Resource allocation for multi-tier web appli- cations in virtualization environments is one of the most important problems in autonomous computing. On one hand, the more resources that are provisioned to a multi- tier...Resource allocation for multi-tier web appli- cations in virtualization environments is one of the most important problems in autonomous computing. On one hand, the more resources that are provisioned to a multi- tier web application, the easier it is to meet service level objectives （SLO）. On the other hand, the virtual machine which hosts the multi-tier web application needs to be consolidated as much as possible in order to maintain high resource utilization. This paper presents an adaptive resource controller which consists of a feedback utiliza- tion controller and an auto-regressive and moving average model （ARMA）-based model estimator. It can meet application-level quality of service （QoS） goals while achieving high resource utilization. To evaluate the proposed controllers, simulations are performed on a testbed simulating a virtual data center using Xen virtual machines. Experimental results indicate that the control- lers can improve CPU utilization and make the best trade- off between resource utilization and performance for multi-tier web applications.展开更多
Energy access remains a critical challenge in rural South Sudan,with communities heavily relying on expensive and unfriendly environmental energy sources such as diesel generators and biomass.This study addresses the ...Energy access remains a critical challenge in rural South Sudan,with communities heavily relying on expensive and unfriendly environmental energy sources such as diesel generators and biomass.This study addresses the predicament by evaluating the feasibility of renewable energy-based decentralized electrification in the selected village ofDoleibHill,UpperNile,South Sudan.Using a demand assessment and theMulti-Tier Framework(MTF)approach,it categorizes households,public facilities,private sector,Non-GovernmentalOrganizations(NGOs)and business energy needs and designs an optimized hybrid energy system incorporating solar Photovoltaic(PV),wind turbines,batteries,and a generator.The proposed system,simulated in Hybrid Optimization Model Electric Renewable(HOMER)Pro,demonstrates strong economic viability,with a present worth of$292,145,an annual worth of$22,854,a return on investment(ROI)of 36.5%,and an internal rate of return(IRR)of 42.1%.The simple payback period is 2.31 years,and the discounted payback period is 2.62 years.The system achieves a levelized cost of energy(LCOE)of$0.276/kWh and significantly reduces dependence on diesel,producing 798,800 kWh annually fromwind energy.This research provides a replicable model for cost-effective,sustainable rural electrification,offering valuable insights for policymakers and energy planners seeking to expand electricity access in off-grid communities.展开更多
This article proposes a multi-tiered fault detection system for series-connected lithium-ion battery modules.Improper use of batteries can lead to electrolyte decomposition,resulting in the formation of lithium dendri...This article proposes a multi-tiered fault detection system for series-connected lithium-ion battery modules.Improper use of batteries can lead to electrolyte decomposition,resulting in the formation of lithium dendrites.These dendrites may pierce the separator,leading to the failure of the insulation layer between electrodes and causing micro short circuits.When a micro short circuit occurs,the electrolyte typically undergoes exothermic reactions,leading to thermal runaway and posing a safety risk to users.Relying solely on temperature-based judgment mechanisms within the battery management system often results in delayed intervention.To address this issue,the article develops a multi-tiered fault detection algorithm for series-connected lithium-ion batteries.This algorithm can effectively diagnose micro short circuits,aging,and normal batteries using minimal battery data,thereby improving diagnostic accuracy and enhancing the flexibility of fault detection.Simulations and experiments conducted under various levels of micro short circuits validate the effectiveness of the algorithm,demonstrating its ability to distinguish between short-circuited,aged,and normal batteries under different conditions.This technology can be applied to electric vehicles and energy storage systems,enabling early warnings to ensure safety and prevent thermal runaway.展开更多
