A method for modeling crosscutting concerns in the concurrent software system is presented based on the aspect-oriented（A-O） technique and the statechart of unified modeling language （UML）. Modeled with UML statec...A method for modeling crosscutting concerns in the concurrent software system is presented based on the aspect-oriented（A-O） technique and the statechart of unified modeling language （UML）. Modeled with UML statechart diagrams, the primary system functions and corresponding traversal features are enveloped into various orthogonal regions of a composite state. The mutual relationships between orthogonal regions are implied by the orders of broadcast events. Using a modular transition system as a basic computational model, the formalization description of A-O statechart models is proposed. The precise semantics of model elements and modeling procedures is given. The example study indicates that the separation strategy of crosscutting concerns is implemented in the design phase of the concurrent software system with this method. Meanwhile, the software modeling method has advantages of loose coupling, adaptability and traceability.展开更多
This paper presents a framework of the distributed concurrent multi-port-testing test system (CMPT-TS) for IP routers under development at Sichuan Network Communication Key Laboratory. Having analyzed the actuality of...This paper presents a framework of the distributed concurrent multi-port-testing test system (CMPT-TS) for IP routers under development at Sichuan Network Communication Key Laboratory. Having analyzed the actuality of concurrent testing for routers, this paper develops a distributed architecture of CMPT-TS and discusses its functional components in detail. Moreover, a new test definition language, CMPT definition language, is also introduced simply.展开更多
This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of en...This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of engineering design, especially conceptual design are reviewed. A deeper scientific analysis of intelligent design is discussed. A new problem solving strategy and methodologies to implement cooperative design are proposed. Finally, a conceptual model of a blackboard system for accomplishing conceptual design automation is presented. Its fundamental principles, system organization and key implementation techniques are investigated in detail.展开更多
Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system gen...Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system generates the assembly scheme using the case? based method, then assigns the design requirements into each component of the assembly. The detail design for each component can be performed under these design constraints. In order to practise concurrent design, the system sends the final design result to the upstream section and downstream section through PDM to achieve information sharing and integration.展开更多
Implementation of simultaneous execution phases in the concurrent engineering (CE) needs careful planning when the downstream phase could be activated as the upstream phase developed to a certain point. The determinat...Implementation of simultaneous execution phases in the concurrent engineering (CE) needs careful planning when the downstream phase could be activated as the upstream phase developed to a certain point. The determination of startup time of overlapping jobs in CE has long been a disturbance in manufacturing industry implementing CE programs. A novel model based on both fuzzy logic and neural network is proposed to mathematically formulate the inter-connective information between the two coupled phases in CE projects, and to determine the startup time of downstream phases in real time. The information transferring between the two coupled phases is quantified by using the negative Shannon entropy. Based on this algorithm, a PDM-based framework is proposed to narrow the gap between pro-duct design and manufacture, in which five modules are built to monitor, reshuffle and implement the simultaneous executing processes. Finally, an example is given to illustrate applications of the algorithm in the real world.展开更多
Tolerance analysis is investigated under an environment of concurrent design in order to lead to optimized tolerance, as traditional tolerance analysis is often inefficient and liable to mistakes. Making full use of k...Tolerance analysis is investigated under an environment of concurrent design in order to lead to optimized tolerance, as traditional tolerance analysis is often inefficient and liable to mistakes. Making full use of knowledge in manufacturing tolerance analysis combined with the beta distribution model is introduced and applied. The use of beta distribution reflects fully actual capabilities in manufacture. Concurrent tolerance design is a manufacturing environment oriented design process paying more attention to influences or restraints on product design caused by such factors as the manufacturing process, machine capabilities, economy in manufacturing, etc. Process environment oriented tolerance analysis is more flexible making the designed results more practical and effective.展开更多
