest path algorithms are not applicable due to non-additive semi-standard deviation. However, the stochastic dominance based approach is preferred because it is more computationally efficient and can always find the true optimal paths.
In addition to semi-standard deviation, on-time arrival probability and scheduling delay measures are also investigated. Although these three measures share similar mathematical structures, they exhibit different behaviors in response to large deviations from the pre-specified travel time benchmark. Theoretical connections between these measures and the first three stochastic dominance rules are also established. This enables us to incorporate on-time arrival probability and scheduling delay measures into the methodology framework as well.
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Pant, Sunil Babu. "Transportation Network Resiliency: A Study of Self-Annealing." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1434.
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Transportation networks, as important lifelines linking communities and goods, are indispensable for the smooth functioning of society. These networks are, however, fragile and vulnerable to natural and manmade disasters, which can disrupt their vital functionality. The role of the transportation sector becomes more crucial during disasters due to its role in pre-disaster evacuation as well as post-disaster recovery. The ability of transportation systems to retain performance during and after disasters undergoing little to no loss and their ability to return to the normal state of operation quickly after disasters defines their resilience. Authorities need to understand the degree of resilience within the transportation system under their jurisdiction and plan for improvements. In this research, attempts have been made to deal with resilience in quantitative ways to provide defensible data to decision makers to support investment strategies.
Total loss in the network performance can be quantified by dealing with the variation of network performance over time after disasters and the network resilience can be measured by the ability to minimize this loss. It has been shown that robust networks retain better performance after disruptions and recovery works, which follow optimized recovery paths, in spite of constraints of resources and time, help to minimize the total losses and enhance the network resilience. The objective of this research is to create a conceptual framework to quantify resilience and discuss quantitatively the properties determining resilience of transportation networks. The concepts presented are applied to a test network to illustrate the mathematical procedures. Such methods can help decision makers analyze relative improvements in resiliency as a consequence of proposed project alternatives and help to perform benefit-cost analysis for such projects.
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Mucci, Richard A. "TRANSPORTATION NETWORK COMPANIES: INFLUENCERS OF TRANSIT RIDERSHIP TRENDS." UKnowledge, 2017. https://uknowledge.uky.edu/ce_etds/61.
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The major transit systems operating in San Francisco are San Francisco Municipal (MUNI), Bay Area Rapid Transit (BART), and Caltrain. The system of interest for this paper is MUNI, in particular the bus and light rail systems. During the past decade transit ridership in the area has experienced diverging growth, with bus ridership declining while rail ridership is growing significantly (Erhardt et al. 2017). Our data show that between 2009 and 2016, MUNI rail ridership increases from 146,000 to 171,400, while MUNI bus ridership decreases from 520,000 to 450,000. Direct ridership models (DRMs) are used to determine what factors are influencing MUNI light rail and bus ridership. The DRMs predict ridership fairly well, within 10% of the observed change. However, the assumption of no multi-collinearity is voided. Variables, such as employment and housing density, are found to be collinear. Fixed-effects panel models are used to combat the multi-collinearity issue. Fixed-effects panel models assign an intercept to every stop, so that any spatial correlation is removed. A transportation network company, Uber and Lyft, variable is introduced (TNC) to the panel models, to quantify the effect they have on MUNI bus and light rail ridership. The addition of a TNC variable and elimination of multi-collinearity helps the panel models predict ridership better than the daily and time-of-day DRMs, both within 5% of the observed change. TNCs are found to complement MUNI light rail and compete with MUNI buses. TNCs contributed to a 7% growth in light rail ridership and a 10% decline in bus ridership. These findings suggest that the relationship TNCs have with transit is complex and that the modes cannot be lumped together.
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Zhang, Xiaoning. "Optimal road pricing in transportation networks /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202003%20ZHANG.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.Includes bibliographical references (leaves 230-240). Also available in electronic version. Access restricted to campus users.
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Dowd, Michael G. "Modeling inundation impacts on transportation network performance : a GIS and four-step transportation modeling analysis." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99567.
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Thesis: M.C.P., Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2015.Thesis: S.M. in Transportation, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2015.
Page 262 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 248-251).
The world's leading climate scientists have reached a consensus that "[w]arming of the climate system is unequivocal" (IPCC, 2007). This warming will carry with it a host of consequences for the global community, including increased occurrence of flooding. Little focus has been placed on the operation of transport systems during, or shortly after inundation events. Inundation affects the availability and quality of network assets (i.e. Transportation Supply) and inhabitable land, which produces and attracts transportation users (i.e. Demand). In this thesis, I apply an altered four-step transportation modeling method to allow for the analysis of impacts in a single set time: modeling an event rather than a future equilibrium scenario. I show how traditional four-step models can be used to produce valuable metrics describing performance of the disrupted transportation system. Such metrics contribute to understanding potential consequences and planning for mitigation and response. Using the Boston Metro Region as a case study, and a four-step model for the year 2010, 1 demonstrate a method (Inundation Impact Assessment) for quantifying transport network impacts under six different inundation levels, one-foot to six-feet. The results indicate that inundation has widespread impacts on the ability of persons to complete trips and the performance of both the auto and transit networks. I then demonstrate how this method can be applied to examine different infrastructure projects in the future, modeling two different demographic scenarios for the year 2030 with two different BRT alignments. The goal is to evaluate potential contribution of BRT to recoup trips lost by the impact of inundation on other transit links. The methods and approaches used in this work show how such four-step models can be used to plan for inundation events. This method provides significant amounts of data that can be used to assess the value of potential interventions, such as the protection of mobility or the reinforcement of transportation network performance.
