Learning-based methods have become mainstream for solving residential energy scheduling problems. In order to improve the learning efficiency of existing methods and increase the utilization of renewable energy, we pr...Learning-based methods have become mainstream for solving residential energy scheduling problems. In order to improve the learning efficiency of existing methods and increase the utilization of renewable energy, we propose the Dyna actiondependent heuristic dynamic programming(Dyna-ADHDP)method, which incorporates the ideas of learning and planning from the Dyna framework in action-dependent heuristic dynamic programming. This method defines a continuous action space for precise control of an energy storage system and allows online optimization of algorithm performance during the real-time operation of the residential energy model. Meanwhile, the target network is introduced during the training process to make the training smoother and more efficient. We conducted experimental comparisons with the benchmark method using simulated and real data to verify its applicability and performance. The results confirm the method's excellent performance and generalization capabilities, as well as its excellence in increasing renewable energy utilization and extending equipment life.展开更多
In this article,a novel model-free coordinated optimal regulation design methodology is proposed for the rigidly connected dual permanent magnet synchronous motor(PMSM)system via adaptive dynamic programming(ADP).Firs...In this article,a novel model-free coordinated optimal regulation design methodology is proposed for the rigidly connected dual permanent magnet synchronous motor(PMSM)system via adaptive dynamic programming(ADP).First,we adopt the classical master-slave structure to maintain torque synchronization by virtue of field-oriented control.Then,a reducedorder model of the dual-PMSM system is established through the application of singular perturbation theory(SPT),which is of significance to decrease the learning time and computational complexity in the outer speed loop design.Afterwards,we design a coordinated adaptive optimal regulator in framework of ADP to drive the speed of girth gear asymptotic tracking the reference signal and accommodate the load torque disturbance,which is independent of the knowledge of model parameters of the system.According to SPT,we analyze the suboptimality,closed-loop stability,and robustness properties of the obtained controller under mild conditions.Finally,comprehensive experimental studies are provided to verify that the proposed control strategy can achieve the speed regulation and the torque synchronization,as well as ameliorate the transient response.展开更多
In this paper,a distributed adaptive dynamic programming(ADP)framework based on value iteration is proposed for multi-player differential games.In the game setting,players have no access to the information of others&#...In this paper,a distributed adaptive dynamic programming(ADP)framework based on value iteration is proposed for multi-player differential games.In the game setting,players have no access to the information of others'system parameters or control laws.Each player adopts an on-policy value iteration algorithm as the basic learning framework.To deal with the incomplete information structure,players collect a period of system trajectory data to compensate for the lack of information.The policy updating step is implemented by a nonlinear optimization problem aiming to search for the proximal admissible policy.Theoretical analysis shows that by adopting proximal policy searching rules,the approximated policies can converge to a neighborhood of equilibrium policies.The efficacy of our method is illustrated by three examples,which also demonstrate that the proposed method can accelerate the learning process compared with the centralized learning framework.展开更多
Online programming platforms are popular in programming education.However,there has been no research investigating students’real opinions and expectations of the error feedback mechanisms,leaving educators without a ...Online programming platforms are popular in programming education.However,there has been no research investigating students’real opinions and expectations of the error feedback mechanisms,leaving educators without a solid data foundation when attempting to improve the error feedback mechanisms.This paper makes a survey of 834 students across various programming courses and investigates student perceptions of error feedback mechanisms on online programming platforms.It explores the effectiveness of existing feedback,student satisfaction,and preferences for potential improvements,focusing on automatic error localization and program repair mechanisms.Results reveal a significant portion of students are dissatisfied with current feedback due to its limited informativeness.Students also express a clear demand for stronger feedback mechanisms,such as error localization and repair hints.Nevertheless,they prefer feedback that subtly guides them toward solutions,rather than providing direct and explicit answers,valuing the opportunity to enhance their debugging skills.The findings suggest a need for balanced,educational-focused feedback mechanisms that aid learning while promoting independent problem-solving.展开更多
Every year, around the world, between 250,000 and 500,000 people suffer a spinal cord injury(SCI). SCI is a devastating medical condition that arises from trauma or disease-induced damage to the spinal cord, disruptin...Every year, around the world, between 250,000 and 500,000 people suffer a spinal cord injury(SCI). SCI is a devastating medical condition that arises from trauma or disease-induced damage to the spinal cord, disrupting the neural connections that allow communication between the brain and the rest of the body, which results in varying degrees of motor and sensory impairment. Disconnection in the spinal tracts is an irreversible condition owing to the poor capacity for spontaneous axonal regeneration in the affected neurons.展开更多
