This paper presents a practical pricing model for backup reserve and wheeling, which attains a balanced strategy that ensures perceived benefits to both the buyer and the seller. The model and the associated computeri...This paper presents a practical pricing model for backup reserve and wheeling, which attains a balanced strategy that ensures perceived benefits to both the buyer and the seller. The model and the associated computerized algorithm deal collectively with diverse issues, including： （1） fulfilling local firm real （and reactive） power demand requirements, （2） fulfilling local power reserve requirements, （3） buying firm real （and reactive） power from the grid, （4） buying reserve power from the grid, （5） exporting firm real （and reactive） power demand to remote load centers via the grid, （6） exporting reserve power via the grid, （7） wheeling of firm power demand to remote owned sites using the grid, and （8） wheeling reserve power to remote owned sites using grid. Practical implementation features of the computerized algorithms are also discussed with an illustrative case example.展开更多
This review addresses four key themes in automotive aerodynamics:flow instability in the wheel region,the aerodynamic characteristics of rims,the aerodynamic behavior of tires,and drag reduction strategies based on fl...This review addresses four key themes in automotive aerodynamics:flow instability in the wheel region,the aerodynamic characteristics of rims,the aerodynamic behavior of tires,and drag reduction strategies based on flow control around the wheels.The wheel region,comprising the tire,rim,and adjacent aerodynamic components,typically represents the major source of vehicle drag owing to the inherently complex flow generated by wheel rotation,tread geometry,and rim design,which gives rise to flow separation,vortex shedding,and turbulence.Drawing on a broad body of experimental and numerical research,this review elucidates the mechanisms governing such dynamics,and considers drag mitigation techniques,including biomimetic surface treatments and multi-element flow control concepts.Particular emphasis is placed on enclosed-spoke rims,rim-edge enclosures,and non-smooth tire microstructures,which have consistently demonstrated notable drag reduction potential.The review further identifies critical shortcomings in current research,most notably the lack of quantitative analyses of aerodynamic energy losses and the absence of integrated optimization strategies that jointly address tire,rim,and fender design.展开更多
In the booming field of handicraft art,pottery art,as a traditional craft that integrates the values of cultural inheritance and artistic innovation,has witnessed a continuous expansion of its teaching market,driven b...In the booming field of handicraft art,pottery art,as a traditional craft that integrates the values of cultural inheritance and artistic innovation,has witnessed a continuous expansion of its teaching market,driven by the increasing emphasis on traditional culture and the rapid development of the cultural and creative industry.However,the traditional pottery throwing equipment currently used in pottery art teaching has become a development bottleneck.Its pedal-based rotation speed control method poses great challenges to beginners.Due to inexperience,beginners often find it extremely difficult to precisely adjust the rotation speed.Moreover,the lack of rotation speed control guidance tailored to different shaped blanks forces students to learn through repeated trial and error,which seriously hinders their systematic mastery of pottery throwing techniques.Meanwhile,in remote pottery art teaching,the high-latency problem of traditional communication technologies disrupts synchronous learning,reduces teaching effectiveness,and may even cause students to develop bad operating habits.A new type of linked pottery teaching and drawing machine and its communication system is developed.Taking advantage of the high-speed and low-latency characteristics of 5G networks,this system enables real-time synchronous rotation of the pottery throwing wheels used by students and those used by teachers in teaching,ensuring near-instant operation feedback in remote teaching scenarios and thus significantly improving teaching efficiency.This innovative achievement propels pottery art teaching towards the direction of intelligence and high efficiency,injecting new vitality into the inheritance and innovation of traditional pottery art techniques.展开更多
Objective To develop a dual-branch deep learning framework for accurate multi-label classification of fundus diseases,addressing the key limitations of insufficient complementary feature extraction and inadequate cros...Objective To develop a dual-branch deep learning framework for accurate multi-label classification of fundus diseases,addressing the key limitations of insufficient complementary feature extraction and inadequate cross-modal feature fusion in existing automated diagnostic methods.Methods The fundus multi-label classification dataset with 12 disease categories(FMLC-12)dataset was constructed by integrating complementary samples from Ocular Disease Intelligent Recognition(ODIR)and Retinal Fundus Multi-Disease Image Dataset(RFMiD),yielding 6936 fundus images across 12 retinal pathology categories,and the framework was validated on both FMLC-12 and ODIR.Inspired by the holistic multi-regional assessment principle of the Five Wheels theory in traditional Chinese medicine(TCM)ophthalmology,the dualbranch multi-label network(DBMNet)was developed as a novel framework integrating complementary visual feature extraction with pathological correlation modeling.The architecture employed a TransNeXt backbone within a dual-branch design:one branch processed redgreen-blue(RGB)images to capture color-dependent features,such as vascular patterns and lesion morphology,while the other processed grayscale-converted images to enhance subtle textural details and contrast variations.A feature interaction module(FIM)effectively integrated the multi-scale features from both branches.Comprehensive ablation studies were conducted to evaluate the contributions of the dual-branch architecture and the FIM.The performance of DBMNet was compared against four state-of-the-art methods,including EfficientNet Ensemble,transfer learning-based convolutional neural network(CNN),BFENet,and EyeDeep-Net,using mean average precision(mAP),F1-score,and Cohen's kappa coefficient.Results The dual-branch architecture improved mAP by 15.44 percentage points over the single-branch TransNeXt baseline,increasing from 34.41%to 44.24%,and the addition of FIM further boosted mAP to 49.85%.On FMLC-12,DBMNet achieved an mAP of 49.85%,a Cohen’s kappa coefficient of 62.14%,and an F1-score of 70.21%.Compared with BFENet(mAP:45.42%,kappa:46.64%,F1-score:71.34%),DBMNet outperformed it by 4.43 percentage points in mAP and 15.50 percentage points in kappa,while BFENet achieved a marginally higher F1-score.On ODIR,DBMNet achieved an F1-score of 85.50%,comparable to state-of-the-art methods.Conclusion DBMNet effectively integrates RGB and grayscale visual modalities through a dual-branch architecture,significantly improving multi-label fundus disease classification.The framework not only addresses the issue of insufficient feature fusion in existing methods but also demonstrates outstanding performance in balancing detection across both common and rare diseases,providing a promising and clinically applicable pathway for standardized,intelligent fundus disease classification.展开更多
