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81.
自适应RBF神经网络在CDMA移动通信上行链路功率控制中的应用研究 总被引:1,自引:0,他引:1
提出了一种自适应RBF神经网络功率控制方案。详细研究了该网络在DS-CDMA通信中,进行上行链路闭环功率控制(基于信扰比(SIR))的应用理论,给出了该网络参数的计算方法。最后用计算机仿真法模拟出该控制器的运行性能。结果表明基于SIR的自适应RBF神经网络功率控制器能自适应地调整移动台的发射功率,使基站接收信号的信扰比始终非常接近于一个常数,且有比定步长功率控制更小的SIR跟踪误差,从而可以降低接收信号的中断概率、提高信道容量。 相似文献
82.
RLL码的计算机辅助设计 总被引:1,自引:1,他引:0
本文着重讨论计算机辅助设计RLL码的具体实现问题.该过程首先根据RLL码两个参数d,k确定一个编码率p/q,然后构造出RLL码的高阶状态转换-输出符号矩阵并求相应的近似特征向量.最后通过状态分裂和状态归并过程,即可得到一个满足d,k约束的编码输出表.其中状态转换-输出符号矩阵为实现计算机辅助设计RLL码提供了有效的数据结构,而且要优化RLL码编码器,就必须有选择地进行状态分裂. 相似文献
83.
The interstitial assemblages of the River Rhine were studied in the Rhinau sector (France). The studied area is located in aVegulated channel of the river, controlled by a hydroelectric dam. Twenty stations were sampled in September 1988. Ten litres of interstitial water were pumped at 50 cm depth in each station using the Bou-Rouch technique. Interstitial waters were poorly oxygenated and the hyporheic fauna had three major characteristics: (1) microcrustaceans were dominant, (2) the insects were rare and (3) the stygofauna was absent. The richest stations were well oxygenated and did not correspond to any particular geomorphological features. These findings contrast with the situation observed on other large European rivers (Rhǒne, Danube) where the interstitial assemblages appear to be locally more diversified and rich in stygofauna. 相似文献
84.
85.
文章给出n-维超立方体网络的容错路径选择算法,该算法具有自适应性,可以防止死锁和活锁现象的发生,应用该算法,可求出一条基于安全优先策略的可行最短路径。 相似文献
86.
Mao Ze yu Chen Chang zhi Department of Hydraulic Engineering Tsinghua University Beijing P.R.China 《水动力学研究与进展(B辑)》1999,(3)
1. INTRODUCTIONThesimulationofstreamwatertemperatureissignificantlyimportantforthestudyofnumericalmodelingofrivericeprocesses[1] .Historically,themathematicalmodelingofthetransportandfateofheatinawaterbodyhasbeenthesubjectofextensivestudyforvariousre… 相似文献
87.
88.
L.J. Webb 《Water research》1985,19(8):969-974
Wastewaters from the manufacture of pulp and paper have given rise to problems of excessive microbial growth in rivers over a number of years. This paper is the first in a series of four articles describing research undertaken by PIRA at four U.K. paper/board mills (one integrated with pulp production) over the period 1978–1980. This first paper briefly reviews the published literature on sewage fungus growth from pulp and paper mill discharges up to 1978, but mainly describes previously unpublished work undertaken by PIRA over the period 1965–1975. This introductory paper thus provides a state-of-the-art review of methods to control sewage fungus growth from pulp and paper mill effluents prior to commencement of the research described in the following three articles. 相似文献
89.
Large woody debris (LWD) can increase stream habitat heterogeneity by providing structure, altering flow patterns, enhancing sediment deposition, forming pools and retaining organic matter. In North America, the role of LWD has been studied extensively in streams of mature forests (e.g. Pacific Northwest), but few studies have assessed LWD in streams of younger forests (e.g. Midwestern USA). Our objectives were to: (1) quantify the volume and abundance of LWD in a set of Midwestern streams; (2) evaluate possible factors influencing LWD quantity; (3) identify the functional roles of LWD; and (4) compare LWD levels in the upper Midwest to those elsewhere in North America. In 2002 and 2003, we measured LWD and geomorphological variables in 15 low‐gradient streams draining previously logged watersheds in the Upper Peninsula of Michigan. Mean (±SE) LWD volume (0.77 ± 0.12 m3 100 m−2) and abundance (33 ± 3 pieces 100 m−1) were 71% and 10% lesser, respectively, than in streams of similar gradient elsewhere in North America. Channel shape (width:depth ratio) explained 30% of the variation in LWD volume (multiple stepwise regression, P = 0.015) while LWD length and length:channel width combined, explained 72% of the variation in LWD density (multiple stepwise regression, P < 0.0001). About 50% of the LWD either stored sediment or stabilized banks and 14% of the LWD formed pools, although pool density was not significantly related to LWD volume or density. LWD levels, overall, were low in upper Midwestern streams, but the relative importance of that LWD to ecosystem function may be magnified in these wood‐poor systems. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
90.
钱塘江光缆管穿越长度2454.15m,穿越深度为32m,穿越中采用了多项新技术、新工艺、新方法。文章介绍了导向孔对穿技术、套管技术、水下磁场电缆铺设技术、长距离泥浆回流技术、长距离穿越钻杆组合技术在钱塘江光缆管穿越施工中的应用。 相似文献