86 results for “Fluctuation”

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Research ArticleOpen accessIn the abstractAerodynamic Noise Prediction Using stochastic Turbulence ModelingArash Ahmadzadegan, Mehran TadjfarAmongst many approaches to determine the sound propagated from turbulent flows, hybrid methods, in which the turbulent noise source field is computed or modeled separately from the far field calculation, are frequently used. For basic estimation of sound propagation, less computationally intensive methods can be developed using stochastic models of the turbulent fluctuations (turbulent noise source field). A simple and … …American Journal of Applied Sciences, Vol. 5, Issue 9 · 30 Sep 2008 · 7,223 accessesView PDF Cite

Research ArticleOpen accessIn the abstractInclusion Identification by Inverse Application of Boundary Element Method, Genetic Algorithm and Conjugate Gradient MethodMahmud Khodadad, Mohsen Dashti ArdakaniCharacterization of the interior of an inhomogeneous body using displacement measurements obtained by conducting a simple tension test was investigated. A homogeneous elastic solid body is assumed to have another solid body with arbitrary shape hidden inside it. The shape and physical properties of this inclusion were unknown. The Boundary Element Method (BEM) coupled with a mete heuristic Genetic Algorithm … …American Journal of Applied Sciences, Vol. 5, Issue 9 · 30 Sep 2008 · 6,758 accessesView PDF Cite

Research ArticleOpen accessIn the abstractHandover Outage Time Optimization in Heterogeneous NetworksS. LouvrosHandover is a very critical parameter in Cellular Networks. The outage handover time is a drawback for Quality of Service in wireless voice applications and heterogeneous cellular wireless networks. Apart from existing handover technique, a novel approach has been developed known as Network Assisted Handover improving the outage handover time and the fluctuations of data throughput. …Journal of Computer Science, Vol. 3, Issue 11 · 30 Nov 2007 · 6,551 accessesView PDF Cite

Research ArticleOpen accessIn the abstractDevelopment of an Axisymmetric Thermal Plume between Vertical PlatesJamil Zinoubi, Adel Gammoudi, Taoufik Naffouti et al.This investigation analyses the turbulent structure of a thermal plume created by a heated disk, evolving between vertical plates. The objective of the study was to understand the development mechanisms of this buoyancy driven flow. The analysis of the average and the fluctuating fields of the temperature as well as the flow visualisation show the existence of three different zones. … …American Journal of Applied Sciences, Vol. 4, Issue 9 · 30 Sep 2007 · 7,038 accessesView PDF Cite

Research ArticleOpen accessIn the abstractA Sudden Change In Rainfall Characteristics In Amman, Jordan During The Mid 1950sMahmoud M. Smadi, Ahmed ZghoulThis study examines recent changes, trends and fluctuations in the total rainfall and number of rainy days at Amman Airport Meteorological (AAM) station in Jordan during the period 1922-2003. The occurrence of abrupt changes and trends were examined and identified using the Pettitt test, a combination of cumulative sum charts (CUSUM) and bootstrapping and the sequential version of Mann-Kendall rank … …American Journal of Environmental Sciences, Vol. 2, Issue 3 · 30 Sep 2006 · 10,007 accessesView PDF Cite

Research ArticleOpen accessIn the abstractStudy of the Flow Structure of A Thermal Plume Evolving in an Unlimited and in A Semi-Enclosed EnvironmentJamil Zinoubi, A. Ould Mohamed Mahmoud, Taoufik Naffouti et al.The basic objective of this study was to better knowledge the fine flow structure of thermal plume created by a heated disk, evolving in an unlimited and in a semi-enclosed environment. The flow visualization and the study of the temperature fluctuations spectrum show clearly a considerable change of the turbulent structure of the internal flow in comparison with the free … …American Journal of Applied Sciences, Vol. 3, Issue 1 · 31 Jan 2006 · 7,030 accessesView PDF Cite