6,170 research outputs found
Tradable Permits with Incomplete Monitoring: Evidence from Santiago’s Particulate Permits Program
I explore the advantages of tradable emission permits over uniform emission standards when the regulator has incomplete information on firms’ emissions and costs of production and abatement (e.g., air pollution in large cities). Because the regulator only observes each firm’s abatement technology but neither its emissions nor its output, there are cases in which standards can lead to lower emissions and, hence, welfare dominate permits. I then empirically examine these issues using evidence from a particulate permits market in Santiago, Chile.asymmetric information, imperfect monitoring, pollution markets, permits
Subjective Quality Assessment of the Impact of Buffer Size in Fine-Grain Parallel Video Encoding
Fine-Grain parallelism is essential for real-time video encoding performance. This usually implies setting a fixed buffer size for each encoded block. The choice of this parameter is critical for both performance and hardware cost. In this paper we analyze the impact of buffer size on image subjective quality, and its relation with other encoding parameters. We explore the consequences on visual quality, when minimizing buffer size to the point of causing the discard of quantized coefficients for highest frequencies. Finally, we propose some guidelines for the choice of buffer size, that has proven to be heavily dependent, in addition to other parameters, on the type of sequence being encoded. These guidelines are useful for the design of efficient realtime encoders, both hardware and software
Pollution Markets with Imperfectly Observed Emissions
I study the advantages of pollution permit markets over traditional standard regulations when the regulator has incomplete information on firms’ emissions and costs of production and abatement (e.g., air pollution in large cities). Because the regulator only observes each firm’s abatement technology but neither its emissions nor its output, there are cases in which standards can lead to lower emissions and, hence, welfare dominate permits. If permits are optimally combined with standards, in many cases this hybrid policy converges to the permits-alone policy but (almost) never to the standards-alone policy.asymmetric information, imperfect monitoring, pollution markets, permits
Natural PQ symmetry in the 3-3-1 model with a minimal scalar sector
In the framework of a 3-3-1 model with a minimal scalar sector we make a
detailed study concerning the implementation of the PQ symmetry in order to
solve the strong CP problem. For the original version of the model, with only
two scalar triplets, we show that the entire Lagrangian is invariant under a
PQ-like symmetry but no axion is produced since an U(1) subgroup remains
unbroken. Although in this case the strong CP problem can still be solved, the
solution is largely disfavored since three quark states are left massless to
all orders in perturbation theory. The addition of a third scalar triplet
removes the massless quark states but the resulting axion is visible. In order
to become realistic the model must be extended to account for massive quarks
and invisible axion. We show that the addition of a scalar singlet together
with a Z_N discrete gauge symmetry can successfully accomplish these tasks and
protect the axion field against quantum gravitational effects. To make sure
that the protecting discrete gauge symmetry is anomaly free we use a discrete
version of the Green-Schwarz mechanism.Comment: 18 pages, 1 figure, 3 table
Higher Education Fine Art in the UK and Spain since 1992: a study in perceptions of change by staff in two universities
This article explores the perceptions of a small sample of academic staff from a university in Spain and another in the United Kingdom towards changes in fine art higher education (HE) in both countries over the last 25 years. The authors sought to understand if, and how, the changing HE context had influenced the provision of fine art in each university, and considered it useful to address whether there was any comparability across the two institutions in terms of the responses to the broad changes in resourcing and quality assurance. They used a series of semi-structured interviews with eight respondents, four in each country, aimed at eliciting staff views. These perceptions were considered alongside available data on student numbers, enrolments, graduation and gender, in order to explore the reactions of teaching staff to shifts in context over the period. The study concludes that the stance of criticality adopted by many fine art academics, who value their academic freedom and autonomy and prioritize the practice of their discipline, is being challenged by many of the recent changes in HE. As a result, staff who are being asked to undertake a wider range of activities are having to adapt their view of the nature of fine art HE
Scaling and universality of critical fluctuations in granular gases
The global energy fluctuations of a low density gas granular gas in the
homogeneous cooling state near its clustering instability are studied by means
of molecular dynamics simulations. The relative dispersion of the fluctuations
is shown to exhibit a power-law divergent behavior. Moreover, the probability
distribution of the fluctuations presents data collapse as the system
approaches the instability, for different values of the inelasticity. The
function describing the collapse turns out to be the same as the one found in
several molecular equilibrium and non-equilibrium systems, except for the
change in the sign of the fluctuations
When are entrepreneurs more environmentally oriented? An analysis of stakeholders' pressures at different stages of evolution of the venture
Entrepreneurs are subjected to increased institutional pressures that encourage them to include environmental issues in their overall business objectives. Despite this, entrepreneurs do not always place the same importance on environmental issues in the overall objectives, but some are more environmentally oriented than others. We contend that these differences are explained by two factors: the stage of evolution of the venture and the intensity of coercive and normative environmental pressures on entrepreneurs. Using a sample of 9781 entrepreneurs from 27 countries, our research shows that entrepreneurs are more environmentally oriented (1) in early stages of evolution, (2) in countries with high coercive pressures, and (3) in countries with high normative pressures. Additionally, our results indicate that the differences in the environmental orientation in the early and late stages are reduced in countries with high normative pressures and that these differences are not influenced by the intensity of coercive pressures
Volume fluctuations and compressibility of a vibrated granular gas
The volume fluctuations in the steady state reached by a vibrated granular
gas of hard particles confined by a movable piston on the top are investigated
by means of event driven simulations. Also, a compressibility factor, measuring
the response in volume of the system to a change in the mass of the piston, is
introduced and measured. From the second moment of the volume fluctuations and
the compressibility factor, an effective temperature is defined, by using the
same relation as obeyed by equilibrium molecular systems. The interpretation of
this effective temperature and its relationship with the granular temperature
of the gas, and also with the velocity fluctuations of the movable piston, is
discussed. It is found that the ratio of the temperature based on the volume
fluctuations to the temperature based on the piston kinetic energy, obeys
simple dependencies on the inelasticity and on the piston-particle mass ratio
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