可更新Datalog的分布式时态逻辑扩展及应用

针对现有的分布式逻辑语言缺乏完整时态表达力等问题,将分布式时态逻辑谓词引入Datalog规则,提出TU-Datalog语言。该语言通过融入U-Datalog的非即时性更新语义,形成完全声明式具有强大时态表达力的逻辑编程语言和环境。通过扩展U-Datalog逻辑固定点语义,提出TU-Datalog语言的固定点时态演化规则,并对该语言的语法、语义、评价算法进行了研究,最后对该语言的应用做了说明和示例。     

带权重谓词的可选事务逻辑及其访问控制应用

逻辑语言由于其表达力和灵活性,是访问控制中授权语言的基础之一。针对Datalog语言缺乏表达事务和多方决策模型的能力,对Datalog进行了扩展,提出了一种带权重谓词的可选事务逻辑WT-Logic。首先对WT-Logic的语法、语义进行了说明;然后解释了其评价方法;最后对WT-Logic语言在工作流授权和多方投票机制中的应用进行了描述和示例,说明了WT-Logic的表达力和可应用性。     

面向对象数据库的推理查询实现*

上文介绍了面向对象数据库系统FOOD的推理查询语言O—Datalog，本文继续讨论对O—Datalog程序的几种变换，并证明这些变换是语义等价的，从而证明了对于一个O—Datalog程序，可以为它构造一个相应的Datalog程序。并能利用该Datalog程序对原程序进行计值．最后本文还给出了对O—Datalog程序计值的算法．     

基于核外计算的Datalog引擎设计与实现

随着新兴技术的迅速发展,领域软件对开发效率提出了新的要求. Datalog语言作为一门具有简洁语法和良好语义的声明式编程语言,能帮助开发人员快速开发和解决问题,近年来越来越受到重视与欢迎.但解决真实场景问题时,现有的单机Datalog引擎计算规模往往受限于内存容量大小,不具有可扩展性.为解决上述问题,设计并实现基于核外计算的Datalog引擎.方法首先设计一系列计算Datalog程序所需的支持核外计算的操作算子,然后将Datalog程序转换合成带核外计算算子的C++程序,接着方法设计基于Hash的分区策略和基于搜索树剪枝的最少置换调度策略,将相应的分区文件调度执行计算并得到最终结果.基于该方法,实现原型工具DDL (disk-based Datalog engine),并选取广泛应用的真实Datalog程序,在合成数据集以及真实数据集上进行实验,实验结果体现了DDL良好性能以及高可扩展性.     

Tuili－Ⅱ里的属性谓词及其实现

Ｔｕｉｌｉ－Ⅱ是一个基于Ｔｕｉｌｉ的知识程序设计语言，属性谓词是其中的一种新的知识表示方法．属性谓词体现了逻辑推理语言Ｔｕｉｌｉ与框架／对象在一定意义下的结合．本文主要介绍属性谓词的提出背景和基本思想，给出属性谓词说明及其使用的语法定义、语义及解释，讨论属性谓词的实现思想和主要算法，并给出一个由属性谓词表示分类知识的专家系统原型的例子．     

Tuili—Ⅱ里的属性谓词及其实现

Ｔｕｉｌｉ－Ⅱ是一个基于Ｔｕｉｌｉ的知识程序设计语言，属性谓词是其中的一种新的知识表示方法。属性谓词体现了逻辑推理语言Ｔｕｉｌｉ与框架／对象在一定意义下的结合。本文主要介绍属性谓词的提出和基本思想，给出属性谓词说明及其使用的语法定义、语义及解释。讨论了属性谓词的实现思想和主要算法，并给出一个由属性谓词表示分类知识的专家系统原型的例子。     

基于嵌入式SQL的Datalog演绎规则解释器的设计

文章提出了一个建立在传统关系数据库基础上的能支持ANSISQL与嵌入式SQL的演绎规则解释器。利用这个解释器,用户能够定义一个蕴含关系并可以像在演绎数据库中使用Datalog规则一样来提出查询。其方法是把演绎规则和查询翻译成嵌入式SQL程序,该程序在执行查询时能被调用。这个解释器可以被认为是扩充RDBMS演绎查询功能的一个前端工具。     

