With the development of computer science,the software technology changes with each passing day,itput forward higher and higher technical requirements for the software developers.Aim at each link in the process of deve...With the development of computer science,the software technology changes with each passing day,itput forward higher and higher technical requirements for the software developers.Aim at each link in the process of development,the present paper put forward a kind of software engineering personnel training system,the system can build a unified learning,management and evaluation system,to avoid the disadvantages of the traditional single system structure;the training process is more flexible,and it couldreduce the complexity of the artificial training and cause it to become more practical value.展开更多
The optimal design of training sequences for channel estimation in multiple-input multiple-output(MIMO)systems under spatially correlated fading is considered.The channel is assumed to be a block-fading model with spa...The optimal design of training sequences for channel estimation in multiple-input multiple-output(MIMO)systems under spatially correlated fading is considered.The channel is assumed to be a block-fading model with spatial correlation known at both the transmitter and the receiver.To minimize the channel estimation error,optimal training sequences are designed to exploit full information of the spatial correlation under the criterion of minimum mean square error(MMSE).It is investigated that the spatial correlation is helpful to decrease the estimation error and the proposed training sequences have good performance via simulations.展开更多
The paper introduces some technology for training, simulation, restoration expert system of power grid, the structure of the system including function composition, hardware and software composition are discussed, know...The paper introduces some technology for training, simulation, restoration expert system of power grid, the structure of the system including function composition, hardware and software composition are discussed, knowledge representation and the method to establish device graphical library for expert system are given, the fault setting and diagnosis for training and simulation as well as restoration technology with deep first searching arithmetic and heuristic inference are presented. The research provides a good base for developing the training, simulation, restoration system of power companies.展开更多
Objective:Stress urinary incontinence(SUI)is a common condition among women that severely impairs quality of life.Pelvic floor proprioceptive training(PFPT)has attracted increasing attention for its potential to enhan...Objective:Stress urinary incontinence(SUI)is a common condition among women that severely impairs quality of life.Pelvic floor proprioceptive training(PFPT)has attracted increasing attention for its potential to enhance pelvic floor muscle function and alleviate SUI symptoms.This study aims to observe and compare the clinical efficacy of PFPT combined with electroacupuncture,electrical stimulation,and biofeedback therapy versus conventional therapy consisting of electroacupuncture,electrical stimulation,and biofeedback alone in women with SUI,and to explore the role of PFPT in improving symptom and functional outcomes.Methods:In this randomized controlled trial,72 women with mild to moderate SUI were recruited from the Department of Rehabilitation Medicine at Third Xiangya Hospital,Central South University,between December 2021 and October 2023.Participants were randomly assigned to an experimental group(n=36)or a control group(n=36).Both groups received health education.The control group underwent electroacupuncture combined with electrical stimulation and biofeedback therapy,while the experimental group additionally received PFPT 3 times per week for 4 weeks.The primary outcome was assessed using the International Consultation on Incontinence Questionnaire-Short Form(ICIQ-SF).Secondary outcomes included pelvic floor muscle strength,bladder neck mobility,and balance ability.The ICIQ-SF was reassessed at 1,3,6,and 12 months post-treatment.Results:Both groups showed statistically significant improvements in all parameters after treatment(all P<0.05).However,there were no statistically significant differences between groups in most measures(all P>0.05).The experimental group demonstrated longer singleleg stance duration with eyes closed than the control group(left leg:P=0.026;right leg:P=0.006),with a significant increase from baseline(P<0.001).At 6 months post-treatment,the cure rate in the experimental group was significantly higher than that in the control group(P=0.037).Conclusion:Conventional therapy effectively improves SUI symptoms,but adding PFPT provides notable additional benefits,including enhanced balance ability and sustained midterm cure rates.These findings suggest that PFPT is a valuable adjunct to standard SUI management strategies.展开更多
