Showing papers on "Grammar systems theory published in 2008"

Design and implementation of a graph grammar based language for functional-structural plant modelling

Abstract: Increasing biological knowledge requires more and more elaborate methods to translate the knowledge into executable model descriptions, and increasing computational power allows to actually execute these descriptions. Such a simulation helps to validate, extend and question the knowledge. For plant modelling, the well-established formal description language of Lindenmayer systems reaches its limits as a method to concisely represent current knowledge and to conveniently assist in current research. On one hand, it is well-suited to represent structural and geometric aspects of plant models - of which units is a plant composed, how are these connected, what is their location in 3D space -, but on the other hand, its usage to describe functional aspects - what internal processes take place in the plant structure, how does this interact with the structure - is not as convenient as desirable. This can be traced back to the underlying representation of structure as a linear chain of units, while the intrinsic nature of the structure is a tree or even a graph. Therefore, we propose to use graphs and graph grammars as a basis for plant modelling which combines structural and functional aspects. In the first part of this thesis, we develop the necessary theoretical framework. Starting with a presentation of the state of the art concerning Lindenmayer systems and graph grammars, we develop the formalism of relational growth grammars as a variant of graph grammars. We show that this formalism has a natural embedding of Lindenmayer systems which keeps all relevant properties, but represents branched structures directly as axial trees and not as linear chains with indirect encoding of branches. In the second part, we develop the main practical result, the XL programming language as an extension of the Java programming language by very general rule-based features. Short examples illustrate the application of the new language features. We describe the built-in pattern matching algorithm of the implemented run-time system for the XL programming language, and we sketch a possible implementation of an XL compiler. The third part is an application of relational growth grammars and the XL programming language. We show how the general XL interfaces can be customized for relational growth grammars. On top of this customization, several examples from a variety of disciplines demonstrate the usefulness of the developed formalism and language to describe plant growth, especially functional-structural plant models, but also artificial life, architecture or interactive games. Some examples operate on custom graphs like XML DOM trees or scene graphs of commercial 3D modellers, while the majority uses the 3D modelling platform GroIMP, a software developed in conjunction with this thesis. The appendix gives an overview of the GroIMP software. The practical usage of its plug-in for relational growth grammars is also illustrated.

Modeling analogy as probabilistic grammar

Abstract: Formal implemented models of analogy face two opposing challenges. On the one hand, they must be powerful and flexible enough to handle gradient and probabilistic data. This requires an ability to notice statistical regularities at many different levels of generality, and in many cases, to adjudicate between multiple conflicting patterns by assessing the relative strength of each, and to generalize them to novel items based on their relative strength. At the same time, when we examine evidence from language change, child errors, psycholinguistic experiments, we find that only a small fraction of the logically possible analogical inferences are actually attested. Therefore, an adequate model of analogy must also be restrictive enough to explain why speakers generalize certain statistical properties of the data and not others. Moreover, in the ideal case, restrictions on possible analogies should follow from intrinsic properties of the architecture of the model, and not need to be stipulated post hoc.

Dynamic Systems Theory and Universal Grammar: Holding up a Turbulent Mirror to Development in Grammars

Abstract: Research over the last decades has shown that language development in its multiple forms is characterized by a succession of stable and unstable states. However, the variation observed is neither expected nor can it be accounted for on the basis of traditional learning concepts conceived of within the Universal Grammar (UG) paradigm. In this paper, I argue that modularly organized grammars bear much more of a dynamic potential than admitted thus far, and I propose a dynamic approach to the development of grammars, based on a conception of change as developed in the realm of Dynamic Systems Theory (DST). In my discussion of the available evidence of system-internal inconsistencies in different types of language acquisition and diachronic language change, I suggest that the nonlinear behavior observed results from a complex information flow modeled by internal and external feedback processes and that changes in grammars are tied to the amplification of new information leading to system-internal conflicts. Finally, I reconsider the role of UG in the apparent dichotomy of chance and necessity in the evolution of grammars. I argue that their stability is tied to universal principles and constraints on the format of natural languages (hence the self-similar or fractal nature of language), whereas the potential for change is given in the functional categories and their associated properties (the loci of grammars' bifurcation sensitivity).

