waashk/dblp huggingface dataset:
xtag system - a wide coverage grammar for english. this paper present the xtag system, a grammar development tool based on the tree adjoining grammar (tag) formalism that includes a wide-coverage syntactic grammar for english. the various components of the system are discussed and preliminary evaluation results from the parsing of various corpora are given. results from the comparison of xtag against the ibm statistical parser and the alvey natural language tool parser are also given.
integrating stress and intonation into a concept-to-speech system. the paper deals with the integration of intonation algorithms into a concept-to-speech system for german. the algorithm for computing the stress hierarchy of a sentence introduced by kiparski (1973) and the theory of syntactic grouping for intonation patterns developed by bierwisch (1973) have been studied extensively, but they have never been implemented in a concept-to-speech system like the one presented here. we describe the back end of this concept-to-speech system: the surface generator transfers a hierarchical dependency structure of a sentence into a phoneme string by traversing it in a recursive-descent manner. surface structures unfold while generation proceeds, which means that at no point of the process does the full syntactic tree structure exist. as they depend on syntactic features, both the indices introduced by the kiparski (degrees of stress) and the bierwisch (indexed border markers) formalism have to be inserted by the generator. this implies some changes to the original algorithms, which are demonstrated in this paper. the generator has been tested in the domain of an expert system that helps to debug electronic circuits. the synthesized utterances of the test domain show significant improvements over monotonous forms of speech produced by systems not making use of intonation information.
semantic-based transfer. this article presents a new semantic-based transfer approach developed and applied within the verbmobil machine translation project. we give an overview of the declarative transfer formalism together with its procedural realization. our approach is discussed and compared with several other approaches from the mt literature. the results presented in this article have been implemented and integrated into the verbmobil system.
parameterization of the interlingua in machine translation. the task of designing as interlingual machine translation system is difficult, first because the designer must have a knowledge of the principles underlying crosslinguistic distinctions for the languages under consideration, and second because the designer must then be able to incorporate this knowledge effectively into the system. this paper provides a catalog of several types of distinctions among spanish, english, and german, and describes a parametric approach that characterizes these distinctions, both at the syntactic level and at the lexical-semantic level. the approach described here is implemented in a system called unitran, a machine translation system that translates english, spanish, and german bidirectionally.
role of word sense disambiguation in lexical acquisition: predicting semantics from syntactic cues. this paper addresses the issue of word-sense ambiguity in extraction from machine-readable resources for the construction of large-scale knowledge sources. we describe two experiments: one which ignored word-sense distinctions, resulting in 6.3% accuracy for semantic classification of verbs based on (levin, 1993); and one which exploited word-sense distinctions, resulting in 97.9% accuracy. these experiments were dual purpose: (1) to validate the central thesis of the work of (levin, 1993), i.e., that verb semantics and syntactic behavior are predictably related; (2) to demonstrate that a 15-fold improvement can be achieved in deriving semantic information from syntactic cues if we first divide the syntactic cues into distinct groupings that correlate with different word senses. finally, we show that we can provide effective acquisition techniques for novel word senses using a combination of online sources.
feature logic with disjunctive unification. we introduce feature terms containing sorts, variables, negation and named disjunction for the specification of feature structures. we show that the possibility to label disjunctions with names has major advantages both for the use of feature logic in computational linguistics and its implementation. we give an open world semantics for feature terms, where the denotation of a term is determined in dependence on the disjunctive context, i.e. the choices taken for the disjunctions. we define context-unique feature descriptions, a relational, constraint-based representation language and give a normalization procedure that allows to test consistency of feature terms. this procedure does not only avoid expansion to disjunctive normal form but maintains also structure sharing between information contained in different disjuncts as much as possible. context-unique feature descriptions can be easily implemented in environments that support ordinary unification (such as prolog).
discourse anaphora. this paper reports on a model that serves anaphora resolution. a distinction will be made between possible antecedents and preferred antecedents. the set of linguistically possible candidates will be defined in terms of compatibility and recency. preferred antecedents are a subset of the possible antecedents, selected by the application of extralinguistic knowledge. motivation for the particular design and comparison with other approaches are extensive.
