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1.
为减轻节点不相交多路径路由负载和解决路径间的耦合问题,提出了一种基于定向天线的最小能量节点不相交多路径自组网路由算法(RMENDMRDA).初始时该算法应用优化波宽选择算法确定定向天线的最小扇形覆盖区域,从而节省能量消耗,在选择累计能量最小的节点不相交多路径时采用链路可靠性选择算法,以满足链路的可靠性要求.分析及模拟结果表明,该算法路由负载更小、路由发现频率更低.与源传输能量选择路由算法和节点不相交多路径路由算法相比,RMENDMRDA的数据包投递率提高了18%,路由负载降低了24%,节省能量约8%.  相似文献   

2.
针对无线传感器网络能量多路径路由算法存在的缺陷及其原因,提出一种基于动态优先级的能量多路径路由算法。该路由算法以节点距汇聚节点的路径跳数值替代路径能耗代价确定其优先级,并在数据传输过程中根据节点的能量消耗不断调整优先级,降低了算法的复杂度,避免了周期性路由维护所带来的时间与能量损失。仿真结果表明,该算法能有效降低和平衡各节点的能耗,延长整个网络的生存周期。  相似文献   

3.
Ad-Hoc网络中一种可靠的节点不相交多路径路由算法   总被引:2,自引:0,他引:2  
提出了一种可靠的节点不相交多路径路由算法(RNDMRA). 结合预测模型和能量模型,利用网格中节点的地理信息,有效减少路由发现泛洪的频率. 同时为了选择与最短路径相似的稳定多路由,RNDMRA应用相似性因子选择相似的稳定节点不相交多路径路由. 模拟结果显示,与AODV和NDMR相比,RNDMRA有更高的投递率,更小的路由延迟和路由负载.  相似文献   

4.
针对移动自组织网络的网络拥塞问题,基于能量感知技术并结合负载均衡和拥塞控制方法,提出了一种能量感知多路径负载均衡路由算法。该算法利用能量感知选择满足条件的节点作为路由节点,建立多条连接源节点和目的节点的有效路径;同时分析路径的跳数、节点缓冲区的占用情况,从有效路径中选出用于传输的最优路径;然后对最优路径上的节点和路径的负载情况进行建模分析,当节点能量、节点负载、路径负载到达设定的阀值,就将最优路径上的流量分流到其它路径。利用NS2仿真软件,在不同的场景下对该算法以及QMRB、SMORT进行仿真测试。仿真结果显示:提出的算法与其它路由算法相比将网络性能提升了近20%,起到了均衡负载的作用,能有效地解决网络拥塞问题。  相似文献   

5.
移动视频技术的广泛应用给移动自组网络的服务质量带来很大的挑战.相较于传统的单路径路由算法,基于多约束的多路径路由算法具有更强的可靠性和适用性.多约束条件路由问题是一个NP困难问题,如何高效求出优化解成为该技术的关键.针对移动自组网络在视频传输过程中存在的链路拥塞及能量损耗问题,设计一种基于鲸鱼优化算法的多路径路由发现算法,有效求解满足多约束条件的多路由路径,提高了移动自组网络的性能和服务质量.  相似文献   

6.
在能量异构传感器网络中,由于节点能量在一定范围内随机分布,平衡能量消耗和延长网络寿命成为此类算法的一个重要挑战.针对该问题,提出了一种基于蚁群算法的异构传感器网络路由算法.算法通过改善网络拓扑结构、优先使用剩余能量较大的节点、构建异构传感器网络多路径路由来实现.模拟实验表明:与传统路由算法(DADC)相比,算法能更好地平衡能量消耗,延长网络寿命.  相似文献   

7.
基于簇的路由协议是无线传感器网络的研究热点,本文针对现有的簇间路由协议没有考虑网络负载的均衡,提出一种高效节能的无线传感器网络簇间多路径路由协议。该协议基于簇头节点到汇聚节点的最小跳数生成从簇头节点到汇聚节点的多条路径,根据簇节点的剩余能量和负载将数据通信均匀分布在不同的路径上,从而达到簇头节点间的负载均衡。仿真实验结果表明,该路由协议能有效地均衡网络负载,节省簇头节点能量,从而延长网络的生存时间。  相似文献   

8.
本文针对无线传感器网络提出了一种实时的能量均衡多路径路由算法RTEB-MR(Real-Time Energy-Balancing Multi-Path Routing)。RTEB-MR是由源节点发起的路由协议,采用受限洪泛传播路由请求消息来建立路由,减少了采用普通洪泛所带来的较大的能量消耗,在保证实时传输的情况下,从多条路由路径中选择能量最大的进行路由。仿真显示,与其它算法比较,RTEB-MR算法在节能及延长网络生命周期等方面有较好的性能。  相似文献   

9.
针对无线传感器网络路由存在能量空洞的问题,提出一种分布式非均匀分簇路由算法.该算法在选择候选簇首时引入位置因子和平均能量因子来平衡全网节点的剩余能量;网络运行过程中,候选簇首通过自适应校正其竞争半径进行非均匀分簇.采用基于能量和距离的能耗函数入簇机制以均衡全网能量消耗,利用多跳动态路由以避免稳定传输阶段转发节点因能耗过大而快速死亡.通过构建网络模型,采用Matlab对文中算法和UCR算法进行仿真分析比较.仿真结果表明:文中算法簇首消耗能量的方差波动不大较稳定,相比UCR更好地均衡了簇首能量消耗,并且能够有效避免能量空洞,均衡网络负载,网络生命周期较UCR算法提高了约34%.  相似文献   

10.
针对传统OLSR算法的传输功率消耗和节点剩余能量之间的矛盾,提出了一种基于组合优化理论的能量感知路由算法(EW OLSR).首先根据传输功率消耗和节点剩余能量构建节点能量消耗数学模型,并将其作为路由选择目标函数,然后在节点剩余能量计算中引入ARIMA LSSVM组合预测模型,最后根据能量消耗最小路径选择数据传输路由.实验结果表明,EW OLSR算法不仅减少了网络能量消耗和传输时延,而且提高了分组到达率,在无线网络中具有广阔的应用前景.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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