The production process plan design and configurations of reconfigurable machine tool （RMT） interact with each other. Reasonable process plans with suitable configurations of RMT help to improve product quality and r...The production process plan design and configurations of reconfigurable machine tool （RMT） interact with each other. Reasonable process plans with suitable configurations of RMT help to improve product quality and reduce production cost. Therefore, a cooperative strategy is needed to concurrently solve the above issue. In this paper, the cooperative optimization model for RMT configurations and production process plan is presented. Its objectives take into account both impacts of process and configuration. Moreover, a novel genetic algorithm is also developed to provide optimal or near-optimal solutions： firstly, its chromosome is redesigned which is composed of three parts, operations, process plan and configurations of RMTs, respectively; secondly, its new selection, crossover and mutation operators are also developed to deal with the process constraints from operation processes （OP） graph, otherwise these operators could generate illegal solutions violating the limits; eventually the optimal configurations for RMT under optimal process plan design can be obtained. At last, a manufacturing line case is applied which is composed of three RMTs. It is shown from the case that the optimal process plan and configurations of RMT are concurrently obtained, and the production cost decreases 6.28% and nonmonetary performance increases 22%. The proposed method can figure out both RMT configurations and production process, improve production capacity, functions and equipment utilization for RMT.展开更多
Existing sub-/super-synchronous oscillation stability control methods are primarily focused on specific operating conditions at discrete frequencies,limiting their adaptation to varying oscillation scenarios in the po...Existing sub-/super-synchronous oscillation stability control methods are primarily focused on specific operating conditions at discrete frequencies,limiting their adaptation to varying oscillation scenarios in the power system connected with direct-drive permanent magnet synchronous generator(PMSG)-based wind farms.Based on supplementary dissipation compensation,this paper proposes an oscillation stability control method incorporating equipment-level and farm-level cooperative optimization to enhance the system-level stability.First,the effects of dynamic self-dissipation and dynamic coupled dissipation on system stability are analyzed,establishing the foundational principle of supplementary dissipation compensation.Subsequently,the optimal locations for supplementary dissipation compensation are identified based on critical control designed to enhance the dynamic self-dissipation effect and suppress the dynamic coupled dissipation effect.Furthermore,by considering energy requirements under the combined wind farm-grid interaction and inter-PMSG interactions and balancing the wind farm-grid interaction dissipation energy with inter-PMSG interaction dissipation energy distribution,an equipment-level control parameter optimization algorithm and a farm-level power cooperative optimization algorithm are established.Finally,the simulation results demonstrate that dynamic coupled dissipation constitutes the root cause of oscillation inception and progression.Through equipment-level and farm-level cooperative optimization,the proposed method can reliably compensate dynamic dissipation energy,while adapting to the variation of oscillation frequency and the oscillation scenario.It can maximize the energy dissipation effect of the interconnected system,achieving rapid suppression of sub-/super-synchronous oscillations.展开更多
In order to improve the throughput of cognitive radio(CR), optimization of sensing time and cooperative user allocation for OR-rule cooperative spectrum sensing was investigated in a CR network that includes multiple ...In order to improve the throughput of cognitive radio(CR), optimization of sensing time and cooperative user allocation for OR-rule cooperative spectrum sensing was investigated in a CR network that includes multiple users and one fusion center. The frame structure of cooperative spectrum sensing was divided into multiple transmission time slots and one sensing time slot consisting of local energy detection and cooperative overhead. An optimization problem was formulated to maximize the throughput of CR network, subject to the constraints of both false alarm probability and detection probability. A joint optimization algorithm of sensing time and number of users was proposed to solve this optimization problem with low time complexity. An allocation algorithm of cooperative users was proposed to preferentially allocate the users to the channels with high utilization probability. The simulation results show that the significant improvement on the throughput can be achieved through the proposed joint optimization and allocation algorithms.展开更多