towards robust patr. we report on the initial stages of development of a robust parsing system, to be used as part of the editor's assistant, a program that detects and corrects textual errors and infelicities in the area of syntax and style. our mechanism extends the standard patr-ii formalism by indexing the constraints on rules and abstracting away control of the application of these constraints. this allows independent specification of grouping and ordering of the constraints, which can improve the efficiency of processing, and in conjunction with information specifying whether constraints are necessary or optional, allows detection of syntactic errors.
hopfield models as nondeterministic finite-state machines. the use of neural networks for integrated linguistic analysis may be profitable. this paper presents the first results of our research on that subject: a hopfield model for syntactical analysis. we construct a neural network as an implementation of a bounded push-down automaton, which can accept context-free languages with limited center-embedding. the network's behavior can be predicted a priori, so the presented theory can be tested. the operation of the network as an implementation of the acceptor is provably correct. furthermore we found a solution to the problem of spurious states in hopfield models: we use them as dynamically constructed representations of sets of states of the implemented acceptor. the so-called neural-network acceptor we propose, is fast but large.
towards discourse-oriented nonmonotonic system. the purpose of this paper is to analyse the phenomenon of nonmonotonicity in a natural language and to formulate a number of general principles which should be taken into consideration while constructing a discourse oriented nonmonotonic formalism.
inferring knowledge from a large semantic network. in this paper, we present a rich semantic network based on a differential analysis. we then detail implemented measures that take into account common and differential features between words. in a last section, we describe some industrial applications.
grice incorporated cooperativity in spoken dialogue. the paper presents a consolidated set of principles of cooperative spoken human-machine dialogue which have the potential for being turned into practically applicable design guidelines. the principles have been validated in three ways. they were established from a wizard of oz simulation corpus used to develop the dialogue model for a spoken language dialogue system. developed independently of gricean theory, some of the principles were refined through comparison with grice's maxims of cooperativity in conversation. finally, the principles were tested in the user test of the implemented dialogue system. the paper shows that grice's maxims constitute a sub-set of the principles. the non-gricean principles and dialogue aspects they introduce are presented and discussed.
text authoring, knowledge acquisition and description logics. we present a principled approach to the problem of connecting a controlled document authoring system with a knowledge base. we start by describing closed-world authoring situations, in which the knowledge base is used for constraining the possible documents and orienting the user's selections. then we move to open-world authoring situations in which, additionally, choices made during authoring are echoed back to the knowledge base. in this way the information implicitly encoded in a document becomes explicit in the knowledge base and can be re-exploited for simplifying the authoring of new documents. we show how a datalog kb is sufficient for is the closed-world situation, while a description logic kb is better-adapted to the more complex open-world situation, all along, we pay special attention to logically sound solutions and to decidability issues in the different processes.
two approaches to commonsense inferencing for discourse analysis. the dominant philosophy regarding the formalization of commonsense inferencing in the physical domain consists in the exploitation of the "tarskian" scheme axiomatization <-> interpretation borrowed from mathematical logic. the commonsense postulates constitute the axiomatization, and the real world provides the "model" for this axiomatization.the observation of the effective activity of linguistic communication and of the commonsense inferencing processes which are involved in it show the unacceptability of this scheme.an alternative is proposed, where the notion of "conceptual category" plays a principal role, and where the principle of logical adequation of an axiomatization to a model is replaced by a notion of "projection" of a conceptual structure onto the observed reality.
a generalized greibach normal form for definite clause grammars. an arbitrary definite clause grammar can be transformed into a so-called generalized greibach normal form (ggnf), a generalization of the classical greibach normal form (gnf) for context-free grammars.the normalized definite clause grammar is declaratively equivalent to the original definite clause grammar, that is, it assigns the same analyses to the same strings. offline-parsability of the original grammar is reflected in an elementary textual property of the transformed grammar. when this property holds, a direct (top-down) prolog implementation of the normalized grammar solves the parsing problem: all solutions are enumerated on backtracking and execution terminates.when specialized to the simpler case of context-free grammars, the ggnf provides a variant to the gnf, where the transformed context-free grammar not only generates the same strings as the original grammar, but also preserves their degrees of ambiguity (this last property does not hold for the gnf).the ggnf seems to be the first normal form result for dcgs. it provides an explicit factorization of the potential sources of undecidability for the parsing problem, and offers valuable insights on the computational structure of unification grammars in general.
