This work was aimed to establish a quality control method for evaluating the effects on glucose and lipids of the fruiting body of Isaria cicadae Miquel from strain Ic-17-7(Ic-17-7fb) using a rat model of type 2 diabe...This work was aimed to establish a quality control method for evaluating the effects on glucose and lipids of the fruiting body of Isaria cicadae Miquel from strain Ic-17-7(Ic-17-7fb) using a rat model of type 2 diabetes(T2DM). Random amplified polymorphic DNA, sequence-characterized amplified region, and high-performance liquid chromatography(HPLC) were used for the quality control of Ic-17-7fb. The pharmacological effects on streptozocin(STZ)-induced high fat diet(HFD)-fed Albino Wistar rats were evaluated. The rats underwent the following treatments: control, metformin, Ic-17-7fb(0.166 and 0.5 g·kg;) or without treatment. The fasting blood glucose(FBG), blood glucose, total cholesterol(TC), triglyceride(TG), high-density lipoprotein(HDL-c), and low-density lipoprotein(LDL-c) were measured. Ic-17-7fb amplified a single specific band by S11-2-F3 and S11-2-R3 primers. An HPLC-based quality and quantity method was established for industrial application. The contents of adenosine and N;-(2-hydroxyethyl) adenosine(HEA) of the cultivated Ic-17-7fb were analyzed. All of the validation lots of cultured Ic-17-7fb passed the quantity control of the training set(0.90 mg·g;of adenosine and 0.89 mg·g;of HEA). After two weeks of administration, the average FBG was 4.89 ± 0.42(control), 26.10 ± 5.77(model), 23.63 ± 6.15(metformin), 17.96 ± 9.36(Ic-17-7fb for 0.166 g·kg;), and 19.69 ±8.71 mmol·L;(Ic-17-7fb for 0.5 g·kg;). The FBG of Ic-17-7fb(0.166 g·kg;) treatment significantly reduced by 31.19%, compared with the model after two weeks of administration(P < 0.01). Metformin, Ic-17-7fb(0.166 g·kg;), and Ic-17-7fb(0.5 g·kg;) reduced TC, TG, HDL-c, and LDL-c compared with the T2DM model treatment at the 6 th week of treatment(P < 0.05). This study established the first quality standard for Ic-17-7fb, which can be effectively applied in the treatment of T2DM. The reliable quality control method and pharmacological effect will broaden its application space.展开更多
An Interval Type-2(IT-2)fuzzy controller design approach is proposed in this research to simultaneously achievemultiple control objectives inNonlinearMulti-Agent Systems(NMASs),including formation,containment,and coll...An Interval Type-2(IT-2)fuzzy controller design approach is proposed in this research to simultaneously achievemultiple control objectives inNonlinearMulti-Agent Systems(NMASs),including formation,containment,and collision avoidance.However,inherent nonlinearities and uncertainties present in practical control systems contribute to the challenge of achieving precise control performance.Based on the IT-2 Takagi-Sugeno Fuzzy Model(T-SFM),the fuzzy control approach can offer a more effective solution for NMASs facing uncertainties.Unlike existing control methods for NMASs,the Formation and Containment(F-and-C)control problem with collision avoidance capability under uncertainties based on the IT-2 T-SFM is discussed for the first time.Moreover,an IT-2 fuzzy tracking control approach is proposed to solve the formation task for leaders in NMASs without requiring communication.This control scheme makes the design process of the IT-2 fuzzy Formation Controller(FC)more straightforward and effective.According to the communication interaction protocol,the IT-2 Containment Controller(CC)design approach is proposed for followers to ensure convergence into the region defined by the leaders.Leveraging the IT-2 T-SFM representation,the analysis methods developed for linear Multi-Agent Systems(MASs)are successfully extended to perform containment analysis without requiring the additional assumptions imposed in existing research.Notably,the IT-2 fuzzy tracking controller can also be applied in collision avoidance situations to track the desired trajectories calculated by the avoidance algorithm under the Artificial Potential Field(APF).Benefiting from the combination of vortex and source APFs,the leaders can properly adjust the system dynamics to prevent potential collision risk.Integrating the fuzzy theory and APFs avoidance algorithm,an IT-2 fuzzy controller design approach is proposed to achieve the F-and-C purposewhile ensuring collision avoidance capability.Finally,amulti-ship simulation is conducted to validate the feasibility and effectiveness of the designed IT-2 fuzzy controller.展开更多
In this paper, the state-feedback Nash game based mixed H2/H∞ design^（[1, 2]）has been extended for output feedback case. The algorithm is applied to control bioreactor system with a Laguerre-Wavelet Network（LWN）^...In this paper, the state-feedback Nash game based mixed H2/H∞ design^（[1, 2]）has been extended for output feedback case. The algorithm is applied to control bioreactor system with a Laguerre-Wavelet Network（LWN）^（[3, 4]）model of the bioreactor.This is achieved by using the LWN model as a deviation model and by successively linearising the deviation model along the state trajectory. For reducing the approximation error and to improve the controller performance, symbolic derivation algorithm, viz.,automatic differentiation is employed. A cautionary note is also given on the fragility of the output feedback mixed H2/H∞ model predictive controller^（[4, 5]）due to its sensitivity to its own parametric changes.展开更多
