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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Auxílio na prevenção de doenças crônicas por meio de mapeamento e relacionamento conceitual de informações em biomedicina / Support in the Prevention of Chronic Diseases by means of Mapping and Conceptual Relationship of Biomedical Information

Juliana Tarossi Pollettini 28 November 2011 (has links)
Pesquisas recentes em medicina genômica sugerem que fatores de risco que incidem desde a concepção de uma criança até o final de sua adolescência podem influenciar no desenvolvimento de doenças crônicas da idade adulta. Artigos científicos com descobertas e estudos inovadores sobre o tema indicam que a epigenética deve ser explorada para prevenir doenças de alta prevalência como doenças cardiovasculares, diabetes e obesidade. A grande quantidade de artigos disponibilizados diariamente dificulta a atualização de profissionais, uma vez que buscas por informação exata se tornam complexas e dispendiosas em relação ao tempo gasto na procura e análise dos resultados. Algumas tecnologias e técnicas computacionais podem apoiar a manipulação dos grandes repositórios de informações biomédicas, assim como a geração de conhecimento. O presente trabalho pesquisa a descoberta automática de artigos científicos que relacionem doenças crônicas e fatores de risco para as mesmas em registros clínicos de pacientes. Este trabalho também apresenta o desenvolvimento de um arcabouço de software para sistemas de vigilância que alertem profissionais de saúde sobre problemas no desenvolvimento humano. A efetiva transformação dos resultados de pesquisas biomédicas em conhecimento possível de ser utilizado para beneficiar a saúde pública tem sido considerada um domínio importante da informática. Este domínio é denominado Bioinformática Translacional (BUTTE,2008). Considerando-se que doenças crônicas são, mundialmente, um problema sério de saúde e lideram as causas de mortalidade com 60% de todas as mortes, o presente trabalho poderá possibilitar o uso direto dos resultados dessas pesquisas na saúde pública e pode ser considerado um trabalho de Bioinformática Translacional. / Genomic medicine has suggested that the exposure to risk factors since conception may influence gene expression and consequently induce the development of chronic diseases in adulthood. Scientific papers bringing up these discoveries indicate that epigenetics must be exploited to prevent diseases of high prevalence, such as cardiovascular diseases, diabetes and obesity. A large amount of scientific information burdens health care professionals interested in being updated, once searches for accurate information become complex and expensive. Some computational techniques might support management of large biomedical information repositories and discovery of knowledge. This study presents a framework to support surveillance systems to alert health professionals about human development problems, retrieving scientific papers that relate chronic diseases to risk factors detected on a patient\'s clinical record. As a contribution, healthcare professionals will be able to create a routine with the family, setting up the best growing conditions. According to Butte, the effective transformation of results from biomedical research into knowledge that actually improves public health has been considered an important domain of informatics and has been called Translational Bioinformatics. Since chronic diseases are a serious health problem worldwide and leads the causes of mortality with 60% of all deaths, this scientific investigation will probably enable results from bioinformatics researches to directly benefit public health.
132

Modèles exponentiels et contraintes sur les espaces de recherche en traduction automatique et pour le transfert cross-lingue / Log-linear Models and Search Space Constraints in Statistical Machine Translation and Cross-lingual Transfer

