2,649 research outputs found
Accelerated Particle Swarm Optimization and Support Vector Machine for Business Optimization and Applications
Business optimization is becoming increasingly important because all business
activities aim to maximize the profit and performance of products and services,
under limited resources and appropriate constraints. Recent developments in
support vector machine and metaheuristics show many advantages of these
techniques. In particular, particle swarm optimization is now widely used in
solving tough optimization problems. In this paper, we use a combination of a
recently developed Accelerated PSO and a nonlinear support vector machine to
form a framework for solving business optimization problems. We first apply the
proposed APSO-SVM to production optimization, and then use it for income
prediction and project scheduling. We also carry out some parametric studies
and discuss the advantages of the proposed metaheuristic SVM.Comment: 12 page
Extremal statistics in the energetics of domain walls
We study at T=0 the minimum energy of a domain wall and its gap to the first
excited state concentrating on two-dimensional random-bond Ising magnets. The
average gap scales as , where , is the energy fluctuation exponent, length scale, and
the number of energy valleys. The logarithmic scaling is due to extremal
statistics, which is illustrated by mapping the problem into the
Kardar-Parisi-Zhang roughening process. It follows that the susceptibility of
domain walls has also a logarithmic dependence on system size.Comment: Accepted for publication in Phys. Rev.
Electron-Like Fermi Surface and Remnant (pi,0) Feature in Overdoped La1.78Sr0.22CuO4
We have performed an angle-resolved photoemission study of overdoped
La1.78Sr0.22CuO4, and have observed sharp nodal quasiparticle peaks in the
second Brillouin zone that are comparable to data from Bi2Sr2CaCu2O8+d. The
data analysis using energy distribution curves, momentum distribution curves
and intensity maps all show evidence of an electron-like Fermi surface, which
is well explained by band structure calculations. Evidence for many-body
effects are also found in the substantial spectral weight remaining below the
Fermi level around (pi,0), where the band is predicted to lie above EF.Comment: 4 pages, 4 figure
Charged exctions in the fractional quantum Hall regime
We study the photoluminescence spectrum of a low density ()
two-dimensional electron gas at high magnetic fields and low temperatures. We
find that the spectrum in the fractional quantum Hall regime can be understood
in terms of singlet and triplet charged-excitons. We show that these spectral
lines are sensitive probes for the electrons compressibility. We identify the
dark triplet charged-exciton and show that it is visible at the spectrum at
K. We find that its binding energy scales like , where is
the magnetic length, and it crosses the singlet slightly above 15 T.Comment: 10 pages, 5 figure
Peculiarities of topographic anatomy and crypt compartment of distal colon in Wistar rats
We studied distal colon of Wistar rats including descending transverse colon and rectum. Feature of distal colon in the left flexure are short mesenterium growing in size towards rectum, common mesenterium with small intestine attached to it on the right side and ligament forming left flexure and attached to it on the left side. It was found that one of the variants of normal blood supply is the absence of a. mesenterica caudalis. In this case blood supply comes from arterial arch formed by a. rectalis media and a. colica media. Moreover, in the classic variant of blood supply we revealed a variation in the amount of straight branches that go to this segment of colon wall from left colic and superior rectal arteries (from 3 to 5 from each artery). The structural features of rectum is weak expression of rectal ampulla that causes the depletion of fecal masses immediately after passing into rectum. Crypt compartment of colon of Wistar rats consists by 80,6 % of obligatory flora represented with Bacteroides ssp., Lactobacillus spp., Bifidobacterium spp., Enterococcus faecalis, E. coli (lac+), Grampositive rods. Facultative flora is represented with Proteus mirabilis, Peptococcus spp., Candida spp., Staphylococcus epidermidis, Citrobacter freundii and makes 19,4 %
Результаты оценки микробиоты в условиях экспериментального язвенного поражения толстой кишки
Background. The increased incidence of inflammatory bowel disease (IBD) in the world and the lack of consensus on the causes and development mechanisms of IBD are the key elements that determine the relevance of the study. According to some authors, in the pathogenesis of the development and occurrence of ulcerative colitis, one of the leading causes is a change in the composition of the colon microflora and the impact of the products of their metabolism on the enteric system and intestinal motility.The aim was to study the qualitative and quantitative changes in the colon microbiota in rats when modeling ulcerative lesions by the original method.Materials and methods. The experimental study was carried out using male Wistar rats (n = 24). Ulcerative colitis was modeled in an original way. The quantitative and qualitative composition of the parietal microflora of the distal colon was determined.Results. When modeling ulcerative lesions of the colon using the original method, changes in the qualitative and quantitative composition of the parietal microflora of the colon were revealed. On the 3rd day there was a decrease in Lactobacillus ssp. and Escherichia coli, as well as the growth of fungal microflora and the appearance of representatives of opportunistic microflora. The changes were progressive in nature, and by the 7th day of the study revealed a marked reduction of the total parietal concentration of the normal flora bacteria and an increased percentage and absolute number of representatives of conditionally pathogenic microflora. By the 10th day of the experiment, with a small increase in the total number of parietal bacteria, the predominant microorganisms were Bacteroides ssp. (26.8%) and Peptococcus ssp. (27.6%). Введение. Язвенный колит – хроническое рецидивирующее системное воспалительное заболевание с преимущественным поражением слизистой оболочки толстой кишки. Каждый год регистрируется до 20 новых случаев заболевания на 100 тыс. населения, в основном среди лиц трудоспособного возраста. По мнению ряда авторов, в патогенезе развития и возникновения заболевания одну из ведущих причин играет изменение в составе микрофлоры толстой кишки, а также продукты их метаболизма, воздействующие на энтериновую систему и моторику кишечника.Цель. Изучить показатели микробиоты толстой кишки у самцов крыс линии Вистар при моделировании язвенного поражения.Материалы и методы. Экспериментальное исследование выполнено с использованием самцов крыс линии Вистар (n = 24). Предложен оригинальный способ модели язвенного колита. Определен количественный и качественный состав пристеночной микрофлоры дистального отдела толстой кишки.Результаты. Выявлены изменения качественного и количественного состава пристеночной микрофлоры толстой кишки: на 3-и сут отмечали снижение концентрации Lactobacillus ssp. и Escherichia coli, а также рост грибковой микрофлоры, появление представителей условно-патогенной микрофлоры. Изменения носили прогрессирующий характер, и уже к 7-м сут выявляли выраженное снижение общей пристеночной концентрации бактерий нормофлоры и повышение процентного и абсолютного числа представителей условно-патогенной микрофлоры. К 10-м сут эксперимента при малом увеличении общей численности пристеночных бактерий преобладающей микрофлорой являются Bacteroides ssp. (26,8%) и Peptococcus ssp. (27,6%).