Vitrimers belong to a class of polymeric materials capable of bond exchange reactions,showing great promise for environmental protection and sustainable development.However,studies on the coupling mechanism between th...Vitrimers belong to a class of polymeric materials capable of bond exchange reactions,showing great promise for environmental protection and sustainable development.However,studies on the coupling mechanism between the bond exchange kinetics and segmental dynamics near the glass transition temperature(T_(g))remain scarce.Herein,we employed molecular dynamics simulations to investigate the dynamic heterogeneity of the segment motion and bond exchange in vitrimers.The simulation results revealed that the bond exchange energy barrier exerts a much stronger influence on the bond exchange kinetics than on the segmental dynamics.At lower temperatures,slower segmental relaxation further constraind the bond exchange rate.Additionally,increasing the bond exchange energy barrier markedly enhanced the dynamic heterogeneity of segment motion.A close correlation was observed between heterogeneity and bond exchange.This study elucidated the coupling mechanism between bond exchange and segmental dynamics at the molecular scale,thereby providing a theoretical basis for designing vitrimer materials with tunable dynamic properties.展开更多
The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of i...The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of its influence on fluid migration are of crucial importance.While previous studies have revealed that salinity changes can modulate fluid migration,the underlying mechanisms remain poorly understood.We employ molecular dynamics simulations to elucidate how salinity variations in ore-forming fluids modulate the adsorption onto calcite nanopore walls,thereby revealing the microscopic mechanisms governing ore fluid transport through calcite nano-fractures.The results show that the adsorption energy Eint of the solution on the calcite surface increased from -14,948.84±182.48 kcal/mol to -12,144.08±118.2 kcal/mol as salinity increased,which is conducive to the long-range transport of the fluid in the calcite nanopore.展开更多
Metabolic dysfunction-associated steatotic liver disease,characterized by pathological intracellular triglyceride(TG)accumulation,is mechanistically associated with the disrupted spatiotemporal regulation of hepatocyt...Metabolic dysfunction-associated steatotic liver disease,characterized by pathological intracellular triglyceride(TG)accumulation,is mechanistically associated with the disrupted spatiotemporal regulation of hepatocyte nuclear factor(HNF)-dependent transcriptional programs.HNFs,including key members such as HNF-1α,HNF-4α,and HNF-6,constitute a liver-enriched family of transcription factors that govern hepatic lipid metabolism through hierarchical transcriptional regulatory networks.These networks critically regulate the dynamic equilibrium of TG metabolism,encompassing TG synthesis,storage,lipolysis,and lipoprotein-mediated export.This review comprehensively deciphers the molecular cascades through which HNF dysfunction exacerbates TG metabolic disorder in metabolic dysfunction-associated steatotic liver disease.Additionally,we evaluate emerging translational strategies targeting key HNF regulatory nodes and discuss current clinical challenges as well as potential solutions.展开更多
The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behav...The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.展开更多
In multi-modal emotion recognition,excessive reliance on historical context often impedes the detection of emotional shifts,while modality heterogeneity and unimodal noise limit recognition performance.Existing method...In multi-modal emotion recognition,excessive reliance on historical context often impedes the detection of emotional shifts,while modality heterogeneity and unimodal noise limit recognition performance.Existing methods struggle to dynamically adjust cross-modal complementary strength to optimize fusion quality and lack effective mechanisms to model the dynamic evolution of emotions.To address these issues,we propose a multi-level dynamic gating and emotion transfer framework for multi-modal emotion recognition.A dynamic gating mechanism is applied across unimodal encoding,cross-modal alignment,and emotion transfer modeling,substantially improving noise robustness and feature alignment.First,we construct a unimodal encoder based on gated recurrent units and feature-selection gating to suppress intra-modal noise and enhance contextual representation.Second,we design a gated-attention crossmodal encoder that dynamically calibrates the complementary contributions of visual and audio modalities to the dominant textual features and eliminates redundant information.Finally,we introduce a gated enhanced emotion transfer module that explicitly models the temporal dependence of emotional evolution in dialogues via transfer gating and optimizes continuity modeling with a comparative learning loss.Experimental results demonstrate that the proposed method outperforms state-of-the-art models on the public MELD and IEMOCAP datasets.展开更多
With the rapid development of intelligent navigation technology,efficient and safe path planning for mobile robots has become a core requirement.To address the challenges of complex dynamic environments,this paper pro...With the rapid development of intelligent navigation technology,efficient and safe path planning for mobile robots has become a core requirement.To address the challenges of complex dynamic environments,this paper proposes an intelligent path planning framework based on grid map modeling.First,an improved Safe and Smooth A*(SSA*)algorithm is employed for global path planning.By incorporating obstacle expansion and cornerpoint optimization,the proposed SSA*enhances the safety and smoothness of the planned path.Then,a Partitioned Dynamic Window Approach(PDWA)is integrated for local planning,which is triggered when dynamic or sudden static obstacles appear,enabling real-time obstacle avoidance and path adjustment.A unified objective function is constructed,considering path length,safety,and smoothness comprehensively.Multiple simulation experiments are conducted on typical port grid maps.The results demonstrate that the improved SSA*significantly reduces the number of expanded nodes and computation time in static environmentswhile generating smoother and safer paths.Meanwhile,the PDWA exhibits strong real-time performance and robustness in dynamic scenarios,achieving shorter paths and lower planning times compared to other graph search algorithms.The proposedmethodmaintains stable performance across maps of different scales and various port scenarios,verifying its practicality and potential for wider application.展开更多
Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may com...Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may compromise their fatigue capacity.The most common structural design for railway noise barriers consists of vertical configurations of posts and panels.However,there have been few dynamic analyses of steel post/wood panel noise barriers under train-induced aerodynamic loads.This study used dynamic finite element analysis to assess the dynamic behavior of such noise barriers.Analysis of a 40-m-long noise barrier model and a triangular simplified load model,the latter of which effectively represented the detailed aerodynamic load,were first used to establish the model and input of the moving load during dynamic simulation.Then,the effects of different parameters on the dynamic response of the noise barrier were evaluated,including the damping ratio,the profile of the steel post,the span length of the panel,the barrier height,and the train speed.Gray relational analysis indicated that barrier height exhibited the highest correlations with the dynamic responses,followed by train speed,post profile,span length,and damping ratio.A reduction in the natural frequency and an increase in the train speed result in a higher peak response and more pronounced fluctuations between the nose and tail waves.The dynamic amplification factor(DAF)was found to be related to both the natural frequency and train speed.A model was proposed showing that the DAF significantly increases as the square of the natural frequency decreases and the cube of the train speed rises.展开更多
In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equ...In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equation,but also analyze the dynamical behaviors of nonlinear local wave propagation in shallow water.Firstly,based on the Hirota bilinear approach,one to four-order soliton solutions of the YTSF equation are obtained,and the effects of different parameters on the amplitude,propagation trajectory,and displacement of solitons are investigated.Secondly,using the long wave limit approach,one to three-order lump solutions and various physical quantities of the YTSF equation are derived.It is found that the real and imaginary parts of the parameter pi dominate the propagation trajectory and the shape of lump waves,respectively.Furthermore,we construct the hybrid solution for the YTSF equation,leading to the conclusion that the interaction between lumps and solitons constitutes an elastic collision.To intuitively understand the dynamic behaviors of these solutions,we conduct numerical simulations to present vivid three-dimensional visualizations.展开更多
Federated Learning(FL)provides an effective framework for efficient processing in vehicular edge computing.However,the dynamic and uncertain communication environment,along with the performance variations of vehicular...Federated Learning(FL)provides an effective framework for efficient processing in vehicular edge computing.However,the dynamic and uncertain communication environment,along with the performance variations of vehicular devices,affect the distribution and uploading processes of model parameters.In FL-assisted Internet of Vehicles(IoV)scenarios,challenges such as data heterogeneity,limited device resources,and unstable communication environments become increasingly prominent.These issues necessitate intelligent vehicle selection schemes to enhance training efficiency.Given this context,we propose a new scenario involving FL-assisted IoV systems under dynamic and uncertain communication conditions,and develop a dynamic interval multi-objective optimization algorithm to jointly optimize various factors including training experiments,system energy consumption,and bandwidth utilization to meet multi-criteria resource optimization requirements.For the problem at hand,we design a dynamic interval multi-objective optimization algorithm based on interval overlap detection.Simulation results demonstrate that our method outperforms other solutions in terms of accuracy,training cost,and server utilization.It effectively enhances training efficiency under wireless channel environments while rationally utilizing bandwidth resources,thus possessing significant scientific value and application potential in the field of IoV.展开更多
The study presents an analysis of the spatiotemporal evolution of vegetation cover in the Izarene forest,using LANDSAT satellite images collected for the years 1984,2003,and 2022.The methodological approach is based o...The study presents an analysis of the spatiotemporal evolution of vegetation cover in the Izarene forest,using LANDSAT satellite images collected for the years 1984,2003,and 2022.The methodological approach is based on the use of ArcGIS 10.8 software for processing multispectral images,as well as the calculation of the Normalized Difference Vegetation Index(NDVI),which enables the observation of variations in vegetation cover over time.The findings show that biodiversity is pretty abundant,but they also show that some places with low vegetation density are under a lot of stress.Due in large part to overuse of natural resources,uncontrolled human activity,and environmental factors,these regions seem to be more vulnerable to degradation.However,a decrease in deforestation over the past 20 years is revealed by comparing the two periods(1984–2003 and 2003–2022).The participation of governmental agencies,especially the Department of Water and Forests,through concrete projects like reforestation,forest fire prevention,and awareness-raising campaigns among local communities,is responsible for this progress.In several areas,these measures have stabilized or even improved the state of the vegetation.The analysis emphasizes how crucial sustainable,integrated,and participatory management is to protecting the Izarene forest,which is a significant resource for maintaining the region’s ecological balance.展开更多
Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLD...Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.展开更多
