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 31 毫秒
1.
The video databases have become popular in various areas due to the recent advances in technology. Video archive systems need user-friendly interfaces to retrieve video frames. In this paper, a user interface based on natural language processing (NLP) to a video database system is described. The video database is based on a content-based spatio-temporal video data model. The data model is focused on the semantic content which includes objects, activities, and spatial properties of objects. Spatio-temporal relationships between video objects and also trajectories of moving objects can be queried with this data model. In this video database system, a natural language interface enables flexible querying. The queries, which are given as English sentences, are parsed using link parser. The semantic representations of the queries are extracted from their syntactic structures using information extraction techniques. The extracted semantic representations are used to call the related parts of the underlying video database system to return the results of the queries. Not only exact matches but similar objects and activities are also returned from the database with the help of the conceptual ontology module. This module is implemented using a distance-based method of semantic similarity search on the semantic domain-independent ontology, WordNet.  相似文献   

2.
面向语言信息处理的朝鲜语知识库研究   总被引:1,自引:3,他引:1  
在自然语言处理系统(包括机器翻译系统) 中,语法、语义信息词典是必不可少的构件。本文以国内外语义工程研究成果为基础,通过对朝鲜语谓词进行句法语义一体化描述,建立面向信息处理的朝鲜语知识库。该研究的语言学理论根据是论元结构理论和语义场理论。我们首先对谓词进行语义分类,然后再对谓词义项作详细的属性描述。在知识库构建上,采用结构体方式将谓词的句法、语义等属性整合在一起。  相似文献   

3.
RNA二级结构预测问题是生物信息学的一个研究重点。该文主要利用自然语言理解中旬法分析的方法来研究RNA二级结构预测。使用基于角色反演算法建立起来的,采用概率上下文无关文法进行分析的句法分析器,来预测RNA二级结构。结合传统Chart算法分析器和广义LR算法分析器的优点,建立角色反演句法分析器;根据RNA二级结构的构建方法建立相应的概率上下文无关文法;给出对RNA二级结构进行预测的具体实例。  相似文献   

4.
组合原则表明句子的语义由其构成成分的语义按照一定规则组合而成,由此基于句法结构的语义组合计算一直是一个重要的探索方向,其中采用树结构的组合计算方法最具有代表性。但是该方法难以应用于大规模数据处理,主要问题是其语义组合的顺序依赖于具体树的结构,无法实现并行处理。该文提出一种基于图的依存句法分析和语义组合计算的联合框架,并借助复述识别任务训练语义组合模型和句法分析模型。一方面,图模型可以在训练和预测阶段采用并行处理,极大地缩短计算时间;另一方面,联合句法分析的语义组合框架不必依赖外部句法分析器,同时两个任务的联合学习可使语义表示同时学习句法结构和语义的上下文信息。我们在公开汉语复述识别数据集LCQMC上进行评测,实验结果显示准确率接近树结构组合方法,达到79.54%,预测速度最高可提升30倍以上。  相似文献   

5.
Natural language and databases are core components of information systems. They are related to each other because they share the same purpose: the conceptualization aspects of the real world in order to deal with them in some way. Natural language processing (NLP) techniques may substantially enhance most phases of the information system lifecycle, starting with requirements analysis, specification and validation, and going up to conflict resolution, result processing and presentation. Furthermore, natural language based query languages and user interfaces facilitate the access to information for anyone and allow for new paradigms in the usage of computerized services. This paper investigates the use of NLP techniques in the design phase of information systems. Then, it reports on data base querying and information retrieval enhanced with NLP.  相似文献   

6.
回指研究一直是语言学研究的一个热点,回指解析则是文本信息处理中亟待解决的问题之一。传统语言学从句法、语用、篇章、认知角度出发对汉语零形回指进行了广泛的研究。在自然语言处理领域,针对汉语零形回指也有一些颇有影响的研究,如基于向心理论的零形回指解析算法,基于HNC理论的零形回指处理方法,以及基于DRT理论和语义分析等方法提出的汉语零形回指解析方法。该文从语言学角度对这些理论研究进行介绍,旨在指出语言信息工作者在注重工程实践的同时,应关注并借鉴语言学基础理论研究的成果,而从事中文信息处理的语言学家也应加强语言形式化的研究。  相似文献   