Most studies have analyzed the aerodynamic characteristics and wind-train(vehicle)-bridge coupled vibration response of trains or vehicles on bridges of a certain structural system,while few comparative studies have b...Most studies have analyzed the aerodynamic characteristics and wind-train(vehicle)-bridge coupled vibration response of trains or vehicles on bridges of a certain structural system,while few comparative studies have been carried out on the wind-train-bridge coupled vibration response on bridges of three different structural systems.This paper takes the main span 1120 m dual-purpose highway-railway bridge as the engineering background,and studies the three bridge types of(122+1120+90+92)m suspension bridge,(130+432+1120+432+130)m cable-stayed bridge and(92+210+1120+210+92)m cable-stayed-suspension collaborative system bridge.The trend of the maximum value of the train dynamic response to the wind-train-bridge coupling of the three structural system bridges as well as the speed thresholds are compared and analyzed,and conclusions are drawn:1)Under the same speed,the maximum value of train safety indexes in three types of bridges increases with the increase of wind speed.2)Under the same wind speed,the safety and smoothness indicators of trains in three types of bridges without wind barriers rank in the order of cable-stayed suspension collaborative system bridge>cable-stayed bridge>suspension bridge.3)At low wind speeds(≤15 m/s),a 3.0 m wind barrier has negligible effect on speed thresholds.The safety ranking of structural systems remains unchanged:cable-stayed-suspension collaborative system bridge>cable-stayed bridge>suspension bridge.4)At high wind speeds(≥20 m/s),the 3.0 m wind barrier can increase the train speed threshold for bridges within the same structural system.The safety ranking of the three bridge types(3.0 m 30%wind barrier)remains unchanged:cable-stayed suspension collaborative system bridge>cable-stayed bridge>suspension bridge.This study represents the first systematic comparative analysis of wind speed critical values and performance ratings across three distinct bridge structural systems.展开更多
The ammunition loading system manipulator is susceptible to gear failure due to high-frequency,heavyload reciprocating motions and the absence of protective gear components.After a fault occurs,the distribution of fau...The ammunition loading system manipulator is susceptible to gear failure due to high-frequency,heavyload reciprocating motions and the absence of protective gear components.After a fault occurs,the distribution of fault characteristics under different loads is markedly inconsistent,and data is hard to label,which makes it difficult for the traditional diagnosis method based on single-condition training to generalize to different conditions.To address these issues,the paper proposes a novel transfer discriminant neural network(TDNN)for gear fault diagnosis.Specifically,an optimized joint distribution adaptive mechanism(OJDA)is designed to solve the distribution alignment problem between two domains.To improve the classification effect within the domain and the feature recognition capability for a few labeled data,metric learning is introduced to distinguish features from different fault categories.In addition,TDNN adopts a new pseudo-label training strategy to achieve label replacement by comparing the maximum probability of the pseudo-label with the test result.The proposed TDNN is verified in the experimental data set of the artillery manipulator device,and the diagnosis can achieve 99.5%,significantly outperforming other traditional adaptation methods.展开更多
The pantograph cavity coupling system(PCCS)of high-speed trains,as a representative region for aerodynamic noise generation,merits further investigation into its scale effects.In this paper,the large-eddy simulation(L...The pantograph cavity coupling system(PCCS)of high-speed trains,as a representative region for aerodynamic noise generation,merits further investigation into its scale effects.In this paper,the large-eddy simulation(LES)and the Ffowcs Williams-Hawkings(FW-H)integral equation are used to calculate and analyze the sound energy intensity distribution pattern and spectral characteristics of the PCCS at different scales(1/1,1/2,1/4,1/8,1/16,1/25,1/50).The research shows that as the scaled model decreases,the relative area of the pantograph submerged by the vehicle boundary layer increases,and its inflow velocity decreases,thereby reducing the overall radiated sound pressure level in this area.For the segments 1/1-1/2 and 1/4-1/16,the dominant scale