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1.
1.概述作为一个高效、鲁棒的自然语言查询接口系统(NLIDB),在进行了自然语言查询的分析之后,要有及时的反馈功能帮助用户理解系统的处理结果,避免用户对结果理解的偏差。具体来说,NLIDB的反馈功能,包括两个层次的含义:一是中间结果的反馈,即把系统对自然语言处理的中间结果(可以认为是系统对语言的一种理解)以某种用户可以接受的形式反馈给用户,常见的形式是把中间结果重新转换为自然语言,即转述(paraphrasi-ng);另一种是查询结果的反馈,即对查询结果作出明确的分析和解释,帮助用户理解系统的处理结果,我们称这一部分为结果语义分析。 NChiql在将自然语言查询转化为数据库查询语言之前,提供一套交互机制来确保系统对自然语言查询的理解和用户真正查询要求一致是极为必要的。 NChiql系统的自然语言理解过程可分为两阶段,即首先将自然语言转化为无歧义的中间形式——语义依存树,然后再将语义依存树转换成为SQL语句。  相似文献   

2.
战场态势时空数据引擎是基于时空数据库技术实现的,面向战场时空数据查询的战场态势辅助分析系统.针对时空数据库查询语言的复杂性,设计了战场态势时空数据引擎的中文查询系统,研究了中文查询任务到时空查询语句的映射过程,设计了时空查询词库,研究了分词算法,查询文法以及STQL生成方法.通过原型系统验证了中文查询技术的可行性,提高了时空数据库查询的可用性和易用性.  相似文献   

3.
基于递归式最大匹配法的数据库查询接口的实现   总被引:1,自引:0,他引:1  
针对中史自然语言应用在数据库查询这一特殊领域,提出了比较适用于数据库查询的递归式最大匹配法,它是最大匹配法的改进算法。在该算法的基础上,实现了一个中文自然语言数据库查询的接口,该接口允许用户随意输入中文自然语言,把用户的输入语句处理后生成存放中间结果的多又树,然后根据多又树生成SQL语句,进行数据库查询。  相似文献   

4.
使数据库自然语言接口(NLIDB)能够处理灵活多变的查询语句,增强NLIDB的可用性,是NLIDB研究的一个重要目标.设计并实现了一种数据库汉语查询接口.该查询接口采用语义依存树作为查询语句向SQL转化的中问语言,在构建了基于Nivre算法的语义依存树生成模型的基础上,提出了解决数据库语义歧义问题的方法以及一种新的将语义依存树划分为集合块的划分策略及其向SQL语句的转化方法.实验表明,该系统能够有效地处理各种形式的查询问句,具有良好的可用性.  相似文献   

5.
数据库汉语查询系统中隐含知识查询的研究   总被引:2,自引:0,他引:2  
该文讨论了目前现有数据库汉语查询系统中的存在问题,根据关系数据库中数据表示与自然语言(汉语)查询句的语义模型不同,提出了数据库汉语查询时隐含知识的查询,对数据库中的隐含知识以概念图来表示,从而建立了自然语言和数据库查询命令SQL语言的直接联系。实现了这种数据库隐含知识查询的实验系统,从一定程度上提高了数据库汉语查询的智能性。  相似文献   

6.
数据库自然语言查询接口可以使用户直接以日常生活中使用的自然语言提出查询请求,获取数据库中的信息。这是一个具有重要理论价值和巨大实用价值的研究领域。本文在总结数据库汉语查询的语言规律基础上,重点介绍了我们设计实现的一个数据库汉语查询接口系统WTCDIS,最后给出了对该系统进行初步测试的结果。  相似文献   

7.
基于面向对象的受限自然语言查询系统的设计与实现   总被引:3,自引:0,他引:3  
该文针对当前研究的热点问题--界面层自然语言理解的应用,设计了一个基于面向对象设计方法的受限自然语言数据库查询系统。该系统允许用户输入比较随意的中文查询命令,把用户的输入转换成标准的SQL语句,在事先规定的数据库中完成用户所要求的查询,并对中文分词的歧义处理,提出了一种新的分词算法IFM算法,有效地解决了交叉型歧义切分问题。  相似文献   

