Background:Acute pancreatitis is an unpredictable and potentially lethal disease,causing tremendous pain in patients.The initial treatment of acute pancreatitis in modern medicine is supportive,but it is generally ine...Background:Acute pancreatitis is an unpredictable and potentially lethal disease,causing tremendous pain in patients.The initial treatment of acute pancreatitis in modern medicine is supportive,but it is generally ineffective in relieving abdominal pain and distension.Traditional Chinese medicine has been shown to be more effective in regulating the body’s homeostasis and reducing the clinical symptoms of pancreatitis.Yi-Dan ointment,derived from Dahuang-Mudan Decoction,is an effective external ointment for treating acute pancreatitis.The aim of this trial is to investigate the clinical efficacy of Yi-Dan ointment,providing a valuable complement to existing treatment options for pancreatitis.Methods:This is a randomized controlled clinical trial with two parallel groups.Patients in the control group were given basic treatment and nursing for 7 days;in the treatment group,Yi-Dan ointment was applied externally in addition to basic treatment and nursing.The main indicator is the overall efficacy,serum amylase,acute physiology and chronic health evaluationⅡscore,symptom score,inflammatory markers,and classification of computed tomography.Conclusion:The trial results will provide high-quality evidence for Yi-Dan ointment,and provide a complement to existing treatment options for pancreatitis.展开更多
An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control...An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.展开更多
In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated...In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.展开更多
In this paper,an integrated guidance and control method based on an adaptive path-following controller is proposed to control a spin-stabilized projectile with only translational motion information under the constrain...In this paper,an integrated guidance and control method based on an adaptive path-following controller is proposed to control a spin-stabilized projectile with only translational motion information under the constraint of an actuator,uncertainties in aerodynamic parameters and measurements,and control system complexity.Owing to the fairly high rotation speed,the dynamic model of this missile is strongly nonlinear,uncertain and coupled in pitch,yaw and roll channels.A theoretical equivalent resultant force and uncertainty compensation method are comprehensively used to realize decoupling of pitch and yaw.In response to the strong nonlinear and time-varying characteristics of the dynamic system,the quasi-linear model whose parameters are obtained by interpolation of points selected as the segmentation points in the trajectory envelope,is used for calculation in each step.To cope with the system uncertainty caused by model approximation,parameter uncertainty and ballistic interference,an extended state estimator is used to compensate the output feedback according to the test ballistic angle.In order to improve the tracking efficiency and ensure the tracking error convergence with only translational motion information,the virtual guide point,whose derivative is deduced according to the Lyapunov principle,is calculated in real time according to the projection relationship between the real-time position and the reference trajectory,and a virtual line-of-sight angle and the backstepping method are used for the design of the guidance and control system.In order to avoid the influence of control input saturation on the guidance and control performance due to the actuator limitation and improve the robustness of the system,an anti-saturation compensator is designed according to the two-step method.The feasibility and effectiveness of the path-following controller is verified through closed-loop flight simulations with measurement,control,and condition uncertainties.The results indicate that the designed controller can converge to the reference path and evidently decrease the distance between the impact point and target under different uncertainties.展开更多
This paper considers a linear-quadratic(LQ) meanfield game governed by a forward-backward stochastic system with partial observation and common noise,where a coupling structure enters state equations,cost functionals ...This paper considers a linear-quadratic(LQ) meanfield game governed by a forward-backward stochastic system with partial observation and common noise,where a coupling structure enters state equations,cost functionals and observation equations.Firstly,to reduce the complexity of solving the meanfield game,a limiting control problem is introduced.By virtue of the decomposition approach,an admissible control set is proposed.Applying a filter technique and dimensional-expansion technique,a decentralized control strategy and a consistency condition system are derived,and the related solvability is also addressed.Secondly,we discuss an approximate Nash equilibrium property of the decentralized control strategy.Finally,we work out a financial problem with some numerical simulations.展开更多
In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relat...In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.展开更多
The liver is in charge of distributing and regulating the movement of qi throughout the whole body,coordinating the transportation and transformation of the internal organs in the middle part of the body,promoting the...The liver is in charge of distributing and regulating the movement of qi throughout the whole body,coordinating the transportation and transformation of the internal organs in the middle part of the body,promoting the biochemical circulation of qi,blood,and body fluids,and regulating emotions.Liver dysfunction can disrupt the transportation and transformation of qi,blood,and body fluids,causing phlegm turbidity,blood stasis,and other unwanted symptoms.Poor regulation of emotion further aggravates the accumulation of pathological substances,resulting in the obstruction of heart vessels,and ultimately coronary heart disease(CHD).Through regulating lipid metabolism,inflammatory reaction,vasoactive substances,platelet function,neuroendocrine,and other factors,liver controlling dispersing qi plays a comprehensive role in the prognosis of atherosclerosis,the primary cause of CHD.Therefore,it is recommended to treat CHD from the perspective of liver-controlling dispersion.展开更多
