WLAN与3G网络融合的接入选择算法研究

3G？WLAN混合组网不但能大幅降低运营商的网络建设和运营成本,还能有效解决数据业务热点区域3G网络的容量与需求之间的矛盾。融合网络中用户接入网络的不均衡性是影响网络性能的重要因素,针对融合网络的负载均衡问题,提出了一种基于博弈论的融合网络接入选择算法。文中给出一种面向群体用户的网络接入选择实现机制,该机制根据用户在网络中获得的效用函数,引入非协作博弈论方法建立网络效用模型,并证明该非协作博弈满足势博弈条件。仿真结果比较了网络融合环境下的各群体接入网络在非协作博弈模式中的收益特性,模拟了用户网络接入选择过程。     

基于组合权重和多属性决策的异构网络接入算法

为提高异构网络的接入性能,提升用户体验,文章提出了一种基于组合权重和多属性决策的异构网络接入算法,该算法可以根据用户业务特性的不同,使用熵权法和模糊层次分析法（FAHP）分别计算网络属性的主观权重和客观权重,然后根据组合权重,使用VIKOR计算网络的最后分值,将网络排序,进行了异构无线网络的接入。最后进行了所提算法与其他3种算法（Entropy-FAHP-SAW、Entropy-FAHP-MEW、Entropy-FAHP-TOPSIS）的对比仿真实验,结果表明,算法在保障业务用户Qos的基础上,降低了网络的切换次数、切换失败,减少了乒乓效应,提高了接入判决的服务质量。     

一种多粒子群切换决策机制

提出了一种切换决策机制,支持总最佳连接ABC(always best connected).该机制综合考虑接入网络状况、应用需求、用户对接入网络编码制式偏好、用户对接入网络供应商偏好、终端当前运动速率和终端当前剩余电量等因素,通过博弈分析,基于含最优变异的多粒子群优化算法,寻找把N个终端分配到M个接入网络的最佳切换决策方案,使用户和网络提供方效用达到或接近Nash均衡下的Pareto最优.仿真结果表明,该机制是可行和有效的.     

基于用户需求的数字图书馆个性化信息服务研究

分析了网络环境下用户信息需求的特点以及数字图书馆个性化信息服务的类型,结合当前我国数字图书馆开展的个性化信息服务实例,提出＂以用户为中心＂的服务理念,探讨了提高我国数字图书馆个性化服务水平的策略。     

基于抽取规则和本体映射的语义搜索算法

针对目前语义搜索过程中存在效率低、 用户推荐误差大等问题, 提出一种基于抽取规则和本体映射的语义搜索算法. 首先根据用户语义搜索要求抽取语义中的元素和属性, 解决数据利用率低的缺陷; 然后建立语义模型, 构建本体之间的元素及属性之间的映射, 消除用户需求和计算机之间的语义偏差; 最后将语义搜索算法应用于用户个性化推荐系统. 实验结果表明, 该语义搜索算法有效提高了搜索效率, 降低了用户个性化推荐误差.     

浅谈基于用户心理需求的个性化信息服务

当前,随着社会经济的发展、科学技术和计算机网络的普及,社会信息资源的增长呈现爆炸性的趋势。同时,信息数量的急剧增长和分布的无序,也给用户日益增长的个性化信息需求带来了严峻挑战。传统模式下的信息服务难以满足不同用户的特定需求,于是个性化信息服务就应运而生了。个性化信息服务能够满足不同用户不同层次的信息需求,为用户提供有针对性的信息服务。在个性化信息服务的基础上,加入用户心理需求的研究,对用户的信息需求加以培养,可以进一步提高信息服务的效率,使信息服务更加具有科学性和针对性。     

快速接入无线局域网解决方案

为顺应人们快速接入网络的要求,根据无线网络的工作原理以及用户对网络性能的要求,制定了采用CISCO设备实现快速接入无线局域网的一个解决方案,以此来达到移动的、稳定的、高速的、安全的接入网络.实验表明,此解决方案基本上可以满足当前的办公及家庭娱乐需求.     

中继网络中基于能量效率的动态用户接入算法

为了解决中继网络中基于能量效率的用户接入问题,将用户数据需求严格受限下基于能量效率最优的动态用户接入问题建模为一个整数优化问题,该问题类似于一个NP-hard的多维背包问题.首先,采用穷搜法分析了该问题最优解的复杂度.然后,提出了一种低复杂度、高效的基于能量效率的动态用户接入算法(UAEEM).该算法在保证用户数据需求严格受限的前提下,按照系统射频端和电路端的能量效率最大原则,动态调整用户归属和中继的工作状态,以实现网络能量效率最大化.最后,通过仿真实验验证所提算法性能.结果表明,UAEEM算法能显著提高系统的能量效率、降低系统的计算复杂度,且其性能接近最优解.     

在线学习平台资源画像的模型构建研究

随着在线学习平台的不断应用,大量的数字化资源数据被积累。如何利用资源背后的大数据,为教学资源建设和在线学习者学习提供优化服务,已经成为新的研究热点。本文通过对在线平台数据资源的基本属性和行为属性以及在线用户的行为属性等数据信息进行深层次挖掘,提出了一套资源画像和用户画像构建方法,并在两种画像之间建立关联,从而为教学资源建设和在线用户个性化学习提供数据支持,为在线用户推荐个性化学习资源提供数据基础。     

ABPAC:一种基于属性的起源访问控制模型

在复杂多变的网络环境下,起源数据的规模、复杂度、敏感度逐渐提升,对起源数据的访问控制比传统数据的访问控制更加复杂.为了防止细粒度的起源数据遭受未授权用户的非法访问,结合W3C标准下起源核心数据模型PROV-DM中定义的起源基本属性,提出了一种基于属性的起源访问控制模型ABPAC和ABPAC模型的属性描述模型.从六个方面对ABPAC模型进行形式化描述,划分了用户属性,并通过起源属性匹配方法实现了用户灵活、准确地对起源数据进行访问,最后给出了模型的实现流程.分析表明,该模型能够较好的满足对细粒度起源数据的访问需求.     

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.     

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.     

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