Investigation of the viability of direct evaluation of natural language queries with respect to event based triplestores

研究基于事件的三元组存储的自然语言查询直接评估的可行性

• 批准号: RGPIN-2016-04502
• 负责人: Frost, Richard
• 金额: $ 1.6万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615106
• 关键词: Investigation; viability; direct; evaluation; natural

The web contains a huge amount of knowledge; much encoded in natural-language (NL) text. To facilitate processing by computer, several projects have been launched to extract data from text, encode it in a common format and store it in flexible data structures, variously called binary-relational stores, graph-based databases or triplestores, in which entities and relationships are given worldwide unique names called Uniform Resource Identifiers (URIs). These flexible data structures are collectively called the “semantic web”. The URIs enable data about the same entity to be added by people across the world. An example triplestore is DBpedia with approximately 3 billion facts extracted from the Wikipedia web knowledge base. The semantic web can be queried using the formal query language SPARQL (similar to the relational database query language SQL). SPARQL requires time to learn and it is not easy for many people. It would be useful if triplestores could be accessed using NL. Users with little or no computer expertise could then ask questions in their preferred NL. Several NL query interfaces (NLQIs) to the semantic web have been built; most convert the NL query to SPARQL. For reasons that are explained later, no existing NLQI can accommodate complex queries containing arbitrarily-nested quantification, negation, and chained complex prepositional phrases, such as in the queries “who discovered a moon that orbits mars with a telescope?”, and “which planet is orbited by no moon?” An alternative approach is to treat NL queries as expressions of the lambda calculus and evaluate them directly with respect to the stored data. This is similar to the way in which arithmetic expressions are evaluated. For NL queries, some words denote values which are retrieved from the triplestores, some words denote mathematical functions, and the order of function application is determined by parsing the query using a grammar for the language in which the query was expressed. Over the last 2 years, we have developed a set of meanings (a semantics) for various words of English for use in Semantic-web query processing. As proof of concept, we have integrated our semantics with an English parser, and have built a prototype interface to a remote triplestore containing 6,000 facts about the planets and moons. The query processor can handle millions of queries such as “which vacuumous moon that orbits jupiter was discovered by nicholson or hall with a telescope in 1938 in mt_wilson?” (more examples given later). The query interface is accessible at: http://speechweb2.cs.uwindsor.ca/solarman2/demo_sparql.html The next steps are to 1) investigate the viability of our approach for use with massive triplestores, such as DBpedia, 2) to investigate how to help overcome users lack of knowledge of the URIs used for naming entities, and 3) to investigate performance with respect to recall and precision using established benchmark query sets.

网络包含了大量的知识；大部分用自然语言（NL）文本编码。为了便于计算机处理，已经开展了几个项目，从文本中提取数据，以通用格式对其进行编码，并将其存储在灵活的数据结构中，这些数据结构被称为二进制关系存储、基于图形的数据库或三重存储，其中实体和关系被赋予称为统一资源标识符（uri）的全球唯一名称。这些灵活的数据结构统称为“语义网”。uri允许世界各地的人添加关于同一实体的数据。triplestore的一个例子是DBpedia，它从Wikipedia的web知识库中提取了大约30亿个事实。