Human posture estimation is a prominent research topic in the fields of human-com-puter interaction,motion recognition,and other intelligent applications.However,achieving highaccuracy in key point localization,which ...Human posture estimation is a prominent research topic in the fields of human-com-puter interaction,motion recognition,and other intelligent applications.However,achieving highaccuracy in key point localization,which is crucial for intelligent applications,contradicts the lowdetection accuracy of human posture detection models in practical scenarios.To address this issue,a human pose estimation network called AT-HRNet has been proposed,which combines convolu-tional self-attention and cross-dimensional feature transformation.AT-HRNet captures significantfeature information from various regions in an adaptive manner,aggregating them through convolu-tional operations within the local receptive domain.The residual structures TripNeck and Trip-Block of the high-resolution network are designed to further refine the key point locations,wherethe attention weight is adjusted by a cross-dimensional interaction to obtain more features.To vali-date the effectiveness of this network,AT-HRNet was evaluated using the COCO2017 dataset.Theresults show that AT-HRNet outperforms HRNet by improving 3.2%in mAP,4.0%in AP75,and3.9%in AP^(M).This suggests that AT-HRNet can offer more beneficial solutions for human posture estimation.展开更多
Human body posture recognition has attracted considerable attention in recent years in wireless body area networks(WBAN). In order to precisely recognize human body posture,many recognition algorithms have been propos...Human body posture recognition has attracted considerable attention in recent years in wireless body area networks(WBAN). In order to precisely recognize human body posture,many recognition algorithms have been proposed.However, the recognition rate is relatively low. In this paper, we apply back propagation(BP) neural network as a classifier to recognizing human body posture, where signals are collected from VG350 acceleration sensor and a posture signal collection system based on WBAN is designed. Human body signal vector magnitude(SVM) and tri-axial acceleration sensor data are used to describe the human body postures. We are able to recognize 4postures: Walk, Run, Squat and Sit. Our posture recognition rate is up to 91.67%. Furthermore, we find an implied relationship between hidden layer neurons and the posture recognition rate. The proposed human body posture recognition algorithm lays the foundation for the subsequent applications.展开更多
Considering the unmanned aerial vehicle(UAV) three-dimensional(3D) posture, a novel 3D non-stationary geometry-based stochastic model(GBSM) is proposed for multiple-input multipleoutput(MIMO) UAV-to-vehicle(U2V) chann...Considering the unmanned aerial vehicle(UAV) three-dimensional(3D) posture, a novel 3D non-stationary geometry-based stochastic model(GBSM) is proposed for multiple-input multipleoutput(MIMO) UAV-to-vehicle(U2V) channels. It consists of a line-of-sight(Lo S) and non-line-of-sight(NLo S) components. The factor of fuselage posture is considered by introducing a time-variant 3D posture matrix. Some important statistical properties, i.e.the temporal autocorrelation function(ACF) and spatial cross correlation function(CCF), are derived and investigated. Simulation results show that the fuselage posture has significant impact on the U2V channel characteristic and aggravate the non-stationarity. The agreements between analytical, simulated, and measured results verify the correctness of proposed model and derivations. Moreover, it is demonstrated that the proposed model is also compatible to the existing GBSM without considering fuselage posture.展开更多
A proper landing posture is significant to the reduction of both the im-pact force acting on the human body and the injury at landing.In this paper theimpact force acting on human feet is studied.The subjects were 3 m...A proper landing posture is significant to the reduction of both the im-pact force acting on the human body and the injury at landing.In this paper theimpact force acting on human feet is studied.The subjects were 3 maleparachuters.The experiments were performed by means of high-speed photography and amotor analyzer.The experimental results are as follows:(1)When the subjectjumped from two platforms 1.0m and 1.5m in height,a vertical impact force onthe feet in half-squat posture was larger than in side spin posture.(2)When thesubject jumped from the platform 1.0m high,the feet gained a horizontal impactforce in the half-squat posture,larger than in the side spin posture.When thesubject jumped from the platform 1.5m high,the horizontal impact force pro-duced by both of the above-mentioned postures were just the same,which needsfurther research.(3)In terms of reducing the impact force acting on the feet,theside spin posture is better than the half-squat posture.展开更多