8.
数据库自然语言查询系统Nchiql中语义依存树向SQL的转换   总被引:4,自引:0,他引:4  
本文介绍了关系数据库受限自然语言查询系统NChiql中语义依存树向SQL的转换算法。文章首先介绍了集合块的概念、划分方法以及集合块向SQL的转换算法,然后再给出最大集合块的再次划分方法,最后形成完整的转化算法。  相似文献   

9.
数据库NL界面上汉语查询的EAAD模型   总被引:6,自引:0,他引:6  
张亚南  徐洁磐 《计算机学报》1993,16(12):881-888
本文给出一种旨在描述数据库NL界面上汉语查询的语法,语义结构的EAAD模型。通过该模型,数据库自然语言界面上的查询分析与理解,可以与其相应的背景知识 机地结合起来,EAAD模型适合于描述任意构形上的ER模型或与其相应的关系模型上的汉语查询,尤其是描述涉及多实体,多路径的查询的结构规律,有利于增强数据库NL界面的理解力和可移植性。  相似文献   

10.
在自然语言处理的研究中,最有希望的应用领域之一是自然语言接口。计算机对自然语言中的查询语言理解的正确程度是自然语言接口质量好坏的关键。通过对汉语查询句——即用于数据库自然语言查询的祈使句和特指问句、是非问句、正反问句、选择问句等共五类句型的研究,建立并研究了复合概念、逻辑概念与标准概念的内在联系,将查询目标概念分解为直接查询目标、逻辑推理目标和比较判断目标三个阶段,研究了这三个阶段的关系。  相似文献   

11.
In this paper a novel word-segmentation algorithm is presented to delimit words in CHinese natural language queries in NChiql system,a Chinese natural language query interface to databases.Although there are sizalbe literatures on Chinese segmentation.,they cannot satisfy particular requirements in this system,The novel word-segmentation algorithm is based on the database semantics,namely Semantic Conceptual Model(SCM) for specific domain Knowledge,Based namely Semantic COnceptual Model(SCM) for specific domain knowledge,Based on SCM,the segmenter labels the database semantics to words directly,which eases the disambiguation and translation(from natural language to database query)in NChiql.  相似文献   

12.
赵猛  陈珂  寿黎但  伍赛  陈刚 《软件学报》2022,33(12):4727-4745
自然语言查询转SQL (NL2SQL)是指将自然语言表达的查询文本自动转化成数据库系统可以理解并执行的结构化查询语言SQL表达式的技术.NL2SQL可以为普通用户提供数据库查询访问的自然交互界面,从而实现基于数据库的自然问答.复杂查询的NL2SQL是当前数据库学术界的研究热点,主流方法采用序列到序列(Seq2seq)的编解码方式对问题进行建模.然而,已有的工作大多基于英文场景,面向中文领域实际应用时,中文特殊的口语化表达导致复杂查询转化困难;此外,现有工作难以正确输出包含复杂计算表达式的查询子句.针对上述问题,提出一种树状模型取代序列表示,将复杂查询自顶向下分解为多叉树,树结点代表SQL的各组成元素,采用深度优先搜索来预测生成SQL语句.在DuSQL中文NL2SQL竞赛的两个官方测试集中,该方法分别取得了第1名和第2名的成绩,验证了其有效性.  相似文献   

13.
This paper introduces a new approach to realize video databases. The approach consists of a VideoText data model based on free text annotations associated with logical video segments and a corresponding query language. Traditional database techniques are inadequate for exploiting queries on unstructured data such as video, supporting temporal queries, and ranking query results according to their relevance to the query. In this paper, we propose to use information retrieval techniques to provide such features and to extend the query language to accommodate interval queries that are particularly suited to video data. Algorithms are provided to show how user queries are evaluated. Finally, a generic and modular video database architecture which is based on VideoText data model is described.  相似文献   

