The Chinese government has raised great attention on water resources and environment over the past several years. In dealing with the issues of water pollution, water management, and the imbalance of water resources, ...The Chinese government has raised great attention on water resources and environment over the past several years. In dealing with the issues of water pollution, water management, and the imbalance of water resources, China’s state council released “Water Pollution Prevention and Control Action Plan” in 2015. This policy has become a guideline to promote water sustainability in the long run. Since then, a number of regulatory policies were released to increase the focus on water conservation. Among those actions, water loss control associated with distribution systems is regarded as a key solution to improve water supply efficiency. This paper provided a comprehensive introduction to the framework of water loss control policy in China.展开更多
Increasing attention has been paid to the efficiency improvement of the induction traction system of high-speed trains due to the high demand for energy saving. In emergency self-propelled mode, however, the dc-link v...Increasing attention has been paid to the efficiency improvement of the induction traction system of high-speed trains due to the high demand for energy saving. In emergency self-propelled mode, however, the dc-link voltage and the traction power of the motor are significantly reduced, resulting in decreased traction efficiency due to the low load and low speed operations. Aiming to tackle this problem, a novel efficiency improved control method is introduced to the emergency mode of high-speed train traction system in this paper. In the proposed method, a total loss model of induction motor considering the behaviors of both iron and copper loss is established. An improved iterative algorithm with decreased computational burden is then introduced, resulting in a fast solving of the optimal flux reference for loss minimization at each control period. In addition, considering the parameter variation problem due to the low load and low speed operations, a parameter estimation method is integrated to improve the controller's robustness. The effectiveness of the proposed method on efficiency improvement at low voltage and low load conditions is demonstrated by simulated and experimental results.展开更多
According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and devel...According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.展开更多
The capacity of soil and water conservation measures, defined as the maximum quantity of suitable soil and water conservation measures contained in a region, were determined for the Loess Plateau based on zones suitab...The capacity of soil and water conservation measures, defined as the maximum quantity of suitable soil and water conservation measures contained in a region, were determined for the Loess Plateau based on zones suitable for establishing terraced fields, forestland and grassland with the support of geographic information system(GIS) software. The minimum possible soil erosion modulus and actual soil erosion modulus in 2010 were calculated using the revised universal soil loss equation(RUSLE), and the ratio of the minimum possible soil erosion modulus under the capacity of soil and water conservation measures to the actual soil erosion modulus was defined as the soil erosion control degree. The control potential of soil erosion and water loss in the Loess Plateau was studied using this concept. Results showed that the actual soil erosion modulus was 3355 t·km^(–2)·a^(–1), the minimum possible soil erosion modulus was 1921 t·km^(–2)·a^(–1), and the soil erosion control degree was 0.57(medium level) in the Loess Plateau in 2010. In terms of zoning, the control degree was relatively high in the river valley-plain area, soil-rocky mountainous area, and windy-sandy area, but relatively low in the soil-rocky hilly-forested area, hilly-gully area and plateau-gully area. The rate of erosion areas with a soil erosion modulus of less than 1000 t·km^(–2)·a^(–1) increased from 50.48% to 57.71%, forest and grass coverage rose from 56.74% to 69.15%, rate of terraced fields increased from 4.36% to 19.03%, and per capita grain available rose from 418 kg·a^(–1) to 459 kg·a^(–1) under the capacity of soil and water conservation measures compared with actual conditions. These research results are of some guiding significance for soil and water loss control in the Loess Plateau.展开更多
The convergence and stability analysis for two end-to-end rate-based congestion control algorithms with unavoidable random loss in packets are presented, which can be caused by, for example, errors on wireless links. ...The convergence and stability analysis for two end-to-end rate-based congestion control algorithms with unavoidable random loss in packets are presented, which can be caused by, for example, errors on wireless links. The convergence rates of these two algorithms are analyzed by linearizing them around their equilibrium points, since they are globally stable and can converge to their unique equilibrium points. Some sufficient conditions for local stability in the presence of round-trip delay are obtained based on the general Nyquist criterion of stability. The stability conditions can be considered to be more general. If random loss in the first congestion control algorithm is not considered, they reduce to the local stability conditions which have been obtained in some literatures. Furthermore, sufficient conditions for local stability of a new congestion control algorithm have also been obtained if random loss is not considered in the second congestion control algorithm.展开更多
