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211.
Detailed field measurements and simulations of three‐dimensional flow structure were used to develop a conceptual model to explain the sustainability of self‐formed pool‐riffle sequences in gravel‐bed rivers. The analysis was conducted at the Red River Wildlife Management Area in Idaho, USA, and enabled characterization of the flow structure through two consecutive pool‐riffle sequences, including: identification of jet concentration and dissipation zones, and the development of local turbulence features (i.e. vertical and horizontal eddies) under different flow conditions. Three‐dimensional hydraulic simulations were used to evaluate how the flow structure varies across a range of flow conditions and with different degrees of sediment aggradation within the upstream pool. The analysis demonstrated a significant influence of the residual pool depth on the flow structure, with reduced residual depth causing a shift in the orientation of the jet and a reduction in the influence of vertical eddies and the size and intensity of horizontal eddies. The proposed conceptual model seeks to explain the sustainability of pools in terms of the flow structure in pool‐riffle morphology and how this flow structure will change as a result of altered external forcing, such as upstream sediment delivery or changes in bank stability. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
212.
在当前低碳经济背景下,对实现建筑装饰产业升级重要手段的集成化设计进行研究;从当下对建筑装饰产业的具体要求入手,对集成化开发所面临的具体问题以及解决方法进行了深入研究.最后以集成化实践应用加以印证,探讨了建筑装饰产业集成化开发的可行性. 相似文献
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802.11b无线网络环境下视频会议系统的流量特性研究 总被引:1,自引:0,他引:1
本文通过对MPEG4IP软件包的修改,测量了802.11b与802.3混和网络环境下视频会议系统的分组流量特性,包括不同视频码率和不同网络结构的组合.并与计算机系统和网络性能评价中常用的负指数分布假设的流量特性进行了比较,表明使用负指数分布与泊松到达模型对于描述无线网络环境下的视频会议系统存在很多不足.本文的测量结果对于设计WLAN环境下视频会议系统具有重要的参考价值. 相似文献
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M. Dolores Jiménez-Gamero Juan Luis Moreno-Rebollo Juan M. Muñoz-Pichardo Ana M. Muñoz-Reyes 《TEST》2005,14(2):515-542
One of the areas of Statistics in which the influence analysis has been widely studied is the multiple linear regression model.
Nevertheless, the influence diagnostics proposed in this context cannot be applied to regression in complex survey, under
randomized inference, since the i.i.d. case does not incorporate any probability weighting or population structure, such as
clustering, stratification or measures of size into the analysis.
In this paper we introduce some influence diagnostics in regression in complex survey. They are built on the conditional bias
concept (Moreno-Rebollo et al., 1999). We emphasize the similarities and differences of the proposed measures with respect
to the existing ones for the i.i.d. case.
Research partly supported by the Spanish MCYT grant BFM2001-3844 and Spanish MEC grant MTM2004-0111433. 相似文献
220.
César Muñoz Víctor Carreño Gilles Dowek Ricky Butler 《International Journal on Software Tools for Technology Transfer (STTT)》2003,4(3):371-380
Safety assessment of new air traffic management systems is a main issue for civil aviation authorities. Standard techniques
such as testing and simulation have serious limitations in new systems that are significantly more autonomous than the older
ones. In this paper, we present an innovative approach for establishing the correctness of conflict detection systems. Fundamental
to our approach is the concept of trajectory, and how we represent a continuous physical trajectory by a continuous path in
the x-y plane constrained by physical laws and operational requirements. From the model of trajectories, we extract, and formally
prove, high-level properties that can serve as a framework to analyze conflict scenarios. We use the AILS (Airborne Information
for Lateral Spacing) alerting algorithm as a case study of our approach.
Published online: 19 November 2002 相似文献