一个领域自然语言理解的知识获取工具的设计实现

本文介绍了一个基于知识的自然语言理解系统和系统的知识库中知识的表示模式,描述了知识库中领域过程树的知识获取过程。根据领域过程树的知识表示模式,本文设计并实现了一个知识获取工具,很好地提高了领域过程树知识获取的速度和准确度。     

MIKRS：用于知识库求精的模型推理系统

知识求精是知识获取的一个重要方面,本文主要介绍了知识库求精的一些概念、理论与方法,给出了在MIKRS系统中所实现的知识库调试和求精的思想及描述算法,并在文章的最后给出了系统运行的一个实例。     

知识求精的基本理论与方法的研究

知识求精属知识获取的一个重要方面,旨在解决因知识不完全和噪音等因素引起的知识库正确性与有效性问题。本文通过知识库建造工具GKD—KBST中求精器KBRS实现方案的介绍,论述知识求精的基本理论。     

基于领域的省略及恢复研究

研究汉语语篇特性时,省略是其一个重点。简要阐述了汉语省略的基本概念,介绍了通过三个平面理论进行的基于领域的省略恢复研究。提出了实现自然语言的真实理解的目标,分析探讨了它所面临的主要困难。提出了基于规则推理的知识库系统构建方案,同时在知识获取这一瓶颈问题中引入自然语言理解技术来进行专家经验性知识的自动获取。构建的省略恢复模型已被运用在领域自然语言理解中,结果表明其在汉语正式体省略恢复中具有一定优越性。     

一个综合知识发现与知识求精系统--XFKDRS

介绍了一个综合知识发现与知识求精系统-XFKDRS.它由分类规则、关联规则、序贯模式、相似模式、聚类模式组成知识发现模块.知识求精首先在领域知识可视化的基础上,集成了基于遗传知识树、知识型人工神经网络和基于解释学习的求精方法.最后将新知识转换成雄风专家系统工具XF6.2的知识表达形式,添加到其知识库中,完成专家系统的自动知识获取.     

基于领域的省略及恢复研究

研究汉语语篇特性时,省略是其一个重点.简要阐述了汉语省略的基本概念,介绍了通过三个平面理论进行的基于领域的省略恢复研究.提出了实现自然语言的真实理解的目标,分析探讨了它所面临的主要困难.提出了基于规则推理的知识库系统构建方案,同时在知识获取这一瓶颈问题中引入自然语言理解技术来进行专家经验性知识的自动获取.构建的省略恢复模型已被运用在领域自然语言理解中,结果表明其在汉语正式体省略恢复中具有一定优越性.     

面向生物医学实体链接的联合式学习方法

生物医学文本蕴含着丰富的探索价值,其为生物医学工作者进行研究提供了宝贵的领域知识.充分且高效地利用海量的生物医学文献,并从中发现重要的隐藏信息、获取专业领域知识,对生物医学研究具有重要的意义.生物医学实体链接是对生物医学文本中的命名实体进行识别,并将表示该实体的某些字符串映射到生物医学领域知识库中对应概念.生物医学实体链接任务通常面临两个主要的挑战：(1)自然语言描述的歧义性.(2)自然语言文本与生物医学知识库的异构性.传统的方法基于特征选择或规则发现,依赖于手动选择特征或定义规则,处理分阶段模型中也可能出现误差传播.因此,本工作提出了一种深度学习和知识库相结合的实体链接方法,通过深度挖掘自然语言文本的隐藏特征,及其与知识库概念图间结构的相似性,将生物医学实体识别与实体-概念对齐两个任务进行联合式处理.该方法旨在通过标准的生物医学知识库,自动获取生物医学实体的语义信息,挖掘生物医学实体之间的语义关系.实验表明,该方法在实体识别与对齐方面取得了较好的效果,显著提高了任务的精确性,在实体链接核心任务上取得了超过10%的性能提升.     

