联邦学习(federated learning,FL)是一种以保护客户隐私数据为中心的分布式处理网络,为解决隐私泄露问题提供了前景良好的解决方案.然而,FL的一个主要困境是高度非独立同分布(non-independent and identically distributed,non-IID)的...联邦学习(federated learning,FL)是一种以保护客户隐私数据为中心的分布式处理网络,为解决隐私泄露问题提供了前景良好的解决方案.然而,FL的一个主要困境是高度非独立同分布(non-independent and identically distributed,non-IID)的数据会导致全局模型性能很差.尽管相关研究已经探讨了这个问题,但本文发现当面对non-IID数据、不稳定的客户端参与以及深度模型时,现有方案和标准基线FedAvg相比,只有微弱的优势或甚至更差,因此严重阻碍了FL的隐私保护应用价值.为解决这个问题,本文提出了一种对non-IID数据鲁棒的优化方案:FedUp.该方案在保留FL隐私保护特点的前提下,进一步提升了全局模型的泛化鲁棒性.FedUp的核心思路是最小化全局经验损失函数的上限来保证模型具有低的泛化误差.大量仿真实验表明,FedUp显著优于现有方案,并对高度non-IID数据以及不稳定和大规模客户端的参与具有鲁棒性.展开更多
The problem of joint radio and cloud resources allocation is studied for heterogeneous mobile cloud computing networks. The objective of the proposed joint resource allocation schemes is to maximize the total utility ...The problem of joint radio and cloud resources allocation is studied for heterogeneous mobile cloud computing networks. The objective of the proposed joint resource allocation schemes is to maximize the total utility of users as well as satisfy the required quality of service(QoS) such as the end-to-end response latency experienced by each user. We formulate the problem of joint resource allocation as a combinatorial optimization problem. Three evolutionary approaches are considered to solve the problem: genetic algorithm(GA), ant colony optimization with genetic algorithm(ACO-GA), and quantum genetic algorithm(QGA). To decrease the time complexity, we propose a mapping process between the resource allocation matrix and the chromosome of GA, ACO-GA, and QGA, search the available radio and cloud resource pairs based on the resource availability matrixes for ACOGA, and encode the difference value between the allocated resources and the minimum resource requirement for QGA. Extensive simulation results show that our proposed methods greatly outperform the existing algorithms in terms of running time, the accuracy of final results, the total utility, resource utilization and the end-to-end response latency guaranteeing.展开更多
The user association and wireless backhaul bandwidth allocation for a two-tier heterogeneous network (HetNet) in the mil- limeter wave (mmWave) band is proposed in this article. The two-tier HetNet is built up wit...The user association and wireless backhaul bandwidth allocation for a two-tier heterogeneous network (HetNet) in the mil- limeter wave (mmWave) band is proposed in this article. The two-tier HetNet is built up with a macro base station (MBS) and several small cell SBSs, where the MBS is assumed to be equipped with large-scale antenna arrays but the SBSs only have single-antenna capa- bility and they rely on the wireless link to the MBS for backhaul. The sum of logarithmic user rate, which is established according to the result of multi-user Multiple Input Mul- tiple Output (MIMO) downlink employing Zero-Force Beamforming (ZFBF), is chosen as the network utility for the objective func- tion. And a distributed optimization algorithm based on primal and dual decomposition is used to jointly optimize the user association variable xj,z and the wireless backhaul band- width factor α. Simulation results reveal that the distributed optimization algorithm jointly optimizing two variables outperforms the con- ventional SINR-based user association strate- gies.展开更多
In order to solve the problem the existing vertical handoff algorithms of vehicle heterogeneous wireless network do not consider the diversification of network's status, an optimized vertical handoff algorithm bas...In order to solve the problem the existing vertical handoff algorithms of vehicle heterogeneous wireless network do not consider the diversification of network's status, an optimized vertical handoff algorithm based on markov process is proposed and discussed in this paper. This algorithm takes into account that the status transformation of available network will affect the quality of service(Qo S) of vehicle terminal's communication service. Firstly, Markov process is used to predict the transformation of wireless network's status after the decision via transition probability. Then the weights of evaluating parameters will be determined by fuzzy logic method. Finally, by comparing the total incomes of each wireless network, including handoff decision incomes, handoff execution incomes and communication service incomes after handoff, the optimal network to handoff will be selected. Simulation results show that: the algorithm proposed, compared to the existing algorithm, is able to receive a higher level of load balancing and effectively improves the average blocking rate, packet loss rate and ping-pang effect.展开更多
