44 research outputs found

    Extending a microsimulation of the Port of Dover

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    Modelling and simulating the traffic of heavily used but secure environments such as seaports and airports is of increasing importance. This paper discusses issues and problems that may arise when extending an existing microsimulation strategy. This paper discusses the simulations and how extensions of these simulations can aid planners with optimal physical and operational feedback. Conclusions are drawn about how microsimulations can be moved forward as a robust planning tool for the 21st century

    Masterplanning at the Port of Dover: The Use of Discrete-Event Simulation in Managing Road Traffic

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    The Port of Dover is Europe’s busiest ferry port, handling £119 billion or 17% of the UK’s annual trade in goods. The Port is constrained geographically to a small area and faces multiple challenges, both short- and long-term, with managing the flow of five million vehicles per year to/from mainland Europe. This article describes some of the work that the Port is doing to minimize the impact of port road traffic on the local community and environment using discrete-event simulation modeling. Modeling is particularly valuable in identifying where future bottlenecks are likely to form within the Port due to projected growth in freight traffic and comparing the effectiveness of different interventions to cope with growth. One of our key findings is that space which can be used flexibly is far more valuable than dedicated space. This is supported by the much greater reduction in traffic congestion that is expected to be achieved given a 10% increase in freight traffic by reallocating space at the front of the system to temporarily hold vehicles waiting to pass through border control and check-in compared to extending the amount of space for ferry embarkation at the rear of the system. The importance of flexible space has implications for port design that can be applied more broadly. Modeling is also useful in identifying critical thresholds for vehicle processing times that would cause the system to become overwhelmed. Increasing the check-in time by just three to five minutes, for example, would completely exceed the Port’s capacity and produce indefinite queueing. This finding has important implications for Brexit planning. From a wider context, the research presented here nicely illustrates how simulation can be used to instill more evidence-based thinking into port masterplanning and support “green port” and other corporate sustainability initiatives

    Toward composing variable structure models and their interfaces: a case of intensional coupling definitions

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    In this thesis, we investigate a combination of traditional component-based and variable structure modeling. The focus is on a structural consistent specification of couplings in modular, hierarchical models with a variable structure. For this, we exploitintensional definitions, as known from logic, and introduce a novel intensional coupling definition, which allows a concise yet expressive specification of complex communication and interaction patterns in static as well as variable structure models, without the need to worryabout structural consistency.In der Arbeit untersuchen wir ein Zusammenbringen von klassischer komponenten-basierter und variabler Strukturmodellierung. Der Fokus liegt dabei auf der Spezifikation von strukturkonsistenten Kopplungen in modular-hierarchischen Modellen mit einer variablen Struktur. DafĂŒr nutzen wir intensionale Definitionen, wie sie aus der Logik bekannt sind, und fĂŒhren ein neuartiges Konzept von intensionalen Kopplungen ein, welches kompakte gleichzeitig ausdrucksstarke Spezifikationen von komplexen Kommunikations- und Interaktionsmuster in statischen und variablen Strukturmodellen erlaubt

    Efficient Automated Driving Strategies Leveraging Anticipation and Optimal Control

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    Automated vehicles and advanced driver assistance systems bring computation, sensing, and communication technologies that exceed human abilities in some ways. For example, automated vehicles may sense a panorama all at once, do not suffer from human impairments and distractions, and could wirelessly communicate precise data with neighboring vehicles. Prototype and commercial deployments have demonstrated the capability to relieve human operators of some driving tasks up to and including fully autonomous taxi rides in some areas. The ultimate impact of this technology’s large-scale market penetration on energy efficiency remains unclear, with potential negative factors like road use by empty vehicles competing with positive ones like automatic eco-driving. Fundamentally enabled by historic and look-ahead data, this dissertation addresses the use of automated driving and driver assistance to optimize vehicle motion for energy efficiency. Facets of this problem include car following, co-optimized acceleration and lane change planning, and collaborative multi-agent guidance. Optimal control, especially model predictive control, is used extensively to improve energy efficiency while maintaining safe and timely driving via constraints. Techniques including chance constraints and mixed integer programming help overcome uncertainty and non-convexity challenges. Extensions of these techniques to tractor trailers on sloping roads are provided by making use of linear parameter-varying models. To approach the wheel-input energy eco-driving problem over generally shaped sloping roads with the computational potential for closed-loop implementation, a linear programming formulation is constructed. Distributed and collaborative techniques that enable connected and automated vehicles to accommodate their neighbors in traffic are also explored and compared to centralized control. Using simulations and vehicle-in-the-loop car following experiments, the proposed algorithms are benchmarked against others that do not make use of look-ahead information