by Michael Dowd.
M.C.P.
S.M. in Transportation
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Zhang, Xinglong. "Network vehicle routing problems." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/21710.
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Sciaretta, Kent J. Trettel David J. "A historical perspective of the Global Transportation Network (GTN) /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA378499.
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Thesis (M.S. in Management) Naval Postgraduate School, March 2000.Thesis advisor(s): Lewis, Ira ; Gates, William. "March 2000." Includes bibliographical references (p. 87-91). Also available online.
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Fang, Yunfei. "Study of lane reservation problems in a transportation network." Thesis, Troyes, 2013. http://www.theses.fr/2013TROY0010/document.
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Le concept de réserve voie a été présenté comme une stratégie de gestion du trafic et a de nombreuses applications dans la vie réelle. Des études antérieures dans la littérature se concentrent principalement sur l'impact de la réservation de la voie dans une région locale du réseau de transport. Dans cette thèse, les problèmes de réservation de voies sont étudiés dans le but de minimiser l'impact sur le trafic total par la réservation optimale des voies dans un réseau de transport. Nous avons d’abord se concentrer sur le problème de réservation de voie (LRP) pour le transport automatisé pour les poids lourds avec temps de déplacement statique. Ce travail est généralisé au problème de réservation voies avec une capacité limitée de la voie (CLRP) pour les grands événements spéciaux. Enfin, le problème de réservation de voies avec le temps de déplacement dépendant du temps (LRP-TT), et le problème de réservation voies avec la vitesse de déplacement dépendant du temps (LRP-TS) sont étudiés. Pour chacun des problèmes étudiés, les modèles mathématiques appropriés sont formulés, leurs complexités sont démontrées. Différentes méthodes de résolution sont explorées, y compris exacte cut-and-solve méthode, cut-and-solve et méthod de coupe combinée, et la méthode de recherche tabou. Les performances des algorithmes proposés sont évaluées par des instances générées au hasard. Les résultats numériques ont montré que les algorithmes proposés sont plus efficaces pour résoudre les problèmes étudiés que le logiciel commercial référence CPLEXThe concept of lane reservation has been introduced as a traffic management strategy and has many applications in real life. Previous studies in the literature mainly focus on the impact of lane reservation in a local region of transportation network. In this thesis optimal lane reservation problems are studied with the objective to minimize impact on total traffic by optimally setting reserved lanes in a transportation network. We firstly focus on the lane reservation problem (LRP) for automated truck freight transportation with static link travel time. This primary work has been extended to the capacitated lane reservation problem (CLRP) for large-scale special events. Finally, lane reservation problem with time-dependent travel time (TTLRP), and lane reservation problem with time-dependent travel speed (TSLRP) are studied. For each of the considered problems, appropriate mathematical models are formulated, their complexities are demonstrated. Different resolution methods are explored including exact cut-and-solve method, cut-and-solve and cutting plane combined method, and Tabu-search method. The performance of the proposed algorithms is evaluated by randomly generated instances. Numerical results have shown that the proposed algorithms are more effective to solve the considered problems than the reference commercial package CPLEX
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Sciaretta, Kent J., and David J. Trettel. "A historical perspective of the Global Transportation Network (GTN)." Thesis, Monterey, California. Naval Postgraduate School, 2000. http://hdl.handle.net/10945/9382.
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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, there has been no definitive documentation showing the initial inception or the subsequent improvements that have taken place in developing the GTN and feeder systems. The inception of the GTN is documented, including some of the "proof of concept" prototypes. The operational prototypes and production systems are also analyzed, including the feeder systems used in the GTN and how the GTN performed during operation Desert Shield/Storm. USTRANSCOM's vision of the future GTN, up to FY04, is explained along with the authors' view of possible future GTN capabilities.
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Chen, Tairui. "Going Deeper with Convolutional Neural Network for Intelligent Transportation." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/144.