With the continuous development of the offshore wind industry,the design concept of composite foundation has been given attention in the past decade.This paper presents an accurate method for investigating the horizon...With the continuous development of the offshore wind industry,the design concept of composite foundation has been given attention in the past decade.This paper presents an accurate method for investigating the horizontal vibration of monopile-friction wheel composite foundations in layered saturated soil.Firstly,the three-dimensional continuum mechanics theory with the range of linear elasticity is introduced to calculate the frictional resistance distributed on the upper soil surface.Then,the resistances of multilayered soils and inviscid seawater to the pile shaft under horizontal harmonic excitation are obtained using Novak's plane strain model,Biot's porous media theory and radiationwave theory.Thirdly,the expressions for the deformation,bending moment and internal force of the Euler-Bernoulli pile are derived using the boundary conditions with definitephysical meaning and transfer matrix method.By comparing with the results of 1g laboratory test and the idealized formula reported by the literature,the rationality and accuracy of the developed dynamical model can be verified.Finally,this paper conducts a series of worked examples to investigate the influencesof the elastic modulus and thickness of three-layer saturated soil and the location of interlayer soil on the horizontal dynamic vibration of composite foundation.The results show that an increase in elastic modulus of the surface soil is an effective way to improve the dynamic stability of the composite foundation in service conditions.The conclusions drawn from the numerical examples can develop some guidelines for the current foundation design of offshore wind turbines.展开更多
Anyone who’s been in China for more than five minutes knows that bar-gaining is a very prominent part of the Chinese culture. But nowhere is this more striking than in a tourist-oriented lo-
Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery ...Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury.展开更多
The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can caus...The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can cause changes in cutting force/heat,resulting in affecting gear machining precision.Therefore,this paper studies the effect of different process parameters on gear machining precision.A multi-objective optimization model is established for the relationship between process parameters and tooth surface deviations,tooth profile deviations,and tooth lead deviations through the cutting speed,feed rate,and cutting depth of the worm wheel gear grinding machine.The response surface method(RSM)is used for experimental design,and the corresponding experimental results and optimal process parameters are obtained.Subsequently,gray relational analysis-principal component analysis(GRA-PCA),particle swarm optimization(PSO),and genetic algorithm-particle swarm optimization(GA-PSO)methods are used to analyze the experimental results and obtain different optimal process parameters.The results show that optimal process parameters obtained by the GRA-PCA,PSO,and GA-PSO methods improve the gear machining precision.Moreover,the gear machining precision obtained by GA-PSO is superior to other methods.展开更多
The integration of exercise prescriptions into cancer adjuvant therapy presents challenges stemming from the ambiguity surrounding the precise mechanism through which exercise intervention mitigates the risk of hepato...The integration of exercise prescriptions into cancer adjuvant therapy presents challenges stemming from the ambiguity surrounding the precise mechanism through which exercise intervention mitigates the risk of hepatocellular carcinoma(HCC)mortality and recurrence.Elucidation of this specific mechanism has substantial social and clinical implications.In this study,tumor-bearing mice engaged in voluntary wheel running exhibited a notable decrease in tumor growth,exceeding 30%.Microarray analysis revealed an upregulation of cytokinerelated pathways as a potential explanation for this effect.The inclusion of granulocyte-macrophage colonystimulating factor(GM-CSF)was found to enhance tumor cell proliferation,while the absence of GM-CSF resulted in a marked inhibition of tumor cell growth.The findings suggest that exercise-induced serum from mice can impede the proliferation of mouse tumor cells,with the adipokine chemerin inhibiting the growth factor GM-CSF.Additionally,exercise was found to stimulate chemerin secretion by brown adipose tissue.Chemerin suppression led to a reduction in the inhibition of tumor cell proliferation.The results of this study suggest that exercise may stimulate the release of adipokines from brown adipose tissue,transport them through the blood to the distant tumor microenvironment,and downregulate GM-CSF expression,alleviating tumor immunosuppression in the tumor microenvironment,thereby inhibiting at HCC progression.These findings provide a theoretical basis for incorporating exercise prescription into cancer treatment.展开更多
This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorp...This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorporating flexible appendages and an orthogonal cluster of magnetically suspended reaction wheel actuators is initially developed.After that,an adaptive attitude controller is designed with a switching surface of variable structure,an adaptive law for estimating inertia matrix uncertainty,and a fuzzy disturbance observer for estimating disturbance torques.Additionally,a Moore-Penrose-based steering law is proposed to derive the tilt angle commands of the orthogonal configuration of the 3D MSW to follow the designed control signal.Finally,numerical simulations are presented to validate the effectiveness of the proposed control strategy.展开更多