Neck injury is a severe problem in traffic accidents.While most studies are focused on the neck injury in rear and front impacts,few are conducted in side impact.This study focuses on the difference of neck injury und...Neck injury is a severe problem in traffic accidents.While most studies are focused on the neck injury in rear and front impacts,few are conducted in side impact.This study focuses on the difference of neck injury under different postures and the difference of 7 cervical vertebras under the same posture using the method of prescribed structure motion（PSM）.The analytical results show that the maximum changes of mean force and mean moment of 7 cervical vertebras under 8 different postures are 20% and 47% respectively.The variation of each cervical vertebra is different under different neck postures.Up cervical vertebras （C1-C4） and low cervical vertebras （C5-C7） suffer different forces and moments under the same neck posture.Generally speaking,No.6 （neck right leaning 40°） is the posture with lowest neck injury risk.展开更多
Quadruped robot is considered to be the most practical locomotion machine to negotiate uneven terrain, and shows superb stability during static walking. To improve the ability to go over rough terrain, this paper is f...Quadruped robot is considered to be the most practical locomotion machine to negotiate uneven terrain, and shows superb stability during static walking. To improve the ability to go over rough terrain, this paper is focused on the stable walking and balance control of quadruped robots. 24 kinds of walking gaits are analyzed in order to derive the most stable and smoothest walking gait. Considering the inefficiency to model a terrain by its specified appearance, a uniform terrain model is established and by means of kinematic analysis, a method to adjust the body posture and center of gravity （COG） height is presented. Simulations demonstrate the effectiveness of the proposed meth- od and the improvement of the adaptation of quadruped robots on rough terrain.展开更多
The influences of different design factors,as well as dummy posture,on an occupants' knee slider compression,were studied in this paper.Based on the vehicle geometry data,the simulation model,including both the mu...The influences of different design factors,as well as dummy posture,on an occupants' knee slider compression,were studied in this paper.Based on the vehicle geometry data,the simulation model,including both the multi-rigid-body and finite element(FE)part,was built up and validated with China New Car Assessment Program(C-NCAP)full impact to ensure the accuracy of the model.By adjusting the design parameters and the posture of the femur and lower leg,different factors affecting the passengers' knee slider compression were evaluated,with the help of MAthematical DYnamic MOdel(MADYMO)simulations.The study indicated that the leg posture,the stiffness of the IP and angles of the carpet have significant effects on the knee slider compression in this case.By decreasing the angle between the femur and lower leg from 133° to 124°,the maximum knee slider compression was decreased by 17.3% and by scaling the IP stiffness from 1 to 0.7,it could be decreased by 18.6%.Also,decreasing the angles of the carpet from 28° to 37°can help reduce the knee slider compression by 18.3%.展开更多
A novel image sequence-based risk behavior detection method to achieve high-precision risk behavior detection for power maintenance personnel is proposed in this paper.In this method,the original image sequence data i...A novel image sequence-based risk behavior detection method to achieve high-precision risk behavior detection for power maintenance personnel is proposed in this paper.In this method,the original image sequence data is first separated from the foreground and background.Then,the free anchor frame detection method is used in the foreground image to detect the personnel and correct their direction.Finally,human posture nodes are extracted from each frame of the image sequence,which are then used to identify the abnormal behavior of the human.Simulation experiment results demonstrate that the proposed algorithm has significant advantages in terms of the accuracy of human posture node detection and risk behavior identification.展开更多
Postural orthostatic tachycardia syndrome （POTS） has been recognized since at least 1940.A review of the literature identifies differences in the definition for this condition and wide variations in treatment and ou...Postural orthostatic tachycardia syndrome （POTS） has been recognized since at least 1940.A review of the literature identifies differences in the definition for this condition and wide variations in treatment and outcomes.This syndrome appears to describe a group of conditions with differing pathophysiology,which requires treatment tailored to the true underlying disorder.Patients need to be fully evaluated to guide treatment.Further research is required to effectively classify the range of underlying pathophysioiogy that can produce this syndrome and to guide optimal management.展开更多
Background: Heavy backpacks are often used by soldiers and firefighters. Weight carrying could reduce the speed and efficiency in task completion by altering the foot sole sensitivity and postural control.Methods: In ...Background: Heavy backpacks are often used by soldiers and firefighters. Weight carrying could reduce the speed and efficiency in task completion by altering the foot sole sensitivity and postural control.Methods: In fifteen healthy subjects, we measured the changes in sensitivity to vibrations applied to the foot sole when standing upright or walking after load carrying(30% body weight). The participants were asked to judge different vibration amplitudes applied on the 2 nd or 5 th metatarsal head and the heel at two frequencies(25 and 150 Hz) to determine the vibration threshold and the global perceptual representation(Ψ)of the vibration amplitude(Φ)given by the Stevens power function(Ψ=k×Φ~n). Any increase in negative k value indicated a reduction in sensitivity to the lowest loads. Pedobarographic measurements, with computation of the center of pressure(COP) and its deviations, were performed during weight carrying.Results: The 25-Hz vibration threshold significantly increased after weight carrying when standing upright or walking.After standing with the added loads, the absolute negative k value increased for the 25 Hz frequency. After walking with the added loads, the k coefficient increased for the two vibration frequencies. Weight carrying significantly increased both the CoP surface and CoP lateral deviation.Conclusions: Our data show that weight carrying reduces the sensory pathways from the foot sole and accentuates the center of pressure deviations.展开更多