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Over last several decades, computer vision researchers have been devoted to find good feature to solve different tasks, object recognition, object detection, object segmentation, activity recognition and so forth. Ideal features transform raw pixel intensity values to a representation in which these computer vision problems are easier to solve. Recently, deep feature from covolutional neural network(CNN) have attracted many researchers to solve many problems in computer vision. In the supervised setting, these hierarchies are trained to solve specific problems by minimizing an objective function for different tasks. More recently, the feature learned from large scale image dataset have been proved to be very effective and generic for many computer vision task. The feature learned from recognition task can be used in the object detection task. This work aims to uncover the principles that lead to these generic feature representations in the transfer learning, which does not need to train the dataset again but transfer the rich feature from CNN learned from ImageNet dataset. This work aims to uncover the principles that lead to these generic feature representations in the transfer learning, which does not need to train the dataset again but transfer the rich feature from CNN learned from ImageNet dataset. We begin by summarize some related prior works, particularly the paper in object recognition, object detection and segmentation. We introduce the deep feature to computer vision task in intelligent transportation system. First, we apply deep feature in object detection task, especially in vehicle detection task. Second, to make fully use of objectness proposals, we apply proposal generator on road marking detection and recognition task. Third, to fully understand the transportation situation, we introduce the deep feature into scene understanding in road. We experiment each task for different public datasets, and prove our framework is robust.
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Wang, Shuo. "Optimization Models for Network-Level Transportation Asset Preservation Strategies." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1416578565.
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Kumar, Anand. "Dust Transportation and Settling within the Mine Ventilation Network." UKnowledge, 2019. https://uknowledge.uky.edu/mng_etds/51.
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Dust is ubiquitous in underground mine activities. Continuous inhalation of dust could lead to irreversible occupational diseases. Dust particles of size lower than 75.0 µm, also known as float coal dust, can trigger a coal dust explosion following a methane ignition. Ventilation air carries the float coal dust from the point of production to some distance before it’s deposited on the surfaces of underground coal mine. Sources of dust are widely studied, but study of dust transportation has been mainly based on experimental data and simplified models. An understanding of dust transportation in the mine airways is instrumental in the implementation of local dust control strategies.
This thesis presents techniques for sampling float coal dust, computational fluid dynamics (CFD) analysis, and mathematical modeling to estimate average dust deposition in an underground coal mine. Dust samples were taken from roof, ribs, and floor at multiple areas along single air splits from longwall and room and pillar mines. Thermogravimetric analysis of these samples showed no conclusive trends in float coal dust deposition rate with location and origin of dust source within the mine network. CFD models were developed using the Lagrangian particle tracking approach to model dust transportation in reduced scale model of mine. Three dimensional CFD analysis showed random deposition pattern of particle on the mine model floor. A pseudo 2D model was generated to approximate the distance dust particles travel when released from a 7 ft. high coal seam. The models showed that lighter particles released in a high airflow field travel farthest. NIOSH developed MFIRE software was adopted to simulate dust transportation in a mine airway analogous to fume migration. The simulations from MFIRE can be calibrated using the dust sampling results to estimate dust transportation in the ventilation network.
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Terelius, Håkan. "Optimization and Control in Dynamical Network Systems." Doctoral thesis, KTH, Reglerteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-194205.
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Dynamical network systems are complex interconnected systems useful to describe many real world problems. The advances in information technology has led the current trend towards connecting more and more systems, creating "intelligent" systems, where the intelligence originates in the scale and complexity of the network. With the growing scale of networked systems comes also higher demands on performance and continuous availability and this creates the need for optimization and control of network systems. This thesis makes four important contributions in this area. In the first contribution, we consider a collaborative road freight transportation system. An efficiency measure for the road utilization in collaborative transportation scenarios is introduced, which evaluates the performance of collaboration strategies in comparison to an optimal central planner. The efficiency measure is used to study a freight transport simulation in Germany and taxi trips using real data from New York City. This is followed by a study of the optimal idling locations for trucks, and the optimal locations for distribution centers. These locations are then exploited in a simulation of a realistic collaborative freight transport system. The second contribution studies the important problem of gathering data that are distributed among the nodes in an anonymous network, i.e., a network where the nodes are not endowed with unique identifies. Two specific tasks are considered: to estimate the size of the network, and to aggregate the distribution of local measurements generated by the nodes. We consider a framework where the nodes require anonymity and have restricted computational resources. We propose probabilistic algorithms with low resource requirements, that quickly generate arbitrarily accurate estimates. For dynamical networks, we improve the accuracy through a regularization term which captures the trade-off between the reliability of the gathered data and a-priori assumptions for the dynamics. In