基于用户查询意图的搜索排序算法

目前互联网技术的研究热点是智能化的、个性化的服务,而传统的Web搜索排序算法和已有的个性化排序已经不能满足政府、企业等用户的信息查询需要.本文将研究核心定位到充分理解用户查询偏好上,提出了基于用户偏好的PageRank算法.文中利用用户互反馈技术修正查询关键词,利用语义相关性技术分析用户查询意图,理解用户偏好.改进的算法完善了搜索查询的可靠性依据,能够较好地挖掘用户的偏好主题,贴近用户的查询目的,提高搜索查询效率和用户满意度.     

基于差分进化算法的语义查询扩展技术

目的提高扩展词与用户查询在语义层面上的关联,解决歧义扩展问题。方法基于差分进化算法的语义查询扩展技术先利用领域本体提供的领域背景知识来获取候选扩展词集,然后通过分析用户日志来获取用户检索偏好信息,最后利用差分进化算法确定同用户检索意图最相符的扩展词集。结果比起前沿的局部上下文分析方法,基于差分进化算法的语义查询扩展技术能够确定更高质量的扩展词集。结论利用用户日志和本体中概念间的语义关系作为背景数据来过滤无关的扩展词可以有效提高后续语义扩展过程的效率,差分进化算法能够有效排除同用户检索意图无关的词集并确定高质量的扩展词集。     

基于自然语言查询的搜索引擎模型

阐述了目前网络上的搜索引擎主要是基于关键词索引查询技术而设计的,这种技术的搜索范围很大,但由于关键词难于表达丰富的概念和用户信息需求中的丰富语义,导致查准率很低。以语义W eb和基于语义的网络信息检索技术为理论根据,从克服目前信息组织和信息检索的矛盾出发,用XML/RDF作为语义描述、组织、存储、查询的工具,试图在未来搜索引擎发展方面做一些尝试性的研究,提出了一个基于自然语言查询的搜索引擎模型。     

一种基于语义词典的局部查询扩展方法

针对基于关键词匹配的搜索引擎存在的问题,提出一种基于语义词典的局部查询扩展方法,首先利用共现分析法和语义相似度选取扩展词,再对原始查询词和扩展词加权,最后计算文档相似度从而获得排序后的扩展查询结果.该方法克服了其它局部扩展方法将大量无关词加入查询的问题.实验表明,该方法有效地提高了查询结果的查准率.     

混合分层抽样统计与贝叶斯个性化排序的旅游景点推荐模型研究

传统协同过滤推荐模型仅处理稀疏的评分数据,未深入挖掘用户及对象的潜在语义,且用户喜好信息也未充分利用.围绕旅游景点推荐这一热点问题,提出全新的混合分层抽样统计与贝叶斯个性化排序的推荐模型：采用分层抽样统计及主观赋值评价法刻画用户旅游喜好;基于矩阵分解算法(Matrix Factorization,简称MF)分析用户及对象(景点)的潜在语义,运用贝叶斯个性化排序算法(Bayesian Personalized Ranking,简称BPR)对推荐模型进行优化;综合用户旅游喜好信息及BPR优化结果,生成混合推荐列表.在新的“Wisdom Tourism”数据集上进行仿真实验.实验表明：推荐模型的RMSE、MAE、F1值较最强基线分别提升16.59%、10.05%、5.04%;相比于分层抽样统计方法,BPR算法在推荐过程中发挥更显著的作用.     

基于Term-Query-URL异构信息网络的查询推荐

查询推荐是一种帮助搜索引擎更好的理解用户检索需求的方法.基于查询的上下文片段训练词汇和查询之间的语义关系,同时结合查询和URL的点击图以及查询中的序列行为构建Term-Query-URL异构信息网络,采用重启动随机游走(Random Walk with Restart,RWR)进行查询推荐.综合利用语义信息和日志信息,提高了稀疏查询的推荐效果.基于概率语言模型构造查询的词汇向量,可以为新的查询进行查询推荐.在大规模商业搜索引擎查询日志上的实验表明本文方法相比传统的查询推荐方法性能提升约为3%~10%.     

元搜索引擎的个性化

提出一种通过产生用户动态偏好来达到个性化搜索的方法．利用RDF的语义表达能力存储和优化基于访问记录的用户偏好,并采用聚类方法划分用户群,实现对用户偏好的有效管理。给出了元搜索引擎选择算法和搜索结果排序算法,实现了一个个性化的元搜索引擎,实验表明,该搜索引擎提高了查询准确率和使用效率,并能够根据用户及其所在群的历史偏好信息重新组织搜索结果．     

基于用户特征和评分的精准推荐策略研究

个性化推荐系统是帮助用户发现内容,克服信息过载的重要工具.为了提高推荐算法的准确率和效率,综合协同过滤推荐算法和K-means聚类算法,设计了一种基于用户特征和评分的精准推荐策略.该策略一方面针对新用户冷启动问题,引入K-means聚类算法对全体用户特征进行聚类,将新用户所属类中其他用户喜好的物品中的Top N个推荐给...     

基于用户意图的搜索结果文本突显方法

信息检索效率在很大程度上取决于用户看到的搜索引擎结果页面所提供的内容.目前,红色突显查询词是商业搜索引擎结果页面主要采用的文本展示方式,但由于查询词可能表达模糊或者包含噪音,与用户的查询意图往往不能完全一致.为了能够充分地反映用户的查询意图,同时突显对于满足用户查询意图最重要的词语,基于人工标注的结果提出一种新的关键词突显策略;综合结构化支持向量机、隐马尔科夫、最大间隔马尔科夫网络及条件随机场4种基础的序列标注机器学习模型,进一步提出一种新的联合序列学习模型并进行用户搜索实验.实验结果表明:该种模型优于4种基础模型,与人工标注的结果相比取得了93.30%的准确率;所提出的关键词突显策略明显优于传统的查询词突显策略,提高了用户的满意度及搜索效益.     

云计算环境下可视化探索式搜索引擎的研究

针对目前搜索引擎返回的信息量过大且缺乏语义关联等问题,提出了一种云计算环境下的可视化探索式搜索引擎模型.该模型通过对元搜索引擎返回的原始信息在云计算环境下语义相似度的计算和语义链的构建,采用探索式搜索方法为用户获取个性化的结果.与传统搜索引擎相比,其结果更加直观地表现了目标信息及其之间丰富的语义关系,该方法使用户能够更为自然而有效地在海量的信息中发现更符合其需求的目标.作为实验模型,还需要更多的元搜索引擎的支持,以及进一步计算优化语义相似度的算法,才能使该模型真正实用化.本研究为云计算环境下构建新一代个性化智能搜索引擎提供了理论和实践上的参考.     

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