Lithium ion battery fire hazard has been well-documented in a variety of applications.Recently,battery train technology has been introduced as a clean energy concept for railway.In the case of heavy locomotives such a...Lithium ion battery fire hazard has been well-documented in a variety of applications.Recently,battery train technology has been introduced as a clean energy concept for railway.In the case of heavy locomotives such as trains,the massive collection of battery stacks required to meet energy demands may pose a significant hazard.The objective of this paper is to review the risk evaluation processes for train fires and investigate the propagation of lithium ion battery fire to a neighboring steel warehouse structure at a rail repair shop through a case study.The methodology of the analyses conducted include a Monte Carlo-based dynamic modeling of fire propagation potentials,an expert-based fire impact analysis,and a finite element(FE)nonlinear fire analysis on the structural frame.The case study is presented as a demonstration of a holistic fire risk analysis for the lithium ion battery fire and results indicate that significant battery fire mitigations strategies should be considered.展开更多
When a subway train catches fire and moves towards the nearest station for personnel evacuation,the piston effect generated by its movement and thermal buoyancy leads to complex smoke spread.A reasonable train speed c...When a subway train catches fire and moves towards the nearest station for personnel evacuation,the piston effect generated by its movement and thermal buoyancy leads to complex smoke spread.A reasonable train speed can reduce both the smoke temperature and the spread range,which benefts personnel evacuation.The Navier-Stokes equations and the fully buoyancy-corrected renormalization group(RNG)k-ε turbulence model are used to develop a smoke spread model.To determine the influence of a moving train and its speed on smoke spread,an emergency operating speed for subway trains is proposed to minimize the impact of smoke spread.The results are as follows.Smoke spread is dominated by piston wind and thermal buoyancy.As the train's speed increases,the piston wind also increases,resulting in higher air velocity,lower smoke temperature and a greater spread range in the downstream area.After the train stops in the tunnel,the average temperature follows a logarithmic distribution relative to the train's speed,while the distribution coefficient exhibits a linear relationship with the stopping time.By fitting the smoke spread distance upstream of the fire source to the train's operating speed,we determine that the emergency operating speed of the train in the event of a fire accident is v=14.47 m/s.This speed corresponds to the shortest smoke spread distance in the downstream area,with no high-temperature smoke spreads in the upstream area.展开更多
BACKGROUND Cognitive frailty and depression are prevalent among the elderly,significantly impairing physical and cognitive functions,psychological well-being,and quality of life.Effective interventions are essential t...BACKGROUND Cognitive frailty and depression are prevalent among the elderly,significantly impairing physical and cognitive functions,psychological well-being,and quality of life.Effective interventions are essential to mitigate these adverse effects and enhance overall health outcomes in this population.AIM To evaluate the effects of exercise-cognitive dual-task training on frailty,cognitive function,psychological status,and quality of life in elderly patients with cognitive frailty and depression.METHODS A retrospective study was conducted on 130 patients with cognitive frailty and depression admitted between December 2021 and December 2023.Patients were divided into a control group receiving routine intervention and an observation group undergoing exercise-cognitive dual-task training in addition to routine care.Frailty,cognitive function,balance and gait,psychological status,and quality of life were assessed before and after the intervention.RESULTS After the intervention,the frailty score of the observation group was(5.32±0.69),lower than that of the control group(5.71±0.55).The Montreal cognitive assessment basic scale score in the observation group was(24.06±0.99),higher than the control group(23.43±1.40).The performance oriented mobility assessment score in the observation group was(21.81±1.24),higher than the control group(21.15±1.26).The self-efficacy in the observation group was(28.27±2.66),higher than the control group(30.05±2.66).The anxiety score in the hospital anxiety and depression scale(HADS)for the observation group was(5.86±0.68),lower than the control group(6.21±0.64).The depression score in the HADS for the observation group was(5.67±0.75),lower than the control group(6.27±0.92).Additionally,the scores for each dimension of the 36-item short form survey in the observation group were higher than those in the control group,with statistically significant differences(P<0.05).CONCLUSION Exercise-cognitive dual-task training is beneficial for improving frailty,enhancing cognitive function,and improving psychological status and quality of life in elderly patients with cognitive frailty and depression.展开更多
Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model a...Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.展开更多
Here we compare the efficacy of anti-obesity drugs alone or combined with exercise training on body weight and exercise capacity of obese patients.Randomized clinical trials that assessed the impact of any anti-obesit...Here we compare the efficacy of anti-obesity drugs alone or combined with exercise training on body weight and exercise capacity of obese patients.Randomized clinical trials that assessed the impact of any anti-obesity drug alone or combined with exercise training on body weight,body fat,fat-free mass and cardiorespiratory fitness in obese patients were retrieved from Pubmed and EMBASE up to May 2024.Risk of bias assessment was performed with RoB 2.0,and the GRADE approach assessed the certainty of evidence(CoE)of each main outcome.We included four publications summing up 202 patients.Two publications used orlistat as an anti-obesity drug treatment,while the other two adopted GLP-1 receptor agonist(liraglutide or tirzepatide)as a pharmacotherapy for weight management.Orlistat combined with exercise was superior to change body weight(mean difference(MD):−2.27 kg;95%CI:−2.86 to−1.69;CoE:very low),fat mass(MD:−2.89;95%CI:−3.87 to−1.91;CoE:very low),fat-free mass(MD:0.56;95%CI:0.40–0.72;CoE:very low),and VO_(2)Peak(MD:2.64;95%CI:2.52–2.76;CoE:very low).GLP-1 receptor agonist drugs combined with exercise had a great effect on body weight(MD:−3.96 kg;95%CI:−5.07 to−2.85;CoE:low),fat mass(MD:−1.76;95%CI:−2.24 to−1.27;CoE:low),fat-free mass(MD:0.50;95%CI:−0.98 to 1.98;CoE:very low)and VO_(2)Peak(MD:2.47;95%CI:1.31–3.63;CoE:very low).The results reported here suggest that exercise training remains an important approach in weight management when combined with pharmacological treatment.展开更多