Loess Plateau is the most serious region of soil and water loss in China and the world. The sediment carried into the Yellow River amounts to 1.6 billion tons every year. This paper reviews the factors and reasons for...Loess Plateau is the most serious region of soil and water loss in China and the world. The sediment carried into the Yellow River amounts to 1.6 billion tons every year. This paper reviews the factors and reasons for erosion in this area, and puts forward a comprehensive controlling policy on the basis of the principles of ecology and practise of Chinese scientists for 40 years. In conformity with the policy, a number of technical measures for controlling soil and water loss are suggested.展开更多
High Voltage Direct Current (HVDC) electric power transmission is a promising technology for integrating offshore wind farms and interconnecting power grids in different regions. In order to maintain the DC voltage, d...High Voltage Direct Current (HVDC) electric power transmission is a promising technology for integrating offshore wind farms and interconnecting power grids in different regions. In order to maintain the DC voltage, droop control has been widely used. Transmission line loss constitutes an import part of the total power loss in a multi-terminal HVDC scheme. In this paper, the relation between droop controller design and transmission loss has been investigated. Different MTDC layout configurations are compared to examine the effect of droop controller design on the transmission loss.展开更多
The objective of this paper is to present the advantages of Model reference adaptive control (MRAC) motion cueing algorithm against the classical motion cueing algorithm in terms of biomechanical reactions of the part...The objective of this paper is to present the advantages of Model reference adaptive control (MRAC) motion cueing algorithm against the classical motion cueing algorithm in terms of biomechanical reactions of the participants during the critical maneuvers like chicane in driving simulator real-time. This study proposes a method and an experimental validation to analyze the vestibular and neuromuscular dynamics responses of the drivers with respect to the type of the control used at the hexapod driving simulator. For each situation, the EMG (electromyography) data were registered from arm muscles of the drivers (flexor carpi radialis, brachioradialis). In addition, the roll velocity perception thresholds (RVT) and roll velocities (RV) were computed from the real-time vestibular level measurements from the drivers via a motion-tracking sensor. In order to process the data of the EMG and RVT, Pearson’s correlation and a two-way ANOVA with a significance level of 0.05 were assigned. Moreover, the relationships of arm muscle power and roll velocity with vehicle CG (center of gravity) lateral displacement were analyzed in order to assess the agility/alertness level of the drivers as well as the vehicle loss of control characteristics with a confidence interval of 95%. The results showed that the MRAC algorithm avoided the loss of adhesion, loss of control (LOA, LOC) more reasonably compared to the classical motion cueing algorithm. According to our findings, the LOA avoidance decreased the neuromuscular-visual cues level conflict with MRAC algorithm. It also revealed that the neuromuscular-vehicle dynamics conflict has influence on visuo-vestibular conflict;however, the visuo-vestibular cue conflict does not influence the neuromuscular-vehicle dynamics interactions.展开更多
In this paper,a fault tolerant control with the consideration of actuator fault for a networked control system (NCS) with packet loss is addressed.The NCS with data packet loss can be described as a switched system ...In this paper,a fault tolerant control with the consideration of actuator fault for a networked control system (NCS) with packet loss is addressed.The NCS with data packet loss can be described as a switched system model.Packet loss dependent Lyapunov function is used and a fault tolerant controller is proposed respectively for arbitrary packet loss process and Markovian packet loss process.Considering a controlled plant with external energy-bounded disturbance,a robust H ∞ fault tolerant controller is designed for the NCS.These results are also expanded to the NCS with packet loss and networked-induced delay.Numerical examples are given to illustrate the effectiveness of the proposed design method.展开更多
Loss of Control (LOC) is the primary factor responsible for the majority of fatal air accidents during past decade. LOC is characterized by the pilot’s inability to control the aircraft and is typically associated wi...Loss of Control (LOC) is the primary factor responsible for the majority of fatal air accidents during past decade. LOC is characterized by the pilot’s inability to control the aircraft and is typically associated with unpredictable behavior, potentially leading to loss of the aircraft and life. In this work, the minimum time dynamic optimization problem to LOC is treated using Pontryagin’s Maximum Principle (PMP). The resulting two point boundary value problem is solved using stochastic shooting point methods via a differential evolution scheme (DE). The minimum time until LOC metric is computed for corresponding spatial control limits. Simulations are performed using a linearized longitudinal aircraft model to illustrate the concept.展开更多
