The hot-dip galvanizing line(HDGL) is a typical order-driven discrete-event process in steelmaking. It has some complicated dynamic characteristics such as a large time-varying delay, strong nonlinearity, and unmeasur...The hot-dip galvanizing line(HDGL) is a typical order-driven discrete-event process in steelmaking. It has some complicated dynamic characteristics such as a large time-varying delay, strong nonlinearity, and unmeasured disturbance, all of which lead to the difficulty of an online coating weight controller design. We propose a novel neural network based control system to solve these problems. The proposed method has been successfully applied to a real production line at Va Lin LY Steel Co., Loudi, China. The industrial application results show the effectiveness and efficiency of the proposed method, including significant reductions in the variance of the coating weight and the transition time.展开更多
The basis weight control loop of the papermaking process is a non-linear system with time-delay and time-varying.It is impractical to identify a model that can restore the model of real papermaking process.Determining...The basis weight control loop of the papermaking process is a non-linear system with time-delay and time-varying.It is impractical to identify a model that can restore the model of real papermaking process.Determining a more accurate identification model is very important for designing the controller of the control system and maintaining the stable operation of the papermaking process.In this study,a strange nonchaotic particle swarm optimization(SNPSO)algorithm is proposed to identify the models of real papermaking processes,and this identification ability is significantly enhanced compared with particle swarm optimization(PSO).First,random particles are initialized by strange nonchaotic sequences to obtain high-quality solutions.Furthermore,the weight of linear attenuation is replaced by strange nonchaotic sequence and the time-varying acceleration coefficients and a mutation rule with strange nonchaotic characteristics are utilized in SNPSO.The above strategies effectively improve the global and local search ability of particles and the ability to escape from local optimization.To illustrate the effectiveness of SNPSO,step response data are used to identify the models of real industrial processes.Compared with classical PSO,PSO with timevarying acceleration coefficients(PSO-TVAC)and modified particle swarm optimization(MPSO),the simulation results demonstrate that SNPSO has stronger identification ability,faster convergence speed,and better robustness.展开更多
BACKGROUND Obesity is an important factor to cause the obstructive sleep apnea-hypopnea syndrome(OSAHS).Higher body mass index(BMI)often results in more severe OSAHS.Currently,the common measures for controlling the w...BACKGROUND Obesity is an important factor to cause the obstructive sleep apnea-hypopnea syndrome(OSAHS).Higher body mass index(BMI)often results in more severe OSAHS.Currently,the common measures for controlling the weight mainly include diet control,increase exercise and so on.Motivational interviewing(MI)could explore the patient’s internal state and make the patient realize his/her ambivalence,resulting in the change in his/her behavior.This process emphasizes respecting the patient’s autonomy.AIM To evaluate the effect of MI on the weight control of patients with OSAHS.METHODS A randomized controlled study was conducted in 100 obese OSAHS patients undergoing surgical treatment at Shengjing Hospital of China Medical University.The patients were divided into an intervention group and a control group,with 50 cases each.The control group was given routine health education after the operation;in addition to the regular health education,the intervention group was given MI according to a predetermined plan.Obesity-related indicators,postoperative complications,and the sleep status of both groups were evaluated before and 6 mo after the intervention.RESULTS Patients in the intervention group had significantly improved body weight,BMI,and waist and neck circumferences compared with patients in the control group(P<0.05).Regarding complications at 6 mo after operation,the incidence of cough and reflux in patients in the intervention group was significantly lower than that in the control group(P<0.05).In addition,the Epworth Sleepiness Scale and Self-Rating Scale of Sleep scores of patients in the intervention group were significantly lower than those in the control group,and the sleep status of patients in the intervention group was improved(P<0.05).CONCLUSION MI intervention has a significant advantage over postoperative routine health education.It can greatly change the lifestyle,further control the postoperative weight,reduce the occurrence of complications,improve the quality of sleep,and improve long-term postoperative efficacy in OSAHS patients.展开更多
