为应对开放型无线接入网(Open Radio Access Network,O-RAN)中的数据传输成本过高及网络兼容不足等问题,研究了面向O-RAN的多级边缘服务资源分配与部署联合优化问题。首先,利用四层融合模型将多目标联合优化问题转化为异构边缘服务器数...为应对开放型无线接入网(Open Radio Access Network,O-RAN)中的数据传输成本过高及网络兼容不足等问题,研究了面向O-RAN的多级边缘服务资源分配与部署联合优化问题。首先,利用四层融合模型将多目标联合优化问题转化为异构边缘服务器数量选择及位置确定问题,并提出了一种负载约束和迭代优化的异构边缘服务器资源分配算法,解决了O-RAN网络中的异构资源分配与数据传输问题。然后,提出了一种能效驱动的异构节点部署优化算法,解决了多级异构资源最佳部署位置问题。最后,利用上海电信基站的真实数据集,验证了所提资源优化与部署算法的有效性,实验结果表明,所提算法较其它算法在部署成本上至少降低了22.5%,能效比值上至少提高了25.96%。展开更多
To design a propeller for ship power plant,the interaction between ship hull and propeller must be taken into account.The main concern is to apply the wake effect of ship stern on the propeller performance.In this pap...To design a propeller for ship power plant,the interaction between ship hull and propeller must be taken into account.The main concern is to apply the wake effect of ship stern on the propeller performance.In this paper,a coupled BEM(Boundary Element Method)/RANS(Renolds-Averaged Navier−Stokes)solver is used to simulate propeller behind the hull in the self-propulsion test.The motivation of this work is to develop a practical tool to design marine propulsion system without suffering long computational time.An unsteady boundary element method which is also known as panel method is chosen to estimate the propeller forces.Propeller wakes are treated using a time marching wake alignment method.Also,a RANS code coupled with VoF equation is developed to consider the ship motions and wake field effects in the problem.A coupling algorithm is developed to interchange ship wake field to the potential flow solver and propeller thrust to the RANS code.Based on the difference between hull resistance and the propeller thrust,a PI controller is developed to compute the propeller RPM in every time step.Verification of the solver is carried out using the towing tank test report of a 50 m oceanography research vessel.Wake factor and trust deduction coefficient are estimated numerically.Also,the wake rollup pattern of the propeller in open water is compared with the propeller in real wake field.展开更多
随着信息技术的迅猛发展和人们对高速、低时延网络需求的不断增长,5G网络正成为实现智能化社会的关键基础设施。5G网络的低时延业务对于实现实时数据传输、物联网、虚拟现实的应用具有重要意义。基于此,介绍5G网络低时延业务对网络架构...随着信息技术的迅猛发展和人们对高速、低时延网络需求的不断增长,5G网络正成为实现智能化社会的关键基础设施。5G网络的低时延业务对于实现实时数据传输、物联网、虚拟现实的应用具有重要意义。基于此,介绍5G网络低时延业务对网络架构的要求,分析无线接入网IP化(internet protocol radio access network, IP RAN)组网技术,并对IP RAN组网架构中的关键技术加以研究,以期为相关人员提供参考。展开更多
[Objective]The aim was to study homology between Ran gene in Allium cepa,Allium sativum and Brassica napus and Ran2 gene in Arabidopsis in order to determine whether three kinds of plant material as substitute for Ara...[Objective]The aim was to study homology between Ran gene in Allium cepa,Allium sativum and Brassica napus and Ran2 gene in Arabidopsis in order to determine whether three kinds of plant material as substitute for Arabidopsis. [Method]By using RT-PCR method,homology gene was cloned from totoal RNA which extracted from splinter cells of Allium cepa,Allium sativum and Brassica napus with Arabidopsis Ran2 primer,then,carrying out sequence and comparative analysis. [Result]The results showed that the open reading frames of Ran genes in Allium cepa,Allium sativum and Brassica napus were 666,663,666 bp,coding 221,220 and 221 amino acids respectively,with the molecular weight of 24.3 kDa. The sequence analysis showed that the amino acid homology of Ran genes between Allium cepa,Allium sativum,Brassica napus and Arabidopsis Ran2 were respectively 99.1 %,100 % （except an Asp D at Allium sativum C terminal）,96.4 %. The phylogenetic tree indicated that Ran genes from Allium cepa and Allium sativum had closer evolutionary relationship with Arabidopsis Ran2. [Conclusion]The research laid a foundation for further study on the biological function of plant Ran gene.展开更多