This paper discusses the model-based predictive controller design of networked nonlinear systems with communica- tion delay and data loss. Based on the analysis of the closed-loop networked predictive control systems,...This paper discusses the model-based predictive controller design of networked nonlinear systems with communica- tion delay and data loss. Based on the analysis of the closed-loop networked predictive control systems, the model-based networked predictive control strategy can compensate for communication delay and data loss in an active way. The designed model-based predictive controller can also guarantee the stability of the closed-loop networked system. The simulation re- suits demonstrate the feasibility and efficacy of the proposed model-based predictive controller design scheme.展开更多
Much research effort has been devoted to economic design of X & S control charts,however,there are some problems in usual methods.On the one hand,it is difficult to estimate the relationship between costs and other m...Much research effort has been devoted to economic design of X & S control charts,however,there are some problems in usual methods.On the one hand,it is difficult to estimate the relationship between costs and other model parameters,so the economic design method is often not effective in producing charts that can quickly detect small shifts before substantial losses occur;on the other hand,in many cases,only one type of process shift or only one pair of process shifts are taken into consideration,which may not correctly reflect the actual process conditions.To improve the behavior of economic design of control chart,a cost & loss model with Taguchi's loss function for the economic design of X & S control charts is embellished,which is regarded as an optimization problem with multiple statistical constraints.The optimization design is also carried out based on a number of combinations of process shifts collected from the field operation of the conventional control charts,thus more hidden information about the shift combinations is mined and employed to the optimization design of control charts.At the same time,an improved particle swarm optimization(IPSO) is developed to solve such an optimization problem in design of X & S control charts,IPSO is first tested for several benchmark problems from the literature and evaluated with standard performance metrics.Experimental results show that the proposed algorithm has significant advantages on obtaining the optimal design parameters of the charts.The proposed method can substantially reduce the total cost(or loss) of the control charts,and it will be a promising tool for economic design of control charts.展开更多
This paper explores and proposes a design solution of an integrated skip cycle mode (SCM) control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V proces...This paper explores and proposes a design solution of an integrated skip cycle mode (SCM) control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply (SMPS) works with low load or without load.展开更多
The sodium and glucose co-transporter inhibitors type 2 (SGLT2) comprises a new class of hypoglycemic drugs to control type 2 diabetes mellitus, in an attempt to add new non-existing benefits to the so far arising cla...The sodium and glucose co-transporter inhibitors type 2 (SGLT2) comprises a new class of hypoglycemic drugs to control type 2 diabetes mellitus, in an attempt to add new non-existing benefits to the so far arising classes. Regarding this new class of drugs, represented by dapaglifozin, canaglifozin and empaglifozin, it is important to highlight the benefits brought by these medications to combat hyperglycemia with insulin-independent mechanisms that are beyond glucose reduction, such as cardiovascular events prevention, reduction in HbA1c, weight loss and blood pressure lowering. Recently, a relevant study (Empa-Reg) brought hope and set the spotlight on the prevention of cardiac events among diabetic patients, which is the main cause of mortality within this group. However, despite coming out as a good treatment option, SGLT2 inhibitors are under constant clinical research and, as a new drug, it should be carefully carried out regarding the long-term effects of glycosuria and other possible side effects, such as the observed increase in the incidence of bladder, breast cancer and bone fractures, which require further studies. Therefore, these compounds might represent a landmark approach for the treatment of diabetes.展开更多
