一种面向传感器网络的蚁群优化路径恢复算法

为了找到动态传感器网络中的能量有效路径,提出了一种基于蚁群优化的传感器网络路径恢复算法.设计了一种新的路径选择概率模型,使得能够找到一条从源节点到sink的能量有效路径,该路径兼顾了路径能量消耗和节点剩余能量情况.为了适应网络动态变化,提出了局部信息素再初始化规则,利用该规则可在网络失效节点的附近进行局部信息素再初始化,在保留大部分原有最优路径的信息的同时,还能进行局部搜寻,以寻找新的路径,从而达到快速路径恢复的目的.仿真实验表明,所提算法在寻找路径上所消耗的能量最少,节点的剩余能量最大,在网络存在失效节点的情况下能够快速恢复路径.     

传感器网络汇聚数据包路由协议

针对移动目标跟踪应用对传感器网络路由协议的性能要求,提出了一种汇聚数据包路由协议,用于由目标区域到sink节点的汇聚数据包路由.协议采取基于sink节点的贪婪转发策略,通过减少通信跳数,减少了数据包从目标节点到sink节点的端到端传输时延;协议以节点能量和距离的综合函数作为转发代价,使其具有较高的能量效率;只要求节点维护自身状态信息,具有较好的可扩展性.仿真实验表明,协议能够满足目标跟踪应用对传感器网络路由协议的性能要求.     

一种基于遗传算法的无线传感器网络路由算法

针对传感器节点在能量储备、计算能力、通信能力方面制约性强等问题,采用进化算法理论,提出一种适用于无线传感器网络的移动Agent路由选择算法.该算法能为移动Agent探测具有最小能耗的路径,同时保证信息收集的完整性.实验结果表明,该算法自适应性强,可减少传感器节点的能量消耗,满足无线传感器网络在实际应用中对移动Agent路由算法的需求.     

基于节点移动和监控质量感知的WSN覆盖方案

针对现有无线传感器网络(WSN)空洞覆盖方案没有考虑监控质量(MQ)的差异性问题,提出一种基于节点移动和监控质量感知的WSN覆盖方案.首先,将网络构建成六边形网格结构.然后,移动传感器根据邻居单元的监控情况进行移动,并根据单元的MQ需求和节点能量适当调整移动路线,同时避免覆盖冗余.最后,形成能够实现WSN全时间和空间覆盖的支持路径.实验结果表明,该方案能够均衡节点能耗,最大化网络的完整覆盖时间,提高网络的生命周期.     

一种新的移动传感器网络部署及管理机制

在移动传感器网络中,传统的基于虚拟力的部署方法通常采用牛顿运动定律计算节点的位置移动.该方法能够实现移动传感器网络的自动部署,但也将简谐振动带入到网络中,使一些节点在达到平衡位置后无法立即停止,从而消耗了传感器大量能量.通过重新定义应用于移动传感器网络中的运动定律,提出了Force-based算法,使节点的运动只与受力相关,较好地解决了该问题.模拟实验表明,该部署方法可以较好地完成节点的自动部署,扩大了覆盖率,降低了能量消耗.     

介入移动汇聚节点的无线传感器网络高效数据收集方法

引入移动汇聚节点解决无线传感器网络高效数据收集问题.网络中固定汇聚节点与移动汇聚节点共存,全部传感器节点都拥有维护到固定汇聚节点的路由,移动汇聚节点进入网络后定期向其附近小范围内的传感器节点扩散自己的声明信息,传感器节点向距自己跳数最小的汇聚节点发送或转发数据包.移动汇聚节点和距离其一跳的传感器节点之间通过有效的应答机制来保证数据的可靠传输.通过仿真结果显示引入移动汇聚节点的数据收集在节省能耗方面明显优于传统网络.在延长网络生存时间的同时,可以获得较高的数据传输成功率和较短的数据传输延迟.     

最大化全移动无线传感器网络寿命的可信信息覆盖重定位算法

针对全移动传感器网络覆盖空洞的修复以及网络寿命最大化问题,研究并设计了一种基于可信信息覆盖模型的传感器节点重定位协议。该协议在可信信息覆盖模型下的信息网格的概念下,设计一种局部信息网格结构,通过使用移动最近的冗余传感器节点修复覆盖空洞区域来维持网络的完全覆盖。仿真结果表明,所设计的协议与现有的协议传感器节点重定位协议相比,可以有效减少重定位的移动能量消耗,明显提升全移动传感器网络的工作寿命。     

最大化网络有效寿命的传感器网络覆盖保持协议

为了保证监测区域覆盖质量,同时延长无线传感器网络有效寿命,构建了一种不需要地理位置信息的异构传感器网络冗余节点决策模型,由此提出了一种最大化网络有效寿命的异构传感器网络覆盖保持协议--ULMPCC.根据节点剩余能量状况,关闭剩余能量相对较少的所有冗余节点,保留最少的工作节点,从而实现了分布式协作节点调度.基于剩余能量的选举策略有效地平衡网络中的能量消耗,最大化了网络的有效寿命.仿真实验表明,UMLPCC能调度最少的工作节点,保证应用要求的覆盖质量,当期望的覆盖质量大于90%时,获得的覆盖质量与期望的覆盖质量的误差小于1%.     

面向移动传感器网络的自适应一致性融合估计方法

研究了具有时延和通信拓扑变换的移动传感器网络（MSN）分布式融合估计问题.结合无色信息滤波、自适应一致性算法并考虑通信时延而设计的基于自适应一致性的融合结构,提出了一种名为基于自适应一致性的分布式无色信息滤波（AC_DUIF）的分布式融合估计算法.以空中移动传感器网络跟踪移动目标为例,通过仿真验证了所提算法的性能.仿真结果表明,该方法能够在以分布形式提高网络中各节点对目标位置估计精度的同时,保证节点之间的一致性,并具备对网络通信延时的适应能力.     

基于位置感知的无线传感器网络聚类算法

针对以能量有效的方式收集传感器网络空间相关性数据的问题,本文提出了一种新的基于位置感知的无线传感器网络聚类算法.算法根据用户查询误差门限和基于位置信息的节点感知数据相异度矩阵,进行无监督数据挖掘,将监测区域划分成信息等价域.每个等价域选取域内当前剩余能量最大的节点作为簇头,网络通过移动代理收集簇头感知信息,从而减少了传输数据量,有效节省了网络能量.     

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.     

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.     

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.     

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.     

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the