Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negat...Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service (IN-DI-ESS) driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis (TS-DEA) to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1) Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2) Spearman's rank correlation test was performed to compare the overall effectiveness in two periods: stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-D1-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.展开更多
This paper presents the design method of hybrid drive system for the minibus with some limited conditions. The approach of design hybrid drive system is based on the dynamic modeling and simulation of the hybrid minib...This paper presents the design method of hybrid drive system for the minibus with some limited conditions. The approach of design hybrid drive system is based on the dynamic modeling and simulation of the hybrid minibus with planetary gear system. The main target of the design is to obtain the optimal design with the proper hybrid drive configuration and control for a given set of design constraints. In oder to meet the design target, it's necessary to adjust some parameters such as mechanical ratios and parameters of battery pack as well as control by simulation. During simulation the transient operating process can be studied in details with the dynamic model in Matlab/Simulink. The control strategy can be optimized by running the simulation and monitoring the operation of each components: the operating area of internal combustion engine (ICE), fuel consumption (energy consumption), the power distribution, the torque and rotary speed of ICE and motor, the operating efficiency of motor, the aheration of battery state of charge (SOC), current and voltage.展开更多
Dynamic running law of the hydraulic driving system decides the hoisting cage velocity curve in a hoisting cycle and is decided by the characteristic of the hydraulic driving system and by the operating speed of hoist...Dynamic running law of the hydraulic driving system decides the hoisting cage velocity curve in a hoisting cycle and is decided by the characteristic of the hydraulic driving system and by the operating speed of hoist driver. The paper studies the dynamic running law of hydraulic driving system, analyses the influence of driver operating speed on the dynamic running characteristic, and points out the reasonable driver operating speed to control the dynamic stress in rope and to reduce the oscillation of rope system.展开更多
The mathematical model of the modem induction traction motor (TRIM and cutting magnetic circuit traction motor), supplied with IPM inverter with different control technique is presented in the paper. In electric and...The mathematical model of the modem induction traction motor (TRIM and cutting magnetic circuit traction motor), supplied with IPM inverter with different control technique is presented in the paper. In electric and hybrid vehicle are applied: FLMC (Fuzzy Logic Mode Control), SLMC (Sliding Mode Control), NRMC (Neural Regulator Control), and Direct Power and Torque Control for Space Vector Modulated inverter (DPTC SVM). In the special solution of the electric and hybrid vehicle are also applied a Random Switching Frequency Modulation. The control of hybrid vehicle should assure the realization of established transport-assignments in the definite time, at the optimum of energy consumption. One can this realize using. The multi criteria control system. Some results of the computer simulations are presented in the paper. Results of numerical calculation were verified for laboratory model of the electric and hybrid wheel vehicles traction motor.展开更多
The paper presents physical and mathematical models of kinetic system, drive system (electric and combustion traction motors), and also wheel and rails traction vehicle supply system (car, special vehicle, modern t...The paper presents physical and mathematical models of kinetic system, drive system (electric and combustion traction motors), and also wheel and rails traction vehicle supply system (car, special vehicle, modern tram vehicle). Selected predictive and quasi dynamic control system algorithms of traction vehicle are presented in the paper. For selected constructions of traction vehicle drive system are presented in simulation models and are results of calculations of different exploitations work state of wheel vehicle with hybrid drive system. Results of computer calculations are verified with laboratory measurement and suitable corrections coefficient to simulations models of vehicles is introduced.展开更多
A surgical manipulator has widely been used for laparoscopic surgery. It has been chosen mainly for the use in supporting human operations and in robot systems like the da Vinci surgical system. These manipulator syst...A surgical manipulator has widely been used for laparoscopic surgery. It has been chosen mainly for the use in supporting human operations and in robot systems like the da Vinci surgical system. These manipulator systems are suitable for careful work, but they have a few problems. One of the problems is that the manipulator is not equipped with haptic sensing functions. Therefore, the operator must know the advanced techniques for visually detecting the physical contact state during surgical operations. These haptic sensing functions thus need to be incorporated into a surgical manipulator. We have developed hydraulic-driven forceps with a micro bearing and a bellows tube that can convey haptic sense to the operator. This system can measure the small forces acting on the tips of the forceps using Pascal's principle. A model of the system is provided from the relationship between the internal pressure of the bellows tube and the refraction angles of the forceps. It was confirmed using this model that the developed system makes it possible to estimate both the strength and the direction of the external force applied to the forceps by measuring the internal pressure of the bellows tube. An operator using a three-dimensional haptic device was able to feel the force response during an experiment in which they used the forceps to hold a blood vessel. This report describes the most appropriate method for letting the operator feel the force conveyed by using our system.展开更多
