774 research outputs found

    Measuring compulsive buying behaviour: Psychometric validity of three different scales and prevalence in the general population and in shopping centres

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    Due to the problems of measurement and the lack of nationally representative data, the extent of compulsive buying behaviour (CBB) is relatively unknown. Methods: The validity of three different instruments was tested: Edwards Compulsive Buying Scale (ECBS; Edwards, 1993), Questionnaire About Buying Behavior (QABB; Lejoyeux & Adès, 1994) and Richmond Compulsive Buying Scale (RCBS; Ridgway, et. al., 2008) using two independent samples. One was nationally representative of the Hungarian population (N=2710) while the other comprised shopping mall customers (N=1447). Results: A new, four-factor solution for the ECBS was developed (ECBS-R), and confirmed the other two measures. Additionally, cut-off scores were defined for all measures. Results showed that the prevalence of CBB is 1.85% (with QABB) in the general population but significantly higher in shopping mall customers (8.7% with ECBS-R, 13.3% with QABB and 2.5% with RCBS-R). Conclusions: Due to the diversity of content, each measure identifies a somewhat different CBB group

    On the Sets of Real Numbers Recognized by Finite Automata in Multiple Bases

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    This article studies the expressive power of finite automata recognizing sets of real numbers encoded in positional notation. We consider Muller automata as well as the restricted class of weak deterministic automata, used as symbolic set representations in actual applications. In previous work, it has been established that the sets of numbers that are recognizable by weak deterministic automata in two bases that do not share the same set of prime factors are exactly those that are definable in the first order additive theory of real and integer numbers. This result extends Cobham's theorem, which characterizes the sets of integer numbers that are recognizable by finite automata in multiple bases. In this article, we first generalize this result to multiplicatively independent bases, which brings it closer to the original statement of Cobham's theorem. Then, we study the sets of reals recognizable by Muller automata in two bases. We show with a counterexample that, in this setting, Cobham's theorem does not generalize to multiplicatively independent bases. Finally, we prove that the sets of reals that are recognizable by Muller automata in two bases that do not share the same set of prime factors are exactly those definable in the first order additive theory of real and integer numbers. These sets are thus also recognizable by weak deterministic automata. This result leads to a precise characterization of the sets of real numbers that are recognizable in multiple bases, and provides a theoretical justification to the use of weak automata as symbolic representations of sets.Comment: 17 page

    Cross Section and Angular Distributions of the (d, p) and (d, n) Reactions in C12 from 1.8 to 6.1 Mev

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    The reaction C12(d, p)C13 has been studied from a deuteron bombarding energy of 1.8 to 6.1 Mev. Resonances were found at 2.47, 2.67, 2.99, 3.39, 4.00, 4.6, 4.8, 5.34, and 5.64 Mev. Angular distributions of protons leaving C13 in the ground state show a pronounced Butler peak at 25° over the entire deuteron energy range. The angular distributions can be explained by assuming small amplitudes for compound nucleus formation interfering with large stripping amplitudes. Angular distributions of the lower energy group of protons leaving C13 excited to 3.09 Mev show a pronounced Butler peak at 0° and an even smaller contribution of compound nucleus formation. The reaction C12(d, n)N13 was also studied, and showed similar resonances and angular distributions. An analysis is made of the phase difference between the resonant and nonresonant parts of the cross section for the (d, p) reaction near the resonance at 4.00 Mev

    Radio-Frequency Spectroscopy

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    Contains reports on three research projects

    Glassy timescale divergence and anomalous coarsening in a kinetically constrained spin chain

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    We analyse the out of equilibrium behavior of an Ising spin chain with an asymmetric kinetic constraint after a quench to a low temperature T. In the limit T\to 0, we provide an exact solution of the resulting coarsening process. The equilibration time exhibits a `glassy' divergence \teq=\exp(const/T^2) (popular as an alternative to the Vogel-Fulcher law), while the average domain length grows with a temperature dependent exponent, \dbar ~ t^{T\ln 2}. We show that the equilibration time \teq also sets the timescale for the linear response of the system at low temperatures.Comment: 4 pages, revtex, includes two eps figures. Proof of energy barrier hierarchy added. Version to be published in Phys Rev Let

    Integrating evolution into ecological modelling: accommodating phenotypic changes in agent based models.

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    PMCID: PMC3733718This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Evolutionary change is a characteristic of living organisms and forms one of the ways in which species adapt to changed conditions. However, most ecological models do not incorporate this ubiquitous phenomenon. We have developed a model that takes a 'phenotypic gambit' approach and focuses on changes in the frequency of phenotypes (which differ in timing of breeding and fecundity) within a population, using, as an example, seasonal breeding. Fitness per phenotype calculated as the individual's contribution to population growth on an annual basis coincide with the population dynamics per phenotype. Simplified model variants were explored to examine whether the complexity included in the model is justified. Outputs from the spatially implicit model underestimated the number of individuals across all phenotypes. When no phenotype transitions are included (i.e. offspring always inherit their parent's phenotype) numbers of all individuals are always underestimated. We conclude that by using a phenotypic gambit approach evolutionary dynamics can be incorporated into individual based models, and that all that is required is an understanding of the probability of offspring inheriting the parental phenotype

    The intrapreneurial state: Singapore's emergence in the smart and sustainable urban solutions field

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    The East Asian developmental state model and the Anglo-American entrepreneurial state model profile varied ways in which the state continues to intervene in economic development. These models are developed by different disciplines and against diverse contexts to capture extrasocietal state responses to neoliberalism and globalization but leave the intrasocietal preconditions for state evolution little explored. We elaborate the concept of state intrapreneurialism as one way of understanding the interrelationship between economic and state transformation – one ingredient of the intrasocietal preconditions underpinning the responses to extrasocietal changes emphasized in the post-developmental state literature. Drawing on the case of Singapore's emergence in the field of smart/sustainable urban solutions, the subsidiary contributions of this paper are to suggest intrapreneurship as a specific and enduring advantage within the developmental state model, especially when set against its limitations signalled in the post-developmental state literature

    Dynamics of the frustrated Ising lattice gas

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    The dynamical properties of a three dimensional model glass, the frustrated Ising lattice gas (FILG) are studied by Monte Carlo simulations. We present results of compression experiments, where the chemical potential is either slowly or abruptly changed, as well as simulations at constant density. One time quantities like density and two time ones like correlations, responses and mean square displacements are measured, and the departure from equilibrium clearly characterized. The aging scenario, particularly in the case of density autocorrelations is reminiscent of spin glass phenomenology with violations of the Fluctuation-dissipation theorem, typical of systems with one replica symmetry breaking. The FILG, as a valid on-lattice model of structural glasses can be described with tools developed in spin glass theory and, being a finite dimensional model, can open the way for a systematic study of activated processes in glasses.Comment: to appear in Phys. Rev. E, november (2000
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