599 research outputs found
Bundle pricing of inventories with stochastic demand
Cataloged from PDF version of article.We consider a retailer selling a fixed inventory of two perishable products over a finite horizon. Assuming Poisson arrivals and a
bivariate reservation price distribution, we determine the optimal product and bundle prices that maximize the expected revenue. Our
results indicate that the performances of mixed bundling, pure bundling and unbundled sales strategies heavily depend on the parameters
of the demand process and the initial inventory levels. Bundling appears to be most effective with negatively correlated reservation prices
and high starting inventory levels. When the starting inventory levels are equal and in excess of average demand, most of the benefits of
bundling can be achieved through pure bundling. However, the mixed bundling strategy dominates the other two when the starting
inventory levels are not equal. We also observe that an incorrect modeling of the reservation prices may lead to significant losses.
The model is extended to allow for price changes during the selling horizon. It is shown that offering price bundles mid-season may
be more effective than changing individual product prices.
2008 Elsevier B.V. All rights reserved
Study of Eclipsing Binary and Multiple Systems in OB Associations: I. Ori OB1a - IM Mon
All available photometric and spectroscopic observations were collected and
used as the basis of a detailed analysis of the close binary IM Mon. The
orbital period of the binary was refined to 1.19024249(0.00000014) days. The
Roche equipotentials, fractional luminosities (in (B, V) and H_p bands) and
fractional radii for the component stars in addition to mass ratio q,
inclination i of the orbit and the effective temperature T_eff of the secondary
cooler less massive component were obtained by the analysis of light curves. IM
Mon is classified to be a detached binary system in contrast to the contact
configuration estimations in the literature. The absolute parameters of IM Mon
were derived by the simultaneous solutions of light and radial velocity curves
as M_1,2=5.50(0.24)M_o and 3.32(0.16)M_o, R1,2=3.15(0.04)R_o and 2.36(0.03)R_o,
T_eff1,2=17500(350) K and 14500(550) K implying spectral types of B4 and B6.5
ZAMS stars for the primary and secondary components respectively. The modelling
of the high resolution spectrum revealed the rotational velocities of the
component stars as V_rot1=147(15) km/s and V_rot2=90(25) km/s. The photometric
distance of 353(59) pc was found more precise and reliable than Hipparcos
distance of 341(85) pc. An evolutionary age of 11.5(1.5) Myr was obtained for
IM Mon. Kinematical and dynamical analysis support the membership of the young
thin-disk population system IM Mon to the Ori OB1a association dynamically.
Finally, we derived the distance, age and metallicity information of Ori OB1a
sub-group using the information of IM Mon parameters.Comment: 26 pages, 5 figures and 6 tables, accepted for publication in
Publication of the Astronomical Society of Japa
Single-hole properties in the - and strong-coupling models
We report numerical results for the single-hole properties in the -
model and the strong-coupling approximation to the Hubbard model in two
dimensions. Using the hopping basis with over states we discuss (for an
infinite system) the bandwidth, the leading Fourier coefficients in the
dispersion, the band masses, and the spin-spin correlations near the hole. We
compare our results with those obtained by other methods. The band minimum is
found to be at () for the - model for , and for the strong-coupling model for . The bandwidth
in both models is approximately at large , in rough agreement with
loop-expansion results but in disagreement with other results. The
strong-coupling bandwidth for t/J\agt6 can be obtained from the - model
by treating the three-site terms in first-order perturbation theory. The
dispersion along the magnetic zone face is flat, giving a large
parallel/perpendicular band mass ratio.Comment: 1 RevTeX file with epsf directives to include 8 .eps figures 8 figure
files encoded using uufile
Quasiparticle Dispersion of the 2D Hubbard Model: From an Insulator to a Metal
On the basis of Quantum-Monte-Carlo results the evolution of the spectral
weight of the two-dimensional Hubbard model is studied from
insulating to metallic behavior. As observed in recent photoemission
experiments for cuprates, the electronic excitations display essentially
doping-independent features: a quasiparticle-like dispersive narrow band of
width of the order of the exchange interaction and a broad valence- and
conduction-band background. The continuous evolution is traced back to one and
the same many-body origin: the doping-dependent antiferromagnetic spin-spin
correlation.Comment: 11 pages, REVtex, 4 figures (in uuencoded postscript format
Superconducting Order Parameter in Bi-Layer Cuprates: Occurrence of Phase Shifts in Corner Junctions
We study the order parameter symmetry in bi-layer cuprates such as YBaCuO,
where interesting phase shifts have been observed in Josephson junctions.
