271 research outputs found

    An artificial immune system for fuzzy-rule induction in data mining

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    This work proposes a classification-rule discovery algorithm integrating artificial immune systems and fuzzy systems. The algorithm consists of two parts: a sequential covering procedure and a rule evolution procedure. Each antibody (candidate solution) corresponds to a classification rule. The classification of new examples (antigens) considers not only the fitness of a fuzzy rule based on the entire training set, but also the affinity between the rule and the new example. This affinity must be greater than a threshold in order for the fuzzy rule to be activated, and it is proposed an adaptive procedure for computing this threshold for each rule. This paper reports results for the proposed algorithm in several data sets. Results are analyzed with respect to both predictive accuracy and rule set simplicity, and are compared with C4.5rules, a very popular data mining algorithm

    Spin-Glass State in CuGa2O4\rm CuGa_2O_4

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    Magnetic susceptibility, magnetization, specific heat and positive muon spin relaxation (\musr) measurements have been used to characterize the magnetic ground-state of the spinel compound CuGa2O4\rm CuGa_2O_4. We observe a spin-glass transition of the S=1/2 Cu2+\rm Cu^{2+} spins below Tf=2.5K\rm T_f=2.5K characterized by a cusp in the susceptibility curve which suppressed when a magnetic field is applied. We show that the magnetization of CuGa2O4\rm CuGa_2O_4 depends on the magnetic histo Well below Tf\rm T_f, the muon signal resembles the dynamical Kubo-Toyabe expression reflecting that the spin freezing process in CuGa2O4\rm CuGa_2O_4 results Gaussian distribution of the magnetic moments. By means of Monte-Carlo simulati we obtain the relevant exchange integrals between the Cu2+\rm Cu^{2+} spins in this compound.Comment: 6 pages, 16 figure

    Abundances of the elements in the solar system

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    A review of the abundances and condensation temperatures of the elements and their nuclides in the solar nebula and in chondritic meteorites. Abundances of the elements in some neighboring stars are also discussed.Comment: 42 pages, 11 tables, 8 figures, chapter, In Landolt- B\"ornstein, New Series, Vol. VI/4B, Chap. 4.4, J.E. Tr\"umper (ed.), Berlin, Heidelberg, New York: Springer-Verlag, p. 560-63

    Precise Measurement of the Absolute Yield of Fluorescence Photons in Atmospheric Gases

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    We have performed a measurement of the absolute yield of fluorescence photons at the Fermilab Test Beam. A systematic uncertainty at 5% level was achieved by the use of Cherenkov radiation as a reference calibration light source. A cross-check was performed by an independent calibration using a laser light source. A significant improvement on the energy scale uncertainty of Ultra-High Energy Cosmic Rays is expected.Comment: To appear in the Proceedings of CRIS 2010, Cosmic Ray International Seminar -- 100 years of Cosmic Ray Physics: from pioneering experiments to physics in space, Catania, Italy, 13-17 September 201

    Solar System Abundances of the Elements

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    Representative abundances of the chemical elements for use as a solar abundance standard in astronomical and planetary studies are summarized. Updated abundance tables for solar system abundances based on meteorites and photospheric measurements are presented.Comment: 46 pages; 5 figures; 8 tables; In: Principles and Perspectives in Cosmochemistry.Lecture Notes of the Kodai School on 'Synthesis of Elements in Stars' held at Kodaikanal Observatory, India, April 29 - May 13, 2008 (Aruna Goswami and B. Eswar Reddy eds.) Astrophysics and Space Science Proceedings, Springer-Verlag Berlin Heidelberg, 2010, p. 379-417 (ISBN 978-3-642-10351-3), 201
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