of sound generation is typical pure tone noise,with distinct similar features in the spectral discrete scales.For the segments 1/25-1/50,the turbulent fluctuation characteristics of the vehicle boundary layer mask the peak features,and the spectrum is dominated by broadband characteristics.Combining the PCCS sound source energy scale correction model and the dimensionless spectrum correction function,a scale correction model for the sound power spectrum of the sound source is obtained,so that the noise results of the reduced-scale model can be corresponded to the full-scale model.This work advances the comprehension of high-speed train aerodynamic noise generation mechanisms and offers critical references for developing precision noise control technologies.展开更多
Subgrade settlement is a common issue in soil ground within earthquake-prone regions,posing a threat to the safe operation of train-slab track coupled system(TSCS)in high-speed railways(HSRs).This study aims to analyz...Subgrade settlement is a common issue in soil ground within earthquake-prone regions,posing a threat to the safe operation of train-slab track coupled system(TSCS)in high-speed railways(HSRs).This study aims to analyze the mechanical behavior evolution of TSCS under subgrade settlement and earthquake excitation.The refined numerical model of slab track under subgrade differential settlement is established.The short settlement wavelength of 10 m causes the separation between the base and subgrade.The dynamic model of TSCS under subgrade settlement and earthquake excitation is developed.The dynamic response of TSCS exhibits more pronounced fluctuations under the combined effects of subgrade settlement and earthquake excitation than under the effects of settlement or earthquake alone.The evaluation indexes for the running safety of train on slab track under different settlement wavelengths exhibit varying degrees of increase with settlement amplitude and are particularly sensitive to the short settlement wavelength of 10 m.The wheel unloading rate and derailment coefficient of TSCS increase with earthquake intensity.Under the settlement wavelength of 10 m and amplitude of 20 mm,the wheel unloading rate of TSCS exceeds the allowable limit when the earthquake intensity exceeds 0.17g,and the derailment coefficient exceeds the allowable limit when the earthquake intensity surpasses 0.29g.展开更多
针对复杂交通场景车辆检测算法自适应能力差的问题,提出了基于Co-training半监督学习方法的车辆鲁棒检测算法.首先,针对手工标记的少量样本,分别训练基于Haar-like特征的AdaBoost分类器和基于HOG(histograms of oriented gradients)特征...针对复杂交通场景车辆检测算法自适应能力差的问题,提出了基于Co-training半监督学习方法的车辆鲁棒检测算法.首先,针对手工标记的少量样本,分别训练基于Haar-like特征的AdaBoost分类器和基于HOG(histograms of oriented gradients)特征的SVM(support vector machines)分类器,使其具有一定的识别能力;然后,基于Co-training半监督学习框架,将利用2种算法进行分类得到的新样本分别加入到对方的样本库中,增加训练样本数量,再次进行分类器的训练.由于这2类特征具有冗余性,各自检测出的正负样本包含对方漏检和误检的图像.由于样本数的增加,再次训练所得到的新分类器的鲁棒性得到了很大提高,能更加准确地检测出车辆,而且由算法对未标记样本进行分类标记,不再需要人为标记,提高了车辆检测算法的自适应能力.展开更多
针对Tri-training算法利用无标记样例时会引入噪声且限制无标记样例的利用率而导致分类性能下降的缺点,提出了AR-Tri-training(Tri-training with assistant and rich strategy)算法。提出辅助学习策略,结合富信息策略设计辅助学习器,...针对Tri-training算法利用无标记样例时会引入噪声且限制无标记样例的利用率而导致分类性能下降的缺点,提出了AR-Tri-training(Tri-training with assistant and rich strategy)算法。提出辅助学习策略,结合富信息策略设计辅助学习器,并将辅助学习器应用在Tri-training训练以及说话声识别中。实验结果表明,辅助学习器在Tri-training训练的基础上不仅降低每次迭代可能产生的误标记样例数,而且能够充分地利用无标记样例以及在验证集上的错分样例信息。从实验结果可以得出,该算法能够弥补Tri-training算法的缺点,进一步提高测试率。展开更多
With the rapid development of artificial intelligence,intelligent air combat maneuver decision-making(ACMD)has garnered global attention.Although deep reinforcement learning provides a promising approach to ACMD,exist...With the rapid development of artificial intelligence,intelligent air combat maneuver decision-making(ACMD)has garnered global attention.Although deep reinforcement learning provides a promising approach to ACMD,existing methods often suffer from rigid reward functions and limited adaptability to evolving adversarial strategies.Moreover,most research assumes open airspace,overlooking the influence of potential obstacles.In this paper,we address one-on-one within-visual-range ACMD in obstructed environments,and propose an improved Soft Actor-Critic(SAC)algorithm trained under a curriculum self-play framework.A maneuver strategy mirroring inference module is integrated to estimate each other's likely positions when visual obstruction occurs.By leveraging curriculum learning to guide progressive experience accumulation and self-play for adversarial evolution,our method enhances both training efficiency and tactical diversity.We further integrate an attention mechanism that dynamically adjusts the weights of sub-rewards,enabling the learned policy to adapt to rapidly changing air combat situations.Numerical simulations demonstrate that our enhanced SAC converges more quickly and achieves higher win rates than other baseline methods.An animation is available at bilibili.com/video/BV1BHVszHE98 for better illustration.展开更多
