否定与不确定信息抽取研究综述

否定与不确定表达在自然语言中广泛存在,正确识别此类信息并将其与准确信息分开处理,在信息抽取、情感分析、文本挖掘等自然语言处理任务中具有重要研究价值。自从2008年BioScope语料库发布以来,针对否定与不确定信息抽取研究举办了多次大规模评测会议和学术论坛,为采集语料、明确任务及性能评测等提供了交流平台,否定与不确定信息抽取逐渐成为自然语言处理领域的研究热点。该文简要介绍了否定与不确定信息抽取的研究背景、任务定义、相关语料等,并通过回顾和分析该领域的研究现状,展望未来的发展趋势。     

面向自然语言文本的否定性与不确定性信息抽取

目前,信息抽取研究主要面向肯定性信息,而自然语言文本中包含了大量否定性和不确定性信息,为了将此类信息与肯定性信息区分开,有必要针对否定性与不确定性信息抽取进行深入研究.针对这一任务,首次构建了一个16 841句的汉语语料资源,利用序列标注模型与卷积树核模型,系统地探索了各种序列化依存特征和结构化句法树特征的有效性,并提出了元决策树模型,对二者进行融合.实验结果显示,该方法在否定性和不确定性信息抽取任务上的精确率分别达到69.84%和58.57%,为相关研究打下了坚实的基础.     

Negation as Failure as Resolution

Providing a clean procedural semantics of the Negation As Failure rule in Logic Programming has been an open problem for some time now. This rule has been treated as a technique in nonmonotonic reasoning, not as a rule in classical logic. This paper contains a demonstration of the negation as failure rule as a resolution procedure in first-order logic. We present a sound and complete resolution scheme for negation as failure rule for the larger class of constraint logic programs. The approach is to consider a canonical partition of the completion of a definite (constraint) program into the IF and the FI programs. We show that a negated goal, provable from the completed definite program is provable from just the FI part. The clauses in this program have a structure dual to that of definite Horn clauses. We describe a sound and complete linear resolution rule for this fragment, and show that a resolution proof of the negated goal from the FI part corresponds to a finite failure tree resulting from classical linear resolution applied to the goal on the If part of the original definite program. Our work shows that negation as failure rule can be computationally efficient in the sense that the SLD-resolution on the If part of a definite program along with the negation as failure rule is more efficient than a direct resolution procedure on the completion of that program.     

Algorithmic Debugging and Hypothetical Reasoning

This paper presents a generalization of Shapiro style algorithmic debugging for generalized Horn clause intuitionistic logic. This logic offers hypothetical reasoning and negation is defined not by failure but by inconsistency. We extend Shapiro's notion of intended interpretation, symptoms and errors and give formal results paralleling those known for definite clauses. We also show how a corresponding diagnosis module for RISC- a logic programming system for generalized Horn clause intuitionistic logic-can be defined by meta interpretation. In contrast to Shapiro's PROLOG modules ours work independently of the specific computation rule that in RISC may be specified by the user.     

汉语逻辑补足义标注框架研究

逻辑补足义是指附加在以谓词为中心的基本命题成分之上的否定、程度、时体、模态和语气等, 具体表现为逻辑语义算子对谓词的语义约束关系,是基本命题成分所表达语义关系的有效补充。在句子中,逻辑补足义所表达的语义是句子深度语义理解的重要层面。该文以深层语义理解为目标,在逻辑补足义已有的研究基础上,建立了否定、程度、时体和语气分类体系,构建了相应的算子词典;制定标注规范,对已经标注了基本命题义语义角色的句子进行各类逻辑补足义的标注;最后,对标注的结果进行统计并对标注过程中出现的问题进行了分析。     

基于可拓方法的策划研究

利用可拓学的基本思想与方法，寻找策划过程中解决矛盾问题的规律，为策划研究提供理论和方法依据，形成形式化的可拓策划方法。     

论我国公司瑕疵设立法律规制的完善

我国公司法虽在2005年进行了较大修改,但对公司瑕疵设立的法律规制并不完善。针对这一现状,文章在比较研究国外立法的基础上,指出我国公司法应将承认瑕疵公司的法人格作为一般原则,同时建立公司瑕疵设立矫正制度,将公司无效诉讼制度作为例外补充,并建立完善的公司瑕疵设立责任体系。     

Lipschitzian De Morgan triplets of fuzzy connectives

After studying Lipschitzian strong negations, Lipschitzian De Morgan triplets (T, S, n), where T is a triangular norm, S a triangular conorm, and n a strong negation, are investigated. The relationships between the best Lipschitzian constants of functions T, S and n are given. Several examples are included.