the third contribution, a peer-to-peer network is utilized to improve a live-streaming media application. In particular, we study how an overlay network, constructed from simple preference functions, can be used to build efficient topologies that reduce both network latency and interruptions. We present necessary and sufficient convergence conditions, as well as convergence rate estimates, and demonstrate the improvements for a real peer-to-peer video streaming application. The final contribution is a distributed optimization algorithm. We consider a distributed multi-agent optimization problem of minimizing the sum of convex objective functions. A decentralized optimization algorithm is introduced, based on dual decomposition, together with the subgradient method for finding the optimal solution. The convergence rate is analyzed for different step size rules, constant and time-varying communication delays, and noisy communication channels.Dynamiska nätverkssystem är komplexa sammankopplade system med många praktiska tillämpningar. Den snabba utvecklingen inom informationsteknologin har drivit trenden att sammankoppla större och större system till nätverk av "intelligenta" system, där intelligensen kommer från komplexiteten av nätverken. Med den ökande storleken på nätverkssystemen kommer också ökade krav på dess prestanda och tillgänglighet, vilket är drivkraften bakom utvecklingen av optimering och styrning av nätverkssystem. Den här avhandlingen presenterar fyra viktiga bidrag inom detta område. Det första bidraget handlar om kooperativ lastbilstransport. Först introduceras ett mått som mäter effektiviteten i systemet jämfört med en central planerare. Detta mått används sedan för att utvärdera vinsterna med kooperativa transporter, men används också för att utvärdera taxiförarnas vägval med verkliga data från New York City. Detta följs av en studie av de optimala vänteplatserna för lastbilar och de optimal placeringarna av distributionscentraler. Dessa positioner används sedan för att förbättra transportprestandan i ett kooperativt transportsystem. I det andra bidraget studeras informationsaggregering i anonyma nätverkssystem, det vill säga nätverk där noderna saknar unika identiteter. Två specifika problem hanteras: att estimera storleken på nätverket, och att sammanställa fördelningen av lokala mätvärden i nätverket. Noderna i detta nätverk kräver anonymitet, men antas också ha strikt begränsad beräkningskapacitet. Vi presenterar stokastiska algoritmer med låga beräkningskrav, som dessutom har snabb konvergens och som kan justeras till att ge godtycklig precision. För dynamiska nätverk förbättras prestandan genom att en regulariseringsterm används för att väga observerad data mot förväntat beteende hos systemet. I tredje bidraget analyseras ett peer-to-peer nätverk för direktsänd videodistribution. Speciellt studeras konvergensen av nätverkstopologin som genereras från lokala preferensfunktioner, och hur resultaten kan används för att minska fördröjningarna och avbrotten under videouppspelning. Vi ger nödvändiga och tillräckliga villkor för konvergens, samt karakteriserar gränsvärden för hur snabbt användare kan ansluta eller lämna nätverket utan att påverka prestandan. Det sista bidraget är en distribuerad optimeringsalgoritm. Problemet består i att minimera summan av konvexa funktioner för varje nod i ett nätverk. En decentraliserad optimeringsalgoritm presenteras som baseras på det duala optimeringsproblemet tillsammans med subgradient-metoden. Konvergenshastigheten analyseras för olika val av steglängder, konstanta samt tidsberoende kommunikationsfördröjningar och brusiga kommunikationskanaler.
QC 20161020
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Bustillos, Brenda. "Investigation and Modeling of Professional Interpersonal Networks: Transportation Planning and Modeling Community Case Study." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/560751.
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The purpose of this research is to investigate, acquire knowledge, and better comprehend the transportation planning and modeling community. This task is accomplished through the investigation of existing social and professional networks within this community by constructing and analyzing an abstract network representation of this community. Specifically, this research explores the actors (i.e., professionals, agencies) and their relationships (i.e., ties, interactions, etc.) within the professional interpersonal (social) network where they conduct business on a regular basis. Actors and relationships are represented in terms of a nodes and links within the constructed network. The network is then analyzed in an effort to answer questions such as, who are the actors, where do interpersonal relationships exist, where are social structures found, what does the evolution of this community look like over time, and what can this evolution tell us. This study has collected information from transportation professionals directly associated with the decision-making, planning and/or modeling process within the transportation planning and modeling community. The data is collected through an in-house designed online survey disseminated to the identified target audience. The designed survey is structured to capture information required for the identification of actors and relationships (or entities and ties) within the transportation planning and modeling community. With the network constructed, analysis methods derived from mathematics, computer science and social network analysis fields are implemented to identify local and global patterns, "influential" actors, and collaborative structures as well as examine network dynamics, which transpire within the environment that these transportation professionals navigate, form bonds, and collect information on frequent basis.
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Ho, Siu-kui. "Sensitivity of parameters in transportation modelling on the implication of network requirement : a case study of Hong Kong /." [Hong Kong] : University of Hong Kong, 1986. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1233361X.
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Gong, Panjing. "Capacitated network design with column generation." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/29913.
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Wan, Zhongjie, Shengyuan Qi, Jian Song, and Haijiao Wang. "Synchronized Data Transportation for Distributed Acquirement System Through Direct Ethernet Connection and TDM." International Foundation for Telemetering, 2015. http://hdl.handle.net/10150/596447.