Generalized H2 （GH2） stability analysis and controller design of the uncertain discrete-time Takagi-Sugeno （T-S） fuzzy systems with state delay are studied based on a switching fuzzy model and piecewise Lyapunov f...Generalized H2 （GH2） stability analysis and controller design of the uncertain discrete-time Takagi-Sugeno （T-S） fuzzy systems with state delay are studied based on a switching fuzzy model and piecewise Lyapunov function. GH2 stability sufficient conditions are derived in terms of linear matrix inequalities （LMIs）. The interactions among the fuzzy subsystems are considered. Therefore, the proposed conditions are less conservative than the previous results. Since only a set of LMIs is involved, the controller design is quite simple and numerically tractable. To illustrate the validity of the proposed method, a design example is provided.展开更多
This paper is concerned with the design problem of non-fragile controller for a class of two-dimensional (2-D) discrete uncertain systems described by the Roesser model. The parametric uncertainties are assumed to be ...This paper is concerned with the design problem of non-fragile controller for a class of two-dimensional (2-D) discrete uncertain systems described by the Roesser model. The parametric uncertainties are assumed to be norm-bounded. The aim of this paper is to design a memoryless non-fragile state feedback control law such that the closed-loop system is asymptotically stable for all admissible parameter uncertainties and controller gain variations. A new linear matrix inequality (LMI) based sufficient condition for the existence of such controllers is established. Finally, a numerical example is provided to illustrate the applicability of the proposed method.展开更多
This paper considers the problem of delay-dependent robust optimal H<sub>∞</sub> control for a class of uncertain two-dimensional (2-D) discrete state delay systems described by the general model (GM). Th...This paper considers the problem of delay-dependent robust optimal H<sub>∞</sub> control for a class of uncertain two-dimensional (2-D) discrete state delay systems described by the general model (GM). The parameter uncertainties are assumed to be norm-bounded. A linear matrix inequality (LMI)-based sufficient condition for the existence of delay-dependent g-suboptimal state feedback robust H<sub>∞</sub> controllers which guarantees not only the asymptotic stability of the closed-loop system, but also the H<sub>∞</sub> noise attenuation g over all admissible parameter uncertainties is established. Furthermore, a convex optimization problem is formulated to design a delay-dependent state feedback robust optimal H<sub>∞</sub> controller which minimizes the H<sub>∞</sub> noise attenuation g of the closed-loop system. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed method.展开更多
This paper investigates the problem of robust optimal H<sub>∞</sub> control for uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model (GM) with norm-bounded uncerta...This paper investigates the problem of robust optimal H<sub>∞</sub> control for uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model (GM) with norm-bounded uncertainties. A sufficient condition for the existence of g-suboptimal robust H<sub><sub></sub></sub><sub>∞</sub> state feedback controllers is established, based on linear matrix inequality (LMI) approach. Moreover, a convex optimization problem is developed to design a robust optimal state feedback controller which minimizes the H<sub><sub><sub></sub></sub></sub><sub>∞</sub> noise attenuation level of the resulting closed-loop system. Finally, two illustrative examples are given to demonstrate the effectiveness of the proposed method.展开更多
Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method...Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method,has been reported.In this method,the customized precursor paste and programmable shape are two main advantages.Here,we have put forward a new way to customize the YBCO 3D-printing precursor paste which is doped with Al_(2)O_(3)nanoparticles to obtain YBCO with higher thermal conductivity.The great rheological properties of precursor paste after being doped with Al_(2)O_(3)nanoparticles can help the macroscopic YBCO samples with high thermal conductivity fabricated stably with high crystalline and lightweight properties.Test results show that the peak thermal conductivity of Al_(2)O_(3)-doped YBCO can reach twice as much as pure YBCO,which makes a great effort to reduce the quench propagation speed.Based on the microstructure analysis,one can find that the thermal conductivity of Al_(2)O_(3)-doped YBCO has been