Bilingual speakers cannot suppress activation from their dominant language while naming pictures in a foreign and less dominant language. Previous research has revealed that this cross-langauge activation is manifested through phonological facilitation, semantic interference and between language competition. However, this research is based exclusively on highly proficient bilinguals. The present study investigates cross-linguistic activation in Swedish learners of Spanish, grouped according to their length of Spanish immersion, and one of the groups is in its very inital stages of learning. Participants named pictures in Spanish in two picture-word interference experiments, one with only non-cognates, and one including cognates. This study addresses the following research questions; (1) do the two groups of participants differ significantly from one another in terms of cross-linguistic activation, (2) what does cross-language activation look like in initial stages of L2 acquisition, (3) how does cognate status affect cross-linguistic activation and does this differ between participants depending on length of immersion? The experiments show that cross-linguistic influence is dependent on length of immersion. The more immersed participants performed very similarly to what is usually the case in highly proficient bilinguals while the less immersed participants did not. The results of the less immersed participants are interpreted as manifestations of lexical processing in initial stages of L2 acquisition. Since this type of learner has never been tested before, there are no previous results to compare to. The results are discussed in relation to the large tradition of offline research which has shown that beginning learners predominantly process their L2 phonologically, and that conceptual processing is something requiring more L2 development. Furthermore, the cognate word induced longer naming latencies in all participants and it turned out that the cognate words were highly unfamiliar. Hence all participants are sensitive to word frequency effects, and this sensitive is greater in early stages of learning. Finally this study suggests that more research must be conducted to establish cross-linguistic influence between the many languages of multi-lingual subjects, even when these languages may not be present in the testing situation.

Most research in word recognition uses words that already exist in the reader's lexicon, and it is therefore of interest to see whether newly learned words are represented and processed in the same way as already known words. For example, are newly learned words immediately represented in a special form of lexical memory, or is there a gradual process of assimilation? As for L2 language learners, are newly learned words incorporated into the same processing system that serves L1, or are they represented quite independently?The current study examines this issue by testing for the existence of the Prime Lexicality Effect (PLE) observed in masked priming experiments (Forster & Veres, 1998). Strong form priming was found with nonword primes (e.g., contrapt-CONTRACT), but not with word primes (e.g., contrast-CONTRACT). This effect is generally assumed to result from competition between the prime and the target. So if the readers had been trained to treat "contrapt" as a new word, would it now function like a word and produce much weaker priming? Elgort (2007) demonstrated such an effect with unmasked primes with L2 bilinguals. The current study investigates the PLE in both L1 and L2 bilinguals under different training conditions. When the training program involves mere familiarization (learning to type the words), a PLE was found with visible primes, but not with masked primes, which suggests that unmasked PLE is not the best indicator of lexicalization. In the case of "real" acquisition where the new word is given a definition and a picture of the object it refers to, and learning is spread over two weeks, a clear PLE was obtained. However, when the same experiment was carried out on Chinese-English bilinguals using the same English materials, completely opposite results were obtained. The learning enhanced priming, rather than reducing it, suggesting that the L2 lexicon might differ qualitatively from the L1 lexicon. The implications of these results for competitive theories of lexical access are discussed, and alternative explanations are considered.

This study investigates the acquisition of conventional metaphorical expressions by Chinese learners of English. A conventional metaphorical expression, following the definition of cognitive semantics, refers to the use of a conventionalised non-literal meaning of a lexical item in a multi-word phrase. For example, the word 'attack' in the phrase 'attack one's idea', which should be interpreted as 'to criticise somebody or something severely', clearly departs from the literal meaning 'to use violence to try to hurt or kill somebody', and thus should be seen as a metaphorically used word. Consequently, the phrase 'attack one's idea' is a conventional metaphorical expression. This study explores learners' behaviour towards and acquisition of metaphorical expressions from two major perspectives: (1) possible cross-linguistic influence in the process of acquisition and factors that could affect cross-linguistic influence; and (2) the organisation of learners' bilingual lexicon and the status of metaphorical expressions in a bilingual lexicon. These two perspectives are considered to be the main factors that can influence learners' acquisition of metaphorical expressions: in order to acquire a metaphorical expression, learners should be able to integrate it into the bilingual lexicon, while the process of integration can be impacted by cross-linguistic influence. Previous research has mainly been conducted on the acquisition of certain figurative expressions in a second language, predominantly idioms; however, a combination of the two perspectives and a joint analysis on the acquisition of figurative language has yet to be accomplished. This study presents a first attempt of such analysis on the acquisition of a specific type of figurative language. The results of the experiments reported in this dissertation show that learners react differently to metaphorical expressions with different cross-linguistic availabilities (shared between Chinese and English or exclusively available in Chinese or English) but in general they encounter difficulty to achieve native-like performance when reading metaphorical expressions available in their second language. Persistent cross-linguistic influence is observed in two aspects, even among highly proficient learners: (1) learners encounter obstacles when acquiring the metaphorical expressions that are only available in their second language; and (2) learners seem to still activate the metaphorical meanings that are only available in their first language even when they read in their second language. These results altogether reflect that metaphorical expressions, regardless of cross-linguistic availability, are more difficult to acquire than literal expressions in a second language.

