30,085 research outputs found

    Fuzzy analytic hierarchy process: a comparison of the existing algorithms with new proposals

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    In a multiple-criteria decision analysis, prioritizing and assigning weights to each criteria with reference to set of available alternatives is key to effective decision making. Analytic Hierarchy Process (AHP) is one such technique through which experts provide pairwise comparisons and this information is processed in a comparison matrix to calculate priority vector which ranks the available alternatives. Original AHP as proposed by Thomas L. Saaty used crisp numbers to represent pairwise comparisons. However, human judgments are often vague and traditional 1-9 scale is not capable to incorporate the inherent human uncertainty into pairwise comparisons. In order to address this issue, fuzzy set theory is being used along side original AHP where human judgments are recorded in the form of fuzzy numbers and thus comparison matrices are formed in such a way that its elements are fuzzy numbers. Various algorithms have been proposed over the past three decades through which priority vector can be calculated from fuzzy comparison matrices. This study performs an extensive review of the most common algorithms proposed in fuzzy AHP (FAHP) and conducts a performance analysis of nine algorithms, out of which ve are existing FAHP algorithms namely Logarithmic Least Square Method (LLSM), Modified LLSM, Fuzzy Extent Analysis (FEA), modified FEA and Buckley's Geometric Mean method, while four models are introduced in this study which includes Geometric Mean method, Arithmetic Mean method, Row Sum method and Inverse of Column Sum method. A separate algorithm is also proposed to construct fuzzy comparison matrices of varying sizes, level of fuzziness and inconsistency, so as to carry out performance analysis of the selected nine FAHP algorithms. We found that Geometric Mean method discussed in this study performs significantly better than other algorithms, while FEA is the worst performing algorithm. Although at high inconsistency levels, performance of FEA method improves however, even at high inconsistency levels, Geometric Mean method performs significantly better. Modi cation to FEA method (Row Sum method) proposed in this study significantly improves its performance and this modified FEA method is the second best performing algorithm among the selected nine FAHP models. In addition, we also conducted a comparative analysis based on popularity, computational time, applicability of fuzzy numbers, ease of understanding and ease of implementation. Through this study, we attempt to consolidate the existing literature on FAHP algorithms and identify the best performing methodologies to calculate priority vector from fuzzy comparison matrices

    Simulating FRSN P Systems with Real Numbers in P-Lingua on sequential and CUDA platforms

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    Fuzzy Reasoning Spiking Neural P systems (FRSN P systems, for short) is a variant of Spiking Neural P systems incorporating fuzzy logic elements that make it suitable to model fuzzy diagnosis knowledge and reasoning required for fault diagnosis applications. In this sense, several FRSN P system variants have been proposed, dealing with real numbers, trapezoidal numbers, weights, etc. The model incorporating real numbers was the first introduced [13], presenting promising applications in the field of fault diagnosis of electrical systems. For this variant, a matrix-based algorithm was provided which, when executed on parallel computing platforms, fully exploits the model maximally parallel capacities. In this paper we introduce a P-Lingua framework extension to parse and simulate FRSN P systems with real numbers. Two simulators, implementing a variant of the original matrix-based simulation algorithm, are provided: a sequential one (written in Java), intended to run on traditional CPUs, and a parallel one, intended to run on CUDAenabled devices.Ministerio de Economía y Competitividad TIN2012-3743

    Monopole Bundles over Fuzzy Complex Projective Spaces

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    We give a construction of the monopole bundles over fuzzy complex projective spaces as projective modules. The corresponding Chern classes are calculated. They reduce to the monopole charges in the N -> infinity limit, where N labels the representation of the fuzzy algebra.Comment: 30 pages, LaTeX, published version; extended discussion on asymptotic Chern number