The safe driving and operation of trains is a necessary condition for ensuring the safe operation of trains.In particular,heavy-haul trains are characterized by the difficulty in driving and operation.Considering the ...The safe driving and operation of trains is a necessary condition for ensuring the safe operation of trains.In particular,heavy-haul trains are characterized by the difficulty in driving and operation.Considering the uncertainties in train driving and operation,this paper analyzes the relationship between the safety of heavy-haul electric locomotive hauled trains and driving and operation.It studies the auxiliary intelligent driving safety operation control methods.Through K-means to identify the characteristics of drivers'driving manipulation,the hidden Markov model adaptively adjusts the train driving and operation sequence,and conducts auxiliary driving reconstruction for heavy-haul locomotive driving and operation.Based on the train running curve and the locomotive traction/braking characteristics,it smoothly controls the exertion of the traction/braking force of heavy-haul locomotives,thereby optimizing the driving safety control of heavy-haul trains in the vehicle-environment-track system.Finally,the train operation simulation and optimized driving verification are carried out by simulating some track sections.The results show that the proposed method can correct and pre-optimize driving operations,improving the smoothness of heavy-haul trains by approximately 10%.It verifies the effectiveness of the proposed train assisted driving control reconstruction method,facilitating the smooth and safe operation of heavy-haul trains.展开更多
Bridges crossing active faults are more likely to suffer serious damage or even collapse due to the wreck capabilities of near-fault pulses and surface ruptures under earthquakes.Taking a high-speed railway simply-sup...Bridges crossing active faults are more likely to suffer serious damage or even collapse due to the wreck capabilities of near-fault pulses and surface ruptures under earthquakes.Taking a high-speed railway simply-supported girder bridge with eight spans crossing an active strike-slip fault as the research object,a refined coupling dynamic model of the high-speed train-CRTS III slab ballastless track-bridge system was established based on ABAQUS.The rationality of the established model was thoroughly discussed.The horizontal ground motions in a fault rupture zone were simulated and transient dynamic analyses of the high-speed train-track-bridge coupling system under 3-dimensional seismic excitations were subsequently performed.The safe running speed limits of a high-speed train under different earthquake levels(frequent occurrence,design and rare occurrence)were assessed based on wheel-rail dynamic(lateral wheel-rail force,derailment coefficient and wheel-load reduction rate)and rail deformation(rail dislocation,parallel turning angle and turning angle)indicators.Parameter optimization was then investigated in terms of the rail fastener stiffness and isolation layer friction coefficient.Results of the wheel-rail dynamic indicators demonstrate the safe running speed limits for the high-speed train to be approximately 200 km/h and 80 km/h under frequent and design earthquakes,while the train is unable to run safely under rare earthquakes.In addition,the rail deformations under frequent,design and rare earthquakes meet the safe running requirements of the high-speed train for the speeds of 250,100 and 50 km/h,respectively.The speed limits determined for the wheel-rail dynamic indicators are lower due to the complex coupling effect of the train-track-bridge system under track irregularity.The running safety of the train was improved by increasing the fastener stiffness and isolation layer friction coefficient.At the rail fastener lateral stiffness of 60 kN/mm and isolation layer friction coefficients of 0.9 and 0.8,respectively,the safe running speed limits of the high-speed train increased to 250 km/h and 100 km/h under frequent and design earthquakes,respectively.展开更多
文摘With the development of computer science,the software technology changes with each passing day,itput forward higher and higher technical requirements for the software developers.Aim at each link in the process of development,the present paper put forward a kind of software engineering personnel training system,the system can build a unified learning,management and evaluation system,to avoid the disadvantages of the traditional single system structure;the training process is more flexible,and it couldreduce the complexity of the artificial training and cause it to become more practical value.