Background In patients with acute ST-segment elevation myocardial infarction(STEMI)who undergo primary percutaneous coronary intervention(PCI),approximately 10%are concomitant with a chronic total occlusion(CTO)in a n...Background In patients with acute ST-segment elevation myocardial infarction(STEMI)who undergo primary percutaneous coronary intervention(PCI),approximately 10%are concomitant with a chronic total occlusion(CTO)in a non-culprit vessel.However,the impact of staged CTO recanalization on prognosis in this cohort remains disputable.This study aimed to compare the long-term outcomes of staged CTO recanalization versus medical therapy in patients with STEMI after primary PCI.Methods Between January 2005 and December 2016,a total of 287 patients were treated with staged CTO-PCI(n=91)or medical therapy(n=196)after primary PCI in our center.The primary endpoint was major adverse cardiovascular and cerebrovascular event(MACCE),defined as a composite of all-cause death,nonfatal myocardial infarction(MI),stroke or unplanned revascularization.After propensity-score matching,77 pairs of well-balanced patients were identified.Results The mean follow-up period was 6.06 years.Overall,the incidence of the primary endpoint of MACCE was significantly lower in staged CTO-PCI group than that in medical therapy group in both overall population(22.0%vs.46.9%;hazard ratio(HR)=0.48,95%CI:0.29-0.77)and propensity-matched cohorts(22.1%vs.42.9%;HR:0.48,95%CI:0.27-0.86).In addition,staged CTO-PCI was also associated with reduced risk of the composite of cardiac death,nonfatal MI or stroke compared with medical therapy in both overall population(9.9%vs.26.5%;hazard ratio(HR)=0.39,95%CI:0.19-0.79)and propensity-matched cohorts(9.1%vs.22.1%;HR:0.40,95%CI:0.16-0.96).After correction of the possible confounders,staged CTO-PCI was independently associated with reduced risks of MACCE(adjusted HR:0.46,95%CI:0.28-0.75),the composite of cardiac death,nonfatal MI or stroke(adjusted HR:0.45,95%CI:0.22-0.94)and all-cause mortality(adjusted HR:0.32,95%CI:0.13-0.83).Moreover,the results of sensitivity analysis were almost concordant with the overall analysis.Conclusions In patients with STEMI and a concurrent CTO who undergo primary PCI,successful staged recanalization of CTO in the non-culprit vessels is associated with better clinical outcomes during long-term follow-up.展开更多
The entanglement evolution of the coupled qubits interacting with a non-Markov environment is investigated in terms of concurrence. The results show that the entanglement of the quantum systems depends not only on the...The entanglement evolution of the coupled qubits interacting with a non-Markov environment is investigated in terms of concurrence. The results show that the entanglement of the quantum systems depends not only on the initial state of the system but also on the coupling between the qubit and the environment. For the initial state （100） ± ｜11〉）/√2, the coupled qubits will always been in the maximum entangled state under an asymmetric coupling. For the initial state （｜01〉 ± ＋10〉）/√2, in contrast, the entangling degree of the coupled qubits is always equal to unity and does not depend on the evolving time under the symmetric coupling. We find that the stronger the interaction between the qubits is, the better the struggle against the entanglement sudden death is.展开更多
The energy Internet operation platform provides market entities such as energy users,energy enterprises,suppliers,and governments with the ability to interact,transact,and manage various operations.Owing to the large ...The energy Internet operation platform provides market entities such as energy users,energy enterprises,suppliers,and governments with the ability to interact,transact,and manage various operations.Owing to the large number of platform users,complex businesses,and large amounts of data-mining tasks,it is necessary to solve the problems afflicting platform task scheduling and the provision of simultaneous access to a large number of users.This study examines the two core technologies of platform task scheduling and multiuser concurrent processing,proposing a distributed task-scheduling method and a technical implementation scheme based on the particle swarm optimization algorithm,and presents a systematic solution in concurrent processing for massive user numbers.Based on the results of this study,the energy internet operation platform can effectively deal with the concurrent access of tens of millions of users and complex task-scheduling problems.展开更多
To overcome inefficiency in traditional logic programming, a declarative programming language COPS is designed based on the notion of concurrent constraint programming (CCP). The improvement is achieved by the adoptio...To overcome inefficiency in traditional logic programming, a declarative programming language COPS is designed based on the notion of concurrent constraint programming (CCP). The improvement is achieved by the adoption of constraint-based heuristic strategy and the introduction of deterministic components in the framework of CCP. Syntax specification and an operational semantic description are presented.展开更多