Focused on the lost circulation control in deep naturally fractured reservoirs, the multiscale structure of fracture plugging zone is proposed based on the theory of granular matter mechanics, and the structural failu...Focused on the lost circulation control in deep naturally fractured reservoirs, the multiscale structure of fracture plugging zone is proposed based on the theory of granular matter mechanics, and the structural failure pattern of plugging zone is developed to reveal the plugging zone failure mechanisms in deep, high temperature, high pressure, and high in-situ stress environment. Based on the fracture plugging zone strength model, key performance parameters are determined for the optimal selection of loss control material(LCM). Laboratory fracture plugging experiments with new LCM are carried out to evaluate the effect of the key performance parameters of LCM on fracture plugging quality. LCM selection strategy for fractured reservoirs is developed. The results show that the force chain formed by LCMs determines the pressure stabilization of macro-scale fracture plugging zone. Friction failure and shear failure are the two major failure patterns of fracture plugging zone. The strength of force chain depends on the performance of micro-scale LCM, and the LCM key performance parameters include particle size distribution, fiber aspect ratio, friction coefficient, compressive strength, soluble ability and high temperature resistance. Results of lab experiments and field test show that lost circulation control quality can be effectively improved with the optimal material selection based on the extracted key performance parameters of LCMs.展开更多
Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing.Disruption to a large number of physiological processes operating at different time s...Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing.Disruption to a large number of physiological processes operating at different time scales can lead to alterations in postural center of pressure(Co P)fluctuations.Multiscale entropy(MSE) has been used to identify differences in fluctuations of postural Co P time series between groups with and without known physiological impairments at multiple time scales.The purpose of this paper is to:1) review basic elements and current developments in entropy techniques used to assess physiological complexity;and 2) identify how MSE can provide insights into the complexity of physiological systems operating at multiple time scales that underlie the control of posture.We review and synthesize evidence from the literature providing support for MSE as a valuable tool to evaluate the breakdown in the physiological processes that accompany changes due to aging and disease in postural control.This evidence emerges from observed lower MSE values in individuals with multiple sclerosis,idiopathic scoliosis,and in older individuals with sensory impairments.Finally,we suggest some future applications of MSE that will allow for further insight into how physiological deficits impact the complexity of postural fluctuations;this information may improve the development and evaluation of new therapeutic interventions.展开更多
[Objective] The study aimed to find out effects of six-fourth generation Cnaphalocrocis medinalis (Guenée) on rice production in Yangzhou district and its control index. [Method] Through artificial control of i...[Objective] The study aimed to find out effects of six-fourth generation Cnaphalocrocis medinalis (Guenée) on rice production in Yangzhou district and its control index. [Method] Through artificial control of insects in field, four different insect volume gradients were set, the effects of different C. medinalis amounts on leaf roll rate and yield loss of Wuyunjing No.23 were determined. [Result] The results showed that within the range of 0-20 head/hill, as the amounts of insect increased, rice yield decreased, leaf roll rate and rice yield loss rate increased. According to 3% economic permit loss rate, the control index of C. medinalis on Wuyunjing No.23 was 173 head/hill. [Conclusion] The study would provide theoretical basis for effective controlling of six-fourth generation C. medinalis in Yangzhou district.展开更多
Two new techniques for efficiency-optimization control(EOC) of induction motor drives were proposed. The first method combined Loss Model and "golden section technique", which was faster than the available m...Two new techniques for efficiency-optimization control(EOC) of induction motor drives were proposed. The first method combined Loss Model and "golden section technique", which was faster than the available methods. Secondly, the low-frequency ripple torque due to decrease of rotor flux was compensated in a feedforward manner. If load torque or speed command changed, the efficiency search algorithm would be abandoned and the rated flux would be established to get the best transient response. The close agreement between the simulation and the experimental results confirmed the validity and usefulness of the proposed techniques.展开更多
There are many reservoirs in China,and serious reservoir sedimentation affects reservoir function and reservoir safety.It is of great significance for restoring the reservoir capacity,improving the efficiency of the r...There are many reservoirs in China,and serious reservoir sedimentation affects reservoir function and reservoir safety.It is of great significance for restoring the reservoir capacity,improving the efficiency of the reservoir and prolonging the service life of the reservoir to carry out the research on reservoir sedimentation control and storage capacity recovery technology,in the case of fewer and fewer good dam sites suitable for the construction of the reservoir and the increasing accumulation of reservoir sedimentation.In this paper,influence factor of the storage loss,sedimentation control and reservoir capacity recovery technology in China are briefly reviewed.It is necessary to carry out research work on reservoir sedimentation investigation and reservoir siltation mechanism and control measures.展开更多