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ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NVTo use Ethernet is the most convenient way to set up a transportation network for a telemetry data acquirement system. However, due to its CSMA/CD (Carrier Sense Multiple Access and Collision Detection) mechanics, Ethernet cannot transport data synchronously. This paper analyzed important features of transportation in a distributed data acquirement system, and presents a resolve for synchronously transporting data in a distributed data acquirement system by using direct Ethernet connection and TDM (time division multiplexing) technique.
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Fonseca, Andrea Esperanza. "Contemporary Network Theory: Concepts and Implications for Transportation Asset Management." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33535.
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This thesis proposes a novel working paradigm for transportation infrastructure asset management by viewing the transportation networks as key components (or nodes) of a broader network of resources, which includes infrastructure linked with societyâ s ecological, social, and economic systems. An extensive review of network science literature suggested that to understand the behavior of a complex network is imperative to characterize its topology. Consequently, this thesis focused on developing a framework to characterize the topology of the transportation infrastructure systems, and understanding how the unveiling topology can be used for supporting transportation asset management decisions.
The proposed methodology determines whether the transportation infrastructure networks can be modeled as scale-free or exponential networks, using a framework for characterizing the agents of the network, their direct and indirect interactions among each other, and their importance as elements of a complex network, and utilizes these data to support transportation asset management. The methodology consist of seven steps: (1) define the networks of interest; (2) identify their intrinsic components; (3) visualize the identified networks using GIS maps; (4) identify direct and indirect interactions through superposition of the networks; (5) represent the relationship between the nodes and their linkages by frequency diagrams in order to determine the intrinsic topology of the network; (6) illustrate (graphically) the overall transportation infrastructure with the help of GIS; and (7) analyze the TINs from the decision-maker point of view, identifying the elements that are more relevant or need more attention on the network.
The procedure is then implemented in a small network in a localized area (Town of Blacksburg, Virginia) to show its practicality, and recommendations for further development and mathematical modeling in order to allow its implementation in larger networks are provided. Based on frequency analysis of the nodes and their connectivity, it was concluded that the transportation infrastructure networks in the case study behave as exponential networks. The study showed that the links determine how the infrastructure network grows and that problems like congestion can be addressed by analyzing other factors related with topology, such as speed, unit size, and lane width. The proposed methodology was found to be useful as an asset management tool. Finally, a list of findings and recommendations for further research are presented as opportunities to enhance the management of transportation infrastructure networks.Master of Science
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Wan, Kam Hung. "Optimal integrated transit network design /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202002%20WAN.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.Includes bibliographical references (leaves 92-95). Also available in electronic version. Access restricted to campus users.
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Geis, Susan R. "The global transportation network : the heart of in-transit visibility." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA361334.
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Tadikamalla, Veera Venkata Gopi Sai Krishna. "Transportation Network Analysis for Reliability Based on Path Failure Strategies." Thesis, California State University, Long Beach, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10639442.
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The transportation network is an essential component to provide a better transport service for both people and goods. Reliability, vulnerability, and robustness are the primary characteristics that can be used to analyze a transport network. The reliability of a transport network is defined as the possibility of moving people or goods from one place to another successfully. Exploring the reliability of a road network has attracted significant attention in the recent times due to increase in natural disasters. Such natural disasters not only damage the connections of the roadways but paralyze the transportation system for a remarkable period. However, the reliability of a transport network can be maintained by closely monitoring and ensuring the safety of critical paths in the network.
Critical paths of a transportation network are the most frequently used paths of that network. Road maintenance, car accidents that cause failure of independent paths or sub-networks have a severe impact on the reliability of the transportation network. Several methods exist to analyze the reliability of the transport network such as the concepts of connect reliability, and network reliability technique to monitor the current traffic status.
In this thesis, a robust network model is proposed;the implementation of this network model includes two approaches: selective path failure strategy, and random path failure strategy using the Betweenness Centrality Index as a metric. These strategies can successfully calculate the reliability and find the critical paths of the transportation network in California.UCINET, a simulation tool, is used to calculate reliability and find the critical paths of a transportation network. UCINET is a software package developed for the analysis of social network data. It comes with the NetDraw network visualization tool.
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Alshudukhi, Jalawi. "Fixed chain-based wireless sensor network for intelligent transportation systems." Thesis, Oxford Brookes University, 2016. https://radar.brookes.ac.uk/radar/items/339e8000-1a19-4363-a307-9df2456c2b27/1/.
