A new numerical manifold （NMM） method is derived on the basis of quartic uniform B-spline interpolation. The analysis shows that the new interpolation function possesses higher-order continuity and polynomial consis...A new numerical manifold （NMM） method is derived on the basis of quartic uniform B-spline interpolation. The analysis shows that the new interpolation function possesses higher-order continuity and polynomial consistency compared with the conven- tional NMM. The stiffness matrix of the new element is well-conditioned. The proposed method is applied for the numerical example of thin plate bending. Based on the prin- ciple of minimum potential energy, the manifold matrices and equilibrium equation are deduced. Numerical results reveal that the NMM has high interpolation accuracy and rapid convergence for the global cover function and its higher-order partial derivatives.展开更多
This paper describes a new method for simulation of the cross section shape of log. The self-developed MQK3102 log shape recognizing machine was used to acquire the finite discrete sampling points on the cross section...This paper describes a new method for simulation of the cross section shape of log. The self-developed MQK3102 log shape recognizing machine was used to acquire the finite discrete sampling points on the cross section of log and those points were fitted with the quadratic B-spline parametric curve. This method can clearly stimulate the real shape of the log cross section and is characterized by limited sampling points and high speed computing. The computed result of the previous curve does not affect the next one, which may avoid the graphic distortion caused by the accumulative error. The method can be used to simulate the whole body shape of log approximately by sampling the cross sections along the length direction of log, thus providing a reference model for optimum saw cutting of log.展开更多
提出了一种根据接收正交频分复用(orthogonal frequency division multiplexing,OFDM)信号估计发射机IQ不平衡与非线性,并以此作为发射机指纹进行通信设备身份认证的方法.首先根据共轭对称导频估计多径信道脉冲响应,接着根据信道脉冲响...提出了一种根据接收正交频分复用(orthogonal frequency division multiplexing,OFDM)信号估计发射机IQ不平衡与非线性,并以此作为发射机指纹进行通信设备身份认证的方法.首先根据共轭对称导频估计多径信道脉冲响应,接着根据信道脉冲响应估计、共轭反对称导频与非线性功放的线性近似放大倍数估计发射机的IQ不平衡参数组合,然后进行发射机非线性的B-Spline神经网络模型系数估计,最后从非线性模型系数估计中提取相似因子,与IQ不平衡参数组合估计构成发射机指纹的特征矢量后进行通信设备身份的识别或确认.理论推导与数值仿真显示,该方法可用于OFDM通信设备的物理层高强度认证与防假冒等.展开更多
基金supported by the Fund of National Engineering and Research Center for Highways in Mountain Area(No.gsgzj-2012-05)the Fundamental Research Funds for the Central Universities of China(No.CDJXS12240003)the Scientific Research Foundation of State Key Laboratory of Coal Mine Disaster Dynamics and Control(No.2011DA105287-MS201213)
文摘A new numerical manifold （NMM） method is derived on the basis of quartic uniform B-spline interpolation. The analysis shows that the new interpolation function possesses higher-order continuity and polynomial consistency compared with the conven- tional NMM. The stiffness matrix of the new element is well-conditioned. The proposed method is applied for the numerical example of thin plate bending. Based on the prin- ciple of minimum potential energy, the manifold matrices and equilibrium equation are deduced. Numerical results reveal that the NMM has high interpolation accuracy and rapid convergence for the global cover function and its higher-order partial derivatives.
基金The research is supported by Project of National Natural Science Foundation of China(30571455)and National "948" Project(2005-4-62)
文摘This paper describes a new method for simulation of the cross section shape of log. The self-developed MQK3102 log shape recognizing machine was used to acquire the finite discrete sampling points on the cross section of log and those points were fitted with the quadratic B-spline parametric curve. This method can clearly stimulate the real shape of the log cross section and is characterized by limited sampling points and high speed computing. The computed result of the previous curve does not affect the next one, which may avoid the graphic distortion caused by the accumulative error. The method can be used to simulate the whole body shape of log approximately by sampling the cross sections along the length direction of log, thus providing a reference model for optimum saw cutting of log.
文摘提出了一种根据接收正交频分复用(orthogonal frequency division multiplexing,OFDM)信号估计发射机IQ不平衡与非线性,并以此作为发射机指纹进行通信设备身份认证的方法.首先根据共轭对称导频估计多径信道脉冲响应,接着根据信道脉冲响应估计、共轭反对称导频与非线性功放的线性近似放大倍数估计发射机的IQ不平衡参数组合,然后进行发射机非线性的B-Spline神经网络模型系数估计,最后从非线性模型系数估计中提取相似因子,与IQ不平衡参数组合估计构成发射机指纹的特征矢量后进行通信设备身份的识别或确认.理论推导与数值仿真显示,该方法可用于OFDM通信设备的物理层高强度认证与防假冒等.
