共查询到20条相似文献,搜索用时 156 毫秒
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随着目前网络访问量和数据流量的不断增加,现有各个核心部分业务量的快速增长,对服务器处理能力和计算强度也提出更高的要求。这也使单一的服务器设备根本无法承担。因此,研究者开始安装利用集群服务器,最大程度的实现群集化资源的可用性,减少单点故障数量。主要介绍服务器集群和负载均衡,并对负载均衡的计算方法进行研究。 相似文献
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为了缓解公共自行车系统在数据存储方面面临的大数据流量以及区域性、时段性的流量不均衡问题,提高数据存储的效率和可靠性,提出了一种数据分流与存储系统.通过负载均衡技术,对公共自行车站点终端上传的数据进行分区转发,实现数据的动态存储.完成了对存储服务器短时间内大量连接请求的处理能力以及长期规律性连接请求的处理能力的测试实验.实验结果表明,该存储系统能够快速、高效地响应高并发的数据连接请求,具有较高的工程应用价值. 相似文献
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杨磊 《中国新技术新产品》2011,(24):27
为了提高Web访问的实时性和吞吐量,本文提出了一种基于WebLogic的负载均衡集群系统的构建方案,应用于我们的In-ternet网络服务器上,将负载分给多个服务器分担,能够解决Internet服务器面临的大量并发访问造成的CPU或I/O的高负载问题。本文对该系统进行了压力测试,实验结果表明该系统能够适应大型商业网站的需求。 相似文献
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针对异构无线通信网络的发展趋势及其负载控制的执行,利用复杂系统中端到端重配置管理能力,结合模糊理论中的决策算法,提出了一种基于模糊理论的增强型多目标决策层次分析法(AHP)终端选择算法--AHP-TS,该算法将可重配置系统中的差异性和不精确性模糊化为相应隶属函数的隶属度,以实现更加及时有效的负载调控,进一步提升系统性能.理论分析和仿真所得出的结果均显示,在平衡可重配置系统中具有重叠覆盖的异构无线通信网络间的业务负荷中,此算法可以更好地实现不同负载条件下系统性能与管理开销间的折中,提高用户满意度. 相似文献
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针对无线传感器网络(WSN)数据汇集应用中负载分配不均衡,使得网络节点出现早死,网络寿命缩短的问题,提出了一种基于蚁群优化(ACO)的负载均衡的数据汇集(Load-balancing data gathering based on ACO,L-ACO)算法。根据不同的任务,L-ACO算法将蚂蚁分为三类:前向探索蚂蚁(FD-ANT)、前向运输蚂蚁(Fr-ANT)和后向蚂蚁(B-ANT)。此算法定义蚂蚁的转移概率与路径信息素成反比,并采用父节点负载作为启发因子,使得蚂蚁趋向于走负载低的路径。通过前向蚂蚁与后向蚂蚁的分工合作,使得各条路径上的负载逐渐趋于均衡,从而延长网络寿命。仿真实验表明L-ACO算法可行。 相似文献
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针对现有异构集群的编程框架着重于异构资源的利用,没有充分考虑共享资源竞争导致作业完成时间延长的情况,基于Hadoop+框架和异构任务模型,提出并实现了异构动态亲和性调度(HDAS)算法,该算法利用Hadoop的心跳机制监测各结点上的资源使用情况和实时负载,对系统中的异构资源用不同的策略计算与任务的亲和性,进行任务分派,使系统的资源利用更充分,从而降低共享资源竞争导致的任务延迟,提高系统的整体吞吐率,且提交到系统中的应用都会在启动后一定时间内被执行。对25种混合负载的试验表明,Hadoop+框架使用HDAS相对于Hadoop的实现可获得平均21.9x的加速比,明显优于基于异构任务模型的调度策略(17.9x),并使其中21个负载的任务平均延迟不超过6%,在任务对系统资源需求多样性丰富的混合负载上优化效果明显。 相似文献
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Jian-Fei Chai Xiao-Mei Hu He-Wei Qu Ming-Hang Li Hui-Jing Xu Yu Liu Tao Yu 《先进制造进展(英文版)》2018,6(1):126-135
New production line management technologies are required and adopted recently with the development of modern manufacturing industry. In this study, a production line three-dimensional (3D) visualization monitoring system based on OpenGL modeling, open database connectivity (ODBC), and database management technology is established on a VC++6.0 platform to satisfy effective production. A client/server model is adopted in the system, and data on processing information, interactive operation, and failure process are stored in the server side database. A client reads the workpiece process information from the server, and the machining process of every workpiece is visually represented in the form of 3D visualization. Production line 3D visualization provides production capacity simulation to optimize the parameter settings. When compared with the analysis results of production line capacity, the key parameters possess the same optimal values, and this proves the accuracy of production line 3D visualization monitoring system. The system provides effective data support for production line monitoring and management in enterprises.