Cryogenic ground support equipment (CGSE) is an important part of a famous particle physics experiment - AMS-02. In this paper a design method which optimizes PID parameters of CGSE control system via the particle swa...Cryogenic ground support equipment (CGSE) is an important part of a famous particle physics experiment - AMS-02. In this paper a design method which optimizes PID parameters of CGSE control system via the particle swarm optimization (PSO) algorithm is presented. Firstly, an improved version of the original PSO, cooperative random learning particle swarm optimization (CRPSO), is put forward to enhance the performance of the conventional PSO. Secondly, the way of finding PID coefficient will be studied by using this algorithm. Finally, the experimental results and practical works demonstrate that the CRPSO-PID controller achieves a good performance.展开更多
This paper addresses the problem of service composition in military organization cloud cooperation（MOCC）. Military service providers（MSP） cooperate together to provide military resources for military service users...This paper addresses the problem of service composition in military organization cloud cooperation（MOCC）. Military service providers（MSP） cooperate together to provide military resources for military service users（MSU）. A group of atom services, each of which has its level of quality of service（QoS）, can be combined together into a certain structure to form a composite service. Since there are a large number of atom services having the same function, the atom service is selected to participate in the composite service so as to fulfill users＇ will. In this paper a method based on discrete particle swarm optimization（DPSO） is proposed to tackle this problem. The method aims at selecting atom services from service repositories to constitute the composite service, satisfying the MSU＇s requirement on QoS. Since the QoS criteria include location-aware criteria and location-independent criteria, this method aims to get the composite service with the highest location-aware criteria and the best-match location-independent criteria. Simulations show that the DPSO has a better performance compared with the standard particle swarm optimization（PSO） and genetic algorithm（GA）.展开更多
In the interception engagement,if the target movement information is not accurate enough for the mid-course guidance of intercepting missiles,the interception mission may fail as a result of large handover errors.This...In the interception engagement,if the target movement information is not accurate enough for the mid-course guidance of intercepting missiles,the interception mission may fail as a result of large handover errors.This paper proposes a novel cooperative mid-course guidance scheme for multiple missiles to intercept a target under the condition of large detection errors.Under this scheme,the launch and interception moments are staggered for different missiles.The earlier launched missiles can obtain a relatively accurate detection to the target during their terminal guidance,based on which the latter missiles are permitted to eliminate the handover error in the mid-course guidance.A significant merit of this scheme is that the available resources are fully exploited and less missiles are needed to achieve the interception mission.To this end,first,the design of cooperative handover parameters is formulated as an optimization problem.Then,an algorithm based on Monte Carlo sampling and stochastic approximation is proposed to solve this optimization problem,and the convergence of the algorithm is proved as well.Finally,simulation experiments are carried out to validate the effectiveness of the proposed cooperative scheme and algorithm.展开更多
China＇s Rural Cooperative Medical System collapsed alongside communal farming at the end of the Maoist period in 1976, leaving most farmers vulnerable[1]. In rural areas, where 80% of people have been without health ...China＇s Rural Cooperative Medical System collapsed alongside communal farming at the end of the Maoist period in 1976, leaving most farmers vulnerable[1]. In rural areas, where 80% of people have been without health insurance of any kind, illness has emerged as a leading cause of poverty[24]. To address the poor state of health care among the rural population, in 2003 the Chinese government launched the New Rural Cooperative Medical System （NCMS）,展开更多
To improve the detection performance of sensing users for primary users in the cognitive radio, an optimal cooperative detection algorithm for many sensing users is proposed. In this paper, optimal decision thresholds...To improve the detection performance of sensing users for primary users in the cognitive radio, an optimal cooperative detection algorithm for many sensing users is proposed. In this paper, optimal decision thresholds of each sensing user are discussed. Theoretical analysis and simulation results indicate that the detection probability of optimal decision threshold rules is better than that of determined threshold rules when the false alarm of the fusion center is constant. The proposed optimal cooperative detection algorithm improves the detection performance of primary users as the attendees grow. The 2 dB gain of detection probability can be obtained when a new sensing user joins in, and there is a 17 dB improvement when the accumulation number increases from 1 to 50.展开更多
