首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 63 毫秒
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.
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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   

16.
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.  相似文献   

17.
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.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号