The magnetically coupled resonant wireless power transfer(MCR-WPT)system for implantable medical devices has gradually become one of the research hotspots.The transmission characteristics of the system in weak-couplin...The magnetically coupled resonant wireless power transfer(MCR-WPT)system for implantable medical devices has gradually become one of the research hotspots.The transmission characteristics of the system in weak-coupling regions are of research significance.The mathematical model of the system's transmission characteristics is established by equivalent circuit theory.Several key factors that affect the transmission characteristics of the system are obtained,to include the self-inductance of the coil,the mutual inductance between the coils,and the load resistance.A magnetically coupled resonant wireless power transfer system is designed.A method of coil design is proposed.The transmission efficiency of the system in the weak-coupling region is improved by optimizing the design of the coil.Simulation and experimental results exhibited good consistency.The results show that the transmission performance of the system in the weak-coupling area is improved.This work provides guidance and practical significance for the research of the MCR-WPT system with implantable medical equipment.展开更多
In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo cameras.Under the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr...In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo cameras.Under the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr)to compute the monocular affine transformations relating images taken by the same camera at different time instants and the binocular affine transformations relating images taken by different cameras at the same time instant.We then show that 3D motion can he recovered from these 2D transformations.A space-time fusion strategy is proposed to aim at robust results.No knowledge of point correspondences is required in the above processes and the computa- lions involved are linear.To find corresponding image regions,new affine invariants,which show stronger invariance,are derived in term of tensor contraction theory.Experiments on real motion images are conducted to verify the proposed method.展开更多
A CMOS voltage reference, which is based on VGs and/x ΔGS in the weak inversion region, has been designed and implemented in standard 0.6μm CMOS technology. No diodes and parasitic bipolar junction transistors （BJT...A CMOS voltage reference, which is based on VGs and/x ΔGS in the weak inversion region, has been designed and implemented in standard 0.6μm CMOS technology. No diodes and parasitic bipolar junction transistors （BJTs） are used. The proposed voltage reference uses a current-mode topology by summing a PTAT current and a CTAT current into a re- sistor to generate the required reference voltage. It can also provide more than one reference voltage output, which is quite suitable for systems requiring many different reference voltages simultaneously. The occupied chip area is 0. 023mm^-2 . The operation supply voltage is from 2.5 to 6V, and the maximum supply current is 8.25μA. The designed three different out- puts are respectively about 203mV, 1.0V, and 2.05V at room temperature when the supply voltage is 4V. The circuit achieves a temperature coefficient of 31ppm/℃ in the temperature range of 0 to 100℃ and an average line regulation of ± 0. 203%/V. The voltage reference has been successfully applied in a white LED backlight driver chip.展开更多
基金Supported by National Natural Science Foundation of China(51307120,51477117).
文摘The magnetically coupled resonant wireless power transfer(MCR-WPT)system for implantable medical devices has gradually become one of the research hotspots.The transmission characteristics of the system in weak-coupling regions are of research significance.The mathematical model of the system's transmission characteristics is established by equivalent circuit theory.Several key factors that affect the transmission characteristics of the system are obtained,to include the self-inductance of the coil,the mutual inductance between the coils,and the load resistance.A magnetically coupled resonant wireless power transfer system is designed.A method of coil design is proposed.The transmission efficiency of the system in the weak-coupling region is improved by optimizing the design of the coil.Simulation and experimental results exhibited good consistency.The results show that the transmission performance of the system in the weak-coupling area is improved.This work provides guidance and practical significance for the research of the MCR-WPT system with implantable medical equipment.
文摘In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo cameras.Under the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr)to compute the monocular affine transformations relating images taken by the same camera at different time instants and the binocular affine transformations relating images taken by different cameras at the same time instant.We then show that 3D motion can he recovered from these 2D transformations.A space-time fusion strategy is proposed to aim at robust results.No knowledge of point correspondences is required in the above processes and the computa- lions involved are linear.To find corresponding image regions,new affine invariants,which show stronger invariance,are derived in term of tensor contraction theory.Experiments on real motion images are conducted to verify the proposed method.
文摘A CMOS voltage reference, which is based on VGs and/x ΔGS in the weak inversion region, has been designed and implemented in standard 0.6μm CMOS technology. No diodes and parasitic bipolar junction transistors （BJTs） are used. The proposed voltage reference uses a current-mode topology by summing a PTAT current and a CTAT current into a re- sistor to generate the required reference voltage. It can also provide more than one reference voltage output, which is quite suitable for systems requiring many different reference voltages simultaneously. The occupied chip area is 0. 023mm^-2 . The operation supply voltage is from 2.5 to 6V, and the maximum supply current is 8.25μA. The designed three different out- puts are respectively about 203mV, 1.0V, and 2.05V at room temperature when the supply voltage is 4V. The circuit achieves a temperature coefficient of 31ppm/℃ in the temperature range of 0 to 100℃ and an average line regulation of ± 0. 203%/V. The voltage reference has been successfully applied in a white LED backlight driver chip.
