Recognizing and predicting the movement and intention of the wearer in control of an exoskeleton robot is very challenging. It is difficult for exoskeleton robots, which measure and drive human movements, to interact ...Recognizing and predicting the movement and intention of the wearer in control of an exoskeleton robot is very challenging. It is difficult for exoskeleton robots, which measure and drive human movements, to interact with humans. Therefore, many different types of sensors are needed. When using various sensors, a data design is needed for effective sensing. An electromyographic(EMG) signal can be used to identify intended motion before the actual movement, and the delay time can be shortened via control of the exoskeleton robot. Before using a lower limb exoskeleton to help in walking, the aim of this work is to distinguish the walking environment and gait period using various sensors, including the surface electromyography(sE MG) sensor. For this purpose, a gait experiment was performed on four subjects using the ground reaction force, human–robot interaction force, and position sensors with sEMG sensors. The purpose of this paper is to show progress with the use of sEMG when recognizing walking environments and the gait period with other sensors. For effective data design, we used a combination of sensor types, sEMG sensor locations, and sEMG features. The results obtained using an individual mechanical sensor together with sEMG showed improvement compared to the case of using an individual sensor, and the combination of sEMG and position information showed the best performance in the same number of combinations of three sensors. When four sensor combinations were used, the environment classification accuracy was 96.1%, and the gait period classification accuracy was 97.8%. Vastus medialis(VM) and gastrocnemius(GAS) were the most effective combinations of two muscle types among the five sEMG sensor locations on the legs, and the results were 74.4% in pre-heel contact(preHC) and 71.7% in pre-toe-off(preTO) for environment classification, and 68.0% for gait period classification, when using only the sE MG sensor. The two effective sE MG feature combinations were "mean absolute value(MAV), zero crossings(ZC)" and "MAV, waveform length(WL)", and the "MAV, ZC" results were 80.0%, 77.1%, and 75.5%. These results suggest that the sEMG signal can be effectively used to control an exoskeleton robot.展开更多
Topological phases and their associated multiple edge states are studied by constructing a one-dimensional non-unitary multi-period quantum walk with parity-time symmetry.It is shown that large topological numbers can...Topological phases and their associated multiple edge states are studied by constructing a one-dimensional non-unitary multi-period quantum walk with parity-time symmetry.It is shown that large topological numbers can be obtained when choosing an appropriate time frame.The maximum value of the winding number can reach the number of periods in the one-step evolution operator.The validity of the bulk-edge correspondence is confirmed,while for an odd-period quantum walk and an even-period quantum walk,they have different configurations of the 0-energy edge state andπ-energy edge state.On the boundary,two kinds of edge states always coexist in equal amount for the odd-period quantum walk,however three cases including equal amount,unequal amount or even only one type may occur for the even-period quantum walk.展开更多
We present a numerical study of a model of quantum walk in a periodic potential on a line. We take the simple view that different potentials have different affects on the way in which the coin state of the walker is c...We present a numerical study of a model of quantum walk in a periodic potential on a line. We take the simple view that different potentials have different affects on the way in which the coin state of the walker is changed. For simplicity and definiteness, we assume that the walker＇s coin state is unaffected at sites without the potential, and rotated in an unbiased way according to the Hadamard matrix at sites with the potential. This is the simplest and most natural model of a quantum walk in a periodic potential with two coins. Six generic cases of such quantum walks are studied numerically. It is found that, of the six cases, four cases display significant localization effect where the walker is confined in the neighborhood of the origin for a sufficiently long time. Associated with such a localization effect is the recurrence of the probability of the walker returning to the neighborhood of the origin.展开更多