Getting Formal Verification into Design Flow

Abstract: The ultimate goal of formal methods is to provide assurances about the quality, performance, security, etc. of systems. While formal tools have advanced greatly over the past two decades, widespread proliferation has not yet occurred, and the full impact of formal methods is still to be realized. This paper presents some ideas on how to catalyze the growth of formal techniques in day-to-day engineering practice. We draw on our experience as hardware engineers that want to use, and have tried to use, formal methods in our own designs. The points we make have probably been made before. However we illustrate each one with concrete designs. Our examples support three major themes: (1) correctness depends highly on the application and even a collection of formal methods cannot handle the whole problem; (2) high-level design languages can facilitate the interaction between design and formal methods; and (3) formal method tools should be presented as integrated debugging aids as opposed to one requiring mastering a foreign language or esoteric concepts.

Formal methods for interactive systems

Abstract: Interactive computer systems are increasingly ubiquitous. Their correct operation depends not only on the software and hardware but also on the human operators that interact with them. Furthermore, we are reliant on them in areas where high reliability is critical, whether due to safety, security or financial considerations. Traditional approaches to the formal verification of computer systems have focussed primarily on the correctness of software and hardware. It is often assumed that users will always act correctly. Results from cognitive psychology show that this is unrealistic. An alternative approach is to include user interfaces and interaction design as subjects for verification and for design and verification techniques to be informed by results from human factors experts like cognitive psychologists. In this way it can be ensured human limitations are explicitly taken into account in design and that we make best use of our strengths. The 1st International Workshop on Formal Methods for Interactive Systems (FMIS 2006) was held on 31 October 2006 in Macau SAR China. Its aim was to act as a forum for researchers in formal methods and cognitive psychology to discuss tools and techniques for the design and evaluation of interactive systems. From the 18 submissions, seven papers were presented at the workshop and their authors were invited to submit extended versions of their workshop papers to be considered for publication in Innovations in Systems and Software Engineering. Five papers were submitted and,

Efficient context-free grammar constraints

Abstract: With the introduction of constraints based on finite automata a new line of research has opened where constraints are based on formal languages. Recently, constraints based on grammars higher up in the Chomsky hierarchy were introduced. We devise a time- and space-efficient incremental arc-consistency algorithm for context-free grammars. Particularly, we show how to filter a sequence of monotonically tightening problems in cubic time and quadratic space. Experiments on a scheduling problem show orders of magnitude improvements in time and space consumption.

An unsupervised incremental learning algorithm for domain-specific language development

Abstract: While grammar inference (or grammar induction) has found extensive application in the areas of robotics, computational biology, and speech recognition, its application to problems in programming language and software engineering domains has been limited. We have found a new application area for grammar inference which intends to make domain-specific language development easier for domain experts not well versed in programming language design, and finds a second application in construction of renovation tools for legacy software systems. As a continuation of our previous efforts to infer context-free grammars (CFGs) for domain-specific languages which previously involved a genetic-programming based CFG inference system, we discuss extensions to the inference capabilities of GenInc, an incremental learning algorithm for inferring CFGs. We show that these extensions enable GenInc to infer more comprehensive grammars, discuss the results of applying GenInc to various domain-specific languages and evaluate the results using a comprehensive suite of grammar metrics.