Real-time monitoring and investigation in fields showed that the disease starting period of Sclerotinia sclerotiorum in mechanical direct seeding fields was earlier. Disease conditions rose with the advancing growth s...Real-time monitoring and investigation in fields showed that the disease starting period of Sclerotinia sclerotiorum in mechanical direct seeding fields was earlier. Disease conditions rose with the advancing growth stage, which grew more quickly during the early stage of anthesis, flower withering period and early si- lique mature period. Yield less rate increased with the increasing stem disease rate and disease index. Yield loss rate( Y1 ) had extremely significant correlation with stem disease rate(X1 )and disease index(X2 ), and the related models were Y1 = 0. 544 330 2X1 -2. 316 1 (n = 14, r --0. 986 0 * * )and YI = 0. 673 408 X2 - 1. 016 4 ( n = 14 ,r = 0.977 2 ~ * ), respectively. Disease control indexes for one time control against S. sclerotlorum in mechanical direct seeding fields were stem disease rate as 11.8% and disease index as 7.6, respectively. The control indexes for twice control against the disease were stem disease rate as 16.8% and disease index as 11.7. This paper provided a new scientific basis for preventing S. sclerotiorum in mechanical direct seeding fields.展开更多
文摘The Chinese government has raised great attention on water resources and environment over the past several years. In dealing with the issues of water pollution, water management, and the imbalance of water resources, China’s state council released “Water Pollution Prevention and Control Action Plan” in 2015. This policy has become a guideline to promote water sustainability in the long run. Since then, a number of regulatory policies were released to increase the focus on water conservation. Among those actions, water loss control associated with distribution systems is regarded as a key solution to improve water supply efficiency. This paper provided a comprehensive introduction to the framework of water loss control policy in China.
基金supported in part by the Science Foundation of the Chinese Academy of Railway Sciences under Grant Number:2023QT001。
文摘Increasing attention has been paid to the efficiency improvement of the induction traction system of high-speed trains due to the high demand for energy saving. In emergency self-propelled mode, however, the dc-link voltage and the traction power of the motor are significantly reduced, resulting in decreased traction efficiency due to the low load and low speed operations. Aiming to tackle this problem, a novel efficiency improved control method is introduced to the emergency mode of high-speed train traction system in this paper. In the proposed method, a total loss model of induction motor considering the behaviors of both iron and copper loss is established. An improved iterative algorithm with decreased computational burden is then introduced, resulting in a fast solving of the optimal flux reference for loss minimization at each control period. In addition, considering the parameter variation problem due to the low load and low speed operations, a parameter estimation method is integrated to improve the controller's robustness. The effectiveness of the proposed method on efficiency improvement at low voltage and low load conditions is demonstrated by simulated and experimental results.
文摘According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.
基金National Natural Science Foundation of China,No.41401305,No.41330858The Open Foundation of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,No.K318009902-14
文摘The capacity of soil and water conservation measures, defined as the maximum quantity of suitable soil and water conservation measures contained in a region, were determined for the Loess Plateau based on zones suitable for establishing terraced fields, forestland and grassland with the support of geographic information system(GIS) software. The minimum possible soil erosion modulus and actual soil erosion modulus in 2010 were calculated using the revised universal soil loss equation(RUSLE), and the ratio of the minimum possible soil erosion modulus under the capacity of soil and water conservation measures to the actual soil erosion modulus was defined as the soil erosion control degree. The control potential of soil erosion and water loss in the Loess Plateau was studied using this concept. Results showed that the actual soil erosion modulus was 3355 t·km^(–2)·a^(–1), the minimum possible soil erosion modulus was 1921 t·km^(–2)·a^(–1), and the soil erosion control degree was 0.57(medium level) in the Loess Plateau in 2010. In terms of zoning, the control degree was relatively high in the river valley-plain area, soil-rocky mountainous area, and windy-sandy area, but relatively low in the soil-rocky hilly-forested area, hilly-gully area and plateau-gully area. The rate of erosion areas with a soil erosion modulus of less than 1000 t·km^(–2)·a^(–1) increased from 50.48% to 57.71%, forest and grass coverage rose from 56.74% to 69.15%, rate of terraced fields increased from 4.36% to 19.03%, and per capita grain available rose from 418 kg·a^(–1) to 459 kg·a^(–1) under the capacity of soil and water conservation measures compared with actual conditions. These research results are of some guiding significance for soil and water loss control in the Loess Plateau.
