4,475 research outputs found

    Performance of an Operating High Energy Physics Data Grid: D0SAR-Grid

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    The D0 experiment at Fermilab's Tevatron will record several petabytes of data over the next five years in pursuing the goals of understanding nature and searching for the origin of mass. Computing resources required to analyze these data far exceed capabilities of any one institution. Moreover, the widely scattered geographical distribution of D0 collaborators poses further serious difficulties for optimal use of human and computing resources. These difficulties will exacerbate in future high energy physics experiments, like the LHC. The computing grid has long been recognized as a solution to these problems. This technology is being made a more immediate reality to end users in D0 by developing a grid in the D0 Southern Analysis Region (D0SAR), D0SAR-Grid, using all available resources within it and a home-grown local task manager, McFarm. We will present the architecture in which the D0SAR-Grid is implemented, the use of technology and the functionality of the grid, and the experience from operating the grid in simulation, reprocessing and data analyses for a currently running HEP experiment.Comment: 3 pages, no figures, conference proceedings of DPF04 tal

    Neutrino-induced deuteron disintegration experiment

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    Cross sections for the disintegration of the deuteron via neutral-current (NCD) and charged-current (CCD) interactions with reactor antineutrinos are measured to be 6.08 +/- 0.77 x 10^(-45) cm-sq and 9.83 +/- 2.04 x 10^(-45) cm-sq per neutrino, respectively, in excellent agreement with current calculations. Since the experimental NCD value depends upon the CCD value, if we use the theoretical value for the CCD reaction, we obtain the improved value of 5.98 +/- 0.54 x 10^(-45) for the NCD cross section. The neutral-current reaction allows a unique measurement of the isovector-axial vector coupling constant in the hadronic weak interaction (beta). In the standard model, this constant is predicted to be exactly 1, independent of the Weinberg angle. We measure a value of beta^2 = 1.01 +/- 0.16. Using the above improved value for the NCD cross section, beta^2 becomes 0.99 +/- 0.10.Comment: 22pages, 9 figure

    Collective Behavior of Asperities in Dry Friction at Small Velocities

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    We investigate a simple model of dry friction based on extremal dynamics of asperities. At small velocities, correlations develop between the asperities, whose range becomes infinite in the limit of infinitely slow driving, where the system is self-organized critical. This collective phenomenon leads to effective aging of the asperities and results in velocity dependence of the friction force in the form F1exp(1/v)F\sim 1- \exp(-1/v).Comment: 7 pages, 8 figures, revtex, submitted to Phys. Rev.

    The employee as 'Dish of the Day’:human resource management and the ethics of consumption

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    This article examines the ethical implications of the growing integration of consumption into the heart of the employment relationship. Human resource management (HRM) practices increasingly draw upon the values and practices of consumption, constructing employees as the ‘consumers’ of ‘cafeteria-style’ benefits and development opportunities. However, at the same time employees are expected to market themselves as items to be consumed on a corporate menu. In relation to this simultaneous position of consumer/consumed, the employee is expected to actively engage in the commodification of themselves, performing an appropriate organizational identity as a necessary part of being a successful employee. This article argues that the relationship between HRM and the simultaneously consuming/consumed employee affects the conditions of possibility for ethical relations within organizational life. It is argued that the underlying ‘ethos’ for the integration of consumption values into HRM practices encourages a self-reflecting, self-absorbed subject, drawing upon a narrow view of individualised autonomy and choice. Referring to Levinas’ perspective that the primary ethical relation is that of responsibility and openness to the Other, it is concluded that these HRM practices affect the possibility for ethical being

    Phenomenology of Quantum Gravity and its Possible Role in Neutrino Anomalies

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    New phenomenological models of Quantum Gravity have suggested that a Lorentz-Invariant discrete spacetime structure may become manifest through a nonstandard coupling of matter fields and spacetime curvature. On the other hand, there is strong experimental evidence suggesting that neutrino oscillations cannot be described by simply considering neutrinos as massive particles. In this manuscript we motivate and construct one particular phenomenological model of Quantum Gravity that could account for the so-called neutrino anomalies.Comment: For the proceedings of "Relativity and Gravitation: 100 Years after Einstein in Prague" (June 2012, Prague