determined by its components and microstructures.In addition,a macroscopic theoretical model has been proposed to assess the thermal conductivity of different microstructures,whose calculated results take good agreement with the experimental results.Meanwhile,a microstructure with high thermal conductivity has been found.Finally,a macroscopic YBCO bulk with the presented high thermal conductivity microstructure has been fabricated by the Al_(2)O_(3)-doped method.Compared with YBCO fabricated by the traditional 3D-printed,the Al_(2)O_(3)-doped structural YBCO bulks present excellent heat transfer performances.Our customized design of 3D-printing precursor pastes and novel concept of structural design for enhancing the thermal conductivity of YBCO superconducting material can be widely used in other DIW 3D-printing materials.展开更多
The design problem of the state filter for the generalized stochastic 2-D Roesser models, which appears when both the state and measurement are simultaneously subjected to the interference from white noise, is discuss...The design problem of the state filter for the generalized stochastic 2-D Roesser models, which appears when both the state and measurement are simultaneously subjected to the interference from white noise, is discussed. The well-known Kalman filter design is extended to the generalized 2-D Roesser models. Based on the method of “scanning line by line”,the filtering problem of generalized 2-D Roesser models with mode-energy reconstruction is solved. The formula of the optimal filtering, which minimizes the variance of the estimation error of the state vectors, is derived. The validity of the designed filter is verified by the calculation steps and the examples are introduced.展开更多
This paper presents an integrated simulation model for full digital controlled PMIG/MAG welding system with Matlab/Simulink, and it consists of power inverter, digital control system and dynamic arc-load model. An int...This paper presents an integrated simulation model for full digital controlled PMIG/MAG welding system with Matlab/Simulink, and it consists of power inverter, digital control system and dynamic arc-load model. An integrated simulation study was done for full digital PMIG/MAG welding, and a method of connecting dynamic arc-load model to the system with controlled current source was presented, in addition, the simulation results were utilized to study the issues of digital control PMIG/MAG welding in this paper. The experimental results validated the developed simulation model, and this simulation study can be applied in implementation of the full digital PMIG/MAG welding and analysis of system dynamic process.展开更多
The sense of touch as a man-machine communication channel can be as acute as the sense of sight and sound. In some scenarios such as those seen in aerobatics, stunt flying, and combat flights, tactile sensors can even...The sense of touch as a man-machine communication channel can be as acute as the sense of sight and sound. In some scenarios such as those seen in aerobatics, stunt flying, and combat flights, tactile sensors can even outperform the conventional non-contact sensors in terms of situation awareness. Fusion of tactile sensory information with those obtained via sight and sound can avoid diverting the user’s attention away from the operational task at hand as well. In this study, the performance of an operator, to servo control the motion of a 2-dof model helicopter with pitch/yaw maneuverability, subjected to an intuitive body-referenced arrangement of a cluster of vibro-tactile sensors is investigated. A blindfolded operator will then control the helicopter to a safe attraction zone via a joystick based on this tactile sensory information. A fine-tuned local controller would take over for the end-of-motion precise homing. This study can pave the way towards a systematic integration and characterization of tactile sensors in high performance weapon platforms with improved situation awareness in visually awkward maneuvers such as those seen in aerial combat scenarios.展开更多
A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93...A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93% and 61.07% are contributed to environment-friendly and resource-saving effects,respectively,by the dramatic decrease in industrial SO2 emission density(nearly 70% from 2001 to 2010).This indicates that China has achieved important progress during the 11th FYP(five-year plan) compared with the 10th FYP.A simultaneous equations model was also employed to analyze the influencing factors by using data from 30 provinces in China.The results imply that the influence of environmental regulation on environment-friendly effect is not obvious during the 10th FYP but obvious during the 11th FYP.Thus,the government should continue promoting the environment-friendly effect by further enhancing environmental regulation and strengthening the role of environmental management.展开更多