This paper introduces the Surrogate-assisted Multi-objective Grey Wolf Optimizer(SMOGWO)as a novel methodology for addressing the complex problem of empty-heavy train allocation,with a focus on line utilization balanc...This paper introduces the Surrogate-assisted Multi-objective Grey Wolf Optimizer(SMOGWO)as a novel methodology for addressing the complex problem of empty-heavy train allocation,with a focus on line utilization balance.By integrating surrogate models to approximate the objective functions,SMOGWO significantly improves the efficiency and accuracy of the optimization process.The effectiveness of this approach is evaluated using the CEC2009 multi-objective test function suite,where SMOGWO achieves a superiority rate of 76.67%compared to other leading multi-objective algorithms.Furthermore,the practical applicability of SMOGWO is demonstrated through a case study on empty and heavy train allocation,which validates its ability to balance line capacity,minimize transportation costs,and optimize the technical combination of heavy trains.The research highlights SMOGWO's potential as a robust solution for optimization challenges in railway transportation,offering valuable contributions toward enhancing operational efficiency and promoting sustainable development in the sector.展开更多
In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of v...In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of vortex-induced vibration(VIV)of the tail car body is established,and the aerodynamics of train-tail swaying is studied.The simulation results were confirmed through a field test of operating EMUs.Furthermore,the influence mechanism of train-tail swaying on the wake flow field is studied in detail through a wind-tunnel experiment and a simulation of a reduced-scaled train model.The results demonstrate that the aerodynamic force frequency(i.e.,vortex-induced frequency)of the train tail increases linearly with train speed.When the train runs at 130 km/h,with a small amplitude of train-tail swaying(within 10 mm),the vortex-induced frequency is 1.7 Hz,which primarily depends on the nose shape of the train tail.After the tail car body nose is extended,the vortex-induced frequency is decreased.As the swaying amplitude of the train tail increases(exceeding 25 mm),the separation point of the high-intensity vortex in the train wake shifts downstream to the nose tip,and the vortex-induced frequency shifts from 1.7 Hz to the nearby car body hunting(i.e.,the primary hunting)frequency of 1.3 Hz,which leads to the frequency-locking phenomenon of VIV,and the resonance intensifies train-tail swaying.For the motor vehicle of the train tail,optimization of the yaw damper to improve its primary hunting stability can effectively alleviate train-tail swaying inside single-line tunnels.Optimization of the tail car body nose shape reduces the amplitude of the vortex-induced force,thereby weakening the aerodynamic effect and solving the problem of train-tail swaying inside the single-line tunnels.展开更多
Purpose–In recent years,the rapid advancement of artificial intelligence(AI)has exerted profound impacts on and provided strong impetus to numerous fields in the industrial sector.Within the railway industry,AI has d...Purpose–In recent years,the rapid advancement of artificial intelligence(AI)has exerted profound impacts on and provided strong impetus to numerous fields in the industrial sector.Within the railway industry,AI has driven continuous upgrading and optimization of intelligent train control technology,thanks to its enhanced computational capabilities derived from advanced algorithms and models,as well as its role in improving safety performance.Integrating AI technology more extensively into train autonomous driving and control has thus become an inevitable trend in the global development of railways.Design/methodology/approach–This paper,therefore,conducts a comprehensive analysis of the development progress and current status of AI technology applications in the field of train driving and control on a global scale.It systematically sorts out and analyzes the advantages of various AI technologies and the positive impacts they bring to the upgrading of train control technology,elucidates the feasibility and future prospects of applying a range of emerging AI technologies from the perspective of technical theory and provides guidance for the intelligent development of this field from a practical perspective.Findings–The application of AI technology in the train driving and control field is still in its infancy.While a large number of AI technologies have been widely adopted,there remains significant room for further optimization and improvement of these technologies.Additionally,a variety of AI technologies that have been applied in other industrial sectors but not yet widely implemented in training autonomous driving and control have demonstrated tremendous development potential.Originality/value–The research findings provide references and guidance for advancing train control technology,promoting the digital transformation of railways,accelerating the overall optimization and upgrading of railway industry technologies,and facilitating the accelerated development of global railways.展开更多
Exercise is a therapeutic approach in cancer treatment,providing several benefits.Moreover,exercise is associated with a reduced risk for developing a range of cancers and for their recurrence,as well as with improvin...Exercise is a therapeutic approach in cancer treatment,providing several benefits.Moreover,exercise is associated with a reduced risk for developing a range of cancers and for their recurrence,as well as with improving survival,even though the underlying mechanisms remain unclear.Preclinical and clinical evidence shows that the acute effects of a single exercise session can suppress the growth of various cancer cell lines in vitro.This suppression is potentially due to altered concentrations of hormones(e.g.,insulin)and cytokines(e.g.,tumor necrosis factor alpha and interleukin 6)after exercise.These factors,known to be involved in tumorigenesis,may explain why exercise is associated with reduced cancer incidence,recurrence,and mortality.However,the effects of short-(<8 weeks)and long-term(≥8 weeks)exercise programs on cancer cells have been reported with mixed results.Although more research is needed,it appears that interventions incorporating both exercise and diet seem to have greater inhibitory effects on cancer cell growth in both apparently healthy subjects as well as in cancer patients.Although speculative,these suppressive effects on cancer cells may be driven by changes in body weight and composition as well as by a reduction in low-grade inflammation often associated with sedentary behavior,low muscle mass,and excess fat mass in cancer patients.Taken together,such interventions could alter the systemic levels of suppressive circulating factors,leading to a less favorable environment for tumorigenesis.While regular exercise and a healthy diet may establish a more cancer-suppressive environment,each acute bout of exercise provides a further“dose”of anticancer medicine.Therefore,integrating regular exercise could potentially play a significant role in cancer management,highlighting the need for future investigations in this promising area of research.展开更多
