Computational models provide additional tools for studying the brain,however,many techniques are currently disconnected from each other.There is a need for new computational approaches that span the range of physics o...Computational models provide additional tools for studying the brain,however,many techniques are currently disconnected from each other.There is a need for new computational approaches that span the range of physics operating in the brain.In this review paper,we offer some new perspectives on how the embedded element method can fill this gap and has the potential to connect a myriad of modeling genre.The embedded element method is a mesh superposition technique used within finite element analysis.This method allows for the incorporation of axonal fiber tracts to be explicitly represented.Here,we explore the use of the approach beyond its original goal of predicting axonal strain in brain injury.We explore the potential application of the embedded element method in areas of electrophysiology,neurodegeneration,neuropharmacology and mechanobiology.We conclude that this method has the potential to provide us with an integrated computational framework that can assist in developing improved diagnostic tools and regeneration technologies.展开更多
For a large-scale array,its realized gain is always smaller than the summation of the element gains in isolation,which is the well-known gain paradox proposed by Hannan.To explain the paradox,embedded element efficien...For a large-scale array,its realized gain is always smaller than the summation of the element gains in isolation,which is the well-known gain paradox proposed by Hannan.To explain the paradox,embedded element efficiency(EEE)was defined to indicate whether the array elements are being fully utilized,and Hannan’s limit was introduced to provide a fundamental upper bound of the EEE.In this paper,Hannan’s limit is extended to assess the beam-scanning capability of a phased array,which can provide a fundamental upper bound of the EEE corresponding to different scanning angles.In addition,the methods for enhancing the EEE of a large-scale array to approach Hannan’s limit are discussed,including selecting an appropriate power pattern for the array element and efficiently decoupling the array elements.For verification,a planar large-scale wide-angle scanning array utilizing a hybrid decoupling strategy is designed in this paper.The proposed decoupling structure improves the isolation between adjacent array elements in both the E-plane and H-plane by approximately 18.3 dB.The beam-scanning range in the E-plane and H-plane can±65°±60°reach and.During beam scanning,the realized gain of the array can be improved by approximately 0.74 dB.After decoup-×ling,the EEE of the 88 wide-angle scanning array can be improved by approximately 12.64%on average during beam scanning,which is closer to Hannan’s limit.展开更多
The strain-temperature cross-sensitivity problem easily occurs in the engineering strain monitoring of the self-sensing embedded with fiber Bragg grating(FBG)sensors.In this work,a theoretical investigation of the str...The strain-temperature cross-sensitivity problem easily occurs in the engineering strain monitoring of the self-sensing embedded with fiber Bragg grating(FBG)sensors.In this work,a theoretical investigation of the strain-temperature cross-sensitivity has been performed using the temperature reference grating method.To experimentally observe and theoretically verify the problem,the substrate materials,the preloading technique,and the FBG initial central wavelength were taken as main parameters.And a series of sensitivity coefficients calibration tests and temperature compensation tests have been designed and carried out.It was found that when the FBG sensors were embedded on different substrates,their coefficients of the temperature sensitivity were significantly changed.Besides,the larger the coefficients of thermal expansion(CTE)of substrates were,the higher the temperature sensitivity coefficients would be.On the other hand,the effect of the preloading technique and FBG initial wavelength was negligible on both the strain monitoring and temperature compensation.In the case of similar substrates,we did not observe any difference between temperature sensitivity coefficients of the temperature compensation FBG with one free end or two free ends.The curves of the force along with temperature were almost overlapped with minor differences(less than 1%)gained by FBG sensors and pressure sensors,which verified the accuracy of the temperature compensation method.We suggest that this work can provide efficient solutions to the strain-temperature cross-sensitivity for engineering strain monitoring with the self-sensing element embedded with FBG sensors.展开更多
基金support provided by Computational Fluid Dynamics Research Corporation(CFDRC)under a sub-contract funded by the Department of Defense,Department of Health Program through contract W81XWH-14-C-0045
文摘Computational models provide additional tools for studying the brain,however,many techniques are currently disconnected from each other.There is a need for new computational approaches that span the range of physics operating in the brain.In this review paper,we offer some new perspectives on how the embedded element method can fill this gap and has the potential to connect a myriad of modeling genre.The embedded element method is a mesh superposition technique used within finite element analysis.This method allows for the incorporation of axonal fiber tracts to be explicitly represented.Here,we explore the use of the approach beyond its original goal of predicting axonal strain in brain injury.We explore the potential application of the embedded element method in areas of electrophysiology,neurodegeneration,neuropharmacology and mechanobiology.We conclude that this method has the potential to provide us with an integrated computational framework that can assist in developing improved diagnostic tools and regeneration technologies.
基金National Natural Science Foundation of China(Grant No.U2141230).
文摘For a large-scale array,its realized gain is always smaller than the summation of the element gains in isolation,which is the well-known gain paradox proposed by Hannan.To explain the paradox,embedded element efficiency(EEE)was defined to indicate whether the array elements are being fully utilized,and Hannan’s limit was introduced to provide a fundamental upper bound of the EEE.In this paper,Hannan’s limit is extended to assess the beam-scanning capability of a phased array,which can provide a fundamental upper bound of the EEE corresponding to different scanning angles.In addition,the methods for enhancing the EEE of a large-scale array to approach Hannan’s limit are discussed,including selecting an appropriate power pattern for the array element and efficiently decoupling the array elements.For verification,a planar large-scale wide-angle scanning array utilizing a hybrid decoupling strategy is designed in this paper.The proposed decoupling structure improves the isolation between adjacent array elements in both the E-plane and H-plane by approximately 18.3 dB.The beam-scanning range in the E-plane and H-plane can±65°±60°reach and.During beam scanning,the realized gain of the array can be improved by approximately 0.74 dB.After decoup-×ling,the EEE of the 88 wide-angle scanning array can be improved by approximately 12.64%on average during beam scanning,which is closer to Hannan’s limit.
基金supported by the National Natural Science Foundation of China(Grant No.52068014)Key Research&Development Projects in the Guangxi Autonomous Region(Grant No.GUIKE AA20302006)Major Construction Program of the Science and Technological Innovation Base in the Guangxi Autonomous Region(Grant No.2018-242-G02).
文摘The strain-temperature cross-sensitivity problem easily occurs in the engineering strain monitoring of the self-sensing embedded with fiber Bragg grating(FBG)sensors.In this work,a theoretical investigation of the strain-temperature cross-sensitivity has been performed using the temperature reference grating method.To experimentally observe and theoretically verify the problem,the substrate materials,the preloading technique,and the FBG initial central wavelength were taken as main parameters.And a series of sensitivity coefficients calibration tests and temperature compensation tests have been designed and carried out.It was found that when the FBG sensors were embedded on different substrates,their coefficients of the temperature sensitivity were significantly changed.Besides,the larger the coefficients of thermal expansion(CTE)of substrates were,the higher the temperature sensitivity coefficients would be.On the other hand,the effect of the preloading technique and FBG initial wavelength was negligible on both the strain monitoring and temperature compensation.In the case of similar substrates,we did not observe any difference between temperature sensitivity coefficients of the temperature compensation FBG with one free end or two free ends.The curves of the force along with temperature were almost overlapped with minor differences(less than 1%)gained by FBG sensors and pressure sensors,which verified the accuracy of the temperature compensation method.We suggest that this work can provide efficient solutions to the strain-temperature cross-sensitivity for engineering strain monitoring with the self-sensing element embedded with FBG sensors.
