750 research outputs found
Auctions for private congestible infrastructures
This paper investigates regulation by auctions of private supply of congestible infrastructures in two networks settings: 1) two serial facilities, where the consumer has to use both in order to consume; and 2) two parallel facilities that are imperfect substitutes. There are four market structures: a monopoly and 3 duopolies that differ in how firms interact. The effects of an auction depend on what the bidders compete. With a bid auction, the bidders compete on how much money they transfer to the government. This auction leads to the same outcome as the unregulated game (for a given market structure), since this gives the maximum profit to transfer. An auction on the capacity of a facility leads to an even lower welfare than no regulation, because firms set very high capacities and usage fees. Conversely, an auction on generalised price or number of users leads to the first-best outcome. Moreover, these two auctions are robust: they attain the first-best regardless of whether the facilities are auctioned off to a single firm or to two firms, and for all market and network structures. On the contrary, the performances (relative to the first-best) of the bid and capacity auctions strongly depend on these considerations
A surprising steric effect on a tandem cycloaddition/ring-opening reaction : rapid syntheses of difluorinated analogues of (hydroxymethyl)conduritols
Difluorinated analogues of (hydroxymethyl)conduritols can be synthesised from selected furans and a difluorinated dienophile in two reaction steps
Ruling out the light weakly interacting massive particle explanation of the Galactic 511 keV line
Private road networks with uncertain demand
We study the efficiency of private supply of roads under demand uncertainty and evaluate various regulatory policies. Due to demand uncertainty, capacity is decided before demand is known but tolls can be adjusted after demand is known. Policy implications can differ from those under deterministic demand. For instance, for serial links, the toll in the second-best zero-profit case is no longer equal to the marginal external congestion cost. In the first-best scenario, the capacity under uncertain demand is higher than that under deterministic demand of the same expected value, though self-financing still holds in expected terms. Regulation by perfect competitive auction cannot replicate the second-best zero-profit result and thus leads to a lower welfare, whereas without uncertainty, various forms of competitive auctions can attain this second-best optimum. For more complex networks, when private firms add capacity in turn, contrary to the case without demand uncertainty, some forms of auction perform better than others with demand uncertainty
Exploring dark matter microphysics with galaxy surveys
We use present cosmological observations and forecasts of future experiments to illustrate the power of large-scale structure (LSS) surveys in probing dark matter (DM) microphysics and unveiling potential deviations from the standard ΛCDM scenario. To quantify this statement, we focus on an extension of ΛCDM with DM-neutrino scattering, which leaves a distinctive imprint on the angular and matter power spectra. After finding that future CMB experiments (such as COrE+) will not significantly improve the constraints set by the Planck satellite, we show that the next generation of galaxy clustering surveys (such as DESI) could play a leading role in constraining alternative cosmologies and even have the potential to make a discovery. Typically we find that DESI would be an order of magnitude more sensitive to DM interactions than Planck, thus probing effects that until now have only been accessible via N-body simulations
On the Existence and Uniqueness of Equilibrium in the Bottleneck Model with Atomic Users
This paper investigates the existence and uniqueness of equilibrium in the Vickrey bottleneck model when each user controls a positive fraction of total traffic. Users simultaneously choose departure schedules for their vehicle fleets. Each user internalizes the congestion cost that each of its vehicles imposes on other vehicles in its fleet. We establish three results. First, a pure strategy Nash equilibrium (PSNE) may not exist. Second, if a PSNE does exist, identical users may incur appreciably different equilibrium costs. Finally, a multiplicity of PSNE can exist in which no queuing occurs but departures begin earlier or later than in the system optimum. The order in which users depart can be suboptimal as well. Nevertheless, by internalizing self-imposed congestion costs individual users can realize much, and possibly all, of the potential cost savings from either centralized traffic control or time-varying congestion tolls
Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert atmospheric observatory
A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA). Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS); nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS). Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a reference cylinder
Reverse shape selectivity in the adsorption of hexane and xylene isomers in MOF UiO-66
An adsorption study of hexane and xylene isomers mixtures was addressed in a rigid zirconium terephthalate UiO-66 (UiO for University of Oslo) with octahedral and tetrahedral cavities of free diameter
close to 1.1 nm and 0.8 nm, respectively. Multicomponent equimolar breakthrough experiments show that the adsorption hierarchy of structural isomers in UiO-66 is opposite to the one observed in conventional
adsorbents. For hexane isomers, it was found that the amount adsorbed increases with the degree of branching, being 2,2-dimethylbutane (22DMB) and 2,3-dimethylbutane (23DMB) the more retained
molecules. Regarding the xylene isomers, the results show that the adsorption of the bulkier ortho-xylene(oX) is favoured compared to its homologues. The structural similarity between MOF UiO-66 and zeolite
MCM-22 suggests that the reverse shape selectivity observed in the adsorption of hexane and xylene isomers might be attributed to the rotational freedom of the molecules inside the small cavities
Evolution of the curvature perturbations during warm inflation
This paper considers warm inflation as an interesting application of
multi-field inflation. Delta-N formalism is used for the calculation of the
evolution of the curvature perturbations during warm inflation. Although the
perturbations considered in this paper are decaying after the horizon exit, the
corrections to the curvature perturbations sourced by these perturbations can
remain and dominate the curvature perturbations at large scales. In addition to
the typical evolution of the curvature perturbations, inhomogeneous diffusion
rate is considered for warm inflation, which may lead to significant
non-Gaussianity of the spectrum.Comment: 23 pages, 1 figure, fixed references, accepted for publication in
JCA
Analysing the Control Software of the Compact Muon Solenoid Experiment at the Large Hadron Collider
The control software of the CERN Compact Muon Solenoid experiment contains
over 30,000 finite state machines. These state machines are organised
hierarchically: commands are sent down the hierarchy and state changes are sent
upwards. The sheer size of the system makes it virtually impossible to fully
understand the details of its behaviour at the macro level. This is fuelled by
unclarities that already exist at the micro level. We have solved the latter
problem by formally describing the finite state machines in the mCRL2 process
algebra. The translation has been implemented using the ASF+SDF
meta-environment, and its correctness was assessed by means of simulations and
visualisations of individual finite state machines and through formal
verification of subsystems of the control software. Based on the formalised
semantics of the finite state machines, we have developed dedicated tooling for
checking properties that can be verified on finite state machines in isolation.Comment: To appear in FSEN'11. Extended version with details of the ASF+SDF
translation of SML into mCRL
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