21,574 research outputs found

    A risk management system for sustainable fleet replacement.

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    This article analyzes the fleet management problem faced by a firm when deciding which vehicles to add to its fleet. Such a decision depends not only on the expected mileage and tasks to be assigned to the vehicle but also on the evolution of fuel and CO2 emission prices and on fuel efficiency. This article contributes to the literature on fleet replacement and sustainable operations by proposing a general decision support system for the fleet replacement problem using stochastic programming and conditional value at risk (CVaR) to account for uncertainty in the decision process. The article analyzes how the CVaR associated with different types of vehicle is affected by the parameters in the model by reporting on the results of a real-world case study

    Quantification of over-speed risk in wind turbine fleets

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    The effective life management of large and diverse fleets of wind turbines is a new problem facing power system utilities. More specifically, the minimization of over-speed risk is of high importance due to the related impacts of possible loss of life and economic implications of over-speed, such as a loss of containment event. Meeting the goal of risk minimization is complicated by the large range of turbine types present in a typical fleet. These turbines may have different pitch systems, over-speed detection systems and also different levels of functional redundancy, implying different levels of risk. The purpose of this work is to carry out a quantitative comparison of over-speed risk in different turbine configurations, using a Markov process to model detection of faults and repair actions. In the medium-long term, the risk associated with different assets can used as a decision making aid. For example if the operator is a utility, it may want to avoid purchasing high risk sites in the future, or may need to develop mitigation strategies for turbines at high risk of over speed

    No Californian Left Behind: Clean and Affordable Transportation Options for All Through Vehicle Replacement

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    As California focuses in on new, high-tech, best-in-class transportation strategies, it risks leaving behind an important subset of households and communities who could most benefit from the transition to a cleaner, cheaper, and more sustainable transportation future. Hundreds of thousands of low-income Californians, particularly those in rural parts of the state, live with some of the worst air pollution in the U.S. They also often drive relatively old, inefficient, unsafe, and highly polluting vehicles, and struggle to cover the costs of their basic transportation needs. For these Californians, getting into a relatively more efficient vehicle is more realistic than getting into a new electric vehicle, which is expensive, or onto public transit, which is often ineffective in serving rural and non-urban households.The state has recognized this problem and attempted to address it by focusing on vehicle repair and retirement programs. However, by merely repairing and retiring vehicles and not replacing them with cleaner, more efficient ones, existing programs do not maximize long-term air benefits or lessen the financial burden these inefficient vehicles currently place on low-income Californians. To help address this issue, Senate Bill 459, signed by Governor Brown in September 2013, directs the California Air Resources Board (ARB) to rewrite the guidelines of California's Enhanced Fleet Modernization Program (EFMP). This program has been in place since 2010, and is designed to allow residents who own the highest-emitting vehicles in the state to retire and/or replace them.In this report, we discuss the contribution made by these highly polluting vehicles to the state's air quality problems; we also discuss the serious drag that driving these vehicles can have on household budgets. After outlining these problems, we discuss the state's current policies aimed at promoting vehicle retirement and replacement and offer some recommendations for improving those programs.California is already a leader in advanced and high-tech transportation and transit solutions. It is time we also became a leader in pragmatic solutions for a population that is sometimes left behind in these discussions: non-urban, low-income, car-dependent households. Bringing solutions to these communities will have a huge impact on our current air quality and family budgets; it will also widen the circle of Californians who play an active part in moving this state toward a cleaner, less oil-dependent future

    Reviving Gujarat State Road Transport Corporation: An Agenda for Action

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    In this article, we examine in detail the reasons related to the declining operating and financial performance of Gujarat State Road Transport Corporation (GSRTC). The contribution of various environmental and governance issues related to the decline of GSRTC are identified. Based on the diagnosis, a detailed revival plan consisting of a set of actions to be undertaken by the management is proposed. The responsibilities of the government, the management, and the employees in implementing the revival plan are briefly discussed. This article concludes with set of strategic priorities that need to be examined by government in reviving GSTRC and other similar state-owned public utilities.

    Examining How Federal Infrastructure Policy Could Help Mitigate and Adapt to Climate Change: Hearing Before the H. Comm. on Transp. & Infrastructure, 116th Cong., Feb. 26, 2019 (Statement of Vicki Arroyo)

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    As the Fourth National Climate Assessment, released in November, describes, the United States is already experiencing serious impacts of climate change—and the risks to communities all across the country are growing rapidly. These findings, along with those in the 2018 Intergovernmental Panel on Climate Change (IPCC)report, are clear and should be a call to immediate action. Even if we manage to limit planetary warming to just 2 degrees C, the world will still face increased chances of economic and social upheaval from more severe flooding, droughts, heatwaves, and other climate impacts as well as devastating environmental consequences, the IPCC report warns. The scientific consensus as described in the IPCC Special Report is that countries around the world must rapidly decarbonize their economies, cutting greenhouse gas emissions in half by 2030 and to near zero by 2050. Yet the current trends are going in the wrong direction. Despite our increasing understanding of the narrowing window to act, U.S. GHG emissions increased by 3.4% in 2018, according to a January report from the Rhodium Group. Clearly more action is needed. The encouraging news is that many states and cities have committed to taking action. They are taking steps to reduce emissions through legislation, executive orders, and pledges made in collaborations such as the US Climate Alliance –now covering roughly half the US population and GDP. In my testimony, I will be focusing on the transportation sector, which is the largest contributor of GHG emissions in the United States, and is already facing significant impacts from climate change. Federal standards have been important in increasing efficiency and reducing emissions, yet transportation-sector emissions are increasing as more vehicle miles are driven, more freight is transported in trucks, and airline travel continues to grow. Transportation is becoming an increasingly large share of U.S. economy-wide emissions as the power sector decarbonizes as a result of market shifts and policy. There is an urgent need, therefore, to transition to a low-carbon transportation system. Such a transition would not only reduce emissions and fight climate change, it also would bring additional important benefits, including protecting public health by reducing conventional air pollution, providing more mobility options, and driving innovation and economic growth through policy action and through public and private investment

    Next stop: sustainable transport

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    Internal report cluster 1: Urban freight innovations and solutions for sustainable deliveries (1/4)

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    Technical report about sustainable urban freight solutions, part 1 of

    Vision and Objectives

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    The purpose of Industry Day is to exchange information with industry to increase understanding of the Government's current vision and objectives for the xEVA Production and Services Contract. The presentation provides industry with the opportunity to provide input into the xEVAPS procurement strategy and encourage offerors to submit questions and comments. A technical overview of the xEVA System serves as the foundation for the content related to draft requirements in the SOW
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