目的分析2008—2024年老年性肌少症与线粒体相关性研究的现状、热点及发展趋势,为该领域的后续研究提供参考。方法检索2008年1月1日至2024年12月31日Web of Science核心合集数据库收录的老年性肌少症与线粒体相关性研究的文献,使用R 4....目的分析2008—2024年老年性肌少症与线粒体相关性研究的现状、热点及发展趋势,为该领域的后续研究提供参考。方法检索2008年1月1日至2024年12月31日Web of Science核心合集数据库收录的老年性肌少症与线粒体相关性研究的文献,使用R 4.2.0软件的Bibliometrix包对发文国家、合作网络、作者、机构、期刊、高被引文献、关键词和文献被引频次进行定量和可视化分析,并运用H指数分析作者的学术影响力。结果共纳入1219篇文献,2008—2024年发文量总体呈上升趋势。累计发文量排名前三位的国家分别是美国、中国和意大利;发文量排名前三位的期刊分别为Journal of Cachexia,Sarcopenia and Muscle、International Journal of Molecular Sciences和Experimental Gerontology;H指数排名前六位的作者分别为Marzettie E、Calvani R、Picca A、Van Remmen H、Leeuwenbugh C和Bernabel R;被引频次最高的文献是“Sarcopenia:agingrelated loss of muscle mass and function”;出现频次排名前五的关键词分别为skeletalmuscle、sarcopenia、oxidative stress、exercise和expression。结论老年性肌少症与线粒体相关性研究领域呈现良好的发展态势。未来需加强跨国家、跨机构和跨学科合作,可重点关注线粒体融合蛋白等对线粒体功能的影响,以及饮食和运动对老年性肌少症的干预作用等方面的探索。展开更多
Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for wa...Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for ways to reduce their drilling costs and be as efficient as possible. A system called the Drilling Comprehensive Information Management and Application System (DCIMAS) is developed and presented here, with an aim at collecting, storing and making full use of the valuable well data and information relating to all drilling activities and operations. The DCIMAS comprises three main parts, including a data collection and transmission system, a data warehouse (DW) management system, and an integrated platform of core applications. With the support of the application platform, the DW management system is introduced, whereby the operation data are captured at well sites and transmitted electronically to a data warehouse via transmission equipment and ETL (extract, transformation and load) tools. With the high quality of the data guaranteed, our central task is to make the best use of the operation data and information for drilling analysis and to provide further information to guide later production stages. Applications have been developed and integrated on a uniform platform to interface directly with different layers of the multi-tier DW. Now, engineers in every department spend less time on data handling and more time on applying technology in their real work with the system.展开更多
文摘Resource allocation for multi-tier web appli- cations in virtualization environments is one of the most important problems in autonomous computing. On one hand, the more resources that are provisioned to a multi- tier web application, the easier it is to meet service level objectives （SLO）. On the other hand, the virtual machine which hosts the multi-tier web application needs to be consolidated as much as possible in order to maintain high resource utilization. This paper presents an adaptive resource controller which consists of a feedback utiliza- tion controller and an auto-regressive and moving average model （ARMA）-based model estimator. It can meet application-level quality of service （QoS） goals while achieving high resource utilization. To evaluate the proposed controllers, simulations are performed on a testbed simulating a virtual data center using Xen virtual machines. Experimental results indicate that the control- lers can improve CPU utilization and make the best trade- off between resource utilization and performance for multi-tier web applications.
文摘Energy access remains a critical challenge in rural South Sudan,with communities heavily relying on expensive and unfriendly environmental energy sources such as diesel generators and biomass.This study addresses the predicament by evaluating the feasibility of renewable energy-based decentralized electrification in the selected village ofDoleibHill,UpperNile,South Sudan.Using a demand assessment and theMulti-Tier Framework(MTF)approach,it categorizes households,public facilities,private sector,Non-GovernmentalOrganizations(NGOs)and business energy needs and designs an optimized hybrid energy system incorporating solar Photovoltaic(PV),wind turbines,batteries,and a generator.The proposed system,simulated in Hybrid Optimization Model Electric Renewable(HOMER)Pro,demonstrates strong economic viability,with a present worth of$292,145,an annual worth of$22,854,a return on investment(ROI)of 36.5%,and an internal rate of return(IRR)of 42.1%.The simple payback period is 2.31 years,and the discounted payback period is 2.62 years.The system achieves a levelized cost of energy(LCOE)of$0.276/kWh and significantly reduces dependence on diesel,producing 798,800 kWh annually fromwind energy.This research provides a replicable model for cost-effective,sustainable rural electrification,offering valuable insights for policymakers and energy planners seeking to expand electricity access in off-grid communities.