With the increasing demand for marine exploration, underwater acoustic sensor networks (UASNs) are prone to have the characteristics of large-scale, long term monitoring, and high data traffic load. Underwater media a...With the increasing demand for marine exploration, underwater acoustic sensor networks (UASNs) are prone to have the characteristics of large-scale, long term monitoring, and high data traffic load. Underwater media access control (MAC) protocols, which allow multiple users to share the common medium fairly and efficiently, are essential for the performance of UASNs. However, the design of MAC protocols is confronted with the challenges of spatial unfairness, data eruption, and low energy efficiency. In this paper, we propose a novel data concurrent transmission (DCT) MAC protocol, which is able to exploit long propagation delay and conduct concurrent transmission. Specifically, we present the theoretical performance analysis of the proposed MAC protocol in detail and give an analytical solution of the success concurrent transmission probability between nodes. In addition, simulation results are provided to demonstrate that our proposed protocol is appropriate for UASNs and can significantly improve the performance in terms of network throughput and energy consumption. Finally, we give some typical future applications of UASNs and discuss the demands on MAC protocol design.展开更多
This paper presents monogamy relations for three-qubit quantum states by using convex-roof extended negativity, which inspires studying the difference between the three entanglement measures, concurrence, negativity a...This paper presents monogamy relations for three-qubit quantum states by using convex-roof extended negativity, which inspires studying the difference between the three entanglement measures, concurrence, negativity and convex- roof extended negativity. It finds that the convex-roof extended negativity is a stronger entanglement measure than concurrence in multipaxtite higher-dimensional quantum system.展开更多
We investigate the tripartite entanglement dynamics of three two-level atoms in a multi-mode vacuum field. By considering the influences of the interatomic distance and the initial condition on the lower bound of conc...We investigate the tripartite entanglement dynamics of three two-level atoms in a multi-mode vacuum field. By considering the influences of the interatomic distance and the initial condition on the lower bound of concurrence and the tripartite negativity, we show that an optimal interatomic distance can be found to minimize the collective damping. Interestingly, at the same optimal distance, the tripartite entanglement would be maximized in the open dynamics process. In the case of shorter interatomic distance, the tripartite entanglement can display the oscillatory behavior in the initial short-time limit and be trapped in a stationary value in the long-time limit. In addition, the tripartite entanglement for the general situation with different interatomic distances is also discussed.展开更多
With the development of self-interference(SI) cancelation technology, full-duplex(FD) communication becomes possible. FD communication can theoretically double the spectral efficiency. When the time slot(TS) resources...With the development of self-interference(SI) cancelation technology, full-duplex(FD) communication becomes possible. FD communication can theoretically double the spectral efficiency. When the time slot(TS) resources are limited and the number of flows is large, the scheduling mechanism of the flows becomes more important. Therefore, the effectiveness of FD scheduling mechanism for the flows is studied in millimeter wave wireless backhaul network with the limited TS resources. We proposed a full duplex concurrent scheduling algorithm based on coalition game(FDCG) to maximize the number of flows with their QoS requirements satisfied. We transformed the problem of maximizing the number of flows with their QoS requirements satisfied into the problem of maximizing sum rate of concurrently scheduled flows in each slot. We obtained the scheduled flows with maximum sum rate in first slot by using coalition game.And then with certain restrictions, the maximum sum rate of concurrently scheduled flows can also be achieved in subsequent time slots. The simulation results show that the proposed FDCG algorithm canachieve superior performance in terms of the number of flows that meet their QoS requirements and system throughput compared with other three algorithms.展开更多
Concurrent signature was introduced as an efficient approach to solving the problem of fair exchange of signatures. Almost all fair exchange e-commerce protocols based on concurrent signature that have been proposed u...Concurrent signature was introduced as an efficient approach to solving the problem of fair exchange of signatures. Almost all fair exchange e-commerce protocols based on concurrent signature that have been proposed until now either do not provide message privacy protection or adopt the sign-then-encrypt scheme to provide confidentiality. However,confidentiality is an important requirement of fair exchange e-commerce protocol. In this paper,a new concept called concurrent signcryption which combines the concepts of concurrent signature and signcryption together to resolve the confidentiality problem in e-commerce systems based on concurrent signature. We also propose a concurrent signcryption scheme using bilinear pairings and prove its security in the random oracle model. Compared with the sign-then-encrypt scheme using bilinear pairings,our scheme enjoys shorter message length and less operation cost. Moreover,in our scheme the two ambiguous signcryptions can be published in any order.展开更多