In response to the increasing demand for hadron therapy facilities,significant efforts have been directed toward enhancing the performance of high-gradient and high-transmission injectors for light ion beams.For carbo...In response to the increasing demand for hadron therapy facilities,significant efforts have been directed toward enhancing the performance of high-gradient and high-transmission injectors for light ion beams.For carbon ion irradiations,which offer greater radiobiological efficiency in tumor treatment,recent research has focused on developing high-production sources of fully stripped C^(6+)ions and highly compact,high-frequency RFQ cavities.This study explores the design possibilities of a carbon ion acceleration section using 750 MHz Interdigital H-mode Drift Tube Linacs(IH-DTLs)as a high-efficiency solution for accelerating ions in the 5-10 MeV per nucleon energy range.A particle-tracking routine based on the TRAVEL code was developed to design the acceleration line through a tailored KONUS-type configuration.Three design solutions were proposed and compared,exploring different alternatives regarding the use of a MEBT to match the output beam phase space of the RFQ to the optics of the line,as well as varying considerations for magnetic systems to focus the beam.Additionally,the compatibility of the proposed solutions with the existing design of the carbon ion bent-linac for hadron therapy was assessed.展开更多
Like-charge pairing is a physical manifestation of the unique solvation properties of certain ion pairs in water.Water's high dielectric constant and related charge screening capability significantly influence the...Like-charge pairing is a physical manifestation of the unique solvation properties of certain ion pairs in water.Water's high dielectric constant and related charge screening capability significantly influence the interaction between like-charged ions,with the possibility to transform it-in exceptional cases when noncovalent interactions are involved-from repulsion to attraction.Guanidinium cations(Gdm^(+))represent a quintessential example of such like-charge pairing due to their specific geometry and electronic structure.In this work,we present experimental validation and quantification of Gdm^(+)-Gdm contact ion pairing in water utilizing nuclear magnetic resonance(NMR)spectroscopy complemented by molecular dynamics(MD)simulations and density functional theory(DFT)calculations.The observed Gdm^(+)-Gdm^(+)interaction is attractive albeit weak-about 0.5 kJ·mol^(-1)-which aligns with theoretical estimation from MD simulations.We contrast the behavior of Gdm^(+) with that of NH_(4)^(+) cations,which exhibit no contact ion pairing in water.DFT calculations predict that the NMR chemical shift of Gdm^(+) dimers is different than that of monomers,in agreement with NMR titration curves that display a nonlinear Langmuir-like behavior.Additionally,we conducted cryo-electron microscopy-to our knowledge,for the first time-on concentrated oligoarginines R9,which,unlike nona-lysines K9,exhibit aggregation in water.These results point to like charge pairing of the guanidinium side chain groups,as corroborated also by MD simulations and free energy calculations.展开更多
In this paper,we study a class of Linear Fractional Programming on a nonempty bounded set,called the Problem(LFP),and design a branch and bound algorithm to find the global optimal solution of the problem(LFP).First,w...In this paper,we study a class of Linear Fractional Programming on a nonempty bounded set,called the Problem(LFP),and design a branch and bound algorithm to find the global optimal solution of the problem(LFP).First,we convert the problem(LFP)to the equivalent problem(EP2).Secondly,by applying the linear relaxation technique to the problem(EP2),the linear relaxation programming problem(LRP2Y)was obtained.Then,the overall framework of the algorithm is given,and the convergence and complexity of the algorithm are analyzed.Finally,experimental results are listed to illustrate the effectiveness of the algorithm.展开更多
The operational demands of a wide range significantly exacerbate combustion instability issues within ramjet combustor.To suppress combustion oscillations,an open-loop control system utilizing Linear Genetic Programmi...The operational demands of a wide range significantly exacerbate combustion instability issues within ramjet combustor.To suppress combustion oscillations,an open-loop control system utilizing Linear Genetic Programming(LGP)has been developed for a full-scale annular ramjet combustor.The LGP is used to generate control laws that include multi-frequency forcing.These laws are then transformed into square waves to actuate the solenoid valve,which modulates the kerosene supply for open-loop control.The results show that the duty cycle has little effect on instability amplitude,whereas an increase in frequency leads to a remarked reduction in combustion amplitude.After five generations evolvements,the pressure amplitude is reduced by 40.6% under the optimal control law generated by LGP.Furthermore,the machine learning process is depicted using a proximity map of control law similarity,with the search pathway visualized by the steepest descent.All individuals go forward to the upper left corner of the map with the evolution process,terminating at the optimal individual of the fifth generation.展开更多
基金supported in part by the National Key Research and Development Program of China(2024YFB4709100,2021YFE0206100)the National Natural Science Foundation of China(62073321)+1 种基金the National Defense Basic Scientific Research Program(JCKY2019203C029)the Science and Technology Development Fund,Macao SAR,China(0015/2020/AMJ)
文摘Learning-based methods have become mainstream for solving residential energy scheduling problems. In order to improve the learning efficiency of existing methods and increase the utilization of renewable energy, we propose the Dyna actiondependent heuristic dynamic programming(Dyna-ADHDP)method, which incorporates the ideas of learning and planning from the Dyna framework in action-dependent heuristic dynamic programming. This method defines a continuous action space for precise control of an energy storage system and allows online optimization of algorithm performance during the real-time operation of the residential energy model. Meanwhile, the target network is introduced during the training process to make the training smoother and more efficient. We conducted experimental comparisons with the benchmark method using simulated and real data to verify its applicability and performance. The results confirm the method's excellent performance and generalization capabilities, as well as its excellence in increasing renewable energy utilization and extending equipment life.
基金supported by the National Natural Science Foundation of China(62073327,62403467,62373090,62273350,62521001)the Natural Science Foundation of Jiangsu Province(BK20241635)+2 种基金the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(GZB20240827)Jiangsu Funding Program for Excellent Postdoctoral Talent(2024ZB604)the China Postdoctoral Science Foundation(2024M763545,2025T054ZGMK).
