Experimental studies on the multistage constant modulus array for the estimation of directions-of-arrival

The performance of the multistage Constant Modulus (CM) array, one of the most striking blind beamforming algorithms, for the source Directions-of-Arrival (DOA) estimation was analyzed via computer simulations and water tank experiments, and was compared to that of other DOA estimation algorithms including the ‘non-blind‘ and the ‘blind‘. Firstly, a nominal array model and an array model with gain and phase perturbations were established,respectively. Secondly, the multistage CM array algorithm was described and computer simulations were conducted. Simulation results showed that the multistage CM array could correctly estimate the DOA at the same time when the sources were blindly recovered, and the angle separating ability of the algorithm was beyond the Rayleigh resolution limit. By changing the variance of the array model errors, it was also verified that the multistage CM array was more robust to the errors than some other algorithms mentioned in this paper. Finally, water tank experiments and data processing results were provided. Situations with different array sizes and source angular separations were considered. It was shown that the results were in good agreement with computer simulations. Results of computer simulations and water tank experiments verified that the DOAs of the multiple independent sources could be blindly and robustly estimated with the multistage CM array.     

化学优质课3C-FIAS常模的建立研究

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本文是关于儿童智力筛查量表浙江省常模的编制报告。取样于浙江省四市二镇七县6～12岁696名儿童。利用前已确定的量表内容逐个进行测试,分别建立城市与农村常模。量表重测信度系数为0.94,效度估计为0.78,0.83,0.89等.常模中对弱智儿童的检出频率为0.02,这与国内外同类量表的检出频率相接近。临床初步应用结果较有效。     

从近年广东高考看2010年广东理科综合化学考纲

2010年广东课改实验区高考模式由"3+1+X"变为"3+理科综合/文科综合",如何更好地适应新形势下高考备考要求?从近年广东高考的命题模式、考试模式、解释模式、试题特点等方面进行分析,对新考纲的外延及内涵进行研读。     

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