Aim To study the development and realization mechanism of concurrent engineering(CE).Methods The realization mechanism based on multi-agent and micro-circulation were dis-cussed.Results The specialties of micro-circul...Aim To study the development and realization mechanism of concurrent engineering(CE).Methods The realization mechanism based on multi-agent and micro-circulation were dis-cussed.Results The specialties of micro-circulation are wholly adaptable to the circulationtheory and information exchange requirement in CE,which can explain the nature of CEsuccessfully.Conclusion The micro-circulation theory can be adopted as a new realizationmechanism of CE.展开更多
A new probability measure for the quantification of entanglement of pure states is introduced.Numerical computations indicate that the derived measure is equal to concurrence,up to the precision of the computer progra...A new probability measure for the quantification of entanglement of pure states is introduced.Numerical computations indicate that the derived measure is equal to concurrence,up to the precision of the computer program used.Hence it also provides a physical interpretation for concurrence.展开更多
Leprosy is characterized by skin lesions and peripheral nerve damage. It may take a long time before the diagnosis can be confirmed if the patients have no typical skin involvements. Here we report an unusual case. A ...Leprosy is characterized by skin lesions and peripheral nerve damage. It may take a long time before the diagnosis can be confirmed if the patients have no typical skin involvements. Here we report an unusual case. A 40-year-old male with lepromatous leprosy showed a gradual onset of bilateral symmetrical neuropathies without characteristic skin manifestations seven years after onset and with pulmonary tuberculosis simultaneously. He was misdiagnosed as having Guillani-Barr6 syndrome and systemic necrotizing vasculitis for 10 years until the skin biopsy was performed. This case indicates that the risk of leprosy exists, though new cases being detected have significantly declined over the last 50 years; neurologists need to pay more attention to leprosy with various manifestations .展开更多
We investigate an entangled three-qubit system in which only one of the qubits experiences the decoherence effect by considering a non-Hermitian Hamiltonian,while the other two qubits are isolated,i.e.,do not interact...We investigate an entangled three-qubit system in which only one of the qubits experiences the decoherence effect by considering a non-Hermitian Hamiltonian,while the other two qubits are isolated,i.e.,do not interact with environment,directly.Then,the time evolution of the density matrix(for the pure as well as mixed initial density matrix)and the corresponding reduced density matrices are obtained,by which we are able to utilize the dissipative non-Hermitian Hamiltonian model with Markovian and non-Markovian regimes via adjusting the strange of the non-Hermitian term of the total Hamiltonian of the under-considered system.展开更多
Entanglement transfer is investigated in a dimerized Heisenberg system. Concurrence as the measure of entanglement is calculated by the time-evolved state starting from an initially entangled state of spin pair. It is...Entanglement transfer is investigated in a dimerized Heisenberg system. Concurrence as the measure of entanglement is calculated by the time-evolved state starting from an initially entangled state of spin pair. It is shown that perfect entanglement transfer can be realized at some special time and suitable interacting.展开更多
文摘A method for modeling crosscutting concerns in the concurrent software system is presented based on the aspect-oriented（A-O） technique and the statechart of unified modeling language （UML）. Modeled with UML statechart diagrams, the primary system functions and corresponding traversal features are enveloped into various orthogonal regions of a composite state. The mutual relationships between orthogonal regions are implied by the orders of broadcast events. Using a modular transition system as a basic computational model, the formalization description of A-O statechart models is proposed. The precise semantics of model elements and modeling procedures is given. The example study indicates that the separation strategy of crosscutting concerns is implemented in the design phase of the concurrent software system with this method. Meanwhile, the software modeling method has advantages of loose coupling, adaptability and traceability.
文摘This paper presents a framework of the distributed concurrent multi-port-testing test system (CMPT-TS) for IP routers under development at Sichuan Network Communication Key Laboratory. Having analyzed the actuality of concurrent testing for routers, this paper develops a distributed architecture of CMPT-TS and discusses its functional components in detail. Moreover, a new test definition language, CMPT definition language, is also introduced simply.
文摘This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of engineering design, especially conceptual design are reviewed. A deeper scientific analysis of intelligent design is discussed. A new problem solving strategy and methodologies to implement cooperative design are proposed. Finally, a conceptual model of a blackboard system for accomplishing conceptual design automation is presented. Its fundamental principles, system organization and key implementation techniques are investigated in detail.