a simple transformation for onine-parsable grammars and its termination properties. we present, in easily reproducible terms, a simple transformation for offline-parsable grammars which results in a provably terminating parsing program directly top-down interpretable in prolog. the transformation consists in two steps: (1) removal of empty-productions, followed by: (2) left-recursion elimination. it is related both to left-corner parsing (where the grammar is compiled, rather than interpreted through a parsing program, and with the advantage of guaranteed termination in the presence of empty productions) and to the generalized greibach normal form for dcgs (with the advantage of implementation simplicity).
extended dependency structures and their formal interpretation. we describe two "semantically-oriented" dependency-structure formalisms, u-forms and s-forms. u-forms have been previously used in machine translation as interlingual representations, but without being provided with a formal interpretation. s-forms, which we introduce in this paper, are a scoped version of u-forms, and we define a compositional semantics mechanism for them. two types of semantic composition are basic: complement incorporation and modifier incorporation. binding of variables is done at the time of incorporation, permitting much flexibility in composition order and a simple account of the semantic effects of permuting several incorporations.
a symmetrical approach to parsing and generation. lexical grammars are a class of unification grammars which share a fixed rule component, for which there exists a simple left-recursion elimination transformation. the parsing and generation programs are seen as two dual non-left-recursive versions of the original grammar, and are implemented through a standard top-down prolog interpreter. formal criteria for termination are given as conditions on lexical entries: during parsing as well as during generation the processing of a lexical entry consumes some amount of a guide; the guide used for parsing is a list of words remaining to be analyzed, while the guide for generation is a list of the semantics of constituents waiting to be generated.
xml and multilingual document authoring: convergent trends. typical approaches to xml authoring view a xml document as a mixture of structure (the tags) and surface (text between the tags). we advocate a radical approach where the surface disappears from the xml document altogether to be handled exclusively by rendering mechanisms. this move is based on the view that the author's choices when authoring xml documents are best seen as language-neutral semantic decisions, that the structure can then be viewed as interlingual content, and that the textual output should be derived from this content by language-specific realization mechanisms, thus assimilating xml authoring to multilingual document authoring. however, standard xml tools have important limitations when used for such a purpose: (1) they are weak at propagating semantic dependencies between different parts of the structure, and, (2) current xml rendering tools are ill-suited for handling the grammatical combination of textual units. we present two related proposals for overcoming these limitations: one (gf) originating in the tradition of mathematical proof editors and constructive type theory, the other (ig), a specialization of definite clause grammars strongly inspired by gf.
context-free grammar rewriting and the transfer of packed linguistic representations. we propose an algorithm for the trausfer of packed linguistic structures, that is, finite collections of labelled graphs which share certain subparts. a labelled graph is seen as a word over a vocabulary of description elements (nodes, arcs, labels), and a collection of graphs as a set of such words, that is, as a language over description elements. a packed representation for the collection of graphs is then viewed as a context-free grammar which generates such a language. we present an algorithm that uses a conventional set of transfer rules but is capable of rewriting the cfg representing the source packed structure into a cfg representing the target packed structure that preserves the compaction properties of the source cfg.
partial ordering and aktionsarten in discourse representation theory. this paper presents an approach to deal with the underspecification of aktionsarten in german sentences. in german the difference between an accomplishment and the associated progressive state is often not marked on the sentence level. this distinction is important for correctly interpreting texts and for translation into languages which provide morphological markings of aktionsarten. to maintain compositionality we suggest a two-step analysis of a text with respect to the temporal relations and the classification as events or states. this analysis is guided by the discourse representation theory developed by kamp and makes use of world knowledge and an inference component.the problem of classification can be reformulated as the problem of finding an embedding function f from the representational entities onto the domain of a model. the models we use are structures built from intervals of time, events and individuals. considering intensional models of this type will allow us to give truth-conditions for progressive states related to corresponding accomplishments. we restrict ourselves to progressive states of intentional actions and use the beliefs of the agent.