This work designs a four-platelet periodic multicrystal configuration in the second harmonic generation of ultra- short pulses as a new walk-off-compensating device. It theoretically investigates a proposed active and...This work designs a four-platelet periodic multicrystal configuration in the second harmonic generation of ultra- short pulses as a new walk-off-compensating device. It theoretically investigates a proposed active and a typical passive compensating scheme with the undepleted-pump approximation. The result shows that the angular and spectral band- widths are proportional to the number of crystal pairs as expected, but the temperature tunability is basically unaltered owing to inter-plate pulse interference. At the same time, an analysis reveals that a misuse of the phase mismatch factor is responsible for a historic controversy about pulse interference. A real design of an ultraviolet second harmonic generation （262.5 nm） is considered in a passive periodic [3-Barium Borate-calcite configuration, where the inter-plate pulse interference is found to form an azimuthal tuning restriction and to lower plate length tolerance. A subsequent numerical simulation with pump depletion is in good accordance with theoretical prediction.展开更多
人体运动雷达微多普勒能够为目标识别提供特征。由于行人雷达回波的复杂性,从雷达回波中提取运动参数难度很大。为了实现目标精确识别,提出了一种估计单人行走平动速度、步态周期和步长的方法。首先应用广义S变换(GST)得到雷达回波的微...人体运动雷达微多普勒能够为目标识别提供特征。由于行人雷达回波的复杂性,从雷达回波中提取运动参数难度很大。为了实现目标精确识别,提出了一种估计单人行走平动速度、步态周期和步长的方法。首先应用广义S变换(GST)得到雷达回波的微多普勒谱,然后提取出躯干部位的微多普勒分量,并将此分量转为一维时间频率序列,最后从序列中直接估计行走的平动速度和步态周期,用这2个估计值间接估计步长。仿真实验证明:本文方法抗噪声性能好,当信噪比大于4 d B时,估计精度高。展开更多
目的应用多普勒超声技术检查餐后高血糖患者的血管肉皮功能,探讨餐后高血糖对动脉粥样硬化的影响。方法选择新诊断2型糖尿病患者46例,采集静脉血测TC、TG、LDL-C、HDL-C、血糖、胰岛素、糖化血红蛋白(HbAlc)、高敏C反应蛋白(high-sensit...目的应用多普勒超声技术检查餐后高血糖患者的血管肉皮功能,探讨餐后高血糖对动脉粥样硬化的影响。方法选择新诊断2型糖尿病患者46例,采集静脉血测TC、TG、LDL-C、HDL-C、血糖、胰岛素、糖化血红蛋白(HbAlc)、高敏C反应蛋白(high-sensitivity C-reactive protein,hs-CRP),并行口服葡萄糖耐量试验后测餐后2 h血糖(2 h PG)及餐后2 h胰岛素(2 h INS)。将其结果分为空腹高血糖组(空腹高血糖惠者21例)及餐后高血糖组(餐后高血糖患者25例),同期选择血糖正常者20例作为对照组,测定3组的肱动脉内皮依赖性舒张功能(endothelium-dependent dilation,EDD)。结果餐后高血糖组和空腹高血糖组患者肱动脉EDD、TC、LDL-C、HDL-C、空腹血糖、2 h PG、2 h INS、HbAlc、hs-CRP与对照组比较.差异有统计学意义(P<0.05,P<0.01)。餐后高血糖组患者肱动脉EDD较空腹高血糖组明显降低[(3.58±1.04)%vs(4.86±0.92)%.P<0.01]。多因素逐步回归分析显示,EDD与2 h PG、HbAlc、TC呈明显负相关(r分别为-0.77、-0.61、-0.57,P<0.01)。结论餐后高血糖较空腹高血糖对血管内皮功能危害更大.加强餐后高血糖的控制对延缓动脉粥样硬化更为重要。展开更多
AIM: To assess the diagnostic value of a combination of continuous intragastric pH and bilirubin monitoring in the detection of duodenogastric reflux (DGR), and the effects of diet on the bilirubin absorbance. METHODS...AIM: To assess the diagnostic value of a combination of continuous intragastric pH and bilirubin monitoring in the detection of duodenogastric reflux (DGR), and the effects of diet on the bilirubin absorbance. METHODS: 30 healthy volunteers were divided into two groups: standard diet group (Group 1) 18 cases, free diet group (Group 2)12 cases. Each subjects were subjected to simultaneous 24-hour intragastric pH and spectrophotometric bilirubin concentration monitoring (Bilitec 2000). RESULTS: There was no difference of preprandial phase bilirubin absorbance between two groups. The absorbance of postprandial phase was significantly increased in group 2 than group 1. There was no difference between preprandial phase and postprandial phase absorbance in group 1. Postprandial phase absorbance was significantly higher in group 2. In a comparison of bile reflux with intragastric pH during night time, there were 4 types of reflux: Simultaneous increase in absorbance and pH in only 19.6%, increase in bilirubin with unchanged pH 33.3%, pH increase with unchanged absorbance 36.3%, and both unchanged in 10.8%. Linear regression analysis showed no correlation between percentage total time of pH【4 and percentage total time of absorbance】0.14, r=0.068 P【0.05. CONCLUSION: Because of the dietary effect, high absorbance fluids or foods should be avoided in detection. Intragastric pH and bilirubin monitoring separately predict the presence of duodenal (and/or pancreatic) reflux and bile reflux. They can not substitute for each other. The detection of DGR is improved if the two parameters are combined simultaneously.展开更多