Pécheux, Nicolas 27 September 2016 (has links)
La plupart des méthodes de traitement automatique des langues (TAL) peuvent être formalisées comme des problèmes de prédiction, dans lesquels on cherche à choisir automatiquement l'hypothèse la plus plausible parmi un très grand nombre de candidats. Malgré de nombreux travaux qui ont permis de mieux prendre en compte la structure de l'ensemble des hypothèses, la taille de l'espace de recherche est généralement trop grande pour permettre son exploration exhaustive. Dans ce travail, nous nous intéressons à l'importance du design de l'espace de recherche et étudions l'utilisation de contraintes pour en réduire la taille et la complexité. Nous nous appuyons sur l'étude de trois problèmes linguistiques — l'analyse morpho-syntaxique, le transfert cross-lingue et le problème du réordonnancement en traduction — pour mettre en lumière les risques, les avantages et les enjeux du choix de l'espace de recherche dans les problèmes de TAL.Par exemple, lorsque l'on dispose d'informations a priori sur les sorties possibles d'un problème d'apprentissage structuré, il semble naturel de les inclure dans le processus de modélisation pour réduire l'espace de recherche et ainsi permettre une accélération des traitements lors de la phase d'apprentissage. Une étude de cas sur les modèles exponentiels pour l'analyse morpho-syntaxique montre paradoxalement que cela peut conduire à d'importantes dégradations des résultats, et cela même quand les contraintes associées sont pertinentes. Parallèlement, nous considérons l'utilisation de ce type de contraintes pour généraliser le problème de l'apprentissage supervisé au cas où l'on ne dispose que d'informations partielles et incomplètes lors de l'apprentissage, qui apparaît par exemple lors du transfert cross-lingue d'annotations. Nous étudions deux méthodes d'apprentissage faiblement supervisé, que nous formalisons dans le cadre de l'apprentissage ambigu, appliquées à l'analyse morpho-syntaxiques de langues peu dotées en ressources linguistiques.Enfin, nous nous intéressons au design de l'espace de recherche en traduction automatique. Les divergences dans l'ordre des mots lors du processus de traduction posent un problème combinatoire difficile. En effet, il n'est pas possible de considérer l'ensemble factoriel de tous les réordonnancements possibles, et des contraintes sur les permutations s'avèrent nécessaires. Nous comparons différents jeux de contraintes et explorons l'importance de l'espace de réordonnancement dans les performances globales d'un système de traduction. Si un meilleur design permet d'obtenir de meilleurs résultats, nous montrons cependant que la marge d'amélioration se situe principalement dans l'évaluation des réordonnancements plutôt que dans la qualité de l'espace de recherche. / Most natural language processing tasks are modeled as prediction problems where one aims at finding the best scoring hypothesis from a very large pool of possible outputs. Even if algorithms are designed to leverage some kind of structure, the output space is often too large to be searched exaustively. This work aims at understanding the importance of the search space and the possible use of constraints to reduce it in size and complexity. We report in this thesis three case studies which highlight the risk and benefits of manipulating the seach space in learning and inference.When information about the possible outputs of a sequence labeling task is available, it may seem appropriate to include this knowledge into the system, so as to facilitate and speed-up learning and inference. A case study on type constraints for CRFs however shows that using such constraints at training time is likely to drastically reduce performance, even when these constraints are both correct and useful at decoding.On the other side, we also consider possible relaxations of the supervision space, as in the case of learning with latent variables, or when only partial supervision is available, which we cast as ambiguous learning. Such weakly supervised methods, together with cross-lingual transfer and dictionary crawling techniques, allow us to develop natural language processing tools for under-resourced languages. Word order differences between languages pose several combinatorial challenges to machine translation and the constraints on word reorderings have a great impact on the set of potential translations that is explored during search. We study reordering constraints that allow to restrict the factorial space of permutations and explore the impact of the reordering search space design on machine translation performance. However, we show that even though it might be desirable to design better reordering spaces, model and search errors seem yet to be the most important issues.
133

Training parsers for low-resourced languages : improving cross-lingual transfer with monolingual knowledge / Apprentissage d'analyseurs syntaxiques pour les langues peu dotées : amélioration du transfert cross-lingue grâce à des connaissances monolingues