AIM:To explore the established method of the diabetic mouse blood glucose control model and preliminar y observation of its influence on the retinas of diabetic mice.METHODS:The db/db BKS-DB(Lepr^(ko/ko))mice were ran...AIM:To explore the established method of the diabetic mouse blood glucose control model and preliminar y observation of its influence on the retinas of diabetic mice.METHODS:The db/db BKS-DB(Lepr^(ko/ko))mice were randomly divided into two groups:the poor blood glucose control group(PG group,n=18)and the stable blood glucose control group(SG group,n=12),with BKS-DB(Lepr^(wt/wt))as the normal blood glucose control group(NG group,n=18).According to the blood glucose values for 5 intervals which were monitored during the period of adaption,the PG group was injected with insulin aspart twice daily,fasted for 2h and then returned to normal.The SG group was injected with insulin aspart twice and insulin glargine once daily and fed with a quantitative ration.Fundus images were collected after eight weeks.The glycosylated hemoglobin(Hb A1c),mean blood glucose level(MBG),standard deviation of blood glucose(SDBG),coefficient of variation of blood glucose(CVBG),and mean amplitude of glycemic excursion(MAGE)in each group were examined and calculated.RESULTS:The Hb A1c,MBG,SDBG,CVBG,and MAGE levels in the PG group were significantly higher than those in the NG and SG groups(all P<0.05).MBG,SDBG,CVBG,and MAGE levels in the SG group were higher than those in the NG group(all P<0.05).There was no significant difference in Hb A1c levels between the NG and SG groups(P>0.05).Preliminary observation of fundus images in the PG group and SG groups showed scattered retinal bleeding spots,while bleeding was more obvious in the PG group.CONCLUSION:The blood glucose control model of type 2 diabetes mellitus mice can be successfully established by subcutaneous injection of insulin aspart insulin glargine and rationed food,which is valuable for studying the mechanism of blood glucose fluctuations in diabetic complications in vivo.展开更多
For a large class of discrete-time multivariable plants with arbitrary relative degrees,the design and analysis of the direct model reference adaptive control scheme are investigated under less restrictive assumptions...For a large class of discrete-time multivariable plants with arbitrary relative degrees,the design and analysis of the direct model reference adaptive control scheme are investigated under less restrictive assumptions.The algorithm is based on a new parametrization derived from the high frequency gain matrix factorization Kp=LDU under the condition that the signs of the leading principal minors of/fp are known.By reproving the discrete-time Lp and L2σnorm relationship between inputs and outputs,establishing the properties of discrete-time adaptive law,defining the normalizing signal,and relating the signal with all signals in the closed-loop system,the stability and convergence of the discrete-time multivariable model reference adaptive control scheme are analyzed rigorously in a systematic fashion as in the continuous-time case.展开更多
The two-dimensional(2-D)system has a wide range of applications in different fields,including satellite meteorological maps,process control,and digital filtering.Therefore,the research on the stability of 2-D systems ...The two-dimensional(2-D)system has a wide range of applications in different fields,including satellite meteorological maps,process control,and digital filtering.Therefore,the research on the stability of 2-D systems is of great significance.Considering that multiple systems exist in switching and alternating work in the actual production process,but the system itself often has external perturbation and interference.To solve the above problems,this paper investigates the output feedback robust H_(∞)stabilization for a class of discrete-time 2-D switched systems,which the Roesser model with uncertainties represents.First,sufficient conditions for exponential stability are derived via the average dwell time method,when the system’s interference and external input are zero.Furthermore,in the case of introducing the external interference,the weighted robust H_(∞)disturbance attenuation performance of the underlying system is further analyzed.An output feedback controller is then proposed to guarantee that the resulting closed-loop system is exponentially stable and has a prescribed disturbance attenuation levelγ.All theorems mentioned in the article will also be given in the form of linear matrix inequalities(LMI).Finally,a numerical example is given,which takes two uncertain values respectively and solves the output feedback controller’s parameters by the theorem proposed in the paper.According to the required controller parameter values,the validity of the theorem proposed in the article is compared and verified by simulation.展开更多
