A geometrical parameters optimization and reducers selection method was proposed for robotic manipulators design. The Lagrangian approach was employed in deriving the dynamic model of a two-DOF manipulator. The flexib...A geometrical parameters optimization and reducers selection method was proposed for robotic manipulators design. The Lagrangian approach was employed in deriving the dynamic model of a two-DOF manipulator. The flexibility of links and joints was taken into account in the mechanical structure dimensions optimization and reducers selection, in which Timoshenko model was used to discretize the hollow links. Two criteria, i.e. maximization of fundamental frequency and minimization of self-mass/load ratio, were utilized to optimize the manipulators. The NSGA-II (fast elitist nondominated sorting genetic algorithms) was employed to solve the multi-objective optimization problem. How the joints flexibility affects the manipulators design was analyzed and shown in the numerical analysis example. The results indicate that simultaneous consideration of the joints and the links flexibility is very necessary for manipulators optimal design. Finally, several optimal combinations were provided. The effectiveness of the optimization method was proved by comparing with ADAMS simulation results. The self-mass/load ratio error of the two methods is within 10%. The maximum error of the natural frequency by the two methods is 23.74%. The method proposed in this work provides a fast and effective pathway for manipulator design and reducers selection.展开更多
Objective： To observe the clinical effect of electroacupuncture （EA） at four sacral points on overactive bladder syndrome. Methods： A total of 120 female patients with overactive bladder syndrome were allocated to...Objective： To observe the clinical effect of electroacupuncture （EA） at four sacral points on overactive bladder syndrome. Methods： A total of 120 female patients with overactive bladder syndrome were allocated to a treatment group of 80 cases and a control group of 40 cases on a voluntary basis. The patients in the treatment group received EA at four sacral points, and the treatment was given three times a week for 6 consecutive weeks, while the patients in the control group received oral administration of M-receptor antagonist tolterodine tartrate, which was given 4 mg each time, once a day for 6 consecutive weeks. Then the symptom scores were compared between the two groups before and after treatment. Results： At the end of treatment, the symptom scores showed statistical significant differences in comparing with those before treatment in both groups （both P〈0.02）; the symptom score in the treatment group was lower than that in the control group, showing a statistically significant difference （P〈0.05）. Conclusion： EA at four sacral points is an effective method for overactive bladder syndrome.展开更多
基金Project(2009AA04Z216) supported by the National High-Tech Research and Development Program (863 Program) of ChinaProject(2009ZX04013-011) supported by the National Science and Technology Major Project of ChinaProject supported by the HIT Oversea Talents Introduction Program,China
文摘A geometrical parameters optimization and reducers selection method was proposed for robotic manipulators design. The Lagrangian approach was employed in deriving the dynamic model of a two-DOF manipulator. The flexibility of links and joints was taken into account in the mechanical structure dimensions optimization and reducers selection, in which Timoshenko model was used to discretize the hollow links. Two criteria, i.e. maximization of fundamental frequency and minimization of self-mass/load ratio, were utilized to optimize the manipulators. The NSGA-II (fast elitist nondominated sorting genetic algorithms) was employed to solve the multi-objective optimization problem. How the joints flexibility affects the manipulators design was analyzed and shown in the numerical analysis example. The results indicate that simultaneous consideration of the joints and the links flexibility is very necessary for manipulators optimal design. Finally, several optimal combinations were provided. The effectiveness of the optimization method was proved by comparing with ADAMS simulation results. The self-mass/load ratio error of the two methods is within 10%. The maximum error of the natural frequency by the two methods is 23.74%. The method proposed in this work provides a fast and effective pathway for manipulator design and reducers selection.
文摘Objective： To observe the clinical effect of electroacupuncture （EA） at four sacral points on overactive bladder syndrome. Methods： A total of 120 female patients with overactive bladder syndrome were allocated to a treatment group of 80 cases and a control group of 40 cases on a voluntary basis. The patients in the treatment group received EA at four sacral points, and the treatment was given three times a week for 6 consecutive weeks, while the patients in the control group received oral administration of M-receptor antagonist tolterodine tartrate, which was given 4 mg each time, once a day for 6 consecutive weeks. Then the symptom scores were compared between the two groups before and after treatment. Results： At the end of treatment, the symptom scores showed statistical significant differences in comparing with those before treatment in both groups （both P〈0.02）; the symptom score in the treatment group was lower than that in the control group, showing a statistically significant difference （P〈0.05）. Conclusion： EA at four sacral points is an effective method for overactive bladder syndrome.