This paper shows an analysis ofMEM S (micro electro mechanical systems) due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity a...This paper shows an analysis ofMEM S (micro electro mechanical systems) due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity and Reynolds equation as well. The model contains a silicon microbeam, which is encircled by a stationary plate. The non-dimensional governing equations and associated boundary conditions are then solved iteratively through the Galerkin weighted method. The results show that pull-in voltage is dependent on the geometry nonlinearity. It is also demonstrated that by increasing voltage between the silicon microbeam and stationary plate, the pull-in instability happens.展开更多
Although hydraulic drives have an advantage of high power density, volumetric shrinkage of hydraulic fluids due to pressure causes various disadvantages such as delay of hydraulic response and compression energy loss....Although hydraulic drives have an advantage of high power density, volumetric shrinkage of hydraulic fluids due to pressure causes various disadvantages such as delay of hydraulic response and compression energy loss. Hydraulic fluids of new concept, high bulk modulus oils, have been developed as a new approach to improve the performance of a hydraulic servo system and verified. In this paper, practical performances of high bulk modulus oil, such as oil temperature rise during pump test, air bubbles generation by ultrasonic wave vibration, oxidation stability and anti-wear property, were studied. And the new oil was confirmed to have excellent practical performances besides advantages in pressure response and volumetric efficiency of pumps. Various new applications of the new oil are promising.展开更多
The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control bec...The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control becomes a complicated question to find a transient optimal control method to distribute the power between the engine and the electric machine(EM).This paper proposes an innovative control method to deal with the complicated transient coupling driving process of the electromechanical coupling driving system,considering the accelerating condition and the cruising condition mostly in the city driving cycle of HEB.The EM might be operated at driving mode or generating mode to assist the diesel engine to work in its high-efficiency area.Therefore,the adaptive torque tracking controller has been brought forward to ensure that the EM implements the demand torque as well as compensate the torque fluctuation of diesel engine.The d?q axis mathematical model and back stepping method are employed to deduce the adaptive controller and its adaptive laws.Simulation results demonstrate that the proposed control scheme can make the output torque of two power sources respond rapidly to the demand torque from the powertrain in the given driving condition.The proposed method could be adopted in the real control of HEB to improve the efficiency of the hybrid driving system.展开更多
For a series plug-in hybrid electric vehicle,higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone.However,the overly complex structure will...For a series plug-in hybrid electric vehicle,higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone.However,the overly complex structure will inevitably lead to a substantial increase in the development cost.To improve the system price-performance ratio,a new kind of series-parallel hybrid system evolved from the series plug-in hybrid system is designed.According to the technical parameters of the selected components,the system model is established,and the vehicle dynamic property and pure electric drive economy are evaluated.Based on the dynamic programming,the energy management strategy for the drive system under the city driving cycle is developed,and the superiority validation of the system is completed.For the studied vehicle driven by the designed series-parallel plug-in hybrid system,compared with the one driven by the described series plug-in hybrid system,the dynamic property is significantly improved because of the multi-power coupling,and the fuel consumption is reduced by 11.4%with 10 city driving cycles.In a word,with the flexible configuration of the designed hybrid system and the optimized control strategy of the energy management,the vehicle performance can be obviously improved.展开更多
The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerieally. In our findings, when the system is with only repuls...The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerieally. In our findings, when the system is with only repulsive twobody interactions or only three-body interactions, the tunneling will be suppressed; while in the case of the coupling between two- and three-body interactions, the tunneling can be either suppressed or enhanced. Particularly, when attractive three-body interactions are twice large as repulsive two-body interactions, CDT occurs at isolated points of driving force, which is similar to the linear case. Considering different interaction, the system can experience different transformation from coherent tunneling to coherent destruction of tunneling (CDT). The quasi-energy of the system as the function of the periodicaJ1y driving force shows a triangular structure, which provides a deep insight into the tunneling dynamics of the system.展开更多
基金Under the auspices of Science and Technology Service Network Initiative Project of the Chinese Academy of Sciences(No.KFJ-EW-STS-002)
文摘Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service (IN-DI-ESS) driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis (TS-DEA) to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1) Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2) Spearman's rank correlation test was performed to compare the overall effectiveness in two periods: stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-D1-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.