This study investigates preschool teachers’post-service training needs and explores strategies to enhance training effectiveness.A total of 31 teachers from A Kindergarten in S City,Jiangsu Province,participated in q...This study investigates preschool teachers’post-service training needs and explores strategies to enhance training effectiveness.A total of 31 teachers from A Kindergarten in S City,Jiangsu Province,participated in questionnaires and semi-structured interviews.Results show that teachers widely recognize the importance of post-service training for professional competence and educational quality.Their main needs center on teaching skills,updated educational theories,and practical experience.Most preferred blended online-offline formats to balance flexibility and efficiency.Challenges remain,including mismatched content,limited resources,lack of personalization,and weak evaluation mechanisms.Drawing on domestic and international research,this paper suggests strengthening needs assessments,optimizing training content and methods,developing personalized profiles,and improving evaluation systems.These approaches are expected to enhance training effectiveness,foster teachers’professional growth,and promote sustainable preschool education.展开更多
Background Schizophrenia is characterised by pervasive cognitive deficits that significantly impair daily functioning and quality of life.Pharmacological treatments have limited efficacy in addressing these deficits,h...Background Schizophrenia is characterised by pervasive cognitive deficits that significantly impair daily functioning and quality of life.Pharmacological treatments have limited efficacy in addressing these deficits,highlighting the need for adjunctive interventions like computerised cognitive training(CCT).Aims This study aimed to evaluate the effects of a 30-session CCT programme on mental well-being and cognitive performance in individuals with schizophrenia.Additionally,it assessed the usability and acceptability of CCT in this population.Methods A double-blind,randomised clinical trial was conducted with 54 participants assigned to intervention and control groups.Cognitive and mental health outcomes were assessed using validated tools such as the Depression Anxiety Stress Scale 21,the Warwick-Edinburgh Mental Wellbeing Scale and the Cambridge Neuropsychological Test Automated Battery.Usability was measured with the System Usability Scale(SUS).Assessments were conducted at baseline,post-intervention and 3 months post-follow-up.Results The CCT intervention significantly improved mental well-being,reduced stress and enhanced working memory(paired associate learning,spatial working memory and spatial span)compared with controls.However,no significant effects were observed for anxiety,depression or executive function.Usability scores were high(SUS=83.51),and compliance rates were strong(92.7%),indicating favourable participant engagement.Conclusion CCT demonstrated potential as an adjunctive treatment for schizophrenia,with significant improvements in targeted cognitive and mental health domains.The high usability and compliance rates support its feasibility for broader implementation.Further research is needed to optimise protocols and explore long-term benefits.CCT offers a promising approach to addressing mental health and cognitive challenges in schizophrenia,particularly for stress and working memory.Its usability and acceptability suggest it could be seamlessly integrated into clinical practice.展开更多
Standardized residency training programs primarily focus on developing clinical diagnostic and treatment skills,often allocating limited time to research activities.However,enhancing research skills is of paramount im...Standardized residency training programs primarily focus on developing clinical diagnostic and treatment skills,often allocating limited time to research activities.However,enhancing research skills is of paramount importance for residents,as it fosters critical thinking,problem-solving abilities,and a deeper understanding of applying scientific principles to clinical practice.This paper explores the necessity and significance of integrating research training into residency programs,emphasizing its role in cultivating well-rounded physicians capable of advancing medical knowledge.This study proposes a competency-based research training model that encompasses research literacy,study design,biostatistics,and scientific writing.Additionally,online asynchronous training modules,robust mentorship,and balanced time management strategies are recommended to enhance residents’research engagement without compromising clinical training.By implementing these measures,residency programs can improve residents’research capabilities,contributing to both individual professional growth and the broader advancement of medical science.展开更多
High-speed maglev trains(HSMTs)can run at high running speeds due to their unique design.The pressure waves that these trains generate while passing each other are therefore very intense,and can even have safety impli...High-speed maglev trains(HSMTs)can run at high running speeds due to their unique design.The pressure waves that these trains generate while passing each other are therefore very intense,and can even have safety implications.In order to reduce the transient impact of such waves,the standard k-ε turbulence model is used in this work to assess the effect of railway spacing on the aerodynamic loads,pressure and surrounding flow field of 600 km/h maglev trains passing each other in open air.The sliding mesh technique is used to determine the relative motion between the considered trains.The results show that the surface pressure is approximately linearly correlated with the square of the speed while the amplitude of the pressure wave on the train surface,side force,and rolling moment all have negative exponential relationships with the railway spacing.展开更多
Global Navigation Satellite Systems(GNSSs)are vulnerable to both unintentional interference and intentional attacks,making it difficult to meet the stringent safety requirements of railway train control systems.The gr...Global Navigation Satellite Systems(GNSSs)are vulnerable to both unintentional interference and intentional attacks,making it difficult to meet the stringent safety requirements of railway train control systems.The growing threat to information security posed by spoofing attacks has received limited attention.This study investigates the impact of GNSS spoofing attacks on train positioning,emphasizing their detrimental effects on the accuracy and availability of train location report functions for train operation control.To explore the antispoofing performance of typical GNSS-based train positioning schemes,specific approaches,and system architectures are designed under two GNSS-alone and two GNSS-integrated train positioning schemes.Field data are utilized to establish spoofing attack scenarios for GNSS-based train positioning,with which the anti-spoofing capabilities of different train positioning schemes are evaluated.Experimental results indicate that under specific conditions,the GNSS-integrated positioning schemes demonstrate superior GNSS spoofing suppression capabilities.Results of the tests present valuable guidance for designers and manufacturers in developing more advanced and resilient train positioning solutions and equipment for the next generation of train control systems,thereby promoting the applications of GNSS technology in railway systems.展开更多
