1,119 research outputs found
UNIETD – Assessment of Third Party Data as Information Source for Drivers and Road Operators
The paper deals with the assessment of third party data such as crowd sourced/social media and floating vehicle data as information source for road operators in addition to traditional infrastructure-based techniques. For purposes of quality assessment of different types of data and available ground truths existing test/evaluation methodologies have been assessed. A new methodology has been designed for assessment of speeds and travel times using normalized (between 0 and 1) quality indicators that can distinguish between “detection rate” and “false alarm rate” concepts. In terms of harvesting social media the relevance of social media content has been assessed against a range of traffic management requirements. Furthermore the level of content that will be available has been estimated as well as commercial sources and business models for road authorities. Analyses cover unstructured data from Twitter and Facebook both historical data and three months of contemporary data. In addition surveys are conducted in England and Austria to retrieve information from the public in terms of which social media platforms are commonly used to share information about traffic related incidents
Transport-Health Equity Outcomes from mobile phone location data - a case study
The digital media convergence has innovated all the information and communication channels. ICTs have adapted to the reticular structure, which can be interpreted as a paradigm of today's Network Society, invoking a reorganization of man-machine relationship, interpersonal interactions and the ways of collecting, processing and storing data. Political communication and its processes of participation are not exempt from this evident change. The aim of this paper is to investigate the transformation dynamics that have taken place through the Internet and social networks, as effectively more democratic tools that are able to stimulate a bottom-up and grassroots participation, in some respects a disintermediate participation compared to the typical unidirectionality of analogue media. In identifying the specific characteristics of the interaction spaces offered by the web, we have examined the digital campaign strategy devised by the political parties during the Italian general election (4th March 2018). The results have returned an unprecedented scenario, in which the social media strategy plays a leading role in the different dimensions of political marketing. The web is proposed to become the ideal social arena for the meeting between political offer and demand
Maternal diet and gut microbiome composition modulate early-life immune development.
In early life, the intestinal mucosa and immune system undergo a critical developmental process to contain the expanding gut microbiome while promoting tolerance toward commensals, yet the influence of maternal diet and microbial composition on offspring immune maturation remains poorly understood. We colonized germ-free mice with a consortium of 14 strains, fed them a standard fiber-rich chow or a fiber-free diet, and then longitudinally assessed offspring development during the weaning period. Unlike pups born to dams fed the fiber-rich diet, pups of fiber-deprived dams demonstrated delayed colonization with Akkermansia muciniphila, a mucin-foraging bacterium that can also use milk oligosaccharides. The pups of fiber-deprived dams exhibited an enrichment of colonic transcripts corresponding to defense response pathways and a peak in Il22 expression at weaning. Removal of A. muciniphila from the community, but maintenance on the fiber-rich diet, was associated with reduced proportions of RORγt-positive innate and adaptive immune cell subsets. Our results highlight the potent influence of maternal dietary fiber intake and discrete changes in microbial composition on the postnatal microbiome assemblage and early immune development
Two-Dimensional Hydrodynamics of Pre-Core Collapse: Oxygen Shell Burning
By direct hydrodynamic simulation, using the Piecewise Parabolic Method (PPM)
code PROMETHEUS, we study the properties of a convective oxygen burning shell
in a SN 1987A progenitor star prior to collapse. The convection is too
heterogeneous and dynamic to be well approximated by one-dimensional
diffusion-like algorithms which have previously been used for this epoch.
Qualitatively new phenomena are seen.