文摘In this article,a novel model-free coordinated optimal regulation design methodology is proposed for the rigidly connected dual permanent magnet synchronous motor(PMSM)system via adaptive dynamic programming(ADP).First,we adopt the classical master-slave structure to maintain torque synchronization by virtue of field-oriented control.Then,a reducedorder model of the dual-PMSM system is established through the application of singular perturbation theory(SPT),which is of significance to decrease the learning time and computational complexity in the outer speed loop design.Afterwards,we design a coordinated adaptive optimal regulator in framework of ADP to drive the speed of girth gear asymptotic tracking the reference signal and accommodate the load torque disturbance,which is independent of the knowledge of model parameters of the system.According to SPT,we analyze the suboptimality,closed-loop stability,and robustness properties of the obtained controller under mild conditions.Finally,comprehensive experimental studies are provided to verify that the proposed control strategy can achieve the speed regulation and the torque synchronization,as well as ameliorate the transient response.
基金supported by the Aeronautical Science Foundation of China(20220001057001)an Open Project of the National Key Laboratory of Air-based Information Perception and Fusion(202437)
文摘In this paper,a distributed adaptive dynamic programming(ADP)framework based on value iteration is proposed for multi-player differential games.In the game setting,players have no access to the information of others'system parameters or control laws.Each player adopts an on-policy value iteration algorithm as the basic learning framework.To deal with the incomplete information structure,players collect a period of system trajectory data to compensate for the lack of information.The policy updating step is implemented by a nonlinear optimization problem aiming to search for the proximal admissible policy.Theoretical analysis shows that by adopting proximal policy searching rules,the approximated policies can converge to a neighborhood of equilibrium policies.The efficacy of our method is illustrated by three examples,which also demonstrate that the proposed method can accelerate the learning process compared with the centralized learning framework.
基金supported by the National Natural Science Foundation of China under Grant No.92582204,No.62577007,and No.62177003the Fundamental Research Funds for the Central Universities under Grant No.JKF-2025011975129.
文摘Online programming platforms are popular in programming education.However,there has been no research investigating students’real opinions and expectations of the error feedback mechanisms,leaving educators without a solid data foundation when attempting to improve the error feedback mechanisms.This paper makes a survey of 834 students across various programming courses and investigates student perceptions of error feedback mechanisms on online programming platforms.It explores the effectiveness of existing feedback,student satisfaction,and preferences for potential improvements,focusing on automatic error localization and program repair mechanisms.Results reveal a significant portion of students are dissatisfied with current feedback due to its limited informativeness.Students also express a clear demand for stronger feedback mechanisms,such as error localization and repair hints.Nevertheless,they prefer feedback that subtly guides them toward solutions,rather than providing direct and explicit answers,valuing the opportunity to enhance their debugging skills.The findings suggest a need for balanced,educational-focused feedback mechanisms that aid learning while promoting independent problem-solving.
基金financially supported by Ministerio de Ciencia e Innovación projects SAF2017-82736-C2-1-R to MTMFin Universidad Autónoma de Madrid and by Fundación Universidad Francisco de Vitoria to JS+2 种基金a predoctoral scholarship from Fundación Universidad Francisco de Vitoriafinancial support from a 6-month contract from Universidad Autónoma de Madrida 3-month contract from the School of Medicine of Universidad Francisco de Vitoria。
文摘Every year, around the world, between 250,000 and 500,000 people suffer a spinal cord injury(SCI). SCI is a devastating medical condition that arises from trauma or disease-induced damage to the spinal cord, disrupting the neural connections that allow communication between the brain and the rest of the body, which results in varying degrees of motor and sensory impairment. Disconnection in the spinal tracts is an irreversible condition owing to the poor capacity for spontaneous axonal regeneration in the affected neurons.
基金financially supported by the National Natural Science Foundation of China(Nos.52173020 and 52573023)。
文摘Vitrimers belong to a class of polymeric materials capable of bond exchange reactions,showing great promise for environmental protection and sustainable development.However,studies on the coupling mechanism between the bond exchange kinetics and segmental dynamics near the glass transition temperature(T_(g))remain scarce.Herein,we employed molecular dynamics simulations to investigate the dynamic heterogeneity of the segment motion and bond exchange in vitrimers.The simulation results revealed that the bond exchange energy barrier exerts a much stronger influence on the bond exchange kinetics than on the segmental dynamics.At lower temperatures,slower segmental relaxation further constraind the bond exchange rate.Additionally,increasing the bond exchange energy barrier markedly enhanced the dynamic heterogeneity of segment motion.A close correlation was observed between heterogeneity and bond exchange.This study elucidated the coupling mechanism between bond exchange and segmental dynamics at the molecular scale,thereby providing a theoretical basis for designing vitrimer materials with tunable dynamic properties.
基金financed jointly by the National Major Science and Technology Special Project on Deep Earth Exploration(2024ZD1001701-5)the National Natural Science Foundation of China(42472127,42172086)+2 种基金the Yunnan Major Project of Basic Research(202401BN070001-002)Yunnan Mineral Resources Prediction and Evaluation Engineering Research Center(2011)Innovation Team Program of Kunming University of Science and Technology,Yunnan Province。
文摘The migration mechanisms of ore-forming fluids have long been a focus in the field of ore deposit studies.Calcite is ubiquitously present in various types of rocks in the lithosphere,and the underlying mechanisms of its influence on fluid migration are of crucial importance.While previous studies have revealed that salinity changes can modulate fluid migration,the underlying mechanisms remain poorly understood.We employ molecular dynamics simulations to elucidate how salinity variations in ore-forming fluids modulate the adsorption onto calcite nanopore walls,thereby revealing the microscopic mechanisms governing ore fluid transport through calcite nano-fractures.The results show that the adsorption energy Eint of the solution on the calcite surface increased from -14,948.84±182.48 kcal/mol to -12,144.08±118.2 kcal/mol as salinity increased,which is conducive to the long-range transport of the fluid in the calcite nanopore.
