The road random torsional excitation is one type of torque rooted from the road roughness and vehicle drive system. This paper aims to study how the road random torsional excitation affects the dynamic characteristics...The road random torsional excitation is one type of torque rooted from the road roughness and vehicle drive system. This paper aims to study how the road random torsional excitation affects the dynamic characteristics of vehicle power train. The method of simulating the random torsional excitation of tracked vehicle is explored at first. Secondly,the road random torsional excitations under different road roughness,vehicle speeds and pre-tensions are obtained. Thirdly,the dynamic analysis model of tracked vehicle power train is constructed with the consideration of the road random torsional excitation. Eventually,the influences of this excitation on output torque,bearing support force,vibration acceleration and dynamic shear stress of transmission shafts are intensively studied.The research conclusions are helpful to correct and refine the present virtual prototype of tracked vehicle power train.展开更多
Electric power training is essential for ensuring the safety and reliability of the system.In this study,we introduce a novel Abnormal Action Recognition(AAR)system that utilizes a Lightweight Pose Estimation Network(...Electric power training is essential for ensuring the safety and reliability of the system.In this study,we introduce a novel Abnormal Action Recognition(AAR)system that utilizes a Lightweight Pose Estimation Network(LPEN)to efficiently and effectively detect abnormal fall-down and trespass incidents in electric power training scenarios.The LPEN network,comprising three stages—MobileNet,Initial Stage,and Refinement Stage—is employed to swiftly extract image features,detect human key points,and refine them for accurate analysis.Subsequently,a Pose-aware Action Analysis Module(PAAM)captures the positional coordinates of human skeletal points in each frame.Finally,an Abnormal Action Inference Module(AAIM)evaluates whether abnormal fall-down or unauthorized trespass behavior is occurring.For fall-down recognition,three criteria—falling speed,main angles of skeletal points,and the person’s bounding box—are considered.To identify unauthorized trespass,emphasis is placed on the position of the ankles.Extensive experiments validate the effectiveness and efficiency of the proposed system in ensuring the safety and reliability of electric power training.展开更多
Multi-train modeling and simulation plays a vital role in railway electrification during operation and planning phase. Study of peak power demand and energy consumed by each traction substation needs to be deter- mine...Multi-train modeling and simulation plays a vital role in railway electrification during operation and planning phase. Study of peak power demand and energy consumed by each traction substation needs to be deter- mined to verify that electrical energy flowing in its railway power feeding system is appropriate or not. Gauss-Seidel, conventional Newton-Raphson, and current injection methods are well-known and widely accepted as a tool for electrical power network solver in DC railway power supply study. In this paper, a simplified Newton-Raphson method has been proposed. The proposed method employs a set of current-balance equations at each electrical node instead of the conventional power-balance equation used in the conventional Newton-Raphson method. This concept can remarkably reduce execution time and computing complexity for multi-train simulation. To evaluate its use, Sukhumvit line of Bangkok transit system （BTS） of Thai- land with 21.6-km line length and 22 passenger stopping stations is set as a test system. The multi-train simulation integrated with the proposed power network solver is developed to simulate 1-h operation service of selected 5-min headway. From the obtained results, the proposed method is more efficient with approximately 18 % faster than the conventional Newton-Raphson method and just over 6 % faster than the current injection method.展开更多
The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In...The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In this paper, an optical motion capture system based on the virtual reality technology is proposed to meet the requirements of the power enterprise for the qualified business ability. Electric power equipment, power equipment model entitative operating environment and the human model are established by electric power simulation unit, ZigBee technology and OpenGL graphics library. The problem of missing feature points is solved by applying the human model driven algorithm and the Kalman filtering algorithm. The experimental results show that it is more accurate to use Kalman filtering algorithm to extract the feature point in tracking process of actual motion capture and real-time animation display. The average absolute error of 3D coordinates is 1.61 mm and the average relative error is 2.23%. The system can improve trainees’ sense of experience and immersion.展开更多
An approach of training working staff of power system operation mode based on state evaluation is proposed. In terms of knowledge features of power system operation mode, we studied a training method based on evaluati...An approach of training working staff of power system operation mode based on state evaluation is proposed. In terms of knowledge features of power system operation mode, we studied a training method based on evaluation of learning state. This training method makes individual learning for different individual condition to give them ability to grasp learning points quickly, evaluate real-time learning effect, update learning style in time and summarize problems after one learning stage, so that learners can master professional knowledge in constant summaries and feedbacks. Obvious effects can be obtained on discontinuous learning time that trainees can master basic theories associated with their working and operations adapted to practical work quickly.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
