Heavy-duty legged robots have been regarded as one of the important developments in the field of legged robots because of their high payload-total mass ratio,terrain adaptability,and multitasking.The problems associat...Heavy-duty legged robots have been regarded as one of the important developments in the field of legged robots because of their high payload-total mass ratio,terrain adaptability,and multitasking.The problems associated with the development and use of heavy-duty legged robots have motivated researchers to conduct many important studies,covering topics related to the mechanical structure,force distribution,control strategy,energy efficiency,etc.Overall,heavy-duty legged robots have three main characteristics:greater body masses,larger body sizes,and higher payload-total mass ratios.Thus,various heavy-duty legged robots and their performances are reviewed here.This review presents the current developments with regard to heavy-duty legged robots.Also,the main characteristics of high-performance heavy-duty legged robots are determined and conclusions are drawn.Furthermore,the current research of key techniques of heavy-duty legged robots,including the mechanical structure,force distribution,control method,and power source,is described.To assess the transportation capacity of heavy-duty legged robots,performance evaluation parameters are proposed.Finally,problems that need further research are addressed.展开更多
Objectives A nurse duty roster is usually prepared monthly in a hospital ward.It is common for nurses to make duty shift requests prior to scheduling.A ward manager normally spends more than a working day to manually ...Objectives A nurse duty roster is usually prepared monthly in a hospital ward.It is common for nurses to make duty shift requests prior to scheduling.A ward manager normally spends more than a working day to manually prepare and subsequently to optimally adjust the schedule upon staff requests and hospital policies.This study aimed to develop an automatic nurse roster scheduling system with the use of open-source operational research tools by taking into account the hospital standards and the constraints from nurses.Methods Artificial intelligence and end user tools operational research tools were used to develop the code for the nurse duty roster scheduling system.To compare with previous research on various heuristics in employee scheduling,the current system was developed on open architecture and adopted with real shift duty requirements in a hospital ward.Results The schedule can be generated within 1 min under both hard and soft constraint optimization.All hard constraints are fulfilled and most nurse soft constraints could be met.Compared with those schedules prepared manually,the computer-generated schedules were more optimally adjusted as real time interaction among nurses and management personnel.The generated schedules were flexible to cope with daily and hourly duty changes by redeploying ward staff in order to maintain safe staffing levels.Conclusions An economical but yet highly efficient and user friendly solution to nurse roster scheduling system has been developed and adopted using open-source operational research methodology.The open-source platform is found to perform satisfactorily in scheduling application.The system can be implemented to different wards in hospitals and be regularly updated with new hospital polices and nurse manpower by hospital information personnel with training in artificial intelligence.展开更多
The paper proposes a novel three-phase voltage-fed quasi-Z-source ac-ac converter topology to overcome the shortcomings of the traditional three-phase AC-AC chopper.The quantitative relationship between the output vol...The paper proposes a novel three-phase voltage-fed quasi-Z-source ac-ac converter topology to overcome the shortcomings of the traditional three-phase AC-AC chopper.The quantitative relationship between the output voltage and duty-ratio is deduced by investigating the topology and operating principle.It can provide buck-boost function,and the output voltage of the circuit can keep stable in the case of voltage sagging.Simulation is performed using the MATLAB software,and the experimental circuit is built based on the simulation results,the simulation and experimental results verify the correctness and feasibility of the proposed ac-ac converter topology.展开更多
基金supported by the National Basic Research Program of China("973" Program)(Grant No.2013CB035502)the International Sci-ence and Technology Cooperation Project with Russia(Grant No.2010DFR70270)+2 种基金the National Natural Science Foundation of China(Grant No.51275106)the"111" Project(Grant No.B07018)the Key Laboratory Opening Funding of Aerospace Mechanism and Control(Grant No.HIT.KLOF.2010057)
文摘Heavy-duty legged robots have been regarded as one of the important developments in the field of legged robots because of their high payload-total mass ratio,terrain adaptability,and multitasking.The problems associated with the development and use of heavy-duty legged robots have motivated researchers to conduct many important studies,covering topics related to the mechanical structure,force distribution,control strategy,energy efficiency,etc.Overall,heavy-duty legged robots have three main characteristics:greater body masses,larger body sizes,and higher payload-total mass ratios.Thus,various heavy-duty legged robots and their performances are reviewed here.This review presents the current developments with regard to heavy-duty legged robots.Also,the main characteristics of high-performance heavy-duty legged robots are determined and conclusions are drawn.Furthermore,the current research of key techniques of heavy-duty legged robots,including the mechanical structure,force distribution,control method,and power source,is described.To assess the transportation capacity of heavy-duty legged robots,performance evaluation parameters are proposed.Finally,problems that need further research are addressed.
文摘Objectives A nurse duty roster is usually prepared monthly in a hospital ward.It is common for nurses to make duty shift requests prior to scheduling.A ward manager normally spends more than a working day to manually prepare and subsequently to optimally adjust the schedule upon staff requests and hospital policies.This study aimed to develop an automatic nurse roster scheduling system with the use of open-source operational research tools by taking into account the hospital standards and the constraints from nurses.Methods Artificial intelligence and end user tools operational research tools were used to develop the code for the nurse duty roster scheduling system.To compare with previous research on various heuristics in employee scheduling,the current system was developed on open architecture and adopted with real shift duty requirements in a hospital ward.Results The schedule can be generated within 1 min under both hard and soft constraint optimization.All hard constraints are fulfilled and most nurse soft constraints could be met.Compared with those schedules prepared manually,the computer-generated schedules were more optimally adjusted as real time interaction among nurses and management personnel.The generated schedules were flexible to cope with daily and hourly duty changes by redeploying ward staff in order to maintain safe staffing levels.Conclusions An economical but yet highly efficient and user friendly solution to nurse roster scheduling system has been developed and adopted using open-source operational research methodology.The open-source platform is found to perform satisfactorily in scheduling application.The system can be implemented to different wards in hospitals and be regularly updated with new hospital polices and nurse manpower by hospital information personnel with training in artificial intelligence.
文摘The paper proposes a novel three-phase voltage-fed quasi-Z-source ac-ac converter topology to overcome the shortcomings of the traditional three-phase AC-AC chopper.The quantitative relationship between the output voltage and duty-ratio is deduced by investigating the topology and operating principle.It can provide buck-boost function,and the output voltage of the circuit can keep stable in the case of voltage sagging.Simulation is performed using the MATLAB software,and the experimental circuit is built based on the simulation results,the simulation and experimental results verify the correctness and feasibility of the proposed ac-ac converter topology.