基金Project supported by the Agency for Defense Development and Defense Acquisition Program Administration(No.UD160059BD)
文摘Recognizing and predicting the movement and intention of the wearer in control of an exoskeleton robot is very challenging. It is difficult for exoskeleton robots, which measure and drive human movements, to interact with humans. Therefore, many different types of sensors are needed. When using various sensors, a data design is needed for effective sensing. An electromyographic(EMG) signal can be used to identify intended motion before the actual movement, and the delay time can be shortened via control of the exoskeleton robot. Before using a lower limb exoskeleton to help in walking, the aim of this work is to distinguish the walking environment and gait period using various sensors, including the surface electromyography(sE MG) sensor. For this purpose, a gait experiment was performed on four subjects using the ground reaction force, human–robot interaction force, and position sensors with sEMG sensors. The purpose of this paper is to show progress with the use of sEMG when recognizing walking environments and the gait period with other sensors. For effective data design, we used a combination of sensor types, sEMG sensor locations, and sEMG features. The results obtained using an individual mechanical sensor together with sEMG showed improvement compared to the case of using an individual sensor, and the combination of sEMG and position information showed the best performance in the same number of combinations of three sensors. When four sensor combinations were used, the environment classification accuracy was 96.1%, and the gait period classification accuracy was 97.8%. Vastus medialis(VM) and gastrocnemius(GAS) were the most effective combinations of two muscle types among the five sEMG sensor locations on the legs, and the results were 74.4% in pre-heel contact(preHC) and 71.7% in pre-toe-off(preTO) for environment classification, and 68.0% for gait period classification, when using only the sE MG sensor. The two effective sE MG feature combinations were "mean absolute value(MAV), zero crossings(ZC)" and "MAV, waveform length(WL)", and the "MAV, ZC" results were 80.0%, 77.1%, and 75.5%. These results suggest that the sEMG signal can be effectively used to control an exoskeleton robot.
基金supported by the National Natural Science Foundation of China(Grant No.12004231).
文摘Topological phases and their associated multiple edge states are studied by constructing a one-dimensional non-unitary multi-period quantum walk with parity-time symmetry.It is shown that large topological numbers can be obtained when choosing an appropriate time frame.The maximum value of the winding number can reach the number of periods in the one-step evolution operator.The validity of the bulk-edge correspondence is confirmed,while for an odd-period quantum walk and an even-period quantum walk,they have different configurations of the 0-energy edge state andπ-energy edge state.On the boundary,two kinds of edge states always coexist in equal amount for the odd-period quantum walk,however three cases including equal amount,unequal amount or even only one type may occur for the even-period quantum walk.
基金supported by the Ministry of Science and Technology of Taiwan,China(Grant Nos.NSC-99-2112-M-032-002-MY3 and NSC 102-2112-M-032-003-MY3)the National Center for Theoretical Sciences(North)(NCTS-n)of China
文摘We present a numerical study of a model of quantum walk in a periodic potential on a line. We take the simple view that different potentials have different affects on the way in which the coin state of the walker is changed. For simplicity and definiteness, we assume that the walker＇s coin state is unaffected at sites without the potential, and rotated in an unbiased way according to the Hadamard matrix at sites with the potential. This is the simplest and most natural model of a quantum walk in a periodic potential with two coins. Six generic cases of such quantum walks are studied numerically. It is found that, of the six cases, four cases display significant localization effect where the walker is confined in the neighborhood of the origin for a sufficiently long time. Associated with such a localization effect is the recurrence of the probability of the walker returning to the neighborhood of the origin.
