In this paper, a protocol for quantum millionaire problem with continuous variables is proposed. In the protocol, two participants can compare the values of their fortune with the assistance of a semi-trusted third pa...In this paper, a protocol for quantum millionaire problem with continuous variables is proposed. In the protocol, two participants can compare the values of their fortune with the assistance of a semi-trusted third party(STTP). Only EPR states are exploited in our protocol while most other protocols exploited d-dimensional Bell states.Two participants are just required to perform single particle operations, which makes our protocol more efficiently. Our protocol can ensure fairness, correctness, security and high efficiency as well. In our protocol, only the two participants can deduce the results of comparisons, others include STTP will learn no information. Our protocol can resist various kinds of attacks from both the outside eavesdroppers and the inside participants, even the STTP.展开更多
A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement ...A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement is feasible because the bipartite entangled states are complete and the squeezed state has a natural representation in the entangled state basis. The calculation is greatly simplified by using the Schmidt decomposition of the entangled states.展开更多
We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formali...We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formalism,teleporting multi-mode coherent state or squeezed state is also possible. Another is that the tripartite entangled state is used as the quantum channel of controlled teleportation of an arbitrary and unknown continuous variable in the case of three participators.展开更多
We propose a scheme for controlled entanglement swapping of continuous variable, where an EPR pair shared by two parties （Alice and Debbie） and a GHZ entangled state shared by three parties （Alice, Bob and Claire）...We propose a scheme for controlled entanglement swapping of continuous variable, where an EPR pair shared by two parties （Alice and Debbie） and a GHZ entangled state shared by three parties （Alice, Bob and Claire） are required. One optical beams of the EPR state will be entangled with the output mode displaced by Bob with the help of Claire. It is shown that the entanglement swapping can occur controlled by the third party （Claire）展开更多
Quantum entanglement is a typical nonclassical correlation.Here,we use this concept to analyze quantum entanglement for continuous variables generated by the Schwinger pair production for constant and pulsed electric ...Quantum entanglement is a typical nonclassical correlation.Here,we use this concept to analyze quantum entanglement for continuous variables generated by the Schwinger pair production for constant and pulsed electric fields.An initial two-mode entangled state evolves into a three-mode entangled state through a Gaussian channel of the Schwinger effect,which encodes the information about the Schwinger effect.By detecting the entanglement of the output three-mode state,we obtain the optimal parameters for easier to generate particle-antiparticle pairs.We find that the generated 1→2 entanglement is more sensitive to the parameters than the generated 1→1 entanglement.Therefore,we should choose the generated 1→2 entanglement to extract information.We argue that extracting the optimal parameters from quantum entanglement may guide future experiments.展开更多
This paper is concerned with the oscillation of nonlinear partial difference equations with continuous variables and the corresponding dual equations. Several sufficientconditions are obtained for the oscillation of t...This paper is concerned with the oscillation of nonlinear partial difference equations with continuous variables and the corresponding dual equations. Several sufficientconditions are obtained for the oscillation of these equations.展开更多
The paper analyzes the basic principles of stabilizer codes, focusing on how to construct stabilizer codes for achieving the continuous-variable quantum error correction. Stabilizer codes can be used in the reconcilia...The paper analyzes the basic principles of stabilizer codes, focusing on how to construct stabilizer codes for achieving the continuous-variable quantum error correction. Stabilizer codes can be used in the reconciliation of continuous-variable quantum key distribution system. The construction method of stabilizer codes is very important and it can be turned into finding the check matrix for stabilizer codes. In this paper, a new algorithm called region elimination algorithm for finding the check matrix of stabilizer codes was presented which can seek the voluntary check matrix for continu-ous-variable stabilizer codes within 8 bit code length quickly and effectively, and it was simulated by Visual C++. The algorithm is mainly realized by initializing search region, reducing the search region and then keeping searching till finding all the commuting generators. The finding of check matrix of stabilizer codes lays important foundations for the further development of stabilizer codes in the con-tinuous-variable quantum key distribution.展开更多