Complexity Characterization in a Probabilistic Approach to Dynamical Systems Through Information Geometry and Inductive Inference
Information geometric techniques and inductive inference methods hold great
promise for solving computational problems of interest in classical and quantum
physics, especially with regard to complexity characterization of dynamical
systems in terms of their probabilistic description on curved statistical
manifolds. In this article, we investigate the possibility of describing the
macroscopic behavior of complex systems in terms of the underlying statistical
structure of their microscopic degrees of freedom by use of statistical
inductive inference and information geometry. We review the Maximum Relative
Entropy (MrE) formalism and the theoretical structure of the information
geometrodynamical approach to chaos (IGAC) on statistical manifolds. Special
focus is devoted to the description of the roles played by the sectional
curvature, the Jacobi field intensity and the information geometrodynamical
entropy (IGE). These quantities serve as powerful information geometric
complexity measures of information-constrained dynamics associated with
arbitrary chaotic and regular systems defined on the statistical manifold.
Finally, the application of such information geometric techniques to several
theoretical models are presented.Comment: 29 page
Direct Detection of Dark Matter in the MSSM with Non-Universal Higgs Masses
We calculate dark matter scattering rates in the minimal supersymmetric
extension of the Standard Model (MSSM), allowing the soft
supersymmetry-breaking masses of the Higgs multiplets, m_{1,2}, to be
non-universal (NUHM). Compared with the constrained MSSM (CMSSM) in which
m_{1,2} are required to be equal to the soft supersymmetry-breaking masses m_0
of the squark and slepton masses, we find that the elastic scattering cross
sections may be up to two orders of magnitude larger than values in the CMSSM
for similar LSP masses. We find the following preferred ranges for the
spin-independent cross section: 10^{-6} pb \ga \sigma_{SI} \ga 10^{-10} pb, and
for the spin-dependent cross section: 10^{-3} pb \ga \sigma_{SD}, with the
lower bound on \sigma_{SI} dependent on using the putative constraint from the
muon anomalous magnetic moment. We stress the importance of incorporating
accelerator and dark matter constraints in restricting the NUHM parameter
space, and also of requiring that no undesirable vacuum appear below the GUT
scale. In particular, values of the spin-independent cross section another
order of magnitude larger would appear to be allowed, for small \tan \beta, if
the GUT vacuum stability requirement were relaxed, and much lower cross-section
values would be permitted if the muon anomalous magnetic moment constraint were
dropped.Comment: 30 pages LaTeX, 40 eps figure
The detection of neutrino interactions in the emulsion/lead target of the OPERA experiment
The OPERA neutrino detector in the underground Gran Sasso Laboratory (LNGS)
was designed to perform the first detection of neutrino oscillations in
appearance mode through the study of oscillations. The
apparatus consists of an emulsion/lead target complemented by electronic
detectors and it is placed in the high energy long-baseline CERN to LNGS beam
(CNGS) 730 km away from the neutrino source. Runs with CNGS neutrinos were
successfully carried out in 2007 and 2008 with the detector fully operational
with its related facilities for the emulsion handling and analysis. After a
brief description of the beam and of the experimental setup we report on the
collection, reconstruction and analysis procedures of first samples of neutrino
interaction events
Energy spectra of fractional quantum Hall systems in the presence of a valence hole
The energy spectrum of a two-dimensional electron gas (2DEG) in the
fractional quantum Hall regime interacting with an optically injected valence
band hole is studied as a function of the filling factor and the
separation between the electron and hole layers. The response of the 2DEG
to the hole changes abruptly at of the order of the magnetic length
. At , the hole binds electrons to form neutral () or
charged () excitons, and the photoluminescence (PL) spectrum probes the
lifetimes and binding energies of these states rather than the original
correlations of the 2DEG. The ``dressed exciton'' picture (in which the
interaction between an exciton and the 2DEG was proposed to merely enhance the
exciton mass) is questioned. Instead, the low energy states are explained in
terms of Laughlin correlations between the constituent fermions (electrons and
's) and the formation of two-component incompressible fluid states in the
electron--hole plasma. At , the hole binds up to two Laughlin
quasielectrons (QE) of the 2DEG to form fractionally charged excitons
QE. The previously found ``anyon exciton'' QE is shown to be
unstable at any value of . The critical dependence of the stability of
different QE complexes on the presence of QE's in the 2DEG leads to the
observed discontinuity of the PL spectrum at or .Comment: 16 pages, 14 figures, submitted to PR
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