Error tolerant retrieval of trees

Cataloged from PDF version of article.We present an efficient algorithm for retrieving from a database of trees, all trees that differ from a given query tree by a small number additional or missing leaves, or leaf label changes. It has natural language processing applications in searching for matches in example-based translation systems, and retrieval from lexical databases containing entries of complex feature structures. For large randomly generated synthetic tree databases (some having tens of thousands of trees), and on databases constructed from Wall Street Journal treebank, it can retrieve for trees with a small error, in a matter of tenths of a second to about a second

Corpus-based lexeme ranking for morphological guessers

Peer reviewe

Two-level description of turkish morphology

This paper describes a full two-level morphological description of Turkish word structures. The description has been implemented using the PC-KIMMO environment and is based on a root word lexicon of about 23,000 root words. The phonetic rules of contemporary Turkish (spoken in Turkey) have been encoded using 22 two-level rules while the morphotactics of the agglutinative word structures have been encoded as finite-state machines for verbal, nominal paradigms and other categories. Almost all the special cases of, and exceptions to phonological and morphological rules have been taken into account. In this paper, we describe the rules and the finite state machines along with examples and a discussion of how various special cases were handled. We also describe some known limitations and problems with this description. © 1994 Oxford University Press

Parsing Turkish using the lexical functional grammar formalism

This paper describes our work on parsing Turkish using the lexical-functional grammar formalism [11]. This work represents the first effort for wide-coverage syntactic parsing of Turkish. Our implementation is based on Tomita's parser developed at Carnegie Mellon University Center for Machine Translation. The grammar covers a substantial subset of Turkish including structurally simple and complex sentences, and deals with a reasonable amount of word order freeness. The complex agglutinative morphology of Turkish lexical structures is handled using a separate two-level morphological analyzer, which has been incorporated into the syntactic parser. After a discussion of the key relevant issues regarding Turkish grammar, we discuss aspects of our system and present results from our implementation. Our initial results suggest that our system can parse about 82% of the sentences directly and almost all the remaining with very minor pre-editing. © 1995 Kluwer Academic Publishers

Design and implementation of a spelling checker for Turkish

This paper presents the design and implementation of a spelling checker for Turkish. Turkish is an agglutinative language in which words are formed by affixing a sequence of morphemes to a root word. Parsing agglutinative word structures has attracted relatively little attention except for application areas for general purpose morphological processors. Parsing words in such languages even for spelling checking purposes requires substantial morphological and morphophonemic analysis techniques, and spelling correction (not addressed in this paper) is significantly more complicated. In this paper, we present the design and implementation of a morphological root-driven parser for Turkish word structures which has been incorporated into a spelling checking kernel for on-line Turkish text. The agglutinative nature of the language complex word formations, various phonetic harmony rules, and subtle exceptions present certain difficulties not usually encountered in the spelling checking of languages like English and make this a very challenging problem. © 1993 Oxford University Press

Regional versus global finite-state error repair

[Abstract] We focus on the domain of a regional least-cost strategy in order to illustrate the viability of non-global repair models over finitestate architectures. Our interest is justified by the difficulty, shared by all repair proposals, to determine how far to validate. A short validation may fail to gather sufficient information, and in a long one most of the effort can be wasted. The goal is to prove that our approach can provide, in practice, a performance and quality comparable to that attained by global criteria, with a significant saving in time and space. To the best of our knowledge, this is the first discussion of its kind.Ministerio de Educación y Ciencia; TIN2004-07246-C03-02Ministerio de Educación y Ciencia; HP2002-0081Xunta de Galcia; PGIDIT03SIN30501PRXunta de Galcia; PGIDIT02SIN01

An English-to-Turkish interlingual MT system

This paper describes the integration of a Turkish generation system with the KANT knowledge-based machine translation system to produce a prototype English-Turkish interlingua-based machine translation system. These two independently constructed systems were successfully integrated within a period of two months, through development of a module which maps KANT interlingua expressions to Turkish syntactic structures. The combined system is able to translate completely and correctly 44 of 52 benchmark sentences in the domain of broadcast news captions. This study is the first known application of knowledge-based machine translation from English to Turkish, and our initial results show promise for future development. © Springer-Verlag Berlin Heidelberg 1998

HFST—Framework for Compiling and Applying Morphologies

HFST–Helsinki Finite-State Technology ( hfst.sf.net ) is a framework for compiling and applying linguistic descriptions with finite-state methods. HFST currently connects some of the most important finite-state tools for creating morphologies and spellers into one open-source platform and supports extending and improving the descriptions with weights to accommodate the modeling of statistical information. HFST offers a path from language descriptions to efficient language applications in key environments and operating systems. HFST also provides an opportunity to exchange transducers between different software providers in order to get the best out of each finite-state library.Peer reviewe

Fifty years of spellchecking

A short history of spellchecking from the late 1950s to the present day, describing its development through dictionary lookup, affix stripping, correction, confusion sets, and edit distance to the use of gigantic databases