In the research of scientific field, it is often necessary to continuously observe different indicators of individuals at different times and analyze the observed results. Among them, variables are mainly of two types...In the research of scientific field, it is often necessary to continuously observe different indicators of individuals at different times and analyze the observed results. Among them, variables are mainly of two types: ordered variables and continuous variables. When analyzing data for different types of variables, it is necessary to consider the correlation between multiple indicators of an individual, and often perform joint analysis on variable observation data of multiple indicators of an individual at different times, in order to achieve more accurate and true analysis results. Joint analysis often yields more information than separate analysis of various variables. In this paper, the ordered variable and the continuous variable are numerically modeled. Based on the potential variable model, the multivariate longitudinal data containing the ordered variable and the continuous variable are jointly analyzed, and the approximate value of the edge likelihood can be obtained by using the method of numerical integration.展开更多
Dear Editor,The distributed constraint optimization problems(DCOPs) [1]-[3]provide an efficient model for solving the cooperative problems of multi-agent systems, which has been successfully applied to model the real-...Dear Editor,The distributed constraint optimization problems(DCOPs) [1]-[3]provide an efficient model for solving the cooperative problems of multi-agent systems, which has been successfully applied to model the real-world problems like the distributed scheduling [4], sensor network management [5], [6], multi-robot coordination [7], and smart grid [8]. However, DCOPs were not well suited to solve the problems with continuous variables and constraint cost in functional form, such as the target tracking sensor orientation [9], the air and ground cooperative surveillance [10], and the sensor network coverage [11].展开更多
Measurement-based quantum computation with continuous variables,which realizes computation by performing measurement and feedforward of measurement results on a large scale Gaussian cluster state,provides a feasible w...Measurement-based quantum computation with continuous variables,which realizes computation by performing measurement and feedforward of measurement results on a large scale Gaussian cluster state,provides a feasible way to implement quantum computation.Quantum error correction is an essential procedure to protect quantum information in quantum computation and quantum communication.In this review,we briefly introduce the progress of measurement-based quantum computation and quantum error correction with continuous variables based on Gaussian cluster states.We also discuss the challenges in the fault-tolerant measurement-based quantum computation with continuous variables.展开更多
The current research on pulse continuously variable transmission(CVT)is mainly focused on reducing the pulse degree and making pulse degrees a constant value.Current research mainly confined to find out new design par...The current research on pulse continuously variable transmission(CVT)is mainly focused on reducing the pulse degree and making pulse degrees a constant value.Current research mainly confined to find out new design parameters by using the method of optimization,and reduce the pulse degree of pulse CVT and its range of variation.But the fact is that the reduction of the pulse degree is not significant.This article presents a new structure of mechanical pulse CVT--the rotational swashplate pulse CVT with driven by helical gear axial meshing.This transmission is simple and compact in structure and low in pulsatile rate(it adopts 6 guide rods),and the pulsatile degree is irrelevant to the transmission ratio.Theoretically,pulsatile rate could be reduced to zero if appropriate curved surface of the swashplate is used.Compared with the connecting rod pulse CVT,the present struc^tre uses helical gear mechanism as transmission part and it avoids unbalanced inertial force in the former model.This paper analyzes the principle of driving of this transmission,presents its mechanical structure,and discusses its motion characteristics.Experimental prototype of this type of CVT has been manufactured.Tests for the transmission efficiency(when the rotational speed of the output shaft is the maximum)and the angular velocity of the output shaft have been carried out,and data have been analyzed.The experimental results show that the speed of the output shaft for the experimental prototype is slightly lower than the theoretical value,and the transmission efficiency of the experimental prototype is about 70%.The pulse degree of the CVT discussed in this paper is less than the existing pulse CVT of other types,and it is irrelevant to the transmission ratio of the CVT.The research provides the new idea to the CVT study.展开更多
The automatic control of clutch starting in car with a metal pushingbelt-planetary gear continuously variable transmission (CVT) is a complex problem. A suited controlstrategy is required to realize quick and smooth s...The automatic control of clutch starting in car with a metal pushingbelt-planetary gear continuously variable transmission (CVT) is a complex problem. A suited controlstrategy is required to realize quick and smooth start. A simulation state space equation isestablished on clutch staring control of a car with CVT by bond graph theory. According to the fuzzycontrol method with the expert system, a fuzzy control system of car starting process to weaken thejerk motion is introduced. The simulation results indicate that the jerk motion of clutch startingis below 10 m/s^3.展开更多
