基于量子逻辑的下推自动机的代数刻画

首先,本文提出量子下推自动机（简记为L-VPDA）的概念,从代数角度出发详细研究了此类自动机的性质,同时建立此类自动机的代数刻画,即利用量子状态构造证明了任意L-VPDA与状态转移为经典函数且具有量子终状态的L-VPDA间的相互等价性;其次详细研究了量子上下文无关语言的代数刻画以及对于正则运算的封闭性。     

模糊Büchi自动机的等价刻画

模糊语言的研究是形式语言研究的焦点之一,然而如何对模糊语言进行刻画甚至更好地分类是其中一个重要研究方向.文章在模糊ω-语言的研究基础上,从模糊逻辑角度研究了模糊ω-正则语言的等价刻画.首先借助广义子集构造方法,证明了任一模糊Büchi自动机与具有分明初始状态和状态转移函数且具有模糊终状态的模糊Büchi自动机是等价的,藉此研究了模糊ω-正则语言的代数刻画和层次刻画,讨论了模糊ω-正则语言关于正则运算的封闭性;其次引入单体二阶(L)ukasiewicz逻辑的概念,给出模糊Büchi自动机识别语言的等价逻辑刻画;最后通过引入ω-星自由和ω-非周期模糊ω-语言,利用“层次化”处理技巧得到了多值逻辑意义下的分类定理,对模糊ω-正则语言给出了一种分类方法.     

扰动值模糊有限自动机及其语言*

引入扰动值模糊有限自动机及其语言的概念,讨论扰动值模糊有限自动机的状态转移函数的扩张问题,证明3类确定型扰动值模糊有限自动机、非确定型扰动值模糊有限自动机相互等价性,研究扰动值模糊有限自动机的语言关于正则运算的封闭性.     

基于量子逻辑的下推自动机与上下文无关文法

给出基于量子逻辑的下推自动机(e-VPDA)的概念,提出广义的子集构造方法,进而证明了一般的e-VPDA与状态转移为分明函数且具有量子终态的e-VPDA的等价性.利用此等价性,给出了量子上下文无关语言的代数刻画与层次刻画,并籍此证明了量子上下文无关语言关于正则运算的封闭性.最后,说明了量子下推自动机和量子上下文无关文法(e-VCFG)的等价性.     

基于Unsharp量子逻辑的自动机和文法理论

初步建立了具有某种分配律的扩展格序效应代数和格序QMV代数这两种unsharp量子结构上的自动机与文法理论的基本框架。引入了ε-值正则文法的概念,证明了任意ε-值自动机识别的语言等价于某种ε-值正则文法所生成的语言;反之,任意[ε]-值正则文法所生成的语言等价于某种ε-值自动机识别的语言。讨论了ε-值正则语言在和、连接及反转运算下的封闭性质。     

格值交替树自动机

交替（树）自动机因其本身关于取补运算的简洁性及其与非确定型（树）自动机的等价性,成为自动机与模型检测领域研究的一个新方向.在格值交替自动机与经典交替树自动机概念的基础上,引入格值交替树自动机的概念,并研究了格值交替树自动机的代数封闭性和表达能力.首先,证明了对格值交替树自动机的转移函数取对偶运算,终止权重取补之后所得自动机与原自动机接受语言互补这一结论.其次,证明了格值交替树自动机关于交、并运算的封闭性.最后,讨论了格值交替树自动机和格值树自动机、格值非确定型自动机的表达能力;证明了格值交替树自动机与格值树自动机的等价性,并给出了二者相互转化的算法及其复杂度分析;同时,提供了用格值非确定型自动机来模拟格值交替树自动机的方法.     

量子Müller自动机与单体二阶量子逻辑

给出量子Müller自动机（简称LVMA）的概念,通过引入量子有限步可识别语言和量子状态构造方法,证明了在量子逻辑意义下4类量子Müller自动机彼此相互等价.利用该等价性,建立了量子无穷正则语言的代数刻画和层次刻画,籍此研究了量子无穷正则语言关于无穷正则运算的封闭性.同时,给出了量子Müller自动机所识别语言的单体二阶逻辑描述,深化和推广了量子逻辑意义下的Büchi基本定理.     

基于完备剩余格值逻辑的自动机和文法理论

初步建立基于完备剩余格值逻辑自动机与文法理论的基本框架。引入l值正则文法的概念,证明了任意l值自动机识别的语言等价于某种l值正则文法所生成的语言,反之,任意l值正则文法所生成的语言等价于某种l值自动机识别的语言。获得l值自动机及被l值自动机识别的语言的连接问题刻画。特别地,建立l值和L值泵引理,并得到l值语言的判定性刻画。最后,揭示带ε移动的l值自动机与不带ε移动的l值自动机之间的两个等价关系。     

基于量子逻辑的自动机和文法理论

初步建立了基于量子逻辑的自动机和文法理论的基本框架.引入了量子文法(称为l值文法),特别是证明了任意l值正规文法生成的语言(称为量子语言)等价于某种基于量子逻辑且含动作(的自动机(称为l值自动机)识别的语言,反之,任意l值自动机识别的语言等价于某l值正规文法生成的语言.建立了l值泵引理,并得到量子语言的判定性刻画.最后简要讨论了正规文法与量子文法(即l值正规文法)的关系.因此,为进一步研究更复杂的量子自动机(如量子下推自动机和Turing机)和量子文法(如量子上下文无关文法和上下文有关文法)奠定了基础.     

