Reasonable allocation of storage and computing resources is the basis of building big data system.With the development of IoT(Internet of Things),more data will be brought.A three-layer architecture includes smart dev...Reasonable allocation of storage and computing resources is the basis of building big data system.With the development of IoT(Internet of Things),more data will be brought.A three-layer architecture includes smart devices layer,edge cloud layer and blockchain-based distributed cloud layer.Blockchain is used in IoT for building a distributed decentralize P2P architecture to deal with the secure issue while edge computing deals with increasing volume of data.Edge caching is one of the important application scenarios.In order to allocate edge cache resources reasonably,to improve the quality of service and to reduce the waste of bandwidth resources,this paper proposes a content selection algorithm of edge cache nodes.The algorithm adopts markov chain model,improves the utilization of cache space and reduces the content transmission delay.The hierarchical caching strategy is adopted and the secondary cache stores slides of contents to expand the coverage of cached content and to reduce user waiting time.Regional node cooperation is adopted to expand the cache space and to support the regional preference of cache content.Compared with the classical substitution algorithm,simulation results show that the algorithm in this paper has higher cache hit ratio and higher space utilization.展开更多
针对航空弹药保障效率和可靠性要求高的问题,在分析保障流程的计划评审技术(PERT,Program Evaluation and Review Technique)网络图中各工序对任务完工影响程度的基础上,提取了工序关键度指标和重要度指标以及各方案下的按期完工概率,...针对航空弹药保障效率和可靠性要求高的问题,在分析保障流程的计划评审技术(PERT,Program Evaluation and Review Technique)网络图中各工序对任务完工影响程度的基础上,提取了工序关键度指标和重要度指标以及各方案下的按期完工概率,建立了保障人员配置方案评价指标体系,表示为评价函数形式.以基于蒙特卡洛方法的PERT网络仿真为核心,选择在遗传算法进化寻优框架下构建优化模型,该方法不仅得到了最优的保障人员配置方案,而且评估了需要注重的关键工序.算例实验证实了其有效性与实用性.展开更多
文摘Reasonable allocation of storage and computing resources is the basis of building big data system.With the development of IoT(Internet of Things),more data will be brought.A three-layer architecture includes smart devices layer,edge cloud layer and blockchain-based distributed cloud layer.Blockchain is used in IoT for building a distributed decentralize P2P architecture to deal with the secure issue while edge computing deals with increasing volume of data.Edge caching is one of the important application scenarios.In order to allocate edge cache resources reasonably,to improve the quality of service and to reduce the waste of bandwidth resources,this paper proposes a content selection algorithm of edge cache nodes.The algorithm adopts markov chain model,improves the utilization of cache space and reduces the content transmission delay.The hierarchical caching strategy is adopted and the secondary cache stores slides of contents to expand the coverage of cached content and to reduce user waiting time.Regional node cooperation is adopted to expand the cache space and to support the regional preference of cache content.Compared with the classical substitution algorithm,simulation results show that the algorithm in this paper has higher cache hit ratio and higher space utilization.
文摘针对航空弹药保障效率和可靠性要求高的问题,在分析保障流程的计划评审技术(PERT,Program Evaluation and Review Technique)网络图中各工序对任务完工影响程度的基础上,提取了工序关键度指标和重要度指标以及各方案下的按期完工概率,建立了保障人员配置方案评价指标体系,表示为评价函数形式.以基于蒙特卡洛方法的PERT网络仿真为核心,选择在遗传算法进化寻优框架下构建优化模型,该方法不仅得到了最优的保障人员配置方案,而且评估了需要注重的关键工序.算例实验证实了其有效性与实用性.