基金supported in part by the National Natural Science Foundation of China (10671170,60404022)the National Outstanding Youth Foundation of China (60525303)and the Natural Science Foundation of Hebei Province (07M005,F2008000864)
文摘The convergence and stability analysis for two end-to-end rate-based congestion control algorithms with unavoidable random loss in packets are presented, which can be caused by, for example, errors on wireless links. The convergence rates of these two algorithms are analyzed by linearizing them around their equilibrium points, since they are globally stable and can converge to their unique equilibrium points. Some sufficient conditions for local stability in the presence of round-trip delay are obtained based on the general Nyquist criterion of stability. The stability conditions can be considered to be more general. If random loss in the first congestion control algorithm is not considered, they reduce to the local stability conditions which have been obtained in some literatures. Furthermore, sufficient conditions for local stability of a new congestion control algorithm have also been obtained if random loss is not considered in the second congestion control algorithm.
文摘Loess Plateau is the most serious region of soil and water loss in China and the world. The sediment carried into the Yellow River amounts to 1.6 billion tons every year. This paper reviews the factors and reasons for erosion in this area, and puts forward a comprehensive controlling policy on the basis of the principles of ecology and practise of Chinese scientists for 40 years. In conformity with the policy, a number of technical measures for controlling soil and water loss are suggested.
文摘High Voltage Direct Current (HVDC) electric power transmission is a promising technology for integrating offshore wind farms and interconnecting power grids in different regions. In order to maintain the DC voltage, droop control has been widely used. Transmission line loss constitutes an import part of the total power loss in a multi-terminal HVDC scheme. In this paper, the relation between droop controller design and transmission loss has been investigated. Different MTDC layout configurations are compared to examine the effect of droop controller design on the transmission loss.
文摘The objective of this paper is to present the advantages of Model reference adaptive control (MRAC) motion cueing algorithm against the classical motion cueing algorithm in terms of biomechanical reactions of the participants during the critical maneuvers like chicane in driving simulator real-time. This study proposes a method and an experimental validation to analyze the vestibular and neuromuscular dynamics responses of the drivers with respect to the type of the control used at the hexapod driving simulator. For each situation, the EMG (electromyography) data were registered from arm muscles of the drivers (flexor carpi radialis, brachioradialis). In addition, the roll velocity perception thresholds (RVT) and roll velocities (RV) were computed from the real-time vestibular level measurements from the drivers via a motion-tracking sensor. In order to process the data of the EMG and RVT, Pearson’s correlation and a two-way ANOVA with a significance level of 0.05 were assigned. Moreover, the relationships of arm muscle power and roll velocity with vehicle CG (center of gravity) lateral displacement were analyzed in order to assess the agility/alertness level of the drivers as well as the vehicle loss of control characteristics with a confidence interval of 95%. The results showed that the MRAC algorithm avoided the loss of adhesion, loss of control (LOA, LOC) more reasonably compared to the classical motion cueing algorithm. According to our findings, the LOA avoidance decreased the neuromuscular-visual cues level conflict with MRAC algorithm. It also revealed that the neuromuscular-vehicle dynamics conflict has influence on visuo-vestibular conflict;however, the visuo-vestibular cue conflict does not influence the neuromuscular-vehicle dynamics interactions.
基金supported by National Natural Science Foundation of China (No. 60874052)
文摘In this paper,a fault tolerant control with the consideration of actuator fault for a networked control system (NCS) with packet loss is addressed.The NCS with data packet loss can be described as a switched system model.Packet loss dependent Lyapunov function is used and a fault tolerant controller is proposed respectively for arbitrary packet loss process and Markovian packet loss process.Considering a controlled plant with external energy-bounded disturbance,a robust H ∞ fault tolerant controller is designed for the NCS.These results are also expanded to the NCS with packet loss and networked-induced delay.Numerical examples are given to illustrate the effectiveness of the proposed design method.
文摘Loss of Control (LOC) is the primary factor responsible for the majority of fatal air accidents during past decade. LOC is characterized by the pilot’s inability to control the aircraft and is typically associated with unpredictable behavior, potentially leading to loss of the aircraft and life. In this work, the minimum time dynamic optimization problem to LOC is treated using Pontryagin’s Maximum Principle (PMP). The resulting two point boundary value problem is solved using stochastic shooting point methods via a differential evolution scheme (DE). The minimum time until LOC metric is computed for corresponding spatial control limits. Simulations are performed using a linearized longitudinal aircraft model to illustrate the concept.
