40,421 research outputs found

    Large-Scale Synchrony in Weakly Interacting Automata

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    We study the behavior of two spatially distributed (sandpile) models which are weakly linked with one another. Using a Monte-Carlo implementation of the renormalization group and algebraic methods, we describe how large-scale correlations emerge between the two systems, leading to synchronized behavior.Comment: 6 pages, 3 figures; to appear PR

    Computer program determines exact two-sided tolerance limits for normal distributions

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    Computer program determines by numerical integration the exact statistical two-sided tolerance limits, when the proportion between the limits is at least a specified number. The program is limited to situations in which the underlying probability distribution for the population sampled is the normal distribution with unknown mean and variance

    Necrotic tumor growth: an analytic approach

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    The present paper deals with a free boundary problem modeling the growth process of necrotic multi-layer tumors. We prove the existence of flat stationary solutions and determine the linearization of our model at such an equilibrium. Finally, we compute the solutions of the stationary linearized problem and comment on bifurcation.Comment: 14 pages, 3 figure

    The structural contradictions and constraints on corporate social responsibility: Challenges for corporate social irresponsibility

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    Purpose - This chapter engages critically with the ideas of corporate social responsibility (CSR) and irresponsibility (CSI) in order to examine their utility for the purposes of realizing more socially just and environmentally sustainable social and economic practices. Methodology/approach - The chapter develops Marx's understanding of the twin pressures of class struggle and inter-capitalist competition in setting the limits of agency for corporate actors. It is thus theoretical and discursive in nature. Findings - The findings of the chapter suggest that the scope for corporate agency in relation to responsibility/irresponsibility is severely limited by inter-capitalist competition and capitalist social relations. It therefore argues that those interested in social justice and environmental sustainability should focus on these structural pressures rather than theorizing corporate agency. Social implications - The research suggests that the focus of academic and government attention should be on resolving the contradictions and exploitative social relations inherent in capitalism. Without this emphasis activism, corporate agency and government action will not eradicate the types of problem that advocates of CSR/CSI are concerned about. Originality/value of paper - The value of the paper is that it contests and engages critically with the utility of the notion of CSR and the emergent concept of CSI. It asks proponents of these concepts to think seriously about the structural pressures and constraints within which business and policy makers act. Copyrightr © 2012 by Emerald Group Publishing Limited

    Future directions in kaonic atom physics

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    Recent progress and open problems in kaonic atom physics are presented. A connection between phenomenological deep potentials and the underlying K−NK^-N interaction is established as well as the need for a theory for multinucleon absorption of kaons. K−K^- absorption at rest to specific Λ\Lambda hypernuclei states is briefly discussed.Comment: 6 pages, 3 figures, proceedings of the EXA2011 conference, to appear in Hyperfine Interaction

    Petrology of the Maxville Limestone from Parts of Muskingum and Perry Counties, Ohio

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    Author Institution: Indiana Geological Survey, Bloomingto

    Medical Information Management System (MIMS): A generalized interactive information system

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    An interactive information system is described. It is a general purpose, free format system which offers immediate assistance where manipulation of large data bases is required. The medical area is a prime area of application. Examples of the system's operation, commentary on the examples, and a complete listing of the system program are included

    Quantum Brownian motion in a quasiperiodic potential

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    We consider a quantum particle subject to Ohmic dissipation, moving in a bichromatic quasiperiodic potential. In a periodic potential the particle undergoes a zero-temperature localization-delocalization transition as dissipation strength is decreased. We show that the delocalized phase is absent in the quasiperiodic case, even when the deviation from periodicity is infinitesimal. Using the renormalization group, we determine how the effective localization length depends on the dissipation. We show that {a similar problem can emerge in} the strong-coupling limit of a mobile impurity moving in a periodic lattice and immersed in a one-dimensional quantum gas.Comment: 5+6 pages, 1 figur

    Localization-protected order in spin chains with non-Abelian discrete symmetries

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    We study the non-equilibrium phase structure of the three-state random quantum Potts model in one dimension. This spin chain is characterized by a non-Abelian D3D_3 symmetry recently argued to be incompatible with the existence of a symmetry-preserving many-body localized (MBL) phase. Using exact diagonalization and a finite-size scaling analysis, we find that the model supports two distinct broken-symmetry MBL phases at strong disorder that either break the Z3{\mathbb{Z}_3} clock symmetry or a Z2{\mathbb{Z}_2} chiral symmetry. In a dual formulation, our results indicate the existence of a stable finite-temperature topological phase with MBL-protected parafermionic end zero modes. While we find a thermal symmetry-preserving regime for weak disorder, scaling analysis at strong disorder points to an infinite-randomness critical point between two distinct broken-symmetry MBL phases.Comment: 5 pages, 3 figures main text; 6 pages, 3 figures supplemental material; Version 2 includes a corrected the form of the chiral order parameter, and corresponding data, as well as larger system size numerics, with no change to the phase structur
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