In South Africa,nurses and doctors are emigrating in significant numbers. Job satisfaction,safety and ensuring career progression are important in retaining doctors to make a career in Republic of South Africa (RSA). ...In South Africa,nurses and doctors are emigrating in significant numbers. Job satisfaction,safety and ensuring career progression are important in retaining doctors to make a career in Republic of South Africa (RSA). Due to budgetary constraints many hospitals have not been upgraded. Coming home after overseas training seems difficult. In RSA it takes a minimum of 13 years for a young specialist to become registered and 15 years for subspecialists. Career progression,creating more specialist trainees in public and private hospitals and shortening the period of professional training are potential solutions to the problem. India,which has a population of more than 1 billion people,is struggling with similar problems. For the past 10-15 years,private hospitals have assisted in manpower development for medical specialist and subspecialist careers. Currently their private sector trains 60% of their recognised (sub)specialities fellows. A national task force for specialist training in RSA should be instituted. It should discuss,based on the current status and projected specialist and subspecialist personnel requirements,thefuture structure and logistics of training needs. This is required in all subspecialities including gastroenterology,as has been done in India. It is hoped that as a consequence well-trained doctors,similar to those in India,might move to provincial hospitals in rural areas,upgrading the medical services and keeping medical power in South Africa. South Africa should become a model for Sub-Saharan Africa,as India already is for South-East Asia.展开更多
To utilize exist SCADA(Supervisory Control and Data Acqui si tion)/EMS (Energy Management System) fully and economize capital, Henan Electric Power Dispatching and Communication Center in China established a set of H...To utilize exist SCADA(Supervisory Control and Data Acqui si tion)/EMS (Energy Management System) fully and economize capital, Henan Electric Power Dispatching and Communication Center in China established a set of Henan Dispatcher Training Simulator (HNDTS) base on its exist SCADA/EMS. In order to i ntegrated with exist SCADA/EMS, the integration method and technique are propose d. Graph data integration discussed with emphasis. After integration implemented , HNDTS can share all data with SCADA/EMS and dispatchers can be trained in same environment as real work situation, in the same time it can avoid amout of work of maintenance engineers. Both advantages and disadvantages of integration are analyzed. In the end of paper, the requirement for future DTS is put forward bas e on the experience of author.展开更多
Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were all...Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group(n = 7)or the plyometric training group(n = 7).The preliminary tests required subjects to perform a treadmill graded exercise test,a countermovement jump test for peak power measurement,and a 10-km time trial.Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week.On completion of the intervention,post-tests were conducted.Results:Both groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period.There were significant improvements in the 10-km time trial performance and peak power.There was also significant improvement in relative peak power for both groups.The 10-km time trial performance and relative peak power showed a moderate inverse correlation.Conclusion:These findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage.The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.展开更多
基金National Natural Science Foundations of China(Nos.51405410,51505402)
文摘The road random torsional excitation is one type of torque rooted from the road roughness and vehicle drive system. This paper aims to study how the road random torsional excitation affects the dynamic characteristics of vehicle power train. The method of simulating the random torsional excitation of tracked vehicle is explored at first. Secondly,the road random torsional excitations under different road roughness,vehicle speeds and pre-tensions are obtained. Thirdly,the dynamic analysis model of tracked vehicle power train is constructed with the consideration of the road random torsional excitation. Eventually,the influences of this excitation on output torque,bearing support force,vibration acceleration and dynamic shear stress of transmission shafts are intensively studied.The research conclusions are helpful to correct and refine the present virtual prototype of tracked vehicle power train.
基金supportted by Natural Science Foundation of Jiangsu Province(No.BK20230696).
文摘Electric power training is essential for ensuring the safety and reliability of the system.In this study,we introduce a novel Abnormal Action Recognition(AAR)system that utilizes a Lightweight Pose Estimation Network(LPEN)to efficiently and effectively detect abnormal fall-down and trespass incidents in electric power training scenarios.The LPEN network,comprising three stages—MobileNet,Initial Stage,and Refinement Stage—is employed to swiftly extract image features,detect human key points,and refine them for accurate analysis.Subsequently,a Pose-aware Action Analysis Module(PAAM)captures the positional coordinates of human skeletal points in each frame.Finally,an Abnormal Action Inference Module(AAIM)evaluates whether abnormal fall-down or unauthorized trespass behavior is occurring.For fall-down recognition,three criteria—falling speed,main angles of skeletal points,and the person’s bounding box—are considered.To identify unauthorized trespass,emphasis is placed on the position of the ankles.Extensive experiments validate the effectiveness and efficiency of the proposed system in ensuring the safety and reliability of electric power training.