Active disturbance-rejection methods are effective in estimating and rejecting disturbances in both transient and steady-state responses.This paper presents a deep observation on and a comparison between two of those ...Active disturbance-rejection methods are effective in estimating and rejecting disturbances in both transient and steady-state responses.This paper presents a deep observation on and a comparison between two of those methods:the generalized extended-state observer(GESO)and the equivalent input disturbance(EID)from assumptions,system configurations,stability conditions,system design,disturbance-rejection performance,and extensibility.A time-domain index is introduced to assess the disturbance-rejection performance.A detailed observation of disturbance-suppression mechanisms reveals the superiority of the EID approach over the GESO method.A comparison between these two methods shows that assumptions on disturbances are more practical and the adjustment of disturbance-rejection performance is easier for the EID approach than for the GESO method.展开更多
This paper presents a thorough review of control technologies that have been applied to wastewater treatment processes in the environmental engineering regime in the past four decades. It aims to provide a comprehensi...This paper presents a thorough review of control technologies that have been applied to wastewater treatment processes in the environmental engineering regime in the past four decades. It aims to provide a comprehensive technological review for both water engineering professionals and control specialists, giving rise to a suite of up-to-date pathways to impact this field in light of the classified technology hubs. The assessment was conducted with respect to linear control, linearizing control,nonlinear control, and artificial intelligence-based control. The application domain of each technology hub was summarized into a set of comparative tables for a holistic assessment. Challenges and perspectives were offered to these field engineers to help orient their future endeavor.展开更多
Levodopa preparations remain the preferred drug for Parkinson's disease.However,long-term use of levodopa may lead to a series of motor complications.Previous studies have shown that the combination of levodopa and Z...Levodopa preparations remain the preferred drug for Parkinson's disease.However,long-term use of levodopa may lead to a series of motor complications.Previous studies have shown that the combination of levodopa and Zishenpingchan granules(consisting of Radix Rehmanniae preparata,Lycium barbarum,Herba Taxilli,Rhizoma Gastrodiae,Stiff Silkorm,Curcuma phaeocaulis,Radix Paeoniae Alba,Rhizoma Arisaematis,Scorpio and Centipede) can markedly improve dyskinesia and delay the progression of Parkinson's disease,with especially dramatic improvements of non-motor symptoms.However,the efficacy of this combination has not been confirmed by randomized controlled trials.The current study was approved by the Hospital Ethics Committee and was registered in the Chinese Clinical Trial Register(registration number:Chi CTR-INR-1701194).From December 2014 to December 2016,128 patients(72 males and 56 females,mean age of 65.78 ± 6.34 years) with Parkinson's disease were recruited from the Department of Neurology of Longhua Hospital and Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine in China.Patients were equally allocated into treatment and control groups.In addition to treatment with dopamine,patients in treatment and control groups were given Zishenpingchan granules or placebo,respectively,for 24 weeks.Therapeutic efficacy was assessed using the Unified Parkinson's Disease Rating Scale,on-off phenomenon,Hoehn-Yahr grade,Scales for Outcomes in Parkinson's disease–Autonomic,Parkinson's disease sleep scale,Hamilton Anxiety Scale,Hamilton Depression Scale,Mini-Mental State Examination,and the Parkinson's Disease Quality of Life Questionnaire.Artificial neural networks were used to determine weights at which to scale these parameters.Our results demonstrated that Zishenpingchan granules significantly reduced the occurrence of motor complications,and were useful for mitigating dyskinesia and non-motor symptoms of Parkinson's disease.This combination of Chinese and Western medicine has the potential to reduce levodopa dosages,and no obvious side effects were found.These findings indicate that Zishenpingchan granules can mitigate symptoms of Parkinson's disease,reduce toxic side effects of dopaminergic agents,and exert synergistic and detoxifying effects.展开更多
To review the preventive approaches for recurrence after curative resection of hepatic metastases from colorectal carcinoma, we have summarized all available publications reporting randomized control trials (RCTs) cov...To review the preventive approaches for recurrence after curative resection of hepatic metastases from colorectal carcinoma, we have summarized all available publications reporting randomized control trials (RCTs) covered in PubMed. The treatment approaches presented above include adjuvant intrahepatic arterial infusion chemotherapy, systemic chemotherapy, neoadjuvant chemotherapy, and immunotherapy. Although no standard treatment has been established, several approaches present promising results, which are both effective and tolerable in post-hepatectomy patients. Intrahepatic arterial infusion chemotherapy should be regarded as effective and tolerable and it increases overall survival (OS) and disease free survival (DFS) of patients, while 5-fluorouracil-based systemic chemotherapy has not shown any significant survival benefit. Fortunately chemotherapy combined with hepatic arterial infusion and intravenous infusion has shown OS and DFS benefit in many researches. Few neoadjuvant RCT studies have been conducted to evaluate its effect on prolonging survivals although many retrospective studies and case reports are published in which unresectable colorectal liver metastases are downstaged and made resectable with neoadjuvant chemotherapy. Liver resection supplemented with immunotherapy is associated with optimal results; however, it is also questioned by others. In conclusion, several adjuvant approaches have been studied for their efficacy on recurrence after hepatectomy for liver metastases from colorectal cancer (CRC), but multi-centric RCT is still needed for further evaluation on their efficacy and systemic or local toxicities. In addition, new adjuvant treatment should be investigated to provide more effective and tolerable methods for the patients with resectable hepatic metastases from CRC.展开更多