文摘Taking a microwave product as an example, a system of integrated assembly structure design is presented. Getting design constraints from the upstream design section through product data management(PDM), the system generates the assembly scheme using the case? based method, then assigns the design requirements into each component of the assembly. The detail design for each component can be performed under these design constraints. In order to practise concurrent design, the system sends the final design result to the upstream section and downstream section through PDM to achieve information sharing and integration.
文摘Implementation of simultaneous execution phases in the concurrent engineering (CE) needs careful planning when the downstream phase could be activated as the upstream phase developed to a certain point. The determination of startup time of overlapping jobs in CE has long been a disturbance in manufacturing industry implementing CE programs. A novel model based on both fuzzy logic and neural network is proposed to mathematically formulate the inter-connective information between the two coupled phases in CE projects, and to determine the startup time of downstream phases in real time. The information transferring between the two coupled phases is quantified by using the negative Shannon entropy. Based on this algorithm, a PDM-based framework is proposed to narrow the gap between pro-duct design and manufacture, in which five modules are built to monitor, reshuffle and implement the simultaneous executing processes. Finally, an example is given to illustrate applications of the algorithm in the real world.
文摘Tolerance analysis is investigated under an environment of concurrent design in order to lead to optimized tolerance, as traditional tolerance analysis is often inefficient and liable to mistakes. Making full use of knowledge in manufacturing tolerance analysis combined with the beta distribution model is introduced and applied. The use of beta distribution reflects fully actual capabilities in manufacture. Concurrent tolerance design is a manufacturing environment oriented design process paying more attention to influences or restraints on product design caused by such factors as the manufacturing process, machine capabilities, economy in manufacturing, etc. Process environment oriented tolerance analysis is more flexible making the designed results more practical and effective.
基金funded by the Ministry of Science and Technology of the People’s Republic of China,State Science and Technology Support Program (No.2011BAI11B05)Beijing Lab for Cardiovascular Precision Medicine, Beijing, China (PXM2019_014226_000023)
文摘Background In patients with acute ST-segment elevation myocardial infarction(STEMI)who undergo primary percutaneous coronary intervention(PCI),approximately 10%are concomitant with a chronic total occlusion(CTO)in a non-culprit vessel.However,the impact of staged CTO recanalization on prognosis in this cohort remains disputable.This study aimed to compare the long-term outcomes of staged CTO recanalization versus medical therapy in patients with STEMI after primary PCI.Methods Between January 2005 and December 2016,a total of 287 patients were treated with staged CTO-PCI(n=91)or medical therapy(n=196)after primary PCI in our center.The primary endpoint was major adverse cardiovascular and cerebrovascular event(MACCE),defined as a composite of all-cause death,nonfatal myocardial infarction(MI),stroke or unplanned revascularization.After propensity-score matching,77 pairs of well-balanced patients were identified.Results The mean follow-up period was 6.06 years.Overall,the incidence of the primary endpoint of MACCE was significantly lower in staged CTO-PCI group than that in medical therapy group in both overall population(22.0%vs.46.9%;hazard ratio(HR)=0.48,95%CI:0.29-0.77)and propensity-matched cohorts(22.1%vs.42.9%;HR:0.48,95%CI:0.27-0.86).In addition,staged CTO-PCI was also associated with reduced risk of the composite of cardiac death,nonfatal MI or stroke compared with medical therapy in both overall population(9.9%vs.26.5%;hazard ratio(HR)=0.39,95%CI:0.19-0.79)and propensity-matched cohorts(9.1%vs.22.1%;HR:0.40,95%CI:0.16-0.96).After correction of the possible confounders,staged CTO-PCI was independently associated with reduced risks of MACCE(adjusted HR:0.46,95%CI:0.28-0.75),the composite of cardiac death,nonfatal MI or stroke(adjusted HR:0.45,95%CI:0.22-0.94)and all-cause mortality(adjusted HR:0.32,95%CI:0.13-0.83).Moreover,the results of sensitivity analysis were almost concordant with the overall analysis.Conclusions In patients with STEMI and a concurrent CTO who undergo primary PCI,successful staged recanalization of CTO in the non-culprit vessels is associated with better clinical outcomes during long-term follow-up.