The application of multiple UAVs in complicated tasks has been widely explored in recent years.Due to the advantages of flexibility,cheapness and consistence,the performance of heterogeneous multi-UAVs with proper coo...The application of multiple UAVs in complicated tasks has been widely explored in recent years.Due to the advantages of flexibility,cheapness and consistence,the performance of heterogeneous multi-UAVs with proper cooperative task allocation is superior to over the single UAV.Accordingly,several constraints should be satisfied to realize the efficient cooperation,such as special time-window,variant equipment,specified execution sequence.Hence,a proper task allocation in UAVs is the crucial point for the final success.The task allocation problem of the heterogeneous UAVs can be formulated as a multi-objective optimization problem coupled with the UAV dynamics.To this end,a multi-layer encoding strategy and a constraint scheduling method are designed to handle the critical logical and physical constraints.In addition,four optimization objectives:completion time,target reward,UAV damage,and total range,are introduced to evaluate various allocation plans.Subsequently,to efficiently solve the multi-objective optimization problem,an improved multi-objective quantum-behaved particle swarm optimization(IMOQPSO)algorithm is proposed.During this algorithm,a modified solution evaluation method is designed to guide algorithmic evolution;both the convergence and distribution of particles are considered comprehensively;and boundary solutions which may produce some special allocation plans are preserved.Moreover,adaptive parameter control and mixed update mechanism are also introduced in this algorithm.Finally,both the proposed model and algorithm are verified by simulation experiments.展开更多
This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of comp...This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of composition interval diagram (CID) with mathematical programming.The total cost target consists of the capital cost of the process units and the operating cost for mass separating agents (MS.As). The value of total cost varies considerablv with the composition differences, so the values of e should be optimized in order to obtain minimum TAC of a MEN. This articleconsiders ε as a set of unequal variables for each equilibrium equation of a rich-lean stream pair, employing them to build the CID and mathematical model, which optimizes the structure and composition differences simultaneously. Two examples are applied to illustrate the proposed method and the results demonstrate that the approach introduced by this article is simpler and more convenient than the methods in previous literatures.展开更多
Developing parallel applications on heterogeneous processors is facing the challenges of 'memory wall',due to limited capacity of local storage,limited bandwidth and long latency for memory access. Aiming at t...Developing parallel applications on heterogeneous processors is facing the challenges of 'memory wall',due to limited capacity of local storage,limited bandwidth and long latency for memory access. Aiming at this problem,a parallelization approach was proposed with six memory optimization schemes for CG,four schemes of them aiming at all kinds of sparse matrix-vector multiplication (SPMV) operation. Conducted on IBM QS20,the parallelization approach can reach up to 21 and 133 times speedups with size A and B,respectively,compared with single power processor element. Finally,the conclusion is drawn that the peak bandwidth of memory access on Cell BE can be obtained in SPMV,simple computation is more efficient on heterogeneous processors and loop-unrolling can hide local storage access latency while executing scalar operation on SIMD cores.展开更多
Based on the cross-layer design, the power-optimization problem of Macro-Femto Heterogeneous Networks (HetNets) has been formulated. The constraints of power and re-source block allocation in the physical layer, del...Based on the cross-layer design, the power-optimization problem of Macro-Femto Heterogeneous Networks (HetNets) has been formulated. The constraints of power and re-source block allocation in the physical layer, delay and target data rate in the medium ac-cess control layer, urgent queue length in the network layer, and packet error rate in the transport layer, have been considered. The original problem is non-deterministic polyno-mial time hard, which cannot be solved practi-cally. After the restrictions of upper layers are translated into constraints with physical layer parameters, and the integer restrictions are relaxed, the original problem can be decom- posed into convex optimization subproblems. The optimal solutions of resource block allo-cation and power allocation can be obtained by using the Lagrangian optimization. Simula-tion results show that the proposed scheme is better than both the round robin algorithm and the max-rain one in terms of energy efficiency, throughput and service fairness. The round robin algorithm and the max-min one only focus on the user fairness rather than quality of service fairness. Compared to the round robin scheme (the max-min one), the proposed scheme improves the energy efficiency 58.85% (62.41%), the throughput 19.09% (25.25%), the service fairness 57.69% (35.48%).展开更多
文摘联邦学习(federated learning,FL)是一种以保护客户隐私数据为中心的分布式处理网络,为解决隐私泄露问题提供了前景良好的解决方案.然而,FL的一个主要困境是高度非独立同分布(non-independent and identically distributed,non-IID)的数据会导致全局模型性能很差.尽管相关研究已经探讨了这个问题,但本文发现当面对non-IID数据、不稳定的客户端参与以及深度模型时,现有方案和标准基线FedAvg相比,只有微弱的优势或甚至更差,因此严重阻碍了FL的隐私保护应用价值.为解决这个问题,本文提出了一种对non-IID数据鲁棒的优化方案:FedUp.该方案在保留FL隐私保护特点的前提下,进一步提升了全局模型的泛化鲁棒性.FedUp的核心思路是最小化全局经验损失函数的上限来保证模型具有低的泛化误差.大量仿真实验表明,FedUp显著优于现有方案,并对高度non-IID数据以及不稳定和大规模客户端的参与具有鲁棒性.
