65,267 research outputs found

    Desire to change one's multimodality and its relationship to the use of different transport means

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    Using data collected from French employees of a transportation institute and residents of the US San Francisco Bay Area, we operationalize a segmentation of mobility patterns based on objective, subjective, and desired amounts of mobility by various modes and overall. We especially focus on the degree of multimodality in an individual's current modal mix and desired changes to that mix through the use of a "multimodality index". The clusters that result showed some similarities and some differences across countries, where the latter are likely due to disparities in the sampling strategies and in the land use/transportation/cultural milieux. In both cases, however, the clusters have useful policy implications, enabling us, for example, to distinguish car users who might be inclined to reduce car use and increase transit use from those who are largely content with their current modal basket

    Accident Analysis and Prevention: Course Notes 1987/88

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    This report consists of the notes from a series of lectures given by the authors for a course entitled Accident Analysis and Prevention. The course took place during the second term of a one year Masters degree course in Transport Planning and Engineering run by the Institute for Transport Studies and the Department of Civil Engineering at the University of Leeds. The course consisted of 18 lectures of which 16 are reported on in this document (the remaining two, on Human Factors, are not reported on in this document as no notes were provided). Each lecture represents one chapter of this document, except in two instances where two lectures are covered in one chapter (Chapters 10 and 14). The course first took place in 1988, and at the date of publication has been run for a second time. This report contains the notes for the initial version of the course. A number of changes were made in the content and emphasis of the course during its second run, mainly due to a change of personnel, with different ideas and experiences in the field of accident analysis and prevention. It is likely that each time the course is run, there will be significant changes, but that the notes provided in this document can be considered to contain a number of the core elements of any future version of the course

    Benchmarking Distributed Stream Data Processing Systems

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    The need for scalable and efficient stream analysis has led to the development of many open-source streaming data processing systems (SDPSs) with highly diverging capabilities and performance characteristics. While first initiatives try to compare the systems for simple workloads, there is a clear gap of detailed analyses of the systems' performance characteristics. In this paper, we propose a framework for benchmarking distributed stream processing engines. We use our suite to evaluate the performance of three widely used SDPSs in detail, namely Apache Storm, Apache Spark, and Apache Flink. Our evaluation focuses in particular on measuring the throughput and latency of windowed operations, which are the basic type of operations in stream analytics. For this benchmark, we design workloads based on real-life, industrial use-cases inspired by the online gaming industry. The contribution of our work is threefold. First, we give a definition of latency and throughput for stateful operators. Second, we carefully separate the system under test and driver, in order to correctly represent the open world model of typical stream processing deployments and can, therefore, measure system performance under realistic conditions. Third, we build the first benchmarking framework to define and test the sustainable performance of streaming systems. Our detailed evaluation highlights the individual characteristics and use-cases of each system.Comment: Published at ICDE 201

    Tanzania Malaria Indicator Surveys 2001 - 2008:\ud Morbidity Indicators and Coverage of Major\ud Malaria Prevention and Control Interventions

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    Background\ud \ud Malaria continues to be a major public health problem in Africa. In Tanzania alone, thereare an estimated 17 to 20 million malaria cases per year resulting in approximately100,000 deaths. The main strategies to control malaria are vector control through insecticide treated nets (ITNs) and idoor residual spraying (IRS), intermittent preventive treatment during pregnancy (IPTp) and early diagnosis and prompt and effective treatment of cases. In 2001, the first Malaria Mid-Term Strategic Plan (MMTSP) was launched in Tanzania followed by the second MMTSP implemented in 2008. In order to evaluate the MMTSP, the NMCP conducted 4 cross-sectional community-based surveys in the years 2001, 2003, 2005 and 2008, as well as one survey collecting only malaria biomarkers in 2006. The findings of the latest survey are presented and analyzed in the present work.\ud \ud Methods\ud The NMCP 2008 malaria indicator survey was carried out in 21 malaria sentinel districts, one per region, in Mainland Tanzania. Demographic data of all household members and information on mosquito net availability and use was collected, as well as data on use of IPTp and prompt and effective treatment of fever in children. Further, malaria prevalence and haemoglobin levels were tested in children under the age of five years and in currently pregnant women. In the analysis, logistic regressions with the outcome variables net use, prevalence of malaria and anaemia, and linear regressions with the outcome haemoglobin level were conducted, using location, altitude, distance to health facility, sex and age group as explanatories.\ud \ud Data found in this work was compared with both, the Tanzania HIV/AIDS and Malaria Indicator Survey (THMIS) and the Tanzania National Insecticide Treated Nets Programme (NATNETS) survey (both conducted in 2008). Principle findings 8377 households were interviewed with a total population of 40,135. 65% of the households owned at least one mosquito net and 40% owned at least one ITN. Household net ownership was associated with location, altitude and distance to health facility. 42% of the population slept under a net the night before the survey and 27% under an ITN.\ud \ud Location, distance to health facility, sex and age group were significant determinants for net use. Among children under the age of five years, net use was found to be 49% for any net and 33% for ITN, while among pregnant women it was 47% for any net and 31% for ITN. Overall, household net ownership and personal net use increased over the survey years.\ud \ud Malaria and anaemia prevalence among children was 16.1% and 5.6%, respectively. Malaria prevalence was associated with location, altitude, age group and use of ITN, while anaemia prevalence was associated with altitude and age group. Both, prevalence of anaemia and malaria among children under five decreased between 2006 and 2008. 26% of the children reported to have had a fever during the past two weeks. 15% of these children received the first line antimalarial drug within 24 hours from onset. 76% of the women who had delivered during the two years prior to the survey used IPTp and 44% took at least two doses of SP as IPTp.\ud \ud Discussion\ud It was shown that increasing coverage of malaria prevention and control interventions is negatively correlated with malaria and anaemia prevalences, hence lower prevalences for both conditions. The results of the NMCP survey were similar to those of the THMIS and the NATNETS survey and were as well externally confirmed by other studies.\ud \u

    From Concept to Policy: Building Regional Innovation Systems in Follower Regions

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    In the spirit of “The Lisbon strategy”, public policies are redirecting support from investment-driven policies to knowledge building as the main driver for competitiveness and innovation. This re-orientation poses different challenges to regions and RIS concept may be the central element, simultaneously goal and toolbox, for devising innovation promotion policies. The RIS framework stresses the need to combine a systemic and inclusive view of innovation along with territorially embedded specificities. In this paper we explore how to operationalize the concept of RIS in terms of innovation policy, arguing against a “one size fits all” approach. Concentrating our analysis on follower regions, we bridge the concept of RIS with the structural deficiencies and challenges posing to this kind of regions, for which innovation policy should seek an adequate combination between science push and demand pull perspectives. We also address the importance of taking advantage of the catching-up status, building upon R&D cost-advantages and clustering around external initiatives as well as the correction of important constraints to the construction of a RIS.Innovation, Regional Innovation Systems, Innovation Policy, Follower Regions

    Spatial variations in road collision propensities in London

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    Propensity to be involved in a road traffic collision in Greater London is likely to depend on many factors, including personal mobility, lifestyle, behaviour, neighbourhood characteristics and environment. This paper seeks to identify in terms of geodemographic type the propensity of individuals to be involved in collisions and to examine geographic variations in such propensities with distance from Central London. Results for Central London suggest only a small number of Mosaic types portray a higher than average index score (over 100), translating into a higher risk for a smaller proportion of London’s geodemographic types. This contrasts with results which show a larger number of Mosaic classifications having higher than average index scores further from Central London. The results highlight a need, through enhanced spatial analysis, for better understanding of the spatially incidence of collisions which are putting at risk the lives of London residents
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