Taking models which represent the measured spin fluctuation spectra of this
cuprate, as well as more general models of Coulomb correlation effects, we
classify the allowed symmetries and determine their associated physical
properties. phase shifts are shown to be a general consequence of
repulsive interactions, independent of whether a magnetic mechanism is
operative. While it is known to occur in d-states, this behavior can also be
associated with (orthorhombic) s-symmetry when the two sub-band gaps have
opposite phase. Implications for the magnitude of are discussed.Comment: 5 pages, RevTeX 3.0, 9 figures (available upon request
Does Fiscal Decentralization Promote Fiscal Discipline?
We investigate the efficiency and equity implications of a redistributive rule that takes into account both local tax collection efforts and deviation of local incomes from respective targets under alternative fiscal mechanisms. We show that, if the general budget constraint is binding, the proposed transfer rule leads to higher fiscal discipline under fiscal decentralization (FD) than under centralized redistribution. Although the centralized decision yields better income distribution than FD, FD also improves income distribution unambiguously when equalization across regions is targeted explicitly. When localities act strategically, the private sectors utility weight enhances the disciplinary effect of decentralization. © 2016 Taylor & Francis Group, LLC
Bilateral Talus and Navicular Fractures accompanied with Unilateral Calcaneal Fracture: A Case Report
An 18-year old male patient, with a history of paragliding accident, sustaining a coronal shear fracture of the body of the talus, an anterior process fracture of the calcaneus extending to the calcaneocuboid joint and a nondisplaced navicular body fracture at the right foot and a displaced fracture of the navicular body accompanied with posteromedial process fracture of the talus at the left side was referred to our emergency clinic. For the right foot, the coronal plane fracture of the talar body was anatomically reduced and fixed with screws. For the left foot, screw fixation was performed through the lateral aspect to fix the large posteromedial fragment. Small bone fragments were removed from the left navicular fracture, and the main fragments were also fixed with screw. The talo-navicular joint was stabilised with a Kirschner wire. At 36 months follow-up, bilateral foot and ankle functions were satisfactory, Maryland scores of the right and left foot were 85 (good) and 90 (excellent), respectively, and the patient regained his full activity level by the 5th month postoperatively. With reference to the number and types of fractures in this one patient, we present a standard protocol for treatment of isolated talus, navicular and calcaneal fractures presenting together in a single foot injury
Electronic spectrum in high-temperature cuprate superconductors
A microscopic theory for electronic spectrum of the CuO2 plane within an
effective p-d Hubbard model is proposed. Dyson equation for the single-electron
Green function in terms of the Hubbard operators is derived which is solved
self-consistently for the self-energy evaluated in the noncrossing
approximation. Electron scattering on spin fluctuations induced by kinematic
interaction is described by a dynamical spin susceptibility with a continuous
spectrum. Doping and temperature dependence of electron dispersions, spectral
functions, the Fermi surface and the coupling constant are studied in the hole
doped case. At low doping, an arc-type Fermi surface and a pseudogap in the
spectral function are observed.Comment: 13 pages (revtex), 18 figures, to be published in JET
One particle spectral weight of the three dimensional single band Hubbard model
Dynamic properties of the three-dimensional single-band Hubbard model are
studied using Quantum Monte Carlo combined with the maximum entropy technique.
At half-filling, there is a clear gap in the density of states and well-defined
quasiparticle peaks at the top (bottom) of the lower (upper) Hubbard band. We
find an antiferromagnetically induced weight above the naive Fermi momentum.
Upon hole doping, the chemical potential moves to the top of the lower band
where a robust peak is observed. Results are compared with spin-density-wave
(SDW) mean-field and self consistent Born approximation results, and also with
the infinite dimensional Hubbard model, and experimental photoemission (PES)
for three dimensional transition-metal oxides.Comment: 11 pages, REVTeX, 16 figures included using psfig.sty. Ref.30
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