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Wireless Sensor Networks (WSNs) are distributed and interconnected wirelessly sensors that are used in a variety of fields of our daily life, such as the manufacturing, utility operations and traffic monitoring. Many WSN applications come with some technical weaknesses and issues, especially when they are used in Intelligent Transportation Systems (ITS). For ITS applications that use a fixed chain topology which contains road studs deployed at ground level, there are some challenges related to radio propagation, energy constraints and the Media Access Control (MAC) protocol. This thesis develops a ground level radio propagation model for communication between road studs, and energy efficiency metrics to manage the resources to overcome the energy constraints, as well as a MAC protocol compatible with chain topology and ground level communication. For the challenges of the physical layer, this thesis investigates the use of a WSN for communicating between road-based nodes. These nodes are situated at ground level, and two-way wireless communication is required between the nodes and from the nodes to a roadside control unit. Field measurements have been carried out to examine the propagation close to the ground to determine the maximum distance between road-based nodes as a function of the antenna height. The results show that for a frequency of 2.4 GHz, a range of up to 8m is achievable with 2mW equivalent isotropically radiated power (EIRP). An empirical near-ground level radio propagation model has been derived, and the predicted results from this model are shown to match closely to the measured results. Since wireless sensor networks have power constraints, green energy efficiency metrics have been proposed for low-power wireless sensors operating at ground level. A numerical analysis is carried out to investigate the utilisation of the green energy efficiency metrics for ground level communication in wireless sensor networks. The proposed metrics have been developed to calculate the optimal sensor deployment, antenna height and energy efficiency level for the near ground wireless sensor. As an application of the proposed metrics, the relationship between the energy efficiency and the spacing between the wireless sensor nodes has been studied. The results provide guidance for energy efficient deployment of near ground level wireless sensors. To manage the communication between large numbers of nodes deployed on a chain topology, this research presents a time division multiple access (TDMA) MAC protocol that is specifically designed for applications requiring periodic sensing of the sensor field. Numerical analysis has been conducted to investigate the optimum transmission scheduling based on the signal-to-interference-plus-noise-ratio (SINR) for ground level propagation model applied on wireless chain topology. The optimised transmission schedule considers the SINR value to enable simultaneous transmission from multiple nodes. The most significant advantages of this approach are reduced delay and improved Packet Received Ratio (PRR). Simulation is performed to evaluate the proposed protocol for intelligent transport system applications. The simulation results validate the MAC protocol for a fixed chain topology compared with similar protocols.
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Bonsra, Kunal (Kunal Baldev), and Joseph Harbolovic. "Estimation of run times in a freight rail transportation network." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77458.
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Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 49-51).
The objective of this thesis is to improve the accuracy of individual freight train run time predictions defined as the time between departure from an origin node to arrival at a destination node not including yard time. A correlation analysis is conducted to identify explanatory variables that capture predictable sources of delay and influence run times for use in a regression model. A regression model is proposed utilizing the following explanatory variables: rolling historical average, congestion window, meets, passes, overtakes, direction, arrival headway, and departure headway to predict train run times. The performance of the proposed regression model is compared against a baseline simple historical averaging technique for a two year period of actual train operational data. The proposed regression model, though subject to specific limitations, offers substantial improvements in accuracy over the baseline technique and is recommended as justifying further exploration by the railroad to ultimately enable more accurate train schedules with subsequent improvements in railroad capacity, customer service, and asset utilization.
by Kunal Bonsra and Joseph Harbolovic.
M.Eng.in Logistics
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Yang, Xing. "Designing a transportation network for Mendoza, Argentina : a strategic approach." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43432.
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Kim, Daeki. "Large scale transportation service network design : models, algorithms and applications." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10366.
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Zhou, Tianli Ph D. Massachusetts Institute of Technology. "Network design for integrated vehicle-sharing and public transportation service." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99570.
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Thesis: S.M. in Transportation, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 81-83).
Vehicle sharing services have become a major urban transportation mode. One-way vehicle sharing service facilitates access to public transportation systems, thereby addressing the first and last mile challenges and creating an integrated vehicle-sharing and public transportation network providing origin-to-destination service. In this thesis we provide models and methods for design one-way vehicle-sharing networks. The location of one-way vehicle sharing stations strongly influence the level of travel time savings achieved by the users of the system. Our goal, then, is to select station locations so as to maximize the connectivity with the public transportation system, increase the accessibility to the urban area, reduce travel times, reduce congestion, and reduce emissions. We select a certain number of stations to install from a set of candidates whose locations are predetermined. In Chapter 2, we review existing literature in which the objective is to minimize total user travel cost. In Chapter 3, we propose a new model with the objective to design a network such that more users experience travel time savings that are sufficiently large to elicit mode shifts to the integrated public transportation option. We develop a decomposition procedure to solve our model and propose cut generation methods to expedite the solution process. Computational results in Chapter 4 show that our algorithm reduces solution times, while increasing the number of travelers who can experience travel time savings of significance by using our newly designed network. In Chapter 5, we propose a heuristic method to generate a network design with (near-) minimal total travel cost. Our decomposition method that searches in a neighborhood around the known best design, and changes the neighborhood center when improved solution are identified or expands the neighborhood if no better solution is found. Computational results show that our algorithm finds improved solutions, compared to existing approaches, for large-scale networks with imposed limits on computation time. In Chapter 6, we conclude the thesis and provide future research guidance.
by Tianli Zhou.