The study investigated the influence of Ce alloying and cold rolling on the activation behavior of V_(70)Ti_(10)Cr_(20)-based alloys.The activation conditions of single cold rolled(V_(70)Ti_(10)Cr_(20)-0.3)and single ...The study investigated the influence of Ce alloying and cold rolling on the activation behavior of V_(70)Ti_(10)Cr_(20)-based alloys.The activation conditions of single cold rolled(V_(70)Ti_(10)Cr_(20)-0.3)and single Ce replaced(V_(70)Ti_(10)Cr_(20)Ce_(1))samples were reduced from the origin-al two heat treatments to one heat treatment,and the incubation time was about 105 min.Unexpectedly,the two modification methods produce excellent synergistic effects that the co-modified sample(V_(70)Ti_(10)Cr_(20)Ce_(1)-0.5)was activated at room temperature(25℃)without incubation period,and reached saturation capacity(4wt%)within 12 min.Further studies show that CeO_(2) formed through Ce doping,serves as an active site for hydrogen absorption,facilitating the passage of hydrogen atoms through the dense oxide layer on the surface of vanadium-based alloys.Upon the foundation of Ce doping,cold rolling leads to the aggregation of dislocations around CeO_(2) sites,thereby further establishing a hydrogen diffusion pathway from the surface into the bulk phase,thus significantly improving the activation performance of the alloy.This work establishes a robust basis for the practical engineering use of vanadium-based hydrogen storage alloys.展开更多
Multiagent reinforcement learning(MARL)has become a dazzling new star in the field of reinforcement learning in recent years,demonstrating its immense potential across many application scenarios.The reward function di...Multiagent reinforcement learning(MARL)has become a dazzling new star in the field of reinforcement learning in recent years,demonstrating its immense potential across many application scenarios.The reward function directs agents to explore their environments and make optimal decisions within them by establishing evaluation criteria and feedback mechanisms.Concurrently,cooperative objectives at the macro level provide a trajectory for agents’learning,ensuring alignment between individual behavioral strategies and the overarching system goals.The interplay between reward structures and cooperative objectives not only bolsters the effectiveness of individual agents but also fosters interagent collaboration,offering both momentum and direction for the development of swarm intelligence and the harmonious operation of multiagent systems.This review delves deeply into the methods for designing reward structures and optimizing cooperative objectives in MARL,along with the most recent scientific advancements in this field.The article meticulously reviews the application of simulation environments in cooperative scenarios and discusses future trends and potential research directions in the field,providing a forward-looking perspective and inspiration for subsequent research efforts.展开更多
The artificial bee colony(ABC) algorithm is improved to construct a hybrid multi-objective ABC algorithm, called HMOABC, for resolving optimal power flow(OPF) problem by simultaneously optimizing three conflicting obj...The artificial bee colony(ABC) algorithm is improved to construct a hybrid multi-objective ABC algorithm, called HMOABC, for resolving optimal power flow(OPF) problem by simultaneously optimizing three conflicting objectives of OPF, instead of transforming multi-objective functions into a single objective function. The main idea of HMOABC is to extend original ABC algorithm to multi-objective and cooperative mode by combining the Pareto dominance and divide-and-conquer approach. HMOABC is then used in the 30-bus IEEE test system for solving the OPF problem considering the cost, loss, and emission impacts. The simulation results show that the HMOABC is superior to other algorithms in terms of optimization accuracy and computation robustness.展开更多
An emerging multi-terminal looped DC(MTDC)collector system is now advocated for collecting and transferring large-scale renewable generation.However,it remains an open question as to improving the cooperative control ...An emerging multi-terminal looped DC(MTDC)collector system is now advocated for collecting and transferring large-scale renewable generation.However,it remains an open question as to improving the cooperative control capability of looped converter stations for flexible and robust response to renewable grid-connection fluctuation.This paper addresses this problem with a novel Power Margin Tracking(PMT)droop control and its corresponding system-level control strategy from the perspective of optimal dispatch of the power system.By introducing a power margin correction factor into the droop coefficient,the converter station can make self-adaptive regulations according to its actual available power margin.For operation verification,a multi-period optimal operation model and a four-terminal simulation model is built to provide optimal control parameters and real-time operation states of converter stations,where the power flow model of the looped MTDC grid with renewables generation is considered.The case results prove that the proposed control strategy can improve the cooperative operation capability of multiple converter stations,mitigating grid-connected power fluctuation.It can effectively reduce the DC voltage deviation to enhance the operation stability of the MTDC grid.The operational robustness of the proposed control strategy under“N−1”fault cases is verified as well.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 51005169, 50875187, 50975209)Shanghai Municipal Natural Science Foundation of China (Grant No. 10ZR1432300)+1 种基金International Science & Technology Cooperation Program of China (Grant No. 2012DFG72210)Zhejiang Provincial Key International Science & Technology Cooperation Program of China (Grant No. 2011C14025)