Rail weld irregularities are one of the primary excitation sources for vehicle-track interaction dynamics in modern high-speed railways.They can cause significant wheel-rail dynamic interactions,leading to wheel-rail ...Rail weld irregularities are one of the primary excitation sources for vehicle-track interaction dynamics in modern high-speed railways.They can cause significant wheel-rail dynamic interactions,leading to wheel-rail noise,component damage,and deterioration.Few researchers have employed the vehicle-track interaction dynamic model to study the dynamic interactions between wheel and rail induced by rail weld geometry irregularities.However,the cosine wave model used to simulate rail weld irregularities mainly focuses on the maximum value and neglects the geometric shape.In this study,novel theoretical models were developed for three categories of rail weld irregularities,based on measurements of the high-speed railway from Beijing to Shanghai.The vertical dynamic forces in the time and frequency domains were compared under different running speeds.These forces generated by the rail weld irregularities that were measured and modeled,respectively,were compared to validate the accuracy of the proposed model.Finally,based on the numerical study,the impact force due to rail weld irrregularity is modeled using an Artificial Neural Network(ANN),and the optimum combination of parameters for this model is found.The results showed that the proposed model provided a more accurate wheel/rail dynamic evaluation caused by rail weld irregularities than that established in the literature.The ANN model used in this paper can effectively predict the impact force due to rail weld irrregularity while reducing the computation time.展开更多
For k given graphs H_(1),...,H_(k) with k≥2,the k-color Ramsey number R(H_(1),...,H_(k)) represents the minimum integer N with the following property:if the edges of the complete graph K_(N) are colored with k colors...For k given graphs H_(1),...,H_(k) with k≥2,the k-color Ramsey number R(H_(1),...,H_(k)) represents the minimum integer N with the following property:if the edges of the complete graph K_(N) are colored with k colors,then there exists some i with 1≤i≤k such that K_(N) has a subgraph in color i isomorphic to H_(i).Let C_(m) be a cycle of length m and K_(1,n) a star of order n+1.In this paper,we systematically introduce the latest research progress on star-quadrilateral Ramsey numbers and provide an overview of Ramsey numbers concerning quadrilaterals,including multicolor cases.展开更多
Nowadays,using mobile robots in different applications has been very important.However,the environment in which they operate can cause the wheels to slip or the robot body to slide,causing the assigned task not to be ...Nowadays,using mobile robots in different applications has been very important.However,the environment in which they operate can cause the wheels to slip or the robot body to slide,causing the assigned task not to be performed successfully.Therefore,the need arises to mathematically determine these external perturbations to predict the behavior of the mobile robot.Based on the above mentioned facts,this work focuses on obtaining the kinematic model of an omnidirectional mobile robot considering lateral and longitudinal sliding disturbances of the body and wheel slippage.To mitigate the effect of the disturbances,a control strategy is considered based on the design of a generalized proportional integral observer(GPIO)that allows the estimation of such perturbations.Then,an active disturbance rejection control(ADRC)methodology is implemented to solve the trajectory tracking problem,and it is theoretically proved that the tracking errors converge to a vicinity near the origin.Numerical simulations and real-time experiments validate the obtained perturbed model and the control strategy performance,achieving the desired trajectory tracking despite these perturbations.展开更多
Non-pneumatic wheels inherently offer explosion-proof advantages compared to pneumatic wheel.Our team innovatively proposed an“elastic ring-hinge group”type non-pneumatic mechanical elastic wheel(ME-Wheel).To analyz...Non-pneumatic wheels inherently offer explosion-proof advantages compared to pneumatic wheel.Our team innovatively proposed an“elastic ring-hinge group”type non-pneumatic mechanical elastic wheel(ME-Wheel).To analyze the gas flow characteristics around the ME-Wheel,this study analyzed the aerodynamic characteristics of the MEWheel for the first time by using CFD calculation method,and studied the influences of speed,steering angle,camber angle and hinge group on the aerodynamic characteristics of the wheel.Compared with camber angle,steering angle has a more significant effect on the aerodynamic characteristics of non-pneumatic mechanical elastic wheels in terms of lift and drag.Speed has no significant effect on the wheel drag coefficient and lift coefficient.The number of hinge groups has a significant effect on wheel aerodynamic characteristics.The deviations between the maximum and minimum values of drag,lift,drag coefficient,and lift coefficient are 6.06%,8.57%,6.05%,and 8.6%,respectively.This study addresses a critical gap in the design optimization of ME-Wheel,provides a theoretical basis for the aerodynamic optimization of ME-Wheel,and has strong practical significance for the commercial development of nonpneumatic mechanical elastic wheels.展开更多
Conventional deformable wheel systems in robots and other mechatronic systems face significant challenges in achieving miniaturization,intelligence,and integration.To address these issues,we propose a novel integrated...Conventional deformable wheel systems in robots and other mechatronic systems face significant challenges in achieving miniaturization,intelligence,and integration.To address these issues,we propose a novel integrated structural design method and four-dimensional printing strategy for deformable wheels capable of shaping among multiple programmable direct-driven deformation configurations.The load-bearing capacity of the printed wheel is strengthened by employing deformed components in various locations and actuated states.Additionally,a novel analytical design method is presented to determine the structure,actuation,and deformation parameters of each component under complex coupled deformation.Our findings reveal that the designed wheel can transform into three different configurations,exhibiting desired deformations of 12.5%in the radial direction and 19.6%in the axial direction.It also demonstrates robust deformation behavior and structural stability under multi-directional loads.By integrating a terrain sensing system,the designed wheel exhibits highly adaptive deformation capabilities on various terrains,showing great potential for exploring complex environments.展开更多