The stratosphere airship provides a unique and promising platform for earth observation. Researches on the project design and control scheme for earth observation platforms are still rarely documented. Nonlinear dynam...The stratosphere airship provides a unique and promising platform for earth observation. Researches on the project design and control scheme for earth observation platforms are still rarely documented. Nonlinear dynamics, model uncertainties, and external disturbances contribute to the difficulty in maneuvering the stratosphere airship. A key technical challenge for the earth observation platform is station keeping, or the ability to remain fixed over a geo-location. This paper investigates the conceptual design, modeling and station-keeping attitude control of the near-space earth observation platform. A conceptual design of the earth observation platform is presented. The dynamics model of the platform is derived from the Newton-Euler formulation, and the station-keeping control system of the platform is formulated. The station-keeping attitude control approach for the platform is proposed. The multi-input multi-output nonlinear control system is decoupled into three single-input single-output linear subsystems via feedback linearization, the attitude controller design is carried out on the new linear systems using terminal sliding mode control, and the global stability of the closed-loop system is proven by using the Lyapunov theorem. The performance of the designed control system is simulated by using the variable step Runge-Kutta integrator. Simulation results show that the control system tracks the commanded attitude with an error of zero, which verify the effectiveness and robustness of the designed control system in the presence of parametric uncertainties. The near-space earth observation platform has several advantages over satellites, such as high resolution, fast to deploy, and convenient to retrieve, and the proposed control scheme provides an effective approach for station-keeping attitude control of the earth observation platform.展开更多
In this paper, a disturbance observer-based safe tracking control scheme is proposed for a medium-scale unmanned helicopter with rotor flapping dynamics in the presence of partial state constraints and unknown externa...In this paper, a disturbance observer-based safe tracking control scheme is proposed for a medium-scale unmanned helicopter with rotor flapping dynamics in the presence of partial state constraints and unknown external disturbances. A safety protection algorithm is proposed to keep the constrained states within the given safe-set. A second-order disturbance observer technique is utilized to estimate the external disturbances. It is shown that the desired tracking performance of the controlled unmanned helicopter can be achieved with the application of the backstepping approach, dynamic surface control technique, and Lyapunov method. Finally, the availability of the proposed control scheme has been shown by simulation results.展开更多
An Euler-Bernoulli beam system under the local internal distributed control and boundary point observation is studied. An infinite-dimensional observer for the open-loop system is designed. The closed-loop system that...An Euler-Bernoulli beam system under the local internal distributed control and boundary point observation is studied. An infinite-dimensional observer for the open-loop system is designed. The closed-loop system that is non- dissipative is obtained by the estimated state feedback. By a detailed spectral analysis, it is shown that there is a set of generalized eigenfunctions, which forms a Riesz basis for the state space. Consequently, both the spectrum-determined growth condition and exponential stability are concluded.展开更多
Sea surface temperature(SST)data obtained from coastal stations in Jiangsu,China during 20102014 are quality controlled before analysis of their characteristic semidiurnal and seasonal cycles,including the correlation...Sea surface temperature(SST)data obtained from coastal stations in Jiangsu,China during 20102014 are quality controlled before analysis of their characteristic semidiurnal and seasonal cycles,including the correlation with the variation of the tide.Quality control of data includes the validation of extreme values and checking of hourly values based on temporally adjacent data points,with 0.15℃/h considered a suitable threshold for detecting abnormal values.The diurnal variation amplitude of the SST data is greater in spring and summer than in autumn and winter.The diurnal variation of SST has bimodal structure on most days,i.e.,SST has a significant semidiurnal cycle.Moreover,the semidiurnal cycle of SST is negatively correlated with the tidal data from March to August,but positively correlated with the tidal data from October to January.Little correlation is detected in the remaining months because of the weak coastal offshore SST gradients.The quality control and understanding of coastal SST data are particularly relevant with regard to the validation of indirect measurements such as satellite-derived data.展开更多
Objective: To study the treatment of B-Thalas-semia (ThE) with Chinese herbal medicine for Bushen Yisui (BSYS), its theoretical base and molecular mechanism. Methods: Seventy-eight patients with ThE were treated with ...Objective: To study the treatment of B-Thalas-semia (ThE) with Chinese herbal medicine for Bushen Yisui (BSYS), its theoretical base and molecular mechanism. Methods: Seventy-eight patients with ThE were treated with BSYS recipe (consisted of 11 Chinese herbal drugs as Dogwood fruit, Fleeceflower root, prepared Rehmannia root and turtle shell, etc.) orally taken, 3 times per day, 10 g/time, 3 months as one therapeutic course. Hemoglobin (Hb), red blood cell (RBC), reticulocyte (Ret) and hemoglobin F (HbF) were checked every month. At the same time, PAGE, PVR, PCR-SSCP, RT-PCR, DNA series analysis, mRNA gene expression analysis techniques were used to conduct the systematic gene analysis in patients to study the molecular mechanism of TCM treatment from aspects of gene mutation, gene expression and control-regulation. Results: All the blood criteria in patients after BSYS treatment were improved significantly with clinical symptoms展开更多
