381 research outputs found

    Real-Time Model of a Large-scale Water Distribution System

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    AbstractThis paper presents a real-time WDS hydraulic model combining with field measurements provided by supervisory control and data acquisition systems (SCADA). The system is composed of three parts, namely SCADA, state estimation server and client terminal. For the real-time demand estimation, a weighted least-squares scheme based recursive state estimator and local linear matrix transform algorithm are applied. The WDS model system is applied in Guangzhou city, which is one of the largest cities in China, and proves that the proposed nodal demand correction algorithms are effective for real-time WDS model

    Who Are the Workers Who Never Joined a Union? : Empirical Evidence from Western and Eastern Germany

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    "Using representative data from the German social survey ALLBUS 2002 and the European Social Survey 2002/03, this paper provides the first empirical analysis of trade union ‘never-membership’ in Germany. We show that between 54 and 59 percent of all employees in Germany have never been members of a trade union. In western Germany, individuals’ probability of ‘never-membership’ is significantly affected by their personal characteristics, their political orientation and (to a lesser degree) their family background. In addition, the presence of a union at the workplace plays a significant role. While the latter factor is also important in eastern Germany, many of the variables which are relevant for ‘never-membership’ in the west prove to be irrelevant in the east. This difference probably reflects the fact that most employees in eastern Germany did not really have a choice not to become union members during the communist regime." (author's abstract)"Mit Daten des ALLBUS 2002 und des European Social Survey 2002/03 analysiert diese Arbeit erstmalig die ‚Nie-Mitgliedschaft’ in deutschen Gewerkschaften. Wir zeigen, dass 54 bis 59 Prozent aller Beschäftigten in Deutschland niemals Mitglied einer Gewerkschaft waren. Die individuelle Wahrscheinlichkeit einer ‚Nie-Mitgliedschaft’ hängt in Westdeutschland signifikant mit persönlichen Merkmalen, der politischen Ausrichtung und (in geringerem Maße) dem familiären Hintergrund zusammen. Darüber hinaus spielt das Vorhandensein einer Gewerkschaft am Arbeitsplatz eine signifikante Rolle. Während letzteres auch in Ostdeutschland von Bedeutung ist, erweisen sich viele der im Westen relevanten Erklärungsvariablen im Osten als irrelevant. Dieser Unterschied spiegelt wahrscheinlich wider, dass die meisten Arbeitnehmer in Ostdeutschland während des SED-Regimes kaum die Wahl hatten, auf eine Gewerkschaftsmitgliedschaft zu verzichten." (Autorenreferat

    K\"{a}hler-Einstein metrics on strictly pseudoconvex domains

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    The metrics of S. Y. Cheng and S.-T. Yau are considered on a strictly pseudoconvex domains in a complex manifold. Such a manifold carries a complete K\"{a}hler-Einstein metric if and only if its canonical bundle is positive. We consider the restricted case in which the CR structure on M\partial M is normal. In this case M must be a domain in a resolution of the Sasaki cone over M\partial M. We give a condition on a normal CR manifold which it cannot satisfy if it is a CR infinity of a K\"{a}hler-Einstein manifold. We are able to mostly determine those normal CR 3-manifolds which can be CR infinities. Many examples are given of K\"{a}hler-Einstein strictly pseudoconvex manifolds on bundles and resolutions.Comment: 30 pages, 1 figure, couple corrections, improved a couple example

    Leituras da Orfandade família, Declínio do Pai e Ausência de Lei. uma Abordagem do Universo Ficcional de Rubem Fonseca.

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    RESUMO Observamos na contemporaneidade que a família assume formas diferentes às que possuía quando foi formulada, no século XVIII. Caracterizada por inúmeras transformações, já não possui uma estrutura tão fixa. A partir das narrativas de Henri, A força humana, Feliz ano novo e O cobrador, de Rubem Fonseca; não deixando de visitar outros trabalhos do escritor, discutiremos e examinaremos as configurações da família contemporânea. Neste sentido, analisaremos as representações da relação do sujeito com as novas estruturas familiares, o declínio da imago paterna e as consequências que essas transformações trazem à subjetividade, bem como as formas pelas quais tais relações são encenadas literariamente pelo escritor brasileir

    Twenty five years after KLS: A celebration of non-equilibrium statistical mechanics

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    When Lenz proposed a simple model for phase transitions in magnetism, he couldn't have imagined that the "Ising model" was to become a jewel in field of equilibrium statistical mechanics. Its role spans the spectrum, from a good pedagogical example to a universality class in critical phenomena. A quarter century ago, Katz, Lebowitz and Spohn found a similar treasure. By introducing a seemingly trivial modification to the Ising lattice gas, they took it into the vast realms of non-equilibrium statistical mechanics. An abundant variety of unexpected behavior emerged and caught many of us by surprise. We present a brief review of some of the new insights garnered and some of the outstanding puzzles, as well as speculate on the model's role in the future of non-equilibrium statistical physics.Comment: 3 figures. Proceedings of 100th Statistical Mechanics Meeting, Rutgers, NJ (December, 2008

    Post-natal parental care in a Cretaceous diapsid from northeastern China

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    Post-natal parental care seems to have evolved numerous times in vertebrates. Among extant amniotes, it is present in crocodilians, birds, and mammals. However, evidence of this behavior is extremely rare in the fossil record and is only reported for two types of dinosaurs, and a varanopid ‘pelycosaur’. Here we report new evidence for post-natal parental care in Philydrosaurus, a choristodere, from the Yixian Formation of western Liaoning Province, China. We review the fossil record of reproduction in choristoderes, and this represents the oldest record of post-natal parental care in diapsids to our knowledge

    No additional prognostic value of genetic information in the prediction of vascular events after cerebral ischemia of arterial origin

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    Background: Patients who have suffered from cerebral ischemia have a high risk of recurrent vascular events. Predictive models based on classical risk factors typically have limited prognostic value. Given that cerebral ischemia has a heritable component, genetic information might improve performance of these risk models. Our aim was to develop and compare two models: one containing traditional vascular risk factors, the other also including genetic information. Methods and Results: We studied 1020 patients with cerebral ischemia and genotyped them with the Illumina Immunochip. Median follow-up time was 6.5 years; the annual incidence of new ischemic events (primary outcome, n=198) was 3.0%. The prognostic model based on classical vascular risk factors had an area under the receiver operating characteristics curve (AUC-ROC) of 0.65 (95% confidence interval 0.61-0.69). When we added a genetic risk score based on prioritized SNPs from a genome-wide association study of ischemic stroke (using summary statistics from the METASTROKE study which included 12389 cases and 62004 controls), the AUC-ROC remained the same. Similar results were found for the secondary outcome ischemic stroke. Conclusions: We found no additional value of genetic information in a prognostic model for the risk of ischemic events in patients with cerebral ischemia of arterial origin. This is consistent with a complex, polygenic architecture, where many genes of weak effect likely act in concert to influence the heritable risk of an individual to develop (recurrent) vascular events. At present, genetic information cannot help clinicians to distinguish patients at high risk for recurrent vascular events

    Can COBE see the shape of the universe?

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    In recent years, the large angle COBE--DMR data have been used to place constraints on the size and shape of certain topologically compact models of the universe. Here we show that this approach does not work for generic compact models. In particular, we show that compact hyperbolic models do not suffer the same loss of large angle power seen in flat or spherical models. This follows from applying a topological theorem to show that generic hyperbolic three manifolds support long wavelength fluctuations, and by taking into account the dominant role played by the integrated Sachs-Wolfe effect in a hyperbolic universe.Comment: 16 Pages, 5 Figures. Version published in Phys. Rev.
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