本文设计出一种针对脉冲噪声的二维鲁棒高分辨率波达方向(DOA,Direction of Arrival)估计算法,以解决雷达、声纳等无线通信领域中脉冲噪声环境下IAA(Iterative Adaptive Approach)无法准确估计出DOA的问题.该算法中,用最小p阶范数代替WL...本文设计出一种针对脉冲噪声的二维鲁棒高分辨率波达方向(DOA,Direction of Arrival)估计算法,以解决雷达、声纳等无线通信领域中脉冲噪声环境下IAA(Iterative Adaptive Approach)无法准确估计出DOA的问题.该算法中,用最小p阶范数代替WLS(Weighted Least Squares)作为最优化求解的代价函数.此外,根据Toeplitz-Block-Toeplitz(TBT)矩阵性质和FFT简化计算过程,提出该算法的快速实现方法,提高算法的计算效率.该算法在对称α-稳定(SαS,Symmetric Alpha-Stable)分布噪声环境下建模,仿真结果表明:与CRCO-MUSIC(Co Rrentropy based COrrelationMUltiple Signal Classification)算法和MUSIC-FLOM(MUltiple Signal Classification-Fractional Lower-Order Moment)算法相比,二维lp-IAA算法可以在低信噪比、单快拍条件下有效分辨出相邻多目标信号;快速算法可以在保证高分辨率的前提下,算法平均运算时间降低至原来的约1/40.展开更多
With the rapid development of wireless technologies, it is possible for Chinese greenhouses to be equipped with wireless sensor networks due to their low-cost, simplicity and mobility. In the current study, we compare...With the rapid development of wireless technologies, it is possible for Chinese greenhouses to be equipped with wireless sensor networks due to their low-cost, simplicity and mobility. In the current study, we compared the advantages of ZigBee with other two similar wireless networking protocols, Wi-Fi and Bluetooth, and proposed a wireless solution for green- house monitoring and control system based on ZigBee technology. As an explorative application of ZigBee technology in Chinese greenhouse, it may promote Chinese protected agriculture.展开更多
This study reviewed the urban passenger transportation(UPT)development of seven typical cities in China from 2000 to 2014,estimated the UPT CO2emission,analyzed the structure,and discussed the main factors of UPT CO,e...This study reviewed the urban passenger transportation(UPT)development of seven typical cities in China from 2000 to 2014,estimated the UPT CO2emission,analyzed the structure,and discussed the main factors of UPT CO,emission.Results showed that increases of GDP,population,and UPT scale of the cities have speeded up.The most significant development of UPT is that the growth of private vehicles is greatly faster than that of public transportation.The total and per-capita UPT CO2 emissions both increased.The share of private vehicles emission to total UPT CO2emission has increased,with the share in range of 65%-88%in 2014,exponentially leading to the increases of total and per-capita UPT CO2 emission.Although UPT CO2 emission structure with more share of public transportation would slow down the UPT CO2emission increase,private vehicle CO2 emission is recognized as the dominated driving factor.Contributions of driving factors,such as GDP,population,private vehicle CO2 emissions,to UPT CO2 emission are different among the cities.Private vehicle CO2 emission.is the dominated factor for UPT CO2emission in Beijing and Taiyuan.Besides private vehicle CO2emission,GDP also plays an important role in UPT CO2emissions of Chengdu,Shanghai,Guangzhou,and Urumqi.Contributions of private vehicle CO2 emission and GDP to UPT CO2 emission are almost same in Xi'an.展开更多
文摘本文设计出一种针对脉冲噪声的二维鲁棒高分辨率波达方向(DOA,Direction of Arrival)估计算法,以解决雷达、声纳等无线通信领域中脉冲噪声环境下IAA(Iterative Adaptive Approach)无法准确估计出DOA的问题.该算法中,用最小p阶范数代替WLS(Weighted Least Squares)作为最优化求解的代价函数.此外,根据Toeplitz-Block-Toeplitz(TBT)矩阵性质和FFT简化计算过程,提出该算法的快速实现方法,提高算法的计算效率.该算法在对称α-稳定(SαS,Symmetric Alpha-Stable)分布噪声环境下建模,仿真结果表明:与CRCO-MUSIC(Co Rrentropy based COrrelationMUltiple Signal Classification)算法和MUSIC-FLOM(MUltiple Signal Classification-Fractional Lower-Order Moment)算法相比,二维lp-IAA算法可以在低信噪比、单快拍条件下有效分辨出相邻多目标信号;快速算法可以在保证高分辨率的前提下,算法平均运算时间降低至原来的约1/40.
基金Project (No. 2005C22060) supported by the Science and Technology Department of Zhejiang Province, China
文摘With the rapid development of wireless technologies, it is possible for Chinese greenhouses to be equipped with wireless sensor networks due to their low-cost, simplicity and mobility. In the current study, we compared the advantages of ZigBee with other two similar wireless networking protocols, Wi-Fi and Bluetooth, and proposed a wireless solution for green- house monitoring and control system based on ZigBee technology. As an explorative application of ZigBee technology in Chinese greenhouse, it may promote Chinese protected agriculture.
基金the National Natural Science Foundation of China(41301033).
文摘This study reviewed the urban passenger transportation(UPT)development of seven typical cities in China from 2000 to 2014,estimated the UPT CO2emission,analyzed the structure,and discussed the main factors of UPT CO,emission.Results showed that increases of GDP,population,and UPT scale of the cities have speeded up.The most significant development of UPT is that the growth of private vehicles is greatly faster than that of public transportation.The total and per-capita UPT CO2 emissions both increased.The share of private vehicles emission to total UPT CO2emission has increased,with the share in range of 65%-88%in 2014,exponentially leading to the increases of total and per-capita UPT CO2 emission.Although UPT CO2 emission structure with more share of public transportation would slow down the UPT CO2emission increase,private vehicle CO2 emission is recognized as the dominated driving factor.Contributions of driving factors,such as GDP,population,private vehicle CO2 emissions,to UPT CO2 emission are different among the cities.Private vehicle CO2 emission.is the dominated factor for UPT CO2emission in Beijing and Taiyuan.Besides private vehicle CO2emission,GDP also plays an important role in UPT CO2emissions of Chengdu,Shanghai,Guangzhou,and Urumqi.Contributions of private vehicle CO2 emission and GDP to UPT CO2 emission are almost same in Xi'an.
