777 research outputs found

    From Buses to BRT: Case Studies of Incremental BRT Projects in North America, MTI Report 09-13

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    Bus Rapid Transit (BRT) uses different combinations of techniques to improve service, such as bus-only lanes and roads, pre-boarding fare collection, transit priority at traffic signals, stylish vehicles with extra doors, bus stops that are more like light rail stations, and high frequency service. This study examines five approaches to BRT systems as implemented by public transit agencies in California, Oregon, and Ontario. The case studies as a group show that BRT can be thought of as a discretionary combination of elements that can be assembled in many different combinations over time. Every element incrementally adds to the quality or attractiveness of the service. This latitude provides transit agencies with many benefits, including the ability to match infrastructure with operating requirements. For example, a BRT service can combine operations serving free flowing arterial roads in the fringes of the downtown with dedicated lanes in areas closer to city center where congestion is greatest. Buses can operate both on and off the guide way, extending the corridors in which passengers are offered a one-seat ride with no transfer required. Transit agencies also can select specific BRT components and strategies, such as traffic signal priority and increased stop spacing, and apply them to existing local bus operations as a way to increase bus speeds and reduce operating costs. The specific elements selected for a BRT route can be implemented all at once, or in incremental stages either or both geographical extensions or additions of features. All of the case studies showed ridership improvements, but the Los Angeles Metro Rapid bus system illustrates the wide geographic coverage, improved ridership, and moderate cost per new rider that is possible with an approach that includes fewer BRT features spread over more miles of route. Quantitative results from the case studies suggest that incremental improvements, applied widely to regional bus networks, may be able to achieve significant benefits at a lower cost than substantial infrastructure investments focused upon just one or a few corridors

    A Method for Rapid Determination of the Icing Limit of a Body in Terms of the Stream Conditions

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    The effects of existing frictional heating were analyzed to determine the conditions under which ice formations on aircraft surfaces can be prevented. A method is presented for rapidly determining by means of charts the combination of-Mach number, altitude, and stream temperature which will maintain an ice-free surface in an icing cloud. The method can be applied to both subsonic and supersonic flow. The charts presented are for Mach numbers up to 1.8 and pressure altitudes from sea level to 45,000 feet

    The sale and shipment of coal

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    The Coal Industry in South Africa exported 54,5 million tons in 1993, providing R4,2 billion in export revenues, second only to gold. Apart from small parcels of coal exported through Durban and Maputo, coal is exported through the Richards Bay Coal Terminal. As new producers such as Indonesia, Columbia and China enters the International Market, equally (and sometimes better) placed than South Africa to penetrate markets in Europe and the Far East, the South African Coal Industry cannot afford to damage its' competitive position through accusations of "hot coal" problems. In this thesis, the phenomenon of spontaneous healing, combustion and methane emission from coal cargoes, will be discussed, and the F.O.B. sales of coal will be commented upon

    Six year clinical study of use of the Omniscience valve prosthesis in 219 patients

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    A 6 year experience of cardiac valve replacement with the Omniscience prosthesis is described. A total of 253 valves were inserted in 219 patients. The survivors were followed up for a total of 536 patient-years and for a mean of 2.8 years. The follow-up was 97.6% complete. Analyses were performed in accordance with recommended criteria regarding definitions of complications and grading thromboembolic events for severity and analysis of anticoagulant status. Results are described both in terms of actuarial and linearized rates.For the patients at risk, actuarial survival at the end of 5 years was 87.9 ± 3.1% overall, 90.4 ± 3.0% for single valve (aortic 88 ± 5%, mitral 93.3 ± 4%) replacement and 71 ± 11% for multiple valve replacement. The actuarial rates of freedom from complications were as follows: endocarditis 95.7 ± 1.8% (aortic 94 ± 3.5%, mitral 100%), periprosthetic leak 98 ± 1% (aortic 96.2 ± 2.6%, mitral 100%), thromboembolism 95.2 ± 2.3% (aortic 90.9 ± 4.6%, mitral 96.7 ± 3.3%), valve thrombosis 98.7 ± 0.9% (aortic 100%, mitral 100%), anticoagulant-induced bleeding 90.3 ± 2.6% and all valve-related complications 79.4 ± 3.6% (aortic 78.8 ± 3.6%, mitral 85.9 ± 4.5%). the functional improvement in patients was very satisfactory and the risk of reoperation was 1.1% per patient-year. Over a 6 year time frame, the Omniscience valve has given excellent clinical performance