With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to des...With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to describe the dynamics of CO2 emission with control inputs: clean technology, reforestation and carbon tax, under stochastic uncertainties. For the efficient resources management, a robust tracking control is designed to force resources tracking a desired reference output. The worst-case effect of stochastic parametric fluctuations, external disturbances and uncertain initial conditions on the tracking performance is considered and minimized from the dynamic game theory perspective. This stochastic game problem, in which one player (stochastic uncertainty) maximizes the tracking error and another player (control input) minimizes the tracking error, could be equivalent to a robust minimax tracking problem. To avoid solving the HJI, a fuzzy model is proposed to approximate the nonlinear CO2 emission model. Then the nonlinear stochastic game problem could be easily solved by fuzzy stochastic game approach via LMI technique.展开更多
基金supported by China Spark Program (No.2015GA700011)。
文摘This work was aimed to establish a quality control method for evaluating the effects on glucose and lipids of the fruiting body of Isaria cicadae Miquel from strain Ic-17-7(Ic-17-7fb) using a rat model of type 2 diabetes(T2DM). Random amplified polymorphic DNA, sequence-characterized amplified region, and high-performance liquid chromatography(HPLC) were used for the quality control of Ic-17-7fb. The pharmacological effects on streptozocin(STZ)-induced high fat diet(HFD)-fed Albino Wistar rats were evaluated. The rats underwent the following treatments: control, metformin, Ic-17-7fb(0.166 and 0.5 g·kg;) or without treatment. The fasting blood glucose(FBG), blood glucose, total cholesterol(TC), triglyceride(TG), high-density lipoprotein(HDL-c), and low-density lipoprotein(LDL-c) were measured. Ic-17-7fb amplified a single specific band by S11-2-F3 and S11-2-R3 primers. An HPLC-based quality and quantity method was established for industrial application. The contents of adenosine and N;-(2-hydroxyethyl) adenosine(HEA) of the cultivated Ic-17-7fb were analyzed. All of the validation lots of cultured Ic-17-7fb passed the quantity control of the training set(0.90 mg·g;of adenosine and 0.89 mg·g;of HEA). After two weeks of administration, the average FBG was 4.89 ± 0.42(control), 26.10 ± 5.77(model), 23.63 ± 6.15(metformin), 17.96 ± 9.36(Ic-17-7fb for 0.166 g·kg;), and 19.69 ±8.71 mmol·L;(Ic-17-7fb for 0.5 g·kg;). The FBG of Ic-17-7fb(0.166 g·kg;) treatment significantly reduced by 31.19%, compared with the model after two weeks of administration(P < 0.01). Metformin, Ic-17-7fb(0.166 g·kg;), and Ic-17-7fb(0.5 g·kg;) reduced TC, TG, HDL-c, and LDL-c compared with the T2DM model treatment at the 6 th week of treatment(P < 0.05). This study established the first quality standard for Ic-17-7fb, which can be effectively applied in the treatment of T2DM. The reliable quality control method and pharmacological effect will broaden its application space.
基金founded by the National Science and Technology Council of the Republic of China under contract NSTC113-2221-E-019-032.
文摘An Interval Type-2(IT-2)fuzzy controller design approach is proposed in this research to simultaneously achievemultiple control objectives inNonlinearMulti-Agent Systems(NMASs),including formation,containment,and collision avoidance.However,inherent nonlinearities and uncertainties present in practical control systems contribute to the challenge of achieving precise control performance.Based on the IT-2 Takagi-Sugeno Fuzzy Model(T-SFM),the fuzzy control approach can offer a more effective solution for NMASs facing uncertainties.Unlike existing control methods for NMASs,the Formation and Containment(F-and-C)control problem with collision avoidance capability under uncertainties based on the IT-2 T-SFM is discussed for the first time.Moreover,an IT-2 fuzzy tracking control approach is proposed to solve the formation task for leaders in NMASs without requiring communication.This control scheme makes the design process of the IT-2 fuzzy Formation Controller(FC)more straightforward and effective.According to the communication interaction protocol,the IT-2 Containment Controller(CC)design approach is proposed for followers to ensure convergence into the region defined by the leaders.Leveraging the IT-2 T-SFM representation,the analysis methods developed for linear Multi-Agent Systems(MASs)are successfully extended to perform containment analysis without requiring the additional assumptions imposed in existing research.Notably,the IT-2 fuzzy tracking controller can also be applied in collision avoidance situations to track the desired trajectories calculated by the avoidance algorithm under the Artificial Potential Field(APF).Benefiting from the combination of vortex and source APFs,the leaders can properly adjust the system dynamics to prevent potential collision risk.Integrating the fuzzy theory and APFs avoidance algorithm,an IT-2 fuzzy controller design approach is proposed to achieve the F-and-C purposewhile ensuring collision avoidance capability.Finally,amulti-ship simulation is conducted to validate the feasibility and effectiveness of the designed IT-2 fuzzy controller.