Arrival headway,the minimum time interval between two trains that consecutively stop in the same railway yard,significantly influences overall railway capacity and becomes a bottleneck in large high-speed railway yard...Arrival headway,the minimum time interval between two trains that consecutively stop in the same railway yard,significantly influences overall railway capacity and becomes a bottleneck in large high-speed railway yards.This occurs because the leading train slows considerably along the long receiving route to the yard;while,the following train continues at top speed,creating a substantial spatial and temporal interval between them.This paper proposes a speed profile intervention(SPI)approach to reduce arrival headway.By setting appropriate speed limits in specific block sections for each train,the following train decelerates in advance,thereby shortening the interval with its predecessor.We first study the impact of speed values and locations on arrival headway theoretically,then validate our findings through a multi-agent simulation approach to quantitatively investigate the relationship between headway and SPI parameters.Simulation experiments using real-world data from the Beijing–Shanghai high-speed railway demonstrate that the SPI approach can significantly reduce arrival headway without any infrastructure modifications.To mitigate potential side effects on travel time associated with this approach,we perform an analysis that involves setting appropriate speed limit values and selecting strategic locations for their implementation.展开更多
Virtual coupling(VC) is an emerging technology for addressing the shortage of rail transportation capacity. As a crucial enabling technology, the VC-specific acquisition of train information, especially train followin...Virtual coupling(VC) is an emerging technology for addressing the shortage of rail transportation capacity. As a crucial enabling technology, the VC-specific acquisition of train information, especially train following distance(TFD), is underdeveloped.In this paper, a novel method is proposed to acquire real-time TFD by analyzing the vibration response of the front and following trains, during which only onboard accelerometers and speedometers are required. In contrast to the traditional arts of train positioning, this method targets a relative position between two adjacent trains in VC operation, rather than the global positions of the trains. For this purpose, an adaptive system containing three strategies is designed to cope with possible adverse factors in train operation. A vehicle dynamics simulation of a heavy-haul railway is implemented for the evaluation of feasibility and performance. Furthermore, a validation is conducted using a set of data measured from in-service Chinese high-speed trains. The results indicate the method achieves satisfactory estimation accuracy using both simulated and actual data. It has favorable adaptability to various uncertainties possibly encountered in train operation. Additionally, the method is preliminarily proven to adapt to different locomotive types and even different rail transportation modes. In general, such a method with good performance, low-cost, and easy implementation is promising to apply.展开更多
In recent years,railway construction in China has developed vigorously.With continuous improvements in the highspeed railway network,the focus is gradually shifting from large-scale construction to large-scale operati...In recent years,railway construction in China has developed vigorously.With continuous improvements in the highspeed railway network,the focus is gradually shifting from large-scale construction to large-scale operations.However,several challenges have emerged within the high-speed railway dispatching and command system,including the heavy workload faced by dispatchers,the difficulty of quantifying subjective expertise,and the need for effective training of professionals.Amid the growing application of artificial intelligence technologies in railway systems,this study leverages Large Language Model(LLM)technology.LLMs bring enhanced intelligence,predictive capabilities,robust memory,and adaptability to diverse real-world scenarios.This study proposes a human-computer interactive intelligent scheduling auxiliary training system built on LLM technology.The system offers capabilities including natural dialogue,knowledge reasoning,and human feedback learning.With broad applicability,the system is suitable for vocational education,guided inquiry,knowledge-based Q&A,and other training scenarios.Validation results demonstrate its effectiveness in auxiliary training,providing substantial support for educators,students,and dispatching personnel in colleges and professional settings.展开更多
This paper reports a case of cerebral stem infarction with quadriplegia and complete dependence on daily life.The course of the disease lasted more than 7 months.Frenchay's improved articulation Disorder Assessmen...This paper reports a case of cerebral stem infarction with quadriplegia and complete dependence on daily life.The course of the disease lasted more than 7 months.Frenchay's improved articulation Disorder Assessment Form has been assessed as severe articulation disorder.The patient has significantly improved his speech function and quality of life after systematic head control training,respiratory function training,articulation motor training,and articulation training.In the course of treatment,emphasis was placed on head postural control training and respiratory function training,and emphasis was placed on the strength and coordination training of articulatory organs,and the results were remarkable.After the patient was discharged from the hospital,the follow-up of basic daily life communication was not limited.展开更多
Endoscopic ultrasound(EUS)is an indispensable tool for the diagnosis and management of various diseases,particularly biliopancreatic disorders,as it provides detailed visualization of the gastrointestinal tract and su...Endoscopic ultrasound(EUS)is an indispensable tool for the diagnosis and management of various diseases,particularly biliopancreatic disorders,as it provides detailed visualization of the gastrointestinal tract and surrounding structures.As the demand for diagnostic and interventional EUS procedures increases,ensuring high-quality training for endoscopists is essential to improve patient outcomes.This mini-review provides an overview of the current state of EUS training and emphasizes the importance of a structured approach that integrates theoretical knowledge and hands-on experience.We discuss different training methods,focusing on the main courses available worldwide,and highlight their advantages and limitations.In addition,we examine the challenges of training for diagnostic and interventional EUS,such as limited access to training centers and the need for personalized feedback.Overall,improving EUS training programs is essential to enhance physician skills and ensure this advanced technique is used safely and efficiently in clinical practice.展开更多
基金The authors would like to acknowledge the funding received under NCDOT Project#2020-40.Additional funding also received from the UNC Charlotte College of Engineering Dean’s Office.Dean Bob Johnson’s support of this effort is greatly appreciated.