Traditionally, basis weight control valve is driven by a constant frequency pulse signal. Therefore, it is difficult for the valve to match the control precision of basis weight. Dynamic simulation research using Matl...Traditionally, basis weight control valve is driven by a constant frequency pulse signal. Therefore, it is difficult for the valve to match the control precision of basis weight. Dynamic simulation research using Matlab/Simulink indicates that there is much more overshoot and fluctuating during the valve-positioning process. In order to improve the valve-positioning precision, the control method of trapezoidal velocity curve was studied. The simulation result showed that the positioning steady-state error was less than 0.0056%, whereas the peak error was less than 0.016% by using trapezoidal velocity curve at 10 positioning steps. A valve-positioning precision experimental device for the stepper motor of basis weight control valve was developed. The experiment results showed that the error ratio of 1/10000 positioning steps was 4% by using trapezoidal velocity curve. Furthermore, the error ratio of 10/10000 positioning steps was 0.5%. It proved that the valve-positioning precision of trapezoidal velocity curve was much higher than that of the constant frequency pulse signal control strategy. The new control method of trapezoidal velocity curve can satisfy the precision requirement of 10000 steps.展开更多
Basis weight is an important indicator for evaluating paper quality and a major factor directly affecting the economic benefits of enterprises.Focusing on the large time-delay,time-varying,and nonlinear characteristic...Basis weight is an important indicator for evaluating paper quality and a major factor directly affecting the economic benefits of enterprises.Focusing on the large time-delay,time-varying,and nonlinear characteristics of a basis weight control system,a two-degree-of-freedom(TDF)internal model control(IMC)method based on a particle swarm optimization(PSO)algorithm was proposed.The method took the integral of time multiplied by the absolute error(ITAE)as the objective function,and the PSO algorithm was used to optimize the time constant of the tuning IMC filter.The simulation results for the control system under the proposed TDF-IMC method based on the PSO algorithm demonstrate good set-point tracking performance,strong anti-interference capabilities,and good robustness properties.The application results revealed that the basis weight fluctuation range of the paper was±2 g/m2,which significantly improved both the control quality and the product quality.展开更多
A new method on the interval stability of networked control systems （NCSs） with random delay and data packet dropout is studied. Combining interval systems and NCSs, a graphic condition on judging interval stability...A new method on the interval stability of networked control systems （NCSs） with random delay and data packet dropout is studied. Combining interval systems and NCSs, a graphic condition on judging interval stability is presented in terms of the weighted diagraph theory in graph theory. Furthermore, utilizing the graph-theoretic algorithm, the delay-depended controller gains are obtained. Aiming at the same delay and data packed dropout, several controller gains are obtained, simultaneously. The example and simulation illustrate the effectiveness of the proposed method.展开更多
As a useful alternative of Shewhart control chart, exponentially weighted moving average （EWMA） control chat has been applied widely to quality control, process monitoring, forecast, etc. In this paper, a method was...As a useful alternative of Shewhart control chart, exponentially weighted moving average （EWMA） control chat has been applied widely to quality control, process monitoring, forecast, etc. In this paper, a method was introduced for optimal design of EWMA and multivariate EWMA （MEWMA） control charts, in which the optimal parameter pair （ λ, k） or （ λ, h ） was searched by using the generalized regression neural network （GRNN）. The results indicate that the optimal parameter pair can be obtained effectively by the proposed strategy for a given in-control average running length （ARLo） and shift to detect under any conditions, removing the drawback of incompleteness existing in the tables that had been reported.展开更多
Background Preeclampsia is a common disease in pregnant women,characterized by clinical manifestations such as hypertension and proteinuria,which not only seriously affect the safety of pregnant women,but also jeopard...Background Preeclampsia is a common disease in pregnant women,characterized by clinical manifestations such as hypertension and proteinuria,which not only seriously affect the safety of pregnant women,but also jeopardize the safety of the fetus,threatening maternal and infant safety.Currently,in addition to routine hypoglycemic and antihypertensive treatments,auxiliary treatment methods such as exercise and diet are gradually gaining clinical recognition.Therefore,this study aimed to observe the effects of comprehensive nutrition care during pregnancy on weight control during pregnancy and maternal and infant outcomes in patients with pregnancy-induced hypertension syndrome.Methods A total of 100 cases of preeclampsia patients in our hospital from August 2021 to May 2022 were selected and randomly divided into a nutrition group and a conventional group,with 50 cases in each group.The