基金supported by the National Natural Science Foundation of China (No. 61741102, No. 61471164)China Scholarship Council
文摘The problem of joint radio and cloud resources allocation is studied for heterogeneous mobile cloud computing networks. The objective of the proposed joint resource allocation schemes is to maximize the total utility of users as well as satisfy the required quality of service(QoS) such as the end-to-end response latency experienced by each user. We formulate the problem of joint resource allocation as a combinatorial optimization problem. Three evolutionary approaches are considered to solve the problem: genetic algorithm(GA), ant colony optimization with genetic algorithm(ACO-GA), and quantum genetic algorithm(QGA). To decrease the time complexity, we propose a mapping process between the resource allocation matrix and the chromosome of GA, ACO-GA, and QGA, search the available radio and cloud resource pairs based on the resource availability matrixes for ACOGA, and encode the difference value between the allocated resources and the minimum resource requirement for QGA. Extensive simulation results show that our proposed methods greatly outperform the existing algorithms in terms of running time, the accuracy of final results, the total utility, resource utilization and the end-to-end response latency guaranteeing.
基金supported by NSFC under Grant (61725101 and 61771036)the ZTE Corporation, State Key Lab of Rail Traffic Control and Safety Project under Grant (RCS2017ZZ004 and RCS2017ZT008)+1 种基金Beijing Natural Science Foundation under Grant L161009supported by the Open Research Fund of National Mobile Communications Research Laboratory, Southeast University, under grant 2015D04
文摘The user association and wireless backhaul bandwidth allocation for a two-tier heterogeneous network (HetNet) in the mil- limeter wave (mmWave) band is proposed in this article. The two-tier HetNet is built up with a macro base station (MBS) and several small cell SBSs, where the MBS is assumed to be equipped with large-scale antenna arrays but the SBSs only have single-antenna capa- bility and they rely on the wireless link to the MBS for backhaul. The sum of logarithmic user rate, which is established according to the result of multi-user Multiple Input Mul- tiple Output (MIMO) downlink employing Zero-Force Beamforming (ZFBF), is chosen as the network utility for the objective func- tion. And a distributed optimization algorithm based on primal and dual decomposition is used to jointly optimize the user association variable xj,z and the wireless backhaul band- width factor α. Simulation results reveal that the distributed optimization algorithm jointly optimizing two variables outperforms the con- ventional SINR-based user association strate- gies.
基金supported in part by the National Natural Science Foundation of China under grant No. 61271259, No. 61301123, No. 61471076Scientific and Technological Research Program of Chongqing Municipal Education Commission of Chongqing of China under Grant No.KJ130536
文摘In order to solve the problem the existing vertical handoff algorithms of vehicle heterogeneous wireless network do not consider the diversification of network's status, an optimized vertical handoff algorithm based on markov process is proposed and discussed in this paper. This algorithm takes into account that the status transformation of available network will affect the quality of service(Qo S) of vehicle terminal's communication service. Firstly, Markov process is used to predict the transformation of wireless network's status after the decision via transition probability. Then the weights of evaluating parameters will be determined by fuzzy logic method. Finally, by comparing the total incomes of each wireless network, including handoff decision incomes, handoff execution incomes and communication service incomes after handoff, the optimal network to handoff will be selected. Simulation results show that: the algorithm proposed, compared to the existing algorithm, is able to receive a higher level of load balancing and effectively improves the average blocking rate, packet loss rate and ping-pang effect.