基金Supported by the Science and Technology Planning Projects of Guizhou Province,No.QKHJC-MS[2025]384the Science and Technology Planning Projects of Zunyi City,No.ZSKHHZ(2023)470+3 种基金the WBE Liver Fibrosis Foundation,No.CFHPC2025028Chinese Foundation for Hepatitis Prevention and Control Muxin Research Fund of Chronic Hepatitis B,No.MX202404Beijing Liver and Gallbladder Mutual Aid Public Welfare Foundation Artificial Liver Special Fund,No.iGandanF-1082024-RGG018the Student Innovation and Entrepreneurship Training Program of Zunyi Medical University,No.2024106610923.
文摘Metabolic dysfunction-associated steatotic liver disease,characterized by pathological intracellular triglyceride(TG)accumulation,is mechanistically associated with the disrupted spatiotemporal regulation of hepatocyte nuclear factor(HNF)-dependent transcriptional programs.HNFs,including key members such as HNF-1α,HNF-4α,and HNF-6,constitute a liver-enriched family of transcription factors that govern hepatic lipid metabolism through hierarchical transcriptional regulatory networks.These networks critically regulate the dynamic equilibrium of TG metabolism,encompassing TG synthesis,storage,lipolysis,and lipoprotein-mediated export.This review comprehensively deciphers the molecular cascades through which HNF dysfunction exacerbates TG metabolic disorder in metabolic dysfunction-associated steatotic liver disease.Additionally,we evaluate emerging translational strategies targeting key HNF regulatory nodes and discuss current clinical challenges as well as potential solutions.
基金financially supported by the National Natural Science Foundation of China(Nos.22341304,22303100 and 12205270)the National Key R&D Program of China(Nos.2023YFA1008800 and 2020YFA0713601)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC0180303)。
文摘The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.
基金funded by“the Fanying Special Program of the National Natural Science Foundation of China,grant number 62341307”“the Scientific research project of Jiangxi Provincial Department of Education,grant number GJJ200839”“theDoctoral startup fund of JiangxiUniversity of Technology,grant number 205200100402”.
文摘In multi-modal emotion recognition,excessive reliance on historical context often impedes the detection of emotional shifts,while modality heterogeneity and unimodal noise limit recognition performance.Existing methods struggle to dynamically adjust cross-modal complementary strength to optimize fusion quality and lack effective mechanisms to model the dynamic evolution of emotions.To address these issues,we propose a multi-level dynamic gating and emotion transfer framework for multi-modal emotion recognition.A dynamic gating mechanism is applied across unimodal encoding,cross-modal alignment,and emotion transfer modeling,substantially improving noise robustness and feature alignment.First,we construct a unimodal encoder based on gated recurrent units and feature-selection gating to suppress intra-modal noise and enhance contextual representation.Second,we design a gated-attention crossmodal encoder that dynamically calibrates the complementary contributions of visual and audio modalities to the dominant textual features and eliminates redundant information.Finally,we introduce a gated enhanced emotion transfer module that explicitly models the temporal dependence of emotional evolution in dialogues via transfer gating and optimizes continuity modeling with a comparative learning loss.Experimental results demonstrate that the proposed method outperforms state-of-the-art models on the public MELD and IEMOCAP datasets.
文摘With the rapid development of intelligent navigation technology,efficient and safe path planning for mobile robots has become a core requirement.To address the challenges of complex dynamic environments,this paper proposes an intelligent path planning framework based on grid map modeling.First,an improved Safe and Smooth A*(SSA*)algorithm is employed for global path planning.By incorporating obstacle expansion and cornerpoint optimization,the proposed SSA*enhances the safety and smoothness of the planned path.Then,a Partitioned Dynamic Window Approach(PDWA)is integrated for local planning,which is triggered when dynamic or sudden static obstacles appear,enabling real-time obstacle avoidance and path adjustment.A unified objective function is constructed,considering path length,safety,and smoothness comprehensively.Multiple simulation experiments are conducted on typical port grid maps.The results demonstrate that the improved SSA*significantly reduces the number of expanded nodes and computation time in static environmentswhile generating smoother and safer paths.Meanwhile,the PDWA exhibits strong real-time performance and robustness in dynamic scenarios,achieving shorter paths and lower planning times compared to other graph search algorithms.The proposedmethodmaintains stable performance across maps of different scales and various port scenarios,verifying its practicality and potential for wider application.
基金financially supported by the Swedish Transport Administration(Trafikverket)through the“Excellence Area 4”and FOI-BBT program(Grant Nos.BBT-2019-022 and BBT-TRV 2024/132497).