    Entrepreneurial sons, patriarchy and the Colonels' experiment in Thessaly, rural Greece

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    Existing studies within the field of institutional entrepreneurship explore how entrepreneurs influence change in economic institutions. This paper turns the attention of scholarly inquiry on the antecedents of deinstitutionalization and more specifically, the influence of entrepreneurship in shaping social institutions such as patriarchy. The paper draws from the findings of ethnographic work in two Greek lowland village communities during the military Dictatorship (1967–1974). Paradoxically this era associated with the spread of mechanization, cheap credit, revaluation of labour and clear means-ends relations, signalled entrepreneurial sons’ individuated dissent and activism who were now able to question the Patriarch’s authority, recognize opportunities and act as unintentional agents of deinstitutionalization. A ‘different’ model of institutional change is presented here, where politics intersects with entrepreneurs, in changing social institutions. This model discusses the external drivers of institutional atrophy and how handling dissensus (and its varieties over historical time) is instrumental in enabling institutional entrepreneurship

    Together forever? Explaining exclusivity in party-firm relations

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    Parties and firms are the key actors of representative democracy and capitalism respectively and the dynamic of attachment between them is a central feature of any political economy. This is the first article to systematically analyse the exclusivity of party-firm relations. We consider exclusivity at a point in time and exclusivity over time. Does a firm have a relationship with only one party at a given point in time, or is it close to more than one party? Does a firm maintain a relationship with only one party over time, or does it switch between parties? Most important, how do patterns of exclusivity impact on a firm’s ability to lobby successfully? We propose a general theory, which explains patterns of party-firm relations by reference to the division of institutions and the type of party competition in a political system. A preliminary test of our theory with Polish survey data confirms our predictions, establishing a promising hypothesis for future research

    Saturation of electrical resistivity

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    Resistivity saturation is observed in many metallic systems with a large resistivity, i.e., when the resistivity has reached a critical value, its further increase with temperature is substantially reduced. This typically happens when the apparent mean free path is comparable to the interatomic separations - the Ioffe-Regel condition. Recently, several exceptions to this rule have been found. Here, we review experimental results and early theories of resistivity saturation. We then describe more recent theoretical work, addressing cases both where the Ioffe-Regel condition is satisfied and where it is violated. In particular we show how the (semiclassical) Ioffe-Regel condition can be derived quantum-mechanically under certain assumptions about the system and why these assumptions are violated for high-Tc cuprates and alkali-doped fullerides.Comment: 16 pages, RevTeX, 15 eps figures, additional material available at http://www.mpi-stuttgart.mpg.de/andersen/saturation

    Frame Theory for Signal Processing in Psychoacoustics

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    This review chapter aims to strengthen the link between frame theory and signal processing tasks in psychoacoustics. On the one side, the basic concepts of frame theory are presented and some proofs are provided to explain those concepts in some detail. The goal is to reveal to hearing scientists how this mathematical theory could be relevant for their research. In particular, we focus on frame theory in a filter bank approach, which is probably the most relevant view-point for audio signal processing. On the other side, basic psychoacoustic concepts are presented to stimulate mathematicians to apply their knowledge in this field

    Measurement of the t-channel single top quark production cross section

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    The D0 collaboration reports direct evidence for electroweak production of single top quarks through the t-channel exchange of a virtual W boson. This is the first analysis to isolate an individual single top quark production channel. We select events containing an isolated electron or muon, missing transverse energy, and two, three or four jets from 2.3 fb^-1 of ppbar collisions at the Fermilab Tevatron Collider. One or two of the jets are identified as containing a b hadron. We combine three multivariate techniques optimized for the t-channel process to measure the t- and s-channel cross sections simultaneously. We measure cross sections of 3.14 +0.94 -0.80 pb for the t-channel and 1.05 +-0.81 pb for the s-channel. The measured t-channel result is found to have a significance of 4.8 standard deviations and is consistent with the standard model prediction.Comment: 7 pages, 6 figure
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