The generation of electricity,considering environmental and eco-nomic factors is one of the most important challenges of recent years.In this article,a thermoelectric generator(TEG)is proposed to use the thermal energ...The generation of electricity,considering environmental and eco-nomic factors is one of the most important challenges of recent years.In this article,a thermoelectric generator(TEG)is proposed to use the thermal energy of an electric water heater(EWH)to generate electricity independently.To improve the energy conversion efficiency of the TEG,a fuzzy logic con-troller(FLC)-based perturb&observe(P&O)type maximum power point tracking(MPPT)control algorithm is used in this study.An EWH is one of the major electricity consuming household appliances which causes a higher electricity price for consumers.Also,a significant amount of thermal energy generated by EWH is wasted every day,especially during the winter season.In recent years,TEGs have been widely developed to convert surplus or unused thermal energy into usable electricity.In this context,the proposed model is designed to use the thermal energy stored in the EWH to generate electricity.In addition,the generated electricity can be easily stored in a battery storage system to supply electricity to various household appliances with low-power-consumption.The proposed MPPT control algorithm helps the system to quickly reach the optimal point corresponding to the maximum power output and maintains the system operating point at the maximum power output level.To validate the usefulness of the proposed scheme,a study model was developed in the MATLAB Simulink environment and its performance was investigated by simulation under steady state and transient conditions.The results of the study confirmed that the system is capable of generating adequate power from the available thermal energy of EWH.It was also found that the output power and efficiency of the system can be improved by maintaining a higher temperature difference at the input terminals of the TEG.Moreover,the real-time temperature data of Abha city in Saudi Arabia is considered to analyze the feasibility of the proposed system for practical implementation.展开更多
This paper provides an improved model-free adaptive control(IMFAC)strategy for solving the surface vessel trajectory tracking issue with time delay and restricted disturbance.Firstly,the original nonlinear time-delay ...This paper provides an improved model-free adaptive control(IMFAC)strategy for solving the surface vessel trajectory tracking issue with time delay and restricted disturbance.Firstly,the original nonlinear time-delay system is transformed into a structure consisting of an unknown residual term and a parameter term with control inputs using a local compact form dynamic linearization(local-CFDL).To take advantage of the resulting structure,use a discrete-time extended state observer(DESO)to estimate the unknown residual factor.Then,according to the study,the inclusion of a time delay has no effect on the linearization structure,and an improved control approach is provided,in which DESO is used to adjust for uncertainties.Furthermore,a DESO-based event-triggered model-free adaptive control(ET-DESO-MFAC)is established by designing event-triggered conditions to assure Lyapunov stability.Only when the system’s indicator fulfills the provided event-triggered condition will the control input signal be updated;otherwise,the control input will stay the same as it is at the last trigger moment.A coordinate compensation approach is developed to reduce the steady-state inaccuracy of trajectory tracking.Finally,simulation experiments are used to assess the effectiveness of the proposed technique for trajectory tracking.展开更多
Pulp and paper industry is responsible for large discharge of highly polluted effluents, which often be treated by biological treatment process. For biological treatment system, pH is an important environmental factor...Pulp and paper industry is responsible for large discharge of highly polluted effluents, which often be treated by biological treatment process. For biological treatment system, pH is an important environmental factor that can influence the activity of microorganisms. In general, the optimal pH for aerobic processes is around neutral pH (7_7.8) and for the anaerobic process is between 6.8_7.2. The control of pH is a difficult link in the biological treatment system due to its nonlinearity and large time-delay. Aiming at the difficult point in the pH control of the biological wastewater treatment system, a mathematical model of pH control is estab-lished in the essay. On this basis, a traditional PID control and a cascade control are adopted to carry out simulation and comparison with MATLAB. The results show that the cascade control has better comprehen-sive effect in terms of response speed, stability and disturbance resistance.展开更多
Gastric cancer is one of the most common malignancies of the digestive system,and the number of deaths continues to increase.The standardized management of the diagnosis and treatment of gastric cancer is challenging ...Gastric cancer is one of the most common malignancies of the digestive system,and the number of deaths continues to increase.The standardized management of the diagnosis and treatment of gastric cancer is challenging due to the great differences in the diagnosis and treatment of gastric cancer in different regions.The Gastric Cancer Expert Committee of the National Cancer Quality Control Center(NCQCC)identified a lack of authoritative quality control standards as an opportunity to utilize its multidisciplinary membership to improve the standardized diagnosis and treatment of gastric cancer.The Gastric Cancer Expert Committee of the NCQCC aims to promote quality control and national standardization,uniformity,and normalization of gastric cancer diagnosis and treatment,which ultimately improved the survival rate and quality of life of gastric cancer patients.A panel of experts with gastrointestinal cancer surgery,gastrointestinal cancer medicine,medical imaging,pathology and radiotherapy were drawn together and determined the quality control standards for the standardized diagnosis and treatment of gastric cancer.The authors then utilized a modified Delphi approach to generate consensus recommendations.展开更多
文摘Background:Acute pancreatitis is an unpredictable and potentially lethal disease,causing tremendous pain in patients.The initial treatment of acute pancreatitis in modern medicine is supportive,but it is generally ineffective in relieving abdominal pain and distension.Traditional Chinese medicine has been shown to be more effective in regulating the body’s homeostasis and reducing the clinical symptoms of pancreatitis.Yi-Dan ointment,derived from Dahuang-Mudan Decoction,is an effective external ointment for treating acute pancreatitis.The aim of this trial is to investigate the clinical efficacy of Yi-Dan ointment,providing a valuable complement to existing treatment options for pancreatitis.Methods:This is a randomized controlled clinical trial with two parallel groups.Patients in the control group were given basic treatment and nursing for 7 days;in the treatment group,Yi-Dan ointment was applied externally in addition to basic treatment and nursing.The main indicator is the overall efficacy,serum amylase,acute physiology and chronic health evaluationⅡscore,symptom score,inflammatory markers,and classification of computed tomography.Conclusion:The trial results will provide high-quality evidence for Yi-Dan ointment,and provide a complement to existing treatment options for pancreatitis.