S.M. in Transportation
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Kim, WoonSoo. "Combined transportation network optimization and spatial allocation of pollution emissions /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487864485228177.
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Nilsson, Emily Michelle. "Seismic risk assessment of the transportation network of Charleston, SC." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22554.
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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.Committee Chair: Dr. Reginald DesRoches; Committee Member: Dr. Barry Goodno; Committee Member: Dr. Laurence Jacobs; Committee Member: Dr. Mulalo Doyoyo.
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Wong, Kum Leoung. "Network governance in US airport taxicab planning activities." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/61732/1/Kum%20Leoung_Wong_Thesis.pdf.
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This thesis examines the use of network governance in US airport transportation planning activities involving taxicab services for airport patrons. The research provides US airports with new insights whereby they can successfully engage with both transportation regulatory agencies and taxicab service providers in developing mutually agreeable policies that foster the development of supply-side taxicab service improvements. A mix of quantitative and qualitative research methods is used to unearth how US airports interact with these actors, and to identify attitudes held by airport staff in their engagements involving airport taxicab planning matters. The research may ultimately lead to the achievement of sustainable increases in the air passenger ground transportation modal share at US airports, resulting in both desirable long-term operational and environmental benefits for airport management, those involved with the provision of airport taxicab services, and the traveling public.
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Gill, Kuldeep S. "Cognitive Radio Connectivity for Railway Transportation Networks." Digital WPI, 2018. https://digitalcommons.wpi.edu/etd-theses/129.
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Reliable wireless networks for high speed trains require a significant amount of data communications for enabling safety features such as train collision avoidance and railway management. Cognitive radio integrates heterogeneous wireless networks that will be deployed in order to achieve intelligent communications in future railway systems. One of the primary technical challenges in achieving reliable communications for railways is the handling of high mobility environments involving trains, which includes significant Doppler shifts in the transmission as well as severe fading scenarios that makes it difficult to estimate wireless spectrum utilization. This thesis has two primary contributions: (1) The creation of a Heterogeneous Cooperative Spectrum Sensing (CSS) prototype system, and (2) the derivation of a Long Term Evolution for Railways (LTE-R) system performance analysis. The Heterogeneous CSS prototype system was implemented using Software-Defined Radios (SDRs) possessing different radio configurations. Both soft and hard-data fusion schemes were used in order to compare the signal source detection performance in real-time fading scenarios. For future smart railways, one proposed solution for enabling greater connectivity is to access underutilized spectrum as a secondary user via the dynamic spectrum access (DSA) paradigm. Since it will be challenging to obtain an accurate estimate of incumbent users via a single-sensor system within a real-world fading environment, the proposed cooperative spectrum sensing approach is employed instead since it can mitigate the effects of multipath and shadowing by utilizing the spatial and temporal diversity of a multiple radio network. Regarding the LTE-R contribution of this thesis, the performance analysis of high speed trains (HSTs) in tunnel environments would provide valuable insights with respect to the smart railway systems operating in high mobility scenarios in drastically impaired channels.
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Su, Qiankun. "Mobile data offloading via urban public transportation networks." Phd thesis, Toulouse, INPT, 2017. http://oatao.univ-toulouse.fr/19394/1/SU_Qiankun.pdf.
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Mobile data traffic is increasing at an exponential rate with the proliferation of mobile devices and easy access to large contents such as video. Traffic demand is expected to soar in the next 5 years and a new generation of mobile networks (5G) is currently being developed to address the looming bandwidth crunch. However, significant 5G deployments are not expected until 2020 or even beyond. As such, any solution that offloads cellular traffic to other available networks is of high interest, the main example being the successful offloading of cellular traffic onto WiFi. In this context, we propose to leverage public transportation networks (PTNs) created by regular bus lines in urban centers to create another offloading option for delay tolerant data such as video on demand. This PhD proposes a novel content delivery infrastructure where wireless access points (APs) are installed on both bus stops and buses. Buses act as data mules, creating a delay tolerant network capable of carrying content users can access while commuting using public transportation. Building such a network raises several core challenges such as: (i) selecting the bus stops on which it is best to install APs, (ii) efficiently routing the data, (iii) relieving congestion points in major hubs and (iv) minimizing the cost of the full architecture. These challenges are addressed in the three parts of this thesis. The first part of the thesis presents our content delivery infrastructure whose primary aim is to carry large volumes of data. We show that it is beneficial to install APs at the end stations of bus lines by analyzing the publicly available time tables of PTN providers of different cities. Knowing the underlying topology and schedule of PTNs, we propose to pre-calculate static routes between stations. This leads to a dramatic decrease in message replications and transfers compared to the state-of-the-art Epidemic delay tolerant protocol. Simulation results for three cities demonstrate that our routing policy increases by 4 to 8 times the number of delivered messages while reducing the overhead ratio. The second part of the thesis addresses the problem of relieving congestion at stations where several bus lines converge and have to exchange data through the AP. The solution proposed leverages XOR network coding where encoding and decoding are performed hop-by-hop for flows crossing at an AP. We conduct a theoretical analysis of the delivery probability and overhead ratio for a general setting. This analysis indicates that the maximum delivery probability is increased by 50% while the overhead ratio is reduced by 50%, if such network coding is applied. Simulations of this general setting corroborate these points, showing, in addition, that the average delay is reduced as well. Introducing our XOR network coding to our content delivery infrastructure using real bus timetables, we demonstrate a 35% - 48% improvement in the number of messages delivered. The third part of the thesis proposes a cost-effective architecture. It classifies PTN bus stops into three categories, each equipped with different types of wireless APs, allowing for a fine-grained cost control. Simulation results demonstrate the viability of our design choices. In particular, the 3-Tier architecture is shown to guarantee end-to-end connectivity and reduce the deployment cost by a factor of 3 while delivering 30% more packets than a baseline architecture. It can offload a large amount of mobile data, as for instance 4.7 terabytes within 12 hours in the Paris topology.