The most remarkable characteristic of a metal belt-planetary gearcontinuously variable transmission is a wider ratio range and a bigger torque capacity than aconventional metal pushing belt continuously variable trans...The most remarkable characteristic of a metal belt-planetary gearcontinuously variable transmission is a wider ratio range and a bigger torque capacity than aconventional metal pushing belt continuously variable transmission. A parallel hybrid car with thistransmission system not only can reduce fuel consumption and pollutant emission at a ECE city cycle,but also can keep the motor working in the most efficiency area and can be started by a lower powermotor by oneself. At the same time, the continuously variable transmission system can realize thesmooth switch between the motor and the engine.展开更多
Associated dynamic performance of the clamping force control valve used in continuously variable transmission(CVT)is optimized.Firstly,the structure and working principle of the valve are analyzed,and then a dynamic m...Associated dynamic performance of the clamping force control valve used in continuously variable transmission(CVT)is optimized.Firstly,the structure and working principle of the valve are analyzed,and then a dynamic model is set up by means of mechanism analysis.For the purpose of checking the validity of the modeling method,a prototype workpiece of the valve is manufactured for comparison test,and its simulation result follows the experimental result quite well.An associated performance index is founded considering the response time,overshoot and saving energy,and five structural parameters are selected to adjust for deriving the optimal associated performance index.The optimization problem is solved by the genetic algorithm(GA)with necessary constraints.Finally,the properties of the optimized valve are compared with those of the prototype workpiece,and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.展开更多
In order to study the influence of die combination on continuous variable cross-section direct extrusion （CVCDE） in the extrusion process, the accumulative strain formula is derived, and it can be known that the ext...In order to study the influence of die combination on continuous variable cross-section direct extrusion （CVCDE） in the extrusion process, the accumulative strain formula is derived, and it can be known that the extrusion ratio of various stages directly determines the size of corresponding stage strain by formula. In this paper, as an example of the two interim dies, three die combinations of different angles and extrusion ratio are designed. Aviation magnesium alloy ZM6 is studied, and the results show that dynamic recrystallization is even more complete when continuous shear deformation occurs, so that the refinement and homogenization of microstructure are obtained. By the use of different die combinations, the accumulative strain increases under the conditions of same total extrusion ratio. Thus, the refined crystalline strengthening effect of extrusion deformation can be further analyzed. Due to the dead-zone defects, the actual accumulative strain decreases significantly and the effect of microstructure and performance improvements also decreases with it. Therefore, the optimal design of die combination is the key to the process and product of CVCDE, which provides a scientific basis for the development of severe plastic deformation.展开更多
A new type continuous variable transmission device, a hydro-mechanical continuously variable transmission （HMCVT） for agricultural tractors is developed, which is composed of a single planetary gear differential tra...A new type continuous variable transmission device, a hydro-mechanical continuously variable transmission （HMCVT） for agricultural tractors is developed, which is composed of a single planetary gear differential train, a hydraulic transmission system consisted of variable displacement pump and fixed displacement motor and a multi-gear fixed step radio transmission. Based on the analysis of types of hydrostatic mechanical transmission （HMT） and styles of hydraulic transmission, the general drive scheme for HMCVT is obtained. The method of selecting mechanical parameters and hydraulic units is explained, and the stepless speed regulation characteristic of HMCVT is analyzed. This paper also specializes the calculating method of transmission efficiency. It shows that tractors assembled with HMCVT can obtain a continuously variable speed and achieve high drive efficiency.展开更多
With the structure of two air gaps and two rotors, the electromagnetic continuously variable transmission（EMCVT） is a novel power-split continuously variable transmission（CVT）. There are two kinds of power flowing...With the structure of two air gaps and two rotors, the electromagnetic continuously variable transmission（EMCVT） is a novel power-split continuously variable transmission（CVT）. There are two kinds of power flowing through the EMCVT, one is mechanical power and the other is electric power. In the mean time, there are three power ports in the EMCVT, one is the outer rotor named mechanical power port and the other two are the inner rotor and the stator named electric power ports. The mechanical power port is connected to the driving wheels through the final gear and the electric ports are connected to the batteries through the transducers. The