基金financially supported by the Sichuan Science and Technology Program(Grant No.2023NSFSC1980)。
文摘An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.
文摘In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.
文摘In this paper,an integrated guidance and control method based on an adaptive path-following controller is proposed to control a spin-stabilized projectile with only translational motion information under the constraint of an actuator,uncertainties in aerodynamic parameters and measurements,and control system complexity.Owing to the fairly high rotation speed,the dynamic model of this missile is strongly nonlinear,uncertain and coupled in pitch,yaw and roll channels.A theoretical equivalent resultant force and uncertainty compensation method are comprehensively used to realize decoupling of pitch and yaw.In response to the strong nonlinear and time-varying characteristics of the dynamic system,the quasi-linear model whose parameters are obtained by interpolation of points selected as the segmentation points in the trajectory envelope,is used for calculation in each step.To cope with the system uncertainty caused by model approximation,parameter uncertainty and ballistic interference,an extended state estimator is used to compensate the output feedback according to the test ballistic angle.In order to improve the tracking efficiency and ensure the tracking error convergence with only translational motion information,the virtual guide point,whose derivative is deduced according to the Lyapunov principle,is calculated in real time according to the projection relationship between the real-time position and the reference trajectory,and a virtual line-of-sight angle and the backstepping method are used for the design of the guidance and control system.In order to avoid the influence of control input saturation on the guidance and control performance due to the actuator limitation and improve the robustness of the system,an anti-saturation compensator is designed according to the two-step method.The feasibility and effectiveness of the path-following controller is verified through closed-loop flight simulations with measurement,control,and condition uncertainties.The results indicate that the designed controller can converge to the reference path and evidently decrease the distance between the impact point and target under different uncertainties.
基金supported by the National Key Research and Development Program of China(2022YFA1006103,2023YFA1009203)the National Natural Science Foundation of China(61925306,61821004,11831010,61977043,12001320)+2 种基金the Natural Science Foundation of Shandong Province(ZR2019ZD42,ZR2020ZD24)the Taishan Scholars Young Program of Shandong(TSQN202211032)the Young Scholars Program of Shandong University。
文摘This paper considers a linear-quadratic(LQ) meanfield game governed by a forward-backward stochastic system with partial observation and common noise,where a coupling structure enters state equations,cost functionals and observation equations.Firstly,to reduce the complexity of solving the meanfield game,a limiting control problem is introduced.By virtue of the decomposition approach,an admissible control set is proposed.Applying a filter technique and dimensional-expansion technique,a decentralized control strategy and a consistency condition system are derived,and the related solvability is also addressed.Secondly,we discuss an approximate Nash equilibrium property of the decentralized control strategy.Finally,we work out a financial problem with some numerical simulations.
文摘In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.
文摘The liver is in charge of distributing and regulating the movement of qi throughout the whole body,coordinating the transportation and transformation of the internal organs in the middle part of the body,promoting the biochemical circulation of qi,blood,and body fluids,and regulating emotions.Liver dysfunction can disrupt the transportation and transformation of qi,blood,and body fluids,causing phlegm turbidity,blood stasis,and other unwanted symptoms.Poor regulation of emotion further aggravates the accumulation of pathological substances,resulting in the obstruction of heart vessels,and ultimately coronary heart disease(CHD).Through regulating lipid metabolism,inflammatory reaction,vasoactive substances,platelet function,neuroendocrine,and other factors,liver controlling dispersing qi plays a comprehensive role in the prognosis of atherosclerosis,the primary cause of CHD.Therefore,it is recommended to treat CHD from the perspective of liver-controlling dispersion.