Formal Concept Analysis

Abstract: Communicative Rationality, Logic, and Mathematics.- Actionability and Formal Concepts: A Data Mining Perspective.- Acquiring Generalized Domain-Range Restrictions.- A Finite Basis for the Set of -Implications Holding in a Finite Model.- Lexico-Logical Acquisition of OWL DL Axioms.- From Concepts to Concept Lattice: A Border Algorithm for Making Covers Explicit.- A Formal Context for Symmetric Dependencies.- The Number of Plane Diagrams of a Lattice.- Spectral Lattices of -Formal Contexts.- About Keys of Formal Context and Conformal Hypergraph.- An Algebraization of Linear Continuum Structures.- On the Complexity of Computing Generators of Closed Sets.- Generating Positive and Negative Exact Rules Using Formal Concept Analysis: Problems and Solutions.- On the Merge of Factor Canonical Bases.- Lattices of Rough Set Abstractions as P-Products.- Scale Coarsening as Feature Selection.- Formal Concept Analysis for the Identification of Combinatorial Biomarkers in Breast Cancer.- Handling Spatial Relations in Logical Concept Analysis to Explore Geographical Data.- Analysis of Social Communities with Iceberg and Stability-Based Concept Lattices.- Formal Concept Analysis Enhances Fault Localization in Software.- Refactorings of Design Defects Using Relational Concept Analysis.- Contingency Structures and Concept Analysis.- Comparison of Dual Orderings in Time II.

Random Context in Regulated Rewriting Versus Cooperating Distributed Grammar Systems

Abstract: It is well known that certain language families generated by cooperating distributed (CD) grammar systems can be characterized in terms of context-free random context grammars In particular, the language families generated by CD grammar systems working in the t- and -modes of derivation obey a characterization in terms of ET0L systems, or equivalently by context-free disjoint forbidding random context grammars, and of context-free random context grammars with appearance checking, respectively Now the question arises whether or not other random context like language families can be characterized in terms of CD grammar systems We positively answer this question, proving that there are derivation modes for CD grammar systems, namely the negated versions of the aforementioned modes, which precisely characterize the family of context-free disjoint forbidding random context languages and that of languages generated by context-free random context grammars without appearance checking In passing we show that every language generated by a context-free random context grammar without appearance checking can also be generated by a context-free recurrent programmed grammar without appearance checking, and vice versa

Some New Modes of Competence-Based Derivations in CD Grammar Systems

Abstract: We introduce some new cooperation protocols for cooperating distributed (CD) grammar systems. They depend on the number of different nonterminals present in the sentential form if a component has finished its work, i.e. on the final competence or efficiency of the grammar on the string (the competence is large if the number of the different nonterminals is small). We prove that if the underlying derivation mode is the t-mode derivation, then some variants of these systems determine the class of random context ET0L languages. If these CD grammar systems use the kstep limited derivations (for ki¾? 3) as underlying derivations, they are able to generate any recursively enumerable language.

System and method for automatically generating sentences of a language

Abstract: A system and method for automatically generating sentences in a language is disclosed. The system comprising a grammar processor for converting an input grammar into a hierarchical representation, and a grammar explorer module for traversing the grammar hierarchy based on an explore specification, which defines what nodes of the hierarchy should be explored. The explorer module takes the exploration specification as input and traverses the hierarchy according to the exploration types specified in the exploration specification. The system and method can be used to automatically generate assembly instructions for a microprocessor given its assembly language grammar, to generate sentences of a natural language like English from its grammar and to generate programs in a high-level programming language like C.

A grammar-based multiagent system in dynamic design

Abstract: This paper deals with the system of agents treated as a concurrent modular system, which is able to support the designer in solving complex design tasks. The behavior of design agents is modeled by sets of grammar rules. Each agent manages a graph grammar and a database of facts concerning the subtask for which it is responsible. The course of designing is determined by the interaction between cooperating specialized agents. The design context is expressed by the environment in which agents act and predicates describing design criteria. The organization, design methodology, and a semantic model of a grammar-based multiagent design system are presented. The notions of a valid design solution and a design solution consistent with the design criteria are also introduced. The proposed approach is illustrated by the example of designing a house estate.

On Formal Explicit and Implicit Grammar Instruction

Abstract: In the field of SLA, the explicit-implicit dimension has long been one of the controversial issues and focuses for researchers. It provides relatively fresh theoretical as well as empirical view angle to formal grammar instruction. This paper overviews both theories of explicit-implicit issues and empirical studies on formal explicit and implicit grammar teaching, and presents some issues that require to be noticed and attached much importance to this kind of studies, expecting to provide some help to the future research and to the real classroom.