two kinds of power are coupled on the outer rotor of the EMCVT. The EMCVT can be equipped on the conventional vehicle being regarded as the CVT and it also can be equipped on the hybrid electric vehicle（HEV） as the multi-energy sources assembly. The power flows of these two kinds of applications are analysed. The back electromotive force（EMF） equations are illatively studied and so the dynamic mathematic model is theorized. In order to certify the feasibility of the above theories, three simulations are carried out in allusion to the above two kinds of mentioned applications of the EMCVT and a five speed automatic transmission（AT） vehicle. The simulation results illustrate that the efficiency of the EMCVT vehicles is higher than that of the AT vehicle owed to the optimized operation area of the engine. Hence the fuel consumption of the EMCVT vehicles is knock-down.展开更多
Quantum key distribution enables unconditionally secure key distribution between two legitimate users.The information-theoretic security is guaranteed by the fundamental laws of quantum physics.Initially,the quantum k...Quantum key distribution enables unconditionally secure key distribution between two legitimate users.The information-theoretic security is guaranteed by the fundamental laws of quantum physics.Initially,the quantum key distribution protocol was proposed based on the qubits.Later on,it was found that quantum continuous variables can also be exploited for this target.The continuous variable quantum key distribution can build upon standard telecommunication technology and exhibits a higher secret key rate per pulse at a relatively short distance due to the possibility of encoding more than 1 bit per pulse.In this article,we review the current status of the continuous variable quantum key distribution research,including its basic principle,experimental implementations,security and future directions;the experimental progress in this field made by our group is also presented.展开更多
We propose an arbitrated quantum signature （AQS） scheme with continuous variable （CV） squeezed vacuum states, which requires three parties, i.e., the signer Alice, the verifier Bob and the arbitrator Charlie trust...We propose an arbitrated quantum signature （AQS） scheme with continuous variable （CV） squeezed vacuum states, which requires three parties, i.e., the signer Alice, the verifier Bob and the arbitrator Charlie trusted by Alice and Bob, and three phases consisting of the initial phase, the signature phase and the verification phase. We evaluate and compare the original state and the teleported state by using the fidelity and the beam splitter （BS） strategy. The security is ensured by the CV-based quantum key distribution （CV-QKD） and quantum teleportation of squeezed states. Security analyses show that the generated signature can be neither disavowed by the signer and the receiver nor counterfeited by anyone with the shared keys. Furthermore, the scheme can also detect other manners of potential attack although they may be successful. Also, the integrality and authenticity of the transmitted messages can be guaranteed. Compared to the signature scheme of CV-based coherent states, our scheme has better encoding efficiency and performance. It is a potential high-speed quantum signature scheme with high repetition rate and detection efficiency which can be achieved by using the standard off-the-shelf components when compared to the discrete-variable （DV） quantum signature scheme.展开更多
Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement dis...Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement distribution.To realize efficient quantum communication based on quantum discord,in this paper,we consider the practical advantages of continuous variables and propose a feasible continuous-variable quantum network coding scheme based on quantum discord.By means of entanglement distribution by separable states,it can achieve quantum entanglement distribution from sources to targets in a butterfly network.Compared with the representative discrete-variable quantum network coding schemes,the proposed continuous-variable quantum network coding scheme has a higher probability of entanglement distribution and defends against eavesdropping and forgery attacks.Particularly,the deduced relationship indicates that the increase in entanglement is less than or equal to quantum discord.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.61170270,61003290,61170221,61100205the Specialized Research Fund for the Doctoral Program of Higher Education under Grant Nos.20091103120014,20090005110010+1 种基金Beijing Natural Science Foundation under Grant No.4122008the ISN open Foundation
文摘In this paper, a protocol for quantum millionaire problem with continuous variables is proposed. In the protocol, two participants can compare the values of their fortune with the assistance of a semi-trusted third party(STTP). Only EPR states are exploited in our protocol while most other protocols exploited d-dimensional Bell states.Two participants are just required to perform single particle operations, which makes our protocol more efficiently. Our protocol can ensure fairness, correctness, security and high efficiency as well. In our protocol, only the two participants can deduce the results of comparisons, others include STTP will learn no information. Our protocol can resist various kinds of attacks from both the outside eavesdroppers and the inside participants, even the STTP.
