The M=7.6 Jiji (Chi-Chi) earthquake, Taiwan Province, on September 21, 1999 (local time) is a thrust fault style earthquake. The empirical attenuation relations of the horizontal and vertical peak ground accelerations...The M=7.6 Jiji (Chi-Chi) earthquake, Taiwan Province, on September 21, 1999 (local time) is a thrust fault style earthquake. The empirical attenuation relations of the horizontal and vertical peak ground accelerations (PGA) for the Jiji (Chi-Chi) earthquake are developed by regression method. By examining the residuals from the Jiji (Chi-Chi) earthquake-specific peak acceleration attenuation relations, it is found that there are systematic differences between PGA on the hanging-wall and footwall. The recorded peak accelerations are higher on the hanging-wall and lower on the footwall. The clear asymmetry of PGA distribution to the surface rupture trace can also be seen from the PGA contour map. These evidences indicate that the PGA attenuates faster on the hanging-wall than on the footwall. In the study of near-source strong motion, seismic hazard assessment, scenario earthquake and seismic disaster prediction, the style-of-faulting must be considered in order that the attenuation model can reflect the characteristic of ground motion in various seismic environmental regions.展开更多
Once working at heights is dangerous,it is a significant accident.These accidents brought substantial economic losses and caused a large number of casualties.Therefore,it is essential to use wall-climbing robots to re...Once working at heights is dangerous,it is a significant accident.These accidents brought substantial economic losses and caused a large number of casualties.Therefore,it is essential to use wall-climbing robots to replace manual work at heights.The design of the wall-climbing robot is inspired by the climbing action of insects or animals.An intelligent bionic robot device can carry special equipment to operate on the wall and perform some dangerous operations instead of firefighters or inspection personnel more efficiently.The scope of application is vast.This paper firstly summarizes the research progress of wall-climbing robots with three different moving methods:wheel-climbing,crawler-based,and leg-footed robots;summarizes the applications and breakthroughs of four adsorption technologies:negative pressure,magnetic force,bionic and electrostatic;discusses the application of motion control algorithms in wall-climbing robots.Secondly,the advantages and disadvantages of different migration modes and adsorption methods are pointed out.The distribution and advantages of the combined application of different migration modes and adsorption methods are analyzed.In addition,the future development trend of wall-climbing robots and the promoting effect of bionic technology development on wall-climbing robots are proposed.The content of this paper will provide helpful guidance for the research of wall-climbing robots.展开更多
In the field of pipeline inner wall inspection,the snake robot demonstrates significant advantages over other inspection methods.While a simple traveling wave or meandering motion will suffice for inspecting the inner...In the field of pipeline inner wall inspection,the snake robot demonstrates significant advantages over other inspection methods.While a simple traveling wave or meandering motion will suffice for inspecting the inner wall of small-diameter pipes,comprehensively and meticulously inspecting the inner wall of large-diameter pipes requires the snake robot to adopt a helical gait that closely adheres to the inner wall.Our review of existing literature indicates that most research and development on the helical gait of snake robots has focused on the outer surface of cylinders,with very few studies dedicated to developing a helical gait specifically for the inspection of the inner wall of pipes.Therefore,in this study,we propose a helical gait that is suitable for the inner wall of pipes and meets the requirements of gas pipeline engineering.The helical gait is designed using the backbone curve method.First,we create a mathematical model for a circular helix curve with constant curvature and torsion,ensuring it is applicable to a snake robot prototype in a laboratory environment.Subsequently.we calculate the joint angles required for two conical spiral curves with variable curvature and torsion,establish a new model,and define the physical significance of the specific parameters.To ensure the feasibility of the proposed gait,we conduct experiments involving meandering and traveling wave motions to verify the communication and control between the host computer and the snake robot.Building upon this foundation,we further validate the mathematical model of the complex helical motion gait through simulation experiments.Our findings provide a theoretical basis for realizing helical movement with a real snake robot.展开更多