文摘Lithium ion battery fire hazard has been well-documented in a variety of applications.Recently,battery train technology has been introduced as a clean energy concept for railway.In the case of heavy locomotives such as trains,the massive collection of battery stacks required to meet energy demands may pose a significant hazard.The objective of this paper is to review the risk evaluation processes for train fires and investigate the propagation of lithium ion battery fire to a neighboring steel warehouse structure at a rail repair shop through a case study.The methodology of the analyses conducted include a Monte Carlo-based dynamic modeling of fire propagation potentials,an expert-based fire impact analysis,and a finite element(FE)nonlinear fire analysis on the structural frame.The case study is presented as a demonstration of a holistic fire risk analysis for the lithium ion battery fire and results indicate that significant battery fire mitigations strategies should be considered.
基金supported by the National Natural Science Foun-dation of China(Grant No.U2468220).
文摘When a subway train catches fire and moves towards the nearest station for personnel evacuation,the piston effect generated by its movement and thermal buoyancy leads to complex smoke spread.A reasonable train speed can reduce both the smoke temperature and the spread range,which benefts personnel evacuation.The Navier-Stokes equations and the fully buoyancy-corrected renormalization group(RNG)k-ε turbulence model are used to develop a smoke spread model.To determine the influence of a moving train and its speed on smoke spread,an emergency operating speed for subway trains is proposed to minimize the impact of smoke spread.The results are as follows.Smoke spread is dominated by piston wind and thermal buoyancy.As the train's speed increases,the piston wind also increases,resulting in higher air velocity,lower smoke temperature and a greater spread range in the downstream area.After the train stops in the tunnel,the average temperature follows a logarithmic distribution relative to the train's speed,while the distribution coefficient exhibits a linear relationship with the stopping time.By fitting the smoke spread distance upstream of the fire source to the train's operating speed,we determine that the emergency operating speed of the train in the event of a fire accident is v=14.47 m/s.This speed corresponds to the shortest smoke spread distance in the downstream area,with no high-temperature smoke spreads in the upstream area.
文摘BACKGROUND Cognitive frailty and depression are prevalent among the elderly,significantly impairing physical and cognitive functions,psychological well-being,and quality of life.Effective interventions are essential to mitigate these adverse effects and enhance overall health outcomes in this population.AIM To evaluate the effects of exercise-cognitive dual-task training on frailty,cognitive function,psychological status,and quality of life in elderly patients with cognitive frailty and depression.METHODS A retrospective study was conducted on 130 patients with cognitive frailty and depression admitted between December 2021 and December 2023.Patients were divided into a control group receiving routine intervention and an observation group undergoing exercise-cognitive dual-task training in addition to routine care.Frailty,cognitive function,balance and gait,psychological status,and quality of life were assessed before and after the intervention.RESULTS After the intervention,the frailty score of the observation group was(5.32±0.69),lower than that of the control group(5.71±0.55).The Montreal cognitive assessment basic scale score in the observation group was(24.06±0.99),higher than the control group(23.43±1.40).The performance oriented mobility assessment score in the observation group was(21.81±1.24),higher than the control group(21.15±1.26).The self-efficacy in the observation group was(28.27±2.66),higher than the control group(30.05±2.66).The anxiety score in the hospital anxiety and depression scale(HADS)for the observation group was(5.86±0.68),lower than the control group(6.21±0.64).The depression score in the HADS for the observation group was(5.67±0.75),lower than the control group(6.27±0.92).Additionally,the scores for each dimension of the 36-item short form survey in the observation group were higher than those in the control group,with statistically significant differences(P<0.05).CONCLUSION Exercise-cognitive dual-task training is beneficial for improving frailty,enhancing cognitive function,and improving psychological status and quality of life in elderly patients with cognitive frailty and depression.
文摘Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.
基金supported by Brazilian agencies CAPES(Finance Code 001)CNPq through PQ productivity scholarship.
文摘Here we compare the efficacy of anti-obesity drugs alone or combined with exercise training on body weight and exercise capacity of obese patients.Randomized clinical trials that assessed the impact of any anti-obesity drug alone or combined with exercise training on body weight,body fat,fat-free mass and cardiorespiratory fitness in obese patients were retrieved from Pubmed and EMBASE up to May 2024.Risk of bias assessment was performed with RoB 2.0,and the GRADE approach assessed the certainty of evidence(CoE)of each main outcome.We included four publications summing up 202 patients.Two publications used orlistat as an anti-obesity drug treatment,while the other two adopted GLP-1 receptor agonist(liraglutide or tirzepatide)as a pharmacotherapy for weight management.Orlistat combined with exercise was superior to change body weight(mean difference(MD):−2.27 kg;95%CI:−2.86 to−1.69;CoE:very low),fat mass(MD:−2.89;95%CI:−3.87 to−1.91;CoE:very low),fat-free mass(MD:0.56;95%CI:0.40–0.72;CoE:very low),and VO_(2)Peak(MD:2.64;95%CI:2.52–2.76;CoE:very low).GLP-1 receptor agonist drugs combined with exercise had a great effect on body weight(MD:−3.96 kg;95%CI:−5.07 to−2.85;CoE:low),fat mass(MD:−1.76;95%CI:−2.24 to−1.27;CoE:low),fat-free mass(MD:0.50;95%CI:−0.98 to 1.98;CoE:very low)and VO_(2)Peak(MD:2.47;95%CI:1.31–3.63;CoE:very low).The results reported here suggest that exercise training remains an important approach in weight management when combined with pharmacological treatment.