基金Project supported by the Key Program for the National Natural Science Foundation of China(Grant No.61333003)the General Program for the National Natural Science Foundation of China(Grant No.61273104)
文摘This paper discusses the model-based predictive controller design of networked nonlinear systems with communica- tion delay and data loss. Based on the analysis of the closed-loop networked predictive control systems, the model-based networked predictive control strategy can compensate for communication delay and data loss in an active way. The designed model-based predictive controller can also guarantee the stability of the closed-loop networked system. The simulation re- suits demonstrate the feasibility and efficacy of the proposed model-based predictive controller design scheme.
基金supported by Defense Industrial Technology Development Program of China (Grant No. A2520110003)
文摘Much research effort has been devoted to economic design of X & S control charts,however,there are some problems in usual methods.On the one hand,it is difficult to estimate the relationship between costs and other model parameters,so the economic design method is often not effective in producing charts that can quickly detect small shifts before substantial losses occur;on the other hand,in many cases,only one type of process shift or only one pair of process shifts are taken into consideration,which may not correctly reflect the actual process conditions.To improve the behavior of economic design of control chart,a cost & loss model with Taguchi's loss function for the economic design of X & S control charts is embellished,which is regarded as an optimization problem with multiple statistical constraints.The optimization design is also carried out based on a number of combinations of process shifts collected from the field operation of the conventional control charts,thus more hidden information about the shift combinations is mined and employed to the optimization design of control charts.At the same time,an improved particle swarm optimization(IPSO) is developed to solve such an optimization problem in design of X & S control charts,IPSO is first tested for several benchmark problems from the literature and evaluated with standard performance metrics.Experimental results show that the proposed algorithm has significant advantages on obtaining the optimal design parameters of the charts.The proposed method can substantially reduce the total cost(or loss) of the control charts,and it will be a promising tool for economic design of control charts.
文摘This paper explores and proposes a design solution of an integrated skip cycle mode (SCM) control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply (SMPS) works with low load or without load.
文摘The sodium and glucose co-transporter inhibitors type 2 (SGLT2) comprises a new class of hypoglycemic drugs to control type 2 diabetes mellitus, in an attempt to add new non-existing benefits to the so far arising classes. Regarding this new class of drugs, represented by dapaglifozin, canaglifozin and empaglifozin, it is important to highlight the benefits brought by these medications to combat hyperglycemia with insulin-independent mechanisms that are beyond glucose reduction, such as cardiovascular events prevention, reduction in HbA1c, weight loss and blood pressure lowering. Recently, a relevant study (Empa-Reg) brought hope and set the spotlight on the prevention of cardiac events among diabetic patients, which is the main cause of mortality within this group. However, despite coming out as a good treatment option, SGLT2 inhibitors are under constant clinical research and, as a new drug, it should be carefully carried out regarding the long-term effects of glycosuria and other possible side effects, such as the observed increase in the incidence of bladder, breast cancer and bone fractures, which require further studies. Therefore, these compounds might represent a landmark approach for the treatment of diabetes.
基金Supported by the National Natural Science Foundation of China(Grant No.51604236)Science and Technology Program of Sichuan Province(Grant No.2018JY0436)the Sichuan Province Youth Science and Technology Innovation Team Project(Grant No.2016TD0016)
文摘Focused on the lost circulation control in deep naturally fractured reservoirs, the multiscale structure of fracture plugging zone is proposed based on the theory of granular matter mechanics, and the structural failure pattern of plugging zone is developed to reveal the plugging zone failure mechanisms in deep, high temperature, high pressure, and high in-situ stress environment. Based on the fracture plugging zone strength model, key performance parameters are determined for the optimal selection of loss control material(LCM). Laboratory fracture plugging experiments with new LCM are carried out to evaluate the effect of the key performance parameters of LCM on fracture plugging quality. LCM selection strategy for fractured reservoirs is developed. The results show that the force chain formed by LCMs determines the pressure stabilization of macro-scale fracture plugging zone. Friction failure and shear failure are the two major failure patterns of fracture plugging zone. The strength of force chain depends on the performance of micro-scale LCM, and the LCM key performance parameters include particle size distribution, fiber aspect ratio, friction coefficient, compressive strength, soluble ability and high temperature resistance. Results of lab experiments and field test show that lost circulation control quality can be effectively improved with the optimal material selection based on the extracted key performance parameters of LCMs.