    The Impact of Electric Cars on Oil Demand and Greenhouse Gas Emissions in Key Markets

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    This thesis explores the extent to which electric cars might reduce oil demand and greenhouse gas emissions in key markets: China, France, Germany, India, Japan and the United States. To meet this objective, a dynamic model capable of simulating the market evolution of nine powertrain technologies between 2000 and 2030 is developed. The model consists of an econometric sub-model, soft-linked with a system dynamics sub-model. The purpose of the time-series econometric sub-model is to project country-specific total car stock. To this end, six single-equation regressions based on autoregressive integrated moving average or autoregressive distributed-lag techniques are estimated. The purpose of the system dynamics sub-model is to represent feedback processes and facilitate policy analysis. The effects of six policy measures are examined: emission standards, energy taxation, electric car purchase subsidies, investment in recharging stations, investment in hydrogen refuelling infrastructure and desired car occupancy. The dynamic hypothesis of the model captures feedback loops that may stimulate the market development of electric cars. The six countries are interlinked to simulate technological progress concerning the electric vehicle battery. In particular, its cost, price and capacity, together with the resulting electric range of the car, are investigated. Two scenarios are constructed: under the Alternative Scenario, the market uptake of electric cars is faster due to a favourable policy package. This leads to a decline in oil demand and direct greenhouse gas emissions as well as to an increase in electricity demand from cars compared to the Reference Scenario. The methodological linkage of econometrics and system dynamics, together with the endogenisation of the electric vehicle battery price evolution by explicitly modelling six major car markets, is the main contribution of this study. Its major limitations prompt further research on the representation of supply-side aspects (i.e. battery and vehicle manufacturers) using alternative methods such as agent-based modelling

    Senate journal, 7 June 2001.

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    Titles and imprints vary; Some volumes include miscellaneous state documents and reports; Rules of the Senat

    Methods and Measures for Analyzing Complex Street Networks and Urban Form

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    Complex systems have been widely studied by social and natural scientists in terms of their dynamics and their structure. Scholars of cities and urban planning have incorporated complexity theories from qualitative and quantitative perspectives. From a structural standpoint, the urban form may be characterized by the morphological complexity of its circulation networks - particularly their density, resilience, centrality, and connectedness. This dissertation unpacks theories of nonlinearity and complex systems, then develops a framework for assessing the complexity of urban form and street networks. It introduces a new tool, OSMnx, to collect street network and other urban form data for anywhere in the world, then analyze and visualize them. Finally, it presents a large empirical study of 27,000 street networks, examining their metric and topological complexity relevant to urban design, transportation research, and the human experience of the built environment.Comment: PhD thesis (2017), City and Regional Planning, UC Berkele

    The Impact of Electric Cars on Oil Demand and Greenhouse Gas Emissions in Key Markets

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    This book explores the extent to which electric cars might reduce oil demand and greenhouse gas emissions in key markets: China, France, Germany, India, Japan and the United States. The developed model consists of an econometric sub-model, soft-linked with a system dynamics sub-model. The model captures feedback loops that may stimulate the market development of electric cars. The six countries are interlinked to simulate technological progress concerning the electric vehicle battery

    "Destitution in the UK 2020" - Technical Report

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    Ten Years of the Agnes Kirsopp Lake Michels Lectures at Bryn Mawr College

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    Table of Contents 1. Marriage and Motherhood in Roman Egypt, Bruce W. Frier2. The Roman Version, W.V. Harris 3. Flora and the Sibyl, Robert Palmer 4. Horace 3.23: Ritual and Art, Michael C.J. Putnam 5. Founding the City, Jerzy Linderski 6. Case Study I: Tullia, Susan Treggiari 7. Thucydides the Prehistorian, Jeffrey Rusten8. Dryden\u27s Virgil and the Politics of Translation, Richard F. Thomas9. The Occasion of Thucydides\u27 History of the Peloponnesian War, Mark Munn 10. Mea Tempora: Patterning of Time in the Metamorphoses, Denis Feeneyhttps://repository.brynmawr.edu/bmc_books/1007/thumbnail.jp
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