To reduce structural modifications and minimize the impact on legged locomotion,this paper presents SlidBot,a quadruped robot with roller-skating capability,designed to improve movement efficiency on sloped surfaces.T...To reduce structural modifications and minimize the impact on legged locomotion,this paper presents SlidBot,a quadruped robot with roller-skating capability,designed to improve movement efficiency on sloped surfaces.Two passive wheels without braking mechanisms are installed on the knee joint and lower leg of the robot.During quadruped movement,these wheels remain off the ground and therefore do not interfere with locomotion.The brakeless design reduces the number of components and simplifies the mechanical structure.When roller skating motion is required,simply adjust the leg posture to make the passive wheel on the lower leg contact the ground.The roller skating mode of the robot can be divided into two-legged roller skating and four-legged roller skating.During two-legged roller skating,the passive wheels of the hind legs support the ground,and the front legs execute backward propulsion to provide power for the robot’s movement.In four-legged roller skating,both the front and hind legs’passive wheels contact the ground,resulting in a large supporting area and a low center of gravity,which helps maintain stability during high-speed movement and facilitates passage through low-lying environments.This paper outlines the robot design method,establishes a kinematic model,plans the gait and mode-switching method.Simulation and physical results indicate that the robot can perform stable diagonal trotting and roller skating movements.Moreover,on flat terrain,the roller skating motion is more energy-efficient than diagonal trotting,and on slopes,its energy and motion efficiency significantly surpasses that of the diagonal trot.This research offers novel insights for quadruped robot design and can considerably enhance the movement efficiency of quadruped robots on sloped terrains.展开更多
The wheeled bipedal robots have great application potential in environments with a mixture of structured and unstructured terrain. However, wheeled bipedal robots have problems such as poor balance ability and low mov...The wheeled bipedal robots have great application potential in environments with a mixture of structured and unstructured terrain. However, wheeled bipedal robots have problems such as poor balance ability and low movement level on rough roads. In this paper, a novel and low-cost wheeled bipedal robot with an asymmetrical five-link mechanism is proposed, and the kinematics of the legs and the dynamics of the Wheeled Inverted Pendulum (WIP) are modeled. The primary balance controller of the wheeled bipedal robot is built based on the Linear Quadratic Regulator (LQR) and the compensation method of the virtual pitch angle adjusting the Center of Mass (CoM) position, then the whole-body hybrid torque-position control is established by combining attitude and leg controllers. The stability of the robot’s attitude control and motion is verified with simulations and prototype experiments, which confirm the robot’s ability to pass through complex terrain and resist external interference. The feasibility and reliability of the proposed control model are verified.展开更多
Governing airflow poses challenges under numerous conditions,particularly for the superposition of aerodynamic behaviors induced by multiple moving boundaries,mainly because of the uncertainty of the aerodynamic mecha...Governing airflow poses challenges under numerous conditions,particularly for the superposition of aerodynamic behaviors induced by multiple moving boundaries,mainly because of the uncertainty of the aerodynamic mechanism.Taking the airflow disturbance in the glass fiber transport process as an example,a numerical method for multidomain coupling is proposed considering dynamic meshing boundaries.Specifically,two-and three-dimensional modeling approaches were utilized to investigate the aerodynamic behavior around a fiber thrower(including a finger wheel and pull wheel)and its axial distribution characteristics,respectively.Some aerodynamic data were obtained through the proposed numerical approach,which is difficult to monitor using experimental strategies.The computational results showed that the flow structure in the external flow field of the fiber thrower was mainly regulated by the pull wheel rather than the finger wheel.The average airflow velocity in a specific region of the fiber thrower was decreased by 25%(from 2 m/s to 1.5 m/s)by improving the cross-sectional shape of the pull wheel.The spatial scale of the vortex clusters around the fiber thrower configured with the improved pull wheel was reduced,providing a novel perspective for understanding the improvement in the aerodynamic behavior.This study on the suppression of multiple-motion boundary-induced airflow is representative of the chemical industry.展开更多
The problem of trajectory tracking for a class of differentially driven wheeled mobile robots(WMRs)under partial loss of the effectiveness of the actuated wheels is investigated in this paper.Such actuator faults may ...The problem of trajectory tracking for a class of differentially driven wheeled mobile robots(WMRs)under partial loss of the effectiveness of the actuated wheels is investigated in this paper.Such actuator faults may cause the loss of strong controllability of the WMR,such that the conventional fault-tolerant control strategies unworkable.In this paper,a new mixed-gain adaption scheme is devised,which is adopted to adapt the gain of a decoupling prescribed performance controller to adaptively compensate for the loss of the effectiveness of the actuators.Different from the existing gain adaption technique which depends on both the barrier functions and their partial derivatives,ours involves only the barrier functions.This yields a lower magnitude of the resulting control signals.Our controller accomplishes trajectory tracking of the WMR with the prescribed rate and accuracy even in the faulty case,and the control design relies on neither the information of the WMR dynamics and the actuator faults nor the tools for function approximation,parameter identification,and fault detection or estimation.The comparative simulation results justify the theoretical findings.展开更多
文摘This paper presents a practical pricing model for backup reserve and wheeling, which attains a balanced strategy that ensures perceived benefits to both the buyer and the seller. The model and the associated computerized algorithm deal collectively with diverse issues, including： （1） fulfilling local firm real （and reactive） power demand requirements, （2） fulfilling local power reserve requirements, （3） buying firm real （and reactive） power from the grid, （4） buying reserve power from the grid, （5） exporting firm real （and reactive） power demand to remote load centers via the grid, （6） exporting reserve power via the grid, （7） wheeling of firm power demand to remote owned sites using the grid, and （8） wheeling reserve power to remote owned sites using grid. Practical implementation features of the computerized algorithms are also discussed with an illustrative case example.
