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《现代电子技术》2015,(20)
传统的多媒体数据流调度方法在云平台环境下,未考虑服务器信息调度的差异性,容易形成数据调度冲突,调度效率低。为了解决上述分析的问题,通过构建多媒体云计算下数据流调度平台,实现对多路大规模多媒体数据流的合理调度,利用多级分层结构将多媒体云计算下的多服务器大规模数据流调度过程划分成管理层面、控制层面以及数据层面,可确保将数据包均匀的分配给各个服务器,充分发挥云计算下的多服务器可并行处理的特性,增强数据流的调度质量。对调度平台的软件框架进行了详细的描述,依据该软件框架的多层次实现大规模数据流调度优化,分析了大规模数据流调度的具体实现过程,并给出大规模数据流调度平台软件代码的设计。实验结果表明,所提方法增强了多媒体云计算下的大规模数据流调度的并发性能,提高数据流调度质量。 相似文献
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数据流的预测技术在金融证券管理、网络监控等应用中具有重要的作用.分析近年来有关数据流预测的技术,并做出总结.提出一种新的数据流预测方法,将输入的数据流构造成有向图数据结构,并随着新数据流的到来对有向图进行维护,从中提取概率矩阵,利用马尔可夫模型进行计算,得出数据流下一时刻可能的到来值.最后通过实验验证其可行性.结论表明,该算法的精度和预测成功率都较高. 相似文献
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数据流图在信息处理中的应用 总被引:1,自引:0,他引:1
简要介绍数据流图的基本成分及画图步骤,叙述了在信息处理系统中用数据流图分层进行软件分析的过程,阐述了应用数据流图的必要性.在信息处理系统中应用数据流图可提高软件分析的可见性和可控性,有助于软件缺陷在软件开发阶段早期被及时发现和消除. 相似文献
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分析了现有云计算系统中机密性的几种保护机制,并提出了一种基于数据流分析的机密性风险评估模型。通过LKM部署的监控器截获系统调用获得系统的数据流,交由评估器与服务提供的数据流模式集进行比较分析,来对服务机密性进行综合评估。实验表明该方法能够有效识别云计算环境中破坏服务和数据机密性的行为。 相似文献
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综合分析了数据流分类算法以及云计算的基本理论,提出了基于Hadoop框架的数据流系综分类算法,算法采用MapReduce并行编程模型对传统基于动态权重系综模型进行改进,以提升算法的分类效率.分析结果表明,该算法在处理快速海量到达的数据流时,其执行效率远高于传统系综算法. 相似文献
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对java平台从多媒体数据流实时传输的运用方面进行了介绍。对网络多媒体中的RTP、RSVP、RTSP和IPV6等数据流实时传输的关键协议从实时传输意义方面进行了分析。 相似文献
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Multichannel cooperative sensing for cognitive radio with users owning heterogeneous sensing ability 下载免费PDF全文
Multichannel cooperative sensing (MCS) is an effective method for dynamic spectrum access in cognitive radio networks. In contrast to most existing work on MCS that considered secondary users with homogeneous sensing ability, this paper studies the MCS problem for secondary users with heterogeneous sensing ability in terms of sensing accuracy. We further take into account different parameters of primary channels such as bandwidth, probability of being idle in each sensing period, and frequency selective fading at the sensing receiver. The MCS problem is formulated as a weapon target assignment problem, where more sensing resources are assigned to channels that are more valuable. This weapon target assignment problem is transformed to an integer generalized network flow problem with convex flow costs to obtain the lower bound solution, and then solved by the branch and bound algorithm with this bound to yield the exact scheme. To reduce computational complexity, a heuristic scheme is also proposed, which has approximate performance compared with the exact scheme. Finally, extensive simulation results for different scenarios illustrate the performance improvements of the proposed schemes over the existing scheme. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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本文介绍一种由一台PC486/586作主机、一台MCS51系统作主站、32台MCS51系统作子站的分布式数据采集通讯系统的总体实现。该系统具有有线、无线两种通讯方式以及自动转换功能。考虑到降低成本,本系统还设计了专门长线发送器、接收器电路,解决了不需中继器有线传输10KM以上的问题。 相似文献