基金Project supported by the National Natural Science Foundation of China (Grant No.10864002)
文摘The entanglement evolution of the coupled qubits interacting with a non-Markov environment is investigated in terms of concurrence. The results show that the entanglement of the quantum systems depends not only on the initial state of the system but also on the coupling between the qubit and the environment. For the initial state （100） ± ｜11〉）/√2, the coupled qubits will always been in the maximum entangled state under an asymmetric coupling. For the initial state （｜01〉 ± ＋10〉）/√2, in contrast, the entangling degree of the coupled qubits is always equal to unity and does not depend on the evolving time under the symmetric coupling. We find that the stronger the interaction between the qubits is, the better the struggle against the entanglement sudden death is.
基金supported by the Science and Technology Project of State Grid Corporation“Research and Application of Internet Operation Platform for Ubiquitous Power Internet of Things”(5700-201955462A-0-0-00).
文摘The energy Internet operation platform provides market entities such as energy users,energy enterprises,suppliers,and governments with the ability to interact,transact,and manage various operations.Owing to the large number of platform users,complex businesses,and large amounts of data-mining tasks,it is necessary to solve the problems afflicting platform task scheduling and the provision of simultaneous access to a large number of users.This study examines the two core technologies of platform task scheduling and multiuser concurrent processing,proposing a distributed task-scheduling method and a technical implementation scheme based on the particle swarm optimization algorithm,and presents a systematic solution in concurrent processing for massive user numbers.Based on the results of this study,the energy internet operation platform can effectively deal with the concurrent access of tens of millions of users and complex task-scheduling problems.
文摘To overcome inefficiency in traditional logic programming, a declarative programming language COPS is designed based on the notion of concurrent constraint programming (CCP). The improvement is achieved by the adoption of constraint-based heuristic strategy and the introduction of deterministic components in the framework of CCP. Syntax specification and an operational semantic description are presented.
基金supported in part by the National Natural Science Foundation of China under Grant 62171405in part by the National Science Fund for Distinguished Young Scholars under Grant 62225114
文摘With the increasing demand for marine exploration, underwater acoustic sensor networks (UASNs) are prone to have the characteristics of large-scale, long term monitoring, and high data traffic load. Underwater media access control (MAC) protocols, which allow multiple users to share the common medium fairly and efficiently, are essential for the performance of UASNs. However, the design of MAC protocols is confronted with the challenges of spatial unfairness, data eruption, and low energy efficiency. In this paper, we propose a novel data concurrent transmission (DCT) MAC protocol, which is able to exploit long propagation delay and conduct concurrent transmission. Specifically, we present the theoretical performance analysis of the proposed MAC protocol in detail and give an analytical solution of the success concurrent transmission probability between nodes. In addition, simulation results are provided to demonstrate that our proposed protocol is appropriate for UASNs and can significantly improve the performance in terms of network throughput and energy consumption. Finally, we give some typical future applications of UASNs and discuss the demands on MAC protocol design.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10871227)the Natural Science Foundation of Beijing (Grant No. 1092008)
文摘This paper presents monogamy relations for three-qubit quantum states by using convex-roof extended negativity, which inspires studying the difference between the three entanglement measures, concurrence, negativity and convex- roof extended negativity. It finds that the convex-roof extended negativity is a stronger entanglement measure than concurrence in multipaxtite higher-dimensional quantum system.
基金supported by the National Natural Science Foundation of China(Grant Nos.61178012,11204156,and 11304179)the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant Nos.20133705110001 and 20123705120002)the Natural Science Foundation of Shandong Province,China(Grant Nos.BS2013DX034,ZR2012FQ024,and ZR2014AP009)
文摘We investigate the tripartite entanglement dynamics of three two-level atoms in a multi-mode vacuum field. By considering the influences of the interatomic distance and the initial condition on the lower bound of concurrence and the tripartite negativity, we show that an optimal interatomic distance can be found to minimize the collective damping. Interestingly, at the same optimal distance, the tripartite entanglement would be maximized in the open dynamics process. In the case of shorter interatomic distance, the tripartite entanglement can display the oscillatory behavior in the initial short-time limit and be trapped in a stationary value in the long-time limit. In addition, the tripartite entanglement for the general situation with different interatomic distances is also discussed.