conventional group received routine care,while the nutrition group received additional comprehensive nutrition care during pregnancy based on routine care.The weight control and blood pressure control during pregnancy and maternal and infant outcomes of the two groups were observed.Results The weight control during pregnancy in the nutrition group was significantly better than that in the conventional group(P<0.05).There was no significant difference in systolic and diastolic blood pressure between the two groups before intervention(P>0.05),but both systolic and diastolic blood pressure in both groups were lower after intervention,with the nutrition group significantly lower than the conventional group(P<0.05).The incidence of neonatal asphyxia,placental abruption,postpartum hemorrhage,and cesarean section in the nutrition group was significantly lower than that in the conventional group(P<0.05).Conclusions Comprehensive nutrition care during pregnancy can effectively control weight and blood pressure levels in patients with preeclampsia,and improve maternal and infant outcomes.[S Chin J Cardiol 2024;25(3):156-161]展开更多
Controlled and homogeneous flee-radical polymerization of acrylamide （AM） in aqueous phase was realized by using S,S＇-bis（α, α＇-dimethyl-α＂-acetic acid）-trithiocarbonate as a reversible addition-fragmentatio...Controlled and homogeneous flee-radical polymerization of acrylamide （AM） in aqueous phase was realized by using S,S＇-bis（α, α＇-dimethyl-α＂-acetic acid）-trithiocarbonate as a reversible addition-fragmentation transfer （RAFT） agent. Linear increases in molecular weight with conversion and narrow molecular weight distribution were observed for polyacrylamide （PAM） throughout the polymerization. By this method, PAMs with controlled molecular weight （up to 1.0 ~ 106） and narrow molecular weight distribution （Mw/Mn 〈 1.2） were prepared. This study provides an effective method for synthesis of PAMs with narrow molecular weight distribution under environmentally friendly conditions.展开更多
In this article, we provide estimates for the degree of V bilipschitz determinacy of weighted homogeneous function germs defined on weighted homogeneous analytic variety V satisfying a convenient Lojasiewicz condition...In this article, we provide estimates for the degree of V bilipschitz determinacy of weighted homogeneous function germs defined on weighted homogeneous analytic variety V satisfying a convenient Lojasiewicz condition.The result gives an explicit order such that the geometrical structure of a weighted homogeneous polynomial function germs is preserved after higher order perturbations.展开更多
The research on rolling bearing early fault detection is mainly focused on degradation index extraction and adaptive setting of alarm threshold.The mainstream methods are to extract degradation indicators based on ada...The research on rolling bearing early fault detection is mainly focused on degradation index extraction and adaptive setting of alarm threshold.The mainstream methods are to extract degradation indicators based on adaptive features and set adaptive alarm thresholds based on the Shewhart control chart.However,the adaptive feature extraction method does not consider the correlation between features,and the Shewhart control chart is not sensitive to small fluctuations caused by early faults.In this study,a rolling bearing early fault detection method based on a feature clustering fusion degradation index is proposed.The multidomain statistical features are extracted to form the initial feature set,and the improved hierarchical clustering algorithm is combined with the feature evaluation index to select features to form a preferred feature subset,to ensure the richness of index information and reduce redundancy.After the construction of the degradation index,to suppress the interference caused by nonstationary and abnormal shocks in early fault detection,the accurate evaluation method and anomaly determination strategy of control chart parameters are studied,and an improved exponential weighted move average control chart is designed to monitor the degradation index.The effectiveness and superiority of the proposed method are verified by public data sets.This research provides a rolling bearing early fault detection method,which can provide comprehensive degradation indicators,eliminate interference caused by random anomalies and running in periods,and achieve an accurate detection of early bearing failures.展开更多
文摘The hot-dip galvanizing line(HDGL) is a typical order-driven discrete-event process in steelmaking. It has some complicated dynamic characteristics such as a large time-varying delay, strong nonlinearity, and unmeasured disturbance, all of which lead to the difficulty of an online coating weight controller design. We propose a novel neural network based control system to solve these problems. The proposed method has been successfully applied to a real production line at Va Lin LY Steel Co., Loudi, China. The industrial application results show the effectiveness and efficiency of the proposed method, including significant reductions in the variance of the coating weight and the transition time.