7.
Wermter  S. Weber  V. 《Computer》1996,29(7):65-74
Our SCREEN (Symbolic Connectionist Robust Enterprise for Natural Language) system analyzes real-world utterances and can be used for relatively large and complex tasks. SCREEN learns a robust flat syntax, semantics, and pragmatics representation. The system also deals with uncommon syntactic and semantic language irregularities. The system is able to produce many utterance hypotheses based on spoken input and can determine which hypotheses are most likely. SCREEN's ability to analyze spoken language, despite encountering mistakes and uncertainties, demonstrates the system's robustness and potential. Because SCREEN is a German spoken-language system, the example of spoken language that we analyze is in German. We provide a literal and, where appropriate, a more easily understood English translation of any German words and sentences that we use  相似文献   

8.
Hyperlog is a declarative, graph based language that supports database querying and update. It visualizes schema information, data, and query output as sets of nested graphs, which can be stored, browsed, and queried in a uniform way. Thus, the user need only be familiar with a very small set of syntactic constructs. Hyperlog queries consist of a set of graphs that are matched against the database. Database updates are supported by means of programs consisting of a set of rules. The paper discusses the formulation, evaluation, expressiveness, and optimization of Hyperlog queries and programs. We also describe a prototype implementation of the language and we compare and contrast our approach with work in a number of related areas, including visual database languages, graph based data models, database update languages, and production rule systems  相似文献   

9.
对于语言表达式的组成成分及它们间的关系的刻画,目前大多数语法研究都着重在句法层面,而本文的范畴表达式演算理论则着重在语义层面。我们首先考察了完全表达式与不完全表达式、句法类型与语义类型、继承、顺序、提取、并列等若干重要的语言现象以及各种语法理论对这些现象的解释,然后提出范畴表达式的形式化定义,分析了句法层面的形式约束对语义层面的内容组织的制导作用,并且用典型的语言例子直观的说明了如何利用短语结构制导,进行范畴表达式的演算。这种机制可形式化、可验证,能很好的捕捉语言的组成成分及它们间的相互关系,揭示一个句子所说的内容。  相似文献   

10.
Minority languages must endeavour to keep up with and avail of language technology advances if they are to prosper in the modern world. Finite state technology is mature, stable and robust. It is scalable and has been applied successfully in many areas of linguistic processing, notably in phonology, morphology and syntax. In this paper, the design, implementation and evaluation of a morphological analyser and generator for Irish using finite state transducers is described. In order to produce a high-quality linguistic resource for NLP applications, a complete set of inflectional morphological rules for Irish is handcrafted, as is the initial test lexicon. The lexicon is then further populated semi-automatically using both electronic and printed lexical resources. Currently we achieve coverage of 89% on unrestricted text. Finally we discuss a number of methodological issues in the design of NLP resources for minority languages.  相似文献   

11.
The design issues encountered during the development of a natural language processor (NLP) for the Italian language are described. The focus is on strategic aspects, namely representation and control, and their implementation with first-order logic. The complexity and the size of the knowledge domain (press agency releases on finance and economics) do not present severe restrictions in the sentence structure; hence a considerable design effort for data structures and control algorithms was required. Logic proved to be an important tool for implementing in a modular and efficient way the knowledge sources along with the programs that derive the morphologic, syntactic, and semantic features of sentences. As for the data structures, we found a considerable advantage in separating linguistic knowledge in three sources: morphologic, syntactic, and semantic. This resulted in a clear and systematic representation scheme and reduced the complexity of the parsing system.  相似文献   

12.
Evidence-based medicine (EBM) requires medical practitioners to select appropriate treatments for individual patients based on the current best evidence, and the results of phase III clinical trials are the major source of such evidence. In this paper, we report results of experiment in extracting important information for EBM from the abstracts of phase III clinical trials, in an effort to investigate how far the existing natural language processing (NLP) techniques could support EBM using MEDLINE database.  相似文献   

13.
14.
Natural language processing (NLP) is a vibrant field of interdisciplinary Computer Science research. Ultimately, NLP seeks to build intelligence into software so that software will be able to process a natural language as skillfully and artfully as humans. Prolog, a general purpose logic programming language, has been used extensively to develop NLP applications or components thereof. This report is concerned with introducing the interested reader to the broad field of NLP with respect to NLP applications that are built in Prolog or from Prolog components.  相似文献   