Background There remains controversy about whether Brugada syndrome （BS） has structural heart changes. We occasionally noted that a patient with BS had a quite unusual regional wall motion abnormality at the basal s...Background There remains controversy about whether Brugada syndrome （BS） has structural heart changes. We occasionally noted that a patient with BS had a quite unusual regional wall motion abnormality at the basal segment of the interventricular septum （IVS） during echocardiographic examination. The unexpected finding promoted us to reexamine our patients with BS by echocardiographic interrogation in the present study. Methods Patients with BS （n=11）, patients with complete right bundle branch block （RBBB） （n=11）, and control subjects （n=11） were enrolled in this study. Two-dimensional echocardiography （2DE） was performed to obtain parasternal left ventricular long axis view on which M-mode scanning line was adjusted to be perpendicular to the basal segment of IVS for delineation of the segmental motion curve, with a simultaneously electrocardiographic tracing. Results 2DE revealed a rapid swing motion shifting toward the right ventricle of the IVS basal segment at early systole in 73% （8/11） patients with BS, which was further confirmed on the M-mode curve evidenced by an early systolic notch toward the right ventricle. The position of the notch corresponded to C-point on the mitral motion curve, lasting for （53±5） ms. There were no similar changes both in patients with RBBB and in the control subjects. Conclusion IVS basal motion abnormalities at early-systolic phase may be the novel finding of BS.展开更多
Ultra-wideband(UWB)through-wall radar has a wide range of applications in non-contact human information detection and monitoring.With the integration of machine learning technology,its potential prospects include the ...Ultra-wideband(UWB)through-wall radar has a wide range of applications in non-contact human information detection and monitoring.With the integration of machine learning technology,its potential prospects include the physiological monitoring of patients in the hospital environment and the daily monitoring at home.Although many target detection methods of UWB through-wall radar based on machine learning have been proposed,there is a lack of an opensource dataset to evaluate the performance of the algorithm.This published dataset is measured by impulse radio UWB(IR-UWB)through-wall radar system.Three test subjects are measured in different environments and several defined motion status.Using the presented dataset,we propose a human-motion-status recognition method using a convolutional neural network(CNN),and the detailed dataset partition method and the recognition process flow are given.On the well-trained network,the recognition accuracy of testing data for three kinds of motion status is higher than 99.7%.The dataset presented in this paper considers a simple environment.Therefore,we call on all organizations in the UWB radar field to cooperate to build opensource datasets to further promote the development of UWB through-wall radar.展开更多
基金National Key Basic Research Project (G1998040700).
文摘The M=7.6 Jiji (Chi-Chi) earthquake, Taiwan Province, on September 21, 1999 (local time) is a thrust fault style earthquake. The empirical attenuation relations of the horizontal and vertical peak ground accelerations (PGA) for the Jiji (Chi-Chi) earthquake are developed by regression method. By examining the residuals from the Jiji (Chi-Chi) earthquake-specific peak acceleration attenuation relations, it is found that there are systematic differences between PGA on the hanging-wall and footwall. The recorded peak accelerations are higher on the hanging-wall and lower on the footwall. The clear asymmetry of PGA distribution to the surface rupture trace can also be seen from the PGA contour map. These evidences indicate that the PGA attenuates faster on the hanging-wall than on the footwall. In the study of near-source strong motion, seismic hazard assessment, scenario earthquake and seismic disaster prediction, the style-of-faulting must be considered in order that the attenuation model can reflect the characteristic of ground motion in various seismic environmental regions.
基金funded by the Science and Technology Development Fund,Macao SAR(SKL-IOTSC-2018-2020)the Shanxi Science and Technology Major Project(Grant Number 20191101014).
文摘Once working at heights is dangerous,it is a significant accident.These accidents brought substantial economic losses and caused a large number of casualties.Therefore,it is essential to use wall-climbing robots to replace manual work at heights.The design of the wall-climbing robot is inspired by the climbing action of insects or animals.An intelligent bionic robot device can carry special equipment to operate on the wall and perform some dangerous operations instead of firefighters or inspection personnel more efficiently.The scope of application is vast.This paper firstly summarizes the research progress of wall-climbing robots with three different moving methods:wheel-climbing,crawler-based,and leg-footed robots;summarizes the applications and breakthroughs of four adsorption technologies:negative pressure,magnetic force,bionic and electrostatic;discusses the application of motion control algorithms in wall-climbing robots.Secondly,the advantages and disadvantages of different migration modes and adsorption methods are pointed out.The distribution and advantages of the combined application of different migration modes and adsorption methods are analyzed.In addition,the future development trend of wall-climbing robots and the promoting effect of bionic technology development on wall-climbing robots are proposed.The content of this paper will provide helpful guidance for the research of wall-climbing robots.
