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1.
一种基于节点行为的无线传感器网络信誉计算模型   总被引:1,自引:0,他引:1  
针对BRSN模型在计算过程中没有考虑节点能量的不足,设计一种基于节点行为的无线传感器网络信誉计算模型.该模型在评价节点信誉时,先计算节点行为的直接信誉参数,再参考邻居节点所提供的间接信誉参数,最终和节点的能量信誉参数进行整合,得到节点的综合信誉评估值,根据其值是否大于等于规定的阀值来确定节点是否可信.仿真结果证明该模型能够更准确反映节点的可信程度,有效防止恶意诽谤,提高系统安全性、可靠性,体现网络的公平性.  相似文献   

2.
针对BRSN模型在计算过程中没有考虑节点能量的不足,设计一种基于节点行为的无线传感器网络信誉计算模型.该模型在评价节点信誉时,先计算节点行为的直接信誉参数,再参考邻居节点所提供的间接信誉参数,最终和节点的能量信誉参数进行整合,得到节点的综合信誉评估值,根据其值是否大于等于规定的阀值来确定节点是否可信.仿真结果证明该模型能够更准确反映节点的可信程度,有效防止恶意诽谤,提高系统安全性、可靠性,体现网络的公平性.  相似文献   

3.
提出了一种基于多基站的无线传感器网络Anycast路由算法,算法为网络中每个基站都建立一棵自己的Anycast树,网络中所有节点选择路径开销最小的邻居节点加入到对应基站的Anycast树中.该Anycast多基站路由算法可以根据不同的网络时延需求设置不同的权重参数来选择最优的路径,以达到实现不同时延要求无线传感器网络的应用.所有源节点采集的数据根据其加入的Anycast树的树状结构进行数据传输并送达基站.仿真实验表明:提出的Anycast路由算法在多基站的无线传感器网络中可以有效降低网络能耗和明显延长网络生命周期,较好地解决多基站的无线传感器网络架构通信模式问题.  相似文献   

4.
随着对无线传感器网络的广泛研究与应用,用户对传感器节点的安全性要求日益提高。由于传统基于密码学的信息安全技术并不能够完美地解决传感器节点面临的复杂安全威胁,信誉系统已经被引入到无线传感器网络中,对节点安全情况进行周期性评估,并分配相应的信誉值。由于信誉系统很难分辨一些节点的某些行为是否处于正常区间如监测数据是否准确,进而导致某些传感器节点能够躲避信誉系统的监测,对用户决策产生不良影响。本文提出了一种结合信誉系统和噪声点检测技术的无线传感器网络节点安全模型。一方面,网络中的信誉系统模块为噪声点检测模块提供数据支撑,以便高效检测到噪声点数据;另一方面,噪声点检测模块对信誉系统进行反馈,加速节点信誉值的收敛,提高系统效率。一系列的仿真表明,相比于传统信誉系统模型,改进后的节点安全模型能够同时检测到网络攻击和数据攻击,同时该模型具有更高的收敛速度。  相似文献   

5.
无线传感器网络节能策略   总被引:1,自引:0,他引:1  
无线传感器网络中,能量问题是核心问题,各种节能机制涉及了协议栈各层,每一层都可以根据自身特点和功能设计不同的节能策略.该文分别从网络的物理层、数据链路层、网络层、传输层和应用层分析了无线传感器网络的节能策略.  相似文献   

6.
多Agent技术被越来越广泛地引入到无线传感器网络领域,但却没有可行有效的Agent协作模型。在此基础上,对传统TOD(Task Oriented Domain)协作模型进行了扩展,提出了基于面向任务域的无线传感器网络多Agent协作模型,使用加权和的方法根据不同网络任务类型制定相应的协作策略,仿真结果表明,与传统模型相比,该模型下采用协作策略可有效地减少节点能耗。  相似文献   

7.
为了降低节点能量消耗,延长网络生存的时间,提出了一种改进蚁群算法的无线传感器网络路由机制.首先将无线传感器网络服务质量分为3类,然后利用蚁群算法可以自适应网络状况动态性的优势,构建传感器节点转移函数、信息素更新规则和自适应构建数据路由.最后采用仿真模拟实验对算法性能进行检验.实验结果表明,相对于现有无线传感器路由算法,通过引入蚁群优化机理挖掘传感器节点之间的关联性,数据传输延迟、可靠性和能量开销上具有更好的性能,使整个网络性能保持最优.  相似文献   

8.
针对现有无线传感器网络恶意节点检测方法效率较低的不足,提出一种基于增强低功耗自适应集簇分层(enhanced low energy adaptive clustering hierarchy,enhanced LEACH)路由协议信誉机制的恶意节点检测(malicious node detection based on enhanced LEACH with reputation,MNDELR)模型.在无线传感器网络中使用增强LEACH路由协议选取簇首节点,其余节点选择对应簇首形成各簇集群并确定网络数据包传递路径.节点在数据包内添加节点编号、信誉评价等信息并按传递路径将数据包发送至汇聚节点;汇聚节点解析获取数据包内节点编号并与源节点编号比较判定,形成可疑节点列表;计算节点信誉值并与阈值比较判定网络中的恶意节点.实验结果表明,与其他方法相比,MNDELR模型在无线传感器网络中对恶意节点的检测效果较为显著.   相似文献   

9.
针对目前无线移动传感器网络中部署算法过于复杂的问题,提出了一种新的基于网格移动的无线移动传感器网络部署算法.降低了常见无线移动传感器网络部署算法的时间复杂度,提高了任务区域的节点覆盖度,减少了覆盖漏洞,适用于无线移动传感器网络的应用.文中论述了该算法的构架,执行过程,并对该算法进行了仿真分析.仿真结果表明,该算法在有效降低算法复杂度的情况下满足了网络部署中关于覆盖率的要求.  相似文献   

10.
针对当前无线传感器网络路由算法存在数据传输成功率低、 网络时延长和丢包率高等缺陷, 为获得更优的数据传输结果, 提出一种基于证据理论加权融合 的无线传感器网络路由算法. 首先引入聚类分析算法对无线传感器网络进行分簇, 使簇首的分布更均匀, 解决簇首过于集中、 簇成员节点分配不合理的问题; 然后采用证据理论计算剩余能量、 节点间通信距离、通信能耗的权值, 并根据权值对每个节点的性能进行综合评价, 根据综合评价结果选择每个簇最合理的簇首; 最后与其他无线传感器网络路由算法进行对比测试. 测试结果表明, 相对于对比算法, 该算法数据时延均值和丢包率均大幅度减少, 改善了数据传输成功率, 使节点之间的能耗更均衡, 延长了无线传感器网络的生存周期, 建立的无线传感器网络路由可靠性更高.  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.
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   

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 discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
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   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

18.
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   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
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   

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