15.
This paper investigates some methods for proving the equivalence of different language specifications that are given in terms of attribute grammars. Different specifications of the same language may be used for different purposes, such as language definition, program verification, or language implementation. The concept of syntactic coverings is extended to the semantic part of attribute grammars. Given two attribute grammars, the paper discusses several propositions that give sufficient conditions for one attribute grammar to be semantically covered by the other one. These tools are used for a comparison of two attribute grammars that specify syntax and semantics of mixed-type expressions. This example shows a trade-off between the complexity of syntactic and semantic specifications. Another example discussed is the equivalence of different attribute grammars for the translation of the while-statement, as used in compilers for top-down and bottom-up syntax analysis.This work was in part supported by the National Research Council of Canada.  相似文献   

16.
龚龙超  郭军军  余正涛 《计算机应用》2022,42(11):3386-3394
当前性能最优的机器翻译模型之一Transformer基于标准的端到端结构,仅依赖于平行句对,默认模型能够自动学习语料中的知识;但这种建模方式缺乏显式的引导,不能有效挖掘深层语言知识,特别是在语料规模和质量受限的低资源环境下,句子解码缺乏先验约束,从而造成译文质量下降。为了缓解上述问题,提出了基于源语言句法增强解码的神经机器翻译(SSED)方法,显式地引入源语句句法信息指导解码。所提方法首先利用源语句句法信息构造句法感知的遮挡机制,引导编码自注意力生成一个额外的句法相关表征;然后将句法相关表征作为原句表征的补充,通过注意力机制融入解码,共同指导目标语言的生成,实现对模型的先验句法增强。在多个IWSLT及WMT标准机器翻译评测任务测试集上的实验结果显示,与Transformer基线模型相比,所提方法的BLEU值提高了0.84~3.41,达到了句法相关研究的最先进水平。句法信息与自注意力机制融合是有效的,利用源语言句法可指导神经机器翻译系统的解码过程,显著提高译文质量。  相似文献   

17.
Based on the approach implementing a deductive object-oriented database system through the underlying relational database,this paper presents and object reasoning language O-Datalog,which is the extension of Datalog in form and can deal with object-oriented data.For any O-Datalog program,an dquivalent Datalog program can be built to help evaluate the original program.This paper focuses on the syntax,semantics and evaluation of O-Datalog.  相似文献   

18.
In order to specify databases completely at the conceptual level, conceptual database specification languages should contain a data definition (sub)language (DDL), for specifying data structures (+constraints), a data retrieval (sub)language (DRL), for specifying queries, as well as a (declarative) data manipulation (sub)language (DML), for specifying transactions.Object Role Modeling (ORM) is a powerful method for designing and querying database models at the conceptual level. By means of verbalization the application is also described in natural language as used by domain experts, for communication and validation purposes. ORM currently comprises a DDL and a DRL (ConQuer). However, the ORM-method does not yet contain an expressive DML for specifying transactions at the conceptual level.In an earlier paper we designed a syntactic extension of the ORM-method with a DML for specifying transactions at the conceptual level in a purely declarative way. For all transactions we proposed syntaxes, verbalizations, and diagrams. However, we did not give a formal semantics then.The purpose of this paper is to add a clear, formal and purely declarative semantics to the proposed ORM-transactions. The paper also formally defines rollbacks and illustrates everything with examples (including a solution to a well-known transaction specification problem). The extension of ORM with an expressive set of completely declaratively specified transactions makes ORM complete as a database specification method at the conceptual level.  相似文献   

19.
We describe a method of syntax extension for programming languages which involves using an augmented BNF notation to add new syntactic constructs to the language, and where the meaning of the constructs is usually given by ordinary user subroutines to be executed at run time. This requires fewer special constructs in the language, and also makes it simpler to specify the extensions because the programmer does not have to worry about compile time vs. run time distinctions. The extended BNF may also be used to give specialized syntax to particular data structures.This research was supported under NSF Grant GJ 34342X.  相似文献   

20.
一个完全的自然语言数据库的存取通常需要既支持查询,也需要支持更新。近几年来,在支持自然语言数据库查询问题的研究上虽然已做了很多工作,但在支持自然语言数据库更新问题的研究上所做的工作却甚少。本文介绍了一种支持自然语言数据库更新的现实世界模型,其目的是设计一个易于移植到不同数据库以及不同DBMS上的系统。  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