The goal of this study is to reduce the energy consumption of the sensing network and enhance the overall life cycle of the network.This study proposes a data fusion algorithm for wireless sensor networks based on imp...The goal of this study is to reduce the energy consumption of the sensing network and enhance the overall life cycle of the network.This study proposes a data fusion algorithm for wireless sensor networks based on improved ant colony optimization(IACO)to reduce the amount of data transmitted by wireless sensor networks(WSN).This study updates pheromones for multiple optimal routes to improve the global optimal route in search function.The algorithm proposed in this study can reduce node energy consumption,improve network load balancing and prolong network life cycle.Through data fusion,regression analysis model and information processing of each node,this study uses an improved ant colony algorithm to identify the transferals avoid superfluous energy waste caused by long-span network transferal,set the shortest route and transmit data to the central node.The algorithm proposed in this study is conducive to improving the life cycle and stable network,that is,the most suitable and effective way to improve the energy consumption rate of the sensing nodes.展开更多
This study proposes and experimentally validates an optimal integrated system to control the automotive continuously variable transmission(CVT)by Model Predictive Control(MPC)to achieve its expected transmission effic...This study proposes and experimentally validates an optimal integrated system to control the automotive continuously variable transmission(CVT)by Model Predictive Control(MPC)to achieve its expected transmission efficiency range.The control system framework consists of top and bottom layers.In the top layer,a driving intention recognition system is designed on the basis of fuzzy control strategy to determine the relationship between the driver intention and CVT target ratio at the corresponding time.In the bottom layer,a new slip state dynamic equation is obtained considering slip characteristics and its related constraints,and a clamping force bench is established.Innovatively,a joint controller based on model predictive control(MPC)is designed taking internal combustion engine torque and slip between the metal belt and pulley as optimization dual targets.A cycle is attained by solving the optimization target to achieve optimum engine torque and the input slip in real-time.Moreover,the new controller provides good robustness.Finally,performance is tested by actual CVT vehicles.Results show that compared with traditional control,the proposed control improves vehicle transmission efficiency by approximately 9.12%-9.35%with high accuracy.展开更多
Heterogeneous cellular networks(HCNs)are envisioned as a promising architecture to provide seamless wireless coverage and increase network capacity.However,the densified multi-tier network architecture introduces exce...Heterogeneous cellular networks(HCNs)are envisioned as a promising architecture to provide seamless wireless coverage and increase network capacity.However,the densified multi-tier network architecture introduces excessive intra-and cross-tier interference and makes HCNs vulnerable to eavesdropping attacks.In this article,a dynamic spectrum control(DSC)-assisted transmission scheme is proposed for HCNs to strengthen network security and increase the network capacity.Specifically,the proposed DSC-assisted transmission scheme leverages the idea of block cryptography to generate sequence families,which represent the transmission decisions,by performing iterative and orthogonal sequence transformations.Based on the sequence families,multiple users can dynamically occupy different frequency slots for data transmission simultaneously.In addition,the collision probability of the data transmission is analyzed,which results in closed-form expressions of the reliable transmission probability and the secrecy probability.Then,the upper and lower bounds of network capacity are further derived with given requirements on the reliable and secure transmission probabilities.Simulation results demonstrate that the proposed DSC-assisted scheme can outperform the benchmark scheme in terms of security performance.Finally,the impacts of key factors in the proposed DSC-assisted scheme on the network capacity and security are evaluated and discussed.展开更多
The significant advantage of proton therapy over other particle-based techniques is in the unique physical characteristics of the Bragg peak.It can achieve a highly conformal dose distribution and maximize the probabi...The significant advantage of proton therapy over other particle-based techniques is in the unique physical characteristics of the Bragg peak.It can achieve a highly conformal dose distribution and maximize the probability of tumor control by varying the irradiation energy.Most proton facilities use cyclotrons for fixed energy beam extraction and are equipped with degrader and collimator systems for energy modulation and emittance suppression.However,interactions between charged particles and degrader materials inevitably cause beam loss and divergence and deteriorate beam performance,which present great challenges for downstream transport and clinical treatment.In this work,we investigate a method of energy reduction by combining boron carbide and graphite in a degrader to obtain greater beam transmission at lower energy.The results demonstrate that the beam size and emittance at the exit of the combined degrader diverge less than those of multi-wedge one in the energy range of 70-160 MeV.Correspondingly,the transmission efficiency after the first dipole also shows improvements of 36.26%at 70 MeV and 70.55%at 110 MeV.As a component with a high activity level,the degrader causes additional ambient radiation during operation.Residual induced radiation even remains several hours after system shutdown.Analysis of material activation and induced radiation based on 1 h irradiation with a 400 nA beam current shows that the combined degrader has a definite advantage in shielding despite producing more secondary particles.Both radioactivity and average ambient dose equivalent are reduced by 50%compared with the multiwedge degrader at the important cooling time of 1 h.After 12 h and 24 h of cooling,the radiation levels of degraders decrease slightly due to the presence of long half-life residual nuclides.The average dose generated from the multi-wedge degrader is still 1.25 times higher than that of the combined one.展开更多
