Synergic movement of finger's joints provides human hand tremendous dexterities,and the detection of kinematics parameters is critical to describe and evaluate the kinesiology functions of the fingers.The present ...Synergic movement of finger's joints provides human hand tremendous dexterities,and the detection of kinematics parameters is critical to describe and evaluate the kinesiology functions of the fingers.The present work is the attempt to investigate how the angular velocity and angular acceleration of the joints of index finger vary with respect to time during conducting a motor task.A high-speed video camera has been employed to visually record the movement of index finger,and miniaturized(5-mm diameter) reflective markers have affixed to the subject's index finger on the side close to thumb and dorsum of thumb at different joint landmarks.Captured images have been reviewed frame by frame to get the coordinate values of each joint,and the angular displacements,angular velocities and angular acceleration can be obtained with triangle function.The experiment results show that the methods here can detect the kinematics parameters of index finger joints during moving,and can be a valid route to study the motor function of index finger.展开更多
The split ratio which is defined as the ratio between rotor and stator outer diameters is critical for permanent magnet(PM)machines.In this paper,the split ratio in small high speed PM machines is optimized analytical...The split ratio which is defined as the ratio between rotor and stator outer diameters is critical for permanent magnet(PM)machines.In this paper,the split ratio in small high speed PM machines is optimized analytically by considering both stator and rotor loss limitations.By this way,the thermal constrains in both stator and rotor parts can be taken into account.It shows that both losses can significantly affect the optimal split ratio and the machine performance.By considering the influence of rotor losses,especially the rotor eddy current loss,the optimal split ratio is increased significantly in certain scenarios.The output torque is calculated analytically and the influences of several key design parameters on the optimal split ratio,i.e.slot/pole combinations and magnet materials,are also investigated in details.Finally,finite element(FE)analyses are carried out for validating of the analytical model.展开更多
The driver’s visibility is degraded when weather conditions deteriorate, which affects the traffic flow and induces traffic congestion or accidents. In particular, traffic accidents can be?led to chain reaction colli...The driver’s visibility is degraded when weather conditions deteriorate, which affects the traffic flow and induces traffic congestion or accidents. In particular, traffic accidents can be?led to chain reaction collisions, with high rate of fatality, when fog occurs in contrast to other weather factors that may restrict visibility. For the development of a traffic risk index, a deviation of the vehicle’s speed was set for the traffic risk index by referring to previous study results. In addition, factors that affected the deviation in a vehicle’s speed were selected as independent variables based on the traffic flow analysis during occurrences of fog. The visible distance, traffic volume, and speed were selected as the independent variables to estimate the optimal parameters in the regression model. The traffic risk index model during occurrences of fog proposed in this study is an exponential model, with the visible distance and the traffic volume defined as independent variables. According to the study model, traffic risk increased as the visible distance decreased and the traffic volume was lower. Thus, the visible distance that can affect traffic flow during occurrences of fog can be determined in the future based on the results of this study. The study results will be expected to contribute to not only traffic safety improvements, but also the facilitation of traffic flow as drivers and traffic operation managers intuitively recognize the level of risk.展开更多
Study on the eco-relationship of regional tourism is a evaluation about the present situation and potential of regional tourist resources. In order to breaking the situation of the lack of coordination on tourist dest...Study on the eco-relationship of regional tourism is a evaluation about the present situation and potential of regional tourist resources. In order to breaking the situation of the lack of coordination on tourist destination in Guizhou province, understanding it after the opening of the Gui-Guang high-speed rail is beneficial. This paper constructs an evaluation index system about the eco-relationship of the regional tourist from five parts- the resource value, the tourist market, the traffic location, the reception conditions and the resource types. To summarize the changes of the tourist eco-relationship of samples before and after the opening of the high-speed rail,it calculates the weight by the judgment matrix, and then uses the cluster analysis of SPSS and the basis for judging the eco-relationship of regional tourist. To choose the emphasis and to guide the direction on tourism industry in Guizhou Province in the future high-speed rail era, a case study of the regional tourist destination in Guizhou section of the Gui-Guang high-speed rail is carried out.展开更多
从社交媒体(以Twitter为例)用户视角出发,通过构建科学知识扩散速度的测度指标,探索科学论文在社交媒体平台上短期和长期扩散速度的差异及其影响因素。以CA-A Cancer Journal for Clinicians第66—68卷全部文献为研究样本,采用熵权法构...从社交媒体(以Twitter为例)用户视角出发,通过构建科学知识扩散速度的测度指标,探索科学论文在社交媒体平台上短期和长期扩散速度的差异及其影响因素。以CA-A Cancer Journal for Clinicians第66—68卷全部文献为研究样本,采用熵权法构建科学知识扩散速度的测度指标,运用SPSS分析科学论文的短期和长期扩散速度的差异,并借助Eviews工具对影响科学论文短期和长期扩散速度的影响因素进行格兰杰因果分析。结果表明,科学知识在社交媒体上的扩散速度显著受到关键词数量和作者数量的影响。具体而言,短期扩散速度主要由第一作者的引用量驱动;而在长期传播中,除了引用量外,第一作者的学术影响力(以h指数衡量)也起到显著作用,并且具有较高学术影响力的学者更能通过其学术声誉推动科学论文在社交媒体上的持续传播,从而促进科学知识的长期扩散。展开更多
基金Supported by the National Natural Science Foundation of China (30770546 )Natural Science Foundation of Chongqing(2006BB2043,2007BB5148)
文摘Synergic movement of finger's joints provides human hand tremendous dexterities,and the detection of kinematics parameters is critical to describe and evaluate the kinesiology functions of the fingers.The present work is the attempt to investigate how the angular velocity and angular acceleration of the joints of index finger vary with respect to time during conducting a motor task.A high-speed video camera has been employed to visually record the movement of index finger,and miniaturized(5-mm diameter) reflective markers have affixed to the subject's index finger on the side close to thumb and dorsum of thumb at different joint landmarks.Captured images have been reviewed frame by frame to get the coordinate values of each joint,and the angular displacements,angular velocities and angular acceleration can be obtained with triangle function.The experiment results show that the methods here can detect the kinematics parameters of index finger joints during moving,and can be a valid route to study the motor function of index finger.