    Joint Total Variation ESTATICS for Robust Multi-Parameter Mapping

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    Quantitative magnetic resonance imaging (qMRI) derives tissue-specific parameters -- such as the apparent transverse relaxation rate R2*, the longitudinal relaxation rate R1 and the magnetisation transfer saturation -- that can be compared across sites and scanners and carry important information about the underlying microstructure. The multi-parameter mapping (MPM) protocol takes advantage of multi-echo acquisitions with variable flip angles to extract these parameters in a clinically acceptable scan time. In this context, ESTATICS performs a joint loglinear fit of multiple echo series to extract R2* and multiple extrapolated intercepts, thereby improving robustness to motion and decreasing the variance of the estimators. In this paper, we extend this model in two ways: (1) by introducing a joint total variation (JTV) prior on the intercepts and decay, and (2) by deriving a nonlinear maximum \emph{a posteriori} estimate. We evaluated the proposed algorithm by predicting left-out echoes in a rich single-subject dataset. In this validation, we outperformed other state-of-the-art methods and additionally showed that the proposed approach greatly reduces the variance of the estimated maps, without introducing bias.Comment: 11 pages, 2 figures, 1 table, conference paper, accepted at MICCAI 202

    G20 2014: the G20 Brisbane Summit, inequality, energy and anti-corruption

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    The 12th edition of the G20 monitor contains an overview from John Lipsky on the G20’s role in global governance after the global financial crisis; a paper by Geoff Weir on the G20, Thomas Piketty, and inequality; thoughts from Hugh Jorgensen and Christian Downie on multilateral energy governance; and a piece by Charles Sampford on integrity and anti-corruption. Key findings Lipsky suggests the Brisbane Summit is a critical moment for the G20, if it does not restore a sense of political momentum to the process, the G20’s relevance will wane Ever-growing inequality is inconsistent with the maintenance of an inclusive, democratic system of governance. The G20 should consider a combination of taxation, education and health reforms to reduce inequality. The world needs better multilateral energy governance. Whether the conditions exist for the G20 to remedy this problem is unclear, but members should pursue energy governance mechanisms that promote trust

    Interpreting the Labour Party: Approaches to Labour politics and history

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    Interpreting the Labour Party consists of twelve essays on some of the principal thinkers and schools of thought concerned with the political and historical development of the Labour Party and the wider labour movement. It examines the major methodologies and approaches in Labour studies and critically evaluates much of the most interesting scholarship in this area of study. The essays are written by contributors who have devoted many years to the study of the Labour Party, the trade union movement and the various ideologies associated with them. The collection begins with chapters that examine Labour's ideological journey and assess the impact of the "new political history" on views of the party. Later contributions focus on how the problematic concept of "Labourism" has been applied to the party by the New Left and analyse how Labour's union link has been conceptualised. Key thinkers analysed include Henry Pelling, Ross McKibbin, Ralph Miliband, Lewis Minkin, David Marquand, Perry Anderson and Tom Nairn. Each chapter situates its subject matter in the context of a broader intellectual legacy, including the works of Sidney and Beatrice Webb, Theodore Rothstein, Stuart Hall and Samuel Beer, among others. The book will be of interest to undergraduate students of British politics and political theory, and to academics concerned with Labour politics and history, trade union history and politics, research methodology and political analysis
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