In some complicated tabletop object manipulation task for robotic system, demonstration based control is an efficient way to enhance the stability of execution. In this paper, we use a new optical hand tracking sensor...In some complicated tabletop object manipulation task for robotic system, demonstration based control is an efficient way to enhance the stability of execution. In this paper, we use a new optical hand tracking sensor, LeapMotion, to perform a non-contact demonstration for robotic systems. A Multi-LeapMotion hand tracking system is developed. The setup of the two sensors is analyzed to gain a optimal way for efficiently use the informations from the two sensors. Meanwhile, the coordinate systems of the Mult-LeapMotion hand tracking device and the robotic demonstration system are developed. With the recognition to the element actions and the delay calibration, the fusion principles are developed to get the improved and corrected gesture recognition. The gesture recognition and scenario experiments are carried out, and indicate the improvement of the proposed Multi-LeapMotion hand tracking system in tabletop object manipulation task for robotic demonstration.展开更多
It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly eval...It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly evaluated and calculated via the classification and regression neural networks. An efficient databasegeneration method is developed for obtaining eight types of free return orbits and then the RD is defined by the orbit’s inclination and right ascension of ascending node(RAAN) at the perilune. A classify neural network and a regression network are trained respectively. The former is built for classifying the type of the RD, and the latter is built for calculating the inclination and RAAN of the RD. The simulation results show that two neural networks are well trained. The classification model has an accuracy of more than 99% and the mean square error of the regression model is less than 0.01°on the test set. Moreover, a serial strategy is proposed to combine the two surrogate models and a recognition tool is built to evaluate whether a lunar site could be reached. The proposed deep learning method shows the superiority in computation efficiency compared with the traditional double two-body model.展开更多
Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embry...Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embryonic stem cells （ESCs） or adult stem cells （ASCs）. It was previously believed that only ESCs hold the ability to differentiate into any cell type, whereas ASCs have the capacity to give rise only to cells of a given germ layer. More recently, however, numerous studies demonstrated the ability of ASCs to differentiate into cell types beyond their tissue origin. The aim of this review was to summarize contemporary evidence regarding stem cell availability, differentiation, and more specifically, the potential of these cells in the diagnosis and treatment of erectile dysfunction （ED） in both animal models and human research. We performed a search on PubMed for articles related to definition, iocalisation and circulation of stem cells as well as the application of stem cells in both diagnosis and treatment of ED. Strong evidence supports the concept that stem cell therapy is potentially the next therapeutic approach for ED. To date, a large spectrum of stem cells, including bone marrow mesenchymal stem cells, adipose tissue-derived stem cells and muscle-derived stem cells, have been investigated for neural, vascular, endothelial or smooth muscle regeneration in animal models for ED. In addition, several subtypes of ASCs are localized in the penis, and circulating endogenous stem cells can be employed to predict the outcome of ED and ED-related cardiovascular diseases.展开更多
基金This research is funded by National Natural Science Foundation of China under Project no. 61210013, Science and Technology Planning Project of Guangdong Province under no. 2014A020215027.
文摘In some complicated tabletop object manipulation task for robotic system, demonstration based control is an efficient way to enhance the stability of execution. In this paper, we use a new optical hand tracking sensor, LeapMotion, to perform a non-contact demonstration for robotic systems. A Multi-LeapMotion hand tracking system is developed. The setup of the two sensors is analyzed to gain a optimal way for efficiently use the informations from the two sensors. Meanwhile, the coordinate systems of the Mult-LeapMotion hand tracking device and the robotic demonstration system are developed. With the recognition to the element actions and the delay calibration, the fusion principles are developed to get the improved and corrected gesture recognition. The gesture recognition and scenario experiments are carried out, and indicate the improvement of the proposed Multi-LeapMotion hand tracking system in tabletop object manipulation task for robotic demonstration.
基金supported by the National Natural Science Foundation of China (12072365)the Natural Science Foundation of Hunan Province of China (2020JJ4657)。
文摘It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly evaluated and calculated via the classification and regression neural networks. An efficient databasegeneration method is developed for obtaining eight types of free return orbits and then the RD is defined by the orbit’s inclination and right ascension of ascending node(RAAN) at the perilune. A classify neural network and a regression network are trained respectively. The former is built for classifying the type of the RD, and the latter is built for calculating the inclination and RAAN of the RD. The simulation results show that two neural networks are well trained. The classification model has an accuracy of more than 99% and the mean square error of the regression model is less than 0.01°on the test set. Moreover, a serial strategy is proposed to combine the two surrogate models and a recognition tool is built to evaluate whether a lunar site could be reached. The proposed deep learning method shows the superiority in computation efficiency compared with the traditional double two-body model.
文摘Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embryonic stem cells （ESCs） or adult stem cells （ASCs）. It was previously believed that only ESCs hold the ability to differentiate into any cell type, whereas ASCs have the capacity to give rise only to cells of a given germ layer. More recently, however, numerous studies demonstrated the ability of ASCs to differentiate into cell types beyond their tissue origin. The aim of this review was to summarize contemporary evidence regarding stem cell availability, differentiation, and more specifically, the potential of these cells in the diagnosis and treatment of erectile dysfunction （ED） in both animal models and human research. We performed a search on PubMed for articles related to definition, iocalisation and circulation of stem cells as well as the application of stem cells in both diagnosis and treatment of ED. Strong evidence supports the concept that stem cell therapy is potentially the next therapeutic approach for ED. To date, a large spectrum of stem cells, including bone marrow mesenchymal stem cells, adipose tissue-derived stem cells and muscle-derived stem cells, have been investigated for neural, vascular, endothelial or smooth muscle regeneration in animal models for ED. In addition, several subtypes of ASCs are localized in the penis, and circulating endogenous stem cells can be employed to predict the outcome of ED and ED-related cardiovascular diseases.