Aufrant, Lauriane 06 April 2018 (has links)
Le récent essor des algorithmes d'apprentissage automatique a rendu les méthodes de Traitement Automatique des Langues d'autant plus sensibles à leur facteur le plus limitant : la qualité des systèmes repose entièrement sur la disponibilité de grandes quantités de données, ce qui n'est pourtant le cas que d'une minorité parmi les 7.000 langues existant au monde. La stratégie dite du transfert cross-lingue permet de contourner cette limitation : une langue peu dotée en ressources (la cible) peut être traitée en exploitant les ressources disponibles dans une autre langue (la source). Les progrès accomplis sur ce plan se limitent néanmoins à des scénarios idéalisés, avec des ressources cross-lingues prédéfinies et de bonne qualité, de sorte que le transfert reste inapplicable aux cas réels de langues peu dotées, qui n'ont pas ces garanties. Cette thèse vise donc à tirer parti d'une multitude de sources et ressources cross-lingues, en opérant une combinaison sélective : il s'agit d'évaluer, pour chaque aspect du traitement cible, la pertinence de chaque ressource. L'étude est menée en utilisant l'analyse en dépendance par transition comme cadre applicatif. Le cœur de ce travail est l'élaboration d'un nouveau méta-algorithme de transfert, dont l'architecture en cascade permet la combinaison fine des diverses ressources, en ciblant leur exploitation à l'échelle du mot. L'approche cross-lingue pure n'étant en l'état pas compétitive avec la simple annotation de quelques phrases cibles, c'est avant tout la complémentarité de ces méthodes que souligne l'analyse empirique. Une série de nouvelles métriques permet une caractérisation fine des similarités cross-lingues et des spécificités syntaxiques de chaque langue, de même que de la valeur ajoutée de l'information cross-lingue par rapport au cadre monolingue. L'exploitation d'informations typologiques s'avère également particulièrement fructueuse. Ces contributions reposent largement sur des innovations techniques en analyse syntaxique, concrétisées par la publication en open source du logiciel PanParser, qui exploite et généralise la méthode dite des oracles dynamiques. Cette thèse contribue sur le plan monolingue à plusieurs autres égards, comme le concept de cascades monolingues, pouvant traiter par exemple d'abord toutes les dépendances faciles, puis seulement les difficiles. / As a result of the recent blossoming of Machine Learning techniques, the Natural Language Processing field faces an increasingly thorny bottleneck: the most efficient algorithms entirely rely on the availability of large training data. These technological advances remain consequently unavailable for the 7,000 languages in the world, out of which most are low-resourced. One way to bypass this limitation is the approach of cross-lingual transfer, whereby resources available in another (source) language are leveraged to help building accurate systems in the desired (target) language. However, despite promising results in research settings, the standard transfer techniques lack the flexibility regarding cross-lingual resources needed to be fully usable in real-world scenarios: exploiting very sparse resources, or assorted arrays of resources. This limitation strongly diminishes the applicability of that approach. This thesis consequently proposes to combine multiple sources and resources for transfer, with an emphasis on selectivity: can we estimate which resource of which language is useful for which input? This strategy is put into practice in the frame of transition-based dependency parsing. To this end, a new transfer framework is designed, with a cascading architecture: it enables the desired combination, while ensuring better targeted exploitation of each resource, down to the level of the word. Empirical evaluation dampens indeed the enthusiasm for the purely cross-lingual approach -- it remains in general preferable to annotate just a few target sentences -- but also highlights its complementarity with other approaches. Several metrics are developed to characterize precisely cross-lingual similarities, syntactic idiosyncrasies, and the added value of cross-lingual information compared to monolingual training. The substantial benefits of typological knowledge are also explored. The whole study relies on a series of technical improvements regarding the parsing framework: this work includes the release of a new open source software, PanParser, which revisits the so-called dynamic oracles to extend their use cases. Several purely monolingual contributions complete this work, including an exploration of monolingual cascading, which offers promising perspectives with easy-then-hard strategies.
134

Cross-Lingual and Genre-Supervised Parsing and Tagging for Low-Resource Spoken Data

Fosteri, Iliana January 2023 (has links)
Dealing with low-resource languages is a challenging task, because of the absence of sufficient data to train machine-learning models to make predictions on these languages. One way to deal with this problem is to use data from higher-resource languages, which enables the transfer of learning from these languages to the low-resource target ones. The present study focuses on dependency parsing and part-of-speech tagging of low-resource languages belonging to the spoken genre, i.e., languages whose treebank data is transcribed speech. These are the following: Beja, Chukchi, Komi-Zyrian, Frisian-Dutch, and Cantonese. Our approach involves investigating different types of transfer languages, employing MACHAMP, a state-of-the-art parser and tagger that uses contextualized word embeddings, mBERT, and XLM-R in particular. The main idea is to explore how the genre, the language similarity, none of the two, or the combination of those affect the model performance in the aforementioned downstream tasks for our selected target treebanks. Our findings suggest that in order to capture speech-specific dependency relations, we need to incorporate at least a few genre-matching source data, while language similarity-matching source data are a better candidate when the task at hand is part-of-speech tagging. We also explore the impact of multi-task learning in one of our proposed methods, but we observe minor differences in the model performance.
135

A Case for Generative Linguistics in New Testament Exegesis : Surveying the Current Theoretical Landscape and Possible Applicability to Biblical Studies

Kristiansson, Per January 2022 (has links)
This essay surveys the current theoretical landscape of modern linguistics, asking whethe generative and possibly transformational linguistics can be applied to syntactic analysis of New Testament texts written in Koine Greek to find lingual hallmarks in the form of personal usage of syntactic rules that uniquely identify the authors of the texts. The conclusion is that there seems to be evidence that an application of a minimalist approach could make the detection of such lingual hallmarks possible.
136