基金support received from the National Natural Science Foundation of China(Grant No.62073206)Technical Innovation Guidance Project of Shaanxi Province(Grant No.2020CGHJ-007).
文摘The basis weight control loop of the papermaking process is a non-linear system with time-delay and time-varying.It is impractical to identify a model that can restore the model of real papermaking process.Determining a more accurate identification model is very important for designing the controller of the control system and maintaining the stable operation of the papermaking process.In this study,a strange nonchaotic particle swarm optimization(SNPSO)algorithm is proposed to identify the models of real papermaking processes,and this identification ability is significantly enhanced compared with particle swarm optimization(PSO).First,random particles are initialized by strange nonchaotic sequences to obtain high-quality solutions.Furthermore,the weight of linear attenuation is replaced by strange nonchaotic sequence and the time-varying acceleration coefficients and a mutation rule with strange nonchaotic characteristics are utilized in SNPSO.The above strategies effectively improve the global and local search ability of particles and the ability to escape from local optimization.To illustrate the effectiveness of SNPSO,step response data are used to identify the models of real industrial processes.Compared with classical PSO,PSO with timevarying acceleration coefficients(PSO-TVAC)and modified particle swarm optimization(MPSO),the simulation results demonstrate that SNPSO has stronger identification ability,faster convergence speed,and better robustness.
基金Supported by the School of Nursing Research Project at China Medical University,No.2017HL-21.
文摘BACKGROUND Obesity is an important factor to cause the obstructive sleep apnea-hypopnea syndrome(OSAHS).Higher body mass index(BMI)often results in more severe OSAHS.Currently,the common measures for controlling the weight mainly include diet control,increase exercise and so on.Motivational interviewing(MI)could explore the patient’s internal state and make the patient realize his/her ambivalence,resulting in the change in his/her behavior.This process emphasizes respecting the patient’s autonomy.AIM To evaluate the effect of MI on the weight control of patients with OSAHS.METHODS A randomized controlled study was conducted in 100 obese OSAHS patients undergoing surgical treatment at Shengjing Hospital of China Medical University.The patients were divided into an intervention group and a control group,with 50 cases each.The control group was given routine health education after the operation;in addition to the regular health education,the intervention group was given MI according to a predetermined plan.Obesity-related indicators,postoperative complications,and the sleep status of both groups were evaluated before and 6 mo after the intervention.RESULTS Patients in the intervention group had significantly improved body weight,BMI,and waist and neck circumferences compared with patients in the control group(P<0.05).Regarding complications at 6 mo after operation,the incidence of cough and reflux in patients in the intervention group was significantly lower than that in the control group(P<0.05).In addition,the Epworth Sleepiness Scale and Self-Rating Scale of Sleep scores of patients in the intervention group were significantly lower than those in the control group,and the sleep status of patients in the intervention group was improved(P<0.05).CONCLUSION MI intervention has a significant advantage over postoperative routine health education.It can greatly change the lifestyle,further control the postoperative weight,reduce the occurrence of complications,improve the quality of sleep,and improve long-term postoperative efficacy in OSAHS patients.
