2,157 research outputs found
Amalia -- A Unified Platform for Parsing and Generation
Contemporary linguistic theories (in particular, HPSG) are declarative in
nature: they specify constraints on permissible structures, not how such
structures are to be computed. Grammars designed under such theories are,
therefore, suitable for both parsing and generation. However, practical
implementations of such theories don't usually support bidirectional processing
of grammars. We present a grammar development system that includes a compiler
of grammars (for parsing and generation) to abstract machine instructions, and
an interpreter for the abstract machine language. The generation compiler
inverts input grammars (designed for parsing) to a form more suitable for
generation. The compiled grammars are then executed by the interpreter using
one control strategy, regardless of whether the grammar is the original or the
inverted version. We thus obtain a unified, efficient platform for developing
reversible grammars.Comment: 8 pages postscrip
Attempto - From Specifications in Controlled Natural Language towards Executable Specifications
Deriving formal specifications from informal requirements is difficult since
one has to take into account the disparate conceptual worlds of the application
domain and of software development. To bridge the conceptual gap we propose
controlled natural language as a textual view on formal specifications in
logic. The specification language Attempto Controlled English (ACE) is a subset
of natural language that can be accurately and efficiently processed by a
computer, but is expressive enough to allow natural usage. The Attempto system
translates specifications in ACE into discourse representation structures and
into Prolog. The resulting knowledge base can be queried in ACE for
verification, and it can be executed for simulation, prototyping and validation
of the specification.Comment: 15 pages, compressed, uuencoded Postscript, to be presented at EMISA
Workshop 'Naturlichsprachlicher Entwurf von Informationssystemen -
Grundlagen, Methoden, Werkzeuge, Anwendungen', May 28-30, 1996, Ev. Akademie
Tutzin
Experiences with the GTU grammar development environment
In this paper we describe our experiences with a tool for the development and
testing of natural language grammars called GTU (German:
Grammatik-Testumgebumg; grammar test environment). GTU supports four grammar
formalisms under a window-oriented user interface. Additionally, it contains a
set of German test sentences covering various syntactic phenomena as well as
three types of German lexicons that can be attached to a grammar via an
integrated lexicon interface. What follows is a description of the experiences
we gained when we used GTU as a tutoring tool for students and as an
experimental tool for CL researchers. From these we will derive the features
necessary for a future grammar workbench.Comment: 7 pages, uses aclap.st
An open source rule induction tool for transfer-based SMT
In this paper we describe an open source tool for automatic induction of transfer rules. Transfer rule induction is carried out on pairs of dependency structures and their node alignment to produce all rules consistent with the node alignment. We describe an efficient algorithm for rule induction and give a detailed description of how to use the tool
An Abstract Machine for Unification Grammars
This work describes the design and implementation of an abstract machine,
Amalia, for the linguistic formalism ALE, which is based on typed feature
structures. This formalism is one of the most widely accepted in computational
linguistics and has been used for designing grammars in various linguistic
theories, most notably HPSG. Amalia is composed of data structures and a set of
instructions, augmented by a compiler from the grammatical formalism to the
abstract instructions, and a (portable) interpreter of the abstract
instructions. The effect of each instruction is defined using a low-level
language that can be executed on ordinary hardware.
The advantages of the abstract machine approach are twofold. From a
theoretical point of view, the abstract machine gives a well-defined
operational semantics to the grammatical formalism. This ensures that grammars
specified using our system are endowed with well defined meaning. It enables,
for example, to formally verify the correctness of a compiler for HPSG, given
an independent definition. From a practical point of view, Amalia is the first
system that employs a direct compilation scheme for unification grammars that
are based on typed feature structures. The use of amalia results in a much
improved performance over existing systems.
In order to test the machine on a realistic application, we have developed a
small-scale, HPSG-based grammar for a fragment of the Hebrew language, using
Amalia as the development platform. This is the first application of HPSG to a
Semitic language.Comment: Doctoral Thesis, 96 pages, many postscript figures, uses pstricks,
pst-node, psfig, fullname and a macros fil
Recommended from our members
Automating class definitions from OWL to English
Text definitions for entities within bio-ontologies are a cor-nerstone of the effort to gain a consensus in understanding and usage of those ontologies. Writing these definitions is, however, a considerable effort and there is often a lag be-tween specification of the entities in the ontology and the development of the text-based definitions. As well as these text definitions, there can also be logical descriptions and definitions of an ontology's entities. The goal of natural lan-guage generation (NLG) from ontologies is to take the logi-cal description of entities and generate fluent natural lan-guage. We should be able to use NLG to automatically pro-vide text-based definitions from an ontology that has logical descriptions of its entities and thus avoid the bottleneck of authoring these definitions by hand. In this paper we present some early work in using NLG to provide such text definitions for the Experimental factor Ontology (EFO). We present our results, discuss issues in generating text definitions, and highlight some future work
- âŠ