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
压裂油井产能评价是进行压裂设计的基础,已取得的研究成果主要针对均质油藏,对储层各向异性油层垂直裂缝井产能未曾涉及.考虑各向异性地层稳定点汇压力分布,将垂直裂缝抽象为一条斜直线汇,根据汇源叠加积分原理得到各向异性地层垂直裂...压裂油井产能评价是进行压裂设计的基础,已取得的研究成果主要针对均质油藏,对储层各向异性油层垂直裂缝井产能未曾涉及.考虑各向异性地层稳定点汇压力分布,将垂直裂缝抽象为一条斜直线汇,根据汇源叠加积分原理得到各向异性地层垂直裂缝井产能通用表达式;应用Gringgarten A G等提出的近似方法,求得无限导流垂直裂缝井的稳态压力分布解及各向异性地层当量井径.计算结果表明:对各向异性油藏,为获得最大的产能,应使裂缝延展方向垂直于主渗透方向.该方法可广泛应用于非均质油藏垂直裂缝井产能评价.展开更多
Dawning Nebulae is a heterogeneous system composed of 9280 multi-core x86 CPUs and 4640 NVIDIA Fermi GPUs. With a Linpack performance of 1.271 petaFLOPS, it was ranked the second in the TOP500 List released in June 20...Dawning Nebulae is a heterogeneous system composed of 9280 multi-core x86 CPUs and 4640 NVIDIA Fermi GPUs. With a Linpack performance of 1.271 petaFLOPS, it was ranked the second in the TOP500 List released in June 2010. In this paper, key issues in the system design of Dawning Nebulae are introduced. System tuning methodologies aiming at petaFLOPS Linpack result are presented, including algorithmic optimization and communication improvement. The design of its file I/O subsystem, including HVFS and the underlying DCFS3, is also described. Performance evaluations show that the Linpack efficiency of each node reaches 69.89%, and 1024-node aggregate read and write bandwidths exceed 100 GB/s and 70 GB/s respectively. The success of Dawning Nebulae has demonstrated the viability of CPU/GPU heterogeneous structure for future designs of supercomputers.展开更多
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.
文摘压裂油井产能评价是进行压裂设计的基础,已取得的研究成果主要针对均质油藏,对储层各向异性油层垂直裂缝井产能未曾涉及.考虑各向异性地层稳定点汇压力分布,将垂直裂缝抽象为一条斜直线汇,根据汇源叠加积分原理得到各向异性地层垂直裂缝井产能通用表达式;应用Gringgarten A G等提出的近似方法,求得无限导流垂直裂缝井的稳态压力分布解及各向异性地层当量井径.计算结果表明:对各向异性油藏,为获得最大的产能,应使裂缝延展方向垂直于主渗透方向.该方法可广泛应用于非均质油藏垂直裂缝井产能评价.
基金supported by the National Hi-Tech Research and Development 863 Program of China under Grant No. 2009AA01A129the National Natural Science Foundation of China under Grant Nos. 60633040,60803030,61033009,the National Natural Science Foundation for Distinguished Young Scholars of China under Grant No. 60925009 and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China under Grant No. 60921002the National Basic Research 973 Program of China under Grant No. 2011CB302500
文摘Dawning Nebulae is a heterogeneous system composed of 9280 multi-core x86 CPUs and 4640 NVIDIA Fermi GPUs. With a Linpack performance of 1.271 petaFLOPS, it was ranked the second in the TOP500 List released in June 2010. In this paper, key issues in the system design of Dawning Nebulae are introduced. System tuning methodologies aiming at petaFLOPS Linpack result are presented, including algorithmic optimization and communication improvement. The design of its file I/O subsystem, including HVFS and the underlying DCFS3, is also described. Performance evaluations show that the Linpack efficiency of each node reaches 69.89%, and 1024-node aggregate read and write bandwidths exceed 100 GB/s and 70 GB/s respectively. The success of Dawning Nebulae has demonstrated the viability of CPU/GPU heterogeneous structure for future designs of supercomputers.
