Dear Editor,This letter deals with the stabilization problem of nonlinear stochastic systems via self-triggered impulsive control(STIC), where the timing of impulsive control actions is not dependent on continuous sta...
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Dear Editor,This letter deals with the stabilization problem of nonlinear stochastic systems via self-triggered impulsive control(STIC), where the timing of impulsive control actions is not dependent on continuous state monitoring. In contrast to the existing self-triggered control method, novel self-triggered mechanism(STM) is proposed by incorporating a waiting time for stabilizing impulses. This allows for direct prediction of the next impulsive instant.
To predict the lithium-ion(Li-ion) battery degradation trajectory in the early phase,arranging the maintenance of battery energy storage systems is of great ***,under different operation conditions,Li-ion batteries pr...
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To predict the lithium-ion(Li-ion) battery degradation trajectory in the early phase,arranging the maintenance of battery energy storage systems is of great ***,under different operation conditions,Li-ion batteries present distinct degradation patterns,and it is challenging to capture negligible capacity fade in early *** the data-driven method showing promising performance,insufficient data is still a big issue since the ageing experiments on the batteries are too slow and *** this study,we proposed twin autoencoders integrated into a two-stage method to predict the early cycles' degradation *** two-stage method can properly predict the degradation from course to *** twin autoencoders serve as a feature extractor and a synthetic data generator,***,a learning procedure based on the long-short term memory(LSTM) network is designed to hybridize the learning process between the real and synthetic *** performance of the proposed method is verified on three datasets,and the experimental results show that the proposed method can achieve accurate predictions compared to its competitors.
Gas pulsation is an efficient enhancing way for fluidized bed drying *** this work,the influence of gas pulsation on mass and heat transfer performance in a fluidized bed with non-spherical wet particles is numericall...
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Gas pulsation is an efficient enhancing way for fluidized bed drying *** this work,the influence of gas pulsation on mass and heat transfer performance in a fluidized bed with non-spherical wet particles is numerically investigated via the computational fluid dynamics−discrete element method(CFD-DEM)approach,where the liquid transfer between particles and the heat transfer by liquid bridge are *** aspect ratio effect of non-spherical particle on drying process is *** is found that the increase of aspect ratio can weaken the overall drying *** influence of gas pulsation on the drying of non-spherical particle is *** results reveal that adjusting a suitable gas pulsation mode can efficiently regulate the drying process of non-spherical wet particles with greater aspect ratios.
The long-lasting expectation"the hotter the engine,the better"calls for the development of high-temperature metallic *** the high specific strengths of titanium alloys are compelling for such applications,th...
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The long-lasting expectation"the hotter the engine,the better"calls for the development of high-temperature metallic *** the high specific strengths of titanium alloys are compelling for such applications,their deleterious softening beyond 600 ℃ imposes serious *** has been known for decades regarding the phase metallurgy for precipitation strengthening design in titanium al-loys,however,the other facile strength promotion mechanism,dispersion strengthening,remains compar-atively less-explored and *** present research concerns the multi-scale dispersion strength-ening in titanium alloys,with mechanistic emphases on the critical plasticity micro-events that affect strength *** to the simultaneous introduction of intragranular dispersoids and intergran-ular reinforcers,the current titanium alloys present superior engineering tensile strength of 519 MPa at 700 ℃.Throughout the examined 25-800 ℃ temperature range,noticeable softening induced by the ther-mal activation occurs above 600 ℃,accompanied by evident strength *** temperature-dependence transition of dominated softening mechanisms from dynamic recovery to dynamic recrystallization has been clarified by theoretical ***,the strengthening effect of multi-scale architec-tures is underpinned as the enhanced dislocation strengthening owing to the introduction of thermally-stable heterointerfaces,which could generically guide the design of similar heat-resistant titanium alloys.
In pumped hydro compressed air energy storage systems,the heat exchange performance between air and water significantly affects the thermodynamic *** study proposes an enhanced heat transfer method by adding trays and...
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In pumped hydro compressed air energy storage systems,the heat exchange performance between air and water significantly affects the thermodynamic *** study proposes an enhanced heat transfer method by adding trays and investigates the effects of parameters such as the number of trays,tray diameter,and tray mounting ***,the working principle of the heat transfer method when adding trays was clarified,and a mathematical model was ***,the effects of the number,diameter,and mounting height of the trays were ***,the thermodynamic,energy,and exergy performances of the system without trays,Tank 1 with trays,Tank 2 with trays,and Tanks 1 and 2 with trays were *** results show that the heat transfer between air and water is enhanced and the variation in air temperature is reduced when Tanks 1 and 2 have *** number and diameter of trays significantly affected the thermodynamic performance of the system,whereas the impact of the tray mounting height was not *** installing 30 trays uniformly in Tanks 1 and 2,the temperature variations in Tanks 1 and 2 were reduced by 8.2%and 15.4%,respectively;additionally,the round-trip and exergy efficiencies of the system were improved by 1.4%and 1.3%,respectively.
Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effec...
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Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effective Hamiltonian method in conjuction with the phase-field model, we have successfully reproduced the thermal hysteresis observed in ferroelectric materials during phase transitions. The computational results regarding the electrocaloric effect from these two different computational scales closely align with experimental measurements. Furthermore, we analyze how the first-order ferroelectric phase transition gradually diminishes with an increasing applied electric field, exhibiting characteristics of second-order-like phase transition. By employing the characteristic parameters of thermal hysteresis, we have established a pathway for calculations across different computational scales, thereby providing theoretical support for further investigations into the properties of ferroelectric materials through concurrent multiscale simulations.
Accurate lateral state estimation is crucial for ensuring the stability and safety of *** Kalman filter is widely utilized to estimate the lateral state of ***,vehicle state measurement suffers from inherent time dela...
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Accurate lateral state estimation is crucial for ensuring the stability and safety of *** Kalman filter is widely utilized to estimate the lateral state of ***,vehicle state measurement suffers from inherent time delays and model *** existence of fractional and random delays necessitates long sampling periods for the inputs of the Kalman filter,leading to update mismatch and deterioration of the accuracy of the *** situation poses a threat to driving *** addition,the tire cornering stiffness,a critical model parameter,exhibits nonlinear and dynamic variations that cannot be measured in real *** inherent variability significantly affects the accuracy of lateral state *** internal and external uncertainties,an observer framework for vehicle lateral state estimation based on the Kalman filter was designed in this ***,a modified delayed Kalman filter method that considers the random fractional delays was *** relationship correlation between the delayed measurement and the prior state was constructed based on a likelihood ***,the tire cornering stiffness was estimated online by an algorithm based on recursive least *** parameter was used to dynamically adjust the vehicle model for the Kalman ***,two simulations and a real vehicle experiment were performed to verify the effectiveness of the proposed *** particular,the root mean squared error(RMSE)of the slip angle decreased by 30.70%,and that of the yaw rate decreased by 61.03%in the double lane change *** vehicle experiments demonstrated that the algorithm can be effectively applied in real situations.
This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver ***,we establish a lateral dynamic model considering...
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This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver ***,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual ***,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown *** whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function ***,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and *** dynamic models are incorporated to ensure physical realizability of designed allocation ***,comparative experimental results validate the effectiveness of the designed control system and control allocation *** NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),*** design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.
This article introduces the 3D-RPDM framework, a method based on 3-D reconstruction for measuring the packing density of gassolid two-phase flow using a structured light system. Packing density, crucial for the manufa...
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In recent years, particle swarm optimization (PSO) has received widespread attention in feature selection due to its simplicity and potential for global search. However, in traditional PSO, particles primarily update ...
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In recent years, particle swarm optimization (PSO) has received widespread attention in feature selection due to its simplicity and potential for global search. However, in traditional PSO, particles primarily update based on two extreme values: personal best and global best, which limits the diversity of information. Ideally, particles should learn from multiple advantageous particles to enhance interactivity and optimization efficiency. Accordingly, this paper proposes a PSO that simulates the evolutionary dynamics of species survival in mountain peak ecology (PEPSO) for feature selection. Based on the pyramid topology, the algorithm simulates the features of mountain peak ecology in nature and the competitive-cooperative strategies among species. According to the principles of the algorithm, the population is first adaptively divided into many subgroups based on the fitness level of particles. Then, particles within each subgroup are divided into three different types based on their evolutionary levels, employing different adaptive inertia weight rules and dynamic learning mechanisms to define distinct learning modes. Consequently, all particles play their respective roles in promoting the global optimization performance of the algorithm, similar to different species in the ecological pattern of mountain peaks. Experimental validation of the PEPSO performance was conducted on 18 public datasets. The experimental results demonstrate that the PEPSO outperforms other PSO variant-based feature selection methods and mainstream feature selection methods based on intelligent optimization algorithms in terms of overall performance in global search capability, classification accuracy, and reduction of feature space dimensions. Wilcoxon signed-rank test also confirms the excellent performance of the PEPSO.
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