14.
This paper addresses some of the issues that arise in representing temporal information in the database context. It deals not only with the explicit representation of temporal information but with mechanisms for reasoning with it as well. It addresses the issue of processing natural language queries with explicit temporal references. The three issues of knowledge representation, natural language processing and query processing are addressed using the axiomatic framework based on equational logic.  相似文献   

15.
Similarity query processing is becoming increasingly important in many applications such as data cleaning, record linkage, Web search, and document analytics. In this paper we study how to provide end-to-end similarity query support natively in a parallel database system. We discuss how to express a similarity predicate in its query language, how to build indexes, how to answer similarity queries (selections and joins) efficiently in the runtime engine, possibly using indexes, and how to optimize similarity queries. One particular challenge is how to incorporate existing similarity join algorithms, which often require a series of steps to achieve a high efficiency, including collecting token frequencies, finding matching record id pairs, and reassembling result records based on id pairs. We present a novel approach that uses existing runtime operators to implement such complex join algorithms without reinventing the wheel; doing so positions the system to automatically benefit from future improvements to those operators. The approach includes a technique to transform a similarity join plan into an efficient operator-based physical plan during query optimization by using a template expressed largely in the system’s user-level query language; this technique greatly simplifies the specification of such a transformation rule. We use Apache AsterixDB, a parallel Big Data management system, to illustrate and validate our techniques. We conduct an experimental study using several large, real datasets on a parallel computing cluster to assess the similarity query support. We also include experiments involving three other parallel systems and report the efficacy and performance results.  相似文献   

16.
跨语言信息检索指以一种语言为检索词,检索出用另一种或几种语言描述的一种信息的检索技术,是信息检索领域重要的研究方向之一。近年来,跨语言词向量为跨语言信息检索提供了良好的词向量表示,受到很多学者的关注。该文首先利用跨语言词向量模型实现汉文查询词到蒙古文查询词的映射,其次提出串联式查询扩展、串联式查询扩展过滤、交叉验证筛选过滤三种查询扩展方法对候选蒙古文查询词进行筛选和排序,最后选取上下文相关的蒙古文查询词。实验结果表明: 在蒙汉跨语言信息检索任务中引入交叉验证筛选方法对信息检索结果有很大的提升。  相似文献   

17.
Chiql is a novel Chinese relational database query language for Chinese users.It supports procedural query style in which users can specify a complex database request in multiple simple statements.This facility renders Chiql simple-to-use and easy-to-remember.However,direct execution of multi-statemen Chiql rueries(i.e.statement by statement)is often inefficient as potential index-based operations(e.g.join) are by-passed.Furthermore,it often incurs additional database operations,such as scan and projection.To improve this situation,the SMA(Statement Merging Algorithm)is proposed.The goal of SMA is to merge as many dependent statments within Chiql query as possible to form a more efficient Chiql query.The ability in achieving improved effciency without sacrificing the simplicity of the language is the major advantage of this algorithm.  相似文献   

18.
目前XML查询语言及查询界面对Web用户过于复杂,该文描述了一种XML文档索引机制,在此基础上建立了一个通用的贝叶斯网络查询模型。用户只需在交互界面输入自然语言描述的查询,系统就能对其实现基于语义的构造,由它生成多个结构化查询;对这些查询建立贝叶斯网络,计算查询在给定文档下的概率,选择概率最大的前3个查询提交给系统执行。  相似文献   

19.
Currently relational databases are widely used, while object-oriented databases are emerging as a new generation of database technology. This paper presents a methodology to provide effective sharing of information in object-oriented databases and relational databases. The object-oriented data model is selected as a common data model to build an integrated view of the diverse databases. An object-oriented query language is used as a standard query language. A method is developed to transform a relational data definition to an equivalent object-oriented data definition and to integrate local data definitions. Two distributed query processing methods are derived. One is for general queries and the other for a special class of restricted queries. Using the methods developed, it is possible to access distributed object-oriented databases and relational databases such that the locations and the structural differences of the databases are transparent to users.  相似文献   

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