基金the National Science Foundation for Distinguished Young Scholars(60725105)the SixthProject of the Key Project of National Nature Science Foundation of China(60496316)+2 种基金the National"863"Project(2007AA012288)the National Nature Science Foundation of China(60572146)the"111"Project(B08038).
文摘The optimal design of training sequences for channel estimation in multiple-input multiple-output(MIMO)systems under spatially correlated fading is considered.The channel is assumed to be a block-fading model with spatial correlation known at both the transmitter and the receiver.To minimize the channel estimation error,optimal training sequences are designed to exploit full information of the spatial correlation under the criterion of minimum mean square error(MMSE).It is investigated that the spatial correlation is helpful to decrease the estimation error and the proposed training sequences have good performance via simulations.
基金TheKeyProblemTacklingProjectinHunanProvince! (No .Izf 9831)
文摘The paper introduces some technology for training, simulation, restoration expert system of power grid, the structure of the system including function composition, hardware and software composition are discussed, knowledge representation and the method to establish device graphical library for expert system are given, the fault setting and diagnosis for training and simulation as well as restoration technology with deep first searching arithmetic and heuristic inference are presented. The research provides a good base for developing the training, simulation, restoration system of power companies.
基金supported by the Natural Science Foundation of Hunan Province(2024JJ8121,2024JJ6626)the Hunan Provincial Key Research and Development Program(2023SK2038),China.
文摘Objective:Stress urinary incontinence(SUI)is a common condition among women that severely impairs quality of life.Pelvic floor proprioceptive training(PFPT)has attracted increasing attention for its potential to enhance pelvic floor muscle function and alleviate SUI symptoms.This study aims to observe and compare the clinical efficacy of PFPT combined with electroacupuncture,electrical stimulation,and biofeedback therapy versus conventional therapy consisting of electroacupuncture,electrical stimulation,and biofeedback alone in women with SUI,and to explore the role of PFPT in improving symptom and functional outcomes.Methods:In this randomized controlled trial,72 women with mild to moderate SUI were recruited from the Department of Rehabilitation Medicine at Third Xiangya Hospital,Central South University,between December 2021 and October 2023.Participants were randomly assigned to an experimental group(n=36)or a control group(n=36).Both groups received health education.The control group underwent electroacupuncture combined with electrical stimulation and biofeedback therapy,while the experimental group additionally received PFPT 3 times per week for 4 weeks.The primary outcome was assessed using the International Consultation on Incontinence Questionnaire-Short Form(ICIQ-SF).Secondary outcomes included pelvic floor muscle strength,bladder neck mobility,and balance ability.The ICIQ-SF was reassessed at 1,3,6,and 12 months post-treatment.Results:Both groups showed statistically significant improvements in all parameters after treatment(all P<0.05).However,there were no statistically significant differences between groups in most measures(all P>0.05).The experimental group demonstrated longer singleleg stance duration with eyes closed than the control group(left leg:P=0.026;right leg:P=0.006),with a significant increase from baseline(P<0.001).At 6 months post-treatment,the cure rate in the experimental group was significantly higher than that in the control group(P=0.037).Conclusion:Conventional therapy effectively improves SUI symptoms,but adding PFPT provides notable additional benefits,including enhanced balance ability and sustained midterm cure rates.These findings suggest that PFPT is a valuable adjunct to standard SUI management strategies.