文摘Railway noise barriers are an essential piece of infrastructure for reducing noise propagation.However,these barriers experience aerodynamic loads generated by high-speed trains,leading to dynamic effects that may compromise their fatigue capacity.The most common structural design for railway noise barriers consists of vertical configurations of posts and panels.However,there have been few dynamic analyses of steel post/wood panel noise barriers under train-induced aerodynamic loads.This study used dynamic finite element analysis to assess the dynamic behavior of such noise barriers.Analysis of a 40-m-long noise barrier model and a triangular simplified load model,the latter of which effectively represented the detailed aerodynamic load,were first used to establish the model and input of the moving load during dynamic simulation.Then,the effects of different parameters on the dynamic response of the noise barrier were evaluated,including the damping ratio,the profile of the steel post,the span length of the panel,the barrier height,and the train speed.Gray relational analysis indicated that barrier height exhibited the highest correlations with the dynamic responses,followed by train speed,post profile,span length,and damping ratio.A reduction in the natural frequency and an increase in the train speed result in a higher peak response and more pronounced fluctuations between the nose and tail waves.The dynamic amplification factor(DAF)was found to be related to both the natural frequency and train speed.A model was proposed showing that the DAF significantly increases as the square of the natural frequency decreases and the cube of the train speed rises.
基金Supported by the National Natural Science Foundation of China(12001424,12271324)the Natural Science Basic research program of Shaanxi Province(2021JZ-21)+1 种基金the China Postdoctoral Science Foundation(2020M673332)Xi’an University,Xi’an Science and Technology Plan Wutongshu Technology Transfer Action Innovation Team(25WTZD07)。
文摘In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equation,but also analyze the dynamical behaviors of nonlinear local wave propagation in shallow water.Firstly,based on the Hirota bilinear approach,one to four-order soliton solutions of the YTSF equation are obtained,and the effects of different parameters on the amplitude,propagation trajectory,and displacement of solitons are investigated.Secondly,using the long wave limit approach,one to three-order lump solutions and various physical quantities of the YTSF equation are derived.It is found that the real and imaginary parts of the parameter pi dominate the propagation trajectory and the shape of lump waves,respectively.Furthermore,we construct the hybrid solution for the YTSF equation,leading to the conclusion that the interaction between lumps and solitons constitutes an elastic collision.To intuitively understand the dynamic behaviors of these solutions,we conduct numerical simulations to present vivid three-dimensional visualizations.
基金supported in part by the Central Guidance for Local Science and Technology Development Funds under Grant No.YDZJSX2025D049Shanxi Provincial Graduate Innovation Research Program under Grant No.2024KY652.
文摘Federated Learning(FL)provides an effective framework for efficient processing in vehicular edge computing.However,the dynamic and uncertain communication environment,along with the performance variations of vehicular devices,affect the distribution and uploading processes of model parameters.In FL-assisted Internet of Vehicles(IoV)scenarios,challenges such as data heterogeneity,limited device resources,and unstable communication environments become increasingly prominent.These issues necessitate intelligent vehicle selection schemes to enhance training efficiency.Given this context,we propose a new scenario involving FL-assisted IoV systems under dynamic and uncertain communication conditions,and develop a dynamic interval multi-objective optimization algorithm to jointly optimize various factors including training experiments,system energy consumption,and bandwidth utilization to meet multi-criteria resource optimization requirements.For the problem at hand,we design a dynamic interval multi-objective optimization algorithm based on interval overlap detection.Simulation results demonstrate that our method outperforms other solutions in terms of accuracy,training cost,and server utilization.It effectively enhances training efficiency under wireless channel environments while rationally utilizing bandwidth resources,thus possessing significant scientific value and application potential in the field of IoV.
文摘The study presents an analysis of the spatiotemporal evolution of vegetation cover in the Izarene forest,using LANDSAT satellite images collected for the years 1984,2003,and 2022.The methodological approach is based on the use of ArcGIS 10.8 software for processing multispectral images,as well as the calculation of the Normalized Difference Vegetation Index(NDVI),which enables the observation of variations in vegetation cover over time.The findings show that biodiversity is pretty abundant,but they also show that some places with low vegetation density are under a lot of stress.Due in large part to overuse of natural resources,uncontrolled human activity,and environmental factors,these regions seem to be more vulnerable to degradation.However,a decrease in deforestation over the past 20 years is revealed by comparing the two periods(1984–2003 and 2003–2022).The participation of governmental agencies,especially the Department of Water and Forests,through concrete projects like reforestation,forest fire prevention,and awareness-raising campaigns among local communities,is responsible for this progress.In several areas,these measures have stabilized or even improved the state of the vegetation.The analysis emphasizes how crucial sustainable,integrated,and participatory management is to protecting the Izarene forest,which is a significant resource for maintaining the region’s ecological balance.
基金financially supported by the Science and Technology Project of PetroChina Company Limited,China(No.2022DJ6314)the National Natural Science Foundation of China(No.52173056)。
文摘Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.