The simulations are two-dimensional, with good resolution in radius and
angle, and use a large (90-degree) slice centered at the equator. The
microphysics and the initial model were carefully treated. Many of the
qualitative features of previous multi-dimensional simulations of convection
are seen, including large kinetic and acoustic energy fluxes, which are not
accounted for by mixing length theory. Small but significant amounts of
carbon-12 are mixed non-uniformly into the oxygen burning convection zone,
resulting in hot spots of nuclear energy production which are more than an
order of magnitude more energetic than the oxygen flame itself. Density
perturbations (up to 8%) occur at the `edges' of the convective zone and are
the result of gravity waves generated by interaction of penetrating flows into
the stable region. Perturbations of temperature and electron fraction at the
base of the convective zone are of sufficient magnitude to create angular
inhomogeneities in explosive nucleosynthesis products, and need to be included
in quantitative estimates of yields. Combined with the plume-like velocity
structure arising from convection, the perturbations will contribute to the
mixing of nickel-56 throughout supernovae envelopes. Runs of different
resolution, and angular extent, were performed to test the robustness of theseComment: For mpeg movies of these simulations, see
http://www.astrophysics.arizona.edu/movies.html Submitted to the
Astrophysical Journa
Implementation Effects and Integration evaluation of a Selection of Transport Management Measures in Beijing
With the serious urban transport challenges that rapid motorization and growth in travel demand for the city of Beijing have brought, the design and implementation of efficient and equitable urban transport polices has become essential to achieve sustainable development targets. This paper investigates a selection of transport management measures that were introduced following the Beijing 2008 Olympic and Paralympic Games. These include priority development of mass transit systems, private car ownership measures, a staggered rush hour plan, modified charging policies for parking and car restrictions based on license plate numbers. Effects of these measures with respect to growth in vehicle and trip numbers are summarized, then qualitatively evaluated within a proposed framework that covers in one dimension equity and efficiency and in another, social, economic and environmental aspects of transport sustainability. The evaluation process is intended to firstly shed light on the effects of transport management measures according to different sustainability dimensions and secondly to support policymakers involved in the practical design of future transport management measures for Beijing and similar city contexts
Effects of a tradable credits scheme on mobility management: a household utility based approach incorporating travel money and travel time budgets
We investigate the influence of a new mobility management measure, the tradable credits scheme (TCS), on the daily travel mode choices of individuals. Generally, we assume the individuals’ travel consists of different modes, e.g. private car mode and mass transit mode. In order to control the rapid increase in use of the private car mode in an area, policy makers may wish to implement a TCS basing on the vehicle kilometre travelled (VKT). The effects of the TCS are investigated in this paper based on a utility-theory travel demand model proposed by Golob et al. (1981), a household utility based model incorporating proposed travel money and travel time budgets. The empirical investigation is based on comparison studies of the short-term response and long-term effects with and without TCS. It finds that the implementation of TCS has not a clear impact to the value of time of household in the short-term, and the presence of TCS does not affect the linear relationship between travel time budget and travel money budget over long term. Numerical results demonstrate that the TCS will affect the travel distance of the available transport modes differentially, according to different levels of annual household income
Does the Use of E-Scooters Bring Well-Being Outcomes for the User?: A Study Based on UK Shared E-Scooter Trials
E-scooters are a relatively new mode of travel in the UK and their impacts on physical and mental health are uncertain. Although their use does not involve physical activity directly, through walking or cycling, they might provide other well-being benefits. Such effects will likely vary according to the user and the context. We aim to assess whether use of shared e-scooters is associated with wider well-being and mental health, arising for example from for example access to local services, exposure to the natural environment, reduced stress, and a perception of having done some exercise. Our secondary question is whether potential well-being impacts vary across population sub-groups. A total of 2,402 responses to an online survey completed during a one-month period (August to September 2021) by shared e-scooters users operated by a sole UK provider. Personal well-being from e-scooter use was assessed using questions on general levels of stress and mood (before, during or after e-scooter journeys), and features of the journey such as exposure to the natural environment and perception of air quality. All well-being questions were reported using a five-point Likert scale. Analysis indicates that people with protected characteristics and those who have personal challenges, for example with respect to personal mobility, are more likely to incur well-being benefits. The results presented are part of on-going research, with the next steps being to measure changes over time. The findings may be of interest to policymakers and the research community
Car use: Intentional, habitual or both? Insights from Anscombe and the mobility biography literature.
Policy-makers have recognised that changing travel behaviour is important. People however do not change their behaviour so readily, particularly the use of the car. A central concept that has been invoked to account for this has been the concept of habit, however, various studies also present people as having concrete reasons for driving: their choices are intentional. This interdisciplinary study attempts to reconcile these two understandings of travel behaviour by drawing on insights from the philosopher Anscombe and a growing body of travel research termed the mobility biography literature. It applies some of Anscombe’s insights from Intention to the act of driving. With regard to the mobility biography literature, it draws out conceptual implications both from theoretical and empirical aspects: in particular, the characterisation of travel decisions as nested in a hierarchy of life decisions and the association of life events with changes in travel decisions. It concludes that a broader conceptualisation of human behaviour leads to a broader view as to what policy-makers can do. It reminds us that transport is ‘special’, that transport and policy are inextricable, and the importance of infrastructure provision should not be ignored
Estimating the social and spatial impacts of Covid mitigation strategies in United Kingdom regions: synthetic data and dashboards
This study advances understanding of the broader social and spatial impacts of COVID-19 restrictive measures, particularly how they may have impacted individuals and households and, in turn, the geographic areas in which these individuals and households are concentrated. Data are combined and linked to a novel individual-level synthetic dataset and an interactive dashboard is developed to assist with the identification and understanding of the social and spatial impacts of restrictions. To illustrate the utility of this approach, the analysis focuses on the impact of three restrictions within a defined spatial area: Yorkshire and Humberside (UK). Results highlight the additive nature of restriction impacts and suggest areas that may have the least future resilience as policy priority areas. This approach is transferable to other regions and the use of the dashboard allows rapid consideration and communication of the social and spatial nature of inequalities to researchers, practitioners and the general public
- …