基金supported by the National Natural Science Foundation of China(Project No.5217232152102391)+2 种基金Sichuan Province Science and Technology Innovation Talent Project(2024JDRC0020)China Shenhua Energy Company Limited Technology Project(GJNY-22-7/2300-K1220053)Key science and technology projects in the transportation industry of the Ministry of Transport(2022-ZD7-132).
文摘This paper introduces the Surrogate-assisted Multi-objective Grey Wolf Optimizer(SMOGWO)as a novel methodology for addressing the complex problem of empty-heavy train allocation,with a focus on line utilization balance.By integrating surrogate models to approximate the objective functions,SMOGWO significantly improves the efficiency and accuracy of the optimization process.The effectiveness of this approach is evaluated using the CEC2009 multi-objective test function suite,where SMOGWO achieves a superiority rate of 76.67%compared to other leading multi-objective algorithms.Furthermore,the practical applicability of SMOGWO is demonstrated through a case study on empty and heavy train allocation,which validates its ability to balance line capacity,minimize transportation costs,and optimize the technical combination of heavy trains.The research highlights SMOGWO's potential as a robust solution for optimization challenges in railway transportation,offering valuable contributions toward enhancing operational efficiency and promoting sustainable development in the sector.
基金supported by the National Natural Science Foundation of China(Nos.52372403 and U2268211)the Natural Science Foundation of Sichuan Province(No.2022NSFSC0034),China+1 种基金the National Railway Group Science and Technology Program(No.2023J071)the Traction Power State Key Laboratory of the Independent Research and Development Projects(No.2022TPL-T02),China.
文摘In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of vortex-induced vibration(VIV)of the tail car body is established,and the aerodynamics of train-tail swaying is studied.The simulation results were confirmed through a field test of operating EMUs.Furthermore,the influence mechanism of train-tail swaying on the wake flow field is studied in detail through a wind-tunnel experiment and a simulation of a reduced-scaled train model.The results demonstrate that the aerodynamic force frequency(i.e.,vortex-induced frequency)of the train tail increases linearly with train speed.When the train runs at 130 km/h,with a small amplitude of train-tail swaying(within 10 mm),the vortex-induced frequency is 1.7 Hz,which primarily depends on the nose shape of the train tail.After the tail car body nose is extended,the vortex-induced frequency is decreased.As the swaying amplitude of the train tail increases(exceeding 25 mm),the separation point of the high-intensity vortex in the train wake shifts downstream to the nose tip,and the vortex-induced frequency shifts from 1.7 Hz to the nearby car body hunting(i.e.,the primary hunting)frequency of 1.3 Hz,which leads to the frequency-locking phenomenon of VIV,and the resonance intensifies train-tail swaying.For the motor vehicle of the train tail,optimization of the yaw damper to improve its primary hunting stability can effectively alleviate train-tail swaying inside single-line tunnels.Optimization of the tail car body nose shape reduces the amplitude of the vortex-induced force,thereby weakening the aerodynamic effect and solving the problem of train-tail swaying inside the single-line tunnels.
文摘Purpose–In recent years,the rapid advancement of artificial intelligence(AI)has exerted profound impacts on and provided strong impetus to numerous fields in the industrial sector.Within the railway industry,AI has driven continuous upgrading and optimization of intelligent train control technology,thanks to its enhanced computational capabilities derived from advanced algorithms and models,as well as its role in improving safety performance.Integrating AI technology more extensively into train autonomous driving and control has thus become an inevitable trend in the global development of railways.Design/methodology/approach–This paper,therefore,conducts a comprehensive analysis of the development progress and current status of AI technology applications in the field of train driving and control on a global scale.It systematically sorts out and analyzes the advantages of various AI technologies and the positive impacts they bring to the upgrading of train control technology,elucidates the feasibility and future prospects of applying a range of emerging AI technologies from the perspective of technical theory and provides guidance for the intelligent development of this field from a practical perspective.Findings–The application of AI technology in the train driving and control field is still in its infancy.While a large number of AI technologies have been widely adopted,there remains significant room for further optimization and improvement of these technologies.Additionally,a variety of AI technologies that have been applied in other industrial sectors but not yet widely implemented in training autonomous driving and control have demonstrated tremendous development potential.Originality/value–The research findings provide references and guidance for advancing train control technology,promoting the digital transformation of railways,accelerating the overall optimization and upgrading of railway industry technologies,and facilitating the accelerated development of global railways.
文摘Exercise is a therapeutic approach in cancer treatment,providing several benefits.Moreover,exercise is associated with a reduced risk for developing a range of cancers and for their recurrence,as well as with improving survival,even though the underlying mechanisms remain unclear.Preclinical and clinical evidence shows that the acute effects of a single exercise session can suppress the growth of various cancer cell lines in vitro.This suppression is potentially due to altered concentrations of hormones(e.g.,insulin)and cytokines(e.g.,tumor necrosis factor alpha and interleukin 6)after exercise.These factors,known to be involved in tumorigenesis,may explain why exercise is associated with reduced cancer incidence,recurrence,and mortality.However,the effects of short-(<8 weeks)and long-term(≥8 weeks)exercise programs on cancer cells have been reported with mixed results.Although more research is needed,it appears that interventions incorporating both exercise and diet seem to have greater inhibitory effects on cancer cell growth in both apparently healthy subjects as well as in cancer patients.Although speculative,these suppressive effects on cancer cells may be driven by changes in body weight and composition as well as by a reduction in low-grade inflammation often associated with sedentary behavior,low muscle mass,and excess fat mass in cancer patients.Taken together,such interventions could alter the systemic levels of suppressive circulating factors,leading to a less favorable environment for tumorigenesis.While regular exercise and a healthy diet may establish a more cancer-suppressive environment,each acute bout of exercise provides a further“dose”of anticancer medicine.Therefore,integrating regular exercise could potentially play a significant role in cancer management,highlighting the need for future investigations in this promising area of research.