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Ultra wide-band (UWB) technologies are being feverishly developed in the technical community. UWB devices are expected to operate at rates of up to 0.5 Gb/s and communicate with other devices at a range of up to 10 m. Thus, UWB technologies are being developed as core technology for high-speed wireless personal area networks. The salient features of UWB networks—high-rate communications, low interference with other radio systems, and low power consumption—bring many benefits to users. Thus, they enable consumers to experience new applications such as wireless universal serial bus for connecting personal computers to their peripherals and the consumer–electronics in people’s living rooms. However, if multiple WiMedia logical link protocol Service Sets (WSSs) coexist in an adjacent area, various conflicts among independent WSSs can occur frequently. In order to solve this problem, we propose a multi-channel scheduling scheme (MCS) for the coexistence of adjacent WSSs. The proposed MCS scheme can scan new idle channel and detect its time offset where a WSS device can transmit a new beacon frame and data frames without conflicts. We also evaluate the performance of the proposed MCS scheme through various simulations in terms of several metrics. Simulation results demonstrate that the MCS scheme can minimize the possibility of data frame collisions by efficiently managing the multiple available channels in a hybrid manner combining proactive and reactive methods. 相似文献
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根据中尺度对流系统(MCS)的识别判定标准,基于数字图像处理和模糊模式识别等技术,研究对MCS云团的自动识别与追踪。利用SUSAN边缘检测算子提取边界轮廓,并以亮温直方图结合云团的多个特征量构建追踪模板,实现云团追踪。通过对2014年5月10日12~17时的追踪实验发现,该方法可快速实现MCS云团的自动识别,并能实现对多时次MCS云团的连续有效追踪。 相似文献
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循环流化床锅炉是一个分布参数、非线性、时变、大滞后、多变量紧密耦合的被控对象,常规控制方法难以取得理想的控制效果。首先介绍了影响循环流化床锅炉控制的主要因素,分析了被控对象的特点。然后对主汽压力调节系统,一次风量调节系统,二次风量调节系统,引风量调节系统,给水调节系统,主汽温度调节系统这些主要回路的控制进行了讨论。最后介绍了炉膛安全保护系统以及锅炉的顺序控制和保护。 相似文献
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无人移动平台无线ad hoc网络在实际应用中经常会出现由于电磁环境、干扰等因素导致通信质量不稳定的情况,在上述条件下传统的基于节点覆盖度的最小主控集(MCS)生成算法难以获得具有较好稳定性、健壮性的最小主控集.为此,提出了一种考虑通信质量的网络最小主控集生成算法,将链路的通信质量纳入网络最小主控集构造的考虑因素,使网络拓扑与链路通信质量特性保持一致;并通过对候选节点集及拟覆盖节点集的压缩,有效控制了网络最小主控集的节点数目.仿真表明,对敏感于通信质量的应用,该算法较基于节点覆盖度算法能取得更好效果. 相似文献
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梁新元 《微电子学与计算机》2005,22(1):92-94,97
复杂系统的最小割集很多,对故障诊断很重要,虽然因果图能够进行故障诊断,但缺乏对最小割集的分析.通过最小割集可以进行故障诊断,本文打算研究基于最小割集的故障诊断方法,并将这种新方法成功运用于煤矿瓦斯爆炸的故障分析中.由于根据故障发生的概率大小依次进行诊断,利用了正常事件的剪枝信息和多故障联合诊断,因此这种方法的诊断速度较快,效率较高.研究表明,基于因果图最小割集的故障分析方法,充分结合多种信息,可以快速有效地进行故障诊断. 相似文献
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A critical issue in mobile crowdsensing (MCS) involves selecting appropriate users from a number of participants to guarantee the completion of a sensing task. Users may upload unnecessary data to the sensing platform, leading to redundancy and low user selection efficiency. Furthermore, using exact values to evaluate the quality of the user-union will further reduce selection accuracy when users form a union. This paper proposes a user selection method based on user-union and relative entropy in MCS. More specifically, a user-union matching scheme based on similarity calculation is constructed to achieve user-union and reduce data redundancy effectively. Then, considering the interval-valued influence, a user-union selection strategy with the lowest relative entropy is proposed. Extensive testing was conducted to investigate the impact of various parameters on user selection. The results obtained are encouraging and provide essential insights into the different aspects impacting the data 相似文献