文摘The production process plan design and configurations of reconfigurable machine tool （RMT） interact with each other. Reasonable process plans with suitable configurations of RMT help to improve product quality and reduce production cost. Therefore, a cooperative strategy is needed to concurrently solve the above issue. In this paper, the cooperative optimization model for RMT configurations and production process plan is presented. Its objectives take into account both impacts of process and configuration. Moreover, a novel genetic algorithm is also developed to provide optimal or near-optimal solutions： firstly, its chromosome is redesigned which is composed of three parts, operations, process plan and configurations of RMTs, respectively; secondly, its new selection, crossover and mutation operators are also developed to deal with the process constraints from operation processes （OP） graph, otherwise these operators could generate illegal solutions violating the limits; eventually the optimal configurations for RMT under optimal process plan design can be obtained. At last, a manufacturing line case is applied which is composed of three RMTs. It is shown from the case that the optimal process plan and configurations of RMT are concurrently obtained, and the production cost decreases 6.28% and nonmonetary performance increases 22%. The proposed method can figure out both RMT configurations and production process, improve production capacity, functions and equipment utilization for RMT.
基金supported by Carbon Neutrality and Energy System Transformation(CNEST)Program。
文摘Existing sub-/super-synchronous oscillation stability control methods are primarily focused on specific operating conditions at discrete frequencies,limiting their adaptation to varying oscillation scenarios in the power system connected with direct-drive permanent magnet synchronous generator(PMSG)-based wind farms.Based on supplementary dissipation compensation,this paper proposes an oscillation stability control method incorporating equipment-level and farm-level cooperative optimization to enhance the system-level stability.First,the effects of dynamic self-dissipation and dynamic coupled dissipation on system stability are analyzed,establishing the foundational principle of supplementary dissipation compensation.Subsequently,the optimal locations for supplementary dissipation compensation are identified based on critical control designed to enhance the dynamic self-dissipation effect and suppress the dynamic coupled dissipation effect.Furthermore,by considering energy requirements under the combined wind farm-grid interaction and inter-PMSG interactions and balancing the wind farm-grid interaction dissipation energy with inter-PMSG interaction dissipation energy distribution,an equipment-level control parameter optimization algorithm and a farm-level power cooperative optimization algorithm are established.Finally,the simulation results demonstrate that dynamic coupled dissipation constitutes the root cause of oscillation inception and progression.Through equipment-level and farm-level cooperative optimization,the proposed method can reliably compensate dynamic dissipation energy,while adapting to the variation of oscillation frequency and the oscillation scenario.It can maximize the energy dissipation effect of the interconnected system,achieving rapid suppression of sub-/super-synchronous oscillations.
基金Project(61471194)supported by the National Natural Science Foundation of ChinaProject(BK20140828)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education,China
文摘In order to improve the throughput of cognitive radio(CR), optimization of sensing time and cooperative user allocation for OR-rule cooperative spectrum sensing was investigated in a CR network that includes multiple users and one fusion center. The frame structure of cooperative spectrum sensing was divided into multiple transmission time slots and one sensing time slot consisting of local energy detection and cooperative overhead. An optimization problem was formulated to maximize the throughput of CR network, subject to the constraints of both false alarm probability and detection probability. A joint optimization algorithm of sensing time and number of users was proposed to solve this optimization problem with low time complexity. An allocation algorithm of cooperative users was proposed to preferentially allocate the users to the channels with high utilization probability. The simulation results show that the significant improvement on the throughput can be achieved through the proposed joint optimization and allocation algorithms.