Multilingual Speech Emotion Recognition using pretrained models powered by Self-Supervised Learning / Flerspråkig känsloigenkänning från tal med hjälp av förtränade tal-modeller baserat på själv-övervakad Inlärning

Luthman, Felix January 2022 (has links)
Society is based on communication, for which speech is the most prevalent medium. In day to day interactions we talk to each other, but it is not only the words spoken that matters, but the emotional delivery as well. Extracting emotion from speech has therefore become a topic of research in the area of speech tasks. This area as a whole has in recent years adopted a Self- Supervised Learning approach for learning speech representations from raw speech audio, without the need for any supplementary labelling. These speech representations can be leveraged for solving tasks limited by the availability of annotated data, be it for low-resource language, or a general lack of data for the task itself. This thesis aims to evaluate the performances of a set of pre-trained speech models by fine-tuning them in different multilingual environments, and evaluating their performance thereafter. The model presented in this paper is based on wav2vec 2.0 and manages to correctly classify 86.58% of samples over eight different languages and four emotional classes when trained on those same languages. Experiments were conducted to garner how well a model trained on seven languages would perform on the one left out, which showed that there is quite a large margin of similarity in how different cultures express vocal emotions, and further investigations showed that as little as just a few minutes of in-domain data is able to increase the performance substantially. This shows promising results even for niche languages, as the amount of available data may not be as large of a hurdle as one might think. With that said, increasing the amount of data from minutes to hours does still garner substantial improvements, albeit to a lesser degree. / Hela vårt samhälle är byggt på kommunikation mellan olika människor, varav tal är det vanligaste mediet. På en daglig basis interagerar vi genom att prata med varandra, men det är inte bara orden som förmedlar våra intentioner, utan även hur vi uttrycker dem. Till exempel kan samma mening ge helt olika intryck beroende på ifall den sägs med ett argt eller glatt tonfall. Talbaserad forskning är ett stort vetenskapligt område i vilket talbaserad känsloigenkänning vuxit fram. Detta stora tal-område har under de senaste åren sett en tendens att utnyttja en teknik kallad själv-övervakad inlärning för att utnyttja omärkt ljuddata för att lära sig generella språkrepresentationer, vilket kan liknas vid att lära sig strukturen av tal. Dessa representationer, eller förtränade modeller, kan sedan utnyttjas som en bas för att lösa problem med begränsad tillgång till märkt data, vilket kan vara fallet för sällsynta språk eller unika uppgifter. Målet med denna rapport är att utvärdera olika applikationer av denna representations inlärning i en flerspråkig miljö genom att finjustera förtränade modeller för känsloigenkänning. I detta syfte presenterar vi en modell baserad på wav2vec 2.0 som lyckas klassifiera 86.58% av ljudklipp tagna från åtta olika språk över fyra olika känslo-klasser, efter att modellen tränats på dessa språk. För att avgöra hur bra en modell kan klassifiera data från ett språk den inte tränats på skapades modeller tränade på sju språk, och evaluerades sedan på det språk som var kvar. Dessa experiment visar att sättet vi uttrycker känslor mellan olika kulturer är tillräckligt lika för att modellen ska prestera acceptabelt även i det fall då modellen inte sett språket under träningsfasen. Den sista undersökningen utforskar hur olika mängd data från ett språk påverkar prestandan på det språket, och visar att så lite som endast ett par minuter data kan förbättra resultet nämnvärt, vilket är lovande för att utvidga modellen för fler språk i framtiden. Med det sagt är ytterligare data att föredra, då detta medför fortsatta förbättringar, om än i en lägre grad.
137

Zero-Shot Cross-Lingual Domain Adaptation for Neural Machine Translation : Exploring The Interplay Between Language And Domain Transferability

Shahnazaryan, Lia January 2024 (has links)
Within the field of neural machine translation (NMT), transfer learning and domain adaptation techniques have emerged as central solutions to overcome the data scarcity challenges faced by low-resource languages and specialized domains. This thesis explores the potential of zero-shot cross-lingual domain adaptation, which integrates principles of transfer learning across languages and domain adaptation. By fine-tuning a multilingual pre-trained NMT model on domain-specific data from one language pair, the aim is to capture domain-specific knowledge and transfer it to target languages within the same domain, enabling effective zero-shot cross-lingual domain transfer. This study conducts a series of comprehensive experiments across both specialized and mixed domains to explore the feasibility and influencing factors of zero-shot cross-lingual domain adaptation. The results indicate that fine-tuned models generally outperform the pre-trained baseline in specialized domains and most target languages. However, the extent of improvement depends on the linguistic complexity of the domain, as well as the transferability potential driven by the linguistic similarity between the pivot and target languages. Additionally, the study examines zero-shot cross-lingual cross-domain transfer, where models fine-tuned on mixed domains are evaluated on specialized domains. The results reveal that while cross-domain transfer is feasible, its effectiveness depends on the characteristics of the pivot and target domains, with domains exhibiting more consistent language being more responsive to cross-domain transfer. By examining the interplay between language-specific and domain-specific factors, the research explores the dynamics influencing zero-shot cross-lingual domain adaptation, highlighting the significant role played by both linguistic relatedness and domain characteristics in determining the transferability potential.
138

