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Transformations for nonideal uniform circular arrays operating in correlated signal environments 总被引:2,自引:0,他引:2
Buon Kiong Lau Yee Hong Leung Yanqun Liu Kok Lay Teo 《Signal Processing, IEEE Transactions on》2006,54(1):34-48
The Davies transformation is a method to transform the steering vector of a uniform circular array (UCA) to one with Vandermonde form. As such, it allows techniques such as spatial smoothing for direction-of-arrival (DOA) estimation in a correlated signal environment, developed originally for uniform linear arrays, to be applied to UCAs. However, the Davies transformation can be highly sensitive to perturbations of the underlying array model. This paper presents a method for deriving a more robust transformation using optimization techniques. The effectiveness of the method is illustrated through a number of DOA estimation examples. 相似文献
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Dual-Mode Microstrip Open-Loop Resonators and Filters 总被引:1,自引:0,他引:1
A miniature dual-mode microstrip open-loop resonator is proposed. Distinct characteristics of this new type of dual-mode resonator are investigated using full-wave electromagnetic simulations. It is shown that the two operating modes, i.e., the even and odd modes, within a single dual-mode resonator of this type do not couple. It is also found that there is a finite-frequency transmission zero inherently associated with the even mode. Two two-pole filters using this type of dual-mode resonator are demonstrated with opposite asymmetric responses, which result from different locations of the transmission zero. Higher order filters of this type are also investigated. Both simulated and measured results are presented. 相似文献
65.
H9000 V4.0计算机监控系统技术特点概要 总被引:8,自引:3,他引:5
为了满足三峡右岸电站的应用需要,在H9000 V3.0计算机监控系统的基础上研制开发了H9000 V4.0系统,改进和完善了原系统已有功能,开发了新功能,进一步提高了系统的性能指标和可靠性指标。文中主要介绍H9000 V4.0系统的设计原则,以及数据采集、人机联系、报表定制、Web信息发布、历史数据管理等主要新功能。 相似文献
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Effects of home preparation on pesticide residues in cabbage 总被引:4,自引:0,他引:4
Experiment was carried out to evaluate the pesticides (chlorpyrifos, p,p-DDT, cypermethrin, chlorothalonil) residue levels in cabbage in the process of home preparation by washing with different concentrations of acetic acid and sodium chlorine, and tap water, preserving in refrigerator, and stir-frying for different time. Results showed that washing by tap water and/or detergent solution for cooking are necessary to decrease the concentration of pesticide residues in cabbage. Washing with acetic acid solutions (at 10% concentration for 20 min) caused 79.8%, 65.8%, 74.0% and 75.0% loss of the above pesticides, respectively. Washing with NaCl solutions (at 10% concentration for 20 min) produced 67.2%, 65.0%, 73.3% and 74.1% loss, respectively, and washing by tap water (for 20 min) were 17.6%, 17.1%, 19.1% and 15.2% loss, respectively. The reductions due to the refrigeration (for 48 h) were 3.4%, 2.6%, 3.1% and 3.6%, respectively, and those due to the stir-frying (for 5 min) were 86.6%, 67.5%, 84.7% and 84.8%, respectively. The data indicated that washing by detergent solutions and stir-frying of cabbage are the most effective home preparations for the elimination of pesticide residues. 相似文献
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