文摘A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement is feasible because the bipartite entangled states are complete and the squeezed state has a natural representation in the entangled state basis. The calculation is greatly simplified by using the Schmidt decomposition of the entangled states.
文摘We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formalism,teleporting multi-mode coherent state or squeezed state is also possible. Another is that the tripartite entangled state is used as the quantum channel of controlled teleportation of an arbitrary and unknown continuous variable in the case of three participators.
基金The project supported by National Natural Science Foundation of China(NSFC)under Grant Nos.60678022 and 10704001the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20060357008+2 种基金Natural Science Foundation of Anhui Province under Grant No.070412060the Key Program of the Education Department of Anhui Province under Grant No.2006KJ070Athe Talent Foundation of Anhui University,and Anhui Key Laboratory of Information Materials and Devices(Anhui University)
文摘We propose a scheme for controlled entanglement swapping of continuous variable, where an EPR pair shared by two parties （Alice and Debbie） and a GHZ entangled state shared by three parties （Alice, Bob and Claire） are required. One optical beams of the EPR state will be entangled with the output mode displaced by Bob with the help of Claire. It is shown that the entanglement swapping can occur controlled by the third party （Claire）
基金supported by the National Natural Science Foundation of China(Grant Nos.12205133,LJKQZ20222315 and 2021BSL013)
文摘Quantum entanglement is a typical nonclassical correlation.Here,we use this concept to analyze quantum entanglement for continuous variables generated by the Schwinger pair production for constant and pulsed electric fields.An initial two-mode entangled state evolves into a three-mode entangled state through a Gaussian channel of the Schwinger effect,which encodes the information about the Schwinger effect.By detecting the entanglement of the output three-mode state,we obtain the optimal parameters for easier to generate particle-antiparticle pairs.We find that the generated 1→2 entanglement is more sensitive to the parameters than the generated 1→1 entanglement.Therefore,we should choose the generated 1→2 entanglement to extract information.We argue that extracting the optimal parameters from quantum entanglement may guide future experiments.
基金Supported by the NSF of China(60174010)Supported by NSF of Hebei Province(102160)Supported by NS of Education Office in Heibei Province(2004123)
文摘This paper is concerned with the oscillation of nonlinear partial difference equations with continuous variables and the corresponding dual equations. Several sufficientconditions are obtained for the oscillation of these equations.
基金Supported by the Science and Technology Foundation of the Education Department of Fujian Province(No.JA08001)
文摘The paper analyzes the basic principles of stabilizer codes, focusing on how to construct stabilizer codes for achieving the continuous-variable quantum error correction. Stabilizer codes can be used in the reconciliation of continuous-variable quantum key distribution system. The construction method of stabilizer codes is very important and it can be turned into finding the check matrix for stabilizer codes. In this paper, a new algorithm called region elimination algorithm for finding the check matrix of stabilizer codes was presented which can seek the voluntary check matrix for continu-ous-variable stabilizer codes within 8 bit code length quickly and effectively, and it was simulated by Visual C++. The algorithm is mainly realized by initializing search region, reducing the search region and then keeping searching till finding all the commuting generators. The finding of check matrix of stabilizer codes lays important foundations for the further development of stabilizer codes in the con-tinuous-variable quantum key distribution.