文摘In this paper, the state-feedback Nash game based mixed H2/H∞ design^（[1, 2]）has been extended for output feedback case. The algorithm is applied to control bioreactor system with a Laguerre-Wavelet Network（LWN）^（[3, 4]）model of the bioreactor.This is achieved by using the LWN model as a deviation model and by successively linearising the deviation model along the state trajectory. For reducing the approximation error and to improve the controller performance, symbolic derivation algorithm, viz.,automatic differentiation is employed. A cautionary note is also given on the fragility of the output feedback mixed H2/H∞ model predictive controller^（[4, 5]）due to its sensitivity to its own parametric changes.
文摘Generalized H2 （GH2） stability analysis and controller design of the uncertain discrete-time Takagi-Sugeno （T-S） fuzzy systems with state delay are studied based on a switching fuzzy model and piecewise Lyapunov function. GH2 stability sufficient conditions are derived in terms of linear matrix inequalities （LMIs）. The interactions among the fuzzy subsystems are considered. Therefore, the proposed conditions are less conservative than the previous results. Since only a set of LMIs is involved, the controller design is quite simple and numerically tractable. To illustrate the validity of the proposed method, a design example is provided.
文摘This paper is concerned with the design problem of non-fragile controller for a class of two-dimensional (2-D) discrete uncertain systems described by the Roesser model. The parametric uncertainties are assumed to be norm-bounded. The aim of this paper is to design a memoryless non-fragile state feedback control law such that the closed-loop system is asymptotically stable for all admissible parameter uncertainties and controller gain variations. A new linear matrix inequality (LMI) based sufficient condition for the existence of such controllers is established. Finally, a numerical example is provided to illustrate the applicability of the proposed method.
文摘This paper considers the problem of delay-dependent robust optimal H<sub>∞</sub> control for a class of uncertain two-dimensional (2-D) discrete state delay systems described by the general model (GM). The parameter uncertainties are assumed to be norm-bounded. A linear matrix inequality (LMI)-based sufficient condition for the existence of delay-dependent g-suboptimal state feedback robust H<sub>∞</sub> controllers which guarantees not only the asymptotic stability of the closed-loop system, but also the H<sub>∞</sub> noise attenuation g over all admissible parameter uncertainties is established. Furthermore, a convex optimization problem is formulated to design a delay-dependent state feedback robust optimal H<sub>∞</sub> controller which minimizes the H<sub>∞</sub> noise attenuation g of the closed-loop system. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed method.
文摘This paper investigates the problem of robust optimal H<sub>∞</sub> control for uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model (GM) with norm-bounded uncertainties. A sufficient condition for the existence of g-suboptimal robust H<sub><sub></sub></sub><sub>∞</sub> state feedback controllers is established, based on linear matrix inequality (LMI) approach. Moreover, a convex optimization problem is developed to design a robust optimal state feedback controller which minimizes the H<sub><sub><sub></sub></sub></sub><sub>∞</sub> noise attenuation level of the resulting closed-loop system. Finally, two illustrative examples are given to demonstrate the effectiveness of the proposed method.
基金supported by the Fund of Natural Science Foundation of China(No.11872196,12232005)supported by the Outstanding Postgraduate‘Innovation Star’Fund for Distinguished of Gansu Province(No.2021CXZX-032).
