Aiming at the problems of low accuracy and poor robustness that existed in the current hot rolling strip width spread model,an improved strip spread prediction model based on a material forming mechanism and Bayesian ...Aiming at the problems of low accuracy and poor robustness that existed in the current hot rolling strip width spread model,an improved strip spread prediction model based on a material forming mechanism and Bayesian optimized adaptive differential evolution algorithm(BADE)was proposed.At first,we improved the original spread mechanism model by adding the weight and bias term to enhance the model robustness based on rolling temperature.Then,the BADE algorithm was proposed to optimize the improved spread mechanism model.The optimization algorithm is based on a novel adaptive differential evolution algorithm,which can effectively achieve the global optimal solution.Finally,the prediction performances of five machine learning algorithms were compared in experiments.The results show that the prediction accuracy of the improved spread model is obviously better than that of the machine learning algorithms,which proves the effectiveness of the proposed method.展开更多
This letter addresses the study titled“Red cell distribution width:A predictor of the severity of hypertriglyceridemia-induced acute pancreatitis”by Lv et al published in the World Journal of Experimental Medicine.T...This letter addresses the study titled“Red cell distribution width:A predictor of the severity of hypertriglyceridemia-induced acute pancreatitis”by Lv et al published in the World Journal of Experimental Medicine.The study offers a valuable analysis of red cell distribution width(RDW)as a predictive marker for persistent organ failure in patients with hypertriglyceridemia-induced acute pancreatitis.The study results suggest that RDW,combined with the Bedside Index for Severity in Acute Pancreatitis score,could enhance the predictive accuracy for severe outcomes.Further investigation into the role of RDW in different severities of acute pancreatitis is recommended.Additionally,the need for large-scale and multicenter prospective studies to validate these findings is emphasized.展开更多
Understanding and predicting droplet breakup is essential in droplet-based microfluidic systems,as it enables precise control over droplet manipulation for various applications.In this study,droplet breakup behavior i...Understanding and predicting droplet breakup is essential in droplet-based microfluidic systems,as it enables precise control over droplet manipulation for various applications.In this study,droplet breakup behavior in a T-junction microchannel is investigated under the influence of microchannel geometry using three-dimensional numerical simulations.A theoretical model is developed based on the balance between surface tension and viscous drag forces acting on the droplet,incorporating the effects of geometric parameters on droplet length.This model predicts the critical Capillary number required for breakup to occur.The theoretical predictions are validated using both previous research data and the present numerical simulations.The results show that the model accurately predicts the transition between breakup and non-breakup regimes.Specifically,an increase in sidearm length ratio inhibits droplet breakup and leads to an asymmetric breakup regime.Furthermore,increasing the outlet-to-inlet width ratio also reduces the likelihood of droplet breakup.These findings provide a predictive framework for understanding and controlling droplet dynamics in microfluidic T-junctions,with potential applications in lab-on-a-chip technologies.展开更多
Reaction control system(RCS) is a powerful and efficient actuator for space vehicles attitude control, which is typically characterized as a pulsed unilateral effector only with two states(off/on). Along with inevitab...Reaction control system(RCS) is a powerful and efficient actuator for space vehicles attitude control, which is typically characterized as a pulsed unilateral effector only with two states(off/on). Along with inevitable internal uncertainties and external disturbances in practice, this inherent nonlinear character always hinders space vehicles autopilot from pursuing precise tracking performance. Compared to most of pre-existing methodologies that passively suppress the uncertainties and disturbances, a design based on predictive functional control(PFC) and generalized extended state observer(GESO) is firstly proposed for three-axis RCS control system to actively reject that with no requirement for additional fuel consumption. To obtain a high fidelity predictive model on which the performance of PFC greatly depends, the nonlinear coupling multiple-input multiple-output(MIMO) flight dynamics model is parameterized as a state-dependent coefficient form. And based on that, a MIMO PFC algorithm in state space domain for a plant of arbitrary orders is deduced in this paper.The internal uncertainties and external disturbances are lumped as a total disturbance, which is estimated and cancelled timely to further enhance the robustness. The continuous control command synthesised by above controller-rejector tandem is finally modulated by pulse width pulse frequency modulator(PWPF) to on-off signals to meet RCS requirement. The robustness and feasibility of the proposed design are validated by a series of performance comparison simulations with some prominent methods in the presence of significant perturbations and disturbances, as well as measurement noise.展开更多
基金support from National Natural Science Foundation of China(Grant Nos.61633019,61533013 and 62273234).
