41,573 research outputs found

    Energy-efficient traffic engineering

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    The energy consumption in telecommunication networks is expected to grow considerably, especially in core networks. In this chapter, optimization of energy consumption is approached from two directions. In a first study, multilayer traffic engineering (MLTE) is used to assign energy-efficient paths and logical topology to IP traffic. The relation with traditional capacity optimization is explained, and the MLTE strategy is applied for daily traffic variations. A second study considers the core network below the IP layer, giving a detailed power consumption model. Optical bypass is evaluated as a technique to achieve considerable power savings over per-hop opticalelectronicoptical regeneration. Document type: Part of book or chapter of boo

    The integrated dynamic land use and transport model MARS

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    Cities worldwide face problems like congestion or outward migration of businesses. The involved transport and land use interactions require innovative tools. The dynamic Land Use and Transport Interaction model MARS (Metropolitan Activity Relocation Simulator) is part of a structured decision making process. Cities are seen as self organizing systems. MARS uses Causal Loop Diagrams from Systems Dynamics to explain cause and effect relations. MARS has been benchmarked against other published models. A user friendly interface has been developed to support decision makers. Its usefulness was tested through workshops in Asia. This paper describes the basis, capabilities and uses of MARS

    The Emergence of Secular Insight Practices in Australia

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    In recent years insight (vipassana) practice in Australia has diversified in content and spawned new institutions that present a more secular face. These changes exemplify the development of global Buddhism elsewhere rather than some local, sui generis divergence from international trends. Nonetheless, the unusual prominence of Buddhist migrants in the Australian population has influenced the interaction between traditional and western Buddhists, and thus the emergence of the new trends. In interpreting the transformations in question, we make heuristic use both of Martin Baumann s periodization of Buddhist history, with its characterization of the present stage as global, and Stephen Batchelor s distinction between religious Buddhism and dharma practice. The Australian experience highlights the value of the earlier interaction between migrant and locally-born Buddhists, and the formative effect their later separation has on lay practice. This experience also points to the salience of forms of association when secular Buddhist practice melds with the Western values of inclusiveness and equality, not least in gender relations

    Antimicrobial resistance and antimicrobial use animal monitoring policies in Europe: Where are we?

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    The World Health Organization has recognized antimicrobial resistance as one of the top three threats to human health. Any use of antibiotics in animals will ultimately affect humans and vice versa. Appropriate monitoring of antimicrobial use and resistance has been repeatedly emphasized along with the need for global policies. Under the auspices of the European Union research project, EFFORT, we mapped antimicrobial use and resistance monitoring programs in ten European countries. We then compared international and European guidelines and policies. In resistance monitoring, we did not find important differences between countries. Current resistance monitoring systems are focused on food animal species (using fecal samples). They ignore companion animals. The scenario is different for monitoring antibiotics use. Recently, countries have tried to harmonize methodologies, but reporting of antimicrobial use remains voluntary. We therefore identified a need for stronger policies

    Expressions for forces and torques in molecular simulations using rigid bodies

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    Expressions for intermolecular forces and torques, derived from pair potentials between rigid non-spherical units, are presented. The aim is to give compact and clear expressions, which are easily generalised, and which minimise the risk of error in writing molecular dynamics simulation programs. It is anticipated that these expressions will be useful in the simulation of liquid crystalline systems, and in coarse-grained modelling of macromolecules

    Performance Improvement for Wideband DOA estimation with White Noise Reduction Based on Uniform Linear Arrays

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    A method is proposed for reducing the effect of white noise in wide- band uniform linear arrays via a combination of a judiciously de- signed transformation followed by highpass filters. The reduced noise level leads to a higher signal to noise ratio for the system, which can have a significant effect on the performance of various direction of arrival (DOA) estimation methods. As a representative example, the compressive sensing-based wideband DOA estimation method is employed here to demonstrate the improved estimation performance, this is confirmed by simulation results

    White noise reduction for wideband beamforming based on uniform rectangular arrays

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    Two methods are proposed for reducing the effect of white noise in wideband uniform rectangular arrays via a combination of judiciously designed transformations followed by a series of highpass filters. The reduced noise level leads to a higher signal to noise ratio for the system, which in turn results in a clear improvement on the performance of various beamforming applications. As a representative example, the reference signal based (RSB) and the linearly constrained minimum variance (LCMV) beamformers are employed here to demonstrate the improved performance, which is also confirmed by simulations

    Evaluación de diseños de un Convertidor de Turbina de Viento considerando el comportamiento térmico

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    Evaluar el diseño de un convertidor de electrónica de potencia de turbinas de viento considerando el comportamiento térmico cuando estå en servicio. Cuando se diseñan convertidores de electrónica de potencia para turbinas de viento, muy frecuentemente solo la tempetratura de unión måxima entre semiconductores es considerada. Para la aplicación de una turbina de viento, el ciclo térmico debido a la fluctuación de potencia puede también retardar el tiempo de vida de los semiconductores de potencia. De ahí que un sobre diseño sea necesario para incrementar su periodo de vida y para determinarlo, es necesario realizar una estimación del periodo de vida de las unidades semiconductoras de potencia

    Ready configuration of machines into an existing manufacturing system

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    This paper focuses on simplifying and easing the integration of a new machine into an existing conventional hierarchical manufacturing system. Based on a distributed manufacturing paradigm, it proposes the functions and interfaces that a new machine and an existing manufacturing system should possess so that ready and simple configuration of additional machines can be achieved. The configuration process is intended to include, not only mechanical and electrical interfaces, but also decision system interfaces (such as planning, scheduling, and shop-floor control). Preliminary laboratory experiments to compare the reconfigurability resulting from a conventional integration method and the proposed distributed method are presented and discussed. © 2007 ISAM
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