Blending cognitive rule-based, process-based, and context-based theories in the development of online grammar instruction

Abstract: This study proposes to blend contemporary educational research in order to design an online instructional environment. The goal was to create an environment that would better educate learners about grammar use in higher education, given the complexity of the rule learning that was being asked of them. By blending approaches from tested educational research on cognitive information processing theories, schema theories, and situated cognitive theories in order to determine how language rules are best learned, eight design principles were derived for the instructional environment. A prototype of the environment was then developed. Two series of formative evaluations, one with a group of subject-matter experts (teachers, linguists, and instructional designers) and one with a group of students, were run against the instruction. Overall, it was found that a database-driven website employing user-defined variables to customize the instruction for each individual user was a useful way to achieve the goals of the study. iii Acknowledgements

Survey of Graph Grammars

Abstract: It is well known that formal language theory plays an important role in the development of computer science,and so will be the research on two dimensional graph grammar formalisms,which is an extension of one dimensional string grammars.Based on a summary of the generation,development and current status of graph grammars,this paper mainly introduces the newly emerging problems caused by the dimension extension and some new approaches,such as the solution to embedding problem,the classification of graph grammars and the decidability of membership problem.By taking some popular graph grammars as examples,especially some typical context-free and context-sensitive graph grammars,the paper discusses their approaches for solving the above mentioned problems,their shortcomings and unsolved research problems and future directions.

Research on a Formal Description Method of Network Behavior Based on Communication Sequential Process

Abstract: Formal description of network behavior is the important part in network management. But some problems have not yet to be adequately addressed are the semantic and behavioral aspects of composition in this domain. Therefore a formal description method was presented to network behavior. The method includes a simple formal language, and its semantic was described by CSP. The formal language has graphical syntax with topology style. And it also has some characters that are suitable for the formal research and analysis about some problems in network management. Consequently, the method can be used to provide precise formal description and analysis about network behavior. And a reliable mathematical foundation is also provided for the correctness and validity of software system design.

Constituent Structure for Filipino: Induction through Probabilistic Approaches

Abstract: The current state of Philippine linguistic resources, which includes formal grammars, electronic dictionaries and corpora are not yet significant to address industrial- strength language technologies. This paper discusses a computational approach in automatically estimating constituent structures from a corpus using unsupervised probabilistic approaches. Two models are presented and results show an F1 measure of greater than 69%. Issues and phenomena of the Filipino language are identified and discussed This paper discusses the algorithms used for the automatic induction of grammar for the Filipino language. The rationale for the study stems on the minimal work done on the development of a computational grammar for the Filipino language for the development of robust and industrial- strength natural language analysis and technologies. Existing Filipino grammars can only handle a subset of declarative type sentences. Considering the difficulty to manually construct a robust grammar capable of parsing a broad scope of sentences, automatic grammar induction is a consideration that can be used for learning language structure. Automated grammar induction systems deals with the generation of a grammar based from input corpora. Existing work for grammar induction fall under two categories based on their input constraints: Supervised and Unsupervised. Slightly supervised systems generate grammar rules from bracketed corpora or tree banks. Bracketed corpora are text documents that have been bracketed by a linguist to represent the skeletal syntactic structure of the sentences. Treebanks are large corpora that have been annotated with the part of speech tags, syntactic structure, and other functional attributes necessary. Unsupervised systems make use of non- bracketed corpora while applying searching and clustering algorithms to attempt to learn the language rules. Works on slightly supervised grammar induction, such as the works of Lari and Young(1991), Brill(1993), Sekine and Grishman(1995), and Charniak(1996), present different output formalisms to represent the grammar. However, Filipino is currently a resource-limited language and does not have the computational resources necessary for the algorithms presented. There are existing corpora available for the language, but these have not yet been bracketed.