文摘This paper presents the design method of hybrid drive system for the minibus with some limited conditions. The approach of design hybrid drive system is based on the dynamic modeling and simulation of the hybrid minibus with planetary gear system. The main target of the design is to obtain the optimal design with the proper hybrid drive configuration and control for a given set of design constraints. In oder to meet the design target, it's necessary to adjust some parameters such as mechanical ratios and parameters of battery pack as well as control by simulation. During simulation the transient operating process can be studied in details with the dynamic model in Matlab/Simulink. The control strategy can be optimized by running the simulation and monitoring the operation of each components: the operating area of internal combustion engine (ICE), fuel consumption (energy consumption), the power distribution, the torque and rotary speed of ICE and motor, the operating efficiency of motor, the aheration of battery state of charge (SOC), current and voltage.
文摘Dynamic running law of the hydraulic driving system decides the hoisting cage velocity curve in a hoisting cycle and is decided by the characteristic of the hydraulic driving system and by the operating speed of hoist driver. The paper studies the dynamic running law of hydraulic driving system, analyses the influence of driver operating speed on the dynamic running characteristic, and points out the reasonable driver operating speed to control the dynamic stress in rope and to reduce the oscillation of rope system.
文摘The mathematical model of the modem induction traction motor (TRIM and cutting magnetic circuit traction motor), supplied with IPM inverter with different control technique is presented in the paper. In electric and hybrid vehicle are applied: FLMC (Fuzzy Logic Mode Control), SLMC (Sliding Mode Control), NRMC (Neural Regulator Control), and Direct Power and Torque Control for Space Vector Modulated inverter (DPTC SVM). In the special solution of the electric and hybrid vehicle are also applied a Random Switching Frequency Modulation. The control of hybrid vehicle should assure the realization of established transport-assignments in the definite time, at the optimum of energy consumption. One can this realize using. The multi criteria control system. Some results of the computer simulations are presented in the paper. Results of numerical calculation were verified for laboratory model of the electric and hybrid wheel vehicles traction motor.
文摘The paper presents physical and mathematical models of kinetic system, drive system (electric and combustion traction motors), and also wheel and rails traction vehicle supply system (car, special vehicle, modern tram vehicle). Selected predictive and quasi dynamic control system algorithms of traction vehicle are presented in the paper. For selected constructions of traction vehicle drive system are presented in simulation models and are results of calculations of different exploitations work state of wheel vehicle with hybrid drive system. Results of computer calculations are verified with laboratory measurement and suitable corrections coefficient to simulations models of vehicles is introduced.
文摘A surgical manipulator has widely been used for laparoscopic surgery. It has been chosen mainly for the use in supporting human operations and in robot systems like the da Vinci surgical system. These manipulator systems are suitable for careful work, but they have a few problems. One of the problems is that the manipulator is not equipped with haptic sensing functions. Therefore, the operator must know the advanced techniques for visually detecting the physical contact state during surgical operations. These haptic sensing functions thus need to be incorporated into a surgical manipulator. We have developed hydraulic-driven forceps with a micro bearing and a bellows tube that can convey haptic sense to the operator. This system can measure the small forces acting on the tips of the forceps using Pascal's principle. A model of the system is provided from the relationship between the internal pressure of the bellows tube and the refraction angles of the forceps. It was confirmed using this model that the developed system makes it possible to estimate both the strength and the direction of the external force applied to the forceps by measuring the internal pressure of the bellows tube. An operator using a three-dimensional haptic device was able to feel the force response during an experiment in which they used the forceps to hold a blood vessel. This report describes the most appropriate method for letting the operator feel the force conveyed by using our system.
