39,254 research outputs found

    Glassy dynamics in thermally-activated list sorting

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    Sorting the integers 1 through NN into an ordered list is a simple task that can be done rapidly. However, using an algorithm based on the thermally-activated pairwise exchanges of neighboring list elements, we find sorting can display many features of a glass, even for lists as small as N=5N = 5. This includes memory and rejuvenation effects during aging --- two hallmarks of glassy dynamics that have been difficult to reproduce in standard glass simulations.Comment: 4 pages, 4 figure

    Secret key generation from Gaussian sources using lattice hashing

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    We propose a simple yet complete lattice-based scheme for secret key generation from Gaussian sources in the presence of an eavesdropper, and show that it achieves strong secret key rates up to 1/2 nat from the optimal in the case of "degraded" source models. The novel ingredient of our scheme is a lattice-hashing technique, based on the notions of flatness factor and channel intrinsic randomness. The proposed scheme does not require dithering.Comment: 5 pages, Conference (ISIT 2013

    Fire extinguishant materials

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    Fire extinguishant composition comprising a mixture of a finely divided aluminum compound and alkali metal, stannous or plumbous halide is provided. Aluminum compound may be aluminum hydroxide, alumina or boehmite but preferably it is an alkali metal dawsonite. The metal halide may be an alkali metal, e.g. potassium iodide, bromide or chloride or stannous or plumbous iodide, bromide or chloride. Potassium iodide is preferred

    Reduction of the radar cross section of arbitrarily shaped cavity structures

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    The problem of the reduction of the radar cross section (RCS) of open-ended cavities was studied. The issues investigated were reduction through lossy coating materials on the inner cavity wall and reduction through shaping of the cavity. A method was presented to calculate the RCS of any arbitrarily shaped structure in order to study the shaping problem. The limitations of this method were also addressed. The modal attenuation was studied in a multilayered coated waveguide. It was shown that by employing two layers of coating, it was possible to achieve an increase in both the magnitude of attenuation and the frequency band of effectiveness. The numerical method used in finding the roots of the characteristic equation breaks down when the coating thickness is very lossy and large in terms of wavelength. A new method of computing the RCS of an arbitrary cavity was applied to study the effects of longitudinal bending on RCS reduction. The ray and modal descriptions for the fields in a parallel plate waveguide were compared. To extend the range of validity of the Shooting and Bouncing Ray (SBR) method, the simple ray picture must be modified to account for the beam blurring

    Modified dispersion relations and black hole physics

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    A modified formulation of energy-momentum relation is proposed in the context of doubly special relativity. We investigate its impact on black hole physics. It turns out that such modification will give corrections to both the temperature and the entropy of black holes. In particular this modified dispersion relation also changes the picture of Hawking radiation greatly when the size of black holes approaching the Planck scale. It can prevent black holes from total evaporation, as a result providing a plausible mechanism to treat the remnant of black holes as a candidate for dark matter.Comment: 4 pages, Revtex. Final version to appear in PR

    Homeownership Rates of Married Couples: An Econometric Investigation

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    Ownership patterns for young (under 45) married couples are striking in two respects. First, ownership rates rise dramatically with age: couples 35- 44 consistently have ownership rates nearly 50 percentage points higher than couples under 25. Second, half of the sharp ownership gains of young married couples in the 1970s were reversed in the first half of the 1980s. These patterns do not hold either for single or other households or for married couples over 44. To increase understanding of this variability by age and over time, we analyze the tenure behavior of young married couples using aggregate income/age-class data from the 1973-83 Annual (American) Housing Surveys (AHS). The income of a household affects its tenure choice both directly (the taste for ownership rises with income) and indirectly (the cost of owning declines as income rises owing to the greater value of investment in a nontaxed asset for investors in higher tax brackets). Age affects tenure choice because older households have higher incomes, are less mobile (annual-equivalent transactions costs are lower), have more wealth (portfolio diversification for owner- occupiers is easier), and have more certain income (and are thus more willing to commit to ownership). Price and income elasticities for tenure choice are computed, the rise in ownership rates between 1973 and 1979 and the subsequent decline are interpreted, and an impact of the Tax Reform Act of 1986 is predicted.

    Beyond the brotherhood: Skoal Bandits' role in the evolution of marketing moist smokeless tobacco pouches.

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    Background:Since 2006, "snus" smokeless tobacco has been sold in the U.S.. However, U.S. Smokeless Tobacco (USST) and Swedish Match developed and marketed pouched moist snuff tobacco (MST) since 1973. Methods:Analysis of previously secret tobacco documents, advertisements and trade press. Results:USST partnered with Swedish Match, forming United Scandia International to develop pouch products as part of the "Lotus Project." Pouched MST was not commonly used, either in Sweden or the U.S. prior to the Lotus Project's innovation in 1973. The project aimed to transform smokeless tobacco from being perceived as an "unsightly habit of old men" into a relevant, socially acceptable urban activity, targeting 15-35 year-old men. While USST's initial pouched product "Good Luck," never gained mainstream traction, Skoal Bandits captured significant market share after its 1983 introduction. Internal market research found that smokers generally used Skoal Bandits in smokefree environments, yet continued to smoke cigarettes in other contexts. Over time, pouch products increasingly featured increased flavor, size, nicotine strength and user imagery variation. Conclusions:Marlboro and Camel Snus advertising mirrors historical advertising for Skoal Bandits, designed to recruit new users and smokers subjected to smokefree places. Despite serious efforts, pouched MST marketing has been unable to dispel its association with traditional smokeless tobacco stereotypes as macho and rural. Public education efforts to discourage new users and dual use of MST and cigarettes should emphasize that "new" pouch products are simply repackaging "old" smokeless tobacco

    CIVIC LIFE: Evidence Base for the Triennial Review

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    This document forms part of the Equality and Human Rights Commission triennial review and covers equalities in civic life. It examines equality in political participation, freedom of language and freedom of worship. The primary aim is to map the various dimensions of equality and inequality in participation in civic and political life. We explore and review equalities, good relations and human rights in relation to civic life, and where possible we examine some of the driving forces behind the differences that we observe
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