Modelling dialogue as inter-action

Abstract: In this paper we introduce a formal model of dialogue based on grammar systems theory: Conversational Grammar Systems (CGS). The model takes into account ideas from the study of human-human dialogue in order to define a flexible mechanism for coherent dialogues that may help in the design of effective and user-friendly computer dialogue systems. The main feature of the model is to present an action view of dialogue. CGS model dialogue as an inter-action, this is a sequence of acts performed by two or more agents in a common environment. We claim that CGS are able to model dialogue with a high degree of flexibility, which means that they are able to accept new concepts and modify rules, protocols and settings during the computation.

Formal Method of Requirement Engineering

Abstract: Based on the basic concept of Requirement Engineering (RE),some concepts of the lift cycle model of RE and RE methodology were presented in this paper.The importance of introducing the formal method into RE was discussed based on the definition and characters of RE.The degree of formalization of RE was improved in two ways,requirements modeling language and formal verification technology.A principle of choosing formal methods was also provided.Finally,some characters of the modeling language were introduced.

Formal Modeling in Systems Biology: An Approach from Theoretical Computer Science

Abstract: Cell Biology, the study of the morphological and functional organization of cells, is an established field in biochemical research. Computer Science can provide biologists with models able to describe complex systems such as cells. This approach belongs to the new research field called Systems Biology. Many formalisms developed to model interactive systems have been applied to Biology. Formal models avoid ambiguity, that is often a problem of the notations used by biologists. Moreover, they allow the development of simulators and the verification of properties by means of tools that are widely used in other application fields of Computer Science, but unknown to biologists. The aim of this work is to study a new formalism, the Calculus of Looping Sequences, with a simple notation and able to describe systems at different abstraction levels. Formal analysis and stochastic simulation tools are developed and applied to examples of real biological systems. This book is addressed to computer scientists interested either in bioinformatics or in formal methods. It can be used by biologists as an introduction to the application of Theoretical Computer Science means to biological systems.

Applying A Formal Language of Command and Control For Interoperability Between Systems

Abstract: : Battle Management Language (BML) is being developed as an open standard that unambiguously specifies Command and Control information, including orders and reports built upon precise representations of tasks. BML is both a methodology and a language specification, based on doctrine and consistent with Coalition standards. Recent work has concentrated on leveraging standard data model semantics (particularly the Joint Consultation, Command and Control Information Exchange Data Model ? JC3IDM) for a Simulation Interoperability Standards Organization (SISO) Coalition BML (C-BML) specification. While current BML work has organized task representations around the Command and Control Information Exchange Data Model and the 5 Ws (WHO, WHAT, WHERE, WHEN and WHY), the grammar is implicit rather than explicit. Development of a formal grammar is necessary for the specification of a complete language. Formalizing BML by defining its grammar follows the conventions determined by the theory of Linguistics. Initially, it must be determined which type of grammar is to be used. The Chomsky hierarchy specifies that grammars can be Type 0 (unrestricted grammars), Type 1 (context-sensitive grammars), Type 2 (context-free grammars) or Type 3 (regular grammars). While humans sometimes use constructions that may best be described by a context-sensitive grammar (type 1), automated processing is best supported by a more constrained one (Type 2 or Type 3). Our analysis indicates that a Type 2 grammar best fits the requirements for a BML. To specify a BML grammar (our implementation is the C2 Lexical Functional Grammar - C2LG), rules are developed to determine how to create valid BML sentences that describe military tasks, requests and reports.