文摘This paper shows an analysis ofMEM S (micro electro mechanical systems) due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity and Reynolds equation as well. The model contains a silicon microbeam, which is encircled by a stationary plate. The non-dimensional governing equations and associated boundary conditions are then solved iteratively through the Galerkin weighted method. The results show that pull-in voltage is dependent on the geometry nonlinearity. It is also demonstrated that by increasing voltage between the silicon microbeam and stationary plate, the pull-in instability happens.
文摘Although hydraulic drives have an advantage of high power density, volumetric shrinkage of hydraulic fluids due to pressure causes various disadvantages such as delay of hydraulic response and compression energy loss. Hydraulic fluids of new concept, high bulk modulus oils, have been developed as a new approach to improve the performance of a hydraulic servo system and verified. In this paper, practical performances of high bulk modulus oil, such as oil temperature rise during pump test, air bubbles generation by ultrasonic wave vibration, oxidation stability and anti-wear property, were studied. And the new oil was confirmed to have excellent practical performances besides advantages in pressure response and volumetric efficiency of pumps. Various new applications of the new oil are promising.
基金supported by the National Natural Science Foundation of China(Grant No.51275557)the National Science-technology Support Plan Projects of China(Grant No.2013BAG14B01)
文摘The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control becomes a complicated question to find a transient optimal control method to distribute the power between the engine and the electric machine(EM).This paper proposes an innovative control method to deal with the complicated transient coupling driving process of the electromechanical coupling driving system,considering the accelerating condition and the cruising condition mostly in the city driving cycle of HEB.The EM might be operated at driving mode or generating mode to assist the diesel engine to work in its high-efficiency area.Therefore,the adaptive torque tracking controller has been brought forward to ensure that the EM implements the demand torque as well as compensate the torque fluctuation of diesel engine.The d?q axis mathematical model and back stepping method are employed to deduce the adaptive controller and its adaptive laws.Simulation results demonstrate that the proposed control scheme can make the output torque of two power sources respond rapidly to the demand torque from the powertrain in the given driving condition.The proposed method could be adopted in the real control of HEB to improve the efficiency of the hybrid driving system.
基金supported by the National Natural Science Foundation of China(Grant No.51405259)China Postdoctoral Science Foundation funded project(Grant Nos.2014T70072&2013M530608)Colleges and Universities in Hebei Province Science and Technology Research Project(Grant No.QN2015056)
文摘For a series plug-in hybrid electric vehicle,higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone.However,the overly complex structure will inevitably lead to a substantial increase in the development cost.To improve the system price-performance ratio,a new kind of series-parallel hybrid system evolved from the series plug-in hybrid system is designed.According to the technical parameters of the selected components,the system model is established,and the vehicle dynamic property and pure electric drive economy are evaluated.Based on the dynamic programming,the energy management strategy for the drive system under the city driving cycle is developed,and the superiority validation of the system is completed.For the studied vehicle driven by the designed series-parallel plug-in hybrid system,compared with the one driven by the described series plug-in hybrid system,the dynamic property is significantly improved because of the multi-power coupling,and the fuel consumption is reduced by 11.4%with 10 city driving cycles.In a word,with the flexible configuration of the designed hybrid system and the optimized control strategy of the energy management,the vehicle performance can be obviously improved.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11274255 and 11305132Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.20136203110001+1 种基金the Natural Science Foundation of Gansu Province under Grant No.2011GS04358Creation of Science and Technology of Northwest Normal University under Grant Nos.NWNUKJCXGC-03-48,NWNU-LKQN-12-12
文摘The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerieally. In our findings, when the system is with only repulsive twobody interactions or only three-body interactions, the tunneling will be suppressed; while in the case of the coupling between two- and three-body interactions, the tunneling can be either suppressed or enhanced. Particularly, when attractive three-body interactions are twice large as repulsive two-body interactions, CDT occurs at isolated points of driving force, which is similar to the linear case. Considering different interaction, the system can experience different transformation from coherent tunneling to coherent destruction of tunneling (CDT). The quasi-energy of the system as the function of the periodicaJ1y driving force shows a triangular structure, which provides a deep insight into the tunneling dynamics of the system.