两类具有输出字符功能的模糊自动机的关系

在文中,对文献8中介绍的具有输出字符功能的模糊自动机和模糊有限状态自动机的定义作了修改,并对它们进行了系统的研究,揭示了此两类自动机和取分配格的代数性质的紧密联系;得到了此两类自动机在:(1)强等价;(2)等价;(3)弱等价条件下的许多重要结论。     

The relationships among several types of fuzzy automata

We discuss the relationships among several types of fuzzy automata in which all fuzzy sets are defined by membership functions whose codomains are a lattice-ordered monoid L. These automata include nondeterministic L-valued finite automata with Λ-move, nondeterministic L-valued finite automata, deterministic L-valued finite automata, and L-valued finite-state automata. We consider all that come with fuzzy initial states and fuzzy final states or with crisp initial states or crisp final states. Some comparative results concerning the power of fuzzy automata used in the existing literature to recognize fuzzy languages are given systematically.     

Controlled finite automata

This paper discusses finite automata regulated by control languages over their states and transition rules. It proves that under both regulations, regular-controlled finite automata and context-free-controlled finite automata characterize the family of regular languages and the family of context-free languages, respectively. It also establishes conditions under which any state-controlled finite automaton can be turned into an equivalent transition-controlled finite automaton and vice versa. The paper also demonstrates a close relation between these automata and programmed grammars. Indeed, it proves that finite automata controlled by languages generated by propagating programmed grammars with appearance checking are computationally complete. In fact, it demonstrates that this computational completeness holds even in terms of these automata with a reduced number of states.     

一类格值自动机的极小化

给出了格值自动机的同余和同态,从代数角度出发详细研究了同余和同态关系的代数性质,揭示了格值自动机的代数性质和取值格半群的紧密联系,利用同余和同态关系最终研究了格值自动机的极小化问题,在正则同余下给出了可在有限步实现具有模糊初始状态和特殊模糊终状态的自动机极小化的算法。     

Retraction and Generalized Extension of Computing With Words

Fuzzy automata, whose input alphabet is a set of numbers or symbols, are a formal model of computing with values. Motivated by Zadeh's paradigm of computing with words rather than numbers, Ying proposed a kind of fuzzy automata, whose input alphabet consists of all fuzzy subsets of a set of symbols, as a formal model of computing with all words. In this paper, we introduce a somewhat general formal model of computing with (some special) words. The new features of the model are that the input alphabet only comprises some (not necessarily all) fuzzy subsets of a set of symbols and the fuzzy transition function can be specified arbitrarily. By employing the methodology of fuzzy control, we establish a retraction principle from computing with words to computing with values for handling crisp inputs and a generalized extension principle from computing with words to computing with all words for handling fuzzy inputs. These principles show that computing with values and computing with all words can be respectively implemented by computing with words. Some algebraic properties of retractions and generalized extensions are addressed as well.     

Stochastic grammars and languages

This paper summarizes some recent results concerned with the extension of formal languages to their corresponding stochastic versions. Weighted grammars and languages are first defined, and stochastic grammars and languages are defined as a special case of weighted grammars and languages. Fuzzy grammars and languages, which have some properties similar to weighted grammars and languages, are also discussed. Stochastic automata are defined from the language recognition viewpoint. Languages accepted by stochastic finite-state and pushdown automata, with and without a cutpoint, are studied. Weighted and stochastic programmed and indexed grammars, and stochastic nested stack automata are defined. Finally, some decidability problems of stochastic (weighted, fuzzy) languages are discussed, and problems for further research are suggested.This work was supported by the National Science Foundation Grant GK-18225.     

Succinct representation of regular languages by boolean automata

Boolean automata are a generalization of finite automata in the sense that the ‘next state’, i.e. the result of the transition function given a state and a letter, is not just a single state (deterministic automata) or a union of states (nondeterministic automata) but a boolean function of states. Boolean automata accept precisely regular languages; furthermore they correspond in a natural way to certain language equations as well as to sequential networks. We investigate the succinctness of representing regular languages by boolean automata. In particular, we show that for every deterministic automaton A with m states there exists a boolean automaton with [log₂m] states which accepts the reverse of the language accepted by A (m≥1). We also show that for every n≥1 there exists a boolean automation with n states such that the smallest deterministic automaton accepting the same language has 2⁽²ⁿ⁾ states; moreover this holds for an alphabet with only two letters.     

正则语言的一个特征

Myhill-Nerode定理利用等价关系描述了正则语言的一个重要特征,它是有限自动机理论中的一个经典、优美的结果。为了将Myhill-Nerode定理推广到更一般的情形,引入了有限自动机M上的状态转移半群和Σ*上的M-半群,讨论了其若干性质。在此基础上,将Myhill-Nerode定理中的等价关系一般化,给出了正则语言的一个新的特征定理,Myhill-Nerode定理成为该定理的一个推论。讨论了正则语言的最一般的特征,提出了有待进一步研究的问题。     

Automata theory based on complete residuated lattice-valued logic

This paper establishes a fundamental framework of automata theory based on complete residuated lattice-valued logic. First it deals with how to extend the transition relation of states and par-ticularly presents a characterization of residuated lattice by fuzzy automata (called (?) valued automata). After that fuzzy subautomata (called (?) valued subautomata), successor and source operators are pro-posed and their basic properties as well as the equivalent relation among them are discussed, from which it follows that the two fuzzy operators are exactly fuzzy closure operators. Finally an L bifuzzy topological characterization of Q valued automata is presented, so a more generalized fuzzy automata theory is built.