面向对象数据库的推理查询语言*

本文基于复旦大学开发的一个面向对象数据库系统FOOD，提出一种推理查询语言O—Datalog．该语言能方便地表达对面向对象数据的各种查询和推理要求；它可以转换成类Datalog形式，能运用各种高效计值算法，比其它一些基于非Horn子句逻辑的语言更易于实现．O—Datalog在形式上是一种Datalog的扩充，本文着重介绍其语法和语义．     

程序设计方法学(下)

十、程序的形式推导技术10.1 程序的形式语义程序变量的一组可能取值,称为是一个状态,Hoare公式{P}S{θ}的前谓词P和后谓词Q分別确定了程序S执行的初始状态和终结状态所需满足的条件,因此,可以说,这种谓词刻画了程序语言结构的语义特征。然而,前谓词P确定的只是一个充分条件,以满足前谓词P的程序状态作为初始状态,执行程序S,导致的结果状态必然满足Q     

基于Hoare逻辑的过程调用的形式化方法

采用Hoare逻辑风格的推理,提出了一些从源代码推导过程和这些过程调用的形式化语义规范的技术和算法。为了推导一个过程调用的语义,将过程看作一个抽象单元从程序分离出来,提取过程的形式化语义规范。对于一个具体的过程调用,形式化这个调用的前置条件,根据这些条件形式化求解调用的最强后置条件,也就是调用的语义作用。     

Parallel and distributed processing of rules by data-reduction

The parallel evaluation of datalog rule programs, mainly by processors that are interconnected by a communication network, is discussed. Data-reduction, a paradigm for the parallel evaluation of a datalog program, is introduced. Parallelization is accomplished by partitioning the rule-instantiations among the processors. After presenting the paradigm, its implementation with seminaive evaluation, its communication overhead, and its application to stratified-negation datalog programs are discussed. It is proven that decomposability, a related concept introduced in previous works, is undecidable     

On the partial semantics for disjunctive deductive databases

Partial stable models for deductive databases, i.e., normal function-free logic programs (also called datalog programs), have two equivalent definitions: one based on 3-valued logics and another based on the notion of unfounded set. The notion of partial stable model has been extended to disjunctive deductive databases using 3-valued logics. In this paper, a characterization of partial stable models for disjunctive datalog programs is given using a suitable extension of the notion of unfounded set. Two interesting sub-classes of partial stable models, M-stable (Maximal-stable) (also called regular models, preferred extension,and maximal stable classes) and L-stable (Least undefined-stable) models, are then extended from normal to disjunctive datalog programs. On the one hand, L-stable models are shown to be the natural relaxation of the notion of total stable model; on the other hand the less strict M-stable models, endowed with a nice modularity property, may be appealing from the programming and computational point of view. M-stable and L-stable models are also compared with the regular models for disjunctive datalog programs recently proposed in the literature.     

面向语言信息处理的朝鲜语知识库研究

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。     

Mechanical reasoning about families of UTP theories

The Unifying Theories of Programming (UTP) of Hoare and He is a general framework in which the semantics of a variety of specification and programming languages can be uniformly defined. In this paper we present a semantic embedding of the UTP into the ProofPower-Z theorem prover; it concisely captures the notion of UTP theory, theory instantiation, and, additionally, type restrictions on the alphabet of UTP predicates. We show how the encoding can be used to reason about UTP theories and their predicates, including models of particular specifications and programs. We support encoding and reasoning about combinations of predicates of various theory instantiations, as typically found in UTP models. Our results go beyond what has already been discussed in the literature in that we support encoding of both theories and programs (or their specifications), and high-level proof tactics. We also create structuring mechanisms that support the incremental construction and reuse of encoded theories, associated laws and proof tactics.     