基金supported by the International S&T Cooperation Program of China(GrantNo.2010DFB43660)National Natural Science Foundation of China(Grant No.51375286)Scientific Research Program Funded by Shaanxi Provincial Education Department(Program No.16JF005)
文摘Traditionally, basis weight control valve is driven by a constant frequency pulse signal. Therefore, it is difficult for the valve to match the control precision of basis weight. Dynamic simulation research using Matlab/Simulink indicates that there is much more overshoot and fluctuating during the valve-positioning process. In order to improve the valve-positioning precision, the control method of trapezoidal velocity curve was studied. The simulation result showed that the positioning steady-state error was less than 0.0056%, whereas the peak error was less than 0.016% by using trapezoidal velocity curve at 10 positioning steps. A valve-positioning precision experimental device for the stepper motor of basis weight control valve was developed. The experiment results showed that the error ratio of 1/10000 positioning steps was 4% by using trapezoidal velocity curve. Furthermore, the error ratio of 10/10000 positioning steps was 0.5%. It proved that the valve-positioning precision of trapezoidal velocity curve was much higher than that of the constant frequency pulse signal control strategy. The new control method of trapezoidal velocity curve can satisfy the precision requirement of 10000 steps.
基金supported by the Shaanxi Key Innovation Team Project of Science and Technology (2014KCT-15)the Shaanxi Science & Technology Co-ordination & InnovationProject (2016KTCQ01-35)
文摘Basis weight is an important indicator for evaluating paper quality and a major factor directly affecting the economic benefits of enterprises.Focusing on the large time-delay,time-varying,and nonlinear characteristics of a basis weight control system,a two-degree-of-freedom(TDF)internal model control(IMC)method based on a particle swarm optimization(PSO)algorithm was proposed.The method took the integral of time multiplied by the absolute error(ITAE)as the objective function,and the PSO algorithm was used to optimize the time constant of the tuning IMC filter.The simulation results for the control system under the proposed TDF-IMC method based on the PSO algorithm demonstrate good set-point tracking performance,strong anti-interference capabilities,and good robustness properties.The application results revealed that the basis weight fluctuation range of the paper was±2 g/m2,which significantly improved both the control quality and the product quality.
基金partially supported by the National Natural Science Foundation of China (60574011).
文摘A new method on the interval stability of networked control systems （NCSs） with random delay and data packet dropout is studied. Combining interval systems and NCSs, a graphic condition on judging interval stability is presented in terms of the weighted diagraph theory in graph theory. Furthermore, utilizing the graph-theoretic algorithm, the delay-depended controller gains are obtained. Aiming at the same delay and data packed dropout, several controller gains are obtained, simultaneously. The example and simulation illustrate the effectiveness of the proposed method.
基金Funded by the National Key Technologies R&D Programs of China (No.2002BA105C)
文摘As a useful alternative of Shewhart control chart, exponentially weighted moving average （EWMA） control chat has been applied widely to quality control, process monitoring, forecast, etc. In this paper, a method was introduced for optimal design of EWMA and multivariate EWMA （MEWMA） control charts, in which the optimal parameter pair （ λ, k） or （ λ, h ） was searched by using the generalized regression neural network （GRNN）. The results indicate that the optimal parameter pair can be obtained effectively by the proposed strategy for a given in-control average running length （ARLo） and shift to detect under any conditions, removing the drawback of incompleteness existing in the tables that had been reported.