文摘The split ratio which is defined as the ratio between rotor and stator outer diameters is critical for permanent magnet(PM)machines.In this paper,the split ratio in small high speed PM machines is optimized analytically by considering both stator and rotor loss limitations.By this way,the thermal constrains in both stator and rotor parts can be taken into account.It shows that both losses can significantly affect the optimal split ratio and the machine performance.By considering the influence of rotor losses,especially the rotor eddy current loss,the optimal split ratio is increased significantly in certain scenarios.The output torque is calculated analytically and the influences of several key design parameters on the optimal split ratio,i.e.slot/pole combinations and magnet materials,are also investigated in details.Finally,finite element(FE)analyses are carried out for validating of the analytical model.
文摘The driver’s visibility is degraded when weather conditions deteriorate, which affects the traffic flow and induces traffic congestion or accidents. In particular, traffic accidents can be?led to chain reaction collisions, with high rate of fatality, when fog occurs in contrast to other weather factors that may restrict visibility. For the development of a traffic risk index, a deviation of the vehicle’s speed was set for the traffic risk index by referring to previous study results. In addition, factors that affected the deviation in a vehicle’s speed were selected as independent variables based on the traffic flow analysis during occurrences of fog. The visible distance, traffic volume, and speed were selected as the independent variables to estimate the optimal parameters in the regression model. The traffic risk index model during occurrences of fog proposed in this study is an exponential model, with the visible distance and the traffic volume defined as independent variables. According to the study model, traffic risk increased as the visible distance decreased and the traffic volume was lower. Thus, the visible distance that can affect traffic flow during occurrences of fog can be determined in the future based on the results of this study. The study results will be expected to contribute to not only traffic safety improvements, but also the facilitation of traffic flow as drivers and traffic operation managers intuitively recognize the level of risk.
基金supported by the Natural Science Project of Guizhou Province (Grant No. 201494)
文摘Study on the eco-relationship of regional tourism is a evaluation about the present situation and potential of regional tourist resources. In order to breaking the situation of the lack of coordination on tourist destination in Guizhou province, understanding it after the opening of the Gui-Guang high-speed rail is beneficial. This paper constructs an evaluation index system about the eco-relationship of the regional tourist from five parts- the resource value, the tourist market, the traffic location, the reception conditions and the resource types. To summarize the changes of the tourist eco-relationship of samples before and after the opening of the high-speed rail,it calculates the weight by the judgment matrix, and then uses the cluster analysis of SPSS and the basis for judging the eco-relationship of regional tourist. To choose the emphasis and to guide the direction on tourism industry in Guizhou Province in the future high-speed rail era, a case study of the regional tourist destination in Guizhou section of the Gui-Guang high-speed rail is carried out.
文摘从社交媒体(以Twitter为例)用户视角出发,通过构建科学知识扩散速度的测度指标,探索科学论文在社交媒体平台上短期和长期扩散速度的差异及其影响因素。以CA-A Cancer Journal for Clinicians第66—68卷全部文献为研究样本,采用熵权法构建科学知识扩散速度的测度指标,运用SPSS分析科学论文的短期和长期扩散速度的差异,并借助Eviews工具对影响科学论文短期和长期扩散速度的影响因素进行格兰杰因果分析。结果表明,科学知识在社交媒体上的扩散速度显著受到关键词数量和作者数量的影响。具体而言,短期扩散速度主要由第一作者的引用量驱动;而在长期传播中,除了引用量外,第一作者的学术影响力(以h指数衡量)也起到显著作用,并且具有较高学术影响力的学者更能通过其学术声誉推动科学论文在社交媒体上的持续传播,从而促进科学知识的长期扩散。