Background:In the military,insufficient postural stability is a risk factor for developing lower extremity injuries.Postural stability training programs are effective in preventing these injuries.However,an objective ...Background:In the military,insufficient postural stability is a risk factor for developing lower extremity injuries.Postural stability training programs are effective in preventing these injuries.However,an objective method for the measurement of postural stability in servicemen is lacking.The primary objective of this study was to assess the influence of the number of repetitions,different foot positions and real-time visual feedback on postural stability,as well as their effects on the intrasession reliability of postural stability measurements in servicemen.The secondary objective was to assess the concurrent validity of the measurements.Methods:Twenty healthy servicemen between 20 and 50 years of age and in active duty were eligible for this quantitative,cross-sectional study.The measurements took place on a force plate,measuring the mean velocity of the center of pressure.The participants were asked to stand as still as possible in three different foot positions(wide stance,small stance,and on one leg),five times each for 45 s each time,and the measurements were performed with and without real-time visual feedback.Results:We observed a significant main effect of foot position(P<0.001),but not of visual feedback(P=0.119)or repetition number(P=0.915).Postural stability decreased in the more challenging foot positions.The ICC estimates varied from 0.809(one repetition in wide stance)to 0.985(five repetitions on one leg).The common variance(R2)between different foot positions without feedback varied between 0.008(wide stance)and 0.412.Conclusions:To yield reliable data,wide-stance measurements should be conducted three times,and small-stance measurements and measurements on one leg should be conducted two times.The scores of a measurement in a particular foot position cannot predict the scores of measurements in other foot positions.展开更多
基金the National Natural Science Foundation of China(No.61975015)the Research and Innovation Project for Graduate Students at Zhongyuan University of Technology(No.YKY2024ZK14).
文摘Human posture estimation is a prominent research topic in the fields of human-com-puter interaction,motion recognition,and other intelligent applications.However,achieving highaccuracy in key point localization,which is crucial for intelligent applications,contradicts the lowdetection accuracy of human posture detection models in practical scenarios.To address this issue,a human pose estimation network called AT-HRNet has been proposed,which combines convolu-tional self-attention and cross-dimensional feature transformation.AT-HRNet captures significantfeature information from various regions in an adaptive manner,aggregating them through convolu-tional operations within the local receptive domain.The residual structures TripNeck and Trip-Block of the high-resolution network are designed to further refine the key point locations,wherethe attention weight is adjusted by a cross-dimensional interaction to obtain more features.To vali-date the effectiveness of this network,AT-HRNet was evaluated using the COCO2017 dataset.Theresults show that AT-HRNet outperforms HRNet by improving 3.2%in mAP,4.0%in AP75,and3.9%in AP^(M).This suggests that AT-HRNet can offer more beneficial solutions for human posture estimation.
基金supported by the National Natural Science Foundation of China(No.61074165 and No.61273064)Jilin Provincial Science&Technology Department Key Scientific and Technological Project(No.20140204034GX)Jilin Province Development and Reform Commission Project(No.2015Y043)
文摘Human body posture recognition has attracted considerable attention in recent years in wireless body area networks(WBAN). In order to precisely recognize human body posture,many recognition algorithms have been proposed.However, the recognition rate is relatively low. In this paper, we apply back propagation(BP) neural network as a classifier to recognizing human body posture, where signals are collected from VG350 acceleration sensor and a posture signal collection system based on WBAN is designed. Human body signal vector magnitude(SVM) and tri-axial acceleration sensor data are used to describe the human body postures. We are able to recognize 4postures: Walk, Run, Squat and Sit. Our posture recognition rate is up to 91.67%. Furthermore, we find an implied relationship between hidden layer neurons and the posture recognition rate. The proposed human body posture recognition algorithm lays the foundation for the subsequent applications.
