An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken ...An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken for drawing particle. To remove the noise from raw data and data processing error, adaptive wavelet filtering with threshold was adopted while data preprocessing and drawing particle. Three algorithms, named EKF-PF, UKF-PF and WM-UKF-PF, were performed for comparison. The proposed WM-UKF-PF algorithm gives better error minimization, and significantly improves performance of multipath mitigation in terms of SNR and coefficient even though it has computation complexity. It is of significance for high-accuracy positioning and non-stationary deformation analysis.展开更多
We have established an elastoplastic analysis model to explore the effect of loading path in an incompressible thin-walled tube under the combined action of axial force and torque based on Mises yield condition and is...We have established an elastoplastic analysis model to explore the effect of loading path in an incompressible thin-walled tube under the combined action of axial force and torque based on Mises yield condition and isotropic linear hardening assumption.Further,four stress areas(σx,τx)are divided according to the characteristics of the final stress,and the plastic stress-strain relationship of twelve stress paths in different stress areas is derived.The"primary effect"of the stress path on plastic strain is demonstrated,namely,the plastic strain caused by the pre-loaded stress in path A(tensile stress is initially applied,followed by shear stress)is always greater than that caused by the post-loaded stress in path C(shear stress is initially applied,followed by tensile stress)irrespective of the value of final stress.The"recency effect"of the strain path on the stress is also established,which indicates that the stress caused by the post-loaded strain in path A is always greater than that caused by the pre-loaded strain in path C irrespective of the value of final strain.From the perspective of deformation,the"primary effect"of the stress path on the plastic strain and the"recency effect"of the strain path on the stress are unified.These effects are succinct and universal,and they provide useful insights on the plastic stress-strain relationship under different loading paths.Furthermore,they can serve as a useful reference for optimizing the processing technologies and construction procedures.展开更多
基金Project(51174206)supported by the National Natural Science Foundation of ChinaProject(2013AA12A201)supported by the National Hi-tech Research and Development Program of China+1 种基金Project(2012ZDP08)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(SZBF2011-6-B35)supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken for drawing particle. To remove the noise from raw data and data processing error, adaptive wavelet filtering with threshold was adopted while data preprocessing and drawing particle. Three algorithms, named EKF-PF, UKF-PF and WM-UKF-PF, were performed for comparison. The proposed WM-UKF-PF algorithm gives better error minimization, and significantly improves performance of multipath mitigation in terms of SNR and coefficient even though it has computation complexity. It is of significance for high-accuracy positioning and non-stationary deformation analysis.
基金Project(51979280)supported by the National Natural Science Foundation of ChinaProjects(2016M602972,2018M643852)supported by the Postdoctoral Science Foundation of China。
文摘We have established an elastoplastic analysis model to explore the effect of loading path in an incompressible thin-walled tube under the combined action of axial force and torque based on Mises yield condition and isotropic linear hardening assumption.Further,four stress areas(σx,τx)are divided according to the characteristics of the final stress,and the plastic stress-strain relationship of twelve stress paths in different stress areas is derived.The"primary effect"of the stress path on plastic strain is demonstrated,namely,the plastic strain caused by the pre-loaded stress in path A(tensile stress is initially applied,followed by shear stress)is always greater than that caused by the post-loaded stress in path C(shear stress is initially applied,followed by tensile stress)irrespective of the value of final stress.The"recency effect"of the strain path on the stress is also established,which indicates that the stress caused by the post-loaded strain in path A is always greater than that caused by the pre-loaded strain in path C irrespective of the value of final strain.From the perspective of deformation,the"primary effect"of the stress path on the plastic strain and the"recency effect"of the strain path on the stress are unified.These effects are succinct and universal,and they provide useful insights on the plastic stress-strain relationship under different loading paths.Furthermore,they can serve as a useful reference for optimizing the processing technologies and construction procedures.