In this masters’ thesis report we present a graph theoretical method used for automatic bilingual lexicon acquisition with parallel texts. We analyze the concept of graph similarity and give an interpretation, of the parallel texts, connected to the vector space model. We represent the parallel texts by a directed, tripartite graph and from here use the corresponding adjacency matrix, A, to compute the similarity of the graph. By solving the eigenvalue problem ρS = ASAT + ATSA we obtain the self-similarity matrix S and the Perron root ρ. A rank k approximation of the self-similarity matrix is computed by implementations of the singular value decomposition and the non-negative matrix factorization algorithm GD-CLS. We construct an algorithm in order to extract the bilingual lexicon from the self-similarity matrix and apply a statistical model to estimate the precision, the correctness, of the translations in the bilingual lexicon. The best result is achieved with an application of the vector space model with a precision of about 80 %. This is a good result and can be compared with the precision of about 60 % found in the literature.

<p>In this masters’ thesis report we present a graph theoretical method used for automatic bilingual lexicon acquisition with parallel texts. We analyze the concept of graph similarity and give an interpretation, of the parallel texts, connected to the vector space model. We represent the parallel texts by a directed, tripartite graph and from here use the corresponding adjacency matrix, A, to compute the similarity of the graph. By solving the eigenvalue problem ρS = ASAT + ATSA we obtain the self-similarity matrix S and the Perron root ρ. A rank k approximation of the self-similarity matrix is computed by implementations of the singular value decomposition and the non-negative matrix factorization algorithm GD-CLS. We construct an algorithm in order to extract the bilingual lexicon from the self-similarity matrix and apply a statistical model to estimate the precision, the correctness, of the translations in the bilingual lexicon. The best result is achieved with an application of the vector space model with a precision of about 80 %. This is a good result and can be compared with the precision of about 60 % found in the literature.</p>

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第19107号 / 情博第553号 / 新制||情||98(附属図書館) / 32058 / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 黒橋 禎夫, 教授 石田 亨, 教授 河原 達也 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

Nous avons observé depuis plusieurs années l’émergence des approches statistiques pour la traduction automatique. Cependant, l’efficacité des modèles construits est soumise aux variabilités inhérentes au langage naturel. Des études ont montré la présence de vocabulaires spécifique et général composant les corpus de textes de domaines spécialisés. Cette particularité peut être prise en charge par des ressources terminologiques comme les lexiques bilingues.Toutefois, nous pensons que si le vocabulaire est différent entre des textes spécialisés ou génériques, le contenu sémantique et la structure syntaxique peuvent aussi varier. Dans nos travaux,nous considérons la tâche d’adaptation aux domaines spécialisés pour la traduction automatique statistique selon deux axes majeurs : l’acquisition de lexiques bilingues et l’édition a posteriori de traductions issues de systèmes automatiques. Nous évaluons l’efficacité des approches proposées dans un contexte spécialisé : le domaine médical. Nos résultats sont comparés aux travaux précédents concernant cette tâche. De manière générale, la qualité des traductions issues de systèmes automatiques pour le domaine médical est améliorée par nos propositions. Des évaluations en oracle tendent à montrer qu’il existe une marge de progression importante / These last years have seen the development of statistical approaches for machine translation. Nevertheless, the intrinsic variations of the natural language act upon the quality of statistical models. Studies have shown that in-domain corpora containwords that can occur in out-of-domain corpora (common words), but also contain domain specific words. This particularity can be handled by terminological resources like bilingual lexicons. However, if the vocabulary differs between out and in-domain data, the syntactic and semantic content may also vary. In our work, we consider the task of domain adaptation for statistical machine translation through two majoraxes : bilingual lexicon acquisition and post-edition of machine translation outputs.We evaluate our approaches on the medical domain. The quality of automatic translations in the medical domain are improved and the results are compared to other works in this field. Oracle evaluations tend to show that further gains are still possible

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第21395号 / 情博第681号 / 新制||情||117(附属図書館) / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 石田 亨, 教授 吉川 正俊, 教授 河原 達也 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

No description available.

Les lexiques bilingues sont des ressources particulièrement utiles pour la Traduction Automatique et la Recherche d’Information Translingue. Leur construction manuelle nécessite une expertise forte dans les deux langues concernées et est un processus coûteux. Plusieurs méthodes automatiques ont été proposées comme une alternative, mais elles qui ne sont disponibles que dans un nombre limité de langues et leurs performances sont encore loin derrière la qualité des traductions manuelles.Notre travail porte sur l'extraction de ces lexiques bilingues à partir de corpus de textes parallèles et comparables, c'est à dire la reconnaissance et l'alignement d'un vocabulaire commun multilingue présent dans ces corpus. / Bilingual lexicons are central components of machine translation and cross-lingual information retrieval systems. Their manual construction requires extensive expertise in both languages involved and it is a costly process. Several automatic methods were proposed as an alternative but they often rely of resources available in a limited number of languages and their performances are still far behind the quality of manual translations.Our work concerns bilingual lexicon extraction from multilingual parallel and comparable corpora, in other words, the process of finding translation pairs among the common multilingual vocabulary available in such corpora.