Showing papers on "Grammar systems theory published in 2001"

Implementing typed feature structure grammars

Abstract: Much of the work in modern formal linguistics is concerned with giving mathematically precise accounts of human languages. Such work is particularly suited for research that involves language processing with computers. This book provides an introduction to one particularly popular approach, typed-feature structure formalisms. Implementing Typed Feature Structure Grammars includes informal (but rigorous) descriptions of typed-feature structure logic as well as formal definitions. The book covers the basics of grammar development by introducing different frameworks to the reader such as categorial grammar and Head-Driven Phrase Structure Grammar, and demonstrates how these can be implemented. Semantic representation is also introduced. The book includes a CD of the LKB system software that allows the reader to experiment with various grammars and learn the details of the formalism. The CD is compatible with Windows, MacOS, Linux and Solaris, and includes a full user manual.

Semi-automatic grammar recovery

Abstract: SUMMARY We propose an approach to the construction of grammars for existing languages. The main characteristic of the approach is that the grammars are not constructed from scratch but they are rather recovered by extracting them from language references, compilers, and other artifacts. We provide a structured process to recover grammars including the adaptation of raw extracted grammars and the derivation of parsers. The process is applicable to possibly all existing languages for which business critical applications exist. We illustrate the approach with a non-trivial case study. Using our process and some basic tools, we constructed in a few weeks a complete and correct VS COBOL II grammar specification for IBM mainframes. In addition, we constructed a parser for VS COBOL II, and were the first to publish a (web-enabled) grammar specification so that others can use this result to construct their own grammar-based tools for VS COBOL II or derivatives.

Grammar authoring system

Abstract: A grammar authoring system uses multiple sources of information to aid grammar authoring. This produces a semantic grammar derived semi-automatically with a relatively small amount of data.

Intelligent language tutoring systems for grammar practice

Abstract: Commonly, publishers of language learning material also provide Web sites that contain vocabulary and grammar practice for second language learners. Mainstream course offerings on the Web, however, often resemble the traditional workbook exercises from which they were adapted, making little use, for instance, of the multimedia capabilities of the Web. For example, a commonly used course package for introductory German(1) contains a companion Web site with vocabulary and grammar exercises for each of the 12 chapters of the textbook. None of these exercises on the Web site, however, contain any graphics, sound or videos which would enhance the static material character of workbooks.

Grammar learning for spoken language understanding

Abstract: Many state-of-the-art conversational systems use semantic-based robust understanding and manually derived grammars, a very time-consuming and error-prone process. This paper describes a machine-aided grammar authoring system that enables a programmer to develop rapidly a high quality grammar for conversational systems. This is achieved with a combination of domain-specific semantics, a library grammar, syntactic constraints and a small number of example sentences that have been semantically annotated. Our experiments show that the learned semantic grammars consistently outperform manually authored grammars, requiring much less authoring load.

Improvements on a semi-automatic grammar induction framework

Abstract: This work extends the semi-automatic grammar induction approach previously proposed (see Meng, H. and Siu, K.C., IEEE Trans. on Knowledge and Data Engineering). The data-driven approach learns semantic and phrasal categories from a training corpus of unannotated natural language queries in a specific domain. The approach can be seeded with prespecified semantic categories to expedite the learning process. Grammar rules are automatically acquired by an agglomerative clustering procedure, and the resulting grammar may be hand-edited easily for refinement. This work attempts to improve the grammar induction framework by leveraging information in the SQL query that accompanies every training query. The SQL expression specifies the action of database access in relation to the query, and hence provides information about meaningful natural language structures that should to be captured in induced grammar. We have also incorporated the use of information gain in place of mutual information to capture phrasal structures, as well as the determination of an automatic stopping criterion for agglomerative clustering.

Transformation of an EGT Grammar: New Grammar, New Designs

Abstract: True design with grammars lies in the creation of the grammar rules, not in the application of the rules to generate design alternatives. Existing grammars can be modified to describe new languages of designs [1-4]. Studying an epicyclic gear train graph grammar leads to purposeful relaxation of grammar rules and subsequent discovery of new designs. A revised new EGT grammar is presented, which is designed to generate a wider selection of valid EGTS.

Representing Embedded System Sequence Diagrams as a Formal Language

Abstract: Sequence Diagrams (SDs) have proven useful for describing transaction-oriented systems, and can form a basis for creating statecharts. However, distributed embedded systems require special support for branching, state information, and composing SDs. Actors must traverse many SDs when using a complex embedded system. Current techniques are insufficiently rich to represent the behavior of real systems, such as elevators, without augmentation, and cannot identify the correct SD to execute next from any given state of the system. We propose the application of formal language theory to ensure that SDs (which can be thought of as specifying a grammar) have sufficient information to create statecharts (which implement the automata that recognize that grammar). A promising approach for SD to statechart synthesis then involves 'compiling' SDs represented in an LL(1) grammar into statecharts, and permits us to bring the wealth of formal language and compiler theory to bear on this problem area.