文摘Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method,has been reported.In this method,the customized precursor paste and programmable shape are two main advantages.Here,we have put forward a new way to customize the YBCO 3D-printing precursor paste which is doped with Al_(2)O_(3)nanoparticles to obtain YBCO with higher thermal conductivity.The great rheological properties of precursor paste after being doped with Al_(2)O_(3)nanoparticles can help the macroscopic YBCO samples with high thermal conductivity fabricated stably with high crystalline and lightweight properties.Test results show that the peak thermal conductivity of Al_(2)O_(3)-doped YBCO can reach twice as much as pure YBCO,which makes a great effort to reduce the quench propagation speed.Based on the microstructure analysis,one can find that the thermal conductivity of Al_(2)O_(3)-doped YBCO has been determined by its components and microstructures.In addition,a macroscopic theoretical model has been proposed to assess the thermal conductivity of different microstructures,whose calculated results take good agreement with the experimental results.Meanwhile,a microstructure with high thermal conductivity has been found.Finally,a macroscopic YBCO bulk with the presented high thermal conductivity microstructure has been fabricated by the Al_(2)O_(3)-doped method.Compared with YBCO fabricated by the traditional 3D-printed,the Al_(2)O_(3)-doped structural YBCO bulks present excellent heat transfer performances.Our customized design of 3D-printing precursor pastes and novel concept of structural design for enhancing the thermal conductivity of YBCO superconducting material can be widely used in other DIW 3D-printing materials.
基金National Nature Science Foundation of China Under Grants (60474078 ,60304001 ,60574015)
文摘The design problem of the state filter for the generalized stochastic 2-D Roesser models, which appears when both the state and measurement are simultaneously subjected to the interference from white noise, is discussed. The well-known Kalman filter design is extended to the generalized 2-D Roesser models. Based on the method of “scanning line by line”,the filtering problem of generalized 2-D Roesser models with mode-energy reconstruction is solved. The formula of the optimal filtering, which minimizes the variance of the estimation error of the state vectors, is derived. The validity of the designed filter is verified by the calculation steps and the examples are introduced.
文摘This paper presents an integrated simulation model for full digital controlled PMIG/MAG welding system with Matlab/Simulink, and it consists of power inverter, digital control system and dynamic arc-load model. An integrated simulation study was done for full digital PMIG/MAG welding, and a method of connecting dynamic arc-load model to the system with controlled current source was presented, in addition, the simulation results were utilized to study the issues of digital control PMIG/MAG welding in this paper. The experimental results validated the developed simulation model, and this simulation study can be applied in implementation of the full digital PMIG/MAG welding and analysis of system dynamic process.
文摘The sense of touch as a man-machine communication channel can be as acute as the sense of sight and sound. In some scenarios such as those seen in aerobatics, stunt flying, and combat flights, tactile sensors can even outperform the conventional non-contact sensors in terms of situation awareness. Fusion of tactile sensory information with those obtained via sight and sound can avoid diverting the user’s attention away from the operational task at hand as well. In this study, the performance of an operator, to servo control the motion of a 2-dof model helicopter with pitch/yaw maneuverability, subjected to an intuitive body-referenced arrangement of a cluster of vibro-tactile sensors is investigated. A blindfolded operator will then control the helicopter to a safe attraction zone via a joystick based on this tactile sensory information. A fine-tuned local controller would take over for the end-of-motion precise homing. This study can pave the way towards a systematic integration and characterization of tactile sensors in high performance weapon platforms with improved situation awareness in visually awkward maneuvers such as those seen in aerial combat scenarios.
基金Project(201009066)supported by the R&D Special Fund for Public Welfare of the Ministry of Finance and Ministry of Science and Technology of China
文摘A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93% and 61.07% are contributed to environment-friendly and resource-saving effects,respectively,by the dramatic decrease in industrial SO2 emission density(nearly 70% from 2001 to 2010).This indicates that China has achieved important progress during the 11th FYP(five-year plan) compared with the 10th FYP.A simultaneous equations model was also employed to analyze the influencing factors by using data from 30 provinces in China.The results imply that the influence of environmental regulation on environment-friendly effect is not obvious during the 10th FYP but obvious during the 11th FYP.Thus,the government should continue promoting the environment-friendly effect by further enhancing environmental regulation and strengthening the role of environmental management.