基金supported by the Tiptop-Talent Fund from Harbin University of Science and Technology
文摘This work designs a four-platelet periodic multicrystal configuration in the second harmonic generation of ultra- short pulses as a new walk-off-compensating device. It theoretically investigates a proposed active and a typical passive compensating scheme with the undepleted-pump approximation. The result shows that the angular and spectral band- widths are proportional to the number of crystal pairs as expected, but the temperature tunability is basically unaltered owing to inter-plate pulse interference. At the same time, an analysis reveals that a misuse of the phase mismatch factor is responsible for a historic controversy about pulse interference. A real design of an ultraviolet second harmonic generation （262.5 nm） is considered in a passive periodic [3-Barium Borate-calcite configuration, where the inter-plate pulse interference is found to form an azimuthal tuning restriction and to lower plate length tolerance. A subsequent numerical simulation with pump depletion is in good accordance with theoretical prediction.
文摘人体运动雷达微多普勒能够为目标识别提供特征。由于行人雷达回波的复杂性,从雷达回波中提取运动参数难度很大。为了实现目标精确识别,提出了一种估计单人行走平动速度、步态周期和步长的方法。首先应用广义S变换(GST)得到雷达回波的微多普勒谱,然后提取出躯干部位的微多普勒分量,并将此分量转为一维时间频率序列,最后从序列中直接估计行走的平动速度和步态周期,用这2个估计值间接估计步长。仿真实验证明:本文方法抗噪声性能好,当信噪比大于4 d B时,估计精度高。
文摘目的应用多普勒超声技术检查餐后高血糖患者的血管肉皮功能,探讨餐后高血糖对动脉粥样硬化的影响。方法选择新诊断2型糖尿病患者46例,采集静脉血测TC、TG、LDL-C、HDL-C、血糖、胰岛素、糖化血红蛋白(HbAlc)、高敏C反应蛋白(high-sensitivity C-reactive protein,hs-CRP),并行口服葡萄糖耐量试验后测餐后2 h血糖(2 h PG)及餐后2 h胰岛素(2 h INS)。将其结果分为空腹高血糖组(空腹高血糖惠者21例)及餐后高血糖组(餐后高血糖患者25例),同期选择血糖正常者20例作为对照组,测定3组的肱动脉内皮依赖性舒张功能(endothelium-dependent dilation,EDD)。结果餐后高血糖组和空腹高血糖组患者肱动脉EDD、TC、LDL-C、HDL-C、空腹血糖、2 h PG、2 h INS、HbAlc、hs-CRP与对照组比较.差异有统计学意义(P<0.05,P<0.01)。餐后高血糖组患者肱动脉EDD较空腹高血糖组明显降低[(3.58±1.04)%vs(4.86±0.92)%.P<0.01]。多因素逐步回归分析显示,EDD与2 h PG、HbAlc、TC呈明显负相关(r分别为-0.77、-0.61、-0.57,P<0.01)。结论餐后高血糖较空腹高血糖对血管内皮功能危害更大.加强餐后高血糖的控制对延缓动脉粥样硬化更为重要。
基金the Public Health Ministry Foundation of China,No.06-9602-13
文摘AIM: To assess the diagnostic value of a combination of continuous intragastric pH and bilirubin monitoring in the detection of duodenogastric reflux (DGR), and the effects of diet on the bilirubin absorbance. METHODS: 30 healthy volunteers were divided into two groups: standard diet group (Group 1) 18 cases, free diet group (Group 2)12 cases. Each subjects were subjected to simultaneous 24-hour intragastric pH and spectrophotometric bilirubin concentration monitoring (Bilitec 2000). RESULTS: There was no difference of preprandial phase bilirubin absorbance between two groups. The absorbance of postprandial phase was significantly increased in group 2 than group 1. There was no difference between preprandial phase and postprandial phase absorbance in group 1. Postprandial phase absorbance was significantly higher in group 2. In a comparison of bile reflux with intragastric pH during night time, there were 4 types of reflux: Simultaneous increase in absorbance and pH in only 19.6%, increase in bilirubin with unchanged pH 33.3%, pH increase with unchanged absorbance 36.3%, and both unchanged in 10.8%. Linear regression analysis showed no correlation between percentage total time of pH【4 and percentage total time of absorbance】0.14, r=0.068 P【0.05. CONCLUSION: Because of the dietary effect, high absorbance fluids or foods should be avoided in detection. Intragastric pH and bilirubin monitoring separately predict the presence of duodenal (and/or pancreatic) reflux and bile reflux. They can not substitute for each other. The detection of DGR is improved if the two parameters are combined simultaneously.
