一种基于无线传感器网络的分布式目标跟踪算法

将无线传感器网络与接收信号强度指示测距技术相结合,研究了移动目标的分布式跟踪算法。根据传感器节点与移动目标的相对位置,将节点动态组织成簇,簇头节点作为簇的数据处理中心,利用扩展卡尔曼滤波形成对移动目标位置的本地估计。随着目标的移动,本地估计在簇头节点间传递。仿真结果表明,基于无线传感器网络的分布式目标跟踪算法在精度、收敛性和实时性等方面达到很好的跟踪效果。     

改进LEACH的传感器网络分簇路由算法

针对当前无线传感器网络分簇路由算法存在的节点能耗不平均、 节点过早死亡等缺陷, 提出一种改进低功耗自适应分簇(LEACH)的无线传感器网络路由算法. 首先针对无线传感器节点过早死亡的问题, 引入簇半径动态确定方式, 将整个无线传感器网络划分为多个不均匀的簇; 然后考虑簇首能量消耗过快的问题, 结合簇首所在位置和节点剩余能量选择每轮中的簇首; 最后改进数据传输机制保证节点能量消耗均衡, 并在MATLAB 2014平台上对无线传感器网络分簇路由算法的性能进行测试. 测试结果表明, 改进LEACH算法较好地解决了节点过早死亡的难题, 延长了无线传感器网络的寿命, 平衡了各节点能量消耗, 整个无线传感器网络的性能显著优于其他对比算法.     

无线传感器网络自适应动态簇目标跟踪策略

考虑到无线传感器网络的特点及目标跟踪对实时性要求较高,提出一种基于动态簇的无线传感器网络目标跟踪策略.当目标出现时,基于节点管理机制采用层次分析法选举簇首,定义节点跟踪权值作为参与跟踪的依据,并建立动态簇.目标监视过程中,根据实际跟踪质量自适应调整动态簇规模;为了避免目标丢失,在自适应机制的基础上提出目标恢复机制.目标离开后,解散动态簇,释放节点资源.采用NS2对所提算法进行仿真测试,结果表明,基于动态簇的跟踪策略能够以较少的通信开销为代价获得很好的目标捕获率.     

基于虚拟力的无线传感器网络分簇部署策略

为提高大规模密集部署的无线传感器网络节点覆盖率,提出了一种基于虚拟力的节点分簇动态部署策略.将传统基于虚拟力的节点动态部署分成簇间部署与簇内部署两阶段,以达到打破网络中部节点受力平衡、降低部署过程中簇间干涉、提高节点覆盖率的目的.利用二元感知模型对算法进行仿真,结果表明,相比于传统VPF算法及VFA算法,该策略在随机部署大量密集节点的网络中具有较快的收敛速度与显著的优化效果,覆盖率最终可达90%以上,可以满足无线传感器网络的覆盖控制要求.     

一种新的无线传感器网络半动态分簇路由协议

在LEACH分簇算法的基础上,提出一种半动态无线传感器网络分簇路由算法。在半动态分簇算法中,新簇形成之后,不需要更换簇内节点信息而仅改变簇头信息,直至簇内节点死亡率超过30%,再重新进行新一轮簇的形成。仿真结果表明,这种分簇算法在很大程度上提高了整个无线传感器网络的寿命。     

基于负载均衡分簇的无线传感器网络目标跟踪算法

针对无线传感器网络目标跟踪算法节点负载不均衡的现状,结合非线性模型下目标跟踪的研究,提出一种基于负载均衡分簇的无线传感器网络目标跟踪算法.采用分簇时选出高能量簇首,簇间通信时通过辅助簇首多跳通信,在跟踪目标时使用分布式扩展卡尔曼滤波的方法.仿真结果表明:本文算法在多次分簇后有效减少了死亡节点数量降低了节点剩余能量差,与分布式卡尔曼滤波相比降低了跟踪误差.该算法均衡了无线传感器网络节点的负载并提高了非线性模型下目标跟踪的精度,在有限的资源下增加了目标跟踪算法的可靠性.     

无线传感器网络动态调度分簇算法

提出了一种基于K均值的无线传感器网络动态调度分簇算法(DSCA),不但考虑了能量感知这一重要问题,还针对无线传感网络的稳定性和可靠性,提出了节点的同步失效概念,通过采用K均值得到更加平衡的分簇,使得能量消耗更加平衡.该算法发展了一种基于信号接收强度指标(RSSI)而无需知道节点坐标的簇质心求解方法,提出了基于局部信息集中的动态多簇头选举机制和动态时分复用(TDMA)通信轮数分配机制,这些机制使无线传感网络的能量消耗达到了高度均衡,保证了节点的同步失效,提高了传感网络的稳定性和可靠性.仿真结果表明,算法可以减少约70%的簇重构次数.     

基于混沌小生境狼群算法的高密度无线传感器网络高能效分簇方法

无线传感器网络节点能量通常由能量有限的电池供应,如何在对节点进行分簇的同时减小通信能耗是研究中的一个重要问题。提出了一种基于混沌小生境狼群算法的高密度无线传感器网络能量高效分簇方法,通过智能选取簇头位置来降低无线传感器网络的单轮通信能耗。在不同节点数和簇头比例的条件下,分别采用了粒子群算法、量子遗传算法、模拟退火算法和混沌小生境狼群算法进行了无线传感器网络分簇。仿真结果表明,基于混沌小生境狼群算法的无线传感器网络分簇能够有效降低无线传感器网络的整体单轮通信能耗和平均节点通信能耗,有效提升了能量利用效率。     

射频供电异构传感器网络分簇路由算法

在大规模无线传感器网络中,针对无线传感器网络中LEACH分簇路由算法能量消耗不均衡,网络生命周期短等问题,提出了一种基于无线射频能量收集的LEACH异构分簇路由算法(LEACH-RFEH)。该算法根据网络中节点剩余能量和当前无线射频补给能量制定了异构无线传感器网络簇头选取机制,高级节点具有无线射频能量收集功能,具有较高的剩余能量和补给能量的节点有更多的机会当选簇头。仿真结果表明:该算法与传统LEACH算法、SEP算法相比,不仅能够均衡网络消耗,而且可以延长网络的工作时间,具有较好的扩展性。     

一种新的无线传感器网络非均匀分簇算法

为避免无线传感器网络的能量空洞问题, 延长无线传感器网络寿命, 提出一种新的基于双簇头的无线传感器网络非均匀分簇算法. 该算法综合考虑节点剩余能量和节点到基站的距离选举分簇簇头, 将无线传感器网络分为不同规模的簇; 为了减小规模较大簇的簇头节点收集与传输数据的负担, 在数据传输阶段构造基于改进最小二 叉树的数据传输路径. 实验结果表明, 该算法能够有效减小节点能量消耗, 可有效延长无线传感器网络的使用寿命.     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.