Accurate target angle estimation is one of the chal-lenges for wideband radars due to the fact that target occupies multiple range bins,resulting in lower energy or signal to noise ratio in a single range bin.This pap...Accurate target angle estimation is one of the chal-lenges for wideband radars due to the fact that target occupies multiple range bins,resulting in lower energy or signal to noise ratio in a single range bin.This paper proposes a processing technique for enhanced accuracy of target angle estimates for wideband monopulse radars.Firstly,to accumulate the energy of the received echo signals from different scatterers on a target,the phase difference between different scatterers on a target is estimated using the minimum entropy phase estimation method combining with the correlation between adjacent pulses.Then,the monopulse ratio is obtained by using the signals from the accumulated sum and difference channels.The target angle is estimated by weighting the accumulated echo energy for accu-racy enhancement.Experimental results based on both numeri-cal simulation and measured data are presented to validate the effectiveness of the proposed technique.展开更多
Objective To compare the performances among three different systems for video head impulse test(vHIT),and to identify an optimal target angle for precisely evaluating the function of vertical semicircular canals in vH...Objective To compare the performances among three different systems for video head impulse test(vHIT),and to identify an optimal target angle for precisely evaluating the function of vertical semicircular canals in vHIT.Methods A two-center prospective study was done.Participants were sit 1.2 m away from the wall in a noise-proved room that dedicated for vHIT experiments.During the comparison experiments,similar settings were ensured in both hospitals,with the same distance to wall and angle of staring.For each equipment,the procedures followed the developers’recommendations.The same examiner performed the comparison between two systems in one location.For the eye-position projects,targets were placed on the wall sequentially at the pre-marked lines for different angles.For the comparison projects,9 and 13 participants were recruited,respectively.Any participant with otologic or vestibular disorders was excluded.A total of 26 healthy participants were recruited in the eye-position experiments,16 of which were further involved in inter-examiner tests.Results Our evaluations of three different systems showed that a new vHIT system,VertiGoggles®ZT-VNG-I(VG)performed as good as the long-tested Otometrics®ICS impulse(Oto)and EyeSeeCam®(ESC).During the comparison,we validated 25-degree,instead of right ahead at 0 degree,is a better place to set the targets when torsion was applied at vertical semicircular canal planes.Conclusion The new VG system is good for clinical practices.Furthermore,we proposed a new protocol to set the targets 25 degrees from right ahead after tilting head 45 degrees to evaluate vertical canals during vHIT.展开更多
Learning and self-adaptation ability is highly required to be integrated in path planning algorithm for underwater robot during navigation through an unspecified underwater environment. High frequency oscillations dur...Learning and self-adaptation ability is highly required to be integrated in path planning algorithm for underwater robot during navigation through an unspecified underwater environment. High frequency oscillations during underwater motion are responsible for nonlinearities in dynamic behavior of underwater robot as well as uncertainties in hydrodynamic coefficients. Reactive behaviors of underwater robot are designed considering the position and orientation of both target and nearest obstacle from robot s current position. Human like reasoning power and approximation based learning skill of neural based adaptive fuzzy inference system（ANFIS）has been found to be effective for underwater multivariable motion control. More than one ANFIS models are used here for achieving goal and obstacle avoidance while avoiding local minima situation in both horizontal and vertical plane of three dimensional workspace.An error gradient approach based on input-output training patterns for learning purpose has been promoted to spawn trajectory of underwater robot optimizing path length as well as time taken. The simulation and experimental results endorse sturdiness and viability of the proposed method in comparison with other navigational methodologies to negotiate with hectic conditions during motion of underwater mobile robot.展开更多
文摘Accurate target angle estimation is one of the chal-lenges for wideband radars due to the fact that target occupies multiple range bins,resulting in lower energy or signal to noise ratio in a single range bin.This paper proposes a processing technique for enhanced accuracy of target angle estimates for wideband monopulse radars.Firstly,to accumulate the energy of the received echo signals from different scatterers on a target,the phase difference between different scatterers on a target is estimated using the minimum entropy phase estimation method combining with the correlation between adjacent pulses.Then,the monopulse ratio is obtained by using the signals from the accumulated sum and difference channels.The target angle is estimated by weighting the accumulated echo energy for accu-racy enhancement.Experimental results based on both numeri-cal simulation and measured data are presented to validate the effectiveness of the proposed technique.
基金supported by grants from the National Science Foundation for Outstanding Young People(No.81922018)the Transformation and Industrialization of Scientific and Technological Achievements in Shanghai(No.18441904000)+3 种基金the National Natural Science Foundation of China(No.81771011)the National Natural Science Foundation of China Young Investigator Program(No.81800907)the Development Fund for Shanghai Talents(No.2017046)the Excellent Personnel Training Plan for the Shanghai Health System(No.2017Q003).
文摘Objective To compare the performances among three different systems for video head impulse test(vHIT),and to identify an optimal target angle for precisely evaluating the function of vertical semicircular canals in vHIT.Methods A two-center prospective study was done.Participants were sit 1.2 m away from the wall in a noise-proved room that dedicated for vHIT experiments.During the comparison experiments,similar settings were ensured in both hospitals,with the same distance to wall and angle of staring.For each equipment,the procedures followed the developers’recommendations.The same examiner performed the comparison between two systems in one location.For the eye-position projects,targets were placed on the wall sequentially at the pre-marked lines for different angles.For the comparison projects,9 and 13 participants were recruited,respectively.Any participant with otologic or vestibular disorders was excluded.A total of 26 healthy participants were recruited in the eye-position experiments,16 of which were further involved in inter-examiner tests.Results Our evaluations of three different systems showed that a new vHIT system,VertiGoggles®ZT-VNG-I(VG)performed as good as the long-tested Otometrics®ICS impulse(Oto)and EyeSeeCam®(ESC).During the comparison,we validated 25-degree,instead of right ahead at 0 degree,is a better place to set the targets when torsion was applied at vertical semicircular canal planes.Conclusion The new VG system is good for clinical practices.Furthermore,we proposed a new protocol to set the targets 25 degrees from right ahead after tilting head 45 degrees to evaluate vertical canals during vHIT.
文摘Learning and self-adaptation ability is highly required to be integrated in path planning algorithm for underwater robot during navigation through an unspecified underwater environment. High frequency oscillations during underwater motion are responsible for nonlinearities in dynamic behavior of underwater robot as well as uncertainties in hydrodynamic coefficients. Reactive behaviors of underwater robot are designed considering the position and orientation of both target and nearest obstacle from robot s current position. Human like reasoning power and approximation based learning skill of neural based adaptive fuzzy inference system（ANFIS）has been found to be effective for underwater multivariable motion control. More than one ANFIS models are used here for achieving goal and obstacle avoidance while avoiding local minima situation in both horizontal and vertical plane of three dimensional workspace.An error gradient approach based on input-output training patterns for learning purpose has been promoted to spawn trajectory of underwater robot optimizing path length as well as time taken. The simulation and experimental results endorse sturdiness and viability of the proposed method in comparison with other navigational methodologies to negotiate with hectic conditions during motion of underwater mobile robot.