文摘In the research of scientific field, it is often necessary to continuously observe different indicators of individuals at different times and analyze the observed results. Among them, variables are mainly of two types: ordered variables and continuous variables. When analyzing data for different types of variables, it is necessary to consider the correlation between multiple indicators of an individual, and often perform joint analysis on variable observation data of multiple indicators of an individual at different times, in order to achieve more accurate and true analysis results. Joint analysis often yields more information than separate analysis of various variables. In this paper, the ordered variable and the continuous variable are numerically modeled. Based on the potential variable model, the multivariate longitudinal data containing the ordered variable and the continuous variable are jointly analyzed, and the approximate value of the edge likelihood can be obtained by using the method of numerical integration.
基金supported by the National Nature Science Foundation of China(62272078)
文摘Dear Editor,The distributed constraint optimization problems(DCOPs) [1]-[3]provide an efficient model for solving the cooperative problems of multi-agent systems, which has been successfully applied to model the real-world problems like the distributed scheduling [4], sensor network management [5], [6], multi-robot coordination [7], and smart grid [8]. However, DCOPs were not well suited to solve the problems with continuous variables and constraint cost in functional form, such as the target tracking sensor orientation [9], the air and ground cooperative surveillance [10], and the sensor network coverage [11].
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11834010,11804001,and 11904160)the Natural Science Foundation of Anhui Province,China(Grant No.1808085QA11)+1 种基金the Program of Youth Sanjin Scholar,National Key R&D Program of China(Grant No.2016YFA0301402)the Fund for Shanxi"1331 Project"Key Subjects Construction.
文摘Measurement-based quantum computation with continuous variables,which realizes computation by performing measurement and feedforward of measurement results on a large scale Gaussian cluster state,provides a feasible way to implement quantum computation.Quantum error correction is an essential procedure to protect quantum information in quantum computation and quantum communication.In this review,we briefly introduce the progress of measurement-based quantum computation and quantum error correction with continuous variables based on Gaussian cluster states.We also discuss the challenges in the fault-tolerant measurement-based quantum computation with continuous variables.
基金supported by Beijing Municipal Natural Science Foundation of China(Grant No.3123036)Science and Technology Project of Beijing Municipal Education Commission of China(Grant No.KM200911417010)
文摘The current research on pulse continuously variable transmission(CVT)is mainly focused on reducing the pulse degree and making pulse degrees a constant value.Current research mainly confined to find out new design parameters by using the method of optimization,and reduce the pulse degree of pulse CVT and its range of variation.But the fact is that the reduction of the pulse degree is not significant.This article presents a new structure of mechanical pulse CVT--the rotational swashplate pulse CVT with driven by helical gear axial meshing.This transmission is simple and compact in structure and low in pulsatile rate(it adopts 6 guide rods),and the pulsatile degree is irrelevant to the transmission ratio.Theoretically,pulsatile rate could be reduced to zero if appropriate curved surface of the swashplate is used.Compared with the connecting rod pulse CVT,the present struc^tre uses helical gear mechanism as transmission part and it avoids unbalanced inertial force in the former model.This paper analyzes the principle of driving of this transmission,presents its mechanical structure,and discusses its motion characteristics.Experimental prototype of this type of CVT has been manufactured.Tests for the transmission efficiency(when the rotational speed of the output shaft is the maximum)and the angular velocity of the output shaft have been carried out,and data have been analyzed.The experimental results show that the speed of the output shaft for the experimental prototype is slightly lower than the theoretical value,and the transmission efficiency of the experimental prototype is about 70%.The pulse degree of the CVT discussed in this paper is less than the existing pulse CVT of other types,and it is irrelevant to the transmission ratio of the CVT.The research provides the new idea to the CVT study.
