1,910 research outputs found
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Energy considerations in a two machine flowshop scheduling problem with sequence dependent setups
Copyright @ 2012 INFORMSA two-machine flowshop permutation scheduling problem is addressed to minimize Cmax and energy consumption as conflicting criteria. We develop a mathematical formulation and propose a Multi-Objective Genetic Algorithm (MOGA) to find approximations of the Pareto front. Performance of the MOGA is compared with Cplex on various problems. The MOGA can support informed decision making via trade-off analysis between Cmax as a measure of service and energy consumption as a measure of sustainability
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Towards green scheduling: A decision support for trade-off analysis between makespan and energy consumption
An optimization-based decision support is proposed for trade-off analysis between makespan, a measure of service and energy consumption, a measure of sustainability in a two machine flowshop scheduling problem. A MIP model is developed and a MOGA to find Pareto fronts to support informed decision making by operations managers
The effect of 12 weeks Anethum graveolens (dill) on metabolic markers in patients with metabolic syndrome; A randomized double blind controlled trial
Background: The clustering of metabolic abnormalities defined as metabolic syndrome is now both a public health and a clinical problem .While interest in herbal medicine has greatly increased, lack of human evidence to support efficacies shown in animals does exist. This clinical trial study designed to investigate whether herbal medicine, Anethum graveolens (dill) extract, could improve metabolic components in patients with metabolic syndrome. Methods: A double-blind, randomized, placebo-controlled trial using a parallel design was conducted. 24 subjects who had metabolic syndrome diagnostic criteria (update of ATP III) were randomly assigned to either dill extract (n = 12) or placebo (n = 12) for 3 months. Results: Across lipid component of metabolic syndrome, no significant differences in triglyceride (TG) concentration and high density lipoprotein cholesterol were seen between the two groups. However TG improved significantly from baseline (257.0 vs. 201.5p = 0.01) with dill treatment but such a significant effect was not observed in placebo group. Moreover, no significant differences in waist circumference, blood pressure and fasting blood sugar were seen between two groups after 3 months follow up period. Conclusion: In this small clinical trial in patients with metabolic syndrome, 12 weeks of dill extract treatment had a beneficial effect in terms of reducing TG from baseline. However dill treatment was not associated with a significant improvement in metabolic syndrome related markers compared to control group. Larger studies might be required to prove the efficacy and safety of long-Term administration of dill to resolve metabolic syndrome components. Ă© 2012 Mansouri et al.; licensee BioMed Central Ltd
Quantum Tests of the Foundations of General Relativity
The role of the equivalence principle in the context of non-relativistic
quantum mechanics and matter wave interferometry, especially atom beam
interferometry, will be discussed. A generalised form of the weak equivalence
principle which is capable of covering quantum phenomena too, will be proposed.
It is shown that this generalised equivalence principle is valid for matter
wave interferometry and for the dynamics of expectation values. In addition,
the use of this equivalence principle makes it possible to determine the
structure of the interaction of quantum systems with gravitational and inertial
fields. It is also shown that the path of the mean value of the position
operator in the case of gravitational interaction does fulfill this generalised
equivalence principle.Comment: Classical and Quantum Gravity 15, 13 (1998
Tests of relativity using a microwave resonator
The frequencies of a cryogenic sapphire oscillator and a hydrogen maser are
compared to set new constraints on a possible violation of Lorentz invariance.
We determine the variation of the oscillator frequency as a function of its
orientation (Michelson-Morley test) and of its velocity (Kennedy-Thorndike
test) with respect to a preferred frame candidate. We constrain the
corresponding parameters of the Mansouri and Sexl test theory to and which is equivalent to the best previous result for the
former and represents a 30 fold improvement for the latter.Comment: 8 pages, 2 figures, submitted to Physical Review Letters (October 3,
2002
Limits on the Time Evolution of Space Dimensions from Newton's Constant
Limits are imposed upon the possible rate of change of extra spatial
dimensions in a decrumpling model Universe with time variable spatial
dimensions (TVSD) by considering the time variation of (1+3)-dimensional
Newton's constant. Previous studies on the time variation of (1+3)-dimensional
Newton's constant in TVSD theory had not been included the effects of the
volume of the extra dimensions and the effects of the surface area of the unit
sphere in D-space dimensions. Our main result is that the absolute value of the
present rate of change of spatial dimensions to be less than about
10^{-14}yr^{-1}. Our results would appear to provide a prima facie case for
ruling the TVSD model out. We show that based on observational bounds on the
present-day variation of Newton's constant, one would have to conclude that the
spatial dimension of the Universe when the Universe was at the Planck scale to
be less than or equal to 3.09. If the dimension of space when the Universe was
at the Planck scale is constrained to be fractional and very close to 3, then
the whole edifice of TVSD model loses credibility.Comment: 22 pages, accepted for publication in Int.J.Mod.Phys.
Probing the Mott-insulating behavior of BaMgReO with DFT+DMFT
We investigate the interplay of spin-orbit coupling, electronic correlations,
and lattice distortions in the double perovskite BaMgReO.
Combining density-functional theory (DFT) and dynamical mean-field theory
(DMFT), we establish the Mott-insulating character of BaMgReO in both
its cubic and tetragonal paramagnetic phases. Despite substantial spin-orbit
coupling, its impact on the formation of the insulating state is minimal,
consistent with theoretical expectations for systems. We further
characterize the electronic properties of the cubic and tetragonal phases by
analyzing spectral functions and local occupations in terms of multipole
moments centered on the Re sites. Our results confirm the presence of
ferroically ordered quadrupoles in addition to the antiferroic
-type order. We compare two equivalent but complementary descriptions
in terms of either effective Re-\ttg frontier orbitals or more localized
atomic-like Re-d and O-p orbitals. The former maps directly on a physically
intuitive picture in terms of nominal Re cations, while the latter
explicitly demonstrates the role of hybridization with the ligands in the
spin-orbit splitting and the formation of the charge quadrupoles around the Re
sites. Finally, we compare our DFT+DMFT results with a previous DFT+ study
of the tetragonal paramagnetic state. We find good qualitative agreement for
the dominant charge quadrupoles, but also notable differences in the
corresponding spectral functions, underscoring the need for more comparative
studies between these two methods
Chaotic Inflation with Time-Variable Space Dimensions
Assuming the space dimension is not constant but decreases during the
expansion of the Universe, we study chaotic inflation with the potential
. Our investigations are based on a model Universe with variable
space dimensions. We write down field equations in the slow-roll approximation,
and define slow-roll parameters by assuming the number of space dimensions
decreases continuously as the Universe expands. The dynamical character of the
space dimension shifts the initial and final value of the inflaton field to
larger values. We obtain an upper limit for the space dimension at the Planck
length. This result is in agreement with previous works for the effective time
variation of the Newtonian gravitational constant in a model Universe with
variable space dimensions.Comment: 19 pages, To be published in Int.J.Mod.Phys.D. Minor changes to match
accepted versio
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