文摘This article proposes a multi-tiered fault detection system for series-connected lithium-ion battery modules.Improper use of batteries can lead to electrolyte decomposition,resulting in the formation of lithium dendrites.These dendrites may pierce the separator,leading to the failure of the insulation layer between electrodes and causing micro short circuits.When a micro short circuit occurs,the electrolyte typically undergoes exothermic reactions,leading to thermal runaway and posing a safety risk to users.Relying solely on temperature-based judgment mechanisms within the battery management system often results in delayed intervention.To address this issue,the article develops a multi-tiered fault detection algorithm for series-connected lithium-ion batteries.This algorithm can effectively diagnose micro short circuits,aging,and normal batteries using minimal battery data,thereby improving diagnostic accuracy and enhancing the flexibility of fault detection.Simulations and experiments conducted under various levels of micro short circuits validate the effectiveness of the algorithm,demonstrating its ability to distinguish between short-circuited,aged,and normal batteries under different conditions.This technology can be applied to electric vehicles and energy storage systems,enabling early warnings to ensure safety and prevent thermal runaway.
文摘目的分析2008—2024年老年性肌少症与线粒体相关性研究的现状、热点及发展趋势,为该领域的后续研究提供参考。方法检索2008年1月1日至2024年12月31日Web of Science核心合集数据库收录的老年性肌少症与线粒体相关性研究的文献,使用R 4.2.0软件的Bibliometrix包对发文国家、合作网络、作者、机构、期刊、高被引文献、关键词和文献被引频次进行定量和可视化分析,并运用H指数分析作者的学术影响力。结果共纳入1219篇文献,2008—2024年发文量总体呈上升趋势。累计发文量排名前三位的国家分别是美国、中国和意大利;发文量排名前三位的期刊分别为Journal of Cachexia,Sarcopenia and Muscle、International Journal of Molecular Sciences和Experimental Gerontology;H指数排名前六位的作者分别为Marzettie E、Calvani R、Picca A、Van Remmen H、Leeuwenbugh C和Bernabel R;被引频次最高的文献是“Sarcopenia:agingrelated loss of muscle mass and function”;出现频次排名前五的关键词分别为skeletalmuscle、sarcopenia、oxidative stress、exercise和expression。结论老年性肌少症与线粒体相关性研究领域呈现良好的发展态势。未来需加强跨国家、跨机构和跨学科合作,可重点关注线粒体融合蛋白等对线粒体功能的影响,以及饮食和运动对老年性肌少症的干预作用等方面的探索。
文摘Expenditure on wells constitute a significant part of the operational costs for a petroleum enterprise, where most of the cost results from drilling. This has prompted drilling departments to continuously look for ways to reduce their drilling costs and be as efficient as possible. A system called the Drilling Comprehensive Information Management and Application System (DCIMAS) is developed and presented here, with an aim at collecting, storing and making full use of the valuable well data and information relating to all drilling activities and operations. The DCIMAS comprises three main parts, including a data collection and transmission system, a data warehouse (DW) management system, and an integrated platform of core applications. With the support of the application platform, the DW management system is introduced, whereby the operation data are captured at well sites and transmitted electronically to a data warehouse via transmission equipment and ETL (extract, transformation and load) tools. With the high quality of the data guaranteed, our central task is to make the best use of the operation data and information for drilling analysis and to provide further information to guide later production stages. Applications have been developed and integrated on a uniform platform to interface directly with different layers of the multi-tier DW. Now, engineers in every department spend less time on data handling and more time on applying technology in their real work with the system.