基金National Natural Science Founda-tion of China (No.59835160).
文摘The automatic control of clutch starting in car with a metal pushingbelt-planetary gear continuously variable transmission (CVT) is a complex problem. A suited controlstrategy is required to realize quick and smooth start. A simulation state space equation isestablished on clutch staring control of a car with CVT by bond graph theory. According to the fuzzycontrol method with the expert system, a fuzzy control system of car starting process to weaken thejerk motion is introduced. The simulation results indicate that the jerk motion of clutch startingis below 10 m/s^3.
基金This project is supported Fok Yingtung Education Foundation(No.81070)and National Natural Science Foundation of China(No.50005026).
文摘The most remarkable characteristic of a metal belt-planetary gearcontinuously variable transmission is a wider ratio range and a bigger torque capacity than aconventional metal pushing belt continuously variable transmission. A parallel hybrid car with thistransmission system not only can reduce fuel consumption and pollutant emission at a ECE city cycle,but also can keep the motor working in the most efficiency area and can be started by a lower powermotor by oneself. At the same time, the continuously variable transmission system can realize thesmooth switch between the motor and the engine.
基金Key Science-Technology Foundation of Hunan Province,China(No.05GK2007).
文摘Associated dynamic performance of the clamping force control valve used in continuously variable transmission(CVT)is optimized.Firstly,the structure and working principle of the valve are analyzed,and then a dynamic model is set up by means of mechanism analysis.For the purpose of checking the validity of the modeling method,a prototype workpiece of the valve is manufactured for comparison test,and its simulation result follows the experimental result quite well.An associated performance index is founded considering the response time,overshoot and saving energy,and five structural parameters are selected to adjust for deriving the optimal associated performance index.The optimization problem is solved by the genetic algorithm(GA)with necessary constraints.Finally,the properties of the optimized valve are compared with those of the prototype workpiece,and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.
基金financially supported by the National Natural Science Foundation of China(No.51205094)
文摘In order to study the influence of die combination on continuous variable cross-section direct extrusion （CVCDE） in the extrusion process, the accumulative strain formula is derived, and it can be known that the extrusion ratio of various stages directly determines the size of corresponding stage strain by formula. In this paper, as an example of the two interim dies, three die combinations of different angles and extrusion ratio are designed. Aviation magnesium alloy ZM6 is studied, and the results show that dynamic recrystallization is even more complete when continuous shear deformation occurs, so that the refinement and homogenization of microstructure are obtained. By the use of different die combinations, the accumulative strain increases under the conditions of same total extrusion ratio. Thus, the refined crystalline strengthening effect of extrusion deformation can be further analyzed. Due to the dead-zone defects, the actual accumulative strain decreases significantly and the effect of microstructure and performance improvements also decreases with it. Therefore, the optimal design of die combination is the key to the process and product of CVCDE, which provides a scientific basis for the development of severe plastic deformation.
基金Fund of Henan Innovation Project for University Prominent Research Talents (2002KYCX010) Youth Scientific Research Foundation of Henan University of Science and Technology (2004QN030)
文摘A new type continuous variable transmission device, a hydro-mechanical continuously variable transmission （HMCVT） for agricultural tractors is developed, which is composed of a single planetary gear differential train, a hydraulic transmission system consisted of variable displacement pump and fixed displacement motor and a multi-gear fixed step radio transmission. Based on the analysis of types of hydrostatic mechanical transmission （HMT） and styles of hydraulic transmission, the general drive scheme for HMCVT is obtained. The method of selecting mechanical parameters and hydraulic units is explained, and the stepless speed regulation characteristic of HMCVT is analyzed. This paper also specializes the calculating method of transmission efficiency. It shows that tractors assembled with HMCVT can obtain a continuously variable speed and achieve high drive efficiency.
基金supported by National Natural Science Foundation of China(No.50605020)Guangdong Provincial Science and Technology Project of China(No.2006A10501001).