基金supported by the National Natural Science Foundation of China,No.62271250the National Key Scientific Instrument and Equipment Development Project,No.61827801+3 种基金Key Technologies R&D Program of Jiangsu(Prospective and Key Technologies for Industry),No.BE2022067,BE2022067-1 and BE2022067-3the Natural Science Foundation of Jiangsu Province,No.BK20211182the open research fund of National Mobile Communications Research Laboratory,Southeast University,No.2022D04the Experimental technology research and development,No.SYJS202304Z。
文摘Considering the unmanned aerial vehicle(UAV) three-dimensional(3D) posture, a novel 3D non-stationary geometry-based stochastic model(GBSM) is proposed for multiple-input multipleoutput(MIMO) UAV-to-vehicle(U2V) channels. It consists of a line-of-sight(Lo S) and non-line-of-sight(NLo S) components. The factor of fuselage posture is considered by introducing a time-variant 3D posture matrix. Some important statistical properties, i.e.the temporal autocorrelation function(ACF) and spatial cross correlation function(CCF), are derived and investigated. Simulation results show that the fuselage posture has significant impact on the U2V channel characteristic and aggravate the non-stationarity. The agreements between analytical, simulated, and measured results verify the correctness of proposed model and derivations. Moreover, it is demonstrated that the proposed model is also compatible to the existing GBSM without considering fuselage posture.
文摘A proper landing posture is significant to the reduction of both the im-pact force acting on the human body and the injury at landing.In this paper theimpact force acting on human feet is studied.The subjects were 3 maleparachuters.The experiments were performed by means of high-speed photography and amotor analyzer.The experimental results are as follows:(1)When the subjectjumped from two platforms 1.0m and 1.5m in height,a vertical impact force onthe feet in half-squat posture was larger than in side spin posture.(2)When thesubject jumped from the platform 1.0m high,the feet gained a horizontal impactforce in the half-squat posture,larger than in the side spin posture.When thesubject jumped from the platform 1.5m high,the horizontal impact force pro-duced by both of the above-mentioned postures were just the same,which needsfurther research.(3)In terms of reducing the impact force acting on the feet,theside spin posture is better than the half-squat posture.
基金Sponsored by the National High Technology Research and Development Program of China("863"Program) (2006AA110102)
文摘Neck injury is a severe problem in traffic accidents.While most studies are focused on the neck injury in rear and front impacts,few are conducted in side impact.This study focuses on the difference of neck injury under different postures and the difference of 7 cervical vertebras under the same posture using the method of prescribed structure motion（PSM）.The analytical results show that the maximum changes of mean force and mean moment of 7 cervical vertebras under 8 different postures are 20% and 47% respectively.The variation of each cervical vertebra is different under different neck postures.Up cervical vertebras （C1-C4） and low cervical vertebras （C5-C7） suffer different forces and moments under the same neck posture.Generally speaking,No.6 （neck right leaning 40°） is the posture with lowest neck injury risk.
基金Supported by the National High Technology Research and Development Program of China(863Program)(2011AA041002)
文摘Quadruped robot is considered to be the most practical locomotion machine to negotiate uneven terrain, and shows superb stability during static walking. To improve the ability to go over rough terrain, this paper is focused on the stable walking and balance control of quadruped robots. 24 kinds of walking gaits are analyzed in order to derive the most stable and smoothest walking gait. Considering the inefficiency to model a terrain by its specified appearance, a uniform terrain model is established and by means of kinematic analysis, a method to adjust the body posture and center of gravity （COG） height is presented. Simulations demonstrate the effectiveness of the proposed meth- od and the improvement of the adaptation of quadruped robots on rough terrain.
基金Supported by the National Natural Science Foundation of China(51405050)Key Laboratory of Advanced Manufacturing Technology for Automobile Parts,Ministry of Education(2016KLMT03)Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ1500912)
文摘The influences of different design factors,as well as dummy posture,on an occupants' knee slider compression,were studied in this paper.Based on the vehicle geometry data,the simulation model,including both the multi-rigid-body and finite element(FE)part,was built up and validated with China New Car Assessment Program(C-NCAP)full impact to ensure the accuracy of the model.By adjusting the design parameters and the posture of the femur and lower leg,different factors affecting the passengers' knee slider compression were evaluated,with the help of MAthematical DYnamic MOdel(MADYMO)simulations.The study indicated that the leg posture,the stiffness of the IP and angles of the carpet have significant effects on the knee slider compression in this case.By decreasing the angle between the femur and lower leg from 133° to 124°,the maximum knee slider compression was decreased by 17.3% and by scaling the IP stiffness from 1 to 0.7,it could be decreased by 18.6%.Also,decreasing the angles of the carpet from 28° to 37°can help reduce the knee slider compression by 18.3%.