基金Project(52327810)supported by the National Natural Science Foundation of ChinaProject(51925808)supported by the National Natural Science Foundation for Distinguished Young Scholars of China+1 种基金Project(U1934209)supported by the Key Project of National Natural Science Foundation of ChinaProject(P2019G002)supported by the Science and Technology Research and Development Program of China National Railway Group Co.,Ltd。
文摘Most studies have analyzed the aerodynamic characteristics and wind-train(vehicle)-bridge coupled vibration response of trains or vehicles on bridges of a certain structural system,while few comparative studies have been carried out on the wind-train-bridge coupled vibration response on bridges of three different structural systems.This paper takes the main span 1120 m dual-purpose highway-railway bridge as the engineering background,and studies the three bridge types of(122+1120+90+92)m suspension bridge,(130+432+1120+432+130)m cable-stayed bridge and(92+210+1120+210+92)m cable-stayed-suspension collaborative system bridge.The trend of the maximum value of the train dynamic response to the wind-train-bridge coupling of the three structural system bridges as well as the speed thresholds are compared and analyzed,and conclusions are drawn:1)Under the same speed,the maximum value of train safety indexes in three types of bridges increases with the increase of wind speed.2)Under the same wind speed,the safety and smoothness indicators of trains in three types of bridges without wind barriers rank in the order of cable-stayed suspension collaborative system bridge>cable-stayed bridge>suspension bridge.3)At low wind speeds(≤15 m/s),a 3.0 m wind barrier has negligible effect on speed thresholds.The safety ranking of structural systems remains unchanged:cable-stayed-suspension collaborative system bridge>cable-stayed bridge>suspension bridge.4)At high wind speeds(≥20 m/s),the 3.0 m wind barrier can increase the train speed threshold for bridges within the same structural system.The safety ranking of the three bridge types(3.0 m 30%wind barrier)remains unchanged:cable-stayed suspension collaborative system bridge>cable-stayed bridge>suspension bridge.This study represents the first systematic comparative analysis of wind speed critical values and performance ratings across three distinct bridge structural systems.
文摘The ammunition loading system manipulator is susceptible to gear failure due to high-frequency,heavyload reciprocating motions and the absence of protective gear components.After a fault occurs,the distribution of fault characteristics under different loads is markedly inconsistent,and data is hard to label,which makes it difficult for the traditional diagnosis method based on single-condition training to generalize to different conditions.To address these issues,the paper proposes a novel transfer discriminant neural network(TDNN)for gear fault diagnosis.Specifically,an optimized joint distribution adaptive mechanism(OJDA)is designed to solve the distribution alignment problem between two domains.To improve the classification effect within the domain and the feature recognition capability for a few labeled data,metric learning is introduced to distinguish features from different fault categories.In addition,TDNN adopts a new pseudo-label training strategy to achieve label replacement by comparing the maximum probability of the pseudo-label with the test result.The proposed TDNN is verified in the experimental data set of the artillery manipulator device,and the diagnosis can achieve 99.5%,significantly outperforming other traditional adaptation methods.