基金This work was supported in part by the JSPS(Japan Society for the Promotion of Science)KAKENHI(20H04566,22H03998)the National Natural Science Foundation of China(61873348)+1 种基金the Natural Science Foundation of Hubei Province,China(2020CFA031)Wuhan Applied Foundational Frontier Project(2020010601012175).
文摘Active disturbance-rejection methods are effective in estimating and rejecting disturbances in both transient and steady-state responses.This paper presents a deep observation on and a comparison between two of those methods:the generalized extended-state observer(GESO)and the equivalent input disturbance(EID)from assumptions,system configurations,stability conditions,system design,disturbance-rejection performance,and extensibility.A time-domain index is introduced to assess the disturbance-rejection performance.A detailed observation of disturbance-suppression mechanisms reveals the superiority of the EID approach over the GESO method.A comparison between these two methods shows that assumptions on disturbances are more practical and the adjustment of disturbance-rejection performance is easier for the EID approach than for the GESO method.
基金supported by the Fulbright Visiting Scholar Program from the Department of State in the U.S.
文摘This paper presents a thorough review of control technologies that have been applied to wastewater treatment processes in the environmental engineering regime in the past four decades. It aims to provide a comprehensive technological review for both water engineering professionals and control specialists, giving rise to a suite of up-to-date pathways to impact this field in light of the classified technology hubs. The assessment was conducted with respect to linear control, linearizing control,nonlinear control, and artificial intelligence-based control. The application domain of each technology hub was summarized into a set of comparative tables for a holistic assessment. Challenges and perspectives were offered to these field engineers to help orient their future endeavor.
基金supported by a grant from Major Project of Shanghai Committee of Science and Technology of China,No.15401970100a grant from the National Natural Science Foundation of China(General Program),No.81673726+2 种基金a grant from the Project of Shanghai Committee of Science and Technology of China,No.17401934600a grant from Longhua Scholar Plan of National Traditional Chinese Medicine Clinical Base of China,No.LYTD-34a grant from Shanghai Traditional Chinese Medicine Science and Technology Innovation Project,No.ZYKC201601002
文摘Levodopa preparations remain the preferred drug for Parkinson's disease.However,long-term use of levodopa may lead to a series of motor complications.Previous studies have shown that the combination of levodopa and Zishenpingchan granules(consisting of Radix Rehmanniae preparata,Lycium barbarum,Herba Taxilli,Rhizoma Gastrodiae,Stiff Silkorm,Curcuma phaeocaulis,Radix Paeoniae Alba,Rhizoma Arisaematis,Scorpio and Centipede) can markedly improve dyskinesia and delay the progression of Parkinson's disease,with especially dramatic improvements of non-motor symptoms.However,the efficacy of this combination has not been confirmed by randomized controlled trials.The current study was approved by the Hospital Ethics Committee and was registered in the Chinese Clinical Trial Register(registration number:Chi CTR-INR-1701194).From December 2014 to December 2016,128 patients(72 males and 56 females,mean age of 65.78 ± 6.34 years) with Parkinson's disease were recruited from the Department of Neurology of Longhua Hospital and Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine in China.Patients were equally allocated into treatment and control groups.In addition to treatment with dopamine,patients in treatment and control groups were given Zishenpingchan granules or placebo,respectively,for 24 weeks.Therapeutic efficacy was assessed using the Unified Parkinson's Disease Rating Scale,on-off phenomenon,Hoehn-Yahr grade,Scales for Outcomes in Parkinson's disease–Autonomic,Parkinson's disease sleep scale,Hamilton Anxiety Scale,Hamilton Depression Scale,Mini-Mental State Examination,and the Parkinson's Disease Quality of Life Questionnaire.Artificial neural networks were used to determine weights at which to scale these parameters.Our results demonstrated that Zishenpingchan granules significantly reduced the occurrence of motor complications,and were useful for mitigating dyskinesia and non-motor symptoms of Parkinson's disease.This combination of Chinese and Western medicine has the potential to reduce levodopa dosages,and no obvious side effects were found.These findings indicate that Zishenpingchan granules can mitigate symptoms of Parkinson's disease,reduce toxic side effects of dopaminergic agents,and exert synergistic and detoxifying effects.
文摘To review the preventive approaches for recurrence after curative resection of hepatic metastases from colorectal carcinoma, we have summarized all available publications reporting randomized control trials (RCTs) covered in PubMed. The treatment approaches presented above include adjuvant intrahepatic arterial infusion chemotherapy, systemic chemotherapy, neoadjuvant chemotherapy, and immunotherapy. Although no standard treatment has been established, several approaches present promising results, which are both effective and tolerable in post-hepatectomy patients. Intrahepatic arterial infusion chemotherapy should be regarded as effective and tolerable and it increases overall survival (OS) and disease free survival (DFS) of patients, while 5-fluorouracil-based systemic chemotherapy has not shown any significant survival benefit. Fortunately chemotherapy combined with hepatic arterial infusion and intravenous infusion has shown OS and DFS benefit in many researches. Few neoadjuvant RCT studies have been conducted to evaluate its effect on prolonging survivals although many retrospective studies and case reports are published in which unresectable colorectal liver metastases are downstaged and made resectable with neoadjuvant chemotherapy. Liver resection supplemented with immunotherapy is associated with optimal results; however, it is also questioned by others. In conclusion, several adjuvant approaches have been studied for their efficacy on recurrence after hepatectomy for liver metastases from colorectal cancer (CRC), but multi-centric RCT is still needed for further evaluation on their efficacy and systemic or local toxicities. In addition, new adjuvant treatment should be investigated to provide more effective and tolerable methods for the patients with resectable hepatic metastases from CRC.