文摘This study investigates preschool teachers’post-service training needs and explores strategies to enhance training effectiveness.A total of 31 teachers from A Kindergarten in S City,Jiangsu Province,participated in questionnaires and semi-structured interviews.Results show that teachers widely recognize the importance of post-service training for professional competence and educational quality.Their main needs center on teaching skills,updated educational theories,and practical experience.Most preferred blended online-offline formats to balance flexibility and efficiency.Challenges remain,including mismatched content,limited resources,lack of personalization,and weak evaluation mechanisms.Drawing on domestic and international research,this paper suggests strengthening needs assessments,optimizing training content and methods,developing personalized profiles,and improving evaluation systems.These approaches are expected to enhance training effectiveness,foster teachers’professional growth,and promote sustainable preschool education.
基金supported by a grant from University of Social Welfare and Rehabilitation Sciences for the research expenses.
文摘Background Schizophrenia is characterised by pervasive cognitive deficits that significantly impair daily functioning and quality of life.Pharmacological treatments have limited efficacy in addressing these deficits,highlighting the need for adjunctive interventions like computerised cognitive training(CCT).Aims This study aimed to evaluate the effects of a 30-session CCT programme on mental well-being and cognitive performance in individuals with schizophrenia.Additionally,it assessed the usability and acceptability of CCT in this population.Methods A double-blind,randomised clinical trial was conducted with 54 participants assigned to intervention and control groups.Cognitive and mental health outcomes were assessed using validated tools such as the Depression Anxiety Stress Scale 21,the Warwick-Edinburgh Mental Wellbeing Scale and the Cambridge Neuropsychological Test Automated Battery.Usability was measured with the System Usability Scale(SUS).Assessments were conducted at baseline,post-intervention and 3 months post-follow-up.Results The CCT intervention significantly improved mental well-being,reduced stress and enhanced working memory(paired associate learning,spatial working memory and spatial span)compared with controls.However,no significant effects were observed for anxiety,depression or executive function.Usability scores were high(SUS=83.51),and compliance rates were strong(92.7%),indicating favourable participant engagement.Conclusion CCT demonstrated potential as an adjunctive treatment for schizophrenia,with significant improvements in targeted cognitive and mental health domains.The high usability and compliance rates support its feasibility for broader implementation.Further research is needed to optimise protocols and explore long-term benefits.CCT offers a promising approach to addressing mental health and cognitive challenges in schizophrenia,particularly for stress and working memory.Its usability and acceptability suggest it could be seamlessly integrated into clinical practice.
基金Research on the Construction of a Course Ideological and Political Education System and Evaluation Framework for the“Traditional Chinese Medicine Internal Medicine”Course(Project No.:2025J0459)Open Research Fund Program of Yunnan Key Laboratory of Integrated Traditional Chinese(Project No.:CWCD2023-002,CWCD2023-003&CWCD2023-009)+2 种基金Western Medicine for Chronic Disease in Prevention and TreatmentYunnan 047 Key Laboratory of Yi Dai Medicine and Yi Medicine(Project No.:2024SS24047)Yunnan 025 Key Laboratory of Yi Dai Medicine and Yi Medicine(Project No.:2024SS24025)。
文摘Standardized residency training programs primarily focus on developing clinical diagnostic and treatment skills,often allocating limited time to research activities.However,enhancing research skills is of paramount importance for residents,as it fosters critical thinking,problem-solving abilities,and a deeper understanding of applying scientific principles to clinical practice.This paper explores the necessity and significance of integrating research training into residency programs,emphasizing its role in cultivating well-rounded physicians capable of advancing medical knowledge.This study proposes a competency-based research training model that encompasses research literacy,study design,biostatistics,and scientific writing.Additionally,online asynchronous training modules,robust mentorship,and balanced time management strategies are recommended to enhance residents’research engagement without compromising clinical training.By implementing these measures,residency programs can improve residents’research capabilities,contributing to both individual professional growth and the broader advancement of medical science.
基金supported by the National Natural Science Foundation of China(12372049)Fundamental Research Funds for the Central Universities(2682023ZTPY036)Research and Development Project of JDD For HTS Maglev Transportation System(JDDKYCF2024002).
文摘High-speed maglev trains(HSMTs)can run at high running speeds due to their unique design.The pressure waves that these trains generate while passing each other are therefore very intense,and can even have safety implications.In order to reduce the transient impact of such waves,the standard k-ε turbulence model is used in this work to assess the effect of railway spacing on the aerodynamic loads,pressure and surrounding flow field of 600 km/h maglev trains passing each other in open air.The sliding mesh technique is used to determine the relative motion between the considered trains.The results show that the surface pressure is approximately linearly correlated with the square of the speed while the amplitude of the pressure wave on the train surface,side force,and rolling moment all have negative exponential relationships with the railway spacing.
基金the National Key Research and Development Program of China(2023YFB3907300)the National Natural Science Foundation of China(U2268206,T2222015)the Beijing Natural Science Foundation(4232031).