基金funded by the National Natural Science Foundation of China,grant numbers 52072156,52272366the Postdoctoral Foundation of China,grant number 2020M682269.
文摘This review addresses four key themes in automotive aerodynamics:flow instability in the wheel region,the aerodynamic characteristics of rims,the aerodynamic behavior of tires,and drag reduction strategies based on flow control around the wheels.The wheel region,comprising the tire,rim,and adjacent aerodynamic components,typically represents the major source of vehicle drag owing to the inherently complex flow generated by wheel rotation,tread geometry,and rim design,which gives rise to flow separation,vortex shedding,and turbulence.Drawing on a broad body of experimental and numerical research,this review elucidates the mechanisms governing such dynamics,and considers drag mitigation techniques,including biomimetic surface treatments and multi-element flow control concepts.Particular emphasis is placed on enclosed-spoke rims,rim-edge enclosures,and non-smooth tire microstructures,which have consistently demonstrated notable drag reduction potential.The review further identifies critical shortcomings in current research,most notably the lack of quantitative analyses of aerodynamic energy losses and the absence of integrated optimization strategies that jointly address tire,rim,and fender design.
基金supported by Key Research and Development Program Project of Jiangxi Province(20232BBE50023)Science and Technology Research Project of Jiangxi Provincial Department of Education(GJJ2400911)Ganpo Talent Support Program(20232BCJ23106).
文摘In the booming field of handicraft art,pottery art,as a traditional craft that integrates the values of cultural inheritance and artistic innovation,has witnessed a continuous expansion of its teaching market,driven by the increasing emphasis on traditional culture and the rapid development of the cultural and creative industry.However,the traditional pottery throwing equipment currently used in pottery art teaching has become a development bottleneck.Its pedal-based rotation speed control method poses great challenges to beginners.Due to inexperience,beginners often find it extremely difficult to precisely adjust the rotation speed.Moreover,the lack of rotation speed control guidance tailored to different shaped blanks forces students to learn through repeated trial and error,which seriously hinders their systematic mastery of pottery throwing techniques.Meanwhile,in remote pottery art teaching,the high-latency problem of traditional communication technologies disrupts synchronous learning,reduces teaching effectiveness,and may even cause students to develop bad operating habits.A new type of linked pottery teaching and drawing machine and its communication system is developed.Taking advantage of the high-speed and low-latency characteristics of 5G networks,this system enables real-time synchronous rotation of the pottery throwing wheels used by students and those used by teachers in teaching,ensuring near-instant operation feedback in remote teaching scenarios and thus significantly improving teaching efficiency.This innovative achievement propels pottery art teaching towards the direction of intelligence and high efficiency,injecting new vitality into the inheritance and innovation of traditional pottery art techniques.
基金Natural Science Foundation of Hunan Province(2025JJ90031)Key Research and Development Program of Hunan Province of China(23A0273)Hunan Provincial Administration of Traditional Chinese Medicine(A2023048).
文摘Objective To develop a dual-branch deep learning framework for accurate multi-label classification of fundus diseases,addressing the key limitations of insufficient complementary feature extraction and inadequate cross-modal feature fusion in existing automated diagnostic methods.Methods The fundus multi-label classification dataset with 12 disease categories(FMLC-12)dataset was constructed by integrating complementary samples from Ocular Disease Intelligent Recognition(ODIR)and Retinal Fundus Multi-Disease Image Dataset(RFMiD),yielding 6936 fundus images across 12 retinal pathology categories,and the framework was validated on both FMLC-12 and ODIR.Inspired by the holistic multi-regional assessment principle of the Five Wheels theory in traditional Chinese medicine(TCM)ophthalmology,the dualbranch multi-label network(DBMNet)was developed as a novel framework integrating complementary visual feature extraction with pathological correlation modeling.The architecture employed a TransNeXt backbone within a dual-branch design:one branch processed redgreen-blue(RGB)images to capture color-dependent features,such as vascular patterns and lesion morphology,while the other processed grayscale-converted images to enhance subtle textural details and contrast variations.A feature interaction module(FIM)effectively integrated the multi-scale features from both branches.Comprehensive ablation studies were conducted to evaluate the contributions of the dual-branch architecture and the FIM.The performance of DBMNet was compared against four state-of-the-art methods,including EfficientNet Ensemble,transfer learning-based convolutional neural network(CNN),BFENet,and EyeDeep-Net,using mean average precision(mAP),F1-score,and Cohen's kappa coefficient.Results The dual-branch architecture improved mAP by 15.44 percentage points over the single-branch TransNeXt baseline,increasing from 34.41%to 44.24%,and the addition of FIM further boosted mAP to 49.85%.On FMLC-12,DBMNet achieved an mAP of 49.85%,a Cohen’s kappa coefficient of 62.14%,and an F1-score of 70.21%.Compared with BFENet(mAP:45.42%,kappa:46.64%,F1-score:71.34%),DBMNet outperformed it by 4.43 percentage points in mAP and 15.50 percentage points in kappa,while BFENet achieved a marginally higher F1-score.On ODIR,DBMNet achieved an F1-score of 85.50%,comparable to state-of-the-art methods.Conclusion DBMNet effectively integrates RGB and grayscale visual modalities through a dual-branch architecture,significantly improving multi-label fundus disease classification.The framework not only addresses the issue of insufficient feature fusion in existing methods but also demonstrates outstanding performance in balancing detection across both common and rare diseases,providing a promising and clinically applicable pathway for standardized,intelligent fundus disease classification.