基金the National Basic Research Program (973) of China (No. 2004CB720703)
文摘Cryogenic ground support equipment (CGSE) is an important part of a famous particle physics experiment - AMS-02. In this paper a design method which optimizes PID parameters of CGSE control system via the particle swarm optimization (PSO) algorithm is presented. Firstly, an improved version of the original PSO, cooperative random learning particle swarm optimization (CRPSO), is put forward to enhance the performance of the conventional PSO. Secondly, the way of finding PID coefficient will be studied by using this algorithm. Finally, the experimental results and practical works demonstrate that the CRPSO-PID controller achieves a good performance.
基金supported by the National Natural Science Foundation of China(61573283)
文摘This paper addresses the problem of service composition in military organization cloud cooperation（MOCC）. Military service providers（MSP） cooperate together to provide military resources for military service users（MSU）. A group of atom services, each of which has its level of quality of service（QoS）, can be combined together into a certain structure to form a composite service. Since there are a large number of atom services having the same function, the atom service is selected to participate in the composite service so as to fulfill users＇ will. In this paper a method based on discrete particle swarm optimization（DPSO） is proposed to tackle this problem. The method aims at selecting atom services from service repositories to constitute the composite service, satisfying the MSU＇s requirement on QoS. Since the QoS criteria include location-aware criteria and location-independent criteria, this method aims to get the composite service with the highest location-aware criteria and the best-match location-independent criteria. Simulations show that the DPSO has a better performance compared with the standard particle swarm optimization（PSO） and genetic algorithm（GA）.
基金partially supported by the National Natural Science Foundation of China(Nos.61333001 and 61473099)
文摘In the interception engagement,if the target movement information is not accurate enough for the mid-course guidance of intercepting missiles,the interception mission may fail as a result of large handover errors.This paper proposes a novel cooperative mid-course guidance scheme for multiple missiles to intercept a target under the condition of large detection errors.Under this scheme,the launch and interception moments are staggered for different missiles.The earlier launched missiles can obtain a relatively accurate detection to the target during their terminal guidance,based on which the latter missiles are permitted to eliminate the handover error in the mid-course guidance.A significant merit of this scheme is that the available resources are fully exploited and less missiles are needed to achieve the interception mission.To this end,first,the design of cooperative handover parameters is formulated as an optimization problem.Then,an algorithm based on Monte Carlo sampling and stochastic approximation is proposed to solve this optimization problem,and the convergence of the algorithm is proved as well.Finally,simulation experiments are carried out to validate the effectiveness of the proposed cooperative scheme and algorithm.
文摘China＇s Rural Cooperative Medical System collapsed alongside communal farming at the end of the Maoist period in 1976, leaving most farmers vulnerable[1]. In rural areas, where 80% of people have been without health insurance of any kind, illness has emerged as a leading cause of poverty[24]. To address the poor state of health care among the rural population, in 2003 the Chinese government launched the New Rural Cooperative Medical System （NCMS）,
基金Sponsored by the National Basic Research Program of China(973 Program)(Grant No.2007CB310601)
文摘To improve the detection performance of sensing users for primary users in the cognitive radio, an optimal cooperative detection algorithm for many sensing users is proposed. In this paper, optimal decision thresholds of each sensing user are discussed. Theoretical analysis and simulation results indicate that the detection probability of optimal decision threshold rules is better than that of determined threshold rules when the false alarm of the fusion center is constant. The proposed optimal cooperative detection algorithm improves the detection performance of primary users as the attendees grow. The 2 dB gain of detection probability can be obtained when a new sensing user joins in, and there is a 17 dB improvement when the accumulation number increases from 1 to 50.
基金supported by the Natural Science Foundation of Zhejiang Province(No.LQ24E010003)the Baima Lake Laboratory Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(Nos.LBMHY24E060004 and LBMHY24E060005)+1 种基金the Guangxi Major Science and Technology Program(No.AA24206007)Science and Technology Plan Project of Zhejiang Province(No.2025C01171).
