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1.
当前许多领域信息都采用表格形式展现,因此,如何从表格中抽取本体逐渐引起了人们的关注.为了提高从Web表格中抽取本体实例的准确性,提出了基于语义相似度的词汇语义类的获取方法.该方法采用了基于SVM的语义相似度计算方法,提高了判断语义相似度的准确性,克服了以前依靠句法相似度分析表格结构存在的局限性.最后,根据实验结果,对该方法的性能进行评估.实验结果显示,该方法可以有效地从Web表格中抽取本体实例.  相似文献   

2.
基于本体的受限领域问答系统研究   总被引:1,自引:1,他引:0  
鉴于使用本体表示知识利于知识的重用及推理,提出基于本体知识库的受限领域问答系统(QA)框架,该框架可以方便地根据本体知识库和问句语义表征抽取答案.定义了本体的结构,以某医疗领域的本体为例分析本体元素之间的抽象关系;描述问句语义分析的方法,给出答案抽取的相关技术;分析问句类型,给出对应的问句语义表征和答案抽取策略.以某医疗领域的问答系统为实验平台,封闭测试F值为83.86%,开放测试F值为76.04%,效果良好.  相似文献   

3.
从领域本体的结构和元素等层次,研究多粒度本体整合方法,开发出面向同一领域的本体整合工具系统.以两个电子类领域本体作为整合案例,分析OWL文件结构特征,抽取本体的主要信息以树型结构进行表示,通过元素层次和结构层次相结合的映射方法,同时采用相似度计算模型并借助本体词典Wordnet和基于统计学的方法,对领域本体进行整合操作,结果不仅实现了基于元素级层次的处理,而且实现了其语义层次上的分析.  相似文献   

4.
Web信息抽取与语义检索框架   总被引:1,自引:1,他引:0  
提出了一种Web信息抽取与语义检索框架,采用定制本体模型,针对Web网页特点设计了抽取与语义标引策略,并在检索过程中引入语义推理机制,从而改善了信息检索的效果.最后介绍了基于Jena实现的该框架的原型系统.  相似文献   

5.
针对Web网页中事物描述信息的特点,提出了一种通过本体指导网页信息抽取的方法。首先建立抽取对象的本体模型,并为本体属性概念添加定位信息映射模型,通过映射模型定位和分离样本页中包含语义信息的数据块,结合路径分析算法生成抽取规则,之后利用抽取规则对同类网页中的事物描述信息进行抽取,最后以资源描述框架(RDF)数据格式储存信息。抽取性能测试实验表明,抽取结果具有较高的准确率,与无规则抽取方法相比,具有更高的抽取效率。  相似文献   

6.
基于分类本体的Web信息集成机制,构建了一个Web信息集成系统的体系结构.根据网站组织结构,抽取网站分类体系,使用该体系进行了基于结构的页面信息分类.在网站分类本体的支持下,集成各信息源网站的分类体系,合并对应类别下的信息,得到集成分类体系下的集成视图,最终以基于portal的集成视图形式展示集成结果,为终端用户提供更为方便的服务和应用.  相似文献   

7.
由于HTML只描述数据怎样显示而不描述数据的内容,因此识别HTML表格并抽取其数据是Web信息抽取领域中重要的研究课题之一,针对现在包装器技术的不足提出了一种新的基于领域本体的HTML表格结构识别技术,为构造HTML表格信息抽取系统打下基础。  相似文献   

8.
为了弥补互联网信息爆炸带来的搜索引擎用户满意度低的问题,提出了一种基于本体的垂直搜索引擎模型。该模型构建一个本体知识树,利用增加了属性提取和相似度算法的NWeb-Crawler对网页进行抓取,并将非相关信息进行隔离;然后,进行网页源代码格式信息和语义信息两方面的抽取;抽取的数据信息通过分词后建立二维索引表,用户的请求通过本体知识树扩展概念集和二维索引表进行检索。该系统模型从入口网页到出口数据逐步贴近检索需求,具有良好的扩展性,对垂直搜索引擎的研究有一定的参考借鉴作用。  相似文献   

9.
现在银行等行业的大型软件拥有非常复杂的结构,并和其他系统有数据交换,这使得需要耗费大量的业务人员做客户端测试工作,业务人员习惯于自然语言描述问题,使得处理分类和抽取这些信息变得困难.本文提出基于语义和本体的自然语言抽取方法,提出软件测试领域规则,并将其组织成数据库、测试数据来自于笔者参与的某银行项目.  相似文献   

10.
基于本体的信息过滤需求模型构造   总被引:1,自引:0,他引:1  
在信息过滤系统中,由于缺乏语义模型作为支撑,基于关键词的用户需求模型难于准确地反映出用户的真实需求,成为影响过滤性能的主要瓶颈.提出了以本体构造用户需求模型的方法:采用领域相关度和领域一致度组合方法来确定查询关键词在特定领域的重要程度,建立查询关键词到本体概念的映射,然后利用本体的概念及属性构造用户需求模型.这种基于本体的用户需求模型构造方法能提高过滤系统性能.  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.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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   

14.
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   

15.
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-  相似文献   

16.
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-  相似文献   

17.
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  相似文献   

18.
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  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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