The effect of teachers' attitudes on the effective implementation of the communicative approach in ESL classrooms

Abd Al-Magid, Mohammed Al-Mamun 30 November 2006 (has links)
This study is an attempt to determine the impact of teachers' attitudes on their classroom behaviour and therefore on their implementation of the Communicative Approach. A descriptive case study was conducted at six secondary schools in Harare, Zimbabwe (as ESL environment) to determine the effect of 38 O-level English teachers' attitudes on their classroom practice. Quantitative and qualitative methods of data collection, including a questionnaire, an observation instrument and a semistructured interview were used to gauge teachers' attitudes, assessing the extent to which attitudes are reflected in their classroom behaviour, and eliciting teachers' verbalisation of how they conceive of their professional task. The findings show that the effective implementation of the Communicative Approach was critically dependent on teachers' positive attitudes towards this approach in the five categories covered by this study. / Linguistics / M.A. (Applied Linguistics)
139

Measuring Semantic Distance using Distributional Profiles of Concepts

Mohammad, Saif 01 August 2008 (has links)
Semantic distance is a measure of how close or distant in meaning two units of language are. A large number of important natural language problems, including machine translation and word sense disambiguation, can be viewed as semantic distance problems. The two dominant approaches to estimating semantic distance are the WordNet-based semantic measures and the corpus-based distributional measures. In this thesis, I compare them, both qualitatively and quantitatively, and identify the limitations of each. This thesis argues that estimating semantic distance is essentially a property of concepts (rather than words) and that two concepts are semantically close if they occur in similar contexts. Instead of identifying the co-occurrence (distributional) profiles of words (distributional hypothesis), I argue that distributional profiles of concepts (DPCs) can be used to infer the semantic properties of concepts and indeed to estimate semantic distance more accurately. I propose a new hybrid approach to calculating semantic distance that combines corpus statistics and a published thesaurus (Macquarie Thesaurus). The algorithm determines estimates of the DPCs using the categories in the thesaurus as very coarse concepts and, notably, without requiring any sense-annotated data. Even though the use of only about 1000 concepts to represent the vocabulary of a language seems drastic, I show that the method achieves results better than the state-of-the-art in a number of natural language tasks. I show how cross-lingual DPCs can be created by combining text in one language with a thesaurus from another. Using these cross-lingual DPCs, we can solve problems in one, possibly resource-poor, language using a knowledge source from another, possibly resource-rich, language. I show that the approach is also useful in tasks that inherently involve two or more languages, such as machine translation and multilingual text summarization. The proposed approach is computationally inexpensive, it can estimate both semantic relatedness and semantic similarity, and it can be applied to all parts of speech. Extensive experiments on ranking word pairs as per semantic distance, real-word spelling correction, solving Reader's Digest word choice problems, determining word sense dominance, word sense disambiguation, and word translation show that the new approach is markedly superior to previous ones.
140

Češi a Němci na Poličsku ve 20. století: regionální sonda do česko-německého soužití na území národnostně smíšeného okresu Polička / Czechs and Germans in the Polička's Region in the 20th Century: Regional Probe Into Czech-German Coexistence in the Ethnically Mixed District of Polička

Najbert, Jaroslav January 2011 (has links)
Using a method of regional probing, the diploma work seeks to map the evolution of relations between the Czech majority and the German minority that resided in the former political district of Policka. The analysis concentrates on the period of 1897-1946, with a concentration focusing on the culture of "remembering" and the ways in which both ethnic groups came to divergent interpretations of their mutually-shared history. The author strives to identify the factors that influneced the actions and positions of the local populace during the key political events of 1918, 1938 and 1945. He concentrates not only on the everday interactions between both ethnic groups, but also on the conditions that both groups found themelves in during the so-called "National Confrontation."

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