基金Supported by the National Natural Science Foundation of China(No.81700856)the Natural Science Foundation of Anhui Province,China(No.1808085QH280No.1908085QH381)。
文摘AIM:To explore the established method of the diabetic mouse blood glucose control model and preliminar y observation of its influence on the retinas of diabetic mice.METHODS:The db/db BKS-DB(Lepr^(ko/ko))mice were randomly divided into two groups:the poor blood glucose control group(PG group,n=18)and the stable blood glucose control group(SG group,n=12),with BKS-DB(Lepr^(wt/wt))as the normal blood glucose control group(NG group,n=18).According to the blood glucose values for 5 intervals which were monitored during the period of adaption,the PG group was injected with insulin aspart twice daily,fasted for 2h and then returned to normal.The SG group was injected with insulin aspart twice and insulin glargine once daily and fed with a quantitative ration.Fundus images were collected after eight weeks.The glycosylated hemoglobin(Hb A1c),mean blood glucose level(MBG),standard deviation of blood glucose(SDBG),coefficient of variation of blood glucose(CVBG),and mean amplitude of glycemic excursion(MAGE)in each group were examined and calculated.RESULTS:The Hb A1c,MBG,SDBG,CVBG,and MAGE levels in the PG group were significantly higher than those in the NG and SG groups(all P<0.05).MBG,SDBG,CVBG,and MAGE levels in the SG group were higher than those in the NG group(all P<0.05).There was no significant difference in Hb A1c levels between the NG and SG groups(P>0.05).Preliminary observation of fundus images in the PG group and SG groups showed scattered retinal bleeding spots,while bleeding was more obvious in the PG group.CONCLUSION:The blood glucose control model of type 2 diabetes mellitus mice can be successfully established by subcutaneous injection of insulin aspart insulin glargine and rationed food,which is valuable for studying the mechanism of blood glucose fluctuations in diabetic complications in vivo.
基金Program for New Century Excellent Talents in Universities of China(No.NCET-05-0607)National Natural Science Foundation ofChina(No.60774010).
文摘For a large class of discrete-time multivariable plants with arbitrary relative degrees,the design and analysis of the direct model reference adaptive control scheme are investigated under less restrictive assumptions.The algorithm is based on a new parametrization derived from the high frequency gain matrix factorization Kp=LDU under the condition that the signs of the leading principal minors of/fp are known.By reproving the discrete-time Lp and L2σnorm relationship between inputs and outputs,establishing the properties of discrete-time adaptive law,defining the normalizing signal,and relating the signal with all signals in the closed-loop system,the stability and convergence of the discrete-time multivariable model reference adaptive control scheme are analyzed rigorously in a systematic fashion as in the continuous-time case.
基金Research supported by the Science and Technology Development Program of Jilin Province,the project named:Research on Key Technologies of Intelligent Virtual Interactive 3D Display System(20180201090GX).
文摘The two-dimensional(2-D)system has a wide range of applications in different fields,including satellite meteorological maps,process control,and digital filtering.Therefore,the research on the stability of 2-D systems is of great significance.Considering that multiple systems exist in switching and alternating work in the actual production process,but the system itself often has external perturbation and interference.To solve the above problems,this paper investigates the output feedback robust H_(∞)stabilization for a class of discrete-time 2-D switched systems,which the Roesser model with uncertainties represents.First,sufficient conditions for exponential stability are derived via the average dwell time method,when the system’s interference and external input are zero.Furthermore,in the case of introducing the external interference,the weighted robust H_(∞)disturbance attenuation performance of the underlying system is further analyzed.An output feedback controller is then proposed to guarantee that the resulting closed-loop system is exponentially stable and has a prescribed disturbance attenuation levelγ.All theorems mentioned in the article will also be given in the form of linear matrix inequalities(LMI).Finally,a numerical example is given,which takes two uncertain values respectively and solves the output feedback controller’s parameters by the theorem proposed in the paper.According to the required controller parameter values,the validity of the theorem proposed in the article is compared and verified by simulation.
文摘With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to describe the dynamics of CO2 emission with control inputs: clean technology, reforestation and carbon tax, under stochastic uncertainties. For the efficient resources management, a robust tracking control is designed to force resources tracking a desired reference output. The worst-case effect of stochastic parametric fluctuations, external disturbances and uncertain initial conditions on the tracking performance is considered and minimized from the dynamic game theory perspective. This stochastic game problem, in which one player (stochastic uncertainty) maximizes the tracking error and another player (control input) minimizes the tracking error, could be equivalent to a robust minimax tracking problem. To avoid solving the HJI, a fuzzy model is proposed to approximate the nonlinear CO2 emission model. Then the nonlinear stochastic game problem could be easily solved by fuzzy stochastic game approach via LMI technique.