Verbs of pain in the light of grammar of constructions

Constructions with predicates from the semantic zone of pain are considered from a typological perspective. A characteristic feature of this field is its lexeme composition: the major portion of it is formed by verbs borrowed from other semantic fields. A brief review of the fields-sources for pain verbs is given and morphological and syntactical mechanisms of the borrowing of original predicates in the zone of pain are analyzed. The study shows that the semantic shift includes not only the change of the lexical meaning proper, but also the restructuring of paradigmatic and syntactic mechanisms of the borrowed unit, which occurs under influence of constructions with participation of original predicates of pain.     

Generalizing the semantic roles in the Chinese Proposition Bank

The Chinese Proposition Bank (CPB) is a corpus annotated with semantic roles for the arguments of verbal and nominalized predicates. The semantic roles for the core arguments are defined in a predicate-specific manner. That is, a set of semantic roles, numerically identified, are defined for each sense of a predicate lemma and recorded in a valency lexicon called frame files. The predicate-specific manner in which the semantic roles are defined reduces the cognitive burden on the annotators since they only need to internalize a few roles at a time and this has contributed to the consistency in annotation. It was also a sensible approach given the contentious issue of how many semantic roles are needed if one were to adopt of set of global semantic roles that apply to all predicates. A downside of this approach, however, is that the predicate-specific roles may not be consistent across predicates, and this inconsistency has a negative impact on training automatic systems. Given the progress that has been made in defining semantic roles in the last decade or so, time is ripe for adopting a set of general semantic roles. In this article, we describe our effort to “re-annotate” the CPB with a set of “global” semantic roles that are predicate-independent and investigate their impact on automatic semantic role labeling systems. When defining these global semantic roles, we strive to make them compatible with a recently published ISO standards on the annotation of semantic roles (ISO 24617-4:2014 SemAF-SR) while taking the linguistic characteristics of the Chinese language into account. We show that in spite of the much larger number of global semantic roles, the accuracy of an off-the-shelf semantic role labeling system retrained on the data re-annotated with global semantic roles is comparable to that trained on the data set with the original predicate-specific semantic roles. We also argue that the re-annotated data set, together with the original data, provides the user with more flexibility when using the corpus.     

VDEA词典的构建及其在情感倾向性分析中的应用

配价语法主要以谓词为中心研究句子的深层语义结构,重点描述动词和形容词与搭配成分间的依存关系,是解决语义分析处理这个颈瓶问题的利器。以英语形容词为主体,构建了包含相关配价信息的形容词配价词典,词典包含3170个英语形容词的配价关系、格关系、释义、褒贬义、语义分类、语义特征和相关例句等信息。此外,基于该词典设计了词汇情感倾向性分析模型,取得了很好的实验结果。     

Mutation testing in UTP

This paper presents a theory of testing that integrates into Hoare and He’s Unifying Theory of Programming (UTP). We give test cases a denotational semantics by viewing them as specification predicates. This reformulation of test cases allows for relating test cases via refinement to specifications and programs. Having such a refinement order that integrates test cases, we develop a testing theory for fault-based testing. Fault-based testing uses test data designed to demonstrate the absence of a set of pre-specified faults. A well-known fault-based technique is mutation testing. In mutation testing, first, faults are injected into a program by altering (mutating) its source code. Then, test cases that can detect these errors are designed. The assumption is that other faults will be caught, too. In this paper, we apply the mutation technique to both, specifications and programs. Using our theory of testing, two new test case generation laws for detecting injected (anticipated) faults are presented: one is based on the semantic level of UTP design predicates, the other on the algebraic properties of a small programming language.     

进程异常检测中淋巴细胞的逻辑语义模型

论文针时反向选择算法无法有效地捕捉某些复杂问题空间的语义信息的缺点,以逻辑程序设计领域中的稳定模型为理论基础,提出一个淋巴细胞的逻辑语义模型。该模型采用逻辑程序表示淋巴细胞和抗原,通过计算它们的稳定模型来进行异常检测。最后,以进程异常检测为背景,设计了一个系统框架。该框架充分考虑了进程系统调用短序列的语义信息。能有效地提高异常检测的准确率。