    New Fuzzy Extra Dimensions from SU(N)SU({\cal N}) Gauge Theories

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    We start with an SU(N)SU(\cal {N}) Yang-Mills theory on a manifold M{\cal M}, suitably coupled to two distinct set of scalar fields in the adjoint representation of SU(N)SU({\cal N}), which are forming a doublet and a triplet, respectively under a global SU(2)SU(2) symmetry. We show that a direct sum of fuzzy spheres SF2Int:=SF2()SF2()SF2(+12)SF2(12)S_F^{2 \, Int} := S_F^2(\ell) \oplus S_F^2 (\ell) \oplus S_F^2 \left ( \ell + \frac{1}{2} \right ) \oplus S_F^2 \left ( \ell - \frac{1}{2} \right ) emerges as the vacuum solution after the spontaneous breaking of the gauge symmetry and lay the way for us to interpret the spontaneously broken model as a U(n)U(n) gauge theory over M×SF2Int{\cal M} \times S_F^{2 \, Int}. Focusing on a U(2)U(2) gauge theory we present complete parameterizations of the SU(2)SU(2)-equivariant, scalar, spinor and vector fields characterizing the effective low energy features of this model. Next, we direct our attention to the monopole bundles SF2±:=SF2()SF2(±12)S_F^{2 \, \pm} := S_F^2 (\ell) \oplus S_F^2 \left ( \ell \pm \frac{1}{2} \right ) over SF2()S_F^2 (\ell) with winding numbers ±1\pm 1, which naturally come forth through certain projections of SF2IntS_F^{2 \, Int}, and discuss the low energy behaviour of the U(2)U(2) gauge theory over M×SF2±{\cal M} \times S_F^{2 \, \pm}. We study models with kk-component multiplet of the global SU(2)SU(2), give their vacuum solutions and obtain a class of winding number ±(k1)\pm (k-1) monopole bundles SF2,±(k1)S_F^{2 \,, \pm (k-1)} as certain projections of these vacuum solutions. We make the observation that SF2IntS_F^{2 \, Int} is indeed the bosonic part of the N=2N=2 fuzzy supersphere with OSP(2,2)OSP(2,2) supersymmetry and construct the generators of the osp(2,2)osp(2,2) Lie superalgebra in two of its irreducible representations using the matrix content of the vacuum solution SF2IntS_F^{2 \, Int}. Finally, we show that our vacuum solutions are stable by demonstrating that they form mixed states with non-zero von Neumann entropy.Comment: 27+1 pages, revised version, added references and corrected typo

    Non-commutative geometry of 4-dimensional quantum Hall droplet

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    We develop the description of non-commutative geometry of the 4-dimensional quantum Hall fluid's theory proposed recently by Zhang and Hu. The non-commutative structure of fuzzy S4S^{4} appears naturally in this theory. The fuzzy monopole harmonics, which are the essential elements in this non-commutative geometry, are explicitly constructed and their obeying the matrix algebra is obtained. This matrix algebra is associative. We also propose a fusion scheme of the fuzzy monopole harmonics of the coupling system from those of the subsystems, and determine the fusion rule in such fusion scheme. By products, we provide some essential ingredients of the theory of SO(5) angular momentum. In particular, the explicit expression of the coupling coefficients, in the theory of SO(5) angular momentum, are given. It is discussed that some possible applications of our results to the 4-dimensional quantum Hall system and the matrix brane construction in M-theory.Comment: latex 22 pages, no figures. some references added. some results are clarifie

    Monopoles and Solitons in Fuzzy Physics

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    Monopoles and solitons have important topological aspects like quantized fluxes, winding numbers and curved target spaces. Naive discretizations which substitute a lattice of points for the underlying manifolds are incapable of retaining these features in a precise way. We study these problems of discrete physics and matrix models and discuss mathematically coherent discretizations of monopoles and solitons using fuzzy physics and noncommutative geometry. A fuzzy sigma-model action for the two-sphere fulfilling a fuzzy Belavin-Polyakov bound is also put forth.Comment: 17 pages, Latex. Uses amstex, amssymb.Spelling of the name of one Author corrected. To appear in Commun.Math.Phy

    Fuzzy Line Bundles, the Chern Character and Topological Charges over the Fuzzy Sphere

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    Using the theory of quantized equivariant vector bundles over compact coadjoint orbits we determine the Chern characters of all noncommutative line bundles over the fuzzy sphere with regard to its derivation based differential calculus. The associated Chern numbers (topological charges) arise to be non-integer, in the commutative limit the well known integer Chern numbers of the complex line bundles over the 2-sphere are recovered.Comment: Latex2e, 13 pages, 1 figure. This paper continues and supersedes math-ph/0103003. v2: Typos correcte
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