文摘为应对开放型无线接入网(Open Radio Access Network,O-RAN)中的数据传输成本过高及网络兼容不足等问题,研究了面向O-RAN的多级边缘服务资源分配与部署联合优化问题。首先,利用四层融合模型将多目标联合优化问题转化为异构边缘服务器数量选择及位置确定问题,并提出了一种负载约束和迭代优化的异构边缘服务器资源分配算法,解决了O-RAN网络中的异构资源分配与数据传输问题。然后,提出了一种能效驱动的异构节点部署优化算法,解决了多级异构资源最佳部署位置问题。最后,利用上海电信基站的真实数据集,验证了所提资源优化与部署算法的有效性,实验结果表明,所提算法较其它算法在部署成本上至少降低了22.5%,能效比值上至少提高了25.96%。
文摘To design a propeller for ship power plant,the interaction between ship hull and propeller must be taken into account.The main concern is to apply the wake effect of ship stern on the propeller performance.In this paper,a coupled BEM(Boundary Element Method)/RANS(Renolds-Averaged Navier−Stokes)solver is used to simulate propeller behind the hull in the self-propulsion test.The motivation of this work is to develop a practical tool to design marine propulsion system without suffering long computational time.An unsteady boundary element method which is also known as panel method is chosen to estimate the propeller forces.Propeller wakes are treated using a time marching wake alignment method.Also,a RANS code coupled with VoF equation is developed to consider the ship motions and wake field effects in the problem.A coupling algorithm is developed to interchange ship wake field to the potential flow solver and propeller thrust to the RANS code.Based on the difference between hull resistance and the propeller thrust,a PI controller is developed to compute the propeller RPM in every time step.Verification of the solver is carried out using the towing tank test report of a 50 m oceanography research vessel.Wake factor and trust deduction coefficient are estimated numerically.Also,the wake rollup pattern of the propeller in open water is compared with the propeller in real wake field.
文摘随着信息技术的迅猛发展和人们对高速、低时延网络需求的不断增长,5G网络正成为实现智能化社会的关键基础设施。5G网络的低时延业务对于实现实时数据传输、物联网、虚拟现实的应用具有重要意义。基于此,介绍5G网络低时延业务对网络架构的要求,分析无线接入网IP化(internet protocol radio access network, IP RAN)组网技术,并对IP RAN组网架构中的关键技术加以研究,以期为相关人员提供参考。
基金Supported by National Natural Science Foundation of China(30070370)~~
文摘[Objective]The aim was to study homology between Ran gene in Allium cepa,Allium sativum and Brassica napus and Ran2 gene in Arabidopsis in order to determine whether three kinds of plant material as substitute for Arabidopsis. [Method]By using RT-PCR method,homology gene was cloned from totoal RNA which extracted from splinter cells of Allium cepa,Allium sativum and Brassica napus with Arabidopsis Ran2 primer,then,carrying out sequence and comparative analysis. [Result]The results showed that the open reading frames of Ran genes in Allium cepa,Allium sativum and Brassica napus were 666,663,666 bp,coding 221,220 and 221 amino acids respectively,with the molecular weight of 24.3 kDa. The sequence analysis showed that the amino acid homology of Ran genes between Allium cepa,Allium sativum,Brassica napus and Arabidopsis Ran2 were respectively 99.1 %,100 % （except an Asp D at Allium sativum C terminal）,96.4 %. The phylogenetic tree indicated that Ran genes from Allium cepa and Allium sativum had closer evolutionary relationship with Arabidopsis Ran2. [Conclusion]The research laid a foundation for further study on the biological function of plant Ran gene.