基金supported by the National Natural Science Foundation of China(Grant No.52178329),the China Scholarship Council(Grant No.202306130155)the Postgraduate Scientific Research Innovation Project of Hunan Province,China(Grant No.CX20230442).
文摘With the continuous development of the offshore wind industry,the design concept of composite foundation has been given attention in the past decade.This paper presents an accurate method for investigating the horizontal vibration of monopile-friction wheel composite foundations in layered saturated soil.Firstly,the three-dimensional continuum mechanics theory with the range of linear elasticity is introduced to calculate the frictional resistance distributed on the upper soil surface.Then,the resistances of multilayered soils and inviscid seawater to the pile shaft under horizontal harmonic excitation are obtained using Novak's plane strain model,Biot's porous media theory and radiationwave theory.Thirdly,the expressions for the deformation,bending moment and internal force of the Euler-Bernoulli pile are derived using the boundary conditions with definitephysical meaning and transfer matrix method.By comparing with the results of 1g laboratory test and the idealized formula reported by the literature,the rationality and accuracy of the developed dynamical model can be verified.Finally,this paper conducts a series of worked examples to investigate the influencesof the elastic modulus and thickness of three-layer saturated soil and the location of interlayer soil on the horizontal dynamic vibration of composite foundation.The results show that an increase in elastic modulus of the surface soil is an effective way to improve the dynamic stability of the composite foundation in service conditions.The conclusions drawn from the numerical examples can develop some guidelines for the current foundation design of offshore wind turbines.
文摘Anyone who’s been in China for more than five minutes knows that bar-gaining is a very prominent part of the Chinese culture. But nowhere is this more striking than in a tourist-oriented lo-
基金supported by the NIH (R01NS103481, R01NS111776, and R01NS131489)Indiana Department of Health (ISDH58180)(all to WW)。
文摘Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury.
基金Projects(U22B2084,52275483,52075142)supported by the National Natural Science Foundation of ChinaProject(2023ZY01050)supported by the Ministry of Industry and Information Technology High Quality Development,China。
文摘The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can cause changes in cutting force/heat,resulting in affecting gear machining precision.Therefore,this paper studies the effect of different process parameters on gear machining precision.A multi-objective optimization model is established for the relationship between process parameters and tooth surface deviations,tooth profile deviations,and tooth lead deviations through the cutting speed,feed rate,and cutting depth of the worm wheel gear grinding machine.The response surface method(RSM)is used for experimental design,and the corresponding experimental results and optimal process parameters are obtained.Subsequently,gray relational analysis-principal component analysis(GRA-PCA),particle swarm optimization(PSO),and genetic algorithm-particle swarm optimization(GA-PSO)methods are used to analyze the experimental results and obtain different optimal process parameters.The results show that optimal process parameters obtained by the GRA-PCA,PSO,and GA-PSO methods improve the gear machining precision.Moreover,the gear machining precision obtained by GA-PSO is superior to other methods.
基金supported by Natural Science Foundation of Sichuan Province:2024NSFSC0644.
文摘The integration of exercise prescriptions into cancer adjuvant therapy presents challenges stemming from the ambiguity surrounding the precise mechanism through which exercise intervention mitigates the risk of hepatocellular carcinoma(HCC)mortality and recurrence.Elucidation of this specific mechanism has substantial social and clinical implications.In this study,tumor-bearing mice engaged in voluntary wheel running exhibited a notable decrease in tumor growth,exceeding 30%.Microarray analysis revealed an upregulation of cytokinerelated pathways as a potential explanation for this effect.The inclusion of granulocyte-macrophage colonystimulating factor(GM-CSF)was found to enhance tumor cell proliferation,while the absence of GM-CSF resulted in a marked inhibition of tumor cell growth.The findings suggest that exercise-induced serum from mice can impede the proliferation of mouse tumor cells,with the adipokine chemerin inhibiting the growth factor GM-CSF.Additionally,exercise was found to stimulate chemerin secretion by brown adipose tissue.Chemerin suppression led to a reduction in the inhibition of tumor cell proliferation.The results of this study suggest that exercise may stimulate the release of adipokines from brown adipose tissue,transport them through the blood to the distant tumor microenvironment,and downregulate GM-CSF expression,alleviating tumor immunosuppression in the tumor microenvironment,thereby inhibiting at HCC progression.These findings provide a theoretical basis for incorporating exercise prescription into cancer treatment.
基金Project supported by the National Natural Science Foundation of China(Nos.W2433004 and 12472015)the Research Fund of the State Key Laboratory of Mechanics and Control of Mechanical Structures(Nanjing University of Aeronautics and Astronautics)(No.MCMS-I-0122K01).
文摘This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorporating flexible appendages and an orthogonal cluster of magnetically suspended reaction wheel actuators is initially developed.After that,an adaptive attitude controller is designed with a switching surface of variable structure,an adaptive law for estimating inertia matrix uncertainty,and a fuzzy disturbance observer for estimating disturbance torques.Additionally,a Moore-Penrose-based steering law is proposed to derive the tilt angle commands of the orthogonal configuration of the 3D MSW to follow the designed control signal.Finally,numerical simulations are presented to validate the effectiveness of the proposed control strategy.
基金supported by Natural Science Foundation of China(52178441)the Scientific Research Projects of the China Academy of Railway Sciences Co.,Ltd.(Grant No.2022YJ043).