一种基于CBR的知识库求精模式

由于领域知识以及人们的认识进程具有进化的特性,领域模型总是不完备的,为了增强基于知识系统的自适应能力和可靠性,知识库求精已成为机译系统等基于知识系统实用化的必经阶段。本文给出了一些知识库求精原则;结合机器翻译知识库建构维护的实际需求,提出了一种基于CBR(Case-basedReasoning)的知识库求精模式。该求精模式以提高系统有效性为核心,以错误严重性为指示器,择重优     

基于自然语言理解的专家系统研究

在论述了面向自然语言文本的知识供应方法已有研究之后,提出了面向推理设计语义关系标记,将自然语言理解与推理技术相结合,使自然语言理解结果可转化为便于计算机推理的语句。立足科技文献开发语义关系树库,提出面向语义关系分析的语句相似度计算方法,实现基于统计与规则相结合的自然语言语义关系分析,使自然语言科技文献可成为专家系统知识库,解决专家系统知识库表现形式不统一及知识获取的瓶颈。     

增量式解释学习算法EBG—plus

传统的解释学习是通过单个实例进行学习的，学习结果往往带有实例本身的特殊性质，知识求精能较正这一缺陷，但学习结果的效用不高。本结合了ＥＢＬ方法和求精算法，提出了综合多个实例的增量式解释学习算法ＥＢＧ－ｐｌｕｓ，学习质量随实例数目增加而单调上升，学习结果效用高，并能够自动改进领域知识的编码质量。     

基于多模态特征频域融合的零样本指称图像分割

为了解决语义分割应用到现实世界的下游任务时无法处理未定义类别的问题,提出了指称对象分割任务,该任务根据自然语言文本的描述找到图像中对应的目标。现有方法大多使用一个跨模态解码器来融合从视觉编码器和语言编码器中独立提取的特征,但是这种方法无法有效利用图像的边缘特征且训练复杂。CLIP（contrastive language-image pre-training）是一个强大的预训练视觉语言跨模态模型,能够有效提取图像与文本特征,因此提出一种在频域融合CLIP编码后的多模态特征方法。首先,使用无监督模型对图像进行粗粒度分割,并提取自然语言文本中的名词用于后续任务。接着利用CLIP的图像编码器与文本编码器分别对图像与文本进行编码。然后使用小波变换分解图像与文本特征,可以充分利用图像的边缘特征与图像内的位置信息在频域进行分解并融合,并在频域分别对图像特征与文本特征进行融合,并将融合后的特征进行反变换。最后将文本特征与图像特征进行逐像素匹配,得到分割结果,并在常用的数据集上进行测试。实验结果证明,网络在无训练零样本的条件下取得了良好的效果,并且具有较好的鲁棒性与泛化能力。     

Redundancy detection in semistructured case bases

With the dramatic proliferation of case-based reasoning systems in commercial applications, many case bases are now becoming legacy systems. They represent a significant portion of an organization's assets, but they are large and difficult to maintain. One of the contributing factors is that these case bases are often large and yet unstructured or semistructured; they are represented in natural language text. Adding to the complexity is the fact that the case bases are often authored and updated by different people from a variety of knowledge sources, making it highly likely for a case base to contain redundant and inconsistent knowledge. We present methods and a system for maintaining large and semistructured case bases. We focus on a difficult problem in case base maintenance: redundancy detection. This problem is particularly pervasive when one deals with a semistructured case base. We discuss an information retrieval-based algorithm and an implemented system for solving this problem. As the ability to contain the knowledge acquisition problem is of paramount importance, our method allows one to express relevant domain expertise for detecting redundancy naturally and effortlessly. Empirical evaluations of the system demonstrate the effectiveness of the methods in several large domains     

TRUMP: A transportable language understanding program

Transportability has perpetually been the nemesis of natural language processing systems, in both the research and commercial sectors. During the last 20 years, the technology has not moved much closer to providing robust coverage of everyday language, and has failed to produce commercial successes beyond a few specialized interfaces and application programs. the redesign required for each application has limited the impact of natural language systems. Trump (TRansportable Understanding Mechanism Package) is a natural language analyzer that functions in a variety of domains, in both interfaces and text processing. While other similar efforts have treated transportability as a problem in knowledge engineering, Trump instead relies mainly on a “core” of knowledge about language and a set of techniques for applying that knowledge within a domain. the information about words, word meanings, and linguistic relations in this generic knowledge base guides the conceptual framework of language interpretation in each domain. Turmp uses this core knowledge to piece together a conceptual representation of a natural language input by combining generic and specialized inforamtion. the result has been a language processing system that is capable of performing fairly extensive analysis with a minimum of customization for each application.     