文摘Background Preeclampsia is a common disease in pregnant women,characterized by clinical manifestations such as hypertension and proteinuria,which not only seriously affect the safety of pregnant women,but also jeopardize the safety of the fetus,threatening maternal and infant safety.Currently,in addition to routine hypoglycemic and antihypertensive treatments,auxiliary treatment methods such as exercise and diet are gradually gaining clinical recognition.Therefore,this study aimed to observe the effects of comprehensive nutrition care during pregnancy on weight control during pregnancy and maternal and infant outcomes in patients with pregnancy-induced hypertension syndrome.Methods A total of 100 cases of preeclampsia patients in our hospital from August 2021 to May 2022 were selected and randomly divided into a nutrition group and a conventional group,with 50 cases in each group.The conventional group received routine care,while the nutrition group received additional comprehensive nutrition care during pregnancy based on routine care.The weight control and blood pressure control during pregnancy and maternal and infant outcomes of the two groups were observed.Results The weight control during pregnancy in the nutrition group was significantly better than that in the conventional group(P<0.05).There was no significant difference in systolic and diastolic blood pressure between the two groups before intervention(P>0.05),but both systolic and diastolic blood pressure in both groups were lower after intervention,with the nutrition group significantly lower than the conventional group(P<0.05).The incidence of neonatal asphyxia,placental abruption,postpartum hemorrhage,and cesarean section in the nutrition group was significantly lower than that in the conventional group(P<0.05).Conclusions Comprehensive nutrition care during pregnancy can effectively control weight and blood pressure levels in patients with preeclampsia,and improve maternal and infant outcomes.[S Chin J Cardiol 2024;25(3):156-161]
文摘Controlled and homogeneous flee-radical polymerization of acrylamide （AM） in aqueous phase was realized by using S,S＇-bis（α, α＇-dimethyl-α＂-acetic acid）-trithiocarbonate as a reversible addition-fragmentation transfer （RAFT） agent. Linear increases in molecular weight with conversion and narrow molecular weight distribution were observed for polyacrylamide （PAM） throughout the polymerization. By this method, PAMs with controlled molecular weight （up to 1.0 ~ 106） and narrow molecular weight distribution （Mw/Mn 〈 1.2） were prepared. This study provides an effective method for synthesis of PAMs with narrow molecular weight distribution under environmentally friendly conditions.
基金Supported by the National Nature Science Foundation of China(10671009,60534080,10871149)
文摘In this article, we provide estimates for the degree of V bilipschitz determinacy of weighted homogeneous function germs defined on weighted homogeneous analytic variety V satisfying a convenient Lojasiewicz condition.The result gives an explicit order such that the geometrical structure of a weighted homogeneous polynomial function germs is preserved after higher order perturbations.
基金Supported by National Key Research and Development Program(Grant No.2023YFB4203402)National Natural Science Foundation of China(Grant No.52375042)+1 种基金Chongqing Technology Innovation and Application Development Project(Grant No.CSTB2022TIAD-KPX0078)Chongqing Transportation Technology Project(Grant No.CQJT-CZKJ2024-10).
文摘The research on rolling bearing early fault detection is mainly focused on degradation index extraction and adaptive setting of alarm threshold.The mainstream methods are to extract degradation indicators based on adaptive features and set adaptive alarm thresholds based on the Shewhart control chart.However,the adaptive feature extraction method does not consider the correlation between features,and the Shewhart control chart is not sensitive to small fluctuations caused by early faults.In this study,a rolling bearing early fault detection method based on a feature clustering fusion degradation index is proposed.The multidomain statistical features are extracted to form the initial feature set,and the improved hierarchical clustering algorithm is combined with the feature evaluation index to select features to form a preferred feature subset,to ensure the richness of index information and reduce redundancy.After the construction of the degradation index,to suppress the interference caused by nonstationary and abnormal shocks in early fault detection,the accurate evaluation method and anomaly determination strategy of control chart parameters are studied,and an improved exponential weighted move average control chart is designed to monitor the degradation index.The effectiveness and superiority of the proposed method are verified by public data sets.This research provides a rolling bearing early fault detection method,which can provide comprehensive degradation indicators,eliminate interference caused by random anomalies and running in periods,and achieve an accurate detection of early bearing failures.
