77,463 research outputs found
Regional environmental efficiency and economic growth: NUTS2 evidence from Germany, France and the UK
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
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
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
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
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
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
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
- …