文摘Global Navigation Satellite Systems(GNSSs)are vulnerable to both unintentional interference and intentional attacks,making it difficult to meet the stringent safety requirements of railway train control systems.The growing threat to information security posed by spoofing attacks has received limited attention.This study investigates the impact of GNSS spoofing attacks on train positioning,emphasizing their detrimental effects on the accuracy and availability of train location report functions for train operation control.To explore the antispoofing performance of typical GNSS-based train positioning schemes,specific approaches,and system architectures are designed under two GNSS-alone and two GNSS-integrated train positioning schemes.Field data are utilized to establish spoofing attack scenarios for GNSS-based train positioning,with which the anti-spoofing capabilities of different train positioning schemes are evaluated.Experimental results indicate that under specific conditions,the GNSS-integrated positioning schemes demonstrate superior GNSS spoofing suppression capabilities.Results of the tests present valuable guidance for designers and manufacturers in developing more advanced and resilient train positioning solutions and equipment for the next generation of train control systems,thereby promoting the applications of GNSS technology in railway systems.
基金supported by the National Natural Science Foundation of China(Nos.52232011 and 52272324)the National Natural Science Foundation of Sichuan Province(No.2022NSFSC0397).
文摘Arrival headway,the minimum time interval between two trains that consecutively stop in the same railway yard,significantly influences overall railway capacity and becomes a bottleneck in large high-speed railway yards.This occurs because the leading train slows considerably along the long receiving route to the yard;while,the following train continues at top speed,creating a substantial spatial and temporal interval between them.This paper proposes a speed profile intervention(SPI)approach to reduce arrival headway.By setting appropriate speed limits in specific block sections for each train,the following train decelerates in advance,thereby shortening the interval with its predecessor.We first study the impact of speed values and locations on arrival headway theoretically,then validate our findings through a multi-agent simulation approach to quantitatively investigate the relationship between headway and SPI parameters.Simulation experiments using real-world data from the Beijing–Shanghai high-speed railway demonstrate that the SPI approach can significantly reduce arrival headway without any infrastructure modifications.To mitigate potential side effects on travel time associated with this approach,we perform an analysis that involves setting appropriate speed limit values and selecting strategic locations for their implementation.
基金supported by the National Natural Science Foundation of China(52222217,52388102,52372435)the Major Science and TechnologyProject of China Energy(GJNY-22-7)
文摘Virtual coupling(VC) is an emerging technology for addressing the shortage of rail transportation capacity. As a crucial enabling technology, the VC-specific acquisition of train information, especially train following distance(TFD), is underdeveloped.In this paper, a novel method is proposed to acquire real-time TFD by analyzing the vibration response of the front and following trains, during which only onboard accelerometers and speedometers are required. In contrast to the traditional arts of train positioning, this method targets a relative position between two adjacent trains in VC operation, rather than the global positions of the trains. For this purpose, an adaptive system containing three strategies is designed to cope with possible adverse factors in train operation. A vehicle dynamics simulation of a heavy-haul railway is implemented for the evaluation of feasibility and performance. Furthermore, a validation is conducted using a set of data measured from in-service Chinese high-speed trains. The results indicate the method achieves satisfactory estimation accuracy using both simulated and actual data. It has favorable adaptability to various uncertainties possibly encountered in train operation. Additionally, the method is preliminarily proven to adapt to different locomotive types and even different rail transportation modes. In general, such a method with good performance, low-cost, and easy implementation is promising to apply.
基金the Talent Fund of Beijing Jiaotong University(Grant No.2024XKRC055).
文摘In recent years,railway construction in China has developed vigorously.With continuous improvements in the highspeed railway network,the focus is gradually shifting from large-scale construction to large-scale operations.However,several challenges have emerged within the high-speed railway dispatching and command system,including the heavy workload faced by dispatchers,the difficulty of quantifying subjective expertise,and the need for effective training of professionals.Amid the growing application of artificial intelligence technologies in railway systems,this study leverages Large Language Model(LLM)technology.LLMs bring enhanced intelligence,predictive capabilities,robust memory,and adaptability to diverse real-world scenarios.This study proposes a human-computer interactive intelligent scheduling auxiliary training system built on LLM technology.The system offers capabilities including natural dialogue,knowledge reasoning,and human feedback learning.With broad applicability,the system is suitable for vocational education,guided inquiry,knowledge-based Q&A,and other training scenarios.Validation results demonstrate its effectiveness in auxiliary training,providing substantial support for educators,students,and dispatching personnel in colleges and professional settings.
基金Teaching and Research Project of Anhui Urban Management Vocational College(Project No.:2024kfkc001)。
文摘This paper reports a case of cerebral stem infarction with quadriplegia and complete dependence on daily life.The course of the disease lasted more than 7 months.Frenchay's improved articulation Disorder Assessment Form has been assessed as severe articulation disorder.The patient has significantly improved his speech function and quality of life after systematic head control training,respiratory function training,articulation motor training,and articulation training.In the course of treatment,emphasis was placed on head postural control training and respiratory function training,and emphasis was placed on the strength and coordination training of articulatory organs,and the results were remarkable.After the patient was discharged from the hospital,the follow-up of basic daily life communication was not limited.
文摘Endoscopic ultrasound(EUS)is an indispensable tool for the diagnosis and management of various diseases,particularly biliopancreatic disorders,as it provides detailed visualization of the gastrointestinal tract and surrounding structures.As the demand for diagnostic and interventional EUS procedures increases,ensuring high-quality training for endoscopists is essential to improve patient outcomes.This mini-review provides an overview of the current state of EUS training and emphasizes the importance of a structured approach that integrates theoretical knowledge and hands-on experience.We discuss different training methods,focusing on the main courses available worldwide,and highlight their advantages and limitations.In addition,we examine the challenges of training for diagnostic and interventional EUS,such as limited access to training centers and the need for personalized feedback.Overall,improving EUS training programs is essential to enhance physician skills and ensure this advanced technique is used safely and efficiently in clinical practice.