基金Project co-funded by European Union in the context of the precommercial public procurement of RD services managed by CDTI E.P.Eco-funded by the European Regional Development Fund(ERDF)as part of the project for the development of a Compact Linear Accelerator for Hadrontherapy,Exp.CPP 03/2023 AB(DCCPI/OCPI)。
文摘In response to the increasing demand for hadron therapy facilities,significant efforts have been directed toward enhancing the performance of high-gradient and high-transmission injectors for light ion beams.For carbon ion irradiations,which offer greater radiobiological efficiency in tumor treatment,recent research has focused on developing high-production sources of fully stripped C^(6+)ions and highly compact,high-frequency RFQ cavities.This study explores the design possibilities of a carbon ion acceleration section using 750 MHz Interdigital H-mode Drift Tube Linacs(IH-DTLs)as a high-efficiency solution for accelerating ions in the 5-10 MeV per nucleon energy range.A particle-tracking routine based on the TRAVEL code was developed to design the acceleration line through a tailored KONUS-type configuration.Three design solutions were proposed and compared,exploring different alternatives regarding the use of a MEBT to match the output beam phase space of the RFQ to the optics of the line,as well as varying considerations for magnetic systems to focus the beam.Additionally,the compatibility of the proposed solutions with the existing design of the carbon ion bent-linac for hadron therapy was assessed.
基金support from the project“National Institute of Virology and Bacteriology(Program EXCELES,ID Project No.LX22NPO5103)Funded by the European Union-Next Generation EU".D.B.also acknowledges VSB-Technical University of Ostrava,IT4Innovations National Supercomputing Center,Czech Republic,for awarding this project access to the LUMI supercomputer,owned by the EuroHPC Joint Undertaking,hosted by CSC(Finland)and the LUMI consortium through the Ministry of Education,Youth and Sports of the Czech Republic through the e-INFRA CZ(Grant ID:90254)+4 种基金project OPEN-35-3.M.V.and J.H.acknowledge the Czech Science Foundation for support via grant number 25-16117S and the project"The Energy Conversion and Storage"funded as project No.CZ.02.01.01/00/22_008/0004617 by Programme Johannes Amos Comeniuscall Excellent Research.M.V.also acknowledges support by the Ministry of Education,Youth and Sports of the Czech Republic through the e-INFRA CZ(ID:90254)Project OPEN-30-53.P.J.acknowledges support from the European Research Council via an ERC Advanced Grant no.101095957The authors would like to acknowledge the contribution of COST Action CA21169,supported by COST(European Cooperation in Science and Technology).
文摘Like-charge pairing is a physical manifestation of the unique solvation properties of certain ion pairs in water.Water's high dielectric constant and related charge screening capability significantly influence the interaction between like-charged ions,with the possibility to transform it-in exceptional cases when noncovalent interactions are involved-from repulsion to attraction.Guanidinium cations(Gdm^(+))represent a quintessential example of such like-charge pairing due to their specific geometry and electronic structure.In this work,we present experimental validation and quantification of Gdm^(+)-Gdm contact ion pairing in water utilizing nuclear magnetic resonance(NMR)spectroscopy complemented by molecular dynamics(MD)simulations and density functional theory(DFT)calculations.The observed Gdm^(+)-Gdm^(+)interaction is attractive albeit weak-about 0.5 kJ·mol^(-1)-which aligns with theoretical estimation from MD simulations.We contrast the behavior of Gdm^(+) with that of NH_(4)^(+) cations,which exhibit no contact ion pairing in water.DFT calculations predict that the NMR chemical shift of Gdm^(+) dimers is different than that of monomers,in agreement with NMR titration curves that display a nonlinear Langmuir-like behavior.Additionally,we conducted cryo-electron microscopy-to our knowledge,for the first time-on concentrated oligoarginines R9,which,unlike nona-lysines K9,exhibit aggregation in water.These results point to like charge pairing of the guanidinium side chain groups,as corroborated also by MD simulations and free energy calculations.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12571317 and 12071133).
文摘In this paper,we study a class of Linear Fractional Programming on a nonempty bounded set,called the Problem(LFP),and design a branch and bound algorithm to find the global optimal solution of the problem(LFP).First,we convert the problem(LFP)to the equivalent problem(EP2).Secondly,by applying the linear relaxation technique to the problem(EP2),the linear relaxation programming problem(LRP2Y)was obtained.Then,the overall framework of the algorithm is given,and the convergence and complexity of the algorithm are analyzed.Finally,experimental results are listed to illustrate the effectiveness of the algorithm.
基金support from the National Natural Science Foundation of China(No.12002372)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2022QNRC001)the Natural Science Foundation of Hunan Province,China(No.2021JJ40674)。
文摘The operational demands of a wide range significantly exacerbate combustion instability issues within ramjet combustor.To suppress combustion oscillations,an open-loop control system utilizing Linear Genetic Programming(LGP)has been developed for a full-scale annular ramjet combustor.The LGP is used to generate control laws that include multi-frequency forcing.These laws are then transformed into square waves to actuate the solenoid valve,which modulates the kerosene supply for open-loop control.The results show that the duty cycle has little effect on instability amplitude,whereas an increase in frequency leads to a remarked reduction in combustion amplitude.After five generations evolvements,the pressure amplitude is reduced by 40.6% under the optimal control law generated by LGP.Furthermore,the machine learning process is depicted using a proximity map of control law similarity,with the search pathway visualized by the steepest descent.All individuals go forward to the upper left corner of the map with the evolution process,terminating at the optimal individual of the fifth generation.
