The hot workability of 7085 aluminum alloys with different initial microstructures （as-homogenized and as-solution treated） was studied by isothermal compression tests at the deformation temperature ranging from 300...The hot workability of 7085 aluminum alloys with different initial microstructures （as-homogenized and as-solution treated） was studied by isothermal compression tests at the deformation temperature ranging from 300 to 450 ℃ and the strain rate ranging from 0.0001 to 1 s 1. The strain rate sensitivity of the alloy was evaluated and used for establishing the power dissipation maps and instability maps on the basis of the flow stress data. The results show that the efficiency of power dissipation for the as-homogenized alloy is lower than that of the as-solution treated alloy. The deformation parameters of the dynamic recrystallization for the as-homogenized and as-solution treated alloy occur at 400 ℃, 0.01 s i and 450 ℃, 0.001 s-1, respectively. The flow instability region of the as-homogenized alloy is narrower than that of the as-solution treated alloy. These differences of the alloys with two different initial microstructures on the processing maps are mainly related to the dynamic precipitation characteristics.展开更多
This paper introduces realization method of kinematics analysis for the planar four bar mechanism based on the MFC. A mathematicat model is established by a simple and effective method, using the computer simulation t...This paper introduces realization method of kinematics analysis for the planar four bar mechanism based on the MFC. A mathematicat model is established by a simple and effective method, using the computer simulation technology can the dynamic demonstration mechanism taotion and automatic drawing trajectory curve of arbitrary point on the connecting rod, and can output various motion displacement, speed and acceleration diagram. The paper provides a simple way for motion analysis of planar four link.展开更多
Respiratory monitoring is increasingly used in clinical and healthcare practices to diagnose chronic cardio-pulmonary functional diseases during various routine activities.Wearable medical devices have realized the po...Respiratory monitoring is increasingly used in clinical and healthcare practices to diagnose chronic cardio-pulmonary functional diseases during various routine activities.Wearable medical devices have realized the possibilities of ubiquitous respiratory monitoring,however,relatively little attention is paid to accuracy and reliability.In previous study,a wearable respiration biofeedback system was designed.In this work,three kinds of signals were mixed to extract respiratory rate,i.e.,respiration inductive plethysmography(RIP),3D-acceleration and ECG.In-situ experiments with twelve subjects indicate that the method significantly improves the accuracy and reliability over a dynamic range of respiration rate.It is possible to derive respiration rate from three signals within mean absolute percentage error 4.37%of a reference gold standard.Similarly studies derive respiratory rate from single-lead ECG within mean absolute percentage error 17%of a reference gold standard.展开更多
Mutual information （MI）-based image registration is effective in registering medical images, but it is computationally expensive. This paper accelerates MI-based image registration by dividing computation of mutual ...Mutual information （MI）-based image registration is effective in registering medical images, but it is computationally expensive. This paper accelerates MI-based image registration by dividing computation of mutual information into spatial transformation and histogram-based calculation, and performing 3D spatial transformation and trilinear interpolation on graphic processing unit （GPU）. The 3D floating image is downloaded to GPU as flat 3D texture, and then fetched and interpolated for each new voxel location in fragment shader. The transformed resuits are rendered to textures by using frame buffer object （FBO） extension, and then read to the main memory used for the remaining computation on CPU. Experimental results show that GPU-accelerated method can achieve speedup about an order of magnitude with better registration result compared with the software implementation on a single-core CPU.展开更多
基金Projects(2010CB731701,2012CB619502) supported by the National Basic Research Program of ChinaProject(CX2012B043) supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject(51021063) supported by Creative Research Group of National Natural Science Foundation of China
文摘The hot workability of 7085 aluminum alloys with different initial microstructures （as-homogenized and as-solution treated） was studied by isothermal compression tests at the deformation temperature ranging from 300 to 450 ℃ and the strain rate ranging from 0.0001 to 1 s 1. The strain rate sensitivity of the alloy was evaluated and used for establishing the power dissipation maps and instability maps on the basis of the flow stress data. The results show that the efficiency of power dissipation for the as-homogenized alloy is lower than that of the as-solution treated alloy. The deformation parameters of the dynamic recrystallization for the as-homogenized and as-solution treated alloy occur at 400 ℃, 0.01 s i and 450 ℃, 0.001 s-1, respectively. The flow instability region of the as-homogenized alloy is narrower than that of the as-solution treated alloy. These differences of the alloys with two different initial microstructures on the processing maps are mainly related to the dynamic precipitation characteristics.
文摘This paper introduces realization method of kinematics analysis for the planar four bar mechanism based on the MFC. A mathematicat model is established by a simple and effective method, using the computer simulation technology can the dynamic demonstration mechanism taotion and automatic drawing trajectory curve of arbitrary point on the connecting rod, and can output various motion displacement, speed and acceleration diagram. The paper provides a simple way for motion analysis of planar four link.
基金Project(2012M510207)supported by the China Postdoctoral Science FoundationProjects(60932001,61072031)supported by the National Natural Science Foundation of China+2 种基金Project(2012AA02A604)supported by the National High Technology Research and Development Program of ChinaProject(2013ZX03005013)supported by the Next Generation Communication Technology Major Project of National Science and Technology,ChinaProject supported by the"One-hundred Talent"and the"Low-cost Healthcare"Programs of Chinese Academy of Sciences
文摘Respiratory monitoring is increasingly used in clinical and healthcare practices to diagnose chronic cardio-pulmonary functional diseases during various routine activities.Wearable medical devices have realized the possibilities of ubiquitous respiratory monitoring,however,relatively little attention is paid to accuracy and reliability.In previous study,a wearable respiration biofeedback system was designed.In this work,three kinds of signals were mixed to extract respiratory rate,i.e.,respiration inductive plethysmography(RIP),3D-acceleration and ECG.In-situ experiments with twelve subjects indicate that the method significantly improves the accuracy and reliability over a dynamic range of respiration rate.It is possible to derive respiration rate from three signals within mean absolute percentage error 4.37%of a reference gold standard.Similarly studies derive respiratory rate from single-lead ECG within mean absolute percentage error 17%of a reference gold standard.
基金Supported by National High Technology Research and Development Program("863"Program)of China(No.863-306-ZD13-03-06)
文摘Mutual information （MI）-based image registration is effective in registering medical images, but it is computationally expensive. This paper accelerates MI-based image registration by dividing computation of mutual information into spatial transformation and histogram-based calculation, and performing 3D spatial transformation and trilinear interpolation on graphic processing unit （GPU）. The 3D floating image is downloaded to GPU as flat 3D texture, and then fetched and interpolated for each new voxel location in fragment shader. The transformed resuits are rendered to textures by using frame buffer object （FBO） extension, and then read to the main memory used for the remaining computation on CPU. Experimental results show that GPU-accelerated method can achieve speedup about an order of magnitude with better registration result compared with the software implementation on a single-core CPU.