文摘Aiming at the problems of low accuracy and poor robustness that existed in the current hot rolling strip width spread model,an improved strip spread prediction model based on a material forming mechanism and Bayesian optimized adaptive differential evolution algorithm(BADE)was proposed.At first,we improved the original spread mechanism model by adding the weight and bias term to enhance the model robustness based on rolling temperature.Then,the BADE algorithm was proposed to optimize the improved spread mechanism model.The optimization algorithm is based on a novel adaptive differential evolution algorithm,which can effectively achieve the global optimal solution.Finally,the prediction performances of five machine learning algorithms were compared in experiments.The results show that the prediction accuracy of the improved spread model is obviously better than that of the machine learning algorithms,which proves the effectiveness of the proposed method.
文摘This letter addresses the study titled“Red cell distribution width:A predictor of the severity of hypertriglyceridemia-induced acute pancreatitis”by Lv et al published in the World Journal of Experimental Medicine.The study offers a valuable analysis of red cell distribution width(RDW)as a predictive marker for persistent organ failure in patients with hypertriglyceridemia-induced acute pancreatitis.The study results suggest that RDW,combined with the Bedside Index for Severity in Acute Pancreatitis score,could enhance the predictive accuracy for severe outcomes.Further investigation into the role of RDW in different severities of acute pancreatitis is recommended.Additionally,the need for large-scale and multicenter prospective studies to validate these findings is emphasized.
基金funded by the Master,Ph D Scholarship Programme of Vingroup Innovation Foundation(VINIF),code VINIF.2023.Th S.118。
文摘Understanding and predicting droplet breakup is essential in droplet-based microfluidic systems,as it enables precise control over droplet manipulation for various applications.In this study,droplet breakup behavior in a T-junction microchannel is investigated under the influence of microchannel geometry using three-dimensional numerical simulations.A theoretical model is developed based on the balance between surface tension and viscous drag forces acting on the droplet,incorporating the effects of geometric parameters on droplet length.This model predicts the critical Capillary number required for breakup to occur.The theoretical predictions are validated using both previous research data and the present numerical simulations.The results show that the model accurately predicts the transition between breakup and non-breakup regimes.Specifically,an increase in sidearm length ratio inhibits droplet breakup and leads to an asymmetric breakup regime.Furthermore,increasing the outlet-to-inlet width ratio also reduces the likelihood of droplet breakup.These findings provide a predictive framework for understanding and controlling droplet dynamics in microfluidic T-junctions,with potential applications in lab-on-a-chip technologies.
文摘Reaction control system(RCS) is a powerful and efficient actuator for space vehicles attitude control, which is typically characterized as a pulsed unilateral effector only with two states(off/on). Along with inevitable internal uncertainties and external disturbances in practice, this inherent nonlinear character always hinders space vehicles autopilot from pursuing precise tracking performance. Compared to most of pre-existing methodologies that passively suppress the uncertainties and disturbances, a design based on predictive functional control(PFC) and generalized extended state observer(GESO) is firstly proposed for three-axis RCS control system to actively reject that with no requirement for additional fuel consumption. To obtain a high fidelity predictive model on which the performance of PFC greatly depends, the nonlinear coupling multiple-input multiple-output(MIMO) flight dynamics model is parameterized as a state-dependent coefficient form. And based on that, a MIMO PFC algorithm in state space domain for a plant of arbitrary orders is deduced in this paper.The internal uncertainties and external disturbances are lumped as a total disturbance, which is estimated and cancelled timely to further enhance the robustness. The continuous control command synthesised by above controller-rejector tandem is finally modulated by pulse width pulse frequency modulator(PWPF) to on-off signals to meet RCS requirement. The robustness and feasibility of the proposed design are validated by a series of performance comparison simulations with some prominent methods in the presence of significant perturbations and disturbances, as well as measurement noise.