基金Project(61801495)supported by the National Natural Science Foundation of China
文摘The application of multiple UAVs in complicated tasks has been widely explored in recent years.Due to the advantages of flexibility,cheapness and consistence,the performance of heterogeneous multi-UAVs with proper cooperative task allocation is superior to over the single UAV.Accordingly,several constraints should be satisfied to realize the efficient cooperation,such as special time-window,variant equipment,specified execution sequence.Hence,a proper task allocation in UAVs is the crucial point for the final success.The task allocation problem of the heterogeneous UAVs can be formulated as a multi-objective optimization problem coupled with the UAV dynamics.To this end,a multi-layer encoding strategy and a constraint scheduling method are designed to handle the critical logical and physical constraints.In addition,four optimization objectives:completion time,target reward,UAV damage,and total range,are introduced to evaluate various allocation plans.Subsequently,to efficiently solve the multi-objective optimization problem,an improved multi-objective quantum-behaved particle swarm optimization(IMOQPSO)algorithm is proposed.During this algorithm,a modified solution evaluation method is designed to guide algorithmic evolution;both the convergence and distribution of particles are considered comprehensively;and boundary solutions which may produce some special allocation plans are preserved.Moreover,adaptive parameter control and mixed update mechanism are also introduced in this algorithm.Finally,both the proposed model and algorithm are verified by simulation experiments.
文摘This article presents a new method to calculate the composition differences (e) for tar g.etin.g the minimum total annualized cost (TAC) of a mass exchange network (MEN),which is based on the combination of composition interval diagram (CID) with mathematical programming.The total cost target consists of the capital cost of the process units and the operating cost for mass separating agents (MS.As). The value of total cost varies considerablv with the composition differences, so the values of e should be optimized in order to obtain minimum TAC of a MEN. This articleconsiders ε as a set of unequal variables for each equilibrium equation of a rich-lean stream pair, employing them to build the CID and mathematical model, which optimizes the structure and composition differences simultaneously. Two examples are applied to illustrate the proposed method and the results demonstrate that the approach introduced by this article is simpler and more convenient than the methods in previous literatures.
基金Project(2008AA01A201) supported the National High-tech Research and Development Program of ChinaProjects(60833004, 60633050) supported by the National Natural Science Foundation of China
文摘Developing parallel applications on heterogeneous processors is facing the challenges of 'memory wall',due to limited capacity of local storage,limited bandwidth and long latency for memory access. Aiming at this problem,a parallelization approach was proposed with six memory optimization schemes for CG,four schemes of them aiming at all kinds of sparse matrix-vector multiplication (SPMV) operation. Conducted on IBM QS20,the parallelization approach can reach up to 21 and 133 times speedups with size A and B,respectively,compared with single power processor element. Finally,the conclusion is drawn that the peak bandwidth of memory access on Cell BE can be obtained in SPMV,simple computation is more efficient on heterogeneous processors and loop-unrolling can hide local storage access latency while executing scalar operation on SIMD cores.
基金supported in part by the project of National Natural Science Foundation of China under Grant No. 61071075National Science and Technology Major Project of China under Grant No. 2010ZX03003-001-02+1 种基金National Science and Technology Major Project of China under Grant No. 2011ZX03004003the Chinese Ministry of Education in the project of the Fundamental Research Funds for the Central Universities under Grant No.2011YJS216
文摘Based on the cross-layer design, the power-optimization problem of Macro-Femto Heterogeneous Networks (HetNets) has been formulated. The constraints of power and re-source block allocation in the physical layer, delay and target data rate in the medium ac-cess control layer, urgent queue length in the network layer, and packet error rate in the transport layer, have been considered. The original problem is non-deterministic polyno-mial time hard, which cannot be solved practi-cally. After the restrictions of upper layers are translated into constraints with physical layer parameters, and the integer restrictions are relaxed, the original problem can be decom- posed into convex optimization subproblems. The optimal solutions of resource block allo-cation and power allocation can be obtained by using the Lagrangian optimization. Simula-tion results show that the proposed scheme is better than both the round robin algorithm and the max-rain one in terms of energy efficiency, throughput and service fairness. The round robin algorithm and the max-min one only focus on the user fairness rather than quality of service fairness. Compared to the round robin scheme (the max-min one), the proposed scheme improves the energy efficiency 58.85% (62.41%), the throughput 19.09% (25.25%), the service fairness 57.69% (35.48%).