An optimization scheme for choosing the optimum number of secondary users in cooperative spectrum sensing based on the cyclostationary feature detection with Neyman-Pearson criterion is proposed in this paper.The opti...An optimization scheme for choosing the optimum number of secondary users in cooperative spectrum sensing based on the cyclostationary feature detection with Neyman-Pearson criterion is proposed in this paper.The optimal soft combination test statistic for the cooperative spectrum sensing based on cyclostationary feature detection is derived according to the generalized likelihood ratio test and its corresponding detection performance is deduced.A target function,considering two important parameters as the resource use efficiency and the number of samples employed by each cooperative secondary user in the system design,is constructed to obtain the optimum number of cooperative secondary users.It can be found that the selection scheme is to make a tradeoff between the system complexity of the cognitive radio network and the global sensing performance of the cooperative spectrum sensing.展开更多
The range accuracy of three-dimensional（3D） ghost imaging is derived. Based on the derived range accuracy equation, the relationship between the slicing number and the range accuracy is analyzed and an optimum slici...The range accuracy of three-dimensional（3D） ghost imaging is derived. Based on the derived range accuracy equation, the relationship between the slicing number and the range accuracy is analyzed and an optimum slicing number（OSN）is determined. According to the OSN, an improved 3D ghost imaging algorithm is proposed to increase the range accuracy. Experimental results indicate that the slicing number can affect the range accuracy significantly and the highest range accuracy can be achieved if the 3D ghost imaging system works with OSN.展开更多
It is expounded that h2/ is the Reynolds number form of thrust bearings and effects of the centrifugal forees can be judged by its magnitude. Three methods improving the configuration of pads are given out to...It is expounded that h2/ is the Reynolds number form of thrust bearings and effects of the centrifugal forees can be judged by its magnitude. Three methods improving the configuration of pads are given out to overcome the haimful influence of the centrifugal forees on the performance of bearings, and the optimized parameters for three kinds of high一speed thrust bearings are provi- ded by solving the varying一viscositied three一dimensional Reynolds equation.展开更多
基金the National Natural Science Foundation of China (Nos.60832009,60872017 and 60802058)the National High Technology Research and Development Program (863) of China (No.2009AA011505)the Important National Science and Technology Specific Projects (Nos.2010ZX03003-002-03 and 2011ZX03003-001-03)
文摘An optimization scheme for choosing the optimum number of secondary users in cooperative spectrum sensing based on the cyclostationary feature detection with Neyman-Pearson criterion is proposed in this paper.The optimal soft combination test statistic for the cooperative spectrum sensing based on cyclostationary feature detection is derived according to the generalized likelihood ratio test and its corresponding detection performance is deduced.A target function,considering two important parameters as the resource use efficiency and the number of samples employed by each cooperative secondary user in the system design,is constructed to obtain the optimum number of cooperative secondary users.It can be found that the selection scheme is to make a tradeoff between the system complexity of the cognitive radio network and the global sensing performance of the cooperative spectrum sensing.
基金Project supported by the Young Scientist Fund of the National Natural Science Foundation of China(Grant No.61108072)
文摘The range accuracy of three-dimensional（3D） ghost imaging is derived. Based on the derived range accuracy equation, the relationship between the slicing number and the range accuracy is analyzed and an optimum slicing number（OSN）is determined. According to the OSN, an improved 3D ghost imaging algorithm is proposed to increase the range accuracy. Experimental results indicate that the slicing number can affect the range accuracy significantly and the highest range accuracy can be achieved if the 3D ghost imaging system works with OSN.
文摘It is expounded that h2/ is the Reynolds number form of thrust bearings and effects of the centrifugal forees can be judged by its magnitude. Three methods improving the configuration of pads are given out to overcome the haimful influence of the centrifugal forees on the performance of bearings, and the optimized parameters for three kinds of high一speed thrust bearings are provi- ded by solving the varying一viscositied three一dimensional Reynolds equation.