基金supported by Hunan Provincial Innovation Foundation for Postgraduate(Grant No. CX2011B005)National University of Defense Technology Innovation Foundation for Postgraduate, China(GranNo. B110105)
文摘The stratosphere airship provides a unique and promising platform for earth observation. Researches on the project design and control scheme for earth observation platforms are still rarely documented. Nonlinear dynamics, model uncertainties, and external disturbances contribute to the difficulty in maneuvering the stratosphere airship. A key technical challenge for the earth observation platform is station keeping, or the ability to remain fixed over a geo-location. This paper investigates the conceptual design, modeling and station-keeping attitude control of the near-space earth observation platform. A conceptual design of the earth observation platform is presented. The dynamics model of the platform is derived from the Newton-Euler formulation, and the station-keeping control system of the platform is formulated. The station-keeping attitude control approach for the platform is proposed. The multi-input multi-output nonlinear control system is decoupled into three single-input single-output linear subsystems via feedback linearization, the attitude controller design is carried out on the new linear systems using terminal sliding mode control, and the global stability of the closed-loop system is proven by using the Lyapunov theorem. The performance of the designed control system is simulated by using the variable step Runge-Kutta integrator. Simulation results show that the control system tracks the commanded attitude with an error of zero, which verify the effectiveness and robustness of the designed control system in the presence of parametric uncertainties. The near-space earth observation platform has several advantages over satellites, such as high resolution, fast to deploy, and convenient to retrieve, and the proposed control scheme provides an effective approach for station-keeping attitude control of the earth observation platform.
基金supported in part by the National Natural ScienceFoundation of China (U2013201)the National Science Fund for Distinguished Young Scholars (61825302)the Postgraduate Research&Practice Innovation Program of Jiangsu Province (KYCX20_0208)。
文摘In this paper, a disturbance observer-based safe tracking control scheme is proposed for a medium-scale unmanned helicopter with rotor flapping dynamics in the presence of partial state constraints and unknown external disturbances. A safety protection algorithm is proposed to keep the constrained states within the given safe-set. A second-order disturbance observer technique is utilized to estimate the external disturbances. It is shown that the desired tracking performance of the controlled unmanned helicopter can be achieved with the application of the backstepping approach, dynamic surface control technique, and Lyapunov method. Finally, the availability of the proposed control scheme has been shown by simulation results.
基金the National Natural Science Foundation of Chinathe Program for New Century Excellent Talents in University of China.
文摘An Euler-Bernoulli beam system under the local internal distributed control and boundary point observation is studied. An infinite-dimensional observer for the open-loop system is designed. The closed-loop system that is non- dissipative is obtained by the estimated state feedback. By a detailed spectral analysis, it is shown that there is a set of generalized eigenfunctions, which forms a Riesz basis for the state space. Consequently, both the spectrum-determined growth condition and exponential stability are concluded.
基金The Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics under contract No.SOED1402the Youth Science and Technology Foundation of East China Sea Branch,SOA under contract No.201624
文摘Sea surface temperature(SST)data obtained from coastal stations in Jiangsu,China during 20102014 are quality controlled before analysis of their characteristic semidiurnal and seasonal cycles,including the correlation with the variation of the tide.Quality control of data includes the validation of extreme values and checking of hourly values based on temporally adjacent data points,with 0.15℃/h considered a suitable threshold for detecting abnormal values.The diurnal variation amplitude of the SST data is greater in spring and summer than in autumn and winter.The diurnal variation of SST has bimodal structure on most days,i.e.,SST has a significant semidiurnal cycle.Moreover,the semidiurnal cycle of SST is negatively correlated with the tidal data from March to August,but positively correlated with the tidal data from October to January.Little correlation is detected in the remaining months because of the weak coastal offshore SST gradients.The quality control and understanding of coastal SST data are particularly relevant with regard to the validation of indirect measurements such as satellite-derived data.
