Large eddy simulation inflow generation using reduced length scales for flows past low-rise buildings

When undertaking wind assessment around buildings using large eddy simulation (LES), the implementation of the integral length scale at the inlet for inflow generation is controversial, as real atmospheric length scales require huge computational domains. While length scales significantly influence inflow generation in the domain, their effect on the downstream flow field has not, as yet, been investigated. In this paper, we validate the effectiveness and accuracy of implementing a reduced turbulence integral length scale for inflow generation in LES results at the rooftop of low-rise buildings and develop a technique to estimate the real local length scales using simulation results. We measure the wind locally and calculate the turbulence length scales from the energy spectrum of the wind data and simulation data. According to these results, there is an excellent agreement between the length scale from simulation and measurement when they are scaled with their corresponding freestream/inlet value. These results indicate that a reduced integral length scale can be safely used for LES to provide a reliable prediction of the energy spectrum as well as the length scales around complex geometries. The simulation results were confidently employed to obtain the best location for a wind turbine installation on low-rise buildings

Large Eddy Simulation Inflow Generation Using Reduced Length Scales for Flows Past Low-Rise Buildings

When undertaking wind assessment around buildings using large eddy simulation (LES), the implementation of the integral length scale at the inlet for inflow generation is controversial, as real atmospheric length scales require huge computational domains. While length scales significantly influence inflow generation in the domain, their effect on the downstream flow field has not, as yet, been investigated. In this paper, we validate the effectiveness and accuracy of implementing a reduced turbulence integral length scale for inflow generation in LES results at the rooftop of low-rise buildings and develop a technique to estimate the real local length scales using simulation results. We measure the wind locally and calculate the turbulence length scales from the energy spectrum of the wind data and simulation data. According to these results, there is an excellent agreement between the length scale from simulation and measurement when they are scaled with their corresponding freestream/inlet value. These results indicate that a reduced integral length scale can be safely used for LES to provide a reliable prediction of the energy spectrum as well as the length scales around complex geometries. The simulation results were confidently employed to obtain the best location for a wind turbine installation on low-rise buildings

Embedding finite and infinite words into overlapping tiles

International audienceIn this paper, we study languages of finite and infinite birooted words. We show how the embedding of free ω-semigroups of finite and infinite words into the monoid of birooted words can be generalized to the embedding of two-sorted ω-semigroups into (some notion of) one- sorted ordered ω-monoids. This leads to an algebraic characterization of regular languages of finite and infinite birooted words that generalizes and unifies the known algebraic characterizations of regular languages of finite and infinite words

Comparing Journalistic Role Performance Across Thematic Beats: A 37-Country Study

Studies suggest that, at the routine level, news beats function as unique “micro-cultures.” Exploring this “particularist” approach in news content, we compare how the interventionist, watchdog, loyal, service, infotainment, and civic roles materialize across 11 thematic news beats and analyze the moderating effect of platforms, ownership, and levels of political freedom on journalistic role performance in hard and soft news. Based on the second wave of the Journalistic Role Performance (JRP) project, this article reports the findings of a content analysis of 148,474 news items from 37 countries. Our results reveal the transversality of interventionism, the strong associations of some topics and roles, and the limited reach of news beat particularism in the face of moderating variables

Multi-mode wave propagation in ribbed plates - Part II : predictions and comparisons

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Multi-mode wave propagation in ribbed plates - Part I : K-space characteristics

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Improved joint preventive maintenance and hedging point policy

We investigate the preventive maintenance and inventory control problem of a one-machine, one-product manufacturing system subject to random breakdowns. Both preventive and corrective interventions have random and non-negligible durations during which an excess of final products inventory is necessary to fulfill demand. The objective of this study is to find the production rate and the preventive maintenance schedule that minimize the total cost of maintenance and inventory/backlog in the case of periodic preventive maintenance. A near-optimal policy characterization with a simple structure is carried out using a numerical approach. Such a policy is a combination of a hedging point policy and a modified periodic preventive maintenance strategy, under which preventive maintenance actions are performed only if the inventory level exceeds a sufficient level. A simulation-based experimental approach is adopted to achieve a close approximation of the optimal control parameters. It is concluded from a sensitivity analysis and a comparative analysis that the near-optimal control policy leads to a significant cost reduction as compared to the combination of a hedging point policy and a classical periodic preventive maintenance policy.Preventive maintenance Stochastic dynamic programming Simulation Response surface methodology

La stérilité mâle nucléo-cytoplasmique 447 chez la féverole (Vicia faba L.). I. - Etude du déterminisme maternel de l'instabilité phénotypique de la stérilité mâle

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bf-pd: Enabling Mediated Communication and Cooperation in Improvised Digital Orchestras

International audienceDigital musical instruments enable new musical collaboration possibilities, extending those of acoustic ensembles. However, the use of these new possibilities remains constrained due to a lack of a common terminology and technical framework for implementing them. Bf-pd is a new software library built in the PureData (Pd) language which enables communication and cooperation between digital instruments. Its design is based on the BOEUF conceptual framework which consists of a classification of modes of collaboration used in collective music performance , and a set of components which affords them. Bf-pd can be integrated into any digital instrument built in Pd, and provides a " collaboration window " from which musicians can easily view each others' activity and share control of instrument parameters and other musical data. We evaluate the implementation and design of bf-pd through workshops and a preliminary study and discuss its impact on collaboration within improvised ensembles of digital instruments