on representing the temporal structure of a natural language text. a proposal to deal with tenses in the framework of discourse representation theory is presented, as it has been implemented for a fragment at the ims for the project lilog. it is based on the theory of tenses of h. kamp and ch. rohrer. the system uses the tense and aspect information, the information about the temporal discourse structure of the preceding text stored in a specific list of possible reference times, and background knowledge. these types of information interact in order to choose a suited temporal anchor for the event of a new sentence.with respect to extended texts, choosing the right reference time for a new event is a problem which has been largely neglected in the literature.
disambiguation by information structure in drt. text understanding and high quality machine translation often necessitate the disambiguation of ambigous structures or lexical elements. drawing inferences from the context can be a means for resolving semantic ambiguities. however, often, this is an expensive strategy that, in addition, not always comes up with a clear preference for one of the alternatives. in this paper, we argue that in a number of cases deep semantic analyses can be avoided by taking into account the constraints that the alternative readings impose onto the information structure. to this end, we present a study of the ambigous german adverb erst and point out the particular circumstances under which the given information structure disambiguates the adverb without further semantic analysis.
formal syntax and semantics of case stacking languages. in this paper the phenomenom of case stacking is investigated from a formal point of view. we will define a formal language with idealized case marking behaviour and prove that stacked cases have the ability to encode structural information on the word thereby allowing for unrestricted word order. furthermore, the case stacks help to compute this structure with a low complexity bound. as a second part we propose a compositional semantics for languages with stacked cases and show how this proposal may work for our formal language as well as for an example from warlpiri.
machine translation method using inductive learning with genetic algorithms. we have proposed a method of machine translation, which acquires translation rules from translation examples using inductive learning, and have evaluated the method. and we have confirmed that the method requires many translation examples. to resolve this problem, we applied genetic algorithms and evaluated it by some experiments. we confirmed that the accuracy rate of translation increased from 52.8% to 61.9% by applying genetic algorithms.
collaboration on reference to objects that are not mutually known. in conversation, a person sometimes has to refer to an object that is not previously known to the other participant. we present a plan-based model of how agents collaborate on reference of this sort. in making a reference, an agent uses the most salient attributes of the referent. in understanding a reference, an agent determines his confidence in its adequacy as a means of identifying the referent. to collaborate, the agents use judgment, suggestion, and elaboration moves to refashion an inadequate referring expression.
towards developing reusable nlp dictionaries. development of resuable dictionaries for nlp applications requires a carefully designed lexicological framework, a lexical acquisition strategy, an integrated development toolbox, and facilities to generate dictionaries for client applications. this paper presents results of the lexic project, which was set up to prepare the development of large multilingual lexical resources.
a lexical functional grammar system in prolog. this paper describes a system in prolog for the automatic transformation of a grammar, written in lfg formalism, into a dcg-based parser. it demonstrates the main principles of the transformation, the representation of f-structures and constraints, the treatment of long-distance dependencies, and left recursion.finally some problem areas of the system and possibilities for overcoming them are discussed.
directional constraint evaluation in optimality theory. weighted finite-state constraints that can count unboundedly many violations make optimality theory more powerful than finite-state transduction (frank and satta, 1998). this result is empirically and computationally awkward. we propose replacing these unbounded constraints, as well as non-finite-state generalized alignment constraints, with a new class of finite-state directional constraints. we give linguistic applications, results on generative power; and algorithms to compile grammars into transducers.
three new probabilistic models for dependency parsing: an exploration. after presenting a novel o(n3) parsing algorithm for dependency grammar, we develop three contrasting ways to stochasticize it. we propose (a) a lexical affinity model where words struggle to modify each other, (b) a sense tagging model where words fluctuate randomly in their selectional preferences, and (c) a generative model where the speaker fleshes out each word's syntactic and conceptual structure without regard to the implications for the hearer. we also give preliminary empirical results from evaluating the three models' parsing performance on annotated wall street journal training text (derived from the penn treebank). in these results, the generative model performs significantly better than the others, and does about equally well at assigning part-of-speech tags.
a formal description of arabic syntax in definite clause grammar. arabic has some special syntax features which lead to complex syntax structures. we have developed a formal description of arabic syntax in definite clause grammar. this grammar is characterized by its high descriptive power due to its dual formulation in terms of functions and in terms of grammatical categories. the developed grammar has a high coverage of arabic language and has context sensitive capabilities. it is suitable for the advanced applications of natural language processing.