19,502 research outputs found
Competitive Charging Station Pricing for Plug-in Electric Vehicles
This paper considers the problem of charging station pricing and plug-in
electric vehicles (PEVs) station selection. When a PEV needs to be charged, it
selects a charging station by considering the charging prices, waiting times,
and travel distances. Each charging station optimizes its charging price based
on the prediction of the PEVs' charging station selection decisions and the
other station's pricing decision, in order to maximize its profit. To obtain
insights of such a highly coupled system, we consider a one-dimensional system
with two competing charging stations and Poisson arriving PEVs. We propose a
multi-leader-multi-follower Stackelberg game model, in which the charging
stations (leaders) announce their charging prices in Stage I, and the PEVs
(followers) make their charging station selections in Stage II. We show that
there always exists a unique charging station selection equilibrium in Stage
II, and such equilibrium depends on the charging stations' service capacities
and the price difference between them. We then characterize the sufficient
conditions for the existence and uniqueness of the pricing equilibrium in Stage
I. We also develop a low complexity algorithm that efficiently computes the
pricing equilibrium and the subgame perfect equilibrium of the two-stage
Stackelberg game.Comment: 15 pages, 21 figure
Empirical metallicity-dependent calibrations of effective temperature against colours for dwarfs and giants based on interferometric data
We present empirical metallicity-dependent calibrations of effective
temperature against colours for dwarfs of luminosity classes IV and V and for
giants of luminosity classes II and III, based on a collection from the
literature of about two hundred nearby stars with direct effective temperature
measurements of better than 2.5 per cent. The calibrations are valid for an
effective temperature range 3,100 - 10,000 K for dwarfs of spectral types M5 to
A0 and 3,100 - 5,700 K for giants of spectral types K5 to G5. A total of
twenty-one colours for dwarfs and eighteen colours for giants of bands of four
photometric systems, i.e. the Johnson (), the Cousins
(), the Sloan Digital Sky Survey (SDSS, ) and the Two
Micron All Sky Survey (2MASS, ), have been calibrated. Restricted
by the metallicity range of the current sample, the calibrations are mainly
applicable for disk stars ([Fe/H]). The normalized percentage
residuals of the calibrations are typically 2.0 and 1.5 per cent for dwarfs and
giants, respectively. Some systematic discrepancies at various levels are found
between the current scales and those available in the literature (e.g. those
based on the infrared flux method IRFM or spectroscopy). Based on the current
calibrations, we have re-determined the colours of the Sun. We have also
investigated the systematic errors in effective temperatures yielded by the
current on-going large scale low- to intermediate-resolution stellar
spectroscopic surveys. We show that the calibration of colour ()
presented in the current work provides an invaluable tool for the estimation of
stellar effective temperature for those on-going or upcoming surveys.Comment: 28 pages, 19 figures, 8 tables, accepted for publication in MNRA
GW26-e1527 Value of neutrophils count in predicting surgery related acute kidney injury in CKD with hypertensive patients: a cohort study
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