文摘The study investigated the influence of Ce alloying and cold rolling on the activation behavior of V_(70)Ti_(10)Cr_(20)-based alloys.The activation conditions of single cold rolled(V_(70)Ti_(10)Cr_(20)-0.3)and single Ce replaced(V_(70)Ti_(10)Cr_(20)Ce_(1))samples were reduced from the origin-al two heat treatments to one heat treatment,and the incubation time was about 105 min.Unexpectedly,the two modification methods produce excellent synergistic effects that the co-modified sample(V_(70)Ti_(10)Cr_(20)Ce_(1)-0.5)was activated at room temperature(25℃)without incubation period,and reached saturation capacity(4wt%)within 12 min.Further studies show that CeO_(2) formed through Ce doping,serves as an active site for hydrogen absorption,facilitating the passage of hydrogen atoms through the dense oxide layer on the surface of vanadium-based alloys.Upon the foundation of Ce doping,cold rolling leads to the aggregation of dislocations around CeO_(2) sites,thereby further establishing a hydrogen diffusion pathway from the surface into the bulk phase,thus significantly improving the activation performance of the alloy.This work establishes a robust basis for the practical engineering use of vanadium-based hydrogen storage alloys.
基金supported by the Key Project of the National Language Commission(No.ZDI145-110)the Key Laboratory Project(No.YYZN-2024-6),the China Disabled Persons’Federation Project(No.2024CDPFAT-22)+3 种基金the National Natural Science Foundation of China(Nos.62171042,62102033,and U24A20331)the Project for the Construction and Support of High-Level Innovative Teams in Beijing Municipal Institutions(No.BPHR20220121)the Beijing Natural Science Foundation(Nos.4232026 and 4242020)the Projects of Beijing Union University(Nos.ZKZD202302 and ZK20202403)。
文摘Multiagent reinforcement learning(MARL)has become a dazzling new star in the field of reinforcement learning in recent years,demonstrating its immense potential across many application scenarios.The reward function directs agents to explore their environments and make optimal decisions within them by establishing evaluation criteria and feedback mechanisms.Concurrently,cooperative objectives at the macro level provide a trajectory for agents’learning,ensuring alignment between individual behavioral strategies and the overarching system goals.The interplay between reward structures and cooperative objectives not only bolsters the effectiveness of individual agents but also fosters interagent collaboration,offering both momentum and direction for the development of swarm intelligence and the harmonious operation of multiagent systems.This review delves deeply into the methods for designing reward structures and optimizing cooperative objectives in MARL,along with the most recent scientific advancements in this field.The article meticulously reviews the application of simulation environments in cooperative scenarios and discusses future trends and potential research directions in the field,providing a forward-looking perspective and inspiration for subsequent research efforts.
基金Projects(61105067,61174164)supported by the National Natural Science Foundation of China
文摘The artificial bee colony(ABC) algorithm is improved to construct a hybrid multi-objective ABC algorithm, called HMOABC, for resolving optimal power flow(OPF) problem by simultaneously optimizing three conflicting objectives of OPF, instead of transforming multi-objective functions into a single objective function. The main idea of HMOABC is to extend original ABC algorithm to multi-objective and cooperative mode by combining the Pareto dominance and divide-and-conquer approach. HMOABC is then used in the 30-bus IEEE test system for solving the OPF problem considering the cost, loss, and emission impacts. The simulation results show that the HMOABC is superior to other algorithms in terms of optimization accuracy and computation robustness.
基金supported in part by the National Key Research and Development Program of China(2016YFB0900100)the Smart Grid Joint Foundation Program of National Natural Science Foundation of China and State Grid Corporation of China(U1866204).
文摘An emerging multi-terminal looped DC(MTDC)collector system is now advocated for collecting and transferring large-scale renewable generation.However,it remains an open question as to improving the cooperative control capability of looped converter stations for flexible and robust response to renewable grid-connection fluctuation.This paper addresses this problem with a novel Power Margin Tracking(PMT)droop control and its corresponding system-level control strategy from the perspective of optimal dispatch of the power system.By introducing a power margin correction factor into the droop coefficient,the converter station can make self-adaptive regulations according to its actual available power margin.For operation verification,a multi-period optimal operation model and a four-terminal simulation model is built to provide optimal control parameters and real-time operation states of converter stations,where the power flow model of the looped MTDC grid with renewables generation is considered.The case results prove that the proposed control strategy can improve the cooperative operation capability of multiple converter stations,mitigating grid-connected power fluctuation.It can effectively reduce the DC voltage deviation to enhance the operation stability of the MTDC grid.The operational robustness of the proposed control strategy under“N−1”fault cases is verified as well.