基金Project(52272363)supported by the National Natural Science Foundation of ChinaProject(2025JJ50308)supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(K-BBY1)supported by the Smart Railway Technology and Application,ChinaProject(1-W32Z)supported by the Postdoc Matching Fund Scheme,ChinaProject(ANCL20200302)supported by the Key Laboratory of Aerodynamic Noise Control,China。
文摘The pantograph cavity coupling system(PCCS)of high-speed trains,as a representative region for aerodynamic noise generation,merits further investigation into its scale effects.In this paper,the large-eddy simulation(LES)and the Ffowcs Williams-Hawkings(FW-H)integral equation are used to calculate and analyze the sound energy intensity distribution pattern and spectral characteristics of the PCCS at different scales(1/1,1/2,1/4,1/8,1/16,1/25,1/50).The research shows that as the scaled model decreases,the relative area of the pantograph submerged by the vehicle boundary layer increases,and its inflow velocity decreases,thereby reducing the overall radiated sound pressure level in this area.For the segments 1/1-1/2 and 1/4-1/16,the dominant scale of sound generation is typical pure tone noise,with distinct similar features in the spectral discrete scales.For the segments 1/25-1/50,the turbulent fluctuation characteristics of the vehicle boundary layer mask the peak features,and the spectrum is dominated by broadband characteristics.Combining the PCCS sound source energy scale correction model and the dimensionless spectrum correction function,a scale correction model for the sound power spectrum of the sound source is obtained,so that the noise results of the reduced-scale model can be corresponded to the full-scale model.This work advances the comprehension of high-speed train aerodynamic noise generation mechanisms and offers critical references for developing precision noise control technologies.
基金Project(52078501)supported by the National Natural Science Foundation of ChinaProject(2022-Major-14)supported by the Science and Technology Research and Development Program Project of China Railway Group LimitedProject(2023ZZTS0342)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Subgrade settlement is a common issue in soil ground within earthquake-prone regions,posing a threat to the safe operation of train-slab track coupled system(TSCS)in high-speed railways(HSRs).This study aims to analyze the mechanical behavior evolution of TSCS under subgrade settlement and earthquake excitation.The refined numerical model of slab track under subgrade differential settlement is established.The short settlement wavelength of 10 m causes the separation between the base and subgrade.The dynamic model of TSCS under subgrade settlement and earthquake excitation is developed.The dynamic response of TSCS exhibits more pronounced fluctuations under the combined effects of subgrade settlement and earthquake excitation than under the effects of settlement or earthquake alone.The evaluation indexes for the running safety of train on slab track under different settlement wavelengths exhibit varying degrees of increase with settlement amplitude and are particularly sensitive to the short settlement wavelength of 10 m.The wheel unloading rate and derailment coefficient of TSCS increase with earthquake intensity.Under the settlement wavelength of 10 m and amplitude of 20 mm,the wheel unloading rate of TSCS exceeds the allowable limit when the earthquake intensity exceeds 0.17g,and the derailment coefficient exceeds the allowable limit when the earthquake intensity surpasses 0.29g.
文摘针对Tri-training算法利用无标记样例时会引入噪声且限制无标记样例的利用率而导致分类性能下降的缺点,提出了AR-Tri-training(Tri-training with assistant and rich strategy)算法。提出辅助学习策略,结合富信息策略设计辅助学习器,并将辅助学习器应用在Tri-training训练以及说话声识别中。实验结果表明,辅助学习器在Tri-training训练的基础上不仅降低每次迭代可能产生的误标记样例数,而且能够充分地利用无标记样例以及在验证集上的错分样例信息。从实验结果可以得出,该算法能够弥补Tri-training算法的缺点,进一步提高测试率。
基金support of the National Key Research and Development Plan(No.2021YFB3302501)the financial support of the National Science Foundation of China(No.12161076)the financial support of the Fundamental Research Funds for the Central Universities(No.DUT25GF207).
文摘With the rapid development of artificial intelligence,intelligent air combat maneuver decision-making(ACMD)has garnered global attention.Although deep reinforcement learning provides a promising approach to ACMD,existing methods often suffer from rigid reward functions and limited adaptability to evolving adversarial strategies.Moreover,most research assumes open airspace,overlooking the influence of potential obstacles.In this paper,we address one-on-one within-visual-range ACMD in obstructed environments,and propose an improved Soft Actor-Critic(SAC)algorithm trained under a curriculum self-play framework.A maneuver strategy mirroring inference module is integrated to estimate each other's likely positions when visual obstruction occurs.By leveraging curriculum learning to guide progressive experience accumulation and self-play for adversarial evolution,our method enhances both training efficiency and tactical diversity.We further integrate an attention mechanism that dynamically adjusts the weights of sub-rewards,enabling the learned policy to adapt to rapidly changing air combat situations.Numerical simulations demonstrate that our enhanced SAC converges more quickly and achieves higher win rates than other baseline methods.An animation is available at bilibili.com/video/BV1BHVszHE98 for better illustration.