文摘Multi-train modeling and simulation plays a vital role in railway electrification during operation and planning phase. Study of peak power demand and energy consumed by each traction substation needs to be deter- mined to verify that electrical energy flowing in its railway power feeding system is appropriate or not. Gauss-Seidel, conventional Newton-Raphson, and current injection methods are well-known and widely accepted as a tool for electrical power network solver in DC railway power supply study. In this paper, a simplified Newton-Raphson method has been proposed. The proposed method employs a set of current-balance equations at each electrical node instead of the conventional power-balance equation used in the conventional Newton-Raphson method. This concept can remarkably reduce execution time and computing complexity for multi-train simulation. To evaluate its use, Sukhumvit line of Bangkok transit system （BTS） of Thai- land with 21.6-km line length and 22 passenger stopping stations is set as a test system. The multi-train simulation integrated with the proposed power network solver is developed to simulate 1-h operation service of selected 5-min headway. From the obtained results, the proposed method is more efficient with approximately 18 % faster than the conventional Newton-Raphson method and just over 6 % faster than the current injection method.
基金supported by the National Natural Science Foundation of China(61203129,61174038,61473151,51507080)the Fundamental Research Funds for the Central Universities(30915011104,30920130121010,30920140112005)
文摘The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In this paper, an optical motion capture system based on the virtual reality technology is proposed to meet the requirements of the power enterprise for the qualified business ability. Electric power equipment, power equipment model entitative operating environment and the human model are established by electric power simulation unit, ZigBee technology and OpenGL graphics library. The problem of missing feature points is solved by applying the human model driven algorithm and the Kalman filtering algorithm. The experimental results show that it is more accurate to use Kalman filtering algorithm to extract the feature point in tracking process of actual motion capture and real-time animation display. The average absolute error of 3D coordinates is 1.61 mm and the average relative error is 2.23%. The system can improve trainees’ sense of experience and immersion.
文摘An approach of training working staff of power system operation mode based on state evaluation is proposed. In terms of knowledge features of power system operation mode, we studied a training method based on evaluation of learning state. This training method makes individual learning for different individual condition to give them ability to grasp learning points quickly, evaluate real-time learning effect, update learning style in time and summarize problems after one learning stage, so that learners can master professional knowledge in constant summaries and feedbacks. Obvious effects can be obtained on discontinuous learning time that trainees can master basic theories associated with their working and operations adapted to practical work quickly.
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.
文摘In South Africa,nurses and doctors are emigrating in significant numbers. Job satisfaction,safety and ensuring career progression are important in retaining doctors to make a career in Republic of South Africa (RSA). Due to budgetary constraints many hospitals have not been upgraded. Coming home after overseas training seems difficult. In RSA it takes a minimum of 13 years for a young specialist to become registered and 15 years for subspecialists. Career progression,creating more specialist trainees in public and private hospitals and shortening the period of professional training are potential solutions to the problem. India,which has a population of more than 1 billion people,is struggling with similar problems. For the past 10-15 years,private hospitals have assisted in manpower development for medical specialist and subspecialist careers. Currently their private sector trains 60% of their recognised (sub)specialities fellows. A national task force for specialist training in RSA should be instituted. It should discuss,based on the current status and projected specialist and subspecialist personnel requirements,thefuture structure and logistics of training needs. This is required in all subspecialities including gastroenterology,as has been done in India. It is hoped that as a consequence well-trained doctors,similar to those in India,might move to provincial hospitals in rural areas,upgrading the medical services and keeping medical power in South Africa. South Africa should become a model for Sub-Saharan Africa,as India already is for South-East Asia.
文摘To utilize exist SCADA(Supervisory Control and Data Acqui si tion)/EMS (Energy Management System) fully and economize capital, Henan Electric Power Dispatching and Communication Center in China established a set of Henan Dispatcher Training Simulator (HNDTS) base on its exist SCADA/EMS. In order to i ntegrated with exist SCADA/EMS, the integration method and technique are propose d. Graph data integration discussed with emphasis. After integration implemented , HNDTS can share all data with SCADA/EMS and dispatchers can be trained in same environment as real work situation, in the same time it can avoid amout of work of maintenance engineers. Both advantages and disadvantages of integration are analyzed. In the end of paper, the requirement for future DTS is put forward bas e on the experience of author.
文摘Purpose:The purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.Methods:Fourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group(n = 7)or the plyometric training group(n = 7).The preliminary tests required subjects to perform a treadmill graded exercise test,a countermovement jump test for peak power measurement,and a 10-km time trial.Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week.On completion of the intervention,post-tests were conducted.Results:Both groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period.There were significant improvements in the 10-km time trial performance and peak power.There was also significant improvement in relative peak power for both groups.The 10-km time trial performance and relative peak power showed a moderate inverse correlation.Conclusion:These findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage.The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.
