823 research outputs found

    Evaluation-Function-based Model-free Adaptive Fuzzy Control

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    Designs of adaptive fuzzy controllers (AFC) are commonly based on the Lyapunov approach, which requires a known model of the controlled plant. They need to consider a Lyapunov function candidate as an evaluation function to be minimized. In this study these drawbacks were handled by designing a model-free adaptive fuzzy controller (MFAFC) using an approximate evaluation function defined in terms of the current state, the next state, and the control action. MFAFC considers the approximate evaluation function as an evaluative control performance measure similar to the state-action value function in reinforcement learning. The simulation results of applying MFAFC to the inverted pendulum benchmark veriïŹed the proposed scheme\u27s efficacy

    Faktor-faktor yang Mempengaruhi Profitabilitas Lembaga Keuangan Mikro di Kecamatan Tandun Kabupaten Rokan Hulu

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    FAKTOR-FAKTOR YANG MEMPENGARUHI PROFITABILITAS LEMBAGA KEUANGAN MIKRO DI KECAMATAN TANDUN KABUPATEN ROKAN HUL

    Cosmological Backreaction from Perturbations

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    We reformulate the averaged Einstein equations in a form suitable for use with Newtonian gauge linear perturbation theory and track the size of the modifications to standard Robertson-Walker evolution on the largest scales as a function of redshift for both Einstein de-Sitter and Lambda CDM cosmologies. In both cases the effective energy density arising from linear perturbations is of the order of 10^-5 the matter density, as would be expected, with an effective equation of state w ~ -1/19. Employing a modified Halofit code to extend our results to quasilinear scales, we find that, while larger, the deviations from Robertson-Walker behaviour remain of the order of 10^-5.Comment: 15 pages, 8 figures; replaced by version accepted by JCA

    osp(1∣2)osp(1|2) off-shell Bethe ansatz equation with boundary terms

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    This work is concerned with the quasi-classical limit of the boundary quantum inverse scattering method for the osp(1∣2)osp(1|2) vertex model with diagonal KK-matrices. In this limit Gaudin's Hamiltonians with boundary terms are presented and diagonalized. Moreover, integral representations for correlation functions are realized to be solutions of the trigonometric Knizhnik-Zamoldchikov equations.Comment: 38 pages, minor revison, LaTe

    The Virtue of Defects in 4D Gauge Theories and 2D CFTs

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    We advance a correspondence between the topological defect operators in Liouville and Toda conformal field theories - which we construct - and loop operators and domain wall operators in four dimensional N=2 supersymmetric gauge theories on S^4. Our computation of the correlation functions in Liouville/Toda theory in the presence of topological defect operators, which are supported on curves on the Riemann surface, yields the exact answer for the partition function of four dimensional gauge theories in the presence of various walls and loop operators; results which we can quantitatively substantiate with an independent gauge theory analysis. As an interesting outcome of this work for two dimensional conformal field theories, we prove that topological defect operators and the Verlinde loop operators are different descriptions of the same operators.Comment: 59 pages, latex; v2 corrections to some formula

    The charges of a twisted brane

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    The charges of the twisted D-branes of certain WZW models are determined. The twisted D-branes are labelled by twisted representations of the affine algebra, and their charge is simply the ground state multiplicity of the twisted representation. It is shown that the resulting charge group is isomorphic to the charge group of the untwisted branes, as had been anticipated from a K-theory calculation. Our arguments rely on a number of non-trivial Lie theoretic identities.Comment: 27 pages, 1 figure, harvmac (b

    Electromagnetic Meson Form Factors in the Salpeter Model

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    We present a covariant scheme to calculate mesonic transitions in the framework of the Salpeter equation for qqˉq\bar{q}-states. The full Bethe Salpeter amplitudes are reconstructed from equal time amplitudes which were obtained in a previous paper\cite{Mue} by solving the Salpeter equation for a confining plus an instanton induced interaction. This method is applied to calculate electromagnetic form factors and decay widths of low lying pseudoscalar and vector mesons including predictions for CEBAF experiments. We also describe the momentum transfer dependence for the processes π0,η,ηâ€Č→γγ∗\pi^0,\eta,\eta'\rightarrow\gamma\gamma^*.Comment: 22 pages including 10 figure

    The Wave Function of 2S Radially Excited Vector Mesons from Data for Diffraction Slope

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    In the color dipole gBFKL dynamics we predict a strikingly different Q^2 and energy dependence of the diffraction slope for the elastic production of ground state V(1S) and radially excited V'(2S) light vector mesons. The color dipole model predictions for the diffraction slope for \rho^0 and \phi^0 production are in a good agreement with the data from the fixed target and collider HERA experiments. We present how a different form of anomalous energy and Q^2 dependence of the diffraction slope for V'(2S) production leads to a different position of the node in radial wave function and discuss a possibility how to determine this position from the fixed target and HERA data.Comment: 20 pages and 6 figures. Title change

    On the crossing relation in the presence of defects

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    The OPE of local operators in the presence of defect lines is considered both in the rational CFT and the c>25c>25 Virasoro (Liouville) theory. The duality transformation of the 4-point function with inserted defect operators is explicitly computed. The two channels of the correlator reproduce the expectation values of the Wilson and 't Hooft operators, recently discussed in Liouville theory in relation to the AGT conjecture.Comment: TEX file with harvmac; v3: JHEP versio

    Pomeron in diffractive processes γ∗(Q2)p→ρ0p\gamma^*(Q^2)p\to\rho^0 p and γ∗(Q2)p→γ∗(Q2)p\gamma^*(Q^2)p\to\gamma^*(Q^2) p at large Q^2: the onset of pQCD

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    We study the reactions γ∗(Q2)p→ρ0p\gamma^*(Q^2)p\to\rho^0 p and γ∗(Q2)p→γ∗(Q2)p\gamma^*(Q^2)p\to\gamma^*(Q^2) p at large Q^2 and W2/Q2W^2/Q^2 and small momentum transfer, Îș⊄2\kappa^2_\perp, to the nucleon where the pomeron exchange dominates. At large Q^2 the virtual photon selects a hard qqˉq\bar q pair, thus selecting the hard pomeron component (the BFKL pomeron). The amplitudes for both transverse and longitudinal polarizations of the initial photon and outgoing ρ\rho-meson (photon) are calculated in the framework of the BFKL pomeron exchange. Our calculations show that one cannot expect the early onset of the pure perturbative regime in the discussed diffractive processes: the small interquark distances, ρqqˉ<0.2\rho_{q\bar q} <0.2 fm, start to dominate not earlier than at Q2≃100GeV2,W2/Q2≃107Q^2 \simeq 100 GeV^2, W^2/Q^2 \simeq 10^7 in γ∗(Q2)p→ρ0p\gamma^*(Q^2)p\to\rho^0 p and Q2≃50GeV2,W2/Q2≃106Q^2 \simeq 50 GeV^2, W^2/Q^2 \simeq 10^6 in γ∗(Q2)p→γ∗(Q2)p\gamma^*(Q^2)p\to\gamma^*(Q^2) p.Comment: 20 pages, LaTeX, epsfig.st
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