基金Project(U2034211)supported by the National Natural Science Foundation of ChinaProject(20232ACE01013)supported by the Major Scientific and Technological Research and Development Special Project of Jiangxi Province,China。
文摘The safe driving and operation of trains is a necessary condition for ensuring the safe operation of trains.In particular,heavy-haul trains are characterized by the difficulty in driving and operation.Considering the uncertainties in train driving and operation,this paper analyzes the relationship between the safety of heavy-haul electric locomotive hauled trains and driving and operation.It studies the auxiliary intelligent driving safety operation control methods.Through K-means to identify the characteristics of drivers'driving manipulation,the hidden Markov model adaptively adjusts the train driving and operation sequence,and conducts auxiliary driving reconstruction for heavy-haul locomotive driving and operation.Based on the train running curve and the locomotive traction/braking characteristics,it smoothly controls the exertion of the traction/braking force of heavy-haul locomotives,thereby optimizing the driving safety control of heavy-haul trains in the vehicle-environment-track system.Finally,the train operation simulation and optimized driving verification are carried out by simulating some track sections.The results show that the proposed method can correct and pre-optimize driving operations,improving the smoothness of heavy-haul trains by approximately 10%.It verifies the effectiveness of the proposed train assisted driving control reconstruction method,facilitating the smooth and safe operation of heavy-haul trains.
基金Project(51378050) supported by the National Natural Science Foundation of ChinaProject(B13002) supported by the “111” Project,China+2 种基金Project (8192035) supported by the Beijing Municipal Natural Science Foundation,ChinaProject(P2019G002) supported by the Science and Technology Research and Development Program of China RailwayProject(2019YJ193) supported by the State Key Laboratory for Track Technology of High-speed Railway,China。
文摘Bridges crossing active faults are more likely to suffer serious damage or even collapse due to the wreck capabilities of near-fault pulses and surface ruptures under earthquakes.Taking a high-speed railway simply-supported girder bridge with eight spans crossing an active strike-slip fault as the research object,a refined coupling dynamic model of the high-speed train-CRTS III slab ballastless track-bridge system was established based on ABAQUS.The rationality of the established model was thoroughly discussed.The horizontal ground motions in a fault rupture zone were simulated and transient dynamic analyses of the high-speed train-track-bridge coupling system under 3-dimensional seismic excitations were subsequently performed.The safe running speed limits of a high-speed train under different earthquake levels(frequent occurrence,design and rare occurrence)were assessed based on wheel-rail dynamic(lateral wheel-rail force,derailment coefficient and wheel-load reduction rate)and rail deformation(rail dislocation,parallel turning angle and turning angle)indicators.Parameter optimization was then investigated in terms of the rail fastener stiffness and isolation layer friction coefficient.Results of the wheel-rail dynamic indicators demonstrate the safe running speed limits for the high-speed train to be approximately 200 km/h and 80 km/h under frequent and design earthquakes,while the train is unable to run safely under rare earthquakes.In addition,the rail deformations under frequent,design and rare earthquakes meet the safe running requirements of the high-speed train for the speeds of 250,100 and 50 km/h,respectively.The speed limits determined for the wheel-rail dynamic indicators are lower due to the complex coupling effect of the train-track-bridge system under track irregularity.The running safety of the train was improved by increasing the fastener stiffness and isolation layer friction coefficient.At the rail fastener lateral stiffness of 60 kN/mm and isolation layer friction coefficients of 0.9 and 0.8,respectively,the safe running speed limits of the high-speed train increased to 250 km/h and 100 km/h under frequent and design earthquakes,respectively.
