77,463 research outputs found

    Regional environmental efficiency and economic growth: NUTS2 evidence from Germany, France and the UK

    Get PDF
    This paper by applying nonparametric techniques measures spatial environmental heterogeneities of 98 regions from Germany, France and the UK. Specifically environmental performance indexes are constructed for the 98 regions (NUTS 2 level) identifying their ability to produce higher growth rates and reduce pollution (in the form of municipal waste) generated from regional economic activity. By applying conditional stochastic kernels and local constant estimators it investigates the regional economic activity – environmental quality relationship. The results indicate several spatial environmental heterogeneities among the examined regions. It appears that regions with higher GDP per capita levels tend to have higher environmental performance.Regional environmental efficiency; directional distance function; conditional stochastic kernel; nonparametric regression

    Stochastic transition model for pedestrian dynamics

    Full text link
    The proposed stochastic model for pedestrian dynamics is based on existing approaches using cellular automata, combined with substantial extensions, to compensate the deficiencies resulting of the discrete grid structure. This agent motion model is extended by both a grid-based path planning and mid-range agent interaction component. The stochastic model proves its capabilities for a quantitative reproduction of the characteristic shape of the common fundamental diagram of pedestrian dynamics. Moreover, effects of self-organizing behavior are successfully reproduced. The stochastic cellular automata approach is found to be adequate with respect to uncertainties in human motion patterns, a feature previously held by artificial noise terms alone.Comment: preprint for Pedestrian and Evacuation Conference (PED2012) contributio

    Impacts of environmental regulations on the efficiency of arable farms in France and Germany

    Get PDF
    This paper develops a methodology for asymmetric treatment of desirable and undesirable outputs. First, a hyperbolic output efficiency measurement is used to describe a middle term transformation of production processes where producers try to improve their competitiveness together with a reduction of the negative impact on the environment. Second, a radial efficiency measurement, called directional output distance function, is used to depict a long-term transformation of the production process. A non-parametric Data Envelopment Analysis (DEA) and a Stochastic Frontier Analysis (SFA) are used to evaluate the impact of agricultural policy changes, both in France and Germany, on the technical and environmental efficiency of arable farms, taking into account participation or not in agri-environmental programs. The results from both methods indicate only limited possibilities for environmental improvements, mainly for farms participating in agri-environmental programs.Frontier analysis, technical and environmental efficiency, environmental regulations, Agricultural and Food Policy, Environmental Economics and Policy, Productivity Analysis,

    Stochastic Geometry Modeling and Performance Evaluation of mmWave Cellular Communications

    Full text link
    In this paper, a new mathematical framework to the analysis of millimeter wave cellular networks is introduced. Its peculiarity lies in considering realistic path-loss and blockage models, which are derived from experimental data recently reported in the literature. The path-loss model accounts for different distributions for line-of-sight and non-line-of-sight propagation conditions and the blockage model includes an outage state that provides a better representation of the outage possibilities of millimeter wave communications. By modeling the locations of the base stations as points of a Poisson point process and by relying upon a noise-limited approximation for typical millimeter wave network deployments, exact integral expressions for computing the coverage probability and the average rate are obtained. With the aid of Monte Carlo simulations, the noise-limited approximation is shown to be sufficiently accurate for typical network densities. Furthermore, it is shown that sufficiently dense millimeter wave cellular networks are capable of outperforming micro wave cellular networks, both in terms of coverage probability and average rate.Comment: Presented at 2015 IEEE International Conference on Communications (ICC), London, UK (June 2015). arXiv admin note: substantial text overlap with arXiv:1410.357

    Average Error Probability Analysis in mmWave Cellular Networks

    Full text link
    In this paper, a mathematical framework for the analysis of average symbol error probability (ASEP) in millimeter wave (mmWave) cellular networks with Poisson Point Process (PPP) distributed base stations (BSs) is developed using tools from stochastic geometry. The distinguishing features of mmWave communications such as directional beamforming and having different path loss laws for line-of-sight (LOS) and non-line-of-sight (NLOS) links are incorporated in the average error probability analysis. First, average pairwise error probability (APEP) expression is obtained by averaging pairwise error probability (PEP) over fading and random shortest distance from mobile user (MU) to its serving BS. Subsequently, average symbol error probability is approximated from APEP using the nearest neighbor (NN) approximation. ASEP is analyzed for different antenna gains and base station densities. Finally, the effect of beamforming alignment errors on ASEP is investigated to get insight on more realistic cases.Comment: Presented at IEEE VTC2015-Fal

    Uplink Performance Analysis in D2D-Enabled mmWave Cellular Networks

    Full text link
    In this paper, we provide an analytical framework to analyze the uplink performance of device-to-device (D2D)-enabled millimeter wave (mmWave) cellular networks. Signal-to- interference-plus-noise ratio (SINR) outage probabilities are derived for both cellular and D2D links using tools from stochastic geometry. The distinguishing features of mmWave communications such as directional beamforming and having different path loss laws for line-of-sight (LOS) and non-line-of-sight (NLOS) links are incorporated into the outage analysis by employing a flexible mode selection scheme and Nakagami fading. Also, the effect of beamforming alignment errors on the outage probability is investigated to get insight on the performance in practical scenarios.Comment: arXiv admin note: text overlap with arXiv:1510.05961, arXiv:1608.0179

    Environmental Efficiency Measurement with Translog Distance Functions: A Parametric Approach

    Get PDF
    We use a flexible parametric hyperbolic distance function to estimate environmental efficiency when some outputs are undesirable. Cuesta and Zofio (J. Prod. Analysis (2005), 31-48) introduced this distance function specification in conventional input-output space to estimate technical efficiency within a stochastic frontier context. We extend their approach to accommodate undesirable outputs and to estimate environmental efficiency within a stochastic frontier context. This provides a parametric counterpart to Färe et al.’s popular nonparametric environmental efficiency measures (Rev. Econ. Stat. 75 (1989), 90-98). The distance function model is applied to a panel of U.S. electricity generating units that produce marketed electricity and non-marketed SO2 emissions.Undesirable outputs; parametric distance functions; stochastic frontier analysis; environmental efficiency
    corecore