To improve the efficiency and fairness of the spectrum allocation for ground communication assisted by unmanned aerial vehicles(UAVs),a joint optimization method for on-demand deployment and spectrum allocation of UAV...To improve the efficiency and fairness of the spectrum allocation for ground communication assisted by unmanned aerial vehicles(UAVs),a joint optimization method for on-demand deployment and spectrum allocation of UAVs is proposed,which is modeled as a mixed-integer non-convex optimization problem(MINCOP).An algorithm to estimate the minimum number of required UAVs is firstly proposed based on the pre-estimation and simulated annealing.The MINCOP is then decomposed into three sub-problems based on the block coordinate descent method,including the spectrum allocation of UAVs,the association between UAVs and ground users,and the deployment of UAVs.Specifically,the optimal spectrum allocation is derived based on the interference mitigation and channel reuse.The association between UAVs and ground users is optimized based on local iterated optimization.A particle-based optimization algorithm is proposed to resolve the subproblem of the UAVs deployment.Simulation results show that the proposed method could effectively improve the minimum transmission rate of UAVs as well as user fairness of spectrum allocation.展开更多
【目的】研究茅尾海无瓣海桑根际土壤细菌多样性及抑菌活性,挖掘更多潜在新物种和高效活性物质,为进一步研究红树植物根际土壤中细菌的次生代谢产物及研发新型高效生物农药提供参考依据。【方法】从广西钦州茅尾海红树林保护区采集无瓣...【目的】研究茅尾海无瓣海桑根际土壤细菌多样性及抑菌活性,挖掘更多潜在新物种和高效活性物质,为进一步研究红树植物根际土壤中细菌的次生代谢产物及研发新型高效生物农药提供参考依据。【方法】从广西钦州茅尾海红树林保护区采集无瓣海桑根际土壤,采用6种分离培养基分离可培养细菌;通过16S r RNA基因序列的系统发育学分析其物种多样性,并采用牛津杯法考察根际细菌对甘蔗鞭黑粉菌的抑制活性。【结果】从无瓣海桑根际中分离得到可培养细菌97株,通过16S r RNA序列比对排重后,从中获得57株不同细菌,可归为4门5纲9目15科21属,有1株Cellvibrio sp.的潜在新种。其中29株细菌能够抑制甘蔗鞭黑粉菌活性,分别有12、14和14株细菌对甘蔗鞭黑粉菌菌丝生长、"+"担孢子增殖和"-"担孢子增殖表现出抑制活性,抑菌圈直径范围为7.54~21.81 mm,其中有9株细菌能够抑制2~3种甘蔗鞭黑粉菌的形态。【结论】广西茅尾海红树林保护区中无瓣海桑根际细菌具有较高的物种多样性,蕴藏着潜在新物种资源,且富含抑菌活性菌株。展开更多
基金supported by Project funded by China Postdoctoral Science Foundation(No.2021MD703980)。
文摘To improve the efficiency and fairness of the spectrum allocation for ground communication assisted by unmanned aerial vehicles(UAVs),a joint optimization method for on-demand deployment and spectrum allocation of UAVs is proposed,which is modeled as a mixed-integer non-convex optimization problem(MINCOP).An algorithm to estimate the minimum number of required UAVs is firstly proposed based on the pre-estimation and simulated annealing.The MINCOP is then decomposed into three sub-problems based on the block coordinate descent method,including the spectrum allocation of UAVs,the association between UAVs and ground users,and the deployment of UAVs.Specifically,the optimal spectrum allocation is derived based on the interference mitigation and channel reuse.The association between UAVs and ground users is optimized based on local iterated optimization.A particle-based optimization algorithm is proposed to resolve the subproblem of the UAVs deployment.Simulation results show that the proposed method could effectively improve the minimum transmission rate of UAVs as well as user fairness of spectrum allocation.
文摘【目的】研究茅尾海无瓣海桑根际土壤细菌多样性及抑菌活性,挖掘更多潜在新物种和高效活性物质,为进一步研究红树植物根际土壤中细菌的次生代谢产物及研发新型高效生物农药提供参考依据。【方法】从广西钦州茅尾海红树林保护区采集无瓣海桑根际土壤,采用6种分离培养基分离可培养细菌;通过16S r RNA基因序列的系统发育学分析其物种多样性,并采用牛津杯法考察根际细菌对甘蔗鞭黑粉菌的抑制活性。【结果】从无瓣海桑根际中分离得到可培养细菌97株,通过16S r RNA序列比对排重后,从中获得57株不同细菌,可归为4门5纲9目15科21属,有1株Cellvibrio sp.的潜在新种。其中29株细菌能够抑制甘蔗鞭黑粉菌活性,分别有12、14和14株细菌对甘蔗鞭黑粉菌菌丝生长、"+"担孢子增殖和"-"担孢子增殖表现出抑制活性,抑菌圈直径范围为7.54~21.81 mm,其中有9株细菌能够抑制2~3种甘蔗鞭黑粉菌的形态。【结论】广西茅尾海红树林保护区中无瓣海桑根际细菌具有较高的物种多样性,蕴藏着潜在新物种资源,且富含抑菌活性菌株。