Formalized analysis of structural characteristics of large complex systems

Abstract: Macrostructural modelization is paramount to the development of large complex systems (LCS). The paper explores the macrostructural modelization of LCS in terms of a block diagram based model and a grammar based model. Firstly, the macrostructural modelization problem of LCS is formulated. Secondly, a block diagram based model is proposed and established for LCS. Specifically, two general-purpose information-processing modules are proposed and constructed, called perception cube and decision spheroid. Thirdly, a grammar based model is proposed and established for LCS through applying formal language theory to the block diagram based model. Specifically, perception cube and decision spheroid are visually represented as context-free grammars, named fusion grammar and synthesis grammar, respectively. Through a stratified constructive linkup between a stream of bottom-up growing fusion grammars and a stream of top-down growing synthesis grammars, a level of LCS is constructively defined and accordingly represented as a context-free grammar, named level grammar. Then, a whole LCS is represented as a context-free grammar through a compounding of all level grammars. Finally, a case study is presented to demonstrate the potential usability of the proposed and established models of LCS.

A Fully Lexicalized Grammar for French Based on Meaning-Text Theory (Invited Talk)

Abstract: The paper presents a formal lexicalized dependency grammar based on Meaning-Text theory. This grammar associates semantic graphs with sentences. We propose a fragment of a grammar for French, including the description of extractions. The main particularity of our grammar is it that it builds bubble trees as syntactic representations, that is, trees whose nodes can be filled by bubbles, which can contain others nodes. Our grammar needs more complex operations of combination of elementary structures than other lexicalized grammars, such as TAG or CG, but avoids the multiplication of elementary structures and provides linguistically well-motivated treatments.1

A Fully Lexicalized Grammar for French Based on Meaning-Text Theory

Abstract: The paper presents a formal lexicalized dependency grammar based on Meaning-Text theory. This grammar associates semantic graphs with sentences. We propose a fragment of a grammar for French, including the description of ex- tractions. The main particularity of our grammar is it that it builds bubble trees as syntactic representations, that is, trees whose nodes can be filled by bubbles, which can contain others nodes. Our grammar needs more complex operations of combination of elementary structures than other lexicalized grammars, such as TAG or CG, but avoids the multiplication of elementary structures and provides linguistically well-motivated treatments.

Algebraic Treatment of Feature-oriented Systems

Abstract: An important aspect of the feature interaction problem is to formally capture the notion of feature interactions. Although this notion is quite well informally understood by the researchers of the domain, the way, they handle it, strongly depends on the field of investigation they decide to work on (formal method application, architectural conception, technological research ... ). In this article, we focus on how formally specifying and studying feature systems, and both integration and interaction of features. More precisely, we aim to give a logic-independent framework to deal with the notions of feature, feature-based systems and feature interactions. Then, to help the reader’s intuition, we instantiate it by a dynamic algebraic formalism and we give concrete examples of interactions between two features previously described in this formalism.

A large-scale systemic functional grammar of greek

Abstract: This paper presents a large-scale computational grammar of Greek, couched in the framework of Systemic Functional Linguistics. The grammar is being developed in the context of M-PIRO, a multilingual natural language generation project, where personalized descriptions of museum exhibits are generated automatically from a single database source. Although the grammar is still under development, it already provides a wide coverage of the Greek syntax and morphology. Our long-term goal is to produce a wide coverage computational grammar of Greek suited to generation applications.

Formal framework for a generic combination of a process algebra with an algebraic specification language: an overview

Abstract: In this paper, we suggest a formal framework as a basis for a genetic combination of formal languages. This makes it possible for the developer to specify the dynamic part of a system with a process algebra, and the static part with an algebraic specification language. The framework is based on a formal kernel composed of an abstract grammar describing the general form of the combination, and a global operational semantics giving the meaning of each language which can be built with our framework.

Teaching formal methods lite via testing

Abstract: A new style of formal methods course is described, based on a pragmatic approach that emphasizes testing. The course introduces students to formal specification using Z, and shows how formal specification and testing can benefit each other, in both the validation and verification phases. It uses a tools-based approach, with practical work that reinforces formal specification techniques as well as traditional software engineering skills, such as unit and system testing, inspection and defensive programming with assertions. The two main results are to identify several practical uses of formal specifications that are not widely practised or taught, and to demonstrate that teaching them results in a more interesting and relevant formal methods course. Copyright © 2001 John Wiley & Sons, Ltd.

Syntax-Directed Translation Schemes for Multi-Agent Systems Conversation Modelling

Abstract: In modem organisations the monolithic information systems of the past are being gradually replaced by networked systems, enabling distributed computing often based on multi-agent system architectures. This new paradigm enables the use of information systems support in new areas of organisational activity, especially those involving the interaction of business agents. All communication-intensive business processes based on formal conversations, i.e. partially ordered sets of communicative acts transmitted among a set of agents, qualify as candidates to, at least partial, automation. Still a very active area of research, this paradigm has been studied in areas such as distributed artificial intelligence, organisational simulation and workflow management. However, in all these areas the basic problem is the adequate representation of agent conversations. In this paper we present a formal method for conversation representation that is inspired in syntactic pattern recognition methods, specifically syntax-directed translation schemes. This method has a clear semantics that can be easily given a declarative implementation, thus becoming flexible enough to accommodate on-line extensions and exception handling.