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Ma, Kunlei. "Spatial Analysis of Chinese Air Transportation." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1446546987.
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Lahkar, Paranjyoti. "Understanding Use of Transport Network Companies(TNC) in Virginia." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/83896.
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This study deals with a) Understanding familiarity with transportation network companies (TNCs) and their use frequency b) Understanding travel choices in alcohol-related situations in Virginia. Ordered logistic regression models were used to identify factors associated with the respondents perceived familiarity with transportation network companies (TNCs) and use frequency. Based on the two models, the consistent factors were using a mobile wallet, a cell phone for entertainment, an app for taxi services, or an app for hotel booking/air transport arrangements, living in Northern Virginia, normally using multiple transportation modes for a single trip, higher education levels, and higher household income which were associated with increased TNC familiarity and use frequency. Self-identifying as White/Caucasian was also associated with increased TNC use frequency. Increased age was associated with decreasing TNC familiarity and use frequency.
Subsequently, travel choices in alcohol related situations were studied with the objective of understanding the role of Transportation Network Companies (TNCs) in these situations and whether they have an impact on DUIs. For this objective, this study analyzes travel-choices associated with three scenarios alcohol related situations: (a) the last time the respondent consumed alcohol, (b) when avoiding driving after drinking, and (c) when avoiding riding with a driver who had been drinking. Multinomial Logistic Regression models were developed for all the three scenarios. For model (a), significant factors included use of a personal vehicle to arrive at the location where last consuming alcohol, being comfortable with having a credit card tied to a cell phone app, age, income, travelling alone when leaving the location where last consuming alcohol, having the highest educational attainment of high school graduate (GED), consumption of alcohol at bar/tavern/club, consumption of alcohol at home of friends/acquaintance place, and transportation network company (TNC – e.g., Uber, Lyft) weekly use frequency. For (b), use of a personal vehicle to arrive at the location where last consuming alcohol, consumption of alcohol at a bar/tavern/club, consumption of alcohol at the home of friends/acquaintance place, comfort with tying of credit card to apps, age, gender, income, multi-modal travel for a regular trip, TNC weekly use frequency, and use of an app for hotel reservations and/or air transportation arrangements are significant factors. For (c), use of a personal vehicle to arrive at the location where last consuming alcohol, walking to the location where last consuming alcohol, consumption of alcohol at a bar/tavern/club, comfort with tying a credit card to apps, age, income, TNC weekly use frequency, previously riding in a car with a driver who may have drunk too much to drive safely, and being employed full time are the significant factors.Master of Science
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Fang, Yi. "An urban traffic network model using GIS technology." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/845978.
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This creative project was proposed to develop a GIS model for transportation planning purposes with the ARC/INFO software. The urban street network in the GIS model was based on urban arterial systems in the city of Muncie, Indiana. The model was also expected to demonstrate the applicability of GIS technology in transportation planning. Several transportation planning techniques were tested with the model which included road and traffic data inventory, optimum pathing, road capacity analysis, traffic shift study modeling, and graphic presentation. The case study was targeted on road capacity analysis of urban arterial network as well as study of alternative traffic route for the urban route of State Road 32 in Muncie. The project began with an discussion of GIS technology, GIS application in planning, and ARC/INFO software programs. Then an urban street information model was developed in form of digital network in the computer database which could perform the functions of data inventory, spatial traffic analysis, and mapping manipulation. Finally the case studies were performed to demonstrate the application of this GIS network model. The findings and analysis results generated by GIS operation were used to evaluate the traffic conditions as well as to determine the feasibility of alternative route for State Road tables, ARC/INFO macro programs, traffic maps, and print-out of analysis results.Department of Urban Planning
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Shatnawi, Ibrahem Mahmoud. "Automated Vehicle Delay and Travel Time Estimation Techniques for Improved Performance Measures of Urban Network System." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1446473677.
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