基金supported by the National Natural Science Foundation of China Grants 61725101 and 61801016the China Postdoctoral Science Foundation under Grant 2017M610040 and 2018T110041+2 种基金National key research and development program under Grant 2016YFE0200900the Beijing Natural Fund under Grant L172020Major projects of Beijing Municipal Science and Technology Commission under Grant No. Z181100003218010
文摘With the development of self-interference(SI) cancelation technology, full-duplex(FD) communication becomes possible. FD communication can theoretically double the spectral efficiency. When the time slot(TS) resources are limited and the number of flows is large, the scheduling mechanism of the flows becomes more important. Therefore, the effectiveness of FD scheduling mechanism for the flows is studied in millimeter wave wireless backhaul network with the limited TS resources. We proposed a full duplex concurrent scheduling algorithm based on coalition game(FDCG) to maximize the number of flows with their QoS requirements satisfied. We transformed the problem of maximizing the number of flows with their QoS requirements satisfied into the problem of maximizing sum rate of concurrently scheduled flows in each slot. We obtained the scheduled flows with maximum sum rate in first slot by using coalition game.And then with certain restrictions, the maximum sum rate of concurrently scheduled flows can also be achieved in subsequent time slots. The simulation results show that the proposed FDCG algorithm canachieve superior performance in terms of the number of flows that meet their QoS requirements and system throughput compared with other three algorithms.
基金supported by the National Natural Science Foundation of China under contract No. 60803131
文摘Concurrent signature was introduced as an efficient approach to solving the problem of fair exchange of signatures. Almost all fair exchange e-commerce protocols based on concurrent signature that have been proposed until now either do not provide message privacy protection or adopt the sign-then-encrypt scheme to provide confidentiality. However,confidentiality is an important requirement of fair exchange e-commerce protocol. In this paper,a new concept called concurrent signcryption which combines the concepts of concurrent signature and signcryption together to resolve the confidentiality problem in e-commerce systems based on concurrent signature. We also propose a concurrent signcryption scheme using bilinear pairings and prove its security in the random oracle model. Compared with the sign-then-encrypt scheme using bilinear pairings,our scheme enjoys shorter message length and less operation cost. Moreover,in our scheme the two ambiguous signcryptions can be published in any order.
文摘Aim To study the development and realization mechanism of concurrent engineering(CE).Methods The realization mechanism based on multi-agent and micro-circulation were dis-cussed.Results The specialties of micro-circulation are wholly adaptable to the circulationtheory and information exchange requirement in CE,which can explain the nature of CEsuccessfully.Conclusion The micro-circulation theory can be adopted as a new realizationmechanism of CE.
文摘A new probability measure for the quantification of entanglement of pure states is introduced.Numerical computations indicate that the derived measure is equal to concurrence,up to the precision of the computer program used.Hence it also provides a physical interpretation for concurrence.
文摘Leprosy is characterized by skin lesions and peripheral nerve damage. It may take a long time before the diagnosis can be confirmed if the patients have no typical skin involvements. Here we report an unusual case. A 40-year-old male with lepromatous leprosy showed a gradual onset of bilateral symmetrical neuropathies without characteristic skin manifestations seven years after onset and with pulmonary tuberculosis simultaneously. He was misdiagnosed as having Guillani-Barr6 syndrome and systemic necrotizing vasculitis for 10 years until the skin biopsy was performed. This case indicates that the risk of leprosy exists, though new cases being detected have significantly declined over the last 50 years; neurologists need to pay more attention to leprosy with various manifestations .
文摘We investigate an entangled three-qubit system in which only one of the qubits experiences the decoherence effect by considering a non-Hermitian Hamiltonian,while the other two qubits are isolated,i.e.,do not interact with environment,directly.Then,the time evolution of the density matrix(for the pure as well as mixed initial density matrix)and the corresponding reduced density matrices are obtained,by which we are able to utilize the dissipative non-Hermitian Hamiltonian model with Markovian and non-Markovian regimes via adjusting the strange of the non-Hermitian term of the total Hamiltonian of the under-considered system.
基金the National Natural Science Foundation of China(10374007 604720210)
文摘Entanglement transfer is investigated in a dimerized Heisenberg system. Concurrence as the measure of entanglement is calculated by the time-evolved state starting from an initially entangled state of spin pair. It is shown that perfect entanglement transfer can be realized at some special time and suitable interacting.