Techniques for context-free grammar induction and applications

Abstract: Grammar Inference is the process of learning a grammar from examples, either positive (i.e., the grammar generates the string) and/or negative (i.e., the grammar does not generate the string). Although grammar inference has been successfully applied to many diverse domains such as speech recognition and robotics, its application to software engineering has been limited. This research investigates the applicability of grammar inference to software engineering and programming language development challenge problems, where grammar inference offers an innovative solution to the problem, while remaining tractable and within the scope of that problem. Specifically, the following challenges are addressed in this research: (1) Recovery of a metamodel from instance models: Within the area of domain-specific modeling (DSM), instance models may evolve independently of the original metamodel resulting in metamodel drift, an inconsistency between the instance model and the associated metamodel such that the instance model may no longer be loaded into the modeling tool. Although prior work has focused on the problem of schema evolution, no previous work addresses the problem of recovering a lost metamodel from instance models. A contribution of this research is the MetAmodel Recovery System (MARS) that uses grammar inference in concert with a host of complementary technologies and tools to address the metamodel drift problem. (2) Recovery of domain-specific language (DSL) specifications from example DSL programs: An open problem in DSL development is a need for reducing the time needed to learn language development tools by incorporating support for the description-by-example (DBE) paradigm of language specifications like syntax. This part of the dissertation focuses on recovering specifications of imperative, explicitly Turing-complete and context-free DSLs. A contribution of this research is GenInc, an unsupervised incremental CFG learning algorithm that allows further progress towards inferring DSLs and finds a second application in recovery of legacy DSLs. The research described in this dissertation makes the following contributions: (i) A metamodel recovery tool for DSM environments, (ii) Easier development of DSLs for domain experts, and (iii) Advances in grammar inference algorithms that may also have new applications in other areas of computer sciences (e.g., bioinformatics).

Using Functional Languages in Formal Methods: The Pet System

Abstract: UsingFunctionalLanguagesinormalMetho ds:ThePetSystemElsaL.GunterandDoronA.PeledBellLab oratories600MountainAve.MurrayHill,NJ07974March13,20001Intro ductionFormalmetho dsareacollectionoftechniquesaimedatincreasingthereliabilityofsoftwareandhardwsystems.Sincethesystemsunderinvestigationoftenquitecomplex,themainchallengeofformalmetho dsisachievingeciency.Therefore,thetendencyistodevelopformalmetho dsto olsinprogramminglanguageslikeC,whereonecanobtainlowerlevelcontrol,evenuptotheofforcingsomecomputationtob ep erformedwithinthemachineregisters.Withtheadvancementofmo dermcompilers,higherlevelprogramminglanguagescannowo erreasonableeciencyinadditiontosp ecialfeaturesnotpresentloerlevellanguages.Inthispap er,weconcentrateonaparticularstrengthoffunctionalprogram-minglanguage,andinparticularSML.Sp eci cally,wefo cusontheabilitytop erformsymb olicmanipulations.Thiscapability,standardinfunctionallan-guages,andinparticularSML,canrequirealotofsp ecialinfrastructuretob epreparedinordertousedwithadeclarativelanguagelikC.Itallowsthecalculationofconditionsrelatedtocertainexecutionsthecheckedsoftware,andtheveri cationtestingofsoftware.Onepreviousexp eriencewheretheconvenientsymb olicmanipulationfeatureofSMLwasusedhasledtotheimplementationaprototyp efortranslatingsp eci cationwritteninlineartemp orallogic[3]toaformthatallowsauto-maticveri cation(mo delchecking)[?]ofsoftware.Thisexp erience,rep ortedin[?],resultedaprototyp eforthistranslation,consistingofab out200linesofSMLco de,writtenduringasingledaywork.TheactualimplementationthealgorithmthatwasintegratedtoSpinmo delcheckingsystem[?],propagatedover4months,andincludedab out5,000linesofCco de.Themain1

Grammar-Based Argument Construction

Abstract: The science of history motivates the investigation on how arguments are constructed, which are later to be used in argumentation frameworks. This is difficult as much arguments in history are frequently built upon sources which are mutually inconsistent. In this paper it is shown how formal grammars can be employed in order to construct arguments. Thereby, it is investigated how the interplay of expressiveness and parsing effciency motivates in particular to use mildly context sensitive grammars. These systems are more expressive than context free grammars, but can still be parsed within polynomial time.

Informational model of natural language processing

Abstract: The formal model of natural language processing in knowledge-based information systems is considered. The components realizing functions of offered formal model are described.