The online detection of metal shaft parameters,such as torque,power and deformation,is widely applied in engineering projects.The power supply of metal shafts is the key to the detection reliability and practicality.H...The online detection of metal shaft parameters,such as torque,power and deformation,is widely applied in engineering projects.The power supply of metal shafts is the key to the detection reliability and practicality.However,traditional slip ring and battery power supply are limited in reliability and service life.In this paper,a side-mounted inductive power supply system for the rotating metal shaft is designed by using a Utype core.The equivalent reluctance and circuit models of the system are analyzed,and the methods of improving the coupling coefficient and transmission efficiency are proposed from theoretical analysis.Through the finite element simulation analysis of the system,the general relationships between the transmission power and efficiency of the system and the number of coil turns,the working frequency and the load are analyzed.The accuracy of theoretical analysis and simulation analysis is verified by the practical power transmission experiments.This paper provides a novel and reliable power supply method for inductive power supply of rotating equipment,and enriches the solutions of rotating power supply.展开更多
The move from internal combustion engine vehicles to electric vehicles is happening rapidly,which demands a stepwise change in priorities for the vehicle design process with rational consideration of emerging technolo...The move from internal combustion engine vehicles to electric vehicles is happening rapidly,which demands a stepwise change in priorities for the vehicle design process with rational consideration of emerging technologies.This paper focuses on the efficiency of a particular form of high fixed-ratio(15:1)traction drive speed reducer.This is suitable for use in conjunction with a high-speed electric motor for automotive applications.A general discussion of the characteristics of other fixed-ratio traction drives is provided followed by an analysis of underlying efficiency issues.The paper presents details of the speed reducer prototype called a"Silk Drive"and the vehicle for which it was designed.Data from laboratory testing of the prototype are presented,and an efficiency map for the transmission is developed.The efficiency map and vehicle parameters are used in a simulation to determine the overall transmission efficiency for the world harmonized light vehicles test cycles(WLTC)class 3b drive cycle.The importance of transmission efficiency at low power levels,in specific input speed and torque regions,is demonstrated using a novel method for identifying those speed torque regions that most strongly affect overall efficiency.The method applies to all drivetrain components and pinpoints those regions that need to be the focus in the optimal design of such components.This paper presents evidence that the efficiency of zero-spin,fixed-ratio traction drives is similar to that of conventional gear drives.展开更多
基金This research was supported by the Department of Electrical Engineering at National Chin-Yi University of Technology.
文摘The goal of this study is to reduce the energy consumption of the sensing network and enhance the overall life cycle of the network.This study proposes a data fusion algorithm for wireless sensor networks based on improved ant colony optimization(IACO)to reduce the amount of data transmitted by wireless sensor networks(WSN).This study updates pheromones for multiple optimal routes to improve the global optimal route in search function.The algorithm proposed in this study can reduce node energy consumption,improve network load balancing and prolong network life cycle.Through data fusion,regression analysis model and information processing of each node,this study uses an improved ant colony algorithm to identify the transferals avoid superfluous energy waste caused by long-span network transferal,set the shortest route and transmit data to the central node.The algorithm proposed in this study is conducive to improving the life cycle and stable network,that is,the most suitable and effective way to improve the energy consumption rate of the sensing nodes.
基金Supported by National Natural Science Foundation of China(Grant No.51905044)Postdoctoral Science Foundation of China(Grant No.2017M611316).
文摘This study proposes and experimentally validates an optimal integrated system to control the automotive continuously variable transmission(CVT)by Model Predictive Control(MPC)to achieve its expected transmission efficiency range.The control system framework consists of top and bottom layers.In the top layer,a driving intention recognition system is designed on the basis of fuzzy control strategy to determine the relationship between the driver intention and CVT target ratio at the corresponding time.In the bottom layer,a new slip state dynamic equation is obtained considering slip characteristics and its related constraints,and a clamping force bench is established.Innovatively,a joint controller based on model predictive control(MPC)is designed taking internal combustion engine torque and slip between the metal belt and pulley as optimization dual targets.A cycle is attained by solving the optimization target to achieve optimum engine torque and the input slip in real-time.Moreover,the new controller provides good robustness.Finally,performance is tested by actual CVT vehicles.Results show that compared with traditional control,the proposed control improves vehicle transmission efficiency by approximately 9.12%-9.35%with high accuracy.