Steps Towards Formal Verification of Agent-based E-Business Applications

Abstract: In this preliminary report about ongoing work, we discuss the issues of formalizing the specification of interaction process types for e-business applications and identifying techniques for proving correctness properties for them We introduce the concept of coherence for interaction processes in the broader context of multiagent communication based on agent communication languages Interaction process types can be sepcified by means of reaction rules in a declarative way In order to make use of the formal analysis techniques established for Petri nets, we investigate possibilities how to translate reaction rules into Petri nets

Efficient Processing with Constraint-Logic Grammars Using Grammar Compilation

Abstract: Technologies such as the Internet have accentuated the need to improve access, manipulation and translation of written language. One of the main goals of researchers in the field of computational linguisitics is to create programs that put to use knowledge of human language in pursuit of technology that can overcome the many obstacles in the interaction between human and computer. A major problem to be tackled by human-interface researchers is finding automated techniques that parse the complexities of human grammar. The intricacy of human grammar poses problems of accuracy and efficiency. This volume investigates programs for automatics analysis and production of written human language. The author proposes various techniques which focus on solutions for practical problems in processing constraint-logic grammars, these solutions allow the grammar writer to abstract over details of grammar processing and in many cases enable more efficient processing.

Evaluation of Recent Speech Grammar Standardization Efforts

Abstract: The “Voice Browser “ activity within the W3C consortium addresses the need for standards for speech grammars, dialogue descriptions etc. in distributed systems. This paper discusses the consortium’s recent speech grammar working draft specification. The W3C specification is based on the Java Speech Grammar Format (JSGF) defined by Sun Microsystems and is with all good and bad qualities characterized by traditions of formal language theory. In a constructive spirit, we suggest some possible improvements based on natural language theory. The suggestions concern compound feature-based semantic presentations, lexicon structure, ambiguity, and exhaustive parsing,

Grammars for learning control knowledge with GP

Abstract: In standard GP there are no constraints on the structure to evolve: any combination of functions and terminals is valid. However, sometimes GP is used to evolve structures that must respect some constraints. Instead of "ad-hoc" mechanisms, grammars can be used to guarantee that individuals comply with the language restrictions. In addition, grammars permit great flexibility to define the search space. EVOCK (Evolution of Control Knowledge) is a GP based system that learns control rules for PRODIGY, an AI planning system. EVOCK uses a grammar to constrain individuals to PRODIGY 4.0 control rule syntax. The authors describe the grammar specific details of EVOCK. Also, the grammar approach flexibility has been used to extend the control rule language utilized by EVOCK in earlier work. Using this flexibility, tests were performed to determine whether using combinations of several types of control rules for planning was better than using only the standard select type. Experiments have been carried out in the blocksworld domain that show that using the combination of types of control rules does not get better individuals, but it produces good individuals more frequently.

A formal data-model of the CORBA security service

Abstract: We use the formal language Z to specify and analyze the security service of CORBA. In doing so, we tackle the problem of how one can apply lightweight formal methods to improve the precision and aid the analysis of a substantial, informal specification. Our approach is scenario-driven: we use representative scenarios to determine which parts of the informal specification should be formalized and then verify the formal specification against the requirements of these scenarios.

Combining context provisions with graph grammar rewriting rules - the three-dimensional case

Abstract: In this paper we consider the representation and generation of three-dimensional structures by means of formal descriptive methods. Graph and graph grammar theory present us with a powerful two-dimensional representational method, and we propose to use these concepts as basis for the threedimensional case. Three-dimensional structures however, often appear in other structures and within a certain context. This context may be defined or influenced by the overall structure, or other related structures. We therefore need to be cognisant of the role that these contexts play when we introduce the concepts of three-dimensional graph and graph grammar systems, with particular reference to contextual rewriting rules. It is the combination of context provisions with graph grammar rewriting rules that results in a formal descriptive method which represents three-dimensional structures. The generative abilities of the concepts we introduce and discuss, are illustrated by considering the generation of various chemical structural formulae.

Functionally Organized Grammars Can Improve Language Learning

Abstract: This paper compares current German grammar books for language learners with regard to their functional usefulness, that is, from an onomasiological (or functional) point of view. Traditional grammars are organized semasiologically (or formally), since they explain first and foremost the formation of grammatical forms and structures and only secondarily their use, rarely giving information about the corresponding functions, let alone about frequency of use or contextual restrictions. In an ironic reversal of priorities, in order to obtain information about a particular communicative functioni from these grammars, one must already know which forms and structures can be used to express it. A linguistically educated native speaker may know the prototypical ones, but relatively few will manage to list out all the existing means, particularly if they are scattered among diverse formal categories. For instance, proceeding from form, relatively few people would look up the future tense in German in order to inform themselves of the possible ways to express supposition; although this is in fact one of the most commonly used means in German to express that function: