This paper introduces to the calculus of

For almost all aspects of information access systems it is still the case that their optimal composition and functionality is hotly debated. Moreover, different application scenarios put different demands on individual components. It is therefore of the essence to be able to quickly build systems that permit exploration of different designs and implementation strategies. This paper presents a software implementation architecture for text retrieval systems that facilitates (a) functional modularization (b) mix-and-match combination of module implementations and (c) definition of inter-module protocols. We show how an object-oriented approach easily accommodates this type of architecture. The design principles are exemplified by code examples in Common Lisp. Taken together these code examples constitute an operational retrieval system. The design principles and protocols implemented have also been instantiated in a large scale retrieval prototype in our research laboratory. 1 Introductio...

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Researchers at PARC were pioneers in developing finite-state methods for applications in computational linguistics, and one of the original motivations was to provide a coherent architecture for the integration of lower-level lexical processing with higher-level syntactic analysis (Kaplan and Kay, 1981;

This paper presents an unsupervised batch learner for the quantity-insensitive stress systems described in Gordon (2002). Unlike previous stress learning models, the learner presented here is neither cue based (Dresher and Kaye, 1990), nor reliant on a priori Optimality-theoretic constraints (Tesar, 1998). Instead our learner exploits a property called neighborhood-distinctness, which is shared by all of the target patterns. Some consequences of this approach include a natural explanation for the occurrence of binary and ternary rhythmic patterns, the lack of higher n-ary rhythms, and the fact that, in these systems, stress always falls within a certain window of word edges.

This paper presents a previously unnoticed universal property of stress patterns in the world’s languages: they are, for small neighborhoods, neighborhood-distinct. Neighborhood-distinctness is a locality condition defined in automata-theoretic terms. This universal is established by examining stress patterns contained in two typological studies, Bailey (1995) and Gordon (2002). Strikingly, many logically possible— but unattested—patterns do not have this property. Not only does neighborhood-distinctness unite the attested patterns in a non-trivial way, it also naturally provides an inductive principle allowing learners to generalise from limited data. A learning algorithm is presented which generalises by failing to distinguish same-neighborhood environments perceived in the learner’s linguistic input—hence learning neighborhood-distinct patterns—as well as almost every stress pattern in the typology. In this way, this work lends support to the idea that properties of the learner can explain certain properties of the attested typology, an idea not straightforwardly available in Optimality-theoretic and Principle and Parameter frameworks.

This paper investigates the implications of cyclic phonological effects for nonderivational theories of phonology, and proposes a declarative theory of the phonology-morphology interface called Sign-Based Morphology that accounts for such effects. The term “cyclicity” refers to the state of affairs in which a subpart of a linguistic form may be subject to

This article describes two practical applications of weighted multi-tape automata (WMTAs) in Natural Language Processing, that demonstrate the augmented descriptive power of WMTAs compared to weighted 1-tape and 2-tape automata. The two examples concern the preservation of intermediate results in transduction cascades and the search for similar words in two languages. As a basis for these applications, the article proposes a number of operations on WMTAs. Among others, it (re-)defines multi-tape intersection, where a number of tapes of one WMTA are intersected with the same number of tapes of another WMTA. In the proposed approach, multi-tape intersection is not an atomic operation but rather a sequence of more elementary ones, which facilitates its implementation.

This report defines various operations and describes algorithms for weighted multi-tape automata (WMTAs). It presents, among others, a new approach to multi-tape intersection, meaning the intersection of a number of tapes of one WMTA with the same number of tapes of another WMTA, which can be seen as a generalization of transducer intersection. In our approach, multi-tape intersection is not considered as an atomic operation but rather as a sequence of more elementary ones. We show an example of multi-tape intersection, actually transducer intersection, that can be compiled with our approach but not with several other methods that we analyzed. Finally we describe an example of practical application, namely the preservation of intermediate results in transduction cascades.

Explaining how children infer grammatical rules based on their limited finite experience is central to the hypothesis of universal grammar—that collection of inductive principles which allows learning to happen. Because children and languages are complex and many factors influence acquisition—physiological, sociolinguistic, articulatory, perceptual,