基金supported by the project“Research and application of key technologies of safe production management and control of substation operation and maintenance based on video semantic analysis”(5700-202133259A-0-0-00)of the State Grid Corporation of China.
文摘A novel image sequence-based risk behavior detection method to achieve high-precision risk behavior detection for power maintenance personnel is proposed in this paper.In this method,the original image sequence data is first separated from the foreground and background.Then,the free anchor frame detection method is used in the foreground image to detect the personnel and correct their direction.Finally,human posture nodes are extracted from each frame of the image sequence,which are then used to identify the abnormal behavior of the human.Simulation experiment results demonstrate that the proposed algorithm has significant advantages in terms of the accuracy of human posture node detection and risk behavior identification.
文摘Postural orthostatic tachycardia syndrome （POTS） has been recognized since at least 1940.A review of the literature identifies differences in the definition for this condition and wide variations in treatment and outcomes.This syndrome appears to describe a group of conditions with differing pathophysiology,which requires treatment tailored to the true underlying disorder.Patients need to be fully evaluated to guide treatment.Further research is required to effectively classify the range of underlying pathophysioiogy that can produce this syndrome and to guide optimal management.
基金supported by the School of Podiatry of Marseille
文摘Background: Heavy backpacks are often used by soldiers and firefighters. Weight carrying could reduce the speed and efficiency in task completion by altering the foot sole sensitivity and postural control.Methods: In fifteen healthy subjects, we measured the changes in sensitivity to vibrations applied to the foot sole when standing upright or walking after load carrying(30% body weight). The participants were asked to judge different vibration amplitudes applied on the 2 nd or 5 th metatarsal head and the heel at two frequencies(25 and 150 Hz) to determine the vibration threshold and the global perceptual representation(Ψ)of the vibration amplitude(Φ)given by the Stevens power function(Ψ=k×Φ~n). Any increase in negative k value indicated a reduction in sensitivity to the lowest loads. Pedobarographic measurements, with computation of the center of pressure(COP) and its deviations, were performed during weight carrying.Results: The 25-Hz vibration threshold significantly increased after weight carrying when standing upright or walking.After standing with the added loads, the absolute negative k value increased for the 25 Hz frequency. After walking with the added loads, the k coefficient increased for the two vibration frequencies. Weight carrying significantly increased both the CoP surface and CoP lateral deviation.Conclusions: Our data show that weight carrying reduces the sensory pathways from the foot sole and accentuates the center of pressure deviations.
基金funded by the Military Rehabilitation Center Aardenburgpart of the Dutch Ministry of Defense。
文摘Background:In the military,insufficient postural stability is a risk factor for developing lower extremity injuries.Postural stability training programs are effective in preventing these injuries.However,an objective method for the measurement of postural stability in servicemen is lacking.The primary objective of this study was to assess the influence of the number of repetitions,different foot positions and real-time visual feedback on postural stability,as well as their effects on the intrasession reliability of postural stability measurements in servicemen.The secondary objective was to assess the concurrent validity of the measurements.Methods:Twenty healthy servicemen between 20 and 50 years of age and in active duty were eligible for this quantitative,cross-sectional study.The measurements took place on a force plate,measuring the mean velocity of the center of pressure.The participants were asked to stand as still as possible in three different foot positions(wide stance,small stance,and on one leg),five times each for 45 s each time,and the measurements were performed with and without real-time visual feedback.Results:We observed a significant main effect of foot position(P<0.001),but not of visual feedback(P=0.119)or repetition number(P=0.915).Postural stability decreased in the more challenging foot positions.The ICC estimates varied from 0.809(one repetition in wide stance)to 0.985(five repetitions on one leg).The common variance(R2)between different foot positions without feedback varied between 0.008(wide stance)and 0.412.Conclusions:To yield reliable data,wide-stance measurements should be conducted three times,and small-stance measurements and measurements on one leg should be conducted two times.The scores of a measurement in a particular foot position cannot predict the scores of measurements in other foot positions.
