179 research outputs found

    SELECTION OF A LEADER FOR A COMPANY BY USING PRIORITIZATION METHODS OF ANALYTIC HIERARCHY PROCESS AN ILLUSTRATION

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    This paper aims at selection of a leader for a company (whose founder is about to retire) with one of the popular decision making techniques. Analytic Hierarchy Process is an approach to decision making that involves structuring multiple criteria into hierarchy. There are several methods to calculate the priority vectors. Three prioritization methods are used to select a leader among three alternatives and four criteria. It is observed that Dick stands first in ranking and Tom stands second and Harry stands third in rankings. Consistency Ratio (C.R) also calculated for all pair-wise comparison matrices and analyzed. &nbsp

    Interest-based RDF Update Propagation

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    Many LOD datasets, such as DBpedia and LinkedGeoData, are voluminous and process large amounts of requests from diverse applications. Many data products and services rely on full or partial local LOD replications to ensure faster querying and processing. While such replicas enhance the flexibility of information sharing and integration infrastructures, they also introduce data duplication with all the associated undesirable consequences. Given the evolving nature of the original and authoritative datasets, to ensure consistent and up-to-date replicas frequent replacements are required at a great cost. In this paper, we introduce an approach for interest-based RDF update propagation, which propagates only interesting parts of updates from the source to the target dataset. Effectively, this enables remote applications to `subscribe' to relevant datasets and consistently reflect the necessary changes locally without the need to frequently replace the entire dataset (or a relevant subset). Our approach is based on a formal definition for graph-pattern-based interest expressions that is used to filter interesting parts of updates from the source. We implement the approach in the iRap framework and perform a comprehensive evaluation based on DBpedia Live updates, to confirm the validity and value of our approach.Comment: 16 pages, Keywords: Change Propagation, Dataset Dynamics, Linked Data, Replicatio

    Magnetooptical sum rules close to the Mott transition

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    We derive new sum rules for the real and imaginary parts of the frequency-dependent Hall constant and Hall conductivity. As an example, we discuss their relevance to the doped Mott insulator that we describe within the dynamical mean-field theory of strongly correlated electron systems.Comment: 4 pages, 4 ps figures; accepted for publication in PR

    Theory of the temperature and doping dependence of the Hall effect in a model with x-ray edge singularities in d=oo

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    We explain the anomalous features in the Hall data observed experimentally in the normal state of the high-Tc superconductors. We show that a consistent treatment of the local spin fluctuations in a model with x-ray edge singularities in d=oo reproduces the temperature and the doping dependence of the Hall constant as well as the Hall angle in the normal state. The model has also been invoked to justify the marginal-Fermi-liquid behavior, and provides a consistent explanation of the Hall anomalies for a non-Fermi liquid in d=oo.Comment: 5 pages, 4 figures, To appear in Phys. Rev. B, title correcte

    A model of semimetallic behavior in strongly correlated electron systems

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    Metals with values of the resistivity and the Hall coefficient much larger than typical ones, e.g., of sodium, are called semimetals. We suggest a model for semimetals which takes into account the strong Coulomb repulsion of the charge carriers, especially important in transition-metal and rare-earth compounds. For that purpose we extend the Hubbard model by coupling one additional orbital per site via hybridization to the Hubbard orbitals. We calculate the spectral function, resistivity and Hall coefficient of the model using dynamical mean-field theory. Starting from the Mott-insulating state, we find a transition to a metal with increasing hybridization strength (``self-doping''). In the metallic regime near the transition line to the insulator the model shows semimetallic behavior. We compare the calculated temperature dependence of the resistivity and the Hall coefficient with the one found experimentally for Yb4As3\rm Yb_4As_3. The comparison demonstrates that the anomalies in the transport properties of Yb4As3\rm Yb_4As_3 possibly can be assigned to Coulomb interaction effects of the charge carriers not captured by standard band structure calculations.Comment: 9 pages RevTeX with 7 ps figures, accepted by PR

    Magnetotransport in the doped Mott insulator

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    We investigate the Hall effect and the magnetoresistance of strongly correlated electron systems using the dynamical mean-field theory. We treat the low- and high-temperature limits analytically and explore some aspects of the intermediate-temperature regime numerically. We observe that a bipartite-lattice condition is responsible for the high-temperature result σxy∼1/T2\sigma_{xy}\sim 1/T^2 obtained by various authors, whereas the general behavior is σxy∼1/T\sigma_{xy}\sim 1/T, as for the longitudinal conductivity. We find that Kohler's rule is neither obeyed at high nor at intermediate temperatures.Comment: 9 pages, 7 figures, accepted for publication in Phys. Rev.