文摘Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing.Disruption to a large number of physiological processes operating at different time scales can lead to alterations in postural center of pressure(Co P)fluctuations.Multiscale entropy(MSE) has been used to identify differences in fluctuations of postural Co P time series between groups with and without known physiological impairments at multiple time scales.The purpose of this paper is to:1) review basic elements and current developments in entropy techniques used to assess physiological complexity;and 2) identify how MSE can provide insights into the complexity of physiological systems operating at multiple time scales that underlie the control of posture.We review and synthesize evidence from the literature providing support for MSE as a valuable tool to evaluate the breakdown in the physiological processes that accompany changes due to aging and disease in postural control.This evidence emerges from observed lower MSE values in individuals with multiple sclerosis,idiopathic scoliosis,and in older individuals with sensory impairments.Finally,we suggest some future applications of MSE that will allow for further insight into how physiological deficits impact the complexity of postural fluctuations;this information may improve the development and evaluation of new therapeutic interventions.
基金Supported by Natural Science Foundation of Yangzhou(YZ2007040)~~
文摘[Objective] The study aimed to find out effects of six-fourth generation Cnaphalocrocis medinalis (Guenée) on rice production in Yangzhou district and its control index. [Method] Through artificial control of insects in field, four different insect volume gradients were set, the effects of different C. medinalis amounts on leaf roll rate and yield loss of Wuyunjing No.23 were determined. [Result] The results showed that within the range of 0-20 head/hill, as the amounts of insect increased, rice yield decreased, leaf roll rate and rice yield loss rate increased. According to 3% economic permit loss rate, the control index of C. medinalis on Wuyunjing No.23 was 173 head/hill. [Conclusion] The study would provide theoretical basis for effective controlling of six-fourth generation C. medinalis in Yangzhou district.
文摘Two new techniques for efficiency-optimization control(EOC) of induction motor drives were proposed. The first method combined Loss Model and "golden section technique", which was faster than the available methods. Secondly, the low-frequency ripple torque due to decrease of rotor flux was compensated in a feedforward manner. If load torque or speed command changed, the efficiency search algorithm would be abandoned and the rated flux would be established to get the best transient response. The close agreement between the simulation and the experimental results confirmed the validity and usefulness of the proposed techniques.
基金Supported by National Key R&D Plan(2017YFC0405201,2018YFC0407404)Achievements Transformation Project of China Institute of Water Resources and Hydropower Research(SE10003A012017)
文摘There are many reservoirs in China,and serious reservoir sedimentation affects reservoir function and reservoir safety.It is of great significance for restoring the reservoir capacity,improving the efficiency of the reservoir and prolonging the service life of the reservoir to carry out the research on reservoir sedimentation control and storage capacity recovery technology,in the case of fewer and fewer good dam sites suitable for the construction of the reservoir and the increasing accumulation of reservoir sedimentation.In this paper,influence factor of the storage loss,sedimentation control and reservoir capacity recovery technology in China are briefly reviewed.It is necessary to carry out research work on reservoir sedimentation investigation and reservoir siltation mechanism and control measures.
基金Supported by Agricultural Key Projects of Science and Technology Plan of Taizhou City(102KY03)
文摘Real-time monitoring and investigation in fields showed that the disease starting period of Sclerotinia sclerotiorum in mechanical direct seeding fields was earlier. Disease conditions rose with the advancing growth stage, which grew more quickly during the early stage of anthesis, flower withering period and early si- lique mature period. Yield less rate increased with the increasing stem disease rate and disease index. Yield loss rate( Y1 ) had extremely significant correlation with stem disease rate(X1 )and disease index(X2 ), and the related models were Y1 = 0. 544 330 2X1 -2. 316 1 (n = 14, r --0. 986 0 * * )and YI = 0. 673 408 X2 - 1. 016 4 ( n = 14 ,r = 0.977 2 ~ * ), respectively. Disease control indexes for one time control against S. sclerotlorum in mechanical direct seeding fields were stem disease rate as 11.8% and disease index as 7.6, respectively. The control indexes for twice control against the disease were stem disease rate as 16.8% and disease index as 11.7. This paper provided a new scientific basis for preventing S. sclerotiorum in mechanical direct seeding fields.