室外非视距(non line of sight,NLOS)环境中障碍物会阻碍终端电磁波信号直接传播到基站,而且该条件下单基站收集的定位信息不足,导致定位精度不高。针对上述问题,提出一种基于空间布局的散射区模型和基于参数聚类的定位算法。根据固定...室外非视距(non line of sight,NLOS)环境中障碍物会阻碍终端电磁波信号直接传播到基站,而且该条件下单基站收集的定位信息不足,导致定位精度不高。针对上述问题,提出一种基于空间布局的散射区模型和基于参数聚类的定位算法。根据固定基站附近的空间布局确定散射区并构建散射区模型,该算法基于该模型收集多径信号的测量参数,将k-means聚类(k-means clustering)和均值漂移聚类(means shift clustering)算法有效结合对参数聚类处理,再根据聚类结果和单站定位系统的几何结构建立方程组,将方程组的求解问题转化为非线性优化问题并利用列文伯格-马夸尔特(Levenberg-Marquardt,LM)算法求解优化问题估计目标位置。仿真结果表明,在室外NLOS环境中,且仅提供单个基站的条件下,该算法可以有效提高定位结果的精度。展开更多
In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-160 elastic scattering is presented based on the α particle model of 160. The differential cross sections, t...In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-160 elastic scattering is presented based on the α particle model of 160. The differential cross sections, the analyzing powers, and the total cross sections of the intermediate energy proton-160 scattering have been calculated by using the obtained optical potential. The main features of the measured angular distributions of the cross section and the analyzing power can be well described. The calculated total cross sections are in good agreement with the experimental data at energies below 0.7 GeV and underestimate the data about 8% at higher energies.展开更多
In this paper,research is conducted on the characteristics of coda Q values of the Jiangsu area,based on the Aki single backscattering model with the waveforms recorded by the Jiangsu digital seismic network. The resu...In this paper,research is conducted on the characteristics of coda Q values of the Jiangsu area,based on the Aki single backscattering model with the waveforms recorded by the Jiangsu digital seismic network. The results show that the Jiangsu area is a high Q value area as a whole,but the Q value differs obviously between different regions,characterized generally as high in the south and low in the north. This study focuses on 4 sub-regions where the stations are relatively dense,the tectonic features are distinguishing,and the calculation results of coda Q0 are fairly concentrated,and obtains the characteristic relationship between the Q value and frequency of the 4 regions. The region from south Jiangsu to the Yangtze River estuary and that around the Maoshan fault zone are the high Q value areas in Jiangsu; the region from central Jiangsu to the waterfront area is the low Q value area in Jiangsu Province,and the Lianyungang region in northern Jiangsu is the moderate Q value area. Comparing the tectonic activity and seismicity of the 4 different Q value sub-regions,there is a certain correlation between Q value,crustal movement and seismicity.展开更多
文摘室外非视距(non line of sight,NLOS)环境中障碍物会阻碍终端电磁波信号直接传播到基站,而且该条件下单基站收集的定位信息不足,导致定位精度不高。针对上述问题,提出一种基于空间布局的散射区模型和基于参数聚类的定位算法。根据固定基站附近的空间布局确定散射区并构建散射区模型,该算法基于该模型收集多径信号的测量参数,将k-means聚类(k-means clustering)和均值漂移聚类(means shift clustering)算法有效结合对参数聚类处理,再根据聚类结果和单站定位系统的几何结构建立方程组,将方程组的求解问题转化为非线性优化问题并利用列文伯格-马夸尔特(Levenberg-Marquardt,LM)算法求解优化问题估计目标位置。仿真结果表明,在室外NLOS环境中,且仅提供单个基站的条件下,该算法可以有效提高定位结果的精度。
基金The project supported by National Natural Science Foundation of China under Grant No. 10465001
文摘In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-160 elastic scattering is presented based on the α particle model of 160. The differential cross sections, the analyzing powers, and the total cross sections of the intermediate energy proton-160 scattering have been calculated by using the obtained optical potential. The main features of the measured angular distributions of the cross section and the analyzing power can be well described. The calculated total cross sections are in good agreement with the experimental data at energies below 0.7 GeV and underestimate the data about 8% at higher energies.
基金jointly funded by the Science & Technology Pillar Program of Jiangsu Province(BE2011814)the Youth Research Project on Earthquake Trend Tracking of China Earthquake Administration(2014020122)the Key Project of Youth Fund of Earthquake Administration of Jiangsu Province(201402)
文摘In this paper,research is conducted on the characteristics of coda Q values of the Jiangsu area,based on the Aki single backscattering model with the waveforms recorded by the Jiangsu digital seismic network. The results show that the Jiangsu area is a high Q value area as a whole,but the Q value differs obviously between different regions,characterized generally as high in the south and low in the north. This study focuses on 4 sub-regions where the stations are relatively dense,the tectonic features are distinguishing,and the calculation results of coda Q0 are fairly concentrated,and obtains the characteristic relationship between the Q value and frequency of the 4 regions. The region from south Jiangsu to the Yangtze River estuary and that around the Maoshan fault zone are the high Q value areas in Jiangsu; the region from central Jiangsu to the waterfront area is the low Q value area in Jiangsu Province,and the Lianyungang region in northern Jiangsu is the moderate Q value area. Comparing the tectonic activity and seismicity of the 4 different Q value sub-regions,there is a certain correlation between Q value,crustal movement and seismicity.