基金supported by the BUCEA Post Graduate Innovation Project,China(PG2023096).
文摘In the field of pipeline inner wall inspection,the snake robot demonstrates significant advantages over other inspection methods.While a simple traveling wave or meandering motion will suffice for inspecting the inner wall of small-diameter pipes,comprehensively and meticulously inspecting the inner wall of large-diameter pipes requires the snake robot to adopt a helical gait that closely adheres to the inner wall.Our review of existing literature indicates that most research and development on the helical gait of snake robots has focused on the outer surface of cylinders,with very few studies dedicated to developing a helical gait specifically for the inspection of the inner wall of pipes.Therefore,in this study,we propose a helical gait that is suitable for the inner wall of pipes and meets the requirements of gas pipeline engineering.The helical gait is designed using the backbone curve method.First,we create a mathematical model for a circular helix curve with constant curvature and torsion,ensuring it is applicable to a snake robot prototype in a laboratory environment.Subsequently.we calculate the joint angles required for two conical spiral curves with variable curvature and torsion,establish a new model,and define the physical significance of the specific parameters.To ensure the feasibility of the proposed gait,we conduct experiments involving meandering and traveling wave motions to verify the communication and control between the host computer and the snake robot.Building upon this foundation,we further validate the mathematical model of the complex helical motion gait through simulation experiments.Our findings provide a theoretical basis for realizing helical movement with a real snake robot.
基金grants from the Science and Technology Bureau of Xiamen(No.3502Z20064001)the Health Bureau of Xiamen(No.WSK0613, No. WSK0520 and No.WQK0614 )
文摘Background There remains controversy about whether Brugada syndrome （BS） has structural heart changes. We occasionally noted that a patient with BS had a quite unusual regional wall motion abnormality at the basal segment of the interventricular septum （IVS） during echocardiographic examination. The unexpected finding promoted us to reexamine our patients with BS by echocardiographic interrogation in the present study. Methods Patients with BS （n=11）, patients with complete right bundle branch block （RBBB） （n=11）, and control subjects （n=11） were enrolled in this study. Two-dimensional echocardiography （2DE） was performed to obtain parasternal left ventricular long axis view on which M-mode scanning line was adjusted to be perpendicular to the basal segment of IVS for delineation of the segmental motion curve, with a simultaneously electrocardiographic tracing. Results 2DE revealed a rapid swing motion shifting toward the right ventricle of the IVS basal segment at early systole in 73% （8/11） patients with BS, which was further confirmed on the M-mode curve evidenced by an early systolic notch toward the right ventricle. The position of the notch corresponded to C-point on the mitral motion curve, lasting for （53±5） ms. There were no similar changes both in patients with RBBB and in the control subjects. Conclusion IVS basal motion abnormalities at early-systolic phase may be the novel finding of BS.
基金This work was supported by the National Key Research and Development Program of China(2018YFC0810202)the National Defence Pre-research Foundation of China(61404130119).
文摘Ultra-wideband(UWB)through-wall radar has a wide range of applications in non-contact human information detection and monitoring.With the integration of machine learning technology,its potential prospects include the physiological monitoring of patients in the hospital environment and the daily monitoring at home.Although many target detection methods of UWB through-wall radar based on machine learning have been proposed,there is a lack of an opensource dataset to evaluate the performance of the algorithm.This published dataset is measured by impulse radio UWB(IR-UWB)through-wall radar system.Three test subjects are measured in different environments and several defined motion status.Using the presented dataset,we propose a human-motion-status recognition method using a convolutional neural network(CNN),and the detailed dataset partition method and the recognition process flow are given.On the well-trained network,the recognition accuracy of testing data for three kinds of motion status is higher than 99.7%.The dataset presented in this paper considers a simple environment.Therefore,we call on all organizations in the UWB radar field to cooperate to build opensource datasets to further promote the development of UWB through-wall radar.