    Memory function approach to the Hall constant in strongly correlated electron systems

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    The anomalous properties of the Hall constant in the normal state of high-TcT_c superconductors are investigated within the single-band Hubbard model. We argue that the Mori theory is the appropriate formalism to address the Hall constant, since it aims directly at resistivities rather than conductivities. More specifically, the frequency dependent Hall constant decomposes into its infinite frequency limit and a memory function contribution. As a first step, both terms are calculated perturbatively in UU and on an infinite dimensional lattice, where UU is the correlation strength. If we allow UU to be of the order of twice the bare band width, the memory function contribution causes the Hall constant to change sign as a function of doping and to decrease as a function of temperature.Comment: 35 pages, RevTex, 3 ps figures include

    Central GIP signaling stimulates peripheral GIP release and promotes insulin and pancreatic polypeptide secretion in nonhuman primates

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    Glucose-dependent insulinotropic polypeptide (GIP) has important actions on whole body metabolic function. GIP and its receptor are also present in the central nervous system and have been linked to neurotrophic actions. Metabolic effects of central nervous system GIP signaling have not been reported. We investigated whether centrally administered GIP could increase peripheral plasma GIP concentrations and influence the metabolic response to a mixed macronutrient meal in nonhuman primates. An infusion and sampling system was developed to enable continuous intracerebroventricular (ICV) infusions with serial venous sampling in conscious nonhuman primates. Male baboons (Papio sp.) that were healthy and had normal body weights (28.9 ± 2.1 kg) were studied (n = 3). Animals were randomized to receive continuous ICV infusions of GIP (20 pmol·kg−1·h−1) or vehicle before and over the course of a 300-min mixed meal test (15 kcal/kg, 1.5g glucose/kg) on two occasions. A significant increase in plasma GIP concentration was observed under ICV GIP infusion (66.5 ± 8.0 vs. 680.6 ± 412.8 pg/ml, P = 0.04) before administration of the mixed meal. Increases in postprandial, but not fasted, insulin (P = 0.01) and pancreatic polypeptide (P = 0.04) were also observed under ICV GIP. Effects of ICV GIP on fasted or postprandial glucagon, glucose, triglyceride, and free fatty acids were not observed. Our data demonstrate that central GIP signaling can promote increased plasma GIP concentrations independent of nutrient stimulation and increase insulin and pancreatic polypeptide responses to a mixed meal

    Self-dual Vortices in the Generalized Abelian Higgs Model with Independent Chern-Simons Interaction

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    Self-dual vortex solutions are studied in detail in the generalized abelian Higgs model with independent Chern-Simons interaction. For special choices of couplings, it reduces to a Maxwell-Higgs model with two scalar fields, a Chern-Simons-Higgs model with two scalar fields, or other new models. We investigate the properties of the static solutions and perform detailed numerical analyses. For the Chern-Simons-Higgs model with two scalar fields in an asymmetric phase, we prove the existence of multisoliton solutions which can be viewed as hybrids of Chern-Simons vortices and CP1CP^1 lumps. We also discuss solutions in a symmetric phase with the help of the corresponding exact solutions in its nonrelativistic limit. The model interpolating all three models---Maxwell-Higgs, Chern-Simons-Higgs, and CP1CP^1 models--- is discussed briefly. Finally we study the possibility of vortex solutions with half-integer vorticity in the special case of the model. Numerical results are negative.Comment: 32 pages, LATEX, SNUTP 92-7

    A numerical study of multi-soliton configurations in a doped antiferromagnetic Mott insulator

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    We evaluate from first principles the self-consistent Hartree-Fock energies for multi-soliton configurations in a doped, spin-1/2, antiferromagnetic Mott insulator on a two-dimensional square lattice. We find that nearest-neighbor Coulomb repulsion stabilizes a regime of charged meron-antimeron vortex soliton pairs over a region of doping from 0.05 to 0.4 holes per site for intermediate coupling 3 < U/t <8. This stabilization is mediated through the generation of ``spin-flux'' in the mean-field antiferromagnetic (AFM) background. Holes cloaked by a meron-vortex in the spin-flux AFM background are charged bosons. Our static Hartree-Fock calculations provide an upper bound on the energy of a finite density of charged vortices. This upper bound is lower than the energy of the corresponding charged stripe configurations. A finite density of charge carrying vortices is shown to produce a large number of unoccupied electronic levels in the Mott-Hubbard charge transfer gap. These levels lead to significant band tailing and a broad mid-infrared band in the optical absorption spectrum as observed experimentally. At very low doping (below 0.05) the doping charges create extremely tightly bound meron-antimeron pairs or even isolated conventional spin-polarons, whereas for very high doping (above 0.4) the spin background itself becomes unstable to formation of a conventional Fermi liquid and the spin-flux mean-field is energetically unfavorable. Our results point to the predominance of a quantum liquid of charged, bosonic, vortex solitons at intermediate coupling and intermediate doping concentrations.Comment: 12 pages, 25 figures; added references, modified/eliminated some figure
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