文摘Rail weld irregularities are one of the primary excitation sources for vehicle-track interaction dynamics in modern high-speed railways.They can cause significant wheel-rail dynamic interactions,leading to wheel-rail noise,component damage,and deterioration.Few researchers have employed the vehicle-track interaction dynamic model to study the dynamic interactions between wheel and rail induced by rail weld geometry irregularities.However,the cosine wave model used to simulate rail weld irregularities mainly focuses on the maximum value and neglects the geometric shape.In this study,novel theoretical models were developed for three categories of rail weld irregularities,based on measurements of the high-speed railway from Beijing to Shanghai.The vertical dynamic forces in the time and frequency domains were compared under different running speeds.These forces generated by the rail weld irregularities that were measured and modeled,respectively,were compared to validate the accuracy of the proposed model.Finally,based on the numerical study,the impact force due to rail weld irrregularity is modeled using an Artificial Neural Network(ANN),and the optimum combination of parameters for this model is found.The results showed that the proposed model provided a more accurate wheel/rail dynamic evaluation caused by rail weld irregularities than that established in the literature.The ANN model used in this paper can effectively predict the impact force due to rail weld irrregularity while reducing the computation time.
基金supported by NSFC(Nos.12161141003,11931006)supported by NSFC(Nos.11801520,12171436,12271489)supported by NSFC(No.11601527)。
文摘For k given graphs H_(1),...,H_(k) with k≥2,the k-color Ramsey number R(H_(1),...,H_(k)) represents the minimum integer N with the following property:if the edges of the complete graph K_(N) are colored with k colors,then there exists some i with 1≤i≤k such that K_(N) has a subgraph in color i isomorphic to H_(i).Let C_(m) be a cycle of length m and K_(1,n) a star of order n+1.In this paper,we systematically introduce the latest research progress on star-quadrilateral Ramsey numbers and provide an overview of Ramsey numbers concerning quadrilaterals,including multicolor cases.
基金supported by Instituto Politécnico Nacional-Secretaría de Investigación y Posgrado under grant 20253806in part by project UNAM PAPIME PE104125.
文摘Nowadays,using mobile robots in different applications has been very important.However,the environment in which they operate can cause the wheels to slip or the robot body to slide,causing the assigned task not to be performed successfully.Therefore,the need arises to mathematically determine these external perturbations to predict the behavior of the mobile robot.Based on the above mentioned facts,this work focuses on obtaining the kinematic model of an omnidirectional mobile robot considering lateral and longitudinal sliding disturbances of the body and wheel slippage.To mitigate the effect of the disturbances,a control strategy is considered based on the design of a generalized proportional integral observer(GPIO)that allows the estimation of such perturbations.Then,an active disturbance rejection control(ADRC)methodology is implemented to solve the trajectory tracking problem,and it is theoretically proved that the tracking errors converge to a vicinity near the origin.Numerical simulations and real-time experiments validate the obtained perturbed model and the control strategy performance,achieving the desired trajectory tracking despite these perturbations.
基金Supported by National Natural Science Foundation of China(Grant Nos.52472411,52272397)the Key Research&Development and Achievement Transformation Program of Wuhu(Grant No.2023YF010)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX25_0566).
文摘Non-pneumatic wheels inherently offer explosion-proof advantages compared to pneumatic wheel.Our team innovatively proposed an“elastic ring-hinge group”type non-pneumatic mechanical elastic wheel(ME-Wheel).To analyze the gas flow characteristics around the ME-Wheel,this study analyzed the aerodynamic characteristics of the MEWheel for the first time by using CFD calculation method,and studied the influences of speed,steering angle,camber angle and hinge group on the aerodynamic characteristics of the wheel.Compared with camber angle,steering angle has a more significant effect on the aerodynamic characteristics of non-pneumatic mechanical elastic wheels in terms of lift and drag.Speed has no significant effect on the wheel drag coefficient and lift coefficient.The number of hinge groups has a significant effect on wheel aerodynamic characteristics.The deviations between the maximum and minimum values of drag,lift,drag coefficient,and lift coefficient are 6.06%,8.57%,6.05%,and 8.6%,respectively.This study addresses a critical gap in the design optimization of ME-Wheel,provides a theoretical basis for the aerodynamic optimization of ME-Wheel,and has strong practical significance for the commercial development of nonpneumatic mechanical elastic wheels.
基金supported by the National Key Research and Development Program of China(Grant No 2022YFB4600102)the National Natural Science Foundation of China(Grant No.U23A20637 and Grant No 52275561)。
文摘Conventional deformable wheel systems in robots and other mechatronic systems face significant challenges in achieving miniaturization,intelligence,and integration.To address these issues,we propose a novel integrated structural design method and four-dimensional printing strategy for deformable wheels capable of shaping among multiple programmable direct-driven deformation configurations.The load-bearing capacity of the printed wheel is strengthened by employing deformed components in various locations and actuated states.Additionally,a novel analytical design method is presented to determine the structure,actuation,and deformation parameters of each component under complex coupled deformation.Our findings reveal that the designed wheel can transform into three different configurations,exhibiting desired deformations of 12.5%in the radial direction and 19.6%in the axial direction.It also demonstrates robust deformation behavior and structural stability under multi-directional loads.By integrating a terrain sensing system,the designed wheel exhibits highly adaptive deformation capabilities on various terrains,showing great potential for exploring complex environments.
基金supported by the National Natural Science Foundation of China(Nos.62103197 and 62473200).