融合多特征图及实体影响力的领域实体消歧

实体消歧作为自然语言处理的关键问题,旨在将文本中出现的歧义实体指称映射到知识库中的目标实体。针对现有方法存在仅实现单实体指称消歧、忽略了实体影响力及候选实体间相似度对消歧结果的影响以及冗余图节点增加图计算复杂性等问题,提出了一种融合多特征图及实体影响力的领域实体消歧方法,以金融领域为例,提取CN-Dbpedia中金融类别相关关键词三元组,构建金融领域知识库;针对金融活动类文本,提取待消歧实体指称,融合字符串及语义的相似特征,筛选出候选实体,利用知识库三元组信息获取候选实体间2-hop内的关系,同时计算候选实体间相似度作为边权值,进而将多特征信息充分融合到图模型当中,完成多特征图构建;采用动态决策策略,利用PageRank算法,并结合实体影响力计算多特征图中候选实体的综合评分,进而获得可信度较高的消歧结果。实验结果验证了提出方法在特定领域实体消歧的精确度及效率。     

Ontology-based information extraction and integration from heterogeneous data sources

In this paper we present the design, implementation and evaluation of SOBA, a system for ontology-based information extraction from heterogeneous data resources, including plain text, tables and image captions. SOBA is capable of processing structured information, text and image captions to extract information and integrate it into a coherent knowledge base. To establish coherence, SOBA interlinks the information extracted from different sources and detects duplicate information. The knowledge base produced by SOBA can then be used to query for information contained in the different sources in an integrated and seamless manner. Overall, this allows for advanced retrieval functionality by which questions can be answered precisely. A further distinguishing feature of the SOBA system is that it straightforwardly integrates deep and shallow natural language processing to increase robustness and accuracy. We discuss the implementation and application of the SOBA system within the SmartWeb multimodal dialog system. In addition, we present a thorough evaluation of the different components of the system. However, an end-to-end evaluation of the whole SmartWeb system is out of the scope of this paper and has been presented elsewhere by the SmartWeb consortium.     

基于词缀的维吾尔谚语识别关键技术研究

在自然语言理解、机器翻译、舆情分析等自然语言处理领域中,维吾尔谚语识别是整个文本实体识别的重要组成部分。为满足维吾尔谚语信息化的需求,本文构建了比较完善的维吾尔谚语语料库。同时,从传统语言学角度对维吾尔谚语的语法、语义结构进行分析,构建了一个由维吾尔谚语功能语类（词缀）组成的、专属维吾尔谚语规则的知识库,并将此知识库与自然语言处理技术相结合,实现一个既能够从文本中识别出维吾尔谚语,又能提供维汉互译等功能的信息软件系统。该系统也为开展计算机理解与处理维吾尔文字奠定了一个崭新的基础。     

Information Extraction and Knowledge Acquisition from Texts Using Bilingual Question–Answering

A novel approach is introduced in this paper for the implementation of a question–answering based tool for the extraction of information and knowledge from texts. This effort resulted in the computer implementation of a system answering bilingual questions directly from a text using Natural Language Processing. The system uses domain knowledge concerning categories of actions and implicit semantic relations. The present state of the art in information extraction is based on the template approach which relies on a predefined user model. The model guides the extraction of information and the instantiation of a template that is similar to a frame or set of attribute value pairs as the result of the extraction process. Our question–answering based approach aims to create flexible information extraction tools accepting natural language questions and generating answers that contain information extracted from text either directly or after applying deductive inference. Our approach also addresses the problem of implicit semantic relations occurring either in the questions or in the texts from which information is extracted. These relations are made explicit with the use of domain knowledge. Examples of application of our methods are presented in this paper concerning four domains of quite different nature. These domains are: oceanography, medical physiology, aspirin pharmacology and ancient Greek law. Questions are expressed both in Greek and English. Another important point of our method is to process text directly avoiding any kind of formal representation when inference is required for the extraction of facts not mentioned explicitly in the text. This idea of using text as knowledge base was first presented in Kontos [7] and further elaborated in [9,11,12] as the ARISTA method. This is a new method for knowledge acquisition from texts that is based on using natural language itself for knowledge representation.