Analysing symbolic music with probabilistic grammars

Recent developments in computational linguistics offer ways to approach the analysis of musical structure by inducing probabilistic models (in the form of grammars) over a corpus of music. These can produce idiomatic sentences from a probabilistic model of the musical language and thus offer explanations of the musical structures they model. This chapter surveys historical and current work in musical analysis using grammars, based on computational linguistic approaches. We outline the theory of probabilistic grammars and illustrate their implementation in Prolog using PRISM. Our experiments on learning the probabilities for simple grammars from pitch sequences in two kinds of symbolic musical corpora are summarized. The results support our claim that probabilistic grammars are a promising framework for computational music analysis, but also indicate that further work is required to establish their superiority over Markov models

Logical ambiguity

The thesis presents research in the field of model theoretic semantics on the problem of ambiguity, especially as it arises for sentences that contain junctions (and,or) and quantifiers (every man, a woman). A number of techniques that have been proposed are surveyed, and I conclude that these ought to be rejected because they do not make ambiguity 'emergent': they all have the feature that subtheories would be able to explain all syntactic facts yet would predict no ambiguity. In other words these accounts have a special purpose mechanism for generating ambiguities.It is argued that categorial grammars show promise for giving an 'emergent' account. This is because the only way to take a subtheory of a particular categorial grammar is by changing one of the small number of clauses by which the categorial grammar axiomatises an infinite set of syntactic rules, and such a change is likely to have a wider range of effects on the coverage of the grammar than simply the subtraction of ambiguity.Of categorial grammars proposed to date the most powerful is Lambek Categorial Grammar, which defines the set of syntactic rules by a notational variant of Gentzen's sequent calculus for implicational propositional logic, and which defines meaning assignment by using the Curry- Howard isomorphism between Natural Deduction proofs in implicational propositional logic and terms of typed lambda calculus. It is shown that no satisfactory account of the junctions and quantifiers is possible in Lambek categorial grammar.I introduce then a framework that I call Polymorphic Lambek Categorial Grammar, which adds variables and their universal quantification, to the language of categorisation. The set of syntac¬ tic rules is specified by a notational variant of Gentzen's sequent calculus for quantified proposi¬ tional logic, and which defines meaning assignment by using Girard's Extended Curry-Howard isomorphism between Natural Deduction proofs in quantified implicational propositional logic and terms of 2nd order polymorphic lambda calculus. It is shown that this allows an account of the junctions and quantifiers, and one which is 'emerg

A novel approach to estimating the debt capacity of European SMEs

Research background: The concept of debt capacity assumes that a maximum value of debt ratio exists that when exceeded triggers unfavourable consequences, such as drop in market value, default or a change in the business' creditworthiness. With the current state of the art there is a priori no theoretical assurance that such a specific value exists, or rather it is repre-sented by an interval of values. Beyond that, our understanding of debt capacity is often limited to a theoretical approximation by firm-specific factors, while the context of macroeco-nomic factors, especially those critical for SMEs, is neglected.Purpose of the article: The aim of this paper is to present a novel approach to estimating SMEs' debt capacity. Further, the aim is to answer the question of what firm-level and macro -economy conditions lead to exhausting the SMEs' debt capacity and under what conditions a specific value of maximum debt capacity could be estimated.Methods: To estimate the debt capacity, we suggest a use of an information entropy minimis-ing heuristic and the Minimal Description Length Principle. In this approach, the observed feature space is categorised into several regions. In this case, such a region represents a set of firm-and macroeconomy-specific conditions forming the debt capacity of the SMEs. To the best of our knowledge, such an approach has not yet been used in debt capacity applications.Findings & value added: We found out that the debt ratio itself provides little explanation of exhausted debt capacity, suggesting that high debt levels are compensated for by other fac-tors. By using the suggested approach, a set of more than 100 different regions was analysed. It was found that in case of five regions (sets of conditions) the debt capacity is exhausted, as the high level of debt has significant distress consequences

Mathematical linguistics

but in fact this is still an early draft, version 0.56, August 1 2001. Please d

Inquiries into the lexicon-syntax relations in Basque

Index:- Foreword. B. Oyharçabal.- Morphosyntactic disambiguation and shallow parsing in computational processing in Basque. I. Aduriz, A. Díaz de Ilarraza.- The transitivity of borrowed verbs in Basque: an outline. X. Alberdi.- Patrixa: a unification-based parser for Basque and its application to the automatic analysis of verbs. I. Aldezabal, M. J. Aranzabe, A. Atutxa, K.Gojenola, K, Sarasola.- Learning argument/adjunct distinction for Basque. I. Aldezabal, M. J. Aranzabe, K. Gojenola, K, Sarasola, A. Atutxa.- Analyzing verbal subcategorization aimed at its computation application. I. Aldezabal, P. Goenaga.- Automatic extraction of verb paterns from “hauta-lanerako euskal hiztegia”. J. M. Arriola, X. Artola, A. Soroa.- The case of an enlightening, provoking an admirable Basque derivational siffux with implications for the theory of argument structure. X. Artiagoitia.- Verb-deriving processes in Basque. J. C. Odriozola.- Lexical causatives and causative alternation in Basque. B. Oyharçabal.- Causation and semantic control; diagnosis of incorrect use in minorized languages. I. Zabala.- Subject index.- Contributions

Catching words in a stream of speach:computational simulations of segmenting transcribed child-directed speech

De segmentatie van continue spraak in lexicale eenheden is één van de eerste vaardigheden die een kind moet leren gedurende de taalverwerving. Dit proefschrift onderzoekt segmentatie met behulp van computationeel modelleren en computationele simulaties. Segmentatie is moeilijker dan het op het eerste gezicht kan lijken. Kinderen moeten woorden vinden in een continue stroom van spraak, zonder kennis van woorden te hebben. Gelukkig laten experimentele studies zien dat kinderen en volwassen een aantal aanwijzingen uit de invoer gebruiken, alsmede simpele strategieën die gebruik maken van deze aanwijzingen, om spraak te segmenteren. Nog interessanter is dat een aantal van deze aanwijzingen taal-onafhankelijk zijn, waardoor een taalverwerver continue input kan segmenteren voordat het een enkel woord kent. De modellen die in dit proefschrift voorgesteld worden, verschillen op twee belangrijke vlakken van modellen uit de literatuur. Ten eerste gebruiken ze lokale strategieën – in tegenstelling tot globale optimalisatie – die gebruik maken van aanwijzingen waarvan bekend is dat kinderen ze gebruiken, namelijk voorspelbaarheidsstatistieken, fonotactiek en lexicale beklemtoning. Ten tweede worden deze aanwijzingen gecombineerd met behulp van een expliciet aanwijzing-combinatie model, dat eenvoudig uitgebreid kan worden met meer aanwijzingen