文摘To reduce structural modifications and minimize the impact on legged locomotion,this paper presents SlidBot,a quadruped robot with roller-skating capability,designed to improve movement efficiency on sloped surfaces.Two passive wheels without braking mechanisms are installed on the knee joint and lower leg of the robot.During quadruped movement,these wheels remain off the ground and therefore do not interfere with locomotion.The brakeless design reduces the number of components and simplifies the mechanical structure.When roller skating motion is required,simply adjust the leg posture to make the passive wheel on the lower leg contact the ground.The roller skating mode of the robot can be divided into two-legged roller skating and four-legged roller skating.During two-legged roller skating,the passive wheels of the hind legs support the ground,and the front legs execute backward propulsion to provide power for the robot’s movement.In four-legged roller skating,both the front and hind legs’passive wheels contact the ground,resulting in a large supporting area and a low center of gravity,which helps maintain stability during high-speed movement and facilitates passage through low-lying environments.This paper outlines the robot design method,establishes a kinematic model,plans the gait and mode-switching method.Simulation and physical results indicate that the robot can perform stable diagonal trotting and roller skating movements.Moreover,on flat terrain,the roller skating motion is more energy-efficient than diagonal trotting,and on slopes,its energy and motion efficiency significantly surpasses that of the diagonal trot.This research offers novel insights for quadruped robot design and can considerably enhance the movement efficiency of quadruped robots on sloped terrains.
基金supported in part by the National Natural Science Foundationof China under Grant(61801122)Natural Science Foundation of FujianProvince(2022J01542).
文摘The wheeled bipedal robots have great application potential in environments with a mixture of structured and unstructured terrain. However, wheeled bipedal robots have problems such as poor balance ability and low movement level on rough roads. In this paper, a novel and low-cost wheeled bipedal robot with an asymmetrical five-link mechanism is proposed, and the kinematics of the legs and the dynamics of the Wheeled Inverted Pendulum (WIP) are modeled. The primary balance controller of the wheeled bipedal robot is built based on the Linear Quadratic Regulator (LQR) and the compensation method of the virtual pitch angle adjusting the Center of Mass (CoM) position, then the whole-body hybrid torque-position control is established by combining attitude and leg controllers. The stability of the robot’s attitude control and motion is verified with simulations and prototype experiments, which confirm the robot’s ability to pass through complex terrain and resist external interference. The feasibility and reliability of the proposed control model are verified.
基金Supported by Jilin Provincial Youth and Middle-Aged Scientific and Technological Innovation and Entrepreneurship Excellence Talents(Grant No.20210509007RQ)Jilin Provincial Key Scientific and Technological Projects(Grant No.20220201026GX)Jilin Provincial Fundamental Research Funds for the Central Universities(Grant No.2022-JCXK-15).
文摘Governing airflow poses challenges under numerous conditions,particularly for the superposition of aerodynamic behaviors induced by multiple moving boundaries,mainly because of the uncertainty of the aerodynamic mechanism.Taking the airflow disturbance in the glass fiber transport process as an example,a numerical method for multidomain coupling is proposed considering dynamic meshing boundaries.Specifically,two-and three-dimensional modeling approaches were utilized to investigate the aerodynamic behavior around a fiber thrower(including a finger wheel and pull wheel)and its axial distribution characteristics,respectively.Some aerodynamic data were obtained through the proposed numerical approach,which is difficult to monitor using experimental strategies.The computational results showed that the flow structure in the external flow field of the fiber thrower was mainly regulated by the pull wheel rather than the finger wheel.The average airflow velocity in a specific region of the fiber thrower was decreased by 25%(from 2 m/s to 1.5 m/s)by improving the cross-sectional shape of the pull wheel.The spatial scale of the vortex clusters around the fiber thrower configured with the improved pull wheel was reduced,providing a novel perspective for understanding the improvement in the aerodynamic behavior.This study on the suppression of multiple-motion boundary-induced airflow is representative of the chemical industry.
基金supported in part by the National Natural Science Foundation of China under Grants 61991404,62103093 and 62473089the Research Program of the Liaoning Liaohe Laboratory,China under Grant LLL23ZZ-05-01+5 种基金the Key Research and Development Program of Liaoning Province of China under Grant 2023JH26/10200011the 111 Project 2.0 of China under Grant B08015,the National Key Research and Development Program of China under Grant 2022YFB3305905the Xingliao Talent Program of Liaoning Province of China under Grant XLYC2203130the Natural Science Foundation of Liaoning Province of China under Grants 2024JH3/10200012 and 2023-MS-087the Open Research Project of the State Key Laboratory of Industrial Control Technology of China under Grant ICT2024B12the Fundamental Research Funds for the Central Universities of China under Grants N2108003 and N2424004.
文摘The problem of trajectory tracking for a class of differentially driven wheeled mobile robots(WMRs)under partial loss of the effectiveness of the actuated wheels is investigated in this paper.Such actuator faults may cause the loss of strong controllability of the WMR,such that the conventional fault-tolerant control strategies unworkable.In this paper,a new mixed-gain adaption scheme is devised,which is adopted to adapt the gain of a decoupling prescribed performance controller to adaptively compensate for the loss of the effectiveness of the actuators.Different from the existing gain adaption technique which depends on both the barrier functions and their partial derivatives,ours involves only the barrier functions.This yields a lower magnitude of the resulting control signals.Our controller accomplishes trajectory tracking of the WMR with the prescribed rate and accuracy even in the faulty case,and the control design relies on neither the information of the WMR dynamics and the actuator faults nor the tools for function approximation,parameter identification,and fault detection or estimation.The comparative simulation results justify the theoretical findings.
