14,007 research outputs found

    Assessment of different urban traffic control strategy impacts on vehicle emissions

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    This paper investigates the influence of traffic signal control strategy on vehicle emissions, vehicle journey time and total throughput flow within a single isolated four-armed junction. Two pre-timed signal plans are considered, one with two-stages involving permissive-only opposing turns and the other with four-stages which has no conflicting traffic. Additionally, the increase in efficiency by utilising actuated signal timing where green time is re-optimised as flow values vary is investigated. A microscopic traffic simulation model is used to model flows and AIRE (Analysis of Instantaneous Road Emissions) microscopic emissions model is utilised to out- put emission levels from the flow data. A simple junction model shows that the two-stage signal plan is more efficient in both emis- sions and journey time. However, as the level of opposed turning vehicles and conflicting movement increases, the two-stage model moves to being the inferior signal plan choice and the four-stage plan outputs fewer emissions than the two-stage plan. A real-world example of a four-armed junction has been used in this study and from the traffic survey data and existing junction layout; it is rec- ommended that a two-stage plan is used as it produces lower amounts of emissions and shorter journey times compared to a four-stage plan. The results also show that nitrogen oxides (NOx) are the most sensitive to changes in flow followed by carbon dioxide (CO2), Black Carbon and then particulate matter (PM10)

    From Anti-equilibrium to The Socialist System and Beyond

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    This essay attempts to understand János Kornai’s works from a political economy perspective. It argues that Kornai has significantly contributed to the formation of a new paradigm of political economy. The main endeavor of Kornai has been the combination of analytical concepts of economics with the empirical description of real economies. After a certain period of theoretical experimentation János Kornai formulated his research program that can be called the shortage economy explanation of the socialist system. The Economics of Shortage and The Socialist System have created a new theoretical paradigm in a framework in which it has become possible to establish a connection between the analytical and empirical, universal and historical aspects of the theory studying the socialist system as a real economic entity. János Kornai has built his analysis of the socialist system on the primary role of politics in the creation of economic institutions. In his present work on capitalism he has extended this thesis to the capitalist system. This seems to be an important contribution of his to a new political economy paradigm that is just in the process of formation

    Energy-balance climate models

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    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed

    Tackling concentrated worklessness: integrating governance and policy across and within spatial scales

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    Spatial concentrations of worklessness remained a key characteristic of labour markets in advanced industrial economies, even during the period of decline in aggregate levels of unemployment and economic inactivity evident from the late 1990s to the economic downturn in 2008. The failure of certain localities to benefit from wider improvements in regional and national labour markets points to a lack of effectiveness in adopted policy approaches, not least in relation to the governance arrangements and policy delivery mechanisms that seek to integrate residents of deprived areas into wider local labour markets. Through analysis of practice in the British context, we explore the difficulties of integrating economic and social policy agendas within and across spatial scales to tackle problems of concentrated worklessness. We present analysis of a number of selected case studies aimed at reducing localised worklessness and identify the possibilities and constraints for effective action given existing governance arrangements and policy priorities to promote economic competitiveness and inclusion

    Social inequalities in the demand, supply and utilisation of psychological treatment

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    Introduction: Socioeconomic deprivation is associated with higher prevalence of mental disorders but poor access to care. We conducted a national workforce survey to examine the demand, supply and utilisation of primary care psychological services. Aim: To understand the variability in the rates of access to psychological care in different geographical areas. Method: This was a cross-sectional survey of Improving Access to Psychological Therapies (IAPT) services. Data were collected from 144 services covering 180 local areas in England, using a freedom of information request. The access gap (AG) was defined as the percentage of cases that did not receive treatment, from the wider pool of cases referred for psychological care. We examined correlations between the demand (number of referrals), and supply (workforce size) of psychological care with local area prevalence rates of common mental disorders and the index of multiple deprivation (IMD). Regression analyses were used to assess if the variability in AG may be explained by IMD and workforce size, controlling for local population statistics. Results: Workforce size was weakly correlated with the IMD (r = 0.16, p = 0.04) and prevalence rates (r = 0.16, p = 0.03). The AG was significantly associated with IMD, number of referrals, prevalence rates and treatment waiting times, but not with workforce size. Together, these variables explained approximately 26% of variance in the AG. Conclusions: Socioeconomic deprivation is associated with psychological service utilisation, irrespective of the demand–supply function, particularly when contrasting the poorest and most affluent areas

    Empirical constraints on vacuum decay in the stringy landscape

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    It is generally considered as self evident that the lifetime of our vacuum in the landscape of string theory cannot be much shorter than the current age of the universe. Here I show why this lower limit is invalid. A certain type of ``parallel universes'' is a necessary consequence of the string-landscape dynamics and might well allow us to ``survive'' vacuum decay. As a consequence our stringy vacuum's lifetime is empirically unconstrained and could be very short. Based on this counter-intuitive insight I propose a novel type of laboratory experiment that searches for an apparent violation of the quantum-mechanical Born rule by gravitational effects on vacuum decay. If the lifetime of our vacuum should turn out to be shorter than 6 x 10^{-13} seconds such an experiment is sufficiently sensitive to determine its value with state-of-the-art equipment.Comment: 13 pages, 2 figures, proposes a laboratory experimen

    Can music move people? : The effects of musical complexity and silence on waiting time

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    Previous research has suggested that music might influence the amount of time for which people are prepared to wait in a given environment. In an attempt to investigate the mechanisms underlying such effects, this study employed three levels of musical complexity and also a “no-music” condition. While one of these played in the background, participants were left to wait in a laboratory for the supposed start of an experiment. The results indicated that participants waited for the least amount of time during the no-music condition, and that there were no differences between the three music conditions. Other evidence indicated that this may be attributable to the music distracting participants’ attention from an internal timing mechanism. The results are discussed in terms of their implications for consumer behavior and research on the psychology of everyday life

    Does rotation of B stars depend on metallicity? preliminary results from GIRAFFE spectra

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    We show the vsini distribution of main sequence B stars in sites of various metallicities, in the absolute magnitude range -3.34 < Mv < -2.17. These include Galactic stars in the field measured by Abt et al. (2002), members of the h & chi Per open clusters measured by North et al. (2004), and five fields in the SMC and LMC measured at ESO Paranal with the FLAMES-GIRAFFE spectrograph, within the Geneva-Lausanne guaranteed time. Following the suggestion by Maeder et al. (1999), we do find a higher rate of rapid rotators in the Magellanic Clouds than in the Galaxy, but the vsini distribution is the same in the LMC and in the SMC in spite of their very different metallicities.Comment: 2 pages, 1 figure, poster presented at the ESO/Arcetri Workshop on "Chemical abundances and mixing in stars in the Milky Way and its satellites", 13-17 Sept. 200
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