为提高系统的整体性能和稳定性,对不间断电源(Uninterruptable Power Supply,UPS)调度现状进行深入分析,以解决存在的问题和挑战。设计一种考虑能效和负载均衡的UPS自动化优化策略,通过实时监测负载变化,动态调整UPS的输出功率和分配方...为提高系统的整体性能和稳定性,对不间断电源(Uninterruptable Power Supply,UPS)调度现状进行深入分析,以解决存在的问题和挑战。设计一种考虑能效和负载均衡的UPS自动化优化策略,通过实时监测负载变化,动态调整UPS的输出功率和分配方式,以实现能效最大化和负载均衡。结果表明,实施该优化策略后,UPS系统的能效得到显著提升,能够实现绿色节能供电。展开更多
This paper describes a novel energy-aware multi-hop cluster-based fault-tolerant load balancing hierarchical routing protocol for a self-organizing wireless sensor network (WSN), which takes into account the broadcast...This paper describes a novel energy-aware multi-hop cluster-based fault-tolerant load balancing hierarchical routing protocol for a self-organizing wireless sensor network (WSN), which takes into account the broadcast nature of radio. The main idea is using hierarchical fuzzy soft clusters enabling non-exclusive overlapping clusters, thus allowing partial multiple membership of a node to more than one cluster, whereby for each cluster the clusterhead (CH) takes in charge intra-cluster issues of aggregating the information from nodes members, and then collaborate and coordinate with its related overlapping area heads (OAHs), which are elected heuristically to ensure inter-clusters communication. This communication is implemented using an extended version of time-division multiple access (TDMA) allowing the allocation of several slots for a given node, and alternating the role of the clusterhead and its associated overlapping area heads. Each cluster head relays information to overlapping area heads which in turn each relays it to other associated cluster heads in related clusters, thus the information propagates gradually until it reaches the sink in a multi-hop fashion.展开更多
As the demand for the development of cloud computing grows, more and more organizations have outsourced their data and query services to the cloud for cost-saving and flexibility. Suppose an organization that has a gr...As the demand for the development of cloud computing grows, more and more organizations have outsourced their data and query services to the cloud for cost-saving and flexibility. Suppose an organization that has a great number of users querying the cloud-deployed multiple proxy servers to achieve cost efficiency and load balancing. Given n queries, each of which is expressed as several keywords, and k proxy servers, the problem to be solved is how to classify n queries into k groups, in order to minimize the difference between each group and the number of distinct keywords in all groups. Since this problem is NP-hard, it is solved in mathematic and heuristic ways. Mathematic grouping uses a local optimization method, and heuristic grouping is based on k-means. Specifically, two extensions are provided： the first one focuses on robustness, i.e., each user obtains search results even if some proxy servers fail; the second one focuses on benefit, i.e., each user can retrieve as many files as possible that may be of interest without increasing the sum. Extensive evaluations have been conducted on both a synthetic dataset and real query traces to verify the effectiveness of our strategies.展开更多
文摘为提高系统的整体性能和稳定性,对不间断电源(Uninterruptable Power Supply,UPS)调度现状进行深入分析,以解决存在的问题和挑战。设计一种考虑能效和负载均衡的UPS自动化优化策略,通过实时监测负载变化,动态调整UPS的输出功率和分配方式,以实现能效最大化和负载均衡。结果表明,实施该优化策略后,UPS系统的能效得到显著提升,能够实现绿色节能供电。
文摘This paper describes a novel energy-aware multi-hop cluster-based fault-tolerant load balancing hierarchical routing protocol for a self-organizing wireless sensor network (WSN), which takes into account the broadcast nature of radio. The main idea is using hierarchical fuzzy soft clusters enabling non-exclusive overlapping clusters, thus allowing partial multiple membership of a node to more than one cluster, whereby for each cluster the clusterhead (CH) takes in charge intra-cluster issues of aggregating the information from nodes members, and then collaborate and coordinate with its related overlapping area heads (OAHs), which are elected heuristically to ensure inter-clusters communication. This communication is implemented using an extended version of time-division multiple access (TDMA) allowing the allocation of several slots for a given node, and alternating the role of the clusterhead and its associated overlapping area heads. Each cluster head relays information to overlapping area heads which in turn each relays it to other associated cluster heads in related clusters, thus the information propagates gradually until it reaches the sink in a multi-hop fashion.
基金This research was supported in part by the National Science Foundation of USA under Grant Nos. CNS-1449860, CNS-1461932, CNS-460971, CNS-1439672, CNS-1301774, and ECCS-1231461, the National Natural Science Foundation of China under Grant Nos. 61632009, 61472451, 61402161, 61472131, 61272151, and 61272546, the Hunan Provincial Natural Science Foundation of China under Grant No. 2015JJ3046, and the Open Foundation of State Key Laboratory of Networking and Switching Technology （Beijing University of Posts and Telecommunications） under Grant No. SKLNST-2016-2-20.
文摘As the demand for the development of cloud computing grows, more and more organizations have outsourced their data and query services to the cloud for cost-saving and flexibility. Suppose an organization that has a great number of users querying the cloud-deployed multiple proxy servers to achieve cost efficiency and load balancing. Given n queries, each of which is expressed as several keywords, and k proxy servers, the problem to be solved is how to classify n queries into k groups, in order to minimize the difference between each group and the number of distinct keywords in all groups. Since this problem is NP-hard, it is solved in mathematic and heuristic ways. Mathematic grouping uses a local optimization method, and heuristic grouping is based on k-means. Specifically, two extensions are provided： the first one focuses on robustness, i.e., each user obtains search results even if some proxy servers fail; the second one focuses on benefit, i.e., each user can retrieve as many files as possible that may be of interest without increasing the sum. Extensive evaluations have been conducted on both a synthetic dataset and real query traces to verify the effectiveness of our strategies.