基金supported by the National Natural Science Foundation of China(61825104 and 91638204)the China Scholarship Council(CSC)+1 种基金the Natural Sciences and Engineering Research Council(NSERC)of CanadaUniversity Innovation Platform Project(2019921815KYPT009JC011)。
文摘Heterogeneous cellular networks(HCNs)are envisioned as a promising architecture to provide seamless wireless coverage and increase network capacity.However,the densified multi-tier network architecture introduces excessive intra-and cross-tier interference and makes HCNs vulnerable to eavesdropping attacks.In this article,a dynamic spectrum control(DSC)-assisted transmission scheme is proposed for HCNs to strengthen network security and increase the network capacity.Specifically,the proposed DSC-assisted transmission scheme leverages the idea of block cryptography to generate sequence families,which represent the transmission decisions,by performing iterative and orthogonal sequence transformations.Based on the sequence families,multiple users can dynamically occupy different frequency slots for data transmission simultaneously.In addition,the collision probability of the data transmission is analyzed,which results in closed-form expressions of the reliable transmission probability and the secrecy probability.Then,the upper and lower bounds of network capacity are further derived with given requirements on the reliable and secure transmission probabilities.Simulation results demonstrate that the proposed DSC-assisted scheme can outperform the benchmark scheme in terms of security performance.Finally,the impacts of key factors in the proposed DSC-assisted scheme on the network capacity and security are evaluated and discussed.
基金supported in part by the National Natural Science Foundation of China (No. 52077211)
文摘The significant advantage of proton therapy over other particle-based techniques is in the unique physical characteristics of the Bragg peak.It can achieve a highly conformal dose distribution and maximize the probability of tumor control by varying the irradiation energy.Most proton facilities use cyclotrons for fixed energy beam extraction and are equipped with degrader and collimator systems for energy modulation and emittance suppression.However,interactions between charged particles and degrader materials inevitably cause beam loss and divergence and deteriorate beam performance,which present great challenges for downstream transport and clinical treatment.In this work,we investigate a method of energy reduction by combining boron carbide and graphite in a degrader to obtain greater beam transmission at lower energy.The results demonstrate that the beam size and emittance at the exit of the combined degrader diverge less than those of multi-wedge one in the energy range of 70-160 MeV.Correspondingly,the transmission efficiency after the first dipole also shows improvements of 36.26%at 70 MeV and 70.55%at 110 MeV.As a component with a high activity level,the degrader causes additional ambient radiation during operation.Residual induced radiation even remains several hours after system shutdown.Analysis of material activation and induced radiation based on 1 h irradiation with a 400 nA beam current shows that the combined degrader has a definite advantage in shielding despite producing more secondary particles.Both radioactivity and average ambient dose equivalent are reduced by 50%compared with the multiwedge degrader at the important cooling time of 1 h.After 12 h and 24 h of cooling,the radiation levels of degraders decrease slightly due to the presence of long half-life residual nuclides.The average dose generated from the multi-wedge degrader is still 1.25 times higher than that of the combined one.
基金the National Natural Science Foundation of China(No.51475306)。
文摘The online detection of metal shaft parameters,such as torque,power and deformation,is widely applied in engineering projects.The power supply of metal shafts is the key to the detection reliability and practicality.However,traditional slip ring and battery power supply are limited in reliability and service life.In this paper,a side-mounted inductive power supply system for the rotating metal shaft is designed by using a Utype core.The equivalent reluctance and circuit models of the system are analyzed,and the methods of improving the coupling coefficient and transmission efficiency are proposed from theoretical analysis.Through the finite element simulation analysis of the system,the general relationships between the transmission power and efficiency of the system and the number of coil turns,the working frequency and the load are analyzed.The accuracy of theoretical analysis and simulation analysis is verified by the practical power transmission experiments.This paper provides a novel and reliable power supply method for inductive power supply of rotating equipment,and enriches the solutions of rotating power supply.
文摘The move from internal combustion engine vehicles to electric vehicles is happening rapidly,which demands a stepwise change in priorities for the vehicle design process with rational consideration of emerging technologies.This paper focuses on the efficiency of a particular form of high fixed-ratio(15:1)traction drive speed reducer.This is suitable for use in conjunction with a high-speed electric motor for automotive applications.A general discussion of the characteristics of other fixed-ratio traction drives is provided followed by an analysis of underlying efficiency issues.The paper presents details of the speed reducer prototype called a"Silk Drive"and the vehicle for which it was designed.Data from laboratory testing of the prototype are presented,and an efficiency map for the transmission is developed.The efficiency map and vehicle parameters are used in a simulation to determine the overall transmission efficiency for the world harmonized light vehicles test cycles(WLTC)class 3b drive cycle.The importance of transmission efficiency at low power levels,in specific input speed and torque regions,is demonstrated using a novel method for identifying those speed torque regions that most strongly affect overall efficiency.The method applies to all drivetrain components and pinpoints those regions that need to be the focus in the optimal design of such components.This paper presents evidence that the efficiency of zero-spin,fixed-ratio traction drives is similar to that of conventional gear drives.