文摘Objective: To study the treatment of B-Thalas-semia (ThE) with Chinese herbal medicine for Bushen Yisui (BSYS), its theoretical base and molecular mechanism. Methods: Seventy-eight patients with ThE were treated with BSYS recipe (consisted of 11 Chinese herbal drugs as Dogwood fruit, Fleeceflower root, prepared Rehmannia root and turtle shell, etc.) orally taken, 3 times per day, 10 g/time, 3 months as one therapeutic course. Hemoglobin (Hb), red blood cell (RBC), reticulocyte (Ret) and hemoglobin F (HbF) were checked every month. At the same time, PAGE, PVR, PCR-SSCP, RT-PCR, DNA series analysis, mRNA gene expression analysis techniques were used to conduct the systematic gene analysis in patients to study the molecular mechanism of TCM treatment from aspects of gene mutation, gene expression and control-regulation. Results: All the blood criteria in patients after BSYS treatment were improved significantly with clinical symptoms
基金Deputyship for Research&Innovation,Ministry of Education in Saudi Arabia for funding this research work through the project number (IF2-PSAU/2022/01/22797).
文摘The generation of electricity,considering environmental and eco-nomic factors is one of the most important challenges of recent years.In this article,a thermoelectric generator(TEG)is proposed to use the thermal energy of an electric water heater(EWH)to generate electricity independently.To improve the energy conversion efficiency of the TEG,a fuzzy logic con-troller(FLC)-based perturb&observe(P&O)type maximum power point tracking(MPPT)control algorithm is used in this study.An EWH is one of the major electricity consuming household appliances which causes a higher electricity price for consumers.Also,a significant amount of thermal energy generated by EWH is wasted every day,especially during the winter season.In recent years,TEGs have been widely developed to convert surplus or unused thermal energy into usable electricity.In this context,the proposed model is designed to use the thermal energy stored in the EWH to generate electricity.In addition,the generated electricity can be easily stored in a battery storage system to supply electricity to various household appliances with low-power-consumption.The proposed MPPT control algorithm helps the system to quickly reach the optimal point corresponding to the maximum power output and maintains the system operating point at the maximum power output level.To validate the usefulness of the proposed scheme,a study model was developed in the MATLAB Simulink environment and its performance was investigated by simulation under steady state and transient conditions.The results of the study confirmed that the system is capable of generating adequate power from the available thermal energy of EWH.It was also found that the output power and efficiency of the system can be improved by maintaining a higher temperature difference at the input terminals of the TEG.Moreover,the real-time temperature data of Abha city in Saudi Arabia is considered to analyze the feasibility of the proposed system for practical implementation.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20201159).
文摘This paper provides an improved model-free adaptive control(IMFAC)strategy for solving the surface vessel trajectory tracking issue with time delay and restricted disturbance.Firstly,the original nonlinear time-delay system is transformed into a structure consisting of an unknown residual term and a parameter term with control inputs using a local compact form dynamic linearization(local-CFDL).To take advantage of the resulting structure,use a discrete-time extended state observer(DESO)to estimate the unknown residual factor.Then,according to the study,the inclusion of a time delay has no effect on the linearization structure,and an improved control approach is provided,in which DESO is used to adjust for uncertainties.Furthermore,a DESO-based event-triggered model-free adaptive control(ET-DESO-MFAC)is established by designing event-triggered conditions to assure Lyapunov stability.Only when the system’s indicator fulfills the provided event-triggered condition will the control input signal be updated;otherwise,the control input will stay the same as it is at the last trigger moment.A coordinate compensation approach is developed to reduce the steady-state inaccuracy of trajectory tracking.Finally,simulation experiments are used to assess the effectiveness of the proposed technique for trajectory tracking.
文摘Pulp and paper industry is responsible for large discharge of highly polluted effluents, which often be treated by biological treatment process. For biological treatment system, pH is an important environmental factor that can influence the activity of microorganisms. In general, the optimal pH for aerobic processes is around neutral pH (7_7.8) and for the anaerobic process is between 6.8_7.2. The control of pH is a difficult link in the biological treatment system due to its nonlinearity and large time-delay. Aiming at the difficult point in the pH control of the biological wastewater treatment system, a mathematical model of pH control is estab-lished in the essay. On this basis, a traditional PID control and a cascade control are adopted to carry out simulation and comparison with MATLAB. The results show that the cascade control has better comprehen-sive effect in terms of response speed, stability and disturbance resistance.
基金supported by“Beijing Municipal Administration of Hospitals Incubating Program”(No.PX2018043)。
文摘Gastric cancer is one of the most common malignancies of the digestive system,and the number of deaths continues to increase.The standardized management of the diagnosis and treatment of gastric cancer is challenging due to the great differences in the diagnosis and treatment of gastric cancer in different regions.The Gastric Cancer Expert Committee of the National Cancer Quality Control Center(NCQCC)identified a lack of authoritative quality control standards as an opportunity to utilize its multidisciplinary membership to improve the standardized diagnosis and treatment of gastric cancer.The Gastric Cancer Expert Committee of the NCQCC aims to promote quality control and national standardization,uniformity,and normalization of gastric cancer diagnosis and treatment,which ultimately improved the survival rate and quality of life of gastric cancer patients.A panel of experts with gastrointestinal cancer surgery,gastrointestinal cancer medicine,medical imaging,pathology and radiotherapy were drawn together and determined the quality control standards for the standardized diagnosis and treatment of gastric cancer.The authors then utilized a modified Delphi approach to generate consensus recommendations.