文摘With the structure of two air gaps and two rotors, the electromagnetic continuously variable transmission（EMCVT） is a novel power-split continuously variable transmission（CVT）. There are two kinds of power flowing through the EMCVT, one is mechanical power and the other is electric power. In the mean time, there are three power ports in the EMCVT, one is the outer rotor named mechanical power port and the other two are the inner rotor and the stator named electric power ports. The mechanical power port is connected to the driving wheels through the final gear and the electric ports are connected to the batteries through the transducers. The two kinds of power are coupled on the outer rotor of the EMCVT. The EMCVT can be equipped on the conventional vehicle being regarded as the CVT and it also can be equipped on the hybrid electric vehicle（HEV） as the multi-energy sources assembly. The power flows of these two kinds of applications are analysed. The back electromotive force（EMF） equations are illatively studied and so the dynamic mathematic model is theorized. In order to certify the feasibility of the above theories, three simulations are carried out in allusion to the above two kinds of mentioned applications of the EMCVT and a five speed automatic transmission（AT） vehicle. The simulation results illustrate that the efficiency of the EMCVT vehicles is higher than that of the AT vehicle owed to the optimized operation area of the engine. Hence the fuel consumption of the EMCVT vehicles is knock-down.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61378010 and 11504219)the Key Project of the Ministry of Science and Technology of China(Grant No.2016YFA0301403)+1 种基金the Natural Science Foundation of Shanxi Province,China(Grant No.2014011007-1)the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province,China
文摘Quantum key distribution enables unconditionally secure key distribution between two legitimate users.The information-theoretic security is guaranteed by the fundamental laws of quantum physics.Initially,the quantum key distribution protocol was proposed based on the qubits.Later on,it was found that quantum continuous variables can also be exploited for this target.The continuous variable quantum key distribution can build upon standard telecommunication technology and exhibits a higher secret key rate per pulse at a relatively short distance due to the possibility of encoding more than 1 bit per pulse.In this article,we review the current status of the continuous variable quantum key distribution research,including its basic principle,experimental implementations,security and future directions;the experimental progress in this field made by our group is also presented.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61379153 and 61572529)
文摘We propose an arbitrated quantum signature （AQS） scheme with continuous variable （CV） squeezed vacuum states, which requires three parties, i.e., the signer Alice, the verifier Bob and the arbitrator Charlie trusted by Alice and Bob, and three phases consisting of the initial phase, the signature phase and the verification phase. We evaluate and compare the original state and the teleported state by using the fidelity and the beam splitter （BS） strategy. The security is ensured by the CV-based quantum key distribution （CV-QKD） and quantum teleportation of squeezed states. Security analyses show that the generated signature can be neither disavowed by the signer and the receiver nor counterfeited by anyone with the shared keys. Furthermore, the scheme can also detect other manners of potential attack although they may be successful. Also, the integrality and authenticity of the transmitted messages can be guaranteed. Compared to the signature scheme of CV-based coherent states, our scheme has better encoding efficiency and performance. It is a potential high-speed quantum signature scheme with high repetition rate and detection efficiency which can be achieved by using the standard off-the-shelf components when compared to the discrete-variable （DV） quantum signature scheme.
基金This project is supported by the National Natural Science Foundation of China(No.61571024,No.61971021)Aeronautical Science Foundation of China(No.2018ZC51016)the National Key Research and Development Program of China(No.2016YFC1000307)for valuable helps.
文摘Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement distribution.To realize efficient quantum communication based on quantum discord,in this paper,we consider the practical advantages of continuous variables and propose a feasible continuous-variable quantum network coding scheme based on quantum discord.By means of entanglement distribution by separable states,it can achieve quantum entanglement distribution from sources to targets in a butterfly network.Compared with the representative discrete-variable quantum network coding schemes,the proposed continuous-variable quantum network coding scheme has a higher probability of entanglement distribution and defends against eavesdropping and forgery attacks.Particularly,the deduced relationship indicates that the increase in entanglement is less than or equal to quantum discord.