The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-018-0217-x 相似文献
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This paper explores the potential of mixed coolants at elevated pressures for Joule-Thomson cryocooling. A numerical model of a Joule-Thomson cryocooler is developed that is capable of simulating operation with mixtures of up to 9 components consisting of hydrocarbons, non-flammable halogenated refrigerants, and inert gases. The numerical model is integrated with a genetic optimization algorithm, which has a high capability for convergence in an environment of discontinuities, constraints and local optima. The genetic optimization algorithm is used to select the optimal mixture compositions that separately maximizes following two objective functions at each elevated pressure for 80, 90 and 95 K cryocooling: the molar specific cooling capacity (the highest attainable is 3200 J/mol) and the produced cooling capacity per thermal conductance which is a measure of the compactness of the recuperator. The optimized cooling capacity for a non-flammable halogenated refrigerant mixture is smaller than for a hydrocarbon mixture; however, the cooling capacity of the two types of mixtures approach one another as pressure becomes higher. The coefficient of performance, the required heat transfer area and the effect of the number of components in the mixture is investigated as a function of the pressure. It is shown that mixtures with more components provide a higher cooling capacity but require larger recuperative heat exchangers. Optimized mixtures for 90 K cryocooling have similar cooling capacity as those for 80 K. Optimized compactness for 80 K is about 50% higher than can be achieved by pure nitrogen. For 90 K, no mixture provides a more compact recuperator than can be achieved using pure argon. The results are discussed in the context of potential applications for closed and open cycle cryocoolers. 相似文献
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为了防止无线传感器网络(WSN)节点因为通信距离过长而过早死亡,有效延长网络生命周期,提出了一种基于距离分区的高能效的多级异构无线传感器网络成簇算法(MHCADP)。此算法将监测区域分为三部分,并根据不同监测区域和基站的距离部署能量不同的三类节点,按照节点剩余能量与网络平均能量的比例来选举簇头节点,让较高初始能量和剩余能量的节点拥有更多的机会成为簇头。另外,在数据传输时,考虑节点和基站的距离以及自身剩余能量,选择单跳或多跳的传输方式。仿真实验结果表明,与现有的重要成簇算法——低能耗自适应分簇分层(LEACH)算法和稳定选举协议(SEP)算法相比,MHCADP算法能够有效减少网络能量消耗和平衡网络负载,使网络稳定周期和生命周期延长50%以上。 相似文献
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概述了传统的MRP计算和板材剪切配送企业MRP计算的不同之处,提出板材剪切配送企业物料需求计算存在的问题;针对这些问题,借鉴制造行业物料需求计划的一般原理并结合板材剪切配送企业行业的特点,给出板材剪切配送企业物料需求模型,提出一种符合板材剪切配送企业特点的、有效的物料需求计算方法. 相似文献
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研究了通过对终端视频帧质量的聚类分析来识别无线视频传输中码率变化的方法,以便为无线视频传输过程中视频码率自适应调整提供参考依据.针对经典模糊C均值(FCM)算法和K均值(K-means)算法需要设定聚类数目的问题,提出一种基于荻利克雷过程(DP)的FCM算法——DP-FCM算法.该算法将Dirichlet过程和FCM算法相结合,由视频帧信息权重峰值信噪比(IWPSNR)值使用DP过程混合模型模拟估计出聚类数目,然后进行FCM模糊聚类,通过设定合理的阈值,合并聚类结果相似项,完成视频帧的聚类,从而实现视频传输码率变化的识别.以LIVE视频库为试验数据源,对该算法进行了性能测试.试验结果表明,DP-FCM算法能够在无需设定聚类数目的前提下实现视频传输码率变化的分类识别. 相似文献
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Yen-Wei Kuo 《中国工程学刊》2013,36(8):678-688
AbstractCoverage and capacity optimization (CCO) is a crucial procedure in Long-Term Evolution (LTE) Self-Organizing Network (SON). In recent studies, fuzzy theory has been widely applied for CCO in centralized SON but not in distributed SON. Distributed SON can be applied in user-deployed small cells such as femtocells. In the present paper, a distributed, autonomous, and low-complexity fuzzy-based coverage and capacity scheme is proposed for LTE heterogeneous networks (HetNet). To accomplish this goal, the proposed scheme manages radio resources to minimize inter-cell interference. A tradeoff exists between cell coverage and capacity due to inter-cell interference. By leveraging three fuzzy memberships, the scheduling decision is adaptively made by a low-complexity intersection function. Different from conventional fuzzy approaches, the proposed approach does not depend on pre-defined fuzzy rules and pre-defined fuzzy membership models. System performance is evaluated in terms of throughput and energy efficiency. The simulation results show that the proposed approach improves system performance by up to about 39% compared with a joint optimization algorithm. 相似文献